WorldWideScience

Sample records for surface phenomena including

  1. Nonlinear surface electromagnetic phenomena

    CERN Document Server

    Ponath, H-E

    1991-01-01

    In recent years the physics of electromagnetic surface phenomena has developed rapidly, evolving into technologies for communications and industry, such as fiber and integrated optics. The variety of phenomena based on electromagnetism at surfaces is rich and this book was written with the aim of summarizing the available knowledge in selected areas of the field. The book contains reviews written by solid state and optical physicists on the nonlinear interaction of electromagnetic waves at and with surfaces and films. Both the physical phenomena and some potential applications are

  2. Surface erosion phenomena in connection with CTR applications

    International Nuclear Information System (INIS)

    Kaminsky, M.; Das, S.K.

    1976-01-01

    The interaction of plasma radiations with the exposed surfaces of components of plasma devices and future controlled thermonuclear fusion reactors (CTR) can cause a variety of surface effects. In turn, such surface effects can cause (a) the release of plasma contaminants, and (b) the damage and erosion of the irradiated surfaces. The contamination of the plasma can have serious effects on plasma stability and on plasma temperature, and the surface erosion can seriously limit the lifetime of the irradiated components. At present, knowledge of surface erosion rates for the plasma parameters and materials envisioned in CTR applications is only fragmentary. To what extent the erosion rates will be affected by synergistic effects due to the simultaneous bombardment of surfaces by high fluxes of energetic particles of various types and by photons is almost completely unknown. A summary of some of the major surface erosion phenomena which have been identified as being important for CTR applications by using single irradiation sources (e.g., accelerators) will be given. A discussion of some potential solutions to reduce surface erosion will be included. The main features of a recently completed two component irradiation facility at ANL for CTR related surface studies will be described

  3. Sunglitter Imagery Of The Ocean Surface Phenomena

    Science.gov (United States)

    Myasoedov, Alexander; Kudryavtsev, Vladimir; Chapron, Bertrand; Johannessen, Johnny

    2010-04-01

    An algorithm for retrieval of spatial variations of the mean square slope (MSS) of the sea surface from sunglint imagery is proposed. The retrieval algorithm is free on a prior suggestion on PDF model. The transfer function, relating the brightness contrast to the MSS contrasts, is found from observed sunglint brightness, where “real” PDF of the sea slopes has built-in. Developed approach was applied for analysis of the sunglint signature of the mesoscale ocean dynamics and internal waves. We found that the ocean currents (eddies, meanders, frontal lines) and internal waves are well visible on the sea surface as the MSS anomalies. Results of this study is further adopted by Kudryavtsev et al. (2010) for development of advanced approach for synergetic use of SAR and optical imagery in studies of meso-scale ocean dynamics.

  4. Internal and surface phenomena in metal combustion

    Science.gov (United States)

    Dreizin, Edward L.; Molodetsky, Irina E.; Law, Chung K.

    1995-01-01

    Combustion of metals has been widely studied in the past, primarily because of their high oxidation enthalpies. A general understanding of metal combustion has been developed based on the recognition of the existence of both vapor-phase and surface reactions and involvement of the reaction products in the ensuing heterogeneous combustion. However, distinct features often observed in metal particle combustion, such as brightness oscillations and jumps (spearpoints), disruptive burning, and non-symmetric flames are not currently understood. Recent metal combustion experiments using uniform high-temperature metal droplets produced by a novel micro-arc technique have indicated that oxygen dissolves in the interior of burning particles of certain metals and that the subsequent transformations of the metal-oxygen solutions into stoichiometric oxides are accompanied with sufficient heat release to cause observed brightness and temperature jumps. Similar oxygen dissolution has been observed in recent experiments on bulk iron combustion but has not been associated with such dramatic effects. This research addresses heterogeneous metal droplet combustion, specifically focusing on oxygen penetration into the burning metal droplets, and its influence on the metal combustion rate, temperature history, and disruptive burning. A unique feature of the experimental approach is the combination of the microgravity environment with a novel micro-arc Generator of Monodispersed Metal Droplets (GEMMED), ensuring repeatable formation and ignition of uniform metal droplets with controllable initial temperature and velocity. The droplet initial temperatures can be adjusted within a wide range from just above the metal melting point, which provides means to ignite droplets instantly upon entering an oxygen containing environment. Initial droplet velocity will be set equal to zero allowing one to organize metal combustion microgravity experiments in a fashion similar to usual microgravity

  5. Canard Phenomena in Oscillations of a Surface Oxidation Reaction

    Science.gov (United States)

    Xie, Feng; Han, Maoan; Zhang, Weijiang

    2005-12-01

    In this paper we investigate canard phenomena occurring in oscillations of a surface oxidation reaction which can be modeled by a three-dimensional singularly perturbed system of ordinary differential equations with two fast variables. By using asymptotic methods, we prove the existence of the maximal canard of the mentioned model, and provide sufficient conditions for the existence of stable canard cycles.

  6. Collective Phenomena In Volume And Surface Barrier Discharges

    Science.gov (United States)

    Kogelschatz, U.

    2010-07-01

    Barrier discharges are increasingly used as a cost-effective means to produce non-equilibrium plasmas at atmospheric pressure. This way, copious amounts of electrons, ions, free radicals and excited species can be generated without appreciable gas heating. In most applications the barrier is made of dielectric material. In laboratory experiments also the use of resistive, ferroelectric and semiconducting materials has been investigated, also porous ceramic layers and dielectric barriers with controlled surface conductivity. Major applications utilizing mainly dielectric barriers include ozone generation, surface cleaning and modification, polymer and textile treatment, sterilization, pollution control, CO2 lasers, excimer lamps, plasma display panels (flat TV screens). More recent research efforts are also devoted to biomedical applications and to plasma actuators for flow control. Sinu- soidal feeding voltages at various frequencies as well as pulsed excitation schemes are used. Volume as well as surface barrier discharges can exist in the form of filamentary, regularly patterned or laterally homogeneous discharges. Reviews of the subject and the older literature on barrier discharges were published by Kogelschatz (2002, 2003), by Wagner et al. (2003) and by Fridman et al. (2005). A detailed discussion of various properties of barrier discharges can also be found in the recent book "Non-Equilibrium Air Plasmas at Atmospheric Pressure" by Becker et al. (2005). The physical effects leading to collective phenomena in volume and surface barrier discharges will be discussed in detail. Special attention will be given to self-organization of current filaments. Main similarities and differences of the two types of barrier discharges will be elaborated.

  7. Nanophenomena at surfaces fundamentals of exotic condensed matter phenomena

    CERN Document Server

    Michailov, Michail

    2011-01-01

    This book presents the state of the art in nanoscale surface physics. It outlines contemporary trends in the field covering a wide range of topical areas: atomic structure of surfaces and interfaces, molecular films and polymer adsorption, biologically inspired nanophysics, surface design and pattern formation, and computer modeling of interfacial phenomena. Bridging 'classical' and 'nano' concepts, the present volume brings attention to the physical background of exotic condensed-matter properties. The book is devoted to Iwan Stranski and Rostislaw Kaischew, remarkable scientists, who played

  8. Experimental and Theoretical Investigations of Glass Surface Charging Phenomena

    Science.gov (United States)

    Agnello, Gabriel

    Charging behavior of multi-component display-type (i.e. low alkali) glass surfaces has been studied using a combination of experimental and theoretical methods. Data obtained by way of a Rolling Sphere Test (RST), streaming/zeta potential and surface energy measurements from commercially available display glass surfaces (Corning EAGLE XGRTM and Lotus(TM) XT) suggest that charge accumulation is highly dependent on surface treatment (chemical and/or physical modification) and measurement environment, presumably through reactionary mechanisms at the surface with atmospheric moisture. It has been hypothesized that water dissociation, along with the corresponding hydroxylation of the glass surface, are important processes related to charging in glass-metal contact systems. Classical Molecular Dynamics (MD) simulations, in conjunction with various laboratory based measurements (RST, a newly developed ElectroStatic Gauge (ESG) and Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS)) on simpler Calcium AluminoSilicate (CAS) glass surfaces were used to further explore these phenomena. Analysis of simulated high-silica content (≥50%) (CAS) glass structures suggest that controlled variation of bulk chemistry can directly affect surface defect concentrations, such as non-bridging oxygen (NBO), which can be suitable high-energy sites for hydrolysis-type reactions to occur. Calculated NBO surface concentrations correlate well with charge based measurements on laboratory fabricated CAS surfaces. The data suggest that a directional/polar shift in contact-charge transfer occurs at low silica content (≤50%) where the highest concentrations of NBOs are observed. Surface charging sensitivity with respect to NBO concentration decreases as the relative humidity of the measurement environment increases; which should be expected as the highly reactive sites are progressively covered by liquid water layers. DRIFTS analysis of CAS powders expand on this analysis showing

  9. Surface Phenomena at Silver Nanoparticles in the Context of Toxicology

    DEFF Research Database (Denmark)

    Miclaus, Teodora

    2015-01-01

    is also observed in the third study, where transformation form metallic to sulphur-bound monovalent silver is shown inside cells. Ag nanoparticles are shown to dissolve much more rapidly inside cells than in cell culture medium and the ions are thought to bind to sulphur-containing proteins, disrupting...... associated with engineered nanomaterials. Among these materials, silver nanoparticles are some of the most widely employed and thus represent a major point of focus in nanotoxicology and the topic of this PhD thesis. While nanoparticles have, upon synthesis, well-defined characteristics, specific...... of nanotoxicology. The main aim of this PhD research is to investigate these phenomena at the surface of silver nanoparticles under conditions that are relevant for in vitro studies in order to understand their implications for nano-silver toxicity. Upon contact with biological fluids, particles get coated...

  10. Structures including network and topology for identifying, locating and quantifying physical phenomena

    Science.gov (United States)

    Richardson, John G.; Moore, Karen A.; Carrington, Robert A.

    2006-04-25

    A method and system for detecting, locating and quantifying a physical phenomena such as strain or a deformation in a structure. A plurality of laterally adjacent conductors may each include a plurality of segments. Each segment is constructed to exhibit a unit value representative of a defined energy transmission characteristic. A plurality of identity groups are defined with each identity group comprising a plurality of segments including at least one segment from each of the plurality of conductors. The segments contained within an identity group are configured and arranged such that each of their associated unit values may be represented by a concatenated digit string which is a unique number relative to the other identity groups. Additionally, the unit values of the segments within an identity group maintain unique ratios with respect to the other unit values in the identity group.

  11. Pipeline including network and topology for identifying, locating and quantifying physical phenomena

    Science.gov (United States)

    Richardson, John G.; Moore, Karen A.; Carrington, Robert A.

    2006-02-14

    A method and system for detecting, locating and quantifying a physical phenomena such as strain or a deformation in a structure. A plurality of laterally adjacent conductors may each include a plurality of segments. Each segment is constructed to exhibit a unit value representative of a defined energy transmission characteristic. A plurality of identity groups are defined with each identity group comprising a plurality of segments including at least one segment from each of the plurality of conductors. The segments contained within an identity group are configured and arranged such that each of their associated unit values may be represented by a concatenated digit string which is a unique number relative to the other identity groups. Additionally, the unit values of the segments within an identity group maintain unique ratios with respect to the other unit values in the identity group.

  12. Free surface and hydraulic phenomena in a windowless symmetrical target

    International Nuclear Information System (INIS)

    Cascone, R.; Salve, M. de; Malandrone, M.; Panella, B.

    2001-01-01

    In the windowless concept for the Accelerator Driven Systems target the liquid flow in the spallation region must be able to remove the volumetric thermal power due to the proton interactions with nuclei. In this paper the hydraulic phenomena of a basic symmetrical windowless target configuration with two concentric cylinders have been studied. The tests were aimed to measure the profile of the free surface of the flow and the liquid velocity field, by using water as hydraulic equivalent to lead-bismuth eutectic fluid. The test section consists of two concentric plexiglass pipes (inner cylinder diameter 200 mm, outer cylinder diameter 290 mm) where the water flows up in the annular region and flows down in the central region. The most important experimental parameters are the fluid level measured from the top edge of the inner cylinder and the imposed flow rate. The experiments have been carried out at room temperature in the following range: flow rate from 2.5 to 20 kg/s; fluid level at zero flow rate from -50 to 186 mm. (authors)

  13. Investigation of Surface Phenomena in Shocked Tin in Converging Geometry

    Energy Technology Data Exchange (ETDEWEB)

    Rousculp, Christopher L. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Oro, David Michael [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Margolin, Len G. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Griego, Jeffrey Randall [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Reinovsky, Robert Emil [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Turchi, Peter John [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-08-06

    There is great interest in the behavior of the free surface of tin under shock loading. While it is known that meso-scale surface imperfections can seed the Richtmyer-Meshkov Instability (RMI) for a surface that is melted on release, much less is known about a tin surface that is solid, but plastically deforming. Here material properties such as shear and yield strength come into play especially in converging geometry. Previous experiments have been driven by direct contact HE. Usually a thin, flat target coupon is fielded with various single-mode, sinusoidal, machined, profiles on the free surface. The free surface is adjacent to either vacuum or an inert receiver gas. Most of these previous driver/target configurations have been nominal planer geometry. With modern HE it has been straightforward to shock tin into melt on release. However it has been challenging to achieve a low enough pressure for solid state on release. Here we propose to extend the existing base of knowledge to include the behavior of the free surface of tin in cylindrical converging geometry. By shock loading a cylindrical tin shell with a magnetically driven cylindrical liner impactor, the free surface evolution can be diagnosed with proton radiography. With the PHELIX capacitor bank, the drive can easily be varied to span the pressure range to achieve solid, mixed, and liquid states on release.

  14. Investigation of Surface Phenomena in Shocked Tin in Converging Geometry

    Energy Technology Data Exchange (ETDEWEB)

    Rousculp, Christopher L. [Los Alamos National Laboratory; Oro, David Michael [Los Alamos National Laboratory; Griego, Jeffrey Randall [Los Alamos National Laboratory; Turchi, Peter John [Los Alamos National Laboratory; Reinovsky, Robert Emil [Los Alamos National Laboratory; Bradley, Joseph Thomas [Los Alamos National Laboratory; Cheng, Baolian [Los Alamos National Laboratory; Freeman, Matthew Stouten [Los Alamos National Laboratory; Patten, Austin Randall [Los Alamos National Laboratory

    2016-03-21

    There is great interest in the behavior of the free surface of tin under shock loading. While it is known that meso-scale surface imperfections can seed the Richtmyer- Meshkov Instability (RMI) for a surface that is melted on release, much less is known about a tin surface that is solid, but plastically deforming. Here material properties such as shear and yield strength come into play especially in converging geometry. Previous experiments have been driven by direct contact HE. Usually a thin, flat target coupon is fielded with various single-mode, sinusoidal, machined, profiles on the free surface. The free surface is adjacent to either vacuum or an inert receiver gas. Most of these previous driver/target configurations have been nominal planer geometry. With modern HE it has been straightforward to shock tin into melt on release. However it has been challenging to achieve a low enough pressure for solid state on release. Here we propose to extend the existing base of knowledge to include the behavior of the free surface of tin in cylindrical converging geometry. By shock loading a cylindrical tin shell with a magnetically driven cylindrical liner impactor, the free surface evolution can be diagnosed with proton radiography. With the PHELIX capacitor bank, the drive can easily be varied to span the pressure range to achieve solid, mixed, and liquid states on release. A conceptual cylindrical liner and target is shown in Figure 1.

  15. Vibration of Piezoelectric Nanowires Including Surface Effects

    Directory of Open Access Journals (Sweden)

    R. Ansari

    2014-04-01

    Full Text Available In this paper, surface and piezoelectric effects on the vibration behavior of nanowires (NWs are investigated by using a Timoshenko beam model. The electric field equations and the governing equations of motion for the piezoelectric NWs are derived with the consideration of surface effects. By the exact solution of the governing equations, an expression for the natural frequencies of NWs with simply-supported boundary conditions is obtained. The effects of piezoelectricity and surface effects on the vibrational behavior of Timoshenko NWs are graphically illustrated. A comparison is also made between the predictions of Timoshenko beam model and those of its Euler-Bernoulli counterpart. Additionally, the present results are validated through comparison with the available data in the literature.

  16. Critical phenomena at perfect and non-perfect surfaces

    International Nuclear Information System (INIS)

    Pleimling, M

    2004-01-01

    In the past, perfect surfaces have been shown to yield local critical behaviour that differs from bulk critical behaviour. On the other hand, surface defects, whether they are of natural origin or created artificially, are known to modify local quantities. It is therefore important to clarify whether these defects are relevant or irrelevant for the surface critical behaviour. The purpose of this review is two-fold. In the first part we summarize some of the important results on surface criticality at perfect surfaces. Special attention is thereby paid to new developments such as for example the study of the surface critical behaviour in systems with competing interactions or of surface critical dynamics. In the second part the effect of surface defects (presence of edges, steps, quenched randomness, lines of adatoms, regular geometric patterns) on local critical behaviour in semi-infinite systems and in thin films is discussed in detail. Whereas most of the defects commonly encountered are shown to be irrelevant, some notable exceptions are highlighted. It is shown furthermore that under certain circumstances non-universal local critical behaviour may be observed at surfaces. (topical review)

  17. Geometrical critical phenomena on a random surface of arbitrary genus

    International Nuclear Information System (INIS)

    Duplantier, B.; Kostov, I.K.

    1990-01-01

    The statistical mechanics of self-avoiding walks (SAW) or of the O(n)-loop model on a two-dimensional random surface are shown to be exactly solvable. The partition functions of SAW and surface configurations (possibly in the presence of vacuum loops) are calculated by planar diagram enumeration techniques. Two critical regimes are found: a dense phase where the infinite walks and loops fill the infinite surface, the non-filled part staying finite, and a dilute phase where the infinite surface singularity on the one hand, and walk and loop singularities on the other, merge together. The configuration critical exponents of self-avoiding networks of any fixed topology G, on a surface with arbitrary genus H, are calculated as universal functions of G and H. For self-avoiding walks, the exponents are built from an infinite set of basic conformal dimensions associated with central charges c = -2 (dense phase) and c = 0 (dilute phase). The conformal spectrum Δ L , L ≥ 1 associated with L-leg star polymers is calculated exactly, for c = -2 and c = 0. This is generalized to the set of L-line 'watermelon' exponents Δ L of the O(n) model on a random surface. The divergences of the partition functions of self-avoiding networks on the random surface, possibly in the presence of vacuum loops, are shown to satisfy a factorization theorem over the vertices of the network. This provides a proof, in the presence of a fluctuating metric, of a result conjectured earlier in the standard plane. From this, the value of the string susceptibility γ str (H,c) is extracted for a random surface of arbitrary genus H, bearing a field theory of central charge c, or equivalently, embedded in d=c dimensions. Lastly, by enumerating spanning trees on a random lattice, we solve the similar problem of hamiltonian walks on the (fluctuating) Manhattan covering lattice. We also obtain new results for dilute trees on a random surface. (orig./HSI)

  18. STUDY OF SURFACE PHENOMENA IN MATERIALS OF PROSTHETIC RESTORATION

    Directory of Open Access Journals (Sweden)

    Mihaela-Păpuşa Vasiliu

    2012-12-01

    Full Text Available As a direct consequence of their application domain – the oral cavity – dental materials are subjected to the corosive action of saliva, being surrounded by microorganisms, fluids and alimentary rests, which modify their surface characteristics. Concerns on the quality of the dental materials explain the numeorus interdisciplinary studies, characterized by a close relation among various scientific domains (physics, chemistry, biology, science of biomaterials, techniques also applied in clinical stomatology. Analysis of the saliva–dental materials interface made use of ceramic surfaces, composites and artificial saliva, permitting to determine the main surface parameters of the materials of prosthetic restoration, calculated with some physical models, starting from measurements of the contact angle: surface energy, its polar and dispersive components, surface rugosity, adhesion mechanic work. All composites showed low values of the adhesion mechanic work, the conclusion being that they are much more hydrophobic than the ceramic materials. Such a property is especially important from an aesthetic perspective, as the hydrophobic materials have a better colour stability in time.

  19. Surface Phenomena at Silver Nanoparticles in the Context of Toxicology

    DEFF Research Database (Denmark)

    Miclaus, Teodora

    2015-01-01

    with proteins. In the first study, a method based on localised surface plasmon resonances characteristic of Ag nanocubes was developed and used to track the formation of short and long-lived protein coronas in cell culture media. Firstly, it provided a much-needed tool to assess the so-far-elusive soft corona...... associated with engineered nanomaterials. Among these materials, silver nanoparticles are some of the most widely employed and thus represent a major point of focus in nanotoxicology and the topic of this PhD thesis. While nanoparticles have, upon synthesis, well-defined characteristics, specific...... sulphide particles in close proximity to the silver nanoparticle surface, as shown in the second study. The identification of spontaneous sulfidation under in vitro settings is a novel finding with important implications for toxicity, as Ag2S traps toxic silver ions into an insoluble compound. Increased...

  20. STUDY OF SURFACE PHENOMENA IN MATERIALS OF PROSTHETIC RESTORATION

    OpenAIRE

    Mihaela-Păpuşa Vasiliu; Carmen Stadoleanu; Daniela Ivona Tomiţa; Cristina-Mihaela Stanilă; S.-C. Jalbă; Nicoleta Dumitraşcu

    2012-01-01

    As a direct consequence of their application domain – the oral cavity – dental materials are subjected to the corosive action of saliva, being surrounded by microorganisms, fluids and alimentary rests, which modify their surface characteristics. Concerns on the quality of the dental materials explain the numeorus interdisciplinary studies, characterized by a close relation among various scientific domains (physics, chemistry, biology, science of biomaterials), techniqu...

  1. Optically induced surface relief phenomena in azobenzene polymers

    DEFF Research Database (Denmark)

    Holme, NCR; Nikolova, Ludmila; Hvilsted, Søren

    1999-01-01

    Azobenzene polymers and oligomers show intriguing surface relief features when irradiated with polarized laser light. We show through atomic force microscopic investigation of side-chain azobenzene polymers after irradiation through an amplitude mask that large peaks or trenches result depending...... on the architecture of the polymer. Extensive mass transport over long distances has been observed, paving the way for easy replication of nanostructures. We also show that it is possible to store microscopic images as topographic features in the polymers just through polarized light irradiation. (C) 1999 American...

  2. Polarization phenomena in nucleon-nucleon scattering at intermediate and high energies including the present status of dibaryons

    Energy Technology Data Exchange (ETDEWEB)

    Yokosawa, A.

    1985-01-01

    We review experimental results concerning polarization phenomena in nucleon-nucleon scattering in which both the elastic scattering and hadron-production reaction are included. We also present summary of S = 0 dibaryon resonances and candidates by reviewing experimental data in the nucleon-nucleon system, ..gamma..d channel, ..pi..d elastic scattering, pp ..-->.. ..pi..d channel, deuteron break-up reactions, and narrow structures in missing-mass spectra. 93 refs., 26 figs.

  3. Guidelines for the development of natural phenomena hazards design criteria for surface facilities

    International Nuclear Information System (INIS)

    Nelson, T.A.; Hossain, Q.A.; Murray, R.C.

    1992-01-01

    This paper discusses the rationale behind the guidelines, criteria, and methodologies that are currently used for natural phenomena hazard design and evaluation of DOE nuclear and non-nuclear facilities. The bases for the performance goals and usage categories specified in UCRL-15910 are examined, and the sources of intentional conservatism in the analyses, design, and evaluation methods and criteria are identified. Outlines of recent developments/changes in DOE Orders related to Natural Phenomena hazard mitigation are also presented. Finally, the authors recommend the use of DOE methodologies as embodied in UCRL-15910 for design and evaluation of surface facilities of the high level nuclear waste repository site

  4. Stability analysis on the free surface phenomena of a magnetic fluid for general use

    International Nuclear Information System (INIS)

    Mizuta, Yo

    2011-01-01

    This paper presents an analysis for elucidating a variety of physical processes on the interface (free surface) of magnetic fluid. The present analysis is composed of the magnetic and the fluid analysis, both of which have no limitations concerning the interface elevation or its profile. The magnetic analysis provides rigorous interface magnetic field under arbitrary distributions of applied magnetic field. For the fluid analysis, the equation for interface motion includes all nonlinear effects. Physical quantities such as the interface magnetic field or the interface stresses, obtained first as the wavenumber components, facilitate confirming the relations with those by the conventional theoretical analyses. The nonlinear effect is formulated as the nonlinear mode coupling between the interface profile and the applied magnetic field. The stability of the horizontal interface profile is investigated by the dispersion relation, and summarized as the branch line. Furthermore, the balance among the spectral components of the interface stresses are shown, within the sufficient range of the wavenumber space. - Research Highlights: → General, rigorous but compact analysis for free surface phenomena is shown. → Analysis is applied without limitations on the interface elevation or its profile. → Nonlinear effects are formulated as the nonlinear mode coupling. → Bifurcation of stability is summarized as the branch line. → Balance among the interface stresses are shown in the wavenumber space.

  5. Extremely high Leidenfrost temperature on nanoparticle-deposited surfaces and its influences on quenching phenomena

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyung Dae [Kyung Hee University, Yongin (Korea, Republic of)

    2010-10-15

    We recently found that quenching behavior of various dilute nanofluids is nearly identical to that of pure water, but due to nanofluids boiling during the quenching process, some nanoparticles deposit on the surface of the rod, which results in much higher quenching rate in subsequent tests with the same object. However the traditional concept of conduction controlled quenching cannot explain the acceleration provided by the nanoparticle layer on the surface. In this study, we study effects of nanoparticle deposition on evaporation and rewetting of a single sessile droplet of water. Leidenfrost temperature closely associated with the quenching phenomena is investigated on clean and nanoparticle-deposited surfaces by measuring total evaporation time of a droplet. The possible mechanisms responsible for the quench acceleration on the nanoparticle-deposited surfaces will be discussed with the relation between the localized rewetting of the heated surface even above the Leidenfrost temperature and the destabilization of the film-boiling vapor film

  6. Surface trapping phenomena in thermionic emission generating l/f noise

    International Nuclear Information System (INIS)

    Stepanescu, A.

    1975-01-01

    A general expression of the power spectrum of''flicker noise'', involving stochastic trapping phenomena and calculated on the basis of a two parameter model, is applied in the case of thermoionic emission from cathode surface. The fluctuation of the work function over the cathode surface is interpreted as being due to a trapping process of foreign atoms by the cathode. Taking into account the very physical nature of the trapping mechanism, under self-consistent assumptions, a 1/f power spectrum is obtained in a certain range of frequency. The two parameter model removes some discrepancies involved in the preceding theories. (author)

  7. Study of luminous phenomena observed on contaminated metallic surfaces submitted to high RF fields

    International Nuclear Information System (INIS)

    Maissa, S.; Junquera, T.; Fouaidy, M.; Le Goff, A.; Bonin, B.; Luong, M.; Safa, H.; Tan, J.

    1995-01-01

    The RF field emission from a sample subjected to high RF fields in a copper cavity has been investigated. The study is focused on the luminous emissions occurring on the RF surface simultaneously with the electron emission. The optical apparatus attached to the cavity permits to observe the evolution of the emitters and the direct effects of the surface conditioning. Also, the parameters of the emitted radiation (intensity, glowing duration, spectral distribution) may provide additional informations on the field emission phenomena. Some results concerning samples intentionally contaminated with particles (metallic or dielectric) are presented. (K.A.)

  8. Ab-initio calculations of the hydrogen-uranium system: Surface phenomena, absorption, transport and trapping

    International Nuclear Information System (INIS)

    Taylor, Christopher D.; Scott Lillard, R.

    2009-01-01

    Density functional theory was applied to the initial steps of uranium hydriding: surface phenomena, absorption, bulk transport and trapping. H adsorbs exothermically to the (0 0 1) surface, yet H absorption into the bulk is endothermic, with off-center octahedral absorption having the lowest absorption energy of 0.39 eV, relative to molecular H 2 . H absorption in interstitial sites causes a local softening of the bulk modulus. Diffusion of H in unstrained α-U has a barrier of 0.6 eV. The energy of H absorption adjacent to the chemical impurities C, S, Si was lowered by an amount proportional to the size of the impurity atom, and the resulting lattice strain Si > S > C. Thus, impurities may promote hydriding by providing surfaces or prestrained zones for H uptake.

  9. Pining phenomena of an evaporated droplet on the hydrophobic micro-textured surfaces

    International Nuclear Information System (INIS)

    Yu, Dong In; Doh, Seung Woo; Park, Hyun Sun; Moriyama Kiyofumia; Kim, Moo Hwan; Kwak, Ho Jae; Ahn, Ho Seon

    2015-01-01

    When the decreased contact angle reaches the receding contact angle, the contact radius is reduced while maintaining a constant contact angle, i.e., this evaporation mode is known as the constant contact angle (CCA) mode. The emphasis of the droplet evaporation is that the transition from CCR to CCA modes is relative with the rate of the droplet evaporation, and it is markedly influenced by the surface wettability. In this study, it is focused on the evaporation mode transition. Especially, the transition from CCR to CCA modes is investigated on the hydrophobic microtextured surfaces. On the basis of the thermodynamics, the transition from CCR to CCA mode is theoretically analyzed. The thermodynamic model is developed to estimate the receding contact angle at the evaporation mode transition. Additionally, to compare between the theoretical model and experimental results, it is shown that the experimental receding contact angle is well estimated by the receding contact angle with the theoretical model. This study was performed to investigate the pinning phenomena of an evaporated droplet on the hydrophobic micro-textured surfaces. The pinning phenomena at the contact line were shown theoretically to be due to the most favorable thermodynamics process that caused the Gibbs free energy to rapidly reach an equilibrium state during droplet evaporation. The evaporation mode underwent a transition when the decrease in the Gibbs free energy was equivalent for the CCR and CCA modes. On the basis of the analysis described here, a theoretical model was developed to estimate the receding contact angle at the mode transition as a function of the surface conditions

  10. Ceramic substrate including thin film multilayer surface conductor

    Energy Technology Data Exchange (ETDEWEB)

    Wolf, Joseph Ambrose; Peterson, Kenneth A.

    2017-05-09

    A ceramic substrate comprises a plurality of ceramic sheets, a plurality of inner conductive layers, a plurality of vias, and an upper conductive layer. The ceramic sheets are stacked one on top of another and include a top ceramic sheet. The inner conductive layers include electrically conductive material that forms electrically conductive features on an upper surface of each ceramic sheet excluding the top ceramic sheet. The vias are formed in each of the ceramic sheets with each via being filled with electrically conductive material. The upper conductive layer includes electrically conductive material that forms electrically conductive features on an upper surface of the top ceramic sheet. The upper conductive layer is constructed from a stack of four sublayers. A first sublayer is formed from titanium. A second sublayer is formed from copper. A third sublayer is formed from platinum. A fourth sublayer is formed from gold.

  11. Dependence of surface smoothing, sputtering and etching phenomena on cluster ion dosage

    CERN Document Server

    Song, J H; Choi, W K

    2002-01-01

    The dependence of surface smoothing and sputtering phenomena of Si (1 0 0) solid surfaces irradiated by CO sub 2 cluster ions on cluster-ion dosage was investigated using an atomic force microscope. The flux and total ion dosage of impinging cluster ions at the acceleration voltage of 50 kV were fixed at 10 sup 9 ions/cm sup 2 s and were scanned from 5x10 sup 1 sup 0 to 5x10 sup 1 sup 3 ions/cm sup 2 , respectively. The density of hillocks induced by cluster ion impact was gradually increased with the dosage up to 5x10 sup 1 sup 1 ions/cm sup 2 , which caused that the irradiated surface became rough from 0.4 to 1.24 nm in root-mean-square roughness (sigma sub r sub m sub s). At the boundary of the ion dosage of 10 sup 1 sup 2 ions/cm sup 2 , the density of the induced hillocks was decreased and sigma sub r sub m sub s was about 1.21 nm, not being deteriorated further. At the dosage of 5x10 sup 1 sup 3 ions/cm sup 2 , the induced hillocks completely disappeared and the surface became very flat as much as sigma...

  12. Nanoparticle technology for treatment of Parkinson's disease: the role of surface phenomena in reaching the brain.

    Science.gov (United States)

    Leyva-Gómez, Gerardo; Cortés, Hernán; Magaña, Jonathan J; Leyva-García, Norberto; Quintanar-Guerrero, David; Florán, Benjamín

    2015-07-01

    The absence of a definitive treatment for Parkinson's disease has driven the emerging investigation in the search for novel therapeutic alternatives. At present, the formulation of different drugs on nanoparticles has represented several advantages over conventional treatments. This type of multifunctional carrier, owing to its size and composition, has different interactions in biological systems that can lead to a decrease in ability to cross the blood-brain barrier. Therefore, this review focuses on the latest advances in obtaining nanoparticles for Parkinson's disease and provides an overview of technical aspects in the design of brain drug delivery of nanoparticles and an analysis of surface phenomena, a key aspect in the development of functional nanoparticles for Parkinson's disease. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. An Experimental Investigation on the Impingement of Water Droplets onto Superhydrophobic Surfaces Pertinent to Aircraft Icing Phenomena

    Science.gov (United States)

    Li, Haixing; Waldman, Rye; Hu, Hui

    2015-11-01

    Superhydrophobic surfaces have self-cleaning properties that make them promising candidates as anti-icing solutions for various engineering applications, including aircraft anti-/de-icing. However, under sufficient external pressure, the liquid water on the surface can transition to a wetted state, defeating the self-cleaning properties of superhydrpphobic surfaces. In the present study, an experimental investigation was conducted to quantify the transient behavior of water droplets impinging onto test surfaces with different hydrophobicity properties under different environmental icing conditions. The experiments were performed in the Icing Research Tunnel of Iowa State University (IRT-ISU) with a NACA0012 airfoil. In addition to using a high-speed imaging system to reveal transient behavior of water droplets impinging onto test surfaces with different hydrophobicity properties, an IR thermometry was also used to quantify the unsteady heat transfer and dynamic phase changing process within the water droplets after impingement onto the test plates with different frozen cold temperatures. The high-speed imaging results were correlated with the quantitatively temperature measurements to elucidate underlying physics in order to gain further insight into the underlying physics pertinent to aircraft icing phenomena. The research work is partially supported by NASA with grant number NNX12AC21A and National Science Foundation under award numbers of CBET-1064196 and CBET-1435590.

  14. Monitoring of tritium-contaminated surfaces, including skin

    International Nuclear Information System (INIS)

    Surette, R.A.; Wood, M.J.

    1994-05-01

    We have examined various commercially available tritium surface contamination monitors along with different swipe media and techniques for direct and indirect (swipe) monitoring of contaminated surfaces, including skin. None of the methods or instruments evaluated were more sensitive than the swipe and liquid scintillation counting (LSC) method. Swipe measurements with open-window proportional counters were, in general, less than half as sensitive as LSC, but have the advantages of having the results available almost immediately, and no sample preparation is required. The Nuclear Measurement Corporation's PC-55 is the most suitable instrument we tested for the analysis of routine swipe measurement. The PC-55 was about one third as sensitive as LSC when used with Ontario Hydro filter paper swipe media. Surface contamination measurement results can be obtained within minutes using the PC-55, compared to hours using LSC. The selection of swipe media for use with proportional counter-based instruments is critical. A medium that is electrically insulating can develop an electrostatic charge on its surface; this may alter the field gradient in the detector and may adversely influence the results. Although the PC-55 is sufficiently sensitive and very convenient, operational experience with the instrument is needed before recommending that it replace current LSC methods. The PC-55's susceptibility to internal tritium contamination may limit its practical usefulness. Because of the complexity of using live animals to evaluate direct and indirect methods for assessing skin contamination, pig skin was investigated as a possible substitute. We concluded that, for the first few hours post-exposure, pig skin mimics the kinetics of animal skin that has contacted a tritium-contaminated surface. (author). 30 refs., 1 tab., 7 figs

  15. Mars atmospheric phenomena during major dust storms, as measured at surface

    Science.gov (United States)

    Ryan, J. A.; Henry, R. M.

    1979-01-01

    Meteorological instrumentation aboard the Viking Mars Landers measures wind, temperature, and pressure. Two global dust storms occurred during northern autumn and winter, observed both by the orbiters and by the landers. The meteorological data from the landers has been analyzed for the period just before first storm arrival to just after second storm arrival, with the objectives of defining the meteorological phenomena during the storm period, determining those associated with storm and dust arrival, and evaluating the effects on synoptic conditions and the general circulation. Times of dust arrival over the sites could be defined fairly closely from optical and pressure (solar tide) data, and dust arrival was also accompanied by changes in diurnal temperature range, temperature maxima, and temperature minima. The arrivals of the storms at Viking Lander 1 were accompanied by significant increases in wind speed and pressure. No such changes were observed at Viking Lander 2. It is possible that surface material could have been raised locally at Viking Lander 1. Throughout the period except for the time following the second dust storm the synoptic picture at Viking Lander 2 was one of eastward moving cyclonic and anticyclonic systems. These disappeared following the second storm, a phenomenon which may be related to the storm.

  16. Exploration Technology Development including Surface Acoustic Wave RFID chips

    Data.gov (United States)

    National Aeronautics and Space Administration — This project is focused on maturing future surface exploration technologies and instrumentation and working towards flight instrumentation and systems to support...

  17. Olkiluoto surface hydrological modelling: Update 2012 including salt transport modelling

    International Nuclear Information System (INIS)

    Karvonen, T.

    2013-11-01

    Posiva Oy is responsible for implementing a final disposal program for spent nuclear fuel of its owners Teollisuuden Voima Oyj and Fortum Power and Heat Oy. The spent nuclear fuel is planned to be disposed at a depth of about 400-450 meters in the crystalline bedrock at the Olkiluoto site. Leakages located at or close to spent fuel repository may give rise to the upconing of deep highly saline groundwater and this is a concern with regard to the performance of the tunnel backfill material after the closure of the tunnels. Therefore a salt transport sub-model was added to the Olkiluoto surface hydrological model (SHYD). The other improvements include update of the particle tracking algorithm and possibility to estimate the influence of open drillholes in a case where overpressure in inflatable packers decreases causing a hydraulic short-circuit between hydrogeological zones HZ19 and HZ20 along the drillhole. Four new hydrogeological zones HZ056, HZ146, BFZ100 and HZ039 were added to the model. In addition, zones HZ20A and HZ20B intersect with each other in the new structure model, which influences salinity upconing caused by leakages in shafts. The aim of the modelling of long-term influence of ONKALO, shafts and repository tunnels provide computational results that can be used to suggest limits for allowed leakages. The model input data included all the existing leakages into ONKALO (35-38 l/min) and shafts in the present day conditions. The influence of shafts was computed using eight different values for total shaft leakage: 5, 11, 20, 30, 40, 50, 60 and 70 l/min. The selection of the leakage criteria for shafts was influenced by the fact that upconing of saline water increases TDS-values close to the repository areas although HZ20B does not intersect any deposition tunnels. The total limit for all leakages was suggested to be 120 l/min. The limit for HZ20 zones was proposed to be 40 l/min: about 5 l/min the present day leakages to access tunnel, 25 l/min from

  18. Including Finite Surface Span Effects in Empirical Jet-Surface Interaction Noise Models

    Science.gov (United States)

    Brown, Clifford A.

    2016-01-01

    The effect of finite span on the jet-surface interaction noise source and the jet mixing noise shielding and reflection effects is considered using recently acquired experimental data. First, the experimental setup and resulting data are presented with particular attention to the role of surface span on far-field noise. These effects are then included in existing empirical models that have previously assumed that all surfaces are semi-infinite. This extended abstract briefly describes the experimental setup and data leaving the empirical modeling aspects for the final paper.

  19. Influence of bulk and surface phenomena on the hydrogen permeation through metals

    International Nuclear Information System (INIS)

    Waelbroeck, F.; Wienhold, P.; Winter, J.; Rota, E.; Bauno, T.

    1984-12-01

    We discuss the permeation of hydrogen through metals and alloys such as iron, nickel, steels and Inconel wherein H dissolves endothermically from an H 2 gas. We assume first that trapping centers, surface contamination layers, the saturation of the H surface coverage and the implantation profile - when energetic ions drive the permeation - can be neglected, that a quasi-equilibrium exists between the H atom concentration ν in the adsorbed layer and c in the near surface layers and that the H solubility and diffusivity are homogeneous in the membrane. We evaluate thereafter separately the influence of these various effects and identify the parameter domains where appreciable corrections result. The permeation phenomenon is complex even when these simplifications are made: the penetration rate is proportional to the flux of thermal molecules, atoms or energetic ions - depending upon the case - which strike the surface; the diffusion in the metal is proportional to the gradient of c; the release rate depends on c 2 ; the time-dependent diffusion equation includes a double spatial derivative of c. Permeation can only be fully described when computer codes such as PERI is used. Simple analytical relations are however obtained in several limiting cases. They are the object of this report. Some of them had already been derived by other authors but they were not shown to be part of a single, self consistent permeation model. A comparison of predicted and experimental results shows that the simplified model describes surprisingly accurately the hydrogen exchange between gas and metal solutions. (orig./GSCH)

  20. Potential energy surface for ? dissociation including spin-orbit effects

    Science.gov (United States)

    Siebert, Matthew R.; Aquino, Adelia J. A.; de Jong, Wibe A.; Granucci, Giovanni; Hase, William L.

    2012-10-01

    Previous experiments [J. Phys. Chem. A 116, 2833 (2012)] have studied the dissociation of 1,2-diiodoethane radical cation ( ? ) and found a one-dimensional distribution of translational energy, an odd finding considering most product relative translational energy distributions are two-dimensional. The goal of this study is to obtain an accurate understanding of the potential energy surface (PES) topology for the unimolecular decomposition reaction ? → C2H4I+ + I•. This is done through comparison of many single-reference electronic structure methods, coupled-cluster single-point (energy) calculations, and multi-reference energy calculations used to quantify spin-orbit (SO) coupling effects. We find that the structure of the ? reactant has a substantial effect on the role of the SO coupling on the reaction energy. Both the BHandH and MP2 theories with an ECP/6-31++G** basis set, and without SO coupling corrections, provide accurate models for the reaction energetics. MP2 theory gives an unsymmetric structure with different C-I bond lengths, resulting in a SO energy for ? similar to that for the product I-atom and a negligible SO correction to the reaction energy. In contrast, DFT gives a symmetric structure for ? , similar to that of the neutral C2H4I2 parent, resulting in a substantial SO correction and increasing the reaction energy by 6.0-6.5 kcalmol-1. Also, we find that, for this system, coupled-cluster single-point energy calculations are inaccurate, since a small change in geometry can lead to a large change in energy.

  1. A Comparison of Numerical Strategies for Modeling the Transport Phenomena in High-Energy Laser Surface Alloying Process

    Directory of Open Access Journals (Sweden)

    Dipankar Chatterjee

    2017-06-01

    Full Text Available A comparative assessment is done on the effectiveness of some developed and reported macroscopic and mesoscopic models deployed for addressing the three-dimensional thermo-fluidic transport during high-power laser surface alloying process. The macroscopic models include the most celebrated k–ε turbulence model and the large eddy simulation (LES model, whereas a kinetic theory-based lattice Boltzmann (LB approach is invoked under the mesoscopic paradigm. The time-dependent Navier–Stokes equations are transformed into the k–ε turbulence model by performing the Reynolds averaging technique, whereas a spatial filtering operation is used to produce the LES model. The models are suitably modified to address the turbulent melt-pool convection by using a modified eddy viscosity expression including a damping factor in the form of square root of the liquid fraction. The LB scheme utilizes three separate distribution functions to monitor the underlying hydrodynamic, thermal and compositional fields. Accordingly, the kinematic viscosity, thermal and mass diffusivities are adjusted independently. A single domain fixed-grid enthalpy-porosity approach is utilized to model the phase change phenomena in conjunction with an appropriate enthalpy updating closure scheme. The performance of these models is recorded by capturing the characteristic nature of the thermo-fluidic transport during the laser material processing. The maximum values of the pertinent parameters in the computational domain obtained from several modeling efforts are compared to assess their capabilities. The comparison shows that the prediction from the k–ε turbulence model is higher than the LES and LB models. In addition, the results from all three models are compared with the available experimental results in the form of dimensionless composition of the alloyed layer along the dimensionless depth of the pool. The comparison reveals that the LB and the LES approaches are better

  2. Study of catastrophic phenomena on the Earth surface from board the ISS

    Science.gov (United States)

    Sekerzh-Zen'kovich, Sergey; Chebotarev, Alexander; Sarmin, Eric; Desinov, Lev; Yurina, Olga; Belyaev, Mikhail

    Monitoring of natural and technogenic catastrophes is one of the priority tasks of the Russian research program onboard the International Space Station. The Russian Segment crew uses photographic and video equipment and manual spectrometers for acquisition of scientific data on inundations, earthquakes, oil spillage, typhoons, fires and other hazardous natural and technogenic phenomena in the scope of "Uragan" experiment. Currently the cosmonauts use onboard spectrophotometrical system (SPMS) allowing to obtain color pictures and spectra of observed objects. The processing results obtained in 2012-2013 of a number of photos of glaciers, the ocean circular wave systems and also volcanic spectrograms are discussed in the report.

  3. Probing adsorption phenomena on a single crystal Pt-alloy surface under oxygen reduction reaction conditions

    DEFF Research Database (Denmark)

    Bondarenko, Alexander S.; Stephens, Ifan E.L.; Bech, Lone

    2012-01-01

    The adsorption dynamics of *OH and *O species at Pt(111) and Cu/Pt(111) near-surface alloy (NSA) surfaces in oxygen-free and O2-saturated 0.1M HClO4 was investigated. Subsurface Cu modifies the electronic structure at the Pt(111) surface resulting in weaker bonding to adsorbates like *OH, *H or *...

  4. NTERACTION BETWEEN SURFACE CHARGE PHENOMENA AND MULTI-SPECIES DIFFUSION IN CEMENT BASED MATERIALS

    DEFF Research Database (Denmark)

    Johannesson, Björn

    2008-01-01

    Measurements strongly indicate that the ‘inner’ surface of the microscopic structure of cement based materials has a fixed negative charge. This charge contributes to the formation of so-called electrical double layers. In the case of cement based materials the ionic species located in such layers...... are typically potassium -, sodium - and calcium ions. Due to the high specific surface area of hydrated cement, a large amount of ions can be located in theses double layers even if the surface charge is relatively low. The attraction force, caused by the fixed surface charge on ions located close to surfaces...

  5. Tracer Studies of the Influence of Foreign Substances at the Surface of the Electrodes. II Influence in electro crystallization phenomena

    International Nuclear Information System (INIS)

    Llopis, J.; Gamboa, J. M.; Arizmendi, L.

    1963-01-01

    The action of foreign substances present on the surface of the electrodes, in electro crystallization phenomena, has been studied. The number of Ag crystals per square centimeter of Pt electrode varies with the polishing, the current density and the presence of multilayers of stearic acid. The statistical distribution of Ag crystals without and with multilayers and their influence on the concentration index and the deformation of Ag crystals has been studied. the size of these crystals increases as the current density decreases. (Author) 16 refs

  6. Evaluation of flyash surface phenomena and the application of surface analysis technology. Summary report: Phase I. [44 elements; 86 references

    Energy Technology Data Exchange (ETDEWEB)

    Smith, R.D.

    1981-06-01

    The factors governing the formation of flyash surfaces during and following coal combustion are reviewed. The competing chemical and physical processes during the evolution of inorganic material in coal during combustion into flyash are described with respect to various surface segregation processes. Two mechanisms leading to surface enrichment are volatilization-condensation processes and diffusion processes within individual flyash particles. The experimental evidence for each of these processes is reviewed. It is shown that the volatilization-condensation process is the major factor leading to trace element enrichment in smaller flyash particles. Evidence also exists from surface analyses of flyash and representative mineral matter that diffusion processes may lead to surface enrichment of elements not volatilized or cause transport of surface-condensed elements into the flyash matrix. The semiquantitative determination of the relative importance of these two processes can be determined by comparison of concentration versus particle size profiles with surface-depth profiles obtained using surface analysis techniques. A brief description of organic transformations on flyash surfaces is also presented. The various surface analytical techniques are reviewed and the relatively new technique of Static-Secondary Ion Mass Spectroscopy is suggested as having significant advantages in studies of surfaces and diffusion processes in model systems. Several recommendations are made for research relevant to flyash formation and processes occurring on flyash surfaces.

  7. Correlating humidity-dependent ionically conductive surface area with transport phenomena in proton-exchange membranes.

    Science.gov (United States)

    He, Qinggang; Kusoglu, Ahmet; Lucas, Ivan T; Clark, Kyle; Weber, Adam Z; Kostecki, Robert

    2011-10-13

    The objective of this effort was to correlate the local surface ionic conductance of a Nafion 212 proton-exchange membrane with its bulk and interfacial transport properties as a function of water content. Both macroscopic and microscopic proton conductivities were investigated at different relative humidity levels, using direct-current voltammetry and current-sensing atomic force microscopy (CSAFM). We were able to identify small ion-conducting domains that grew with humidity at the surface of the membrane. Numerical analysis of the surface ionic conductance images recorded at various relative humidity levels helped determine the fractional area of ion-conducting active sites. A simple square-root relationship between the fractional conducting area and observed interfacial mass-transport resistance was established. Furthermore, the relationship between the bulk ionic conductivity and surface ionic conductance pattern of the Nafion membrane was examined.

  8. Correlating Humidity-Dependent Ionically Conductive Surface Area with Transport Phenomena in Proton-Exchange Membranes

    Energy Technology Data Exchange (ETDEWEB)

    He, Qinggang; Kusoglu, Ahmet; Lucas, Ivan T.; Clark, Kyle; Weber, Adam Z.; Kostecki, Robert

    2011-08-01

    The objective of this effort was to correlate the local surface ionic conductance of a Nafion? 212 proton-exchange membrane with its bulk and interfacial transport properties as a function of water content. Both macroscopic and microscopic proton conductivities were investigated at different relative humidity levels, using electrochemical impedance spectroscopy and current-sensing atomic force microscopy (CSAFM). We were able to identify small ion-conducting domains that grew with humidity at the surface of the membrane. Numerical analysis of the surface ionic conductance images recorded at various relative humidity levels helped determine the fractional area of ion-conducting active sites. A simple square-root relationship between the fractional conducting area and observed interfacial mass-transport resistance was established. Furthermore, the relationship between the bulk ionic conductivity and surface ionic conductance pattern of the Nafion? membrane was examined.

  9. Microimpact phenomena on Australasian microtektites: Implications for ejecta plume characteristics and lunar surface processes

    Digital Repository Service at National Institute of Oceanography (India)

    ShyamPrasad, M.; Sudhakar, M.

    and dust, craters generated by projectiles defining an oblique trajectory, high-velocity "pitless" craters, and the conventional hypervelocity craters with well-defined central pits and radial and concentric cracks-found commonly on lunar surface materials...

  10. Mechanisms for SAR imaging of ocean surface phenomena: Theory and experiment

    Science.gov (United States)

    Vesecky, J. F.

    1983-01-01

    Understanding the SAR response to surface wave is a central issue in the analysis of SAR ocean images. The imaging mechanism for gravity waves and the practical question of just which characteristics of the ocean wave field can be measured remotely using SAR were examined. Assessments of wave imaging theory are based primarily on comparisons of the directional wave height variance spectrum psi (K) measured by in situ buoys with estimates from SAR images. Other criteria are also recommended, e.g., the effects of focus adjustments. It is assumed that fluctuations in SAR image intensity are proportional to fluctuations in ocean surface height. If this were true, the Fourier power spectrum of a SAR image and corresponding surface measurements of psi would coincide. Differences between SAR estimates based on this hypothesis and buoy measurements of psi are then used to begin the assessment of rival wave imaging theories.

  11. On the Concept of Electrode to Discharge Phenomena in Surface Roughness With Reference Strongly Electronegative Gases

    DEFF Research Database (Denmark)

    McAllister, Iain Wilson

    1986-01-01

    The use of geometrically well-defined protrusions in studies es of the effects of electrode surface roughness upon the insulation strength of strongly electronegative gases is discussed. It is argued that, with respect to the roughness associated with production processes, the dimensions of artif......The use of geometrically well-defined protrusions in studies es of the effects of electrode surface roughness upon the insulation strength of strongly electronegative gases is discussed. It is argued that, with respect to the roughness associated with production processes, the dimensions...

  12. Double layer of platinum electrodes: Non-monotonic surface charging phenomena and negative double layer capacitance

    Science.gov (United States)

    Huang, Jun; Zhou, Tao; Zhang, Jianbo; Eikerling, Michael

    2018-01-01

    In this study, a refined double layer model of platinum electrodes accounting for chemisorbed oxygen species, oriented interfacial water molecules, and ion size effects in solution is presented. It results in a non-monotonic surface charging relation and a peculiar capacitance vs. potential curve with a maximum and possibly negative values in the potential regime of oxide-formation.

  13. Surface tension phenomena in the xylem sap of three diffuse porous temperate tree species

    Science.gov (United States)

    K. K. Christensen-Dalsgaard; M. T. Tyree; P. G. Mussone

    2011-01-01

    In plant physiology models involving bubble nucleation, expansion or elimination, it is typically assumed that the surface tension of xylem sap is equal to that of pure water, though this has never been tested. In this study we collected xylem sap from branches of the tree species Populus tremuloides, Betula papyrifera and Sorbus...

  14. Structural Investigations of Surfaces and Orientation-SpecificPhenomena in Nanocrystals and Their Assemblies

    Energy Technology Data Exchange (ETDEWEB)

    Aruguete, Deborah Michiko [Univ. of California, Berkeley, CA (United States)

    2006-01-01

    Studies of colloidal nanocrystals and their assemblies are presented. Two of these studies concern the atomic-level structural characterization of the surfaces, interfaces, and interiors present in II-VI semiconductor nanorods. The third study investigates the crystallographic arrangement of cobalt nanocrystals in self-assembled aggregates. Crystallographically-aligned assemblies of colloidal CdSe nanorods are examined with linearly-polarized Se-EXAFS spectroscopy, which probes bonding along different directions in the nanorod. This orientation-specific probe is used, because it is expected that the presence of specific surfaces in a nanorod might cause bond relaxations specific to different crystallographic directions. Se-Se distances are found to be contracted along the long axis of the nanorod, while Cd-Se distances display no angular dependence, which is different from the bulk. Ab-initio density functional theory calculations upon CdSe nanowires indicate that relaxations on the rod surfaces cause these changes. ZnS/CdS-CdSe core-shell nanorods are studied with Se, Zn, Cd, and S X-ray absorption spectroscopy (XAS). It is hypothesized that there are two major factors influencing the core and shell structures of the nanorods: the large surface area-to-volume ratio, and epitaxial strain. The presence of the surface may induce bond rearrangements or relaxations to minimize surface energy; epitaxial strain might cause the core and shell lattices to contract or expand to minimize strain energy. A marked contraction of Zn-S bonds is observed in the core-shell nanorods, indicating that surface relaxations may dominate the structure of the nanorod (strain might otherwise drive the Zn-S lattice to accommodate the larger CdS or CdSe lattices via bond expansion). EXAFS and X-ray diffraction (XRD) indicate that Cd-Se bond relaxations might be anisotropic, an expected phenomenon for a rod-shaped nanocrystal. Ordered self-assembled aggregates of cobalt nanocrystals are

  15. Biphotonic holographic gratings in azobenzene polyesters: Surface relief phenomena and polarization effects

    DEFF Research Database (Denmark)

    Sánchez, C.; Alcalá, R.; Hvilsted, Søren

    2000-01-01

    Biphotonic holographic gratings have been recorded in a side-chain azobenzene liquid crystalline polyester using a blue incoherent source and a He-Ne laser. Intensity gratings and the appearance of surface relief have been observed when two linearly polarized beams from a He-Ne laser are made...... to interfere on a film illuminated with blue light. Polarized holographic gratings are also created with two orthogonally circularly polarized He-Ne beams. All these gratings are stable in darkness but can be erased with blue light. (C) 2000 American Institute of Physics....

  16. Study of surface phenomena in biomaterials: The influence of physical factors

    Science.gov (United States)

    Sachelarie, Liliana; Vasiliu, Mihaela Papusa; Ciobanu, Catalina

    2015-10-01

    This study's purpose is pointing out the phenomenon that occurs at time of interaction between the tissue with implant. The materials used are Ti and its alloys. The oral tissue must be compatible with the materials used in surgical implant to human body. The bio-materials surface behavior is influenced by physical characteristics. The methods we use show a number of bio-compatibility aspects. The success of an implant in a hard tissue depends not only on the initial attachment and the osteogenic cells consecutive proliferation, but also on their capacity to create a new bone.

  17. Study of surface phenomena in biomaterials: The influence of physical factors

    Energy Technology Data Exchange (ETDEWEB)

    Sachelarie, Liliana, E-mail: lisachero@yahoo.com; Vasiliu, Mihaela Papusa; Ciobanu, Catalina

    2015-10-15

    This study's purpose is pointing out the phenomenon that occurs at time of interaction between the tissue with implant. The materials used are Ti and its alloys. The oral tissue must be compatible with the materials used in surgical implant to human body. The bio-materials surface behavior is influenced by physical characteristics. The methods we use show a number of bio-compatibility aspects. The success of an implant in a hard tissue depends not only on the initial attachment and the osteogenic cells consecutive proliferation, but also on their capacity to create a new bone.

  18. Normal and anomalous transport phenomena in two-dimensional NaCl, MoS2 and honeycomb surfaces

    Science.gov (United States)

    Mbemmo, A. M. Fopossi; Kenmoé, G. Djuidjé; Kofané, T. C.

    2018-04-01

    Understanding the effects of anisotropy and substrate shape on the stochastic processes is critically needed for the improvement of the quality of the transport information. The effect of biharmonic force on the transport phenomena of a particle in two-dimensional is investigated in the framework of three representative substrate lattices: NaCl, MoS2 and honeycomb. We focus on the particles drift velocity, to characterize the transport properties in the system. Normal and anomalous transport are identified for a particular set of the system parameters such as the biharmonic parameter, the bias force, the phase-lag of two signals, as well as the noise amplitude. According to the direction ψ where the bias force is applied, we determine the biharmonic parameter ɛ for the presence of anomalous transport and show that for the NaCl surface, the anomalous transport is observed for 2 transport is generated for 0 ⩽ ɛ 30 °.

  19. Lineaments of Texas - possible surface expressions of deep-seated phenomena. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Woodruff, C.M. Jr.; Caran, S.C.

    1984-04-01

    Lineaments were identified on 51 Landsat images covering Texas and parts of adjacent states in Mexico and the United States. A method of identifying lineaments was designed so that the findings would be consistent, uncomplicated, objective, and reproducible. Lineaments denoted on the Landsat images were traced onto 1:250,000-scale work maps and then rendered cartographically on maps representing each of the 51 Landsat images at a scale of 1:500,000. At this stage more than 31,000 lineaments were identified. It included significant areas outside of Texas. In preparing the final lineament map of Texas at 1:1,000,000-scale from the 1:500,000-scale maps, all features that lay outside Texas and repetition among features perceived by individual workers were eliminated. Cultural features were checked for before reducing and cartographically fitting the mosaic of 51 individual map sheets to a single map base. Lineaments that were partly colinear but with different end points were modified into a single lineament trace with the combined length of the two or more colinear lineaments. Each lineament was checked to determine its validity according to our definition. The features were edited again to eliminate processing artifacts within the image itself, as well as representations of cultural features (fencelines, roads, and the like) and geomorphic patterns unrelated to bedrock structure. Thus the more than 31,000 lineaments originally perceived were reduced to the approximately 15,000 presented on the 1:1,000,000 map. Interpretations of the lineaments are presented.

  20. On the modelling of semi-insulating GaAs including surface tension and bulk stresses

    Energy Technology Data Exchange (ETDEWEB)

    Dreyer, W.; Duderstadt, F.

    2004-07-01

    Necessary heat treatment of single crystal semi-insulating Gallium Arsenide (GaAs), which is deployed in micro- and opto- electronic devices, generate undesirable liquid precipitates in the solid phase. The appearance of precipitates is influenced by surface tension at the liquid/solid interface and deviatoric stresses in the solid. The central quantity for the description of the various aspects of phase transitions is the chemical potential, which can be additively decomposed into a chemical and a mechanical part. In particular the calculation of the mechanical part of the chemical potential is of crucial importance. We determine the chemical potential in the framework of the St. Venant-Kirchhoff law which gives an appropriate stress/strain relation for many solids in the small strain regime. We establish criteria, which allow the correct replacement of the St. Venant-Kirchhoff law by the simpler Hooke law. The main objectives of this study are: (i) We develop a thermo-mechanical model that describes diffusion and interface motion, which both are strongly influenced by surface tension effects and deviatoric stresses. (ii) We give an overview and outlook on problems that can be posed and solved within the framework of the model. (iii) We calculate non-standard phase diagrams, i.e. those that take into account surface tension and non-deviatoric stresses, for GaAs above 786 C, and we compare the results with classical phase diagrams without these phenomena. (orig.)

  1. Transport Phenomena and Materials Processing

    Science.gov (United States)

    Kou, Sindo

    1996-10-01

    An extremely useful guide to the theory and applications of transport phenomena in materials processing This book defines the unique role that transport phenomena play in materials processing and offers a graphic, comprehensive treatment unlike any other book on the subject. The two parts of the text are, in fact, two useful books. Part I is a very readable introduction to fluid flow, heat transfer, and mass transfer for materials engineers and anyone not yet thoroughly familiar with the subject. It includes governing equations and boundary conditions particularly useful for studying materials processing. For mechanical and chemical engineers, and anyone already familiar with transport phenomena, Part II covers the many specific applications to materials processing, including a brief description of various materials processing technologies. Readable and unencumbered by mathematical manipulations (most of which are allocated to the appendixes), this book is also a useful text for upper-level undergraduate and graduate-level courses in materials, mechanical, and chemical engineering. It includes hundreds of photographs of materials processing in action, single and composite figures of computer simulation, handy charts for problem solving, and more. Transport Phenomena and Materials Processing: * Describes eight key materials processing technologies, including crystal growth, casting, welding, powder and fiber processing, bulk and surface heat treating, and semiconductor device fabrication * Covers the latest advances in the field, including recent results of computer simulation and flow visualization * Presents special boundary conditions for transport phenomena in materials processing * Includes charts that summarize commonly encountered boundary conditions and step-by-step procedures for problem solving * Offers a unique derivation of governing equations that leads to both overall and differential balance equations * Provides a list of publicly available computer

  2. Nonlocal continuum-based modeling of breathing mode of nanowires including surface stress and surface inertia effects

    International Nuclear Information System (INIS)

    Ghavanloo, Esmaeal; Fazelzadeh, S. Ahmad; Rafii-Tabar, Hashem

    2014-01-01

    Nonlocal and surface effects significantly influence the mechanical response of nanomaterials and nanostructures. In this work, the breathing mode of a circular nanowire is studied on the basis of the nonlocal continuum model. Both the surface elastic properties and surface inertia effect are included. Nanowires can be modeled as long cylindrical solid objects. The classical model is reformulated using the nonlocal differential constitutive relations of Eringen and Gurtin–Murdoch surface continuum elasticity formalism. A new frequency equation for the breathing mode of nanowires, including small scale effect, surface stress and surface inertia is presented by employing the Bessel functions. Numerical results are computed, and are compared to confirm the validity and accuracy of the proposed method. Furthermore, the model is used to elucidate the effect of nonlocal parameter, the surface stress, the surface inertia and the nanowire orientation on the breathing mode of several types of nanowires with size ranging from 0.5 to 4 nm. Our results reveal that the combined surface and small scale effects are significant for nanowires with diameter smaller than 4 nm.

  3. Nonlocal continuum-based modeling of breathing mode of nanowires including surface stress and surface inertia effects

    Science.gov (United States)

    Ghavanloo, Esmaeal; Fazelzadeh, S. Ahmad; Rafii-Tabar, Hashem

    2014-05-01

    Nonlocal and surface effects significantly influence the mechanical response of nanomaterials and nanostructures. In this work, the breathing mode of a circular nanowire is studied on the basis of the nonlocal continuum model. Both the surface elastic properties and surface inertia effect are included. Nanowires can be modeled as long cylindrical solid objects. The classical model is reformulated using the nonlocal differential constitutive relations of Eringen and Gurtin-Murdoch surface continuum elasticity formalism. A new frequency equation for the breathing mode of nanowires, including small scale effect, surface stress and surface inertia is presented by employing the Bessel functions. Numerical results are computed, and are compared to confirm the validity and accuracy of the proposed method. Furthermore, the model is used to elucidate the effect of nonlocal parameter, the surface stress, the surface inertia and the nanowire orientation on the breathing mode of several types of nanowires with size ranging from 0.5 to 4 nm. Our results reveal that the combined surface and small scale effects are significant for nanowires with diameter smaller than 4 nm.

  4. Transport Phenomena.

    Science.gov (United States)

    Shah, D. B.

    1984-01-01

    Describes a course designed to achieve a balance between exposing students to (1) advanced topics in transport phenomena, pointing out similarities and differences between three transfer processes and (2) common methods of solving differential equations. (JN)

  5. Nanocoating of titanium implant surfaces with organic molecules. Polysaccharides including glycosaminoglycans

    DEFF Research Database (Denmark)

    Gurzawska, Katarzyna Aleksandra; Svava, Rikke; Jørgensen, Niklas Rye

    2012-01-01

    Long-term stability of titanium implants are dependent on a variety of factors. Nanocoating with organic molecules is one of the method used to improve osseointegration. Nanoscale modification of titanium implants affects surface properties, such as hydrophilicity, biochemical bonding capacity...... with focus on polysaccharides including glycosaminoglycans, and how these molecules change surface properties, cell reactions and affect on osseointegartion. The included in vitro studies demonstrated increased cell adhesion, proliferation and mineralization of a number of the tested polysaccharide...

  6. A light reflecting apparatus including a multi-aberration light reflecting surface

    Science.gov (United States)

    Sawicki, R.H.; Sweatt, W.

    1985-11-21

    A light reflecting apparatus including a multi-aberration bendable light reflecting surface is disclosed herein. This apparatus includes a structural assembly comprised of a rectangular plate which is resiliently bendable, to a limited extent, and which has a front side defining the multi-aberration light reflecting surface and an opposite back side, and a plurality of straight leg members rigidly connected with the back side of the plate and extending rearwardly therefrom. The apparatus also includes a number of different adjustment mechanisms, each of which is connected with specific ones of the leg members. These mechanisms are adjustably movable in different ways for applying corresponding forces to the leg members in order to bend the rectangular plate and light reflecting surface into different predetermined curvatures and which specifically include quadratic and cubic curvatures corresponding to different optical aberrations.

  7. Surface phenomena associated with thermal cycling of copper and their impact on the service life of particle accelerator structures

    CERN Document Server

    Aicheler, Markus; Theisen, Werner; Sgobba, Stefano

    2010-01-01

    The performance of accelerating structures (AS) in the Compact LInear Collider (CLIC) is sensitive to a variety of parameters, including the surface quality of key elements of the AS. Processes which affect the surface quality are therefore of particular concern. The present work addresses surface modifications associated with thermal cycling during operation. This type of operating condition represents a specific type of fatigue loading. Four fatigue test procedures were used in the present study in order to investigate the fatigue behaviour of oxygen{free{electronic (OFE) copper, the candidate material of the CLIC-AS: conventional fatigue (CVF), ultrasonic swinger (USS), laser fatigue (LAF) and radio{frequency fatigue (RFF). During operation of the accelerator the material of the AS will be subjected to cyclic temperature changes of approx. Delta T = 56 K, from about 40° C to about 100° C. These temperature changes will result in cyclic biaxial strains in the surface of the order of epsilon(biax) = 9.2 x ...

  8. Full-dimensional diabatic potential energy surfaces including dissociation: the ²E″ state of NO₃.

    Science.gov (United States)

    Eisfeld, Wolfgang; Vieuxmaire, Olivier; Viel, Alexandra

    2014-06-14

    A scheme to produce accurate full-dimensional coupled diabatic potential energy surfaces including dissociative regions and suitable for dynamical calculations is proposed. The scheme is successfully applied to model the two-sheeted surface of the (2)E″ state of the NO3 radical. An accurate potential energy surface for the NO₃⁻ anion ground state is developed as well. Both surfaces are based on high-level ab initio calculations. The model consists of a diabatic potential matrix, which is expanded to higher order in terms of symmetry polynomials of symmetry coordinates. The choice of coordinates is key for the accuracy of the obtained potential energy surfaces and is discussed in detail. A second central aspect is the generation of reference data to fit the expansion coefficients of the model for which a stochastic approach is proposed. A third ingredient is a new and simple scheme to handle problematic regions of the potential energy surfaces, resulting from the massive undersampling by the reference data unavoidable for high-dimensional problems. The final analytical diabatic surfaces are used to compute the lowest vibrational levels of NO₃⁻ and the photo-electron detachment spectrum of NO₃⁻ leading to the neutral radical in the (2)E″ state by full dimensional multi-surface wave-packet propagation for NO3 performed using the Multi-Configuration Time Dependent Hartree method. The achieved agreement of the simulations with available experimental data demonstrates the power of the proposed scheme and the high quality of the obtained potential energy surfaces.

  9. Improving weather predictability by including land-surface model parameter uncertainty

    Science.gov (United States)

    Orth, Rene; Dutra, Emanuel; Pappenberger, Florian

    2016-04-01

    The land surface forms an important component of Earth system models and interacts nonlinearly with other parts such as ocean and atmosphere. To capture the complex and heterogenous hydrology of the land surface, land surface models include a large number of parameters impacting the coupling to other components of the Earth system model. Focusing on ECMWF's land-surface model HTESSEL we present in this study a comprehensive parameter sensitivity evaluation using multiple observational datasets in Europe. We select 6 poorly constrained effective parameters (surface runoff effective depth, skin conductivity, minimum stomatal resistance, maximum interception, soil moisture stress function shape, total soil depth) and explore their sensitivity to model outputs such as soil moisture, evapotranspiration and runoff using uncoupled simulations and coupled seasonal forecasts. Additionally we investigate the possibility to construct ensembles from the multiple land surface parameters. In the uncoupled runs we find that minimum stomatal resistance and total soil depth have the most influence on model performance. Forecast skill scores are moreover sensitive to the same parameters as HTESSEL performance in the uncoupled analysis. We demonstrate the robustness of our findings by comparing multiple best performing parameter sets and multiple randomly chosen parameter sets. We find better temperature and precipitation forecast skill with the best-performing parameter perturbations demonstrating representativeness of model performance across uncoupled (and hence less computationally demanding) and coupled settings. Finally, we construct ensemble forecasts from ensemble members derived with different best-performing parameterizations of HTESSEL. This incorporation of parameter uncertainty in the ensemble generation yields an increase in forecast skill, even beyond the skill of the default system. Orth, R., E. Dutra, and F. Pappenberger, 2016: Improving weather predictability by

  10. Systems and methods for producing metal clusters; functionalized surfaces; and droplets including solvated metal ions

    Science.gov (United States)

    Cooks, Robert Graham; Li, Anyin; Luo, Qingjie

    2017-08-01

    The invention generally relates to systems and methods for producing metal clusters; functionalized surfaces; and droplets including solvated metal ions. In certain aspects, the invention provides methods that involve providing a metal and a solvent. The methods additionally involve applying voltage to the solvated metal to thereby produce solvent droplets including ions of the metal containing compound, and directing the solvent droplets including the metal ions to a target. In certain embodiments, once at the target, the metal ions can react directly or catalyze reactions.

  11. Evaluation of the susceptibility to pitting corrosion of structural steels, including steels with modified surface

    International Nuclear Information System (INIS)

    Lunarska, E.; Nikiforow, K.

    2001-01-01

    Although the low alloy ferrite-perlite and bainite-martensite steels mostly undergo the general corrosion, pitting corrosion occurring under certain conditions jeopardizes the safety of installations, causing perforation of walls or initiation of crack. On the basis of electrochemical, corrosion and microscopic examinations, the conditions simulating typical industrial corrosion environments, containing Cl - ions have been selected, to which the parts of machines, devices and installation are subjected. The test parameters provide the preferential pitting corrosion without prevailing general corrosion, and provide the similar type of corrosion of different kinds of ferrite-perlite and bainite-martensite steels, including steels with modified surface layer. The proposed express method allows to evaluate the susceptibility to pitting corrosion and to evaluate the effect of surface modification on susceptibility to pitting corrosion in environments containing Cl - ions. The method may be applied for the proper selection of materials exploited under pitting corrosion conditions and for preparation of precorroded samples for mechanical testing. (author)

  12. SHARC: ab Initio Molecular Dynamics with Surface Hopping in the Adiabatic Representation Including Arbitrary Couplings.

    Science.gov (United States)

    Richter, Martin; Marquetand, Philipp; González-Vázquez, Jesús; Sola, Ignacio; González, Leticia

    2011-05-10

    We present a semiclassical surface-hopping method which is able to treat arbitrary couplings in molecular systems including all degrees of freedom. A reformulation of the standard surface-hopping scheme in terms of a unitary transformation matrix allows for the description of interactions like spin-orbit coupling or transitions induced by laser fields. The accuracy of our method is demonstrated in two systems. The first one, consisting of two model electronic states, validates the semiclassical approach in the presence of an electric field. In the second one, the dynamics in the IBr molecule in the presence of spin-orbit coupling after laser excitation is investigated. Due to an avoided crossing that originates from spin-orbit coupling, IBr dissociates into two channels: I + Br((2)P3/2) and I + Br*((2)P1/2). In both systems, the obtained results are in very good agreement with those calculated from exact quantum dynamical simulations.

  13. A novel technique for including surface tension in PLIC-VOF methods

    Energy Technology Data Exchange (ETDEWEB)

    Meier, M.; Yadigaroglu, G. [Swiss Federal Institute of Technology, Nuclear Engineering Lab. ETH-Zentrum, CLT, Zurich (Switzerland); Smith, B. [Paul Scherrer Inst. (PSI), Villigen (Switzerland). Lab. for Thermal-Hydraulics

    2002-02-01

    Various versions of Volume-of-Fluid (VOF) methods have been used successfully for the numerical simulation of gas-liquid flows with an explicit tracking of the phase interface. Of these, Piecewise-Linear Interface Construction (PLIC-VOF) appears as a fairly accurate, although somewhat more involved variant. Including effects due to surface tension remains a problem, however. The most prominent methods, Continuum Surface Force (CSF) of Brackbill et al. and the method of Zaleski and co-workers (both referenced later), both induce spurious or 'parasitic' currents, and only moderate accuracy in regards to determining the curvature. We present here a new method to determine curvature accurately using an estimator function, which is tuned with a least-squares-fit against reference data. Furthermore, we show how spurious currents may be drastically reduced using the reconstructed interfaces from the PLIC-VOF method. (authors)

  14. Ion exchange phenomena

    Energy Technology Data Exchange (ETDEWEB)

    Bourg, I.C.; Sposito, G.

    2011-05-01

    Ion exchange phenomena involve the population of readily exchangeable ions, the subset of adsorbed solutes that balance the intrinsic surface charge and can be readily replaced by major background electrolyte ions (Sposito, 2008). These phenomena have occupied a central place in soil chemistry research since Way (1850) first showed that potassium uptake by soils resulted in the release of an equal quantity of moles of charge of calcium and magnesium. Ion exchange phenomena are now routinely modeled in studies of soil formation (White et al., 2005), soil reclamation (Kopittke et al., 2006), soil fertilitization (Agbenin and Yakubu, 2006), colloidal dispersion/flocculation (Charlet and Tournassat, 2005), the mechanics of argillaceous media (Gajo and Loret, 2007), aquitard pore water chemistry (Tournassat et al., 2008), and groundwater (Timms and Hendry, 2007; McNab et al., 2009) and contaminant hydrology (Chatterjee et al., 2008; van Oploo et al., 2008; Serrano et al., 2009).

  15. Consistent retrieval of land surface radiation products from EO, including traceable uncertainty estimates

    Science.gov (United States)

    Kaminski, Thomas; Pinty, Bernard; Voßbeck, Michael; Lopatka, Maciej; Gobron, Nadine; Robustelli, Monica

    2017-05-01

    Earth observation (EO) land surface products have been demonstrated to provide a constraint on the terrestrial carbon cycle that is complementary to the record of atmospheric carbon dioxide. We present the Joint Research Centre Two-stream Inversion Package (JRC-TIP) for retrieval of variables characterising the state of the vegetation-soil system. The system provides a set of land surface variables that satisfy all requirements for assimilation into the land component of climate and numerical weather prediction models. Being based on a 1-D representation of the radiative transfer within the canopy-soil system, such as those used in the land surface components of advanced global models, the JRC-TIP products are not only physically consistent internally, but they also achieve a high degree of consistency with these global models. Furthermore, the products are provided with full uncertainty information. We describe how these uncertainties are derived in a fully traceable manner without any hidden assumptions from the input observations, which are typically broadband white sky albedo products. Our discussion of the product uncertainty ranges, including the uncertainty reduction, highlights the central role of the leaf area index, which describes the density of the canopy. We explain the generation of products aggregated to coarser spatial resolution than that of the native albedo input and describe various approaches to the validation of JRC-TIP products, including the comparison against in situ observations. We present a JRC-TIP processing system that satisfies all operational requirements and explain how it delivers stable climate data records. Since many aspects of JRC-TIP are generic, the package can serve as an example of a state-of-the-art system for retrieval of EO products, and this contribution can help the user to understand advantages and limitations of such products.

  16. Tracer Studies of the Influence of Foreign Substances at the Surface of the Electrodes. I. Polarization Phenomena

    International Nuclear Information System (INIS)

    Llopis, J.; Gamboa, J. M.; Arizmendi, L.

    1961-01-01

    Radioactive stearic acid ( 1 4C) has been used to determine the number of molecular layers present on copper electrode surfaces and its distribution. The stability of these layers under the experimental conditions has been studied and it has been shown that its presence has no influence on the anodic and cathodic polarization. an increase of these polarizations has been observed with mixed multilayers of stearic acid and sterolamide. (Author) 13 refs

  17. On the molecular mechanism of surface charge amplification and related phenomena at aqueous polyelectrolyte-graphene interfaces

    Directory of Open Access Journals (Sweden)

    J.M. Simonson

    2011-09-01

    Full Text Available In this communication we illustrate the occurrence of a recently reported new phenomenon of surface-charge amplification, SCA, (originally dubbed overcharging, OC, [Jimenez-Angeles F. and Lozada-Cassou M., J. Phys. Chem. B, 2004, 108, 7286] by means of molecular dynamics simulation of aqueous electrolytes solutions involving multivalent cations in contact with charged graphene walls and the presence of short-chain lithium polystyrene sulfonates where the solvent water is described explicitly with a realistic molecular model. We show that the occurrence of SCA in these systems, in contrast to that observed in primitive models, involves neither contact co-adsorption of the negatively charged macroions nor divalent cations with a large size and charge asymmetry as required in the case of implicit solvents. In fact the SCA phenomenon hinges around the preferential adsorption of water (over the hydrated ions with an average dipolar orientation such that the charges of the water's hydrogen and oxygen sites induce magnification rather than screening of the positive-charged graphene surface, within a limited range of surface-charge density.

  18. Fundamentals of wave phenomena

    CERN Document Server

    Hirose, Akira

    2010-01-01

    This textbook provides a unified treatment of waves that either occur naturally or can be excited and propagated in various media. This includes both longitudinal and transverse waves. The book covers both mechanical and electrical waves, which are normally covered separately due to their differences in physical phenomena.

  19. ARPES view on surface and bulk hybridization phenomena in the antiferromagnetic Kondo lattice CeRh2Si2.

    Science.gov (United States)

    Patil, S; Generalov, A; Güttler, M; Kushwaha, P; Chikina, A; Kummer, K; Rödel, T C; Santander-Syro, A F; Caroca-Canales, N; Geibel, C; Danzenbächer, S; Kucherenko, Yu; Laubschat, C; Allen, J W; Vyalikh, D V

    2016-03-18

    The hybridization between localized 4f electrons and itinerant electrons in rare-earth-based materials gives rise to their exotic properties like valence fluctuations, Kondo behaviour, heavy-fermions, or unconventional superconductivity. Here we present an angle-resolved photoemission spectroscopy (ARPES) study of the Kondo lattice antiferromagnet CeRh2Si2, where the surface and bulk Ce-4f spectral responses were clearly resolved. The pronounced 4f (0) peak seen for the Ce terminated surface gets strongly suppressed in the bulk Ce-4f spectra taken from a Si-terminated crystal due to much larger f-d hybridization. Most interestingly, the bulk Ce-4f spectra reveal a fine structure near the Fermi edge reflecting the crystal electric field splitting of the bulk magnetic 4f (1)5/2 state. This structure presents a clear dispersion upon crossing valence states, providing direct evidence of f-d hybridization. Our findings give precise insight into f-d hybridization penomena and highlight their importance in the antiferromagnetic phases of Kondo lattices.

  20. Ion desorption phenomena induced by various types of multiply charged projectiles and by photons on solid surfaces

    International Nuclear Information System (INIS)

    Beyec, Y. Le.

    1991-01-01

    Ion desorption experiments are described in two regions of primary ion velocities corresponding to two distinct classes of interaction mechanism. At low speeds, atomic collisions take place, at higher speeds than the electron velocity, electronic collisions occur. Experiments with fast ions above 0.2 MeV/u are described, using 32 S and 235 U ions obtained in a cyclotron and a linear accelerator. Emission of H + ions from solid surfaces is measured and analyzed, and applied to the determination of the charge state of a fast ion in a solid. Experiments using single atomic and polyatomic, keV ions, and organic and CsI cluster ions as projectiles are also presented. Finally, laser desorption is discussed. (R.P.) 81 refs., 27 figs., 2 tabs

  1. Technology of surface wastewater purification, including high-rise construction areas

    Science.gov (United States)

    Tsyba, Anna; Skolubovich, Yury

    2018-03-01

    Despite on the improvements in the quality of high-rise construction areas and industrial wastewater treatment, the pollution of water bodies continues to increase. This is due to the organized and unorganized surface untreated sewage entry into the reservoirs. The qualitative analysis of some cities' surface sewage composition is carried out in the work. Based on the published literature review, the characteristic contamination present in surface wastewater was identified. The paper proposes a new technology for the treatment of surface sewage and presents the results of preliminary studies.

  2. Heat transfer and thermographic analysis of catalyst surface during multiphase phenomena under spray-pulsed conditions for dehydrogenation of cyclohexane over Pt catalysts.

    Science.gov (United States)

    Biniwale, Rajesh B; Kariya, N; Yamashiro, H; Ichikawa, Masaru

    2006-02-23

    Dehydrogenation of cyclohexane over Pt/alumite and Pt/activated carbon catalysts has been carried out for hydrogen storage and supply to fuel cell applications. An unsteady state has been created using spray pulsed injection of cyclohexane over the catalyst surface to facilitate the endothermic reaction to occur efficiently. Higher temperature of the catalyst surface is more favorable for the reaction, thus the heat transfer phenomena and temperature profile under alternate wet and dry conditions created using spray pulsed injection becomes important. IR thermography has been used for monitoring of temperature profile of the catalyst surface simultaneously with product analysis. The heat flux from the plate-type heater to the catalyst has been estimated using a rapid temperature recording and thermocouple arrangement. The estimated heat flux under transient conditions was in the range of 10-15 kW/m(2), which equates the requirement for endothermic reactions to the injection frequency of 0.5 Hz, as used in this study. The analysis of temperature profiles, reaction products over two different supports namely activated carbon cloth and alumite, reveals that the more conductive support such as alumite is more suitable for dehydrogenation of cyclohexane.

  3. Electron density in reasonably real metallic surfaces, including interchange and correlation effects

    International Nuclear Information System (INIS)

    Moraga, L.A.; Martinez, G.

    1981-01-01

    By means of a new method, the electron density in a jellium surface is calculated taking in account interchange and correlation effects; reproducing, in this way, the Lang and Kohn results. The new method is self-consistent but not iterative and hence is possible extend it to the solution of the same problem in more reasonably real metallic surfaces. (L.C.) [pt

  4. Microwave effective surface impedance of structures including a high-Tc superconducting film

    International Nuclear Information System (INIS)

    Hartemann, P.

    1992-01-01

    The microwave effective surface impedances of different stacks made of high-temperature superconducting films, dielectric materials and bulk normal metals were computed. The calculations were based on the two-fluid model of superconductors and the conventional transmission line theory. These effective impedances are compared to the calculated intrinsic surface impedances of the stacked superconducting films. The considered superconducting material has been the oxide YBa 2 Cu 3 O 7 epitaxially grown on crystalline substrates (MgO, LaAlO 3 , SrTiO 3 ), the film thickness ranging from a few nm to 1μm. Discrepancies between the effective surface resistances or reactances and the corresponding intrinsic values were determined at 10 GHz for non resonant or resonant structures. At resonance the surface resistance discrepancy exhibits a sharp peak which reaches 10 4 or more in relative value according to the geometry and the used materials. Obviously the effective surface reactance shows also huge variations about the resonance and may be negative. Moreover geometries allowing to obtain an effective resistance smaller than the film intrinsic value have been found. The effects of the resonance phenomenon on the electromagnetic wave reflectivity and reflection phase shift are investigated. Therefore the reported theoretical results demonstrate that the effective surface impedance of YBCO films with a thickness smaller than 500 nm can be very different from the intrinsic film impedance according to the structures. (Author). 3 refs., 10 figs., 2 tabs

  5. CHAIRMEN'S FOREWORD: The Seventh International Conference on New Phenomena in Mesoscopic Structures & The Fifth International Conference on Surfaces and Interfaces of Mesoscopic Devices

    Science.gov (United States)

    Aoyagi, Yoshinobu; Goodnick, Stephen M.

    2006-05-01

    This special issue of the Journal of Physics: Conference Series contains the proceedings of the joint Seventh International Conference on New Phenomena in Mesoscopic Structures and Fifth International Conference on Surfaces and Interfaces of Mesoscopic Devices, which was held from November 27th - December 2nd, 2005, at the Ritz Carlton Kapalua, Maui, Hawaii. The string of these conferences dates back to the first one in 1989. Of special importance is that this year's conference was dedicated to Professor Gottfried Landwehr, in recognition of his many outstanding contributions to semiconductor physics. A personal tribute to Prof Landwehr by Dr K von Klitzing leads off this issue. The scope of NPMS-7/SIMD-5 spans nano-fabrication through complex phase coherent mesoscopic systems including nano-transistors and nano-scale characterization. Topics of interest include: •Nanoscale fabrication: high-resolution electron lithography, FIB nano-patterning, scanning- force-microscopy (SFM) lithography, SFM-stimulated growth, novel patterning, nano-imprint lithography, special etching, and self-assembled monolayers •Nanocharacterization: SFM characterization, ballistic-electron emission microscopy (BEEM), optical studies of nanostructures, tunneling, properties of discrete impurities, phase coherence, noise, THz studies, and electro-luminescence in small structures •Nanodevices: ultra-scaled FETs, quantum single-electron transistors (SETS), resonant tunneling diodes, ferromagnetic and spin devices, superlattice arrays, IR detectors with quantum dots and wires, quantum point contacts, non-equilibrium transport, simulation, ballistic transport, molecular electronic devices, carbon nanotubes, spin selection devices, spin-coupled quantum dots, and nanomagnetics •Quantum-coherent transport: the quantum Hall effect, ballistic quantum systems, quantum-computing implementations and theory, and magnetic spin systems •Mesoscopic structures: quantum wires and dots, quantum chaos

  6. Interfacial Transport Phenomena (Second edition)

    NARCIS (Netherlands)

    Slattery, J.C.; Sagis, L.M.C.; Oh, E.S.

    2007-01-01

    Gives a presentation of transport phenomena or continuum mechanics focused on momentum, energy, and mass transfer at interfaces. This work includes a discussion of transport phenomena at common lines or three-phase lines of contact, and a theory for the extension of continuum mechanics to the

  7. Simultaneous measurements of work function and H‒ density including caesiation of a converter surface

    Science.gov (United States)

    Cristofaro, S.; Friedl, R.; Fantz, U.

    2017-08-01

    Negative hydrogen ion sources rely on the surface conversion of neutral atomic hydrogen and positive hydrogen ions to H-. The efficiency of this process depends on the actual work function of the converter surface. By introducing caesium into the source the work function decreases, enhancing the negative ion yield. In order to study the impact of the work function on the H- surface production at similar conditions to the ones in ion sources for fusion devices like ITER and DEMO, fundamental investigations are performed in a flexible laboratory experiment. The work function of the converter surface can be absolutely measured by photoelectric effect, while a newly installed cavity ring-down spectroscopy system (CRDS) measures the H- density. The CRDS is firstly tested and characterized by investigations on H- volume production. Caesiation of a stainless steel sample is then performed in vacuum and the plasma effect on the Cs layer is investigated also for long plasma-on times. A minimum work function of (1.9±0.1) eV is reached after some minutes of plasma treatment, resulting in a reduction by a value of 0.8 eV compared to vacuum measurements. The H- density above the surface is (2.1±0.5)×1015 m-3. With further plasma exposure of the caesiated surface, the work function increases up to 3.75 eV, due to the impinging plasma particles which gradually remove the Cs layer. As a result, the H- density decreases by a factor of at least 2.

  8. Transport phenomena in environmental engineering

    Science.gov (United States)

    Sander, Aleksandra; Kardum, Jasna Prlić; Matijašić, Gordana; Žižek, Krunoslav

    2018-01-01

    A term transport phenomena arises as a second paradigm at the end of 1950s with high awareness that there was a strong need to improve the scoping of chemical engineering science. At that point, engineers became highly aware that it is extremely important to take step forward from pure empirical description and the concept of unit operations only to understand the specific process using phenomenological equations that rely on three elementary physical processes: momentum, energy and mass transport. This conceptual evolution of chemical engineering was first presented with a well-known book of R. Byron Bird, Warren E. Stewart and Edwin N. Lightfoot, Transport Phenomena, published in 1960 [1]. What transport phenomena are included in environmental engineering? It is hard to divide those phenomena through different engineering disciplines. The core is the same but the focus changes. Intention of the authors here is to present the transport phenomena that are omnipresent in treatment of various process streams. The focus in this chapter is made on the transport phenomena that permanently occur in mechanical macroprocesses of sedimentation and filtration for separation in solid-liquid particulate systems and on the phenomena of the flow through a fixed and a fluidized bed of particles that are immanent in separation processes in packed columns and in environmental catalysis. The fundamental phenomena for each thermal and equilibrium separation process technology are presented as well. Understanding and mathematical description of underlying transport phenomena result in scoping the separation processes in a way that ChEs should act worldwide.

  9. Surface wave site characterization at 27 locations near Boston, Massachusetts, including 2 strong-motion stations

    Science.gov (United States)

    Thompson, Eric M.; Carkin, Bradley A.; Baise, Laurie G.; Kayen, Robert E.

    2014-01-01

    The geotechnical properties of the soils in and around Boston, Massachusetts, have been extensively studied. This is partly due to the importance of the Boston Blue Clay and the extent of landfill in the Boston area. Although New England is not a region that is typically associated with seismic hazards, there have been several historical earthquakes that have caused significant ground shaking (for example, see Street and Lacroix, 1979; Ebel, 1996; Ebel, 2006). The possibility of strong ground shaking, along with heightened vulnerability from unreinforced masonry buildings, motivates further investigation of seismic hazards throughout New England. Important studies that are pertinent to seismic hazards in New England include source-parameter studies (Somerville and others, 1987; Boore and others, 2010), wave-propagation studies (Frankel, 1991; Viegas and others, 2010), empirical ground-motion prediction equations (GMPE) for computing ground-motion intensity (Tavakoli and Pezeshk, 2005; Atkinson and Boore, 2006), site-response studies (Hayles and others, 2001; Ebel and Kim, 2006), and liquefaction studies (Brankman and Baise, 2008). The shear-wave velocity (VS) profiles collected for this report are pertinent to the GMPE, site response, and liquefaction aspects of seismic hazards in the greater Boston area. Besides the application of these data for the Boston region, the data may be applicable throughout New England, through correlations with geologic units (similar to Ebel and Kim, 2006) or correlations with topographic slope (Wald and Allen, 2007), because few VS measurements are available in stable tectonic regions.Ebel and Hart (2001) used felt earthquake reports to infer amplification patterns throughout the greater Boston region and noted spatial correspondence with the dominant period and amplification factors obtained from ambient noise (horizontal-to-vertical ratios) by Kummer (1998). Britton (2003) compiled geotechnical borings in the area and produced a

  10. Determining surface wave attenuation by modeling surface wave amplitudes including finite-frequency focusing and defocusing effects

    Science.gov (United States)

    Ma, Z.; Masters, G.

    2011-12-01

    We have developed a technique that uses cluster analysis method to efficiently measure Rayleigh wave phase and amplitude anomalies. Amplitude anomaly measurements have been made on the vertical components of all permanent stations recording LHZ data from IRIS. We currently consider earthquakes with Ms>5.5 between 1990 and 2004 and correct for source phase and magnitude according to the CMT. This technique leads to a large set of amplitude measurements at 7mHz, 10mHz, 15mHz and 20mHz. We discard data with erroneously large amplitude anomalies (|dlnA|>1) and inconsistent instrument responses and we only use earthquakes recorded by more than 30 stations. Out of about 250000 raw measurements for each frequency, about 140000 measurements are retained for inverting for attenuation structure. Similar to Dalton and Ekstrom (2006), phase and amplitude data are inverted together for phase velocity maps, attenuation maps, and source and receiver terms. However, we use the 2D finite frequency amplitude kernel of Zhou et al, (2004) to model the focusing-defocusing effects. Ray theory, which has been used to date, gives amplitude anomaly predictions which depend strongly on short wavelength structure and so are very sensitive to how phase velocity maps are smoothed. Our resulting attenuation maps show structures correlating well with surface tectonics, with high attenuation in regions of ridges, back-arc basins and western North America, and low attenuation in stable continental shields. The success of getting reasonable attenuation structures demonstrates the feasibility of applying 2D finite frequency amplitude kernel to real data.

  11. Micro transport phenomena during boiling

    Energy Technology Data Exchange (ETDEWEB)

    Peng, Xiaofeng [Tsinghua Univ., Beijing (China). Inst. of Thermal Engineering and Science

    2010-07-01

    ''Micro Transport Phenomena During Boiling'' reviews the new achievements and contributions in recent investigations at microscale. The content mainly includes (i) fundamentals for conducting investigations of micro boiling, (ii) microscale boiling and transport phenomena, (iii) boiling characteristics at microscale, (iv) some important applications of micro boiling transport phenomena. This book is intended for researchers and engineers in the field of micro energy systems, electronic cooling, and thermal management in various compact devices/systems at high heat removal and/or heat dissipation. (orig.)

  12. Conditioning and breakdown phenomena in accelerator tubes

    International Nuclear Information System (INIS)

    Skorka, S.J.

    1979-01-01

    Important breakdown mechanisms in accelerator tubes are reviewed, and discharge phenomena in NEC tubes are deduced from the surface appearance of the electrodes and insulators of a used tube. Microphotos of these surfaces are shown

  13. Expansion Hamiltonian model for a diatomic molecule adsorbed on a surface: Vibrational states of the CO/Cu(100) system including surface vibrations

    Energy Technology Data Exchange (ETDEWEB)

    Meng, Qingyong, E-mail: mengqingyong@dicp.ac.cn [State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Zhongshan Road 457, 116023 Dalian (China); Meyer, Hans-Dieter, E-mail: hans-dieter.meyer@pci.uni-heidelberg.de [Theoretische Chemie, Physikalisch-Chemisches Institut, Ruprecht-Karls Universität Heidelberg, Im Neuenheimer Feld 229, D-69120 Heidelberg (Germany)

    2015-10-28

    Molecular-surface studies are often done by assuming a corrugated, static (i.e., rigid) surface. To be able to investigate the effects that vibrations of surface atoms may have on spectra and cross sections, an expansion Hamiltonian model is proposed on the basis of the recently reported [R. Marquardt et al., J. Chem. Phys. 132, 074108 (2010)] SAP potential energy surface (PES), which was built for the CO/Cu(100) system with a rigid surface. In contrast to other molecule-surface coupling models, such as the modified surface oscillator model, the coupling between the adsorbed molecule and the surface atoms is already included in the present expansion SAP-PES model, in which a Taylor expansion around the equilibrium positions of the surface atoms is performed. To test the quality of the Taylor expansion, a direct model, that is avoiding the expansion, is also studied. The latter, however, requests that there is only one movable surface atom included. On the basis of the present expansion and direct models, the effects of a moving top copper atom (the one to which CO is bound) on the energy levels of a bound CO/Cu(100) system are studied. For this purpose, the multiconfiguration time-dependent Hartree calculations are carried out to obtain the vibrational fundamentals and overtones of the CO/Cu(100) system including a movable top copper atom. In order to interpret the results, a simple model consisting of two coupled harmonic oscillators is introduced. From these calculations, the vibrational levels of the CO/Cu(100) system as function of the frequency of the top copper atom are discussed.

  14. Evolutionary phenomena in galaxies

    International Nuclear Information System (INIS)

    Beckman, J.E.; Pagel, B.E.J.

    1989-01-01

    This book reviews the subject of evolutionary phenomena in galaxies, bringing together contributions by experts on all the relevant physics and astrophysics necessary to understand galaxies and how they work. The book is based on the proceedings of a conference held in July 1988 in Puerto de la Cruz, Tenerife which was timed to coincide with the first year of operation of the 4.2 m William Herschel Telescope. The broad topics covered include formation of galaxies and their ages, stellar dynamics, galactic scale gas and its role in star formation and the production and distribution of the chemical elements within galaxies. (author)

  15. Transport phenomena I essentials

    CERN Document Server

    REA, The Editors of

    2012-01-01

    REA's Essentials provide quick and easy access to critical information in a variety of different fields, ranging from the most basic to the most advanced. As its name implies, these concise, comprehensive study guides summarize the essentials of the field covered. Essentials are helpful when preparing for exams, doing homework and will remain a lasting reference source for students, teachers, and professionals. Transport Phenomena I includes viscosity, flow of Newtonian fluids, velocity distribution in laminar flow, velocity distributions with more than one independent variable, thermal con

  16. Strings, fields and critical phenomena

    International Nuclear Information System (INIS)

    Ambjoern, J.

    1987-07-01

    The connection between field theory and critical phenomena is reviewed. Emphasis is put on the use of Monte Carlo methods in the study of non-perturbative aspects of field theory. String theory is then described as a statistical theory of random surfaces and the critical behaviour is analyzed both by analytical and numerical methods. (orig.)

  17. The use of in situ Fourier-transform infrared spectroscopy for the study of surface phenomena on electrodes in selected lithium battery electrolyte solutions

    Science.gov (United States)

    Aurbach, D.; Chusid, O.

    This paper presents some examples of surface studies of noble metals and Li electrodes in Li battery electrolyte solutions using in situ FT-IR spectroscopic techniques. These examples include the study of a mixture of solvents, the role of the reduction of salt in the build-up of surface films on the electrodes and the impact of contaminants such as traces of oxgen and water. The techniques included multiple and single internal reflectance modes and external reflectance (SNIFTIRS-type) mode. The following conclusions were drawn from this study: (i) salts containing the -SO 2CF 3 group are much more reactive on Li than LiAsF 6. Their reduction dominates the surface chemistry developed on Li in ethereal solutions; (ii) water reduction on Li in wet 1,3-dioxolane solution may not form stable LiOH films due to the further reaction of the hydroxy group with the solvent; (iii) in spite of its low solubility, oxygen dissolved in propylene carbonate and tetrahydrofuran solutions has some impact on the surface chemistry developed on Li in these solutions (probably due to Li 2O formation).

  18. Workshop on Interface Phenomena

    CERN Document Server

    Kreuzer, Hans

    1987-01-01

    This book contains the proceedings of the first Workshop on Interface Phenomena, organized jointly by the surface science groups at Dalhousie University and the University of Maine. It was our intention to concentrate on just three topics related to the kinetics of interface reactions which, in our opinion, were frequently obscured unnecessarily in the literature and whose fundamental nature warranted an extensive discussion to help clarify the issues, very much in the spirit of the Discussions of the Faraday Society. Each session (day) saw two principal speakers expounding the different views; the session chairmen were asked to summarize the ensuing discussions. To understand the complexity of interface reactions, paradigms must be formulated to provide a framework for the interpretation of experimen­ tal data and for the construction of theoretical models. Phenomenological approaches have been based on a small number of rate equations for the concentrations or mole numbers of the various species involved i...

  19. Micro- and nanoscale phenomena in tribology

    CERN Document Server

    Chung, Yip-Wah

    2011-01-01

    Drawn from presentations at a recent National Science Foundation Summer Institute on Nanomechanics, Nanomaterials, and Micro/Nanomanufacturing, Micro- and Nanoscale Phenomena in Tribology explores the convergence of the multiple science and engineering disciplines involved in tribology and the connection from the macro to nano world. Written by specialists from computation, materials science, mechanical engineering, surface physics, and chemistry, each chapter provides up-to-date coverage of both basic and advanced topics and includes extensive references for further study.After discussing the

  20. Remote sensing of natural phenomena

    Directory of Open Access Journals (Sweden)

    Miodrag D. Regodić

    2014-06-01

    Full Text Available There has always been a need to directly perceive and study the events whose extent is beyond people's possibilities. In order to get new data and to make observations and studying much more objective in comparison with past syntheses - a new method of examination called remote sensing has been adopted. The paper deals with the principles and elements of remote sensing, as well as with the basic aspects of using remote research in examining meteorological (weather parameters and the conditions of the atmosphere. The usage of satellite images is possible in all phases of the global and systematic research of different natural phenomena when airplane and satellite images of different characteristics are used and their analysis and interpretation is carried out by viewing and computer added procedures. Introduction Remote sensing of the Earth enables observing and studying global and local events that occur on it. Satellite images are nowadays used in geology, agriculture, forestry, geodesy, meteorology, spatial and urbanism planning, designing of infrastructure and other objects, protection from natural and technological catastrophes, etc. It it possible to use satellite images in all phases of global and systematic research of different natural phenomena. Basics of remote sensing Remote sensing is a method of the acquisition and interpretation of information about remote objects without making a physical contact with them. The term Daljinska detekcija is a literal translation of the English term Remote Sensing. In French it isTeledetection, in German - Fernerkundung, in Russian - дистанционие иследования. We also use terms such as: remote survailance, remote research, teledetection, remote methods, and distance research. The basic elements included in Remote Sensing are: object, electromagnetic energy, sensor, platform, image, analysis, interpretation and the information (data, fact. Usage of satellite remote research in

  1. Active faulting Vs other surface displacing complex geomorphic phenomena. Case studies from a tectonically active area, Abruzzi Region, central Apennines, Italy

    Science.gov (United States)

    Lo Sardo, Lorenzo; Gori, Stefano; Falcucci, Emanuela; Saroli, Michele; Moro, Marco; Galadini, Fabrizio; Lancia, Michele; Fubelli, Giandomenico; Pezzo, Giuseppe

    2016-04-01

    How can be univocally inferred the genesis of a linear surface scarp as the result of an active and capable fault (FAC) in tectonically active regions? Or, conversely, how it is possible to exclude that a scarp is the result of a capable fault activation? Trying to unravel this open questions, we show two ambiguous case studies about the problem of the identification of active and capable faults in a tectonically active area just based on the presence of supposed fault scarps at surface. The selected cases are located in the area comprised between the Middle Aterno Valley Fault (MAVF) and the Campo Imperatore Plain (Abruzzi Region, central Apennines), nearby the epicentral area of the April 6th, 2009 L'Aquila earthquake. In particular, the two case studies analysed are located in a region characterized by a widespread Quaternary faults and by several linear scarps: the case studies of (i) Prata D'Ansidonia area and (ii) Santo Stefano di Sessanio area. To assess the origin and the state of activity of the investigated geomorphic features, we applied a classical geological and geomorphological approach, based on the analysis of the available literature, the interpretation of the aerial photographs, field surveying and classical paleoseismological approach, the latter consisting in digging excavations across the analysed scarps. These analysis were then integrated by morphometrical analyses. As for case (i), we focused on determining the geomorphic "meaning" of linear scarps carved onto fluvial-deltaic conglomerates (dated to the Early Pleistocene; Bertini and Bosi, 1993), up to 3 meters high and up to 1,5 km long, that border a narrow, elongated and flat-bottom depressions, filled by colluvial deposits. These features groove the paleo-landsurface of Valle Daria (Bosi and Bertini, 1970), wide landsurface located between Barisciano and Prata D'Ansidonia. Entwining paleoseismological trenching with geophysical analyses (GPR, ERT and microgravimetrical prospections), it

  2. Containment severe accident thermohydraulic phenomena

    International Nuclear Information System (INIS)

    Frid, W.

    1991-08-01

    This report describes and discusses the containment accident progression and the important severe accident containment thermohydraulic phenomena. The overall objective of the report is to provide a rather detailed presentation of the present status of phenomenological knowledge, including an account of relevant experimental investigations and to discuss, to some extent, the modelling approach used in the MAAP 3.0 computer code. The MAAP code has been used in Sweden as the main tool in the analysis of severe accidents. The dependence of the containment accident progression and containment phenomena on the initial conditions, which in turn are heavily dependent on the in-vessel accident progression and phenomena as well as associated uncertainties, is emphasized. The report is in three parts dealing with: * Swedish reactor containments, the severe accident mitigation programme in Sweden and containment accident progression in Swedish PWRs and BWRs as predicted by the MAAP 3.0 code. * Key non-energetic ex-vessel phenomena (melt fragmentation in water, melt quenching and coolability, core-concrete interaction and high temperature in containment). * Early containment threats due to energetic events (hydrogen combustion, high pressure melt ejection and direct containment heating, and ex-vessel steam explosions). The report concludes that our understanding of the containment severe accident progression and phenomena has improved very significantly over the parts ten years and, thereby, our ability to assess containment threats, to quantify uncertainties, and to interpret the results of experiments and computer code calculations have also increased. (au)

  3. Whistlers and related ionospheric phenomena

    CERN Document Server

    Helliwell, Robert A

    2006-01-01

    The investigation of whistlers and related phenomena is a key element in studies of very-low-frequency propagation, satellite communication, the outer ionosphere, and solar-terrestrial relationships. This comprehensive text presents a history of the study of the phenomena and includes all the elements necessary for the calculation of the characteristics of whistlers and whistler-mode signals.An introduction and brief history are followed by a summary of the theory of whistlers and a detailed explanation of the calculation of their characteristics. Succeeding chapters offer a complete atlas of

  4. Transport phenomena in particulate systems

    CERN Document Server

    Freire, José Teixeira; Ferreira, Maria do Carmo

    2012-01-01

    This volume spans 10 chapters covering different aspects of transport phenomena including fixed and fluidized systems, spouted beds, electrochemical and wastewater treatment reactors. This e-book will be valuable for students, engineers and researchers aiming to keep updated on the latest developments on particulate systems.

  5. Investigation of GaAs and InP surface passivation phenomena by sulfur; Badanie zjawiska pasywacji powierzchni GaAs i InP przy pomocy siarki

    Energy Technology Data Exchange (ETDEWEB)

    Przyborowska, K.; Surma, B. [Instytut Technologii Materialow Elektronicznych, Warsaw (Poland); Zakroczymski, T. [Polska Akademia Nauk, Warsaw (Poland). Inst. Chemii Fizycznej

    1997-12-01

    Some different chemical methods for sulfur passivation of GaAs and InP surface have been tried. The photoluminescence intensity has been compared for surfaces being sulfurized in different processes. Surface composition have been analysed by means of Auger electron spectroscopy. It has been found that passivation by sulfur of A{sup III}B{sup V} compounds diminishes the concentration of surface states and can be applied for preparing the epi-ready plates. 5 refs, 3 figs.

  6. Nuclear fuel deformation phenomena

    International Nuclear Information System (INIS)

    Van Brutzel, L.; Dingreville, R.; Bartel, T.J.

    2015-01-01

    Nuclear fuel encounters severe thermomechanical environments. Its mechanical response is profoundly influenced by an underlying heterogeneous microstructure but also inherently dependent on the temperature and stress level histories. The ability to adequately simulate the response of such microstructures, to elucidate the associated macroscopic response in such extreme environments is crucial for predicting both performance and transient fuel mechanical responses. This chapter discusses key physical phenomena and the status of current modelling techniques to evaluate and predict fuel deformations: creep, swelling, cracking and pellet-clad interaction. This chapter only deals with nuclear fuel; deformations of cladding materials are discussed elsewhere. An obvious need for a multi-physics and multi-scale approach to develop a fundamental understanding of properties of complex nuclear fuel materials is presented. The development of such advanced multi-scale mechanistic frameworks should include either an explicit (domain decomposition, homogenisation, etc.) or implicit (scaling laws, hand-shaking,...) linkage between the different time and length scales involved, in order to accurately predict the fuel thermomechanical response for a wide range of operating conditions and fuel types (including Gen-IV and TRU). (authors)

  7. Ultrashort Laser Pulse Phenomena

    CERN Document Server

    Diels, Jean-Claude

    2006-01-01

    Ultrashort Laser Pulse Phenomena, 2e serves as an introduction to the phenomena of ultra short laser pulses and describes how this technology can be used to examine problems in areas such as electromagnetism, optics, and quantum mechanics. Ultrashort Laser Pulse Phenomena combines theoretical backgrounds and experimental techniques and will serve as a manual on designing and constructing femtosecond (""faster than electronics"") systems or experiments from scratch. Beyond the simple optical system, the various sources of ultrashort pulses are presented, again with emphasis on the basic

  8. Science and Paranormal Phenomena

    Energy Technology Data Exchange (ETDEWEB)

    Noyes, H. Pierre

    1999-06-03

    In order to ground my approach to the study of paranormal phenomena, I first explain my operational approach to physics, and to the ''historical'' sciences of cosmic, biological, human, social and political evolution. I then indicate why I believe that ''paranormal phenomena'' might-but need not- fit into this framework. I endorse the need for a new theoretical framework for the investigation of this field presented by Etter and Shoup at this meeting. I close with a short discussion of Ted Bastin's contention that paranormal phenomena should be defined as contradicting physics.

  9. Surface potential based modeling of charge, current, and capacitances in DGTFET including mobile channel charge and ambipolar behaviour

    Science.gov (United States)

    Jain, Prateek; Yadav, Chandan; Agarwal, Amit; Chauhan, Yogesh Singh

    2017-08-01

    We present a surface potential based analytical model for double gate tunnel field effect transistor (DGTFET) for the current, terminal charges, and terminal capacitances. The model accounts for the effect of the mobile charge in the channel and captures the device physics in depletion as well as in the strong inversion regime. The narrowing of the tunnel barrier in the presence of mobile charges in the channel is incorporated via modeling of the inverse decay length, which is constant under channel depletion condition and bias dependent under inversion condition. To capture the ambipolar current behavior in the model, tunneling at the drain junction is also included. The proposed model is validated against TCAD simulation data and it shows close match with the simulation data.

  10. Interfacial transport phenomena

    CERN Document Server

    Slattery, John C; Oh, Eun-Suok

    2007-01-01

    Revised and updated extensively from the previous editionDiscusses transport phenomena at common lines or three-phase lines of contactProvides a comprehensive summary about the extensions of continuum mechanics to the nanoscale.

  11. Observation of Celestial Phenomena in Ancient China

    Science.gov (United States)

    Sun, Xiaochun

    Because of the need for calendar-making and portent astrology, the Chinese were diligent and meticulous observers of celestial phenomena. China has maintained the longest continuous historical records of celestial phenomena in the world. Extraordinary or abnormal celestial events were particularly noted because of their astrological significance. The historical records cover various types of celestial phenomena, which include solar and lunar eclipses, sunspots, "guest stars" (novae or supernovae as we understand today), comets and meteors, and all kinds of planetary phenomena. These records provide valuable historical data for astronomical studies today.

  12. Severe accident phenomena

    International Nuclear Information System (INIS)

    Jokiniemi, J.; Kilpi, K.; Lindholm, I.; Maekynen, J.; Pekkarinen, E.; Sairanen, R.; Silde, A.

    1995-02-01

    Severe accidents are nuclear reactor accidents in which the reactor core is substantially damaged. The report describes severe reactor accident phenomena and their significance for the safety of nuclear power plants. A comprehensive set of phenomena ranging from accident initiation to containment behaviour and containment integrity questions are covered. The report is based on expertise gained in the severe accident assessment projects conducted at the Technical Research Centre of Finland (VTT). (49 refs., 32 figs., 12 tabs.)

  13. Integration phenomena Paralympic cyclists

    OpenAIRE

    Diepoldová, Tereza

    2017-01-01

    Title: Integration phenomena Paralympic cyclists. Objectives of work: Try to find integration phenomena in relation to sport training and its impact on selected cyclists with disabilities. Methods: Case report structured interview, data collection method - the method of interrogation. Results: Based on case studies developed a structured interview, we found differences in the integration, which we have divided into phases - before obtaining disability, acclimatization, sports integration. Fur...

  14. Modelling of Transport Phenomena

    OpenAIRE

    K., Itoh; S.-I., Itoh; A., Fukuyama

    1993-01-01

    In this review article, we discuss key features of the transport phenomena and theoretical modelling to understand them. Experimental observations have revealed the nature of anomalous transport, i.e., the enhancement of the transport coefficients by the gradients of the plasma profiles, the pinch phenomena, the radial profile of the apomalous transport coefficients, the variation of the transport among the Bohm diffusion, Pseudo-classical confinement, L-mode and variety of improved confineme...

  15. Fundamentals of Fire Phenomena

    DEFF Research Database (Denmark)

    Quintiere, James

    analyses. Fire phenomena encompass everything about the scientific principles behind fire behaviour. Combining the principles of chemistry, physics, heat and mass transfer, and fluid dynamics necessary to understand the fundamentals of fire phenomena, this book integrates the subject into a clear...... as a visiting professor at BYG.DTU financed by the Larsen and Nielsen Foundation, and is entered to the research database by Kristian Hertz responsible for the visiting professorship....

  16. Rheological phenomena in focus

    CERN Document Server

    Boger, DV

    1993-01-01

    More than possibly any other scientific discipline, rheology is easily visualized and the relevant literature contains many excellent photographs of unusual and often bizarre phenomena. The present book brings together these photographs for the first time. They are supported by a full explanatory text. Rheological Phenomena in Focus will be an indispensable support manual to all those who teach rheology or have to convince colleagues of the practical relevance of the subject within an industrial setting. For those who teach fluid mechanics, the book clearly illustrates the difference be

  17. Bioelectrochemistry II membrane phenomena

    CERN Document Server

    Blank, M

    1987-01-01

    This book contains the lectures of the second course devoted to bioelectro­ chemistry, held within the framework of the International School of Biophysics. In this course another very large field of bioelectrochemistry, i. e. the field of Membrane Phenomena, was considered, which itself consists of several different, but yet related subfields. Here again, it can be easily stated that it is impossible to give a complete and detailed picture of all membrane phenomena of biological interest in a short course of about one and half week. Therefore the same philosophy, as the one of the first course, was followed, to select a series of lectures at postgraduate level, giving a synthesis of several membrane phenomena chosen among the most'important ones. These lectures should show the large variety of membrane-regulated events occurring in living bodies, and serve as sound interdisciplinary basis to start a special­ ized study of biological phenomena, for which the investigation using the dual approach, physico-che...

  18. The Generation of Surface-bound Exospheres via Electron-Stimulated Desorption (and Related Phenomena): Results from Apollo samples and Hermian Regolith Simulants

    Science.gov (United States)

    Bennett, C.; Poston, M.; McLain, J. L.; Orlando, T. M.

    2014-12-01

    The generation of surface-bound exospheres present around the Moon, Mercury and other airless rocky bodies are produced primarily by the interaction of micrometeoroid impacts and charged particles from the solar wind, and magnetospheres with those surfaces. While the study of the interactions of both micrometeoroids and ion sputtering are well investigated, the contributions arising from energetic electron interactions are typically less-well established. Observations from the Fast Imaging Plasma Spectrometer (FIPS), taken < 400 km from the surface, have shown a plasma cusp with energetic heavy ions (i.e. Na+- and O+-groups) for which the source has not been determined. However, the precipitation of keV electrons onto the surfaces of Mercury has recently been inferred from measurements using the X-Ray Spectrometer (XRS) instrument onboard the MESSENGER spacecraft observations of the night-side of Mercury. A newly developed global kinetic transport model suggests that electron-stimulated desorption (ESD), and possibly light ion stimulated desorption (ISD), can directly yield ions that can be transported and dynamically accelerated to the plasma cusp regions observed by FIPS. In addition, keV electrons and ions from the solar wind and Earth's magnetosphere frequently bombard with the lunar surface. Here, we present some of the most recent results from our ongoing work studying the effects of photon-stimulated desorption (PSD), ion-stimulated desorption (ISD) and implantation, as well as electron-stimulated desorption (ESD). Apollo samples collected from both the lunar highland and Mare regions, as well as simulants of the Mercury Regolith have been investigated. The temperature- (100-600 K) and energy-dependence (threshold - 2 keV) of ESD time-of-flight (ToF) results will be presented for these materials along with some preliminary results from our group based on photon-desorption studies of water on lunar material, temperature-programmed desorption (TPD) studies of

  19. The significance of electrokinetic characterization for interpreting interfacial phenomena at planar, macroscopic interfaces.

    Science.gov (United States)

    Fa, Keqing; Paruchuri, Vamsi K; Brown, Scott C; Moudgil, Brij M; Miller, Jan D

    2005-02-21

    Streaming potential measurements provide valuable information for the validation and interpretation of interfacial phenomena that occur at flat macroscopic surfaces. Planar substrates have been extensively used for the interpretation of events, which occur at particulate surfaces; however, these flat surfaces are often only questionably representative of their particulate counterparts due to variations in surface chemistry and topography. In this study, the zeta potential from planar macroscopic surfaces of PMMA, mica, graphite, fluorite, and calcite have been calculated from streaming potentials measured in aqueous solutions using an asymmetric clamping cell. These zeta potentials have been found to significantly contribute to understanding and interpretation of interfacial phenomena influenced by Coulombic interactions including adsorption, surface forces, and the structure of surface micelles.

  20. Theory of threshold phenomena

    International Nuclear Information System (INIS)

    Hategan, Cornel

    2002-01-01

    Theory of Threshold Phenomena in Quantum Scattering is developed in terms of Reduced Scattering Matrix. Relationships of different types of threshold anomalies both to nuclear reaction mechanisms and to nuclear reaction models are established. Magnitude of threshold effect is related to spectroscopic factor of zero-energy neutron state. The Theory of Threshold Phenomena, based on Reduced Scattering Matrix, does establish relationships between different types of threshold effects and nuclear reaction mechanisms: the cusp and non-resonant potential scattering, s-wave threshold anomaly and compound nucleus resonant scattering, p-wave anomaly and quasi-resonant scattering. A threshold anomaly related to resonant or quasi resonant scattering is enhanced provided the neutron threshold state has large spectroscopic amplitude. The Theory contains, as limit cases, Cusp Theories and also results of different nuclear reactions models as Charge Exchange, Weak Coupling, Bohr and Hauser-Feshbach models. (author)

  1. Transport phenomena in nanofluidics

    OpenAIRE

    Schoch, Reto Bruno; Han, J.; Renaud, Philippe

    2008-01-01

    Transport of fluid in and around nanometer-sized objects with at least one characteristic dimension below 100 nm renders possible phenomena that are not accessible at bigger length scales. This research field is termed nanofluidics and received its name only recently, but the roots in science and technology are broad. Nanofluidics has experienced a big growth during the last few years, confirmed by significant scientific and practical achievements. This review focuses on physical proper...

  2. Transport phenomena II essentials

    CERN Document Server

    REA, The Editors of

    2012-01-01

    REA's Essentials provide quick and easy access to critical information in a variety of different fields, ranging from the most basic to the most advanced. As its name implies, these concise, comprehensive study guides summarize the essentials of the field covered. Essentials are helpful when preparing for exams, doing homework and will remain a lasting reference source for students, teachers, and professionals. Transport Phenomena II covers forced convention, temperature distribution, free convection, diffusitivity and the mechanism of mass transfer, convective mass transfer, concentration

  3. Large momentum transfer phenomena

    International Nuclear Information System (INIS)

    Imachi, Masahiro; Otsuki, Shoichiro; Matsuoka, Takeo; Sawada, Shoji.

    1978-01-01

    The large momentum transfer phenomena in hadron reaction drastically differ from small momentum transfer phenomena, and are described in this paper. Brief review on the features of the large transverse momentum transfer reactions is described in relation with two-body reactions, single particle productions, particle ratios, two jet structure, two particle correlations, jet production cross section, and the component of momentum perpendicular to the plane defined by the incident protons and the triggered pions and transverse momentum relative to jet axis. In case of two-body process, the exponent N of the power law of the differential cross section is a value between 10 to 11.5 in the large momentum transfer region. The breaks of the exponential behaviors into the power ones are observed at the large momentum transfer region. The break would enable to estimate the order of a critical length. The large momentum transfer phenomena strongly suggest an important role of constituents of hadrons in the hard region. Hard rearrangement of constituents from different initial hadrons induces large momentum transfer reactions. Several rules to count constituents in the hard region have been proposed so far to explain the power behavior. Scale invariant quark interaction and hard reactions are explained, and a summary of the possible types of hard subprocess is presented. (Kato, T.)

  4. Statistical investigation of surface bound ions and further development of BION server to include pH and salt dependence.

    Science.gov (United States)

    Petukh, Marharyta; Zhang, Min; Alexov, Emil

    2015-12-15

    Ions are engaged in multiple biological processes in cells. By binding to the macromolecules or being mobile in the solvent, they maintain the integrity of the structure of macromolecules; participate in their enzymatic activity; or screen electrostatic interactions. While experimental methods are not always able to assign the exact location of ions, computational methods are in demand. Although the majority of computational methods are successful in predicting the position of ions buried inside macromolecules, they are less effective in deciphering positions of surface bound ions. Here, we propose the new BION algorithm (http://compbio.clemson.edu/bion_server_ph/) that predicts the location of the surface bound ions. It is more efficient and accurate compared to the previous version since it uses more advanced clustering algorithm in combination with pairing rules. In addition, the BION webserver allows specifying the pH and the salt concentration in predicting ions positions. © 2015 Wiley Periodicals, Inc.

  5. Modeling the contributions of global air temperature, synoptic-scale phenomena and soil moisture to near-surface static energy variability using artificial neural networks

    Science.gov (United States)

    Pryor, Sara C.; Sullivan, Ryan C.; Schoof, Justin T.

    2017-12-01

    The static energy content of the atmosphere is increasing on a global scale, but exhibits important subglobal and subregional scales of variability and is a useful parameter for integrating the net effect of changes in the partitioning of energy at the surface and for improving understanding of the causes of so-called warming holes (i.e., locations with decreasing daily maximum air temperatures (T) or increasing trends of lower magnitude than the global mean). Further, measures of the static energy content (herein the equivalent potential temperature, θe) are more strongly linked to excess human mortality and morbidity than air temperature alone, and have great relevance in understanding causes of past heat-related excess mortality and making projections of possible future events that are likely to be associated with negative human health and economic consequences. New nonlinear statistical models for summertime daily maximum and minimum θe are developed and used to advance understanding of drivers of historical change and variability over the eastern USA. The predictor variables are an index of the daily global mean temperature, daily indices of the synoptic-scale meteorology derived from T and specific humidity (Q) at 850 and 500 hPa geopotential heights (Z), and spatiotemporally averaged soil moisture (SM). SM is particularly important in determining the magnitude of θe over regions that have previously been identified as exhibiting warming holes, confirming the key importance of SM in dictating the partitioning of net radiation into sensible and latent heat and dictating trends in near-surface T and θe. Consistent with our a priori expectations, models built using artificial neural networks (ANNs) out-perform linear models that do not permit interaction of the predictor variables (global T, synoptic-scale meteorological conditions and SM). This is particularly marked in regions with high variability in minimum and maximum θe, where more complex models

  6. Second DOE natural phenomena hazards mitigation conference

    International Nuclear Information System (INIS)

    1989-01-01

    This conference has been organized into ten presentation sessions which include an overview of the DOE Natural Phenomena Guidelines, Seismic Analysis, Seismic Design, Modifying Existing Facilities, DOE Orders, Codes, and Standards (2 sessions), Seismic Hazard (2 sessions), and Probabilistic Risk Assessment (2 sessions). Two poster sessions were also included in the program to provide a different forum for communication of ideas. Over the past fourteen years, Lawrence Livermore National Laboratory, Nuclear Systems Safety Program, has been working with the US Department of Energy, Office of Safety Appraisals and their predecessors in the area of natural phenomena hazards. During this time we have developed seismic, extreme wind/tornado, and flood hazard models for DOE sites in the United States. Guidelines for designing and evaluating DOE facilities for natural phenomena have been developed and are in interim use throughout the DOE community. A series of state-of-the practice manuals have also been developed to aid the designers. All of this material is listed in the Natural Phenomena Hazards Bibliography included in these proceedings. This conference provides a mechanism to disseminate current information on natural phenomena hazards and their mitigation. It provides an opportunity to bring together members of the DOE community to discuss current projects, to share information, and to hear practicing members of the structural engineering community discuss their experiences from past natural phenomena, future trends, and any changes to building codes. Each paper or poster presented is included in these proceedings. We have also included material related to the luncheon and dinner talks

  7. Surface discharge phenomena of solid insulators under negative impulse voltage in atmospheric air. Taikichu fu impulse den'atsu inkaji no kotai yudentai no enmen hoden gensho

    Energy Technology Data Exchange (ETDEWEB)

    Shimazaki, T.; Hayashi, T.; Manabe, Y. (Fukuoka Univ., Fukuoka (Japan). Faculty of Engineering)

    1991-09-01

    In the case where PET film thickness is varied as a characteristic of creeping discharge in such a electrode arrangement that a rear electrode exists over the whole surface of an insulator, a relation was derived among a creeping distance d'' when negative impulse voltage was applied, a creeping flashover voltage V{sub 50} and a 50% creeping corona onset voltage V{sub C50}. As a result, the V{sub 50}-d characteristic is shown by approximately two straight lines with a certain creeping distance dc'' determined by t'' as a boundary. When a range of d'' being 0.4 cm-dc is called the region C' and a range of dc-10 cm the region A', the V{sub 50} takes the same expression as in the case of acrylic plate in the region C', but in the region A', takes a different expression from that for the acrylic plate. The creeping flashover process in the region A' is approximately identical with that for the acrylic plate. However, the negative streamer's progress distance shortens with an increase in the intrinsic capacity, so does the generation interval. The creeping flashover process in the region C' is the same as for the acrylic plate. 9 refs., 16 figs.

  8. Sixteenth International Conference on Ultrafast Phenomena

    CERN Document Server

    Corkum, Paul; Nelson, Keith A; Riedle, Eberhard; Schoenlein, Robert W; Ultrafast Phenomena XVI

    2009-01-01

    Ultrafast Phenomena XVI presents the latest advances in ultrafast science, including both ultrafast optical technology and the study of ultrafast phenomena. It covers picosecond, femtosecond and attosecond processes relevant to applications in physics, chemistry, biology, and engineering. Ultrafast technology has a profound impact in a wide range of applications, amongst them biomedical imaging, chemical dynamics, frequency standards, material processing, and ultrahigh speed communications. This book summarizes the results presented at the 16th International Conference on Ultrafast Phenomena and provides an up-to-date view of this important and rapidly advancing field.

  9. Measuring evapotranspiration: comparison of in situ micrometeorological methods including eddy covariance, scintillometer, Bowen ratio, and surface renewal method

    Science.gov (United States)

    Poznikova, G.; Fischer, M.; Orsag, M.; Trnka, M.

    2016-12-01

    Quantifying evapotranspiration (ET) is a challenging task as different methods can induce large discrepancies. Comparisons of various techniques are not rare, however it is demanding to maintain several in situ measurements for longer time. In our study, we aimed to compare four micrometeorological methods measuring ET at relatively large homogeneous area. The study took place on a winter wheat field in Polkovice, the Czech Republic (49°23'42.8"N 17°14'47.3"E) from Jul 1st 2015 until Sep 15th 2015. In the centre of 26-ha experimental field we deployed the eddy covariance (EC) system, the Bowen ratio energy balance (BREB) system, thermocouples for surface renewal technique, and the surface layer scintillometer with 106 m path length. Additionally, we installed the large aperture scintillometer with 617 m path length across the field. Our results showed good agreement of compared methods during the wetter periods of the measurements with slight overestimation of the scintillometry. The BREB method agreed the best with EC. Both scintillometers gave very consistent results throughout the whole measurement period. The EC tended to underestimate other methods. One of potential reasons is energy balance disclosure which reached 27.4 % for the measured period. The surface renewal method showed good potential however, need to be further tested in our conditions. Our experimental locality is one of several we are running as a part of ground based measurement network for ET estimation. Gained results helped us to enhance and optimise our network to ensure effective and reliable data acquisition for future validation of airborne images (satellite based drought monitoring).

  10. Radiation-curing of acrylate composites including carbon fibres: A customized surface modification for improving mechanical performances

    International Nuclear Information System (INIS)

    Martin, Arnaud; Pietras-Ozga, Dorota; Ponsaud, Philippe; Kowandy, Christelle; Barczak, Mariusz; Defoort, Brigitte; Coqueret, Xavier

    2014-01-01

    The lower transverse mechanical properties of radiation-cured acrylate-based composites reinforced with carbon-fibre with respect to the thermosettable analogues was investigated from the viewpoint of chemical interactions at the interface between the matrix and the carbon material. XPS analysis of representative commercial carbon fibres revealed the presence of a significant amount of chemical functions potentially exerting an adverse effect on the initiation and propagation of the free radical polymerization initiated under high energy radiation. The EB-induced polymerization of n-butyl acrylate as a simple model monomer was conducted in the presence of various aromatic additives exhibiting a strong inhibiting effect, whereas thiols efficiently sensitize the initiation mechanism and undergo transfer reactions. A method based on the surface modification of sized fibres by thiomalic acid is proposed for overcoming the localized inhibition phenomenon and for improving the mechanical properties of the resulting acrylate-based composites. - Highlights: • Surface functions of C-fibres are analyzed for their effect on radical reaction. • Irradiation of nBu-acrylate in presence of aromatic additives reveals inhibition. • Thiol groups sensitize the radiation-initiated polymerization of nBu-acrylate. • Modification of C-fibres with thiomalic acid enhances composite properties

  11. Nonlinear Dynamic Phenomena in Mechanics

    CERN Document Server

    Warminski, Jerzy; Cartmell, Matthew P

    2012-01-01

    Nonlinear phenomena should play a crucial role in the design and control of engineering systems and structures as they can drastically change the prevailing dynamical responses. This book covers theoretical and applications-based problems of nonlinear dynamics concerned with both discrete and continuous systems of interest in civil and mechanical engineering. They include pendulum-like systems, slender footbridges, shape memory alloys, sagged elastic cables and non-smooth problems. Pendulums can be used as a dynamic absorber mounted in high buildings, bridges or chimneys. Geometrical nonlinear

  12. Transport phenomena an introduction to advanced topics

    CERN Document Server

    Glasgow, Larry A

    2010-01-01

    Enables readers to apply transport phenomena principles to solve advanced problems in all areas of engineering and science This book helps readers elevate their understanding of, and their ability to apply, transport phenomena by introducing a broad range of advanced topics as well as analytical and numerical solution techniques. Readers gain the ability to solve complex problems generally not addressed in undergraduate-level courses, including nonlinear, multidimensional transport, and transient molecular and convective transport scenarios. Avoiding rote memorization, the author em

  13. Multiscale Modeling of Mesoscale and Interfacial Phenomena

    Science.gov (United States)

    Petsev, Nikolai Dimitrov

    With rapidly emerging technologies that feature interfaces modified at the nanoscale, traditional macroscopic models are pushed to their limits to explain phenomena where molecular processes can play a key role. Often, such problems appear to defy explanation when treated with coarse-grained continuum models alone, yet remain prohibitively expensive from a molecular simulation perspective. A prominent example is surface nanobubbles: nanoscopic gaseous domains typically found on hydrophobic surfaces that have puzzled researchers for over two decades due to their unusually long lifetimes. We show how an entirely macroscopic, non-equilibrium model explains many of their anomalous properties, including their stability and abnormally small gas-side contact angles. From this purely transport perspective, we investigate how factors such as temperature and saturation affect nanobubbles, providing numerous experimentally testable predictions. However, recent work also emphasizes the relevance of molecular-scale phenomena that cannot be described in terms of bulk phases or pristine interfaces. This is true for nanobubbles as well, whose nanoscale heights may require molecular detail to capture the relevant physics, in particular near the bubble three-phase contact line. Therefore, there is a clear need for general ways to link molecular granularity and behavior with large-scale continuum models in the treatment of many interfacial problems. In light of this, we have developed a general set of simulation strategies that couple mesoscale particle-based continuum models to molecular regions simulated through conventional molecular dynamics (MD). In addition, we derived a transport model for binary mixtures that opens the possibility for a wide range of applications in biological and drug delivery problems, and is readily reconciled with our hybrid MD-continuum techniques. Approaches that couple multiple length scales for fluid mixtures are largely absent in the literature, and

  14. A neural network potential energy surface for the F + CH4reaction including multiple channels based on coupled cluster theory.

    Science.gov (United States)

    Chen, Jun; Xu, Xin; Liu, Shu; Zhang, Dong H

    2018-03-22

    We report here a new global and full dimensional potential energy surface (PES) for the F + CH4 reaction. This PES was constructed by using neural networks (NN) fitting to about 99 000 ab initio energies computed at the UCCSD(T)-F12a/aug-cc-pVTZ level of theory, and the correction terms considering the influence of a larger basis set as well as spin-orbit couplings were further implemented with a hierarchial scheme. This PES, covering both the abstraction and substitution channels, has an overall fitting error of 8.24 meV in total, and 4.87 meV for energies within 2.5 eV using a segmented NN fitting method, and is more accurate than the previous PESs.

  15. 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

  16. Crystallography and Magnetic Phenomena

    Directory of Open Access Journals (Sweden)

    Vojtěch Kopský

    2015-02-01

    Full Text Available This essay describes the development of groups used for the specification of symmetries from ordinary and magnetic point groups to Fedorov and magnetic space groups, as well as other varieties of groups useful in the study of symmetric objects. In particular, we consider the problem of some incorrectness in Vol. A of the International Tables for Crystallography. Some results of tensor calculus are presented in connection with magnetoelectric phenomena, where we demonstrate the use of Ascher’s trinities and Opechowski’s magic relations and their connection. Specific tensor decomposition calculations on the grounds of Clebsch Gordan products are illustrated.

  17. Direct channel problems and phenomena

    International Nuclear Information System (INIS)

    Cutkosky, R.E.

    1975-01-01

    Direct channel problems and phenomena are considered covering the need for precision hadron spectroscopy, the data base for precision hadron spectroscopy, some relations between direct-channel and cross-channel effects, and spin rotation phenomena

  18. Locating critical points on multi-dimensional surfaces by genetic algorithm: test cases including normal and perturbed argon clusters

    Science.gov (United States)

    Chaudhury, Pinaki; Bhattacharyya, S. P.

    1999-03-01

    It is demonstrated that Genetic Algorithm in a floating point realisation can be a viable tool for locating critical points on a multi-dimensional potential energy surface (PES). For small clusters, the standard algorithm works well. For bigger ones, the search for global minimum becomes more efficient when used in conjunction with coordinate stretching, and partitioning of the strings into a core part and an outer part which are alternately optimized The method works with equal facility for locating minima, local as well as global, and saddle points (SP) of arbitrary orders. The search for minima requires computation of the gradient vector, but not the Hessian, while that for SP's requires the information of the gradient vector and the Hessian, the latter only at some specific points on the path. The method proposed is tested on (i) a model 2-d PES (ii) argon clusters (Ar 4-Ar 30) in which argon atoms interact via Lennard-Jones potential, (iii) Ar mX, m=12 clusters where X may be a neutral atom or a cation. We also explore if the method could also be used to construct what may be called a stochastic representation of the reaction path on a given PES with reference to conformational changes in Ar n clusters.

  19. SWRT: A package for semi-analytical solutions of surface wave propagation, including mode conversion, across transversely aligned vertical discontinuities

    Directory of Open Access Journals (Sweden)

    A. Datta

    2018-03-01

    Full Text Available We present a suite of programs that implement decades-old algorithms for computation of seismic surface wave reflection and transmission coefficients at a welded contact between two laterally homogeneous quarter-spaces. For Love as well as Rayleigh waves, the algorithms are shown to be capable of modelling multiple mode conversions at a lateral discontinuity, which was not shown in the original publications or in the subsequent literature. Only normal incidence at a lateral boundary is considered so there is no Love–Rayleigh coupling, but incidence of any mode and coupling to any (other mode can be handled. The code is written in Python and makes use of SciPy's Simpson's rule integrator and NumPy's linear algebra solver for its core functionality. Transmission-side results from this code are found to be in good agreement with those from finite-difference simulations. In today's research environment of extensive computing power, the coded algorithms are arguably redundant but SWRT can be used as a valuable testing tool for the ever evolving numerical solvers of seismic wave propagation. SWRT is available via GitHub (https://github.com/arjundatta23/SWRT.git.

  20. SWRT: A package for semi-analytical solutions of surface wave propagation, including mode conversion, across transversely aligned vertical discontinuities

    Science.gov (United States)

    Datta, Arjun

    2018-03-01

    We present a suite of programs that implement decades-old algorithms for computation of seismic surface wave reflection and transmission coefficients at a welded contact between two laterally homogeneous quarter-spaces. For Love as well as Rayleigh waves, the algorithms are shown to be capable of modelling multiple mode conversions at a lateral discontinuity, which was not shown in the original publications or in the subsequent literature. Only normal incidence at a lateral boundary is considered so there is no Love-Rayleigh coupling, but incidence of any mode and coupling to any (other) mode can be handled. The code is written in Python and makes use of SciPy's Simpson's rule integrator and NumPy's linear algebra solver for its core functionality. Transmission-side results from this code are found to be in good agreement with those from finite-difference simulations. In today's research environment of extensive computing power, the coded algorithms are arguably redundant but SWRT can be used as a valuable testing tool for the ever evolving numerical solvers of seismic wave propagation. SWRT is available via GitHub (https://github.com/arjundatta23/SWRT.git).

  1. Measured Properties of Turbulent Premixed Flames for Model Assessment, Including Burning Velocities, Stretch Rates, and Surface Densities (Postprint)

    Science.gov (United States)

    2006-10-01

    conditions was stabilized on a large two-dimensional slot Bunsen burner . It was found that the turbulent burning velocity of Bunsen flames depends...burning velocity of Bunsen flames are inadequate because they should include two additional parameters: mean velocity Ū and burner width W. These...corru- gated) flame with well-defined boundary conditions was stabilized on a large two-dimensional slot Bunsen burner . It was found that the turbulent

  2. High Temperature Phenomena in Shock Waves

    CERN Document Server

    2012-01-01

    The high temperatures generated in gases by shock waves give rise to physical and chemical phenomena such as molecular vibrational excitation, dissociation, ionization, chemical reactions and inherently related radiation. In continuum regime, these processes start from the wave front, so that generally the gaseous media behind shock waves may be in a thermodynamic and chemical non-equilibrium state. This book presents the state of knowledge of these phenomena. Thus, the thermodynamic properties of high temperature gases, including the plasma state are described, as well as the kinetics of the various chemical phenomena cited above. Numerous results of measurement and computation of vibrational relaxation times, dissociation and reaction rate constants are given, and various ionization and radiative mechanisms and processes are presented. The coupling between these different phenomena is taken into account as well as their interaction with the flow-field. Particular points such as the case of rarefied flows an...

  3. Crystallization phenomena in slags

    Science.gov (United States)

    Orrling, Carl Folke

    2000-09-01

    The crystallization of the mold slag affects both the heat transfer and the lubrication between the mold and the strand in continuous casting of steel. In order for mold slag design to become an engineering science rather than an empirical exercise, a fundamental understanding of the melting and solidification behavior of a slag must be developed. Thus it is necessary to be able to quantify the phenomena that occur under the thermal conditions that are found in the mold of a continuous caster. The double hot thermocouple technique (DHTT) and the Confocal Laser Scanning Microscope used in this study are two novel techniques for investigating melting and solidification phenomena of transparent slags. Results from these techniques are useful in defining the phenomena that occur when the slag film infiltrates between the mold and the shell of the casting. TTT diagrams were obtained for various slags and indicated that the onset of crystallization is a function of cooling rate and slag chemistry. Crystal morphology was found to be dependent upon the experimental temperature and four different morphologies were classified based upon the degree of melt undercooling. Continuous cooling experiments were carried out to develop CCT diagrams and it was found that the amount and appearance of the crystalline fraction greatly depends on the cooling conditions. The DHTT can also be used to mimic the cooling profile encountered by the slag in the mold of a continuous caster. In this differential cooling mode (DCT), it was found that the details of the cooling rate determine the actual response of the slag to a thermal gradient and small changes can lead to significantly different results. Crystal growth rates were measured and found to be in the range between 0.11 mum/s to 11.73 mum/s depending on temperature and slag chemistry. Alumina particles were found to be effective innoculants in oxide melts reducing the incubation time for the onset of crystallization and also extending

  4. Mixed Fluid Conditions: Capillary Phenomena

    KAUST Repository

    Santamarina, Carlos

    2017-07-06

    Mixed fluid phenomena in porous media have profound implications on soil-atmosphere interaction, energy geotechnology, environmental engineering and infrastructure design. Surface tension varies with pressure, temperature, solute concentration, and surfactant concentration; on the other hand, the contact angle responds to interfacial tensions, surface topography, invasion velocity, and chemical interactions. Interfaces are not isolated but interact through the fluid pressure and respond to external fields. Jumps, snap-offs and percolating wetting liquids along edges and crevices are ubiquitous in real, non-cylindrical porous networks. Pore- and macroscale instabilities together with pore structure variability-and-correlation favor fluid trapping and hinder recovery efficiency. The saturation-pressure characteristic curve is affected by the saturation-history, flow-rate, the mechanical response of the porous medium, and time-dependent reactive and diffusive processes; in addition, there are salient differences between unsaturation by internal gas nucleation and gas invasion. Capillary forces add to other skeletal forces in the porous medium and can generate open-mode discontinuities when the capillary entry pressure is high relative to the effective stress. Time emerges as an important variable in mixed-fluid conditions and common quasi-static analyses may fail to capture the system response.

  5. Acid Deposition Phenomena

    International Nuclear Information System (INIS)

    Ramadan, A.E.K.

    2004-01-01

    Acid deposition, commonly known as acid rain, occurs when emissions from the combustion of fossil fuels and other industrial processes undergo complex chemical reactions in the atmosphere and fall to the earth as wet deposition (rain, snow, cloud, fog) or dry deposition (dry particles, gas). Rain and snow are already naturally acidic, but are only considered problematic when less than a ph of 5.0 The main chemical precursors leading to acidic conditions are atmospheric concentrations of sulfur dioxide (SO 2 ) and nitrogen oxides (NO x ). When these two compounds react with water, oxygen, and sunlight in the atmosphere, the result is sulfuric (H 2 SO 4 ) and nitric acids (HNO 3 ), the primary agents of acid deposition which mainly produced from the combustion of fossil fuel and from petroleum refinery. Airborne chemicals can travel long distances from their sources and can therefore affect ecosystems over broad regional scales and in locations far from the sources of emissions. According to the concern of petroleum ministry with the environment and occupational health, in this paper we will discussed the acid deposition phenomena through the following: Types of acidic deposition and its components in the atmosphere Natural and man-made sources of compounds causing the acidic deposition. Chemical reactions causing the acidic deposition phenomenon in the atmosphere. Factors affecting level of acidic deposition in the atmosphere. Impact of acid deposition. Procedures for acidic deposition control in petroleum industry

  6. Immune phenomena in echinoderms.

    Science.gov (United States)

    Gliński, Z; Jarosz, J

    2000-01-01

    Advances in biochemistry and molecular biology have made it possible to identify a number of mechanisms active in the immune phenomena of echinoderms. It is obvious that echinoderms have the ability to distinguish between different foreign objects (pathologically changed tissues, microorganisms, parasites, grafts) and to express variable effector mechanisms which are elicited specifically and repeatably after a variety of non-self challenges. The molecular and biochemical basis for the expression of these variable defense mechanisms and the specific signals which elicit one type of effector mechanism are not, however, yet well known. The high capacity of coelomocytes to phagocytose, entrap and encapsulate invading microorganisms is a valid immune cell-mediated mechanism of echinoderms. The entrapped bacteria, discharged cellular materials and disintegrating granular cells are compacted and provoke the cellular encapsulation reaction. Moreover, humoral-based reactions form an integral part of the echinoderm defense system against microbial invaders. Factors such as lysozyme, perforins (hemolysins) vitellogenin and lectins are normal constituents of hemolymph, while cytokines are synthesized by echinoderms in response to infection.

  7. Transport phenomena in porous media

    CERN Document Server

    Ingham, Derek B

    1998-01-01

    Research into thermal convection in porous media has substantially increased during recent years due to its numerous practical applications. These problems have attracted the attention of industrialists, engineers and scientists from many very diversified disciplines, such as applied mathematics, chemical, civil, environmental, mechanical and nuclear engineering, geothermal physics and food science. Thus, there is a wealth of information now available on convective processes in porous media and it is therefore appropriate and timely to undertake a new critical evaluation of this contemporary information. Transport Phenomena in Porous Media contains 17 chapters and represents the collective work of 27 of the world's leading experts, from 12 countries, in heat transfer in porous media. The recent intensive research in this area has substantially raised the expectations for numerous new practical applications and this makes the book a most timely addition to the existing literature. It includes recent major deve...

  8. Haters Phenomena in Social Media

    OpenAIRE

    Pradipta, Angga; Lailiyah, S.Sos, M.I.Kom, Nuriyatul

    2016-01-01

    Social media is internet-basic media, functioned as interaction media room based on multimedia technology. And social media created some effects. One of the negative effects of social media is haters phenomena. Haters are a person who easily said dirty words, harass, and humiliate to others. This phenomena causes anxiety—especially in Indonesia, even the Government issued public policy and letter of regulation about this phenomena, through Paragraph 27 verse (3) IT Constitution, Paragraph 45 ...

  9. Comparing Multiple Evapotranspiration-calculating Methods, Including Eddy Covariance and Surface Renewal, Using Empirical Measurements from Alfalfa Fields in the Sacramento-San Joaquin River Delta

    Science.gov (United States)

    Clay, J.; Kent, E. R.; Leinfelder-Miles, M.; Lambert, J. J.; Little, C.; Paw U, K. T.; Snyder, R. L.

    2016-12-01

    Eddy covariance and surface renewal measurements were used to estimate evapotranspiration (ET) over a variety of crop fields in the Sacramento-San Joaquin River Delta during the 2016 growing season. However, comparing and evaluating multiple measurement systems and methods for determining ET was focused upon at a single alfalfa site. The eddy covariance systems included two systems for direct measurement of latent heat flux: one using a separate sonic anemometer and an open path infrared gas analyzer and another using a combined system (Campbell Scientific IRGASON). For these methods, eddy covariance was used with measurements from the Campbell Scientific CSAT3, the LI-COR 7500a, the Campbell Scientific IRGASON, and an additional R.M. Young sonic anemometer. In addition to those direct measures, the surface renewal approach included several energy balance residual methods in which net radiation, ground heat flux, and sensible heat flux (H) were measured. H was measured using several systems and different methods, including using multiple fast-response thermocouple measurements and using the temperatures measured by the sonic anemometers. The energy available for ET was then calculated as the residual of the surface energy balance equation. Differences in ET values were analyzed between the eddy covariance and surface renewal methods, using the IRGASON-derived values of ET as the standard for accuracy.

  10. Terminology of allergic phenomena.

    Science.gov (United States)

    Ring, Johannes

    2014-01-01

    Over the last 2,000 years a variety of terms have been used for the description of phenomena possibly related to allergy. Many have been forgotten, while some of them have remained. In Greco-Roman literature the term 'idiosyncrasy' was used to describe an individual characterization of a health condition, possibly comparable to 'constitution'. The same term was also used to describe individual reaction patterns, and the term 'antipathy' was used in a similar sense. 'Hypersensitivity' originated from the German word 'Überempfindlichkeit' and was first used in a medical sense by Emil von Behring when he described untoward reactions to his antitoxin containing serum therapy. 'Anaphylaxis' was coined by Richet and Portier to describe the new phenomenon of a life-threatening general pathogenic reaction after repeated injection of antigen. In 1906, Clemens von Pirquet introduced the term 'allergy' in order to bring more clarity to the confusing debate regarding protective and harmful immunity. In order to characterize the familial occurrence of hypersensitivity reactions such as asthma, hay fever and others, the American allergists A.F. Coca and R.A. Cooke introduced the term 'atopy'. Contrary to anaphylaxis, which was experimentally induced, this type of 'hypersensitiveness' occurred spontaneously. The nature of the pathogenic factor was called the 'atopic reagin' and was found to be transferable with serum by Prausnitz and Küstner. After the detection of immunoglobulin (Ig) E as the carrier of this type of hypersensitivity, the term 'atopy' gained a new sense, since IgE is a characteristic - yet not exclusive - parameter of the so-called atopic diseases. Clinically similar diseases such as asthma, rhinoconjunctivitis or eczema can be found in the absence of IgE, and are then called 'intrinsic' variants of the same disease. © 2014 S. Karger AG, Basel.

  11. Mirror reactor surface study

    Energy Technology Data Exchange (ETDEWEB)

    Hunt, A. L.; Damm, C. C.; Futch, A. H.; Hiskes, J. R.; Meisenheimer, R. G.; Moir, R. W.; Simonen, T. C.; Stallard, B. W.; Taylor, C. E.

    1976-09-01

    A general survey is presented of surface-related phenomena associated with the following mirror reactor elements: plasma first wall, ion sources, neutral beams, director converters, vacuum systems, and plasma diagnostics. A discussion of surface phenomena in possible abnormal reactor operation is included. Several studies which appear to merit immediate attention and which are essential to the development of mirror reactors are abstracted from the list of recommended areas for surface work. The appendix contains a discussion of the fundamentals of particle/surface interactions. The interactions surveyed are backscattering, thermal desorption, sputtering, diffusion, particle ranges in solids, and surface spectroscopic methods. A bibliography lists references in a number of categories pertinent to mirror reactors. Several complete published and unpublished reports on surface aspects of current mirror plasma experiments and reactor developments are also included.

  12. Mirror reactor surface study

    International Nuclear Information System (INIS)

    Hunt, A.L.; Damm, C.C.; Futch, A.H.; Hiskes, J.R.; Meisenheimer, R.G.; Moir, R.W.; Simonen, T.C.; Stallard, B.W.; Taylor, C.E.

    1976-01-01

    A general survey is presented of surface-related phenomena associated with the following mirror reactor elements: plasma first wall, ion sources, neutral beams, director converters, vacuum systems, and plasma diagnostics. A discussion of surface phenomena in possible abnormal reactor operation is included. Several studies which appear to merit immediate attention and which are essential to the development of mirror reactors are abstracted from the list of recommended areas for surface work. The appendix contains a discussion of the fundamentals of particle/surface interactions. The interactions surveyed are backscattering, thermal desorption, sputtering, diffusion, particle ranges in solids, and surface spectroscopic methods. A bibliography lists references in a number of categories pertinent to mirror reactors. Several complete published and unpublished reports on surface aspects of current mirror plasma experiments and reactor developments are also included

  13. PREFACE Integrability and nonlinear phenomena Integrability and nonlinear phenomena

    Science.gov (United States)

    Gómez-Ullate, David; Lombardo, Sara; Mañas, Manuel; Mazzocco, Marta; Nijhoff, Frank; Sommacal, Matteo

    2010-10-01

    , Manton and Rink [29] explore vortex solutions on hyperbolic surfaces extending an approach by Witten. These solutions can be interpreted as self-dual SU(2) Yang-Mills fields on R4. Shah and Woodhouse [30] use the Penrose-Ward correspondence from twistor theory to relate generalized anti self-duality equations to certain isomonodromic problems whose solutions are expressed in terms of generalized hypergeometric functions. Applications of integrable systems and nonlinear phenomena in other fields are also present in some of the papers. Kanna et al [31] study the collision of soliton solutions to coherently coupled NLS equations using a variant of the Hirota bilinearization method. Their results have applications in pulse shaping in nonlinear optics. Calogero et al [32] present examples of systems of ODEs with quadratic nonlinearities that could describe rate equations in chemical dynamics. They derive explicit conditions on the parameters of the problem for which the solutions are periodic and isochronous. Ablowitz and Haut [33] study the motion of large amplitude water waves with surface tension using asymptotic expansions and providing a comparison with experimental results. This issue is the result of the collaboration of many individuals. We would like to thank the editors and staff of the Journal of Physics A: Mathematical and Theoretical for their enthusiastic support and efficient help during the preparation of this issue. A key factor has been the work of many anonymous referees who performed careful analysis and scrutiny of the research papers submitted to this issue, often making remarks which helped to improve their quality and readability. They carried out dedicated, altruistic work with a very high standard and this issue would not exist without their contribution. Finally, we would like to thank the authors who responded to our open call, sending us their most recent results and sharing with us the enthusiasm and interest for this fascinating field of

  14. Inverse Analysis of Cavitation Impact Phenomena on Structures

    National Research Council Canada - National Science Library

    Lambrakos, S. G; Tran, N. E

    2007-01-01

    A general methodology is presented for in situ detection of cavitation impact phenomena on structures based on inverse analysis of luminescent emissions resulting from the collapsing of bubbles onto surfaces...

  15. Simulations of Biomechanical Phenomena

    Science.gov (United States)

    Gonzalez, Jose Cruz

    Recent studies have published breakthroughs in the application of finite element (FEA) studies in the design and analysis of advanced orthodontics. However, FEA has not captured bone remodeling responses to advanced orthodontics. The results of these simulations report unrealistic displacement around the nasal bridge, which impeded correlation with clinical data. Bone remodeling has been previously documented in FEA and has shown bone response to mechanical stimulus in femur bone models. However, the relationship between mechanical stimulus and bone remodeling has not been reported in orthodontic studies due to the complexity of the skull. In the current study, strain energy is used as the mechanical stimulus to control remodeling, from which density and modulus evolve. Due to the localization of forces in orthodontics, current remodeling algorithms have limited application. In turn, we developed an algorithm that dynamically collects, sorts, and bins stresses in all elements for regional remodeling based on the proximity of the element to the load. The results demonstrate that bone response to orthodontic appliances is different than that of an FEA without bone remodeling, due to load path changes based upon evolution of the bone properties. It was also found that density and moduli proximal to the load application site exhibit faster remodeling than those located remotely. Modeling another biomechanical phenomena, a 3D simulation was created to simulate recent experimental results that discovered a difference in impact mitigation properties of dense-polymer/foam bilayer structure based on the orientation of the dense-polymer with respect to the impact site. The impact energy transmitted varied in time of arrival and amplitude depending on the orientation of the structure (thin layer up or down). By creating a 3D explicit dynamic FEA simulation, it is expected to reduce costly experiments and time consumed in set up, and offer opportunities for optimization for

  16. Teaching Optical Phenomena with Tracker

    Science.gov (United States)

    Rodrigues, M.; Carvalho, P. Simeão

    2014-01-01

    Since the invention and dissemination of domestic laser pointers, observing optical phenomena is a relatively easy task. Any student can buy a laser and experience at home, in a qualitative way, the reflection, refraction and even diffraction phenomena of light. However, quantitative experiments need instruments of high precision that have a…

  17. Arcing phenomena in fusion devices workshop

    Energy Technology Data Exchange (ETDEWEB)

    Clausing, R.E.

    1979-01-01

    The workshop on arcing phenomena in fusion devices was organized (1) to review the pesent status of our understanding of arcing as it relates to confinement devices, (2) to determine what informaion is needed to suppress arcing and (3) to define both laboratory and in-situ experiments which can ultimately lead to reduction of impurities in the plasma caused by arcing. The workshop was attended by experts in the area of vacuum arc electrode phenomena and ion source technology, materials scientists, and both theoreticians and experimentalists engaged in assessing the importance of unipolar arcing in today's tokamaks. Abstracts for papers presented at the workshop are included.

  18. Third DOE natural phenomena hazards mitigation conference

    International Nuclear Information System (INIS)

    1991-01-01

    This conference on Natural Phenomena Hazards Mitigation has been organized into 15 presentation, panel, and poster sessions. The sessions included an overview of activities at DOE Headquarters; natural phenomena hazards tasks underway for DOE; two sessions on codes, standards, orders, criteria, and guidelines; two sessions on seismic hazards; equipment qualification; wind; PRA and margin assessments; modifications, retrofit, and restart; underground structures with a panel discussion; seismic analysis; seismic evaluation and design; and a poster session. Individual projects are processed separately for the data bases

  19. Arcing phenomena in fusion devices workshop

    International Nuclear Information System (INIS)

    Clausing, R.E.

    1979-01-01

    The workshop on arcing phenomena in fusion devices was organized (1) to review the pesent status of our understanding of arcing as it relates to confinement devices, (2) to determine what informaion is needed to suppress arcing and (3) to define both laboratory and in-situ experiments which can ultimately lead to reduction of impurities in the plasma caused by arcing. The workshop was attended by experts in the area of vacuum arc electrode phenomena and ion source technology, materials scientists, and both theoreticians and experimentalists engaged in assessing the importance of unipolar arcing in today's tokamaks. Abstracts for papers presented at the workshop are included

  20. 19th International Conference on Ultrafast Phenomena

    CERN Document Server

    Cundiff, Steven; Vivie-Riedle, Regina; Kuwata-Gonokami, Makoto; DiMauro, Louis

    2015-01-01

    This book presents the latest advances in ultrafast science, including both ultrafast optical technology and the study of ultrafast phenomena. It covers picosecond, femtosecond, and attosecond processes relevant to applications in physics, chemistry, biology, and engineering. Ultrafast technology has a profound impact in a wide range of applications, amongst them biomedical imaging, chemical dynamics, frequency standards, material processing, and ultrahigh-speed communications. This book summarizes the results presented at the 19th International Conference on Ultrafast Phenomena and provides an up-to-date view of this important and rapidly advancing field.

  1. DOE natural phenomena hazards mitigation conference: proceedings

    International Nuclear Information System (INIS)

    1985-10-01

    The conference includes sessions which present an overview of DOE programs, available codes, standards and criteria, examples of designs and upgrades from the DOE complex, lessons learned from past natural phenomena, ground motion, seismic evaluation of equipment, and applications of probabilistic risk assessment techniques to DOE facilities. Separate abstracts have been prepared for individual papers

  2. Transport phenomena in materials processing---1990

    International Nuclear Information System (INIS)

    Bishop, B.J.; Lior, N.; Lavine, A.; Flik, M.; Karwe, M.V.; Bergman, T.L.; Beckermann, C.; Charmchi, M.

    1990-01-01

    The papers contained in this volume represent a wide range of current research interests in processes such as food and polymer processing, casting, welding, machining, laser cutting, and superconductor processing. This volume includes papers presented in four sessions: Heat Transfer in Materials Processing; Thermal Phenomena in Superconductor Processing; Heat Transfer in Food and Polymer Processing; Heat Transfer in CAsting and Welding

  3. Interfacial phenomena and microscale transport processes in evaporating ultrathin menisci

    Science.gov (United States)

    Panchamgam, Sashidhar S.

    The study of interfacial phenomena in the three-phase contact line region, where a liquid-vapor interface intersects a solid surface, is of importance to many equilibrium and non-equilibrium processes. However, lack of experimental data on microscale transport processes controlled by interfacial phenomena has restricted progress. This thesis includes a high resolution image analyzing technique, based on reflectivity measurements, that accurately measures the thickness, contact angle and curvature profiles of ultrathin films, drops and curved menisci. In particular, the technique was used to emphasize measurements for thicknesses, delta contact line region. Experiments included flow instabilities in HFE-7000 meniscus on quartz (System S1), the spreading of a pentane (System S2 and S3), octane (System S4) and binary mixture menisci (System S5) during evaporation. The main objectives of the work are to present a new experimental technique, new observations, new data, and the use of a simple control volume, continuum and Kelvin-Clapeyron models to discuss the results. In addition, the interplay and importance of the microscopic fundamental forces, i.e., van der Waals forces, capillary forces and Marangoni stresses, during evaporation of the wetting fluids on the quartz surface is emphasized.

  4. Importance of including small-scale tile drain discharge in the calibration of a coupled groundwater-surface water catchment model

    DEFF Research Database (Denmark)

    Hansen, Anne Lausten; Refsgaard, Jens Christian; Christensen, Britt Stenhøj Baun

    2013-01-01

    the catchment. In this study, a coupled groundwater-surface water model based on the MIKE SHE code was developed for the 4.7 km2 Lillebæk catchment in Denmark, where tile drain flow is a major contributor to the stream discharge. The catchment model was calibrated in several steps by incrementally including...... the observation data into the calibration to see the effect on model performance of including diverse data types, especially tile drain discharge. For the Lillebæk catchment, measurements of hydraulic head, daily stream discharge, and daily tile drain discharge from five small (1–4 ha) drainage areas exist....... The results showed that including tile drain data in the calibration of the catchment model improved its general performance for hydraulic heads and stream discharges. However, the model failed to correctly describe the local-scale dynamics of the tile drain discharges, and, furthermore, including the drain...

  5. Advanced diffusion processes and phenomena

    CERN Document Server

    Öchsner, Andreas; Belova, Irina

    2014-01-01

    This topical volume on Advanced Diffusion Processes and Phenomena addresses diffusion in a wider sense of not only mass diffusion but also heat diffusion in fluids and solids. Both diffusion phenomena play an important role in the characterization of engineering materials and corresponding structures. Understanding these different transport phenomena at many levels, from atomistic to macro, has therefore long attracted the attention of many researchers in materials science and engineering and related disciplines. The present topical volume captures a representative cross-section of some of the

  6. Automatic construction of subject-specific human airway geometry including trifurcations based on a CT-segmented airway skeleton and surface

    Science.gov (United States)

    Miyawaki, Shinjiro; Tawhai, Merryn H.; Hoffman, Eric A.; Wenzel, Sally E.; Lin, Ching-Long

    2016-01-01

    We propose a method to construct three-dimensional airway geometric models based on airway skeletons, or centerlines (CLs). Given a CT-segmented airway skeleton and surface, the proposed CL-based method automatically constructs subject-specific models that contain anatomical information regarding branches, include bifurcations and trifurcations, and extend from the trachea to terminal bronchioles. The resulting model can be anatomically realistic with the assistance of an image-based surface; alternatively a model with an idealized skeleton and/or branch diameters is also possible. This method systematically identifies and classifies trifurcations to successfully construct the models, which also provides the number and type of trifurcations for the analysis of the airways from an anatomical point of view. We applied this method to 16 normal and 16 severe asthmatic subjects using their computed tomography images. The average distance between the surface of the model and the image-based surface was 11% of the average voxel size of the image. The four most frequent locations of trifurcations were the left upper division bronchus, left lower lobar bronchus, right upper lobar bronchus, and right intermediate bronchus. The proposed method automatically constructed accurate subject-specific three-dimensional airway geometric models that contain anatomical information regarding branches using airway skeleton, diameters, and image-based surface geometry. The proposed method can construct (i) geometry automatically for population-based studies, (ii) trifurcations to retain the original airway topology, (iii) geometry that can be used for automatic generation of computational fluid dynamics meshes, and (iv) geometry based only on a skeleton and diameters for idealized branches. PMID:27704229

  7. Micro transport phenomena during boiling

    CERN Document Server

    Peng, Xiaofeng

    2011-01-01

    "Micro Transport Phenomena During Boiling" reviews the new achievements and contributions in recent investigations at microscale. It presents some original research results and discusses topics at the frontier of thermal and fluid sciences.

  8. Renormalization group and critical phenomena

    International Nuclear Information System (INIS)

    Ji Qing

    2004-01-01

    The basic clue and the main steps of renormalization group method used for the description of critical phenomena is introduced. It is pointed out that this method really reflects the most important physical features of critical phenomena, i.e. self-similarity, and set up a practical solving method from it. This way of setting up a theory according to the features of the physical system is really a good lesson for today's physicists. (author)

  9. Characterization of genotoxic response to 15 multiwalled carbon nanotubes with variable physicochemical properties including surface functionalizations in the FE1-Muta(TM) mouse lung epithelial cell line.

    Science.gov (United States)

    Jackson, Petra; Kling, Kirsten; Jensen, Keld Alstrup; Clausen, Per Axel; Madsen, Anne Mette; Wallin, Håkan; Vogel, Ulla

    2015-03-01

    Carbon nanotubes vary greatly in physicochemical properties. We compared cytotoxic and genotoxic response to 15 multiwalled carbon nanotubes (MWCNT) with varying physicochemical properties to identify drivers of toxic responses. The studied MWCNT included OECD Working Party on Manufactured Nanomaterials (WPMN) (NM-401, NM-402, and NM-403), materials (NRCWE-026 and MWCNT-XNRI-7), and three sets of surface-modified MWCNT grouped by physical characteristics (thin, thick, and short I-III, respectively). Each Groups I-III included pristine, hydroxylated and carboxylated MWCNT. Group III also included an amino-functionalized MWCNT. The level of surface functionalization of the MWCNT was low. The level and type of elemental impurities of the MWCNT varied by <2% of the weight, with exceptions. Based on dynamic light scattering data, the MWCNT were well-dispersed in stock dispersion of nanopure water with 2% serum, but agglomerated and sedimented during exposure. FE1-Muta(TM) Mouse lung epithelial cells were exposed for 24 hr. The levels of DNA strand breaks (SB) were evaluated using the comet assay, a screening assay suitable for genotoxicity testing of nanomaterials. Exposure to MWCNT (12.5-200 µg/ml) did not induce significant cytotoxicity (viability above 92%). Cell proliferation was reduced in highest doses of some MWCNT after 24 hr, and was associated with generation of reactive oxygen species and high surface area. Increased levels of DNA SB were only observed for Group II consisting of MWCNT with large diameters and high Fe2 O3 and Ni content. Significantly, increased levels of SB were only observed at 200 µg/ml of MWCNT-042. Overall, the MWCNT were not cytotoxic and weakly genotoxic after 24 hr exposure to doses up to 200 µg/ml. © 2014 Wiley Periodicals, Inc.

  10. Disposal project for LLW and VLLW generated from research facilities in Japan: A feasibility study for the near surface disposal of VLLW that includes uranium

    International Nuclear Information System (INIS)

    Sakai, Akihiro; Hasegawa, M.; Sakamoto, Y.; Nakatani, T.

    2016-01-01

    Conclusion and future work: • JAEA plans trench disposal of U-bearing waste with less than 100 Bq/g. • Two safety measures of trench disposal of U-bearing waste have been discussed taking into account increasing radioactivity over a long period of time. 1. First is to carry out dose assessment of site use scenario by using a conservatively stylized condition. 2. Second is to control the average concentration of U in the trench facilities based on the concept of the existing exposure situation. • We are continuously developing the method for safety measures of near surface disposal of VLLW including U-bearing waste.

  11. Modelling of condensation phenomena

    International Nuclear Information System (INIS)

    Jeong, Jae Jun; Chang, Won Pyo

    1996-07-01

    Condensation occurs when vapor is cooled sufficiently below the saturation temperature to induce the nucleation of droplets. Such nucleation may occur homogeneously within the vapor or heterogeneously on entrained particular matter. Heterogeneous nucleation may occur on the walls of the system, where the temperature is below the saturation temperature. There are two forms of heterogeneous condensation, drop-wise and film-wise. Another form of condensation occurs when vapor directly contacts to subcooled liquid. In nuclear power plant systems, all forms of condensation may occur during normal operation or accident conditions. In this work the modelling of condensation is surveyed, including the Nusselts' laminar film condensation theory in 1916, Rohsenow's turbulent film condensation model in 1950s, and Chen's models in 1987. Major attention is paid on the film condensation models among various research results because of its importance in engineering applications. It is found that theory, experiment, and empirical correlations for film condensation are well established, but research for drop-wise and direct-contact condensation are not sufficient yet. Condensation models in the best-estimate system codes such as RELAP5/MOD3 and CATHARE2 are also investigated. 3 tabs., 11 figs., 36 refs. (Author)

  12. Surface optical vortices

    Science.gov (United States)

    Lembessis, V. E.; Babiker, M.; Andrews, D. L.

    2009-01-01

    It is shown how the total internal reflection of orbital-angular-momentum-endowed light can lead to the generation of evanescent light possessing rotational properties in which the intensity distribution is firmly localized in the vicinity of the surface. The characteristics of these surface optical vortices depend on the form of the incident light and on the dielectric mismatch of the two media. The interference of surface optical vortices is shown to give rise to interesting phenomena, including pattern rotation akin to a surface optical Ferris wheel. Applications are envisaged to be in atom lithography, optical surface tweezers, and spanners.

  13. Natural phenomena hazards site characterization criteria

    Energy Technology Data Exchange (ETDEWEB)

    1994-03-01

    The criteria and recommendations in this standard shall apply to site characterization for the purpose of mitigating Natural Phenomena Hazards (wind, floods, landslide, earthquake, volcano, etc.) in all DOE facilities covered by DOE Order 5480.28. Criteria for site characterization not related to NPH are not included unless necessary for clarification. General and detailed site characterization requirements are provided in areas of meteorology, hydrology, geology, seismology, and geotechnical studies.

  14. Workshop on Nonlinear Phenomena in Complex Systems

    CERN Document Server

    1989-01-01

    This book contains a thorough treatment of neural networks, cellular-automata and synergetics, in an attempt to provide three different approaches to nonlinear phenomena in complex systems. These topics are of major interest to physicists active in the fields of statistical mechanics and dynamical systems. They have been developed with a high degree of sophistication and include the refinements necessary to work with the complexity of real systems as well as the more recent research developments in these areas.

  15. Critical Phenomena in Gravitational Collapse

    Directory of Open Access Journals (Sweden)

    Gundlach Carsten

    1999-01-01

    Full Text Available As first discovered by Choptuik, the black hole threshold in the space of initial data for general relativity shows both surprising structure and surprising simplicity. Universality, power-law scaling of the black hole mass, and scale echoing have given rise to the term 'critical phenomena'. They are explained by the existence of exact solutions which are attractors within the black hole threshold, that is, attractors of codimension one in phase space, and which are typically self-similar. This review gives an introduction to the phenomena, tries to summarize the essential features of what is happening, and then presents extensions and applications of this basic scenario. Critical phenomena are of interest particularly for creating surprising structure from simple equations, and for the light they throw on cosmic censorship and the generic dynamics of general relativity.

  16. Quenching phenomena in natural circulation loop

    Energy Technology Data Exchange (ETDEWEB)

    Umekawa, Hisashi; Ozawa, Mamoru [Kansai Univ., Osaka (Japan); Ishida, Naoki [Daihatsu Motor Company, Osaka (Japan)

    1995-09-01

    Quenching phenomena has been investigated experimentally using circulation loop of liquid nitrogen. During the quenching under natural circulation, the heat transfer mode changes from film boiling to nucleate boiling, and at the same time flux changes with time depending on the vapor generation rate and related two-phase flow characteristics. Moreover, density wave oscillations occur under a certain operating condition, which is closely related to the dynamic behavior of the cooling curve. The experimental results indicates that the occurrence of the density wave oscillation induces the deterioration of effective cooling of the heat surface in the film and the transition boiling regions, which results in the decrease in the quenching velocity.

  17. Quenching phenomena in natural circulation loop

    International Nuclear Information System (INIS)

    Umekawa, Hisashi; Ozawa, Mamoru; Ishida, Naoki

    1995-01-01

    Quenching phenomena has been investigated experimentally using circulation loop of liquid nitrogen. During the quenching under natural circulation, the heat transfer mode changes from film boiling to nucleate boiling, and at the same time flux changes with time depending on the vapor generation rate and related two-phase flow characteristics. Moreover, density wave oscillations occur under a certain operating condition, which is closely related to the dynamic behavior of the cooling curve. The experimental results indicates that the occurrence of the density wave oscillation induces the deterioration of effective cooling of the heat surface in the film and the transition boiling regions, which results in the decrease in the quenching velocity

  18. Second-sphere complexation of thorium(IV) by cucurbit[6]uril with included perrhenate counterions. Crystal structure and Hirshfeld surface analysis

    Energy Technology Data Exchange (ETDEWEB)

    Thuery, Pierre [CEA, IRAMIS, UMR 3685 NIMBE, Laboratoire de Chimie Moleculaire et Catalyse pour l' Energie (LCMCE), Gif-sur-Yvette (France)

    2015-04-15

    The reaction of thorium(IV) nitrate with cucurbit[6]uril (CB6) in the presence of perrhenic acid in water gives the complex [Th(NO{sub 3})(H{sub 2}O){sub 8}][(ReO{sub 4})(CB6)](ReO{sub 4}){sub 2}.3H{sub 2}O (1). Aquated cations are held at both CB6 portals by ion-dipole and hydrogen-bonding interactions, and one of the ReO{sub 4}{sup -} anions is included in the CB6 cavity. The packing displays columns of alternate cations and encapsulated anions. Hirshfeld surfaces are used to visualize short contacts between the species present. (Copyright copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  19. Collective Phenomena in Kidney Autoregulation

    DEFF Research Database (Denmark)

    Mosekilde, Erik; Sosnovtseva, Olga; Holstein-Rathlou, N.-H.

    2004-01-01

    By controling the excretion of water and salts, the kidneys play all important role ill regulating the blood pressure and maintaining a proper environment for the cells of the body. This control depends to a large extent oil mechanisms that are associated with the individual functional unit...... for the observed synchronization phenomena, and discuss the possible physiological significance of these phenomena. We are particularly interested ill synchronization effects that call occur among neighboring nephrons that individually display irregular (or chaotic) dynamics in their pressure and flow regulation....

  20. Basic transport phenomena in materials engineering

    CERN Document Server

    Iguchi, Manabu

    2014-01-01

    This book presents the basic theory and experimental techniques of transport phenomena in materials processing operations. Such fundamental knowledge is highly useful for researchers and engineers in the field to improve the efficiency of conventional processes or develop novel technology. Divided into four parts, the book comprises 11 chapters describing the principles of momentum transfer, heat transfer, and mass transfer in single phase and multiphase systems. Each chapter includes examples with solutions and exercises to facilitate students’ learning. Diagnostic problems are also provided at the end of each part to assess students’ comprehension of the material.  The book is aimed primarily at students in materials science and engineering. However, it can also serve as a useful reference text in chemical engineering as well as an introductory transport phenomena text in mechanical engineering. In addition, researchers and engineers engaged in materials processing operations will find the material use...

  1. Plasma phenomena around comets: interaction with the solar wind

    International Nuclear Information System (INIS)

    Sagdeev, R.Z.; Shapiro, V.D.; Shevchenko, V.I.; Szegoe, K.

    1987-08-01

    The most important plasma physical experimental data measured during the cometary missions are summarized. These data do not include tail phenomena. Theoretical considerations are also presented concerning the upstream and bow shock regions. (author) 47 refs.; 15 figs

  2. Psychic phenomena and early emotional states.

    Science.gov (United States)

    Reiner, Annie

    2004-06-01

    This paper examines the relationship between severe early trauma and the development of psychic intuition. A case presentation with extensive dream work helps to illustrate this connection by exploring the psychological meaning of one patient's acute receptivity to unconscious communications. The paper includes a historical overview of Freud's attitudes toward occultism, as distinct from later psychoanalytic views, including those of Wilfred Bion. Many of Bion's views have more in common with Jung's perspective than with Freud's, with particular reference made to spiritual and religious differences. Bion clearly states that Freud and psychoanalysts have focused on phenomena, not on noumena, which Bion considers to be the essence of the psychoanalytic point of view.

  3. Surface chemistry essentials

    CERN Document Server

    Birdi, K S

    2013-01-01

    Surface chemistry plays an important role in everyday life, as the basis for many phenomena as well as technological applications. Common examples range from soap bubbles, foam, and raindrops to cosmetics, paint, adhesives, and pharmaceuticals. Additional areas that rely on surface chemistry include modern nanotechnology, medical diagnostics, and drug delivery. There is extensive literature on this subject, but most chemistry books only devote one or two chapters to it. Surface Chemistry Essentials fills a need for a reference that brings together the fundamental aspects of surface chemistry w

  4. Bion and Tustin: the autistic phenomena.

    Science.gov (United States)

    Korbivcher, Celia Fix

    2013-08-01

    This article examines the implications of the proposal of autistic transformations within the general context of Bion's theory of Transformations. The aim is to confirm the coherence of this proposal of autistic transformations within the overall structure of Bion's theory of Transformations. She examines the relation between emotional links and their negatives, particularly -K. She questions in which of the dimensions of the mind the autistic phenomena are located, the relation between autistic phenomena and beta elements, and where to place them in the Grid. The author tries to form metapsychological support for the incorporation of the autistic area in Bion's theory of Transformations. She argues that, despite the incongruence and imprecision of this incorporation, such autistic phenomena cannot be excluded from the complexus of the human mind and should therefore be accounted for in Bion's transformations. She discusses the idea that the theory of transformations includes the field of the neurosis and psychosis and deals with emotions, whereas the autistic area is dominated by sensations. The author asks how to add the autistic area to Bion's theory. Clinical material of a child for whom the non-psychotic part of the personality predominates and who presents autistic nuclei provides material for the discussion. Copyright © 2013 Institute of Psychoanalysis.

  5. Thermal transport phenomena in nanoparticle suspensions

    International Nuclear Information System (INIS)

    Cardellini, Annalisa; Fasano, Matteo; Bozorg Bigdeli, Masoud; Chiavazzo, Eliodoro; Asinari, Pietro

    2016-01-01

    Nanoparticle suspensions in liquids have received great attention, as they may offer an approach to enhance thermophysical properties of base fluids. A good variety of applications in engineering and biomedicine has been investigated with the aim of exploiting the above potential. However, the multiscale nature of nanosuspensions raises several issues in defining a comprehensive modelling framework, incorporating relevant molecular details and much larger scale phenomena, such as particle aggregation and their dynamics. The objectives of the present topical review is to report and discuss the main heat and mass transport phenomena ruling macroscopic behaviour of nanosuspensions, arising from molecular details. Relevant experimental results are included and properly put in the context of recent observations and theoretical studies, which solved long-standing debates about thermophysical properties enhancement. Major transport phenomena are discussed and in-depth analysis is carried out for highlighting the role of geometrical (nanoparticle shape, size, aggregation, concentration), chemical (pH, surfactants, functionalization) and physical parameters (temperature, density). We finally overview several computational techniques available at different scales with the aim of drawing the attention on the need for truly multiscale predictive models. This may help the development of next-generation nanoparticle suspensions and their rational use in thermal applications. (topical review)

  6. Thermal transport phenomena in nanoparticle suspensions

    Science.gov (United States)

    Cardellini, Annalisa; Fasano, Matteo; Bozorg Bigdeli, Masoud; Chiavazzo, Eliodoro; Asinari, Pietro

    2016-12-01

    Nanoparticle suspensions in liquids have received great attention, as they may offer an approach to enhance thermophysical properties of base fluids. A good variety of applications in engineering and biomedicine has been investigated with the aim of exploiting the above potential. However, the multiscale nature of nanosuspensions raises several issues in defining a comprehensive modelling framework, incorporating relevant molecular details and much larger scale phenomena, such as particle aggregation and their dynamics. The objectives of the present topical review is to report and discuss the main heat and mass transport phenomena ruling macroscopic behaviour of nanosuspensions, arising from molecular details. Relevant experimental results are included and properly put in the context of recent observations and theoretical studies, which solved long-standing debates about thermophysical properties enhancement. Major transport phenomena are discussed and in-depth analysis is carried out for highlighting the role of geometrical (nanoparticle shape, size, aggregation, concentration), chemical (pH, surfactants, functionalization) and physical parameters (temperature, density). We finally overview several computational techniques available at different scales with the aim of drawing the attention on the need for truly multiscale predictive models. This may help the development of next-generation nanoparticle suspensions and their rational use in thermal applications.

  7. Transport phenomena in multiphase flows

    CERN Document Server

    Mauri, Roberto

    2015-01-01

    This textbook provides a thorough presentation of the phenomena related to the transport of mass, momentum and energy.  It lays all the basic physical principles, then for the more advanced readers, it offers an in-depth treatment with advanced mathematical derivations and ends with some useful applications of the models and equations in specific settings. The important idea behind the book is to unify all types of transport phenomena, describing them within a common framework in terms of cause and effect, respectively represented by the driving force and the flux of the transported quantity. The approach and presentation are original in that the book starts with a general description of transport processes, providing the macroscopic balance relations of fluid dynamics and heat and mass transfer, before diving into the mathematical realm of continuum mechanics to derive the microscopic governing equations at the microscopic level. The book is a modular teaching tool and can be used either for an introductory...

  8. Solar Neutrons and Related Phenomena

    CERN Document Server

    Dorman, Lev

    2010-01-01

    This book presents the first comprehensive compilation and review of the extensive body of experimental and theoretical material on solar neutrons and related phenomena published in the scientific literature over the last sixty years. Phenomena related to solar neutrons are more specifically: the decay products of solar neutrons solar gamma rays generated in processes like nuclear reactions between solar energetic charged particles and matter of the solar atmosphere, as well as by the capture of solar neutrons by hydrogen atoms in the solar atmosphere the propagation of solar neutrons, solar gamma rays and other secondary particles through the solar photosphere, chromosphere and corona, as well as through interplanetary space and through the Earth's atmosphere. Models and simulations of particle acceleration, interactions, and propagation processes show that observations of solar neutrons and gamma rays in space and in the Earth's atmosphere yield essential and unique information on the source function of ene...

  9. Mathematical Modeling of Diverse Phenomena

    Science.gov (United States)

    Howard, J. C.

    1979-01-01

    Tensor calculus is applied to the formulation of mathematical models of diverse phenomena. Aeronautics, fluid dynamics, and cosmology are among the areas of application. The feasibility of combining tensor methods and computer capability to formulate problems is demonstrated. The techniques described are an attempt to simplify the formulation of mathematical models by reducing the modeling process to a series of routine operations, which can be performed either manually or by computer.

  10. Gravitational anomaly and transport phenomena

    OpenAIRE

    Landsteiner, Karl

    2011-01-01

    Quantum anomalies give rise to new transport phenomena. In particular, a magnetic field can induce an anomalous current via the chiral magnetic effect and a vortex in the relativistic fluid can also induce a current via the chiral vortical effect. The related transport coefficients can be calculated via Kubo formulas. We evaluate the Kubo formula for the anomalous vortical conductivity at weak coupling and show that it receives contributions proportional to the gravitational anomaly coefficie...

  11. A Review of Low Frequency Electromagnetic Wave Phenomena Related to Tropospheric-Ionospheric Coupling Mechanisms

    Science.gov (United States)

    Simoes, Fernando; Pfaff, Robert; Berthelier, Jean-Jacques; Klenzing, Jeffrey

    2012-01-01

    Investigation of coupling mechanisms between the troposphere and the ionosphere requires a multidisciplinary approach involving several branches of atmospheric sciences, from meteorology, atmospheric chemistry, and fulminology to aeronomy, plasma physics, and space weather. In this work, we review low frequency electromagnetic wave propagation in the Earth-ionosphere cavity from a troposphere-ionosphere coupling perspective. We discuss electromagnetic wave generation, propagation, and resonance phenomena, considering atmospheric, ionospheric and magnetospheric sources, from lightning and transient luminous events at low altitude to Alfven waves and particle precipitation related to solar and magnetospheric processes. We review in situ ionospheric processes as well as surface and space weather phenomena that drive troposphere-ionosphere dynamics. Effects of aerosols, water vapor distribution, thermodynamic parameters, and cloud charge separation and electrification processes on atmospheric electricity and electromagnetic waves are reviewed. We also briefly revisit ionospheric irregularities such as spread-F and explosive spread-F, sporadic-E, traveling ionospheric disturbances, Trimpi effect, and hiss and plasma turbulence. Regarding the role of the lower boundary of the cavity, we review transient surface phenomena, including seismic activity, earthquakes, volcanic processes and dust electrification. The role of surface and atmospheric gravity waves in ionospheric dynamics is also briefly addressed. We summarize analytical and numerical tools and techniques to model low frequency electromagnetic wave propagation and solving inverse problems and summarize in a final section a few challenging subjects that are important for a better understanding of tropospheric-ionospheric coupling mechanisms.

  12. Estimates of effective elastic thickness of oceanic lithosphere using model including surface and subsurface loads and effective elastic thickness of subduction zones

    Science.gov (United States)

    Yang, A.; Yongtao, F.

    2016-12-01

    The effective elastic thickness (Te) is an important parameter that characterizes the long term strength of the lithosphere, which has great significance on understanding the mechanical properties and evolution of the lithosphere. In contrast with many controversies regarding elastic thickness of continent lithosphere, the Te of oceanic lithosphere is thought to be in a simple way that is dependent on the age of the plate. However, rescent studies show that there is no simple relationship between Te and age at time of loading for both seamounts and subduction zones. As subsurface loading is very importand and has large influence in the estimate of Te for continent lithosphere, and many oceanic features such as subduction zones also have considerable subsurface loading. We introduce the method to estimate the effective elastic thickness of oceanic lithosphere using model including surface and subsurface loads by using free-air gravity anomaly and bathymetric data, together with a moving window admittance technique (MWAT). We use the multitaper spectral estimation method to calculate the power spectral density. Through tests with synthetic subduction zone like bathymetry and gravity data show that the Te can be recovered in an accurance similar to that in the continent and there is also a trade-off between spatial resolution and variance for different window sizes. We estimate Te of many subduction zones (Peru-Chile trench, Middle America trench, Caribbean trench, Kuril-Japan trench, Mariana trench, Tonga trench, Java trench, Ryukyu-Philippine trench) with an age range of 0-160 Myr to reassess the relationship between elastic thickness and the age of the lithosphere at the time of loading. The results do not show a simple relationship between Te and age.

  13. Application of atomic mutations included in nuclear reactions, 40Ar(γ, p)39Cl(β decay)39Ar, to surface study

    International Nuclear Information System (INIS)

    Ohkuma, Juzo

    1987-01-01

    It has been found that the nuclear transformation processes which are initiated by photonuclear reactions can be used for studying the adsorption and chemical reactions taking place on solid surfaces. Chemically reactive 39 Cl was produced by irradiating 40 Ar with high-energy bremsstrahlung, and its blow was directed onto several material surfaces. The amount of chlorine adsorption was ascertained by detecting its radioactivity. Desorption without heating the adsorber samples inevitably occurred owing to the nuclear decay of 39 Cl. The adsorption and desorption rates were compared for several elements. A fast growth of oxide islands on sample surfaces was observed during the adsorption-desorption process. (author)

  14. Tracer Studies of the Influence of Foreign Substances at the Surface of the Electrodes. II Influence in electro crystallization phenomena; Accion de las sustancias extranas en la superficies de los electrodos. Estudio mediante radiotrazadores. II. Influencia en los procesos de electrocristalizacion

    Energy Technology Data Exchange (ETDEWEB)

    Llopis, J.; Gamboa, J. M.; Arizmendi, L.

    1963-07-01

    The action of foreign substances present on the surface of the electrodes, in electro crystallization phenomena, has been studied. The number of Ag crystals per square centimeter of Pt electrode varies with the polishing, the current density and the presence of multilayers of stearic acid. The statistical distribution of Ag crystals without and with multilayers and their influence on the concentration index and the deformation of Ag crystals has been studied. the size of these crystals increases as the current density decreases. (Author) 16 refs.

  15. Cooperative phenomena in flows; Poster abstracts

    Energy Technology Data Exchange (ETDEWEB)

    Loekseth, Trine (ed.)

    2011-05-15

    The objective of this 'Geilo School' was to bring together researchers with various interests and background including theoretical experimental physicists, material scientists and molecular biologists to identify and discuss areas where synergism between these disciplines may be most fruitfully applied to the study of various aspects of 'Cooperative phenomena in flows'. There were altogether 21 lecturers at the School with about 80 participants from 19 countries. This was the 21. Geilo School held biannually since the first one in I971. Reference to the earlier Geilo Schools 1971-2009 may be found here: http://www.ife.no/departments/physics/projects/geilo (Author)

  16. Results on large transverse momentum phenomena

    CERN Document Server

    Büsser, F W; Blumenfeld, B; Camilleri, L L; Cool, R L; Di Lella, L; Gladding, G; Lederman, Leon Max; Litt, L; Placci, A; Pope, B G; Segler, S L; Smith, A M; Yoh, J K; Zavattini, E

    1973-01-01

    Preliminary results of an experiment on large transverse momentum phenomena performed at the CERN-ISR at centre-of-mass energies of 52.7 and 44.8 GeV are presented. The topics studied were the inclusive reaction p+p to pi /sup 0/+'anything', where the pi /sup 0/ was emitted around 90 degrees in the centre- of-mass system, ( pi /sup 0/ pi /sup 0/) correlations, and the charged multiplicity associated with large transverse momentum pi /sup 0/'s. In addition, results of a search for electrons and electron pairs are included. (4 refs).

  17. Layered phenomena in the mesopause region

    Science.gov (United States)

    Plane, J. M. C.; Bailey, S. M.; Baumgarten, G.; Rapp, M.

    2015-05-01

    This special issue of the Journal of Atmospheric and Solar-Terrestrial Physics comprises a collection of papers which were mostly presented at the 11th Layered Phenomena in the Mesopause Region (LPMR) Workshop, held at the University of Leeds between 29th July 2013 and 1st August 2013. The topics covered at the workshop included atmospheric dynamics, mesospheric ice clouds, meteoric metal layers, meteoric smoke particles, and airglow layers. There was also a session on the potential of planned sub-orbital spacecraft for making measurements in the mesosphere and lower thermosphere (MLT).

  18. Chalcogenides Metastability and Phase Change Phenomena

    CERN Document Server

    Kolobov, Alexander V

    2012-01-01

    A state-of-the-art description of metastability observed in chalcogenide alloys is presented with the accent on the underlying physics. A comparison is made between sulphur(selenium)-based chalcogenide glasses, where numerous photo-induced phenomena take place entirely within the amorphous phase, and tellurides where a reversible crystal-to-amorphous phase-change transformation is a major effect. Applications of metastability in devices¿optical memories and nonvolatile electronic phase-change random-access memories among others are discussed, including the latest trends. Background material essential for understanding current research in the field is also provided.

  19. Modeling transport phenomena and uncertainty quantification in solidification processes

    Science.gov (United States)

    Fezi, Kyle S.

    Direct chill (DC) casting is the primary processing route for wrought aluminum alloys. This semicontinuous process consists of primary cooling as the metal is pulled through a water cooled mold followed by secondary cooling with a water jet spray and free falling water. To gain insight into this complex solidification process, a fully transient model of DC casting was developed to predict the transport phenomena of aluminum alloys for various conditions. This model is capable of solving mixture mass, momentum, energy, and species conservation equations during multicomponent solidification. Various DC casting process parameters were examined for their effect on transport phenomena predictions in an alloy of commercial interest (aluminum alloy 7050). The practice of placing a wiper to divert cooling water from the ingot surface was studied and the results showed that placement closer to the mold causes remelting at the surface and increases susceptibility to bleed outs. Numerical models of metal alloy solidification, like the one previously mentioned, are used to gain insight into physical phenomena that cannot be observed experimentally. However, uncertainty in model inputs cause uncertainty in results and those insights. The analysis of model assumptions and probable input variability on the level of uncertainty in model predictions has not been calculated in solidification modeling as yet. As a step towards understanding the effect of uncertain inputs on solidification modeling, uncertainty quantification (UQ) and sensitivity analysis were first performed on a transient solidification model of a simple binary alloy (Al-4.5wt.%Cu) in a rectangular cavity with both columnar and equiaxed solid growth models. This analysis was followed by quantifying the uncertainty in predictions from the recently developed transient DC casting model. The PRISM Uncertainty Quantification (PUQ) framework quantified the uncertainty and sensitivity in macrosegregation, solidification

  20. Phase transitions and critical phenomena

    CERN Document Server

    Domb, Cyril

    2001-01-01

    The field of phase transitions and critical phenomena continues to be active in research, producing a steady stream of interesting and fruitful results. It has moved into a central place in condensed matter studies.Statistical physics, and more specifically, the theory of transitions between states of matter, more or less defines what we know about 'everyday' matter and its transformations.The major aim of this serial is to provide review articles that can serve as standard references for research workers in the field, and for graduate students and others wishing to obtain reliable in

  1. Phase transitions and critical phenomena

    CERN Document Server

    Domb, Cyril

    2000-01-01

    The field of phase transitions and critical phenomena continues to be active in research, producing a steady stream of interesting and fruitful results. No longer an area of specialist interest, it has acquired a central focus in condensed matter studies. The major aim of this serial is to provide review articles that can serve as standard references for research workers in the field, and for graduate students and others wishing to obtain reliable information on important recent developments.The two review articles in this volume complement each other in a remarkable way. Both deal with what m

  2. Violent phenomena in the Universe

    CERN Document Server

    Narlikar, Jayant V

    2007-01-01

    The serenity of a clear night sky belies the evidence-gathered by balloons, rockets, satellites, and telescopes-that the universe contains centers of furious activity that pour out vast amounts of energy, some in regular cycles and some in gigantic bursts. This reader-friendly book, acclaimed by Nature as ""excellent and uncompromising,"" traces the development of modern astrophysics and its explanations of these startling celestial fireworks.This lively narrative ranges from the gravitational theories of Newton and Einstein to recent exciting discoveries of such violent phenomena as supernova

  3. Gravitational anomaly and transport phenomena.

    Science.gov (United States)

    Landsteiner, Karl; Megías, Eugenio; Pena-Benitez, Francisco

    2011-07-08

    Quantum anomalies give rise to new transport phenomena. In particular, a magnetic field can induce an anomalous current via the chiral magnetic effect and a vortex in the relativistic fluid can also induce a current via the chiral vortical effect. The related transport coefficients can be calculated via Kubo formulas. We evaluate the Kubo formula for the anomalous vortical conductivity at weak coupling and show that it receives contributions proportional to the gravitational anomaly coefficient. The gravitational anomaly gives rise to an anomalous vortical effect even for an uncharged fluid.

  4. Phenomena and Diosignes of Aratous

    Science.gov (United States)

    Avgoloupis, S. I.

    2013-01-01

    Aratous (305-240B.C.) was a singular intellectual, writer and poet which engage himself to compose a very interesting astronomical poet, using the "Dactylous sixstage' style, the formal style of the ancient Greek Epic poetry. This astronomic poem of Aratous "Phenomena and Diosignes" became very favorite reading during the Alexandrine, the Romman and the Byzandin eras as well and had received many praises from significant poets and particularly from Hipparchous and from Theonas from Alexandria, an astronomer of 4rth century A.C.(in Greeks)

  5. Quantum theory of collective phenomena

    CERN Document Server

    Sewell, G L

    2014-01-01

    ""An excellent and competent introduction to the field … [and] … a source of information for the expert."" - Physics Today""This a book of major importance…. I trust that this book will be used as a basis for the teaching of a balanced, modern and rigorous course on statistical mechanics in all universities."" - Bulletin of the London Mathematical Society""This is one of the best introductions to the subject, and it is strongly recommended to anyone interested in collective phenomena."" - Physics Bulletin ""The book may be recommended for students as a well-balanced introduction to this rich s

  6. Unipolar arcing phenomena observed in laboratory and nature

    Energy Technology Data Exchange (ETDEWEB)

    Sanduloviciu, M. [Al. I. Cuza Univ. (Romania)

    1995-12-31

    Unipolar arcing phenomena observed as coherent {open_quotes}plasma{close_quotes} balls operating on a surface of constant potential are explained in the frame of a new already proposed self-organisation mechanism considered at the origin of the formation and stability of extended coherent structures observed in plasma devices.

  7. Thermo-hydrodynamic transport phenomena in partially wetting ...

    Indian Academy of Sciences (India)

    Thepresence of gas–liquid interfaces, dominance of surface forces, moving contact lines, wettability, dynamic contact angle hysteresis and flow in confined geometries are some of the unique features of two-phase systems,which manifest into complex transport phenomena. While Taylor plug/bubble flow is a fairly common ...

  8. Extreme wave phenomena in down-stream running modulated waves

    NARCIS (Netherlands)

    Andonowati, A.; Karjanto, N.; van Groesen, Embrecht W.C.

    Modulational, Benjamin-Feir, instability is studied for the down-stream evolution of surface gravity waves. An explicit solution, the soliton on finite background, of the NLS equation in physical space is used to study various phenomena in detail. It is shown that for sufficiently long modulation

  9. Molecular dynamics simulation of laser shock phenomena

    Energy Technology Data Exchange (ETDEWEB)

    Fukumoto, Ichirou [Japan Atomic Energy Research Inst., Kansai Research Establishment, Advanced Photon Research Center, Neyagawa, Osaka (Japan).

    2001-10-01

    Recently, ultrashort-pulse lasers with high peak power have been developed, and their application to materials processing is expected as a tool of precision microfabrication. When a high power laser irradiates, a shock wave propagates into the material and dislocations are generated. In this paper, laser shock phenomena of the metal were analyzed using the modified molecular dynamics method, which has been developed by Ohmura and Fukumoto. The main results obtained are summarized as follows: (1) The shock wave induced by the Gaussian beam irradiation propagates radially from the surface to the interior. (2) A lot of dislocations are generated at the solid-liquid interface by the propagation of a shock wave. (3) Some dislocations are moved instantaneously with the velocity of the longitudinal wave when the shock wave passes, and their velocity is not larger than the transverse velocity after the shock wave has passed. (author)

  10. Transitional Phenomena on Phase Change Materials

    Directory of Open Access Journals (Sweden)

    Wójcik Tadeusz M.

    2014-03-01

    Full Text Available One of the most significant problem with technology development is transferring of large heat fluxes, which requires constant heat transfer temperature (in the specified temperature range. This problem concern mainly the nuclear energetics, space technologies, military technologies and most of all electronics containing integrated circuits with very large scale of integrations. Intensive heat transfer and thermal energy storage are possible by the use of phase change materials (PCMs. In the paper there are presented preliminary results of research on the use of liquid-gas (L-G PCMs and solid-solid phase change materials (S-S PCMs. For L-G PCMs the boiling characteristics were determined by increasing and decreasing the heat flux, which for certain sets of structural parameters of the heating surface and the physical properties of the liquid induce a variety of forms of transitional phenomena. Thermal energy storage is much more effective when using PCMs than sensible heat.

  11. Light-induced phenomena in one-component gas: The transport phenomena

    Science.gov (United States)

    Chermyaninov, I. V.; Chernyak, V. G.

    2016-09-01

    The article presents the theory of transport processes in a one-component gas located in the capillary under the action of resonant laser radiation and the temperature and pressure gradients. The expressions for the kinetic coefficients determining heat and mass transport in the gas are obtained on the basis of the modified Boltzmann equations for the excited and unexcited particles. The Onsager reciprocal relations for cross kinetic coefficients are proven for all Knudsen numbers and for any law interaction of gas particles with each other and boundary surface. Light-induced phenomena associated with the possible non-equilibrium stationary states of system are analyzed.

  12. Transport phenomena in nanoporous materials.

    Science.gov (United States)

    Kärger, Jörg

    2015-01-12

    Diffusion, that is, the irregular movement of atoms and molecules, is a universal phenomenon of mass transfer occurring in all states of matter. It is of equal importance for fundamental research and technological applications. The present review deals with the challenges of the reliable observation of these phenomena in nanoporous materials. Starting with a survey of the different variants of diffusion measurement, it highlights the potentials of "microscopic" techniques, notably the pulsed field gradient (PFG) technique of NMR and the techniques of microimaging by interference microscopy (IFM) and IR microscopy (IRM). Considering ensembles of guest molecules, these techniques are able to directly record mass transfer phenomena over distances of typically micrometers. Their concerted application has given rise to the clarification of long-standing discrepancies, notably between microscopic equilibrium and macroscopic non-equilibrium measurements, and to a wealth of new information about molecular transport under confinement, hitherto often inaccessible and sometimes even unimaginable. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Sound conversion phenomena at the free surface of liquid helium. I. Calculation of the coefficients of reflection, transmission, and transformation of sound waves incident on the liquid--vapor interface of helium

    International Nuclear Information System (INIS)

    Wiechert, H.; Buchholz, F.I.

    1980-01-01

    On the basis of a set of boundary conditions describing quite generally mass and energy transport processes across the free surface of helium II, the acoustic coefficients of reflection, transmission, and transformation of first sound, second sound, and the sound wave propagating in the vapor are calculated in the case of perpendicular incidence of sound waves against the liquid--vapor phase boundary. Considering rigoroulsy the influences of the Onsager surface coefficients, the isobaric thermal expansion coefficients, and the thermal conductivities of the liquid and the vapor, we derive sets of equations from which the acoustic coefficients are determined numerically. For estimations, simple explicit formulas of the acoustic coefficients are given. It is shown that the evaporation and energy transport processes occurring at the free surface of helium II due to the incidence of sound waves may be connected with appreciable energy dissipation. The surface absorption coefficients of first, second, and gas sound waves are deduced

  14. Natural phenomena hazards, Hanford Site, Washington

    International Nuclear Information System (INIS)

    Conrads, T.J.

    1998-01-01

    This document presents the natural phenomena hazard loads for use in implementing DOE Order 5480.28, Natural Phenomena Hazards Mitigation, and supports development of double-shell tank systems specifications at the Hanford Site in south-central Washington State. The natural phenomena covered are seismic, flood, wind, volcanic ash, lightning, snow, temperature, solar radiation, suspended sediment, and relative humidity

  15. Augmented Visual Experience of Simulated Solar Phenomena

    Science.gov (United States)

    Tucker, A. O., IV; Berardino, R. A.; Hahne, D.; Schreurs, B.; Fox, N. J.; Raouafi, N.

    2017-12-01

    The Parker Solar Probe (PSP) mission will explore the Sun's corona, studying solar wind, flares and coronal mass ejections. The effects of these phenomena can impact the technology that we use in ways that are not readily apparent, including affecting satellite communications and power grids. Determining the structure and dynamics of corona magnetic fields, tracing the flow of energy that heats the corona, and exploring dusty plasma near the Sun to understand its influence on solar wind and energetic particle formation requires a suite of sensors on board the PSP spacecraft that are engineered to observe specific phenomena. Using models of these sensors and simulated observational data, we can visualize what the PSP spacecraft will "see" during its multiple passes around the Sun. Augmented reality (AR) technologies enable convenient user access to massive data sets. We are developing an application that allows users to experience environmental data from the point of view of the PSP spacecraft in AR using the Microsoft HoloLens. Observational data, including imagery, magnetism, temperature, and density are visualized in 4D within the user's immediate environment. Our application provides an educational tool for comprehending the complex relationships of observational data, which aids in our understanding of the Sun.

  16. Laboratory simulation of space plasma phenomena*

    Science.gov (United States)

    Amatucci, B.; Tejero, E. M.; Ganguli, G.; Blackwell, D.; Enloe, C. L.; Gillman, E.; Walker, D.; Gatling, G.

    2017-12-01

    Laboratory devices, such as the Naval Research Laboratory's Space Physics Simulation Chamber, are large-scale experiments dedicated to the creation of large-volume plasmas with parameters realistically scaled to those found in various regions of the near-Earth space plasma environment. Such devices make valuable contributions to the understanding of space plasmas by investigating phenomena under carefully controlled, reproducible conditions, allowing for the validation of theoretical models being applied to space data. By working in collaboration with in situ experimentalists to create realistic conditions scaled to those found during the observations of interest, the microphysics responsible for the observed events can be investigated in detail not possible in space. To date, numerous investigations of phenomena such as plasma waves, wave-particle interactions, and particle energization have been successfully performed in the laboratory. In addition to investigations such as plasma wave and instability studies, the laboratory devices can also make valuable contributions to the development and testing of space plasma diagnostics. One example is the plasma impedance probe developed at NRL. Originally developed as a laboratory diagnostic, the sensor has now been flown on a sounding rocket, is included on a CubeSat experiment, and will be included on the DoD Space Test Program's STP-H6 experiment on the International Space Station. In this presentation, we will describe several examples of the laboratory investigation of space plasma waves and instabilities and diagnostic development. *This work supported by the NRL Base Program.

  17. BWR core melt progression phenomena: Experimental analyses

    International Nuclear Information System (INIS)

    Ott, L.J.

    1992-01-01

    In the BWR Core Melt in Progression Phenomena Program, experimental results concerning severe fuel damage and core melt progression in BWR core geometry are used to evaluate existing models of the governing phenomena. These include control blade eutectic liquefaction and the subsequent relocation and attack on the channel box structure; oxidation heating and hydrogen generation; Zircaloy melting and relocation; and the continuing oxidation of zirconium with metallic blockage formation. Integral data have been obtained from the BWR DF-4 experiment in the ACRR and from BWR tests in the German CORA exreactor fuel-damage test facility. Additional integral data will be obtained from new CORA BWR test, the full-length FLHT-6 BWR test in the NRU test reactor, and the new program of exreactor experiments at Sandia National Laboratories (SNL) on metallic melt relocation and blockage formation. an essential part of this activity is interpretation and use of the results of the BWR tests. The Oak Ridge National Laboratory (ORNL) has developed experiment-specific models for analysis of the BWR experiments; to date, these models have permitted far more precise analyses of the conditions in these experiments than has previously been available. These analyses have provided a basis for more accurate interpretation of the phenomena that the experiments are intended to investigate. The results of posttest analyses of BWR experiments are discussed and significant findings from these analyses are explained. The ORNL control blade/canister models with materials interaction, relocation and blockage models are currently being implemented in SCDAP/RELAP5 as an optional structural component

  18. In vessel core melt progression phenomena

    International Nuclear Information System (INIS)

    Courtaud, M.

    1993-01-01

    For all light water reactor (LWR) accidents, including the so called severe accidents where core melt down can occur, it is necessary to determine the amount and characteristics of fission products released to the environment. For existing reactors this knowledge is used to evaluate the consequences and eventual emergency plans. But for future reactors safety authorities demand decrease risks and reactors designed in such a way that fission products are retained inside the containment, the last protective barrier. This requires improved understanding and knowledge of all accident sequences. In particular it is necessary to be able to describe the very complex phenomena occurring during in vessel core melt progression because they will determine the thermal and mechanical loads on the primary circuit and the timing of its rupture as well as the fission product source term. On the other hand, in case of vessel failure, knowledge of the physical and chemical state of the core melt will provide the initial conditions for analysis of ex-vessel core melt progression and phenomena threatening the containment. Finally a good understanding of in vessel phenomena will help to improve accident management procedures like Emergency Core Cooling System water injection, blowdown and flooding of the vessel well, with their possible adverse effects. Research and Development work on this subject was initiated a long time ago and is still in progress but now it must be intensified in order to meet the safety requirements of the next generation of reactors. Experiments, limited in scale, analysis of the TMI 2 accident which is a unique source of global information and engineering judgment are used to establish and assess physical models that can be implemented in computer codes for reactor accident analysis

  19. Oscillating heat pipe simulation considering dryout phenomena

    Science.gov (United States)

    Senjaya, Raffles; Inoue, Takayoshi

    2014-10-01

    In heat transport devices such as oscillating heat pipe (OHP), dryout phenomena is very important and avoided in order to give the optimum performance. However, from the previous studies (including our studies), the dryout phenomena in OHP and its mechanism are still unclear. In our studies of OHP (Senjaya and Inoue in Appl Thermal Eng 60:251-255, 2013; Int J Heat Mass Transfer 60:816-824, 2013; Int J Heat Mass Transfer 60:825-835, 2013), we introduced the importance and roles of liquid film in the operating principle of OHP. In our previous simulation, the thickness of liquid film was assumed to be uniform along a vapor plug. Then, dryout never occurred because there was the liquid transfer from the liquid film in the cooling section to that in the heating section. In this research, the liquid film is not treated uniformly but it is meshed similarly with the vapor plugs and liquid slugs. All governing equations are also solved in each control volume of liquid film. The simulation results show that dryout occurs in the simulation without bubble generation and growth. Dryout is started in the middle of vapor plug, because the liquid supply from the left and right liquid slugs cannot reach until the liquid film in the middle of vapor plug, and propagates to the left and right sides of a vapor plug. By inserting the bubble generation and growth phenomena, dryout does not occur because the wall of heating section is always wetted during the bubble growth and the thickness of liquid film is almost constant. The effects of meshing size of liquid film and wall temperature of heating section are also investigated. The results show that the smaller meshing size, the smaller liquid transfer rate and the faster of dryout propagation. In the OHP with higher wall temperature of heating section, dryout and its propagation also occur faster.

  20. Analysis of a Free Surface Film from a Controlled Liquid Impinging Jet over a Rotating Disk Including Conjugate Effects, with and without Evaporation

    Science.gov (United States)

    Sankaran, Subramanian (Technical Monitor); Rice, Jeremy; Faghri, Amir; Cetegen, Baki M.

    2005-01-01

    A detailed analysis of the liquid film characteristics and the accompanying heat transfer of a free surface controlled liquid impinging jet onto a rotating disk are presented. The computations were run on a two-dimensional axi-symmetric Eulerian mesh while the free surface was calculated with the volume of fluid method. Flow rates between 3 and 15 1pm with rotational speeds between 50 and 200 rpm are analyzed. The effects of inlet temperature on the film thickness and heat transfer are characterized as well as evaporative effects. The conjugate heating effect is modeled, and was found to effect the heat transfer results the most at both the inner and outer edges of the heated surface. The heat transfer was enhanced with both increasing flow rate and increasing rotational speeds. When evaporative effects were modeled, the evaporation was found to increase the heat transfer at the lower flow rates the most because of a fully developed thermal field that was achieved. The evaporative effects did not significantly enhance the heat transfer at the higher flow rates.

  1. MHD phenomena at ASDEX Upgrade

    International Nuclear Information System (INIS)

    Guenter, S.; Gude, A.; Maraschek, M.; Pinches, S.D.; Sesnic, S.; Wolf, R.C.; Yu, Q.; Zohm, M.

    2001-01-01

    The onset of neoclassical tearing modes leads to the most serious β limit at ASDEX Upgrade. The β p value for the onset of neoclassical tearing modes is found to be proportional to the ion gyro-radius for collisionless plasmas as proposed by the ion polarisation current model. Larger collisionalities have a stabilizing effect. Sawtooth crashes or fishbones can trigger the mode, and in a few cases it appears spontaneously. Fishbones are shown to be able to cause magnetic reconnection. The fractional energy loss due to a (3,2) mode saturates for large pressures at around 25 %. In discharges with large impurity accumulation unusual MHD phenomena such as cascades of high-n tearing modes and modes driven by positive pressure gradients have been found. (author)

  2. MHD phenomena at ASDEX Upgrade

    International Nuclear Information System (INIS)

    Guenter, S.; Gude, A.; Maraschek, M.; Pinches, S.D.; Sesnic, S.; Wolf, R.C.; Yu, Q.; Zohm, H.

    1999-01-01

    The onset of neoclassical tearing modes leads to the most serious β limit at ASDEX Upgrade. The β p value for the onset of neoclassical tearing modes is found to be proportional to the ion gyro-radius for collisionless plasmas as proposed by the ion polarisation current model. Larger collisionalities have a stabilizing effect. Sawtooth crashes or fishbones can trigger the mode, and in a few cases it appears spontaneously. Fishbones are shown to be able to cause magnetic reconnection. The fractional energy loss due to a (3,2) mode saturates for large pressures at around 25%. In discharges with large impurity accumulation unusual MHD phenomena such as cascades of high-n tearing modes and modes driven by positive pressure gradients have been found. (author)

  3. Critical Phenomena in Gravitational Collapse

    Directory of Open Access Journals (Sweden)

    Martín-García José M.

    2007-12-01

    Full Text Available As first discovered by Choptuik, the black hole threshold in the space of initial data for general relativity shows both surprising structure and surprising simplicity. Universality, power-law scaling of the black hole mass, and scale echoing have given rise to the term “critical phenomena”. They are explained by the existence of exact solutions which are attractors within the black hole threshold, that is, attractors of codimension one in phase space, and which are typically self-similar. Critical phenomena give a natural route from smooth initial data to arbitrarily large curvatures visible from infinity, and are therefore likely to be relevant for cosmic censorship, quantum gravity, astrophysics, and our general understanding of the dynamics of general relativity.

  4. Emergent Phenomena at Oxide Interfaces

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, H.Y.

    2012-02-16

    Transition metal oxides (TMOs) are an ideal arena for the study of electronic correlations because the s-electrons of the transition metal ions are removed and transferred to oxygen ions, and hence the strongly correlated d-electrons determine their physical properties such as electrical transport, magnetism, optical response, thermal conductivity, and superconductivity. These electron correlations prohibit the double occupancy of metal sites and induce a local entanglement of charge, spin, and orbital degrees of freedom. This gives rise to a variety of phenomena, e.g., Mott insulators, various charge/spin/orbital orderings, metal-insulator transitions, multiferroics, and superconductivity. In recent years, there has been a burst of activity to manipulate these phenomena, as well as create new ones, using oxide heterostructures. Most fundamental to understanding the physical properties of TMOs is the concept of symmetry of the order parameter. As Landau recognized, the essence of phase transitions is the change of the symmetry. For example, ferromagnetic ordering breaks the rotational symmetry in spin space, i.e., the ordered phase has lower symmetry than the Hamiltonian of the system. There are three most important symmetries to be considered here. (i) Spatial inversion (I), defined as r {yields} -r. In the case of an insulator, breaking this symmetry can lead to spontaneous electric polarization, i.e. ferroelectricity, or pyroelectricity once the point group belongs to polar group symmetry. (ii) Time-reversal symmetry (T) defined as t {yields} -t. In quantum mechanics, the time-evolution of the wave-function {Psi} is given by the phase factor e{sup -iEt/{h_bar}} with E being the energy, and hence time-reversal basically corresponds to taking the complex conjugate of the wave-function. Also the spin, which is induced by the 'spinning' of the particle, is reversed by time-reversal. Broken T-symmetry is most naturally associated with magnetism, since the

  5. The quest for new phenomena

    International Nuclear Information System (INIS)

    Hinchliffe, I.

    1996-12-01

    The Standard Model of particle physics has been very successful in describing experimental data with great precision. With the exception of some neutrino anomalies, there is no data that is in disagreement with it. Nevertheless, the model is regarded as incomplete and unsatisfactory. There is no explanation of the pattern of quark and lepton masses and, possibly more important, no understanding of the scale of electroweak interactions. Electroweak symmetry breaking is implemented in the Standard Model from the presence of a scalar electroweak doublet, the Higgs field, that acquires a vacuum expectation value of order 250 GeV and leaves as a remnant one physical state, the electrically neutral Higgs boson whose mass is not predicted. In this talk, the author compares the techniques used at, and capabilities of, various facilities in searching for new phenomena. The author emphasizes the cases where information from more than one facility may be needed to fully explore the physics

  6. Studies of Novel Quantum Phenomena in Ruthenates

    Energy Technology Data Exchange (ETDEWEB)

    Mao, Zhiqiang

    2011-04-08

    Strongly correlated oxides have been the subject of intense study in contemporary condensed matter physics, and perovskite ruthenates (Sr,Ca)n+1RunO3n+1 have become a new focus in this field. One of important characteristics of ruthenates is that both lattice and orbital degrees of freedom are active and are strongly coupled to charge and spin degrees of freedom. Such a complex interplay of multiple degrees of freedom causes the properties of ruthenates to exhibit a gigantic response to external stimuli under certain circumstances. Magnetic field, pressure, and chemical composition all have been demonstrated to be effective in inducing electronic/magnetic phase transitions in ruthenates. Therefore, ruthenates are ideal candidates for searching for novel quantum phenomena through controlling external parameters. The objective of this project is to search for novel quantum phenomena in ruthenate materials using high-quality single crystals grown by the floating-zone technique, and investigate the underlying physics. The following summarizes our accomplishments. We have focused on trilayered Sr4Ru3O10 and bilayered (Ca1-xSrx)3Ru2O7. We have succeeded in growing high-quality single crystals of these materials using the floating-zone technique and performed systematic studies on their electronic and magnetic properties through a variety of measurements, including resistivity, Hall coefficient, angle-resolved magnetoresistivity, Hall probe microscopy, and specific heat. We have also studied microscopic magnetic properties for some of these materials using neutron scattering in collaboration with Los Alamos National Laboratory. We have observed a number of unusual exotic quantum phenomena through these studies, such as an orbital selective metamagnetic transition, bulk spin valve effect, and a heavy-mass nearly ferromagnetic state with a surprisingly large Wilson ratio. Our work has also revealed underlying physics of these exotic phenomena. Exotic phenomena of correlated

  7. In-vessel phenomena -- CORA

    International Nuclear Information System (INIS)

    Ott, L.J.; Rij, W.I. van.

    1991-01-01

    Experiment-specific models have been employed since 1986 by Oak Ridge National Laboratory (ORNL) severe accident analysis programs for the purpose of boiling water reactor experimental planning and optimum interpretation of experimental results. The large integral tests performed to date, which start from an initial undamaged core state, have involved significantly different-from-prototypic boundary and experimental conditions because of either normal facility limitations or specific experimental constraints. These experiments (ACRR: DF-4, NRU: FLHT-6, and CORA) were designed to obtain specific phenomenological information such as the degradation and interaction of prototypic components and the effects on melt progression of control-blade materials and channel boxes. Applications of ORNL models specific to the KfK CORA-16 and CORA-17 experiments are discussed and significant findings from the experimental analyses such as the following are presented: applicability of available Zircaloy oxidation kinetics correlations; influence of cladding strain on Zircaloy oxidation; influence of spacer grids on the structural heatup; and the impact of treating the gaseous coolant as a gray interacting medium. The experiment-specific models supplement and support the systems-level accident analysis codes. They allow the analyst to accurately quantify the observed experimental phenomena and to compensate for the effect of known uncertainties. They provide a basis for the efficient development of new models for phenomena that are currently not modeled (such as material interactions). They can provide validated phenomenological models (from the results of the experiments) as candidates for incorporation in the systems-level ''whole-core'' codes

  8. Investigations of corrosion phenomena on gold coins with SIMS

    International Nuclear Information System (INIS)

    Mayerhofer, K.E.; Piplits, K.; Traum, R.; Griesser, M.; Hutter, H.

    2005-01-01

    In order to establish a new handling procedure for contaminated coins, the Coin Cabinet and the Conservation Science Department of the Kunsthistorisches Museum, Vienna, initiated a research project on corrosion effects of gold coins. By now, investigations on historic and contemporary coins included optical microscopy, scanning electron microscopy (SEM), Auger electron microscopy (AES), X-ray photoelectron microscopy (XPS), and electrochemical methods showing the distribution of pollutants. This work focuses on secondary ion mass spectrometry (SIMS) investigations merely showing the distribution of electronegative elements, such as sulfur, oxygen, and chlorine on the surface. Sulfur is highly suspected of causing the observed corrosion phenomena, and is indeed enriched near polluting splints. Since SIMS is a destructive method, the investigated samples are test coins with intentionally added impurities. These coins were manufactured in cooperation with the Austrian Mint. They were treated with potassium polysulfide (K 2 S x ) for 8 h gaining a rapid corrosion of the surface. SIMS mass spectra, depth profiles, and images were done (a) at non-polluted areas (b) near polluted areas with slight coloring, and (c) directly at polluting stains showing enrichments of sulfur and chlorine. Due to the success of these investigations further studies on historic coins are intended

  9. Fluid models and simulations of biological cell phenomena

    Science.gov (United States)

    Greenspan, H. P.

    1982-01-01

    The dynamics of coated droplets are examined within the context of biofluids. Of specific interest is the manner in which the shape of a droplet, the motion within it as well as that of aggregates of droplets can be controlled by the modulation of surface properties and the extent to which such fluid phenomena are an intrinsic part of cellular processes. From the standpoint of biology, an objective is to elucidate some of the general dynamical features that affect the disposition of an entire cell, cell colonies and tissues. Conventionally averaged field variables of continuum mechanics are used to describe the overall global effects which result from the myriad of small scale molecular interactions. An attempt is made to establish cause and effect relationships from correct dynamical laws of motion rather than by what may have been unnecessary invocation of metabolic or life processes. Several topics are discussed where there are strong analogies droplets and cells including: encapsulated droplets/cell membranes; droplet shape/cell shape; adhesion and spread of a droplet/cell motility and adhesion; and oams and multiphase flows/cell aggregates and tissues. Evidence is presented to show that certain concepts of continuum theory such as suface tension, surface free energy, contact angle, bending moments, etc. are relevant and applicable to the study of cell biology.

  10. WHC natural phenomena hazards mitigation implementation plan

    Energy Technology Data Exchange (ETDEWEB)

    Conrads, T.J.

    1996-09-11

    Natural phenomena hazards (NPH) are unexpected acts of nature which pose a threat or danger to workers, the public or to the environment. Earthquakes, extreme winds (hurricane and tornado),snow, flooding, volcanic ashfall, and lightning strike are examples of NPH at Hanford. It is the policy of U.S. Department of Energy (DOE) to design, construct and operate DOE facilitiesso that workers, the public and the environment are protected from NPH and other hazards. During 1993 DOE, Richland Operations Office (RL) transmitted DOE Order 5480.28, ``Natural Phenomena Hazards Mitigation,`` to Westinghouse Hanford COmpany (WHC) for compliance. The Order includes rigorous new NPH criteria for the design of new DOE facilities as well as for the evaluation and upgrade of existing DOE facilities. In 1995 DOE issued Order 420.1, ``Facility Safety`` which contains the same NPH requirements and invokes the same applicable standards as Order 5480.28. It will supersede Order 5480.28 when an in-force date for Order 420.1 is established through contract revision. Activities will be planned and accomplished in four phases: Mobilization; Prioritization; Evaluation; and Upgrade. The basis for the graded approach is the designation of facilities/structures into one of five performance categories based upon safety function, mission and cost. This Implementation Plan develops the program for the Prioritization Phase, as well as an overall strategy for the implemention of DOE Order 5480.2B.

  11. Surface Tension of Binary Mixtures Including Polar Components Modeled by the Density Gradient Theory Combined with the PC-SAFT Equation of State

    Czech Academy of Sciences Publication Activity Database

    Vinš, Václav; Planková, Barbora; Hrubý, Jan

    2013-01-01

    Roč. 34, č. 5 (2013), s. 792-812 ISSN 0195-928X R&D Projects: GA AV ČR IAA200760905; GA ČR(CZ) GPP101/11/P046; GA ČR GA101/09/1633 Institutional research plan: CEZ:AV0Z20760514 Institutional support: RVO:61388998 Keywords : chemical polarity * gradient theory * surface tension Subject RIV: BJ - Thermodynamics Impact factor: 0.623, year: 2013 http://www.springerlink.com/openurl.asp?genre=article&id=doi:10.1007/s10765-012-1207-z

  12. Fracture Phenomena in Amorphous Selenium

    DEFF Research Database (Denmark)

    Lindegaard-Andersen, Asger; Dahle, Birgit

    1966-01-01

    Fracture surfaces of amorphous selenium broken in flexure at room temperature have been studied. The fracture velocity was found to vary in different regions of the fracture surface. Peculiar features were observed in a transition zone between fast and slower fracture. In this zone cleavage steps...

  13. Adsorption phenomena and anchoring energy in nematic liquid crystals

    CERN Document Server

    Barbero, Giovanni

    2005-01-01

    Despite the large quantity of phenomenological information concerning the bulk properties of nematic phase liquid crystals, little is understood about the origin of the surface energy, particularly the surface, interfacial, and anchoring properties of liquid crystals that affect the performance of liquid crystal devices. Self-contained and unique, Adsorption Phenomena and Anchoring Energy in Nematic Liquid Crystals provides an account of new and established results spanning three decades of research into the problems of anchoring energy and adsorption phenomena in liquid crystals.The book contains a detailed discussion of the origin and possible sources of anchoring energy in nematic liquid crystals, emphasizing the dielectric contribution to the anchoring energy in particular. Beginning with fundamental surface and anchoring properties of liquid crystals and the definition of the nematic phase, the authors explain how selective ion adsorption, dielectric energy density, thickness dependence, and bias voltage...

  14. The Plasmodium falciparum transcriptome in severe malaria reveals altered expression of genes involved in important processes including surface antigen–encoding var genes

    Science.gov (United States)

    Tonkin-Hill, Gerry Q.; Trianty, Leily; Noviyanti, Rintis; Nguyen, Hanh H. T.; Sebayang, Boni F.; Lampah, Daniel A.; Marfurt, Jutta; Cobbold, Simon A.; Rambhatla, Janavi S.; McConville, Malcolm J.; Rogerson, Stephen J.; Brown, Graham V.; Day, Karen P.; Price, Ric N.; Anstey, Nicholas M.

    2018-01-01

    Within the human host, the malaria parasite Plasmodium falciparum is exposed to multiple selection pressures. The host environment changes dramatically in severe malaria, but the extent to which the parasite responds to—or is selected by—this environment remains unclear. From previous studies, the parasites that cause severe malaria appear to increase expression of a restricted but poorly defined subset of the PfEMP1 variant, surface antigens. PfEMP1s are major targets of protective immunity. Here, we used RNA sequencing (RNAseq) to analyse gene expression in 44 parasite isolates that caused severe and uncomplicated malaria in Papuan patients. The transcriptomes of 19 parasite isolates associated with severe malaria indicated that these parasites had decreased glycolysis without activation of compensatory pathways; altered chromatin structure and probably transcriptional regulation through decreased histone methylation; reduced surface expression of PfEMP1; and down-regulated expression of multiple chaperone proteins. Our RNAseq also identified novel associations between disease severity and PfEMP1 transcripts, domains, and smaller sequence segments and also confirmed all previously reported associations between expressed PfEMP1 sequences and severe disease. These findings will inform efforts to identify vaccine targets for severe malaria and also indicate how parasites adapt to—or are selected by—the host environment in severe malaria. PMID:29529020

  15. Characterization of Genotoxic Response to 15 Multiwalled Carbon Nanotubes with Variable Physicochemical Properties Including Surface Functionalizations in the FE1-Muta(TM) Mouse Lung Epithelial Cell Line

    DEFF Research Database (Denmark)

    Jackson, Petra; Kling, Kirsten; Jensen, Keld Alstrup

    2015-01-01

    Carbon nanotubes vary greatly in physicochemical properties. We compared cytotoxic and genotoxic response to 15 multiwalled carbon nanotubes (MWCNT) with varying physicochemical properties to identify drivers of toxic responses. The studied MWCNT included OECD Working Party on Manufactured Nanoma...

  16. Tracer Studies of the Influence of Foreign Substances at the Surface of the Electrodes. I. Polarization Phenomena; Accion de las sustancias extranas en la superficie de los electrodos. Estudio mediante radiotrazadores

    Energy Technology Data Exchange (ETDEWEB)

    Llopis, J.; Gamboa, J. M.; Arizmendi, L.

    1961-07-01

    Radioactive stearic acid ({sup 1}4C) has been used to determine the number of molecular layers present on copper electrode surfaces and its distribution. The stability of these layers under the experimental conditions has been studied and it has been shown that its presence has no influence on the anodic and cathodic polarization. an increase of these polarizations has been observed with mixed multilayers of stearic acid and sterolamide. (Author) 13 refs.

  17. Surface phenomena of high energy Li(Ni1/3Co1/3Mn1/3)O2/graphite cells at high temperature and high cutoff voltages

    Science.gov (United States)

    Liu, Ting; Garsuch, Arnd; Chesneau, Frederick; Lucht, Brett L.

    2014-12-01

    Layered Li(Ni1/3Co1/3Mn1/3)O2 (NCM) materials have been investigated at high working potential and elevated temperature to correlate electrochemical performance with changes to the electrode interface. Graphite/NCM cells were cycled to either 4.2 or 4.5 V vs Li/Li+ at room temperature (25 °C) followed by moderately elevated temperature (55 °C). Cells cycled to 4.2 and 4.5 V have similar capacity retention, but the cells cycled to 4.5 V have poorer first cycle efficiency, efficiency upon cycling at 55 °C, and greater increases in cell resistance. Surface analyses indicate thicker surface films on the cathode after cycling to 4.5 V, compared to cycling at a lower voltage of 4.2 V. The thicker surface film on the cathode is the result of electrolyte oxidation to generate poly(ethylene carbonate) and lithium alkyl carbonates. Electrochemical impedance spectroscopy of three-electrode cells reveals that the cathode dominates the cell impedance and the cathode impedance is much greater for cells cycled to 4.5 V than cells cycled to 4.2 V.

  18. EDITORIAL: Quantum phenomena in Nanotechnology Quantum phenomena in Nanotechnology

    Science.gov (United States)

    Loss, Daniel

    2009-10-01

    Twenty years ago the Institute of Physics launched the journal Nanotechnology from its publishing house based in the home town of Paul Dirac, a legendary figure in the development of quantum mechanics at the turn of the last century. At the beginning of the 20th century, the adoption of quantum mechanical descriptions of events transformed the existing deterministic world view. But in many ways it also revolutionised the progress of research itself. For the first time since the 17th century when Francis Bacon established inductive reasoning as the means of advancing science from fact to axiom to law, theory was progressing ahead of experiments instead of providing explanations for observations that had already been made. Dirac's postulation of antimatter through purely theoretical investigation before its observation is the archetypal example of theory leading the way for experiment. The progress of nanotechnology and the development of tools and techniques that enabled the investigation of systems at the nanoscale brought with them many fascinating observations of phenomena that could only be explained through quantum mechanics, first theoretically deduced decades previously. At the nanoscale, quantum confinement effects dominate the electrical and optical properties of systems. They also render new opportunities for manipulating the response of systems. For example, a better understanding of these systems has enabled the rapid development of quantum dots with precisely determined properties, which can be exploited in a range of applications from medical imaging and photovoltaic solar cells to quantum computation, a radically new information technology being currently developed in many labs worldwide. As the first ever academic journal in nanotechnology, {\\it Nanotechnology} has been the forum for papers detailing progress of the science through extremely exciting times. In the early years of the journal, the investigation of electron spin led to the formulation

  19. Poorly studied phenomena in geoelectrics

    Directory of Open Access Journals (Sweden)

    В. С. Могилатов

    2016-12-01

    Full Text Available Undoubtedly, modern geoelectric technologies emerge in the result of the development of traditional approaches and techniques. However of more interest is the appearance of completely new technologies based on new effects and new models of interaction of geological medium and electromagnetic field. The author does not commit to indicate principally new directions, but only wants to discuss some poorly known facts from the theory and practice of geoelectrics. The outcome of this study could be considered attracting the attention of experts to non-traditional signals in geoelectrics. The reviewed phenomena of interest, not fully implemented in practice in the author’s opinion, are field split into two polarizations: transverse electric (the ТЕ-field and transverse magnetic (the ТМ-field, then some poorly known properties of ТМ-field, the role of bias currents, the anisotropy of horizontal resistances, the role of geomagnetic field in geoelectric sounding, the unique resolution of CSEM (Controlled Source Electro-Magnetic techniques at sea.

  20. Understanding empathy and related phenomena.

    Science.gov (United States)

    Shamasundar, C

    1999-01-01

    Over a period of time, the author arrived at a few tentative postulates concerning empathy and related processes based on some of his experiences and observations. The central theme of these postulates is, firstly, that interpersonal interaction is an interaction of the personal-space fields. Secondly, empathy, therapeutic benefit, and the professional stress are all related to the same process of interpersonal interaction. This interaction takes place as an enmeshment of personal spaces of the interacting individuals, and involves transfer of a wide range of information in the affective, cognitive, and other areas. This is because the personal spaces have fieldlike qualities analogous to what Kurt Lewin described. Thus, such phenomena as empathy, therapeutic benefit, professional stress are all consequences of the same process. It is possible to substantiate these postulates by diverse evidences in the published literature. The natural consequences of such an interpersonal interaction are empathic understanding, transfer of mood states (like hope, distress or expectancy), affective states (like anxiety, sadness, anger or hostility), ideas, images and even attitudes and values, etc. This phenomenon of transfer can explain such processes as therapeutic benefit in individual and group settings, professional stress, shared delusions, and even experimenter bias. Whether one becomes aware of such transferred information or not depends upon the intent and sensitivity of the participants.

  1. Conductance phenomena in microcrystalline cellulose

    Science.gov (United States)

    Nilsson, M.

    2006-02-01

    We have investigated the conduction phenomena in compacted tablets of cellulose with varying relative humidity (RH) with techniques such as Low Frequency Dielectric Spectroscopy (LFDS) and Transient Current (TC) at room temperature. Two exponential decaying regions in the transient current measurements indicate two ionic species contributing to the conduction mechanism. A high power-law exponent of 9 for the conductance with moisture content has been found. The mobility initially decreases with RH up to monolayer coverage, and further water vapor increases the mobility, indicating a blocking of available positions for the charge carrier ions. When the amount of water molecules present in the tablet increases one order of magnitude, the number of charge carriers increases 5-6 orders of magnitude, suggesting a transition from a power-law increase to a linear effective medium theory for the conduction. The charge carrier dependence on RH suggests that a percolating network of water molecules adsorbed to 6-OH units on the cellulose chain span through the sample. The conductivity mechanisms in cellulose are still not clear.

  2. Modeling temperature and moisture fields in conditioned spaces using zonal approach, including sorption phenomena in buildings materials; Modelisation thermo-hydro-aeraulique des locaux climatises selon l'approche zonale (prise en compte des phenomenes de sorption d'humidite)

    Energy Technology Data Exchange (ETDEWEB)

    Cordeiro Mendoca, K.

    2004-05-15

    Building simulation models represent in our days an important tool for building conception and performance analysis. Although moisture interacts in many ways with the whole building affecting therefore its behavior, frequently these models neglects the interactions between them. In addition, in most of them, indoor air conditions are considered uniform, which is a non-realistic assumption in conditioned spaces. In this work, a model to predict temperature and moisture fields in conditioned spaces, using zonal approach, is proposed. This method is based in dividing spatially a room in a relative small number of zones, typically on the order of tens to hundreds, where the state variables of air are considered uniform, with the exception of pressure that varies hydrostatically. While not as fine-grained as CFD simulation, zonal models do give useful information about temperature and moisture distributions that is important in comfort analysis. The proposed model was structured in three groups of sub-models representing the three building domains: indoor air, envelope and HVAC system. The indoor air sub-model is related to the indoor air space, where airflow speed can be considered weak. The envelope sub-model is related to the radiation exchanges between envelope and its neighborhood, and to the simultaneous heat and mass transfers across the envelope material. This latest can be represented by four sub-models of different complexity levels, with two of them taking into account moisture adsorption and desorption by building materials. Concerning to the HVAC system model, it refers to the whole system that means equipment, control and specific airflow from equipment. All sub-models were coupled into a modular simulation environment, SPARK, well-adapted to compare different models. The applicability of the proposed model is shown by two examples. The first one shows the importance of considering moisture sorption phenomena in the prediction of indoor air conditions

  3. Efficacy of humidity retention bags for the reduced adsorption and improved cleaning of tissue proteins including prion-associated amyloid to surgical stainless steel surfaces.

    Science.gov (United States)

    Secker, T J; Pinchin, H E; Hervé, R C; Keevil, C W

    2015-01-01

    Increasing drying time adversely affects attachment of tissue proteins and prion-associated amyloid to surgical stainless steel, and reduces the efficacy of commercial cleaning chemistries. This study tested the efficacy of commercial humidity retention bags to reduce biofouling on surgical stainless steel and to improve subsequent cleaning. Surgical stainless steel surfaces were contaminated with ME7-infected brain homogenates and left to dry for 15 to 1,440 min either in air, in dry polythene bags or within humidity retention bags. Residual contamination pre/post cleaning was analysed using Thioflavin T/SYPRO Ruby dual staining and microscope analysis. An increase in biofouling was observed with increased drying time in air or in sealed dry bags. Humidity retention bags kept both protein and prion-associated amyloid minimal across the drying times both pre- and post-cleaning. Therefore, humidity bags demonstrate a cheap, easy to implement solution to improve surgical instrument reprocessing and to potentially reduce associated hospital acquired infections.

  4. Renner-Teller effect in linear tetra-atomic molecules. I. Variational method including couplings between all degrees of freedom on six-dimensional potential energy surfaces

    Science.gov (United States)

    Jutier, L.; Léonard, C.; Gatti, F.

    2009-04-01

    For electronically degenerate states of linear tetra-atomic molecules, a new method is developed for the variational treatment of the Renner-Teller and spin-orbit couplings. The approach takes into account all rotational and vibrational degrees of freedom, the dominant couplings between the corresponding angular momenta as well as the couplings with the electronic and electron spin angular momenta. The complete rovibrational kinetic energy operator is expressed in Jacobi coordinates, where the rovibrational angular momenta ĴN have been replaced by L̂ez-Ŝ and the spin-orbit coupling has been described by the perturbative term ASO×L̂ezṡŜz. Attention has been paid on the electronic wave functions, which require additional phase for linear tetra-atomic molecules. Our implemented rovibrational basis functions and the integration of the different parts of the total Hamiltonian operator are described. This new variational approach is tested on the electronic ground state X Π2u of HCCH+ for which new six-dimensional potential energy surfaces have been computed using the internally contracted multireference configuration interaction method and the cc-pV5Z basis set. The calculated rovibronic energies and their comparisons with previous theoretical and experimental works are presented in the next paper.

  5. Development of symmetric composition-gradient materials including hard particles in its surface layer; Hyosobu ni koshitsu ryushi wo fukumu taishogata sosei keisha zairyo no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

    Development of new materials with both thermal resistance and thermal shock resistance was studied on the basis of symmetric ceramics/metal/ceramics gradient composition. Al2O3/TiC/Ni/TiC/Al2O3 was used as material model of basic composition, and the system was selected where WC-Co system alloy hard particles were dispersed into the Al2O3 ceramic surface layer. The layered material was sintered in N2 gas atmosphere by SHS/HIP method using exothermic caused by nitriding reaction. Since cracks were generated in some specimens of 5-layer structure, improved specimens of 7-layer structure were prepared. To examine the effect of a particle size on toughness, WC-Co system alloy specimens with different particle sizes were also prepared. As a result, no cracks were found, and residual stress and fracture toughness were affected by particle size. In addition, the following were studied: technique of mass production, observation of fine structures, analysis of thermal stress, thermal shock resistance, and friction and abrasion characteristics. 13 refs., 65 figs., 15 tabs.

  6. Using Spatial Gradients to Model Localization Phenomena

    Energy Technology Data Exchange (ETDEWEB)

    D.J.Bammann; D.Mosher; D.A.Hughes; N.R.Moody; P.R.Dawson

    1999-07-01

    We present the final report on a Laboratory-Directed Research and Development project, Using Spatial Gradients to Model Localization Phenomena, performed during the fiscal years 1996 through 1998. The project focused on including spatial gradients in the temporal evolution equations of the state variables that describe hardening in metal plasticity models. The motivation was to investigate the numerical aspects associated with post-bifurcation mesh dependent finite element solutions in problems involving damage or crack propagation as well as problems in which strain Localizations occur. The addition of the spatial gradients introduces a mathematical length scale that eliminates the mesh dependency of the solution. In addition, new experimental techniques were developed to identify the physical mechanism associated with the numerical length scale.

  7. Teaching wave phenomena via biophysical applications

    Science.gov (United States)

    Reich, Daniel; Robbins, Mark; Leheny, Robert; Wonnell, Steven

    2014-03-01

    Over the past several years we have developed a two-semester second-year physics course sequence for students in the biosciences, tailored in part to the needs of undergraduate biophysics majors. One semester, ``Biological Physics,'' is based on the book of that name by P. Nelson. This talk will focus largely on the other semester, ``Wave Phenomena with Biophysical Applications,'' where we provide a novel introduction to the physics of waves, primarily through the study of experimental probes used in the biosciences that depend on the interaction of electromagnetic radiation with matter. Topic covered include: Fourier analysis, sound and hearing, diffraction - culminating in an analysis of x-ray fiber diffraction and its use in the determination of the structure of DNA - geometrical and physical optics, the physics of modern light microscopy, NMR and MRI. Laboratory exercises tailored to this course will also be described.

  8. Heat Transfer Phenomena of Supercritical Fluids

    Energy Technology Data Exchange (ETDEWEB)

    Krau, Carmen Isabella; Kuhn, Dietmar; Schulenberg, Thomas [Forschungszentrum Karlsruhe, Institute for Nuclear and Energy Technologies, 76021 Karlsruhe (Germany)

    2008-07-01

    In concepts for supercritical water cooled reactors, the reactor core is cooled and moderated by water at supercritical pressures. The significant temperature dependence of the fluid properties of water requires an exact knowledge of the heat transfer mechanism to avoid fuel pin damages. Near the pseudo-critical point a deterioration of heat transfer might happen. Processes, that take place in this case, are not fully understood and are due to be examined systematically. In this paper a general overview on the properties of supercritical water is given, experimental observations of different authors will be reviewed in order to identify heat transfer phenomena and onset of occurrence. The conceptional design of a test rig to investigate heat transfer in the boundary layer will be discussed. Both, water and carbon dioxide, may serve as operating fluids. The loop, including instrumentation and safety devices, is shown and suitable measuring methods are described. (authors)

  9. Heat Transfer Phenomena of Supercritical Fluids

    International Nuclear Information System (INIS)

    Krau, Carmen Isabella; Kuhn, Dietmar; Schulenberg, Thomas

    2008-01-01

    In concepts for supercritical water cooled reactors, the reactor core is cooled and moderated by water at supercritical pressures. The significant temperature dependence of the fluid properties of water requires an exact knowledge of the heat transfer mechanism to avoid fuel pin damages. Near the pseudo-critical point a deterioration of heat transfer might happen. Processes, that take place in this case, are not fully understood and are due to be examined systematically. In this paper a general overview on the properties of supercritical water is given, experimental observations of different authors will be reviewed in order to identify heat transfer phenomena and onset of occurrence. The conceptional design of a test rig to investigate heat transfer in the boundary layer will be discussed. Both, water and carbon dioxide, may serve as operating fluids. The loop, including instrumentation and safety devices, is shown and suitable measuring methods are described. (authors)

  10. Novel nuclear phenomena in quantum chromodynamics

    International Nuclear Information System (INIS)

    Brodsky, S.J.

    1987-08-01

    Many of the key issues in understanding quantum chromodynamics involve processes in nuclear targets at intermediate energies. A range of hadronic and nuclear phenomena-exclusive processes, color transparency, hidden color degrees of freedom in nuclei, reduced nuclear amplitudes, jet coalescence, formation zone effects, hadron helicity selection rules, spin correlations, higher twist effects, and nuclear diffraction were discussed as tools for probing hadron structure and the propagation of quark and gluon jets in nuclei. Several areas were also reviewed where there has been significant theoretical progress determining the form of hadron and nuclear wave functions, including QCD sum rules, lattice gauge theory, and discretized light-cone quantization. A possible interpretation was also discussed of the large spin correlation A/sub NN/ in proton-proton scattering, and how relate this effect to an energy and angular dependence of color transparency in nuclei. 76 refs., 24 figs

  11. Noise-driven phenomena in hysteretic systems

    CERN Document Server

    Dimian, Mihai

    2014-01-01

    Noise-Driven Phenomena in Hysteretic Systems provides a general approach to nonlinear systems with hysteresis driven by noisy inputs, which leads to a unitary framework for the analysis of various stochastic aspects of hysteresis. This book includes integral, differential and algebraic models that are used to describe scalar and vector hysteretic nonlinearities originating from various areas of science and engineering. The universality of the authors approach is also reflected by the diversity of the models used to portray the input noise, from the classical Gaussian white noise to its impulsive forms, often encountered in economics and biological systems, and pink noise, ubiquitous in multi-stable electronic systems. The book is accompanied by HysterSoft© - a robust simulation environment designed to perform complex hysteresis modeling – that can be used by the reader to reproduce many of the results presented in the book as well as to research both disruptive and constructive effects of noise in hysteret...

  12. Determination of drugs in surface water and wastewater samples by liquid chromatography-mass spectrometry: Methods and preliminary results including toxicity studies with Vibrio fischeri

    Science.gov (United States)

    Farre, M.; Ferrer, I.; Ginebreda, A.; Figueras, M.; Olivella, L.; Tirapu, L.; Vilanova, M.; Barcelo, D.

    2001-01-01

    In the present work a combined analytical method involving toxicity and liquid chromatography-electrospray ionization-mass spectrometry (LC-ESI-MS) was developed for the determination of pharmaceutical compounds in water samples. The drugs investigated were the analgesics: ibuprofen, ketoprofen, naproxen, and diclofenac, the decomposition product of the acetyl salicylic acid: salicylic acid and one lipid lowering agent, gemfibrozil. The selected compounds are acidic substances, very polar and all of them are analgesic compounds that can be purchased without medical prescription. The developed protocol consisted, first of all, on the use Microtox?? and ToxAlert??100 toxicity tests with Vibrio fischeri for the different pharmaceutical drugs. The 50% effective concentration (EC50) values and the toxicity units (TU) were determined for every compound using both systems. Sample enrichment of water samples was achieved by solid-phase extraction procedure (SPE), using the Merck LiChrolut?? EN cartridges followed by LC-ESI-MS. Average recoveries loading 1 l of samples with pH=2 varied from 69 to 91% and the detection limits in the range of 15-56 ng/l. The developed method was applied to real samples from wastewater and surface-river waters of Catalonia (north-east of Spain). One batch of samples was analyzed in parallel also by High Resolution Gas Chromatography coupled with Mass Spectrometry (HRGC-MS) and the results have been compared with the LC-ESI-MS method developed in this work. ?? 2001 Elsevier Science B.V. All rights reserved.

  13. Drone Use in Monioring Open Ocean Surface Debris, Including Paired Manta and Tucker Trawls for Relateing Sea State to Vertical Debris Distribution

    Science.gov (United States)

    Lattin, G.

    2016-02-01

    Monitoring debris at sea presents challenges not found in beach or riverine habitats, and is typically done with trawl nets of various apertures and mesh sizes, which limits the size of debris captured and the area surveyed. To partially overcome these limitations in monitoring floating debris, a Quadcopter drone with video transmitting and recording capabilities was deployed at the beginning and the end of manta trawl transects within the North Pacific Subtropical Gyre's eastern convergence zone. Subsurface tucker trawls at 10 meters were conducted at the same time as the manta trawls, in order to assess the effect of sea state on debris dispersal. Trawls were conducted on an 11 station grid used repeatedly since 1999. For drone observations, the operator and observer were stationed on the mother ship while two researchers collected observed debris using a rigid inflatable boat (RIB). The drone was flown to a distance of approximately 100 meters from the vessel in a zigzag or circular search pattern. Here we examine issues arising from drone deployment during the survey: 1) relation of area surveyed by drone to volume of water passing through trawl; 2) retrieval of drone-spotted and associated RIB spotted debris. 3) integrating post- flight image analysis into retrieved debris quantification; and 4) factors limiting drone effectiveness at sea. During the survey, debris too large for the manta trawl was spotted by the drone, and significant debris not observed using the drone was recovered by the RIB. The combination of drone sightings, RIB retrieval, and post flight image analysis leads to improved monitoring of debris at sea. We also examine the issue of the distribution of floating debris during sea states varying from 0-5 by comparing quantities from surface manta trawls to the tucker trawls at a nominal depth of 10 meters.

  14. [Paraneoplastic phenomena in patients with a thymoma].

    Science.gov (United States)

    Strijbos, Ellen; Pomp, Jacqueline; Gilhuis, H Jacobus

    2013-01-01

    A thymoma arises from the epithelial cells of the thymus. Local tumour growth may cause symptoms like coughing, dyspnoea or chest pain. Paraneoplastic phenomena can also occur in patients with a thymoma; myasthenia gravis is a well-known example. Other neurological, dermatological, cardiological and haematological disorders are not always recognised as being paraneoplastic phenomena. There is no clear relationship between tumour activity and the clinical course of paraneoplastic phenomena. The three cases in this article illustrate how the clinical presentation of these phenomena can vary.

  15. Simulation of Magnetic Phenomena at Realistic Interfaces

    KAUST Repository

    Grytsyuk, Sergiy

    2016-02-04

    splitting at non-magnetic 5d(4d) and ferromagnetic 3d-metal interfaces and their dependences on aspects such as interdiffusion, surface oxidation, thin film thickness and lattice mismatch. We find that changes of structural details strongly alter the electronic states, which in turn influences the magnetic properties and phenomena related to spin-orbit coupling. Since the interfaces studied in this work have complex electronic structures, a computational approach has been developed in order to estimate the strength of the Rashba band splitting below and at the Fermi level. We apply this approach to the interfaces between a Co monolayer and 4d (Tc, Ru, Rh, Pd, and Ag) or 5d (Re, Os, Ir, Pt, and Au) transition metals and find a clear correlation between the overall size of the band splitting and the charge transfer between the d-orbitals at the interface. Furthermore, we show that the spin splitting at the Fermi surface scales with the induced orbital moment weighted by the strength of the spin-orbit coupling.

  16. Occurrence and Ecotoxicological Effects of Free, Conjugated, and Halogenated Steroids Including 17α-Hydroxypregnanolone and Pregnanediol in Swiss Wastewater and Surface Water.

    Science.gov (United States)

    Zhang, Kun; Zhao, Yanbin; Fent, Karl

    2017-06-06

    Apart from estrogens, the occurrence and ecotoxicity of steroids in aquatic environments is poorly known. Here, we analyzed 33 steroids, including estrogens, androgens, progestins, and glucocorticoids, in hospital wastewaters, river water, and municipal wastewater treatment plant (WTP) influents and effluents at different sites in Switzerland. In addition, wastewater from different treatment steps of two WTPs with advanced treatment, such as ozonation or pulverized activated carbon, were analyzed to study the steroid's behavior during treatment. Considerable levels of different steroids occurred in hospital and raw municipal wastewater, but they were low (lower than 1 ng/L) or below the detection level in effluents of WTPs and river water. In WTP influents, estrogens (estrone, 17β-estradiol, and estriol), androgens (androstenedione, androsterone, trans-androsterone, and testosterone), progestins and metabolites (progesterone, medroxyprogesterone acetate, megestrol acetate, mifepristone, pregnanediol, 17α-hydroxypregnanolone, 17α-hydroxyprogesterone, and 21α-hydroxyprogesterone) were detected and removed effectively during biological treatment. Ozonation further removed the steroids. Exposure of zebrafish embryos demonstrated negligible effects of pregnanediol and 17α-hydroxypregnanolone, while mixtures that mimic wastewater and river water composition affected embryo development and led to the alteration of steroidogenesis gene transcripts at nanogram per liter concentrations. Although steroid concentrations are low in Swiss rivers, the possibility of additive effects may be of concern.

  17. APRI-6. Accident Phenomena of Risk Importance

    International Nuclear Information System (INIS)

    Garis, Ninos; Ljung, J

    2009-06-01

    Since the early 1980s, nuclear power utilities in Sweden and the Swedish Radiation Safety Authority (SSM) collaborate on the research in severe reactor accidents. In the beginning focus was mostly on strengthening protection against environmental impacts after a severe reactor accident, for example by develop systems for the filtered relief of the reactor containment. Since the early 90s, this focus has shifted to the phenomenological issues of risk-dominant significance. During the years 2006-2008, the partnership continued in the research project APRI-6. The aim was to show whether the solutions adopted in the Swedish strategy for incident management provides adequate protection for the environment. This is done by studying important phenomena in the core melt estimating the amount of radioactivity that can be released to the atmosphere in a severe accident. To achieve these objectives the research has included monitoring of international research on severe accidents and evaluation of results and continued support for research of severe accidents at the Royal Inst. of Technology (KTH) and Chalmers University. The follow-up of international research has promoted the exchange of knowledge and experience and has given access to a wealth of information on various phenomena relevant to events in severe accidents. The continued support to KTH has provided increased knowledge about the possibility of cooling the molten core in the reactor tank and the processes associated with coolability in the confinement and about steam explosions. Support for Chalmers has increased knowledge of the accident chemistry, mainly the behavior of iodine and ruthenium in the containment after an accident

  18. APRI-6. Accident Phenomena of Risk Importance

    Energy Technology Data Exchange (ETDEWEB)

    Garis, Ninos; Ljung, J (eds.) (Swedish Radiation Safety Authority, Stockholm (Sweden)); Agrenius, Lennart (ed.) (Agrenius Ingenjoersbyraa AB, Stockholm (Sweden))

    2009-06-15

    Since the early 1980s, nuclear power utilities in Sweden and the Swedish Radiation Safety Authority (SSM) collaborate on the research in severe reactor accidents. In the beginning focus was mostly on strengthening protection against environmental impacts after a severe reactor accident, for example by develop systems for the filtered relief of the reactor containment. Since the early 90s, this focus has shifted to the phenomenological issues of risk-dominant significance. During the years 2006-2008, the partnership continued in the research project APRI-6. The aim was to show whether the solutions adopted in the Swedish strategy for incident management provides adequate protection for the environment. This is done by studying important phenomena in the core melt estimating the amount of radioactivity that can be released to the atmosphere in a severe accident. To achieve these objectives the research has included monitoring of international research on severe accidents and evaluation of results and continued support for research of severe accidents at the Royal Inst. of Technology (KTH) and Chalmers University. The follow-up of international research has promoted the exchange of knowledge and experience and has given access to a wealth of information on various phenomena relevant to events in severe accidents. The continued support to KTH has provided increased knowledge about the possibility of cooling the molten core in the reactor tank and the processes associated with coolability in the confinement and about steam explosions. Support for Chalmers has increased knowledge of the accident chemistry, mainly the behavior of iodine and ruthenium in the containment after an accident.

  19. Skin physiology in men and women: in vivo evaluation of 300 people including TEWL, SC hydration, sebum content and skin surface pH.

    Science.gov (United States)

    Luebberding, S; Krueger, N; Kerscher, M

    2013-10-01

    Evidence is given that differences in skin physiological properties exist between men and women. However, despite an assessable number of available publications, the results are still inconsistent. Therefore, the aim of this clinical study is the first systematic assessment of gender-related differences in skin physiology in men and women, with a special focus on changes over lifetime. A total of 300 healthy male and female subjects (20-74 years) were selected following strict criteria including age, sun behaviour or smoking habits. TEWL, hydration level, sebum production and pH value were measured with worldwide-acknowledged biophysical measuring methods at forehead, cheek, neck, volar forearm and dorsum of hand. Until the age of 50 men's TEWL is significantly lower than the water loss of women of the same age, regardless of the location. With ageing gender-related differences in TEWL assimilate. Young men show higher SC hydration in comparison with women. But, whereas SC hydration is stable or even increasing in women over lifetime, the skin hydration in men is progressively decreasing, beginning at the age of 40. Sebum production in male skin is always higher and stays stable with increasing age, whereas sebum production in women progressively decreases over lifetime. Across all localizations and age groups, the pH value in men is below 5, the pH value of female subjects is, aside from limited expectations, higher than 5. Skin physiological distinctions between the sexes exist and are particularly remarkable with regard to sebum production and pH value. © 2013 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

  20. A Connection between Transport Phenomena and Thermodynamics

    Science.gov (United States)

    Swaney, Ross; Bird, R. Byron

    2017-01-01

    Although students take courses in transport phenomena and thermodynamics, they probably do not ask whether these two subjects are related. Here we give an answer to that question. Specifically we give relationships between the equations of change for total energy, internal energy, and entropy of transport phenomena and key equations of equilibrium…

  1. Nonlinear dynamical phenomena in liquid crystals

    International Nuclear Information System (INIS)

    Wang, X.Y.; Sun, Z.M.

    1988-09-01

    Because of the existence of the orientational order and anisotropy in liquid crystals, strong nonlinear phenomena and singular behaviors, such as solitary wave, transient periodic structure, chaos, fractal and viscous fingering, can be excited by a very small disturbance. These phenomena and behaviors are in connection with physics, biology and mathematics. 12 refs, 6 figs

  2. Electrical breakdown phenomena of dielectric elastomers

    DEFF Research Database (Denmark)

    Mateiu, Ramona Valentina; Yu, Liyun; Skov, Anne Ladegaard

    2017-01-01

    years. However, optimization with respect to the dielectric permittivity solely may lead to other problematic phenomena such as premature electrical breakdown. In this work, we investigate the electrical breakdown phenomena of various types of permittivity-enhanced silicone elastomers. Two types...

  3. RELAP5-3D code validation for RBMK phenomena

    International Nuclear Information System (INIS)

    Fisher, J.E.

    1999-01-01

    The RELAP5-3D thermal-hydraulic code was assessed against Japanese Safety Experiment Loop (SEL) and Heat Transfer Loop (HTL) tests. These tests were chosen because the phenomena present are applicable to analyses of Russian RBMK reactor designs. The assessment cases included parallel channel flow fluctuation tests at reduced and normal water levels, a channel inlet pipe rupture test, and a high power, density wave oscillation test. The results showed that RELAP5-3D has the capability to adequately represent these RBMK-related phenomena

  4. Mesoscopic Modeling of Multiphysicochemical Transport Phenomena in Porous Media

    Directory of Open Access Journals (Sweden)

    Qinjun Kang

    2010-01-01

    Full Text Available We present our recent progress on mesoscopic modeling of multiphysicochemical transport phenomena in porous media based on the lattice Boltzmann method. Simulation examples include injection of CO2-saturated brine into a limestone rock, two-phase behavior and flooding phenomena in polymer electrolyte fuel cells, and electroosmosis in homogeneously charged porous media. It is shown that the lattice Boltzmann method can account for multiple, coupled physicochemical processes in these systems and can shed some light on the underlying physics occurring at the fundamental scale. Therefore, it can be a potential powerful numerical tool to analyze multiphysicochemical processes in various energy, earth, and environmental systems.

  5. The Center for Natural Phenomena Engineering (CNPE), 1990--1991

    Energy Technology Data Exchange (ETDEWEB)

    None

    1992-07-01

    The Center for Natural Phenomena Engineering (CNPE) was established to provide a natural phenomena (NP) engineering oversight role within Martin Marietta Energy Systems, Inc. (MMES). In this oversight role CNPE`s goals are to provide coordination and direction of activities related to earthquake and other natural phenomena engineering, including development of hazard definition, development of design criteria, conducting new facility design, development and conducting of testing, performance of analysis and vulnerability studies, development of analysis methodology, and provision of support for preparation of safety analysis reports for the five MMES sites. In conducting these activities it is CNPE`s goal to implement the elements of Total Quality Management (TQM) in a cost-effective manner, providing its customers with a quality product. This report describes 1990--1991 activities.

  6. The Center for Natural Phenomena Engineering (CNPE), 1990--1991

    International Nuclear Information System (INIS)

    1992-07-01

    The Center for Natural Phenomena Engineering (CNPE) was established to provide a natural phenomena (NP) engineering oversight role within Martin Marietta Energy Systems, Inc. (MMES). In this oversight role CNPE's goals are to provide coordination and direction of activities related to earthquake and other natural phenomena engineering, including development of hazard definition, development of design criteria, conducting new facility design, development and conducting of testing, performance of analysis and vulnerability studies, development of analysis methodology, and provision of support for preparation of safety analysis reports for the five MMES sites. In conducting these activities it is CNPE's goal to implement the elements of Total Quality Management (TQM) in a cost-effective manner, providing its customers with a quality product. This report describes 1990--1991 activities

  7. Rotary kilns - transport phenomena and transport processes

    Energy Technology Data Exchange (ETDEWEB)

    Boateng, A.

    2008-01-15

    Rotary kilns and rotating industrial drying ovens are used for a wide variety of applications including processing raw minerals and feedstocks as well as heat-treating hazardous wastes. They are particularly critical in the manufacture of Portland cement. Their design and operation is critical to their efficient usage, which if done incorrectly can result in improperly treated materials and excessive, high fuel costs. This book treats all engineering aspects of rotary kilns, including thermal and fluid principles involved in their operation, as well as how to properly design an engineering process that uses rotary kilns. Chapter 1: The Rotary Kiln Evolution and Phenomenon Chapter 2: Basic Description of Rotary Kiln Operation Chapter 3: Freeboard Aerodynamic Phenomena Chapter 4: Granular Flows in Rotary Kilns Chapter 5: Mixing and Segregation Chapter 6: Combustion and Flame - includes section on types of fuels used in rotary kilns, coal types, ranking and analysis, petroleum coke combustion, scrap tire combustion, pulverized fuel (coal/coke) firing in kilns, pulverized fuel delivery and firing systems. Chapter 7: Freeboard Heat Transfer Chapter 8: Heat Transfer Processes in the Rotary Kiln Bed Chapter 9: Mass and Energy Balance Chapter 10: Rotary Kiln Minerals Process Applications.

  8. Atomic phenomena in dense plasmas

    International Nuclear Information System (INIS)

    Weisheit, J.C.

    1981-03-01

    The following chapters are included: (1) the plasma environment, (2) perturbations of atomic structure, (3) perturbations of atomic collisions, (4) formation of spectral lines, and (5) dielectronic recombination

  9. Equilibrium and Non-Equilibrium Condensation Phenomena in Tuneable 3D and 2D Bose Gases

    Science.gov (United States)

    2016-04-01

    AFRL-AFOSR-UK-TR-2016-0009 Equilibrium and non- equilibrium condensation phenomena in tuneable 3D and 2D Bose gases Zoran Hadzibabic THE CHANCELLOR...31-Aug-2015 4. TITLE AND SUBTITLE Equilibrium and non- equilibrium condensation phenomena in tuneable 3D and 2D Bose gases 5a. CONTRACT NUMBER... equilibrium and non- equilibrium many-body phenomena, trapping ultracold atomic gases in different geometries including both 3 and 2 spatial dimensions

  10. Global-Change-Induced Disturbances of Water-Related Phenomena - The European Perspective

    OpenAIRE

    Falkenmark, M.

    1989-01-01

    Impact of global change on human society will first be felt through disturbances of water-related phenomena. Traditionally, land use discussions only seldom reflect water phenomena. Present methods may therefore be poor tools in addressing the impact of global change. This report takes an alternative approach to land use by addressing a number of water-related phenomena from the perspective of their relation to land use and land-use-related societal activities. Such activities include both th...

  11. Yield Surface for Bars Including Warping Restraint.

    Science.gov (United States)

    1982-02-01

    Kreyenhagen Stragetic Air Command Columbia University ATTN: NRI-STINFO Library ATTN: H. Bleich ATTN: F. Dimaggio DEPARTMENT OF ENERGY University of Denver...TIC-Library SRI International ATTN: G. Abrahamson M & T Company ATTN: W. Wilkinson ATTN: D. McNaight ATTN: A. Florence Management Science Associates

  12. Experimental studies of diffractive phenomena

    International Nuclear Information System (INIS)

    Cool, R.L.

    1984-01-01

    The coherent inelastic scattering process, usually called inclusive diffraction dissociation, is discussed. Topics include: t and M/sub x/ dependence, factorization, finite mass sum rule and charged particle multiplicities. 6 references, 14 figures

  13. Interface-Induced Phenomena in Magnetism.

    Science.gov (United States)

    Hellman, Frances; Hoffmann, Axel; Tserkovnyak, Yaroslav; Beach, Geoffrey S D; Fullerton, Eric E; Leighton, Chris; MacDonald, Allan H; Ralph, Daniel C; Arena, Dario A; Dürr, Hermann A; Fischer, Peter; Grollier, Julie; Heremans, Joseph P; Jungwirth, Tomas; Kimel, Alexey V; Koopmans, Bert; Krivorotov, Ilya N; May, Steven J; Petford-Long, Amanda K; Rondinelli, James M; Samarth, Nitin; Schuller, Ivan K; Slavin, Andrei N; Stiles, Mark D; Tchernyshyov, Oleg; Thiaville, André; Zink, Barry L

    2017-01-01

    This article reviews static and dynamic interfacial effects in magnetism, focusing on interfacially-driven magnetic effects and phenomena associated with spin-orbit coupling and intrinsic symmetry breaking at interfaces. It provides a historical background and literature survey, but focuses on recent progress, identifying the most exciting new scientific results and pointing to promising future research directions. It starts with an introduction and overview of how basic magnetic properties are affected by interfaces, then turns to a discussion of charge and spin transport through and near interfaces and how these can be used to control the properties of the magnetic layer. Important concepts include spin accumulation, spin currents, spin transfer torque, and spin pumping. An overview is provided to the current state of knowledge and existing review literature on interfacial effects such as exchange bias, exchange spring magnets, spin Hall effect, oxide heterostructures, and topological insulators. The article highlights recent discoveries of interface-induced magnetism and non-collinear spin textures, non-linear dynamics including spin torque transfer and magnetization reversal induced by interfaces, and interfacial effects in ultrafast magnetization processes.

  14. Echo phenomena in a plasma

    International Nuclear Information System (INIS)

    Pavlenko, V.N.

    1983-01-01

    The mechanism of echo phenomenon in different plasma media: laboratory and cosmic plasma, metals and semiconductors is analyzed to get a more comprehensive idea on collective processes in a plasma and for practical applications in radiophysics and plasma diagnostics. The echo phenomenon permitted to confirm a reversible nature of the Landau damping, to prove the fact that the information on perturbation is conserved in a plasma (as non-damping oscillations of the distribution function) even after disappearing of the macroscopic field. The dependence of the diffusion coefficient on the velocity is measured, microturbulences in a plasma are investigated. New ways of the plasma wave conversion are suggested, as well as ''lightning'' of super-critical plasma layers and regions of plasma non-transparency. Prospective advantages of using echo for studying the mechanisms of charged particle interaction with the surface bounding a plasma are revealed

  15. Nonlinear Photonics and Novel Optical Phenomena

    CERN Document Server

    Morandotti, Roberto

    2012-01-01

    Nonlinear Photonics and Novel Optical Phenomena contains contributed chapters from leading experts in nonlinear optics and photonics, and provides a comprehensive survey of fundamental concepts as well as hot topics in current research on nonlinear optical waves and related novel phenomena. The book covers self-accelerating airy beams, integrated photonics based on high index doped-silica glass, linear and nonlinear spatial beam dynamics in photonic lattices and waveguide arrays, polariton solitons and localized structures in semiconductor microcavities, terahertz waves, and other novel phenomena in different nanophotonic and optical systems.

  16. Computational transport phenomena for engineering analyses

    CERN Document Server

    Farmer, Richard C; Cheng, Gary C; Chen, Yen-Sen

    2009-01-01

    Computational Transport PhenomenaOverviewTransport PhenomenaAnalyzing Transport PhenomenaA Computational Tool: The CTP CodeVerification, Validation, and GeneralizationSummaryNomenclatureReferencesThe Equations of ChangeIntroductionDerivation of The Continuity EquationDerivation of The Species Continuity EquationDerivation of The Equation Of MotionDerivation of The General Energy EquationNon-Newtonian FluidsGeneral Property BalanceAnalytical and Approximate Solutions for the Equations of ChangeSummaryNomenclatureReferencesPhysical PropertiesOverviewReal-Fluid ThermodynamicsChemical Equilibrium

  17. Transient phenomena in electrical power systems

    CERN Document Server

    Venikov, V A; Higinbotham, W

    1964-01-01

    Electronics and Instrumentation, Volume 24: Transient Phenomena in Electrical Power Systems presents the methods for calculating the stability and the transient behavior of systems with forced excitation control. This book provides information pertinent to the analysis of transient phenomena in electro-mechanical systems.Organized into five chapters, this volume begins with an overview of the principal requirements in an excitation system. This text then explains the electromagnetic and electro-mechanical phenomena, taking into account the mutual action between the components of the system. Ot

  18. Black hole critical phenomena without black holes

    Indian Academy of Sciences (India)

    Black holes; numerical relativity; nonlinear sigma. Abstract. Studying the threshold of black hole formation via numerical evolution has led to the discovery of fascinating nonlinear phenomena. ... Theoretical and Computational Studies Group, Southampton College, Long Island University, Southampton, NY 11968, USA ...

  19. Periglacial phenomena affecting nuclear waste disposal

    Directory of Open Access Journals (Sweden)

    Niini, H.

    1997-12-01

    Full Text Available Slow future changes in astronomic phenomena seem to make it likely that Finland nll suffer several cold periods during the next 100,000 years. The paper analyses the characteristics of the periglacial factors that are most likely to influence the long-term safety of high-level radioactive waste disposed of in bedrock. These factors and their influences have been divided into two categories, natural and human. It is concluded that the basically natural phenomena are theoretically better understood than the complicated phenomena caused by man. It is therefore important in future research into periglacial phenomena, as well as of the disposal problem, to emphasize not only the proper applications of the results of natural sciences, but especially the effects and control of mankind's own present and future activities.

  20. Random walks, critical phenomena, and triviality in quantum field theory

    International Nuclear Information System (INIS)

    Fernandez, R.; Froehlich, J.; Sokal, A.D.

    1992-01-01

    The subject of this book is equilibrium statistical mechanics - in particular the theory of critical phenomena - and quantum field theory. A general review of the theory of critical phenomena in spin systems, field theories, and random-walk and random-surface models is presented. Among the more technical topics treated in this book, the central theme is the use of random-walk representations as a tool to derive correlation inequalities. The consequences of these inequalities for critical-exponent theory and the triviality question in quantum field theory are expounded in detail. The book contains some previously unpublished results. It addresses both the researcher and the graduate student in modern statistical mechanics and quantum field theory. (orig.)

  1. Evidence on Dropout Phenomena at Universities

    DEFF Research Database (Denmark)

    Larsen, Malene Rode; Sommersel, Hanna Bjørnøy; Larsen, Michael Søgaard

    This publication is an excerpt from the full technical report ‘Dropout Phenomena at Universities: What is Dropout? Why does Dropout Occur? What Can be Done by the Universities to Prevent or Reduce it? A systematic review’, which was completed in April 2013. The purpose of this excerpt is to prese...... the knowledge we have on dropout phenomena at European universities in a short, precise and comprehensible form to allow readers to orient themselves on the subject in a more readable manner....

  2. Infrared thermometry study of nanofluid pool boiling phenomena

    Science.gov (United States)

    2011-01-01

    Infrared thermometry was used to obtain first-of-a-kind, time- and space-resolved data for pool boiling phenomena in water-based nanofluids with diamond and silica nanoparticles at low concentration (boiling heat transfer (by as much as 50%) and an increase in the CHF (by as much as 100%). The bubble departure frequency and NSD were found to be lower in nanofluids compared with water for the same wall superheat. Furthermore, it was found that a porous layer of nanoparticles built up on the heater surface during nucleate boiling, which improved surface wettability compared with the water-boiled surfaces. Using the prevalent nucleate boiling models, it was possible to correlate this improved surface wettability to the experimentally observed reductions in the bubble departure frequency, NSD, and ultimately to the deterioration in the nucleate boiling heat transfer and the CHF enhancement. PMID:21711754

  3. Investigation of Surface Phenomena in Shocked Tin in Converging Geometry

    Energy Technology Data Exchange (ETDEWEB)

    Rousculp, Christopher L. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Oro, David Michael [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Griego, Jeffrey Randall [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Turchi, Peter John [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Reinovsky, Robert Emil [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Bradley, Joseph Thomas [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Cheng, Baolian [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Freeman, Matthew Stouten [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Patten, Austin Randall [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-04-14

    There is a great interest in RMI as source of ejecta from metal shells. Previous experiments have explored wavelength amplitude (kA) variation but they have a small range of drive pressures and are in planer geometry. Simulations, both MD and hydro, have explored RMI in planer geometry. The ejecta source model from RMI is an area of active algorithm and code development in ASCI-IC Lagrangian Applications Project. PHELIX offers precise, reproducible variable driver for Hydro and material physics diagnoses with proton radiography.

  4. Computer-Aided Discovery of Earth Surface Deformation Phenomena

    Data.gov (United States)

    National Aeronautics and Space Administration — Key Objectives: Earth scientists are struggling to extract new insights from a sea of large data sets originating from multiple instruments. The goal of this...

  5. Internal and Surface Phenomena in Heterogenous Metal Combustion

    Science.gov (United States)

    Dreizin, Edward L.

    1997-01-01

    The phenomenon of gas dissolution in burning metals was observed in recent metal combustion studies, but it could not be adequately explained by the traditional metal combustion models. The research reported here addresses heterogeneous metal combustion with emphasis on the processes of oxygen penetration inside burning metal and its influence on the metal combustion rate, temperature history, and disruptive burning. The unique feature of this work is the combination of the microgravity environment with a novel micro-arc generator of monodispersed metal droplets, ensuring repeatable formation and ignition of uniform metal droplets with a controllable initial temperature and velocity. Burning droplet temperature is measured in real time with a three wavelength pyrometer. In addition, particles are rapidly quenched at different combustion times, cross-sectioned, and examined using SEM-based techniques to retrieve the internal composition history of burning metal particles. When the initial velocity of a spherical particle is nearly zero, the microgravity environment makes it possible to study the flame structure, the development of flame nonsymmetry, and correlation of the flame shape with the heterogeneous combustion processes.

  6. Efferent feedback can explain many hearing phenomena

    Science.gov (United States)

    Holmes, W. Harvey; Flax, Matthew R.

    2015-12-01

    The mixed mode cochlear amplifier (MMCA) model was presented at the last Mechanics of Hearing workshop [4]. The MMCA consists principally of a nonlinear feedback loop formed when an efferent-controlled outer hair cell (OHC) is combined with the cochlear mechanics and the rest of the relevant neurobiology. Essential elements of this model are efferent control of the OHC motility and a delay in the feedback to the OHC. The input to the MMCA is the passive travelling wave. In the MMCA amplification is localized where both the neural and tuned mechanical systems meet in the Organ of Corti (OoC). The simplest model based on this idea is a nonlinear delay line resonator (DLR), which is mathematically described by a nonlinear delay-differential equation (DDE). This model predicts possible Hopf bifurcations and exhibits its most interesting behaviour when operating near a bifurcation. This contribution presents some simulation results using the DLR model. These show that various observed hearing phenomena can be accounted for by this model, at least qualitatively, including compression effects, two-tone suppression and some forms of otoacoustic emissions (OAEs).

  7. Two-Stage Modelling Of Random Phenomena

    Science.gov (United States)

    Barańska, Anna

    2015-12-01

    The main objective of this publication was to present a two-stage algorithm of modelling random phenomena, based on multidimensional function modelling, on the example of modelling the real estate market for the purpose of real estate valuation and estimation of model parameters of foundations vertical displacements. The first stage of the presented algorithm includes a selection of a suitable form of the function model. In the classical algorithms, based on function modelling, prediction of the dependent variable is its value obtained directly from the model. The better the model reflects a relationship between the independent variables and their effect on the dependent variable, the more reliable is the model value. In this paper, an algorithm has been proposed which comprises adjustment of the value obtained from the model with a random correction determined from the residuals of the model for these cases which, in a separate analysis, were considered to be the most similar to the object for which we want to model the dependent variable. The effect of applying the developed quantitative procedures for calculating the corrections and qualitative methods to assess the similarity on the final outcome of the prediction and its accuracy, was examined by statistical methods, mainly using appropriate parametric tests of significance. The idea of the presented algorithm has been designed so as to approximate the value of the dependent variable of the studied phenomenon to its value in reality and, at the same time, to have it "smoothed out" by a well fitted modelling function.

  8. Attractors, bifurcations, & chaos nonlinear phenomena in economics

    CERN Document Server

    Puu, Tönu

    2003-01-01

    The present book relies on various editions of my earlier book "Nonlinear Economic Dynamics", first published in 1989 in the Springer series "Lecture Notes in Economics and Mathematical Systems", and republished in three more, successively revised and expanded editions, as a Springer monograph, in 1991, 1993, and 1997, and in a Russian translation as "Nelineynaia Economicheskaia Dinamica". The first three editions were focused on applications. The last was differ­ ent, as it also included some chapters with mathematical background mate­ rial -ordinary differential equations and iterated maps -so as to make the book self-contained and suitable as a textbook for economics students of dynamical systems. To the same pedagogical purpose, the number of illus­ trations were expanded. The book published in 2000, with the title "A ttractors, Bifurcations, and Chaos -Nonlinear Phenomena in Economics", was so much changed, that the author felt it reasonable to give it a new title. There were two new math­ ematics ch...

  9. Thermal phenomenae in nuclear fuel rods

    International Nuclear Information System (INIS)

    Baigorria, Carlos.

    1983-12-01

    Thermal phenomenae occurring in a nuclear fuel rod under irradiation are studied. The most important parameters of either steady or transient thermal states are determined. The validity of applying the Fourier's approximation equations to these problems is also studied. A computer program TRANS is developed in order to study the transient cases. This program solves a system of coupled, non-linear partial differential equations, of parabolic type, in cylindrical coordinates with various boundary conditions. The benchmarking of the TRANS program is done by comparing its predictions with the analytical solution of some simplified transient cases. Complex transient cases such as those corresponding to characteristic reactor accidents are studied, in particular for typical pressurized heavy water reactor (PHWR) fuel rods, such as those of Atucha I. The Stefan problem emerging in the case of melting of the fuel element is solved. Qualitative differences between the classical Stefan problem, without inner sources, and that one, which includes sources are discussed. The MSA program, for solving the Stefan problem with inner sources is presented; and furthermore, it serves to predict thermal evolution, when the fuel element melts. Finally a model for fuel phase change under irradiation is developed. The model is based on the dimensional invariants of the percolation theory when applied to the connectivity of liquid spires nucleated around each fission fragment track. Suggestions for future research into the subject are also presented. (autor) [es

  10. Pattern formations and oscillatory phenomena

    CERN Document Server

    Kinoshita, Shuichi

    2013-01-01

    Patterns and their formations appear throughout nature, and are studied to analyze different problems in science and make predictions across a wide range of disciplines including biology, physics, mathematics, chemistry, material science, and nanoscience. With the emergence of nanoscience and the ability for researchers and scientists to study living systems at the biological level, pattern formation research has become even more essential. This book is an accessible first of its kind guide for scientists, researchers, engineers, and students who require a general introduction to thi

  11. SUPERCOMPUTER SIMULATION OF CRITICAL PHENOMENA IN COMPLEX SOCIAL SYSTEMS

    Directory of Open Access Journals (Sweden)

    Petrus M.A. Sloot

    2014-09-01

    Full Text Available The paper describes a problem of computer simulation of critical phenomena in complex social systems on a petascale computing systems in frames of complex networks approach. The three-layer system of nested models of complex networks is proposed including aggregated analytical model to identify critical phenomena, detailed model of individualized network dynamics and model to adjust a topological structure of a complex network. The scalable parallel algorithm covering all layers of complex networks simulation is proposed. Performance of the algorithm is studied on different supercomputing systems. The issues of software and information infrastructure of complex networks simulation are discussed including organization of distributed calculations, crawling the data in social networks and results visualization. The applications of developed methods and technologies are considered including simulation of criminal networks disruption, fast rumors spreading in social networks, evolution of financial networks and epidemics spreading.

  12. Kinetic theory and transport phenomena

    CERN Document Server

    Soto, Rodrigo

    2016-01-01

    This textbook presents kinetic theory, which is a systematic approach to describing nonequilibrium systems. The text is balanced between the fundamental concepts of kinetic theory (irreversibility, transport processes, separation of time scales, conservations, coarse graining, distribution functions, etc.) and the results and predictions of the theory, where the relevant properties of different systems are computed. The book is organised in thematic chapters where different paradigmatic systems are studied. The specific features of these systems are described, building and analysing the appropriate kinetic equations. Specifically, the book considers the classical transport of charges, the dynamics of classical gases, Brownian motion, plasmas, and self-gravitating systems, quantum gases, the electronic transport in solids and, finally, semiconductors. Besides these systems that are studied in detail, concepts are applied to some modern examples including the quark–gluon plasma, the motion of bacterial suspen...

  13. Eighty Phenomena About the Self: Representation, Evaluation, Regulation, and Change

    Directory of Open Access Journals (Sweden)

    Paul eThagard

    2015-03-01

    Full Text Available We propose a new approach for examining self-related aspects and phenomena. The approach includes (1 a taxonomy and (2 an emphasis on multiple levels of mechanisms. The taxonomy categorizes approximately eighty self-related phenomena according to three primary functions involving the self: representing, effecting, and changing. The representing self encompasses the ways in which people depict themselves, either to themselves or to others (e.g., self-concepts, self-presentation. The effecting self concerns ways in which people facilitate or limit their own traits and behaviors (e.g., self-enhancement, self-regulation. The changing self is less time-limited than the regulating self; it concerns phenomena that involve lasting alterations in how people represent and control themselves (e.g., self-expansion, self-development. Each self-related phenomenon within these three categories may be examined at four levels of interacting mechanisms (social, individual, neural, and molecular. We illustrate our approach by focusing on seven self-related phenomena.

  14. Maxwell Prize Talk: Scaling Laws for the Dynamical Plasma Phenomena

    Science.gov (United States)

    Ryutov, Livermore, Ca 94550, Usa, D. D.

    2017-10-01

    The scaling and similarity technique is a powerful tool for developing and testing reduced models of complex phenomena, including plasma phenomena. The technique has been successfully used in identifying appropriate simplified models of transport in quasistationary plasmas. In this talk, the similarity and scaling arguments will be applied to highly dynamical systems, in which temporal evolution of the plasma leads to a significant change of plasma dimensions, shapes, densities, and other parameters with respect to initial state. The scaling and similarity techniques for dynamical plasma systems will be presented as a set of case studies of problems from various domains of the plasma physics, beginning with collisonless plasmas, through intermediate collisionalities, to highly collisional plasmas describable by the single-fluid MHD. Basic concepts of the similarity theory will be introduced along the way. Among the results discussed are: self-similarity of Langmuir turbulence driven by a hot electron cloud expanding into a cold background plasma; generation of particle beams in disrupting pinches; interference between collisionless and collisional phenomena in the shock physics; similarity for liner-imploded plasmas; MHD similarities with an emphasis on the effect of small-scale (turbulent) structures on global dynamics. Relations between astrophysical phenomena and scaled laboratory experiments will be discussed.

  15. Eighty phenomena about the self: representation, evaluation, regulation, and change

    Science.gov (United States)

    Thagard, Paul; Wood, Joanne V.

    2015-01-01

    We propose a new approach for examining self-related aspects and phenomena. The approach includes (1) a taxonomy and (2) an emphasis on multiple levels of mechanisms. The taxonomy categorizes approximately eighty self-related phenomena according to three primary functions involving the self: representing, effecting, and changing. The representing self encompasses the ways in which people depict themselves, either to themselves or to others (e.g., self-concepts, self-presentation). The effecting self concerns ways in which people facilitate or limit their own traits and behaviors (e.g., self-enhancement, self-regulation). The changing self is less time-limited than the effecting self; it concerns phenomena that involve lasting alterations in how people represent and control themselves (e.g., self-expansion, self-development). Each self-related phenomenon within these three categories may be examined at four levels of interacting mechanisms (social, individual, neural, and molecular). We illustrate our approach by focusing on seven self-related phenomena. PMID:25870574

  16. Geochemical modelling: what phenomena are missing

    International Nuclear Information System (INIS)

    Jacquier, P.

    1989-12-01

    In the framework of safety assessment of radioactive waste disposal, retention phenomena are usually taken into account by the Kd concept. It is well recognized that this concept is not enough for safety assessment models, because of the several and strong assumptions which are involved in this kind of representation. One way to have a better representation of the retention phenomena, is to substitute for this Kd concept an explicit description of geochemical phenomena and then couple transport codes with geochemical codes in a fully or a two-step procedure. We use currently such codes, but the scope of this paper is to display the limits today of the geochemical modelling in connection with sites analysis for deep disposal. In this paper, we intend to give an overview of phenomena which are missing in the geochemical models, or which are not completely introduced in the models. We can distinguish, on one hand phenomena for which modelling concepts exist such as adsorption/desorption and, on the other hand, phenomena for which modelling concepts do not exist for the moment such as colloids, and complexation by polyelectrolyte solutions (organics). Moreover we have to take care of very low concentrations of radionuclides, which can be expected from the leaching processes in the repository. Under those conditions, some reactions may not occur. After a critical review of the involved phenomena, we intend to stress the main directions of the wishful evolution of the geochemical modelling. This evolution should improve substantially the quality of the above-mentioned site assessments

  17. New phenomena in neutrino physics

    International Nuclear Information System (INIS)

    Kopp, Joachim

    2009-01-01

    In this thesis, we discuss two new concepts in neutrino physics: The neutrino Moessbauer effect and non-standard neutrino interactions. We show that neutrinos emitted and absorbed in recoil-free processes (Moessbauer neutrinos) can oscillate in spite of their near monochromaticity. We support this statement by quantum mechanical wave packet arguments and by a quantum field theoretical (QFT) calculation of the combined rate of Moessbauer neutrino emission, propagation and absorption. The QFT approach does not require any a priori assumptions on the neutrino wave function, and it allows us to include a realistic treatment of the different mechanisms leading to broadening of the emission and absorption lines. In the second part of this work, we study the phenomenology of non-standard neutrino interactions (NSI). We classifying the allowed NSI operators according to their impact on future oscillation experiments and present numerical results for the NSI sensitivities of reactor, superbeam and neutrino factory experiments. We point out that NSI could mimic standard oscillation effects, and might therefore lead to incorrect fit values for the oscillation parameters. For the case of the neutrino factory, we perform a detailed optimisation study to determine the optimum muon energy and detector configuration. (orig.)

  18. New phenomena in neutrino physics

    Energy Technology Data Exchange (ETDEWEB)

    Kopp, Joachim

    2009-04-15

    In this thesis, we discuss two new concepts in neutrino physics: The neutrino Moessbauer effect and non-standard neutrino interactions. We show that neutrinos emitted and absorbed in recoil-free processes (Moessbauer neutrinos) can oscillate in spite of their near monochromaticity. We support this statement by quantum mechanical wave packet arguments and by a quantum field theoretical (QFT) calculation of the combined rate of Moessbauer neutrino emission, propagation and absorption. The QFT approach does not require any a priori assumptions on the neutrino wave function, and it allows us to include a realistic treatment of the different mechanisms leading to broadening of the emission and absorption lines. In the second part of this work, we study the phenomenology of non-standard neutrino interactions (NSI). We classifying the allowed NSI operators according to their impact on future oscillation experiments and present numerical results for the NSI sensitivities of reactor, superbeam and neutrino factory experiments. We point out that NSI could mimic standard oscillation effects, and might therefore lead to incorrect fit values for the oscillation parameters. For the case of the neutrino factory, we perform a detailed optimisation study to determine the optimum muon energy and detector configuration. (orig.)

  19. Noise induced phenomena in combustion

    Science.gov (United States)

    Liu, Hongliang

    Quantitative models of combustion usually consist of systems of deterministic differential equations. However, there are reasons to suspect that noise may have a significant influence. In this thesis, our primary objective is to study the effect of noise on measurable quantities in the combustion process. Our first study involves combustion in a homogeneous gas. With a one step reaction model, we analytically estimate the requirements under which noise is important to create significant differences. Our simulation shows that a bi-modality phenomenon appears when appropriate parameters are applied, which agrees with our analytical result. Our second study involves steady planar flames. We use a relatively complete chemical model of the H2/air reaction system, which contains all eight reactive species (H2, O2, H, O, OH, H2O, HO2, H2O2) and N2. Our mathematical model for this system is a reacting flow model. We derive noise terms related to transport processes by a method advocated by Landau & Lifshitz, and we also derive noise terms related to chemical reactions. We develop a code to simulate this system. The numerical implementation relies on a good Riemann solver, suitable initial and boundary conditions, and so on. We also implement a code on a continuation method, which not only can be used to study approximate properties of laminar flames under deterministic governing equations, but also eliminates the difficulty of providing a suitable initial condition for governing equations with noise. With numerical experiments, we find the difference of flame speed exist when the noise is turned on or off although it is small when compared with the influence of other parameters, for example, the equivalence ratio. It will be a starting point for further studies to include noise in combustion.

  20. Polarization phenomena in quantum chromodynamics

    Energy Technology Data Exchange (ETDEWEB)

    Brodsky, S.J. [Stanford Univ., CA (United States)

    1994-12-01

    The author discusses a number of interrelated hadronic spin effects which test fundamental features of perturbative and nonperturbative QCD. For example, the anomalous magnetic moment of the proton and the axial coupling g{sub A} on the nucleon are shown to be related to each other for fixed proton radius, independent of the form of the underlying three-quark relativistic quark wavefunction. The renormalization scale and scheme ambiguities for the radiative corrections to the Bjorken sum rule for the polarized structure functions can be eliminated by using commensurate scale relations with other observables. Other examples include (a) new constraints on the shape and normalization of the polarized quark and gluon structure functions of the proton at large and small x{sub bj}; (b) consequences of the principle of hadron retention in high x{sub F} inclusive reactions; (c) applications of hadron helicity conservation to high momentum transfer exclusive reactions; and (d) the dependence of nuclear structure functions and shadowing on virtual photon polarization. The author also discusses the implications of a number of measurements which are in striking conflict with leading-twist perturbative QCD predictions, such as the extraordinarily large spin correlation A{sub NN} observed in large angle proton-proton scattering, the anomalously large {rho}{pi} branching ratio of the J/{psi}, and the rapidly changing polarization dependence of both J/{psi} and continuum lepton pair hadroproduction observed at large x{sub F}. The azimuthal angular dependence of the Drell-Yan process is shown to be highly sensitive to the projectile distribution amplitude, the fundamental valence light-cone wavefunction of the hadron.

  1. [Spiritual phenomena occurring in everybody and health].

    Science.gov (United States)

    Krsiak, M

    2008-01-01

    The past several years have seen an explosion of research in the area of spirituality and health. However, confusion and incomprehension of the conception of spirituality (e.g. confounding spirituality with various conventional views on religiousness) hampers better understanding in this area. The present paper proposes definition of spiritual phenomena in man based on natural epistemological and instrumental criteria (whether a certain phenomenon can be objectively known and evoked): spiritual phenomena in man are those, which cannot be objectively known nor evoked, but which act (e.g., love, idea). Spiritual phenomena can be really known only in the self ("in spirit"). Objectively known can be only manifestations of spiritual phenomena. Some attributes of love (e.g. its personal uniqueness) or ideas (e.g., sense of own life) whose satisfaction appears to be important for health are briefly outlined. A review of some frequently cited recent papers investigating the role of spirituality in health and discussion of frequent pitfalls in this area is given. Spirituality is a universal human phenomenon. All human beings, secular or religious, encounter with spiritual phenomena. Although the present conception of spirituality distances from some conventional views on religiousness, it is not atheistic. On the contrary, it accommodates the basic religious concept "God is love". Conceptual clarification is essential for further progress in the study of impact of spirituality on health.

  2. Inertial confinement fusion reactor cavity phenomena

    International Nuclear Information System (INIS)

    Bohachevsky, I.O.; Hafer, J.F.; Devaney, J.J.; Pendergrass, J.H.

    1978-01-01

    Cavity phenomena in Inertial Confinement Fusion (ICF) are created by the interaction of energy released by the fuel pellet microexplosion with the medium inside the reactor cavity. The ambient state of the medium in ICF reactor cavities is restricted primarily by its effects on laser beam propagation and on the fuel pellet trajectory. Therefore, a relatively wide choice of ambient conditions can be exploited to gain first-wall protection and advantages in energy extraction. Depending on the choice of ambient cavity conditions and on fuel pellet design, a variety of physical phenomena may develop and dominate the ICF reactor cavity design. Because of the cavity phenomena, the forms of energy released by the fuel-pellet microexplosion are modified before reaching the first wall, thus giving rise to different cavity design problems. The types of cavity phenomena encountered in the conceptual design of ICF reactors are examined, the approaches available for their modeling and analysis are discussed, and some results are presented. Most phenomena are sufficiently well understood to permit valid engineering assessments of the proposed ICF reactor concepts

  3. Sixth Microgravity Fluid Physics and Transport Phenomena Conference Abstracts

    Science.gov (United States)

    Singh, Bhim (Compiler)

    2002-01-01

    The Sixth Microgravity Fluid Physics and Transport Phenomena Conference provides the scientific community the opportunity to view the current scope of the Microgravity Fluid Physics and Transport Phenomena Program, current research opportunities, and plans for the near future. The conference focuses not only on fundamental research but also on applications of this knowledge towards enabling future space exploration missions. A whole session dedicated to biological fluid physics shows increased emphasis that the program has placed on interdisciplinary research. The conference includes invited plenary talks, technical paper presentations, poster presentations, and exhibits. This TM is a compilation of abstracts of the papers and the posters presented at the conference. Web-based proceedings, including the charts used by the presenters, will be posted on the web shortly after the conference.

  4. IUTAM Symposium on Fracture Phenomena in Nature and Technology

    CERN Document Server

    Carini, Angelo; Gei, Massimiliano; Salvadori, Alberto

    2014-01-01

    This book contains contributions presented at the IUTAM Symposium "Fracture Phenomena in Nature and Technology" held in Brescia, Italy, 1-5 July, 2012.The objective of the Symposium was fracture research, interpreted broadly to include new engineering and structural mechanics treatments of damage development and crack growth, and also large-scale failure processes as exemplified by earthquake or landslide failures, ice shelf break-up, and hydraulic fracturing (natural, or for resource extraction or CO2 sequestration), as well as small-scale rupture phenomena in materials physics including, e.g., inception of shear banding, void growth, adhesion and decohesion in contact and friction, crystal dislocation processes, and atomic/electronic scale treatment of brittle crack tips and fundamental cohesive properties.Special emphasis was given to multiscale fracture description and new scale-bridging formulations capable to substantiate recent experiments and tailored to become the basis for innovative computationa...

  5. An Experimental Analysis of the Basic Phenomena Involved in Modern Diffraction Theories.

    Science.gov (United States)

    1980-01-21

    of surface fields very close to smoothly curved scatterers is also observed. These phenomena can, in general, be identified with Franz -type creeping...observed. These phenomena can, in general, be identified with Franz -type creeping waves. However, they appear to 4r depend only loosely on the shape of the...Sabih I. Hayek, Jiri Tichy , and William Thompson, Jr. for their instruction and active participation in the author’s doctoral committee. The author

  6. Topographic characterization of polymer materials at different length scales and the mechanistic understanding of wetting phenomena

    OpenAIRE

    Calvimontes, Alfredo

    2010-01-01

    The present study suggests new insights into topographic characterisation of engineering polymer surfaces towards to physical-chemical and mechanistic understanding of wetting phenomena on rough surfaces. Non-contact chromatic confocal imaging was chosen and justified as the optimal measuring method to study and correlate surface topography and surface properties of Sheet Moulding Compounds (SMC) as well as polyester and cotton fabrics. Before topographical characterisation, an adequate se...

  7. Undergraduate Engineering Students’ Conceptual and Procedural Knowledge of Wave Phenomena

    OpenAIRE

    Mioković, Željka; Varvodić, Sanda; Radolić, Vanja

    2012-01-01

    The engineering students’ education at the university level is mainly focused on procedural knowledge which includes proficiency in problem-solving and calculation whereas their conceptual knowledge, as another very important factor associated with the enhancement of engineering skills, is often insufficient. The aim of this study is to assess the undergraduate engineering students’ conceptual and procedural knowledge of wave phenomena as one of basic topics in introductory physics courses ei...

  8. The making of extraordinary psychological phenomena.

    Science.gov (United States)

    Lamont, Peter

    2012-01-01

    This article considers the extraordinary phenomena that have been central to unorthodox areas of psychological knowledge. It shows how even the agreed facts relating to mesmerism, spiritualism, psychical research, and parapsychology have been framed as evidence both for and against the reality of the phenomena. It argues that these disputes can be seen as a means through which beliefs have been formulated and maintained in the face of potentially challenging evidence. It also shows how these disputes appealed to different forms of expertise, and that both sides appealed to belief in various ways as part of the ongoing dispute about both the facts and expertise. Finally, it shows how, when a formal Psychology of paranormal belief emerged in the twentieth century, it took two different forms, each reflecting one side of the ongoing dispute about the reality of the phenomena. © 2012 Wiley Periodicals, Inc.

  9. Phenomena that disturb the measurement of potentials in concrete

    Energy Technology Data Exchange (ETDEWEB)

    Myrdal, R. [Rescon AS, Sagstua (Norway)

    1996-10-01

    Potential measurements are commonly used in corrosion surveys of steel reinforced concrete structures. The potential difference between the steel and a reference electrode, either placed on the concrete surface or permanently embedded in the concrete, is indicative of the state of corrosion of the steel. However, the electrolytic nature of concrete gives rise to disturbing phenomena that might introduce errors in the potential readings. The error that is most problematic originates from liquid junction potentials in the concrete. The origin and magnitude of junction potentials have been studied both theoretically and experimentally.

  10. Current-driven phenomena in nanoelectronics

    CERN Document Server

    Seideman, Tamar

    2010-01-01

    Consisting of ten chapters written by some of the world's leaders in the field, this book combines experimental, theoretical and numerical studies of current-driven phenomena in the nanoscale. The topics covered range from single-molecule, site-specific nanochemistry induced by a scanning tunneling microscope, through inelastic tunneling spectroscopy and current-induced heating, to current-triggered molecular machines. The various chapters focus on experimental and numerical method development, the description of specific systems, and new ideas and novel phenomena.

  11. Dissipative phenomena in condensed matter some applications

    CERN Document Server

    Dattagupta, Sushanta

    2004-01-01

    From the field of nonequilibrium statistical physics, this graduate- and research-level volume treats the modeling and characterization of dissipative phenomena. A variety of examples from diverse disciplines like condensed matter physics, materials science, metallurgy, chemical physics etc. are discussed. Dattagupta employs the broad framework of stochastic processes and master equation techniques to obtain models for a wide range of experimentally relevant phenomena such as classical and quantum Brownian motion, spin dynamics, kinetics of phase ordering, relaxation in glasses, dissipative tunneling. It provides a pedagogical exposition of current research material and will be useful to experimentalists, computational physicists and theorists.

  12. Synchronization Phenomena in Coupled Colpitts Circuits

    Directory of Open Access Journals (Sweden)

    Ch. K. Volos

    2014-11-01

    Full Text Available In this work, the case of coupling (bidirectional and unidirectional between two identical nonlinear chaotic circuits via a linear resistor, is studied. The produced dynamical systems have different structure, in regard to other similar works, due to the choice of coupling nodes. As a circuit, a modification of the most well-known nonlinear circuit that can operate in a wide range of radiofrequencies, the Colpitts oscillator, is chosen. The simulation and the experimental results show a variety of dynamical phenomena, such as periodic, quasi-periodic and chaotic behaviors, as well as anti-phase and complete synchronization phenomena, depending on the value of the coupling coefficient.

  13. Loss experience from natural phenomena hazards in the Department of Energy (50 years of natural phenomena hazard losses)

    International Nuclear Information System (INIS)

    Hill, J.R.

    1993-01-01

    This paper presents a historical prespective on losses due to natural hazard incidents (1943-1993) at Department of Energy (DOE) and predecessor agencies including the Atomic Energy Commission (AEC) and the Energy Research and Development Agency (ERDA). This paper also demonstrates how an existing DOE resource can be used to gain valuable insight into injury or property damage incidents. That resource is the Computerized Accident/Incident Reporting System (CAIRS) module of DOE's Safety Performance Measurement System. CAIRS data selected the 1981-1991 DOE injury/illness reports, from all the accident reports of the AEC that cited a natural phenomena hazard as either the direct or indirect cause of the injury/property damage. Specifically, injury or property damage reports were selected for analysis if they had a causal factor link to severe weather or natural phenomena hazard categories. Natural phenomena hazard categories are injury/property damage caused by hurricane/tornado, earthquake, lightning, or flood. Severe weather categories are injury/property damage associated with other than normal weather conditions. The lessons learned, as a result of reviewing case histories, are presented, as are suggestions on how to reduce the likelihood of future injuries/property damage as a result of similar events. A significant finding, is that most injuries and property damage were the result of an indirect causal link to a natural phenomena hazard and thus, may be more preventable than previously thought possible. The primary message, however, is that CAIRS and other incident data bases are valuable resources and should be considered for use by those interested in identifying new ways of protecting the health and safety of the worker and for reducing building losses due to the effects of natural phenomena hazards

  14. Modelling of flow phenomena during DC casting

    NARCIS (Netherlands)

    Zuidema, J.

    2005-01-01

    Modelling of Flow Phenomena during DC Casting Jan Zuidema The production of aluminium ingots, by semi-continuous casting, is a complex process. DC Casting stands for direct chill casting. During this process liquid aluminium transforms to solid aluminium while cooling down. This is not an

  15. Novel experimentally observed phenomena in soft matter

    Indian Academy of Sciences (India)

    The resulting flow is non-Newtonian and is characterized by features such as shear rate-dependent viscosities and nonzero normal stresses. This article begins with an introduction to some unusual flow properties displayed by soft matter. Experiments that report a spectrum of novel phenomena exhibited by these materials, ...

  16. Fourier Series The Mathematics of Periodic Phenomena

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 1; Issue 10. Fourier Series The Mathematics of Periodic Phenomena. S Thangavelu ... Author Affiliations. S Thangavelu1. Department of Mathematics and Statistics, University of New Mexico, Humanities Building 419, Albuquerque, NM 87131-1141, USA ...

  17. Simple classical approach to spin resonance phenomena

    DEFF Research Database (Denmark)

    Gordon, R A

    1977-01-01

    A simple classical method of describing spin resonance in terms of the average power absorbed by a spin system is discussed. The method has several advantages over more conventional treatments, and a number of important spin resonance phenomena, not normally considered at the introductory level...

  18. Geophysical phenomena classification by artificial neural networks

    Science.gov (United States)

    Gough, M. P.; Bruckner, J. R.

    1995-01-01

    Space science information systems involve accessing vast data bases. There is a need for an automatic process by which properties of the whole data set can be assimilated and presented to the user. Where data are in the form of spectrograms, phenomena can be detected by pattern recognition techniques. Presented are the first results obtained by applying unsupervised Artificial Neural Networks (ANN's) to the classification of magnetospheric wave spectra. The networks used here were a simple unsupervised Hamming network run on a PC and a more sophisticated CALM network run on a Sparc workstation. The ANN's were compared in their geophysical data recognition performance. CALM networks offer such qualities as fast learning, superiority in generalizing, the ability to continuously adapt to changes in the pattern set, and the possibility to modularize the network to allow the inter-relation between phenomena and data sets. This work is the first step toward an information system interface being developed at Sussex, the Whole Information System Expert (WISE). Phenomena in the data are automatically identified and provided to the user in the form of a data occurrence morphology, the Whole Information System Data Occurrence Morphology (WISDOM), along with relationships to other parameters and phenomena.

  19. Analysis of induction phenomena in thermonuclear experiments

    International Nuclear Information System (INIS)

    Deeds, W.E.; Dodd, C.V.

    1976-01-01

    Many of the problems involving transients induced by changing currents in the large coils of thermonuclear machines are identical to those arising in nondestructive testing by eddy currents. There are three chief methods used for calculating such induction phenomena: analytical boundary-value solutions, relaxation or iteration techniques, and model experiments. Some of the results obtained by each of these methods are described below

  20. Quantum phenomena in magnetic nano clusters

    Indian Academy of Sciences (India)

    While semiconductor structures have provided paradigms of nanosystems from the stand point of electronic phenomena, the synthesis of high nuclearity transition metal complexes have provided examples of nano magnets. The range and diversity of the properties exhibited by these systems rivals its electronic counterparts ...

  1. Hyperchaotic phenomena in dynamic decision making

    DEFF Research Database (Denmark)

    Thomsen, Jesper Skovhus; Mosekilde, Erik; Sterman, John David

    1992-01-01

    of this article is to show how the decision making behavior of real people in simulated corporate environments can lead to chaotic, hyperchaotic and higher-order hyperchaotic phenomena. Characteristics features of these complicated forms of behavior are analyzed with particular emphasis on an interesting form...

  2. Transport phenomena in strongly correlated Fermi liquids

    Energy Technology Data Exchange (ETDEWEB)

    Kontani, Hiroshi [Nagoya Univ., Aichi (Japan). Dept. of Physics

    2013-03-01

    Comprehensive overview. Written by an expert of this topic. Provides the reader with current developments in the field. In conventional metals, various transport coefficients are scaled according to the quasiparticle relaxation time, {tau}, which implies that the relaxation time approximation (RTA) holds well. However, such a simple scaling does not hold in many strongly correlated electron systems, reflecting their unique electronic states. The most famous example would be cuprate high-Tc superconductors (HTSCs), where almost all the transport coefficients exhibit a significant deviation from the RTA results. To better understand the origin of this discrepancy, we develop a method for calculating various transport coefficients beyond the RTA by employing field theoretical techniques. Near the magnetic quantum critical point, the current vertex correction (CVC), which describes the electron-electron scattering beyond the relaxation time approximation, gives rise to various anomalous transport phenomena. We explain anomalous transport phenomena in cuprate HTSCs and other metals near their magnetic or orbital quantum critical point using a uniform approach. We also discuss spin related transport phenomena in strongly correlated systems. In many d- and f-electron systems, the spin current induced by the spin Hall effect is considerably greater because of the orbital degrees of freedom. This fact attracts much attention due to its potential application in spintronics. We discuss various novel charge, spin and heat transport phenomena in strongly correlated metals.

  3. Quantum phenomena in magnetic nano clusters

    Indian Academy of Sciences (India)

    Unknown

    Abstract. One of the fascinating fields of study in magnetism in recent years has been the study of quantum phenomena in nanosystems. While semiconductor structures .... or discrete steps provided the sweep rate of the magnetic field is not too low 10. ... to the Landau–Zener two-level treatment within the spin-10 manifold.

  4. Imaging unsteady three-dimensional transport phenomena

    Indian Academy of Sciences (India)

    2014-01-05

    Jan 5, 2014 ... physical domains with unsteady processes can be accommodated. Optical methods promise to breach the holy grail of measurements by extracting unsteady three-dimensional data in applications related to transport phenomena. Keywords. Optical measurement; fluid flow and transport; refractive index ...

  5. Neuropsychiatric phenomena in the medieval text Cantigas de Santa Maria.

    Science.gov (United States)

    Gondim, Francisco De Assis Aquino; Griesbach, Sarah H; Thomas, Florian P

    2015-05-12

    To discuss the neuropsychiatric phenomena described in Cantigas de Santa Maria (Canticles of St. Mary [CSM]). CSM is a collection of 427 canticles composed in Galician-Portuguese between 1252 and 1284 at the Court of King Alfonso X the Wise of Spain (1221-1284). The canticles (of which 9 are repeated) include devotional and liturgical poems and 353 narrative stories consisting mainly of depictions of Marian miracles. Most are set to music and many are illustrated. We reviewed the canticles for description of miracles and other neuropsychiatric phenomena. Two neurologists reached a consensus about the descriptions. Of the 353 miracles, 279 medically relevant facts (from 187 canticles) and 25 instances of resurrection were reported. Possible neuropsychiatric conditions were described in 98 canticles. Physicians were mentioned in 16 narratives. The most common neurologic conditions detailed were blindness (n = 17), dystonia, weakness, and deformities (n = 20). Other common conditions included psychosis (n = 15), speech disorder/deaf-mutism (n = 12), infections (n = 15), sexual dysfunction/infertility/obstetrical-gynecologic issues (n = 18), head trauma (n = 5), ergotism/St. Anthony's fire (n = 7), and others. There were 9 instances of prodromic mystical experiences/hallucinations heralding death. While limited by retrospection and interpretation of neuropsychiatric phenomena in the medieval context, these short accounts are among the first descriptions of neuropsychiatric conditions in early Portuguese/Galician. They reflect how medieval societies used rational and irrational approaches to understand occurrences in their lives. © 2015 American Academy of Neurology.

  6. Preface to special issue: Layered Phenomena in the Mesopause Region

    Science.gov (United States)

    Chu, Xinzhao; Marsh, Daniel R.

    2017-09-01

    Historically, the Layered Phenomena in the Mesopause Region (LPMR) workshops have focused on studies of mesospheric clouds and their related science, including spectacular noctilucent clouds (NLCs), polar mesospheric clouds (PMCs), and polar mesospheric summer echoes (PMSEs). This is because, in the pre-technology era, these high-altitude ( 85 km) clouds revealed the existence of substance above the 'normal atmosphere' - our near-space environment is not empty! The occurrence and nature of these clouds have commanded the attention of atmospheric and space scientists for generations. Modern technologies developed in the last 50 years have enabled scientists to significantly advance our understanding of these layered phenomena. Satellite observations expanded these studies to global scales, while lidar and radar observations from the ground enabled fine-scale studies. The launch of the Aeronomy of Ice in the Mesosphere (AIM) satellite in 2007 brought mesospheric cloud research to a more mature level.

  7. Phenomena of synchronized response in biosystems and the possible mechanism.

    Science.gov (United States)

    Xu, Jingjing; Yang, Fan; Han, Danhong; Xu, Shengyong

    2018-02-05

    Phenomena of synchronized response is common among organs, tissues and cells in biosystems. We have analyzed and discussed three examples of synchronization in biosystems, including the direction-changing movement of paramecia, the prey behavior of flytraps, and the simultaneous discharge of electric eels. These phenomena and discussions support an electrical communication mechanism that in biosystems, the electrical signals are mainly soliton-like electromagnetic pulses, which are generated by the transient transmembrane ionic current through the ion channels and propagate along the dielectric membrane-based softmaterial waveguide network to complete synchronized responses. This transmission model implies that a uniform electrical communication mechanism might have been naturally developed in biosystem. Copyright © 2018 Elsevier Inc. All rights reserved.

  8. Autoscopic phenomena and one's own body representation in dreams.

    Science.gov (United States)

    Occhionero, Miranda; Cicogna, Piera Carla

    2011-12-01

    Autoscopic phenomena (AP) are complex experiences that include the visual illusory reduplication of one's own body. From a phenomenological point of view, we can distinguish three conditions: autoscopic hallucinations, heautoscopy, and out-of-body experiences. The dysfunctional pattern involves multisensory disintegration of personal and extrapersonal space perception. The etiology, generally either neurological or psychiatric, is different. Also, the hallucination of Self and own body image is present during dreams and differs according to sleep stage. Specifically, the representation of the Self in REM dreams is frequently similar to the perception of Self in wakefulness, whereas in NREM dreams, a greater polymorphism of Self and own body representation is observed. The parallels between autoscopic phenomena in pathological cases and the Self-hallucination in dreams will be discussed to further the understanding of the particular states of self awareness, especially the complex integration of different memory sources in Self and body representation. Copyright © 2011 Elsevier Inc. All rights reserved.

  9. Atmospheric and surface properties of Mars obtained by infrared spectroscopy on Mariner 9

    Science.gov (United States)

    Conrath, B.; Curran, R.; Hanel, R.; Kunde, V.; Maguire, W.; Pearl, J.; Pirraglia, J.; Welker, J.; Burke, T.

    1973-01-01

    The infrared spectroscopy experiment on Mariner 9 obtained data over much of Mars. Interpretation of the thermal emission of Mars in terms of atmospheric temperatures, wind fields and dynamics, surface temperatures, surface pressure and topography, mineral composition, and minor atmospheric constituents including isotopic ratios, as well as a search for unexpected phenomena are reported.

  10. A thermodynamic model for predicting surface melting and overheating of different crystal planes in BCC, FCC and HCP pure metallic thin films

    International Nuclear Information System (INIS)

    Jahangir, Vafa; Riahifar, Reza; Sahba Yaghmaee, Maziar

    2016-01-01

    In order to predict as well as study the surface melting phenomena in contradiction to surface overheating, a generalized thermodynamics model including the surface free energy of solid and the melt state along with the interfacial energy of solid–liquid (melt on substrate) has been introduced. In addition, the effect of different crystal structures of surfaces in fcc, bcc and hcp metals was included in surface energies as well as in the atomistic model. These considerations lead us to predict surface melting and overheating as two contradictory melting phenomena. The results of the calculation are demonstrated on the example of Pb and Al thin films in three groups of (100), (110) and (111) surface planes. Our conclusions show good agreement with experimental results and other theoretical investigations. Moreover, a computational algorithm has been developed which enables users to investigate the surface melt or overheating of single component metallic thin film with variable crystal structures and different crystalline planes. This model and developed software can be used for studying all related surface phenomena. - Highlights: • Investigating the surface melting and overheating phenomena • Effect of crystal orientations, surface energies, geometry and different atomic surface layers • Developing a computational algorithm and its related code (free-software SMSO-Ver1) • Thickness and orientation of surface plane dominate the surface melting or overheating. • Total excess surface energy as a function of thickness and temperature explains melting.

  11. Studying the hydrological cycle in the Iberian Peninsula using the LEAFHYDRO LSM: Influence of groundwater dynamics on soil moisture and land-atmosphere coupling. Impacts of artificial water extraction in the regional water cycle, including land-surface f

    Science.gov (United States)

    Martinez, A.; Miguez-Macho, G.

    2012-04-01

    We perform long-term (10 year) simulations over the Iberian Peninsula at 2.5 km resolution with the LEAFHYDRO LSM, which includes groundwater dynamics and river routing. Atmospheric forcing comes from ERA-interim and a regional high-resolution analysis of precipitation over Spain and Portugal. The model simulates the coupled evolution of the groundwater, land surface (soil moisture and vegetation) and river reservoirs and we validate the simulation with all available observations of river flow and water table depth. In an experiment, we impose an artificial water extraction rate from the groundwater reservoir based on observations and estimations of irrigation withdrawals and we investigate the impact on the regional water cycle. The extraction rates induce a depression of the water table that over the years becomes quite significant and that matches observed decreasing rates of water table levels. The depressed water table discontinues groundwater input into rivers and the stream flow is diminished notably, in particular during the dry summer. Moreover, in areas with semiarid climate where the water table was naturally relatively shallow and connected to soil moisture and vegetation, which include most of the agricultural areas inland Spain, the depression of the water table has a significant impact on soil moisture and land-surface fluxes, with a decrease of root zone soil water availability and evapotranspiration and increasing water stress for the vegetation. The land hydrology alteration is more pronounced in the summer when there is an absence of precipitation, and as the model shows, through the induced changes in land-surface fluxes can potentially have a noticeably impact on the regional climate.

  12. The fluid phenomena in the crystallization of the protein crystal

    International Nuclear Information System (INIS)

    Duan Li; Kang Qi

    2008-01-01

    This paper reports that an optical diagnostic system consisting of Mach–Zehnder interferometer with a phase shift device and image processor has been used for study of the kinetics of protein crystal growing process. The crystallization process of protein crystal by vapour diffusion is investigated. The interference fringes are observed in real time. The present experiment demonstrates that the diffusion and the sedimentation influence the crystallization of protein crystal which grows in solution, and the concentration capillary convection associated with surface tension occurs at the vicinity of free surface of the protein mother liquor, and directly affects on the outcome of protein crystallization. So far the detailed analysis and the important role of the fluid phenomena in protein crystallization have been discussed a little in both space- and ground-based crystal growth experiments. It is also found that these fluid phenomena affect the outcome of protein crystallization, regular growth, and crystal quality. This may explain the fact that many results of space-based investigation do not show overall improvement. (cross-disciplinary physics and related areas of science and technology)

  13. Elementary particle physics and high energy phenomena

    International Nuclear Information System (INIS)

    Barker, A.R.; Cumalat, J.P.; De Alwis, S.P.; DeGrand, T.A.; Ford, W.T.; Mahanthappa, K.T.; Nauenberg, U.; Rankin, P.; Smith, J.G.

    1992-06-01

    Experimental and theoretical high-energy physics programs at the University of Colorado are reported. Areas of concentration include the following: study of the properties of the Z 0 with the SLD detector; fixed-target K-decay experiments; the R ampersand D program for the muon system: the SDC detector; high-energy photoproduction of states containing heavy quarks; electron--positron physics with the CLEO II detector at CESR; lattice QCD; and spin models and dynamically triangulated random surfaces. 24 figs., 2 tabs., 117 refs

  14. ARISK PHENOMENA IN THE SILVANIA MOUNTAINS, INTUITIVE AND GENETIC REFLEXES

    Directory of Open Access Journals (Sweden)

    CAMELIA BOGDAN

    2014-05-01

    Full Text Available Risk phenomena in the Silvania Mountains, intuitive and genetic reflexes. In the contemporary period, the scientific research under the auspices of the global development has experienced a real quantitative and qualitative revolution. Theoretically and methodologically, the widespread promotion of the “concept of discontinuity” in terms of content, significances, manifestation, implications is observed, which has become a new imperative of the nowadays geography. The phenomena of discontinuity happen as real “paroxysmal, rhythm and intensity ruptures“ in relation to the normal occurrence defined either through the average value, determined on statistical basis as hydrological, meteorological, climatic phenomena or in discrete forms, when the phenomena occur in a veiled manner and they are perceptible only through their effects, respectively the environmental reflexes. Among the notions used with reference to extreme evolutionary discontinuities, we quote: the hazard, the disaster, the calamity and the risk to which was added a series of related notions: stability, sensitivity, resilience, fragility and vulnerability. The Silvania Mountains, a representative territorial unit within Silvania Land, with a fascinating and controversial geological origin, a real petrographic synthesis with uncovered crystalline stone, brought to the surface due to erosion under the layers of Neogene sediments, as a last remaining of a grandiose Hercynian chain with a varied orientation SW-NE of which were part the Massif Central –France, the east side, the Vosges Mountains, the Black Forest Mountains, the Harz Mountains and Bohemia. In this range of mountains, we also mention the Silvania Hercynian Mountains, respectively Plopiș and Meseș Mountains.This mountainous elevation level has an important role within the landscape as "geographical discontinuity factor” on one hand, between the Someșan Plateau and the Silvania piedmontan hills (Meseș Mountains

  15. Transport phenomena and dimensionless numbers: towards a new methodological approach

    Science.gov (United States)

    Bezuglyi, B. A.; Ivanova, N. A.; Sizova, L. V.

    2017-05-01

    This review presents a new methodical approach to the classification of dimensionless numbers as pair relationships of the main forces controlling transport phenomena in fluids at the macroscopic level by using a tabulated form. To memorize the transfer numbers at the molecular level a rule in the form of a mnemonic triangle is suggested. The structure of some traditional dimensional numbers presented as the ratio of more than two forces, or the ratio of a force to a geometric mean of two other ones, is also discussed. A classification of natural convection as the interaction of body forces and surface forces, taking into account that sensitive to the force field the fluid density and the surface tension depends on temperature or composition, is presented.

  16. Phenomena, dynamics and instabilities of vortex pairs

    International Nuclear Information System (INIS)

    Williamson, C H K; Asselin, D J; Leweke, T; Harris, D M

    2014-01-01

    Our motivation for studying the dynamics of vortex pairs stems initially from an interest in the trailing wake vortices from aircraft and the dynamics of longitudinal vortices close to a vehicle surface. However, our motivation also comes from the fact that vortex–vortex interactions and vortex–wall interactions are fundamental to many turbulent flows. The intent of the paper is to present an overview of some of our recent work concerning the formation and structure of counter-rotating vortex pairs. We are interested in the long-wave and short-wave three-dimensional instabilities that evolve for an isolated vortex pair, but also we would like to know how vortex pairs interact with a wall, including both two-dimensional interactions, and also the influence of the surface on the three-dimensional instabilities. The emphasis of this presentation is on physical mechanisms by which vortices interact with each other and with surfaces, principally from an experimental approach, but also coupled with analytical studies. (paper)

  17. Fundamentals of Cryobiology Physical Phenomena and Mathematical Models

    CERN Document Server

    Zhmakin, Alexander I

    2009-01-01

    The book gives a summary of the state-of-the-art of cryobiology and its applications. The accent is on the underlying physical phenomena, which are common in such opposite applications as cryosurgery and cryoconservation, and the corresponding mathematical models, including numerical ones. The treatment of some more special issues is moved to the appendices. The glossary contains definitions and explanations of the major entities. All the topics considered are well referenced. The book is useful to both biologists and physicits of different level including practioners and graduate students.

  18. Experimental and analytical study of the sputtering phenomena

    International Nuclear Information System (INIS)

    Howard, P.A.

    1976-03-01

    One form of the sputtering phenomena, the heat-transfer process that occurs when an initially hot vertical surface is cooled by a falling liquid film, was examined from a new experimental approach. The sputtering front is the lowest wetted position on the vertical surface and is characterized by a short region of intense nucleate boiling. The sputtering front progresses downward at nearly a constant rate, the surface below the sputtering front being dry and almost adiabatic. This heat-transfer process is of interest in the analysis of some of the performance aspects of emergency core-cooling systems of light-water reactors. An experimental apparatus was constructed to examine the heat-transfer characteristics of a sputtering front. In the present study, a heat source of sufficient intensity was located immediately below the sputtering front, which prevented its downward progress, thus permitting detailed measurements of steady-state surface temperatures throughout a sputtering front. Experimental evidence showed the sputtering front to correspond to a critical heat-flux (CHF) phenomenon. Data were obtained with water flow rates of 350-1600 lb/sub m//hr-ft and subcoolings of 40-140 0 F on a 3 / 8 -in. solid copper rod at 1 atm. A two-dimensional analytical model was developed to describe a stationary sputtering front where the wet-dry interface corresponds to a CHF phenomena and the dry zone is adiabatic. This model is nonlinear because of the temperature dependence of the heat-transfer coefficient in the wetted region and has yielded good agreement with data. A simplified one-dimensional approximation was developed which adequately describes these data. Finally, by means of a coordinate transformation and additional simplifying assumptions, this analysis was extended to analyze moving sputtering fronts, and reasonably good agreement with reported data was shown

  19. Transport phenomena and drying of solids and particulate materials

    CERN Document Server

    Lima, AG

    2014-01-01

    The purpose of this book, Transport Phenomena and Drying of Solids and Particulate Materials, is to provide a collection of recent contributions in the field of heat and mass transfer, transport phenomena, drying and wetting of solids and particulate materials. The main benefit of the book is that it discusses some of the most important topics related to the heat and mass transfer in solids and particulate materials. It includes a set of new developments in the field of basic and applied research work on the physical and chemical aspects of heat and mass transfer phenomena, drying and wetting processes, namely, innovations and trends in drying science and technology, drying mechanism and theory, equipment, advanced modelling, complex simulation and experimentation. At the same time, these topics will be going to the encounter of a variety of scientific and engineering disciplines. The book is divided in several chapters that intend to be a resume of the current state of knowledge for benefit of professional c...

  20. Auroral and sub-auroral phenomena: an electrostatic picture

    Directory of Open Access Journals (Sweden)

    J. De Keyser

    2010-02-01

    Full Text Available Many auroral and sub-auroral phenomena are manifestations of an underlying magnetosphere-ionosphere coupling. In the electrostatic perspective the associated auroral current circuit describes how the generator (often in the magnetosphere is connected to the load (often in the ionosphere through field-aligned currents. The present paper examines the generic properties of the current continuity equation that characterizes the auroral circuit. The physical role of the various elements of the current circuit is illustrated by considering a number of magnetospheric configurations, various auroral current-voltage relations, and different types of behaviour of the ionospheric conductivity. Based on realistic assumptions concerning the current-voltage relation and the ionospheric conductivity, a comprehensive picture of auroral and sub-auroral phenomena is presented, including diffuse aurora, discrete auroral arcs, black aurora, and subauroral ion drift. The electrostatic picture of field-aligned potential differences, field-aligned currents, ionospheric electric fields and plasma drift, and spatial scales for all these phenomena is in qualitative agreement with observations.

  1. Coherence Phenomena in Coupled Optical Resonators

    Science.gov (United States)

    Smith, D. D.; Chang, H.

    2004-01-01

    We predict a variety of photonic coherence phenomena in passive and active coupled ring resonators. Specifically, the effective dispersive and absorptive steady-state response of coupled resonators is derived, and used to determine the conditions for coupled-resonator-induced transparency and absorption, lasing without gain, and cooperative cavity emission. These effects rely on coherent photon trapping, in direct analogy with coherent population trapping phenomena in atomic systems. We also demonstrate that the coupled-mode equations are formally identical to the two-level atom Schrodinger equation in the rotating-wave approximation, and use this result for the analysis of coupled-resonator photon dynamics. Notably, because these effects are predicted directly from coupled-mode theory, they are not unique to atoms, but rather are fundamental to systems of coherently coupled resonators.

  2. Transport phenomena in strongly correlated Fermi liquids

    CERN Document Server

    Kontani, Hiroshi

    2013-01-01

    In conventional metals, various transport coefficients are scaled according to the quasiparticle relaxation time, \\tau, which implies that the relaxation time approximation (RTA) holds well. However, such a simple scaling does not hold in many strongly correlated electron systems, reflecting their unique electronic states. The most famous example would be cuprate high-Tc superconductors (HTSCs), where almost all the transport coefficients exhibit a significant deviation from the RTA results. To better understand the origin of this discrepancy, we develop a method for calculating various transport coefficients beyond the RTA by employing field theoretical techniques. Near the magnetic quantum critical point, the current vertex correction (CVC), which describes the electron-electron scattering beyond the relaxation time approximation, gives rise to various anomalous transport phenomena. We explain anomalous transport phenomena in cuprate HTSCs and other metals near their magnetic or orbital quantum critical poi...

  3. An introduction to the neutron transport phenomena

    International Nuclear Information System (INIS)

    Kulikowska, T.

    2001-01-01

    The main goal of the present lecture is to is to give a short description of neutron transport phenomena limited to those definitions that are necessary to understand the approach to practical solution of the problem given in the second lecture on reactor lattice transport calculations. The discussion of the neutron cross sections has been skipped as other lecturers have treated this subject in detail. (author)

  4. A LCIA Model Considering Pollution Transfer Phenomena

    OpenAIRE

    Yu, Xi; Sekhari, Aicha; Nongaillard, Antoine; Bouras, Abdelaziz; Yu, Suiran; Yang, Qingyan

    2013-01-01

    Part 7: PLM and Influence of/from Social Networks; International audience; Due to market pressure and government regulations, environmental consciousness in manufacturing is becoming increasingly important. Currently, the global environmental impact (EI) of a product is a crucial criterion to judge its environmental performance. Many models were proposed in the last three decades to evaluate the global EI of products, but none of them considers the pollution transfer phenomena (PTP) of produc...

  5. Occult Phenomena in Sherlock Holmes the Movie

    OpenAIRE

    NAMAZCARRA, CHRIESHER

    2014-01-01

    Keywords: Occult phenomena, Sherlock Holmes, movie. Lately, it is not difficult for people to find occult practices. There are many television programs and movie which air mystical programme aggressively to raise the rating and attract the viewers. A movie that raise occultism theme is Sherlock Holmes, the Movie. This movie tells about the struggle of detective Sherlock Holmes to fight the black magic power of Lord Blackwood.To carry out the study, the theories of Occultism such as the secrec...

  6. Attophysics of Thermal Phenomena in Carbon Nanotubes

    OpenAIRE

    Kozlowski, Miroslaw; Marciak-Kozlowska, Janina

    2005-01-01

    In this paper heat transport in carbon nanotubes is investigated. When the dimension of the structure is of the order of the de Broglie wave length transport phenomena must be analysed by quantum mechanics. In this paper we derived the Dirac type thermal equation .The solution of the equation for the temperature fields for electrons can either be damped or can oscillate depending on the dynamics of the scattering. Key words: Carbon nanotubes, ultrashort laser pulses, Dirac thermal equation, t...

  7. Guilt phenomena in medicine, psychology, and psychiatry

    OpenAIRE

    Germanavičius, Arūnas

    2014-01-01

    This article gives an overview of various aspects of guilt arising in psychiatry as an interdisciplinary field, where different conceptions of medical ethics and of psychology lead to different practices. The analysis of modern psychiatric phenomena of guilt using a historical approach is based on the concept of guilt expounded by one of the world’s greatest philosophers, Karl Theodor Jaspers, who has made a huge impact on the formation of psychiatric research. The author presents an original...

  8. Quantum Chess: Making Quantum Phenomena Accessible

    Science.gov (United States)

    Cantwell, Christopher

    Quantum phenomena have remained largely inaccessible to the general public. There tends to be a scare factor associated with the word ``Quantum''. This is in large part due to the alien nature of phenomena such as superposition and entanglement. However, Quantum Computing is a very active area of research and one day we will have games that run on those quantum computers. Quantum phenomena such as superposition and entanglement will seem as normal as gravity. Is it possible to create such games today? Can we make games that are built on top of a realistic quantum simulation and introduce players of any background to quantum concepts in a fun and mentally stimulating way? One of the difficulties with any quantum simulation run on a classical computer is that the Hilbert space grows exponentially, making simulations of an appreciable size physically impossible due largely to memory restrictions. Here we will discuss the conception and development of Quantum Chess, and how to overcome some of the difficulties faced. We can then ask the question, ``What's next?'' What are some of the difficulties Quantum Chess still faces, and what is the future of quantum games?

  9. An interpretation of passive containment cooling phenomena

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Bum-Jin [Ministry of Science & Technology, Kyunggi-Do (Korea, Democratic People`s Republic of); Kang, Chang-Sun, [Seoul National Univ. (Korea, Democratic People`s Republic of)

    1995-09-01

    A simplified interpretation model for the cooling capability of the Westinghouse type PCCS is proposed in this paper. The PCCS domain was phenomenologically divided into 3 regions; water entrance effect region, asymptotic region, and air entrance effect region. The phenomena in the asymptotic region is focused in this paper. Due to the very large height to thickness ratio of the water film, the length of the asymptotic region is estimated to be over 90% of the whole domain. Using the analogy between heat and mass transfer phenomena in a turbulent situation, a new dependent variable combining temperature and vapor mass fraction was defined. The similarity between the PCCS phenomena, which contains the sensible and latent heat transfer, and the buoyant air flow on a vertical heated plate is derived. The modified buoyant coefficient and thermal conductivity were defined. Using these newly defined variable and coefficients, the modified correlation for the interfacial heat fluxes and the ratios of latent heat transfer to sensible heat transfer is established. To verify the accuracy of the correlation, the results of this study were compared with the results of other numerical analyses performed for the same configuration and they are well within the range of 15% difference.

  10. A treatise on interpolar transport phenomena

    Energy Technology Data Exchange (ETDEWEB)

    Einarsrud, Kristian Etienne

    2012-07-01

    This thesis contributes to the understanding of mechanisms for mass transport in aluminium electrolysis cells. Fundamental studies are undertaken of flow patterns and mass transport in the interpolar region under various operating conditions. A coupled model predicting the turbulent electrolyte flow, under the influence of both electromagnetism and forces from buoyant gas bubbles, crucial for better prediction of mass transfer mechanisms and voltage oscillations, has been developed from first principles. The model is validated against experiments performed on a lab scale electrolysis cell. Both modelling and experiments are performed within the scope of this thesis. Experiments on lab- and industrial scale cells have been conducted in order to study the behaviour of anodic gas bubbles under various operating conditions. On industrial scale, bubble related signals show typical frequencies in the range 0.5 to 2 Hz, with amplitudes up to 5% around the mean voltage. Results indicate that the bubble related voltage oscillations increase in both frequency and magnitude with increasing anode age, the latter of which due to the diminishing in influence of slots. No significant correlation between anode pairs is identified, suggesting that models treating individual anodes are meaningful also on an industrial scale. Due to challenges related to multiple simultaneous phenomena occurring on industrial scales, a series of lab scale measurements have been performed, in order to obtain quantitative data for model validation. The lab scale experimental cell allowed for different current densities, interpolar distances and inclination angles, thus spanning ranges typically encountered on the industrial scale. Lab scale frequencies are found to be in the range 0.25 to 0.65 Hz, with magnitude of up to 4% around the mean voltage. The magnitude of the oscillations decreases with increasing anode age, due to increased rounding of the initially sharp anode edges. The traditional voltage

  11. Application of digital image processing techniques to faint solar flare phenomena

    Science.gov (United States)

    Glackin, D. L.; Martin, S. F.

    1980-01-01

    Digital image processing of eight solar flare events was performed using the Video Information Communication and Retrieval language in order to study moving emission fronts, flare halos, and Moreton waves. The techniques used include contrast enhancement, isointensity contouring, the differencing of images, spatial filtering, and geometrical registration. The spatial extent and temporal behavior of the faint phenomena is examined along with the relation of the three types of phenomena to one another. The image processing techniques make possible the detailed study of the history of the phenomena and provide clues to their physical nature.

  12. Application of digital image processing techniques to faint solar flare phenomena

    International Nuclear Information System (INIS)

    Glackin, D.L.; Martin, S.F.

    1980-01-01

    Digital image processing of eight solar flare events was performed using the Video Information Communication and Retrieval language in order to study moving emission fronts, flare halos, and Moreton waves. The techniques used include contrast enhancement, isointensity contouring, the differencing of images, spatial filtering, and geometrical registration. The spatial extent and temporal behavior of the faint phenomena is examined along with the relation of the three types of phenomena to one another. The image processing techniques make possible the detailed study of the history of the phenomena and provide clues to their physical nature

  13. Power-law phenomena in adhesive de-bonding

    Science.gov (United States)

    Kendall, Gay

    Acoustic emission (AE) was recorded during the peeling of pressure-sensitive adhesive (PSA) tapes from their surfaces. The viscous and non-linear behavior of PSA tapes produces significant energy dissipation in the form of adhesive fibril formation, elongation and final failure within the peel zone. AE generated during the peeling process corresponds to the final de-bonding event, in which elastic energy is rapidly released to the substrate. The recording and analyzing of AE generated during peeling is used here in a novel application for characterizing microscopic de-bonding events. Present results indicate that the distribution of AE event magnitudes have the form of power-laws and the power spectral densities have the form of flicker noise. Both power-law dependencies and flicker noise are recognized as consequences of SOC in homogeneous systems. A significant feature of power-law dependencies is the absence of any characteristic length or time scales. The present results, however, indicate that the interface is not homogeneous and that pre-existing surface conditions cause non-uniform adhesive bonding. This is heavily supported by the literature regarding the nature of engineering surfaces. Consequentially, Mandelbrot's fractal concepts were applied to characterize the heterogeneous adhesive interface, and to investigate the relation of interfacial structure with the power-law features of the PSA de-bonding process. It is concluded that fractally distributed variations in adhesive bond strengths at the PSA-glass interface produce the observed hyperbolic distributions in AE events. All the formalism of SOC: applies under this alternative explanation of PSA de-bonding phenomena because of the observed hyperbolic distributions of the AE data. It may be that the explanation based on an underlying fractal structure may be a more general explanation to power law and flicker noise phenomena than the SOC model for heterogeneous systems.

  14. Earth is speaking: listen her! On-line questionnaire about anomalous geological and biological phenomena

    Science.gov (United States)

    Sciarra, Alessandra; Quattrocchi, Fedora; Cantucci, Barbara; Mazzarini, Francesco

    2014-05-01

    Earthquakes can be associated with non-seismic phenomena which may manifest many weeks before and after the main shock. These phenomena are characterized by ground fractures and soil liquefactions at surface often coupled with degassing events, chemical alterations of water and soils, changes in temperature and/or waters level in the epicentral area. Further manifestations include radio disturbances and light emissions. On the other hand, anomalous behavior of animals has been reported to occur before environmental changes. The co-occurrence of several phenomena may be considered as a signal of subsurface changes, and their analysis may be used as possible forecast indicators for seismic events, landslides, damages in infrastructure (e.g., dam) and groundwaters contamination. In order to obtain an accurate statistical analysis of these factors, a pre-crisis large database over a prolonged period of time is a pre-requisite. To this end, we elaborated a questionnaire for the population to pick up signs about anomalous phenomena like as: animal behavior, geological manifestations, effect on vegetation, degassing, changes on aquifers, wells and springs. After the January 25, 2013, mainshock (ML 4.8) in the Garfagnana seismic district, the Bagni di Lucca Municipality was selected as pilot site for testing this questionnaire. The complexity, variety and extension of this territory (165 kmq) sound suitable for this project. Bagni di Lucca is located in the southern border of the Garfagnana seismogenic source, characterized by the carbonate Mesozoic sequences and the Tertiary terrigenous sedimentary deposits of the Tuscan Nappe. The questionnaire was published on Bagni di Lucca web site (https://docs.google.com/file/d/0Bzw3vOYX47XoTGltTVJRbkJuajA/edit) in collaboration with Municipal Commitee, Local Civil Protection and Local Red Cross, and sent by ordinary mail to the citizenry. It is possible to answer to the questionnaire, also anonymously, direct on line (https

  15. Uranium Pyrophoricity Phenomena and Prediction (FAI/00-39)

    Energy Technology Data Exchange (ETDEWEB)

    PLYS, M.G.

    2000-10-10

    The purpose of this report is to provide a topical reference on the phenomena and prediction of uranium pyrophoricity for the Hanford Spent Nuclear Fuel (SNF) Project with specific applications to SNF Project processes and situations. Spent metallic uranium nuclear fuel is currently stored underwater at the K basins in the Hanford 100 area, and planned processing steps include: (1) At the basins, cleaning and placing fuel elements and scrap into stainless steel multi-canister overpacks (MCOs) holding about 6 MT of fuel apiece; (2) At nearby cold vacuum drying (CVD) stations, draining, vacuum drying, and mechanically sealing the MCOs; (3) Shipping the MCOs to the Canister Storage Building (CSB) on the 200 Area plateau; and (4) Welding shut and placing the MCOs for interim (40 year) dry storage in closed CSB storage tubes cooled by natural air circulation through the surrounding vault. Damaged fuel elements have exposed and corroded fuel surfaces, which can exothermically react with water vapor and oxygen during normal process steps and in off-normal situations, A key process safety concern is the rate of reaction of damaged fuel and the potential for self-sustaining or runaway reactions, also known as uranium fires or fuel ignition. Uranium metal and one of its corrosion products, uranium hydride, are potentially pyrophoric materials. Dangers of pyrophoricity of uranium and its hydride have long been known in the U.S. Department of Energy (Atomic Energy Commission/DOE) complex and will be discussed more below; it is sufficient here to note that there are numerous documented instances of uranium fires during normal operations. The motivation for this work is to place the safety of the present process in proper perspective given past operational experience. Steps in development of such a perspective are: (1) Description of underlying physical causes for runaway reactions, (2) Modeling physical processes to explain runaway reactions, (3) Validation of the method

  16. Introduction to wave scattering, localization, and mesoscopic phenomena

    CERN Document Server

    Sheng, Ping

    1995-01-01

    This book gives readers a coherent picture of waves in disordered media, including multiple scattered waves. The book is intended to be self-contained, with illustrated problems and solutions at the end of each chapter to serve the double purpose of filling out the technical and mathematical details and giving the students exercises if used as a course textbook.The study of wave behavior in disordered media has applications in:Condensed matter physics (semi and superconductor nanostructures and mesoscopic phenomena)Materials science/analytical chemistry (analysis of composite and crystalline structures and properties)Optics and electronics (microelectronic and optoelectronic devices)Geology (seismic exploration of Earths subsurface)

  17. Linguistic Phenomena in Men and Women - TOT, FOK, Verbal Fluency

    OpenAIRE

    Ewa Szepietowska; Barbara Gawda; Agnieszka Gawda

    2013-01-01

    The aim of this study is to describe the differences between women and men in the phenomena of feeling of knowing/know (FOK), tip of the tongue (TOT), and verbal fluency. Two studies are presented. The first included a group of 60 participants and focused on the analysis of FOK and TOT in men and women. The second study described the performance of 302 participants in verbal fluency tasks. Both studies showed that sex is not a significant predictor of linguistic abilities. Rather, the main fa...

  18. Impact of measurable physical phenomena on contact thermal comfort

    Science.gov (United States)

    Fojtlín, Miloš; Pokorný, Jan; Fišer, Jan; Toma, Róbert; Tuhovčák, Ján

    Cabin HVAC (Heating Ventilation and Air-conditioning) systems have become an essential part of personal vehicles as demands for comfortable transport are still rising. In fact, 85 % of the car trips in Europe are shorter than 18 km and last only up to 30 minutes. Under such conditions, the HVAC unit cannot often ensure desired cabin environment and passengers are prone to experience thermal stress. For this reason, additional comfort systems, such as heated or ventilated seats, are available on the market. However, there is no straightforward method to evaluate thermal comfort at the contact surfaces nowadays. The aim of this work is to summarise information about heated and ventilated seats. These technologies use electrical heating and fan driven air to contact area in order to achieve enhanced comfort. It is also expected, that such measures may contribute to lower energy consumption. Yet, in real conditions it is almost impossible to measure the airflow through the ventilated seat directly. Therefore, there is a need for an approach that would correlate measurable physical phenomena with thermal comfort. For this reason, a method that exploits a measurement of temperatures and humidity at the contact area is proposed. Preliminary results that correlate comfort with measurable physical phenomena are demonstrated.

  19. Impact of measurable physical phenomena on contact thermal comfort

    Directory of Open Access Journals (Sweden)

    Fojtlín Miloš

    2017-01-01

    Full Text Available Cabin HVAC (Heating Ventilation and Air-conditioning systems have become an essential part of personal vehicles as demands for comfortable transport are still rising. In fact, 85 % of the car trips in Europe are shorter than 18 km and last only up to 30 minutes. Under such conditions, the HVAC unit cannot often ensure desired cabin environment and passengers are prone to experience thermal stress. For this reason, additional comfort systems, such as heated or ventilated seats, are available on the market. However, there is no straightforward method to evaluate thermal comfort at the contact surfaces nowadays. The aim of this work is to summarise information about heated and ventilated seats. These technologies use electrical heating and fan driven air to contact area in order to achieve enhanced comfort. It is also expected, that such measures may contribute to lower energy consumption. Yet, in real conditions it is almost impossible to measure the airflow through the ventilated seat directly. Therefore, there is a need for an approach that would correlate measurable physical phenomena with thermal comfort. For this reason, a method that exploits a measurement of temperatures and humidity at the contact area is proposed. Preliminary results that correlate comfort with measurable physical phenomena are demonstrated.

  20. Analysis and design of Fuel Cycle Plant for natural phenomena hazards

    International Nuclear Information System (INIS)

    Horsager, B.K.

    1985-01-01

    A description of the Design Basis and the analysis and design methods used for natural phenomena at the Fuel Cycle Plant at Hanford, Washington is presented. A physical description of the main process facility and the auxiliary emergency and support facilities is given. The mission of the facility is presented and a brief description of the processes which will take place within the facility is given. The Design Criteria and design bases for natural phenomena including tornados, earthquakes and volcanic eruptions are described

  1. ACCIDENT PHENOMENA OF RISK IMPORTANCE PROJECT - Continued RESEARCH CONCERNING SEVERE ACCIDENT PHENOMENA AND MANAGEMENT IN Sweden

    International Nuclear Information System (INIS)

    Rolandson, S.; Mueller, F.; Loevenhielm, G.

    1997-01-01

    Since 1988 all reactors in Sweden have mitigating measures, such as filtered vents, implemented. In parallel with the work of implementing these measures, a cooperation effort (RAMA projects) between the Swedish utilities and the Nuclear Power Inspectorate was performed to acquire sufficient knowledge about severe accident research work. The on-going project has the name Accident Phenomena of Risk Importance 3. In this paper, we will give background information about severe accident management in Sweden. In the Accident Phenomena of Risk Importance 3 project we will focus on the work concerning coolability of melted core in lower plenum which is the main focus of the In-vessel Coolability Task Group within the Accident Phenomena of Risk Importance 3 project. The Accident Phenomena of Risk Importance 3 project has joined on international consortium and the in-vessel cooling experiments are performed by Fauske and Associates, Inc. in Burr Ridge, Illinois, United States America, Sweden also intends to do one separate experiment with one instrument penetration we have in Swedish/Finnish BWR's. Other parts of the Accident Phenomena of Risk Importance 3 project, such as support to level 2 studies, the research at Royal Institute of Technology and participation in international programs, such as Cooperative Severe Accident Research Program, Advanced Containment Experiments and PHEBUS will be briefly described in the paper

  2. Rod Driven Frequency Entrainment and Resonance Phenomena

    Directory of Open Access Journals (Sweden)

    Christina Salchow

    2016-08-01

    Full Text Available A controversy exists on photic driving in the human visual cortex evoked by intermittent photic stimulation. Frequency entrainment and resonance phenomena are reported for frequencies higher than 12 Hz in some studies while missing in others. We hypothesized that this might be due to different experimental conditions, since both high and low intensity light stimulation were used. However, most studies do not report radiometric measurements, which makes it impossible to categorize the stimulation according to photopic, mesopic, and scotopic vision. Low intensity light stimulation might lead to scotopic vision, where rod perception dominates. In this study, we investigated photic driving for rod-dominated visual input under scotopic conditions. Twelve healthy volunteers were stimulated with low intensity light flashes at 20 stimulation frequencies, leading to rod activation only. The frequencies were multiples of the individual alpha frequency (α of each volunteer in the range from 0.40–2.30*α. 306-channel whole head magnetoencephalography recordings were analyzed in time, frequency, and spatiotemporal domains with the Topographic Matching Pursuit algorithm. We found resonance phenomena and frequency entrainment for stimulations at or close to the individual alpha frequency (0.90–1.10*α and half of the alpha frequency (0.40–0.55*α. No signs of resonance and frequency entrainment phenomena were revealed around 2.00*α. Instead, on-responses at the beginning and off-responses at the end of each stimulation train were observed for the first time in a photic driving experiment at frequencies of 1.30–2.30*α, indicating that the flicker fusion threshold was reached. All results, the resonance and entrainment as well as the fusion effects, provide evidence for rod-dominated photic driving in the visual cortex.

  3. Fast Particle Methods for Multiscale Phenomena Simulations

    Science.gov (United States)

    Koumoutsakos, P.; Wray, A.; Shariff, K.; Pohorille, Andrew

    2000-01-01

    We are developing particle methods oriented at improving computational modeling capabilities of multiscale physical phenomena in : (i) high Reynolds number unsteady vortical flows, (ii) particle laden and interfacial flows, (iii)molecular dynamics studies of nanoscale droplets and studies of the structure, functions, and evolution of the earliest living cell. The unifying computational approach involves particle methods implemented in parallel computer architectures. The inherent adaptivity, robustness and efficiency of particle methods makes them a multidisciplinary computational tool capable of bridging the gap of micro-scale and continuum flow simulations. Using efficient tree data structures, multipole expansion algorithms, and improved particle-grid interpolation, particle methods allow for simulations using millions of computational elements, making possible the resolution of a wide range of length and time scales of these important physical phenomena.The current challenges in these simulations are in : [i] the proper formulation of particle methods in the molecular and continuous level for the discretization of the governing equations [ii] the resolution of the wide range of time and length scales governing the phenomena under investigation. [iii] the minimization of numerical artifacts that may interfere with the physics of the systems under consideration. [iv] the parallelization of processes such as tree traversal and grid-particle interpolations We are conducting simulations using vortex methods, molecular dynamics and smooth particle hydrodynamics, exploiting their unifying concepts such as : the solution of the N-body problem in parallel computers, highly accurate particle-particle and grid-particle interpolations, parallel FFT's and the formulation of processes such as diffusion in the context of particle methods. This approach enables us to transcend among seemingly unrelated areas of research.

  4. Simple models of equilibrium and nonequilibrium phenomena

    International Nuclear Information System (INIS)

    Lebowitz, J.L.

    1987-01-01

    This volume consists of two chapters of particular interest to researchers in the field of statistical mechanics. The first chapter is based on the premise that the best way to understand the qualitative properties that characterize many-body (i.e. macroscopic) systems is to study 'a number of the more significant model systems which, at least in principle are susceptible of complete analysis'. The second chapter deals exclusively with nonequilibrium phenomena. It reviews the theory of fluctuations in open systems to which they have made important contributions. Simple but interesting model examples are emphasised

  5. Earthquake Prediction: Seismo-Electromagnetic Phenomena

    Science.gov (United States)

    Park, Stephen

    Earthquake Prediction: Seismo-Electromagnetic Phenomena is a review of research on electromagnetic emissions (EME) as precursors to earthquakes. The authors state in the introduction that the book is primarily based on their own work, so there is heavy emphasis on the Russian literature. Fewer than 15% of the references are taken from European, Asian, and North American sources. Though the title implies a diverse range of signals, the authors focus mostly on EME in the kHz-MHz range. There is little discussion of signals in the ULFand lower-frequency bands.

  6. Modeling in transport phenomena a conceptual approach

    CERN Document Server

    Tosun, Ismail

    2007-01-01

    Modeling in Transport Phenomena, Second Edition presents and clearly explains with example problems the basic concepts and their applications to fluid flow, heat transfer, mass transfer, chemical reaction engineering and thermodynamics. A balanced approach is presented between analysis and synthesis, students will understand how to use the solution in engineering analysis. Systematic derivations of the equations and the physical significance of each term are given in detail, for students to easily understand and follow up the material. There is a strong incentive in science and engineering to

  7. Electrodiffusion phenomena in neuroscience: a neglected companion.

    Science.gov (United States)

    Savtchenko, Leonid P; Poo, Mu Ming; Rusakov, Dmitri A

    2017-09-19

    The emerging technological revolution in genetically encoded molecular sensors and super-resolution imaging provides neuroscientists with a pass to the real-time nano-world. On this small scale, however, classical principles of electrophysiology do not always apply. This is in large part because the nanoscopic heterogeneities in ionic concentrations and the local electric fields associated with individual ions and their movement can no longer be ignored. Here, we review basic principles of molecular electrodiffusion in the cellular environment of organized brain tissue. We argue that accurate interpretation of physiological observations on the nanoscale requires a better understanding of the underlying electrodiffusion phenomena.

  8. Ricci flows, wormholes and critical phenomena

    Energy Technology Data Exchange (ETDEWEB)

    Husain, Viqar; Seahra, Sanjeev S [Department of Mathematics and Statistics, University of New Brunswick, Fredericton, NB E3B 5A3 (Canada)

    2008-11-21

    We study the evolution of wormhole geometries under the Ricci flow using numerical methods. Depending on values of initial data parameters, wormhole throats either pinch off or evolve to a monotonically growing state. The transition between these two behaviors exhibits a form of critical phenomena reminiscent of that observed in gravitational collapse. Similar results are obtained for initial data that describe space bubbles attached to asymptotically flat regions. Our numerical methods are applicable to 'matter-coupled' Ricci flows derived from conformal invariance in string theory. (fast track communication)

  9. Nanoscale and microscale phenomena fundamentals and applications

    CERN Document Server

    Khandekar, Sameer

    2015-01-01

    The book is an outcome of research work in the areas of nanotechnology, interfacial science, nano- and micro-fluidics and manufacturing, soft matter, and transport phenomena at nano- and micro-scales. The contributing authors represent prominent research groups from Indian Institute of Technology Bombay, Indian Institute of Technology Kanpur and Indian Institute of Science, Bangalore. The book has 13 chapters and the entire work presented in the chapters is based on research carried out over past three years. The chapters are designed with number of coloured illustrations, figures and tables. The book will be highly beneficial to academicians as well as industrial professionals working in the mentioned areas.

  10. Phenomena and parameters important to burnup credit

    International Nuclear Information System (INIS)

    Parks, C.V.; Dehart, M.D.; Wagner, J.C.

    2001-01-01

    Since the mid-1980s, a significant number of studies have been directed at understanding the phenomena and parameters important to implementation of burnup credit in out-of-reactor applications involving pressurized-water- reactor (PWR) spent fuel. The efforts directed at burnup credit involving boiling-water-reactor (BWR) spent fuel have been more limited. This paper reviews the knowledge and experience gained from work performed in the United States and other countries in the study of burnup credit. Relevant physics and analysis phenomenon are identified, and an assessment of their importance to burnup credit implementation for transport and dry cask storage is given. (author)

  11. Advances in modelling of condensation phenomena

    Energy Technology Data Exchange (ETDEWEB)

    Liu, W.S.; Zaltsgendler, E. [Ontario Hydro Nuclear, Toronto (Canada); Hanna, B. [Atomic Energy of Canada Limited, Pinawa, Manitoba (Canada)

    1997-07-01

    The physical parameters in the modelling of condensation phenomena in the CANDU reactor system codes are discussed. The experimental programs used for thermal-hydraulic code validation in the Canadian nuclear industry are briefly described. The modelling of vapour generation and in particular condensation plays a key role in modelling of postulated reactor transients. The condensation models adopted in the current state-of-the-art two-fluid CANDU reactor thermal-hydraulic system codes (CATHENA and TUF) are described. As examples of the modelling challenges faced, the simulation of a cold water injection experiment by CATHENA and the simulation of a condensation induced water hammer experiment by TUF are described.

  12. Heavenly Bodies and Phenomena in Petroglyphs

    Science.gov (United States)

    Tokhatyan, Karen

    2016-12-01

    In Armenian culture are amply reflected realities connected with Universe. Their figurative expressions are also petroglyphs in which there are representations of solar signs, swastika, Moon crescend, planets, stars, star groups, constellations, Milky Way, Earth. Among heavenly and atmospheric phenomena are: eclipce, meteor, comet, ligthning, cloud, rain and rainbow. There are many products of scientific thinking: stellar maps, calendars, compasses, astronomical records, Zodiac signs and ideograms. Thousands of the Armenian petroglyphs that were created millennia ago by an indigenous ethnos - Armenians, point to the significant place of celestial bodies and luminaries, especially the Sun, stars, and stellar constellations in our ancestors' cosmological perceptions.

  13. Electrical breakdown phenomena of dielectric elastomers

    DEFF Research Database (Denmark)

    Yu, Liyun; Mateiu, Ramona Valentina; Skov, Anne Ladegaard

    years. However, optimization with respect to the dielectric permittivity solely may lead to other problematic phenomena such as premature electrical breakdown. In this work, we focus on the chloro propyl functionalized silicone elastomers prepared in Madsen et al[2] and we investigate the electrical...... breakdown patterns of two similar chloro propyl functionalized silicone elastomers which break down electrically in a rather different way as well as we compare them to a silicone based reference. Scanning Electron Microscopy (SEM) and Energy Dispersive X-Ray Spectroscopy (EDS) are used to evaluate...... the elastomers after electrical breakdown....

  14. Ion transport phenomena in polymeric electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Ciosek, M.; Sannier, L.; Siekierski, M.; Wieczorek, W. [Warsaw University of Technology, Faculty of Chemistry, Noakowskiego 3, 00-664 Warsaw (Poland); Golodnitsky, D.; Peled, E. [School of Chemistry, Tel Aviv University, Tel Aviv 69978 (Israel); Scrosati, B. [Dipartimento di Chimica, Universita di Roma ' ' La Sapienza' ' , P. le A. Moro 4, 00185 Rome (Italy); Glowinkowski, S. [Faculty of Physics, Adam Mickiewicz University, Ulmultowska 86, 61-614 Poznan (Poland)

    2007-12-31

    The aim of the present work is to generalize an ion transport phenomena observed in composite polymeric electrolytes using the previously developed models as well as design a new approach which would be helpful in describing changes in conductivity and lithium ion transference numbers occurring upon addition of fillers to polymeric electrolytes. The concept is based on the observation of changes in ionic associations in the polymeric electrolytes studied in a wide salt concentration range. The idea is illustrated by the results coming from a variety of electrochemical and structural data obtained for composite electrolytes containing specially designed inorganic and organic fillers. (author)

  15. Generalized Bloch theorem and chiral transport phenomena

    Science.gov (United States)

    Yamamoto, Naoki

    2015-10-01

    Bloch theorem states the impossibility of persistent electric currents in the ground state of nonrelativistic fermion systems. We extend this theorem to generic systems based on the gauged particle number symmetry and study its consequences on the example of chiral transport phenomena. We show that the chiral magnetic effect can be understood as a generalization of the Bloch theorem to a nonequilibrium steady state, similarly to the integer quantum Hall effect. On the other hand, persistent axial currents are not prohibited by the Bloch theorem and they can be regarded as Pauli paramagnetism of relativistic matter. An application of the generalized Bloch theorem to quantum time crystals is also discussed.

  16. Current position on severe accident phenomena

    International Nuclear Information System (INIS)

    Henry, Robert E.

    2004-01-01

    The phenomena addressed in this lecture are: in-vessel and ex-vessel hydrogen generation; in-vessel and in-containment natural circulation, steam explosions, direct containment heating, core-concrete interaction; debris coolability, containment strength/failure. The following events were modeled: axial and radial power distribution, two-phase level in the core, steam generation in covered section, decay heat generation, convection to gas, cladding oxidation, cold ballooning and rupture, natural circulation between the core and upper plenum, hydrogen generation, core meltdown, reflooding. Differences between PWR and BWR type reactors

  17. Space Commercial Opportunities for Fluid Physics and Transport Phenomena Applications

    Science.gov (United States)

    Gavert, R.

    2000-01-01

    Microgravity research at NASA has been an undertaking that has included both science and commercial approaches since the late 80s and early 90s. The Fluid Physics and Transport Phenomena community has been developed, through NASA's science grants, into a valuable base of expertise in microgravity science. This was achieved through both ground and flight scientific research. Commercial microgravity research has been primarily promoted thorough NASA sponsored Centers for Space Commercialization which develop cost sharing partnerships with industry. As an example, the Center for Advanced Microgravity Materials Processing (CAMMP)at Northeastern University has been working with cost sharing industry partners in developing Zeolites and zeo-type materials as an efficient storage medium for hydrogen fuel. Greater commercial interest is emerging. The U.S. Congress has passed the Commercial Space Act of 1998 to encourage the development of a commercial space industry in the United States. The Act has provisions for the commercialization of the International Space Station (ISS). Increased efforts have been made by NASA to enable industrial ventures on-board the ISS. A Web site has been established at http://commercial/nasa/gov which includes two important special announcements. One is an open request for entrepreneurial offers related to the commercial development and use of the ISS. The second is a price structure and schedule for U.S. resources and accommodations. The purpose of the presentation is to make the Fluid Physics and Transport Phenomena community, which understands the importance of microgravity experimentation, aware of important aspects of ISS commercial development. It is a desire that this awareness will be translated into a recognition of Fluid Physics and Transport Phenomena application opportunities coordinated through the broad contacts of this community with industry.

  18. Proceedings of the 17. International conference on phenomena in ionized gases held at Budapest, Hungary, 8-12 Jul 1985 v. 1

    International Nuclear Information System (INIS)

    Bakos, J.S.; Soerlei, Zsuzsa

    1985-06-01

    In the first part of the Conference Proceedings the complete text of papers are published in the following sessions (with the number of papers in each session in parentheses): Kinetics and Thermodynamics of Plasmas Including Transport Phenomena (19), Waves and Instabilities in Plasmas (54), Plasma-Beam Interactions Including Laser Beams (18), Plasmas in Astrophysics (12), Physical Aspects of Plasma Chemistry (13), Non-Ideal Plasmas (11), Elementary Processes (32), Electrode and Surface Effects (29). Papers falling in the INIS scope are indexed separately. (R.P.)

  19. Structure and reactivity of heterogeneous surfaces and study of the geometry of surface complexes. Progress report, January 1, 1984-December 31, 1984

    International Nuclear Information System (INIS)

    Landman, U.

    1984-01-01

    Since the beginning of this project, our group has been involved in theoretical studies of surface phenomena and processes, aimed toward increasing our understanding of fundamental processes which govern the properties of material surfaces. Our studies cover a wide spectrum of surface phenomena: surface reactivity, surface crystallography, electronic and vibrational structure, dynamical processes, phase transformations and phase change, the properties of interfaces and investigations of material processing and novel materials preparation techniques. In these investigations we develop and employ analytical and novel numerical, simulation, methods for the study of complex surface phenomena. Our recent surface molecular dynamics studies and simulations of laser annealing phenomena opened new avenues for the investigation of the microscopic dynamics and evolution of equilibrium and non-equilibrium processes at surfaces and interfaces. Our current studies of metallic glasses using a new langrangian formulation which includes all components of the total energy (density dependent electron gas, single particle and pair interactions) of the system, represents a novel approach for theoretical studies of this important class of systems

  20. Electrostrictive Effect in Cancer Cell Reflected in Capacitance Relaxation Phenomena

    Directory of Open Access Journals (Sweden)

    Tapas Kumar Basak

    2008-12-01

    Full Text Available The present paper has focus on the composite dielectric property of the cancer cell on concomitant with the capacitance relaxation phenomena. In this respect it has been found from MAT lab simulation the electrostrictive process in cancer cell is a complex one for which the electrostatic surfaces surrounding the cell changes with the incremental changes in the capacitance present in the capacitance relaxation curve. From these incremental changes in capacitance it is also possible to find out the electrostrictive energy of the cancer cell. It is interesting to note that the electrostrictive energy corresponding to the cell incremental changes in the capacitance is more in the first order system than that present in the second order system representing the equivalent configuration of the composite dielectric associated with the cell membrane. This is due the fact that during the process DNA synthesis and cell division the change in capacitance of the membrane for the first order system is relatively slow.

  1. Device including a contact detector

    DEFF Research Database (Denmark)

    2011-01-01

    The present invention relates to a probe for determining an electrical property of an area of a surface of a test sample, the probe is intended to be in a specific orientation relative to the test sample. The probe may comprise a supporting body defining a first surface. A plurality of cantilever...... of cantilever arms (12) contacting the surface of the test sample when performing the movement....... arms (12) may extend from the supporting body in co-planar relationship with the first surface. The plurality of cantilever arms (12) may extend substantially parallel to each other and each of the plurality of cantilever arms (12) may include an electrical conductive tip for contacting the area...

  2. Predicting the liquefaction phenomena from shear velocity profiling: Empirical approach to 6.3 Mw, May 2006 Yogyakarta earthquake

    Science.gov (United States)

    Hartantyo, Eddy; Brotopuspito, Kirbani S.; Sismanto, Waluyo

    2015-04-01

    The liquefactions phenomena have been reported after a shocking 6.5Mw earthquake hit Yogyakarta province in the morning at 27 May 2006. Several researchers have reported the damage, casualties, and soil failure due to the quake, including the mapping and analyzing the liquefaction phenomena. Most of them based on SPT test. The study try to draw the liquefaction susceptibility by means the shear velocity profiling using modified Multichannel Analysis of Surface Waves (MASW). This paper is a preliminary report by using only several measured MASW points. The study built 8-channel seismic data logger with 4.5 Hz geophones for this purpose. Several different offsets used to record the high and low frequencies of surface waves. The phase-velocity diagrams were stacked in the frequency domain rather than in time domain, for a clearer and easier dispersion curve picking. All codes are implementing in Matlab. From these procedures, shear velocity profiling was collected beneath each geophone's spread. By mapping the minimum depth of shallow water table, calculating PGA with soil classification, using empirical formula for saturated soil weight from shear velocity profile, and calculating CRR and CSR at every depth, the liquefaction characteristic can be identify in every layer. From several acquired data, a liquefiable potential at some depth below water table was obtained.

  3. Predicting the liquefaction phenomena from shear velocity profiling: Empirical approach to 6.3 Mw, May 2006 Yogyakarta earthquake

    Energy Technology Data Exchange (ETDEWEB)

    Hartantyo, Eddy, E-mail: hartantyo@ugm.ac.id [PhD student, Physics Department, FMIPA, UGM. Sekip Utara Yogyakarta 55281 Indonesia (Indonesia); Brotopuspito, Kirbani S.; Sismanto; Waluyo [Geophysics Laboratory, FMIPA, Universitas Gadjah Mada, Sekip Utara Yogyakarta 55281 (Indonesia)

    2015-04-24

    The liquefactions phenomena have been reported after a shocking 6.5Mw earthquake hit Yogyakarta province in the morning at 27 May 2006. Several researchers have reported the damage, casualties, and soil failure due to the quake, including the mapping and analyzing the liquefaction phenomena. Most of them based on SPT test. The study try to draw the liquefaction susceptibility by means the shear velocity profiling using modified Multichannel Analysis of Surface Waves (MASW). This paper is a preliminary report by using only several measured MASW points. The study built 8-channel seismic data logger with 4.5 Hz geophones for this purpose. Several different offsets used to record the high and low frequencies of surface waves. The phase-velocity diagrams were stacked in the frequency domain rather than in time domain, for a clearer and easier dispersion curve picking. All codes are implementing in Matlab. From these procedures, shear velocity profiling was collected beneath each geophone’s spread. By mapping the minimum depth of shallow water table, calculating PGA with soil classification, using empirical formula for saturated soil weight from shear velocity profile, and calculating CRR and CSR at every depth, the liquefaction characteristic can be identify in every layer. From several acquired data, a liquefiable potential at some depth below water table was obtained.

  4. PREFACE: Transport phenomena in proton conducting media Transport phenomena in proton conducting media

    Science.gov (United States)

    Eikerling, Michael

    2011-06-01

    Proton transport phenomena are of paramount importance for acid-base chemistry, energy transduction in biological organisms, corrosion processes, and energy conversion in electrochemical systems such as polymer electrolyte fuel cells. The relevance for such a plethora of materials and systems, and the ever-lasting fascination with the highly concerted nature of underlying processes drive research across disciplines in chemistry, biology, physics and chemical engineering. A proton never travels alone. Proton motion is strongly correlated with its environment, usually comprised of an electrolyte and a solid or soft host material. For the transport in nature's most benign proton solvent and shuttle, water that is, insights from ab initio simulations, matured over the last 15 years, have furnished molecular details of the structural diffusion mechanism of protons. Excess proton movement in water consists of sequences of Eigen-Zundel-Eigen transitions, triggered by hydrogen bond breaking and making in the surrounding water network. Nowadays, there is little debate about the validity of this mechanism in water, which bears a stunning resemblance to the basic mechanistic picture put forward by de Grotthuss in 1806. While strong coupling of an excess proton with degrees of freedom of solvent and host materials facilitates proton motion, this coupling also creates negative synergies. In general, proton mobility in biomaterials and electrochemical proton conducting media is highly sensitive to the abundance and structure of the proton solvent. In polymer electrolyte membranes, in which protons are bound to move in nano-sized water-channels, evaporation of water or local membrane dehydration due to electro-osmotic coupling are well-known phenomena that could dramatically diminish proton conductivity. Contributions in this special issue address various vital aspects of the concerted nature of proton motion and they elucidate important structural and dynamic effects of solvent

  5. Molecular modelling studies of clay-exopolysaccharide complexes: Soil aggregation and water retention phenomena

    Energy Technology Data Exchange (ETDEWEB)

    Henao, Lina J. [Centre de Recherches sur les Macromolecules Vegetales (CERMAV-CNRS), BP53, 38041 Grenoble cedex 9 (France); Mazeau, Karim, E-mail: karim.mazeau@cermav.cnrs.fr [Centre de Recherches sur les Macromolecules Vegetales (CERMAV-CNRS), BP53, 38041 Grenoble cedex 9 (France)

    2009-10-15

    In soils, the bacterial exopolysaccharides (EPS) aggregate mineral particles, enhancing their cohesion and their ability to retain water. These phenomena have been studied at the atomic scale by molecular modelling; we have considered seven rhizospheric polysaccharides interacting with the basal surfaces of montmorillonite. Models accounted for the aggregation phenomena induced by EPS: some segments of the polysaccharide were adsorbed on the mineral surfaces while others formed loops and bridges linking two surfaces. Adsorption energies were favourable and depended mostly on the interacting area. Cohesion of aggregates was estimated by the adhesion work, predicted values differed from one EPS to the other, suggesting that the chemical structure influences interaction strength with the mineral surface. Mechanisms of water uptake and release have also been investigated: hydration energies revealed that EPS strongly retain water at low water concentrations.

  6. Modelling of thermohydraulic emergency core cooling phenomena

    International Nuclear Information System (INIS)

    Yadigaroglu, G.; Andreani, M.; Lewis, M.J.

    1990-10-01

    The codes used in the early seventies for safety analysis and licensing were based either on the homogeneous model of two-phase flow or on the so-called separate-flow models, which are mixture models accounting, however, for the difference in average velocity between the two phases. In both cases the behavior of the mixture is prescribed a priori as a function of local parameters such as the mass flux and the quality. The modern best-estimate codes used for analyzing LWR LOCA's and transients are often based on a two-fluid or 6-equation formulation of the conservation equations. In this case the conservation equations are written separately for each phase; the mixture is allowed to evolve on its own, governed by the interfacial exchanges of mass, momentum and energy between the phases. It is generally agreed that such relatively sophisticated 6-equation formulations of two-phase flow are necessary for the correct modelling of a number of phenomena and situations arising in LWR accidental situations. They are in particular indispensible for the analysis of stratified or countercurrent flows and of situations in which large departures from thermal and velocity equilibrium exist. This report will be devoted to a discussion of the need for, the capacity and the limitations of the two-phase flow models (with emphasis on the 6-equation formulations) in modelling these two-phase flow and heat transfer phenomena and/or different core cooling situations. 18 figs., 1 tab., 72 refs

  7. Study of catalytic phenomena in radiation chemistry

    International Nuclear Information System (INIS)

    Dran, J.C.

    1965-01-01

    Two phenomena have been studied: the action of γ rays from radio-cobalt on the adsorption and catalytic properties of ZnO and NiO in. relationship with the heterogeneous oxidation of CO, and the homogeneous catalysis by OsO 4 of the oxidation of various aqueous phase solutes by the same radiation. The prior irradiation of ZnO and of NiO does not modify their catalytic activity but generally increases the adsorption energy of -the gases CO and O 2 . The influence of the radiations appears to be connected with the presence of traces of water on ZnO and of an excess of oxygen on NiO. Osmium tetroxide which is not degraded by irradiation in acid solution, accelerates the radiolytic oxidation of certain compounds (Te IV , Pt 11 , As 111 ) in the presence of oxygen, as a result of its sensitizing effect on the oxidation by H 2 O 2 . In the case of phosphites on the other hand, OsO 4 has a protecting action under certain conditions of acidity and may suppress entirely the chain reaction which characterizes the oxidation of this solute byγ rays. A general mechanism is proposed for these phenomena. The rate constant for the OsO 4 + HO 2 reaction is calculated to be 5.7 x 10 5 l.mol -1 . sec -1 . (author) [fr

  8. Shock Wave Diffraction Phenomena around Slotted Splitters

    Directory of Open Access Journals (Sweden)

    Francesca Gnani

    2015-01-01

    Full Text Available In the field of aerospace engineering, the study of the characteristics of vortical flows and their unsteady phenomena finds numerous engineering applications related to improvements in the design of tip devices, enhancement of combustor performance, and control of noise generation. A large amount of work has been carried out in the analysis of the shock wave diffraction around conventional geometries such as sharp and rounded corners, but the employment of splitters with lateral variation has hardly attracted the attention of researchers. The investigation of this phenomenon around two-dimensional wedges has allowed the understanding of the basic physical principles of the flow features. On the other hand, important aspects that appear in the third dimension due to the turbulent nature of the vortices are omitted. The lack of studies that use three-dimensional geometries has motivated the current work to experimentally investigate the evolution of the shock wave diffraction around two splitters with spike-shaped structures for Mach numbers of 1.31 and 1.59. Schlieren photography was used to obtain an insight into the sequential diffraction processes that take place in different planes. Interacting among them, these phenomena generate a complicated turbulent cloud with a vortical arrangement.

  9. Study Of Severe Accident Phenomena In Nuclear Power Plant

    International Nuclear Information System (INIS)

    Sugiyanto; Antariksawan; Anhar, R.; Arifal

    2001-01-01

    Several phenomena that occurred in the light water reactor type of nuclear power plant during severe accident were studied. The study was carried out based on the results of severe accident researches in various countries. In general, severe accident phenomena can be classified into in-vessel phenomena, retention in the reactor coolant system, and ex-vessel phenomena. In-vessel retention has been recommended as a severe accident management strategy

  10. Separation phenomena in Liquids and Gases

    Energy Technology Data Exchange (ETDEWEB)

    Louvet, P.; Dr Soubbaramayer [CEA Saclay, Dept. des Lasers et de la Physico-Chimie, DESICP/DLPC/SPP, 91 - Gif-sur-Yvette (France); Noe, P

    1989-07-01

    The Proceedings of the 1989 Workshop are presented in two volumes: volume 1 contains 4 papers on plasma processes and 7 papers on centrifugation. The papers on plasma processes deal with two main methods: ion cyclotron resonance and rotating plasmas. A survey lecture reviews extensively the physics of the two processes, the published experimental results and includes an abundant bibliography of about 200 references. The 3 other papers communicate original and recent experiments carried out by the authors. The plasma process remains as a possible technology to separate stable isotopes and isotopes of metals located in the middle of the Mendeleev Table. Regarding the stable isotopes, the ion cyclotron resonance might be an alternative to the Calutron process. The sessions on centrifugation include 2 review papers by URENCO authors and 5 specialized communications. The review papers take stock of the centrifuge research and gives the current status of the centrifuge technology in URENCO. The authors say that the centrifugation is presently an established industrial and commercial process ready to enter in competition for any new construction of enrichment capacity. Volume 2 contains the papers on 3 topics: basic studies (11 papers), chemical process (2 papers) and laser processes (7 papers). The papers on basic studies include investigations on rotating flows. A special attention is given to studies on convection flows, driven by acceleration field or (and) capillary forces. The interest of convection is obvious, as it has applications in important fields: the hydrodynamics of liquid uranium in the evaporation crucible of AVLIS Process, the crystal growth experiments on earth or under microgravity conditions (future experiments planned in space-labs) and the welding by electron or photon beams. Two papers are presented on the chemical process and both of them are by French authors. The French CEA has, in the past, developed with success the CHEMEX process. The

  11. Separation phenomena in Liquids and Gases

    International Nuclear Information System (INIS)

    Louvet, P.; Dr Soubbaramayer; Noe, P.

    1989-01-01

    The Proceedings of the 1989 Workshop are presented in two volumes: volume 1 contains 4 papers on plasma processes and 7 papers on centrifugation. The papers on plasma processes deal with two main methods: ion cyclotron resonance and rotating plasmas. A survey lecture reviews extensively the physics of the two processes, the published experimental results and includes an abundant bibliography of about 200 references. The 3 other papers communicate original and recent experiments carried out by the authors. The plasma process remains as a possible technology to separate stable isotopes and isotopes of metals located in the middle of the Mendeleev Table. Regarding the stable isotopes, the ion cyclotron resonance might be an alternative to the Calutron process. The sessions on centrifugation include 2 review papers by URENCO authors and 5 specialized communications. The review papers take stock of the centrifuge research and gives the current status of the centrifuge technology in URENCO. The authors say that the centrifugation is presently an established industrial and commercial process ready to enter in competition for any new construction of enrichment capacity. Volume 2 contains the papers on 3 topics: basic studies (11 papers), chemical process (2 papers) and laser processes (7 papers). The papers on basic studies include investigations on rotating flows. A special attention is given to studies on convection flows, driven by acceleration field or (and) capillary forces. The interest of convection is obvious, as it has applications in important fields: the hydrodynamics of liquid uranium in the evaporation crucible of AVLIS Process, the crystal growth experiments on earth or under microgravity conditions (future experiments planned in space-labs) and the welding by electron or photon beams. Two papers are presented on the chemical process and both of them are by French authors. The French CEA has, in the past, developed with success the CHEMEX process. The

  12. The physics of nanoelectronics transport and fluctuation phenomena at low temperatures

    CERN Document Server

    Heikkila, Tero T

    2013-01-01

    Advances in nanotechnology have allowed physicists and engineers to miniaturize electronic structures to the limit where finite-size related phenomena start to impact their properties. This book discusses such phenomena and models made for their description. The book starts from the semiclassical description of nonequilibrium effects, details the scattering theory used for quantum transport calculations, and explains the main interference effects. It also describes how to treat fluctuations and correlations, how interactions affect transport through small islands, and how superconductivity modifies these effects. The last two chapters describe new emerging fields related with graphene and nanoelectromechanics. The focus of the book is on the phenomena rather than formalism, but the book still explains in detail the main models constructed for these phenomena. It also introduces a number of electronic devices, including the single-electron transistor, the superconducting tunnel junction refrigerator, and the s...

  13. Heat Transfer Phenomena in Concentrating Solar Power Systems.

    Energy Technology Data Exchange (ETDEWEB)

    Armijo, Kenneth Miguel; Shinde, Subhash L.

    2016-11-01

    Concentrating solar power (CSP) utilizes solar thermal energy to drive a thermal power cycle for the generation of electricity. CSP systems are facilitated as large, centralized power plants , such as power towers and trough systems, to take advantage of ec onomies of scale through dispatchable thermal energy storage, which is a principle advantage over other energy generation systems . Additionally, the combination of large solar concentration ratios with high solar conversion efficiencies provides a strong o pportunity of employment of specific power cycles such as the Brayton gas cycle that utilizes super critical fluids such as supercritical carbon dioxide (s CO 2 ) , compared to other sola r - fossil hybrid power plants. A comprehensive thermal - fluids examination is provided by this work of various heat transfer phenomena evident in CSP technologies. These include sub - systems and heat transfer fundamental phenomena evident within CSP systems , which include s receivers, heat transfer fluids (HTFs), thermal storage me dia and system designs , thermodynamic power block systems/components, as well as high - temperature materials. This work provides literature reviews, trade studies, and phenomenological comparisons of heat transfer media (HTM) and components and systems, all for promotion of high performance and efficient CSP systems. In addition, f urther investigations are also conducted that provide advanced heat transfer modeling approaches for gas - particle receiver systems , as well as performance/efficiency enhancement re commendations, particularly for solarized supercritical power systems .

  14. Manipulating novel quantum phenomena using synthetic gauge fields

    Science.gov (United States)

    Zhang, Shao-Liang; Zhou, Qi

    2017-11-01

    The past few years have seen fascinating progress in the creation and utilization of synthetic gauge fields for charge-neutral ultracold atoms. Whereas the synthesis of gauge fields in itself is readily interesting, it is more exciting to explore the new era that will be brought by the interplay between synthetic gauge fields and many other degrees of freedom of highly tunable ultracold atoms. This topical review surveys recent developments in using synthetic gauge fields to manipulate novel quantum phenomena that are not easy to access in other systems. We first summarize current experimental methods of creating synthetic gauge fields, including the use of Raman schemes, shaken lattices, and Raman-dressed lattices. We then discuss how synthetic gauge fields bring new physics to non-interacting systems, including degenerate single-particle ground states, quartic dispersions, topological band structures in lattices, and synthetic dimensions. As for interacting systems, we focus on novel quantum many-body states and quantum macroscopic phenomena induced by interactions in the presence of unconventional single-particle dispersions. For bosons, we discuss how a quartic dispersion leads to non-condensed bosonic states at low temperatures and at the ground state. For fermions, we discuss chiral superfluids in the presence of attractive s-wave interaction, where high partial-wave interactions are not required. Finally, we discuss the challenges in current experiments, and conclude with an outlook for what new exciting developments synthetic gauge fields may bring us in the near future.

  15. Thermal-Fluid Transport Phenomena between Twin Rotating Parallel Disks

    Directory of Open Access Journals (Sweden)

    Shuichi Torii

    2008-01-01

    Full Text Available This paper investigates thermal-fluid transport phenomena in laminar flow between twin rotating parallel disks from whose center a circular jet is impinged on the heated horizontal bottom disk surface. Emphasis is placed on the effects of the Reynolds number, rotation speed, and disk spacing on both the formations of velocity and thermal fields and the heat transfer rate along the heated wall surface. The governing equations are discretized by means of a finite-difference technique and are numerically solved to determine the distributions of velocity vector and fluid temperature under the appropriate boundary conditions. It is found from the study that (i the recirculation zone which appears on the bottom disk moves along the outward direction with an increase in the Reynolds number, (ii when the Reynolds number is increased, heat transfer performance is intensified over the whole disk surface and the minimum value of the heat transfer rate moves in the downstream direction, and (iii the heat transfer rate is induced due to the disk rotation, whose effect becomes larger due to the upper disk rotation.

  16. Hydration Phenomena of Functionalized Carbon Nanotubes (CNT/Cement Composites

    Directory of Open Access Journals (Sweden)

    Bhuvaneshwari Balasubramaniam

    2017-10-01

    Full Text Available The exciting features of carbon nanotubes (CNTs, such as high elastic modulus, high thermal and electrical conductivities, robustness, and nanoscopic surface properties make them attractive candidates for the cement industry. They have the potential to significantly enhanceengineering properties. CNTs play an important and critical role as nano-anchors in concrete, which enhance the strength by bridging pores in the composite matrix, thereby ensuring robust mechanical strength. The diameter, dispersion, aspect ratio, and interfacial surface interaction of CNTs affect the physical and mechanical properties of concrete, if due care is not taken. In this paper, the usable amount of CNT is scaled down considerably from 0.5% to 0.025% by weight of the cement and the fluctuation caused by these phenomena is assessed. It is observed that the properties and exact quantities of incorporated CNTs influence the hydration and consistency of the composites. In order to address these issues, the surface functionalization of CNTs and rheological studies of the composites are performed. The hydration products and functional groups are carefully optimized and characterized by using X-ray diffraction (XRD, Fourier transform infrared spectroscopy (FTIR, scanning electron microscopy (SEM, and a Zeta potential analyzer. For Mixes 6 and 7, the compressive and tensile strength of CNTs incorporated in mortar specimens caused77% and 48% increases in split tensile strength, respectively, and 17% and 35% increases in compressive strength, respectively, after 28 days of curing and compared withthe control Mix.

  17. Modelling transport phenomena in a multi-physics context

    Science.gov (United States)

    Marra, Francesco

    2015-01-01

    Innovative heating research on cooking, pasteurization/sterilization, defrosting, thawing and drying, often focuses on areas which include the assessment of processing time, evaluation of heating uniformity, studying the impact on quality attributes of the final product as well as considering the energy efficiency of these heating processes. During the last twenty years, so-called electro-heating-processes (radio-frequency - RF, microwaves - MW and ohmic - OH) gained a wide interest in industrial food processing and many applications using the above mentioned technologies have been developed with the aim of reducing processing time, improving process efficiency and, in many cases, the heating uniformity. In the area of innovative heating, electro-heating accounts for a considerable portion of both the scientific literature and commercial applications, which can be subdivided into either direct electro-heating (as in the case of OH heating) where electrical current is applied directly to the food or indirect electro-heating (e.g. MW and RF heating) where the electrical energy is firstly converted to electromagnetic radiation which subsequently generates heat within a product. New software packages, which make easier solution of PDEs based mathematical models, and new computers, capable of larger RAM and more efficient CPU performances, allowed an increasing interest about modelling transport phenomena in systems and processes - as the ones encountered in food processing - that can be complex in terms of geometry, composition, boundary conditions but also - as in the case of electro-heating assisted applications - in terms of interaction with other physical phenomena such as displacement of electric or magnetic field. This paper deals with the description of approaches used in modelling transport phenomena in a multi-physics context such as RF, MW and OH assisted heating.

  18. Modelling transport phenomena in a multi-physics context

    Energy Technology Data Exchange (ETDEWEB)

    Marra, Francesco [Dipartimento di Ingegneria Chimica e Alimentare - Università degli studi di Salerno Via Ponte Don Melillo - 84084 Fisciano SA (Italy)

    2015-01-22

    Innovative heating research on cooking, pasteurization/sterilization, defrosting, thawing and drying, often focuses on areas which include the assessment of processing time, evaluation of heating uniformity, studying the impact on quality attributes of the final product as well as considering the energy efficiency of these heating processes. During the last twenty years, so-called electro-heating-processes (radio-frequency - RF, microwaves - MW and ohmic - OH) gained a wide interest in industrial food processing and many applications using the above mentioned technologies have been developed with the aim of reducing processing time, improving process efficiency and, in many cases, the heating uniformity. In the area of innovative heating, electro-heating accounts for a considerable portion of both the scientific literature and commercial applications, which can be subdivided into either direct electro-heating (as in the case of OH heating) where electrical current is applied directly to the food or indirect electro-heating (e.g. MW and RF heating) where the electrical energy is firstly converted to electromagnetic radiation which subsequently generates heat within a product. New software packages, which make easier solution of PDEs based mathematical models, and new computers, capable of larger RAM and more efficient CPU performances, allowed an increasing interest about modelling transport phenomena in systems and processes - as the ones encountered in food processing - that can be complex in terms of geometry, composition, boundary conditions but also - as in the case of electro-heating assisted applications - in terms of interaction with other physical phenomena such as displacement of electric or magnetic field. This paper deals with the description of approaches used in modelling transport phenomena in a multi-physics context such as RF, MW and OH assisted heating.

  19. Modelling transport phenomena in a multi-physics context

    International Nuclear Information System (INIS)

    Marra, Francesco

    2015-01-01

    Innovative heating research on cooking, pasteurization/sterilization, defrosting, thawing and drying, often focuses on areas which include the assessment of processing time, evaluation of heating uniformity, studying the impact on quality attributes of the final product as well as considering the energy efficiency of these heating processes. During the last twenty years, so-called electro-heating-processes (radio-frequency - RF, microwaves - MW and ohmic - OH) gained a wide interest in industrial food processing and many applications using the above mentioned technologies have been developed with the aim of reducing processing time, improving process efficiency and, in many cases, the heating uniformity. In the area of innovative heating, electro-heating accounts for a considerable portion of both the scientific literature and commercial applications, which can be subdivided into either direct electro-heating (as in the case of OH heating) where electrical current is applied directly to the food or indirect electro-heating (e.g. MW and RF heating) where the electrical energy is firstly converted to electromagnetic radiation which subsequently generates heat within a product. New software packages, which make easier solution of PDEs based mathematical models, and new computers, capable of larger RAM and more efficient CPU performances, allowed an increasing interest about modelling transport phenomena in systems and processes - as the ones encountered in food processing - that can be complex in terms of geometry, composition, boundary conditions but also - as in the case of electro-heating assisted applications - in terms of interaction with other physical phenomena such as displacement of electric or magnetic field. This paper deals with the description of approaches used in modelling transport phenomena in a multi-physics context such as RF, MW and OH assisted heating

  20. Foam rheology: a model of viscous phenomena

    International Nuclear Information System (INIS)

    Kraynik, A.M.; Hansen, M.G.

    1987-01-01

    A theoretical model for foam rheology that includes viscous forces is developed by considering the deformation of two-dimensional, spatially periodic cells in simple shearing and planar extensional flow. The undeformed hexagonal cells are separated by thin liquid films. Plateau border curvature and liquid drainage between films is neglected. Interfacial tension and viscous tractions due to stretching lamellar liquid determine the individual film tensions. The network motion is described by a system of nonlinear ordinary differential equations for which numerical solutions are obtained. Coalescense and disproportionation of Plateau borders results in the relative separation of cells and provides a mechanism for yielding and flow. This process is assumed to occur when a film's length reduces to its thickness. The time and position dependence of the cell-scale dynamics are computed explicitly. The effective continuum stress of the foam is described by instantaneous and time-averaged quantities. The capillary number, a dimensionless deformation rate, represents the relative importance of viscous and surface tension effects. The small-capillary-number or quasistatic response determines a yield stress. The dependence of the shear and normal stress material functions upon deformation rate, foam structure and physical properties is determined. A plausible mechanism for shear-induced material failure, which would determine a shear strength, is revealed for large capillary numbers. The mechanism involves large cell distortion and film thinning, which provide favorable conditions for film rupture

  1. Autistic phenomena in The Adventures of Pinocchio.

    Science.gov (United States)

    Smith, Adrian

    2017-04-01

    This paper seeks to demonstrate that the protagonist of Carlo Collodi's The Adventures of Pinocchio illustrates numerous autistic phenomena such as communication difficulties, sensory and perceptual distortions and mindblindness. While Pinocchio is viewed as a literary construct with contraindications of autism, it will be argued that his autistic traits are sufficient to suggest the possibility that Collodi had a partial intuition of the syndrome 60 years before it was identified by Leo Kanner. Approaching Collodi's text in this manner is taken as an opportunity to survey and reflect upon the psychoanalytic literature on autism and to position it in relation to contemporary theories from cognitive neuroscience. © 2017, The Society of Analytical Psychology.

  2. Modeling electrical dispersion phenomena in Earth materials

    Directory of Open Access Journals (Sweden)

    D. Patella

    2008-06-01

    Full Text Available It is illustrated that IP phenomena in rocks can be described using conductivity dispersion models deduced as solutions to a 2nd-order linear differential equation describing the motion of a charged particle immersed in an external electrical field. Five dispersion laws are discussed, namely: the non-resonant positive IP model, which leads to the classical Debye-type dispersion law and by extension to the Cole-Cole model, largely used in current practice; the non-resonant negative IP model, which allows negative chargeability values, known in metals at high frequencies, to be explained as an intrinsic physical property of earth materials in specific field cases; the resonant flat, positive or negative IP models, which can explain the presence of peak effects at specific frequencies superimposed on flat, positive or negative dispersion spectra.

  3. Social phenomena from data analysis to models

    CERN Document Server

    Perra, Nicola

    2015-01-01

    This book focuses on the new possibilities and approaches to social modeling currently being made possible by an unprecedented variety of datasets generated by our interactions with modern technologies. This area has witnessed a veritable explosion of activity over the last few years, yielding many interesting and useful results. Our aim is to provide an overview of the state of the art in this area of research, merging an extremely heterogeneous array of datasets and models. Social Phenomena: From Data Analysis to Models is divided into two parts. Part I deals with modeling social behavior under normal conditions: How we live, travel, collaborate and interact with each other in our daily lives. Part II deals with societal behavior under exceptional conditions: Protests, armed insurgencies, terrorist attacks, and reactions to infectious diseases. This book offers an overview of one of the most fertile emerging fields bringing together practitioners from scientific communities as diverse as social sciences, p...

  4. Discrete computational mechanics for stiff phenomena

    KAUST Repository

    Michels, Dominik L.

    2016-11-28

    Many natural phenomena which occur in the realm of visual computing and computational physics, like the dynamics of cloth, fibers, fluids, and solids as well as collision scenarios are described by stiff Hamiltonian equations of motion, i.e. differential equations whose solution spectra simultaneously contain extremely high and low frequencies. This usually impedes the development of physically accurate and at the same time efficient integration algorithms. We present a straightforward computationally oriented introduction to advanced concepts from classical mechanics. We provide an easy to understand step-by-step introduction from variational principles over the Euler-Lagrange formalism and the Legendre transformation to Hamiltonian mechanics. Based on such solid theoretical foundations, we study the underlying geometric structure of Hamiltonian systems as well as their discrete counterparts in order to develop sophisticated structure preserving integration algorithms to efficiently perform high fidelity simulations.

  5. Astrophysical disks Collective and Stochastic Phenomena

    CERN Document Server

    Fridman, Alexei M; Kovalenko, Ilya G

    2006-01-01

    The book deals with collective and stochastic processes in astrophysical discs involving theory, observations, and the results of modelling. Among others, it examines the spiral-vortex structure in galactic and accretion disks , stochastic and ordered structures in the developed turbulence. It also describes sources of turbulence in the accretion disks, internal structure of disk in the vicinity of a black hole, numerical modelling of Be envelopes in binaries, gaseous disks in spiral galaxies with shock waves formation, observation of accretion disks in a binary system and mass distribution of luminous matter in disk galaxies. The editors adaptly brought together collective and stochastic phenomena in the modern field of astrophysical discs, their formation, structure, and evolution involving the methodology to deal with, the results of observation and modelling, thereby advancing the study in this important branch of astrophysics and benefiting Professional Researchers, Lecturers, and Graduate Students.

  6. Implicit particle simulation of electromagnetic plasma phenomena

    International Nuclear Information System (INIS)

    Kamimura, T.; Montalvo, E.; Barnes, D.C.; Leboeuf, J.N.; Tajima, T.

    1986-11-01

    A direct method for the implicit particle simulation of electromagnetic phenomena in magnetized, multi-dimensional plasmas is developed. The method is second-order accurate for ωΔt < 1, with ω a characteristic frequency and time step Δt. Direct time integration of the implicit equations with simplified space differencing allows the consistent inclusion of finite particle size. Decentered time differencing of the Lorentz force permits the efficient simulation of strongly magnetized plasmas. A Fourier-space iterative technique for solving the implicit field corrector equation, based on the separation of plasma responses perpendicular and parallel to the magnetic field and longitudinal and transverse to the wavevector, is described. Wave propagation properties in a uniform plasma are in excellent agreement with theoretical expectations. Applications to collisionless tearing and coalescence instabilities further demonstrate the usefulness of the algorithm. (author)

  7. Density turbulence and disruption phenomena in TEXTOR

    International Nuclear Information System (INIS)

    Waidmann, G.; Kuang, G.; Jadoul, M.

    1992-01-01

    Disruptive processes are observed in tokamak plasmas not only at the operating limits (density limit or q-limit) but can be found under a variety of experimental conditions. Large forces are exerted then on vessel components and support structures. The sudden release of stored plasma energy presents a serious erosion problem for the first wall already in the next generation of large tokamak machines. Strong energy losses from the plasma and an influx of impurities are already present in minor plasma disruptions which do not immediately lead to a plasma current termination. The rapid loss of energy confinement was investigated within the framework of a systematic study on plasma disruption phenomena in TEXTOR. (author) 4 refs., 4 figs

  8. Quantum field theory and critical phenomena

    CERN Document Server

    Zinn-Justin, Jean

    1996-01-01

    Over the last twenty years quantum field theory has become not only the framework for the discussion of all fundamental interactions except gravity, but also for the understanding of second-order phase transitions in statistical mechanics. This advanced text is based on graduate courses and summer schools given by the author over a number of years. It approaches the subject in terms of path and functional intergrals, adopting a Euclidean metric and using the language of partition and correlation functions. Renormalization and the renormalization group are examined, as are critical phenomena and the role of instantons. Changes for this edition 1. Extensive revision to eliminate a few bugs that had survived the second edition and (mainly) to improve the pedagogical presentation, as a result of experience gathered by lecturing. 2. Additional new topics; holomorphic or coherent state path integral; functional integral and representation of the field theory S-matrix in the holomorphic formalis; non-relativistic li...

  9. Characterizing critical phenomena via the Purcell effect

    Science.gov (United States)

    Silva Neto, M. B.; Szilard, D.; Rosa, F. S. S.; Farina, C.; Pinheiro, F. A.

    2017-12-01

    We investigate the role of phase transitions into the spontaneous-emission rate of a single quantum emitter embedded in a critical medium. Using a Landau-Ginzburg approach, we find that in the broken symmetry phase, the emission rate is reduced, or even suppressed, due to the photon mass generated by the Higgs mechanism. Remarkably, its sensitivity to the critical exponents of the phase transition allows for an optical determination of universality classes. When applied to the cases of superconductivity and superfluidity, we show that the Purcell effect also provides valuable information on spectroscopic and thermodynamic quantities, such as the size of the superconducting gap and the discontinuity in the specific heat at the transition. By unveiling that a deeper connection between the Purcell effect and phase transitions exists, we demonstrate that the former is an efficient optical probe of distinct critical phenomena and their associated observables.

  10. Peridynamic Formulation for Coupled Thermoelectric Phenomena

    Directory of Open Access Journals (Sweden)

    Migbar Assefa

    2017-01-01

    Full Text Available Modeling of heat and electrical current flow simultaneously in thermoelectric convertor using classical theories do not consider the influence of defects in the material. This is because traditional methods are developed based on partial differential equations (PDEs and lead to infinite fluxes at the discontinuities. The usual way of solving such PDEs is by using numerical technique, like Finite Element Method (FEM. Although FEM is robust and versatile, it is not suitable to model evolving discontinuities. To avoid such shortcomings, we propose the concept of peridynamic theory to derive the balance of energy and charge equations in the coupled thermoelectric phenomena. Therefore, this paper presents the transport of heat and charge in thermoelectric material in the framework of peridynamic (PD theory. To illustrate the reliability of the PD formulation, numerical examples are presented and results are compared with those from literature, analytical solutions, or finite element solutions.

  11. Fast imaging of visible phenomena in TFTR

    International Nuclear Information System (INIS)

    Maqueda, R.J.; Wurden, G.A.

    1999-01-01

    A commercial fast framing visible imaging system was used at TFTR to study edge plasma phenomena. This system was typically operated at 1000 frames/s, with exposures as short as 10 μs. These short exposures ar made possible by the image intensification of the camera, which also allows narrow band interference filters to be used. Sequences of over 1600 digital images (239 pixel x 192 pixel x 8 bit) can be captured into temporary memory banks for later slow play-back and/or storage into computer archives. Examples are shown illustrating plasma disruption, flying debris, lithium pellet injection, shallow deposition of lithium by laser outside the plasma (DOLLOP) and edge plasma turbulence. The characteristics of this system make it also very useful to the machine operator, since they provide slow motion video coverage of the interior of the device. (author)

  12. Atom optics simulator of lattice transport phenomena

    Science.gov (United States)

    An, Fangzhao; Meier, Eric; Gadway, Bryce

    2016-05-01

    We report on a novel scheme for studying lattice transport phenomena, based on the controlled momentum-space dynamics of ultracold atomic matter waves. In the effective tight binding models that can be simulated, we demonstrate that this technique allows for a local and time-dependent control over all system parameters, and additionally allows for single-site resolved detection of atomic populations. We demonstrate full control over site-to-site off-diagonal tunneling elements (amplitude and phase) and diagonal site-energies, through the observation of continuous time quantum walks, Bloch oscillations, and negative tunneling. These capabilities open up new prospects in the experimental study of disordered and topological systems.

  13. Reversion phenomena of Cu-Cr alloys

    Science.gov (United States)

    Nishikawa, S.; Nagata, K.; Kobayashi, S.

    1985-01-01

    Cu-Cr alloys which were given various aging and reversion treatments were investigated in terms of electrical resistivity and hardness. Transmission electron microscopy was one technique employed. Some results obtained are as follows: the increment of electrical resistivity after the reversion at a constant temperature decreases as the aging temperature rises. In a constant aging condition, the increment of electrical resistivity after the reversion increases, and the time required for a maximum reversion becomes shorter as the reversion temperature rises. The reversion phenomena can be repeated, but its amount decreases rapidly by repetition. At first, the amount of reversion increases with aging time and reaches its maximum, and then tends to decrease again. Hardness changes by the reversion are very small, but the hardness tends to soften slightly. Any changes in transmission electron micrographs by the reversion treatment cannot be detected.

  14. Surfactant-based critical phenomena in microgravity

    Science.gov (United States)

    Kaler, Eric W.; Paulaitis, Michael E.

    1994-01-01

    The objective of this research project is to characterize by experiment and theoretically both the kinetics of phase separation and the metastable structures produced during phase separation in a microgravity environment. The particular systems we are currently studying are mixtures of water, nonionic surfactants, and compressible supercritical fluids at temperatures and pressures where the coexisting liquid phases have equal densities (isopycnic phases). In this report, we describe experiments to locate equilibrium isopycnic phases and to determine the 'local' phase behavior and critical phenomena at nearby conditions of temperature, pressure, and composition. In addition, we report the results of preliminary small angle neutron scattering (SANS) experiments to characterize microstructures that exist in these mixtures at different fluid densities.

  15. Cheshire cat phenomena and quarks in nuclei

    International Nuclear Information System (INIS)

    Rho, M.

    1986-11-01

    The notion of the ''Cheshire Cat'' principle in hadron structure is developed rigorously in (1+1) dimensions and approximately in (3+1) dimensions for up- and down-quark flavor systems. This phenomenon is invoked to address the issue as to whether or not direct quark-gluon signatures can be ''seen'' in low-energy nuclear phenomena. How addition of the third flavor -strangeness- can modify the Cheshire Cat property is discussed. It is proposed that one of the primary objectives of nuclear physics be to probe -and disturb- the ''vacuum'' of the strong interactions (QCD) and that for this purpose the chiral symmetry SU(3)xSU(3) can play a crucial role in normal and extreme conditions. As an illustration, kaon condensation at a density ρ>∼ 3ρ 0 is discussed in terms of a toy model and is related to ''cleansing'' of the quark condensates from the vacuum

  16. Experimental study of the natural circulation phenomena

    International Nuclear Information System (INIS)

    Sabundjian, Gaiane; Andrade, Delvonei Alves de; Umbehaun, Pedro E.; Torres, Walmir M.; Castro, Alfredo Jose Alvim de; Belchior Junior, Antonio; Rocha, Ricardo Takeshi Vieira da; Damy, Osvaldo Luiz de Almeida; Torres, Eduardo

    2006-01-01

    The objective of this paper is to study the natural circulation in experimental loops and extend the results to nuclear facilities. New generation of compact nuclear power plants use the natural circulation as cooling and residual heat removal systems in case of accidents or shutdown. Lately the interest in this phenomenon, by scientific community, has increased. The experimental loop, described in this paper, was assembled at Escola Politecnica - USP at the Chemical Engineering Department. It is the goal to generate information to help with the understanding of the one and two phase natural circulation phenomena. Some experiments were performed with different levels of heat power and different flow of the cooling water at the secondary circuit. The data generated from these experiments are going to be used to validate some computational thermal hydraulic codes. Experimental results for one and two phase regimes are presented as well as the proposed model to simulate the flow regimes with the RELAP5 code. (author)

  17. Meteorological phenomena in Western classical orchestral music

    Science.gov (United States)

    Williams, P. D.; Aplin, K. L.

    2012-12-01

    The creative output of composers, writers, and artists is often influenced by their surroundings. To give a literary example, it has been claimed recently that some of the characters in Oliver Twist and A Christmas Carol were based on real-life people who lived near Charles Dickens in London. Of course, an important part of what we see and hear is not only the people with whom we interact, but also our geophysical surroundings. Of all the geophysical phenomena to influence us, the weather is arguably the most significant, because we are exposed to it directly and daily. The weather was a great source of inspiration for Monet, Constable, and Turner, who are known for their scientifically accurate paintings of the skies. But to what extent does weather inspire composers? The authors of this presentation, who are atmospheric scientists by day but amateur classical musicians by night, have been contemplating this question. We have built a systematic musical database, which has allowed us to catalogue and analyze the frequencies with which weather is depicted in a sample of classical orchestral music. The depictions vary from explicit mimicry using traditional and specialized orchestral instruments, through to subtle suggestions. We have found that composers are generally influenced by their own environment in the type of weather they choose to represent. As befits the national stereotype, British composers seem disproportionately keen to depict the UK's variable weather patterns and stormy coastline. Reference: Aplin KL and Williams PD (2011) Meteorological phenomena in Western classical orchestral music. Weather, 66(11), pp 300-306. doi:10.1002/wea.765

  18. Self-organization phenomena in plasma physics

    International Nuclear Information System (INIS)

    Sanduloviciu, M.; Popescu, S.

    2001-01-01

    The self-assembling in nature and laboratory of structures in systems away from thermodynamic equilibrium is one of the problems that mostly fascinates the scientists working in all branches of science. In this context a substantial progress has been obtained by investigating the appearance of spatial and spatiotemporal patterns in plasma. These experiments revealed the presence of a scenario of self-organization able to suggest an answer to the central problem of the 'Science of Complexity', why matter transits spontaneously from a disordered into an ordered state? Based on this scenario of self-organization we present arguments proving the possibility to explain the challenging problems of nonequilibrium physics in general. These problems refer to: (i) genuine origin of phase transitions observed in gaseous conductors and semiconductors; (ii) the elucidation of the role played by self-organization in the simulation of oscillations; (iii) the physical basis of anomalous transport of matter and energy with special reference to the possibilities of improving the economical performance of fusion devices; (iv) the possibility to use self-confined gaseous space charged configurations as an alternative to the magnetically confined plasma used at present in fusion devices. In other branches of sciences, as for instance in Biology, the self-organization scenario reveals a new insight into a mechanism able to explain the appearance of the simplest possible space charge configuration able to evolve, under suitable conditions, into prebiotic structures. Referring to phenomena observed in nature, the same self-organization scenario suggests plausible answers to the appearance of ball lightening but also to the origin of the flickering phenomena observed in the light emission of the Sun and stars. For theory the described self-organization scenario offers a new physical basis for many problems of nonlinear science not solved yet and also a new model for the so-called 'self

  19. Sulfur-induced structural motifs on copper and gold surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Walen, Holly [Iowa State Univ., Ames, IA (United States)

    2016-01-01

    The interaction of sulfur with copper and gold surfaces plays a fundamental role in important phenomena that include coarsening of surface nanostructures, and self-assembly of alkanethiols. Here, we identify and analyze unique sulfur-induced structural motifs observed on the low-index surfaces of these two metals. We seek out these structures in an effort to better understand the fundamental interactions between these metals and sulfur that lends to the stability and favorability of metal-sulfur complexes vs. chemisorbed atomic sulfur. The experimental observations presented here—made under identical conditions—together with extensive DFT analyses, allow comparisons and insights into factors that favor the existence of metal-sulfur complexes, vs. chemisorbed atomic sulfur, on metal terraces. We believe this data will be instrumental in better understanding the complex phenomena occurring between the surfaces of coinage metals and sulfur.

  20. Astrophysical phenomena related to supermassive black holes

    Science.gov (United States)

    Pott, Jörg-Uwe

    2006-12-01

    innermost region of a galaxy. Furthermore an increasing number of apparently totally distinct phenomena and properties of the SMBH/host system appear to be related to each other, provoking unifying ideas and models to explain the galaxy formation and evolution. For example several different types of AGN are understood as projection or orientation effects, claiming that the same AGN looks totally different as viewed from different sides (e.g. Antonucci & Miller 1985). The thesis is structured to reflect this general perception. All scales of size, AGN luminosity, and nuclear activity appear. The thesis consists of six chapters. The first two compile astrophysical and technical background of the individual projects, which themselves are presented in the following four chapters. While the first project (Chapter 3) deals with observations of the innermost parsec of our Galaxy, Chapter 4 presents data of the inner kpc of an active galaxy. The subjects of Chapters 5 and 6 are very luminous AGN/host systems, so-called QSOs. Whereas Chapter 5 presents global, spatially unresolved properties of SMBH/host systems, the radio jet, analyzed in the final Chapter 6, combines all size scales. It is investigated from close to its origin out to several kpc. The accretion onto the black hole of the Milky Way (Chapter 3) is extremely inefficient (Genzel et al. 2003a) and the SMBH possibly interacts dominantly via tidal forces only. The next discussed system (Chapter 4) is the prototype of moderately luminous Seyfert 2 AGN, NGC 1068. Here a strong local influence of the nuclear X-ray radiation is observed (Usero et al. 2004). Chapter 5 deals with the possible global importance of radiative interaction between highly luminous QSO AGN and the host. The radio jet in Chapter 6 definitely shows signs of interaction with the matter of its host several kpc away from the nucleus. Chapters 3-6 include a dedicated introductory and a conclusive section, which put the results obtained in the larger

  1. Coherent Nonlinear Longitudinal Phenomena in Unbunched Synchrotron Beams

    Energy Technology Data Exchange (ETDEWEB)

    Spentzouris, Linda Klamp [Northwestern U.

    1996-12-01

    Coherent nonlinear longitudinal phenomena are studied in proton and antiproton synchrotron beams. Theoretical development done in the eld of plasma physics for resonant wave-wave coupling is applied to the case of a particle beam. Results are given from experiments done to investigate the nature of the weakly nonlinear three-wave coupling processes known as parametric coupling and echoes. Storage ring impedances are shown to amplify the parametric coupling process, underlining the possibility that machine impedances might be extracted from coupling events instigated by external excitation. Echo amplitudes are demonstrated to be sensitive to diusion processes, such as intrabeam scattering, which degrade a beam. The result of a fast diusion rate measurement using echo amplitudes is presented. In addition to the wave-wave interactions, observations of moderately nonlinear waveparticle interactions are also included. The manifestations of these interactions that are documented include nonlinear Landau damping, higher harmonic generation, and signs of the possible formation of solitons.

  2. Current status of models for transient phenomena in dopant diffusion and activation

    International Nuclear Information System (INIS)

    Pichler, P.; Stiebel, D.

    2002-01-01

    Transient phenomena caused by ion-implantation processes have been studied for more than 25 years now with a continuously increasing number of research articles published in this field per year. One driving force of this research is the ongoing miniaturization of ULSI MOS and bipolar technology which uses extensively the capabilities of technology-computer-aided-design (TCAD). The other driving force which attracts also academic institutions and research institutes is the high complexity of the phenomena, involving the interaction of dopants, intrinsic point defects, extended defects and impurities like carbon as well as the interactions of mobile defects with surfaces and interfaces and their redistribution in multilayer structures. This paper outlines some recent advances towards a quantitative description of such phenomena

  3. PREFACE: Physics and Mathematics of Nonlinear Phenomena 2013 (PMNP2013)

    Science.gov (United States)

    Konopelchenko, B. G.; Landolfi, G.; Martina, L.; Vitolo, R.

    2014-03-01

    Modern theory of nonlinear integrable equations is nowdays an important and effective tool of study for numerous nonlinear phenomena in various branches of physics from hydrodynamics and optics to quantum filed theory and gravity. It includes the study of nonlinear partial differential and discrete equations, regular and singular behaviour of their solutions, Hamitonian and bi- Hamitonian structures, their symmetries, associated deformations of algebraic and geometrical structures with applications to various models in physics and mathematics. The PMNP 2013 conference focused on recent advances and developments in Continuous and discrete, classical and quantum integrable systems Hamiltonian, critical and geometric structures of nonlinear integrable equations Integrable systems in quantum field theory and matrix models Models of nonlinear phenomena in physics Applications of nonlinear integrable systems in physics The Scientific Committee of the conference was formed by Francesco Calogero (University of Rome `La Sapienza', Italy) Boris A Dubrovin (SISSA, Italy) Yuji Kodama (Ohio State University, USA) Franco Magri (University of Milan `Bicocca', Italy) Vladimir E Zakharov (University of Arizona, USA, and Landau Institute for Theoretical Physics, Russia) The Organizing Committee: Boris G Konopelchenko, Giulio Landolfi, Luigi Martina, Department of Mathematics and Physics `E De Giorgi' and the Istituto Nazionale di Fisica Nucleare, and Raffaele Vitolo, Department of Mathematics and Physics `E De Giorgi'. A list of sponsors, speakers, talks, participants and the conference photograph are given in the PDF. Conference photograph

  4. COMPUTER GRAPHICS IN SIMULATION OF CARDIOVASCULAR TRANSPORT PHENOMENA*

    Science.gov (United States)

    Sidell, P. M.; Anderson, D. U.; Knopp, T. J.; Bassingthwaighte, J. B.

    2010-01-01

    Simulation is a necessary tool if we are to understand better the complexities involved in cardiovascular transport. While some of the phenomena modeled can be described analytically, perusal of the equations alone often doesn’t result in full appreciation of the model system. It therefore becomes pertinent to utilize computer graphics in order to enhance simulation of physiologic transport processes. Graphic representation not only facilitates interaction between the investigator and the simulation, it provides a juxtaposition of the model to the real system, as well as a simplification of relationships between various features of the model. Increased mathematical sophistication required in the investigation of cardiovascular transport phenomena often makes traditional graphic representation cumbersome. Therefore several different types of graphics have been utilized, including 2-, 3-, and 4-dimensional displays. The methods and algorithms for these displays have been generalized to make them easy to use over a broad spectrum of applications. In some cases we have generated motion pictures of sequential model solutions which have increased and accelerated model comprehension, as well as been valuable for teaching purposes. PMID:21743760

  5. Sensory phenomena related to tics, obsessive-compulsive symptoms, and global functioning in Tourette syndrome.

    Science.gov (United States)

    Kano, Yukiko; Matsuda, Natsumi; Nonaka, Maiko; Fujio, Miyuki; Kuwabara, Hitoshi; Kono, Toshiaki

    2015-10-01

    Sensory phenomena, including premonitory urges, are experienced by patients with Tourette syndrome (TS) and obsessive-compulsive disorder (OCD). The goal of the present study was to investigate such phenomena related to tics, obsessive-compulsive symptoms (OCS), and global functioning in Japanese patients with TS. Forty-one patients with TS were assessed using the University of São Paulo Sensory Phenomena Scale (USP-SPS), the Premonitory Urge for Tics Scale (PUTS), the Yale Global Tic Severity Scale (YGTSS), the Dimensional Yale-Brown Obsessive-Compulsive Scale (DY-BOCS), and the Global Assessment of Functioning (GAF) Scale. USP-SPS and PUTS total scores were significantly correlated with YGTSS total and vocal tics scores. Additionally, both sensory phenomena severity scores were significantly correlated with DY-BOCS total OCS scores. Of the six dimensional OCS scores, the USP-SPS scores were significantly correlated with measures of aggression and sexual/religious dimensions. Finally, the PUTS total scores were significantly and negatively correlated with GAF scores. By assessing premonitory urges and broader sensory phenomena, and by viewing OCS from a dimensional approach, this study provides significant insight into sensory phenomena related to tics, OCS, and global functioning in patients with TS. Copyright © 2015 Elsevier Inc. All rights reserved.

  6. Experimental study on fundamental phenomena in HTGR small break air-ingress accident

    International Nuclear Information System (INIS)

    Kim, Jae Soon; Hwang, Jin-Seok; Kim, Eung Soo; Kim, Byung Jun; Oh, Chang Ho

    2016-01-01

    Highlights: • Air-ingress phenomena on the small break in a HTGR are experimentally investigated. • Experiment is investigated for various break sizes, angles, and density ratios. • Maximum air-ingress rate is observed at 120° in break angle. • This study reveals that air-ingress in the small break is governed by; buoyancy and flow inertia. • A non-dimensional parameter is newly proposed to determine the air-ingress flow regimes. • Newly proposed parameter is based on buoyancy versus inertia force. - Abstract: This study experimentally investigates fundamental phenomena in the HTGR small break air-ingress accident. Several important parameters including density ratio, break angle, break size, and main flow velocity are considered in the measurement and the analysis. The test-section is made of a circular pipe with small holes drilled around the surface and it is installed in the helium/air flow circulation loop. Oxygen concentrations and flow rates are recorded during the tests with fixed break angles, break sizes, and flow velocities for measurement of the air-ingress rates. According to the experimental results, the higher density difference leads to the higher rates of air-ingress with large sensitivity of the break angles. It is also found that the break angle significantly affects the air-ingress rates, which is gradually increased from 0° to 120° and suddenly decreased to 180°. The minimum air ingress rate is found at 0° and the maximum, at 110°. The air-ingress rate increases with the break size due to the increased flow-exchange area. However, it is not directly proportional to the break area due to the complexity of the phenomena. The increased flow velocity in the channel inside enhances the air-ingress process. However, among all the parameters, the main flow velocity exhibits the lowest effect on this process. In this study, the Froude Number relevant to the small break air-ingress conditions are newly defined considering both heavy

  7. Statistical mechanics of random surfaces

    International Nuclear Information System (INIS)

    Froehlich, J.

    1984-01-01

    The statistical mechanics of random surfaces has proven to be of growing importance in quantum field theory (string theory, random surface representations of gauge theory) and condensed matter physics (domain walls and interfaces, incommensurate phases, spin glasses, crystal surfaces, surface phenomena such as wetting, etc.). Various applications to quantum field theory and condensed matter physics are outlined. (Auth.)

  8. Advanced modelling of the transport phenomena across horizontal clothing microclimates with natural convection.

    Science.gov (United States)

    Mayor, T S; Couto, S; Psikuta, A; Rossi, R M

    2015-12-01

    The ability of clothing to provide protection against external environments is critical for wearer's safety and thermal comfort. It is a function of several factors, such as external environmental conditions, clothing properties and activity level. These factors determine the characteristics of the different microclimates existing inside the clothing which, ultimately, have a key role in the transport processes occurring across clothing. As an effort to understand the effect of transport phenomena in clothing microclimates on the overall heat transport across clothing structures, a numerical approach was used to study the buoyancy-driven heat transfer across horizontal air layers trapped inside air impermeable clothing. The study included both the internal flow occurring inside the microclimate and the external flow occurring outside the clothing layer, in order to analyze the interdependency of these flows in the way heat is transported to/from the body. Two-dimensional simulations were conducted considering different values of microclimate thickness (8, 25 and 52 mm), external air temperature (10, 20 and 30 °C), external air velocity (0.5, 1 and 3 m s(-1)) and emissivity of the clothing inner surface (0.05 and 0.95), which implied Rayleigh numbers in the microclimate spanning 4 orders of magnitude (9 × 10(2)-3 × 10(5)). The convective heat transfer coefficients obtained along the clothing were found to strongly depend on the transport phenomena in the microclimate, in particular when natural convection is the most important transport mechanism. In such scenario, convective coefficients were found to vary in wavy-like manner, depending on the position of the flow vortices in the microclimate. These observations clearly differ from data in the literature for the case of air flow over flat-heated surfaces with constant temperature (which shows monotonic variations of the convective heat transfer coefficients, along the length of the surface). The flow

  9. Advanced modelling of the transport phenomena across horizontal clothing microclimates with natural convection

    Science.gov (United States)

    Mayor, T. S.; Couto, S.; Psikuta, A.; Rossi, R. M.

    2015-12-01

    The ability of clothing to provide protection against external environments is critical for wearer's safety and thermal comfort. It is a function of several factors, such as external environmental conditions, clothing properties and activity level. These factors determine the characteristics of the different microclimates existing inside the clothing which, ultimately, have a key role in the transport processes occurring across clothing. As an effort to understand the effect of transport phenomena in clothing microclimates on the overall heat transport across clothing structures, a numerical approach was used to study the buoyancy-driven heat transfer across horizontal air layers trapped inside air impermeable clothing. The study included both the internal flow occurring inside the microclimate and the external flow occurring outside the clothing layer, in order to analyze the interdependency of these flows in the way heat is transported to/from the body. Two-dimensional simulations were conducted considering different values of microclimate thickness (8, 25 and 52 mm), external air temperature (10, 20 and 30 °C), external air velocity (0.5, 1 and 3 m s-1) and emissivity of the clothing inner surface (0.05 and 0.95), which implied Rayleigh numbers in the microclimate spanning 4 orders of magnitude (9 × 102-3 × 105). The convective heat transfer coefficients obtained along the clothing were found to strongly depend on the transport phenomena in the microclimate, in particular when natural convection is the most important transport mechanism. In such scenario, convective coefficients were found to vary in wavy-like manner, depending on the position of the flow vortices in the microclimate. These observations clearly differ from data in the literature for the case of air flow over flat-heated surfaces with constant temperature (which shows monotonic variations of the convective heat transfer coefficients, along the length of the surface). The flow patterns and

  10. Fluid mechanics phenomena in microgravity; ASME Winter Annual Meeting, Anaheim, CA, Nov. 8-13, 1992

    Science.gov (United States)

    Siginer, Dennis A. (Editor); Weislogel, Mark M. (Editor)

    1992-01-01

    This paper is the first in a series of symposia presenting research activity in microgravity fluid mechanics. General topics addressed include two-phase flow and transport phenomena, thermo-capillary flow, and interfacial stability. Papers present mathmatical models of fluid dynamics in the microgravity environment. Applications suggested include space manufacturing and storage of liquids in low gravity.

  11. Pump apparatus including deconsolidator

    Energy Technology Data Exchange (ETDEWEB)

    Sonwane, Chandrashekhar; Saunders, Timothy; Fitzsimmons, Mark Andrew

    2014-10-07

    A pump apparatus includes a particulate pump that defines a passage that extends from an inlet to an outlet. A duct is in flow communication with the outlet. The duct includes a deconsolidator configured to fragment particle agglomerates received from the passage.

  12. Pathways toward understanding Macroscopic Quantum Phenomena

    International Nuclear Information System (INIS)

    Hu, B L; Subaşi, Y

    2013-01-01

    Macroscopic quantum phenomena refer to quantum features in objects of 'large' sizes, systems with many components or degrees of freedom, organized in some ways where they can be identified as macroscopic objects. This emerging field is ushered in by several categories of definitive experiments in superconductivity, electromechanical systems, Bose-Einstein condensates and others. Yet this new field which is rich in open issues at the foundation of quantum and statistical physics remains little explored theoretically (with the important exception of the work of A J Leggett [1], while touched upon or implied by several groups of authors represented in this conference. Our attitude differs in that we believe in the full validity of quantum mechanics stretching from the testable micro to meso scales, with no need for the introduction of new laws of physics.) This talk summarizes our thoughts in attempting a systematic investigation into some key foundational issues of quantum macroscopic phenomena, with the goal of ultimately revealing or building a viable theoretical framework. Three major themes discussed in three intended essays are the large N expansion [2], the correlation hierarchy [3] and quantum entanglement [4]. We give a sketch of the first two themes and then discuss several key issues in the consideration of macro and quantum, namely, a) recognition that there exist many levels of structure in a composite body and only by judicious choice of an appropriate set of collective variables can one give the best description of the dynamics of a specific level of structure. Capturing the quantum features of a macroscopic object is greatly facilitated by the existence and functioning of these collective variables; b) quantum entanglement, an exclusively quantum feature [5], is known to persist to high temperatures [6] and large scales [7] under certain conditions, and may actually decrease with increased connectivity in a quantum network [8]. We use entanglement as a

  13. Tribological issues of polysilicon surface-micromachining

    Energy Technology Data Exchange (ETDEWEB)

    Sniegowski, J.J.

    1997-12-01

    Polysilicon surface-micromachining is a Micro-Electro-Mechanical Systems (MEMS) manufacturing technology where the infrastructure for manufacturing silicon integrated circuits is used to fabricate micro-miniature mechanical devices. This presentation describes a multi-level mechanical polysilicon surface-micromachining technology and includes a discussion of the issues which affect device manufacture and performance. The multi-level technology was developed and is employed primarily to fabricate microactuated mechanisms. The intricate and complex motion offered by these devices is naturally accompanied by various forms of fraction and wear in addition to the classical stiction phenomena associated with micromechanical device fabrication and usage.

  14. Optical modulator including grapene

    Science.gov (United States)

    Liu, Ming; Yin, Xiaobo; Zhang, Xiang

    2016-06-07

    The present invention provides for a one or more layer graphene optical modulator. In a first exemplary embodiment the optical modulator includes an optical waveguide, a nanoscale oxide spacer adjacent to a working region of the waveguide, and a monolayer graphene sheet adjacent to the spacer. In a second exemplary embodiment, the optical modulator includes at least one pair of active media, where the pair includes an oxide spacer, a first monolayer graphene sheet adjacent to a first side of the spacer, and a second monolayer graphene sheet adjacent to a second side of the spacer, and at least one optical waveguide adjacent to the pair.

  15. Highly energetic phenomena in water electrolysis

    Science.gov (United States)

    Postnikov, A. V.; Uvarov, I. V.; Lokhanin, M. V.; Svetovoy, V. B.

    2016-01-01

    Water electrolysis performed in microsystems with a fast change of voltage polarity produces optically invisible nanobubbles containing H2 and O2 gases. In this form the gases are able to the reverse reaction of water formation. Here we report extreme phenomena observed in a millimeter-sized open system. Under a frequency of driving pulses above 100 kHz the process is accompanied by clicking sounds repeated every 50 ms or so. Fast video reveals that synchronously with the click a bubble is growing between the electrodes which reaches a size of 300 μm in 50 μs. Detailed dynamics of the system is monitored by means of a vibrometer by observing a piece of silicon floating above the electrodes. The energy of a single event is estimated as 0.3 μJ and a significant part of this energy is transformed into mechanical work moving the piece. The observations are explained by the combustion of hydrogen and oxygen mixture in the initial bubble with a diameter of about 40 μm. Unusual combustion mechanism supporting spontaneous ignition at room temperature is responsible for the process. The observed effect demonstrates a principal possibility to build a microscopic internal combustion engine. PMID:27982103

  16. Condensation phenomena in a turbine blade passage

    International Nuclear Information System (INIS)

    Skillings, S.A.

    1989-02-01

    The mechanisms associated with the formation and growth of water droplets in the large low-pressure (LP) turbines used for electrical power generation are poorly understood and recent measurements have indicated that an unusually high loss is associated with the initial nucleation of these droplets. In order to gain an insight into the phenomena which arise in the turbine situation, some experiments were performed to investigate the behaviour of condensing steam flows in a blade passage. This study has revealed the fundamental significance of droplet nucleation in modifying the single-phase flow structure and results are presented which show the change in shock wave pattern when inlet superheat and outlet Mach number are varied. The trailing-edge shock wave structure appears considerably more robust towards variation of inlet superheat than purely one-dimensional considerations may suggest and the inadequacies of adopting a one-dimensional theory to analyse multi-dimensional condensing flows are demonstrated. Over a certain range of outlet Mach numbers an oscillating shock wave will establish in the throat region of the blade passage and this has been shown to interact strongly with droplet nucleation, resulting in a considerably increased mean droplet size. The possible implications of these results for turbine performance are also discussed. (author)

  17. Phantom black holes and critical phenomena

    Energy Technology Data Exchange (ETDEWEB)

    Azreg-Aïnou, Mustapha [Engineering Faculty, Başkent University, Bağlıca Campus, Ankara (Turkey); Marques, Glauber T. [Universidade Federal Rural da Amazônia ICIBE-LASIC, Av. Presidente Tancredo Neves 2501, CEP 66077-901—Belém/PA (Brazil); Rodrigues, Manuel E., E-mail: azreg@baskent.edu.tr, E-mail: gtadaiesky@hotmail.com, E-mail: esialg@gmail.com [Faculdade de Ciências Exatas e Tecnologia, Universidade Federal do Pará, Campus Universitário de Abaetetuba, CEP 68440-000, Abaetetuba, Pará (Brazil)

    2014-07-01

    We consider the two classes cosh and sinh of normal and phantom black holes of Einstein-Maxwell-dilaton theory. The thermodynamics of these holes is characterized by heat capacities that may have both signs depending on the parameters of the theory. Leaving aside the normal Reissner-Nordström black hole, it is shown that only some phantom black holes of both classes exhibit critical phenomena. The two classes share a nonextremality, but special, critical point where the transition is continuous and the heat capacity, at constant charge, changes sign with an infinite discontinuity. This point yields a classification scheme for critical points. It is concluded that the two unstable and stable phases coexist on one side of the criticality state and disappear on the other side, that is, there is no configuration where only one phase exists. The sinh class has an extremality critical point where the entropy diverges. The transition from extremality to nonextremality with the charge held constant is accompanied by a loss of mass and an increase in the temperature. A special case of this transition is when the hole is isolated (microcanonical ensemble), it will evolve by emission of energy, which results in a decrease of its mass, to the final state of minimum mass and vanishing heat capacity. The Ehrenfest scheme of classification is inaccurate in this case but the generalized one due to Hilfer leads to conclude that the transition is of order less than unity. Fluctuations near criticality are also investigated.

  18. Macroscopic quantum systems and gravitational phenomena

    International Nuclear Information System (INIS)

    Pikovski, I.

    2014-01-01

    Low-energy quantum systems are studied theoretically in light of possible experiments to test the interplay between quantum theory and general relativity. The research focus in this thesis is on quantum systems which can be controlled with very high precision and which allow for tests of quantum theory at novel scales in terms of mass and size. The pulsed regime of opto-mechanics is explored and it is shown how short optical pulses can be used to prepare and characterize quantum states of a massive mechanical resonator, and how some phenomenological models of quantum gravity can be probed. In addition, quantum interferometry with photons and matter-waves in the presence of gravitational time dilation is considered. It is shown that time dilation causes entanglement between internal states and the center-of-mass position and that it leads to decoherence of all composite quantum systems. The results of the thesis show that the interplay between quantum theory and general relativity affects even low-energy quantum systems and that it offers novel phenomena which can be probed in experiments. (author) [de

  19. Ultrashort Phenomena in Biochemistry and Biological Signaling

    Science.gov (United States)

    Splinter, Robert

    2014-11-01

    In biological phenomena there are indications that within the long pulse-length of the action potential on millisecond scale, there is additional ultrashort perturbation encoding that provides the brain with detailed information about the origin (location) and physiological characteristics. The objective is to identify the mechanism-of-action providing the potential for encoding in biological signal propagation. The actual molecular processes involved in the initiation of the action potential have been identified to be in the femtosecond and pico-second scale. The depolarization process of the cellular membrane itself, leading to the onset of the actionpotential that is transmitted to the brain, however is in the millisecond timeframe. One example of the femtosecond chemical interaction is the photoresponse of bacteriorhodopsin. No clear indication for the spatial encoding has so far been verified. Further research will be required on a cellular signal analysis level to confirm or deny the spatial and physiological encoding in the signal wave-trains of intercellular communications and sensory stimuli. The pathological encoding process for cardiac depolarization is however very pronounced and validated, however this electro-chemical process is in the millisecond amplitude and frequency modulation spectrum.

  20. Condensed matter view of giant resonance phenomena

    International Nuclear Information System (INIS)

    Zangwill, A.

    1987-01-01

    The intent of this article is to present a view of giant resonance phenomena (an essentially atomic phenomenon) from the perspective of a condensed matter physicist with an interest in the optical properties of matter. As we shall see, this amounts to a particular prejudice about how one should think about many-body effects in a system of interacting electrons. Some of these effects are special to condensed matter systems and will be dealt with in the second half of this paper. However, it turns out that the authors view of the main ingredient to a giant resonance differs significantly from that normally taken by scientists trained in the traditional methods of atomic physics. Therefore, in the first section the author will take advantage of the fact that his contribution to this volume was composed and delivered to the publishers somewhat after the conclusion of the School (rather than before as requested by the organizers) and try to clearly distinguish the differences of opinion presented by the lecturers from the unalterable experimental facts. 46 references, 9 figures

  1. Highly energetic phenomena in water electrolysis

    Science.gov (United States)

    Postnikov, A. V.; Uvarov, I. V.; Lokhanin, M. V.; Svetovoy, V. B.

    2016-12-01

    Water electrolysis performed in microsystems with a fast change of voltage polarity produces optically invisible nanobubbles containing H2 and O2 gases. In this form the gases are able to the reverse reaction of water formation. Here we report extreme phenomena observed in a millimeter-sized open system. Under a frequency of driving pulses above 100 kHz the process is accompanied by clicking sounds repeated every 50 ms or so. Fast video reveals that synchronously with the click a bubble is growing between the electrodes which reaches a size of 300 μm in 50 μs. Detailed dynamics of the system is monitored by means of a vibrometer by observing a piece of silicon floating above the electrodes. The energy of a single event is estimated as 0.3 μJ and a significant part of this energy is transformed into mechanical work moving the piece. The observations are explained by the combustion of hydrogen and oxygen mixture in the initial bubble with a diameter of about 40 μm. Unusual combustion mechanism supporting spontaneous ignition at room temperature is responsible for the process. The observed effect demonstrates a principal possibility to build a microscopic internal combustion engine.

  2. Photon management of GaN-based optoelectronic devices via nanoscaled phenomena

    KAUST Repository

    Tsai, Yu-Lin

    2016-09-06

    Photon management is essential in improving the performances of optoelectronic devices including light emitting diodes, solar cells and photo detectors. Beyond the advances in material growth and device structure design, photon management via nanoscaled phenomena have also been demonstrated as a promising way for further modifying/improving the device performance. The accomplishments achieved by photon management via nanoscaled phenomena include strain-induced polarization field management, crystal quality improvement, light extraction/harvesting enhancement, radiation pattern control, and spectrum management. In this review, we summarize recent development, challenges and underlying physics of photon management in GaN-based light emitting diodes and solar cells. (C) 2016 Elsevier Ltd. All rights reserved.

  3. On the mechanism of phenomena in the contact of a honing tool with a workable article

    International Nuclear Information System (INIS)

    Fragin, I.E.

    1975-01-01

    The hypothesis on phenomena mechanism in the point of contact between the diamond honing blocks and processed surface is presented. It is shown that the function of the cooling lubricant, containing surface-active agents, consists in redistribution of energy-increase of the energy spent for metal dispersion and decrease of the energy consumed for wear-out of the honing blocks. The wear-out of the binder takes place at the first stage of the honing cycle because of its contact with the surface irregularities and at the subsequent stages due to presence of metal chips and diamond particles in-between the honing block and the part

  4. Polar Coordinate Lattice Boltzmann Kinetic Modeling of Detonation Phenomena

    International Nuclear Information System (INIS)

    Lin Chuan-Dong; Li Ying-Jun; Xu Ai-Guo; Zhang Guang-Cai

    2014-01-01

    A novel polar coordinate lattice Boltzmann kinetic model for detonation phenomena is presented and applied to investigate typical implosion and explosion processes. In this model, the change of discrete distribution function due to local chemical reaction is dynamically coupled into the modified lattice Boltzmann equation which could recover the Navier—Stokes equations, including contribution of chemical reaction, via the Chapman—Enskog expansion. For the numerical investigations, the main focuses are the nonequilibrium behaviors in these processes. The system at the disc center is always in its thermodynamic equilibrium in the highly symmetric case. The internal kinetic energies in different degrees of freedom around the detonation front do not coincide. The dependence of the reaction rate on the pressure, influences of the shock strength and reaction rate on the departure amplitude of the system from its local thermodynamic equilibrium are probed. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

  5. Observations of fast, transient gamma-ray phenomena

    International Nuclear Information System (INIS)

    Kouveliotou, C.

    1981-01-01

    The present work is devoted primarily to the study of the solar GRBs as seen by the ISEE-3 satellite, in the energy range between 100 keV and 6.5 MeV. We have also included the cosmic GRB observations from ISEE-3, as a direct comparison for the two phenomena. Thus this thesis comprises 7 chapters: introduction, a chapter providing information on the instruments used, a discussion on the physics of the gamma-ray emission, a chapter describing the cosmic GRBs, and a chapter analysing the solar ones. Finally, we give the conclusions and a summary of our results and indications for the future observations. (orig./UPO)

  6. Observations of fast, transient gamma-ray phenomena

    International Nuclear Information System (INIS)

    Kouveliotou, C.

    1981-09-01

    The present work is devoted primarily to the study of the solar GRBs as seen by the ISEE-3 satellite, in the energy range between 100 keV and 6.5 MeV. We have also included the cosmic GRB observations from ISEE-3, as a direct comparison for the two phenomena. Thus this thesis comprises 7 chapters: introduction, a chapter providing information on the instruments used, a discussion on the physics of the gamma-ray emission, a chapter describing the cosmic GRBs, and a chapter analysing the solar ones. Finally, we give the conclusions and a summary of our results and indications for the future observations. (orig./WL)

  7. Critical Phenomena of the Disorder Driven Localization-Delocalization Transition

    International Nuclear Information System (INIS)

    Marc Ruehlaender

    2001-01-01

    Metal-to-insulator transitions are generally linked to two phenomena: electron-electron correlations and disorder. Although real systems are usually responding to a mixture of both, they can be classified as undergoing a Mott-transition, if the former process dominates, or an Anderson-transition, if the latter dominates. High-T c superconductors, e.g., are a candidate for the first class. Materials in which disorder drives the metal-to-insulator transition include doped semiconductors and amorphous materials. After briefly reviewing the previous research on transport in disordered materials and the disorder-induced metal-to-insulator transition, a summary of the model and the methods used in subsequent chapters is given

  8. Thermodynamics and Transport Phenomena in High Temperature Steam Electrolysis Cells

    Energy Technology Data Exchange (ETDEWEB)

    James E. O' Brien

    2012-03-01

    Hydrogen can be produced from water splitting with relatively high efficiency using high temperature electrolysis. This technology makes use of solid-oxide cells, running in the electrolysis mode to produce hydrogen from steam, while consuming electricity and high temperature process heat. The overall thermal-to-hydrogen efficiency for high temperature electrolysis can be as high as 50%, which is about double the overall efficiency of conventional low-temperature electrolysis. Current large-scale hydrogen production is based almost exclusively on steam reforming of methane, a method that consumes a precious fossil fuel while emitting carbon dioxide to the atmosphere. An overview of high temperature electrolysis technology will be presented, including basic thermodynamics, experimental methods, heat and mass transfer phenomena, and computational fluid dynamics modeling.

  9. Comments on the measurements of multiple muon phenomena

    Science.gov (United States)

    Sato, T.; Takahashi, T.; Higashi, S.

    1985-01-01

    The extensive air showers in the energy around 10 to the 15th power eV include those initiated by astrophysical primary gamma-rays. The observations need a precise measurement on the directions of primary particles. It is one of the methods to measure the directions of high-energy muons in air showers. The accuracy in measuring the direction, by calculating the cosmic-ray phenomena in the atmosphere at very high energy was investgated. The results calculated by Monte Carlo method suggest that one may determine the direction of primary cosmic-rays within errors of 10/3 rad in observing muons of above 100 GeV at sea level.

  10. Colloquium: Strong-field phenomena in periodic systems

    Science.gov (United States)

    Kruchinin, Stanislav Yu.; Krausz, Ferenc; Yakovlev, Vladislav S.

    2018-04-01

    The advent of visible-infrared laser pulses carrying a substantial fraction of their energy in a single field oscillation cycle has opened a new era in the experimental investigation of ultrafast processes in semiconductors and dielectrics (bulk as well as nanostructured), motivated by the quest for the ultimate frontiers of electron-based signal metrology and processing. Exploring ways to approach those frontiers requires insight into the physics underlying the interaction of strong high-frequency (optical) fields with electrons moving in periodic potentials. This Colloquium aims at providing this insight. Introduction to the foundations of strong-field phenomena defines and compares regimes of field-matter interaction in periodic systems, including (perfect) crystals as well as optical and semiconductor superlattices, followed by a review of recent experimental advances in the study of strong-field dynamics in crystals and nanostructures. Avenues toward measuring and controlling electronic processes up to petahertz frequencies are discussed.

  11. Dissociative electron attachment: Threshold phenomena and multimode effects

    International Nuclear Information System (INIS)

    Fabrikant, Ilya I

    2009-01-01

    We present a summary of recent progress on studies of threshold phenomena in low-energy dissociative electron attachment to polyatomic molecules: vibrational Feshbach resonances and threshold cusps. The theoretical approach is based on the resonance R-matrix theory. It allows us to analyze threshold effects in other channels, particularly vibrational excitation. If the molecular long-range field is not strong enough, virtual-state cusps are observed at vibrational excitation thresholds. The second part of the paper illustrates the multimode effects in dissociative attachment using attachment to the CF 3 Cl molecule as an example. Symmetric stretch C-Cl vibrations v 3 and symmetric deformation (or so-called u mbrella ) vibrations v 2 are included. Calculations allow us to study the final-state vibrational distribution in the CF 3 (v 2 ) fragment.

  12. Macroscopic Modeling of Transport Phenomena in Direct Methanol Fuel Cells

    DEFF Research Database (Denmark)

    Olesen, Anders Christian

    An increasing need for energy efficiency and high energy density has sparked a growing interest in direct methanol fuel cells for portable power applications. This type of fuel cell directly generates electricity from a fuel mixture consisting of methanol and water. Although this technology...... for studying their transport. In this PhD dissertation the macroscopic transport phenomena governing direct methanol fuel cell operation are analyzed, discussed and modeled using the two-fluid approach in the computational fluid dynamics framework of CFX 14. The overall objective of this work is to extend...... the present fundamental understanding of direct methanol fuel cell operation by developing a three-dimensional, two-phase, multi-component, non-isotherm mathematical model including detailed non-ideal thermodynamics, non-equilibrium phase change and non-equilibrium sorption-desorption of methanol and water...

  13. Study of interfacial phenomena for bio/chemical sensing applications

    Science.gov (United States)

    Min, Hwall

    This work presents the fundamental study of biological and chemical interfacial phenomena and (bio)chemical sensing applications using high frequency resonator arrays. To realize a versatile (bio)chemical sensing system for the fundamental study as well as their practical applications, the following three distinct components were studied and developed: i) detection platforms with high sensitivity, ii) novel innovative sensing materials with high selectivity, iii) analytical model for data interpretation. 8-pixel micromachined quartz crystal resonator (muQCR) arrays with a fundamental resonance frequency of 60 ¡V 90 MHz have been used to provide a reliable detection platform with high sensitivity. Room temperature ionic liquid (RTIL) has been explored and integrated into the sensing system as a smart chemical sensing material. The use of nanoporous gold (np-Au) enables the combination of the resonator and surface-enhanced Raman spectroscopy for both quantitative and qualitative measurement. A statistical model for the characterization of resonator behavior to study the protein adsorption kinetics is developed by random sequential adsorption (RSA) approach with the integration of an effective surface depletion theory. The investigation of the adsorption kinetics of blood proteins is reported as the fundamental study of biological phenomena using the proposed sensing system. The aim of this work is to study different aspects of protein adsorption and kinetics of adsorption process with blood proteins on different surfaces. We specifically focus on surface depletion effect in conjunction with the RSA model to explain the observed adsorption isotherm characteristics. A number of case studies on protein adsorption conducted using the proposed sensing system has been discussed. Effort is specifically made to understand adsorption kinetics, and the effect of surface on the adsorption process as well as the properties of the adsorbed protein layer. The second half of the

  14. Synergistic effects in plasma surface interactions

    International Nuclear Information System (INIS)

    Roberto, J.B.; Behrisch, R.

    1984-01-01

    The possible synergistic effects which can contribute to plasma surface interaction phenomena in fusion devices are reviewed. These effects include the influence of reactive ions, surface modification, temperature, radiation damage, and external forces and fields on erosion yields, hydrogen retention and release, and other surface processes. The important synergistic effects are described in terms of surface and edge conditions encountered in present fusion devices and expected in future reactors. Priority data needs include the chemical erosion of graphite at high particle fluxes, melt-layer stability under disruption-induced eddy current forces, the influence of bulk neutron damage on hydrogen retention, and an in-situ evaluation of synergistic effects in operating fusion devices

  15. Transport phenomena and the effects of reactor geometry for epitaxial GaN growth in a vertical MOCVD reactor

    Science.gov (United States)

    Tseng, Chien-Fu; Tsai, Tsung-Yen; Huang, Yen-Hsiu; Lee, Ming-Tsang; Horng, Ray-Hua

    2015-12-01

    In this study a numerical simulation was carried out to analyze the transport phenomena in a vertical type metal organic chemical vapor deposition (MOCVD) reactor for Gallium Nitride (GaN) growth. The simulated results were compared and validated by experiment. The effects of showerhead design and chamber height are investigated and discussed. It was found that, by properly adjusting the height of the chamber, both the growth rate and film uniformity could be significantly improved. This is attributed to the suppression of the thermal and mass transfer boundary layers by the injection flow of reacting gas mixtures, as well as the confined vertical vortices caused by the geometry of the reduced space. However, inappropriate design of the distance between the showerhead and the susceptor can result in uneven distribution of the organic source in the vicinity of the substrate surface resulting in an uneven growth rate of the GaN film. Consequently, there exists an optimal chamber height that will give the best growth rate and uniformity to the GaN film as discussed in this study. This study provides comprehensive insight into the transport phenomena of GaN growth that includes coupled heat and mass transfer as well as chemical reactions. The results provide important information in a succinct format and enable decisions to be made about the showerhead and the geometrical design and size of a vertical MOCVD reactor.

  16. Nonlinear friction dynamics on polymer surface under accelerated movement

    Directory of Open Access Journals (Sweden)

    Yuuki Aita

    2017-04-01

    Full Text Available Nonlinear phenomena on the soft material surface are one of the most exciting topics of chemical physics. However, only a few reports exist on the friction phenomena under accelerated movement, because friction between two solid surfaces is considered a linear phenomenon in many cases. We aim to investigate how nonlinear accelerated motion affects friction on solid surfaces. In the present study, we evaluate the frictional forces between two polytetrafluoroethylene (PTFE resins using an advanced friction evaluation system. On PTFE surfaces, the normalized delay time δ, which is the time lag in the response of the friction force to the accelerated movement, is observed in the pre-sliding friction process. Under high-velocity conditions, kinetic friction increases with velocity. Based on these experimental results, we propose a two-phase nonlinear model including a pre-sliding process (from the beginning of sliding of a contact probe to the establishment of static friction and a kinetic friction process. The present model consists of several factors including velocity, acceleration, stiffness, viscosity, and vertical force. The findings reflecting the viscoelastic properties of soft material is useful for various fields such as in the fabrication of clothes, cosmetics, automotive materials, and virtual reality systems as well as for understanding friction phenomena on soft material surfaces.

  17. Mathematics for Nonlinear Phenomena : Analysis and Computation : International Conference in honor of Professor Yoshikazu Giga on his 60th birthday

    CERN Document Server

    Jimbo, Shuichi

    2017-01-01

    This volume covers some of the most seminal research in the areas of mathematical analysis and numerical computation for nonlinear phenomena. Collected from the international conference held in honor of Professor Yoshikazu Giga’s 60th birthday, the featured research papers and survey articles discuss partial differential equations related to fluid mechanics, electromagnetism, surface diffusion, and evolving interfaces. Specific focus is placed on topics such as the solvability of the Navier-Stokes equations and the regularity, stability, and symmetry of their solutions, analysis of a living fluid, stochastic effects and numerics for Maxwell’s equations, nonlinear heat equations in critical spaces, viscosity solutions describing various kinds of interfaces, numerics for evolving interfaces, and a hyperbolic obstacle problem. Also included in this volume are an introduction of Yoshikazu Giga’s extensive academic career and a long list of his published work. Students and researchers in mathematical analy...

  18. Statistical trend analysis methods for temporal phenomena

    International Nuclear Information System (INIS)

    Lehtinen, E.; Pulkkinen, U.; Poern, K.

    1997-04-01

    We consider point events occurring in a random way in time. In many applications the pattern of occurrence is of intrinsic interest as indicating a trend or some other systematic feature in the rate of occurrence. The purpose of this report is to survey briefly different statistical trend analysis methods and illustrate their applicability to temporal phenomena in particular. The trend testing of point events is usually seen as the testing of the hypotheses concerning the intensity of the occurrence of events. When the intensity function is parametrized, the testing of trend is a typical parametric testing problem. In industrial applications the operational experience generally does not suggest any specified model and method in advance. Therefore, and particularly, if the Poisson process assumption is very questionable, it is desirable to apply tests that are valid for a wide variety of possible processes. The alternative approach for trend testing is to use some non-parametric procedure. In this report we have presented four non-parametric tests: The Cox-Stuart test, the Wilcoxon signed ranks test, the Mann test, and the exponential ordered scores test. In addition to the classical parametric and non-parametric approaches we have also considered the Bayesian trend analysis. First we discuss a Bayesian model, which is based on a power law intensity model. The Bayesian statistical inferences are based on the analysis of the posterior distribution of the trend parameters, and the probability of trend is immediately seen from these distributions. We applied some of the methods discussed in an example case. It should be noted, that this report is a feasibility study rather than a scientific evaluation of statistical methods, and the examples can only be seen as demonstrations of the methods

  19. Novel Phenomena in Modern Studies of Magnetism

    Science.gov (United States)

    Makhfudz, Imam

    In this PhD Dissertation, we present investigation of contemporary problems in magnetism. We focus on two important themes that have been active research topics in condensed matter community: 1. Topological defects in magnet and their dynamics 2. Exotic states and critical phenomena in frustrated spin systems. In the first topic, we consider the dynamics of topological defect known as Skyrmion in thin film ferromagnet. We first discuss the nontrivial dynamics exhibited by a Skyrmion bubble confined in thin film disk as observed by numerical simulation. We propose a phenomenological theory that can reproduce the peculiar dynamics of the Skyrmion bubble. We show that, unlike previously studied topological defects, a Skyrmion bubble possesses inertia. We derive a theoretical description of the dynamics using standard theory of ferromagnet. We discover the presence of two counter propagating chiral edge modes. Most importantly, we derive the mass (inertia) from the theory and express it in terms of microscopic parameters. In the second topic, a quantum phase transition in U(1) quantum spin liquid phase of 3-d pyrochlore quantum spin ice is investigated. Starting from microscopic spin model, we map the spin to slave-boson, derive continuum theory, and finally arrive at a U(1) gauge theory which takes the form of scalar quantum electrodynamics (QED). The effective free energy for quantum spin liquid (QSL) to antiferromagnetic (AFM) phase transition mimics the one for Bardeen-Cooper-Schrieffer (BCS) superconductors classical transition under magnetic field. We show that, provided Ginzburg criterion is satisfied, the gauge field fluctuations drive the originally continuous QSL to AFM phase transition at mean field level into discontinuous one. We predict the location of quantum critical point which agrees well with gauge mean field theory result. We calculate the size of phase transition and find that it is a weakly first order.

  20. Magnetoacoustic Phenomena in Saturated Porous Media

    Science.gov (United States)

    Perepechko, Y.

    2007-12-01

    This work deals with dynamic interaction between electromagnetic and hydrodynamic types of motions in a porous medium, saturated with electrolyte. The system of equations is a coupling of equations of the two-velocity continuous filtration theory and Maxwell equations in quasi-stationary approximation. The method of separation by the physical processes is used for numerical solution, and the hyperbolic system is approximated by the explicit expanded Godunov scheme, and the parabolic system is approximated by the inexplicit Crank-Nicolson scheme. Generation of the magnetic field was modeled in the process of 2D electrolyte filtration in a porous medium, which is considered to be conducing because of a double electric layer. An entrainment in the external magnetic field over the electrolyte flow into a porous medium is observed, and the location of magnetic field maximum relative to the inlet boundary is determined by the ratio of kinematic viscosity to magnetic viscosity. A rise of this ratio provides more intensive drag of a filtered liquid and increasing magnetic field, reached in a porous medium. Downward the flow the field decreases because of magnetic field diffusion. The problem with simultaneous excitation of acoustic and electromagnetic perturbations at the boundary of saturated porous medium was also considered, and this allows us to obtain additional knowledge about accompanying effects and phenomena, what is the main scientific and practical goal of geophysics and oil survey. This research was supported by the Russian Foundation for Basic Research grant 06-05-65110, by the President's grants NSh-1573.2003.5, and by the Russian Ministry Science and Education grant RNP.2.1.1.702.

  1. The Fragility of Interdependency: Coupled Networks Switching Phenomena

    Science.gov (United States)

    Stanley, H. Eugene

    2013-03-01

    Recent disasters ranging from abrupt financial ``flash crashes'' and large-scale power outages to sudden death among the elderly dramatically exemplify the fact that the most dangerous vulnerability is hiding in the many interdependencies among different networks. In the past year, we have quantified failures in model of interconnected networks, and demonstrated the need to consider mutually dependent network properties in designing resilient systems. Specifically, we have uncovered new laws governing the nature of switching phenomena in coupled networks, and found that phenomena that are continuous ``second order'' phase transitions in isolated networks become discontinuous abrupt ``first order'' transitions in interdependent networks [S. V. Buldyrev, R. Parshani, G. Paul, H. E. Stanley, and S. Havlin, ``Catastrophic Cascade of Failures in Interdependent Networks,'' Nature 464, 1025 (2010); J. Gao, S. V. Buldyrev, H. E. Stanley, and S. Havlin, ``Novel Behavior of Networks Formed from Interdependent Networks,'' Nature Physics 8, 40 (2012). We conclude by discussing the network basis for understanding sudden death in the elderly, and the possibility that financial ``flash crashes'' are not unlike the catastrophic first-order failure incidents occurring in coupled networks. Specifically, we study the coupled networks that are responsible for financial fluctuations. It appears that ``trend switching phenomena'' that we uncover are remarkably independent of the scale over which they are analyzed. For example, we find that the same laws governing the formation and bursting of the largest financial bubbles also govern the tiniest finance bubbles, over a factor of 1,000,000,000 in time scale [T. Preis, J. Schneider, and H. E. Stanley, ``Switching Processes in Financial Markets,'' Proc. Natl. Acad. Sci. USA 108, 7674 (2011); T. Preis and H. E. Stanley, ``Bubble Trouble: Can a Law Describe Bubbles and Crashes in Financial Markets?'' Physics World 24, No. 5, 29 (May 2011

  2. Improvement in understanding of natural circulation phenomena in water cooled nuclear power plants

    International Nuclear Information System (INIS)

    Choi, Jong-Ho; Cleveland, John; Aksan, Nusret

    2011-01-01

    Highlights: ► Phenomena influencing natural circulation in passive systems. ► Behaviour in large pools of liquid. ► Effect of non-condensable gas on condensation heat transfer. ► Behaviour of containment emergency systems. ► Natural circulation flow and pressure drop in various geometries. - Abstract: The IAEA has organized a coordinated research project (CRP) on “Natural Circulation Phenomena, Modelling, and Reliability of Passive Systems That Utilize Natural Circulation.” Specific objectives of CRP were to (i) establish the status of knowledge: reactor start-up and operation, passive system initiation and operation, flow stability, 3-D effects, and scaling laws, (ii) investigate phenomena influencing reliability of passive natural circulation systems, (iii) review experimental databases for the phenomena, (iv) examine the ability of computer codes to predict natural circulation and related phenomena, and (v) apply methodologies for examining the reliability of passive systems. Sixteen institutes from 13 IAEA Member States have participated in this CRP. Twenty reference advanced water cooled reactor designs including evolutionary and innovative designs were selected to examine the use of natural circulation and passive systems in their designs. Twelve phenomena influencing natural circulation were identified and characterized: (1) behaviour in large pools of liquid, (2) effect of non-condensable gases on condensation heat transfer, (3) condensation on the containment structures, (4) behaviour of containment emergency systems, (5) thermo-fluid dynamics and pressure drops in various geometrical configurations, (6) natural circulation in closed loop, (7) steam liquid interaction, (8) gravity driven cooling and accumulator behaviour, (9) liquid temperature stratification, (10) behaviour of emergency heat exchangers and isolation condensers, (11) stratification and mixing of boron, and (12) core make-up tank behaviour. This paper summarizes the

  3. Review on mechanisms and continuum models of multi-phase transport phenomena in porous structures of non-aqueous Li-Air batteries

    Science.gov (United States)

    Yuan, Jinliang; Yu, Jong-Sung; Sundén, Bengt

    2015-03-01

    During recent years intensive research activities involving both experimental and modeling approaches have appeared for different aspects of Lithium-air (Li-air) battery. Multi-phase transport phenomena including dissolved oxygen and lithium ions (Li+) in the liquid electrolyte, as well as electrons in the solid materials, are strongly coupled with the porous structures and various reactions, particularly the solid product grown in the porous cathode during battery discharge. Understanding the mechanisms of transport phenomena and accurate evaluation of effective transport properties are significant for improving the battery capacities and design, especially at high rate conditions. In this paper, the transport governing equations commonly used for macroscopic continuum models at porous-average level are outlined and highlighted, with a purpose to provide a general overview of the validity and the limitation of these approaches. The most often used models in the open literature are reviewed and discussed focusing on the effective properties involving tortuosity factors, solid product morphologies, as well as effects on the void space clogging, surface area reduction and passivation. Comments and suggestions are also provided for better understanding of multi-phase transport phenomena and implementation of the detailed models for solid product generation and morphology growth in Li-air battery cathodes.

  4. Friction phenomena in hydrostatic extrusion of magnesium

    NARCIS (Netherlands)

    Moodij, Ellen

    2014-01-01

    When magnesium is hydrostatically extruded an inconsistent and sometimes bad surface quality is encountered. In hydrostatic extrusion the billet is surrounded by a lubricant, usually castor oil. The required pressure to deform the material is applied onto this lubricant and not directly to the

  5. Reflection Phenomena in Underground Pumped Storage Reservoirs

    Directory of Open Access Journals (Sweden)

    Elena Pummer

    2018-04-01

    Full Text Available Energy storage through hydropower leads to free surface water waves in the connected reservoirs. The reason for this is the movement of water between reservoirs at different elevations, which is necessary for electrical energy storage. Currently, the expansion of renewable energies requires the development of fast and flexible energy storage systems, of which classical pumped storage plants are the only technically proven and cost-effective technology and are the most used. Instead of classical pumped storage plants, where reservoirs are located on the surface, underground pumped storage plants with subsurface reservoirs could be an alternative. They are independent of topography and have a low surface area requirement. This can be a great advantage for energy storage expansion in case of environmental issues, residents’ concerns and an unusable terrain surface. However, the reservoirs of underground pumped storage plants differ in design from classical ones for stability and space reasons. The hydraulic design is essential to ensure their satisfactory hydraulic performance. The paper presents a hybrid model study, which is defined here as a combination of physical and numerical modelling to use the advantages and to compensate for the disadvantages of the respective methods. It shows the analysis of waves in ventilated underground reservoir systems with a great length to height ratio, considering new operational aspects from energy supply systems with a great percentage of renewable energies. The multifaceted and narrow design of the reservoirs leads to complex free surface flows; for example, undular and breaking bores arise. The results show excessive wave heights through wave reflections, caused by the impermeable reservoir boundaries. Hence, their knowledge is essential for a successful operational and constructive design of the reservoirs.

  6. Experimental studies of light emission phenomena in superconducting RF cavities

    Energy Technology Data Exchange (ETDEWEB)

    Anthony, P.L. [SLAC National Accelerator Laboratory, Menlo Park, CA 94025 (United States); Delayen, J.R. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport, News, VA 23606 (United States); Center for Accelerator Science, Old Dominion University, Norfolk, VA, 23529 (United States); Fryberger, D., E-mail: fryberger@slac.stanford.ed [SLAC National Accelerator Laboratory, Menlo Park, CA 94025 (United States); Goree, W.S. [2G Enterprises, Pacific Grove, CA 93950 (United States); Mammosser, J. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport, News, VA 23606 (United States); Szalata, Z.M.; Weisend, J.G. [SLAC National Accelerator Laboratory, Menlo Park, CA 94025 (United States)

    2009-12-21

    Experimental studies of light emission phenomena in superconducting RF cavities, which we categorize under the general heading of cavity lights, are described. The cavity lights data, which were obtained using a small CCD video camera, were collected in a series of nine experimental runs ranging from approx1/2 to approx2 h in duration. The video data were recorded on a standard VHS tape. As the runs progressed, additional instrumentation was added. For the last three runs a LabVIEW-controlled data acquisition system was included. These runs furnish evidence for several, possibly related, light emission phenomena. The most intriguing of these is what appear to be small luminous objects <=1.5 mm in size, freely moving about in the vacuum space, generally without wall contact, as verified by reflections of the tracks in the cavity walls. In addition, on a number of occasions, these objects were observed to bounce off of the cavity walls. The wall-bounce aspect of most of these events was clearly confirmed by pre-bounce and post-bounce reflections concurrent with the tracks. In one of the later runs, a mode of behavior was observed that was qualitatively different from anything observed in the earlier runs. Perhaps the most perplexing aspect of this new mode was the observation of as many as seven luminous objects arrayed in what might be described as a macromolecular formation, coherently moving about in the interior of the cavity for extended periods of time, evidently without any wall contact. It is suggested that these mobile luminous objects are without explanation within the realm of established physics. Some remarks about more exotic theoretical possibilities are made, and future plans are discussed.

  7. Experimental Studies of Light Emission Phenomena in Superconducting RF Cavitites

    Energy Technology Data Exchange (ETDEWEB)

    Anthony, P.L.; /SLAC; Delayen, J.R.; /Jefferson Lab; Fryberger, D.; /SLAC; Goree, W.S.; Mammosser, J.; /Jefferson Lab /SNS Project, Oak Ridge; Szalata, Z.M.; II, J.G.Weisend /SLAC

    2009-08-04

    Experimental studies of light emission phenomena in superconducting RF cavities, which we categorize under the general heading of cavity lights, are described. The cavity lights data, which were obtained using a small CCD video camera, were collected in a series of nine experimental runs ranging from {approx} 1/2 to {approx} 2 h in duration. The video data were recorded on a standard VHS tape. As the runs progressed, additional instrumentation was added. For the last three runs a LabVIEW controlled data acquisition system was included. These runs furnish evidence for several, possibly related, light emission phenomena. The most intriguing of these is what appear to be small luminous objects {le} 1.5 mm in size, freely moving about in the vacuum space, generally without wall contact, as verified by reflections of the tracks in the cavity walls. In addition, on a number of occasions, these objects were observed to bounce off of the cavity walls. The wall-bounce aspect of most of these events was clearly confirmed by pre-bounce and post-bounce reflections concurrent with the tracks. In one of the later runs, a mode of behavior was observed that was qualitatively different from anything observed in the earlier runs. Perhaps the most perplexing aspect of this new mode was the observation of as many as seven luminous objects arrayed in what might be described as a macromolecular formation, coherently moving about in the interior of the cavity for extended periods of time, evidently without any wall contact. It is suggested that these mobile luminous objects are without explanation within the realm of established physics. Some remarks about more exotic theoretical possibilities are made, and future plans are discussed.

  8. Saving the Phenomena in Medieval Astronomy

    Science.gov (United States)

    Seeskin, K.

    2011-06-01

    Aristotle's theory of motion is based on two principles: (1) all motion to either from the midpoint of the Earth, toward it, or around it, and (2) circular motion must proceed around an immovable point. On this view, the heavenly bodies are individual points of light carried around by a series of concentric spheres rotating at a constant pace around the midpoint of the Earth. But even in Aristotle's day, it was known that this theory had a great deal of difficulty accounting for planetary motion. Ptolemy's alternative was to introduce epicycles and eccentric orbits, thus denying Aristotle's view of natural motion. There was no doubt that Ptolemy's predictions were far better than Aristotle's. But for the medievals, Aristotle's theory made better intuitive sense. Moreover, Ptolemy's theory raised the question of how one sphere could pass through another. What to do? The solution of Moses Maimonides (1138-1204) was to say that it is not the job of the astronomer to tell us how things actually are but merely to propose a series of hypotheses that allow us to explain the relevant data. This view had obvious theological implications. If astronomy could explain planetary motion in an acceptable way, there was reason to believe that the order or structure of the heavens is what it is by necessity. This suggests that God did not exercise any degree of choice in making it that way. But if astronomy cannot explain planetary motion, the most reasonable explanation is that we are dealing with contingent phenomena rather than necessary ones. If there is contingency, there is reason to think God did exercise a degree of choice in making the heavens the way they are. A God who exercises choice is much closer to the God of Scripture. Although Galileo changed all of this, and paved the way for a vastly different view of astronomy, the answer to one set of questions raises a whole different set. In short, the heavenly motion still poses ultimate questions about God, existence, and

  9. In search of high density collective phenomena in nuclear collision

    International Nuclear Information System (INIS)

    Gyulassy, M.

    1979-06-01

    The progress made toward uncovering signatures of collective phenomena is reviewed. Elements of the basic reaction mechanism leading to a complex background are first discussed. Possible hints of collective phenomena in proton and pion single and double inclusive spectra as well as π - multiplicity data are then described. 6 figures, 2 tables

  10. Ether and interpretation of some physical phenomena and concepts

    International Nuclear Information System (INIS)

    Rzayev, S.G.

    2008-01-01

    On the basis of the concept of existence of an ether representation about time, space, matters and physical field are profound and also the essence of such phenomena, as corpuscular - wave dualism, change of time, scale and mass at movement body's is opened. The opportunity of transition from probability-statistical interpretation of the quantum phenomena to Laplace's determinism is shown

  11. Amplitude various angles (AVA) phenomena in thin layer reservoir: Case study of various reservoirs

    International Nuclear Information System (INIS)

    thfloor, Physics Dept., FMIPA, Institut Teknologi Bandung (Indonesia); Rock Fluid Imaging Lab., Bandung (Indonesia))" data-affiliation=" (Wave Inversion and Subsurface Fluid Imaging Research Laboratory (WISFIR), Basic Science Center A 4thfloor, Physics Dept., FMIPA, Institut Teknologi Bandung (Indonesia); Rock Fluid Imaging Lab., Bandung (Indonesia))" >Nurhandoko, Bagus Endar B.; Susilowati

    2015-01-01

    Amplitude various offset is widely used in petroleum exploration as well as in petroleum development field. Generally, phenomenon of amplitude in various angles assumes reservoir’s layer is quite thick. It also means that the wave is assumed as a very high frequency. But, in natural condition, the seismic wave is band limited and has quite low frequency. Therefore, topic about amplitude various angles in thin layer reservoir as well as low frequency assumption is important to be considered. Thin layer reservoir means the thickness of reservoir is about or less than quarter of wavelength. In this paper, I studied about the reflection phenomena in elastic wave which considering interference from thin layer reservoir and transmission wave. I applied Zoeppritz equation for modeling reflected wave of top reservoir, reflected wave of bottom reservoir, and also transmission elastic wave of reservoir. Results show that the phenomena of AVA in thin layer reservoir are frequency dependent. Thin layer reservoir causes interference between reflected wave of top reservoir and reflected wave of bottom reservoir. These phenomena are frequently neglected, however, in real practices. Even though, the impact of inattention in interference phenomena caused by thin layer in AVA may cause inaccurate reservoir characterization. The relation between classes of AVA reservoir and reservoir’s character are different when effect of ones in thin reservoir and ones in thick reservoir are compared. In this paper, I present some AVA phenomena including its cross plot in various thin reservoir types based on some rock physics data of Indonesia

  12. US Department of Energy natural phenomena design/evaluation guidelines/lessons learned

    International Nuclear Information System (INIS)

    Conrads, T.J.

    1991-08-01

    In the spring of 1988, DOE Order 6430.1A, General Design Criteria [1], was issued for use. This document references UCRL-15910, Design and Evaluation Guidelines for DOE Facilities Subjected to Natural Phenomena Hazards [2], which is to be used as the basis for the design and evaluation of new and existing facilities to natural phenomena loading. Rather than use the historical deterministic methods for computing structural and component loading from potential natural phenomena, UCRL-15910 incorporated the years of hazards studies conducted throughout the US Department of Energy complex into probabilistic-based methods. This paper describes the process used to incorporate US Department of Energy natural phenomena design guidelines into the Hanford Plant Standards -- Standard Design Criteria for Architectural and Civil Standards [3]. It also addresses the subsequent use of these criteria during structural assessments of facilities, systems, and components of various vintage in support of updating safety analysis reports. The paper includes comparison of results using these most recent probabilistic-based natural phenomena loading criteria to those obtained from previous assessments, and it addresses the lessons learned from the many structural evaluations of 1940--1960 vintage buildings

  13. SBWR PCCS vent phenomena and suppression pool mixing

    Energy Technology Data Exchange (ETDEWEB)

    Coddington, P. [Thermal-Hydraulics Lab., Paul Scherrer Institute, Villigen (Switzerland); Andreani, M. [Nuclear Engineering Lab., Swiss Federal Institute of Technology, Zurich (Switzerland)

    1995-09-01

    The most important phenomena influencing the effectiveness of the pressure suppression capability of the water pool within the Wetwell compartment of the SBWR Containment, during the period of Passive Containment Cooling System (PCCS) venting, have been critically reviewed. In addition, calculations have been carried-out to determine the condensation of the vented steam and the distribution of the energy deposited in the liquid pool. It has been found that a large contribution to the vapour suppression is due to condensation inside the vent pipe. The condensation rate of the steam inside the bubbles, produced at the vent exit, during their rise to the surface, may however be rather low, because of the large size bubbles. This can lead to vapour channelling to the Wetwell gas space. The above comments are likely to be ameliorated if the vent exit is a distributed source or sparger. Due to the large water flow rates within the {open_quotes}bubbly two-phase plume{close_quotes} generated by the gas injection, the water in the pool above the vent exit is likely to be heated nearly isothermally (perfect mixing). The effect of the suppression pool walls would be to enhance the recirculation and, consequently to promote mixing. The large size of the bubbles therein and of the walls on pool mixing are the most severe difficulties in extrapolating the results from scaled experiments to prototypical conditions.

  14. Transport Phenomena of Water in Molecular Fluidic Channels

    Science.gov (United States)

    Vo, Truong Quoc; Kim, Bohung

    2016-09-01

    In molecular-level fluidic transport, where the discrete characteristics of a molecular system are not negligible (in contrast to a continuum description), the response of the molecular water system might still be similar to the continuum description if the time and ensemble averages satisfy the ergodic hypothesis and the scale of the average is enough to recover the classical thermodynamic properties. However, even in such cases, the continuum description breaks down on the material interfaces. In short, molecular-level liquid flows exhibit substantially different physics from classical fluid transport theories because of (i) the interface/surface force field, (ii) thermal/velocity slip, (iii) the discreteness of fluid molecules at the interface and (iv) local viscosity. Therefore, in this study, we present the result of our investigations using molecular dynamics (MD) simulations with continuum-based energy equations and check the validity and limitations of the continuum hypothesis. Our study shows that when the continuum description is subjected to the proper treatment of the interface effects via modified boundary conditions, the so-called continuum-based modified-analytical solutions, they can adequately predict nanoscale fluid transport phenomena. The findings in this work have broad effects in overcoming current limitations in modeling/predicting the fluid behaviors of molecular fluidic devices.

  15. Surface optical vortices

    OpenAIRE

    Lembessis, V. E.; Babiker, M.; Andrews, D L.

    2009-01-01

    It is shown how the total internal reflection of orbital-angular-momentum-endowed light can lead to the generation of evanescent light possessing rotational properties in which the intensity distribution is firmly localized in the vicinity of the surface. The characteristics of these surface optical vortices depend on the form of the incident light and on the dielectric mismatch of the two media. The interference of surface optical vortices is shown to give rise to interesting phenomena, incl...

  16. Geometric methods to treat energy transport phenomena

    CERN Document Server

    Passow, C

    1998-01-01

    In the framework of the proposed technique, the calculation procedure is divided into the phases: 1. Set up of the initial conditions; 2. Calculating the flux field; 3. Calculating the intensity distributions. The initial conditions, necessary to construct the first atlas surface, may be taken from experimental results and/or from auxiliary models. To test the model accuracy, local and global invariance principles, defined at point or by finite surface or volume integrals can be used. Finally it has to be mentioned, the here described method allows to investigate at point disturbances, as attractors, bifurcations, that means the influence of critical phase- space points related to background, as well as calculated fields. Self-consistent effects can be taken into account by subroutines. (8 refs).

  17. Sixth Microgravity Fluid Physics and Transport Phenomena Conference: Exposition Topical Areas 1-6. Volume 2

    Science.gov (United States)

    Singh, Bhim (Compiler)

    2002-01-01

    The Sixth Microgravity Fluid Physics and Transport Phenomena Conference provides the scientific community the opportunity to view the current scope of the Microgravity Fluid Physics and Transport Phenomena Program, current research opportunities, and plans for the near future. The conference focuses not only on fundamental research but also on applications of this knowledge towards enabling future space exploration missions. A whole session dedicated to biological fluid physics shows increased emphasis that the program has placed on interdisciplinary research. The conference includes invited plenary talks, technical paper presentations, poster presentations, and exhibits. This CP (conference proceeding) is a compilation of the abstracts, presentations, and posters presented at the conference.

  18. Exclusive processes: Tests of coherent QCD phenomena and nucleon substructure at CEBAF

    International Nuclear Information System (INIS)

    Brodsky, S.J.

    1994-07-01

    Measurements of exclusive processes such as electroproduction, photoproduction, and Compton scattering are among the most sensitive probes of proton structure and coherent phenomena in quantum chromodynamics. The continuous electron beam at CEBAF, upgraded in laboratory energy to 10--12 GeV, will allow a systematic study of exclusive, semi-inclusive, and inclusive reactions in a kinematic range well-tuned to the study of fundamental nucleon and nuclear substructure. I also discuss the potential at CEBAF for studying novel QCD phenomena at the charm production threshold, including the possible production of nuclear-bound quarkonium

  19. Mesoscopic modeling of multi-physicochemical transport phenomena in porous media

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Qinjin [Los Alamos National Laboratory; Wang, Moran [Los Alamos National Laboratory; Mukherjee, Partha P [Los Alamos National Laboratory; Lichtner, Peter C [Los Alamos National Laboratory

    2009-01-01

    We present our recent progress on mesoscopic modeling of multi-physicochemical transport phenomena in porous media based on the lattice Boltzmann method. Simulation examples include injection of CO{sub 2} saturated brine into a limestone rock, two-phase behavior and flooding phenomena in polymer electrolyte fuel cells, and electroosmosis in homogeneously charged porous media. It is shown that the lattice Boltzmann method can account for multiple, coupled physicochemical processes in these systems and can shed some light on the underlying physics occuning at the fundamental scale. Therefore, it can be a potential powerful numerical tool to analyze multi-physicochemical processes in various energy, earth, and environmental systems.

  20. Improved Insight into Transport Phenomena in Porous Materials at Submicrometer Resolution

    DEFF Research Database (Denmark)

    Gooya, Reza

    of magnitude dependent on porosity and microstructure. ŒThechange in resolution clearly inƒfluences the calculated properties and the changes dependon the overall rock morphology and pore size distribution.In the next part, two phase flƒow was investigated at the pore scale to beŠer understanddisplacement....... In this thesis, transport phenomena- including single phaseƒow, two phase ƒow and reactive transport, were investigated at the pore scale. Œe motivationwas to €nd cheaper, easier and faster alternatives to macroscale investigations.In the fi€rst part, single phase ƒuid flƒow models were tested on experimentally...... in porous media. Surface properties of the pores are important toinclude in simulation of two phase flƒow. ThŒese properties can be parameterized in termsof contact angles between the two liquid and the solid phases. O‰en the contact angle istreated as a constant, i.e. static and not dependent on the flƒuid...

  1. Parasitic phenomena in the dynamics of industrial devices

    CERN Document Server

    Borboni, Alberto

    2011-01-01

    In the real world the dynamic behavior of a real machine presents either unforeseen or limiting phenomena: both are undesired, and can be therefore be classified as parasitic phenomena - unwanted, unforeseen, or limiting behaviors. Parasitic Phenomena in the Dynamics of Industrial Devices describes the potential causes and effects of these behaviors and provides indications that could minimize their influence on the mechanical system in question. The authors introduce the phenomena and explore them through real cases, avoiding academic introductions, but inserting the entire academic and experimental knowledge that is useful to understand and solve real-world problems. They then examine these parasitic phenomena in the machine dynamics, using two cases that cover the classical cultural division between cam devices and mechanisms. They also present concrete cases with an amount of experimental data higher than the proposed ones and with a modern approach that can be applied to various mechanical devices, acqui...

  2. Discovering, Understanding and Predicting Emergent Phenomena at Strongly Correlated Oxide Interfaces

    Science.gov (United States)

    2013-03-31

    avenues to test our hypothesis that RP phases would be less accommodating than perovskites to point defects: comparison of the properties of (i) the... properties of materials, the next question is how does it impact transport properties ? Emergent phenomena, including superconductivity and magnetism ...oxide analogs of lattice-matched perovskites that offer increased oxygen stability, higher carrier densities, and an intrinsically reduced dimensionality

  3. PREFACE: XI Latin American Workshop on Nonlinear Phenomena

    Science.gov (United States)

    Anteneodo, Celia; da Luz, Marcos G. E.

    2010-09-01

    The XI Latin American Workshop on Nonlinear Phenomena (LAWNP) has been held in Búzios-RJ, Brazil, from 5-9 October 2009. This international conference is one in a series that have gathered biennially, over the past 21 years, physicists and other scientists who direct their work towards several aspects of nonlinear phenomena and complex systems. The main purpose of LAWNP meetings is to create a friendly and motivating environment, such that researchers from Latin America and from other parts of the globe can discuss not only their own latest results but also the trends and perspectives in this very interdisciplinary field of investigation. Hence, it constitutes a forum for promoting scientific collaboration and fomenting the emergence of new ideas, helping to advance the field. The XI edition (LAWNP'09) has gathered more than 230 scientists and students (most from Latin America), covering all of the world (27 different countries from North and South America, Asia, Europe, and Oceania). In total there were 18 plenary lectures, 80 parallel talks, and 140 poster contributions. A stimulating round-table discussion also took place devoted to the present and future of the Latin American Institutions in Complex Phenomena (a summary can be found at http://lawnp09.fis.puc-rio.br, in the Round-Table report link). The 2009 workshop was devoted to a wide scope of themes and points of view, pursuing to include the latest trends and developments in the science of nonlinearity. In this way, we have a great pleasure in publishing this Proceedings volume based on the high quality scientific works presented at LAWNP'09, covering already established methods as well as new approaches, discussing both theoretical and practical aspects, and addressing paradigmatic systems and also completely new problems, in nonlinearity and complexity. In fact, the present volume may be a very valuable reference for those interested in an overview on how nonlinear interactions can affect different

  4. Colloidal transport phenomena of milk components during convective droplet drying.

    Science.gov (United States)

    Fu, Nan; Woo, Meng Wai; Chen, Xiao Dong

    2011-10-15

    Material segregation has been reported for industrial spray-dried milk powders, which indicates potential material migration during drying process. The relevant colloidal transport phenomenon and the underlying mechanism are still under debate. This study extended the glass-filament single droplet drying technique to observe not only the drying behaviour but also the dissolution behaviour of the correspondingly dried single particle. At progressively longer drying stage, a solvent droplet (water or ethanol) was attached to the semi-dried milk particle and the interaction between the solvent and the particle was video-recorded. Based on the different dissolution and wetting behaviours observed, material migration during milk drying was studied. Fresh skim milk and fresh whole milk were investigated using water and ethanol as solvents. Fat started to accumulate on the surface as soon as drying was started. At the initial stage of drying, the fat layer remained thin and the solubility of the semi-dried milk particle was much affected by lactose and protein present underneath the fat layer. Fat kept accumulating at the surface as drying progressed and the accumulation was completed by the middle stage of drying. The results from drying of model milk materials (pure sodium caseinate solution and lactose/sodium caseinate mixed solution) supported the colloidal transport phenomena observed for the milk drying. When mixed with lactose, sodium caseinate did not form an apparent solvent-resistant protein shell during drying. The extended technique of glass-filament single droplet approach provides a powerful tool in examining the solubility of individual particle after drying. Copyright © 2011 Elsevier B.V. All rights reserved.

  5. The surface energy of metals

    DEFF Research Database (Denmark)

    Vitos, Levente; Ruban, Andrei; Skriver, Hans Lomholt

    1998-01-01

    We have used density functional theory to establish a database of surface energies for low index surfaces of 60 metals in the periodic table. The data may be used as a consistent starting point for models of surface science phenomena. The accuracy of the database is established in a comparison...

  6. Reproducibility in Psychological Science: When Do Psychological Phenomena Exist?

    Directory of Open Access Journals (Sweden)

    Seppo E. Iso-Ahola

    2017-06-01

    Full Text Available Scientific evidence has recently been used to assert that certain psychological phenomena do not exist. Such claims, however, cannot be made because (1 scientific method itself is seriously limited (i.e., it can never prove a negative; (2 non-existence of phenomena would require a complete absence of both logical (theoretical and empirical support; even if empirical support is weak, logical and theoretical support can be strong; (3 statistical data are only one piece of evidence and cannot be used to reduce psychological phenomena to statistical phenomena; and (4 psychological phenomena vary across time, situations and persons. The human mind is unreproducible from one situation to another. Psychological phenomena are not particles that can decisively be tested and discovered. Therefore, a declaration that a phenomenon is not real is not only theoretically and empirically unjustified but runs counter to the propositional and provisional nature of scientific knowledge. There are only “temporary winners” and no “final truths” in scientific knowledge. Psychology is a science of subtleties in human affect, cognition and behavior. Its phenomena fluctuate with conditions and may sometimes be difficult to detect and reproduce empirically. When strictly applied, reproducibility is an overstated and even questionable concept in psychological science. Furthermore, statistical measures (e.g., effect size are poor indicators of the theoretical importance and relevance of phenomena (cf. “deliberate practice” vs. “talent” in expert performance, not to mention whether phenomena are real or unreal. To better understand psychological phenomena, their theoretical and empirical properties should be examined via multiple parameters and criteria. Ten such parameters are suggested.

  7. Diffusion processes in bombardment-induced surface topography

    International Nuclear Information System (INIS)

    Robinson, R.S.

    1984-01-01

    The bombardment of surfaces with moderate energy ions can lead to the development of various micron-sized surface structures. These structures include ridges, ledges, flat planes, pits and cones. The causal phenomena in the production of these features are sputtering, ion reflection, redeposition of sputtered material, and surface diffusion of both impurity and target-atom species. The authors concentrate on the formation of ion bombardment-induced surface topography wherein surface diffusion is a dominant process. The most thoroughly understood aspect of this topography development is the generation of cone-like structures during sputtering. The formation of cones during sputtering has been attributed to three effects. These are: (1) the presence of asperities, defects, or micro-inclusions in the surface layers, (2) the presence of impurities on the surfaces, and (3) particular crystal orientations. (Auth.)

  8. Performance Tests of Snow-Related Variables Over the Tibetan Plateau and Himalayas Using a New Version of NASA GEOS-5 Land Surface Model that Includes the Snow Darkening Effect

    Science.gov (United States)

    Yasunari, Tppei J.; Lau, K.-U.; Koster, Randal D.; Suarez, Max; Mahanama, Sarith; Dasilva, Arlindo M.; Colarco, Peter R.

    2011-01-01

    The snow darkening effect, i.e. the reduction of snow albedo, is caused by absorption of solar radiation by absorbing aerosols (dust, black carbon, and organic carbon) deposited on the snow surface. This process is probably important over Himalayan and Tibetan glaciers due to the transport of highly polluted Atmospheric Brown Cloud (ABC) from the Indo-Gangetic Plain (IGP). This effect has been incorporated into the NASA Goddard Earth Observing System model, version 5 (GEOS-5) atmospheric transport model. The Catchment land surface model (LSM) used in GEOS-5 considers 3 snow layers. Code was developed to track the mass concentration of aerosols in the three layers, taking into account such processes as the flushing of the compounds as liquid water percolates through the snowpack. In GEOS-5, aerosol emissions, transports, and depositions are well simulated in the Goddard Chemistry Aerosol Radiation and Transport (GO CART) module; we recently made the connection between GOCART and the GEOS-5 system fitted with the revised LSM. Preliminary simulations were performed with this new system in "replay" mode (i.e., with atmospheric dynamics guided by reanalysis) at 2x2.5 degree horizontal resolution, covering the period 1 November 2005 - 31 December 2009; we consider the final three years of simulation here. The three simulations used the following variants of the LSM: (1) the original Catchment LSM with a fixed fresh snowfall density of 150 kg m-3 ; (2) the LSM fitted with the new snow albedo code, used here without aerosol deposition but with changes in density formulation and melting water effect on snow specific surface area, (3) the LSM fitted with the new snow albedo code as same as (2) but with fixed aerosol deposition rates (computed from GOCART values averaged over the Tibetan Plateau domain [Ion.: 60-120E; lat.: 20-50N] during March-May 2008) applied to all grid points at every time step. For (2) and (3), the same setting on the fresh snowfall density as in (1

  9. Performance tests of snow-related variables over the Tibetan Plateau and Himalayas using a new version of NASA GEOS-5 land surface model that includes the snow darkening effect

    Science.gov (United States)

    Yasunari, T. J.; Lau, W. K.; Koster, R. D.; Suarez, M.; Mahanama, S. P.; da Silva, A.; Colarco, P. R.

    2011-12-01

    The snow darkening effect, i.e. the reduction of snow albedo, is caused by absorption of solar radiation by absorbing aerosols (dust, black carbon, and organic carbon) deposited on the snow surface. This process is probably important over Himalayan and Tibetan glaciers due to the transport of highly polluted Atmospheric Brown Cloud (ABC) from the Indo-Gangetic Plain (IGP). This effect has been incorporated into the NASA Goddard Earth Observing System model, version 5 (GEOS-5) atmospheric transport model. The Catchment land surface model (LSM) used in GEOS-5 considers 3 snow layers. Code was developed to track the mass concentration of aerosols in the three layers, taking into account such processes as the flushing of the compounds as liquid water percolates through the snowpack. In GEOS-5, aerosol emissions, transports, and depositions are well simulated in the Goddard Chemistry Aerosol Radiation and Transport (GOCART) module; we recently made the connection between GOCART and the GEOS-5 system fitted with the revised LSM. Preliminary simulations were performed with this new system in "replay" mode (i.e., with atmospheric dynamics guided by reanalysis) at 2x2.5 degree horizontal resolution, covering the period 1 November 2005 - 31 December 2009; we consider the final three years of simulation here. The three simulations used the following variants of the LSM: (1) the original Catchment LSM with a fixed fresh snowfall density of 150 kg m-3; (2) the LSM fitted with the new snow albedo code, used here without aerosol deposition but with changes in density formulation and melting water effect on snow specific surface area, (3) the LSM fitted with the new snow albedo code as same as (2) but with fixed aerosol deposition rates (computed from GOCART values averaged over the Tibetan Plateau domain [lon.: 60-120E; lat.: 20-50N] during March-May 2008) applied to all grid points at every time step. For (2) and (3), the same setting on the fresh snowfall density as in (1) was

  10. Aspects of Hydrate Management - Deposition Phenomena

    OpenAIRE

    Langen, Heidi

    2016-01-01

    The purpose of this thesis has been to investigate the factors with the largest influence on the adhesion strength of a hydrate deposit on a solid surface. This has been done through a literature study on the subject, and a thorough experimental project in a laboratory. The experiments involved forming hydrate deposits on a pipe of steel, before removing the deposits and finding the pressure required to do so. The hydrate was formed by a solution of tetrahydrofuran and water in a tank where t...

  11. Centrifugal Compressors, Flow Phenomena and Performance.

    Science.gov (United States)

    1980-11-01

    des variations de rayon (done de "%,) et de Ia pr~sence d’ondes de choc (pr~s des bords d’attaque notansuent). Le maillage du champ eat...duit imiidiatement par (19). Un tableau peut r~sumer le nombre de ces conditions Front i~res Axaont Aval Supersonique 3 1 0 Fronti~re amont Sboiu Dans...calculating velocities and streamlines on a blade-to-blade stream surface of a turbomachine". NASA TM X-1764 -(1969). 5-8 tm BORDS FUITE’ ATTAOUE TUBE

  12. Solid surfaces, interfaces and thin films

    CERN Document Server

    Lüth, Hans

    2015-01-01

    This book emphasises both experimental and theoretical aspects of surface, interface and thin-film physics. As in previous editions the preparation of surfaces and thin films, their atomic and morphological structure, their vibronic and electronic properties as well as fundamentals of adsorption are treated. Because of their importance in modern information technology and nanostructure research, particular emphasis is paid to electronic surface and interface states, semiconductor space charge layers and heterostructures. A special chapter of the book is devoted to collective phenomena at interfaces and in thin films such as superconductivity and magnetism. The latter topic includes the meanwhile important issues giant magnetoresistance and spin-transfer torque mechanism, both effects being of high interest in information technology. In this new edition, for the first time, the effect of spin-orbit coupling on surface states is treated. In this context the class of the recently detected topological insulators,...

  13. Relaxation phenomena during polyelectrolyte complex formation

    NARCIS (Netherlands)

    Lindhoud, S.; Cohen Stuart, M.A.

    2013-01-01

    Polyelectrolyte complex formation is a well-studied subject in colloid science. Several types of complex formation have been studied, including PEMs, macroscopic polyelectrolyte complexes, soluble complexes and polyelectrolyte complex micelles. The chemical nature of the complex-forming

  14. Ionization phenomena and sources of negative ions

    International Nuclear Information System (INIS)

    Alton, G.D.

    1983-01-01

    Negative ion source technology has rapidly advanced during the past several years as a direct consequence of the discovery of Krohn that negative ion yields can be greatly enhanced by sputtering in the presence of Group IA elements. Today, most negative ion sources use this discovery directly or the principles implied to effect negative ion formation through surface ionization. As a consequence, the more traditional direct extraction plasma and charge exchange sources are being used less frequently. However, the charge exchange generation mechanism appears to be as universal, is very competitive in terms of efficiency and has the advantage in terms of metastable ion formation. In this review, an attempt has been made to briefly describe the principal processes involved in negative ion formation and sources which are representative of a particular principle. The reader is referred to the literature for specific details concerning the operational characteristics, emittances, brightnesses, species and intensity capabilities of particular sources. 100 references

  15. Electron impact phenomena and the properties of gaseous ions

    CERN Document Server

    Field, F H; Massey, H S W; Brueckner, Keith A

    1970-01-01

    Electron Impact Phenomena and the Properties of Gaseous Ions, Revised Edition deals with data pertaining to electron impact and to molecular gaseous ionic phenomena. This book discusses electron impact phenomena in gases at low pressure that involve low-energy electrons, which result in ion formation. The text also describes the use of mass spectrometers in electron impact studies and the degree of accuracy obtained when measuring electron impact energies. This book also reviews relatively low speed electrons and the transitions that result in the ionization of the atomic system. This text the

  16. Seepage phenomena on Mars at subzero temperature

    Science.gov (United States)

    Kereszturi, Akos; Möhlmann, Diedrich; Berczi, Szaniszlo; Ganti, Tibor; Horvath, Andras; Kuti, Adrienn; Pocs, Tamas; Sik, Andras; Szathmary, Eors

    At the southern hemisphere of Mars seasonal slope structures emanating from Dark Dune Spots are visible on MGS MOC, and MRO HiRISE images. Based on their analysis two groups of streaks could be identified: diffuse and fan shaped ones forming in an earlier phase of local spring, probably by CO2 gas jets, and confined streaks forming only on steep slopes during a later seasonal phase. The dark color of the streaks may arise from the dark color of the dune grains where surface frost disappeared above them, or caused by the phase change of the water ice to liquid-like water, or even it may be influenced by the solutes of salts in the undercooled interfacial water The second group's morphology (meandering style, ponds at their end), morphometry, and related theoretical modelling suggest they may form by undercooled water that remains in liquid phase in a thin layer around solid grains. We analyzed sequence of images, temperature and topographic data of Russel (54S 12E), Richardson (72S 180E) and an unnamed crater (68S 2E) during southern spring. The dark streaks here show slow motion, with an average speed of meter/day, when the maximal daytime temperature is between 190 and 220 K. Based on thermophysical considerations a thin layer of interfacial water is inevitable on mineral surfaces under the present conditions of Mars. With 10 precipitable micrometer of atmospheric water vapor, liquid phase can be present down about 190 K. Under such conditions dark streaks may form by the movement of grains lubricatred by interfacial water. This possibility have various consequences on chemical, mechanical or even possible astrobiological processes on Mars. Acknowledgment: This work was supported by the ESA ECS-project No. 98004 and the Pro Renovanda Cultura Hungariae Foundation.

  17. Power system dynamics: same phenomena; new challenges

    Energy Technology Data Exchange (ETDEWEB)

    Mansour, Yakout; Vaahedi, Ebraim; Xu, Wilsun; Chang, Allen [British Columbia Hydro, Vancouver, BC (Canada). Regional System Planning

    1994-12-31

    This paper presents a summary of how a utility met some challenges recently in two areas: transient angular stability and voltage stability. The paper also includes a view of what is evolving in these two areas. (author) 7 refs., 11 figs., 1 tab.

  18. Study on thermal-hydraulic phenomena in porous media. Semiannual report Apr. 1998 to Mar. 1999

    International Nuclear Information System (INIS)

    Matsui, Goichi; Monji, Hideaki; Sakakibara, Jun; Saito, Katsuhiro; Tanaka, Masa-aki; Kobayashi, Jun; Kamide, Hideki

    1999-03-01

    This study deals with thermal-hydraulic phenomena in a porous media. When the foreign substances flow into the fuel subassembly with wire spacer, they would choke up the subchannel and form a porous blockage. The objective of this study is to clarify the thermalhydraulic phenomena in porous media and to develop the analytical method to predict the thermal-hydraulic field, deciding the maximum temperature on the fuel pin surface. This study is performed in cooperation with University of Tsukuba and Japan Nuclear Cycle Development Institute (JNC) from November 1997 to March 2000. This report describes the results for the second period from April 1998 to March 1999. In the last year, we confirmed that the visualization method used NaI solution as working fluid was applicable to flow visualization in the porous media. In this year period, we conducted the experiment to measure the velocity field inside and outside the blockage used Particle Image Velocimetry (PIV) analysis and Laser Doppler Velocimetry (LDV). The test section was simplified and 20 times enlarged the two subchannel of the fuel subassembly in the reactor, included the porous blockage consisted of the Pyrex grass spheres. NaI solution was used as the working fluid. When the concentration of NaI is 56.9wt% in the solution, the refraction-rate is correspond to that of the Pyrex grass. Before the experiment, we measured the density, viscosity, and thermal conductivity of 56.9wt% NaI solution. The velocity profile inside and outside the blockage was measured in detail. The knowledge was acquired of the relation of the flow in between the blockage and the unplugged channel. Moreover, we tried to measure the fluid temperature inside the blockage in the NaI solution, used Laser Induced Fluorescence (LIF) method. At the fist, we checked the relation between the brightness of the fluorescence and solution temperature. And then, we revealed that the LIF method could be used even in the NaI solution. (author)

  19. Dimensional Analysis with space discrimination applied to Fickian difussion phenomena

    International Nuclear Information System (INIS)

    Diaz Sanchidrian, C.; Castans, M.

    1989-01-01

    Dimensional Analysis with space discrimination is applied to Fickian difussion phenomena in order to transform its partial differen-tial equations into ordinary ones, and also to obtain in a dimensionl-ess fom the Ficks second law. (Author)

  20. Phase Plane Analysis Method of Nonlinear Traffic Phenomena

    Directory of Open Access Journals (Sweden)

    Wenhuan Ai

    2015-01-01

    Full Text Available A new phase plane analysis method for analyzing the complex nonlinear traffic phenomena is presented in this paper. This method makes use of variable substitution to transform a traditional traffic flow model into a new model which is suitable for the analysis in phase plane. According to the new model, various traffic phenomena, such as the well-known shock waves, rarefaction waves, and stop-and-go waves, are analyzed in the phase plane. From the phase plane diagrams, we can see the relationship between traffic jams and system instability. So the problem of traffic flow could be converted into that of system stability. The results show that the traffic phenomena described by the new method is consistent with that described by traditional methods. Moreover, the phase plane analysis highlights the unstable traffic phenomena we are chiefly concerned about and describes the variation of density or velocity with time or sections more clearly.