WorldWideScience

Sample records for transport experiments conducted

  1. Transport properties of olivine grain boundaries from electrical conductivity experiments

    Science.gov (United States)

    Pommier, Anne; Kohlstedt, David L.; Hansen, Lars N.; Mackwell, Stephen; Tasaka, Miki; Heidelbach, Florian; Leinenweber, Kurt

    2018-05-01

    Grain boundary processes contribute significantly to electronic and ionic transports in materials within Earth's interior. We report a novel experimental study of grain boundary conductivity in highly strained olivine aggregates that demonstrates the importance of misorientation angle between adjacent grains on aggregate transport properties. We performed electrical conductivity measurements of melt-free polycrystalline olivine (Fo90) samples that had been previously deformed at 1200 °C and 0.3 GPa to shear strains up to γ = 7.3. The electrical conductivity and anisotropy were measured at 2.8 GPa over the temperature range 700-1400 °C. We observed that (1) the electrical conductivity of samples with a small grain size (3-6 µm) and strong crystallographic preferred orientation produced by dynamic recrystallization during large-strain shear deformation is a factor of 10 or more larger than that measured on coarse-grained samples, (2) the sample deformed to the highest strain is the most conductive even though it does not have the smallest grain size, and (3) conductivity is up to a factor of 4 larger in the direction of shear than normal to the shear plane. Based on these results combined with electrical conductivity data for coarse-grained, polycrystalline olivine and for single crystals, we propose that the electrical conductivity of our fine-grained samples is dominated by grain boundary paths. In addition, the electrical anisotropy results from preferential alignment of higher-conductivity grain boundaries associated with the development of a strong crystallographic preferred orientation of the grains.

  2. Conducting interactive experiments online.

    Science.gov (United States)

    Arechar, Antonio A; Gächter, Simon; Molleman, Lucas

    2018-01-01

    Online labor markets provide new opportunities for behavioral research, but conducting economic experiments online raises important methodological challenges. This particularly holds for interactive designs. In this paper, we provide a methodological discussion of the similarities and differences between interactive experiments conducted in the laboratory and online. To this end, we conduct a repeated public goods experiment with and without punishment using samples from the laboratory and the online platform Amazon Mechanical Turk. We chose to replicate this experiment because it is long and logistically complex. It therefore provides a good case study for discussing the methodological and practical challenges of online interactive experimentation. We find that basic behavioral patterns of cooperation and punishment in the laboratory are replicable online. The most important challenge of online interactive experiments is participant dropout. We discuss measures for reducing dropout and show that, for our case study, dropouts are exogenous to the experiment. We conclude that data quality for interactive experiments via the Internet is adequate and reliable, making online interactive experimentation a potentially valuable complement to laboratory studies.

  3. Heat-flow patterns in Tian-Calvet microcalorimeters: Conductive, convective, and radiative transport in gas dosing experiments

    International Nuclear Information System (INIS)

    Vilchiz, Luis Enrique; Pacheco-Vega, Arturo; Handy, Brent E.

    2005-01-01

    Mathematical models of a Tian-Calvet microcalorimeter were solved numerically by the finite-element method in an effort to understand the relative importance of the three basic heat transfer mechanisms operative during gas dosing experiments typically used to determine heats of adsorption on catalysts and adsorbents. The analysis pays particular attention to the quantitative release of heat through various elements of the cell and sensor cups to assess time delays and the deg.ree of thermal shunting that may result in inaccuracies in calorimetric measurements. Conductive transfer predominates in situations where there is high gas headspace pressure. The convection currents that arise when dosing with considerable gas pressure in the cell headspace region are not sufficiently strong to shunt significant amounts of sample heat away from being sensed by the surrounding thermopiles. Therefore, the heat capture fraction (heat sensed/heat produced) does not vary significantly with gas headspace pressure. During gas dosing under very low gas headspace pressure, radiation losses from the top of the sample bed may significantly affect the heat capture fraction, leading to underestimations of adsorption heats, unless the heat radiated from the top of the catalyst bed is effectively reflected back to the sample region or absorbed by an inert packing layer also in thermal contact with the thermopile wall

  4. Neutralized transport experiment

    International Nuclear Information System (INIS)

    Roy, P.K.; Yu, S.S.; Eylon, S.; Henestroza, E.; Anders, A.; Gilson, E.P.; Bieniosek, F.M.; Greenway, W.G.; Logan, B.G.; Waldron, W.L.; Shuman, D.B.; Vanecek, D.L.; Welch, D.R.; Rose, D.V.; Thoma, C.; Davidson, R.C.; Efthimion, P.C.; Kaganovich, I.; Sefkow, A.B.; Sharp, W.M.

    2005-01-01

    Experimental details on providing active neutralization of high brightness ion beam have been demonstrated for Heavy Ion Fusion program. A K + beam was extracted from a variable-perveance injector and transported through 2.4 m long quadrupole lattice for final focusing. Neutralization was provided by a localized cathode arc plasma plug and a RF volume plasma system. Effects of beam perveance, emittance, convergence focusing angle, and axial focusing position on neutralization have been investigated. Good agreement has been observed with theory and experiment throughout the study

  5. DETERMINANTS DESTRUCTIVE TO BUSINESS CONDUCT TRANSPORT

    Directory of Open Access Journals (Sweden)

    Natalia Anatol’evna Loginova

    2017-03-01

    Full Text Available The article examines the determinants of destructive behavior in the transport business with the aim to identify their causes and to clarify the features of influence on them by all business stakeholders in transport. It is shown that the key determinants are: submission to the will of one business entity to another, the implementation of state support only in distressed periods of functioning of transport organizations, business obligations to the state are often perceived as a back-breaking businessmen, unfair, unnecessary. The main conclusions of the work are reduced to the following recommendations: to form a focused pulse of the state in support of the transport business; improve enforcement culture; more efficient use of the transport business capital. The goal – to identify the cause of the destructive business behavior and clarify the characteristics of their research on the part of all stakeholders in the transport sector. Method or methodology of work: in the article used analytical methods, and statistical analysis methods. Results for: received informative pictures that describe deterministic minanaty-destructive conduct business on the road, on the basis of which developed recommendations to neutralize their influence on the behavior of entrepreneurs. Application of results: the results the expediency applied differently businesses and government agencies operating in the field of transport.

  6. Culture experiments on conductive polymers

    International Nuclear Information System (INIS)

    Onoda, Mitsuyoshi

    2012-01-01

    Fibroblast L929 and myoblast C2C12 cells of the mouse connective tissue origin were sown on the surface of conductive polymer films (polypyrrole, PPy and poly(3,4-ethylenedioxythiophene), PEDOT) in the cell culture medium, and the proliferative process of these cells was observed. Without changing the form, fibroblast L929 and myoblast C2C12 cells were observed to proliferate almost similarly to the cell which cultured on a dish on the market and to maintain compatibility. In other word, it has been understood these two kinds of conductive polymers used in this study, the PEDOT films maintain the secretion function of the cell cultured on the surface of these polymers. Therefore, the PPy- and the PEDOT-coated electrode suggested the possibility usable as a nerve stimulation electrode with biocompatibility, because these polymers were effective to culture the cell.

  7. Radioactive materials transport experience

    International Nuclear Information System (INIS)

    Langhaar, J.W.

    1976-01-01

    This paper presents a brief review of the kinds of packaging suitable for different types of waste, the roles of highway and rail transport, restrictions imposed by political entities and carriers, and safety. The U. S. accident record is described, with some statistics given

  8. Analysis of Proton Transport Experiments.

    Science.gov (United States)

    1980-09-05

    which can inhibit transport, may grow . The abrupt loss of transport at higher currents in the small channel suggests this possibility. Future experiments... Unicorn Park Drive Woburn, MA 01801 Attn: H. Linnerud 1 copy Lawrence Livermore Laboratory P. 0. Box 808 Livermore, CA 94550 Attn: R. J. Briggs 1 copy R

  9. Long conduction time POs experiments on MITE

    International Nuclear Information System (INIS)

    Woodall, H.N.; McDaniel, D.H.; Mendel, C.W.; Rochau, G.E.; Zagar, D.M.; Simpson, W.W.; Zuchowski, N.P.

    1990-01-01

    MITE is a power flow test bed that has been modified to conduct experiments in high power plasma opening switch (POS) technology and apply this technology to Inertial Confinement Fusion. The goal of the experiment is to develop a plasma opening switch that conducts megampere currents for 300 ns, then opens in 5--10 ns. MITE/POS is an advanced power flow experiment that uses a magnetically insulated transmission line (MITL) as the inductive energy store and as a means to shape the output pulse. This experiment demonstrates that a simplified, lower-cost facility can be built by eliminating water pulse-forming lines and water-switching. Another advantage of this approach is that high energy efficiency at peak power can be achieved. The disadvantage is that a new technology, the triggered POS, must be implemented. The triggered POS is necessary for synchronization of multiple modules with a long conduction-time POS. The MITE facility has been modified to drive a 250 nH, 16.6 Ohm MITL at 0.9 MA to accommodate this power flow experiment. A MITL inductive energy storage of 101 kJ is available for POS switching to a matched load. Experiments have been conducted using segmented flashboards and magnetic-field controlled plasma sources. These experiments will lead to the development of the triggered POS. The initial experiments with plasma conduction times of 120 ns to 800 ns are discussed

  10. 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

  11. Conductance of Ion Channels - Theory vs. Experiment

    Science.gov (United States)

    Pohorille, Andrew; Wilson, Michael; Mijajlovic, Milan

    2013-01-01

    Transmembrane ion channels mediate a number of essential physiological processes in a cell ranging from regulating osmotic pressure to transmission of neural signals. Kinetics and selectivity of ion transport is of critical importance to a cell and, not surprisingly, it is a subject of numerous experimental and theoretical studies. In this presentation we will analyze in detail computer simulations of two simple channels from fungi - antiamoebin and trichotoxin. Each of these channels is made of an alpha-helical bundle of small, nongenomically synthesized peptides containing a number of rare amino acids and exhibits strong antimicrobial activity. We will focus on calculating ionic conductance defined as the ratio of ionic current through the channel to applied voltage. From molecular dynamics simulations, conductance can be calculated in at least two ways, each involving different approximations. Specifically, the current, given as the number of charges transferred through the channel per unit of time, can be obtained from the number of events in which ions cross the channel during the simulation. This method works well for large currents (high conductance values and/or applied voltages). If the number of crossing events is small, reliable estimates of current are difficult to achieve. Alternatively, conductance can be estimated assuming that ion transport can be well approximated as diffusion in the external potential given by the free energy profile. Then, the current can be calculated by solving the one-dimensional diffusion equation in this external potential and applied voltage (the generalized Nernst-Planck equation). To do so three ingredients are needed: the free energy profile, the position-dependent diffusion coefficient and the diffusive flux of ions into the channel. All these quantities can be obtained from molecular dynamics simulations. An important advantage of this method is that it can be used equally well to estimating large and small currents

  12. Transport analysis of TFTR experiments

    International Nuclear Information System (INIS)

    Goldston, R.; McCune, D.; Zarnstorff, M.; Hammett, G.; Scott, S.

    1991-01-01

    The purpose of this investigation was to complete the analysis of TFTR data which was under progress. The main emphasis was to study the effects of heating profile and resulting density and temperature profiles on transport through the comparison between beam heated plasmas with hollow and centrally peaked heating profiles (edge vs. center heating). The analysis has been completed and a manuscript has been prepared for publication in Nuclear Fusion. A proposal to perform a similar experiment using ICRF heating to decouple heating profile effects from density profile effects was submitted and was approved by the TFTR. ICRF heating enables the heating profile and the power partition between ions and electrons to be controlled. The experiment was scheduled twice, but it had to be postponed both times

  13. Cell biology experiments conducted in space

    Science.gov (United States)

    Taylor, G. R.

    1977-01-01

    A review of cell biology experiments conducted during the first two decades of space flight is provided. References are tabulated for work done with six types of living test system: isolated viruses, bacteriophage-host, bacteria, yeasts and filamentous fungi, protozoans, and small groups of cells (such as hamster cell tissue and fertilized frog eggs). The general results of studies involving the survival of cells in space, the effect of space flight on growing cultures, the biological effects of multicharged high-energy particles, and the effects of space flight on the genetic apparatus of microorganisms are summarized. It is concluded that cell systems remain sufficiently stable during space flight to permit experimentation with models requiring a fixed cell line during the space shuttle era.

  14. Transport studies for ignition experiments

    International Nuclear Information System (INIS)

    Nocentini, A.; Schultz, G.

    1990-07-01

    The results of a predictive study of plasma energy confinement in IGNITOR, performed with a 1 1/2-D transport code and the Tang an Redi transport model, are reported. For comparison, performance predictions for NET adopting similar assumptions on plasma transport are also presented. (author) 16 figs., 5 tabs., 13 refs

  15. Electron transport through supported biomembranes at the nanoscale by conductive atomic force microscopy

    International Nuclear Information System (INIS)

    Casuso, I; Fumagalli, L; Samitier, J; Padros, E; Reggiani, L; Akimov, V; Gomila, G

    2007-01-01

    We present a reliable methodology to perform electron transport measurements at the nanoscale on supported biomembranes by conductive atomic force microscopy (C-AFM). It allows measurement of both (a) non-destructive conductive maps and (b) force controlled current-voltage characteristics in wide voltage bias range in a reproducible way. Tests experiments were performed on purple membrane monolayers, a two-dimensional (2D) crystal lattice of the transmembrane protein bacteriorhodopsin. Non-destructive conductive images show uniform conductivity of the membrane with isolated nanometric conduction defects. Current-voltage characteristics under different compression conditions show non-resonant tunneling electron transport properties, with two different conduction regimes as a function of the applied bias, in excellent agreement with theoretical predictions. This methodology opens the possibility for a detailed study of electron transport properties of supported biological membranes, and of soft materials in general

  16. Electron transport through supported biomembranes at the nanoscale by conductive atomic force microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Casuso, I [Department Electronica, Universitat de Barcelona and Laboratori de Nanobioenginyeria-IBEC, Parc CientIfic de Barcelona, Barcelona (Spain); Fumagalli, L [Department Electronica, Universitat de Barcelona and Laboratori de Nanobioenginyeria-IBEC, Parc CientIfic de Barcelona, Barcelona (Spain); Samitier, J [Department Electronica, Universitat de Barcelona and Laboratori de Nanobioenginyeria-IBEC, Parc CientIfic de Barcelona, Barcelona (Spain); Padros, E [Unitat de BiofIsica, Departamento de BioquImica i de Biologia Molecular, Facultat de Medicina i Centre d' Estudis en BiofIsica, Universitat Autonoma de Barcelona, Barcelona (Spain); Reggiani, L [CNR-INFM National Nanotechnology Laboratory, Dipartimento di Ingegneria dell' Innovazione, Universita di Lecce, Lecce (Italy); Akimov, V [CNR-INFM National Nanotechnology Laboratory, Dipartimento di Ingegneria dell' Innovazione, Universita di Lecce, Lecce (Italy); Gomila, G [Department Electronica, Universitat de Barcelona and Laboratori de Nanobioenginyeria-IBEC, Parc CientIfic de Barcelona, Barcelona (Spain)

    2007-11-21

    We present a reliable methodology to perform electron transport measurements at the nanoscale on supported biomembranes by conductive atomic force microscopy (C-AFM). It allows measurement of both (a) non-destructive conductive maps and (b) force controlled current-voltage characteristics in wide voltage bias range in a reproducible way. Tests experiments were performed on purple membrane monolayers, a two-dimensional (2D) crystal lattice of the transmembrane protein bacteriorhodopsin. Non-destructive conductive images show uniform conductivity of the membrane with isolated nanometric conduction defects. Current-voltage characteristics under different compression conditions show non-resonant tunneling electron transport properties, with two different conduction regimes as a function of the applied bias, in excellent agreement with theoretical predictions. This methodology opens the possibility for a detailed study of electron transport properties of supported biological membranes, and of soft materials in general.

  17. Transnucleaire's experience in maritime transportation

    International Nuclear Information System (INIS)

    Vallette-Fontaine, M.

    1998-01-01

    Since the INF code requirement has been implemented in early 1995 laying down stringent requirements for ships transporting irradiated nuclear fuel, plutonium and high level radioactive waste, Transnucleaire has upgraded and operates two sister ships belonging a CMN shipping company and is well involved in the maritime transportation of radioactive materials. This paper aims at analysing the various principles implemented by Transnucleaire: operate ships such as Bouguenais and Beaulieu in compliance will all existing regulations such as INF Code, Japanese KAISA...; keep the sea transportation of nuclear material at affordable price for all nuclear organizations especially those involved in research activities; avoid for non routine transports, the use of nuclear dedicated ships often precluded by its high costs; adapt the means to all possible evolutions, i.e. be prepared to offer improved ships to satisfy all the scale of requirements; find optimised technical solutions to comply with Japanese type B ship regulations at a reasonable cost. (authors)

  18. Detecting Electron Transport of Amino Acids by Using Conductance Measurement

    Directory of Open Access Journals (Sweden)

    Wei-Qiong Li

    2017-04-01

    Full Text Available The single molecular conductance of amino acids was measured by a scanning tunneling microscope (STM break junction. Conductance measurement of alanine gives out two conductance values at 10−1.85 G0 (1095 nS and 10−3.7 G0 (15.5 nS, while similar conductance values are also observed for aspartic acid and glutamic acid, which have one more carboxylic acid group compared with alanine. This may show that the backbone of NH2–C–COOH is the primary means of electron transport in the molecular junction of aspartic acid and glutamic acid. However, NH2–C–COOH is not the primary means of electron transport in the methionine junction, which may be caused by the strong interaction of the Au–SMe (methyl sulfide bond for the methionine junction. The current work reveals the important role of the anchoring group in the electron transport in different amino acids junctions.

  19. Antimonene: Experiments and theory of surface conductivity

    Science.gov (United States)

    Palacios, Juan Jose; Ares, Pablo; Pakdel, Sahar; Paz, Wendel; Zamora, Felix; Gomez-Herrero, Julio

    Very recently antimony has been demonstrated to be amenable to standard exfoliation procedures opening the possibility of studying the electronic properties of isolated few-layers flakes of this material, a.k.a. antimonene. Antimony is a topological semimetal, meaning that its electronic structure presents spin-split helical states (or Dirac cones) on the surface, but it is still trivially metallic in bulk. Antimonene, on the other hand, may present a much reduced electronic bulk contribution for a small number of layers. A novel technique to make electrical contacts on the surface of individual thin flakes (5-10 monolayers) has allowed us to measure the (surface) conductivity of these in ambient conditions. Our measurements show a high conductivity in the range of 1 - 2e2 / h , which we attribute to the surface Dirac electrons. We have also carried out theoretical work to address the origin of this value, in particular, the importance of scattering between the Dirac electrons and the bulk bands. Our calculations are based on density functional theory for the electronic structure and Kubo formalism for the conductivity, the latter considering random disorder and the presence of water. Ministerio de Economia y Competitividad, Grant FIS2016-80434-P.

  20. Heat conduction in multifunctional nanotrusses studied using Boltzmann transport equation

    International Nuclear Information System (INIS)

    Dou, Nicholas G.; Minnich, Austin J.

    2016-01-01

    Materials that possess low density, low thermal conductivity, and high stiffness are desirable for engineering applications, but most materials cannot realize these properties simultaneously due to the coupling between them. Nanotrusses, which consist of hollow nanoscale beams architected into a periodic truss structure, can potentially break these couplings due to their lattice architecture and nanoscale features. In this work, we study heat conduction in the exact nanotruss geometry by solving the frequency-dependent Boltzmann transport equation using a variance-reduced Monte Carlo algorithm. We show that their thermal conductivity can be described with only two parameters, solid fraction and wall thickness. Our simulations predict that nanotrusses can realize unique combinations of mechanical and thermal properties that are challenging to achieve in typical materials

  1. United Kingdom experience in plutonium transportation

    International Nuclear Information System (INIS)

    1978-08-01

    Plutonium has already been transported within the UK over a period of 20 years and to destinations overseas since the early 60's. Experience is recounted with regard to the forms of plutonium transported, regulations, insurance, container design, mode of transport, volume of traffic, physical protection, safety analysis and costs. It is concluded that this traffic could be expanded in the future without danger to the community or the environment

  2. United Kingdom experience in plutonium transportation

    International Nuclear Information System (INIS)

    1978-11-01

    This paper describes the extensive experience of the UKAEA and British Nuclear Fuels Limited in transporting plutonium within the UK over the last 20 years and to destinations overseas since the early 1960s. The aspects covered include: the form of plutonium transported (nitrate, oxide, mixed oxide etc.); UK and international regulations (e.g. covering safety and safeguards matters); insurance; container design; mode of transport; physical protection; and a safety analysis. Costs are estimated to be largely independent of quantity

  3. Plasma thermal energy transport: theory and experiments

    International Nuclear Information System (INIS)

    Coppi, B.

    Experiments on the transport across the magnetic field of electron thermal energy are reviewed (Alcator, Frascati Torus). In order to explain the experimental results, a transport model is described that reconfirmed the need to have an expression for the local diffusion coefficient with a negative exponent of the electron temperature

  4. Spectral mapping of thermal conductivity through nanoscale ballistic transport

    Science.gov (United States)

    Hu, Yongjie; Zeng, Lingping; Minnich, Austin J.; Dresselhaus, Mildred S.; Chen, Gang

    2015-08-01

    Controlling thermal properties is central to many applications, such as thermoelectric energy conversion and the thermal management of integrated circuits. Progress has been made over the past decade by structuring materials at different length scales, but a clear relationship between structure size and thermal properties remains to be established. The main challenge comes from the unknown intrinsic spectral distribution of energy among heat carriers. Here, we experimentally measure this spectral distribution by probing quasi-ballistic transport near nanostructured heaters down to 30 nm using ultrafast optical spectroscopy. Our approach allows us to quantify up to 95% of the total spectral contribution to thermal conductivity from all phonon modes. The measurement agrees well with multiscale and first-principles-based simulations. We further demonstrate the direct construction of mean free path distributions. Our results provide a new fundamental understanding of thermal transport and will enable materials design in a rational way to achieve high performance.

  5. Conductivity and transport studies of plasticized chitosan-based proton conducting biopolymer electrolytes

    International Nuclear Information System (INIS)

    Shukur, M F; Yusof, Y M; Zawawi, S M M; Illias, H A; Kadir, M F Z

    2013-01-01

    This paper focuses on the conductivity and transport properties of chitosan-based solid biopolymer electrolytes containing ammonium thiocyanate (NH 4 SCN). The sample containing 40 wt% NH 4 SCN exhibited the highest conductivity value of (1.81 ± 0.50) × 10 −4  S cm −1 at room temperature. Conductivity has increased to (1.51 ± 0.12) × 10 −3  S cm −1 with the addition of 25 wt% glycerol. The temperature dependence of conductivity for both salted and plasticized systems obeyed the Arrhenius rule. The activation energy (E a ) was calculated for both systems and it is found that the sample with 40 wt% NH 4 SCN in the salted system obtained an E a value of 0.148 eV and that for the sample containing 25 wt% glycerol in the plasticized system is 0.139 eV. From the Fourier transform infrared studies, carboxamide and amine bands shifted to lower wavenumbers, indicating that chitosan has interacted with NH 4 SCN salt. Changes in the C–O stretching vibration band intensity are observed at 1067 cm −1 with the addition of glycerol. The Rice and Roth model was used to explain the transport properties of the salted and plasticized systems. (paper)

  6. Conductivity and transport studies of plasticized chitosan-based proton conducting biopolymer electrolytes

    Science.gov (United States)

    Shukur, M. F.; Yusof, Y. M.; Zawawi, S. M. M.; Illias, H. A.; Kadir, M. F. Z.

    2013-11-01

    This paper focuses on the conductivity and transport properties of chitosan-based solid biopolymer electrolytes containing ammonium thiocyanate (NH4SCN). The sample containing 40 wt% NH4SCN exhibited the highest conductivity value of (1.81 ± 0.50) × 10-4 S cm-1 at room temperature. Conductivity has increased to (1.51 ± 0.12) × 10-3 S cm-1 with the addition of 25 wt% glycerol. The temperature dependence of conductivity for both salted and plasticized systems obeyed the Arrhenius rule. The activation energy (Ea) was calculated for both systems and it is found that the sample with 40 wt% NH4SCN in the salted system obtained an Ea value of 0.148 eV and that for the sample containing 25 wt% glycerol in the plasticized system is 0.139 eV. From the Fourier transform infrared studies, carboxamide and amine bands shifted to lower wavenumbers, indicating that chitosan has interacted with NH4SCN salt. Changes in the C-O stretching vibration band intensity are observed at 1067 cm-1 with the addition of glycerol. The Rice and Roth model was used to explain the transport properties of the salted and plasticized systems.

  7. Air medical transportation in India: Our experience.

    Science.gov (United States)

    Khurana, Himanshu; Mehta, Yatin; Dubey, Sunil

    2016-01-01

    Long distance air travel for medical needs is on the increase worldwide. The condition of some patients necessitates specially modified aircraft, and monitoring and interventions during transport by trained medical personnel. This article presents our experience in domestic and international interhospital air medical transportation from January 2010 to January 2014. Hospital records of all air medical transportation undertaken to the institute during the period were analyzed for demographics, primary etiology, and events during transport. 586 patients, 453 (77.3%) males and 133 (22.6%) females of ages 46.7 ± 12.6 years and 53.4 ± 9.7 years were transported by us to the institute. It took 3030 flying hours with an average of 474 ± 72 min for each mission. The most common indication for transport was cardiovascular diseases in 210 (35.8%) and central nervous system disease in 120 (20.4%) cases. The overall complication rate was 5.3% There was no transport related mortality. Cardiac and central nervous system ailments are the most common indication for air medical transportation. These patients may need attention and interventions as any critical patient in the hospital but in a difficult environment lacking space and help. Air medical transport carries no more risk than ground transportation.

  8. Field experiments on airborne moisture transport

    NARCIS (Netherlands)

    Oldengarm, J.; Gids, W.F. de

    1990-01-01

    Within the framework of the Dutch participation in the IEA Annex XIV “Condensation” field experiments have been carried out to study airbome moisture transport in realistic circumstances. The experiments were done in an unoccupied 3-story dwelling in Leidschendam in the Netherlands. Some of the

  9. Three-dimensional Simulation of Gas Conductance Measurement Experiments on Alcator C-Mod

    International Nuclear Information System (INIS)

    Stotler, D.P.; LaBombard, B.

    2004-01-01

    Three-dimensional Monte Carlo neutral transport simulations of gas flow through the Alcator C-Mod subdivertor yield conductances comparable to those found in dedicated experiments. All are significantly smaller than the conductance found with the previously used axisymmetric geometry. A benchmarking exercise of the code against known conductance values for gas flow through a simple pipe provides a physical basis for interpreting the comparison of the three-dimensional and experimental C-Mod conductances

  10. MOX fuel transport: the French experience

    International Nuclear Information System (INIS)

    Sanchis, H.; Verdier, A.; Sanchis, H.

    1999-01-01

    In the back-end of the fuel cycle, several leading countries have chosen the Reprocessing, Conditioning, Recycling (RCR) option. Plutonium recycling in the form of MOX fuel is a mature industry, with successful operational experience and large-scale fabrication plants an several European countries. The COGEMA Group has developed the industrialized products to master the RCR operation including transport COGEMA subsidiary, TRANSNUCLEAIRE has been operating MOX fuel transports on an industrial scale for more than 10 years. In 1998, around 200 transports of Plutonium materials have been organised by TRANSNUCLEAIRE. These transports have been carried out by road between various facilities in Europe: reprocessing plants, manufacturing plants and power plants. The materials transported are either: PuO 2 and MOX powder; BWR and PWR MOX fuel rods; BWR and PWR MOX fuel assemblies. Because MOX fuel transport is subject to specific safety, security and fuel integrity requirements, the MOX fuel transport system implemented by TRANSNUCLEAIRE is fully dedicated. Packaging have been developed, licensed and manufactured for each kind of MOX material in compliance with relevant regulations. A fleet of vehicles qualified according to existing physical protection regulations is operated by TRANSNUCLEAIRE. TRANSNUCLEAIRE has gained a broad experience in MOX transport in 10 years. Technical and operational know-how has been developed and improved for each step: vehicles and packaging design and qualification; vehicle and packaging maintenance; transport operations. Further developments are underway to increase the payload of the packaging and to improve the transport conditions, safety and security remaining of course top priority. (authors)

  11. Transport Task Force workshop: basic experiments highlights

    Energy Technology Data Exchange (ETDEWEB)

    Linford, R.K. (Los Alamos National Lab., NM (USA)); Luckhardt, S. (Massachusetts Inst. of Tech., Cambridge, MA (USA)); Lyon, J.F. (Oak Ridge National Lab., TN (USA)); Navratil, G.A. (Columbia Univ., New York, NY (USA)); Schoenberg, K.F. (Los Alamos National Lab., NM (USA))

    1990-01-01

    Selected topics are summarized from the Basic Experiments session of the Transport Task Force Workshop held August 21-24, 1989, in San Diego, California. This session included presentations on paradigm experiments, stellarators, reversed-field pinches, and advanced tokamaks. Recent advances in all of these areas illustrate the importance of these experiments in advancing our understanding of toroidal transport. Progress has been made in measuring the details of particle diffusion, isolating specific modes, measuring fluctuation variations with field geometry and beta, and comparing all these with theoretical predictions. The development of experimental tools for determining which fluctuations dominate transport are also reported. Continued significant advances are anticipated in a number of areas highlighted. (author).

  12. Transport Task Force workshop: basic experiments highlights

    International Nuclear Information System (INIS)

    Linford, R.K.; Luckhardt, S.; Lyon, J.F.; Navratil, G.A.; Schoenberg, K.F.

    1990-01-01

    Selected topics are summarized from the Basic Experiments session of the Transport Task Force Workshop held August 21-24, 1989, in San Diego, California. This session included presentations on paradigm experiments, stellarators, reversed-field pinches, and advanced tokamaks. Recent advances in all of these areas illustrate the importance of these experiments in advancing our understanding of toroidal transport. Progress has been made in measuring the details of particle diffusion, isolating specific modes, measuring fluctuation variations with field geometry and beta, and comparing all these with theoretical predictions. The development of experimental tools for determining which fluctuations dominate transport are also reported. Continued significant advances are anticipated in a number of areas highlighted. (author)

  13. Experiments on microsecond conduction time plasma opening switch mechanisms

    International Nuclear Information System (INIS)

    Rix, W.; Coleman, M.; Miller, A.R.; Parks, D.; Robertson, K.; Thompson, J.; Waisman, E.; Wilson, A.

    1993-01-01

    The authors describe a series of experiments carried out on ACE 2 and ACE 4 to elucidate the mechanisms controlling the conduction and opening phases on plasma opening switches in a radial geometry with conduction times on the order of a microsecond. The results indicate both conduction and opening physics are similar to that observed on lower current systems in a coaxial geometry

  14. An experiment in heat conduction using hollow cylinders

    Energy Technology Data Exchange (ETDEWEB)

    Ortuno, M; Marquez, A; Gallego, S; Neipp, C; Belendez, A, E-mail: a.belendez@ua.es [Departamento de Fisica, IngenierIa de Sistemas y TeorIa de la Senal, Universidad de Alicante, Apartado 99, E-03080 Alicante (Spain)

    2011-07-15

    An experimental apparatus was designed and built to allow students to carry out heat conduction experiments in hollow cylinders made of different materials, as well as to determine the thermal conductivity of these materials. The evolution of the temperature difference between the inner and outer walls of the cylinder as a function of time is analysed, and when the process reaches the steady state regime the thermal conductivity can be easily calculated. Several materials such as wood, plastic and metals are considered and the values of their thermal conductivities, obtained experimentally, are compared with those given in the reference list.

  15. High current beam transport experiments at GSI

    International Nuclear Information System (INIS)

    Klabunde, J.; Schonlein, A.; Spadtke, P.

    1985-01-01

    The status of the high current ion beam transport experiment is reported. 190 keV Ar 1+ ions were injected into six periods of a magnetic quadrupole channel. Since the pulse length is > 0.5 ms partial space charge neutralization occurs. In our experiments, the behavior of unneutralized and partially space charge compensated beams is compared. With an unneutralized beam, emittance growth has been measured for high intensities even in case of the zero-current phase advance sigma 0 0 . This initial emittance growth at high tune depression we attribute to the homogenization effect of the space charge density. An analytical formula based on this assumption describes the emittance growth very well. Furthermore the predicted envelope instabilities for sigma 0 > 90 0 were observed even after 6 periods. In agreement with the theory, unstable beam transport was also experimentally found if a beam with different emittances in the two transverse phase planes was injected into the transport channel. Although the space charge force is reduced for a partially neutralized beam a deterioration of the beam quality was measured in a certain range of beam parameters. Only in the range where an unneutralized beam shows the initial emittance growth, the partial neutralization reduces this effect, otherwise the partially neutralized beam is more unstable

  16. Bacterial transport in heterogeneous porous media: Observations from laboratory experiments

    Science.gov (United States)

    Silliman, S. E.; Dunlap, R.; Fletcher, M.; Schneegurt, M. A.

    2001-11-01

    Transport of bacteria through heterogeneous porous media was investigated in small-scale columns packed with sand and in a tank designed to allow the hydraulic conductivity to vary as a two-dimensional, lognormally distributed, second-order stationary, exponentially correlated random field. The bacteria were Pseudomonas ftuorescens R8, a strain demonstrating appreciable attachment to surfaces, and strain Ml, a transposon mutant of strain R8 with reduced attachment ability. In bench top, sand-filled columns, transport was determined by measuring intensity of fluorescence of stained cells in the effluent or by measuring radiolabeled cells that were retained in the sand columns. Results demonstrated that strain Ml was transported more efficiently than strain R8 through columns packed with either a homogeneous silica sand or a more heterogeneous sand with iron oxide coatings. Two experiments conducted in the tank involved monitoring transport of bacteria to wells via sampling from wells and sample ports in the tank. Bacterial numbers were determined by direct plate count. At the end of the first experiment, the distribution of the bacteria in the sediment was determined by destructive sampling and plating. The two experiments produced bacterial breakthrough curves that were quite similar even though the similarity between the two porous media was limited to first- and second-order statistical moments. This result appears consistent with the concept of large-scale, average behavior such as has been observed for the transport of conservative chemical tracers. The transported bacteria arrived simultaneously with a conservative chemical tracer (although at significantly lower normalized concentration than the tracer). However, the bacterial breakthrough curves showed significant late time tailing. The concentrations of bacteria attached to the sediment surfaces showed considerably more spatial variation than did the concentrations of bacteria in the fluid phase. This

  17. Nevada commercial spent nuclear fuel transportation experience

    International Nuclear Information System (INIS)

    1991-09-01

    The purpose of this report is to present an historic overview of commercial reactor spent nuclear fuel (SNF) shipments that have occurred in the state of Nevada, and to review the accident and incident experience for this type of shipments. Results show that between 1964 and 1990, 309 truck shipments covering approximately 40,000 miles moved through Nevada; this level of activity places Nevada tenth among the states in the number of truck shipments of SNF. For the same period, 15 rail shipments moving through the State covered approximately 6,500 miles, making Nevada 20th among the states in terms of number of rail shipments. None of these shipments had an accident or an incident associated with them. Because the data for Nevada are so limited, national data on SNF transportation and the safety of truck and rail transportation in general were also assessed

  18. DC conductivity of twisted bilayer graphene: Angle-dependent transport properties and effects of disorder

    Science.gov (United States)

    Andelković, M.; Covaci, L.; Peeters, F. M.

    2018-03-01

    The in-plane dc conductivity of twisted bilayer graphene is calculated using an expansion of the real-space Kubo-Bastin conductivity in terms of Chebyshev polynomials. We investigate within a tight-binding approach the transport properties as a function of rotation angle, applied perpendicular electric field, and vacancy disorder. We find that for high-angle twists, the two layers are effectively decoupled, and the minimum conductivity at the Dirac point corresponds to double the value observed in monolayer graphene. This remains valid even in the presence of vacancies, hinting that chiral symmetry is still preserved. On the contrary, for low twist angles, the conductivity at the Dirac point depends on the twist angle and is not protected in the presence of disorder. Furthermore, for low angles and in the presence of an applied electric field, we find that the chiral boundary states emerging between AB and BA regions contribute to the dc conductivity, despite the appearance of localized states in the AA regions. The results agree qualitatively with recent transport experiments in low-angle twisted bilayer graphene.

  19. Centrifuge Techniques and Apparatus for Transport Experiments in Porous Media

    Energy Technology Data Exchange (ETDEWEB)

    Earl D. Mattson; Carl D. Paler; Robert W. Smith; Markus Flury

    2010-06-01

    This paper describes experimental approaches and apparatus that we have developed to study solute and colloid transport in porous media using Idaho National Laboratory's 2-m radius centrifuge. The ex-perimental techniques include water flux scaling with applied acceleration at the top of the column and sub-atmospheric pressure control at the column base, automation of data collection, and remote experimental con-trol over the internet. These apparatus include a constant displacement piston pump, a custom designed liquid fraction collector based on switching valve technology, and modified moisture monitoring equipment. Suc-cessful development of these experimental techniques and equipment is illustrated through application to transport of a conservative tracer through unsaturated sand column, with centrifugal acceleration up to 40 gs. Development of such experimental equipment that can withstand high accelerations enhances the centrifuge technique to conduct highly controlled unsaturated solute/colloid transport experiments and allows in-flight liquid sample collection of the effluent.

  20. Stochastic analysis of transport of conservative solutes in caisson experiments

    International Nuclear Information System (INIS)

    Dagan, G.

    1995-01-01

    The Los Alamos National Laboratory has conducted in the past a series of experiments of transport of conservative and reactive solutes. The experimental setup and the experimental results are presented in a series of reports. The main aim of the experiments was to validate models of transport of solutes in unsaturated flow at the caisson intermediate scale, which is much larger than the one pertaining to laboratory columns. First attempts to analyze the experimental results were by one-dimensional convective-dispersion models. These models could not explain the observed solute breakthrough curves and particularly the large solute dispersion in the caisson effluent Since there were some question marks about the uniformity of water distribution at the caisson top, the transport experiments were repeated under conditions of saturated flow. In these experiments constant heads were applied at the top and the bottom of the caisson and the number of concentration monitoring stations was quadrupled. The analysis of the measurements by the same one-dimensional model indicated clearly that the fitted dispersivity is much larger than the pore-sole dispersivity and that it grows with the distance in an approximately linear fashion. This led to the conclusion, raised before, that transport in the caisson is dominated by heterogeneity effects, i.e. by spatial variability of the material Such effects cannot be captured by traditional one-dimensional models. In order to account for the effect of heterogeneity, the saturated flow experiments have been analyzed by using stochastic transport modeling. The apparent linear growth of dispersivity with distance suggested that the system behaves like a stratified one. Consequently, the model of Dagan and Bresier has been adopted in order to interpret concentration measurements. In this simple model the caisson is viewed as a bundle of columns of different permeabilities, which are characterized by a p.d.f. (probability denasity function)

  1. Experiences in transferring the techniques for the economical conduction of the Mexico`s vehicular transport; Experiencias de la transferencia de las tecnicas de conduccion economica en el autotransporte en Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Osorio, Francisco Javier [Comision Nacional para el Ahorro de Energia, Mexico, D. F. (Mexico)

    1996-12-31

    The Comision Nacional para el Ahorro de Energia (CONAE) (National Commission for Energy Conservation) developed the training program that through the dictation of pilot courses of technical-economical conduction of auto-motor vehicles is addressed to private enterprises, agencies and governmental institutions. This paper presents the background and the obtained results of the same. This methodology is presented in detail and a description of the courses is also presented as well as its characteristics. The comparative results are annexed of the tests between the conduction normally performed and the technical-economical conduction. The fuel saving obtained varies from 9% to 22.5%. Then, the reasons why the training in the technical- economical conduction results in one of the actions more profitable in fuel saving are explained, but also the difficulties for its implementation are also discussed. A conclusion is offered. [Espanol] La Comision Nacional para el Ahorro de Energia (CONAE) desarrollo el programa de capacitacion que a traves de la imparticion de cursos pilotos de conduccion tecnico- economica de vehiculos automotores, se dirige a las empresas privadas, dependencias e instituciones gubernamentales. En este trabajo se presentan los antecedentes y resultados obtenidos del mismo. Se detalla esta metodologia y se presenta una descripcion de los cursos y sus caracteristicas. Se anexan resultados comparativos de las pruebas entre la conduccion que se realiza normalmente y la conduccion tecnico-economica. Los ahorros de combustible obtenidos van desde 9% hasta 22.5%. Luego, se explican las razones por las que la capacitacion en conduccion tecnico-economica resulta ser una de las acciones mas rentables del ahorro de combustibles, pero tambien se discuten las dificultades para implantarla. Se ofrece una conclusion.

  2. Experiences in transferring the techniques for the economical conduction of the Mexico`s vehicular transport; Experiencias de la transferencia de las tecnicas de conduccion economica en el autotransporte en Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Osorio, Francisco Javier [Comision Nacional para el Ahorro de Energia, Mexico, D. F. (Mexico)

    1997-12-31

    The Comision Nacional para el Ahorro de Energia (CONAE) (National Commission for Energy Conservation) developed the training program that through the dictation of pilot courses of technical-economical conduction of auto-motor vehicles is addressed to private enterprises, agencies and governmental institutions. This paper presents the background and the obtained results of the same. This methodology is presented in detail and a description of the courses is also presented as well as its characteristics. The comparative results are annexed of the tests between the conduction normally performed and the technical-economical conduction. The fuel saving obtained varies from 9% to 22.5%. Then, the reasons why the training in the technical- economical conduction results in one of the actions more profitable in fuel saving are explained, but also the difficulties for its implementation are also discussed. A conclusion is offered. [Espanol] La Comision Nacional para el Ahorro de Energia (CONAE) desarrollo el programa de capacitacion que a traves de la imparticion de cursos pilotos de conduccion tecnico- economica de vehiculos automotores, se dirige a las empresas privadas, dependencias e instituciones gubernamentales. En este trabajo se presentan los antecedentes y resultados obtenidos del mismo. Se detalla esta metodologia y se presenta una descripcion de los cursos y sus caracteristicas. Se anexan resultados comparativos de las pruebas entre la conduccion que se realiza normalmente y la conduccion tecnico-economica. Los ahorros de combustible obtenidos van desde 9% hasta 22.5%. Luego, se explican las razones por las que la capacitacion en conduccion tecnico-economica resulta ser una de las acciones mas rentables del ahorro de combustibles, pero tambien se discuten las dificultades para implantarla. Se ofrece una conclusion.

  3. Interpreting equilibrium-conductivity and conductivity-relaxation measurements to establish thermodynamic and transport properties for multiple charged defect conducting ceramics.

    Science.gov (United States)

    Zhu, Huayang; Ricote, Sandrine; Coors, W Grover; Kee, Robert J

    2015-01-01

    A model-based interpretation of measured equilibrium conductivity and conductivity relaxation is developed to establish thermodynamic, transport, and kinetics parameters for multiple charged defect conducting (MCDC) ceramic materials. The present study focuses on 10% yttrium-doped barium zirconate (BZY10). In principle, using the Nernst-Einstein relationship, equilibrium conductivity measurements are sufficient to establish thermodynamic and transport properties. However, in practice it is difficult to establish unique sets of properties using equilibrium conductivity alone. Combining equilibrium and conductivity-relaxation measurements serves to significantly improve the quantitative fidelity of the derived material properties. The models are developed using a Nernst-Planck-Poisson (NPP) formulation, which enables the quantitative representation of conductivity relaxations caused by very large changes in oxygen partial pressure.

  4. Temperature-dependent ionic conductivity and transport properties ...

    Indian Academy of Sciences (India)

    Administrator

    A conductivity cell containing two stainless-steel block- ing electrodes ... tions by matching the device impedance to the cable .... reveals that the presence of large negative value in the ... site exhibits VTF phenomenological relationship. 1/2 dc.

  5. Conducting Family Nursing in Heart Failure outpatient clinics: Nurses experiences

    DEFF Research Database (Denmark)

    Voltelen, Barbara; Konradsen, Hanne; Østergaard, Birte

    Aim: This study aimed to explore what was documented during structured Family Nursing (FN) conversations with patients diagnosed with Heart Failure and their families, and to gain knowledge about the nurses’ experiences conducting FN. Background: Patients with HF face many challenges, and so do...... throughout the FN intervention and a Focus group interview with 6 nurses who were conducting the conversations. Content analyses of all text material dealt with both manifest and latent content, and were analyzed through a deductive and inductive process. Results: Enabling bonding emerged as the overall...

  6. Modeling and conduct of turbine missile concrete impact experiments

    International Nuclear Information System (INIS)

    Woodfin, R.L.

    1981-01-01

    The overall objective of the subject experiments was to provide full scale data on the response of reinforced concrete containment walls to impact and penetration by postulated turbine-produced missiles. These data can be used to validate analytical or scale modeling methods and to assess the applicability of current design formulas to penetration by large, irregularly shaped missiles. These data and results will be used in providing more realistic estimates of turbine missile damage probability in nuclear power plants with a non-peninsula arrangement. This paper describes the derivation of the test matrix and the method of conducting the experiments. (orig./HP)

  7. Experiments on thermal conductivity in buffer materials for geologic repository

    International Nuclear Information System (INIS)

    Kanno, T.; Yano, T.; Wakamatsu, H.; Matsushima, E.

    1989-01-01

    Engineered barriers for geologic disposal for HLW are planned to consist of canister, overpack and buffer elements. One of important physical characteristics of buffer materials is determining temperature profiles within the near field in a repository. Buffer materials require high thermal conductivity to disperse radiogenic heat away to the host rock. As the buffer materials, compacted blocks of the mixture of sodium bentonite and sand have been the most promising candidate in some countries, e.g. Sweden, Switzerland and Japan. The authors have been carrying out a series of thermal dispersion experiments to evaluate thermal conductivity of bentonite/quartz sand blocks. In this study, the following two factors considered to affect thermal properties of the near field were examined: effective thermal conductivities of buffer materials, and heat transfer characteristics of the gap between overpack and buffer materials

  8. Quantum transport through disordered 1D wires: Conductance via localized and delocalized electrons

    International Nuclear Information System (INIS)

    Gopar, Víctor A.

    2014-01-01

    Coherent electronic transport through disordered systems, like quantum wires, is a topic of fundamental and practical interest. In particular, the exponential localization of electron wave functions-Anderson localization-due to the presence of disorder has been widely studied. In fact, Anderson localization, is not an phenomenon exclusive to electrons but it has been observed in microwave and acoustic experiments, photonic materials, cold atoms, etc. Nowadays, many properties of electronic transport of quantum wires have been successfully described within a scaling approach to Anderson localization. On the other hand, anomalous localization or delocalization is, in relation to the Anderson problem, a less studied phenomenon. Although one can find signatures of anomalous localization in very different systems in nature. In the problem of electronic transport, a source of delocalization may come from symmetries present in the system and particular disorder configurations, like the so-called Lévy-type disorder. We have developed a theoretical model to describe the statistical properties of transport when electron wave functions are delocalized. In particular, we show that only two physical parameters determine the complete conductance distribution

  9. Fluctuation theory for transport properties in multicomponent mixtures: thermodiffusion and heat conductivity

    DEFF Research Database (Denmark)

    Shapiro, Alexander

    2004-01-01

    The theory of transport properties in multicomponent gas and liquid mixtures, which was previously developed for diffusion coefficients, is extended onto thermodiffusion coefficients and heat conductivities. The derivation of the expressions for transport properties is based on the general statis...... of the heat conductivity coefficient for ideal gas. (C) 2003 Elsevier B.V. All rights reserved.......The theory of transport properties in multicomponent gas and liquid mixtures, which was previously developed for diffusion coefficients, is extended onto thermodiffusion coefficients and heat conductivities. The derivation of the expressions for transport properties is based on the general...

  10. A two-parameter nondiffusive heat conduction model for data analysis in pump-probe experiments

    Science.gov (United States)

    Ma, Yanbao

    2014-12-01

    Nondiffusive heat transfer has attracted intensive research interests in last 50 years because of its importance in fundamental physics and engineering applications. It has unique features that cannot be described by the Fourier law. However, current studies of nondiffusive heat transfer still focus on studying the effective thermal conductivity within the framework of the Fourier law due to a lack of a well-accepted replacement. Here, we show that nondiffusive heat conduction can be characterized by two inherent material properties: a diffusive thermal conductivity and a ballistic transport length. We also present a two-parameter heat conduction model and demonstrate its validity in different pump-probe experiments. This model not only offers new insights of nondiffusive heat conduction but also opens up new avenues for the studies of nondiffusive heat transfer outside the framework of the Fourier law.

  11. Ben Macdhui High Altitude Trace Gas and Aerosol Transport Experiment

    CSIR Research Space (South Africa)

    Piketh, SJ

    1999-01-01

    Full Text Available The Ben Macdhui High Altitude Aerosol and Trace Gas Transport Experiment (BHATTEX) was started to characterize the nature and magnitude of atmospheric, aerosol and trace gas transport paths recirculation over and exiting from southern Africa...

  12. Air medical transportation in India: Our experience

    Directory of Open Access Journals (Sweden)

    Himanshu Khurana

    2016-01-01

    Conclusion: Cardiac and central nervous system ailments are the most common indication for air medical transportation. These patients may need attention and interventions as any critical patient in the hospital but in a difficult environment lacking space and help. Air medical transport carries no more risk than ground transportation.

  13. Enhanced bulk conductivity and bipolar transport in mixtures of MoOx and organic hole transport materials

    International Nuclear Information System (INIS)

    Tian, Baolin; Ban, Dayan; Aziz, Hany

    2013-01-01

    We study the conductivity of thin films of molybdenum oxide (MoO x ) mixed with an organic hole transport material, such as N,N′-bis(naphthalen-1-yl)-N,N′-bis (phenyl)benzidine or 4′,4″-tri(N-carbazolyl)triphenylamine, in lateral test devices. Contrary to previous reports, the conductivity of the mixture is found to exceed that of neat MoO x , exhibiting ∼ 5 orders of magnitude higher conductivity in comparison to the neat films. Studies also show that the mixing enhances both hole and electron transport. The higher conductivity may be attributed to a higher concentration of “free” carriers in the mixture, as a result of the formation of a charge transfer complex between the MoO x and the hole transport material. The findings shed light on the potential of hybrid composites of inorganic and organic materials in realizing enhanced conductivity. - Highlights: • We investigate the conductivity of mixtures of MoO x and hole transport material (HTM). • Materials are studied in lateral devices instead of conventional vertical devices. • Mixing MoO x with HTM brings > 5 orders of magnitude increase in bulk conductivity. • The mixture of MoO x and HTM enhances both hole and electron transport

  14. Novel electrical transport properties in conducting polymers such as polythiophene and Poly(3-Methylthiophene)

    International Nuclear Information System (INIS)

    Kazama, Shigeo; Masubuchi, Shin-ichi; Matsuyama, Tomochika; Matsushita, Rokuji.

    1994-01-01

    Electric transport properties in most of the conducting organic polymers have provided a riddle that prevents a thorough physical understanding of the conduction mechanism. Major difficulties for approaching the most substantial aspect in the electrical transport properties underlie in complicated higher order structure inherent to polymeric materials consisting of crystalline regions entangled with disordered amorphous regions. In order to clearly understand the origin of the metallic nature of conducting polymers, we have to extract the proper transport properties characteristics of the ordered crystalline regions. We have made a series of experimental studies of the transport properties in conductive polythiophene and poly(3-methylthiophene) obtained with the electrochemical polymerization. For polythiophene, we have investigated both the as-grown samples and the ones that contain controlled amount of dopant species exchanged after the neutralization aiming to see the effect of dopant concentration on the transport properties. (author)

  15. Sand box experiments with bioclogging of porous media: Hydraulic conductivity reductions

    DEFF Research Database (Denmark)

    Seifert, Dorte; Engesgaard, Peter

    2012-01-01

    Tracer experiments during clogging and de-clogging experiments in a 2D sand box were via an image analysis used to establish a data set on the relation between changes in hydraulic conductivity (K) and relative porosity (β). Clogging appears to create a finger-like tracer transport, which could...... and closer to the substrate source during the experiments suggesting that the zone of clogging moved upstream. Three clogging models, K(β), from the literature were tested for their ability to describe the temporal changes in clogging at the scale of the sand box; the model of Clement et al. (1996......) that makes no assumption on biomass distribution, the plug formation model of Thullner et al. (2002a), and the biofilm-plug formation model of Vandevivere (1995). The plug formation and biofilm-plug formation models both match the observed changes between the hydraulic conductivity of the sand box...

  16. Transport of oxide spent fuel. Industrial experience of COGEMA

    International Nuclear Information System (INIS)

    Lenail, B.

    1985-01-01

    COGEMA, the world leading Company in the reprocessing industry who is also involved in the transport activity, is ruling all transports of spent fuel to La Hague reprocessing plant. The paper summarizes some aspects of the experience gained in this field (road, rail and sea transports) and describes the standards defined by COGEMA as regards transport casks. These standards are as follows: - casks of dry type, - casks of the maximum size compatible with rail transports, - capability to be unloaded with standardized equipment and following standard procedures. Considering: 1) the extremely large experience of COGEMA for all transport modes and, 2) the fact that all these transports are performed in full compliance with the IAEA recommendations, COGEMA is convinced that its experience could serve to help countries or utilities willing to undertake to establish a transport system within their own country COGEMA is prepared to contribute to this task on terms to be agreed [fr

  17. Nano wire conductance experiments above and below the reservoirs Curie temperature

    Energy Technology Data Exchange (ETDEWEB)

    Costa-Kraemer, J. L.; Briones, F. [Instituto de Microelectronica de Madrid, Madrid (Spain); Serena, P. A. [Instituto de Ciencias de Materiales de Madrid, Madrid (Spain)

    2001-03-01

    The transport properties of Ni nano wires are studied using a Scanning Tunneling Microscope (STM) under clean high vacuum conditions. A basically flat nano wire conductance histogram is found independently of the magnetic state of the electrodes. This agrees with our previous studies in air but disagrees with recently published results. The possible origin of these discrepancies, together with additional experiments trying to discern the existence of a spin-dependent conductance in ferromagnetic nano wires, are presented. [Spanish] Las propiedades de transporte de nanoalambres de Ni son estudiadas usando un microscopio de efecto tunel bajo condiciones limpias de alto vacio. Se encuentra un histograma esencialmente plano independiente del estado magnetico de los electrodos. Esto concuerda con nuestros estudios previos en aire pero contrasta con resultados publicados recientemente. Se presentara una discusion sobre el posible origen experimental de estas discrepancias, con el fin de discernir sobre la existencia de una conductancia dependiente del espin en nanoalambres ferromagneticos.

  18. European experience with spent fuel transport

    International Nuclear Information System (INIS)

    Hunter, I.A.

    1995-01-01

    Nuclear Transport Ltd has transported 5000 tonnes of spent fuel from 35 reactors in 8 European countries since 1972. Transport management is governed by the Quality Plan for: transport administration, packaging and shipment procedures at the shipping plant, operations at the power plant, and packaging and shipment organization at the power plant. Selection of a suitable carrier device is made with regard to the shipping plant requirements, physical limitations of the reactor, fuel characteristics, and transport route constraints. The transport plan is set up taking into account exploitation of the casks, reactor shut-down requirements, fuel acceptance plans at the reprocessing plant, and cask maintenance periods. A transport cycle involving spent fuel shipment to La Hague or to Sellafield takes typically two or four weeks, respectively. Most transports through Europe are by rail. A special-design railway ferry boat serves transports to the United Kingdom. Both wet or dry casks are employed. Modern casks are designed for high burnups and for oxide fuels. (J.B.)

  19. IPROP simulations of the GAMBLE II proton transport experiment

    International Nuclear Information System (INIS)

    Welch, D.R.

    1993-01-01

    The author has simulated the proton transport of the 6-kA, 1-MV GAMBLE II experiment using a modified version of the IPROP particle-in-cell code. IPROP now uses a hybrid model in which plasma electrons are divided into high-energy macro particle and thermal-fluid components. This model includes open-quotes knock-onclose quotes bound-electron collision and runaway sources for high-energy electrons. Using IPROP, the authors has calculated net currents in reasonable agreement with the experiment ranging from 5-11% of the total current in pressures from 0.25-4 torr helium. In the simulations, the pinch current sample by the 1.5-cm beam was 2-3 times larger than the net current at 4 cm radius. The attenuation of net current at larger radii was the result of a highly-conductive energetic component of plasma electrons surrounding the beam. Having benchmarked IPROP against experiment, the author has examined higher-current ion beams with respect to possible transport for inertial confinement fusion

  20. Lived experience of involuntary transport under mental health legislation.

    Science.gov (United States)

    Bradbury, Joanne; Hutchinson, Marie; Hurley, John; Stasa, Helen

    2017-12-01

    Police have historically been responsible for transporting people during a mental health crisis in Australia. A major change to the New South Wales (NSW) Mental Health Act (MHA) in 2007 expanded the range of coercive transportation agencies to include NSW Ambulance (paramedics) and NSW Health (mental health nurses). Anecdotal reports, however, describe a lack of clarity around how these changes should be implemented in practice. This research aims to explore this lack of clarity through qualitative analysis of interviews with people with the lived experience of involuntary transport under the MHA. Sixteen interviews were conducted; most (n = 14) interviews in northern NSW regions: six with people who had been transported (consumers), four with carers, and six with service providers (two police, one paramedic, and three mental health nurses). For consumers and carers, the police response was often perceived as too intense, particularly if the person was not violent. Carers were often conflicted by having to call for emergency intervention. Service providers were frustrated by a lack of a coordinated interagency response, resourcing issues, delays at emergency departments, and lack of adequate training. A central theme across all groups was the importance of communication styles. As one participant (consumer) said: 'Everybody needs a lesson in kindness'. All groups agreed that high-risk situations necessitate police involvement. However, invocation of the MHA during a high-risk situation is fraught with stress and difficulties, leaving little room for empathetic communications. Effective and diverse, evidence-based, early intervention strategies - both consensual and non-consensual - are necessary to reduce the requirement for police involvement in mental health transports. © 2016 Australian College of Mental Health Nurses Inc.

  1. Hopping transport and electrical conductivity in one-dimensional systems with off-diagonal disorder

    International Nuclear Information System (INIS)

    Ma Songshan; Xu Hui; Li Yanfeng; Song Zhaoquan

    2007-01-01

    In this paper, we present a model to describe hopping transport and electrical conductivity of one-dimensional systems with off-diagonal disorder, in which electrons are transported via hopping between localized states. We find that off-diagonal disorder leads to delocalization and drastically enhances the electrical conductivity of systems. The model also quantitatively explains the temperature and electrical field dependence of the conductivity in one-dimensional systems with off-diagonal disorder. In addition, we also show the dependence of the conductivity on the strength of off-diagonal disorder

  2. Transport of oxide spent fuel. Industrial experience of COGEMA

    International Nuclear Information System (INIS)

    Lenail, B.

    1983-01-01

    COGEMA is ruling all transports of spent fuel to La Hague reprocessing plant. The paper summarizes some aspects of the experience gained in this field (road, rail and sea transports) and describes the standards defined by COGEMA as regards transport casks. These standards are as follows: - casks of dry type, - casks of the maximum size compatible with rail transports, - capability to be unloaded with standardized equipment and following standard procedures

  3. Significant Electronic Thermal Transport in the Conducting Polymer Poly(3,4‐ethylenedioxythiophene)

    DEFF Research Database (Denmark)

    Weathers, Annie; Khan, Zia Ullah; Brooke, Robert

    2015-01-01

    Suspended microdevices are employed to measure the in-plane electrical conductivity, thermal conductivity, and Seebeck coefficient of suspended poly(3,4-ethylenedioxythiophene) (PEDOT) thin films. The measured thermal conductivity is higher than previously reported for PEDOT and generally increases...... with the electrical conductivity. The increase exceeds that predicted by the Wiedemann–Franz law for metals and can be explained by significant electronic thermal transport in PEDOT....

  4. French experience in research reactor fuel transportation

    International Nuclear Information System (INIS)

    Raisonnier, Daniele

    1996-01-01

    Since 1963 Transnucleaire has safely performed a large number of national and international transports of radioactive material. Transnucleaire has also designed and supplied suitable packaging for all types of nuclear fuel cycle radioactive material from front-end and back-end products and for power or for research reactors. Transportation of spent fuel from power reactors are made on a regular and industrial basis, but this is not yet the case for the transport of spent fuel coming from research reactors. Each shipment is a permanent challenge and requires a reactive organization dealing with all the transportation issues. This presentation will explain the choices made by Transnucleaire and its associates to provide and optimize the corresponding services while remaining in full compliance with the applicable regulations and customer requirements. (author)

  5. Transport in porous media containing residual hydrocarbon. 2: Experiments

    International Nuclear Information System (INIS)

    Hatfield, K.; Ziegler, J.; Burris, D.R.

    1993-01-01

    When liquid hydrocarbons or nonaqueous-phase liquids (NAPLs) become entrapped below the water table, flowing ground waters carry soluble NAPL components away from the spill zone. Transport of these dissolved NAPL components is controlled by several processes including advection, dispersion, sorption to aquifer materials, and liquid-liquid partitioning. To better understand these processes, miscible displacement experiments were conducted to generate break-through curves (BTCs) of pentafluorobenzoic acid (PFBA), benzene, and toluene on sand column with and without a fixed decane residual. A departure from equilibrium transport is observed in BTCs from the sand-decane system. These BTCs show characteristics of early breakthrough, asymmetry, and tailing. The cause of nonequilibrium is hypothesized to be rate-limited solute exchange between decane and water. A new transport model, capable of handling time-dependent exchange processes, is successfully applied to reproduce experimental BATCs. Results indicate that time-dependent partitioning becomes increasingly important as the solute decane-water partition coefficient and the aqueous-phase fluid velocity increase

  6. Self-pinched lithium beam transport experiments on SABRE

    International Nuclear Information System (INIS)

    Hanson, D.L.; Olson, C.L.; Poukey, J.W.; Shokir, I.; Cuneo, M.E.; Menge, P.R.; Johnston, R.R.; Welch, D.R.

    1996-01-01

    Self-pinched transport of ion beams has many advantages for ion-driven ICF applications involving high yield and energy production. The authors are currently preparing for a self-pinched lithium beam transport experiment on the SABRE accelerator. There are three transport elements that must eventually be demonstrated: (1) efficient lithium beam generation and ballistic transport to a focus at the self-pinched transport channel entrance; (2) self-pinched transport in the channel, requiring optimized injection conditions and gas breakdown; and (3) self-pinched transport of the equilibrated beam from the channel into free space, with associated aiming and stability considerations. In the present experiment, a hollow annular lithium beam from an applied-B extraction ion diode will be focused to small radius (r ≤ 2 cm) in a 60 cm long ballistic focus section containing argon gas at a pressure of a few Torr. The self-pinched transport channel will contain a low pressure background gas of 10--40 mTorr argon to allow sufficient net current to confine the beam for long distance transport. IPROP simulations are in progress to optimize the design of the ballistic and self-pinched transport sections. Progress on preparation of this lithium self-pinched transport experiment, including a discussion of transport system design, important gas breakdown issues, and diagnostics, will be presented

  7. Action at sea: Transport security exercise conducted off the coast of Sweden

    International Nuclear Information System (INIS)

    Isaksson, Stig; Jawerth, Nicole

    2015-01-01

    As in an action movie, ships, helicopters and uniformed people set the scene off the coast of Sweden on 6 May 2015 when national authorities conducted an exercise on security while transporting spent nuclear fuel. The exercise was part of a joint project with the IAEA to test and evaluate a new IAEA guide on planning, conducting and evaluating transport security exercises. The test subject and model was the security framework of Sweden’s national nuclear transport system, which regularly ships used fuel from power plants along the coast to the country’s interim storage facility for spent nuclear fuel.

  8. Imaging and controlling intracellular reactions: Lysosome transport as a function of diameter and the intracellular synthesis of conducting polymers

    Science.gov (United States)

    Payne, Christine

    2014-03-01

    Eukaryotic cells are the ultimate complex environment with intracellular chemical reactions regulated by the local cellular environment. For example, reactants are sequestered into specific organelles to control local concentration and pH, motor proteins transport reactants within the cell, and intracellular vesicles undergo fusion to bring reactants together. Current research in the Payne Lab in the School of Chemistry and Biochemistry at Georgia Tech is aimed at understanding and utilizing this complex environment to control intracellular chemical reactions. This will be illustrated using two examples, intracellular transport as a function of organelle diameter and the intracellular synthesis of conducting polymers. Using single particle tracking fluorescence microscopy, we measured the intracellular transport of lysosomes, membrane-bound organelles, as a function of diameter as they underwent transport in living cells. Both ATP-dependent active transport and diffusion were examined. As expected, diffusion scales with the diameter of the lysosome. However, active transport is unaffected suggesting that motor proteins are insensitive to cytosolic drag. In a second example, we utilize intracellular complexity, specifically the distinct micro-environments of different organelles, to carry out chemical reactions. We show that catalase, found in the peroxisomes of cells, can be used to catalyze the polymerization of the conducting polymer PEDOT:PSS. More importantly, we have found that a range of iron-containing biomolecules are suitable catalysts with different iron-containing biomolecules leading to different polymer properties. These experiments illustrate the advantage of intracellular complexity for the synthesis of novel materials.

  9. Tunable electronic transport properties of silicon-fullerene-linked nanowires: Semiconductor, conducting wire, and tunnel diode

    OpenAIRE

    Nishio, Kengo; Ozaki, Taisuke; Morishita, Tetsuya; Mikami, Masuhiro

    2010-01-01

    We explore the possibility of controllable tuning of the electronic transport properties of silicon-fullerene-linked nanowires by encapsulating guest atoms into their cages. Our first-principles calculations demonstrate that the guest-free nanowires are semiconductors, and do not conduct electricity. The iodine or sodium doping improves the transport properties, and makes the nanowires metallic. In the junctions of I-doped and Na-doped NWs, the current travels through the boundary by quantum ...

  10. Quadrupole transport experiment with space charge dominated cesium ion beam

    International Nuclear Information System (INIS)

    Faltens, A.; Keefe, D.; Kim, C.; Rosenblum, S.; Tiefenback, M.; Warwick, A.

    1984-08-01

    The purpose of the experiment is to investigate the beam current transport limit in a long quadrupole-focussed transport channel in the space charge dominated region where the space charge defocussing force is almost as large as the average focussing force of the channel

  11. How to Conduct Clinical Qualitative Research on the Patient's Experience

    Science.gov (United States)

    Chenail, Ronald J.

    2011-01-01

    From a perspective of patient-centered healthcare, exploring patients' (a) preconceptions, (b) treatment experiences, (c) quality of life, (d) satisfaction, (e) illness understandings, and (f) design are all critical components in improving primary health care and research. Utilizing qualitative approaches to discover patients' experiences can…

  12. Charge Transport in Metal-Molecule-Metal Junctions Probed by Conducting Atomic Force Microscopy

    International Nuclear Information System (INIS)

    Lee, Min Hyung; Song, Hyunwook

    2013-01-01

    We have demonstrated a proof of intrinsic charge transport properties in alkanedithiol molecular junctions using a multiprobe approach combining a variety of transport techniques. The temperature-independent I(V) behavior and the correct exponential decay of conductance with respect to molecular length shows that the dominant charge transport mechanism is off-resonant tunneling. Length-dependent TVS measurements for the saturated alkane-dithiol series indicate that we did indeed probe a molecular system with CAFM. These results can provide stringent criteria to establish a valid molecular transport junction via a probabilistic measurement technique. In this study, we report a study of charge transport in alkanedithiol SAMs formed in metal-molecule-metal junctions using CAFM in combination with a variety of molecular transport techniques including temperature-and length-variable transport measurements and transition voltage spectroscopy. The main goal of this study is to probe the intrinsic transport properties of component molecules using CAFM, but not parasitic or defect-related effects

  13. 30 years of experience in safe transportation of nuclear materials

    International Nuclear Information System (INIS)

    Kaneko, K.

    2004-01-01

    In April 2003, Nuclear Fuel Transport Co., Ltd. (NFT) marked the 30 th anniversary of its founding. NFT was established in 1973 and in 1978, commenced SF transport to the reprocessing plant in Tokai-mura. And then, after making preparations to transport nuclear materials to the various facilities at the Nuclear Fuel Cycle Center in Rokkasho-mura, NFT successfully started transportation of LLW (low level waste) to Rokksho-mura's LLW disposal center in 1992, domestic land transportation of HLW returned from overseas to the HLW storage center in 1995, domestic land transportation of natural hexafluoride delivered from overseas to the uranium enrichment plant in 1996, and transportation of SF to the reprocessing plant in 2000. NFT has realized an annual SF transportation capacity of 300 MTU and is currently making great company wide efforts to meet the Rokkasho Reprocessing Plant's future SF annual reprocessing capacity of 800MTU. At the end of FY2003, NFT had successfully transported 560 casks (about 1,730 MTU) of SF in more than 200 voyages in total, about 160,000 drums of LLW in around 100 voyages in total. This paper introduces the record of safe transport and its experience over the past 30 years and prospect for future transport business

  14. Spent fuel and HLW transportation the French experience

    International Nuclear Information System (INIS)

    Giraud, J.P.; Charles, J.L.

    1995-01-01

    With 53 nuclear power plants in operation at EDF and a fuel cycle with recycling policy of the valuable materials, COGEMA is faced with the transport of a wide range of radioactive materials. In this framework, the transport activity is a key link in closing the fuel cycle. COGEMA has developed a comprehensive Transport Organization System dealing with all the sectors of the fuel cycle. The paper will describe the status of transportation of spent fuel and HLW in France and the experience gathered. The Transport Organization System clearly defines the role of all actors where COGEMA, acting as the general coordinator, specifies the tasks to be performed and brings technical and commercial support to its various subcontractors: TRANSNUCLEAIRE, specialized in casks engineering and transport operations, supplies packaging and performs transport operations, LEMARECHAL and CELESTIN operate transport by truck in the Vicinity of the nuclear sites while French Railways are in charge of spent fuel transport by train. HLW issued from the French nuclear program is stored for 30 years in an intermediate storage installation located at the La Hague reprocessing plant. Ultimately, these canisters will be transported to the disposal site. COGEMA has set up a comprehensive transport organization covering all operational aspects including adapted procedures, maintenance programs and personnel qualification

  15. 30 years of experience in safe transportation of nuclear materials

    Energy Technology Data Exchange (ETDEWEB)

    Kaneko, K. [Nuclear Fuel Transport Co., Ltd., Tokyo (Japan)

    2004-07-01

    In April 2003, Nuclear Fuel Transport Co., Ltd. (NFT) marked the 30{sup th} anniversary of its founding. NFT was established in 1973 and in 1978, commenced SF transport to the reprocessing plant in Tokai-mura. And then, after making preparations to transport nuclear materials to the various facilities at the Nuclear Fuel Cycle Center in Rokkasho-mura, NFT successfully started transportation of LLW (low level waste) to Rokksho-mura's LLW disposal center in 1992, domestic land transportation of HLW returned from overseas to the HLW storage center in 1995, domestic land transportation of natural hexafluoride delivered from overseas to the uranium enrichment plant in 1996, and transportation of SF to the reprocessing plant in 2000. NFT has realized an annual SF transportation capacity of 300 MTU and is currently making great company wide efforts to meet the Rokkasho Reprocessing Plant's future SF annual reprocessing capacity of 800MTU. At the end of FY2003, NFT had successfully transported 560 casks (about 1,730 MTU) of SF in more than 200 voyages in total, about 160,000 drums of LLW in around 100 voyages in total. This paper introduces the record of safe transport and its experience over the past 30 years and prospect for future transport business.

  16. JET internal transport barriers: experiment vs theory

    Energy Technology Data Exchange (ETDEWEB)

    Esposito, B [Associazione Euratom - ENEA sulla Fusione, C.R. Frascati, CP 65, I-00040, Frascati, Rome (Italy); Crisanti, F [Associazione Euratom - ENEA sulla Fusione, C.R. Frascati, CP 65, I-00040, Frascati, Rome (Italy); Parail, V [Euratom/UKAEA Fusion Association, Cuhlam Science Centre, Abingdon, Oxon OX14 3DB (United Kingdom); Maget, P [Association Euratom - CEA pour la Fusion, CEA Cadarache, F-13108 Saint Paul-lez-Durance Cedex (France); Baranov, Y [Euratom/UKAEA Fusion Association, Cuhlam Science Centre, Abingdon, Oxon OX14 3DB (United Kingdom); Becoulet, A [Association Euratom - CEA pour la Fusion, CEA Cadarache, F-13108 Saint Paul-lez-Durance Cedex (France); Castaldo, C [Associazione Euratom - ENEA sulla Fusione, C.R. Frascati, CP 65, I-00040, Frascati, Rome (Italy); Challis, C D [Euratom/UKAEA Fusion Association, Cuhlam Science Centre, Abingdon, Oxon OX14 3DB (United Kingdom); Angelis, R De [Associazione Euratom - ENEA sulla Fusione, C.R. Frascati, CP 65, I-00040, Frascati, Rome (Italy); Garbet, X [Association Euratom - CEA pour la Fusion, CEA Cadarache, F-13108 Saint Paul-lez-Durance Cedex (France); Giroud, C [Association Euratom - CEA pour la Fusion, CEA Cadarache, F-13108 Saint Paul-lez-Durance Cedex (France); Hawkes, N [Euratom/UKAEA Fusion Association, Cuhlam Science Centre, Abingdon, Oxon OX14 3DB (United Kingdom); Joffrin, E [Association Euratom - CEA pour la Fusion, CEA Cadarache, F-13108 Saint Paul-lez-Durance Cedex (France); Litaudon, X [Association Euratom - CEA pour la Fusion, CEA Cadarache, F-13108 Saint Paul-lez-Durance Cedex (France); Mazon, D [Association Euratom - CEA pour la Fusion, CEA Cadarache, F-13108 Saint Paul-lez-Durance Cedex (France); Riva, M [Associazione Euratom - ENEA sulla Fusione, C.R. Frascati, CP 65, I-00040, Frascati, Rome (Italy); Zastrow, K D [Euratom/UKAEA Fusion Association, Cuhlam Science Centre, Abingdon, Oxon OX14 3DB (United Kingdom)

    2003-06-01

    A large variety of JET discharges with internal transport barriers (ITBs) has been analysed in order to determine the main features which characterize turbulence stabilization at the barrier. It is found that the location of barriers is well correlated with regions where the ExB flow shearing rate exceeds the linear growth rate of the ion temperature gradient mode instability ({gamma}{sub {eta}{sub i}}). A key point is the dependence of {gamma}{sub {eta}{sub i}} on the magnetic shear: in the discharges of this database the reduction of {gamma}{sub {eta}{sub i}} associated to very low or null magnetic shear favours the formation of an ITB. After the ITB formation a positive feedback occurs in which the ExB flow shear mechanism has the leading role and the position of the barrier may be no longer linked to the low shear region.

  17. Transport simulations of ohmic ignition experiment: IGNITEX

    International Nuclear Information System (INIS)

    Uckan, N.A.; Howe, H.C.

    1987-01-01

    The IGNITEX device, proposed by Rosenbluth et al., is a compact, super-high-field, high-current, copper-coil tokamak envisioned to reach ignition with ohmic (OH) heating alone. Several simulations of IGNITEX were made with a 0-D global model and with the 1-D PROCTR transport code. It is shown that OH ignition is a sensitive function of the assumptions about density profile, wall reflectivity of synchrotron radiation, impurity radiation, plasma edge conditions, and additional anomalous losses. In IGNITEX, OH ignition is accessible with nearly all scalings based on favorable OH confinement (such as neo-Alcator). Also, OH ignition appears to be accessible for most (not all) L-mode scalings (such as Kaye-Goldston), provided that the density profile is not too broad (parabolic or more peaked profiles are needed), Z/sub eff/ is not too large (≤2), and anomalous radiation and alpha losses and/or other enhanced transport losses (/eta//sub i/ modes, edge convective energy losses, etc.) are not present. In IGNITEX, because the figure-of-merit parameters (aB 0 2 /q* /approximately/ IB 0 , etc.) are large, ignition can be accessed (either with OH heating alone or with the aid of a small amount of auxiliary power) at relatively low beta, far from stability limits. Once the plasma is ignited, thermal runaway is prevented naturally by a combination of increased synchrotron radiation, burnout of the fuel in the plasma core and replacement by thermal alphas, and the reduction in the thermal plasma confinement assumed in L-mode-like scalings. 12 refs., 5 figs., 1 tab

  18. Transport simulations of ohmic ignition experiment: IGNITEX

    International Nuclear Information System (INIS)

    Uckan, N.A.; Howe, H.C.

    1987-12-01

    The IGNITEX device, proposed by Rosenbluth et al., is a compact, super-high-field, high-current, copper-coil tokamak envisioned to reach ignition with ohmic (OH) heating alone. Several simulations of IGNITEX were made with a 0-D global model and with the 1-D PROCTR transport code. It is shown that OH ignition is a sensitive function of the assumptions about density profile, wall reflectivity of synchrotron radiation, impurity radiation, plasma edge conditions, and additional anomalous losses. In IGNITEX, OH ignition is accessible with nearly all scalings based on favorable OH confinement (such as neo-Alcator). Also, OH ignition appears to be accessible for most (not all) L-mode scalings (such as Kaye-Goldston), provided that the density profile is not too broad (parabolic or more peaked profiles are needed), Z/sub eff/ is not too large, and anomalous radiation and alpha losses and/or other enhanced transport losses (eta/sub i/ modes, edge convective energy losses, etc.) are not present. In IGNITEX, because the figure-of-merit parameters are large, ignition can be accessed (either with OH heating alone or with the aid of a small amount of auxiliary power) at relatively low beta, far from stability limits. Once the plasma is ignited, thermal runaway is prevented naturally by a combination of increased synchrotron radiation, burnout of the fuel in the plasma core and replacement by thermal alphas, and the reduction in the thermal plasma confinement assumed in L-mode-like scalings. 12 refs., 5 figs., 1 tab

  19. Experience feedback from the transportation of Framatome fuel assemblies

    International Nuclear Information System (INIS)

    Robin, M.E.; Gaillard, G.; Aubin, C.

    1998-01-01

    Framatome, the foremost world nuclear fuel manufacturer, has for 25 years been delivering fuel elements from its three factories (Dessel, Romans, Pierrelatte) to the various sites in France and abroad (Germany, Sweden, Belgium, China, Korea, South Africa, Switzerland). During this period, Framatome has built up experience and expertise in fuel element transportation by road, rail and sea. In this filed, the range of constraints is very wide: safety and environmental protection constraints; constraints arising from the control and protection of nuclear materials, contractual and financial constraints, media watchdogs. Through the experience feedback from the transportation of FRAMATOME assemblies, this paper addresses all the phases in the transportation of fresh fuel assemblies. (authors)

  20. DOE's foreign research reactor transportation services contract: Perspective and experience

    International Nuclear Information System (INIS)

    Patterson, John

    1997-01-01

    DOE committed to low- and moderate-income countries participating in the foreign research reactor spent fuel returns program that the United States government would provide for the transportation of the spent fuel. In fulfillment of that commitment, DOE entered into transportation services contracts with qualified, private-sector firms. NAC will discuss its experience as a transportation services provider, including range of services available to the foreign reactors, advantages to DOE and to the foreign research reactors, access to contract services by high income countries and potential advantages, and experience with initial tasks performed under the contract. (author)

  1. Colloid Facilitated Transport of Radioactive Cations in the Vadose Zone: Field Experiments Oak Ridge

    Energy Technology Data Exchange (ETDEWEB)

    James E. Saiers

    2012-09-20

    The overarching goal of this study was to improve understanding of colloid-facilitated transport of radioactive cations through unsaturated soils and sediments. We conducted a suite of laboratory experiments and field experiments on the vadose-zone transport of colloids, organic matter, and associated contaminants of interest to the U.S. Department of Energy (DOE). The laboratory and field experiments, together with transport modeling, were designed to accomplish the following detailed objectives: 1. Evaluation of the relative importance of inorganic colloids and organic matter to the facilitation of radioactive cation transport in the vadose zone; 2. Assessment of the role of adsorption and desorption kinetics in the facilitated transport of radioactive cations in the vadose zone; 3. Examination of the effects of rainfall and infiltration dynamics and in the facilitated transport of radioactive cations through the vadose zone; 4. Exploration of the role of soil heterogeneity and preferential flow paths (e.g., macropores) on the facilitated transport of radioactive cations in the vadose zone; 5. Development of a mathematical model of facilitated transport of contaminants in the vadose zone that accurately incorporates pore-scale and column-scale processes with the practicality of predicting transport with readily available parameters.

  2. Development and Testing of a Variable Conductance Thermal Acquisition, Transport, and Switching System

    Science.gov (United States)

    Bugby, David C.; Farmer, Jeffery T.; Stouffer, Charles J.

    2013-01-01

    This paper describes the development and testing of a scalable thermal management architecture for instruments, subsystems, or systems that must operate in severe space environments with wide variations in sink temperature. The architecture involves a serial linkage of one or more hot-side variable conductance heat pipes (VCHPs) to one or more cold-side loop heat pipes (LHPs). The VCHPs provide wide area heat acquisition, limited distance thermal transport, modest against gravity pumping, concentrated LHP startup heating, and high switching ratio variable conductance operation. The LHPs provide localized heat acquisition, long distance thermal transport, significant against gravity pumping, and high switching ratio variable conductance operation. The single-VCHP, single-LHP system described herein was developed to maintain thermal control of a small robotic lunar lander throughout the lunar day-night thermal cycle. It is also applicable to other variable heat rejection space missions in severe environments. Operationally, despite a 60-70% gas blocked VCHP condenser during ON testing, the system was still able to provide 2-4 W/K ON conductance, 0.01 W/K OFF conductance, and an end-to-end switching ratio of 200-400. The paper provides a detailed analysis of VCHP condenser performance, which quantified the gas blockage situation. Future multi-VCHP/multi-LHP thermal management system concepts that provide power/transport length scalability are also discussed.

  3. Conductivity equations of protons transporting through 2D crystals obtained with the rate process theory and free volume concept

    Science.gov (United States)

    Hao, Tian; Xu, Yuanze; Hao, Ting

    2018-04-01

    The Eyring's rate process theory and free volume concept are employed to treat protons (or other particles) transporting through a 2D (two dimensional) crystal like graphene and hexagonal boron nitride. The protons are assumed to be activated first in order to participate conduction and the conduction rate is dependent on how much free volume available in the system. The obtained proton conductivity equations show that only the number of conduction protons, proton size and packing structure, and the energy barrier associated with 2D crystals are critical; the quantization conductance is unexpectedly predicted with a simple Arrhenius type temperature dependence. The predictions agree well with experimental observations and clear out many puzzles like much smaller energy barrier determined from experiments than from the density function calculations and isotope separation rate independent of the energy barrier of 2D crystals, etc. Our work may deepen our understandings on how protons transport through a membrane and has direct implications on hydrogen related technology and proton involved bioprocesses.

  4. Mini-columns for Conducting Breakthrough Experiments. Design and Construction

    Energy Technology Data Exchange (ETDEWEB)

    Dittrich, Timothy M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Reimus, Paul William [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Ware, Stuart Douglas [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-06-11

    Experiments with moderately and strongly sorbing radionuclides (i.e., U, Cs, Am) have shown that sorption between experimental solutions and traditional column materials must be accounted for to accurately determine stationary phase or porous media sorption properties (i.e., sorption site density, sorption site reaction rate coefficients, and partition coefficients or Kd values). This report details the materials and construction of mini-columns for use in breakthrough columns to allow for accurate measurement and modeling of sorption parameters. Material selection, construction techniques, wet packing of columns, tubing connections, and lessons learned are addressed.

  5. Two decades' experience with interfacility transport on extracorporeal membrane oxygenation.

    Science.gov (United States)

    Bryner, Benjamin; Cooley, Elaine; Copenhaver, William; Brierley, Kristin; Teman, Nicholas; Landis, Denise; Rycus, Peter; Hemmila, Mark; Napolitano, Lena M; Haft, Jonathan; Park, Pauline K; Bartlett, Robert H

    2014-10-01

    Interfacility transport of patients on extracorporeal membrane oxygenation (ECMO) has been performed in large numbers at only a few programs. Limited data are available on outcomes after ECMO transport to justify expanding or discontinuing these programs. This was a retrospective review of a 20-year, single-institution experience with interhospital ECMO transport as well as a systematic review of reports of transfers of patients on ECMO. Results of both were compared with historical data from the international registry of the Extracorporeal Life Support Organization (ELSO). Between 1990 and 2012, ECMO was used to facilitate transport of 221 patients to our institution, and 135 (62%) survived to discharge. Review of an additional 27 case series describing ECMO transport of 643 patients showed an overall survival of 61%. After stratifying by age and primary indication for ECMO, survival of transported patients was not significantly different compared with all ECMO patients in the ELSO registry, with the exception of pediatric patients treated for respiratory failure (transported patients in this category had higher survival than those in the ELSO registry). Interfacility transport on ECMO is feasible and can be accomplished safely in the critically ill. Survival of transported patients is comparable to age-matched and treatment-matched ECMO patients at large. Copyright © 2014 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

  6. Bentonite electrical conductivity: a model based on series–parallel transport

    KAUST Repository

    Lima, Ana T.

    2010-01-30

    Bentonite has significant applications nowadays, among them as landfill liners, in concrete industry as a repairing material, and as drilling mud in oil well construction. The application of an electric field to such perimeters is under wide discussion, and subject of many studies. However, to understand the behaviour of such an expansive and plastic material under the influence of an electric field, the perception of its electrical properties is essential. This work serves to compare existing data of such electrical behaviour with new laboratorial results. Electrical conductivity is a pertinent parameter since it indicates how much a material is prone to conduct electricity. In the current study, total conductivity of a compacted porous medium was established to be dependent upon density of the bentonite plug. Therefore, surface conductivity was addressed and a series-parallel transport model used to quantify/predict the total conductivity of the system. © The Author(s) 2010.

  7. Conducting organizational safety reviews - requirements, methods and experience

    International Nuclear Information System (INIS)

    Reiman, T.; Oedewald, P.; Wahlstroem, B.; Rollenhagen, C.; Kahlbom, U.

    2008-03-01

    Organizational safety reviews are part of the safety management process of power plants. They are typically performed after major reorganizations, significant incidents or according to specified review programs. Organizational reviews can also be a part of a benchmarking between organizations that aims to improve work practices. Thus, they are important instruments in proactive safety management and safety culture. Most methods that have been used for organizational reviews are based more on practical considerations than a sound scientific theory of how various organizational or technical issues influence safety. Review practices and methods also vary considerably. The objective of this research is to promote understanding on approaches used in organizational safety reviews as well as to initiate discussion on criteria and methods of organizational assessment. The research identified a set of issues that need to be taken into account when planning and conducting organizational safety reviews. Examples of the issues are definition of appropriate criteria for evaluation, the expertise needed in the assessment and the organizational motivation for conducting the assessment. The study indicates that organizational safety assessments involve plenty of issues and situations where choices have to be made regarding what is considered valid information and a balance has to be struck between focus on various organizational phenomena. It is very important that these choices are based on a sound theoretical framework and that these choices can later be evaluated together with the assessment findings. The research concludes that at its best, the organizational safety reviews can be utilised as a source of information concerning the changing vulnerabilities and the actual safety performance of the organization. In order to do this, certain basic organizational phenomena and assessment issues have to be acknowledged and considered. The research concludes with recommendations on

  8. Conducting organizational safety reviews - requirements, methods and experience

    Energy Technology Data Exchange (ETDEWEB)

    Reiman, T.; Oedewald, P.; Wahlstroem, B. [Technical Research Centre of Finland, VTT (Finland); Rollenhagen, C. [Royal Institute of Technology, KTH, (Sweden); Kahlbom, U. [RiskPilot (Sweden)

    2008-03-15

    Organizational safety reviews are part of the safety management process of power plants. They are typically performed after major reorganizations, significant incidents or according to specified review programs. Organizational reviews can also be a part of a benchmarking between organizations that aims to improve work practices. Thus, they are important instruments in proactive safety management and safety culture. Most methods that have been used for organizational reviews are based more on practical considerations than a sound scientific theory of how various organizational or technical issues influence safety. Review practices and methods also vary considerably. The objective of this research is to promote understanding on approaches used in organizational safety reviews as well as to initiate discussion on criteria and methods of organizational assessment. The research identified a set of issues that need to be taken into account when planning and conducting organizational safety reviews. Examples of the issues are definition of appropriate criteria for evaluation, the expertise needed in the assessment and the organizational motivation for conducting the assessment. The study indicates that organizational safety assessments involve plenty of issues and situations where choices have to be made regarding what is considered valid information and a balance has to be struck between focus on various organizational phenomena. It is very important that these choices are based on a sound theoretical framework and that these choices can later be evaluated together with the assessment findings. The research concludes that at its best, the organizational safety reviews can be utilised as a source of information concerning the changing vulnerabilities and the actual safety performance of the organization. In order to do this, certain basic organizational phenomena and assessment issues have to be acknowledged and considered. The research concludes with recommendations on

  9. Recent experiences and problems in conducting pressure vessel surveillance examinations

    International Nuclear Information System (INIS)

    Perrin, J.S.

    1979-01-01

    Each of the commercial power reactors in the U.S.A. has a pressure vessel surveillance program. The purpose of the programs is to monitor the effects of radiation on the mechanical properties on the steel pressure vessels. A program for a given reactor includes a series of irradiation capsules containing neutron dosimeters and mechanical property specimens. The capsules are periodically removed during the life of the reactor and evaluated. The surveillance capsule examinations conducted to date have been valuable in assessing the effects of radiation on pressure vessels. However, a number of problems have been observed in the course of capsule examinations which potentially could reduce the maximum value of the data obtained. These problems are related to specimen design and preparation, capsule design and preparation, capsule installation and removal, capsule disassembly, specimen testing and evaluation, program documentation, and quality assurance. Examples of problems encountered in the preceding areas are presented in the present paper, and recommendations are made for minimization or prevention of these problems in future programs. Included in the recommendations is that appropriate ASTM standards, ASME Boiler and Pressure Vessel Code sections, and NRC regulations provide the appropriate framework for prevention of problems

  10. Carrier mediated transport through supported liquid membranes; determination of transport parameters from a single transport experiment

    NARCIS (Netherlands)

    Chrisstoffels, L.A.J.; Struijk, Wilhelmina; de Jong, Feike; Reinhoudt, David

    1996-01-01

    This paper describes a time-dependent transport model for carrier assisted cation transport through supported liquid membranes. The model describes the flux of salt as a function of time and two parameters viz. the diffusion coefficient of the cation complex (D), and the extraction constant (Kex).

  11. Conventional transport fuels quality and ATF : recent Asian experience

    Energy Technology Data Exchange (ETDEWEB)

    Desbiens, R. [Consultec, Montreal, PQ (Canada)

    2002-07-01

    The experience gained in Manila, Philippines, with regard to transport fuels, was discussed during this presentation. It is estimated that 70 to 80 per cent of air pollution in the city of Manila is generated by vehicular traffic. Diesel-fueled vehicles operate all hours of the day, and motorized tricycles powered by a two-stroke engine, are cause for concern for local authorities. Several factors play a role in the problems experienced: vehicle ownership, poor air, congestion and noise in urban areas, poor transport infrastructure, coupled with policy problems such as fuel and vehicle quality standards, poor monitoring, ancient technologies, etc. The motorization of cities was examined, and special emphasis was places on the situation in Asia. The situation in China was looked at, where approximately 15 million automobiles are in use, with an annual increase of 11 to 13 per cent. The air pollution caused by motor vehicles in China was discussed, and new vehicle emission standards for China were presented. The issue of fuel injection systems for motorcycles in China was discussed, and the author mentioned that cost and reliability problems require further improvement. The use of compressed natural gas vehicles in Beijing was looked at, and some of the barriers are lack of public awareness, capital shortages, high price of natural gas, and shortage of advanced technologies. A feasibility study for the introduction of compressed natural gas vehicles in Beijing was conducted and the main findings presented. Public transport management in Hong Kong was reviewed, including the use of alternative environmentally friendly vehicles and fuel. A look at India, and specifically Delhi, was presented. The norms concerning vehicle emissions in India were briefly reviewed, followed by fuel quality improvements, and compressed natural gas vehicles. The author then discussed alternative fuels in Korea and the country's compressed natural gas bus promotion policy. The next

  12. Ruthenium transport experiments in air ingress accident conditions

    Energy Technology Data Exchange (ETDEWEB)

    Teemu, Karkele; Ulrika, Backman; Ari, Auvinen; Unto, Tapper; Jorma, Jokiniemi [VTT Technical Research Centre of Finland, Fine Particles (Finland); Riitta, Zilliacus; Maija, Lipponen; Tommi, Kekki [VTT Technical Research Centre of Finland, Accident Management (Finland); Jorma, Jokiniemi [Kuopio Univ., Dept. of Environmental Sciences, Fine Particle and Aerosol Technology Lab. (Finland)

    2007-07-01

    In this study the release, transport and speciation of ruthenium in conditions simulating an air ingress accident was studied. Ruthenium dioxide was exposed to oxidising environment at high temperature (1100-1700 K) in a tubular flow furnace. At these conditions volatile ruthenium species were formed. A large fraction of the released ruthenium was deposited in the tube as RuO{sub 2}. Depending on the experimental conditions 1-26 wt% of the released ruthenium was trapped in the outlet filter as RuO{sub 2} particles. In stainless steel tube 0-8.8 wt% of the released ruthenium reached the trapping bottle as gaseous RuO{sub 4}. A few experiments were carried out, in which revaporization of ruthenium deposited on the tube walls was studied. In these experiments, oxidation of RuO{sub 2} took place at a lower temperature. During revaporization experiments 35-65 % of ruthenium was transported as gaseous RuO{sub 4}. In order to close mass balance and achieve better time resolution 4 experiments were carried out using a radioactive tracer. In these experiments ruthenium profiles were measured. These experiments showed that the most important retention mechanism was decomposition of gaseous RuO{sub 3} into RuO{sub 2} as the temperature of the furnace was decreasing. In these experiments the transport rate of gaseous ruthenium was decreasing while the release rate was constant.

  13. UrbanTransport Solution An Experience From Prague | Jeremiah ...

    African Journals Online (AJOL)

    This paper examines the urban transport problems in Prague in Czech Republic. Based on the result of the research conducted, it was found that with the collapsed of Communism in Czech Republic, there was an upsurge in the use of private cars which was not possible during communism because the law does not ...

  14. Conducting Closed Habitation Experiments: Experience from the Lunar Mars Life Support Test Project

    Science.gov (United States)

    Barta, Daniel J.; Edeen, Marybeth A.; Henninger, Donald L.

    2006-01-01

    The Lunar-Mars Life Support Test Project (LMLSTP) was conducted from 1995 through 1997 at the National Aeronautics and Space Administration s (NASA) Johnson Space Center (JSC) to demonstrate increasingly longer duration operation of integrated, closed-loop life support systems that employed biological and physicochemical techniques for water recycling, waste processing, air revitalization, thermal control, and food production. An analog environment for long-duration human space travel, the conditions of isolation and confinement also enabled studies of human factors, medical sciences (both physiology and psychology) and crew training. Four tests were conducted, Phases I, II, IIa and III, with durations of 15, 30, 60 and 91 days, respectively. The first phase focused on biological air regeneration, using wheat to generate enough oxygen for one experimental subject. The systems demonstrated in the later phases were increasingly complex and interdependent, and provided life support for four crew members. The tests were conducted using two human-rated, atmospherically-closed test chambers, the Variable Pressure Growth Chamber (VPGC) and the Integrated Life Support Systems Test Facility (ILSSTF). Systems included test articles (the life support hardware under evaluation), human accommodations (living quarters, kitchen, exercise equipment, etc.) and facility systems (emergency matrix system, power, cooling, etc.). The test team was managed by a lead engineer and a test director, and included test article engineers responsible for specific systems, subsystems or test articles, test conductors, facility engineers, chamber operators and engineering technicians, medical and safety officers, and science experimenters. A crew selection committee, comprised of psychologists, engineers and managers involved in the test, evaluated male and female volunteers who applied to be test subjects. Selection was based on the skills mix anticipated for each particular test, and utilized

  15. The French nuclear safety authority's experience with radioactive transport inspection

    International Nuclear Information System (INIS)

    Jacob, E.; Aguilar, J.

    2004-01-01

    About 300,000 radioactive material packages are transported annually in France. Most consist of radioisotopes for medical, pharmaceutical or industrial use. On the other hand, the nuclear industry deals with the transport of fuel cycle materials (uranium, fuel assemblies, etc.) and waste from power plants, reprocessing plants and research centers. France is also a transit country for shipments such as spent fuel packages from Switzerland or Germany, which are bound for Sellafield in Great Britain. The French nuclear safety authority (DGSNR: Directorate General for Nuclear Safety and Radioprotection) has been responsible since 1997 for the safety of radioactive material transport. This paper presents DGNSR's experience with transport inspection: a feedback of key points based on 300 inspections achieved during the past five years is given

  16. My Experience. My Perspective. Transportation to Work Presents Problems

    Science.gov (United States)

    Stegers, Markus

    2008-01-01

    Transportation challenges can often be one of the biggest stumbling blocks to having a successful vocational experience. The author presents a personal account of the difficulties people with disabilities encounter in trying to get themselves to their workplaces due to the limitations of various mobility services.

  17. Roles and significance of water conducting features for transport models in performance assessment

    International Nuclear Information System (INIS)

    Carrera, J.; Sanchez-Vila, X.; Medina, A.

    1999-01-01

    The term water conducting features (WCF) refers to zones of high hydraulic conductivity. In the context of waste disposal, it is further implied that they are narrow so that chances of sampling them are low. Yet, they may carry significant amounts of water. Moreover, their relatively small volumetric water content causes solutes to travel fast through them. Water-conducting features are a rather common feature of natural media. The fact that they have become a source of concern in recent years, reflects more the increased level of testing and monitoring than any intrinsic property of low permeability media. Accurate simulations of solute transport require a realistic accounting for water conducting features. Methods are presented to do so and examples are shown to illustrate these methods. Since detailed accounting of WCF's will not be possible in actual performance assessments, efforts should be directed towards typification, so as to identify the essential effects of WCF's on solute transport through different types of rocks. Field evidence suggests that, although individual WCF's may be difficult to characterize, their effects are quite predictable. (author)

  18. Transport and dielectric studies on silver based molybdo-tungstate quaternary superionic conducting glasses

    International Nuclear Information System (INIS)

    Prasad, P.S.S.; Radhakrishna, S.

    1988-01-01

    The molybdo-tungstate (MoO 3 -WO 3 ) combination of glass formers with silver oxide (Ag 2 O) as glass modifier and silver iodide (AgI) as ionic conductor were prepared to study the transport and dielectric properties of 60% AgI-40% (x Ag 2 O-y(WO 3 -MoO 3 )) for x/y=0.33 to 3.0 and establish the feasibility of using these glasses as electrolytes in the fabrication and characterisation of solid state batteries and potential memory devices. The details of the preparation of glasses and methods of measurement of their capacitance, dielectric loss factor and ac conductivity in the frequency range 100 Hz - 100 kHz from 30-120 C have been reported. The electronic contribution to the total conductivity, the ionic and electronic transport numbers were determined using Wagners dc polarisation technique. The observed high ionic and low electronic conductivities were attributed to the formation of ionic clusters in the glass and the effect of mixing two glass formers. The observed total ionic conductivity and its temperature dependence was explained using Arrhenius relation σ=σ 0 /T exp(-E/RT) and the measured dielectric constant and dielectric loss were explained on the basis of Jonschers theory. The frequency dependence of dielectric constant obeys the theory based on the polarisation of ions. 25 refs.; 8 figs

  19. Mass transport in fracture media: impact of the random function model assumed for fractures conductivity

    International Nuclear Information System (INIS)

    Capilla, J. E.; Rodrigo, J.; Gomez Hernandez, J. J.

    2003-01-01

    Characterizing the uncertainty of flow and mass transport models requires the definition of stochastic models to describe hydrodynamic parameters. Porosity and hydraulic conductivity (K) are two of these parameters that exhibit a high degree of spatial variability. K is usually the parameter whose variability influence to a more extended degree solutes movement. In fracture media, it is critical to properly characterize K in the most altered zones where flow and solutes migration tends to be concentrated. However, K measurements use to be scarce and sparse. This fact calls to consider stochastic models that allow quantifying the uncertainty of flow and mass transport predictions. This paper presents a convective transport problem solved in a 3D block of fractured crystalline rock. the case study is defined based on data from a real geological formation. As the scarcity of K data in fractures does not allow supporting classical multi Gaussian assumptions for K in fractures, the non multi Gaussian hypothesis has been explored, comparing mass transport results for alternative Gaussian and non-Gaussian assumptions. The latter hypothesis allows reproducing high spatial connectivity for extreme values of K. This feature is present in nature, might lead to reproduce faster solute pathways, and therefore should be modeled in order to obtain reasonably safe prediction of contaminants migration in a geological formation. The results obtained for the two alternative hypotheses show a remarkable impact of the K random function model in solutes movement. (Author) 9 refs

  20. Transport and solid state battery characteristic studies of silver based super ion conducting glasses

    International Nuclear Information System (INIS)

    Jayaseelan, S.; Muralidharan, P.; Venkateswarlu, M.; Satyanarayana, N.

    2005-01-01

    Silverarsenotellurite (SAT), silverphosphotellurite (SPT) and silvervanadotellurite (SVT) quaternary glass systems were prepared with various formers compositions by a melt quenching method. Glass nature, glass transition temperature (T g ) and structure of the prepared glasses were identified respectively by X-ray diffraction (XRD), differential scanning calorimetric (DSC) and Fourier transform infrared (FT-IR) technique. Electrical conductivity studies were carried out by impedance measurement in the frequency range 40 Hz to 100 KHz at different temperatures for all three sets of AgI-Ag 2 O-[TeO 2 -M 2 O 5 ] (M 2 O 5 = As 2 O 5 , P 2 O 5 , V 2 O 5 ) glasses. The high conducting compositions of SAT, SPT and SVT glass samples were fixed from the results of total conductivity (σ t ). Electronic conductivity (σ e ) studies were made on high conducting composition of each glass system by Wagner's polarization method. Total current (i t ) is due to ion and electron. Electronic current (i e ) due to electron were estimated through mobility studies. Ionic conductivity (σ i ) and ionic current (i i ) were calculated respectively using the conductivity (σ t and σ e ) and current (i t and i e ) results for the SAT, SPT and SVT glasses. Transport numbers due to ion (t i ) and electron (t e ) were calculated using the conductivity and mobility results for each glass system. The high conducting composition of the SAT, SPT and SVT glasses were used as solid electrolytes with silver metal as an anode and iodine:graphite (I:C) as a cathode for the fabrication of solid state batteries (SSBs). All the fabricated batteries were characterized by measuring the open circuit voltage (OCV) and polarization properties and estimated the batteries performances

  1. Radon transport in fractured soil. Laboratory experiments and modelling

    International Nuclear Information System (INIS)

    Hoff, A.

    1997-10-01

    Radon (Rn-222) transport in fractured soil has been investigated by laboratory experiments and by modelling. Radon transport experiments have been performed with two sand columns (homogeneous and inhomogeneous) and one undisturbed clayey till column containing a net of preferential flow paths (root holes). A numerical model (the finite-element model FRACTRAN) and an analytic model (a pinhole model) have been applied in simulations if soil gas and radon transport in fractured soil. Experiments and model calculations are included in a discussion of radon entry rates into houses placed on fractured soil. The main conclusion is, that fractures does not in general alter transport of internally generated radon out of soil, when the pressure and flow conditions in the soil is comparable to the conditions prevailing under a house. This indicates the important result, that fractures in soil have no impact on radon entry into a house beyond that of an increased gas permeability, but a more thorough investigation of this subject is needed. Only in the case where the soil is exposed to large pressure gradients, relative to gradients induced by a house, may it be possible to observe effects of radon exchange between fractures and matrix. (au) 52 tabs., 60 ill., 5 refs

  2. Radon transport in fractured soil. Laboratory experiments and modelling

    Energy Technology Data Exchange (ETDEWEB)

    Hoff, A

    1997-10-01

    Radon (Rn-222) transport in fractured soil has been investigated by laboratory experiments and by modelling. Radon transport experiments have been performed with two sand columns (homogeneous and inhomogeneous) and one undisturbed clayey till column containing a net of preferential flow paths (root holes). A numerical model (the finite-element model FRACTRAN) and an analytic model (a pinhole model) have been applied in simulations if soil gas and radon transport in fractured soil. Experiments and model calculations are included in a discussion of radon entry rates into houses placed on fractured soil. The main conclusion is, that fractures does not in general alter transport of internally generated radon out of soil, when the pressure and flow conditions in the soil is comparable to the conditions prevailing under a house. This indicates the important result, that fractures in soil have no impact on radon entry into a house beyond that of an increased gas permeability, but a more thorough investigation of this subject is needed. Only in the case where the soil is exposed to large pressure gradients, relative to gradients induced by a house, may it be possible to observe effects of radon exchange between fractures and matrix. (au) 52 tabs., 60 ill., 5 refs.

  3. Ionic charge transport between blockages: Sodium cation conduction in freshly excised bulk brain tissue

    Energy Technology Data Exchange (ETDEWEB)

    Emin, David, E-mail: emin@unm.edu [Department of Physics and Astronomy, University of New Mexico, Albuquerque, NM 87131 (United States); Akhtari, Massoud [Semple Institutes for Neuroscience and Human Behavior, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA 90095 (United States); Ellingson, B. M. [Department of Radiology, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA 90095 (United States); Mathern, G. W. [Department of Neurosurgery, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA 90095 (United States)

    2015-08-15

    We analyze the transient-dc and frequency-dependent electrical conductivities between blocking electrodes. We extend this analysis to measurements of ions’ transport in freshly excised bulk samples of human brain tissue whose complex cellular structure produces blockages. The associated ionic charge-carrier density and diffusivity are consistent with local values for sodium cations determined non-invasively in brain tissue by MRI (NMR) and diffusion-MRI (spin-echo NMR). The characteristic separation between blockages, about 450 microns, is very much shorter than that found for sodium-doped gel proxies for brain tissue, >1 cm.

  4. Perturbative Heat Transport Experiments on TJ-II

    International Nuclear Information System (INIS)

    Eguilor, S.; Castejon, F.; Luna, E. de la; Cappa, A.; Likin, K.; Fernandez, A.; Tj-II, T.

    2002-01-01

    Heat wave experiments are performed on TJ-II stellarator plasmas to estimate both heat diffusivity and power deposition profiles. High frequency ECRH modulation experiments are used to obtain the power deposition profiles, which is observed to be wider and duller than estimated by tracing techniques. The causes of this difference are discussed in the paper. Fourier analysis techniques are used to estimate the heat diffusivity in low frequency ECRH modulation experiments. This include the power deposition profile as a new ingredient. ECHR switch on/off experiments are exploited to obtain power deposition and heat diffusivities profile. Those quantities are compared with the obtained by modulation experiments and transport analysis, showing a good agreement. (Author) 18 refs

  5. Perturbative Heat Transport Experiments on TJ-II

    Energy Technology Data Exchange (ETDEWEB)

    Eguilor, S.; Castejon, F.; Luna, E. de la; Cappa, A.; Likin, K.; Fernandez, A.; Tj-II, T.

    2002-07-01

    Heat wave experiments are performed on TJ-II stellarator plasmas to estimate both heat diffusivity and power deposition profiles. High frequency ECRH modulation experiments are used to obtain the power deposition profiles, which is observed to be wider and duller than estimated by tracing techniques. The causes of this difference are discussed in the paper. Fourier analysis techniques are used to estimate the heat diffusivity in low frequency ECRH modulation experiments. This include the power deposition profile as a new ingredient. ECHR switch on/off experiments are exploited to obtain power deposition and heat diffusivities profile. Those quantities are compared with the obtained by modulation experiments and transport analysis, showing a good agreement. (Author) 18 refs.

  6. Layered-disk transport experiments at 1.064μm and 0.355μm

    International Nuclear Information System (INIS)

    Campbell, E.M.; Mead, W.C.; Turner, R.E.

    1981-01-01

    The results of electron transport experiments conducted at 1.064μm and 0.355μm with the Argus Laser will be presented. The experiments were conducted at a fixed absorbed intensity and pulse width of approximately 1-2x10 14 W/cm 2 and 600 psec (FWHM) respectively. Energy on target ranged from 30 to 90 joules. To explore axial transport a variable thickness beryllium layer is coated onto an aluminum substrate. The effectiveness of electron heat conduction is studied by measuring the fall-off in aluminum x-ray yield (line and continuum) as the beryllium thickness is increased. In addition to the axial transport studies, lateral conduction is examined by placing the axial transport target onto a titanium disk

  7. Bacterial Transport in Heterogeneous Porous Media: Laboratory and Field Experiments

    Science.gov (United States)

    Fuller, M. E.

    2001-12-01

    A fully instrumented research site for examining field-scale bacterial transport has been established on the eastern shore of Virginia. Studies employing intact sediment cores from the South Oyster site have been performed to examine the effects of physical and chemical heterogeneity, to derive transport parameters, and to aid in the selection of bacterial strains for use in field experiments. A variety of innovative methods for tracking bacteria were developed and evaluated under both laboratory and field conditions, providing the tools to detect target cell concentrations in groundwater down to effects of physical and chemical heterogeneity on field-scale bacterial transport. The results of this research not only contribute to the development of more effective bioremediation strategies, but also have implications for a better understanding of bacterial movement in the subsurface as it relates to public health microbiology and general microbial ecology.

  8. Existence of negative differential thermal conductance in one-dimensional diffusive thermal transport

    Science.gov (United States)

    Hu, Jiuning; Chen, Yong P.

    2013-06-01

    We show that in a finite one-dimensional (1D) system with diffusive thermal transport described by the Fourier's law, negative differential thermal conductance (NDTC) cannot occur when the temperature at one end is fixed and there are no abrupt junctions. We demonstrate that NDTC in this case requires the presence of junction(s) with temperature-dependent thermal contact resistance (TCR). We derive a necessary and sufficient condition for the existence of NDTC in terms of the properties of the TCR for systems with a single junction. We show that under certain circumstances we even could have infinite (negative or positive) differential thermal conductance in the presence of the TCR. Our predictions provide theoretical basis for constructing NDTC-based devices, such as thermal amplifiers, oscillators, and logic devices.

  9. High current transport experiment for heavy ion inertial fusion

    Directory of Open Access Journals (Sweden)

    L. R. Prost

    2005-02-01

    Full Text Available The High Current Experiment at Lawrence Berkeley National Laboratory is part of the U.S. program to explore heavy-ion beam transport at a scale representative of the low-energy end of an induction linac driver for fusion energy production. The primary mission of this experiment is to investigate aperture fill factors acceptable for the transport of space-charge-dominated heavy-ion beams at high intensity (line charge density ∼0.2  μC/m over long pulse durations (4  μs in alternating gradient focusing lattices of electrostatic or magnetic quadrupoles. This experiment is testing transport issues resulting from nonlinear space-charge effects and collective modes, beam centroid alignment and steering, envelope matching, image charges and focusing field nonlinearities, halo, and electron and gas cloud effects. We present the results for a coasting 1 MeV K^{+} ion beam transported through ten electrostatic quadrupoles. The measurements cover two different fill factor studies (60% and 80% of the clear aperture radius for which the transverse phase space of the beam was characterized in detail, along with beam energy measurements and the first halo measurements. Electrostatic quadrupole transport at high beam fill factor (≈80% is achieved with acceptable emittance growth and beam loss, even though the initial beam distribution is not ideal (but the emittance is low nor in thermal equilibrium. We achieved good envelope control, and rematching may only be needed every ten lattice periods (at 80% fill factor in a longer lattice of similar design. We also show that understanding and controlling the time dependence of the envelope parameters is critical to achieving high fill factors, notably because of the injector and matching section dynamics.

  10. Dopant controlled trap-filling and conductivity enhancement in an electron-transport polymer

    Energy Technology Data Exchange (ETDEWEB)

    Higgins, Andrew, E-mail: aehiggin@princeton.edu, E-mail: kahn@princeton.edu; Kahn, Antoine, E-mail: aehiggin@princeton.edu, E-mail: kahn@princeton.edu [Department of Electrical Engineering, Princeton University, Princeton, New Jersey 08544-5263 (United States); Mohapatra, Swagat K.; Barlow, Stephen; Marder, Seth R. [Center for Organic Photonics and Electronics and School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332-0400 (United States)

    2015-04-20

    Charge transport in organic semiconductors is often inhibited by the presence of tail states that extend into the band gap of a material and act as traps for charge carriers. This work demonstrates the passivation of acceptor tail states by solution processing of ultra-low concentrations of a strongly reducing air-stable organometallic dimer, the pentamethylrhodocene dimer, [RhCp*Cp]{sub 2}, into the electron transport polymer poly([N,N′-bis(2-octyldodecyl)-naphthalene-1,4,5,8-bis(dicarboximide) -2,6-diyl]-alt-5,5′-(2,2′-bithiophene)), P(NDI{sub 2}OD-T{sub 2}). Variable-temperature current-voltage measurements of n-doped P(NDI{sub 2}OD-T{sub 2}) are presented with doping concentration varied through two orders of magnitude. Systematic variation of the doping parameter is shown to lower the activation energy for hopping transport and enhance film conductivity and electron mobility.

  11. Atomistic simulations of highly conductive molecular transport junctions under realistic conditions

    KAUST Repository

    French, William R.; Iacovella, Christopher R.; Rungger, Ivan; Souza, Amaury Melo; Sanvito, Stefano; Cummings, Peter T.

    2013-01-01

    We report state-of-the-art atomistic simulations combined with high-fidelity conductance calculations to probe structure-conductance relationships in Au-benzenedithiolate (BDT)-Au junctions under elongation. Our results demonstrate that large increases in conductance are associated with the formation of monatomic chains (MACs) of Au atoms directly connected to BDT. An analysis of the electronic structure of the simulated junctions reveals that enhancement in the s-like states in Au MACs causes the increases in conductance. Other structures also result in increased conductance but are too short-lived to be detected in experiment, while MACs remain stable for long simulation times. Examinations of thermally evolved junctions with and without MACs show negligible overlap between conductance histograms, indicating that the increase in conductance is related to this unique structural change and not thermal fluctuation. These results, which provide an excellent explanation for a recently observed anomalous experimental result [Bruot et al., Nat. Nanotechnol., 2012, 7, 35-40], should aid in the development of mechanically responsive molecular electronic devices. © 2013 The Royal Society of Chemistry.

  12. Photo control of transport properties in a disordered wire: Average conductance, conductance statistics, and time-reversal symmetry

    International Nuclear Information System (INIS)

    Kitagawa, Takuya; Oka, Takashi; Demler, Eugene

    2012-01-01

    In this paper, we study the full conductance statistics of a disordered 1D wire under the application of light. We develop the transfer matrix method for periodically driven systems to analyze the conductance of a large system with small frequency of light, where coherent photon absorptions play an important role to determine not only the average but also the shape of conductance distributions. The average conductance under the application of light results from the competition between dynamic localization and effective dimension increase, and shows non-monotonic behavior as a function of driving amplitude. On the other hand, the shape of conductance distribution displays a crossover phenomena in the intermediate disorder strength; the application of light dramatically changes the distribution from log-normal to normal distributions. Furthermore, we propose that conductance of disordered systems can be controlled by engineering the shape, frequency and amplitude of light. Change of the shape of driving field controls the time-reversals symmetry and the disordered system shows analogous behavior as negative magneto-resistance known in static weak localization. A small change of frequency and amplitude of light leads to a large change of conductance, displaying giant opto-response. Our work advances the perspective to control the mean as well as the full conductance statistics by coherently driving disordered systems. - Highlights: ► We study conductance of disordered systems under the application of light. ► Full conductance distributions are obtained. ► A transfer matrix method is developed for driven systems. ► Conductances are dramatically modified upon the application of light. ► Time-reversal symmetry can also be controlled by light application.

  13. Electron effects in the Neutralized Transport Experiment (NTX)

    Energy Technology Data Exchange (ETDEWEB)

    Eylon, S. [Lawrence Berkeley National Laboratory (LBNL), MS47R 0112, 1 Cyclotron Road, Berkeley, CA 94720 (United States) and Heavy Ion Fusion Virtual National Laboratory, Cyclotron Road, CA 94720 (United States)]. E-mail: S_Eylon@lbl.gov; Henestroza, E. [Lawrence Berkeley National Laboratory (LBNL), MS47R 0112, 1 Cyclotron Road, Berkeley, CA 94720 (United States); Heavy Ion Fusion Virtual National Laboratory, Cyclotron Road, CA 94720 (United States); Roy, P.K. [Lawrence Berkeley National Laboratory (LBNL), MS47R 0112, 1 Cyclotron Road, Berkeley, CA 94720 (United States); Heavy Ion Fusion Virtual National Laboratory, Cyclotron Road, CA 94720 (United States); Yu, S.S. [Lawrence Berkeley National Laboratory (LBNL), MS47R 0112, 1 Cyclotron Road, Berkeley, CA 94720 (United States); Heavy Ion Fusion Virtual National Laboratory, Cyclotron Road, CA 94720 (United States)

    2005-05-21

    The Neutralized Transport Experiment (NTX) at the Heavy Ion Fusion Virtual National Laboratory is exploring the performance of neutralized final focus systems for high-perveance heavy ion beams. To focus a high-intensity beam to a small spot requires a high-brightness beam. In the NTX experiment, a potassium ion beam of up to 400 keV and 80 mA is generated in a Pierce-type diode. At the diode exit, an aperture with variable opening provides the capability to vary the beam perveance. The beam is transported through four quadrupole magnets to a distance of 2.5 m. The beam can be neutralized and focused using a MEVVA plasma plug and a RF plasma source. We shall report on the measurement of the electron effects and the ways to mitigate the effects. Furthermore, we shall present the results of EGUN calculations consistent with the measurements effects of the electrons.

  14. Electron effects in the Neutralized Transport Experiment (NTX)

    International Nuclear Information System (INIS)

    Eylon, S.; Henestroza, E.; Roy, P.K.; Yu, S.S.

    2005-01-01

    The Neutralized Transport Experiment (NTX) at the Heavy Ion Fusion Virtual National Laboratory is exploring the performance of neutralized final focus systems for high-perveance heavy ion beams. To focus a high-intensity beam to a small spot requires a high-brightness beam. In the NTX experiment, a potassium ion beam of up to 400 keV and 80 mA is generated in a Pierce-type diode. At the diode exit, an aperture with variable opening provides the capability to vary the beam perveance. The beam is transported through four quadrupole magnets to a distance of 2.5 m. The beam can be neutralized and focused using a MEVVA plasma plug and a RF plasma source. We shall report on the measurement of the electron effects and the ways to mitigate the effects. Furthermore, we shall present the results of EGUN calculations consistent with the measurements effects of the electrons

  15. Electron effects in the Neutralized Transport Experiment (NTX)

    Science.gov (United States)

    Eylon, S.; Henestroza, E.; Roy, P. K.; Yu, S. S.

    2005-05-01

    The Neutralized Transport Experiment (NTX) at the Heavy Ion Fusion Virtual National Laboratory is exploring the performance of neutralized final focus systems for high-perveance heavy ion beams. To focus a high-intensity beam to a small spot requires a high-brightness beam. In the NTX experiment, a potassium ion beam of up to 400 keV and 80 mA is generated in a Pierce-type diode. At the diode exit, an aperture with variable opening provides the capability to vary the beam perveance. The beam is transported through four quadrupole magnets to a distance of 2.5 m. The beam can be neutralized and focused using a MEVVA plasma plug and a RF plasma source. We shall report on the measurement of the electron effects and the ways to mitigate the effects. Furthermore, we shall present the results of EGUN calculations consistent with the measurements effects of the electrons.

  16. Nonlocal neoclassical transport in tokamak and spherical torus experiments

    International Nuclear Information System (INIS)

    Wang, W. X.; Rewoldt, G.; Tang, W. M.; Hinton, F. L.; Manickam, J.; Zakharov, L. E.; White, R. B.; Kaye, S.

    2006-01-01

    Large ion orbits can produce nonlocal neoclassical effects on ion heat transport, the ambipolar radial electric field, and the bootstrap current in realistic toroidal plasmas. Using a global δf particle simulation, it is found that the conventional local, linear gradient-flux relation is broken for the ion thermal transport near the magnetic axis. With regard to the transport level, it is found that details of the ion temperature profile determine whether the transport is higher or lower when compared with the predictions of standard neoclassical theory. Particularly, this nonlocal feature is suggested to exist in the National Spherical Torus Experiment (NSTX) [M. Ono, S. M. Kaye, Y.-K. M. Peng et al., Nucl. Fusion 40, 557 (2000)], being consistent with NSTX experimental evidence. It is also shown that a large ion temperature gradient can increase the bootstrap current. When the plasma rotation is taken into account, the toroidal rotation gradient can drive an additional parallel flow for the ions and then additional bootstrap current, either positive or negative, depending on the gradient direction. Compared with the carbon radial force balance estimate for the neoclassical poloidal flow, our nonlocal simulation predicts a significantly deeper radial electric field well at the location of an internal transport barrier of an NSTX discharge

  17. Perturbative transport experiments in JET Advanced Tokamak plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Mantica, P.; Gorini, G.; Sozzi, C. [Istituto di Fisica del Plasma, EURATOM-ENEA-CNR Association, Milan (Italy); Imbeaux, F.; Sarazin, Y.; Garbet, X. [Association Euratom-CEA, St. Paul-lez-Durance Cedex (France); Kinsey, J. [Lehigh Univ., Bethlehem, Pennsylvania (United States); Budny, R. [Princeton Plasma Physics Lab, New Jersey (United States); Coffey, I.; Parail, V.; Walden, A. [Euratom/UKAEA Fusion Association, Abingdon, Oxon (United Kingdom); Dux, R. [Max-Planck-Institut fuer Plasmaphysik, Garching (Germany); Garzotti, L. [Istituto Gas Ionizzati, Padova (Italy); Ingesson, C. [FOM-Instituut voor Plasmafysica, Nieuwegein (Netherlands); Kissick, M. [University of California, Los Angeles (United States)

    2003-07-01

    Perturbative transport experiments have been performed in JET Advanced Tokamak plasmas either in conditions of fully developed Internal Transport Barrier (ITB) or during a phase where an ITB was not observed. Transient peripheral cooling was induced by either Laser Ablation or Shallow Pellet Injection and the ensuing travelling cold pulse was used to probe the plasma transport in the electron and, for the first time, also in the ion channel. Cold pulses travelling through ITBs are observed to erode the ITB outer part, but, if the inner ITB portion survives, it strongly damps the propagating wave. The result is discussed in the context of proposed possible pictures for ITB formation. In the absence of an ITB, the cold pulse shows a fast propagation in the outer plasma half, which is consistent with a region of stiff transport, while in the inner half it slows down but shows the peculiar feature of amplitude growing while propagating. The data are powerful tests for the validation of theoretical transport models. (author)

  18. Verification of Monte Carlo transport codes by activation experiments

    OpenAIRE

    Chetvertkova, Vera

    2013-01-01

    With the increasing energies and intensities of heavy-ion accelerator facilities, the problem of an excessive activation of the accelerator components caused by beam losses becomes more and more important. Numerical experiments using Monte Carlo transport codes are performed in order to assess the levels of activation. The heavy-ion versions of the codes were released approximately a decade ago, therefore the verification is needed to be sure that they give reasonable results. Present work is...

  19. Structural, thermal and ion transport properties of radiation grafted lithium conductive polymer electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Nasef, Mohamed Mahmoud [Business and Advanced Technology Centre (BATC), Universiti Teknologi Malaysia, Jalan Semarak, 54100 Kuala Lumpur (Malaysia)]. E-mail: mahmoudeithar@mailcity.com; Saidi, Hamdani [Business and Advanced Technology Centre (BATC), Universiti Teknologi Malaysia, Jalan Semarak, 54100 Kuala Lumpur (Malaysia)

    2006-10-10

    Structural, thermal and ion transport properties of lithium conductive polymer electrolytes prepared by radiation-induced grafting of styrene onto poly(vinylidene fluoride) (PVDF) films and subsequent activation with LiPH{sub 6}/EC/DEC liquid electrolyte were investigated in correlation with the content of the grafted polystyrene (Y%). The changes in the structure were studied using Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and differential scanning calorimetry (DSC). Thermal gravimetric analysis (TGA) was used to evaluate the thermal stability. The ionic conductivity was measured by means of ac impedance spectroscopy at various temperatures. The polymer electrolytes were found to undergo considerable structural and morphological changes that resulted in a noticeable increase in their ionic conductivity with the increase in Y% at various temperatures (25-65 deg. C). The ionic conductivity achieved a value of 1.61 x 10{sup -3} S cm{sup -1} when Y of the polymer electrolyte reached 50% and at 25 deg. C. The polymer electrolytes also showed a multi-step degradation behaviour and thermal stability up to 120 deg. C, which suits normal lithium battery operation temperature range. The overall results of this work suggest that the structural changes took place in PVDF matrix during the preparation of these polymer electrolytes have a strong impact on their various properties.

  20. Fluid Physical and Transport Phenomena Studies aboard the International Space Station: Planned Experiments

    Science.gov (United States)

    Singh, Bhim S.

    1999-01-01

    This paper provides an overview of the microgravity fluid physics and transport phenomena experiments planned for the International Spare Station. NASA's Office of Life and Microgravity Science and Applications has established a world-class research program in fluid physics and transport phenomena. This program combines the vast expertise of the world research community with NASA's unique microgravity facilities with the objectives of gaining new insight into fluid phenomena by removing the confounding effect of gravity. Due to its criticality to many terrestrial and space-based processes and phenomena, fluid physics and transport phenomena play a central role in the NASA's Microgravity Program. Through widely publicized research announcement and well established peer-reviews, the program has been able to attract a number of world-class researchers and acquired a critical mass of investigations that is now adding rapidly to this field. Currently there arc a total of 106 ground-based and 20 candidate flight principal investigators conducting research in four major thrust areas in the program: complex flows, multiphase flow and phase change, interfacial phenomena, and dynamics and instabilities. The International Space Station (ISS) to be launched in 1998, provides the microgravity research community with a unprecedented opportunity to conduct long-duration microgravity experiments which can be controlled and operated from the Principal Investigators' own laboratory. Frequent planned shuttle flights to the Station will provide opportunities to conduct many more experiments than were previously possible. NASA Lewis Research Center is in the process of designing a Fluids and Combustion Facility (FCF) to be located in the Laboratory Module of the ISS that will not only accommodate multiple users but, allow a broad range of fluid physics and transport phenomena experiments to be conducted in a cost effective manner.

  1. Transport experience of new ''TNF-XI'' powder package

    International Nuclear Information System (INIS)

    Nomura, I.; Fujiwara, T.; Naigeon, P.

    2004-01-01

    Since the Tokai criticality accident in 1999, there has been no specialized manufacturer conducting uranium re-conversion in Japan. For this reason, Nuclear Fuel Industries, Ltd. (NFI) imports from overseas almost all the uranium oxide powder used for manufacturing pellets for nuclear fuel assemblies. To date, an NT-IX package has been used for transporting the uranium oxide powder. However, due to the adoption of IAEA TS-R-1 into Japanese domestic regulations, we have begun to use a new TNF-XI powder package because the NT-IX package can suffer major deformation under the drop test III condition. The TNF-XI package was jointly developed by COGEMA LOGISTICS of France and NFI from 2000, and started to be used for actual transportation in 2003. This package has improved transport efficiency, handling operability and safety performance in comparison to its predecessor. This paper describes the characteristics of the new TNF-XI package and its actual transportation records and performance

  2. Perceived discrimination, serotonin transporter linked polymorphic region status, and the development of conduct problems.

    Science.gov (United States)

    Brody, Gene H; Beach, Steven R H; Chen, Yi-Fu; Obasi, Ezemenari; Philibert, Robert A; Kogan, Steven M; Simons, Ronald L

    2011-05-01

    This study examined the prospective relations of adolescents' perceptions of discrimination and their genetic status with increases in conduct problems. Participants were 461 African American youths residing in rural Georgia (Wave 1 mean age = 15.5 years) who provided three waves of data and a saliva sample from which a polymorphism in the SCL6A4 (serotonin transporter [5-HTT]) gene polymorphism known as the 5-HTT linked promoter region (5-HTTLPR) was genotyped. Data analyses using growth curve modeling indicated that perceived discrimination was significantly related to the slope of conduct problems. As hypothesized, interactions between perceived discrimination and genetic status emerged for male but not female youths. Compared with those carrying two copies of the long allele variant of 5-HTTLPR, male youths carrying one or two copies of its short allele variant evinced higher rates of conduct problems over time when they perceived high levels of racial discrimination. These findings are consistent with resilience and differential susceptibility propositions stating that genes can both foster sensitivity to adverse events and confer protection from those events.

  3. European experience in transport/storage cask for vitrified residues

    International Nuclear Information System (INIS)

    Otton, Camille; Sicard, Damien

    2007-01-01

    Available in abstract form only. Full text of publication follows: Because of the evolution of burnup of spent fuel to be reprocessed, the high activity vitrified residues would not be transported in the existing cask designs. Therefore, TN International has decided in the late nineties to develop a brand new design of casks with optimized capacity able to store and transport the most active and hottest canisters: the TN TM 81 casks currently in use in Switzerland and the TN TM 85 cask which shall permit in the near future in Germany the storage and the transport of the most active vitrified residues defining a thermal power of 56 kW (kilowatts). The challenges for the TN TM 81 and TN TM 85 cask designs were that the geometry entry data were very restrictive and were combined with a fairly wide range set by the AREVA NC Specification relative to vitrified residue canister. The TN TM 81 and the TN TM 85 casks have been designed to fully anticipate shipment constraints of the present vitrified residue production. It also used the feedback of current shipments and the operational constraints and experience of receiving and shipping facilities. The casks had to fit as much as possible in the existing procedures for the already existing flasks such as the TN TM 28 cask and TS 28 V cask, all along the logistics chain of loading, unloading, transport and maintenance. (authors)

  4. Enhancing oxygen transport through Mixed-Ionic-and-Electronic-Conducting ceramic membranes

    Science.gov (United States)

    Yu, Anthony S.

    Ceramic membranes based on Mixed-Ionic-and-Electronic-Conducting (MIEC) oxides are capable of separating oxygen from air in the presence of an oxygen partial-pressure gradient. These MIEC membranes show great promise for oxygen consuming industrial processes, such as the production of syngas from steam reforming of natural gas (SRM), as well as for electricity generation in Solid Oxide Fuel Cells (SOFC). For both applications, the overall performance is dictated by the rate of oxygen transport across the membrane. Oxygen transport across MIEC membranes is composed of a bulk oxygen-ion diffusion process and surface processes, such as surface reactions and adsorption/desorption of gaseous reactants/products. The main goal of this thesis was to determine which process is rate-limiting in order to significantly enhance the overall rate of oxygen transport in MIEC membrane systems. The rate-limiting step was determined by evaluating the total resistance to oxygen transfer, Rtot. Rtot is the sum of a bulk diffusion resistance in the membrane itself, Rb, and interfacial loss components, Rs. Rb is a function of the membrane's ionic conductivity and thickness, while Rs arises primarily from slow surface-exchange kinetics that cause the P(O2) at the surfaces of the membrane to differ from the P(O 2) in the adjacent gas phases. Rtot can be calculated from the Nernst potential across the membrane and the measured oxygen flux. The rate-limiting process can be determined by evaluating the relative contributions of the various losses, Rs and Rb, to Rtot. Using this method, this thesis demonstrates that for most membrane systems, Rs is the dominating factor. In the development of membrane systems with high oxygen transport rates, thin membranes with high ionic conductivities are required to achieve fast bulk oxygen-ion diffusion. However, as membrane thickness is decreased, surface reaction kinetics become more important in determining the overall transport rate. The two

  5. Transport tensors in perfectly aligned low-density fluids: Self-diffusion and thermal conductivity

    International Nuclear Information System (INIS)

    Singh, G. S.; Kumar, B.

    2001-01-01

    The modified Taxman equation for the kinetic theory of low-density fluids composed of rigid aspherical molecules possessing internal degrees of freedom is generalized to obtain the transport tensors in a fluid of aligned molecules. The theory takes care of the shape of the particles exactly but the solution has been obtained only for the case of perfectly aligned hard spheroids within the framework of the first Sonine polynomial approximation. The expressions for the thermal-conductivity components have been obtained for the first time whereas the self-diffusion components obtained here turn out to be exactly the same as those derived by Kumar and Masters [Mol. Phys. >81, 491 (1994)] through the solution of the Lorentz-Boltzmann equation. All our expressions yield correct results in the hard-sphere limit

  6. Conductance and activation energy for electron transport in series and parallel intramolecular circuits.

    Science.gov (United States)

    Hsu, Liang-Yan; Wu, Ning; Rabitz, Herschel

    2016-11-30

    We investigate electron transport through series and parallel intramolecular circuits in the framework of the multi-level Redfield theory. Based on the assumption of weak monomer-bath couplings, the simulations depict the length and temperature dependence in six types of intramolecular circuits. In the tunneling regime, we find that the intramolecular circuit rule is only valid in the weak monomer coupling limit. In the thermally activated hopping regime, for circuits based on two different molecular units M a and M b with distinct activation energies E act,a > E act,b , the activation energies of M a and M b in series are nearly the same as E act,a while those in parallel are nearly the same as E act,b . This study gives a comprehensive description of electron transport through intramolecular circuits from tunneling to thermally activated hopping. We hope that this work can motivate additional studies to design intramolecular circuits based on different types of building blocks, and to explore the corresponding circuit laws and the length and temperature dependence of conductance.

  7. Divalent Metal Ion Transport across Large Biological Ion Channels and Their Effect on Conductance and Selectivity

    Directory of Open Access Journals (Sweden)

    Elena García-Giménez

    2012-01-01

    Full Text Available Electrophysiological characterization of large protein channels, usually displaying multi-ionic transport and weak ion selectivity, is commonly performed at physiological conditions (moderate gradients of KCl solutions at decimolar concentrations buffered at neutral pH. We extend here the characterization of the OmpF porin, a wide channel of the outer membrane of E. coli, by studying the effect of salts of divalent cations on the transport properties of the channel. The regulation of divalent cations concentration is essential in cell metabolism and understanding their effects is of key importance, not only in the channels specifically designed to control their passage but also in other multiionic channels. In particular, in porin channels like OmpF, divalent cations modulate the efficiency of molecules having antimicrobial activity. Taking advantage of the fact that the OmpF channel atomic structure has been resolved both in water and in MgCl2 aqueous solutions, we analyze the single channel conductance and the channel selectivity inversion aiming to separate the role of the electrolyte itself, and the counterion accumulation induced by the protein channel charges and other factors (binding, steric effects, etc. that being of minor importance in salts of monovalent cations become crucial in the case of divalent cations.

  8. Transient groundwater chemistry near a river: Effects on U(VI) transport in laboratory column experiments

    Science.gov (United States)

    Yin, Jun; Haggerty, Roy; Stoliker, Deborah L.; Kent, Douglas B.; Istok, Jonathan D.; Greskowiak, Janek; Zachara, John M.

    2011-01-01

    In the 300 Area of a U(VI)-contaminated aquifer at Hanford, Washington, USA, inorganic carbon and major cations, which have large impacts on U(VI) transport, change on an hourly and seasonal basis near the Columbia River. Batch and column experiments were conducted to investigate the factors controlling U(VI) adsorption/desorption by changing chemical conditions over time. Low alkalinity and low Ca concentrations (Columbia River water) enhanced adsorption and reduced aqueous concentrations. Conversely, high alkalinity and high Ca concentrations (Hanford groundwater) reduced adsorption and increased aqueous concentrations of U(VI). An equilibrium surface complexation model calibrated using laboratory batch experiments accounted for the decrease in U(VI) adsorption observed with increasing (bi)carbonate concentrations and other aqueous chemical conditions. In the column experiment, alternating pulses of river and groundwater caused swings in aqueous U(VI) concentration. A multispecies multirate surface complexation reactive transport model simulated most of the major U(VI) changes in two column experiments. The modeling results also indicated that U(VI) transport in the studied sediment could be simulated by using a single kinetic rate without loss of accuracy in the simulations. Moreover, the capability of the model to predict U(VI) transport in Hanford groundwater under transient chemical conditions depends significantly on the knowledge of real-time change of local groundwater chemistry.

  9. Neutron and gamma-ray transport experiments in liquid air

    International Nuclear Information System (INIS)

    Farley, W.E.

    1976-01-01

    Accurate estimates of neutron and gamma radiations from a nuclear explosion and their subsequent transport through the atmosphere are vital to nuclear-weapon employment studies: i.e., for determining safety radii for aircraft crews, casualty and collateral-damage risk radii for tactical weapons, and the kill range from a high-yield defensive burst for a maneuvering reentry vehicle. Radiation transport codes, such as the Laboratory's TARTNP, are used to calculate neutron and gamma fluences. Experiments have been performed to check and update these codes. Recently, a 1.3-m-radius liquid-air (21 percent oxygen) sphere, with a pulsed source of 14-MeV neutrons at its center, was used to measure the fluence and spectra of emerging neutrons and secondary gamma rays. Comparison of measured radiation dose with TARTNP showed agreement within 10 percent

  10. Ion Transport in Confined Geometries below the Nanoscale: Access Resistance Dominates Protein Channel Conductance in Diluted Solutions.

    Science.gov (United States)

    Alcaraz, Antonio; López, M Lidón; Queralt-Martín, María; Aguilella, Vicente M

    2017-10-24

    Synthetic nanopores and mesoscopic protein channels have common traits like the importance of electrostatic interactions between the permeating ions and the nanochannel. Ion transport at the nanoscale occurs under confinement conditions so that the usual assumptions made in microfluidics are challenged, among others, by interfacial effects such as access resistance (AR). Here, we show that a sound interpretation of electrophysiological measurements in terms of channel ion selective properties requires the consideration of interfacial effects, up to the point that they dominate protein channel conductance in diluted solutions. We measure AR in a large ion channel, the bacterial porin OmpF, by means of single-channel conductance measurements in electrolyte solutions containing varying concentrations of high molecular weight PEG, sterically excluded from the pore. Comparison of experiments performed in charged and neutral planar membranes shows that lipid surface charges modify the ion distribution and determine the value of AR, indicating that lipid molecules are more than passive scaffolds even in the case of large transmembrane proteins. We also found that AR may reach up to 80% of the total channel conductance in diluted solutions, where electrophysiological recordings register essentially the AR of the system and depend marginally on the pore characteristics. These findings may have implications for several low aspect ratio biological channels that perform their physiological function in a low ionic strength and macromolecule crowded environment, just the two conditions enhancing the AR contribution.

  11. Plans for longitudinal and transverse neutralized beam compression experiments, and initial results from solenoid transport experiments

    International Nuclear Information System (INIS)

    Seidl, P.A.; Armijo, J.; Baca, D.; Bieniosek, F.M.; Coleman, J.; Davidson, R.C.; Efthimion, P.C.; Friedman, A.; Gilson, E.P.; Grote, D.; Haber, I.; Henestroza, E.; Kaganovich, I.; Leitner, M.; Logan, B.G.; Molvik, A.W.; Rose, D.V.; Roy, P.K.; Sefkow, A.B.; Sharp, W.M.; Vay, J.L.; Waldron, W.L.; Welch, D.R.; Yu, S.S.

    2007-01-01

    This paper presents plans for neutralized drift compression experiments, precursors to future target heating experiments. The target-physics objective is to study warm dense matter (WDM) using short-duration (∼1 ns) ion beams that enter the targets at energies just above that at which dE/dx is maximal. High intensity on target is to be achieved by a combination of longitudinal compression and transverse focusing. This work will build upon recent success in longitudinal compression, where the ion beam was compressed lengthwise by a factor of more than 50 by first applying a linear head-to-tail velocity tilt to the beam, and then allowing the beam to drift through a dense, neutralizing background plasma. Studies on a novel pulse line ion accelerator were also carried out. It is planned to demonstrate simultaneous transverse focusing and longitudinal compression in a series of future experiments, thereby achieving conditions suitable for future WDM target experiments. Future experiments may use solenoids for transverse focusing of un-neutralized ion beams during acceleration. Recent results are reported in the transport of a high-perveance heavy ion beam in a solenoid transport channel. The principal objectives of this solenoid transport experiment are to match and transport a space-charge-dominated ion beam, and to study associated electron-cloud and gas effects that may limit the beam quality in a solenoid transport system. Ideally, the beam will establish a Brillouin-flow condition (rotation at one-half the cyclotron frequency). Other mechanisms that potentially degrade beam quality are being studied, such as focusing-field aberrations, beam halo, and separation of lattice focusing elements

  12. United States experience in the transportation of radioactive materials

    International Nuclear Information System (INIS)

    Platt, A.M.; Rhoads, R.E.; Hall, R.J.; Williams, L.D.; Brobst, W.A.; Shappert, L.B.; Jefferson, R.M.

    1977-01-01

    The transport of radioactive material forms a vital link in the nuclear fuel cycle in the United States. Actual U.S. experience and practice with such systems for the packaging and transport of uranium ore concentrates, uranium hexafluoride, fresh fuel, irradiated fuel, non-high-level waste, and plutonium with low heat generation rates are described. Specific shipping systems in current use for these services are illustrated. A comparison will be made of shipping requirements for nuclear parks versus dispersed facilities. Shipping systems for other fuel cycle materials (e.g., high-level waste and cladding hulls) have not been developed because there has been no need to transport these materials commercially. However, conceptual designs for packaging and transport of such materials have been developed. Selected systems are reviewed and summarized. Transport safety in the U.S. is regulated by the U.S. Department of Transportation and the Nuclear Regulatory Commission. Key regulations defining packaging requirements, allowable radiation dose rates, and handling procedures are reviewed. Although the radioactive material shipping industry has an outstanding safety record, opposition to nuclear fuel cycle shipments has surfaced in several areas. The U.S. congressional ban on the shipment of plutonium by air, the actions of New York City to prohibit certain shipments within the city limits, and the requirement of U.S. railroads to ship spent fuel casks only in dedicated trains are reviewed. In an attempt to provide information on the safety margins inherent in the design of radioactive materials packages, ERDA has undertaken a series of accident studies and full scale crash tests that stress the packages beyond the levels expected in severe accidents. In addition, the level of total risk associated with radioactive materials shipments is being evaluated. Current ERDA crash test and transportation risk assessment studies are reviewed. Concern about the possibility of

  13. Conductivity behavior of very thin gold films ruptured by mass transport in photosensitive polymer film

    Energy Technology Data Exchange (ETDEWEB)

    Linde, Felix; Sekhar Yadavalli, Nataraja; Santer, Svetlana [Department of Experimental Physics, Institute for Physics and Astronomy, University of Potsdam, 14476 Potsdam (Germany)

    2013-12-16

    We report on conductivity behavior of very thin gold layer deposited on a photosensitive polymer film. Under irradiation with light interference pattern, the azobenzene containing photosensitive polymer film undergoes deformation at which topography follows a distribution of intensity, resulting in the formation of a surface relief grating. This process is accompanied by a change in the shape of the polymer surface from flat to sinusoidal together with a corresponding increase in surface area. The gold layer placed above deforms along with the polymer and ruptures at a strain of 4%. The rupturing is spatially well defined, occurring at the topographic maxima and minima resulting in periodic cracks across the whole irradiated area. We have shown that this periodic micro-rupturing of a thin metal film has no significant impact on the electrical conductivity of the films. We suggest a model to explain this phenomenon and support this by additional experiments where the conductivity is measured in a process when a single nanoscopic scratch is formed with an AFM tip. Our results indicate that in flexible electronic materials consisting of a polymer support and an integrated metal circuit, nano- and micro cracks do not alter significantly the behavior of the conductivity unless the metal is disrupted completely.

  14. Effect of conducting polypyrrole on the transport properties of carbon nanotube yarn

    International Nuclear Information System (INIS)

    Foroughi, Javad; Kimiaghalam, Bahram; Ghorbani, Shaban Reza; Safaei, Farzad; Abolhasan, Mehran

    2012-01-01

    Experiments were conducted to measure the electrical conductivity in three types of pristine and carbon nanotube-polypyrrole (CNT-PPy) composite yarns and its dependence on over a wide temperature range. The experimental results fit well with the analytical models developed. The effective energy separation between localized states of the pristine CNT yarn is larger than that for both the electrochemically and chemically prepared CNT-PPy yarns. It was found that all samples are in the critical regime in the insulator–metal transition, or close to the metallic regime at low temperature. The electrical conductivity results are in good agreement with a Three Dimensional Variable Range Hopping model at low temperatures, which provides a strong indication that electron hopping is the main means of current transfer in CNT yarns at T < 100 K. We found that the two shell model accurately describes the electronic properties of CNT and CNT-PPy composite yarns in the temperature range of 5–350 K. - Highlights: ► We developed hybrid carbon nanotube conducting polypyrrole composite yarns. ► The main current transfer scheme in yarn is via three dimensional electrons hopping. ► Two shell model describes well electronic properties of yarns in range of 5-350 K.

  15. Evaluation of axial fission gas transport in power ramping experiments

    International Nuclear Information System (INIS)

    Kinoshita, Motoyasu

    1986-01-01

    The LINUS code calculates advective and diffusional transport of fission gas towards an upper plenum through the pellet-cladding gap. The basic equations were modified for analyzing a multi-component gas mixture in the gap and also for dealing with opening and/or closing of the gap, which induces additional axial gas flow. Analysis of the Petten ramp experiment shows that helium pressurization is effective in suppressing an ascending rate of fission gas concentration. After the maximum concentration is achieved through power ramping, the gas concentration could be described by a steady state analytical solution which does not depend on the filling gas pressure. (author)

  16. Air medical transport personnel experiences with and opinions about research.

    Science.gov (United States)

    Fox, Jolene; Thomas, Frank; Carpenter, Judi; Handrahan, Diana

    2010-01-01

    This study examined air medical transport (AMT) personnel's experiences with and opinions about prehospital and AMT research. A Web-based questionnaire was sent to eight randomly selected AMT programs from each of six Association of Air Medical Services (AAMS) regions. Responders were defined by university association (UA) and AMT professional role. Forty-eight of 54 (89%) contacted programs and 536 of 1,282 (42%) individuals responded. Non-UA responders (74%) had significantly more work experience in emergency medical services (EMS) (13.5 +/- 8.5 vs. 10.8 +/- 8.3 years, P = .002) and AMT (8.3 +/- 6.3 vs. 6.8 +/- 5.7 years, P = .008), whereas UA responders (26%) had more research training (51% vs. 37%, P = .006), experience (79% vs. 59%, P < .001), and grants (7% vs. 2%, P = .006). By AMT role, administrators had the most work experience, and physicians had the most research experience. Research productivity of responders was low, with only 9% having presented and 10% having published research; and UA made no difference in productivity. A majority of responders advocated research: EMS (66%) and AMT (68%), program (53%). Willingness to participate in research was high for both EMS research (87%) and AMT research (92%). Although AMT personnel were strong advocates of and willing to participate in research, few had research knowledge. For AMT personnel, disparity exists between advocating for and producing research. Copyright 2010 Air Medical Journal Associates. Published by Elsevier Inc. All rights reserved.

  17. Dynamical renormalization group approach to transport in ultrarelativistic plasmas: The electrical conductivity in high temperature QED

    International Nuclear Information System (INIS)

    Boyanovsky, Daniel; Vega, Hector J. de; Wang Shangyung

    2003-01-01

    The dc electrical conductivity of an ultrarelativistic QED plasma is studied in real time by implementing the dynamical renormalization group. The conductivity is obtained from the real-time dependence of a dissipative kernel closely related to the retarded photon polarization. Pinch singularities in the imaginary part of the polarization are manifest as secular terms that grow in time in the perturbative expansion of this kernel. The leading secular terms are studied explicitly and it is shown that they are insensitive to the anomalous damping of hard fermions as a result of a cancellation between self-energy and vertex corrections. The resummation of the secular terms via the dynamical renormalization group leads directly to a renormalization group equation in real time, which is the Boltzmann equation for the (gauge invariant) fermion distribution function. A direct correspondence between the perturbative expansion and the linearized Boltzmann equation is established, allowing a direct identification of the self-energy and vertex contributions to the collision term. We obtain a Fokker-Planck equation in momentum space that describes the dynamics of the departure from equilibrium to leading logarithmic order in the coupling. This equation determines that the transport time scale is given by t tr =24 π/e 4 T ln(1/e). The solution of the Fokker-Planck equation approaches asymptotically the steady-state solution as ∼e -t/(4.038...t tr ) . The steady-state solution leads to the conductivity σ=15.698 T/e 2 ln(1/e) to leading logarithmic order. We discuss the contributions beyond leading logarithms as well as beyond the Boltzmann equation. The dynamical renormalization group provides a link between linear response in quantum field theory and kinetic theory

  18. psiTurk: An open-source framework for conducting replicable behavioral experiments online.

    Science.gov (United States)

    Gureckis, Todd M; Martin, Jay; McDonnell, John; Rich, Alexander S; Markant, Doug; Coenen, Anna; Halpern, David; Hamrick, Jessica B; Chan, Patricia

    2016-09-01

    Online data collection has begun to revolutionize the behavioral sciences. However, conducting carefully controlled behavioral experiments online introduces a number of new of technical and scientific challenges. The project described in this paper, psiTurk, is an open-source platform which helps researchers develop experiment designs which can be conducted over the Internet. The tool primarily interfaces with Amazon's Mechanical Turk, a popular crowd-sourcing labor market. This paper describes the basic architecture of the system and introduces new users to the overall goals. psiTurk aims to reduce the technical hurdles for researchers developing online experiments while improving the transparency and collaborative nature of the behavioral sciences.

  19. Electrical transport across nanometric SrTiO3 and BaTiO3 barriers in conducting/insulator/conducting junctions

    Science.gov (United States)

    Navarro, H.; Sirena, M.; González Sutter, J.; Troiani, H. E.; del Corro, P. G.; Granell, P.; Golmar, F.; Haberkorn, N.

    2018-01-01

    We report the electrical transport properties of conducting/insulator/conducting heterostructures by studying current-voltage IV curves at room temperature. The measurements were obtained on tunnel junctions with different areas (900, 400 and 100 μm2) using a conducting atomic force microscope. Trilayers with GdBa2Cu3O7 (GBCO) as the bottom electrode, SrTiO3 or BaTiO3 (thicknesses between 1.6 and 4 nm) as the insulator barrier, and GBCO or Nb as the top electrode were grown by DC sputtering on (100) SrTiO3 substrates For SrTiO3 and BaTiO3 barriers, asymmetric IV curves at positive and negative polarization can be obtained using electrodes with different work function. In addition, hysteretic IV curves are obtained for BaTiO3 barriers, which can be ascribed to a combined effect of the FE reversal switching polarization and an oxygen vacancy migration. For GBCO/BaTiO3/GBCO heterostructures, the IV curves correspond to that expected for asymmetric interfaces, which indicates that the disorder affects differently the properties at the bottom and top interfaces. Our results show the role of the interface disorder on the electrical transport of conducting/insulator/conduction heterostructures, which is relevant for different applications, going from resistive switching memories (at room temperature) to Josephson junctions (at low temperatures).

  20. Verification of Monte Carlo transport codes by activation experiments

    Energy Technology Data Exchange (ETDEWEB)

    Chetvertkova, Vera

    2012-12-18

    With the increasing energies and intensities of heavy-ion accelerator facilities, the problem of an excessive activation of the accelerator components caused by beam losses becomes more and more important. Numerical experiments using Monte Carlo transport codes are performed in order to assess the levels of activation. The heavy-ion versions of the codes were released approximately a decade ago, therefore the verification is needed to be sure that they give reasonable results. Present work is focused on obtaining the experimental data on activation of the targets by heavy-ion beams. Several experiments were performed at GSI Helmholtzzentrum fuer Schwerionenforschung. The interaction of nitrogen, argon and uranium beams with aluminum targets, as well as interaction of nitrogen and argon beams with copper targets was studied. After the irradiation of the targets by different ion beams from the SIS18 synchrotron at GSI, the γ-spectroscopy analysis was done: the γ-spectra of the residual activity were measured, the radioactive nuclides were identified, their amount and depth distribution were detected. The obtained experimental results were compared with the results of the Monte Carlo simulations using FLUKA, MARS and SHIELD. The discrepancies and agreements between experiment and simulations are pointed out. The origin of discrepancies is discussed. Obtained results allow for a better verification of the Monte Carlo transport codes, and also provide information for their further development. The necessity of the activation studies for accelerator applications is discussed. The limits of applicability of the heavy-ion beam-loss criteria were studied using the FLUKA code. FLUKA-simulations were done to determine the most preferable from the radiation protection point of view materials for use in accelerator components.

  1. Educational experiment for students using natural radioactivity. 2. Practical example of radiochemical experiment conducted at Tottori University

    International Nuclear Information System (INIS)

    Nakamura, Mariko; Esaka, Takao; Kamata, Masahiro

    1999-01-01

    This paper presents a practical example of educational experiment conducted at Tottori University, whose theme is to separate 214 Bi(+ 214 Pb) from superphosphate of lime or the soil sampled at Ningyo-Touge mountain pass. The results of this experiment are quantitative enough for educational purpose, although the amount of radioactivity is so small that it is free from any regulation in Japan. (author)

  2. Thermal conductivity and heat transport properties of nitrogen-doped graphene.

    Science.gov (United States)

    Goharshadi, Elaheh K; Mahdizadeh, Sayyed Jalil

    2015-11-01

    In the present study, the thermal conductivity (TC) and heat transport properties of nitrogen doped graphene (N-graphene) were investigated as a function of temperature (107-400K) and N-doped concentration (0.0-7.0%) using equilibrium molecular dynamics simulation based on Green-Kubo method. According to the results, a drastic decline in TC of graphene observed at very low N-doped concentration (0.5 and 1.0%). Substitution of just 1.0% of carbon atoms with nitrogens causes a 77.2, 65.4, 59.2, and 53.7% reduction in TC at 107, 200, 300, and 400K, respectively. The values of TC of N-graphene at different temperatures approach to each other as N-doped concentration increases. The results also indicate that TC of N-graphene is much less sensitive to temperature compared with pristine graphene and the sensitivity decreases as N-doped concentration increases. The phonon-phonon scattering relaxation times and the phonon mean free path of phonons were also calculated. The contribution of high frequency optical phonons for pristine graphene and N-graphene with 7.0% N-doped concentration is 0-2% and 4-8%, respectively. These findings imply that it is potentially feasible to control heat transfer on the nanoscale when designing N-graphene based thermal devices. Copyright © 2015 Elsevier Inc. All rights reserved.

  3. Abnormal serotonin transporter availability in the brains of adults with conduct disorder.

    Science.gov (United States)

    Chang, Chieh; Gau, Susan Shur-Fen; Huang, Wen-Sheng; Shiue, Chyng-Yann; Yeh, Chin-Bin

    2017-06-01

    The aims of the current study were to determine whether patients with conduct disorder (CD) showed an abnormal availability of serotonin reuptake transporter (SERT), and if their hyperkinetic symptoms, impulsivity, and quality of life were correlated with the availability of SERT. We recruited 14 drug-naïve patients with CD and eight age-matched healthy controls (HCs). The adult attention-deficit/hyperactivity disorder (ADHD) self-report scale (ASRS), Barrett impulsivity scale (BIS), and the World Health Organization quality of life-brief version (WHOQOL-BREF) scale were administered. Positron emission tomography (PET) of the brain with 4-[ 18 F]-ADAM was arranged for SERT imaging. SERT availability was significantly reduced in the striatum and midbrain of patients with CD. Quality of life and inattention symptoms were also significantly correlated with the availability of SERT in the prefrontal cortex. The study suggested that a reduction in the availability of SERT might be associated with CD and could potentially predict poor quality of life or symptoms of inattention for these patients. The implications of our results might be limited to individuals with CD; a future study with a larger sample to validate our preliminary results is warranted. Copyright © 2016. Published by Elsevier B.V.

  4. Virginia Power and Department of Energy spent fuel transportation experience

    International Nuclear Information System (INIS)

    Ruska, M.D.; Schoonen, D.H.

    1986-12-01

    Spent fuel assemblies for the Spent Fuel Storage Cask Testing Program conducted by EG and G Idaho, Inc., at the Idaho National Engineering Laboratory (INEL) were transported to the INEL. A total of 69 spent fuel assemblies (23 shipments) were shipped from Virginia Power's nuclear power plant at Surry, Virginia, to the INEL between July 1985 and June 1986 to fill and test three spent fuel storage casks. The shipments were made over the highway system in Transnuclear, Inc., TN-8L shipping casks on specially constructed trailers. The shipments were moved by diesel tractors owned and operated by Tri-State Motor Transit Company of Joplin, Missouri. The gross vehicle weight for each shipment was 112,000 lb, which was a major consideration when selecting routes for the shipments. Cooperative negotiations with officials for the 17 states involved obtained authorization to transport through their states. The shipping campaign was successfully completed through close communication and cooperation and careful planning and operation by all organizations involved

  5. Electrical conductivity and transport properties of cement-based materials measured by impedance spectroscopy

    Science.gov (United States)

    Shane, John David

    The use of Impedance Spectroscopy (IS) as a tool to evaluate the electrical and transport properties of cement-based materials was critically evaluated. Emphasis was placed on determining the efficacy of IS by applying it as a tool to investigate several families of cement-based materials. Also, the functional aspects of electroding and null corrections were also addressed. The technique was found to be advantageous for these analyses, especially as a non-destructive, in-situ, rapid test. Moreover, key insights were gained into several cement-based systems (e.g., cement mortars and oil-well grouts) as well as the effect that certain testing techniques can have on materials (e.g., the rapid chloride permeability test). However, some limitations of IS were identified. For instance, improper electroding of samples can lead to erroneous results and incorrect interpretations for both two-point and multi-point measurements. This is an area of great importance, but it has received very little attention in the literature. Although the analysis of cement/electrode techniques is in its infancy, much progress was made in gaining a full understand of how to properly and reliably connect electrodes to cement-based materials. Through the application of IS to materials such as oil-well grouts, cement mortars and concretes, a great deal of valuable information about the effectiveness of IS has been gained. Oil-well cementing is somewhat limited by the inability to make measurements in the well-bore. By applying IS to oil-well grouts in a laboratory environment, it was demonstrated that IS is a viable technique with which to test the electrical and transport properties of these materials in-situ. Also, IS was shown to have the ability to measure the electrical conductivity of cement mortars with such accuracy, that very subtle changes in properties can be monitored and quantified. Through the use of IS and theoretical models, the complex interplay between the interfacial transition

  6. Power transport to the poloidal divertor experiment scoop limiter

    International Nuclear Information System (INIS)

    Kugel, H.W.; Budny, R.; Fonck, R.

    1987-01-01

    Power transport to the Poloidal Divertor Experiment graphite scoop limiter was measured during both ohmic- and neutral-beam-heated discharges by observing its front face temperatures using an infrared camera. Measurements were made as a function of a plasma density, current, position, fueling mode, and heating power for both co- and counter-neutral beam injection. The measured thermal load on the scoop limiter was 25 to 50%. of the total plasma heating power. The measured peak front face midplane temperature was 1500 0 C, corresponding to a peak surface power density of 3 kW/cm/sup 2/. This power density implies an effective parallel power flow of 54 kW/cm/sup 2/ in agreement with the radial power distribution extrapolated from television Thomson scattering and calorimetry measurements

  7. High Fill-Factor Transport Experiments on the HCX

    International Nuclear Information System (INIS)

    Prost, L R; Seidl, P A; Lund, S M

    2004-01-01

    Heavy-ion induction linacs have application as drivers for high energy density physics studies and ultimately as drivers for inertial fusion energy. Experiments on the High-Current Experiment (HCX) at LBNL explore heavy-ion beam transport at high fill factors (i.e., the ratio of the maximum transverse extent of the beam to the physical aperture). The fill factor has a large impact on the cost of multi-beam induction accelerators, the 80% fill factor compared with 60% would reduce the cost of an HIF driver by about 1/3. With a coasting low-emittance 1 MeV K + beam, transport through ten electrostatic quadrupoles was achieved at high beam fill factor (80%) without observed emittance growth and with little beam loss ((le) 1%), even though the initial beam distribution is neither ideal nor in thermal equilibrium, see Figure. While 10 quadrupoles are too few for settling questions of emittance evolution in a long system, they are very relevant for studying the rapid initial evolution of the emittance and beam profile that is expected in the front end of an accelerator. Studies at higher fill factors are planned, so that the failure mode can be established. Good envelope control was achieved, suggesting that, in a longer lattice of similar design, rematching only every ten lattice periods (at 80% fill factor) will be sufficient. Agreement was reached between an improved envelope model and the data. Improvements to the model are: realistic quadrupole fringe fields based on 3D field calculations; quadrupole E z from the 3D lattice structure and corresponding radial focusing force; and corrections due to the grounded slit plates of the intercepting diagnostics that short out the self-field of the beam near those plates. We also find that understanding and controlling the time dependence of the envelope parameters is critical to achieving high fill factors, notably because of the injector and matching section dynamics

  8. Reactive transport modeling of the ABM experiment with Comsol Multiphysics

    International Nuclear Information System (INIS)

    Pekala, Marek; Idiart, Andres; Arcos, David

    2012-01-01

    Document available in extended abstract form only. The Swedish Organisation for Radioactive Waste Disposal (SKB) is considering disposal of the High Level Waste in a deep underground repository in a crystalline rock. According to the disposal concept, bentonite clay will be used in the near-field of the waste packages as buffer material. From solute transport point of view, the bentonite buffer is expected to provide a favourable environment, where radionuclide migration would be limited to slow diffusion and further retarded by sorption. In the KBS-3 repository design, the MX-80 bentonite is the reference buffer material. However, SKB has also been investigating alternative buffer materials. To this end, the field experiment Alternative Buffer Materials (ABM) was started at the Aespoe URL in 2006. Three packages of eleven different compacted bentonite blocks in different configurations have been tested over varying time scales. The packages with outer diameter of 0.28 m were deposited into 3 meter deep boreholes. After installation, packages were saturated and heated differently to target values. This contribution concerns the evolution of Package 1, which was initiated in December 2006 and ran for about 2.5 years. Post-mortem examination after retrieval showed that the initially contrasting chloride concentrations and cation-exchanger compositions between different bentonite blocks became significantly homogenised. It is thought that this behaviour could be explained as a first approximation by diffusion of major ions between the bentonite blocks coupled with cation-exchange. In this work, a modelling study to verify this hypothesis has been undertaken. In addition, the feasibility of implementing a reactive transport model into the Finite Element code COMSOL Multiphysics has been tested. The model considers a two-dimensional axisymmetric geometry of the depositional borehole, and includes coupled diffusion and cation-exchange of Na, K, Ca and Mg (as a chloride

  9. Modal analysis of the thermal conductivity of nanowires: examining unique thermal transport features

    Science.gov (United States)

    Samaraweera, Nalaka; Larkin, Jason M.; Chan, Kin L.; Mithraratne, Kumar

    2018-06-01

    In this study, unique thermal transport features of nanowires over bulk materials are investigated using a combined analysis based on lattice dynamics and equilibrium molecular dynamics (EMD). The evaluation of the thermal conductivity (TC) of Lenard–Jones nanowires becomes feasible due to the multi-step normal mode decomposition (NMD) procedure implemented in the study. A convergence issue of the TC of nanowires is addressed by the NMD implementation for two case studies, which employ pristine nanowires (PNW) and superlattice nanowires. Interestingly, mode relaxation times at low frequencies of acoustic branches exhibit signs of approaching constant values, thus indicating the convergence of TC. The TC evaluation procedure is further verified by implementing EMD-based Green–Kubo analysis, which is based on a fundamentally different physical perspective. Having verified the NMD procedure, the non-monotonic trend of the TC of nanowires is addressed. It is shown that the principal cause for the observed trend is due to the competing effects of long wavelength phonons and phonon–surface scatterings as the nanowire’s cross-sectional width is changed. A computational procedure is developed to decompose the different modal contribution to the TC of shell alloy nanowires (SANWs) using virtual crystal NMD and the Allen–Feldman theory. Several important conclusions can be drawn from the results. A propagons to non-propagons boundary appeared, resulting in a cut-off frequency (ω cut); moreover, as alloy atomic mass is increased, ω cut shifts to lower frequencies. The existence of non-propagons partly causes the low TC of SANWs. It can be seen that modes with low frequencies demonstrate a similar behavior to corresponding modes of PNWs. Moreover, lower group velocities associated with higher alloy atomic mass resulted in a lower TC of SANWs.

  10. FOREIGN EXPERIENCE OF MANAGEMENT AND NORMATIVELY-LEGAL ADJUSTING BY INTERNATIONAL TRANSPORTATIONS

    Directory of Open Access Journals (Sweden)

    Nataliya Grigorievna Kuftinova

    2015-09-01

    Full Text Available In this article foreign experience of management is examined by international transportations and prospects of development of management information by bus transportations and transportations of loads. Normatively-legal adjusting, basic norms of domestic law as article of intergovernmental agreements on international transportations.

  11. Permeable barrier materials for strontium immobilization: Unsaturated flow apparatus determination of hydraulic conductivity -- Column sorption experiments

    International Nuclear Information System (INIS)

    Moody, T.E.; Conca, J.

    1996-09-01

    Selected materials were tested to emulate a permeable barrier and to examine the (1) capture efficiency of these materials relating to the immobilization of strontium-90 and hexavalent chromium (Cr 6+ ) in Hanford Site groundwater; and (2) hydraulic conductivity of the barrier material relative to the surrounding area. The emplacement method investigated was a permeable reactive barrier to treat contaminated groundwater as it passes through the barrier. The hydraulic conductivity function was measured for each material, and retardation column experiments were performed for each material. Measurements determining the hydraulic conductivity at unsaturated through saturated water content were executed using the Unsaturated Flow Apparatus

  12. Computer-assisted comparison of analysis and test results in transportation experiments

    International Nuclear Information System (INIS)

    Knight, R.D.; Ammerman, D.J.; Koski, J.A.

    1998-01-01

    As a part of its ongoing research efforts, Sandia National Laboratories' Transportation Surety Center investigates the integrity of various containment methods for hazardous materials transport, subject to anomalous structural and thermal events such as free-fall impacts, collisions, and fires in both open and confined areas. Since it is not possible to conduct field experiments for every set of possible conditions under which an actual transportation accident might occur, accurate modeling methods must be developed which will yield reliable simulations of the effects of accident events under various scenarios. This requires computer software which is capable of assimilating and processing data from experiments performed as benchmarks, as well as data obtained from numerical models that simulate the experiment. Software tools which can present all of these results in a meaningful and useful way to the analyst are a critical aspect of this process. The purpose of this work is to provide software resources on a long term basis, and to ensure that the data visualization capabilities of the Center keep pace with advancing technology. This will provide leverage for its modeling and analysis abilities in a rapidly evolving hardware/software environment

  13. Using Coupled Mesoscale Experiments and Simulations to Investigate High Burn-Up Oxide Fuel Thermal Conductivity

    Science.gov (United States)

    Teague, Melissa C.; Fromm, Bradley S.; Tonks, Michael R.; Field, David P.

    2014-12-01

    Nuclear energy is a mature technology with a small carbon footprint. However, work is needed to make current reactor technology more accident tolerant and to allow reactor fuel to be burned in a reactor for longer periods of time. Optimizing the reactor fuel performance is essentially a materials science problem. The current understanding of fuel microstructure have been limited by the difficulty in studying the structure and chemistry of irradiated fuel samples at the mesoscale. Here, we take advantage of recent advances in experimental capabilities to characterize the microstructure in 3D of irradiated mixed oxide (MOX) fuel taken from two radial positions in the fuel pellet. We also reconstruct these microstructures using Idaho National Laboratory's MARMOT code and calculate the impact of microstructure heterogeneities on the effective thermal conductivity using mesoscale heat conduction simulations. The thermal conductivities of both samples are higher than the bulk MOX thermal conductivity because of the formation of metallic precipitates and because we do not currently consider phonon scattering due to defects smaller than the experimental resolution. We also used the results to investigate the accuracy of simple thermal conductivity approximations and equations to convert 2D thermal conductivities to 3D. It was found that these approximations struggle to predict the complex thermal transport interactions between metal precipitates and voids.

  14. Conducting Action Research in Kenyan Primary Schools: A Narrative of Lived Experiences

    Science.gov (United States)

    Otienoh, Ruth

    2015-01-01

    This paper is a narrative of my personal experiences of conducting action research in Kenyan primary schools. It highlights the opportunities, successes, challenges and dilemmas I encountered during the process: from the school hunting period, to the carrying out of the actual research in two schools, with four teachers. This study reveals that…

  15. Experiment and prediction on thermal conductivity of Al2O3/ZnO ...

    Indian Academy of Sciences (India)

    Administrator

    Experiment and prediction on thermal conductivity of Al2O3/ZnO nano thin film interface structure. PING YANG*, LIQIANG ZHANG, HAIYING YANG†, DONGJING LIU and XIALONG LI. Laboratory of Advanced Manufacturing and Reliability for MEMS/NEMS/OEDS,. School of Mechanical Engineering, Jiangsu University, ...

  16. Using Conductivity Measurements to Determine the Identities and Concentrations of Unknown Acids: An Inquiry Laboratory Experiment

    Science.gov (United States)

    Smith, K. Christopher; Garza, Ariana

    2015-01-01

    This paper describes a student designed experiment using titrations involving conductivity measurements to identify unknown acids as being either HCl or H[subscript 2]SO[subscript 4], and to determine the concentrations of the acids, thereby improving the utility of standard acid-base titrations. Using an inquiry context, students gain experience…

  17. 21 CFR 101.108 - Temporary exemptions for purposes of conducting authorized food labeling experiments.

    Science.gov (United States)

    2010-04-01

    ... authorized food labeling experiments. 101.108 Section 101.108 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION FOOD LABELING Exemptions From Food Labeling Requirements § 101.108 Temporary exemptions for purposes of conducting authorized food...

  18. Radiation and gas conduction heat transport across a helium dewer multilayer insulation system

    Energy Technology Data Exchange (ETDEWEB)

    Green, M.A. [Lawrence Berkeley Lab., CA (United States)

    1995-02-01

    This report describes a method for calculating mixed heat transfer through the multilayer insulation used to insulated a 4K liquid helium cryostat. The method described permits one to estimate the insulation potential for a multilayer insulation system from first principles. The heat transfer regimes included are: radiation, conduction by free molecule gas conduction, and conduction through continuum gas conduction. Heat transfer in the transition region between the two gas conduction regimes is also included.

  19. Experience and prospects of WWER-1000 reactor spent fuel transport

    International Nuclear Information System (INIS)

    Kondratyev, A.N.; Yershov, V.N.; Kozlov, Yu.V.; Kosarev, Yu.A.; Ilyin, Yu.V.; Pavlov, M.S.

    1989-01-01

    The paper deals with the USSR experience in shipping the commercial WWER-1000 reactor spent fuel in TK-10 and TK-13 casks. The cask designs, their basic characteristics and the WWER-1000 spent fuel features are described. An example of calculational/experimental approach in the design of a basket (one of the most important components) for spent fuel assembly (SFA) accommodation in a cask is given. The main problems of future development works are presented in brief. A concept of development of nuclear power industry with the closed fuel cycle is assumed in the Soviet Union, hence the spent nuclear fuel is to be transported from NPPs to reprocessing plants. To transport WWER-1000 spent fuel, the casks of two types were developed. These are: a pilot TK-10 cask of 3t capacity in fuel; a commercial TK-13 cask of ∼6t capacity in fuel. The pilot TK-10 cask is thick-walled (360mm) cylindrical vessel manufactured of steel shells and a bottom welded to each other. The material of the body is carbon steel. There is a steel jacket on the outer side of the cask body and at 120 mm distance off the bottom. On its cylindrical part between the jacket and the body there are T-shaped circular ribs acting as shock-absorbers. The space between the jacket and the body is filled with ethylene glycol solution of 65 degree C crystallization temperature, which functions as a neutron shielding. The TK-10 cask coolant is water or air (nitrogen) at minor excess pressure resulted from FA heatup after the cask sealing

  20. Feedback from operational experience in front-end transportation

    International Nuclear Information System (INIS)

    Mondonel, J.L.; Parison, C.

    1998-01-01

    Transport forms an integral part of the nuclear fuel cycle, representing the strategic link between each stage of the cycle. In a way there is a transport cycle that parallels the nuclear fuel cycle. This concerns particularly the front-end of the cycle whose steps - mining conversion, enrichment and fuel fabrication - require numerous transports. Back-end shipments involve a handful of countries, but front-end transports involve all five continents, and many exotic countries. All over Europe such transports are routinely performed with an excellent safety track record. Transnucleaire dominates the French nuclear transportation market and carries out both front and back-end transports. For instance in 1996 more than 28,400 front-end packages were transported as well as more than 3,600 back-end packages. However front-end transport is now a business undergoing much change. A nuclear transportation company must now cope with an evolving picture including new technical requirements, new transportation schemes and new business conditions. This paper describes the latest evolutions in terms of front-end transportation and the way this activity is carried out by Transnucleaire, and goes on to discuss future prospects. (authors)

  1. Developing a Rubric and Best Practices for Conducting Counts of Non-Motorized Transportation Users

    Science.gov (United States)

    2016-01-01

    Over the past five years non-motorized modes of transportation have become ever more prevalent on Utahs roadways. Historically, these modes have not been included in traffic counts nor are they accurately represented in the long range planning mod...

  2. Mesoscopic conductance fluctuations in high-T{sub c} grain boundary Josephson junctions: Coherent quasiparticle transport

    Energy Technology Data Exchange (ETDEWEB)

    Tafuri, F. [Dip. Ingegneria dell' Informazione, Seconda Universita di Napoli, 81031 Aversa (Italy); CNR-INFM Coherentia, Dip. Scienze Fisiche, Universita di Napoli Federico II, 80125 Naples (Italy)], E-mail: tafuri@na.infn.it; Tagliacozzo, A.; Born, D.; Stornaiuolo, D. [CNR-INFM Coherentia, Dip. Scienze Fisiche, Universita di Napoli Federico II, 80125 Naples (Italy); Gambale, E.; Dalena, D. [Dip. Ingegneria dell' Informazione, Seconda Universita di Napoli, 81031 Aversa (Italy); Lombardi, F. [Department of Microelectronics and Nanoscience, MINA, Chalmers University of Technology, 41296 Goeteborg (Sweden)

    2007-09-01

    Magneto-fluctuations of the normal resistance R{sub N} have been reproducibly observed in YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} (HTS) biepitaxial grain boundary junctions at low temperatures. We attribute them to mesoscopic transport in narrow channels across the grain boundary line. The Thouless energy appears to be the relevant energy scale. Possible implications on the understanding of coherent transport of quasiparticles in HTS and of the dissipation mechanisms are discussed.

  3. Effect of gravity on colloid transport through water-saturated columns packed with glass beads: modeling and experiments.

    Science.gov (United States)

    Chrysikopoulos, Constantinos V; Syngouna, Vasiliki I

    2014-06-17

    The role of gravitational force on colloid transport in water-saturated columns packed with glass beads was investigated. Transport experiments were performed with colloids (clays: kaolinite KGa-1b, montmorillonite STx-1b). The packed columns were placed in various orientations (horizontal, vertical, and diagonal) and a steady flow rate of Q = 1.5 mL/min was applied in both up-flow and down-flow modes. All experiments were conducted under electrostatically unfavorable conditions. The experimental data were fitted with a newly developed, analytical, one-dimensional, colloid transport model. The effect of gravity is incorporated in the mathematical model by combining the interstitial velocity (advection) with the settling velocity (gravity effect). The results revealed that flow direction influences colloid transport in porous media. The rate of particle deposition was shown to be greater for up-flow than for down-flow direction, suggesting that gravity was a significant driving force for colloid deposition.

  4. Laboratory experiments on solute transport in bimodal porous media under cyclic precipitation-evaporation boundary conditions

    Science.gov (United States)

    Cremer, Clemens; Neuweiler, Insa

    2016-04-01

    Flow and solute transport in the shallow subsurface is strongly governed by atmospheric boundary conditions. Erratically varying infiltration and evaporation cycles lead to alternating upward and downward flow, as well as spatially and temporally varying water contents and associated hydraulic conductivity of the prevailing materials. Thus presenting a highly complicated, dynamic system. Knowledge of subsurface solute transport processes is vital to assess e.g. the entry of, potentially hazardous, solutes to the groundwater and nutrient uptake by plant roots and can be gained in many ways. Besides field measurements and numerical simulations, physical laboratory experiments represent a way to establish process understanding and furthermore validate numerical schemes. With the aim to gain a better understanding and to quantify solute transport in the unsaturated shallow subsurface under natural precipitation conditions in heterogeneous media, we conduct physical laboratory experiments in a 22 cm x 8 cm x 1 cm flow cell that is filled with two types of sand and apply cyclic infiltration-evaporation phases at the soil surface. Pressure at the bottom of the domain is kept constant. Following recent studies (Lehmann and Or, 2009; Bechtold et al., 2011a), heterogeneity is introduced by a sharp vertical interface between coarse and fine sand. Fluorescent tracers are used to i) qualitatively visualize transport paths within the domain and ii) quantify solute leaching at the bottom of the domain. Temporal and spatial variations in water content during the experiment are derived from x-ray radiographic images. Monitored water contents between infiltration and evaporation considerably changed in the coarse sand while the fine sand remained saturated throughout the experiments. Lateral solute transport through the interface in both directions at different depths of the investigated soil columns were observed. This depended on the flow rate applied at the soil surface and

  5. Ion transport study in polymer-nanocomposite films by dielectric spectroscopy and conductivity scaling

    Science.gov (United States)

    Tripathi, Namrata; Thakur, Awalendra K.; Shukla, Archana; Marx, David T.

    2015-07-01

    The dielectric and conductivity response of polymer nanocomposite electrolytes (films of PMMA4LiClO4 dispersed with nano-CeO2 powder) have been investigated. The dielectric behavior was analyzed via the dielectric permittivity (ε‧) and dissipation factor (tan δ) of the samples. The analysis has shown the presence of space charge polarization at lower frequencies. The real part of ac conductivity spectra of materials obeys the Jonscher power law. Parameters such as dc conductivity, hopping rate, activation energies and the concentration of charge carriers were determined from conductivity data using the Almond West formalism. It is observed that the higher ionic conductivity at higher temperature is due to increased thermally-activated hopping rates accompanied by a significant increase in carrier concentration. The contribution of carrier concentration to the total conductivity is also confirmed from activation energy of migration conduction and from Summerfield scaling. The ac conductivity results are also well correlated with TEM results.

  6. Transient Transport Experiments in the CDX-U Spherical Torus

    International Nuclear Information System (INIS)

    T. Munsat; P.C. Efthimion; B. Jones; R. Kaita; R. Majeski; D. Stutman; G. Taylor

    2001-01-01

    Electron transport has been measured in the Current Drive Experiment-Upgrade (CDX-U) using two separate perturbative techniques. Gas modulation at the plasma edge was used to introduce cold-pulses which propagate towards the plasma center, providing time-of-flight information leading to a determination of chi(subscript e) as a function of radius. Sawteeth at the q=1 radius (r/a ∼ 0.15) induced heat-pulses which propagated outward towards the plasma edge, providing a complementary time-of-flight based chi(subscript e) profile measurement. This work represents the first localized measurement of chi(subscript e) in a spherical torus. It is found that chi(subscript e) = 1-2 meters squared per second in the plasma core (r/a < 1/3), increasing by an order of magnitude or more outside of this region. Furthermore, the chi(subscript e) profile exhibits a sharp transition near r/a = 1/3. Spectral and profile analyses of the soft X-rays, scanning interferometer, and edge probe data show no evidence of a significant magnetic island causing the high chi(subscript e) region

  7. The influence of mass transfer on solute transport in column experiments with an aggregated soil

    Science.gov (United States)

    Roberts, Paul V.; Goltz, Mark N.; Summers, R. Scott; Crittenden, John C.; Nkedi-Kizza, Peter

    1987-06-01

    The spreading of concentration fronts in dynamic column experiments conducted with a porous, aggregated soil is analyzed by means of a previously documented transport model (DFPSDM) that accounts for longitudinal dispersion, external mass transfer in the boundary layer surrounding the aggregate particles, and diffusion in the intra-aggregate pores. The data are drawn from a previous report on the transport of tritiated water, chloride, and calcium ion in a column filled with Ione soil having an average aggregate particle diameter of 0.34 cm, at pore water velocities from 3 to 143 cm/h. The parameters for dispersion, external mass transfer, and internal diffusion were predicted for the experimental conditions by means of generalized correlations, independent of the column data. The predicted degree of solute front-spreading agreed well with the experimental observations. Consistent with the aggregate porosity of 45%, the tortuosity factor for internal pore diffusion was approximately equal to 2. Quantitative criteria for the spreading influence of the three mechanisms are evaluated with respect to the column data. Hydrodynamic dispersion is thought to have governed the front shape in the experiments at low velocity, and internal pore diffusion is believed to have dominated at high velocity; the external mass transfer resistance played a minor role under all conditions. A transport model such as DFPSDM is useful for interpreting column data with regard to the mechanisms controlling concentration front dynamics, but care must be exercised to avoid confounding the effects of the relevant processes.

  8. Application of the three-dimensional transport code to analysis of the neutron streaming experiment

    International Nuclear Information System (INIS)

    Chatani, K.; Slater, C.O.

    1990-01-01

    The neutron streaming through an experimental mock-up of a Clinch River Breeder Reactor (CRBR) prototypic coolant pipe chaseway was recalculated with a three-dimensional discrete ordinates code. The experiment was conducted at the Tower Shielding Facility at Oak Ridge National Laboratory in 1976 and 1977. The measurement of the neutron flux, using Bonner ball detectors, indicated nine orders of attenuation in the empty pipeway, which contained two 90-deg bends and was surrounded by concrete walls. The measurement data were originally analyzed using the DOT3.5 two-dimensional discrete ordinates radiation transport code. However, the results did not agree with measurement data at the bend because of the difficulties in modeling the three-dimensional configurations using two-dimensional methods. The two-dimensional calculations used a three-step procedure in which each of the three legs making the two 90-deg bends was a separate calculation. The experiment was recently analyzed with the TORT three-dimensional discrete ordinates radiation transport code, not only to compare the calculational results with the experimental results, but also to compare with results obtained from analyses in Japan using DOT3.5, MORSE, and ENSEMBLE, which is a three-dimensional discrete ordinates radiation transport code developed in Japan

  9. OGUMI-A new mobile application to conduct common-pool resource experiments in continuous time.

    Directory of Open Access Journals (Sweden)

    Gunnar Brandt

    Full Text Available OGUMI is an Android-based open source mobile application for conducting Common-Pool Resource Experiments, Choice Experiments, and Questionnaires in the field, in the laboratory, and online. A main feature of OGUMI is its capacity to capture real-time changes in human behaviour in response to a dynamically varying resource. OGUMI is simple (for example, likewise other existing software, it does not require expertise in behavioural game theory, stable, and extremely flexible with respect to the user-resource model running in the background. Here we present the motivation for the development of OGUMI and we discuss its main features with an example application.

  10. Video of Miscible Fluid Experiment Conducted on NASA Low Gravity Airplane

    Science.gov (United States)

    2003-01-01

    This is a video of dyed water being injected into glycerin in a 2.2 centimeter (cm) diameter test tube. The experiment was conducted on the KC-135 aircraft, a NASA plane that creates microgravity and 2g conditions as it maneuvers through multiple parabolas. The water is less dense and so it rises to the top of the glycerin. The goal of the experiment was to determine if a blob of a miscible fluid would spontaneously become spherical in a microgravity environment.

  11. Tax and green transport plans: a survey of UK experience

    International Nuclear Information System (INIS)

    Potter, S.; Smith, M.; Rye, T.

    1999-01-01

    The widespread adoption of Green Transport Plans (GTPs) by employer has become an important aim of the UK government transport policy as it tries to find ways of reducing transport demand. However, the tax treatment of employee benefits that form part of many GTPs has been identified by the government and others as a potential barrier to their adoption. Based on telephone interviews with employers and meetings with tax and transport experts, this paper confirms this perception. It also explains precisely how tax forms a barrier to GTP implementation, reviews the approaches taken to this problem in three other countries and makes outline proposals for reform and further research. (Author)

  12. Barriers to Conducting Supervised Agricultural Experiences as Perceived by Preservice Agricultural Education Teachers

    Directory of Open Access Journals (Sweden)

    J. Joey Blackburn

    2014-10-01

    Full Text Available The purpose of this descriptive study was to assess preservice agriculture teachers’ perceptions of the importance of Supervised Agricultural Experience (SAE and their views on barriers to conducting SAE. A census of the sophomore-level agricultural education course at Oklahoma State University was conducted to measure perceptions at the beginning and end of the course. This study was framed upon Ajzen’s Theory of Planned Behavior. Results indicated that preservice teachers perceived SAE was an important component of agricultural education and important at the secondary school they attended. The greatest barrier to conducting SAE was their lack of familiarity with newer SAE categories. This was true at both the beginning and end of the course. It is recommended that preservice teachers receive instruction on and experiences in all types of SAE. This would increase the likelihood of preservice teachers perceiving they have control over this barrier regarding SAE implementation. This cohort of preservice teachers should be surveyed over time to determine change in their perceptions of barriers to SAE implementation as they progress in the agricultural education program and through their careers. Further, the views of in-service teachers should also be assessed to determine if perceived barriers differ with professional experience.

  13. Conduction band splitting and transport properties of Bi2Se3

    Czech Academy of Sciences Publication Activity Database

    Navrátil, Jiří; Horák, Jaromír; Plecháček, T.; Kamba, Stanislav; Lošťák, P.; Dyck, J. S.; Chen, W.; Uher, C.

    2004-01-01

    Roč. 177, č. 4-5 (2004), s. 1704-1712 ISSN 0022-4596 R&D Projects: GA AV ČR KSK2050602; GA AV ČR KSK1010104 Keywords : transport properties * carrier scattering Subject RIV: CA - Inorganic Chemistry Impact factor: 1.815, year: 2004

  14. Spaceflight hardware for conducting plant growth experiments in space: the early years 1960-2000

    Science.gov (United States)

    Porterfield, D. M.; Neichitailo, G. S.; Mashinski, A. L.; Musgrave, M. E.

    2003-01-01

    The best strategy for supporting long-duration space missions is believed to be bioregenerative life support systems (BLSS). An integral part of a BLSS is a chamber supporting the growth of higher plants that would provide food, water, and atmosphere regeneration for the human crew. Such a chamber will have to be a complete plant growth system, capable of providing lighting, water, and nutrients to plants in microgravity. Other capabilities include temperature, humidity, and atmospheric gas composition controls. Many spaceflight experiments to date have utilized incomplete growth systems (typically having a hydration system but lacking lighting) to study tropic and metabolic changes in germinating seedlings and young plants. American, European, and Russian scientists have also developed a number of small complete plant growth systems for use in spaceflight research. Currently we are entering a new era of experimentation and hardware development as a result of long-term spaceflight opportunities available on the International Space Station. This is already impacting development of plant growth hardware. To take full advantage of these new opportunities and construct innovative systems, we must understand the results of past spaceflight experiments and the basic capabilities of the diverse plant growth systems that were used to conduct these experiments. The objective of this paper is to describe the most influential pieces of plant growth hardware that have been used for the purpose of conducting scientific experiments during the first 40 years of research. c2002 COSPAR. Published by Elsevier Science Ltd. All rights reserved.

  15. Ion transport study in polymer-nanocomposite films by dielectric spectroscopy and conductivity scaling

    Energy Technology Data Exchange (ETDEWEB)

    Tripathi, Namrata, E-mail: ntripat@ilstu.edu [Department of Physics, Illinois State University, Normal, IL 61790 (United States); Thakur, Awalendra K. [Department of Physics, Indian Institute of Technology Patna, Bihar 800013 (India); Shukla, Archana [Department of Metallurgical Engineering & Materials Science, Indian Institute of Technology, Bombay 721302 (India); Marx, David T. [Department of Physics, Illinois State University, Normal, IL 61790 (United States)

    2015-07-15

    The dielectric and conductivity response of polymer nanocomposite electrolytes (films of PMMA{sub 4}LiClO{sub 4} dispersed with nano-CeO{sub 2} powder) have been investigated. The dielectric behavior was analyzed via the dielectric permittivity (ε′) and dissipation factor (tan δ) of the samples. The analysis has shown the presence of space charge polarization at lower frequencies. The real part of ac conductivity spectra of materials obeys the Jonscher power law. Parameters such as dc conductivity, hopping rate, activation energies and the concentration of charge carriers were determined from conductivity data using the Almond West formalism. It is observed that the higher ionic conductivity at higher temperature is due to increased thermally-activated hopping rates accompanied by a significant increase in carrier concentration. The contribution of carrier concentration to the total conductivity is also confirmed from activation energy of migration conduction and from Summerfield scaling. The ac conductivity results are also well correlated with TEM results.

  16. Flow and transport at the Las Cruces trench site: Experiment IIb

    International Nuclear Information System (INIS)

    Vinson, J.; Hills, R.G.; Wierenga, P.J.; Young, M.H.

    1997-07-01

    The US Nuclear Regulatory Commission (NRC) has been directed by Congress in the Low Level Waste Policy Act of 1980 to develop regulatory guidance and assist the individual states and compacts in siting and assessing future low level radioactive waste (LLW) disposal facilities. Three water flow and solute transport experiments were performed as part of a comprehensive field trench study near Las Cruces, New Mexico to test deterministic and stochastic models of vadose zone flow and transport. This report presents partial results from the third experiment (experiment IIb). Experiments IIa and b were conducted on the North side of the trench, on a plot 1.22 m wide by 12 m long, perpendicular to the trench. The area was drip irrigated during two time periods with water containing a variety of tracers. The advance of the water front during the two irrigation episodes was measured with tensiometers and neutron probes. Solute front positions were determined from soil solution sampling through suction samplers and from disturbed sampling. The results from experiment IIb show predominantly downward water movement through the layered unsaturated soil, as evidenced from neutron probe data and gravimetric sampling. Tritium plumes were only half as deep and half as wide as the water plumes at 310 days after the beginning of experiment IIb. Chromium, applied as Cr(VI), moved a readily as, and similar to tritium, but there was a loss of mass due to reduction of Cr(VI) to Cr(III). Chloride and nitrate, initially present at high concentrations in the soil solution, were displaced by the low concentration irrigation water, resulting in chloride and nitrate concentration distributions that looked like negative images of the tritium distributions. The extensive data presented should serve well as a data base for model testing

  17. Flow and transport at the Las Cruces trench site: Experiment IIb

    Energy Technology Data Exchange (ETDEWEB)

    Vinson, J.; Hills, R.G. [New Mexico State Univ., Las Cruces, NM (United States); Wierenga, P.J.; Young, M.H. [Arizona Univ., Tucson, AZ (United States). Dept. of Soil and Water Science

    1997-07-01

    The US Nuclear Regulatory Commission (NRC) has been directed by Congress in the Low Level Waste Policy Act of 1980 to develop regulatory guidance and assist the individual states and compacts in siting and assessing future low level radioactive waste (LLW) disposal facilities. Three water flow and solute transport experiments were performed as part of a comprehensive field trench study near Las Cruces, New Mexico to test deterministic and stochastic models of vadose zone flow and transport. This report presents partial results from the third experiment (experiment IIb). Experiments IIa and b were conducted on the North side of the trench, on a plot 1.22 m wide by 12 m long, perpendicular to the trench. The area was drip irrigated during two time periods with water containing a variety of tracers. The advance of the water front during the two irrigation episodes was measured with tensiometers and neutron probes. Solute front positions were determined from soil solution sampling through suction samplers and from disturbed sampling. The results from experiment IIb show predominantly downward water movement through the layered unsaturated soil, as evidenced from neutron probe data and gravimetric sampling. Tritium plumes were only half as deep and half as wide as the water plumes at 310 days after the beginning of experiment IIb. Chromium, applied as Cr(VI), moved a readily as, and similar to tritium, but there was a loss of mass due to reduction of Cr(VI) to Cr(III). Chloride and nitrate, initially present at high concentrations in the soil solution, were displaced by the low concentration irrigation water, resulting in chloride and nitrate concentration distributions that looked like negative images of the tritium distributions. The extensive data presented should serve well as a data base for model testing.

  18. Aeolian transport of biota with dust: A wind tunnel experiment

    Science.gov (United States)

    Rivas, J. A., Jr.; Gill, T. E.; Van Pelt, R. S.; Walsh, E.

    2015-12-01

    Ephemeral wetlands are ideal sources for dust emission, as well as repositories for dormant stages of aquatic invertebrates. An important component of invertebrate dispersal and colonization to new areas is the ability to be entrained into the atmosphere. Aquatic invertebrate eggs fall within the size of dust and sand grains (30-600μm), are less dense and aerodynamically shaped. We have shown previously that aquatic invertebrates can be dispersed long distances in dust storms but the extent of transport of taxa based on diapausing egg size/morphology has not been investigated. Here, we control the wind erosion process in a wind tunnel to test entrainment of diapausing stages of brine shrimp, clam shrimp, tadpole shrimp, fairy shrimp, Daphnia, and the rotifers Brachionus plicatilis and B. calyciflorus into the air by saltation. Diapausing eggs were mixed with sterilized wind-erodible soil. The soil/egg mixture was moistened with distilled water and air dried to form a crust. Dust was generated in a wind tunnel by releasing sand grains that act as saltator material similar to wind-entrained natural sands. Maximum wind velocity was 10m/s and entrained particles were sampled through an isokinetic horizontal intake opening. Aeolian sediment was collected from three points in the system; transfer section for coarse sediment, the pan subtending a settling chamber for finer saltation-sized sediment, and two paper filters for suspension-sized sediment. Samples were then passed through 250 and 350 μm sieves to remove abrader sand and rehydrated with various sterile media depending on the type of organism. We retrieved viable brine, fairy, and tadpole shrimp, ostracods, Daphnia, and diapausing eggs of the rotifers after hydration. This experiment demonstrates that resting stages of many invertebrates can be wind-eroded due to size and egg morphology and remain viable under controlled conditions mimicking dust emission.

  19. Theoretical studies of optics and charge transport in organic conducting oligomers and polymers: Rational design of improved transparent and conducting polymers

    Science.gov (United States)

    Hutchison, Geoffrey Rogers

    Theoretical studies on a variety of oligo- and polyheterocycles elucidate their optical and charge transport properties, suggesting new, improved transparent conductive polymers. First-principles calculations provide accurate methodologies for predicting both optical band gaps of neutral and cationic oligomers and intrinsic charge transfer rates. Multidimensional analysis reveals important motifs in chemical tailorability of oligoheterocycle optical and charge transport properties. The results suggest new directions for design of novel materials. Using both finite oligomer and infinite polymer calculations, the optical band gaps in polyheterocycles follow a modified particle-in-a-box formalism, scaling approximately as 1/N (where N is the number of monomer units) in short chains, saturating for long chains. Calculations demonstrate that band structure changes upon heteroatom substitution, (e.g., from polythiophene to polypyrrole) derive from heteroatom electron affinity. Further investigation of chemical variability in substituted oligoheterocycles using multidimensional statistics reveals the interplay between heteroatom and substituent in correlations between structure and redox/optical properties of neutral and cationic species. A linear correlation between band gaps of neutral and cationic species upon oxidation of conjugated oligomers, shows redshifts of optical absorption for most species and blueshifts for small band gap species. Interstrand charge-transport studies focus on two contributors to hopping-style charge transfer rates: internal reorganization energy and the electronic coupling matrix element. Statistical analysis of chemical variability of reorganization energies in oligoheterocycles proves the importance of reorganization energy in determining intrinsic charge transfer rates (e.g., charge mobility in unsubstituted oligothiophenes). Computed bandwidths across several oligothiophene crystal packing motifs show similar electron and hole bandwidths

  20. The influence of Ga{sup +} irradiation on the transport properties of mesoscopic conducting thin films

    Energy Technology Data Exchange (ETDEWEB)

    Barzola-Quiquia, J; Dusari, S; Bridoux, G; Bern, F; Molle, A; Esquinazi, P, E-mail: j.barzola@physik.uni-leipzig.de, E-mail: esquin@physik.uni-leipzig.de [Division of Superconductivity and Magnetism, Universitaet Leipzig, Linnestrasse 5, D-04103 Leipzig (Germany)

    2010-04-09

    We studied the influence of 30 keV Ga{sup +}-ions-commonly used in focused-ion-beam (FIB) devices-on the transport properties of thin crystalline graphite flakes, and La{sub 0.7}Ca{sub 0.3}MnO{sub 3} and Co thin films. The changes in electrical resistance were measured in situ during irradiation and also the temperature and magnetic field dependence before and after irradiation. Our results show that the transport properties of these materials strongly change at Ga{sup +} fluences much below those used for patterning and ion-beam-induced deposition (IBID), seriously limiting the use of FIB when the intrinsic properties of the materials of interest are of importance. We present a method that can be used to protect the sample as well as to produce selectively irradiation-induced changes.

  1. Electronic Transport Properties of Carbon-Nanotube Networks: The Effect of Nitrate Doping on Intratube and Intertube Conductances

    Science.gov (United States)

    Ketolainen, T.; Havu, V.; Jónsson, E. Ö.; Puska, M. J.

    2018-03-01

    The conductivity of carbon-nanotube (CNT) networks can be improved markedly by doping with nitric acid. In the present work, CNTs and junctions of CNTs functionalized with NO3 molecules are investigated to understand the microscopic mechanism of nitric acid doping. According to our density-functional-theory band-structure calculations, there is charge transfer from the CNT to adsorbed molecules indicating p -type doping. The average doping efficiency of the NO3 molecules is higher if the NO3 molecules form complexes with water molecules. In addition to electron transport along individual CNTs, we also study electron transport between different types (metallic, semiconducting) of CNTs. Reflecting the differences in the electronic structures of semiconducting and metallic CNTs, we find that in addition to turning semiconducting CNTs metallic, doping further increases electron transport most efficiently along semiconducting CNTs as well as through the junctions between them.

  2. CFD Analysis of a Slug Mixing Experiment Conducted on a VVER-1000 Model

    Directory of Open Access Journals (Sweden)

    F. Moretti

    2009-01-01

    Full Text Available A commercial CFD code was applied, for validation purposes, to the simulation of a slug mixing experiment carried out at OKB “Gidropress” scaled facility in the framework of EC TACIS project R2.02/02: “Development of safety analysis capabilities for VVER-1000 transients involving spatial variations of coolant properties (temperature or boron concentration at core inlet.” Such experimental model reproduces a VVER-1000 nuclear reactor and is aimed at investigating the in-vessel mixing phenomena. The addressed experiment involves the start-up of one of the four reactor coolant pumps (the other three remaining idle, and the presence of a tracer slug on the starting loop, which is thus transported to the reactor pressure vessel where it mixes with the clear water. Such conditions may occur in a boron dilution scenario, hence the relevance of the addressed phenomena for nuclear reactor safety. Both a pretest and a posttest CFD simulations of the mentioned experiment were performed, which differ in the definition of the boundary conditions (based either on nominal quantities or on measured quantities, resp.. The numerical results are qualitatively and quantitatively analyzed and compared against the measured data in terms of space and time tracer distribution at the core inlet. The improvement of the results due to the optimization of the boundary conditions is evidenced, and a quantification of the simulation accuracy is proposed.

  3. Experience of air transport of nuclear fuel material in Japan

    International Nuclear Information System (INIS)

    Yamashita, T.; Toguri, D.; Kawasaki, M.

    2004-01-01

    Certified Reference Materials (hereafter called as to CRMs), which are indispensable for Quality Assurance and Material Accountability in nuclear fuel plants, are being provided by overseas suppliers to Japanese nuclear entities as Type A package (non-fissile) through air transport. However, after the criticality accident at JCO in Japan, special law defining nuclear disaster countermeasures (hereafter called as to the LAW) has been newly enforced in June 2000. Thereafter, nuclear fuel materials must meet not only to the existing transport regulations but also to the LAW for its transport

  4. Structural Origins of Conductance Fluctuations in Gold–Thiolate Molecular Transport Junctions

    KAUST Repository

    French, William R.

    2013-03-21

    We report detailed atomistic simulations combined with high-fidelity conductance calculations to probe the structural origins of conductance fluctuations in thermally evolving Au-benzene-1,4-dithiolate-Au junctions. We compare the behavior of structurally ideal junctions (where the electrodes are modeled as flat surfaces) to structurally realistic, experimentally representative junctions resulting from break-junction simulations. The enhanced mobility of metal atoms in structurally realistic junctions results in significant changes to the magnitude and origin of the conductance fluctuations. Fluctuations are larger by a factor of 2-3 in realistic junctions compared to ideal junctions. Moreover, in junctions with highly deformed electrodes, the conductance fluctuations arise primarily from changes in the Au geometry, in contrast to results for junctions with nondeformed electrodes, where the conductance fluctuations are dominated by changes in the molecule geometry. These results provide important guidance to experimentalists developing strategies to control molecular conductance, and also to theoreticians invoking simplified structural models of junctions to predict their behavior. © 2013 American Chemical Society.

  5. Structural Origins of Conductance Fluctuations in Gold–Thiolate Molecular Transport Junctions

    KAUST Repository

    French, William R.; Iacovella, Christopher R.; Rungger, Ivan; Souza, Amaury Melo; Sanvito, Stefano; Cummings, Peter T.

    2013-01-01

    We report detailed atomistic simulations combined with high-fidelity conductance calculations to probe the structural origins of conductance fluctuations in thermally evolving Au-benzene-1,4-dithiolate-Au junctions. We compare the behavior of structurally ideal junctions (where the electrodes are modeled as flat surfaces) to structurally realistic, experimentally representative junctions resulting from break-junction simulations. The enhanced mobility of metal atoms in structurally realistic junctions results in significant changes to the magnitude and origin of the conductance fluctuations. Fluctuations are larger by a factor of 2-3 in realistic junctions compared to ideal junctions. Moreover, in junctions with highly deformed electrodes, the conductance fluctuations arise primarily from changes in the Au geometry, in contrast to results for junctions with nondeformed electrodes, where the conductance fluctuations are dominated by changes in the molecule geometry. These results provide important guidance to experimentalists developing strategies to control molecular conductance, and also to theoreticians invoking simplified structural models of junctions to predict their behavior. © 2013 American Chemical Society.

  6. NON-LINEAR TRANSIENT HEAT CONDUCTION ANALYSIS OF INSULATION WALL OF TANK FOR TRANSPORTATION OF LIQUID ALUMINUM

    Directory of Open Access Journals (Sweden)

    Miroslav M Živković

    2010-01-01

    Full Text Available This paper deals with transient nonlinear heat conduction through the insulation wall of the tank for transportation of liquid aluminum. Tanks designed for this purpose must satisfy certain requirements regarding temperature of loading and unloading, during transport. Basic theoretical equations are presented, which describe the problem of heat conduction finite element (FE analysis, starting from the differential equation of energy balance, taking into account the initial and boundary conditions of the problem. General 3D problem for heat conduction is considered, from which solutions for two- and one-dimensional heat conduction can be obtained, as special cases. Forming of the finite element matrices using Galerkin method is briefly described. The procedure for solving equations of energy balance is discussed, by methods of resolving iterative processes of nonlinear transient heat conduction. Solution of this problem illustrates possibilities of PAK-T software package, such as materials properties, given as tabular data, or analytical functions. Software also offers the possibility to solve nonlinear and transient problems with incremental methods. Obtained results for different thicknesses of the tank wall insulation materials enable its comparison in regards to given conditions

  7. Spent fuel and HLW transportation: The French experience

    International Nuclear Information System (INIS)

    Giraud, J.P.; Charles, J.L.

    1996-01-01

    Transportation of nuclear materials is a key component of the nuclear industry. Transportation takes place in the public domain. This relation with both population and environment has put transportation in the middle of a hard-toned debate. The nuclear transportation system has demonstrated its maturity in terms of safety, reliability, cost-efficiency and environmental respect, through a remarkable track record of successful accomplishments. For 30 years, large quantities of nuclear materials have been shipped smoothly and safely in France, Europe and overseas. General principles and safety rules have been carefully established by international experts, published as recommendations by the IAEA and enforced worldwide through national legislations. The international nuclear industry closely follows this framework, operating with comprehensive quality assurance programs

  8. UrbanTransport Solution An Experience From Prague

    African Journals Online (AJOL)

    unique firstlady

    Based on the result of the research ... associated with road transport like its impact on environment ..... Prague is utilizing a variety of marketing strategies used for many years in ... at strategic metro stations providing customers with maps , time ...

  9. Water transport through tall trees: A vertically-explicit, analytical model of xylem hydraulic conductance in stems.

    Science.gov (United States)

    Couvreur, Valentin; Ledder, Glenn; Manzoni, Stefano; Way, Danielle A; Muller, Erik B; Russo, Sabrina E

    2018-05-08

    Trees grow by vertically extending their stems, so accurate stem hydraulic models are fundamental to understanding the hydraulic challenges faced by tall trees. Using a literature survey, we showed that many tree species exhibit continuous vertical variation in hydraulic traits. To examine the effects of this variation on hydraulic function, we developed a spatially-explicit, analytical water transport model for stems. Our model allows Huber ratio, stem-saturated conductivity, pressure at 50% loss of conductivity, leaf area, and transpiration rate to vary continuously along the hydraulic path. Predictions from our model differ from a matric flux potential model parameterized with uniform traits. Analyses show that cavitation is a whole-stem emergent property resulting from nonlinear pressure-conductivity feedbacks that, with gravity, cause impaired water transport to accumulate along the path. Because of the compounding effects of vertical trait variation on hydraulic function, growing proportionally more sapwood and building tapered xylem with height, as well as reducing xylem vulnerability only at branch tips while maintaining transport capacity at the stem base, can compensate for these effects. We therefore conclude that the adaptive significance of vertical variation in stem hydraulic traits is to allow trees to grow tall and tolerate operating near their hydraulic limits. This article is protected by copyright. All rights reserved.

  10. UK experience of managing a radioactive materials transport event database

    International Nuclear Information System (INIS)

    Barton, N.J.; Barrett, J.A.

    1999-01-01

    A description is given of the transport event database RAMTED and the related annual accident and incident reports. This database covers accidents and incidents involving the transport of radioactive material in the UK from 1958 to the present day. The paper discusses the history and content of the database, the origin of event data contained in it, the criteria for inclusion and future developments. (author)

  11. Sustainable Transport: BRT experiences from Mexico and India

    DEFF Research Database (Denmark)

    Rogat, Jorge; Dhar, Subash; Joshi, Rutul

    2015-01-01

    Increasing population and urbanization is creating a steadily increasing demand for transportation in the cities of many developing countries, coinciding with rapid economic growth leading to increasing demand for higher standards of living and faster and more efficient modes of transportation...... transit (BRT). The BRT systems of Curitiba and Bogotá have subsequently been adopted all over the world with some variations. Implementation of two recent BRTs, Mexico City and Ahmedabad in India, are examined in this paper....

  12. Experience with fuel damage caused by abnormal conditions in handling and transporting operations

    International Nuclear Information System (INIS)

    Bailey, W.J.

    1983-01-01

    Pacific Northwest Laboratory (PNL) conducted a study to determine the expected condition of spent USA light-water reactor (LWR) fuel upon arrival at interim storage or fuel reprocessing facilities or, if fuel is declared a waste, at disposal facilities. Initial findings were described in an earlier PNL paper at PATRAM '80 and in a report. Updated findings are described in this paper, which includes an evaluation of information obtained from the literature and a compilation of cases of known or suspected damage to fuel as a result of handling and/or transporting operations. To date, PNL has evaluated 123 actual cases (98 USA and 25 non-USA). Irradiated fuel was involved in all but 10 of the cases. From this study, it is calculated that the frequency of unusual occurrences involving fuel damage from handling and transporting operations has been low. The damage that did occur was generally minor. The current base of experience with fuel handling and transporting operations indicates that nearly all of these unusual occurrences had only a minor or negligible effect on spent fuel storage facility operations

  13. Urban form and energy use for transport. A Nordic experience

    Energy Technology Data Exchange (ETDEWEB)

    Naess, P

    1995-02-10

    The main research problem addressed in this thesis is the possible influence of several urban form variables on the amount of transportation, on the modal split between different means of transport, and on energy use for transportation. This problem is elucidated through five empirical investigations covering different geographic levels in a Nordic context, from individual employees and households to commuting regions. A main feature of the study is the combination of socioeconomic and urban form variables in empirical investigations, employing techniques of multivariate analysis. The investigations of residential areas and job sites have been based on travel surveys, while the investigations where the units of analysis are towns or regions have been based on fuel sales. The socioeconomic data have been collected from official statistics and from questionnaires. It is found that urban form variables exert important influences on transportation energy use. Urban density affects energy use for transportation. A central location of residences as well as workplaces is favourable with respect to energy conservation on an intra-urban scale, but not in a wider geographical context, where decentralization into several dense, relatively self-contained local communities distributed over the region is the most energy-saving pattern of regional development. Urban form characteristics favourable for minimizing transport energy requirements also seem favourable for energy conservation in buildings. 160 refs., 39 figs., 46 tabs.

  14. Electrical conductivity of highly ionized dense hydrogen plasma. II. Comparison of experiment and theory

    Energy Technology Data Exchange (ETDEWEB)

    Guenther, K [Akademie der Wissenschaften der DDR, Berlin. Zentralinstitut fuer Elektronenphysik; Popovic, M M; Popovic, S S; Radtke, R

    1976-05-11

    The electrical conductivity of a non-ideal hydrogen plasma at p = 10 atm and T = 14,000-21,500 K is derived from electrical measurements and the radial temperature distribution of a pulsed wall-stabilized hydrogen arc using the theoretical temperature dependence of conductivity in an ideal binary collision plasma. From the comparison of theory and experiment, a suggestion to modify the cut-off parameter for charged particle potential from rsub(D) is derived, where rsub(D) is the Debye length. An estimate of Kaklyugin and Norman (Kaklyugin, A.S. and Norman, G.E., 1973 Teplofiz. vysok. temp., vol.11, 238-244) which takes into account both particle correlation and electron localisation in the environment of ions agrees very well with the experimental results over the whole temperature range.

  15. Pore-scale and Continuum Simulations of Solute Transport Micromodel Benchmark Experiments

    Energy Technology Data Exchange (ETDEWEB)

    Oostrom, Martinus; Mehmani, Yashar; Romero Gomez, Pedro DJ; Tang, Y.; Liu, H.; Yoon, Hongkyu; Kang, Qinjun; Joekar Niasar, Vahid; Balhoff, Matthew; Dewers, T.; Tartakovsky, Guzel D.; Leist, Emily AE; Hess, Nancy J.; Perkins, William A.; Rakowski, Cynthia L.; Richmond, Marshall C.; Serkowski, John A.; Werth, Charles J.; Valocchi, Albert J.; Wietsma, Thomas W.; Zhang, Changyong

    2016-08-01

    Four sets of micromodel nonreactive solute transport experiments were conducted with flow velocity, grain diameter, pore-aspect ratio, and flow focusing heterogeneity as the variables. The data sets were offered to pore-scale modeling groups to test their simulators. Each set consisted of two learning experiments, for which all results was made available, and a challenge experiment, for which only the experimental description and base input parameters were provided. The experimental results showed a nonlinear dependence of the dispersion coefficient on the Peclet number, a negligible effect of the pore-aspect ratio on transverse mixing, and considerably enhanced mixing due to flow focusing. Five pore-scale models and one continuum-scale model were used to simulate the experiments. Of the pore-scale models, two used a pore-network (PN) method, two others are based on a lattice-Boltzmann (LB) approach, and one employed a computational fluid dynamics (CFD) technique. The learning experiments were used by the PN models to modify the standard perfect mixing approach in pore bodies into approaches to simulate the observed incomplete mixing. The LB and CFD models used these experiments to appropriately discretize the grid representations. The continuum model use published non-linear relations between transverse dispersion coefficients and Peclet numbers to compute the required dispersivity input values. Comparisons between experimental and numerical results for the four challenge experiments show that all pore-scale models were all able to satisfactorily simulate the experiments. The continuum model underestimated the required dispersivity values and, resulting in less dispersion. The PN models were able to complete the simulations in a few minutes, whereas the direct models needed up to several days on supercomputers to resolve the more complex problems.

  16. Results from transient transport experiments in Rijnhuizen tokamak project: Heat convection, transport barriers and 'non-local' effects

    International Nuclear Information System (INIS)

    Mantica, P.; Gorini, G.; Hogeweij, G.M.D.; Kloe, J. de; Lopez Cardozo, N.J.; Schilham, A.M.R.

    2001-01-01

    An overview of experimental transport studies performed on the Rijnhuizen Tokamak Project (RTP) using transient transport techniques in both Ohmic and ECH dominated plasmas is presented. Modulated Electron Cyclotron Heating (ECH) and oblique pellet injection (OPI) have been used to induce electron temperature (T e ) perturbations at different radial locations. These were used to probe the electron transport barriers observed near low order rational magnetic surfaces in ECH dominated steady-state RTP plasmas. Layers of inward electron heat convection in off-axis ECH plasmas were detected with modulated ECH. This suggests that RTP electron transport barriers consist of heat pinch layers rather than layers of low thermal diffusivity. In a different set of experiments, OPI triggered a transient rise of the core T e due to an increase of the T e gradient in the 1< q<2 region. These transient transport barriers were probed with modulated ECH and found to be due to a transient drop of the electron heat diffusivity, except for off-axis ECH plasmas, where a transient inward pinch is also observed. Transient transport studies in RTP could not solve this puzzling interplay between heat diffusion and convection in determining an electron transport barrier. They nevertheless provided challenging experimental evidence both for theoretical modelling and for future experiments. (author)

  17. Generation, transport and conduct of radioactive wastes of low and intermediate level

    International Nuclear Information System (INIS)

    Lizcano, D.; Jimenez, J.

    2005-01-01

    The technological development of the last decades produced an increment in the application of the radiations in different human activities. The effect of it has been it the production of radioactive wastes of all the levels. In Mexico, some of the stages of the administration of the waste of low and intermediate level have not been completely resolved, as the case of the treatment and the final storage. In this work aspects of the generation, the transport and the administration of radioactive waste of low and intermediate level produced in the non energy applications from the radioactive materials to national level, indicating the generated average quantities, transported and tried annually by the National Institute of Nuclear Research (ININ). The main generators of wastes in Mexico, classified according to the activity in which the radioactive materials are used its are listed. Some of the main processes of treatment of radioactive wastes broadly applied in the world and those that are used at the moment in our country are also presented. (Author)

  18. Equilibrium and transient conductivity for gadolinium-doped ceria under large perturbations: I. Experiments

    DEFF Research Database (Denmark)

    Ricote, Sandrine; Zhu, Huayang; Coors, W. Grover

    2014-01-01

    (97% O2, 3% H2O) and vice versa reveal great asymmetries in relaxation times. Virtually instantaneous relaxations are observed in the first case, while the oxidizing-to-reducing relaxations take as long as 0.5h. This paper reports conductivity relaxations with over 20 orders of magnitude in the gas......-phase oxygen partial pressure. Models and experiments are used to show that the observed asymmetries cannot be explained by electrode defects or two-dimensional end effects. The companion paper develops a Nernst–Planck–Poisson model to assist the quantitative interpretation of the measurements reported...

  19. A 201-MHz Normal Conducting RF Cavity for the International MICE Experiment

    International Nuclear Information System (INIS)

    Li, D.; DeMello, A.J.; Virostek, Steve; Zisman, Michael S.; Rimmer, Robert

    2008-01-01

    MICE is a demonstration experiment for the ionization cooling of muon beams. Eight RF cavities are proposed to be used in the MICE cooling channel. These cavities will be operated in a strong magnetic field; therefore, they must be normal conducting. The cavity design and construction are based on the successful experience and techniques developed for a 201-MHz prototype cavity for the US MUCOOL program. Taking advantage of a muon beamΛ s penetration property, the cavity employs a pair of curved thin beryllium windows to terminate conventional beam irises and achieve higher cavity shunt impedance. The cavity resembles a round, closed pillbox cavity. Two half-shells spun from copper sheets are joined by e-beam welding to form the cavity body. There are four ports on the cavity equator for RF couplers, vacuum pumping and field probes. The ports are formed by means of an extruding technique.

  20. Zinc Potentiates an Uncoupled Anion Conductance Associated with the Dopamine Transporter

    DEFF Research Database (Denmark)

    Meinild, Anne-Kristine; Sitte, Harald H; Gether, Ulrik

    2004-01-01

    but by a marked increase in the charge/DA flux coupling ratio as assessed from concomitant measurements of [(3)H]DA uptake and currents in voltage-clamped oocytes. These data suggest that Zn(2+) facilitates an uncoupled ion conductance mediated by DAT. Whereas this required substrate in the wild type (WT), we...

  1. Design of an intermediate-scale experiment to validate unsaturated- zone transport models

    International Nuclear Information System (INIS)

    Siegel, M.D.; Hopkins, P.L.; Glass, R.J.; Ward, D.B.

    1991-01-01

    An intermediate-scale experiment is being carried out to evaluate instrumentation and models that might be used for transport-model validation for the Yucca Mountain Site Characterization Project. The experimental test bed is a 6-m high x 3-m diameter caisson filled with quartz sand with a sorbing layer at an intermediate depth. The experiment involves the detection and prediction of the migration of fluid and tracers through an unsaturated porous medium. Pre-test design requires estimation of physical properties of the porous medium such as the relative permeability, saturation/pressure relations, porosity, and saturated hydraulic conductivity as well as geochemical properties such as surface complexation constants and empircial K d 'S. The pre-test characterization data will be used as input to several computer codes to predict the fluid flow and tracer migration. These include a coupled chemical-reaction/transport model, a stochastic model, and a deterministic model using retardation factors. The calculations will be completed prior to elution of the tracers, providing a basis for validation by comparing the predictions to observed moisture and tracer behavior

  2. Analysis of in-situ electrical conductivity data from the HFIR TRIST-ER1 experiment

    Energy Technology Data Exchange (ETDEWEB)

    Zinkle, S.J.; Snead, L.L. [Oak Ridge National Lab., TN (United States); Shikama, T. [Tohoku Univ. (Japan)] [and others

    1997-08-01

    The current vs. applied voltage data generated from the HFIR TRIST-ER1 experiment have been analyzed to determine the electrical conductivity of the 15 aluminum oxide specimens and the MgO-insulated electrical cables as a function of irradiation dose. With the exception of the 0.05%Cr-doped sapphire (ruby) specimen, the electrical conductivity of the alumina specimens remained at the expected radiation induced conductivity (RIC) level of <10{sup -6} S/m during full-power reactor irradiation (10-16 kGy/s) at 450-500{degrees}C up to a maximum dose of {approximately}3 dpa. The ruby specimen showed a rapid initial increase in conductivity to {approximately}2 x 10{sup -4} S/m after {approximately}0.1 dpa, followed by a gradual decrease to <1 x 10{sup -6} S/m after 2 dpa. Nonohmic electrical behavior was observed in all of the specimens, and was attributed to preferential attraction of ionized electrons in the capsule gas to the unshielded low-side bare electrical leads emanating from the subcapsules. The electrical conductivity was determined from the slope of the specimen current vs. voltage curve at negative voltages, where the gas ionization effect was minimized. Dielectric breakdown tests performed on unirradiated mineral-insulated coaxial cables identical to those used in the high voltage coaxial cables during the 3-month irradiation is attributable to thermal dielectric breakdown in the glass seals at the end of the cables, as opposed to a radiation-induced electrical degradation (RIED) effect.

  3. Analysis of in-situ electrical conductivity data from the HFIR TRIST-ER1 experiment

    International Nuclear Information System (INIS)

    Zinkle, S.J.; Snead, L.L.; Shikama, T.

    1997-01-01

    The current vs. applied voltage data generated from the HFIR TRIST-ER1 experiment have been analyzed to determine the electrical conductivity of the 15 aluminum oxide specimens and the MgO-insulated electrical cables as a function of irradiation dose. With the exception of the 0.05%Cr-doped sapphire (ruby) specimen, the electrical conductivity of the alumina specimens remained at the expected radiation induced conductivity (RIC) level of -6 S/m during full-power reactor irradiation (10-16 kGy/s) at 450-500 degrees C up to a maximum dose of ∼3 dpa. The ruby specimen showed a rapid initial increase in conductivity to ∼2 x 10 -4 S/m after ∼0.1 dpa, followed by a gradual decrease to -6 S/m after 2 dpa. Nonohmic electrical behavior was observed in all of the specimens, and was attributed to preferential attraction of ionized electrons in the capsule gas to the unshielded low-side bare electrical leads emanating from the subcapsules. The electrical conductivity was determined from the slope of the specimen current vs. voltage curve at negative voltages, where the gas ionization effect was minimized. Dielectric breakdown tests performed on unirradiated mineral-insulated coaxial cables identical to those used in the high voltage coaxial cables during the 3-month irradiation is attributable to thermal dielectric breakdown in the glass seals at the end of the cables, as opposed to a radiation-induced electrical degradation (RIED) effect

  4. Australian Experience in Implementing Transport Safety Regulations and Transport Security Recommendations

    International Nuclear Information System (INIS)

    Sarkar, S.

    2016-01-01

    Australian transport safety and security regulatory framework is governed by Commonwealth, State and Territory legislations. There are eleven competent authorities in Australia that includes three Commonwealth authorities, six states and two territory authorities. IAEA Regulations for Safe Transport of Radioactive Material (TS-R-1, 2005 edition) is applied through Australian Radiation Protection and Nuclear Safety Agency (ARPANSA) Code of Practice for Transport of Radioactive Material 2008 by road, rail and waterways not covered by marine legislations. All states and territories apply this Transport Code through their regulatory system. For air transport, the Civil Aviation Act 1988 adopts the requirements of the ICAO Technical Instructions for the Safe Transport of Dangerous Goods by Air DOC 9284, which also adopts TS-R-1. The security of radioactive material in air transport is achieved via the Aviation Transport Security Act 2004. For sea transport Australian Marine Order 41 applies the requirements of IMDG (International Maritime Dangerous Goods) Code which also adopts TS-R-1. The security of radioactive material (nuclear material) is governed by two Commonwealth Agencies namely, ARPANSA and ASNO (Australian Safeguards and Non-proliferation Office) . ARPANSA regulates the security of radioactive sources through ARPANSA Code of Practice for the Security of Radioactive Sources 2007 which is based on the IAEA Draft Security Series. ASNO regulates security of nuclear material including U, Th and Pu through the Nuclear Non-Proliferation (Safeguards) Act, and the object of which is to give effect to certain obligations that Australia has as a party to the NPT, Australia’s safeguards agreement with the IAEA, and other bilateral safeguards agreements and certain obligations that Australia has as a party to the Convention for the Physical Protection of Nuclear Materials (CPPNM). This paper presents the effectiveness of regulatory approaches for safe and secure

  5. How to conduct a workshop on medical writing: Tips, advice and experience sharing.

    Science.gov (United States)

    Rathore, Farooq Azam; Mansoor, Sahibzada Nasir

    2015-06-01

    Medical writing has become an essential skill for anybody in academia and engaged in teaching. Workshops on medical writing are an effective way to teach the essential skills of medical writing to students and faculty members. There is a huge demand for these workshops all around the globe. Usually there is no curriculum of medical writing for the undergraduates or dedicated structured training sessions for the faculty members. One of the authors won an Author AID grant to conduct a series of workshops on medical writing. Eight workshops were conducted in three months, benefitting more than 200 students and faculty staff. We share our experience of holding this successful series of workshops with the aim that it might serve as a guide for researchers and faculty members who are eager to share and transfer their skills and knowledge. We also offer lessons learnt during this educational activity, tips to improve the quality and delivery of the content with limited resources and maximizing the impact. Experienced medical writers need to conduct these workshops to transfer their skills and to facilitate their colleagues and students to become better medical writers. Planning, rehearsal, motivation, resource management, good team work, audience analysis and feedback can make a workshop successful. Well prepared workshop content delivered in an interactive way with a variety of activities makes the workshop an engaging and interesting educational activity.

  6. Comparisons of theoretically predicted transport from ion temperature gradient instabilities to L-mode tokamak experiments

    International Nuclear Information System (INIS)

    Kotschenreuther, M.; Wong, H.V.; Lyster, P.L.; Berk, H.L.; Denton, R.; Miner, W.H.; Valanju, P.

    1991-12-01

    The theoretical transport from kinetic micro-instabilities driven by ion temperature gradients is a sheared slab is compared to experimentally inferred transport in L-mode tokamaks. Low noise gyrokinetic simulation techniques are used to obtain the ion thermal transport coefficient X. This X is much smaller than in experiments, and so cannot explain L-mode confinement. Previous predictions based on fluid models gave much greater X than experiments. Linear and nonlinear comparisons with the fluid model show that it greatly overestimates transport for experimental parameters. In addition, disagreements among previous analytic and simulation calculations of X in the fluid model are reconciled

  7. Experiments and modelling on biomass transport inside upflow ...

    African Journals Online (AJOL)

    This paper describes the experimental and theoretical activities developed to study the biomass transport phenomena occurring in upflow anaerobic reactors influencing the biomass washout. Particularly, the experimental investigations have been carried out on a full-scale ABR and on a pilot UASB intermittently fed with ...

  8. The YES2 Experience : Towards Sustainable Space Transportation using Tethers

    NARCIS (Netherlands)

    Van der Heide, E.J.; Kruijff, M.; Ockels, W.J.

    2008-01-01

    Today there is no common vision on sustainable space transportation. Rockets expel gasses and solid rockets often small particles. These have negative effect on the environment, but it is not understood to what extent. With ever growing demand for access to space, sustainable technology developments

  9. High-current beam dynamics and transport, theory and experiment

    International Nuclear Information System (INIS)

    Reiser, M.

    1986-01-01

    Recent progress in the understanding of beam physics and technology factors determining the current and brightness of ion and electron beams in linear accelerators will be reviewed. Topics to be discussed including phase-space density constraints of particle sources, low-energy beam transport include charge neutralization, emittance growth due to mismatch, energy exchange, instabilities, nonlinear effects, and longitudinal bunching

  10. Long-term financial transportation rights : An experiment

    NARCIS (Netherlands)

    Henze, B.; Noussair, C.N.; Willems, Bert; Kristainsen, T.; Rosellon, J.

    2013-01-01

    One challenge facing operators of network infrastructure, such as gas pipelines and electricity grids, is that large new investments in capacity must be undertaken as overall demand increases. In the European Union alone, roughly 200 Billion Euro must be invested in the energy transport networks

  11. Laboratory experiments on the formation and recoil jet transport of aerosol by laser ablation

    Science.gov (United States)

    Hirooka, Yoshi; Tanaka, Kazuo A.; Imamura, Keisuke; Okazaki, Katsuya

    2016-05-01

    In a high-repetition rate inertial fusion reactor, the first wall will be subjected to repeated ablation along with pellet implosions, which then leads to the formation of aerosol to scatter and/or deflect laser beams for the subsequent implosion, affecting the overall reactor performance. Proposed in the present work is a method of in-situ directed transport of aerosol particles by the use of laser ablation-induced jet recoil momenta. Lithium and carbon are used as the primary ablation targets, the former of which is known to form aerosol in the form of droplet, and the latter of which tends to form carbon nanotubes. Laboratory-scale experiments have been conducted to irradiate airborne aerosol particles with high-intensity laser to produce ablation-induced jet. Data have indicated a change in aerosol flow direction, but only in the case of lithium.

  12. Conductivity relaxation and charge transport of trihexyl tetradecyl phosphonium dicyanamide ionic liquid by broadband dielectric spectroscopy

    Science.gov (United States)

    Thasneema K., K.; Thayyil, M. Shahin; Krishna Kumar N., S.; Govindaraj, G.; Saheer, V. C.

    2018-04-01

    Usually ionic liquids consists of a large organic cation with low symmetry such as imidazolium, pyridinium, quaternary ammonium or phosponium etc combined with enormously wide range of inorganic or organic symmetric anion with melting point below 100. Ionic liquids existing in an extremely large number of possible ion pair combinations. It offers a very wide range of thermo physical properties led to the concept of designer solvents for specific applications. Due to the features of high chemical and thermal stability, low vapor pressure non flammability high ionic conductivity, and they show a good solvent ability towards a great variety of organic or inorganic compounds, ionic liquids have a widespread use in many areas such as batteries, fuel cell, solar cells, super capacitors etc. The main focus of this work is the study of molecular dynamics and conductivity relaxation of amorphous Trihexyl tetradecyl phosphonium dicyanamide ([P14,6,6,6][N(CN)2]) ionic liquid which is proved as a better electrolyte in super capacitors, over a wide frequency 10-2 Hz to 107 Hz and the temperature range between 123k and 265 k by means of Broadband Dielectric Spectroscopy. We observe alpha conductivity relaxation and secondary relaxation above and below Glass Transition Temperature. The experimental results were analyzed using electric modulus representation. The analysis emphasis the inter molecular interaction and the nature of glass forming system, whether it is fragile or strong system. The ionic liquid shows a fragile behavior and the fragility index m=123.59. TGA result of the sample exhibit a good resistance to thermal decomposition, up to 300°C.

  13. Electrode Conduction Processes Segmented Electrode-Insulator Ratio Effects in MHD Power Generation Experiments

    Energy Technology Data Exchange (ETDEWEB)

    Pain, H. J.; Fearn, D. G.; Distefano, E. [Imperial College. London (United Kingdom)

    1966-10-15

    (a) Electrode conduction processes have been investigated using a plasma produced in an electromagnetic shock tube operating with argon at 70 {mu}mHg pressure. Complete voltage-current characteristics were obtained by the variation of load and applied voltage. These indicated the existence of two conduction regimes with a complex transition region. In the first regime the current, controlled by ion mobility, rose linearly with voltage to saturate between 10 mA and 1 A depending on conditions. Electrode contamination was significant. The second regime involved large currents controlled by electron mobility and emission from the cathode. The current again increased linearly with voltage and reached 200 A. Observation of induced voltages in transverse magnetic fields and of plasma deceleration in non-uniform fields showed that in the electromagnetic shock tube the plasma was heated predominantly by the driver discharge. Its conductivity was calculated using properties measured by a Langmuir double probe. In both regimes the plasma conductivity was also found from the gradient of the voltage current characteristics using experimental electric field fringing factors and the experimental values were compared with theory. (b) Larger-scale experiments used a combustion-driven shock tube where argon plasma flow, magnetic field and induced current flow were mutually orthogonal. The supersonic flow velocity and thermodynamic parameters of the plasma were accurately known. The electrode channel consisted of a segmented system of 12 electrode pairs with an electrode insulator ratio ranging from 1 to 21, with electrode plus insulator length remaining constant, and with maximum Hall parameter values of unity. Different electrode load combinations (Faraday and Hall generators) have been studied in measuring the power generated and the flow of longitudinal currents between adjacent electrodes. A maximum power of 0,8 MW was obtained, the power output decreasing inversely with the

  14. Electrode Conduction Processes Segmented Electrode-Insulator Ratio Effects in MHD Power Generation Experiments

    International Nuclear Information System (INIS)

    Pain, H.J.; Fearn, D.G.; Distefano, E.

    1966-01-01

    (a) Electrode conduction processes have been investigated using a plasma produced in an electromagnetic shock tube operating with argon at 70 μmHg pressure. Complete voltage-current characteristics were obtained by the variation of load and applied voltage. These indicated the existence of two conduction regimes with a complex transition region. In the first regime the current, controlled by ion mobility, rose linearly with voltage to saturate between 10 mA and 1 A depending on conditions. Electrode contamination was significant. The second regime involved large currents controlled by electron mobility and emission from the cathode. The current again increased linearly with voltage and reached 200 A. Observation of induced voltages in transverse magnetic fields and of plasma deceleration in non-uniform fields showed that in the electromagnetic shock tube the plasma was heated predominantly by the driver discharge. Its conductivity was calculated using properties measured by a Langmuir double probe. In both regimes the plasma conductivity was also found from the gradient of the voltage current characteristics using experimental electric field fringing factors and the experimental values were compared with theory. (b) Larger-scale experiments used a combustion-driven shock tube where argon plasma flow, magnetic field and induced current flow were mutually orthogonal. The supersonic flow velocity and thermodynamic parameters of the plasma were accurately known. The electrode channel consisted of a segmented system of 12 electrode pairs with an electrode insulator ratio ranging from 1 to 21, with electrode plus insulator length remaining constant, and with maximum Hall parameter values of unity. Different electrode load combinations (Faraday and Hall generators) have been studied in measuring the power generated and the flow of longitudinal currents between adjacent electrodes. A maximum power of 0,8 MW was obtained, the power output decreasing inversely with the

  15. Optical conductivity and optical effective mass in a high-mobility organic semiconductor: Implications for the nature of charge transport

    KAUST Repository

    Li, Yuan

    2014-12-03

    We present a multiscale modeling of the infrared optical properties of the rubrene crystal. The results are in very good agreement with the experimental data that point to nonmonotonic features in the optical conductivity spectrum and small optical effective masses. We find that, in the static-disorder approximation, the nonlocal electron-phonon interactions stemming from low-frequency lattice vibrations can decrease the optical effective masses and lead to lighter quasiparticles. On the other hand, the charge-transport and infrared optical properties of the rubrene crystal at room temperature are demonstrated to be governed by localized carriers driven by inherent thermal disorders. Our findings underline that the presence of apparently light carriers in high-mobility organic semiconductors does not necessarily imply bandlike transport.

  16. Optical conductivity and optical effective mass in a high-mobility organic semiconductor: Implications for the nature of charge transport

    KAUST Repository

    Li, Yuan; Yi, Yuanping; Coropceanu, Veaceslav; Bredas, Jean-Luc

    2014-01-01

    We present a multiscale modeling of the infrared optical properties of the rubrene crystal. The results are in very good agreement with the experimental data that point to nonmonotonic features in the optical conductivity spectrum and small optical effective masses. We find that, in the static-disorder approximation, the nonlocal electron-phonon interactions stemming from low-frequency lattice vibrations can decrease the optical effective masses and lead to lighter quasiparticles. On the other hand, the charge-transport and infrared optical properties of the rubrene crystal at room temperature are demonstrated to be governed by localized carriers driven by inherent thermal disorders. Our findings underline that the presence of apparently light carriers in high-mobility organic semiconductors does not necessarily imply bandlike transport.

  17. Design of a mixed ionic/electronic conducting oxygen transport membrane pilot module

    Energy Technology Data Exchange (ETDEWEB)

    Pfaff, E.M.; Kaletsch, A.; Broeckmann, C. [RWTH Aachen University, IWM, Aachen (Germany)

    2012-03-15

    In the last years, a lot of ceramic materials were developed that, at higher temperatures, have a high electrical conductivity and a high conductivity of oxygen ions. Such mixed ionic/electronic conductors can be used to produce high-purity oxygen. This work focuses on the realization of a pilot membrane module, with BSCF (Ba{sub 0.5}Sr{sub 0.5}Co{sub 0.8}Fe{sub 0.2}O{sub 3-{delta}}) perovskite selected as the membrane material. An amount of 500 kg of powder was industrially fabricated, spray-granulized and pressed into tubes. The best operation conditions concerning energy consumption were calculated, and a module reactor was designed operating at 850 C, with an air pressure of 15-20 bar on the feed site and a low vacuum of about 0.8 bar on the permeate site. Special emphasis was placed on joining alternatives for ceramic tubes in metallic bottoms. A first laboratory module was tested with a membrane area of 1 m{sup 2} and then advanced to a pilot module with 570 tubes and a capability of more than 300 000 L of pure oxygen per day. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  18. Transport and confinement studies in the RFX-mod reversed-field pinch experiment

    International Nuclear Information System (INIS)

    Innocente, P.; Alfier, A.; Carraro, L.; Lorenzini, R.; Pasqualotto, R.; Terranova, D.

    2007-01-01

    In the modified RFX experiment (RFX-mod) external magnetic field coils and a close fitting thin conductive shell control radial magnetic fields. In the so-called virtual shell (VS) operation, radial field zeroing at the thin shell radius is stationary provided by the feedback-controlled coils. First experiments on RFX-mod proved the capability of the active scheme to steadily reduce the radial magnetic field. Furthermore it has been found that such edge magnetic field control extends its beneficial effects to the whole plasma. With respect to the old RFX, where magnetohydrodynamic modes amplitude was controlled by the use of a passive thick conductive shell, a stationary 2- to 3-fold reduction of the B r field amplitude in the core is obtained. The reduction of field fluctuations positively reflects on confinement. In fact, a strong reduction of the loop voltage is observed and correspondingly a 3-fold increase in pulse length is achieved by using the same poloidal flux swing. Temperature and particle measurements confirm the improved confinement properties of the VS operation. With a lower ohmic input power, higher electron temperature and lower particle influx are measured. Particle and heat transport have been studied by means of a 1D code. Local power balance was used to compute the heat conductivity profile: for the VS discharges a lower conductivity over a significant region of the plasma is found. The improved properties of RFX-mod VS operation provide a better confinement scaling in terms of plasma current. The results show that compared with the thick shell configuration, a significant confinement improvement can be obtained under stationary conditions by actively controlling the plasma magnetic boundary

  19. Multidisciplinary Education in Transportation. Proceedings of a Conference conducted by the Highway Research Board (University of Pennsylvania, Philadelphia, September 7 and 8, 1973).

    Science.gov (United States)

    National Academy of Sciences - National Research Council, Washington, DC. Transportation Research Board.

    A discussion of the problem of providing multidisciplinary education in transportation and a means for educators to communicate their approaches and experiences provided the purpose of the conference. Among the areas discussed were the comprehensiveness of transportation education, societal issues, systems aspects, transportation research,…

  20. Glial and Neuronal Glutamate Transporters Differ in the Na+ Requirements for Activation of the Substrate-Independent Anion Conductance

    Directory of Open Access Journals (Sweden)

    Christopher B. Divito

    2017-05-01

    Full Text Available Excitatory amino acid transporters (EAATs are secondary active transporters of L-glutamate and L- or D-aspartate. These carriers also mediate a thermodynamically uncoupled anion conductance that is gated by Na+ and substrate binding. The activation of the anion channel by binding of Na+ alone, however, has only been demonstrated for mammalian EAAC1 (EAAT3 and EAAT4. To date, no difference has been observed for the substrate dependence of anion channel gating between the glial, EAAT1 and EAAT2, and the neuronal isoforms EAAT3, EAAT4 and EAAT5. Here we describe a difference in the Na+-dependence of anion channel gating between glial and neuronal isoforms. Chloride flux through transporters without glutamate binding has previously been described as substrate-independent or “leak” channel activity. Choline or N-methyl-D-glucamine replacement of external Na+ ions significantly reduced or abolished substrate-independent EAAT channel activity in EAAT3 and EAAT4 yet has no effect on EAAT1 or EAAT2. The interaction of Na+ with the neuronal carrier isoforms was concentration dependent, consistent with previous data. The presence of substrate and Na+-independent open states in the glial EAAT isoforms is a novel finding in the field of EAAT function. Our results reveal an important divergence in anion channel function between glial and neuronal glutamate transporters and highlight new potential roles for the EAAT-associated anion channel activity based on transporter expression and localization in the central nervous system.

  1. A robotic system to conduct radiation and contamination surveys on nuclear waste transport casks

    International Nuclear Information System (INIS)

    Harrigan, R.W.; Sanders, T.L.

    1990-06-01

    The feasibility of performing, numerous spent fuel cask operations using fully integrated robotic systems is under evaluation. Using existing technology, operational and descriptive software and hardware in the form of robotic end effectors are being designed in conjunction with interfacing cask components. A robotic radiation and contamination survey system has been developed and used on mock-up cask hardware to evaluate the impact of such fully automated operations on cask design features and productivity. Based on experience gained from the survey system, numerous health physics operations can be reliably performed with little human intervention using a fully automated system. Such operations can also significantly reduce time requirements for cask-receiving operations. 7 refs., 51 figs., 6 tabs

  2. Comparison of three labeled silica nanoparticles used as tracers in transport experiments in porous media. Part II: Transport experiments and modeling

    International Nuclear Information System (INIS)

    Vitorge, Elsa; Szenknect, Stéphanie; Martins, Jean M.-F.; Barthès, Véronique; Gaudet, Jean-Paul

    2014-01-01

    Three types of labeled silica nanoparticles were used in transport experiments in saturated sand. The goal of this study was to evaluate both the efficiency of labeling techniques (fluorescence (FITC), metal (Ag(0) core) and radioactivity ( 110m Ag(0) core)) in realistic transport conditions and the reactive transport of silica nanocolloids of variable size and concentration in porous media. Experimental results obtained under contrasted experimental conditions revealed that deposition in sand is controlled by nanoparticles size and ionic strength of the solution. A mathematical model is proposed to quantitatively describe colloid transport. Fluorescent labeling is widely used to study fate of colloids in soils but was the less sensitive one. Ag(0) labeling with ICP-MS detection was found to be very sensitive to measure deposition profiles. Radiolabeled ( 110m Ag(0)) nanoparticles permitted in situ detection. Results obtained with radiolabeled nanoparticles are wholly original and might be used for improving the modeling of deposition and release dynamics. -- Highlights: • Three kinds of labeled nanotracers were used in transport experiments in sand columns. • They were used as surrogates of silica nanoparticles or mineral colloid. • Deposition depending on colloid size and ionic strength was observed and modeled. • Fluorescence labeling had the worse detection limit but was the more convenient. • Radiolabeled nanotracers were detected in situ in a non destructive way. -- Follow the kinetics of transport, deposition and release of silica nanoparticles with suitably labeled nanoparticles

  3. Charge transport through conducting organic poly(2-methoxy-5- (2-ethylhexyloxy)-1, 4-phenylenevinylene)

    International Nuclear Information System (INIS)

    Kumar, Pankaj; Misra, Aparna; Kamalasanan, M N; Jain, S C; Kumar, Vikram

    2007-01-01

    Current-voltage (J-V) characteristics of poly(2-methoxy-5- (2-ethyhexyloxy)-1, 4-phenylenevinylene)(MEH-PPV) have been studied in the hole-only devices ITO/PEDOT : PSS/MEH-PPV/Au, as a function of temperature from 300 to 98 K. Hole conduction in MEH-PPV has been well explained by an exponential trap-controlled drift model. In a considerable range of applied voltages, current obeys the power law J ∼ V l+1 , where l = T c /T and T c is the characteristic temperature of the exponential trap distribution. Assuming the effective density of states N ν = 2.7 x 10 18 cm -3 , the holes trap density (H b ) and characteristic temperature (T c ) have been calculated to be 1 x 10 18 cm -3 and 550 K, respectively. As the voltage further increases current deviates and becomes smaller than J ∼ V l+1 . At low temperatures and sufficiently high-applied voltages, current follows the V 2 law. At higher temperatures slopes less than 2 of the log J-log V plots have been observed. The possible reasons for this behaviour are mentioned

  4. Transport, Optical, and Magnetic Properties of the Conducting Halide Perovskite CH 3NH 3SnI 3

    Science.gov (United States)

    Mitzi, D. B.; Feild, C. A.; Schlesinger, Z.; Laibowitz, R. B.

    1995-01-01

    A low-temperature ( T ≤ 100°C) solution technique is described for the preparation of polycrystalline and single crystal samples of the conducting halide perovskite, CH 3NH 3SnI 3. Transport, Hall effect, magnetic, and optical properties are examined over the temperature range 1.8-300 K, confirming that this unusual conducting halide perovskite is a low carrier density p-type metal with a Hall hole density, 1/ RHe ≃ 2 × 10 19 cm -3. The resistivity of pressed pellet samples decreases with decreasing temperature with resistivity ratio ρ(300 K)/ρ(2 K) ≃ 3 and room temperature resistivity ρ(300 K) ≃ 7 mΩ-cm. A free-carrier infrared reflectivity spectrum with a plasma edge observed at approximately 1600 cm -1 further attests to the metallic nature of this compound and suggests a small optical effective mass, m* ≃ 0.2.

  5. The Importance of Conducting Life Sciences Experiments on the Deep Space Gateway Platform

    Science.gov (United States)

    Bhattacharya, S.

    2018-01-01

    Over the last several decades important information has been gathered by conducting life science experiments on the Space Shuttle and on the International Space Station. It is now time to leverage that scientific knowledge, as well as aspects of the hardware that have been developed to support the biological model systems, to NASA's next frontier - the Deep Space Gateway. In order to facilitate long duration deep space exploration for humans, it is critical for NASA to understand the effects of long duration, low dose, deep space radiation on biological systems. While carefully controlled ground experiments on Earth-based radiation facilities have provided valuable preliminary information, we still have a significant knowledge gap on the biological responses of organisms to chronic low doses of the highly ionizing particles encountered beyond low Earth orbit. Furthermore, the combined effects of altered gravity and radiation have the potential to cause greater biological changes than either of these parameters alone. Therefore a thorough investigation of the biological effects of a cis-lunar environment will facilitate long term human exploration of deep space.

  6. Planning for Integrated Transport in Indonesia: Some Lessons from the UK’s Experience

    Directory of Open Access Journals (Sweden)

    Yos Sunitiyoso

    2012-01-01

    Full Text Available Traffic congestion has been a major problem in many cities in Indonesia, thus requiring abetter transport policy. Many developed countries, including the United Kingdom, has beenimplementing the integrated transport policy to replace traditional transport policy that focuson only building roads to anticipate traffic demand. This paper provides a highlight on theimplementation of integrated transport policy in the United Kingdom. Some key issues thatcan be learnt by the Indonesian government from their experience are discussed. This includesthe integration within and between all types of transport, integration with land use planning,integration with environment policy and integration with policies for education, health andwealth creations. In the implementation, the policy requires continuity and stability inorganization and politics, coordination in local transport plans, more devolution on powerand revenue funding from the government in addition to capital funding.Key words: traffic congestion, integrated transport policy

  7. Transportation of radioactive materials routing analysis: The Nevada experience

    International Nuclear Information System (INIS)

    Ardila-Coulson, M.V.

    1991-01-01

    In 1987, the Nevada State Legislature passed a Bill requiring the Nevada Dept. of Transportation to develop and enforce a plan for highway routing of highway route controlled quantity shipments of radioactive materials and high-level radioactive waste. A large network with all the major highways in Nevada was created and used in a computer model developed by Sandia National Labs. Twenty-eight highway parameters that included geometrics, traffic characteristics, environment and special facilities were collected. Alternative routes were identified by minimizing primary parameters (population density and accident rates). An analysis using the US DOT Guidelines were performed to identify a preferred route from the alternative routes

  8. Some UK experience and practice in the packaging and transport of irradiated fuel

    International Nuclear Information System (INIS)

    Edney, C.J.; Rutter, R.L.

    1977-01-01

    The origin and growth of irradiated fuel transport within and to the U.K. is described and the role of the organisations presently carrying out transport operations is explained. An explanation of the relevant U.K. regulations and laws affecting irradiated fuel transport and the role of the controlling body, the Department of the Environment is given. An explanation is given of the technical requirements for the transport of irradiated Magnox fuel and of the type of flask used, and the transport arrangements, both within the U.K. and to the U.K., from overseas is discussed. The technical requirements for the transport of C.A.G.R. fuel are outlined and the flask and transport arrangements are discussed. The transport requirements of oxide fuel from water reactors is outlined and the flask and shipping arrangements under which this fuel is brought to the U.K. from overseas is explained. The shipping arrangements are explained with particular reference to current international and national requirements. The requirements of the transport of M.T.R. fuel are discussed and the flask type explained. The expected future expansion of the transport of irradiated fuel within and to the U.K. is outlined and the proposed operating methods are briefly discussed. A summary is given of the U.K. experience and the lessons to be drawn from that experience

  9. The use of synthetic colloids in tracer transport experiments in saturated rock fractures

    International Nuclear Information System (INIS)

    Reimus, P.W.

    1995-08-01

    Studies of groundwater flow and contaminant transport in saturated, fractured geologic media are of great interest to researchers studying the potential long-term storage of hazardous wastes in or near such media. A popular technique for conducting such studies is to introduce tracers having different chemical and physical properties into a system and then observe the tracers at one or more downstream locations, inferring flow and transport mechanisms from the breakthrough characteristics of the different tracers. Many tracer studies have been conducted in saturated, fractured media to help develop and/or refine models capable of predicting contaminant transport over large scales in such media

  10. First Aid and Transportation Course Contents Based on Experience gained in the Iran-Iraq War: a Qualitative Study.

    Science.gov (United States)

    Sarhangi, Forogh; Gholami, Hamid Reza; Khaghanizade, Morteza; Najafi Mehri, Soheil

    2015-02-01

    Effective first aid and transportation influences injury-induced mortality. But few qualitative studies have been conducted so far in this area. The aim of this study was to identify the content of the first aid and patient transportation course based on experience gained from the Iran-Iraq war. This was a conventional qualitative content analysis study; a purposeful sample of 14 first aid and transportation experts who had worked during the Iran-Iraq war was recruited. We collected and analyzed the study data by using the semi-structured interview method and the conventional content analysis approach respectively. Each interview transcript was reviewed several times. Words, sentences, and paragraphs were labeled with codes. Codes were compared with each other and categorized according to their similarities. Similar sub-categories and categories were also grouped together and formed themes. Study participants' experiences of wartime first aid and transportation (FAT) education fell into two main themes including 'the congruence of education and educational needs' and 'managers' engagement in FAT education. The four main categories of these two themes were use of appropriate educational facilities, adopting effective teaching strategies, universal FAT education and specialized training skills. The two key requirements of the first aid and transportation courses are practicality and managerial engagement. We developed and provided specific guidance of FAT curriculum by using the study findings. This curriculum is recommended for educating FAT staffs, paramedics, emergency technicians, and military nurses.

  11. Weather, transport mode choices and emotional travel experiences

    NARCIS (Netherlands)

    Böcker, L.; Dijst, M.J.; Faber, J.

    2016-01-01

    With climate change high on the political agenda, weather has emerged as an important issue in travel behavioral research and urban planning. While various studies demonstrate profound effects of weather on travel behaviors, limited attention has been paid to subjective weather experiences and the

  12. Field tracer transport experiments at the site of Canada's underground research laboratory

    International Nuclear Information System (INIS)

    Frost, L.H.; Davison, C.C.; Vandergraaf, T.T.; Scheier, N.W.; Kozak, E.T.

    1997-01-01

    To gain a better understanding of the processes affecting solute transport in fractured crystalline rock, groundwater tracer experiments are being performed within natural fracture domains and excavation damage zones at various scales at the site of AECL's Underground Research Laboratory (URL). The main objective of these experiments is to develop and demonstrate methods for characterizing the solute transport properties within fractured crystalline rock. Estimates of these properties are in turn being used in AECL's conceptual and numerical models of groundwater flow and solute transport through the geosphere surrounding a nuclear fuel waste disposal vault in plutonic rock of the Canadian Shield. (author)

  13. Evaluation of a numerical model's ability to predict bed load transport observed in braided river experiments

    Science.gov (United States)

    Javernick, Luke; Redolfi, Marco; Bertoldi, Walter

    2018-05-01

    New data collection techniques offer numerical modelers the ability to gather and utilize high quality data sets with high spatial and temporal resolution. Such data sets are currently needed for calibration, verification, and to fuel future model development, particularly morphological simulations. This study explores the use of high quality spatial and temporal data sets of observed bed load transport in braided river flume experiments to evaluate the ability of a two-dimensional model, Delft3D, to predict bed load transport. This study uses a fixed bed model configuration and examines the model's shear stress calculations, which are the foundation to predict the sediment fluxes necessary for morphological simulations. The evaluation is conducted for three flow rates, and model setup used highly accurate Structure-from-Motion (SfM) topography and discharge boundary conditions. The model was hydraulically calibrated using bed roughness, and performance was evaluated based on depth and inundation agreement. Model bed load performance was evaluated in terms of critical shear stress exceedance area compared to maps of observed bed mobility in a flume. Following the standard hydraulic calibration, bed load performance was tested for sensitivity to horizontal eddy viscosity parameterization and bed morphology updating. Simulations produced depth errors equal to the SfM inherent errors, inundation agreement of 77-85%, and critical shear stress exceedance in agreement with 49-68% of the observed active area. This study provides insight into the ability of physically based, two-dimensional simulations to accurately predict bed load as well as the effects of horizontal eddy viscosity and bed updating. Further, this study highlights how using high spatial and temporal data to capture the physical processes at work during flume experiments can help to improve morphological modeling.

  14. Experience of air transport of nuclear fuel material as type A package

    International Nuclear Information System (INIS)

    Kawasaki, Masashi; Kageyama, Tomio; Suzuki, Toru

    2004-01-01

    Special law on nuclear disaster countermeasures (hereafter called as to nuclear disaster countermeasures low) that is domestic law for dealing with measures for nuclear disaster, was enforced in June, 2000. Therefore, nuclear enterprise was obliged to report accidents as required by nuclear disaster countermeasures law, besides meeting the technical requirement of existent transport regulation. For overseas procurement of plutonium reference materials that are needed for material accountability, A Type package must be transported by air. Therefore, concept of air transport of nuclear fuel materials according to the nuclear disaster countermeasures law was discussed, and the manual including measures against accident in air transport was prepared for the oversea procurement. In this presentation, the concept of air transport of A Type package containing nuclear fuel materials according to the nuclear disaster countermeasures law, and the experience of a transportation of plutonium solution from France are shown. (author)

  15. [Patient safety culture in hospitals: experiences in planning, organising and conducting a survey among hospital staff].

    Science.gov (United States)

    van Vegten, Amanda; Pfeiffer, Yvonne; Giuliani, Francesca; Manser, Tanja

    2011-01-01

    This article presents the first hospital-wide survey on patient safety climate, involving all staff (medical and non-medical), in the German-speaking area. Its aim is to share our experiences with planning, organising and conducting this survey. The study was performed at the university hospital in Zurich and had a response rate of 46.8% (2,897 valid questionnaires). The survey instrument ("Patientensicherheitsklimainventar") was based on the Hospital Survey on Patient Safety Culture (AHRQ). Primarily it allowed for assessing the current patient safety climate as well as identifying specific areas for improvement and creating a hospital-wide awareness and acceptance for patient safety issues and interventions (e.g., the introduction of a Critical Incident Reporting System [CIRS]). We discuss the basic principles and the feedback concept guiding the organisation of the overall project. Critical to the success of this project were the guaranteed anonymity of the respondents, adequate communication through well-established channels within the organisation and the commitment of the management across all project phases. Copyright © 2011. Published by Elsevier GmbH.

  16. Temperature dependence of the cosphi conductance in Josephson tunnel junctions determined from plasma resonance experiments

    International Nuclear Information System (INIS)

    Pedersen, N.F.; Soerensen, O.H.; Mygind, J.

    1978-01-01

    The microwave response at 9 GHz of Sn-O-Sn tunnel-junction current biased at zero dc voltage has been measured just below the critical temperature T/sub c/ of the Sn films. The temperature dependence of the cosphi conductance is determined from the resonant response at the junction plasma frequency f/sub p/ as the temperature is decreased from T/sub c/. We used three different schemes for observation of the plasma oscillations: (a) second-harmonic generation (excitation at approx. 4.5 GHz, f/sub p/ approx. 4.5 GHz); (b) mixing (excitations at approx. 9 and approx. 18 GHz, f/sub p/ approx. 9 GHz); (c) parametric half-harmonic oscillation (excitation at approx. 18 GHz, f/sub p/ approx. 9 GHz). Measurements were possible in two temperature intervals; 0.994 or = T/T/sub c/ > or = 0.930, with the result that as the temperature was decreased the cosphi amplitude first increased from about zero to positive values and then at lower temperatures decreased approaching -1 at the lowest temperatures of the experiment

  17. Long conduction time plasma opening switch experiments at Sandia National Laboratories

    International Nuclear Information System (INIS)

    Savage, M.E.; Simpson, W.W.; Cooper, G.W.; Usher, M.A.

    1993-01-01

    Sandia National Laboratories has undertaken an ambitious program to reduce the size and cost of large pulsed power drivers. The program basis is inductive energy storage and Plasma Opening Switches (POS). Inductive energy storage has well known advantages, including increased efficiency and reduced stress on the vacuum interface. The Sandia approach is to retain the reliable and efficient Marx generator and the temporal pulse compression of the water dielectric capacitor. A triggered closing switch, developed at Sandia, transfers the capacitor charge into the energy storage inductor. This approach has several advantages, including relaxed requirements on Marx jitter and inductance, and much faster current risetime in the energy storage inductor. The POS itself is the key to the Sandia program. The switch design uses an auxiliary magnetic field to inject the plasma and hold it in place during conduction. After opening begins, the self magnetic field of the power pulse pushes on the plasma to increase the opened gap. The authors use magnetic pressure because they desire POS gaps of several cm. Typical plasma opening switches do not achieve large gaps. Improved opening allows more efficient transfer to loads. They present results from recent experiments at Sandia. Their driver presently supplies 650 kA with a 240 ns risetime to the input of the POS. The storage inductor is a 17 Ohm magnetically insulated transmission line (MITL) that is five meters long. They discuss the ways in which magnetic field influences the POS, and the ways in which they control the magnetic fields

  18. Double tracer experiments to evaluate atmospheric transport and dose models

    International Nuclear Information System (INIS)

    Nielsen, S.P.; Gryning, S.-E.; Thykier-Nielsen, S.; Karlberg, O.; Lyck, E.

    1986-05-01

    Two tracers, sulphurhexafluoride (SF 6 ) and radioactive noble gases, were released simultaneously from a 110-m stack and detected downwind at distances of 3-4 km. The experiments were made at the Swedish nuclear power plant Ringhals in 1981. The radioactive tracer was routine emissions from unit 1 (BWR). The one-hour measurements yielded crosswind profiles at ground level of SF 6 -concentrations and of gamma radiation from the plume. The measured profiles were compared to profiles calculated with computer models. The comparison showed that the models sometimes underestimate and sometimes overestimate the results, which seems to indicate that the models within their limited accuracy yield unbiased results. The ratios between measured and calculated values range from 0.2 to 3. The measurements revealed a surplus of gamma radiations from the noble gas daughters compared to those from the gases. This was interpreted as due to ground desposition and the estimated deposition velocities range from 2 to 10 cm/s. The meteorological conditions were monitored from a 100-m meteorological tower and from an 11-m mast. Measurements were made of wind speed, wind direction, and temperatures at different heights, and during each experiment a mini-radiosonde was released giving information on a possible inversion layer. The SF 6 -tracer was injected to the stack prior to the experiments. Air-samples were collected downwind in plastic bags by radio-controlled sampling units. The SF 6 -concentrations in the bags were determined with gas chromatography. Measurements of the gamma radiation from the plume were made with ionisation chambers and GM-counters. Furthermore, a few mobile gamma spectrometers were available giving information on the unscattered gamma radiation, thereby permitting identification of the radioactive isotopes. The work was partly financed by the Nuclear Safety Board of the Swedish Utilities and by the Danish association of utilities in Jutland and on Funen, Elsam

  19. Effects of variations in hydraulic conductivity and flow conditions on groundwater flow and solute transport in peatlands

    Energy Technology Data Exchange (ETDEWEB)

    Kellner, Erik [Dept. of Forest Ecology, Univ. of Helsinki (Finland)

    2007-02-15

    In this report it is examined to what extent the variation in hydraulic conductivity within a peatland and adjoining sediments would affect the flow patterns within it under some certain hydraulic-head gradients and other certain border conditions. The first part of the report contains a short review of organic and mineral-soil sediment types and characteristics and what we know about present peatlands and underlying sediments in the SKB investigation areas today. In the next part, a 2-dimensional model is used to simulate flows and transports in different settings of a peatland, with the objective of studying the effects of some particular factors: 1. The magnitude of the hydraulic conductivity of the peat and of underlying layers. 2. Presence and positions of cracks in underlying clay layers. 3. Anisotropy and heterogeneity in peat hydraulic conductivity. 4. The size of the water recharge at the peatland surface. 5. The seasonal variation of the water recharge. The modelling results show that the importance of flow direction decreases with decreasing hydraulic conductivity in the peatland. This occurs as the convective flux is slowed down and the transport is taken over by the diffusive flux. Because the lowest hydraulic conductivity layer to large extent determines the size of the flow, presence of a low-conductivity layer, such as a layer of clay, is an important factor. Presence of cracks in such tight layers can increase the transport of solutes into the peat. The highest inflow rates are reached when such cracks occur in discharge areas with strong upward flow. On the other hand, a conservative solute can spread efficiently if there is a crack in low-flow locations. The effect of anisotropy is found to be small, partly because the horizontal gradients become smaller as distances are larger. The effect of layers with high or low permeability varies depending on the location and the prevailing gradients. One tight layer has a strong effect on the flow pattern

  20. Effects of variations in hydraulic conductivity and flow conditions on groundwater flow and solute transport in peatlands

    International Nuclear Information System (INIS)

    Kellner, Erik

    2007-02-01

    In this report it is examined to what extent the variation in hydraulic conductivity within a peatland and adjoining sediments would affect the flow patterns within it under some certain hydraulic-head gradients and other certain border conditions. The first part of the report contains a short review of organic and mineral-soil sediment types and characteristics and what we know about present peatlands and underlying sediments in the SKB investigation areas today. In the next part, a 2-dimensional model is used to simulate flows and transports in different settings of a peatland, with the objective of studying the effects of some particular factors: 1. The magnitude of the hydraulic conductivity of the peat and of underlying layers. 2. Presence and positions of cracks in underlying clay layers. 3. Anisotropy and heterogeneity in peat hydraulic conductivity. 4. The size of the water recharge at the peatland surface. 5. The seasonal variation of the water recharge. The modelling results show that the importance of flow direction decreases with decreasing hydraulic conductivity in the peatland. This occurs as the convective flux is slowed down and the transport is taken over by the diffusive flux. Because the lowest hydraulic conductivity layer to large extent determines the size of the flow, presence of a low-conductivity layer, such as a layer of clay, is an important factor. Presence of cracks in such tight layers can increase the transport of solutes into the peat. The highest inflow rates are reached when such cracks occur in discharge areas with strong upward flow. On the other hand, a conservative solute can spread efficiently if there is a crack in low-flow locations. The effect of anisotropy is found to be small, partly because the horizontal gradients become smaller as distances are larger. The effect of layers with high or low permeability varies depending on the location and the prevailing gradients. One tight layer has a strong effect on the flow pattern

  1. Comparison of empirical transport models with transient transport experiments in LHD

    International Nuclear Information System (INIS)

    Yakovlev, Mikhail; Inagaki, Shigeru; Ida, Katsumi

    2004-01-01

    A study of the electron transport in helical plasma of Large Helical Device (LHD) has been performed using a perturbation to an equilibrium state. The periodic perturbation in plasma is induced by on-axis Electron Cyclotron Heating (ECH) modulated signal for different temperatures of plasma electron. The experimental data are compared with results from simulation within framework of the diffusive model with additional convective term. The convection heat flux is introduced to describe the heat propagation in LHD. It has been shown that the dynamic plasma heat diffusivity coefficient χ e estimated from the transient analysis becomes larger with increasing electron temperature in LHD plasma. (author)

  2. Electrical transport properties of spray deposited transparent conducting ortho-Zn2SnO4 thin films

    Science.gov (United States)

    Ramarajan, R.; Thangaraju, K.; Babu, R. Ramesh; Joseph, D. Paul

    2018-04-01

    Ortho Zinc Stannate (Zn2SnO4) exhibits excellent electrical and optical properties to serve as alternate transparent electrode in optoelectronic devices. Here we have optimized ortho-Zn2SnO4 thin film by spray pyrolysis method. Deposition was done onto a pre-heated glass substrate at a temperature of 400 °C. The XRD pattern indicated films to be polycrystalline with cubic structure. The surface of films had globular and twisted metal sheet like morphologies. Films were transparent in the visible region with band gap around 3.6 eV. Transport properties were studied by Hall measurements at 300 K. Activation energies were calculated from Arrhenius's plot from temperature dependent electrical measurements and the conduction mechanism is discussed.

  3. Conducting Integrated Objective Structured Clinical Examination: Experiences at KIST Medical College, Nepal

    Directory of Open Access Journals (Sweden)

    Rano Mal Piryani

    2013-01-01

    Full Text Available Background: Objective structured clinical examination (OSCE, an important tool for assessment of clinical skills, introduced more than 4 decades ago. KIST Medical College, a new medical school of Nepal, affiliated to Tribhuvan University Institute of Medicine, has made learning of physical examination skills structured and integrated with greater involvement of different clinical science departments. Students learn physical examination skills in second year MBBS as a part of early clinical exposure. Objective: To share the experiences regarding implementation of integrated OSCE. Materials and Methods: At the end of clinical posting of learning of physical examination skills, assessment was done with OSCE. Fifteen OSCE stations including each of 5 minutes were developed and arranged. Standardized patients and validated checklist were used. OSCE was conducted in novel way. Prior to the OSCE session: Suitable venue was selected, assessors were identified, standardized patients were selected, running order of the stations in circuit was developed, list of equipments/instruments required was prepared, and tasks, checklists, feedback questionnaires were printed. The day before the OSCE session: OSCE stations were inspected and clearly labeled, condition of required equipments/instruments was checked, a pack of the documents for each OSCE station were made available, and signs were displayed at proper places. On the day of the OSCE session: Reliable stop watch and loud manual bell were used, support staffs were placed to direct the candidates, examiners, and standardized patients (SPs, assessors explained SPs, students were briefed, supervisors observed the session, and feedback were taken from students, assessors, and SPs. At the end of the OSCE session: Checklists and feedback questionnaires were collected, token money was paid to SPs, and a contribution of everyone was appreciated. After the OSCE session: Score was compiled and result declared, and

  4. Transport of significant metals recovered in real sea experiment of adsorbents

    International Nuclear Information System (INIS)

    Takeda, Hayato; Tamada, Masao; Kasai, Noboru; Katakai, Akio; Hasegawa, Shin; Seko, Noriaki; Sugo, Takanobu; Kawabata, Yukiya

    2001-10-01

    Real sea experiment for the recovery of significant metals such as uranium and vanadium which dissolved in seawater with extremely low concentration has been carried out at the offing of Mutsu establishment to evaluate the adsorption performance of adsorbent synthesized by radiation-induced graft-polymerization. The significant metals of uranium and vanadium eluted from the adsorbent which was soaked in the real sea were adsorbed onto the conventional chelate resin. The chelate resin which adsorbed the metals was packed in a plastic (PVC) column and further put in a cylindrical stainless transport container. This container was transported to the facility for separation and purification by a truck for the exclusive loading. Then the recovers metals were purified there. The recovered metals contained the uranium of 150g (1.92 MBq) and less in one recovery experiment. The maximum concentration is 60 Bq/g when the uranium is adsorbed on the chelate resin. Transport of recovered metals can be treated as general substance since these amount and concentration are out of legal control. However, the recovered metals were transported in conformity to L type Transport as a voluntary regulation. Though there is no requirements of structural strength for L type package legally, the structural strength of container was designed on that of IP-2 type which is higher transport grade than L type to take its safety measure. Its strength analysis proved the safety under general transport process. The transport was based on the plan made in advance. (author)

  5. Gyrokinetic Simulation of Global Turbulent Transport Properties in Tokamak Experiments

    Energy Technology Data Exchange (ETDEWEB)

    Wang, W.X.; Lin, Z.; Tang, W.M.; Lee, W.W.; Ethier, S.; Lewandowski, J.L.V.; Rewoldt, G.; Hahm, T.S.; Manickam, J.

    2006-01-01

    A general geometry gyro-kinetic model for particle simulation of plasma turbulence in tokamak experiments is described. It incorporates the comprehensive influence of noncircular cross section, realistic plasma profiles, plasma rotation, neoclassical (equilibrium) electric fields, and Coulomb collisions. An interesting result of global turbulence development in a shaped tokamak plasma is presented with regard to nonlinear turbulence spreading into the linearly stable region. The mutual interaction between turbulence and zonal flows in collisionless plasmas is studied with a focus on identifying possible nonlinear saturation mechanisms for zonal flows. A bursting temporal behavior with a period longer than the geodesic acoustic oscillation period is observed even in a collisionless system. Our simulation results suggest that the zonal flows can drive turbulence. However, this process is too weak to be an effective zonal flow saturation mechanism.

  6. Biochar-Induced Changes in Soil Hydraulic Conductivity and Dissolved Nutrient Fluxes Constrained by Laboratory Experiments

    Science.gov (United States)

    Barnes, Rebecca T.; Gallagher, Morgan E.; Masiello, Caroline A.; Liu, Zuolin; Dugan, Brandon

    2014-01-01

    The addition of charcoal (or biochar) to soil has significant carbon sequestration and agronomic potential, making it important to determine how this potentially large anthropogenic carbon influx will alter ecosystem functions. We used column experiments to quantify how hydrologic and nutrient-retention characteristics of three soil materials differed with biochar amendment. We compared three homogeneous soil materials (sand, organic-rich topsoil, and clay-rich Hapludert) to provide a basic understanding of biochar-soil-water interactions. On average, biochar amendment decreased saturated hydraulic conductivity (K) by 92% in sand and 67% in organic soil, but increased K by 328% in clay-rich soil. The change in K for sand was not predicted by the accompanying physical changes to the soil mixture; the sand-biochar mixture was less dense and more porous than sand without biochar. We propose two hydrologic pathways that are potential drivers for this behavior: one through the interstitial biochar-sand space and a second through pores within the biochar grains themselves. This second pathway adds to the porosity of the soil mixture; however, it likely does not add to the effective soil K due to its tortuosity and smaller pore size. Therefore, the addition of biochar can increase or decrease soil drainage, and suggests that any potential improvement of water delivery to plants is dependent on soil type, biochar amendment rate, and biochar properties. Changes in dissolved carbon (C) and nitrogen (N) fluxes also differed; with biochar increasing the C flux from organic-poor sand, decreasing it from organic-rich soils, and retaining small amounts of soil-derived N. The aromaticity of C lost from sand and clay increased, suggesting lost C was biochar-derived; though the loss accounts for only 0.05% of added biochar-C. Thus, the direction and magnitude of hydraulic, C, and N changes associated with biochar amendments are soil type (composition and particle size) dependent

  7. Creating an infrastructure for training in the responsible conduct of research: the University of Pittsburgh's experience.

    Science.gov (United States)

    Barnes, Barbara E; Friedman, Charles P; Rosenberg, Jerome L; Russell, Joanne; Beedle, Ari; Levine, Arthur S

    2006-02-01

    In response to public concerns about the consequences of research misconduct, academic institutions have become increasingly cognizant of the need to implement comprehensive, effective training in the responsible conduct of research (RCR) for faculty, staff, students, and external collaborators. The ability to meet this imperative is challenging as universities confront declining financial resources and increasing complexity of the research enterprise. The authors describe the University of Pittsburgh's design, implementation, and evaluation of a Web-based, institution-wide RCR training program called Research and Practice Fundamentals (RPF). This project, established in 2000, was embedded in the philosophy, organizational structure, and technology developed through the Integrated Advanced Information Management Systems grant from the National Library of Medicine. Utilizing a centralized, comprehensive approach, the RPF system provides an efficient mechanism for deploying content to a large, diverse cohort of learners and supports the needs of research administrators by providing access to information about who has successfully completed the training. During its first 3 years of operation, the RPF served over 17,000 users and issued more than 38,000 training certificates. The 18 modules that are currently available address issues required by regulatory mandates and other content areas important to the research community. RPF users report high levels of satisfaction with content and ease of using the system. Future efforts must explore methods to integrate non-RCR education and training into a centralized, cohesive structure. The University of Pittsburgh's experience with the RPF demonstrates the importance of developing an infrastructure for training that is comprehensive, scalable, reliable, centralized, affordable, and sustainable.

  8. Report on Beryllium Strength Experiments Conducted at the TA-55 40 mm Impact Test Facility, Fiscal Year 2017

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, William Wyatt [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Hollowell, Benjamin Charles [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Martinez, Todd P. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Owens, Charles Thomas [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Rivera, Joseph Lee [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-10-10

    A series of experiments is currently in progress at eth 40 mm Impact Test Facility (ITF), located at TA-55, to understand the strength behavior of Beryllium metal at elevated temperature and pressure. In FY 2017, three experiments were conducted as a part of this project.

  9. Statistical description of flume experiments on mixed-size bed-load transport and bed armoring processes

    Science.gov (United States)

    Chen, D.; Zhang, Y.

    2008-12-01

    The objective of this paper is to describe the statistical properties of experiments on non-uniform bed-load transport as well as the mechanism of bed armoring processes. Despite substantial effort made over the last two decades, the ability to compute the bed-load flux in a turbulent system remains poor. The major obstacles include the poor understanding of the formation of armor lays on bed surfaces. Such a layer is much flow-resistible than the underlying material and therefore significantly inhibits sediment transport from the reach. To study the problem, we conducted a flume study for mixed sand/gravel sediments. We observed that aggregated sediment blocks were the most common characters in armor layers - the largest sizes resist hydraulic forces, while the smaller sizes add interlocking support and prevent loss of fine material through gaps between the larger particles. Fractional transport rates with the existing of armor layers were measured with time by sediment trapping method at the end of flume. To address the intermittent and time-varying behavior of bed-load transport during bed armoring processes, we investigated the probability distribution of the fractional bed-load transport rates, and the underlying dynamic model derived from the continuous time random walk framework. Results indicate that it is critical to consider the impact of armor layers when a flow is sufficient to move some of the finer particles and yet insufficient to move all the larger particles on a channel bed.

  10. Transport experience with the NAC-1 radioactive materials shipping cask

    International Nuclear Information System (INIS)

    Rollins, J.D.; Hoffman, C.C.

    1976-01-01

    During the first one and one-half years of operation of Nuclear Assurance Corporation's (NAC) four (4) second-generation NAC-1 truck casks, shipments of spent fuel assemblies, fuel rods, and other highly irradiated reactor components have involved over 300,000 cask miles of travel by land, and cask handling at some ten different nuclear facilities. This on-site experience has included the use of various types of auxiliary lifting devices, operational problems with which have identified the need to establish related Quality Assurance procedures in the area of post-fabrication testing. During the course of pre-shipment checkout and testing of the casks minor defects in the upper impact limiter and lower cask shielding wall have been detected and repaired according to procedure. One enroute occurrence with the cask in which an emergency response was implemented has emphasized the need for rigid adherence to procedural checkout before shipment. Periodic inspection and testing are performed as part of the cask license requirement whereby cask components are inspected and/or replaced. During such test periods leaking ball valves and a leaking neutron shield tank have been detected and repaired. (author)

  11. Effect of surface states of layered double hydroxides on conductive and transport properties of nanocomposite polymer electrolytes

    International Nuclear Information System (INIS)

    Liao, C.-S.; Ye, W.-B.

    2004-01-01

    All solid-state poly(ethylene oxide) (PEO) nanocomposite electrolytes were made containing nanoscale fillers of layered double hydroxides (LDHs). Two kinds of LDHs with different surface states were prepared by aqueous co-precipitation method. The LDHs were added into PEO matrix to study the structures, conductivities and ionic transport properties of nanocomposite electrolytes. The structures of LDHs were characterized by infrared spectra, thermogravimetric analysis and wide-angle X-ray diffraction. With enhanced compatibility of LDH sheets by oligo(ethylene oxide) surface modification, the PEO/OMLDH nanocomposite electrolyte exhibits an amorphous morphology and an enhancement of conductivity by three orders of magnitude as compared to pure PEO electrolyte. The lithium ion transference number T Li + of PEO/LDH nanocomposite electrolyte measured with a value of 0.42 is two times higher than the one of pure PEO electrolyte, which can be attributed to the Lewis acid-base interaction between surface states of metal hydroxides and counter anions of lithium salts

  12. Coupling Solute and Fine Particle Transport with Sand Bed Morphodynamics within a Field Experiment

    Science.gov (United States)

    Phillips, C. B.; Ortiz, C. P.; Schumer, R.; Jerolmack, D. J.; Packman, A. I.

    2017-12-01

    Fine suspended particles are typically considered to pass through streams and rivers as wash load without interacting with the bed, however experiments have demonstrated that hyporheic flow causes advective exchange of fine particles with the stream bed, yielding accumulation of fine particle deposits within the bed. Ultimately, understanding river morphodynamics and ecosystem dynamics requires coupling both fine particle and solute transport with bed morphodynamics. To better understand the coupling between these processes we analyze a novel dataset from a controlled field experiment conducted on Clear Run, a 2nd order sand bed stream located within the North Carolina coastal plain. Data include concentrations of continuously injected conservative solutes and fine particulate tracers measured at various depths within the stream bed, overhead time lapse images of bed forms, stream discharge, and geomorphological surveys of the stream. We use image analysis of bed morphodynamics to assess exchange, retention, and remobilization of solutes and fine particles during constant discharge and a short duration experimental flood. From the images, we extract a time series of bedform elevations and scour depths for the duration of the experiment. The high-resolution timeseries of bed elevation enables us to assess coupling of bed morphodynamics with both the solute and fine particle flux during steady state mobile bedforms prior to the flood and to changing bedforms during the flood. These data allow the application of a stochastic modeling framework relating bed elevation fluctuations to fine particle residence times. This combined experimental and modeling approach ultimately informs our ability to predict not only the fate of fine particulate matter but also associated nutrient and carbon dynamics within streams and rivers.

  13. Protective Behaviour of Citizens to Transport Accidents Involving Hazardous Materials: A Discrete Choice Experiment Applied to Populated Areas nearby Waterways.

    Directory of Open Access Journals (Sweden)

    Esther W de Bekker-Grob

    Full Text Available To improve the information for and preparation of citizens at risk to hazardous material transport accidents, a first important step is to determine how different characteristics of hazardous material transport accidents will influence citizens' protective behaviour. However, quantitative studies investigating citizens' protective behaviour in case of hazardous material transport accidents are scarce.A discrete choice experiment was conducted among subjects (19-64 years living in the direct vicinity of a large waterway. Scenarios were described by three transport accident characteristics: odour perception, smoke/vapour perception, and the proportion of people in the environment that were leaving at their own discretion. Subjects were asked to consider each scenario as realistic and to choose the alternative that was most appealing to them: staying, seeking shelter, or escaping. A panel error component model was used to quantify how different transport accident characteristics influenced subjects' protective behaviour.The response was 44% (881/1,994. The predicted probability that a subject would stay ranged from 1% in case of a severe looking accident till 62% in case of a mild looking accident. All three transport accident characteristics proved to influence protective behaviour. Particularly a perception of strong ammonia or mercaptan odours and visible smoke/vapour close to citizens had the strongest positive influence on escaping. In general, 'escaping' was more preferred than 'seeking shelter', although stated preference heterogeneity among subjects for these protective behaviour options was substantial. Males were less willing to seek shelter than females, whereas elderly people were more willing to escape than younger people.Various characteristics of transport accident involving hazardous materials influence subjects' protective behaviour. The preference heterogeneity shows that information needs to be targeted differently depending on

  14. Portable Conduction Velocity Experiments Using Earthworms for the College and High School Neuroscience Teaching Laboratory

    Science.gov (United States)

    Shannon, Kyle M.; Gage, Gregory J.; Jankovic, Aleksandra; Wilson, W. Jeffrey; Marzullo, Timothy C.

    2014-01-01

    The earthworm is ideal for studying action potential conduction velocity in a classroom setting, as its simple linear anatomy allows easy axon length measurements and the worm's sparse coding allows single action potentials to be easily identified. The earthworm has two giant fiber systems (lateral and medial) with different conduction velocities…

  15. FRACTEX: an experiment aiming at characterizing the transport properties of a secondary fault

    International Nuclear Information System (INIS)

    Wittebroodt, C.; Matray, J.M.; Dick, P.; Cabrera, J.; Barnichon, J.D.

    2012-01-01

    Document available in extended abstract form only. Because of their favourable transport and retention properties, argillaceous rocks are considered as potential host rocks for radioactive waste repositories. At the request of the French Authority of Nuclear Safety (ASN), the French Institute for Radioprotection and Nuclear Safety (IRSN) is in charge of an independent expertise of the French industrial (Andra's) project. Therefore, IRSN develops experimental research programs in such geological formations at the Tournemire Underground Research Laboratory (URL, Aveyron, France). One of the objectives of this project is to evaluate the occurrence and the driving processes controlling the radionuclide migration through an argillaceous formation similar to those studied elsewhere for nuclear waste disposal. Since undisturbed argillaceous rocks display very low values for both hydraulic conductivity (K h ) and water content (θ e ), diffusion is considered to be the main transport mechanism governing radionuclide migration through the argillite. On the other hand, in the presence of fracture in the argillaceous formation, the flux of water through this preferential pathway could dramatically accelerate the migration of the radionuclide it contains. Thus, the implementation of a radwaste disposal facility requires a precise sedimentary and structural characterization of the preselected site to guarantee the presence of a regular, homogenous and fault-free clay layer over a large area and so to determine its ability to ensure an effective radionuclide confinement. The site characterization and fracture detection can be performed using complementary approaches such as geological studies, in situ measurements and non-destructive geophysical methods. In order to evaluate both the capacity and the limit of these seismic methods to detect a secondary fault in an argillaceous media, IRSN performed a 3D HR seismic survey from the surface of its Tournemire URL. Due to the weak

  16. Beyond the Usability Lab Conducting Large-scale Online User Experience Studies

    CERN Document Server

    Albert, William; Tullis, Thomas

    2010-01-01

    Usability testing and user experience research typically take place in a controlled lab with small groups. While this type of testing is essential to user experience design, more companies are also looking to test large sample sizes to be able compare data according to specific user populations and see how their experiences differ across user groups. But few usability professionals have experience in setting up these studies, analyzing the data, and presenting it in effective ways.  Online usability testing offers the solution by allowing testers to elicit feedback simultaneously from 1,0

  17. The role of parental risk judgements, transport safety attitudes, transport priorities and accident experiences on pupils' walking to school.

    Science.gov (United States)

    Mehdizadeh, Milad; Nordfjaern, Trond; Mamdoohi, Amir Reza; Shariat Mohaymany, Afshin

    2017-05-01

    Walking to school could improve pupils' health condition and might also reduce the use of motorized transport modes, which leads to both traffic congestion and air pollution. The current study aims to examine the role of parental risk judgements (i.e. risk perception and worry), transport safety attitudes, transport priorities and accident experiences on pupils' walking and mode choices on school trips in Iran, a country with poor road safety records. A total of 1078 questionnaires were randomly distributed among pupils at nine public and private schools in January 2014 in Rasht, Iran. Results from valid observations (n=711) showed that parents with high probability assessments of accidents and strong worry regarding pupils' accident risk while walking were less likely to let their children walk to school. Parents with high safety knowledge were also more likely to allow their pupils to walk to school. Parents who prioritized convenience and accessibility in transport had a stronger tendency to choose motorized modes over walking modes. Also, parents who prioritized safety and security in transport were less likely to allow pupils to walk to school. Elasticities results showed that a one percent increase in priorities of convenience and accessibility, priorities of safety and security, car ownership and walking time from home to school reduced walking among pupils by a probability of 0.62, 0.20, 0.86 and 0.57%, respectively. A one percent increase in parental safety knowledge increased the walking probability by around 0.25%. A 1 unit increase in parental probability assessment and worry towards pupils' walking, decreased the probability of choosing walking mode by 0.11 and 0.05, respectively. Policy-makers who aim to promote walking to schools should improve safety and security of the walking facilities and increase parental safety knowledge. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Applying distributions of hydraulic conductivity for anisotropic systems and applications to Tc Transport at the U.S. Department of Energy Hanford Site

    International Nuclear Information System (INIS)

    Hunt, Allen G.

    2008-01-01

    43Tc99 is spreading mostly laterally through the U.S. Department of Energy Hanford site sediments. At higher tensions in the unsaturated zone, the hydraulic conductivity may be strongly anisotropic as a consequence of finer soils to retain more water than coarser ones, and for these soils to have been deposited primarily in horizontal structures. We have tried to develop a consistent modeling procedure that could predict the behavior of Tc plumes. Our procedure consists of: (1) Adapting existing numerical recipes based on critical path analysis to calculate the hydraulic conductivity, K, as a function of tension, h, (2) Statistically correlating the predicted K at various values of the tension with fine content, (3) Seeking a tension value, for which the anisotropy and the horizontal K values are both sufficiently large to accommodate multi-kilometer spreading, (4) Predicting the distribution of K values for vertical flow as a function of system support volume, (5) Comparing the largest likely K value in the vertical direction with the expected K in the horizontal direction, (6) Finding the length scale at which the two K values are roughly equal, (7) Comparing that length scale with the horizontal spreading of the plume. We find that our predictions of the value of the tension at which the principle spreading is likely occurring compares very well with experiment. However, we seem to underestimate the physical length scale at which the predominantly horizontal spreading begins to take on significant vertical characteristics. Our data and predictions would seem to indicate that this should happen after horizontal transport of somewhat over a km, but the chiefly horizontal transport appears to continue out to scales of 10km or so.

  19. Required momentum, heat, and mass transport experiments for liquid-metal blankets

    International Nuclear Information System (INIS)

    Tillack, M.S.; Sze, D.K.; Abdou, M.A.

    1986-01-01

    Through the effects on fluid flow, many aspects of blanket behavior are affected by magnetohydrodynamic (MHD) effects, including pressure drop, heat transfer, mass transfer, and structural behavior. In this paper, a set of experiments is examined that could be performed in order to reduce the uncertainties in the highly related set of issues dealing with momentum, heat, and mass transport under the influence of a strong magnetic field (i.e., magnetic transport phenomena). By improving our basic understanding and by providing direct experimental data on blanket behavior, these experiments will lead to improved designs and an accurate assessment of the attractiveness of liquid-metal blankets

  20. Variably Saturated Flow and Multicomponent Biogeochemical Reactive Transport Modeling of a Uranium Bioremediation Field Experiment

    International Nuclear Information System (INIS)

    Yabusaki, Steven B.; Fang, Yilin; Williams, Kenneth H.; Murray, Christopher J.; Ward, Anderson L.; Dayvault, Richard; Waichler, Scott R.; Newcomer, Darrell R.; Spane, Frank A.; Long, Philip E.

    2011-01-01

    Field experiments at a former uranium mill tailings site have identified the potential for stimulating indigenous bacteria to catalyze the conversion of aqueous uranium in the +6 oxidation state to immobile solid-associated uranium in the +4 oxidation state. This effectively removes uranium from solution resulting in groundwater concentrations below actionable standards. Three-dimensional, coupled variably-saturated flow and biogeochemical reactive transport modeling of a 2008 in situ uranium bioremediation field experiment is used to better understand the interplay of transport rates and biogeochemical reaction rates that determine the location and magnitude of key reaction products. A comprehensive reaction network, developed largely through previous 1-D modeling studies, was used to simulate the impacts on uranium behavior of pulsed acetate amendment, seasonal water table variation, spatially-variable physical (hydraulic conductivity, porosity) and geochemical (reactive surface area) material properties. A principal challenge is the mechanistic representation of biologically-mediated terminal electron acceptor process (TEAP) reactions whose products significantly alter geochemical controls on uranium mobility through increases in pH, alkalinity, exchangeable cations, and highly reactive reduction products. In general, these simulations of the 2008 Big Rusty acetate biostimulation field experiment in Rifle, Colorado confirmed previously identified behaviors including (1) initial dominance by iron reducing bacteria that concomitantly reduce aqueous U(VI), (2) sulfate reducing bacteria that become dominant after ∼30 days and outcompete iron reducers for the acetate electron donor, (3) continuing iron-reducer activity and U(VI) bioreduction during dominantly sulfate reducing conditions, and (4) lower apparent U(VI) removal from groundwater during dominantly sulfate reducing conditions. New knowledge on simultaneously active metal and sulfate reducers has been

  1. The Lattice and Thermal Radiation Conductivity of Thermal Barrier Coatings: Models and Experiments

    Science.gov (United States)

    Zhu, Dongming; Spuckler, Charles M.

    2010-01-01

    The lattice and radiation conductivity of ZrO2-Y2O3 thermal barrier coatings was evaluated using a laser heat flux approach. A diffusion model has been established to correlate the coating apparent thermal conductivity to the lattice and radiation conductivity. The radiation conductivity component can be expressed as a function of temperature, coating material scattering, and absorption properties. High temperature scattering and absorption of the coating systems can be also derived based on the testing results using the modeling approach. A comparison has been made for the gray and nongray coating models in the plasma-sprayed thermal barrier coatings. The model prediction is found to have a good agreement with experimental observations.

  2. Prosocial Conduct in Urban Middle Schools: Do Young Adolescents' Experiences of the School Context Matter?

    OpenAIRE

    White, Samantha Jane Almaraz Simmons

    2013-01-01

    Young adolescents spend the majority of their time in school, yet little is known about how the school context is associated with their prosocial conduct. The current study focused on 1) the extent to which individual students were teamed with their classmates and 2) their exposure to ethnically diverse peers, and examined the processes by which these aspects of the school context were associated with their prosocial conduct. Multilevel mediation models were fit to multiply imputed question...

  3. Interplay between total thickness and period thickness in the phonon thermal conductivity of superlattices from the nanoscale to the microscale: Coherent versus incoherent phonon transport

    Science.gov (United States)

    Cheaito, Ramez; Polanco, Carlos A.; Addamane, Sadhvikas; Zhang, Jingjie; Ghosh, Avik W.; Balakrishnan, Ganesh; Hopkins, Patrick E.

    2018-02-01

    We report on the room temperature thermal conductivity of AlAs-GaAs superlattices (SLs), in which we systematically vary the period thickness and total thickness between 2 -24 nm and 20.1 -2 ,160 nm , respectively. The thermal conductivity increases with the SL thickness and plateaus at a thickness around 200 nm, showing a clear transition from a quasiballistic to a diffusive phonon transport regime. These results demonstrate the existence of classical size effects in SLs, even at the highest interface density samples. We use harmonic atomistic Green's function calculations to capture incoherence in phonon transport by averaging the calculated transmission over several purely coherent simulations of independent SL with different random mixing at the AlAs-GaAs interfaces. These simulations demonstrate the significant contribution of incoherent phonon transport through the decrease in the transmission and conductance in the SLs as the number of interfaces increases. In spite of this conductance decrease, our simulations show a quasilinear increase in thermal conductivity with the superlattice thickness. This suggests that the observation of a quasilinear increase in thermal conductivity can have important contributions from incoherent phonon transport. Furthermore, this seemingly linear slope in thermal conductivity versus SL thickness data may actually be nonlinear when extended to a larger number of periods, which is a signature of incoherent effects. Indeed, this trend for superlattices with interatomic mixing at the interfaces could easily be interpreted as linear when the number of periods is small. Our results reveal that the change in thermal conductivity with period thickness is dominated by incoherent (particlelike) phonons, whose properties are not dictated by changes in the AlAs or GaAs phonon dispersion relations. This work demonstrates the importance of studying both period and sample thickness dependencies of thermal conductivity to understand the

  4. The Potential of Online Respondent Data for Choice Modeling in Transportation Research: Evidence from Stated Preference Experiments using Web-based Samples: Evidence from Stated Preference Experiments using Web-based Samples

    OpenAIRE

    Hoffer, Brice

    2015-01-01

    The aim of this thesis is to analyze the potential of online survey services for conducting stated preference experiments in the field of transportation planning. Several web-products for hosting questionnaires are evaluated considering important features required when conducting a stated preference survey. Based on this evaluation, the open-source platform LimeSurvey is the most appropriated for this kind of research. A stated preference questionnaire about pedestrians’ route choice in a Sin...

  5. Used Fuel Logistics: Decades of Experience with transportation and Interim storage solutions

    Energy Technology Data Exchange (ETDEWEB)

    Orban, G.; Shelton, C.

    2015-07-01

    Used fuel inventories are growing worldwide. While some countries have opted for a closed cycle with recycling, numerous countries must expand their interim storage solutions as implementation of permanent repositories is taking more time than foreseen. In both cases transportation capabilities will have to be developed. AREVA TN has an unparalleled expertise with transportation of used fuel. For more than 50 years AREVA TN has safely shipped more than 7,000 used fuel transport casks. The transportation model that was initially developed in the 1970s has been adapted and enhanced over the years to meet more restrictive regulatory requirements and evolving customer needs, and to address public concerns. The numerous “lessons learned” have offered data and guidance that have allowed for also efficient and consistent improvement over the decades. AREVA TN has also an extensive experience with interim dry storage solutions in many countries on-site but also is working with partners to developed consolidated interim storage facility. Both expertise with storage and transportation contribute to safe, secure and smooth continuity of the operations. This paper will describe decades of experience with a very successful transportation program as well as interim storage solutions. (Author)

  6. Human Nutrition Research Conducted at State Agricultural Experiment Stations and 1890/Tuskegee Agricultural Research Programs.

    Science.gov (United States)

    Driskell, Judy A.; Myers, John R.

    1989-01-01

    Cooperative State Research Service-administered and state-appropriated State Agriculture Experiment Station funds for human nutrition research increased about two-fold from FY70-FY86, while the percentage of budget expended for this research decreased. (JOW)

  7. Experience of European LWR irradiated fuel transport: the first five hundred tonnes

    International Nuclear Information System (INIS)

    Curtis, H.W.

    1978-01-01

    The paper describes the service provided by an international company specializing in the transport of LWR irradiated fuel throughout Europe. Methods of transport used to the reprocessing plants at La Hague and Windscale include road transport of 38 te flasks over the whole route; transport of flasks between 55 and 105 te by rail, with rail-head and the reprocessing plant, where required, performed by road using heavy trailers; roll-on, roll-off sea ferries; and charter ships. Different modes of transport have been developed to cater for the various limitations on access to reactor sites arising from geographical and routing considerations. The experience of transporting more than 500 tonnes of irradiated uranium from twenty-one power reactors is used to illustrate the flexibility which the transport organization requires when the access and handling facilities are different at almost every reactor. Variations in fuel cross sections and lengths of fuel elements used in first generation reactors created the need for first generation flasks with sufficient variants to accommodate all reactor fuels but the trend now is towards standardization of flasks to perhaps two basic types. The safety record of irradiated fuel transport is examined with explanation of the means whereby this has been achieved. The problems of programming the movement of a pool of eighteen flasks for twenty-one reactors in eight countries are discussed together with the steps taken to ensure that the service operates fairly to give priority to those reactors with the greatest problems. The transport of irradiated fuel across several national frontiers is an international task which requires an international company. The transport of European irradiated fuel can be presented as an example of international collaboration which works

  8. Experiment and Artificial Neural Network Prediction of Thermal Conductivity and Viscosity for Alumina-Water Nanofluids.

    Science.gov (United States)

    Zhao, Ningbo; Li, Zhiming

    2017-05-19

    To effectively predict the thermal conductivity and viscosity of alumina (Al₂O₃)-water nanofluids, an artificial neural network (ANN) approach was investigated in the present study. Firstly, using a two-step method, four Al₂O₃-water nanofluids were prepared respectively by dispersing different volume fractions (1.31%, 2.72%, 4.25%, and 5.92%) of nanoparticles with the average diameter of 30 nm. On this basis, the thermal conductivity and viscosity of the above nanofluids were analyzed experimentally under various temperatures ranging from 296 to 313 K. Then a radial basis function (RBF) neural network was constructed to predict the thermal conductivity and viscosity of Al₂O₃-water nanofluids as a function of nanoparticle volume fraction and temperature. The experimental results showed that both nanoparticle volume fraction and temperature could enhance the thermal conductivity of Al₂O₃-water nanofluids. However, the viscosity only depended strongly on Al₂O₃ nanoparticle volume fraction and was increased slightly by changing temperature. In addition, the comparative analysis revealed that the RBF neural network had an excellent ability to predict the thermal conductivity and viscosity of Al₂O₃-water nanofluids with the mean absolute percent errors of 0.5177% and 0.5618%, respectively. This demonstrated that the ANN provided an effective way to predict the thermophysical properties of nanofluids with limited experimental data.

  9. Acceleration ion focusing (IFR) and transport experiments with the recirculating linear accelerator (RLA)

    International Nuclear Information System (INIS)

    Mazarakis, M.G.; Smith, D.L.; Puokey, J.W.; Bennett, L.F.; Wagner, J.S.; Olson, W.R.; George, M.; Turman, B.N.; Prestwich, K.R.; Struve, K.W.

    1992-01-01

    The focusing and transport of intense relativistic electron beams in the Sandia Laboratories Recirculating Linear Accelerator (RLA) is accomplished with the aid of an ion focusing channel (IFR). We report here experiments evaluating the beam generation in the injector and its subsequent acceleration and transport through the first post-accelerating cavity. Two injectors and one type of post-accelerating cavity were studied. Beams of 6-20 kA current were injected and successfully transported and accelerated through the cavity. The transport efficiencies were 90% - 100%, and the beam Gaussian profile (4 MeV injector) and radius (5 mm) remained the same through acceleration. We describe the RLA, present the experimental results and compare them with numerical simulations. (Author) 3 refs., 7 figs

  10. Ion thermal conductivity and convective energy transport in JET hot-ion regimes and H-modes

    International Nuclear Information System (INIS)

    Tibone, F.; Balet, B.; Cordey, J.G.

    1989-01-01

    Local transport in a recent series of JET experiments has been studied using interpretive codes. Auxiliary heating, mainly via neutral beam injection, was applied on low-density target plasmas confined in the double-null X-point configuration. This has produced two-component plasmas with high ion temperature and neutron yield and, above a threshold density, H-modes characterised by peak density and power deposition profiles. H-mode confinement was also obtained for the first time with 25 MW auxiliary power, of which 10 MW was from ion cyclotron resonance heating. We have used profile measurements of electron temperature T e from electron cyclotron emission and LIDAR Thomson scattering, ion temperature T i from charge-exchange recombination spectroscopy (during NBI), electron density n e from LIDAR and Abel-inverted interferometer measurements. Only sparse information is, however, available to date concerning radial profiles of effective ionic charge and radiation losses. Deuterium depletion due to high impurity levels is an important effect in these discharges, and our interpretation of thermal ion energy content, neutron yield and ion particle fluxes needs to be confirmed using measured Z eff -profiles. (author) 4 refs., 4 figs

  11. Low frequency complex dielectric (conductivity) response of dilute clay suspensions: Modeling and experiments.

    Science.gov (United States)

    Hou, Chang-Yu; Feng, Ling; Seleznev, Nikita; Freed, Denise E

    2018-04-11

    In this work, we establish an effective medium model to describe the low-frequency complex dielectric (conductivity) dispersion of dilute clay suspensions. We use previously obtained low-frequency polarization coefficients for a charged oblate spheroidal particle immersed in an electrolyte as the building block for the Maxwell Garnett mixing formula to model the dilute clay suspension. The complex conductivity phase dispersion exhibits a near-resonance peak when the clay grains have a narrow size distribution. The peak frequency is associated with the size distribution as well as the shape of clay grains and is often referred to as the characteristic frequency. In contrast, if the size of the clay grains has a broad distribution, the phase peak is broadened and can disappear into the background of the canonical phase response of the brine. To benchmark our model, the low-frequency dispersion of the complex conductivity of dilute clay suspensions is measured using a four-point impedance measurement, which can be reliably calibrated in the frequency range between 0.1 Hz and 10 kHz. By using a minimal number of fitting parameters when reliable information is available as input for the model and carefully examining the issue of potential over-fitting, we found that our model can be used to fit the measured dispersion of the complex conductivity with reasonable parameters. The good match between the modeled and experimental complex conductivity dispersion allows us to argue that our simplified model captures the essential physics for describing the low-frequency dispersion of the complex conductivity of dilute clay suspensions. Copyright © 2018 Elsevier Inc. All rights reserved.

  12. First experience in international air transportation of RR SFA in Russian-made TUK-19 casks

    International Nuclear Information System (INIS)

    Kanashov, B.A.; Barinkov, O.P.; Dorofeev, A.N.; Komarov, S.V.; Smirnov, A.V.; Biro, L.; Budu, M.; Ciocanescu, M.

    2010-01-01

    Traditionally, spent fuel assemblies (SFA) have been transported across the Russian Federation by rail in special railcars. New conditions required SFA shipments by other conveyance, i.e. road, sea and even air transport. The air shipment of the VVR-S research reactor SNF in TUK-19 casks from Magurele, Romania in June 2009 was the first experience after new Russian and international regulations for the safe transport of radioactive material came into effect. The preparatory stage of the shipment focused on the issues associated with radiation and nuclear safety both during the loading and transport operations. The project covered development of a technology and equipment for SFA loading into TUK-19 casks and that for the air shipment. The SFAs were loaded into the TUK-19 casks with a specially designed transfer cask, and the SFA-containing packages were transported in specialized freight 20-foot ISO-containers. The safety of the loading and transport operations was ensured both by reliable engineering solutions, and selected conveyances and routes. The paper shows that the loading and the air shipment of the Romanian SFAs in TUK-19 casks does not contradict Romanian, Russian and international regulations for the safe transport of radioactive material. The outcomes of the SNF shipment from Romania confirmed correctness of the solutions and demonstrated high environmental safety. (author)

  13. The TN-GEMINI: experience on a versatile alpha waste transport container

    International Nuclear Information System (INIS)

    Roland, V.; Chanzy, Y.

    2001-01-01

    The present paper discusses experience gained in moving alpha wastes and its teachings regarding transport aspects of D and D. Alpha wastes are generated in fuel cycle facilities such as those involved in reprocessing, in manufacture of mixed oxide fuel, and by research laboratories. If a significant amount of wastes has to be transported, then a Type B packaging is required. Developed by Transnucleaire and COGEMA, the TN GEMINI container enables nuclear facilities operators to optimise their alpha waste transport management, and more generally contribute to their D and D projects. After describing succinctly the design of the TN GEMINI, the paper will explain how the packaging is being operated. Teachings from experience will be shared. (orig.)

  14. A new treatment of the heat transport equation with a transport barrier and applications to ECRH experiments in Tore Supra

    Energy Technology Data Exchange (ETDEWEB)

    Zou, X.L.; Giruzzi, A.G.; Bouquey, F.; Clary, J.; Darbos, C.; Lennholm, M.; Magne, R.; Segui, J.L. [CEA Cadarache, Dept. de Recherches sur la Fusion Controlee, 13 - Saint-Paul-lez-Durance (France); Clemencon, A. [MIT, Electrochemical Energy Laboratory, Cambridge, MA (United States); Guivarch, C. [Ecole Nationale des Ponts et Chaussees, 77 - Marne-la-Vallee (France)

    2004-07-01

    An exact analytical solution of the electron heat diffusion equation in a cylinder has been found with a step-like diffusion coefficient, plus a monomial increase in the radial direction and a constant damping term. This model is sufficiently general to describe heat diffusion in the presence of a critical gradient threshold or a transport barrier, superimposed to the usual trend of increasing heat diffusivity from the plasma core to the edge. This type of representation allows us to see some well-known properties of heat transport phenomena in a different light. For instance, it has been shown that the contributions of the Eigenmodes to the time dependent solution grow at speeds that depend on the Eigenmode order i.e. at the beginning of the heating phase all the Eigenmodes are equally involved, whereas at the end only the lower order ones are left. This implies, e.g., that high frequency modulation experiments provide a characterization of transport phenomena that is intrinsically different with respect to power balance analysis of a stationary phase. It is particularly useful to analyse power switch on/off events and whenever high frequency modulations are not technically feasible. Low-frequency (1-2 Hz) ECRH modulation experiments have been performed on Tore Supra. A large jump (a factor of 8) in the heat diffusivity has been clearly identified at the ECRH power deposition layer. The amplitude and phase of several harmonics of the Fourier transform of the modulated temperature, as well as the time evolution of the modulated temperature have been reproduced by the analytical solution. The jump is found to be much weaker at lower ECRH power (one gyrotron)

  15. Emotionally Excited Eyeblink-Rate Variability Predicts an Experience of Transportation into the Narrative World

    Directory of Open Access Journals (Sweden)

    Ryota eNomura

    2015-04-01

    Full Text Available Collective spectator communications such as oral presentations, movies, and storytelling performances are ubiquitous in human culture. This study investigated the effects of past viewing experiences and differences in expressive performance on an audience’s transportive experience into a created world of a storytelling performance. In the experiment, 60 participants (mean age = 34.12 yrs., SD = 13.18 yrs., range 18–63 yrs. were assigned to watch one of two videotaped performances that were played (1 in an orthodox way for frequent viewers and (2 in a modified way aimed at easier comprehension for first-time viewers. Eyeblink synchronization among participants was quantified by employing distance-based measurements of spike trains, Dspike and Dinterval (Victor & Purpura, 1997. The results indicated that even non-familiar participants’ eyeblinks were synchronized as the story progressed and that the effect of the viewing experience on transportation was weak. Rather, the results of a multiple regression analysis demonstrated that the degrees of transportation could be predicted by a retrospectively reported humor experience and higher real-time variability (i.e., logarithmic transformed standard deviation of inter blink intervals during a performance viewing. The results are discussed from the viewpoint in which the extent of eyeblink synchronization and eyeblink-rate variability acts as an index of the inner experience of audience members.

  16. Database of full-scale laboratory experiments on wave-driven sand transport processes

    NARCIS (Netherlands)

    van der Werf, Jebbe J.; Schretlen, Johanna Lidwina Maria; Ribberink, Jan S.; O'Donoghue, Tom

    2009-01-01

    A new database of laboratory experiments involving sand transport processes over horizontal, mobile sand beds under full-scale non-breaking wave and non-breaking wave-plus-current conditions is described. The database contains details of the flow and bed conditions, information on which quantities

  17. The operational and logistic experience on transportation of Brazilian spent fuel to USA

    International Nuclear Information System (INIS)

    Maiorino, Jose Rubens; Frajndlich, Roberto; Mandlae, Martin; Bensberg, Werner; Renger, August; Grabow, Karsten

    2000-01-01

    A shipment of 127 spent MTR fuel assemblies was made from IEA-R1 Research Reactor located at the Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN/SP), Sao Paulo, Brazil to Savannah River Site Laboratory in the United States. This paper describes the operational and logistic experience on this transportation made by IPEN staff and the Consortium NCS/GNS. (author)

  18. Insights into organic carbon oxidation potential during fluvial transport from controlled laboratory and natural field experiments

    Science.gov (United States)

    Scheingross, Joel S.; Dellinger, Mathieu; Golombek, Nina; Hilton, Robert G.; Hovius, Niels; Sachse, Dirk; Turowski, Jens M.; Vieth-Hillebrand, Andrea; Wittmann, Hella

    2017-04-01

    Over geologic timescales, the exchange of organic carbon (OC) between the atmosphere, biosphere and geosphere is thought to be a major control on atmospheric carbon dioxide (CO2) concentrations, and hence global climate. The carbon fluxes from the oxidation of rock-derived OC (a CO2 source) and erosion and transport of biospheric OC (a potential CO2 sink) during fluvial transit are approximately the same order of magnitude or larger than those from silicate weathering (France-Lanord and Derry, 1997; Bouchez et al., 2010). Despite field data showing oxidation of OC moving downstream in lowland rivers, it is unclear if losses occur primarily during active fluvial transport within the river, where OC is in continual motion within an aerated environment, or during longer periods when OC is temporarily stored in river floodplains which may be anoxic. This represents a major knowledge gap, as the unknown location of OC oxidation (i.e., river vs. floodplain) limits our ability to develop process-based models that can be employed to predict OC losses, constrain carbon budgets, and unravel links between climate, tectonics, and erosion. To fill this gap, we investigated the potential for OC oxidation in both controlled laboratory experiments and a simplified field setting. We consider both rock-derived and biospheric OC. Our experiments simulated fluvial transport without floodplain storage, allowing mixtures of OC-rich and siliciclastic sediment to be transported for distances of 1000 km in annular flumes while making time-series measurements of OC concentration in both the solid (POC) and dissolved (DOC) loads, as well as measurements of rhenium concentration, which serves as a proxy for the oxidation of rock-derived OC. These transport experiments were compared to static, control experiments where water and sediment in the same proportion were placed in still water. Initial results for transport of OC-rich soil show similar behavior between the transport and static

  19. Insights into organic carbon oxidation potential during fluvial transport from laboratory and field experiments

    Science.gov (United States)

    Scheingross, J. S.; Dellinger, M.; Eglinton, T. I.; Fuchs, M. C.; Golombek, N.; Hilton, R. G.; Hovius, N.; Lupker, M.; Repasch, M. N.; Sachse, D.; Turowski, J. M.; Vieth-Hillebrand, A.; Wittmann, H.

    2017-12-01

    Over geologic timescales, the exchange of organic carbon (OC) between the atmosphere, hydropshere, biosphere and geosphere can be a major control on atmospheric carbon dioxide concentrations. The carbon fluxes from the oxidation of rock-derived OC (a CO2 source) and erosion, transport, and burial of biospheric OC (a potential CO2 sink) during fluvial transit are approximately the same order of magnitude or larger than those from silicate weathering. Despite field data showing increasing oxidation of OC moving downstream in lowland rivers, it is unclear if losses occur primarily during active fluvial transport, where OC is in continual motion within an aerated river, or during periods of temporary storage in river floodplains which may be anoxic. The unknown location of OC oxidation (i.e., river vs. floodplain) limits our ability to mechanistically link geochemical and geomorphic processes which are required to develop models capable of predicting OC losses, constrain carbon budgets, and unravel links between climate, tectonics, and erosion. To fill this knowledge gap, we investigated OC oxidation in controlled laboratory experiments and a simplified field setting. We performed experiments in annular flumes that simulate fluvial transport without floodplain storage, allowing mixtures of OC-rich and siliciclastic sediment to be transported for distances of 1000 km. Preliminary experiments exploring both rock-derived and biospheric OC sources show minimal OC oxidation during active river transport, consistent with the idea that the majority of OC loss occurs during transient floodplain storage. These results are also consistent with new field data collected in the Rio Bermejo, Argentina, a lowland river traversing 800 km with no tributary inputs, where aged floodplain deposits have 3 to 10 times lower OC concentrations compared to modern river sediments. Together our field data and experiments support the hypothesis that oxidation of OC occurs primarily during

  20. First clinical experiences with an implantable bone conduction hearing aid at the University of Amsterdam

    NARCIS (Netherlands)

    van der Hulst, R. J.; Dreschler, W. A.; Tange, R. A.

    1993-01-01

    A transcutaneous bone-conduction hearing aid was implanted in 11 patients who were not suitable for transcranial sound amplification. Audiological and surgical selection criteria were followed strictly. One device had to be explanted and minor revision surgery was needed in two cases for skin

  1. Comparison of the Volume Charge Density of Nanofiltration Membranes Obtained from Retention and Conductivity Experiments

    DEFF Research Database (Denmark)

    Benavente, J.; Silva, V.; Pradanos, P.

    2010-01-01

    A version of the Donnan steric-partitioning pore model with dielectrical exclusion (DSPM-DE) has been used to get information on the pore size and charge density of a commercial membrane, NF45 from FilmTec, from its retention of KCl solutions. The conductivity inside the pores has been measured b...

  2. Temperature dependence of the cosphi conductance in Josephson tunnel junctions determined from plasma resonance experiments

    DEFF Research Database (Denmark)

    Pedersen, Niels Falsig; Sørensen, O. H.; Mygind, Jesper

    1978-01-01

    The microwave response at 9 GHz of Sn-O-Sn tunnel-junction current biased at zero dc voltage has been measured just below the critical temperature Tc of the Sn films. The temperature dependence of the cosφ conductance is determined from the resonant response at the junction plasma frequency fp...

  3. Professionals and students in a lobbying experiment. Professional rules of conduct and subject surrogacy

    NARCIS (Netherlands)

    Potters, J.; van Winden, F.A.A.M.

    2000-01-01

    Lobbying is studied in a series of signaling game experiments. Students as well as professional lobbyists are used as subjects. In contrast with some earlier studies, comparing students and professionals, we find significant differences in the behavior of the two subject pools. Professional subjects

  4. A critique to Akdemir and Oguz : Methodological and statistical issues to consider when conducting educational experiments

    NARCIS (Netherlands)

    Albers, Casper J.; Boevé, Anja J.; Meijer, Rob R.

    Abstract In the paper “Computer-based testing: An alternative for the assessment of Turkish undergraduate students”, Akdemir and Oguz (2008) discuss an experiment to compare student performance in paper-and-pencil tests with computer-based tests, and conclude that students taking computer-based

  5. A Laboratory Experiment, Based on the Maillard Reaction, Conducted as a Project in Introductory Statistics

    Science.gov (United States)

    Kravchuk, Olena; Elliott, Antony; Bhandari, Bhesh

    2005-01-01

    A simple laboratory experiment, based on the Maillard reaction, served as a project in Introductory Statistics for undergraduates in Food Science and Technology. By using the principles of randomization and replication and reflecting on the sources of variation in the experimental data, students reinforced the statistical concepts and techniques…

  6. Using Satellite Technology to Increase Professional Communications Among Teachers: a Report of Experiments Conducted by the National Education Association.

    Science.gov (United States)

    National Education Association, Washington, DC. Div. of Instruction and Professional Development.

    The National Education Association (NEA) in conjunction with the National Aeronautics and Space Administration, the National Library of Medicine, The Alaska Broadcasting Commission, and the Pacific PEACESAT Network, conducted four satellite experiments designed to improve professional communication among teachers. These programs were the Satellite…

  7. Soil Science self-learning based on the design and conduction of experiments

    Science.gov (United States)

    Jordán, A.; Bárcenas-Moreno, G.; Zavala, L. M.

    2012-04-01

    This paper presents an experience for introducing the methodology of project-based learning (PBL) in the area of Soil Science in the University of Sevilla (Spain). Currently, teachers try to enhance practical experience of university students in a complementary manner to theoretical knowledge. However, many times this is a difficult process. Practice is an important part of personal work in the vast majority of subjects that degree students receive, since the implementation of the EHEA. In most cases, these experiences are presented as partial small experiments or projects, assigned to the area-specific knowledge agenda. Certain sciences, such as Soil Science, however, require synthesis and integration capabilities of previous knowledge. It is therefore necessary to develop practical programs that address the student not only to the performance of laboratory determinations, but to the formulation of hypotheses, experimental design and problem solving, whether in groups or individually, situated in a wide context and allowing students to make connections with other areas of knowledge. This project involves the development of teamwork experiments, for the study real cases and problems and making decisions in the field of Soil Science. The results of the experimental work were publicly exposed as posters and oral presentations and were discussed during a mini-congress open to students and a general audience. The open and dynamic nature of the project substantially improves student motivation, which adds value to our project. Due to the multidisciplinary character of Soil Science it is relatively easy to propose projects of some complexity, and therefore, provides good conditions for introducing the PBL methodology. The teacher's role is also important and is not limited to observe or qualify the students, but it is a catalyst for learning. It is important that teacher give the leadership of the process and make the students themselves feel the protagonists of the

  8. Non-LTE considerations in spectral diagnostics of thermal transport and implosion experiments

    International Nuclear Information System (INIS)

    Epstein, R.; Skupsky, S.; Delettrez, J.; Yaakobi, B.

    1984-01-01

    Recent thermal-transport and target-implosion experiments have used the emission of radiation from highly-ionized ions to signal the advance of laser-driven heat fronts and to mark the trajectories and stagnation points of imploding shells. We examine the results of such experiments with particular attention given to non-LTE effects of non-Maxwellian electrons and of finite ionization times on the populations of signature-emitting atomic species and on the formation of signature spectra and x-ray images in these experiments

  9. An evaluation of the results of the HTR fuel programme conducted in the Dragon reactor experiment

    International Nuclear Information System (INIS)

    Shepherd, L.R.

    1982-01-01

    The Dragon Reactor Experiment was used over a period of ten years to investigate the behaviour of HTR fuel elements under realistic service conditions. The purpose of the work was to develop fuel capable of meeting the requirements of commercial power reactors. The studies divided into areas concerned with the mechanical behaviour of the graphite core structure under fast neutron irradiation and the ability of the coated particle fuel to retain fissile products over commercially viable life-cycles. (author)

  10. [The infectious diseases experiments conducted on human guinea pigs by Nazis in concentration camps].

    Science.gov (United States)

    Sabbatani, Sergio

    2013-06-01

    The author systematically examined all available publications and web documents, with regard to scientifically documented experiments carried out by Nazi physicians in their concentration camps during World War II. This research focused on human experiments dealing with: malaria, tuberculosis, petechial typhus, viral hepatitis, and those regarding sulphonamides as antimicrobial agents. The concentration camps involved by experimental programmes on human guinea pigs were: Natzweiler Struthof, Dachau, Mauthausen, Buchenwald, Neuengamme, Ravensbrück, Sachsenhausen and Auschwitz. Overall, around 7,200 deported prisoners went to their deaths during or because of these experiments (also considering human trials other than previously quoted ones). At the end of the war several physicians were charged with war crimes in two trials (Nuremberg and Dachau), and those found guilty were sentenced to death, or years of imprisonment. Some of them, including the notorious Josef Mengele, succeeded in escaping capture and being brought to justice. Thanks to these trials, partial light has been shed on these crimes, which not infrequently had children as designated victims, selected with excruciating cruelty in special segregation sections. The SS was the key structure which ensured maximum efficiency for these experimental programmes, from both logistic planning through to an operative control system carried out in concentration camps, and thanks to an autonomous, dedicated medical structure, which included a rigid hierarchy of physicians directly dependent on the head of SS forces (Reichsführer), i.e. Dr. Heinrich Himmler. Moreover, it is worth noting that also physicians who were not part of the SS corps collaborated in the above experiments on human guinea pigs: these included military personnel belonging to the Wehrmacht, academic physicians from German universities, and researchers who worked in some German pharmaceutical industries, such as IG Farben, Bayer and Boehring.

  11. Experience of European irradiated fuel transport - the first four hundred tonnes

    International Nuclear Information System (INIS)

    Curtis, H.W.

    1977-01-01

    The paper describes the successful integration of the experience of its three shareholders into an international company providing an irradiated fuel transport service throughout Europe. The experience of transporting more than 400 tonnes of irradiated uranium from fifteen power reactors is used to illustrate the flexibility which the transport organisation requires when the access and handling facilities are different at almost every reactor. Variations in fuel cross sections and lengths of fuel elements used in first generation reactors created the need for first generation flasks with sufficient variants to accommodate all reactor fuels but the trend now is towards standardisation of flasks to perhaps two basic types. Increases in fuel rating have raised the flask shielding and heat dissipation requirements and have influenced the design of later flasks. More stringent criticality acceptance criteria have tended to reduce the flask capacity below the maximum number of elements which could physically be contained. Reprocessing plant acceptance criteria initiated because of the presence of substantial quantities of loose crud released in the flask and the need to transport substantial numbers of failed elements have also reduced the flask capacity. Different modes of transport have been developed to cater for the various limitations on access to reactor sites arising from geographical and routing considerations. The safety record of irradiated fuel transport is examined with explanation of the means whereby this has been achieved. The problems of programming the movement of a pool of flasks for fifteen reactors in eight countries are discussed together with the steps taken to ensure that the service operates fairly to give priority to those reactors with the greatest problems. The transport of European irradiated fuel can be presented as an example of international collaboration which works

  12. Materials to be used for radionuclide transport experiments (milestones SPL3A1M4)

    International Nuclear Information System (INIS)

    Viani, B.

    1998-02-01

    Experiments to determine the effect of canister corrosion products on the transport of radionuclides will be undertaken using the FE(III) oxides goethite and hematite as proxies for the expected corrosion envelope that will form as a result of alteration of the corrosion allowance overpack prior to the breaching of the waste container. Samples of ESF invert concrete that have been crushed, or left intact but fractured, and that have been subjected to hydrothermal alteration will be used to determine the effect of cementitious materials on transport of radionuclides. A mixture of CaCO 3 , Si0 2 , and aggregate will be used as a proxy for completely carbonated concrete

  13. Involving Freight Transport Actors in Production of Knowledge - Experience with Future Workshop Methodology

    DEFF Research Database (Denmark)

    Jespersen, Per Homann; Drewes, Lise

    2005-01-01

    the experience and knowledge of actors in the freight transport sector are included directly in a scientific process in order to develop future and strategic studies. Future research is often produced as desktop research and presented as the results of scientists’ forecasting and scenario building...... in the format of a future workshop included freight transport stakeholders in the research process in order to produce knowledge meeting scientific quality criteria and at the same time in a form suitable for improving the problem solving capabilities of the participants....

  14. A model experiment of liquefaction and fluid transport: quantifying the effect of permeability discontinuity

    Science.gov (United States)

    Yasuda, N.; Sumita, I.

    2013-12-01

    Model experiments of liquefaction of a water-saturated sand (quick sand) is commonly conducted in class and in public. Various phenomena caused by liquefaction are reproduced within a closed bottle containing push-pins (Nohguchi, 2004). Experiments for tilted and layered case have also been conducted (Peacock, 2006). However quantitative measurements of liquid transport in these experiments have rarely been made. Here we show that such measurements are possible by analyzing the video images taken during such experiments. In addition, we show that a simple physical model is capable of explaining the time scales needed to expel the interstitial liquid. An experimental cell (cross section 22.0 mm x 99.4 mm, height 107.6 mm) is filled with a granular matter and water. The lower 33.0 mm consists of a two-layered granular medium, the upper layer consists of fine particles and the lower layer consists of coarse particles, with particle sizes of 0.05 mm and 0.2 mm, respectively. Since permeability depends on the square of the particle size, the upper layer becomes a low-permeability layer. We liquefy the cell by an impulsive vibration and study how the liquid migrates afterwards. We also vary the particle size combinations (upper layer: 0.05-0.15 mm, lower layer: 0.15-0.6 mm) and the thickness ratio of the 2 layers, and study how the time scale of the liquid migration depends on these changeable parameters. In a two-layered medium, we find that the pore water which originated from the bottom layer temporary accumulates at the interface of the two layers, and then ascends through the upper layer in the form of horizontal sheet or vertical channels. We find that these two different discharge styles are controlled by the permeability ratio of the two layers. We study the temporal change of the thicknesses of the two layers and find that there are three stages; 1: the slope of the upper surface is leveled by the impulse, 2: the pore water is discharged from the bottom layer

  15. Practical strategies and perceptions from community pharmacists following their experiences with conducting pharmacy practice research: a qualitative content analysis.

    Science.gov (United States)

    De Vera, Mary A; Campbell, Natasha K J; Chhina, Harpreet; Galo, Jessica S; Marra, Carlo

    2017-10-26

    While prior research identified barriers to conducting research in community pharmacies, there remains a need to better understand facilitators to ensure successful collaborations between academic researchers and pharmacists. Our objective was to determine the experiences and perspectives of community pharmacists who have recently conducted a pharmacy practice-based research study to gain in-depth understanding of challenges as well as facilitators and identify strategies and solutions. We conducted a qualitative study involving one-on-one semi-structured telephone interviews with community pharmacists following the completion of a practice-based research study in their pharmacies. Interview transcripts were analysed using inductive content analysis involving open coding, creating categories and abstraction into final themes. Eleven pharmacists participated in the qualitative interviews. We identified six major themes including: (1) barriers (e.g. time constraints); (2) facilitators (e.g. ideal pharmacy layout); (3) support and resources from academic researchers (e.g. helpfulness of training, easy-to-use study materials); (4) pharmacist-initiated strategies for conducting research (beyond prior suggestions from researchers); (5) suggestions for future pharmacy practice research; and (6) motivation for conducting pharmacy practice research. These findings informed practical strategies targeted at academic researchers and pharmacists, respectively, to facilitate the conduct of research in community pharmacists across various stages of the research process. Our study adds to better understanding of community pharmacists' perspectives on conducting research and identifies practical solutions that can be readily implemented by academic researchers and pharmacists participating in research. © 2017 Royal Pharmaceutical Society.

  16. Essential Data and Techniques for Conducting Microbial Fuel Cell and other Types of Bioelectrochemical System Experiments

    KAUST Repository

    Logan, Bruce E.

    2012-01-01

    Microbial fuel cells (MFCs) and other bioelectrochemical systems are new technologies that require expertise in a variety of technical areas, ranging from electrochemistry to biological wastewater treatment. There are certain data and critical information that should be included in every MFC study, such as specific surface area of the electrodes, solution conductivity, and power densities normalized to electrode surface area and volumes. Electrochemical techniques such as linear sweep voltammetry can be used to understand the performance of the MFC, but extremely slow scans are required for these biological systems compared to more traditional fuel cells. In this Minireview, the critical information needed for MFC studies is provided with examples of how results can be better conveyed through a full description of materials, the use of proper controls, and inclusion of a more complete electrochemical analysis. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Essential Data and Techniques for Conducting Microbial Fuel Cell and other Types of Bioelectrochemical System Experiments

    KAUST Repository

    Logan, Bruce E.

    2012-04-19

    Microbial fuel cells (MFCs) and other bioelectrochemical systems are new technologies that require expertise in a variety of technical areas, ranging from electrochemistry to biological wastewater treatment. There are certain data and critical information that should be included in every MFC study, such as specific surface area of the electrodes, solution conductivity, and power densities normalized to electrode surface area and volumes. Electrochemical techniques such as linear sweep voltammetry can be used to understand the performance of the MFC, but extremely slow scans are required for these biological systems compared to more traditional fuel cells. In this Minireview, the critical information needed for MFC studies is provided with examples of how results can be better conveyed through a full description of materials, the use of proper controls, and inclusion of a more complete electrochemical analysis. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. “... And Gladly Teach”: The American Hospital Association's Experience in Conducting Institutes on Hospital Librarianship

    Science.gov (United States)

    Yast, Helen

    1964-01-01

    As part of its overall educational program, the American Hospital Association has since 1959 conducted three institutes on hospital librarianship to meet the demand for more competent librarians in medical, nursing school, and patients' libraries. The purpose of such institutes is to teach the basic elements of library science to untrained personnel in hospital libraries. Discussed are steps in initiating an institute; factors determining length, date, and place; financing; publicity; choice and responsibility of local advisory committee; program content; qualifications of instructors; characteristics of registrants; materials for distribution; evaluations. Details of the most recent institute are outlined. A summary of problems still facing this type of educational program and suggestions for future improvements conclude the paper. PMID:14119309

  19. Development of female medfly attractants to support the sterile insect technique: experiments conducted in Madeira, Portugal

    International Nuclear Information System (INIS)

    Pereira, R.

    1999-01-01

    With the availability of genetic sexing strains of Mediterranean fruit fly, Ceratitis capitata (Wied.), it is possible to release only sterile males in SIT programs. The availability of a new female medfly attractant can reduce labor costs because program progress can be monitored by trapping females instead of the usual male trapping with its labor intensive identification of sterile and wild males. Three Madeira studies evaluated new female attractants; ammonium acetate, putrescine and trimethylamine. One study was carried out in the same area during two different periods of 1996 (8 June to 27 July and 12 October to 30 November). A second study was conducted between 24 May to 05 July, 1997, in two different areas at the same altitude. One area had a wild fly population (sex ratio 1: 1) and the other was in an area where sterile males were released (sex ratio > 9: 1). The third study, conducted from 18 October to 29 November, 1997, compared wild fly captures at low elevations (80 m) with those at high elevations (700 m). The first study showed that the inclusion of the attractant trimethylamine significantly increased the wild female medfly. The percentage of medfly females in the traps with the two and the three attractants (FA-2 and FA-3) was more than 70%. In the second and third studies, the dry traps were more effective than wet traps in capturing wild medfly females. In areas with only wild females, the percentage of females captured was more than 62%. In areas where sterile males were released, the percentage of females captured was between 12% and 19%. In conclusion, the new attractants captured high percentages of females and, when combined with medfly genetic sexing strains, can reduce program costs significantly. (author)

  20. Narrative transportation and product involvement : how narrativity factors are used to enchance transportive experience in advertising for high vs. low involvement products

    OpenAIRE

    Phusapan, Panida

    2013-01-01

    This paper examines and presents how narrativity factors are used to enhance consumers‟ transportive experience when advertising for high and low involvement products. It specifically looks at processing experiences among Thai online consumers when viewing TV commercials available on a YouTube channel. The paper brings the theory of product involvement into a field of narrative transportation. Results show that narrativity factors should be used with the right balance across all narrativity l...

  1. BNFL's experience in the sea transport of irradiated research reactor fuel to the USA

    International Nuclear Information System (INIS)

    Hudson, I.A.; Porter, I.

    2000-01-01

    BNFL provides worldwide transport for a wide range of nuclear materials. BNFL Transport manages an unique fleet of vessels, designed, built, and operated to the highest safety standards, including the highest rating within the INF Code recommended by the International Maritime Organisation. The company has some 20 years of experience of transporting irradiated research reactor fuel in support of the United States' programme for returning US obligated fuel from around the world. Between 1977 and 1988 BNFL performed 11 shipments of irradiated research reactor fuel from the Japan Atomic Energy Research Institute to the US. Since 1997, a further 3 shipments have been performed as part of an ongoing programme for Japanese research reactor operators. Where possible, shipments of fuel from European countries such as Sweden and Spain have been combined with those from Japan for delivery to the US. (author)

  2. Preliminary characterization of materials for a reactive transport model validation experiment

    International Nuclear Information System (INIS)

    Siegel, M.D.; Ward, D.B.; Cheng, W.C.; Bryant, C.; Chocas, C.S.; Reynolds, C.G.

    1993-01-01

    The geochemical properties of a porous sand and several tracers (Ni, Br, and Li) have been characterized for use in a caisson experiment designed to validate sorption models used in models of inactive transport. The surfaces of the sand grains have been examined by a combination of techniques including potentiometric titration, acid leaching, optical microscopy, and scanning electron microscopy with energy-dispersive spectroscopy. The surface studies indicate the presence of small amounts of carbonate, kaolinite and iron-oxyhydroxides. Adsorption of nickel, lithium and bromide by the sand was measured using batch techniques. Bromide was not sorbed by the sand. A linear (K d ) or an isotherm sorption model may adequately describe transport of Li; however, a model describing the changes of pH and the concentrations of other solution species as a function of time and position within the caisson and the concomitant effects on Ni sorption may be required for accurate predictions of nickel transport

  3. Electronic transport in single-helical protein molecules: Effects of multiple charge conduction pathways and helical symmetry

    Energy Technology Data Exchange (ETDEWEB)

    Kundu, Sourav, E-mail: sourav.kunduphy@gmail.com; Karmakar, S.N.

    2016-07-15

    We propose a tight-binding model to investigate electronic transport properties of single helical protein molecules incorporating both the helical symmetry and the possibility of multiple charge transfer pathways. Our study reveals that due to existence of both the multiple charge transfer pathways and helical symmetry, the transport properties are quite rigid under influence of environmental fluctuations which indicates that these biomolecules can serve as better alternatives in nanoelectronic devices than its other biological counterparts e.g., single-stranded DNA.

  4. Operating experience review -- Conduct of operations at Department of Energy facilities

    International Nuclear Information System (INIS)

    1994-08-01

    This research examined human error related occurrences, reported in the ORPS database, for the purpose of identifying weaknesses in the implementation of the guidance regarding the Conduct of Operations contained in DOE 5480.19. Specifically, this research examined three separate samples of occurrence reports from Defense Program facilities, which cited human error as a direct or contributing cause. These reports were evaluated using a coding scheme which incorporated the guidelines present in 5480.19, as well as a number of generic human factors concerns. The second chapter of this report summarizes the coding scheme which was used to evaluate the occurrence reports. Since the coding scheme is quite lengthy, only the parts of the scheme needed to make the remainder of the report clear are included in this chapter. Details on the development and content of the coding scheme are reported in Appendices A, B, and C. Chapter 3 presents the analysis of three different data sets. This chapter demonstrates that similar results were obtained across different data sets, collected at different points in time, and coded by different raters. The implications of the results obtained in Chapter 3 are discussed in Chapter 4. This chapter makes a number of suggestions for reducing the problems found in the occurrence reports. Chapter 5 applies the methodology that has been developed in this report to two facilities at Los Alamos National Laboratory. Finally, Chapter 6 reiterates the major findings of this report. Several additional analyses appear in appendices at the end of this report

  5. Conducting a user-centered information needs assessment: the Via Christi Libraries' experience.

    Science.gov (United States)

    Perley, Cathy M; Gentry, Camillia A; Fleming, A Sue; Sen, Kristin M

    2007-04-01

    The research sought to provide evidence to support the development of a long-term strategy for the Via Christi Regional Medical Center Libraries. An information needs assessment was conducted in a large medical center serving approximately 5,900 physicians, clinicians, and nonclinical staff in 4 sites in 1 Midwestern city. Quantitative and qualitative data from 1,295 self-reporting surveys, 75 telephone interviews, and 2 focus groups were collected and analyzed to address 2 questions: how could the libraries best serve their patrons, given realistic limitations on time, resources, and personnel, and how could the libraries best help their institution improve patient care and outcomes? Clinicians emphasized the need for "just in time" information accessible at the point of care. Library nonusers emphasized the need to market library services and resources. Both clinical and nonclinical respondents emphasized the need for information services customized to their professional information needs, preferences, and patterns of use. Specific information needs in the organization were identified. The results of this three-part, user-centered information needs assessment were used to develop an evidence-based strategic plan. The findings confirmed the importance of promoting library services in the organization and suggested expanded, collaborative roles for hospital librarians.

  6. A planar conducting micro-loop structure for transportation of magnetic beads: An approach towards rapid sensing and quantification of biological entities

    KAUST Repository

    Gooneratne, Chinthaka Pasan; Giouroudi, Ioanna; Kosel, Jü rgen

    2012-01-01

    tools for accurate and rapid cell sorting and counting. Effective manipulation of beads is a critical factor for the performance of LOC devices. In this paper we propose a planar conducting micro-loop structure to trap, manipulate and transport magnetic

  7. First experiment on liquid hydrogen transportation by ship inside Osaka bay

    Science.gov (United States)

    Maekawa, K.; Takeda, M.; Hamaura, T.; Suzuki, K.; Miyake, Y.; Matsuno, Y.; Fujikawa, S.; Kumakura, H.

    2017-12-01

    A project to import a large amount of liquid hydrogen (LH2) from Australia by a cargo carrier, which is equipped with two 1250 m3 tanks, is underway in Japan. It is important to understand sloshing and boil-off characteristics inside the LH2 tank during marine transportation. However, the LH2 sloshing and boil-off characteristics on the sea have not yet been clarified. First experiment on the LH2 transportation of 20 liter with magnesium diboride (MgB2) level sensors by the training ship “Fukae-maru”, which has 50 m long and 449 ton gross weight, was carried out successfully inside Osaka bay on February 2, 2017. In the experiment, synchronous measurements of liquid level, temperature, pressure, ship motions, and accelerations as well as the rapid depressurization test were done. The increase rate of the temperature and the pressure inside the LH2 tank were discussed under the rolling and the pitching conditions.

  8. A field experiment on the controls of sediment transport on bedrock erosion

    Science.gov (United States)

    Beer, A. R.; Turowski, J. M.; Fritschi, B.; Rieke-Zapp, D.; Campana, L.; Lavé, J.

    2012-12-01

    The earth`s surface is naturally shaped by interactions of physical and chemical processes. In mountainous regions with steep topography river incision fundamentally controls the geomorphic evolution of the whole landscape. There, erosion of exposed bedrock sections by fluvial sediment transport is an important mechanism forming mountain river channels. The links between bedload transport and bedrock erosion has been firmly established using laboratory experiments. However, there are only few field datasets linking discharge, sediment transport, impact energy and erosion that can be used for process understanding and model evaluation. To fill this gap, a new measuring setup has been commissioned to raise an appropriate simultaneous dataset of hydraulics, sediment transport and bedrock erosion at high temporal and spatial resolution. Two natural stone slabs were installed flush with the streambed of the Erlenbach, a gauged stream in the Swiss Pre-Alps. They are mounted upon force sensors recording vertical pressure und downstream shear caused by passing sediment particles. The sediment transport rates can be assessed using geophone plates and an automated moving basket system taking short-term sediment samples. These devices are located directly downstream of the stone slabs. Bedrock erosion rates are measured continuously with erosion sensors at sub-millimeter accuracy at three points on each slab. In addition, the whole slab topography is surveyed with photogrammetry and a structured-light 3D scanner after individual flood events. Since the installation in 2011, slab bedrock erosion has been observed during several transport events. We discuss the relation between hydraulics, bedload transport, resulting pressure forces on the stone slabs and erosion rates. The aim of the study is the derivation of an empirical process law for fluvial bedrock erosion driven by moving sediment particles.

  9. Internal electron transport barrier due to neoclassical ambipolarity in the Helically Symmetric Experiment

    International Nuclear Information System (INIS)

    Lore, J.; Briesemeister, A.; Anderson, D. T.; Anderson, F. S. B.; Likin, K. M.; Talmadge, J. N.; Zhai, K.; Guttenfelder, W.; Deng, C. B.; Spong, D. A.

    2010-01-01

    Electron cyclotron heated plasmas in the Helically Symmetric Experiment (HSX) feature strongly peaked electron temperature profiles; central temperatures are 2.5 keV with 100 kW injected power. These measurements, coupled with neoclassical predictions of large 'electron root' radial electric fields with strong radial shear, are evidence of a neoclassically driven thermal transport barrier. Neoclassical transport quantities are calculated using the PENTA code [D. A. Spong, Phys. Plasmas 12, 056114 (2005)], in which momentum is conserved and parallel flow is included. Unlike a conventional stellarator, which exhibits strong flow damping in all directions on a flux surface, quasisymmetric stellarators are free to rotate in the direction of symmetry, and the effect of momentum conservation in neoclassical calculations may therefore be significant. Momentum conservation is shown to modify the neoclassical ion flux and ambipolar ion root radial electric fields in the quasisymmetric configuration. The effect is much smaller in a HSX configuration where the symmetry is spoiled. In addition to neoclassical transport, a model of trapped electron mode turbulence is used to calculate the turbulent-driven electron thermal diffusivity. Turbulent transport quenching due to the neoclassically predicted radial electric field profile is needed in predictive transport simulations to reproduce the peaking of the measured electron temperature profile [Guttenfelder et al., Phys. Rev. Lett. 101, 215002 (2008)].

  10. International Road Freight Transport in France: Experiences from Germany, the Netherlands and Driver Costs Analysis

    Directory of Open Access Journals (Sweden)

    Laurent Guihery

    2009-06-01

    Full Text Available These last few years, French international road freight transport has been undergoing a loss of influence within Europe while traffic has increased and great manoeuvres are taking place since the opening of the European Union towards East. Some of the French transporters are then focusing back on the French market showing a worrying loss in competitiveness. On the contrary, German and Dutch companies are increasing their shares in the French market and have reorganized themselves within Europe to face Eastern Europe competition: follow-up on customers delocalizing in the East, networking, hyperproductivity, markets segmentation between high quality transport in the West, specific markets and low cost segment in Eastern Germany and East Europe (Poland, Romania, ..., intensive geographical closeness to a great harbour (Rotterdam... What should France learn from German and Dutch experiences? On the basis of a comparison of our neighbours' driving costs and road freight transport structure, our contribution - a synthesis of two recent studies ordered by the Comite National Routier (CNR, studies free to be downloaded by www.cnr.fr - will first propose a cooperation with German or Dutch companies in order to propose a winner-winner model based on exchange of competencies: North Africa (Morocco for instance and Southern Europe for French partners (specialization Storage - Logistics and transport business model and opening towards the East for the German and Dutch partners.

  11. Perturbative transport experiments in JET low or reverse magnetic shear plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Mantica, P. [Istituto di Fisica del Plasma, EURATOM-ENEA-CNR Association, Milan (Italy); Gorini, G. [Istituto di Fisica del Plasma, EURATOM-ENEA-CNR Association, Milan (Italy); INFM, Department of Physics, University of Milano-Bicocca, Milan (Italy); Imbeaux, F. [Association Euratom-CEA, CEA Cadarache, St. Paul-lez-Durance (France)] (and others)

    2002-10-01

    Perturbative transport experiments have been performed in JET low or reverse magnetic shear plasmas either in conditions of fully developed internal transport barrier (ITB) or during a phase where an ITB was not observed. Transient peripheral cooling was induced either by laser ablation or by shallow pellet injection, and the ensuing travelling cold pulse was used to probe the plasma transport in the electron and, for the first time, also in the ion channel. Cold pulses travelling through ITBs are observed to erode the ITB outer part, but, if the inner ITB portion survives, it strongly damps the propagating wave. The result is discussed in the context of proposed possible pictures for ITB formation. In the absence of an ITB, the cold pulse shows a fast propagation in the outer plasma half, which is consistent with a region of stiff transport, while in the inner half it slows down but shows the peculiar feature of amplitude growing while propagating. The data are powerful tests for the validation of theoretical transport models. (author)

  12. Pore Formation and Mobility Investigation (PFMI): Concept, Hardware Development, and Initial Analysis of Experiments Conducted Aboard the International Space Station

    Science.gov (United States)

    Grugel, Richard N.

    2003-01-01

    Porosity in the form of "bubbles and pipes" can occur during controlled directional solidification processing of metal alloys. This is a consequence that 1) precludes obtaining any meaningful scientific results and 2) is detrimental to desired material properties. Unfortunately, several Microgravity experiments have been compromised by porosity. The intent of the PFMl investigation is to conduct a systematic effort directed towards understanding porosity formation and mobility during controlled directional solidification (DS) in a microgravity environment. PFMl uses a pure transparent material, succinonitrile (SCN), as well as SCN "alloyed" with water, in conjunction with a translating temperature gradient stage so that direct observation and recording of pore generation and mobility can be made. PFMl is investigating the role of thermocapillary forces and temperature gradients in affecting bubble dynamics as well as other solidification processes in a microgravity environment. This presentation will cover the concept, hardware development, operations, and the initial results from experiments conducted aboard the International Space Station.

  13. Analysis of pin removal experiments conducted in an SCWR-like test lattice

    Energy Technology Data Exchange (ETDEWEB)

    Chawla, R. [Paul Scherrer Institue, CH-5232 Villigen PSI (Switzerland); Swiss Federal Inst. of Technology EPFL, CH-1015 Lausanne (Switzerland); Raetz, D. [Paul Scherrer Institue, CH-5232 Villigen PSI (Switzerland); Resun AG, CH-5001 Aarau (Switzerland); Jordan, K. A. [Paul Scherrer Institue, CH-5232 Villigen PSI (Switzerland); Univ. of Florida, Gainesville, FL (United States); Perret, G. [Paul Scherrer Institue, CH-5232 Villigen PSI (Switzerland)

    2012-07-01

    A comprehensive program of integral experiments, largely based on the measurement of reaction rate distributions, was carried out recently on an SCWR-like fuel lattice in the central test zone of the PROTEUS zero-power research reactor at the Paul Scherrer Inst. in Switzerland. The present paper reports on the analysis of a complementary set of measurements, in which the reactivity effects of removing individual pins from the unperturbed, heterogeneously moderated reference lattice were investigated. It has been found that the detailed Monte Carlo modeling of the whole reactor using MCNPX is able - as in the case of the reaction rate distributions - to reproduce the experimental results for the pin removal worths within the achievable statistical accuracy. A comparison of reduced-geometry calculations between MCNPX and the deterministic LWR assembly code CASMO-4E has revealed certain discrepancies. On the basis of a reactivity decomposition analysis of the differences between the codes, it has been suggested that these could be due to CASMO-4E deficiencies in calculating the effect, upon pin removal, of the extra moderation in the neighboring fuel pins. (authors)

  14. Comparison of GAP-3 and GAP-4 experiments with conduction freezing calculations

    International Nuclear Information System (INIS)

    Sienicki, J.J.; Spencer, B.W.

    1983-01-01

    Experiments GAP-3 and GAP-4 were performed at ANL to investigate the ability of molten fuel to penetrate downward through the narrow channels separating adjacent subassemblies during an LMFBR hypothetical core disruptive accident. Molten fuel-metal mixtures (81% UO 2 , 19% Mo) at an initial temperature of 3470 0 K generated by a thermite reaction were injected downward into 1 m long rectangular test sections (gap thickness = 0.43 cm, channel width = 20.3 cm) initially at 1170 0 K simulating the nominal Clinch River Breeder Reactor intersubassembly gap. In the GAP-3 test, a prolonged reaction time of approx. 15 s resulted in segregation of the metallic Mo and oxidic UO 2 constituents within the reaction vessel prior to injection. Consequently, Mo entered the test section first and froze, forming a complete plug at a penetration distance of 0.18 m. In GAP-4, the reaction time was reduced to approx. 3 s and the constituents remained well mixed upon injection with the result that the leading edge penetration distance increased to 0.35 m. Posttest examination of the cut-open test sections has revealed the existence of stable insulating crusts upon the underlying steel walls with melting and ablation of the walls only very localized

  15. Estimation of Knudsen diffusion coefficients from tracer experiments conducted with a binary gas system and a porous medium

    Science.gov (United States)

    Hibi, Yoshihiko; Kashihara, Ayumi

    2018-03-01

    A previous study has reported that Knudsen diffusion coefficients obtained by tracer experiments conducted with a binary gas system and a porous medium are consistently smaller than those obtained by permeability experiments conducted with a single-gas system and a porous medium. To date, however, that study is the only one in which tracer experiments have been conducted with a binary gas system. Therefore, to confirm this difference in Knudsen diffusion coefficients, we used a method we had developed previously to conduct tracer experiments with a binary carbon dioxide-nitrogen gas system and five porous media with permeability coefficients ranging from 10-13 to 10-11 m2. The results showed that the Knudsen diffusion coefficient of N2 (DN2) (cm2/s) was related to the effective permeability coefficient ke (m2) as DN2 = 7.39 × 107ke0.767. Thus, the Knudsen diffusion coefficients of N2 obtained by our tracer experiments were consistently 1/27 of those obtained by permeability experiments conducted with many porous media and air by other researchers. By using an inversion simulation to fit the advection-diffusion equation to the distribution of concentrations at observation points calculated by mathematically solving the equation, we confirmed that the method used to obtain the Knudsen diffusion coefficient in this study yielded accurate values. Moreover, because the Knudsen diffusion coefficient did not differ when columns with two different lengths, 900 and 1500 mm, were used, this column property did not influence the flow of gas in the column. The equation of the dusty gas model already includes obstruction factors for Knudsen diffusion and molecular diffusion, which relate to medium heterogeneity and tortuosity and depend only on the structure of the porous medium. Furthermore, there is no need to take account of any additional correction factor for molecular diffusion except the obstruction factor because molecular diffusion is only treated in a multicomponent

  16. Correlation between the transport mechanisms in conductive filaments inside Ta2O5-based resistive switching devices and in substoichiometric TaOx thin films

    Science.gov (United States)

    Rosário, Carlos M. M.; Thöner, Bo; Schönhals, Alexander; Menzel, Stephan; Wuttig, Matthias; Waser, Rainer; Sobolev, Nikolai A.; Wouters, Dirk J.

    2018-05-01

    Conductive filaments play a key role in redox-based resistive random access memory (ReRAM) devices based on the valence change mechanism, where the change of the resistance is ascribed to the modulation of the oxygen content in a local region of these conductive filaments. However, a deep understanding of the filaments' composition and structure is still a matter of debate. We approached the problem by comparing the electronic transport, at temperatures from 300 K down to 2 K, in the filaments and in TaOx films exhibiting a substoichiometric oxygen content. The filaments were created in Ta (15 nm)/Ta2O5 (5 nm)/Pt crossbar ReRAM structures. In the TaOx thin films with various oxygen contents, the in-plane transport was studied. There is a close similarity between the electrical properties of the conductive filaments in the ReRAM devices and of the TaOx films with x ˜ 1, evidencing also no dimensionality difference for the electrical transport. More specifically, for both systems there are two different conduction processes: one in the higher temperature range (from 50 K up to ˜300 K), where the conductivity follows a √{ T } dependence, and one at lower temperatures (<50 K), where the conductivity follows the exp(-1 / √{ T } ) dependence. This suggests a strong similarity between the material composition and structure of the filaments and those of the substoichiometric TaOx films. We also discuss the temperature dependence of the conductivity in the framework of possible transport mechanisms, mainly of those normally observed for granular metals.

  17. Biogeochemical processes in a clay formation in situ experiment: Part F - Reactive transport modelling

    Energy Technology Data Exchange (ETDEWEB)

    Tournassat, Christophe, E-mail: c.tournassat@brgm.fr [BRGM, French Geological Survey, Orleans (France); Alt-Epping, Peter [Rock-Water Interaction Group, Institute of Geological Sciences, University of Bern (Switzerland); Gaucher, Eric C. [BRGM, French Geological Survey, Orleans (France); Gimmi, Thomas [Rock-Water Interaction Group, Institute of Geological Sciences, University of Bern (Switzerland)] [Laboratory for Waste Management, Paul Scherrer Institut, Villigen (Switzerland); Leupin, Olivier X. [NAGRA, CH-5430 Wettingen (Switzerland); Wersin, Paul [Gruner Ltd., CH-4020 Basel (Switzerland)

    2011-06-15

    Highlights: > Reactive transport modelling was used to simulate simultaneously solute transport, thermodynamic reactions, ion exchange and biodegradation during an in-situ experiment in a clay-rock formation. > Opalinus clay formation has a high buffering capacity in terms of chemical perturbations caused by bacterial activity. > Buffering capacity is mainly attributed to the carbonate system and to the reactivity of clay surfaces (cation exchange, pH buffering). - Abstract: Reactive transport modelling was used to simulate solute transport, thermodynamic reactions, ion exchange and biodegradation in the Porewater Chemistry (PC) experiment at the Mont Terri Rock Laboratory. Simulations show that the most important chemical processes controlling the fluid composition within the borehole and the surrounding formation during the experiment are ion exchange, biodegradation and dissolution/precipitation reactions involving pyrite and carbonate minerals. In contrast, thermodynamic mineral dissolution/precipitation reactions involving alumo-silicate minerals have little impact on the fluid composition on the time-scale of the experiment. With the accurate description of the initial chemical condition in the formation in combination with kinetic formulations describing the different stages of bacterial activities, it has been possible to reproduce the evolution of important system parameters, such as the pH, redox potential, total organic C, dissolved inorganic C and SO{sub 4} concentration. Leaching of glycerol from the pH-electrode may be the primary source of organic material that initiated bacterial growth, which caused the chemical perturbation in the borehole. Results from these simulations are consistent with data from the over-coring and demonstrate that the Opalinus Clay has a high buffering capacity in terms of chemical perturbations caused by bacterial activity. This buffering capacity can be attributed to the carbonate system as well as to the reactivity of

  18. Design and characterization of a neutralized-transport experiment for heavy-ion fusion

    Directory of Open Access Journals (Sweden)

    Enrique Henestroza

    2004-08-01

    Full Text Available In heavy-ion inertial-confinement fusion systems, intense beams of ions must be transported from the exit of the final-focus magnet system through the fusion chamber to hit spots on the target with radii of about 2 mm. For the heavy-ion-fusion power-plant scenarios presently favored in the U.S., a substantial fraction of the ion-beam space charge must be neutralized during this final transport. The most effective neutralization technique found in numerical simulations is to pass each beam through a low-density plasma after the final focusing. To provide quantitative comparisons of these theoretical predictions with experiment, the Virtual National Laboratory for Heavy Ion Fusion has completed the construction and has begun experimentation with the neutralized-transport experiment. The experiment consists of three main sections, each with its own physics issues. The injector is designed to generate a very high-brightness, space-charge-dominated potassium beam, while still allowing variable perveance by a beam aperturing technique. The magnetic-focusing section, consisting of four pulsed quadrupoles, permits the study of magnet tuning, as well as the effects of phase-space dilution due to higher-order nonlinear fields. In the final section, the converging ion beam exiting the magnetic section is transported through a drift region with plasma sources for beam neutralization, and the final spot size is measured under various conditions of neutralization. In this paper, we discuss the design and characterization of the three sections in detail and present initial results from the experiment.

  19. A summary of the test procedures and operational details of an ocean dumping pollution monitoring experiment conducted 7 October 1976

    Science.gov (United States)

    Hypes, W. D.; Wallace, J. W.; Gurganus, E. A.

    1977-01-01

    A remote sensor experiment was conducted at a sewage sludge dump site off the Delaware/Maryland coast. Two aircraft serving as remote sensor platforms flew over the dump site during a sludge dump. One aircraft carried a multispectral scanner and the other aircraft carried a rapid scanning spectrometer. Data from sea-truth stations were collected concurrent with overpasses of the aircraft. All sensors were operational and produced good digital data.

  20. Study of point defects in non crystalline alloys by high temperature mass transport experiments

    International Nuclear Information System (INIS)

    Limoge, Y.

    1986-09-01

    We present in this communication the results of new experiments designed to study the mass transport mechanism in non-crystalline metallic alloys. They are based on the isothermal measurement of the crystallization kinetics, either without constraint or under electron irradiation or hydrostatic pressure. These experiments show that in the alloys studied, (FeNi) 8 (Pb) 2 and Ni 6 Nb 4 ), irradiation enhances the diffusion on the one hand, and on the other that there exist an activation volume for diffusion, of the order of one atomic volume. We discuss then the atomic model of diffusion needed to explain our results

  1. Simulation and modeling of the Gamble II self-pinched ion beam transport experiment

    International Nuclear Information System (INIS)

    Rose, D.V.; Ottinger, P.F.; Hinshelwood, D.D.

    1999-01-01

    Progress in numerical simulations and modeling of the self-pinched ion beam transport experiment at the Naval Research Laboratory (NRL) is reviewed. In the experiment, a 1.2-MeV, 100-kA proton beam enters a 1-m long, transport region filled with a low pressure gas (30--250 mTorr helium, or 1 Torr air). The time-dependent velocity distribution function of the injected ion beam is determined from an orbit code that uses a pinch-reflex ion diode model and the measured voltage and current from this diode on the Gamble II generator at NRL. This distribution function is used as the beam input condition for numerical simulations carried out using the hybrid particle-in-cell code IPROP. Results of the simulations will be described, and detailed comparisons will be made with various measurements, including line-integrated electron-density, proton-fluence, and beam radial-profile measurements. As observed in the experiment, the simulations show evidence of self-pinching for helium pressures between 35 and 80 mTorr. Simulations and measurements in 1 Torr air show ballistic transport. The relevance of these results to ion-driven inertial confinement fusion will be discussed

  2. Fresh MOX fuel transport in Germany: experience for using the MX6

    Energy Technology Data Exchange (ETDEWEB)

    Lallemant, T. [COGEMA Logistics (AREVA Group), Bagnols/sur Ceze (France); Marien, L. [FBFC-I (AREVA Group), Dessel (Belgium); Wagner, R. [RWE, Gundremmingen (Germany); Jahreiss, W. [FRAMATOME ANP GmbH (AREVA Group), Erlangen (Germany); Tschiesche, H. [NCS, Hanau (Germany)

    2004-07-01

    The MX6 packaging developed by COGEMA LOGISTICS replaces the BWR SIEMENS packaging and SIEMENS III packaging for the transport of either BWR or PWR fresh MOX assemblies. It is licensed in France, Germany and Belgium according to TS-R-1 requirements (IAEA 1996). The associated security transport system was developed in co-operation with NCS (Nuclear Cargo + Service GmbH). The MX6 packaging is based on innovative solutions implemented at each step of the design. In 2004, RWE GUNDREMMINGEN Nuclear Power Plant (NPP) will be the first NPP delivered with the MX6 system and MOX assemblies manufactured by BELGONUCLEAIRE and FBFC in Belgium. Before this first transport, successful cold tests were performed for qualification of the whole system with the participation of all parties involved: NPP, carrier, fuel supplier and local Authorities. These tests were conducted by the NPP's operators in FBFC and GUNDREMMINGEN facilities and lead to the validation of the operating manual. Specific conditions for the return of the empty MX6 were also agreed between all parties. Similar operation will be conducted in each NPP before the first use of the MX 6. The large payload of the MX6: - 16 BWR MOX assemblies in one packaging instead of 2 - 6 PWR MOX assemblies in one packaging instead of 3 contributes to the optimisation of the dose uptake during unloading in the NPP. In this paper, the main contributors to the first MOX transport to Germany with the MX6 will present their involvement and feedback at each step of the transport of this new type of packaging, including loading and unloading operations. The use of the MX6 will be extended to other German NPP's from the next year. After FBFC in Belgium, MELOX in France will load the MX6 as well as the current MX8 packaging for the delivery to the French NPP's.

  3. Fresh MOX fuel transport in Germany: experience for using the MX6

    International Nuclear Information System (INIS)

    Lallemant, T.; Marien, L.; Wagner, R.; Jahreiss, W.; Tschiesche, H.

    2004-01-01

    The MX6 packaging developed by COGEMA LOGISTICS replaces the BWR SIEMENS packaging and SIEMENS III packaging for the transport of either BWR or PWR fresh MOX assemblies. It is licensed in France, Germany and Belgium according to TS-R-1 requirements (IAEA 1996). The associated security transport system was developed in co-operation with NCS (Nuclear Cargo + Service GmbH). The MX6 packaging is based on innovative solutions implemented at each step of the design. In 2004, RWE GUNDREMMINGEN Nuclear Power Plant (NPP) will be the first NPP delivered with the MX6 system and MOX assemblies manufactured by BELGONUCLEAIRE and FBFC in Belgium. Before this first transport, successful cold tests were performed for qualification of the whole system with the participation of all parties involved: NPP, carrier, fuel supplier and local Authorities. These tests were conducted by the NPP's operators in FBFC and GUNDREMMINGEN facilities and lead to the validation of the operating manual. Specific conditions for the return of the empty MX6 were also agreed between all parties. Similar operation will be conducted in each NPP before the first use of the MX 6. The large payload of the MX6: - 16 BWR MOX assemblies in one packaging instead of 2 - 6 PWR MOX assemblies in one packaging instead of 3 contributes to the optimisation of the dose uptake during unloading in the NPP. In this paper, the main contributors to the first MOX transport to Germany with the MX6 will present their involvement and feedback at each step of the transport of this new type of packaging, including loading and unloading operations. The use of the MX6 will be extended to other German NPP's from the next year. After FBFC in Belgium, MELOX in France will load the MX6 as well as the current MX8 packaging for the delivery to the French NPP's

  4. Transportation

    National Research Council Canada - National Science Library

    Adams, James; Carr, Ron; Chebl, Maroun; Coleman, Robert; Costantini, William; Cox, Robert; Dial, William; Jenkins, Robert; McGovern, James; Mueller, Peter

    2006-01-01

    ...., trains, ships, etc.) and maximizing intermodal efficiency. A healthy balance must be achieved between the flow of international commerce and security requirements regardless of transportation mode...

  5. Actions conducted in Switzerland for energy conservation and CO2 emission reduction, particularly in the transport sector

    International Nuclear Information System (INIS)

    Cattin, J.

    1991-01-01

    The aim of Switzerland is to stabilize the CO 2 emissions by year 2000 and to reduce them from 20 pc by 2005 and from 50 pc by 2025. In order to attain these objectives, several measures should be taken: in the residential sector, the heating appliances (space heating and hot water production) should be efficiency-enhanced and an individual counting system should be used; energy audits should be enforced in industry; in the transportation sector, railway transportation should be enhanced and a pollution tax on automobile fuel should be applied

  6. Confinement and Local Transport in the National Spherical Torus Experiment NSTX

    International Nuclear Information System (INIS)

    Kaye, S.M.; Levinton, F.M.; Stutman, D.; Tritz, K.; Yuh, H.; Bell, M.G.; Bell, R.E.; Domier, C.W.; Gates, D.; Horton, W.; Kim, J.; LeBlanc, B.P.; Luhmann, N.C. Jr.; Maingi, T.; Mazzucato, E.; Menard, J.E.; Mikkelsen, D.; Mueller, D; Park, H.; Rewoldt, G.; Sabbagh, S.A.; Smith, D.R.; Wang, W.

    2007-01-01

    NSTX operates at low aspect ratio (R/a∼1.3) and high beta (up to 40%), allowing tests of global confinement and local transport properties that have been established from higher aspect ratio devices. NSTX plasmas are heated by up to 7 MW of deuterium neutral beams with preferential electron heating as expected for ITER. Confinement scaling studies indicate a strong B T dependence, with a current dependence that is weaker than that observed at higher aspect ratio. Dimensionless scaling experiments indicate a strong increase of confinement with decreasing collisionality and a weak degradation with beta. The increase of confinement with B T is due to reduced transport in the electron channel, while the improvement with plasma current is due to reduced transport in the ion channel related to the decrease in the neoclassical transport level. Improved electron confinement has been observed in plasmas with strong reversed magnetic shear, showing the existence of an electron internal transport barrier (eITB). The development of the eITB may be associated with a reduction in the growth of microtearing modes in the plasma core. Perturbative studies show that while L-mode plasmas with reversed magnetic shear and an eITB exhibit slow changes of L Te across the profile after the pellet injection, H-mode plasmas with a monotonic q-profile and no eITB show no change in this parameter after pellet injection, indicating the existence of a critical gradient that may be related to the q-profile. Both linear and non-linear simulations indicate the potential importance of ETG modes at the lowest B T . Localized measurements of high-k fluctuations exhibit a sharp decrease in signal amplitude levels across the L-H transition, associated with a decrease in both ion and electron transport, and a decrease in calculated linear microinstability growth rates across a wide k-range, from the ITG/TEM regime up to the ETG regime

  7. Recommended nuclear criticality safety experiments in support of the safe transportation of fissile material

    International Nuclear Information System (INIS)

    Tollefson, D.A.; Elliott, E.P.; Dyer, H.R.; Thompson, S.A.

    1993-01-01

    Validation of computer codes and nuclear data (cross-section) libraries using benchmark quality critical (or certain subcritical) experiments is an essential part of a nuclear criticality safety evaluation. The validation results establish the credibility of the calculational tools for use in evaluating a particular application. Validation of the calculational tools is addressed in several American National Standards Institute/American Nuclear Society (ANSI/ANS) standards, with ANSI/ANS-8.1 being the most relevant. Documentation of the validation is a required part of all safety analyses involving significant quantities of fissile materials. In the case of transportation of fissile materials, the safety analysis report for packaging (SARP) must contain a thorough discussion of benchmark experiments, detailing how the experiments relate to the significant packaging and contents materials (fissile, moderating, neutron absorbing) within the package. The experiments recommended in this paper are needed to address certain areas related to transportation of unirradiated fissile materials in drum-type containers (packagings) for which current data are inadequate or are lacking

  8. The relationship between manual handling performance and recent flying experience in air transport pilots.

    Science.gov (United States)

    Ebbatson, Matt; Harris, Don; Huddlestone, John; Sears, Rodney

    2010-02-01

    Modern jet transport aircraft are typically flown using the on-board automation by the pilot programming commands into the auto-flight systems. Anecdotal evidence exists suggesting that pilots of highly automated aircraft experience manual flying skills decay as a result of a lack of opportunity to practise hand-flying during line operations. The ability of a pilot to revert to basic manual control is essential, for example, in cases where the aircraft's automatic capability is diminished or when reconfiguring the automatics is an ineffective use of crew capacity. However, there is a paucity of objective data to substantiate this perceived threat to flight safety. Furthermore, traditional performance measurement techniques may lack the ability to identify subtle but significant differences in pilots' manual handling ability in large transport aircraft. This study examines the relationship between pilot manual handling performance and their recent flying experience using both traditional flight path tracking measures and frequency-based control strategy measures. Significant relationships are identified between pilots' very recent flying experience and their manual control strategy. Statement of Relevance: The study demonstrates a novel application of frequency analysis, which produces a broader and more sensitive analysis of pilot performance than has been offered in previous research. Additionally, the relationships that are found to exist between recent flying experience and manual flying performance will help to guide future pilot assessment and training.

  9. Transportation

    International Nuclear Information System (INIS)

    Anon.

    1998-01-01

    Here is the decree of the thirtieth of July 1998 relative to road transportation, to trade and brokerage of wastes. It requires to firms which carry out a road transportation as well as to traders and to brokers of wastes to declare their operations to the prefect. The declaration has to be renewed every five years. (O.M.)

  10. Analysis and modelling of power modulation experiments in JET plasmas with internal transport barriers

    Energy Technology Data Exchange (ETDEWEB)

    Marinoni, A [Politecnico di Milano, dipartimento di Ingegneria Nucleare, Milano (Italy); Mantica, P [Istituto di Fisica del Plasma, Euratom-ENEA-CNR Association, Milan (Italy); Eester, D Van [LPP-ERM/KMS, Association EURATOM-Belgian State, TEC, B-1000 Brussels (Belgium); Imbeaux, F [Association EURATOM-CEA, CEA/DSM/DRFC, CEA Cadarache, 13108 Saint Paul lez Durance (France); Mantsinen, M [Helsinki University of Technology, Association Euratom-Tekes, PO Box 2200 (Finland); Hawkes, N [Euratom-UKAEA Fusion Association, Culham Science Centre, Abingdon, Oxon (United Kingdom); Joffrin, E [Association EURATOM-CEA, CEA/DSM/DRFC, CEA Cadarache, 13108 Saint Paul lez Durance (France); Kiptily, V [Euratom-UKAEA Fusion Association, Culham Science Centre, Abingdon, Oxon (United Kingdom); Pinches, S D [Max Plank Institut fur Plasmaphysik, Euratom Association, Garching (Germany); Salmi, A [Helsinki University of Technology, Association Euratom-Tekes, PO Box 2200 (Finland); Sharapov, S [Euratom-UKAEA Fusion Association, Culham Science Centre, Abingdon, Oxon (United Kingdom); Voitsekhovitch, I [Euratom-UKAEA Fusion Association, Culham Science Centre, Abingdon, Oxon (United Kingdom); Vries, P de [FOM Institut voor Plasmafysica, Association Euratom-FOM, Nieuwegein, The (Netherlands); Zastrow, K D [Euratom-UKAEA Fusion Association, Culham Science Centre, Abingdon, Oxon (United Kingdom)

    2006-10-15

    Understanding the physics of internal transport barriers (ITBs) is a crucial issue in developing ITER relevant advanced tokamak scenarios. To gain new information on ITBs, RF power modulation experiments, mainly devoted to the study of electron heat transport through ITBs, have been performed on the JET tokamak. The main physics results have been reported in [1]. The present paper describes in detail the data analysis and numerical modelling work carried out for the interpretation of the experiments. ITBs located in the negative shear region behave as localized insulating layers able to stop the heat wave propagation, thus implying that the ITB is a region of low diffusivity characterized by a loss of stiffness. Various sources of spurious effects affecting the interpretation of the results are analysed and discussed. First principle based models have so far failed to predict the temperature profile in the first place, which prevented their application to modulation results, while empirical transport models have been set up and reproduce the major part of the data.

  11. Identity physics experiment on internal transport barriers in JT-60U and JET

    Energy Technology Data Exchange (ETDEWEB)

    De Vries, P C; Beurskens, M N A; Brix, M; Giroud, C; Hawkes, N C; Parail, V [EURATOM/UKAEA Association, Culham Science Centre, OX14 3DB, Abingdon (United Kingdom); Sakamoto, Y; Fujita, T; Hayashi, N; Matsunaga, G; Oyama, N; Shinohara, K; Suzuki, T; Takechi, M [Japan Atomic Energy Agency, Naka, Ibaraki-ken 311-0193 (Japan); Litaudon, X; Joffrin, E [CEA, IRFM, F-13108 St-Paul-Lez-Durance (France); Crombe, K [Department of Applied Physics, Ghent University, Rozier 44, 9000 Gent (Belgium); Mantica, P [Istituto di Fisica del Plasma, EURATOM/ENEA-CNR Association, Milano (Italy); Salmi, A [Association Euratom-Tekes, Helsinki University of Technology, PO Box 4100 (Finland); Strintzi, D, E-mail: Peter.de.Vries@jet.u [National Technical University of Athens, EURATOM Association, GR-15773, Athens (Greece)

    2009-12-15

    A series of experiments have been carried out in 2008 at JT-60U and JET to find common characteristics and explain differences between internal transport barriers (ITBs). The identity experiments succeeded in matching the profiles of most dimensionless parameters at the time ITBs were triggered. Thereafter the q-profile development deviated due to differences in non-inductive current density profile, affecting the ITB. Furthermore, the ITBs in JET were more strongly influenced by the H-mode pedestal or edge localized modes. It was found to be difficult to match the plasma rotation characteristics in both devices. However, the wide range of Mach numbers obtained in these experiments shows that the rotation has little effect on the triggering of ITBs in plasmas with reversed magnetic shear. On the other hand the toroidal rotation and more specifically the rotational shear had an impact on the subsequent growth and allowed the formation of strong ITBs.

  12. Xylem anisotropy and water transport--a model for the double sawcut experiment

    Science.gov (United States)

    Paul J. Schulte; David G. Costa

    2010-01-01

    Early experiments with overlapping cuts to the stems of trees demonstrated that lateral flow within the stem must be possible to allow such trees to maintain water flow to their leaves. We present a mathematical approach to considering lateral flow in stems by treating the xylem as an anisotropic medium for flow and develop an expression of its conductivity in the form...

  13. Tsunami-induced boulder transport - combining physical experiments and numerical modelling

    Science.gov (United States)

    Oetjen, Jan; Engel, Max; May, Simon Matthias; Schüttrumpf, Holger; Brueckner, Helmut; Prasad Pudasaini, Shiva

    2016-04-01

    Coasts are crucial areas for living, economy, recreation, transportation, and various sectors of industry. Many of them are exposed to high-energy wave events. With regard to the ongoing population growth in low-elevation coastal areas, the urgent need for developing suitable management measures, especially for hazards like tsunamis, becomes obvious. These measures require supporting tools which allow an exact estimation of impact parameters like inundation height, inundation area, and wave energy. Focussing on tsunamis, geological archives can provide essential information on frequency and magnitude on a longer time scale in order to support coastal hazard management. While fine-grained deposits may quickly be altered after deposition, multi-ton coarse clasts (boulders) may represent an information source on past tsunami events with a much higher preservation potential. Applying numerical hydrodynamic coupled boulder transport models (BTM) is a commonly used approach to analyse characteristics (e.g. wave height, flow velocity) of the corresponding tsunami. Correct computations of tsunamis and the induced boulder transport can provide essential event-specific information, including wave heights, runup and direction. Although several valuable numerical models for tsunami-induced boulder transport exist (e. g. Goto et al., 2007; Imamura et al., 2008), some important basic aspects of both tsunami hydrodynamics and corresponding boulder transport have not yet been entirely understood. Therefore, our project aims at these questions in four crucial aspects of boulder transport by a tsunami: (i) influence of sediment load, (ii) influence of complex boulder shapes other than idealized rectangular shapes, (iii) momentum transfers between multiple boulders, and (iv) influence of non-uniform bathymetries and topographies both on tsunami and boulder. The investigation of these aspects in physical experiments and the correct implementation of an advanced model is an urgent need

  14. Atmospherical experiment in Angra I plant for characterizing the effluent transport threw in the atmospheric

    International Nuclear Information System (INIS)

    Silva Lobo, M.A. da; Kronemberger, B.M.E.

    1989-01-01

    Available as short communication only. The Environmental Safety Division of the Nuclear Safety and Fuel Department from FURNAS Electric Station S.A. joint with the National Oceanic and Atmospheric Administration (NOAA), achieved a field experiment for characterizing the atmospheric transport and diffusion in the site complex of Angra I Nuclear Power Plant. The complex topography with the thick vegetation and the neighbour building bring problems for the modelling of the effluent transport and the dispersion. The actual meteorological measure system is automatic and compound with four towers. An intensive atmospheric measure with captive balloon is included, and the collected data shows that the site flux is strongly influenced by the topography and insolation. (C.G.C.). 2 figs

  15. Measurement of CO2 emissions from road freight transport: A review of UK experience

    International Nuclear Information System (INIS)

    McKinnon, A.C.; Piecyk, M.I.

    2009-01-01

    It is possible to estimate CO 2 emissions from road freight transport in different ways, depending on the definition of trucking activity, the degree of reliance on survey, vehicle test-cycle and traffic count data and the geographical scope of the calculation. The emergence of differing road freight-related CO 2 estimates from official sources and revisions to statistical series can frustrate the policy-making process and erode the confidence of industry stakeholders in the validity of the figures. Using UK data, this paper examines the various methods of carbon auditing road freight transport at the national level and compares the results both for a single year (2006) and over a time period. It highlights a series of statistical anomalies and approximations and tries to explain discrepancies that have arisen in the UK data sets. A concluding section considers the general lessons that can be learned from the recent UK experience in this field.

  16. Characterization of ion heat conduction in JET and ASDEX Upgrade plasmas with and without internal transport barriers

    Energy Technology Data Exchange (ETDEWEB)

    Wolf, R C [Institut fuer Plasmaphysik, Forschungszentrum Juelich, Association EURATOM/FZJ, Trilateral Euregio Cluster, D-52425 Juelich (Germany); Baranov, Y [UKAEA/EURATOM Fusion Association, Culham Science Centre, Abingdon, OX14 3DB (United Kingdom); Garbet, X [Association EURATOM-CEA sur la fusion, CEA Cadarache, F-13108 St Paul lez Durance (France); Hawkes, N [UKAEA/EURATOM Fusion Association, Culham Science Centre, Abingdon, OX14 3DB (United Kingdom); Peeters, A G [Max-Planck-Institut fuer Plasmaphysik, EURATOM-Assoziation, D-85748 Garching (Germany); Challis, C [UKAEA/EURATOM Fusion Association, Culham Science Centre, Abingdon, OX14 3DB (United Kingdom); Baar, M de [FOM Instituut voor Plasmafyisica Rijnhuizen, Association EURATO-FOM, Trilateral Euregio Cluster, PO Box 1207, 3430 BE Nieuwegein (Netherlands); Giroud, C [FOM Instituut voor Plasmafyisica Rijnhuizen, Association EURATO-FOM, Trilateral Euregio Cluster, PO Box 1207, 3430 BE Nieuwegein (Netherlands); Joffrin, E [Association EURATOM-CEA sur la fusion, CEA Cadarache, F-13108 St Paul lez Durance (France); Mantsinen, M [Helsinki University of Technology, Association-EURATOM Tekes, FIN-02015 HUT (Finland); Mazon, D [Association EURATOM-CEA sur la fusion, CEA Cadarache, F-13108 St Paul lez Durance (France); Meister, H [Max-Planck-Institut fuer Plasmaphysik, EURATOM-Assoziation, D-85748 Garching (Germany); Suttrop, W [Max-Planck-Institut fuer Plasmaphysik, EURATOM-Assoziation, D-85748 Garching (Germany); Zastrow, K-D [UKAEA/EURATOM Fusion Association, Culham Science Centre, Abingdon, OX14 3DB (United Kingdom)

    2003-09-01

    In ASDEX Upgrade and JET, the ion temperature profiles can be described by R/L{sub Ti} which exhibits only little variations, both locally, when comparing different discharges, and radially over a wide range of the poloidal cross-section. Considering a change of the local ion heat flux of more than a factor of two, this behaviour indicates some degree of profile stiffness. In JET, covering a large ion temperature range from 1 to 25 keV, the normalized ion temperature gradient, R/L{sub Ti}, shows a dependence on the electron to ion temperature ratio or toroidal rotational shear. In particular, in hot ion plasmas, produced predominantly by neutral beam heating at low densities, in which large T{sub i}/T{sub e} is coupled to strong toroidal rotation, the effect of the two quantities cannot be distinguished. Both in ASDEX Upgrade and JET, plasmas with internal transport barriers (ITBs), including the PEP mode in JET, are characterized by a significant increase of R/L{sub Ti} above the value of L- and H-mode plasmas. In agreement with previous ASDEX Upgrade results, no increase of the ion heat transport in reversed magnetic shear ITB plasmas is found in JET when raising the electron heating. Evidence is presented that magnetic shear directly influences R/L{sub Ti}, namely decreasing the ion heat transport when going from weakly positive to negative magnetic shear.

  17. Tungsten Transport in the Core of JET H-mode Plasmas, Experiments and Modelling

    Science.gov (United States)

    Angioni, Clemente

    2014-10-01

    The physics of heavy impurity transport in tokamak plasmas plays an essential role towards the achievement of practical fusion energy. Reliable predictions of the behavior of these impurities require the development of realistic theoretical models and a complete understanding of present experiments, against which models can be validated. Recent experimental campaigns at JET with the ITER-like wall, with a W divertor, provide an extremely interesting and relevant opportunity to perform this combined experimental and theoretical research. Theoretical models of both neoclassical and turbulent transport must consistently include the impact of any poloidal asymmetry of the W density to enable quantitative predictions of the 2D W density distribution over the poloidal cross section. The agreement between theoretical predictions and experimentally reconstructed 2D W densities allows the identification of the main mechanisms which govern W transport in the core of JET H-mode plasmas. Neoclassical transport is largely enhanced by centrifugal effects and the neoclassical convection dominates, leading to central accumulation in the presence of central peaking of the density profiles and insufficiently peaked ion temperature profiles. The strength of the neoclassical temperature screening is affected by poloidal asymmetries. Only around mid-radius, turbulent diffusion offsets neoclassical transport. Consistently with observations in other devices, ion cyclotron resonance heating in the plasma center can flatten the electron density profile and peak the ion temperature profile and provide a means to reverse the neoclassical convection. MHD activity may hamper or speed up the accumulation process depending on mode number and plasma conditions. Finally, the relationship of JET results to a parallel modelling activity of the W behavior in the core of ASDEX Upgrade plasmas is presented. This project has received funding from the European Union's Horizon 2020 research and innovation

  18. Transportation

    National Research Council Canada - National Science Library

    Allshouse, Michael; Armstrong, Frederick Henry; Burns, Stephen; Courts, Michael; Denn, Douglas; Fortunato, Paul; Gettings, Daniel; Hansen, David; Hoffman, D. W; Jones, Robert

    2007-01-01

    .... The ability of the global transportation industry to rapidly move passengers and products from one corner of the globe to another continues to amaze even those wise to the dynamics of such operations...

  19. Coupling between particle and heat transport during power modulation experiments in Tore Supra

    International Nuclear Information System (INIS)

    Zou, X.L.; Giruzzi, G.; Artaud, J.F.; Bouquey, F.; Bremond, S.; Clary, J.; Darbos, C.; Eury, S.P.; Lennholm, M.; Magne, R.; Segui, J.L.

    2004-01-01

    Power modulations are a powerful tool often used to investigate heat transport processes in tokamaks. In some situations, this could also be an interesting method for the investigation of the particle transport due to the anomalous pinch. Low frequency (∼ 1 Hz) power modulation experiments, using both electron cyclotron resonance heating (ECRH) and ion cyclotron resonance heating (ICRH), have been performed in the Tore Supra tokamak. Strong coupling has been observed between the temperature and density modulations during the low frequency ECRH and ICRH modulation experiments. It has been shown that mechanisms as outgassing, Ware pinch effect, curvature driven pinch are not likely to be responsible for this density modulation. Because of its dependence on temperature or temperature gradient, the thermodiffusion is a serious candidate to be the driving source for this density modulation. This analysis shows that low frequency power modulation experiments have a great potential for the investigation of the anomalous particle pinch in tokamaks. Future plans will include the use of more precise density profile measurements using X-mode reflectometry

  20. Evaluation of the MOCAGE Chemistry Transport Model during the ICARTT/ITOP Experiment

    Science.gov (United States)

    Bousserez, N.; Attie, J. L.; Peuch, V. H.; Michou, M.; Pfister, G.; Edwards, D.; Emmons, L.; Arnold, S.; Heckel, A.; Richter, A.; hide

    2007-01-01

    We evaluate the Meteo-France global chemistry transport 3D model MOCAGE (MOdele de Chimie Atmospherique a Grande Echelle) using the important set of aircraft measurements collected during the ICARRT/ITOP experiment. This experiment took place between US and Europe during summer 2004 (July 15-August 15). Four aircraft were involved in this experiment providing a wealth of chemical data in a large area including the North East of US and western Europe. The model outputs are compared to the following species of which concentration is measured by the aircraft: OH, H2O2, CO, NO, NO2, PAN, HNO3, isoprene, ethane, HCHO and O3. Moreover, to complete this evaluation at larger scale, we used also satellite data such as SCIAMACHY NO2 and MOPITT CO. Interestingly, the comprehensive dataset allowed us to evaluate separately the model representation of emissions, transport and chemical processes. Using a daily emission source of biomass burning, we obtain a very good agreement for CO while the evaluation of NO2 points out incertainties resulting from inaccurate ratio of emission factors of NOx/CO. Moreover, the chemical behavior of O3 is satisfactory as discussed in the paper.

  1. Coupling between particle and heat transport during power modulation experiments in Tore Supra

    Energy Technology Data Exchange (ETDEWEB)

    Zou, X.L.; Giruzzi, G.; Artaud, J.F.; Bouquey, F.; Bremond, S.; Clary, J.; Darbos, C.; Eury, S.P.; Lennholm, M.; Magne, R.; Segui, J.L

    2004-07-01

    Power modulations are a powerful tool often used to investigate heat transport processes in tokamaks. In some situations, this could also be an interesting method for the investigation of the particle transport due to the anomalous pinch. Low frequency ({approx} 1 Hz) power modulation experiments, using both electron cyclotron resonance heating (ECRH) and ion cyclotron resonance heating (ICRH), have been performed in the Tore Supra tokamak. Strong coupling has been observed between the temperature and density modulations during the low frequency ECRH and ICRH modulation experiments. It has been shown that mechanisms as outgassing, Ware pinch effect, curvature driven pinch are not likely to be responsible for this density modulation. Because of its dependence on temperature or temperature gradient, the thermodiffusion is a serious candidate to be the driving source for this density modulation. This analysis shows that low frequency power modulation experiments have a great potential for the investigation of the anomalous particle pinch in tokamaks. Future plans will include the use of more precise density profile measurements using X-mode reflectometry.

  2. Cyclic voltammetry modeling of proton transport effects on redox charge storage in conductive materials: application to a TiO2 mesoporous film.

    Science.gov (United States)

    Kim, Y S; Balland, V; Limoges, B; Costentin, C

    2017-07-21

    Cyclic voltammetry is a particularly useful tool for characterizing charge accumulation in conductive materials. A simple model is presented to evaluate proton transport effects on charge storage in conductive materials associated with a redox process coupled with proton insertion in the bulk material from an aqueous buffered solution, a situation frequently encountered in metal oxide materials. The interplay between proton transport inside and outside the materials is described using a formulation of the problem through introduction of dimensionless variables that allows defining the minimum number of parameters governing the cyclic voltammetry response with consideration of a simple description of the system geometry. This approach is illustrated by analysis of proton insertion in a mesoporous TiO 2 film.

  3. Generation, transport and conduct of radioactive wastes of low and intermediate level; Generacion, transporte y gestion de desechos radiactivos de nivel bajo e intermedio

    Energy Technology Data Exchange (ETDEWEB)

    Lizcano, D.; Jimenez, J. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)]. e-mail: dlc@nuclear.inin.mx

    2005-07-01

    The technological development of the last decades produced an increment in the application of the radiations in different human activities. The effect of it has been it the production of radioactive wastes of all the levels. In Mexico, some of the stages of the administration of the waste of low and intermediate level have not been completely resolved, as the case of the treatment and the final storage. In this work aspects of the generation, the transport and the administration of radioactive waste of low and intermediate level produced in the non energy applications from the radioactive materials to national level, indicating the generated average quantities, transported and tried annually by the National Institute of Nuclear Research (ININ). The main generators of wastes in Mexico, classified according to the activity in which the radioactive materials are used its are listed. Some of the main processes of treatment of radioactive wastes broadly applied in the world and those that are used at the moment in our country are also presented. (Author)

  4. Electronic transport and conduction mechanism transition in La1∕3Sr2∕3FeO3 thin films

    International Nuclear Information System (INIS)

    Devlin, R. C.; Krick, A. L.; Sichel-Tissot, R. J.; Xie, Y. J.; May, S. J.

    2014-01-01

    We report on the electronic transport properties of epitaxial La 1∕3 Sr 2∕3 FeO 3 films using temperature dependent resistivity, Hall effect, and magnetoresistance measurements. We show that the electronic phase transition, which occurs near 190 K, results in a change in conduction mechanism from nonadiabatic polaron transport at high temperatures to resistivity behavior following a power law temperature dependence at low temperatures. The phase transition is also accompanied by an abrupt increase in apparent mobility and Hall coefficient below the critical temperature (T*). We argue that the exotic low temperature transport properties are a consequence of the unusually long-range periodicity of the antiferromagnetic ordering, which also couples to the electronic transport in the form of a negative magnetoresistance below T* and a sign reversal of the Hall coefficient at T*. By comparing films of differing thicknesses, stoichiometry, and strain states, we demonstrate that the observed conduction behavior is a robust feature of La 1∕3 Sr 2∕3 FeO 3 .

  5. Electronic transport and conduction mechanism transition in La{sub 1∕3}Sr{sub 2∕3}FeO{sub 3} thin films

    Energy Technology Data Exchange (ETDEWEB)

    Devlin, R. C.; Krick, A. L.; Sichel-Tissot, R. J.; Xie, Y. J.; May, S. J., E-mail: smay@coe.drexel.edu [Department of Materials Science and Engineering, Drexel University, Philadelphia, Pennsylvania 19104 (United States)

    2014-06-21

    We report on the electronic transport properties of epitaxial La{sub 1∕3}Sr{sub 2∕3}FeO{sub 3} films using temperature dependent resistivity, Hall effect, and magnetoresistance measurements. We show that the electronic phase transition, which occurs near 190 K, results in a change in conduction mechanism from nonadiabatic polaron transport at high temperatures to resistivity behavior following a power law temperature dependence at low temperatures. The phase transition is also accompanied by an abrupt increase in apparent mobility and Hall coefficient below the critical temperature (T*). We argue that the exotic low temperature transport properties are a consequence of the unusually long-range periodicity of the antiferromagnetic ordering, which also couples to the electronic transport in the form of a negative magnetoresistance below T* and a sign reversal of the Hall coefficient at T*. By comparing films of differing thicknesses, stoichiometry, and strain states, we demonstrate that the observed conduction behavior is a robust feature of La{sub 1∕3}Sr{sub 2∕3}FeO{sub 3}.

  6. Plutonium-239 sorption and transport on/in unsaturated sediments. Comparison of batch and column experiments for determining sorption coefficients

    International Nuclear Information System (INIS)

    Jinchuan Xie; Jiachun Lu; Xiaohua Zhou; Xuhui Wang; Mei Li; Lili Du; Yueheng Liu; Guoqing Zhou

    2013-01-01

    Sorption (distribution) coefficients of plutonium were most often derived by static batch experiments. However, it is not clear how unsaturated flow conditions including moisture content and pore water velocity change the sorption coefficients. Transport experiments of plutonium through the unsaturated sediments packed into the columns were then performed in order to determine the sorption coefficients (column-K ds ). Static batch experiments were also conducted to obtain batch-K ds and then compare the differences between batch-K ds and column-K ds . The results show that unsaturated flow conditions had no significant effect on column-K ds , and the average column-K d value was 1.74 ± 0.02 m 3 /kg. By comparison, batch-K d values spanned several orders of magnitude, regardless of the specified liquid-solid conditions. Moreover, the batch-K d (22.7 m 3 /kg) at the standard L/S (4 mL/g) recommended by ASTM D 4319 was over an order of magnitude larger than the average column-K d . (author)

  7. Coupled-analysis of current transport performance and thermal behaviour of conduction-cooled Bi-2223/Ag double-pancake coil for magnetic sail spacecraft

    Energy Technology Data Exchange (ETDEWEB)

    Nagasaki, Y., E-mail: nagasaki@rish.kyoto-u.ac.jp [Research Institute of Sustainable Humanosphere, Kyoto University, Gokasho, Uji, Kyoto 611-0011 (Japan); Nakamura, T. [Graduate School of Engineering, Kyoto University, Kyotodaigakukatsura, Nishikyo, Kyoto 615-8530 (Japan); Funaki, I. [Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, Sagamihara, Kanagawa 252-5210 (Japan); Ashida, Y.; Yamakawa, H. [Research Institute of Sustainable Humanosphere, Kyoto University, Gokasho, Uji, Kyoto 611-0011 (Japan)

    2013-09-15

    Highlights: • We model current transport and thermal performances of conduction-cooled HTS coil. • We investigate the effect of the longitudinal inhomogeneity of the HTS tape. • The analysis can precisely estimate performances of the conduction-cooled coil. • The longitudinal inhomogeneity of the HTS tape deteriorates coil performances. • Quench currents of the HTS coil are not consistent with the critical currents. -- Abstract: This paper investigated the quantitative current transport performance and thermal behaviour of a high temperature superconducting (HTS) coil, and the effect of the critical current inhomogeneity along the longitudinal direction of HTS tapes on the coil performances. We fabricated a double-pancake coil using a Bi-2223/Ag tape with a length of 200 m as a scale-down model for a magnetic sail spacecraft. We measured the current transport property and temperature rises during current applications of the HTS coil in a conduction-cooled system, and analytically reproduced the results on the basis of the percolation depinning model and three-dimensional heat balance equation. The percolation depinning model can describe the electric field versus current density of HTS tapes as a function of temperature and magnetic field vector, and we also introduced the longitudinal distribution of the local critical current of the HTS tape into this model. As a result, we can estimate the critical currents of the HTS coil within 10% error for a wide range of the operational temperatures from 45 to 80 K, and temperature rises on the coil during current applications. These results showed that our analysis and conduction-cooled system were successfully realized. The analysis also suggested that the critical current inhomogeneity along the length of the HTS tape deteriorated the current transport performance and thermal stability of the HTS coil. The present study contributes to the characterization of HTS coils and design of a coil system for the

  8. Coupled-analysis of current transport performance and thermal behaviour of conduction-cooled Bi-2223/Ag double-pancake coil for magnetic sail spacecraft

    International Nuclear Information System (INIS)

    Nagasaki, Y.; Nakamura, T.; Funaki, I.; Ashida, Y.; Yamakawa, H.

    2013-01-01

    Highlights: • We model current transport and thermal performances of conduction-cooled HTS coil. • We investigate the effect of the longitudinal inhomogeneity of the HTS tape. • The analysis can precisely estimate performances of the conduction-cooled coil. • The longitudinal inhomogeneity of the HTS tape deteriorates coil performances. • Quench currents of the HTS coil are not consistent with the critical currents. -- Abstract: This paper investigated the quantitative current transport performance and thermal behaviour of a high temperature superconducting (HTS) coil, and the effect of the critical current inhomogeneity along the longitudinal direction of HTS tapes on the coil performances. We fabricated a double-pancake coil using a Bi-2223/Ag tape with a length of 200 m as a scale-down model for a magnetic sail spacecraft. We measured the current transport property and temperature rises during current applications of the HTS coil in a conduction-cooled system, and analytically reproduced the results on the basis of the percolation depinning model and three-dimensional heat balance equation. The percolation depinning model can describe the electric field versus current density of HTS tapes as a function of temperature and magnetic field vector, and we also introduced the longitudinal distribution of the local critical current of the HTS tape into this model. As a result, we can estimate the critical currents of the HTS coil within 10% error for a wide range of the operational temperatures from 45 to 80 K, and temperature rises on the coil during current applications. These results showed that our analysis and conduction-cooled system were successfully realized. The analysis also suggested that the critical current inhomogeneity along the length of the HTS tape deteriorated the current transport performance and thermal stability of the HTS coil. The present study contributes to the characterization of HTS coils and design of a coil system for the

  9. Real-Time Management and Control of a Bus Public Transport Network: The STCP Experience

    Directory of Open Access Journals (Sweden)

    Jorge Freire Sousa

    2009-11-01

    Full Text Available STCP is the main bus operator in the Porto Metropolitan Area. The experimental phase of using fleet tracking and management systems fitted on public transport vehicles began in the late eighties, but only in 2002 the current system (SAEI covered all the buses of the company. Nowadays, these systems are integral company management systems. In this paper, the experience of the past six years or so is presented. The main reasons for the use of such systems are detailed, the architecture and functionalities are described and the importance of accessing real-time information together with subsequent analysis of the data obtained is underlined.

  10. NASA Experiment on Tropospheric-Stratospheric Water Vapor Transport in the Intertropical Convergence Zone

    Science.gov (United States)

    Page, William A.

    1982-01-01

    The following six papers report preliminary results obtained from a field experiment designed to study the role of tropical cumulo-nimbus clouds in the transfer of water vapor from the troposphere to the stratosphere over the region of Panama. The measurements were made utilizing special NOAA enhanced IR satellite images, radiosonde-ozonesondes and a NASA U-2 aircraft carrying. nine experiments. The experiments were provided by a group of NASA, NOAA, industry, and university scientists. Measurements included atmospheric humidity, air and cloud top temperatures, atmospheric tracer constituents, cloud particle characteristics and cloud morphology. The aircraft made a total of eleven flights from August 30 through September 18, 1980, from Howard Air Force Base, Panama; the pilots obtained horizontal and vertical profiles in and near convectively active regions and flew around and over cumulo-nimbus towers and through the extended anvils in the stratosphere. Cumulo-nimbus clouds in the tropics appear to play an important role in upward water vapor transport and may represent the principal source influencing the stratospheric water vapor budget. The clouds provide strong vertical circulation in the troposphere, mixing surface air and its trace materials (water vapor, CFM's sulfur compounds, etc.) quickly up to the tropopause. It is usually assumed that large scale mean motions or eddy scale motions transport the trace materials through the tropopause and into the stratosphere where they are further dispersed and react with other stratospheric constituents. The important step between the troposphere and stratosphere for water vapor appears to depend upon the processes occurring at or near the tropopause at the tops of the cumulo-nimbus towers. Several processes have been sugested: (1) The highest towers penetrate the tropopause and carry water in the form of small ice particles directly into the stratosphere. (2) Water vapor from the tops of the cumulonimbus clouds is

  11. The role of space communication in promoting national development with specific reference to experiments conducted in India

    Science.gov (United States)

    Chitnis, E. V.

    The paper describes the role of space communication in promoting national development with special reference to experiments conducted in India, namely SITE (1975-1976), STEP (1977-1979) and APPLE (1981 onwards). The impact of these experiments in economic, cultural and educational terms are discussed, pointing out social implications involved in using advance space communication technology for instruction and information in the areas of education, national integration and development. The paper covers special requirements which arise when a communication system covers backward and remote rural areas in a developing country. The impact on the population measured by conducting social surveys has been discussed - especially the gains of predominently illiterate new media - participants have been highlighted. Possibilities of improving skills of teachers, the quality of the primary and higher education have been covered. The preparation required both on ground as well as space to derive benefits of space technology are considered. A profile of INSAT which marks the culmination of the experimental phase and the beginning of operational domestic satellite system is sketched.

  12. Adverse events during air and ground neonatal transport: 13 years' experience from a neonatal transport team in Northern Sweden.

    Science.gov (United States)

    van den Berg, Johannes; Olsson, Linn; Svensson, Amelie; Håkansson, Stellan

    2015-07-01

    To study the prevalence of adverse events (AEs) associated with neonatal transport, and to categorize, classify and assess the risk estimation of these events. Written comments in 1082 transport records during the period 1999-2011 were reviewed. Comments related to events that infringed on patient and staff safety were included as AEs, and categorized and further classified as complaint, imminent risk of incident/negative event, actual incident or actual negative event. AEs were also grouped into emergency or planned transports, and risk estimation was calculated according to a risk assessment tool and defined as low, intermediate, high or extreme risk. AEs (N = 883) were divided into five categories: logistics (n = 337), organization (n = 177), equipment (n = 165), vehicle (n = 129) and medical/nursing care (n = 75). Eighty-five percent of AEs were classified as incidents or negative events. The majority of AEs were estimated to be of low or intermediate risk in both planned and emergency transports. AEs estimated to be of high or extreme risk were significantly more frequent in emergency transports (OR = 10.1; 95% CI: 5.0-20.9; p transport, often related to imperfect transport logistics or equipment failure. AEs of high or extreme risk were more frequent in emergency transports.

  13. Effect of adverse childhood experiences on physical health in adulthood: Results of a study conducted in Baghdad city

    Directory of Open Access Journals (Sweden)

    Ameel F Al-Shawi

    2015-01-01

    Full Text Available Background: Studies have revealed a powerful relationship between adverse childhood experiences (ACEs and physical and mental health in adulthood. Literature documents the conversion of traumatic emotional experiences in childhood into organic disease later in life. Objective: The aim was to estimate the effect of childhood experiences on the physical health of adults in Baghdad city. Subjects and Methods: A cross-sectional study was conducted from January 2013 to January 2014. The study sample was drawn from Baghdad city. Multistage sampling techniques were used in choosing 13 primary health care centers and eight colleges of three universities in Baghdad. In addition, teachers of seven primary schools and two secondary schools were chosen by a convenient method. Childhood experiences were measured by applying a modified standardized ACEs-International Questionnaire form and with questions for bonding to family and parental monitoring. Physical health assessment was measured by a modified questionnaire derived from Health Appraisal Questionnaire of Centers for Disease Control and Prevention. The questionnaire includes questions on cerebrovascular diseases, diabetes mellitus, tumor, respiratory and gastrointestinal diseases. Results: Logistic regression model showed that a higher level of bonding to family (fourth quartile is expected to reduce the risk of chronic physical diseases by almost the half (odds ratio = 0.57 and exposure to a high level of household dysfunction and abuse (fourth quartile is expected to increase the risk of chronic physical diseases by 81%. Conclusion: Childhood experiences play a major role in the determination of health outcomes in adulthood, and early prevention of ACEs. Encouraging strong family bonding can promote physical health in later life.

  14. Physics holo.lab learning experience: using smartglasses for augmented reality labwork to foster the concepts of heat conduction

    Science.gov (United States)

    Strzys, M. P.; Kapp, S.; Thees, M.; Klein, P.; Lukowicz, P.; Knierim, P.; Schmidt, A.; Kuhn, J.

    2018-05-01

    Fundamental concepts of thermodynamics rely on abstract physical quantities such as energy, heat and entropy, which play an important role in the process of interpreting thermal phenomena and statistical mechanics. However, these quantities are not covered by human visual perception, and since heat sensation is purely qualitative and easy to deceive, an intuitive understanding often is lacking. Today immersive technologies like head-mounted displays of the newest generation, especially HoloLens, allow for high-quality augmented reality learning experiences, which can overcome this gap in human perception by presenting different representations of otherwise invisible quantities directly in the field of view of the user on the experimental apparatus, which simultaneously avoids a split-attention effect. In a mixed reality (MR) scenario as presented in this paper—which we call a holo.lab—human perception can be extended to the thermal regime by presenting false-color representations of the temperature of objects as a virtual augmentation directly on the real object itself in real-time. Direct feedback to experimental actions of the users in the form of different representations allows for immediate comparison to theoretical principles and predictions and therefore is supposed to intensify the theory–experiment interactions and to increase students’ conceptual understanding. We tested this technology for an experiment on thermal conduction of metals in the framework of undergraduate laboratories. A pilot study with treatment and control groups (N = 59) showed a small positive effect of MR on students’ performance measured with a standardized concept test for thermodynamics, pointing to an improvement of the understanding of the underlying physical concepts. These findings indicate that complex experiments could benefit even more from augmentation. This motivates us to enrich further experiments with MR.

  15. A review of radionuclide release and transport in recent in-pile experiments

    International Nuclear Information System (INIS)

    Harman, N.F.; Clough, P.N.

    1992-01-01

    The experimental series, reviewed in this work, are LOFT-LP-FP-2, PBF SFD ST to 1-4, Treat/STEP I to 4, and ACRR ST-1 and ST-2. These have the common features of in-core heating of a test fuel bundle to high temperatures (usually with some fuel melting) in an experimental reactor core, and of collecting and analysing the released fission products. They were designed to provide detailed information on the release from fuel of fission products and other radionuclides under LWR severe accident conditions, and on the chemical and physical forms and transport of the fission products. The main aim of this review is to bring together, in a systematic way, information on the conduct of the tests, on their successes and failures, and particularly on the information they generated on the chemical and physical behaviour of released fission products. By examining and analysing the data from all of the tests together, patterns of fission product behaviour may become apparent and insights may be gained, which would not be arrived at from individual test results. Moreover, important lessons may be learned, and useful guidance obtained, relating to the aims and conduct of future experimental programmes of fission product release from fuel and transport behaviour. The conclusions should be particularly relevant to the imminent Phebus-FP in-pile test series at Cadarache

  16. Reward: commentary. Temporal discounting in conduct disorder: toward an experience-adaptation hypothesis of the role of psychosocial insecurity.

    Science.gov (United States)

    Sonuga-Barke, Edmund J S

    2014-02-01

    Young people with conduct disorder often experience histories of psychosocial adversity and socioeconomic insecurity. For these individuals, real-world future outcomes are not only delayed in their delivery but also highly uncertain. Under such circumstances, accentuated time preference (extreme favoring of the present over the future) is a rational response to the everyday reality of social and economic transactions. Building on this observation, the author sets out the hypothesis that the exaggerated temporal discounting displayed by individuals with conduct disorder reported by White et al. (2014) is an adaptation to chronic exposure to psychosocial insecurity during development. The author postulates that this adaptation leads to (a) a decision-making bias whereby delay and uncertainty are coded as inseparable characteristics of choice outcomes and/or (b) reprogramming of the brain networks regulating intertemporal decision making. Future research could explore the putative role of environmental exposures to adversity in the development of exaggerated temporal discounting in conduct disorder as well as the mediating role of putative cognitive and neurobiological adaptations.

  17. Optimizing beam transport in rapidly compressing beams on the neutralized drift compression experiment – II

    Directory of Open Access Journals (Sweden)

    Anton D. Stepanov

    2018-03-01

    Full Text Available The Neutralized Drift Compression Experiment-II (NDCX-II is an induction linac that generates intense pulses of 1.2 MeV helium ions for heating matter to extreme conditions. Here, we present recent results on optimizing beam transport. The NDCX-II beamline includes a 1-m-long drift section downstream of the last transport solenoid, which is filled with charge-neutralizing plasma that enables rapid longitudinal compression of an intense ion beam against space-charge forces. The transport section on NDCX-II consists of 28 solenoids. Finding optimal field settings for a group of solenoids requires knowledge of the envelope parameters of the beam. Imaging the beam on the scintillator gives the radius of the beam, but the envelope angle is not measured directly. We demonstrate how the parameters of the beam envelope (radius, envelop angle, and emittance can be reconstructed from a series of images taken by varying the B-field strengths of a solenoid upstream of the scintillator. We use this technique to evaluate emittance at several points in the NDCX-II beamline and for optimizing the trajectory of the beam at the entry of the plasma-filled drift section. Keywords: Charged-particle beams, Induction accelerators, Beam dynamics, Beam emittance, Ion beam diagnostics, PACS Codes: 41.75.-i, 41.85.Ja, 52.59.Sa, 52.59.Wd, 29.27.Eg

  18. The International Experience of the State Support for Creating the Transport and Logistics Centers

    Directory of Open Access Journals (Sweden)

    Zharska Iryna O.

    2017-02-01

    Full Text Available The article is aimed at analysis and synthesis of the international experience as to the State support for creating the transport and logistics centers (TLCs. The causes for emergence of the first TLCs in Europe (60-80-ies of XX century were considered. Values of the LPI index for the countries occupying the first 40 positions of the ranking as of 2014 and of 2016 have been provided, and the major changes during this time have been analyzed. The ranking position of Ukraine is displayed separately. Features of the logistics infrastructure of nine countries with a high value of the LPI index have been considered, degree of the State involvement in the formation of the TLC network has been analyzed. It has been substantiated that creation of the transport and logistics centers allows to reduce the logistics costs of individual producers and contributes to enhancing the efficiency of operation of the national economy in general by attracting investments in the infrastructure development, increasing the number of jobs and tax revenues. The basic motifs that determine the interest of the State authorities in providing support for creating the transportation and logistics centers have been defined. Prospect for further research in this direction will be determining the efficiency of using the different models of the State support for creation and development of TLCs

  19. A TCP/IP transport layer for the DAQ of the CMS experiment

    International Nuclear Information System (INIS)

    Kozlovszky, M.

    2004-01-01

    The CMS collaboration is currently investigating various networking technologies that may meet the requirements of the CMS Data Acquisition System (DAQ). During this study, a peer transport component based on TCP/IP has been developed using object-oriented techniques for the distributed DAQ framework named XDAQ. This framework has been designed to facilitate the development of distributed data acquisition systems within the CMS Experiment. The peer transport component has to meet 3 main requirements. Firstly, it had to provide fair access to the communication medium for competing applications. Secondly, it had to provide as much of the available bandwidth to the application layer as possible. Finally, it had to hide the complexity of using non-blocking TCP/IP connections from the application layer. This paper describes the development of the peer transport component and then presents and draws conclusions on the measurements made during tests. The major topics investigated include: blocking versus non-blocking communication, TCP/IP configuration options, multi-rail connections

  20. Modelling of Pesticide Transport During An Injection Experiment In A Physical and Geochemical Heterogeneous Aquifer

    Science.gov (United States)

    Hojberg, A. L.; Engesgaard, P.; Bjerg, P. L.

    The fate of selected pesticides under natural groundwater conditions was studied by natural gradient short and long term injection experiments in a shallow uncon- fined aerobic aquifer. Bentazone, DNOC, MCPP, dichlorprop, isoproturon, and BAM (dichlobenil metabolite) were injected in aqueous solution with bromide as a nonre- active tracer. The Bromide and pesticide plumes were sampled during the initial 25 m of migration in a dense monitoring net of multilevel samplers. The aquifer was physical and geochemical heterogeneous, which affected transport of several of the pesticides. A 3D reactive transport code was developed including one- and two-site linear/nonlinear equilibrium/nonequilibrium sorption and first-order as well as single Monod degradation kinetic coupled to microbial growth. Model simulations demon- strated that microbial growth was likely supported by the phenoxy acids MCPP and dichlorprop, while degradation of DNOC was adequately described by first-order degradation with no initial lag time. An observed vertical increase in pH was observed at the site and implemented in the transport code. The numerical analysis indicated that degradation of the three degradable pesticides may have been affected by vertical pH variations. Spatial variability in observed DNOC sorption was similarly suspected to be an effect of varying pH. pH dependency on DNOC sorption was confirmed by the model recognized by a match to observed breakthrough at the individual sampling points, when pH variation was included in the simulations.

  1. Solute transport and extraction by a single root in unsaturated soils: model development and experiment

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jaisoo; Sung, Kijune; Corapcioglu, M. Yavuz; Drew, Malcolm C

    2004-09-01

    A contaminant transport model was developed to simulate the fate and transport of organic compounds such as TNT (2,4,6-trinitrotoluene), using the single-root system. Onions were planted for this system with 50-ml plastic tubes. Mass in the soil, soil solution, root and leaf was monitored using {sup 14}C-TNT. Model parameters were acquired from the experiments in the single-root system and were used to simulate total TNT concentration in soil, providing the average concentrations in the rhizosphere and bulk soil as well as root and leaf compartments. Because the existing RCF (root concentration factor) and TSCF (transpiration stream concentration factor) equations based on log K{sub ow} (octanol-water partition coefficient) were not correlated to TNT uptake, a new term, root uptake rate (R{sub ur}), and a new T{sub scf} equation, based on the experimental data, were introduced in the proposed model. The results from both modeling and experimental studies showed higher concentrations of TNT in the rhizosphere than in the bulk soil, because mass transported from the surrounding soil into the rhizosphere was higher than that by root uptake.

  2. Experiences in the transport of radiopharmaceuticals and labelled compounds in the last decade in Cuba

    International Nuclear Information System (INIS)

    Amador B, Z.H.; Perez P, S.; Ayra P, F.E.; Torres B, M.B.

    2006-01-01

    The Center of Isotopes (CENTIS) it is the main transport entity of radioactive materials of the Republic of Cuba in whose activity almost accumulates a decade. Its are executed the design, the production, the maintenance and/or repair of the packings, as well as the preparation, remission, charges, transporting (including the in traffic storage), it discharges and reception in the final destination, of the remittances. Presently work the results of the implementation of the radiological safety and quality assurance programs developed for the safe transport of radioactive bulks and the experiences in the design and essay of bulks type A are shown. The postulated radiological events are evaluated. Three courses of 10 school hours each one, they are imparted, with theoretical and practical exams. The maximum, minimum and average values of the annual effective doses of the workers and the collective doses per year are reported, for the period 1996-2005. It is guaranteed the administrative control and the traceability of the bundles. (Author)

  3. Three-Dimensional Neutral Transport Simulations of Gas Puff Imaging Experiments

    International Nuclear Information System (INIS)

    Stotler, D.P.; DIppolito, D.A.; LeBlanc, B.; Maqueda, R.J.; Myra, J.R.; Sabbagh, S.A.; Zweben, S.J.

    2003-01-01

    Gas Puff Imaging (GPI) experiments are designed to isolate the structure of plasma turbulence in the plane perpendicular to the magnetic field. Three-dimensional aspects of this diagnostic technique as used on the National Spherical Torus eXperiment (NSTX) are examined via Monte Carlo neutral transport simulations. The radial width of the simulated GPI images are in rough agreement with observations. However, the simulated emission clouds are angled approximately 15 degrees with respect to the experimental images. The simulations indicate that the finite extent of the gas puff along the viewing direction does not significantly degrade the radial resolution of the diagnostic. These simulations also yield effective neutral density data that can be used in an approximate attempt to infer two-dimensional electron density and temperature profiles from the experimental images

  4. MTX [Microwave Tokamak Experiment] diagnostic and auxiliary systems for confinement, transport, and plasma physics studies

    International Nuclear Information System (INIS)

    Hooper, E.B.; Allen, S.L.; Casper, T.A.; Thomassen, K.I.

    1989-01-01

    This note describes the diagnostics and auxiliary systems on the Microwave Tokamak Experiment (MTX) for confinement, transport, and other plasma physics studies. It is intended as a reference on the installed and planned hardware on the machine for those who need more familiarity with this equipment. Combined with the tokamak itself, these systems define the opportunities and capabilities for experiments in the MTX facility. We also illustrate how these instruments and equipment are to be used in carrying out the MTX Operations Plan. Near term goals for MTX are focussed on the absorption and heating by the microwave beam from the FEL, but the Plan also includes using the facility to study fundamental phenomena in the plasma, to control MHD activity, and to drive current noninductively

  5. Experiences for the Safe and Secure transport of Radioactive Material in Islamic Republic of Iran

    International Nuclear Information System (INIS)

    Hajizadeh, B.; Eshraghi, A.; Deevband, M.R.; Kardan, M.R.

    2016-01-01

    The Iranian Nuclear Regulatory Authority (INRA) has been addressed the actions to be taken in respect of the safe and secure transport of radioactive material. Firstly, INRA translated TS-R-1 and approved it as national standard and imparted it to all entities that engage in transport of radioactive material. Training course was provided for the designers, consignors, carriers and consignees based on their actions in transport of radioactive material. All radioactive material carrier companies were enforced to observe all aspects of national standard and receive an authorized license of National Radiation Protection Department (NRPD). The NRPD has written procedures to regain control of the radiation sources together with the National Waste Management Department. Transport arrangements are in place for imported and exported sources. According to the Code of Conduct on safety and security, the sources category I, II and III have been registered in data bases carefully so far. All the licensees are obligated to inform the Regulatory Authority for any changes in position, application, possession, transfer or waste of radiation sources. There is a formal agreement with the National Security Council to permit the import of scrap metal at major entry points on the borders. Scrap metal importers are required to use these points of entry which are monitored by officers of the NRPD and portal gate monitors which are installed at the main entry points and be controlled from unique centre. If required, the NRPD will supply staff to other border entry points. Presently some portal gate monitors are in progress at the borderline customs also. All the major metal recycling facilities in IRAN have installed portal gate monitors to recheck their scrap metal imports. (author)

  6. Experiences for the Safe and Secure Transport of Radioactive Material in Islamic Republic of Iran

    International Nuclear Information System (INIS)

    Hajizadeh, B.; Eshraghi, A.; Deevband, M.R.; Kardan, M.R.

    2011-01-01

    The Iranian Nuclear Regulatory Authority (INRA) has been addressed the actions to be taken in respect of the safe and secure transport of radioactive material. Firstly, INRA translated TS-R-1 and approved it as national standard and imparted it to all entities that engage in transport of radioactive material. Training course was provided for the designers, consignors, carriers and consignees based on their actions in transport of radioactive material. All radioactive material carrier companies were enforced to observe all aspects of national standard and receive an authorized license of National Radiation Protection Department (NRPD). The NRPD has written procedures to regain control of the radiation sources together with the National Waste Management Department. Transport arrangements are in place for imported and exported sources. According to the Code of Conduct on safety and security, the sources category I, II and III have been registered in data bases carefully so far. All the licensees are obligated to inform the Regulatory Authority for any changes in position, application, possession, transfer or waste of radiation sources. There is a formal agreement with the National Security Council to permit the import of scrap metal at major entry points on the borders. Scrap metal importers are required to use these points of entry which are monitored by officers of the NRPD and portal gate monitors which are installed at the main entry points and be controlled from unique centre. If required, the NRPD will supply staff to other border entry points. Presently some portal gate monitors are in progress at the borderline customs also. All the major metal recycling facilities in IRAN have installed portal gate monitors to recheck their scrap metal imports. (author)

  7. Using trajectory analyses to refine phenotype for genetic association: conduct problems and the serotonin transporter (5HTTLPR).

    Science.gov (United States)

    Sakai, Joseph T; Boardman, Jason D; Gelhorn, Heather L; Smolen, Andrew; Corley, Robin P; Huizinga, David; Menard, Scott; Hewitt, John K; Stallings, Michael C

    2010-10-01

    Conduct disorder is a serious, relatively common disorder of childhood and adolescence. Findings from genetic association studies searching for genetic determinants of the liability toward such behaviors have been inconsistent. One possible explanation for differential results is that most studies define phenotype from a single assessment; for many adolescents conduct problems decrease in severity over time, whereas for others such behaviors persist. Therefore, longitudinal datasets offer the opportunity to refine phenotype. We used Caucasians that were first assessed during adolescence from the National Youth Survey Family Study. Nine waves of data were used to create latent growth trajectories and test for associations between trajectory class and 5HTTLPR genotype. For the full sample, 5HTTLPR was not associated with conduct problem phenotypes. However, the short (s) allele was associated with chronic conduct problems in females; a nominally significant sex by 5HTTLPR genotype interaction was noted. Longitudinal studies provide unique opportunities for phenotypic refinement and such techniques, with large samples, may be useful for phenotypic definition with other study designs, such as whole genome association studies.

  8. Mesophyll conductance to CO2 transport estimated by two independent methods: effect of variable CO2 concentration and abscisic acid

    Czech Academy of Sciences Publication Activity Database

    Vrábl, D.; Vašková, M.; Hronková, Marie; Flexas, J.; Šantrůček, Jiří

    2009-01-01

    Roč. 60, č. 8 (2009), s. 2315-2323 ISSN 0022-0957 R&D Projects: GA AV ČR(CZ) IAA601410505 Institutional research plan: CEZ:AV0Z50510513 Keywords : Carbon dioxide * mesophyll conductance * Helianthus annuus Subject RIV: ED - Physiology Impact factor: 4.271, year: 2009

  9. Conduction and transport numbers in metacomposites MeWO4 · WO3 (Me = Ca, Sr, Ba)

    International Nuclear Information System (INIS)

    Nejman, A.Ya.; Pestereva, N.N.; Sharafutdinov, A.R.; Kostikov, Yu.P.

    2005-01-01

    The conductivity and transfer numbers of charge carriers for composites in the MeWO 4 -WO 3 (Me = Ca, Sr, Ba) systems are studied as a function of the temperature and the activity of oxygen in a gas phase. The transfer numbers are determined by the emf method and are estimated from dependences of conductivity on the activity of oxygen in a gas phase. The deficiencies of the given procedure as applied to investigation of properties of composite phases are analyzed. The materials under study are classified as metacomposites. The concentration intervals of the ionic, mixed, and electronic conductivities are determined. The conductivity of (100-x)MeWO 4 · xWO 3 composites is predominantly ionic at x ≤ 10 (Me = Ca), x ≤ 60 (Me = Sr), and x ≤ 45 (Me = Ba). The obtained data are explained in the framework of a model that represents a composite as a distributed matrix system where a film of surface phase MeW-s with a high mobility of oxygen ions plays the role of a connected matrix. It is presumed that the surface phase MeW-s possesses double-sided surface activity (α MeW-s ≤ α WO 3 , α MeWO 4 ) and a higher mobility with respect to MeWO 4 and WO 3 . The discovered anomalies of dependences σ O 2- (T) and partial conductivities σ O 2- , σ el (T) are explained by a change in the stoichiometry, morphology, and the degree of tie-up of surface phase MeW-s caused by a change in the temperature and composition of composites [ru

  10. Hydraulic experiment on formation mechanism of tsunami deposit and verification of sediment transport model for tsunamis

    Science.gov (United States)

    Yamamoto, A.; Takahashi, T.; Harada, K.; Sakuraba, M.; Nojima, K.

    2017-12-01

    An underestimation of the 2011 Tohoku tsunami caused serious damage in coastal area. Reconsideration for tsunami estimation needs knowledge of paleo tsunamis. The historical records of giant tsunamis are limited, because they had occurred infrequently. Tsunami deposits may include many of tsunami records and are expected to analyze paleo tsunamis. However, present research on tsunami deposits are not able to estimate the tsunami source and its magnitude. Furthermore, numerical models of tsunami and its sediment transport are also important. Takahashi et al. (1999) proposed a model of movable bed condition due to tsunamis, although it has some issues. Improvement of the model needs basic data on sediment transport and deposition. This study investigated the formation mechanism of tsunami deposit by hydraulic experiment using a two-dimensional water channel with slope. In a fixed bed condition experiment, velocity, water level and suspended load concentration were measured at many points. In a movable bed condition, effects of sand grains and bore wave on the deposit were examined. Yamamoto et al. (2016) showed deposition range varied with sand grain sizes. In addition, it is revealed that the range fluctuated by number of waves and wave period. The measurements of velocity and water level showed that flow was clearly different near shoreline and in run-up area. Large velocity by return flow was affected the amount of sand deposit near shoreline. When a cutoff wall was installed on the slope, the amount of sand deposit repeatedly increased and decreased. Especially, sand deposit increased where velocity decreased. Takahashi et al. (1999) adapted the proposed model into Kesennuma bay when the 1960 Chilean tsunami arrived, although the amount of sand transportation was underestimated. The cause of the underestimation is inferred that the velocity of this model was underestimated. A relationship between velocity and sediment transport has to be studied in detail, but

  11. Reactive transport modelling of a heating and radiation experiment in the Boom clay (Belgium)

    International Nuclear Information System (INIS)

    Montenegro, L.; Samper, J.; Delgado, J.

    2003-01-01

    Most countries around the world consider Deep Geological Repositories (DGR) as the most safe option for the final disposal of high level radioactive waste (HLW). DGR is based on adopting a system of multiple barriers between the HLW and the biosphere. Underground laboratories provide information about the behaviour of these barriers at real conditions. Here we present a reactive transport model for the CERBERUS experiment performed at the HADES underground laboratory at Mol (Belgium) in order to characterize the thermal (T), hydrodynamic (H) and geochemical (G) behaviour of the Boon clay. This experiment is unique because it addresses the combined effect of heat and radiation produced by the storage of HLW in a DGR. Reactive transport models which are solved with CORE, are used to perform quantitative predictions of Boom clay thermo-hydro-geochemical (THG) behaviour. Numerical results indicate that heat and radiation cause a slight oxidation near of the radioactive source, pyrite dissolution, a pH decrease and slight changes in the pore water chemical composition of the Boom clay. (Author) 33 refs

  12. The phase diagram and transport properties of MgO from theory and experiment

    Science.gov (United States)

    Shulenburger, Luke

    2013-06-01

    Planetary structure and the formation of terrestrial planets have received tremendous interest due to the discovery of so called super-earth exoplanets. MgO is a major constituent of Earth's mantle, the rocky cores of gas giants and is a likely component of the interiors of many of these exoplanets. The high pressure - high temperature behavior of MgO directly affects equation of state models for planetary structure and formation. In this work, we examine MgO under extreme conditions using experimental and theoretical methods to determine its phase diagram and transport properties. Using plate impact experiments on Sandia's Z facility the solid-solid phase transition from B1 to B2 is clearly determined. The melting transition, on the other hand, is subtle, involving little to no signal in us-up space. Theoretical work utilizing density functional theory (DFT) provides a complementary picture of the phase diagram. The solid-solid phase transition is identified through a series of quasi-harmonic phonon calculations and thermodynamic integration, while the melt boundary is found using phase coexistence calculations. One issue of particular import is the calculation of reflectivity along the Hugoniot and the influence of the ionic structure on the transport properties. Particular care is necessary because of the underestimation of the band gap and attendant overestimation of transport properties due to the use of semi-local density functional theory. We will explore the impact of this theoretical challenge and its potential solutions in this talk. The integrated use of DFT simulations and high-accuracy shock experiments together provide a comprehensive understanding of MgO under extreme conditions. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Company, for the U.S. DOE's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  13. CURITIBA ET RECIFE, DANS L'EXPERIENCE BRÉSILIENNE D'ORGANISATION DES TRANSPORTS

    Directory of Open Access Journals (Sweden)

    Hostilio Xavier Ratton Neto

    2010-04-01

    Full Text Available

    A tarefa de organizar sistemas de transporte urbano, se encarada em sua essência, poderia ser resumida em dois pontos: prover acessibilidade aos deslocamentos nas cidades e garantir a mobilidade das pessoas na realização desses deslocamentos. Na pratica, essa equação aparentemente simples se configura em vários e complexos problemas, na medida em que os contextos onde se localizam os deslocamentos, as possibilidades de efetuados, as pessoas envolvidas, seus horários e motivos são diferentes e, em principio, não seriam contemplados pelas mesmas soluções. A diversidade dos processos implantados para a provisão dos serviços de transporte publico reflete essas diferenças. No entanto, nós, planejadores de transporte, vivemos obcecados pela idéia de que é possível racionalizar e parametrizar essas diferenças, descobrindo a formula mágica que resolveria, em condições ótimas, todas as questões envolvidas. Um dos caminhos trilhados para a busca dessa formula e o de encontrar, nas diferenças, as respostas para tratar certos aspectos que ficam mais evidentes numa determinada conjuntura do que em outras, incorporando-as e avaliando os seus impactos. Nesse sentido, a experiência francesa, de transferir seu modelo de organização e gestão de transportes a muitos países em desenvolvimento, sem aprofundar o exame das peculiaridades de cada local, o que resultou em grandes fracassos, acabou dando a pista para essa trilha. Os franceses têm, desde então, se interessado pelas questões de transporte dos países em desenvolvimento, tentando levantar exatamente os aspectos que escaparam em sua formulação original. A propósito, não teria sido por acaso que criaram, em 1980, as Conferencias sobre o Desenvolvimento e Planejamento de Transporte Urbano nos Países em Desenvolvimento (CODATU. O livro de Anísio Brasileiro é fruto da conjugação de todas as perspectivas. Ele é o desdobramento, três anos mais tarde, de sua tese de

  14. Mg-doping experiment and electrical transport measurement of boron nanobelts

    International Nuclear Information System (INIS)

    Kirihara, K.; Hyodo, H.; Fujihisa, H.; Wang, Z.; Kawaguchi, K.; Shimizu, Y.; Sasaki, T.; Koshizaki, N.; Soga, K.; Kimura, K.

    2006-01-01

    We measured electrical conductance of single crystalline boron nanobelts having α-tetragonal crystalline structure. The doping experiment of Mg was carried out by vapor diffusion method. The pure boron nanobelt is a p-type semiconductor and its electrical conductivity was estimated to be on the order of 10 -3 (Ω cm) -1 at room temperature. The carrier mobility of pure boron nanobelt was measured to be on the order of 10 -3 (cm 2 Vs -1 ) at room temperature and has an activation energy of ∼0.19 eV. The Mg-doped boron nanobelts have the same α-tetragonal crystalline structure as the pristine nanobelts. After Mg vapor diffusion, the nanobelts were still semiconductor, while the electrical conductance increased by a factor of 100-500. Transition to metal or superconductor by doping was not observed. - Graphical abstract: SEM micrographs of boron nanobelt after Ni/Au electrode fabrication by electron beam lithography. Display Omitted

  15. Conduct Disorder

    Science.gov (United States)

    ... objections runs away from home often truant from school Children who exhibit these behaviors should receive a comprehensive evaluation by an experience mental health professional. Many children with a conduct disorder may ...

  16. Evaluation of long-term patient satisfaction and experience with the Baha(®) bone conduction implant

    DEFF Research Database (Denmark)

    Rasmussen, Jacob; Olsen, Steen Østergaard; Nielsen, Lars Holme

    2012-01-01

    Objective: Evaluate long-term patient satisfaction with bone-anchored hearing aids (the Baha(R), now referred to by Cochlear as a 'bone conduction implant') in our hospital clinic spanning the eighteen-year period from the inception of our Baha program. The researchers further wished to analyse...... the various factors leading to patient satisfaction/dissatisfaction with their Baha. We developed a new questionnaire to obtain a comprehensive impression of individual patient practices, general satisfaction, and experiences with their Baha in respect to time spent using Baha, sound quality, annoyance from...... noise disturbance, ease of communication, cosmetic appearance, and satisfaction with the Baha amongst patient relatives, an aspect not previously investigated. Design: The study design was retrospective and executed as a postal questionnaire. The questionnaire was developed by the authors of this paper...

  17. Review of US accident/incident experience involving the transportation of radioactive material (RAM) 1971-1980

    International Nuclear Information System (INIS)

    McClure, J.D.; Emerson, E.L.

    1980-01-01

    This paper analyzes the transportation accidents and incidents which have occurred in the United States in the period 1971-1980 based upon the information in the Radioactive Material Transportation Accident/Incident Data Base developed by the Transportation Technology Center (TTC) at Sandia National Laboratories. The accident/incident data base incorporates the files of the Hazardous Material Incident Report (HMIR) system operated by the Material Transportation Bureau of the US Department of Transportation (DOT) with additional information obtained from the files of the US Nuclear Regulatory Commission (NRC). A principal objective of this paper is to summarize US accident/incident experience for the past ten years, providing a concise statement of radioactive material (RAM) package failure description for the transport modes of truck, rail and air

  18. Experience in developing control integrated multilevel systems for gas transport; Developpement de systemes integres de gestion multi-niveaux pour le transport du gaz

    Energy Technology Data Exchange (ETDEWEB)

    Kostyukov, V.Y. [NIIIS, (Russian Federation); Bityukov, V.S. [Gasprom, (Russian Federation)

    2000-07-01

    This report describes the experience of the integrated control multilevel system (IACS) development and implementation for gas transport at the regional enterprises of JSC 'Gasprom', specificity of IACS creation by the Russian enterprises on the basis of the technical and licensed basic software SCADA Geamatics purchased from AEG company under the contract. (authors)

  19. Functional separation of oxidation–reduction reactions and electron transport in PtRu/ND and conductive additive hybrid electrocatalysts during methanol oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yan; Wang, Yanhui [State Key Laboratory of Metastable Materials Science and Technology, College of Materials Science and Engineering, Yanshan University, Qinhuangdao 066004 (China); Bian, Linyan [College of Physics and Chemistry, Henan Polytechnic University, Jiaozuo, Henan 454000 (China); Lu, Rui [State Key Laboratory of Metastable Materials Science and Technology, College of Materials Science and Engineering, Yanshan University, Qinhuangdao 066004 (China); Zang, Jianbing, E-mail: jbzang@ysu.edu.cn [State Key Laboratory of Metastable Materials Science and Technology, College of Materials Science and Engineering, Yanshan University, Qinhuangdao 066004 (China)

    2016-02-28

    Graphical abstract: - Highlights: • Functional separation of reactions and electron transport in PtRu/ND + AB (or CNT). • A conductive network was formed after the addition of AB or CNT. • PtRu/ND + AB (or CNT) exhibited enhanced activity and stability than PtRu/ND. - Abstract: Undoped nanodiamond (ND) supported PtRu (PtRu/ND) electrocatalyst for methanol oxidation reactions (MOR) in direct methanol fuel cells was prepared by a microwave-assisted polyol reduction method. Sp{sup 3}-bonded ND possesses high electrochemical stability but low conductivity, while sp{sup 2}-bonded carbon nanomaterials with high conductivity are prone to oxidation. Therefore, the functions of the supporting material were separated in this study. ND (sp{sup 3}), as a support, and AB or CNTs (sp{sup 2}), as a conductive additive, were combined to form the hybrid electrocatalysts PtRu/ND + AB and PtRu/ND + CNT for MOR. The morphology of the electrocatalysts was characterized by scanning electron microscopy and electrochemical measurements were performed using an electrochemical workstation. The results indicated that the electrocatalytic activity of PtRu/ND for MOR was improved with the addition of AB or CNTs as a conductive additive. Moreover, adding CNTs to PtRu/ND as a conductive additive showed better electrocatalytic activities than adding AB, which can be ascribed to the better electron-transfer ability of CNTs.

  20. Study of transport properties and conduction mechanism of pure and composite resorcinol formaldehyde aerogel doped with Co-ferrite

    International Nuclear Information System (INIS)

    Attia, S.M.; Sharshar, T.; Abd-Elwahed, A.R.; Tawfik, A.

    2013-01-01

    Highlights: • A novel composite RF aerogels with Co-ferrite were prepared by sol–gel process. • RF aerogels exhibit a semiconducting behavior. • The dielectric constant of RF aerogel is very low (4 times as that of air) and can be controlled by adding Co-ferrite. • Large overlapping polaron (OLP) was found to be the preferred conduction mechanism in these materials. -- Abstract: A series of resorcinol formaldehyde aerogels (RF aerogels) composite with nanoparticles of CoFe 2 O 4 have been prepared by sol–gel method. Four samples of pure RF aerogels were prepared at different concentrations of Na 2 CO 3 as catalyst (0.02, 0.025, 0.03, and 0.04 wt.%) and four samples of composite RF aerogels were prepared at different concentration of doped CoFe 2 O 4 (0.075, 0.1, 0.125, and 0.15 wt.%; Na 2 CO 3 concentration = 0.03 wt.%). DC electrical conductivity as a function of temperature was studied in the temperature range 25 °C–200 °C for all samples. AC electrical conductivity and dielectric properties were determined using RLC Bridge in the frequency range 100 Hz–1 MHz at different temperature (25–200 °C). The pore size of the samples was determined using positron annihilation lifetime spectroscopy (PALS). RF aerogels are found to exhibit a semiconducting behavior and characterized by two transition temperatures T 1 and T 2 . Also σ DC increases with increase of Co-ferrite contents. Pure RF aerogels posses a very low dielectric constant, where the lowest value of ε′ is ∼4 times as that of air. ε′ decreases with increase of frequency, and increases with increase of temperature. Large overlapping polaron (OLP) is found to be the preferred conduction mechanism in these materials. The results of PALS show that there are two types of pore size in these samples; the first ranges from 1.9 to 2.5 nm, while the second ranges from 3.2 to 5.3 nm

  1. Analytical solutions for benchmarking cold regions subsurface water flow and energy transport models: one-dimensional soil thaw with conduction and advection

    Science.gov (United States)

    Kurylyk, Barret L.; McKenzie, Jeffrey M; MacQuarrie, Kerry T. B.; Voss, Clifford I.

    2014-01-01

    Numerous cold regions water flow and energy transport models have emerged in recent years. Dissimilarities often exist in their mathematical formulations and/or numerical solution techniques, but few analytical solutions exist for benchmarking flow and energy transport models that include pore water phase change. This paper presents a detailed derivation of the Lunardini solution, an approximate analytical solution for predicting soil thawing subject to conduction, advection, and phase change. Fifteen thawing scenarios are examined by considering differences in porosity, surface temperature, Darcy velocity, and initial temperature. The accuracy of the Lunardini solution is shown to be proportional to the Stefan number. The analytical solution results obtained for soil thawing scenarios with water flow and advection are compared to those obtained from the finite element model SUTRA. Three problems, two involving the Lunardini solution and one involving the classic Neumann solution, are recommended as standard benchmarks for future model development and testing.

  2. Investigation of phonon transport and thermal boundary conductance at the interface of functionalized SWCNT and poly (ether-ketone)

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Haoxiang; Kumar, Satish, E-mail: satish.kumar@me.gatech.edu [G.W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332 (United States); Chen, Liang [School of Energy and Power Engineering, Xi' an Jiaotong University, Xi' an, Shaanxi (China); Varshney, Vikas [Materials and Manufacturing Directorate, Air Force Research Laboratory, Wright-Patterson Air Force Base, Dayton, Ohio 45433 (United States); Universal Technology Corporation, Dayton, Ohio 45432 (United States); Roy, Ajit K. [Materials and Manufacturing Directorate, Air Force Research Laboratory, Wright-Patterson Air Force Base, Dayton, Ohio 45433 (United States)

    2016-09-07

    Carbon nanostructures such as carbon nanotube (CNT), graphene, and carbon fibers can be used as fillers in amorphous polymers to improve their thermal properties. In this study, the effect of covalent bonding of CNT with poly(ether ketone) (PEK) on interfacial thermal interactions is investigated using non-equilibrium molecular dynamics simulations. The number of covalent bonds between (20, 20) CNT and PEK is varied in the range of 0–80 (0%–6.25%), and the thermal boundary conductance is computed. The analysis reveals that covalent functionalization of CNT atoms can enhance the thermal boundary conductance by an order of magnitude compared to the non-functionalized CNT-PEK interface at a high degree of CNT functionalization. Besides strengthening the thermal coupling, covalent functionalization is also shown to modify the phonon spectra of CNT. The transient spectral energy analysis shows that the crosslinks cause faster energy exchange from CNT to PEK in different frequency bands. The oxygen atom of hydroxyl group of PEK contributes energy transfer in the low frequency band, while aromatic and carbonyl carbon atoms play a more significant role in high frequency bands. In addition, by analyzing the relaxation time of the spectral temperature of different frequency bands of CNT, it is revealed that with increasing number of bonds, both lower frequency vibrational modes and higher frequency modes efficiently couple across the CNT-PEK interface and contribute in thermal energy transfer from CNT to the matrix.

  3. Experience with the loading and transport of fuel assembly transport casks, including CASTOR casks, and the radiation exposure of personnel

    International Nuclear Information System (INIS)

    Bentele, W.; Kinzelmann, T.

    1999-01-01

    In 1997 and 1998, six spent fuel assembly transports started from the nuclear power plant Gemeinschaftskernkraftwerk Neckar (GKN), using CASTOR-V19 casks. Professor Kuni of Marburg University challenged the statement made by the German Federal Office for Radiation Protection (Bundesamt fuer Strahlenschutz (BfS)) based on accepted scientific knowledge, according to which so-called CASTOR transports present no risk, either to the population or to the escorting police units. This paper shows that the collective dose during the loading of the CASTOR casks amounted to 4.5 mSv (gamma and neutrons) per cask at the most, and that the maximum individual dose amounted to 0.26 mSv. In addition to these doses, the collective dose during handling and transport must be considered: this amounted to 0.35 mSv (gamma and neutrons). The dose to the police escort was -2 (limit for surface contamination), presented degrees of contamination >4 Bq cm -2 upon reaching the Valognes/Cogema terminal. However, transport casks coming from French plants also revealed degrees of contamination >4 Bq cm -2 , as well as 'hot spots'. No such contamination was found on NTL 11 casks transported from the GKN to Sellafield. Neither was any increased contamination found upon the arrival of CASTOR-V19 casks transported from GKN to Gorleben or Ahaus. The partially sensationalist media reports were inversely proportional to the actual radiological relevance of the matter. The German Commission on Radiation Protection (SSK) confirmed that the radiological effect of such contaminated spent fuel transports is negligible. (author)

  4. Transportation

    Science.gov (United States)

    2007-01-01

    Faculty ii INDUSTRY TRAVEL Domestic Assistant Deputy Under Secretary of Defense (Transportation Policy), Washington, DC Department of...developed between the railroad and trucking industries. Railroads: Today’s seven Class I freight railroad systems move 42% of the nation’s intercity ...has been successfully employed in London to reduce congestion and observed by this industry study during its travels . It is currently being

  5. Experiences in conducting multiple community-based HIV prevention trials among women in KwaZulu-Natal, South Africa

    Directory of Open Access Journals (Sweden)

    Moodley Jothi

    2010-04-01

    Full Text Available Abstract Background South Africa, with its scientific capacity, good infrastructure and high HIV incidence rates, is ideally positioned to conduct large-scale HIV prevention trials. The HIV Prevention Research Unit of the South African Medical Research Council conducted four phase III and one phase IIb trials of women-initiated HIV prevention options in KwaZulu-Natal between 2003 and 2009. A total of 7046 women participated, with HIV prevalence between 25% and 45% and HIV incidence ranging from 4.5-9.1% per year. Unfortunately none of the interventions tested had any impact on reducing the risk of HIV acquisition; however, extremely valuable experience was gained, lessons learned and capacity built, while the communities gained associated benefits. Experience Our experience in conducting these trials ranged from setting up community partnerships to developing clinical research sites and dissemination of trial results. Community engagement included setting up community-based research sites with approval from both political and traditional leaders, and developing community advisory groups to assist with the research process. Community-wide education on HIV/sexually transmitted infection prevention, treatment and care was provided to over 90 000 individuals. Myths and misconceptions were addressed through methods such as anonymous suggestion boxes in clinic waiting areas and intensive education and counselling. Attempts were made to involve male partners to foster support and facilitate recruitment of women. Peer educator programmes were initiated to provide ongoing education and also to facilitate recruitment of women to the trials. Recruitment strategies such as door-to-door recruitment and community group meetings were initiated. Over 90% of women enrolled were retained. Community benefits from the trial included education on HIV prevention, treatment and care and provision of ancillary care (such as Pap smears, reproductive health care and

  6. Numerical Experiments on Advective Transport in Large Three-Dimensional Discrete Fracture Networks

    Science.gov (United States)

    Makedonska, N.; Painter, S. L.; Karra, S.; Gable, C. W.

    2013-12-01

    Modeling of flow and solute transport in discrete fracture networks is an important approach for understanding the migration of contaminants in impermeable hard rocks such as granite, where fractures provide dominant flow and transport pathways. The discrete fracture network (DFN) model attempts to mimic discrete pathways for fluid flow through a fractured low-permeable rock mass, and may be combined with particle tracking simulations to address solute transport. However, experience has shown that it is challenging to obtain accurate transport results in three-dimensional DFNs because of the high computational burden and difficulty in constructing a high-quality unstructured computational mesh on simulated fractures. An integrated DFN meshing [1], flow, and particle tracking [2] simulation capability that enables accurate flow and particle tracking simulation on large DFNs has recently been developed. The new capability has been used in numerical experiments on advective transport in large DFNs with tens of thousands of fractures and millions of computational cells. The modeling procedure starts from the fracture network generation using a stochastic model derived from site data. A high-quality computational mesh is then generated [1]. Flow is then solved using the highly parallel PFLOTRAN [3] code. PFLOTRAN uses the finite volume approach, which is locally mass conserving and thus eliminates mass balance problems during particle tracking. The flow solver provides the scalar fluxes on each control volume face. From the obtained fluxes the Darcy velocity is reconstructed for each node in the network [4]. Velocities can then be continuously interpolated to any point in the domain of interest, thus enabling random walk particle tracking. In order to describe the flow field on fractures intersections, the control volume cells on intersections are split into four planar polygons, where each polygon corresponds to a piece of a fracture near the intersection line. Thus

  7. MODELING AND ANALYSIS OF FISSION PRODUCT TRANSPORT IN THE AGR-3/4 EXPERIMENT

    Energy Technology Data Exchange (ETDEWEB)

    Humrickhouse, Paul W.; Collin, Blaise P.; Hawkes, Grant L.; Harp, Jason M.; Demkowicz, Paul A.; Petti, David A.

    2016-11-01

    In this work we describe the ongoing modeling and analysis efforts in support of the AGR-3/4 experiment. AGR-3/4 is intended to provide data to assess fission product retention and transport (e.g., diffusion coefficients) in fuel matrix and graphite materials. We describe a set of pre-test predictions that incorporate the results of detailed thermal and fission product release models into a coupled 1D radial diffusion model of the experiment, using diffusion coefficients reported in the literature for Ag, Cs, and Sr. We make some comparisons of the predicted Cs profiles to preliminary measured data for Cs and find these to be reasonable, in most cases within an order of magnitude. Our ultimate objective is to refine the diffusion coefficients using AGR-3/4 data, so we identify an analytical method for doing so and demonstrate its efficacy via a series of numerical experiments using the model predictions. Finally, we discuss development of a post-irradiation examination plan informed by the modeling effort and simulate some of the heating tests that are tentatively planned.

  8. Application of multiphysics models to efficient design of experiments of solute transport across articular cartilage.

    Science.gov (United States)

    Pouran, Behdad; Arbabi, Vahid; Weinans, Harrie; Zadpoor, Amir A

    2016-11-01

    Transport of solutes helps to regulate normal physiology and proper function of cartilage in diarthrodial joints. Multiple studies have shown the effects of characteristic parameters such as concentration of proteoglycans and collagens and the orientation of collagen fibrils on the diffusion process. However, not much quantitative information and accurate models are available to help understand how the characteristics of the fluid surrounding articular cartilage influence the diffusion process. In this study, we used a combination of micro-computed tomography experiments and biphasic-solute finite element models to study the effects of three parameters of the overlying bath on the diffusion of neutral solutes across cartilage zones. Those parameters include bath size, degree of stirring of the bath, and the size and concentration of the stagnant layer that forms at the interface of cartilage and bath. Parametric studies determined the minimum of the finite bath size for which the diffusion behavior reduces to that of an infinite bath. Stirring of the bath proved to remarkably influence neutral solute transport across cartilage zones. The well-stirred condition was achieved only when the ratio of the diffusivity of bath to that of cartilage was greater than ≈1000. While the thickness of the stagnant layer at the cartilage-bath interface did not significantly influence the diffusion behavior, increase in its concentration substantially elevated solute concentration in cartilage. Sufficient stirring attenuated the effects of the stagnant layer. Our findings could be used for efficient design of experimental protocols aimed at understanding the transport of molecules across articular cartilage. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Indian experience with radionuclide transport, deposition and decontamination in water-cooled nuclear power reactors

    International Nuclear Information System (INIS)

    Narasimhan, S.V.; Das, P.C.; Lawrence, D.A.; Mathur, P.K.; Venkateswarlu, K.S.

    1983-01-01

    The present generation of water-cooled nuclear reactors uses construction materials chosen with utmost care so that minimum corrosion occurs during the life of the reactor. As interaction between the primary coolant and the construction materials is unavoidable, the coolant is chemically treated to achieve maximum compatibility. First measurements of the chemical and radiochemical composition of the crud present on the in-core and out-of-core primary heat transport system surfaces of a pressurized heavy-water-moderated and cooled reactor (PHWR) are given; then experience in India in the development of a low temperature, one-stage decontaminating formulation for chemical decontamination of the radioactive deposits formed on stainless steel surfaces under BWR conditions is discussed. The effect of the magnitude of the transients in parameters such as reactor power, system temperature, dissolved oxygen content in the coolant, etc. on the nature and migration behaviour of primary heat transport system crud in a PHWR is described. Contributions to radioactive sources and insoluble crud from different primary heat transport system materials are identified and correlated with reactor operations in a PHWR. Man-rem problems faced by nuclear reactors, especially during off-line maintenance, stress the need for reducing the deposited radioactive sources from system surfaces which would otherwise be accessible. Laboratory and on-site experimentation was carried out to effect chemical decontamination on the radioactive deposits formed on the stainless steel surfaces under BWR conditions. Both the reducing and oxidizing formulations were subsequently used in a small-scale, in-plant trial in the clean-up system of a BWR. More than 85% of the deposited 60 Co activity was found to have been removed by the oxidizing formulation. Efforts to develop a decontaminating mixture containing a reducing agent with the help of a circulating loop are in progress in the laboratory. (author)

  10. Highlight report local initiatives. Experiences with electric transport; Highlight report lokale initiatieven. Ervaringen met elektrisch vervoer

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2013-06-15

    In March 2013 Linkingreen and XTNT started a survey on local electric transportation initiatives. The aim is to learn from the experiences, problems and obstacles of business users of electric vehicles: cars, vans or trucks, scooters, boats and special vehicles (e.g. garbage trucks) that are all-electric or plug-in (with plug). In this brief report, the main results are presented [Dutch] In maart 2013 is door Linkingreen en XTNT in opdracht van Agentschap NL een enquete uitgezet naar lokale initiatieven elektrisch vervoer. Doel is te leren wat de ervaringen, knelpunten en belemmeringen zijn van zakelijke gebruikers van elektrisch vervoer: personenauto's, bestel- of vrachtauto's, scooters, vaartuigen en bijzondere voertuigen (vuilniswagens etc.) die volledig elektrische of plug in (met stekker) zijn. In dit korte verslag zijn de belangrijkste resultaten opgenomen.

  11. X-ray transport and radiation response assessment (XTRRA) experiments at the National Ignition Facility

    Energy Technology Data Exchange (ETDEWEB)

    Fournier, K. B., E-mail: fournier2@llnl.gov; Brown, C. G.; Yeoman, M. F.; Compton, S.; Holdener, F. R.; Kemp, G. E.; Blue, B. E. [Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94551 (United States); Fisher, J. H.; Newlander, C. D.; Gilliam, R. P.; Froula, N. [Fifth Gait Technologies, Inc., 14040 Camden Circle, Huntsville, Alabama 35803 (United States); Seiler, S. W.; Davis, J. F.; Lerch, MAJ. A. [Defense Threat Reduction Agency, 8725 John J. Kingman Road, Fort Belvoir, Virginia 22060-6201 (United States); Hinshelwood, D. [Naval Research Laboratory, 4555 Overlook Ave. SW, Washington, DC 20375 (United States); Lilly, M. [Dynasen, Inc., 20 Arnold Pl., Goleta, California 93117 (United States)

    2016-11-15

    Our team has developed an experimental platform to evaluate the x-ray-generated stress and impulse in materials. Experimental activities include x-ray source development, design of the sample mounting hardware and sensors interfaced to the National Ignition Facility’s diagnostics insertion system, and system integration into the facility. This paper focuses on the X-ray Transport and Radiation Response Assessment (XTRRA) test cassettes built for these experiments. The test cassette is designed to position six samples at three predetermined distances from the source, each known to within ±1% accuracy. Built-in calorimeters give in situ measurements of the x-ray environment along the sample lines of sight. The measured accuracy of sample responses as well as planned modifications to the XTRRA cassette is discussed.

  12. Quadrupole beam-transport experiment for heavy ions under extreme space charge conditions

    International Nuclear Information System (INIS)

    Chupp, W.; Faltens, A.; Hartwig, E.C.

    1983-03-01

    A Cs ion-beam-transport experiment is in progress to study beam behavior under extreme space-charge conditions. A five-lens section matches the beam into a periodic electrostatic quadrupole FODO channel and its behavior is found to agree with predictions. With the available parameters (less than or equal to 200 keV, less than or equal to 20 mA, πepsilon/sub n/ greater than or equal to 10 - 7 π rad-m, up to 41 periods) the transverse (betatron) occillation frequency (nu) can be depressed down to one-tenth of its zero current value (nu/sub 0/), where nu/sup 2/ = nu/sub 0//sup 2/ -#betta#/sub p/ 2 /2, and #betta#/sub p/ is the beam plasma frequency. The current can be controlled by adjustment of the gun and the emittance can be controlled independently by means of a set of charged grids

  13. Zeroing of the TL signal of sediment undergoing fluvial transportation: a laboratory experiment

    International Nuclear Information System (INIS)

    Gemmell, A.M.D.

    1985-01-01

    Rates of bleaching of suspended sediment undergoing fluvial transportation in a closed laboratory flume beneath a u.v. lamp were measured. It was found that the speed of zeroing is inversely related to the speed of flow. This is attributed to the effects of flow turbulence in keeping sediment in suspension, thereby reducing the penetration of u.v. radiation, and to the re-entrainment of partially bleached or unbleached sediment into the flow. The time required to reduce TL to the residual levels indicated by sunlamp bleaching experiments are such as to suggest that at faster flows sediments in a heavily-laden stream may never attain a complete bleaching. (author)

  14. Analysis of NSPP experiment with ART code for analyzing transport behavior of Aerosol and radionuclides

    International Nuclear Information System (INIS)

    Ishigami, Tsutomu; Kobayashi, Kensuke; Kajimoto, Mitsuhiro.

    1989-01-01

    The ART code calculates transport behavior of aerosols and radionuclides during core meltdown accidents in the light water reactors. Since aerosols play an important role in carrying fission products from the core region to the environment, the ART code includes detailed models of aerosol behavior. Aerosols including several radionuclides are classified into many groups according to the aerosol mass. The models of aerosol behavior include agglomeration processes caused by Brownian motion, aerosol settling velocity difference and turbulent flow, and natural deposition processes due to diffusion, thermophoresis, diffusiophoresis, gravitational settling and forced convection. In order to examine validity of the ART models, the NSPP aerosol experiment was analyzed. The ART calculated results showed good agreement with the experimental data. It was ascertained that aerosol growth due to agglomeration, gravitational settling, thermophoresis in an air atmosphere, and diffusiophoresis in an air-steam atmosphere were important physical phenomena in the aerosol behavior. (author)

  15. Engineering and management experience at Texas A&M Transportation Institute

    Science.gov (United States)

    Chowdhury, Arif Tahjibul

    This manuscript presents the author's engineering and management experience during his internship in the Materials and Pavements (M&P) Division at the Texas A&M Transportation Institute (TTI), and is a record of study for the Doctor of Engineering at Texas A&M University. Through this internship, he met his established internship objectives of gaining technical knowledge as well as knowledge and skills in project management, organizational communication, and quality management of pavement condition data, and of attaining professional development. In meeting these objectives, the author describes the history, mission, and organizational structure of his workplace. He also presents his experience of developing and delivering a two-week training course on pavement design and construction in Kosovo. Participating in a number of professional development training courses and other activities prepared him for working as an engineering manager. These activities include Delta-T leadership training, an instructor development course, a time management and organizational skills course, and the M&P Division lecture series. Leadership and skills learned through the Delta-T program were beneficial for the employee as well as the employer. For the class project, the author and his teammates performed a study dealing with improving TTI's deliverables. The Delta-T team composed a report summarizing their efforts of examining the current state of TTI's project deliverables, the deliverables' shortcomings, and potential enhancements to expand the deliverables' appeal to additional types of potential users outside the traditional research community. The team also developed a prototype web-based model of deliverables and presented some implementation recommendations. Participating in the Texas Department of Transportation's (TxDOT's) pavement surface distress data collection program enabled the author to become familiar with pavement distress data quality management and thus attain the

  16. Neutral Transport Simulations of Gas Puff Imaging Experiments on Alcator C-Mod

    International Nuclear Information System (INIS)

    Stotler, D.P.; LaBombard, B.; Terry, J.L.; Zweben, S.J.

    2002-01-01

    Visible imaging of gas puffs has been used on the Alcator C-Mod tokamak to characterize edge plasma turbulence, yielding data that can be compared with plasma turbulence codes. Simulations of these experiments with the DEGAS 2 Monte Carlo neutral transport code have been carried out to explore the relationship between the plasma fluctuations and the observed light emission. By imposing two-dimensional modulations on the measured time-average plasma density and temperature profiles, we demonstrate that the spatial structure of the emission cloud reflects that of the underlying turbulence. However, the photon emission rate depends on the plasma density and temperature in a complicated way, and no simple scheme for inferring the plasma parameters directly from the light emission patterns is apparent. The simulations indicate that excited atoms generated by molecular dissociation are a significant source of photons, further complicating interpretation of the gas puff imaging results.Visibl e imaging of gas puffs has been used on the Alcator C-Mod tokamak to characterize edge plasma turbulence, yielding data that can be compared with plasma turbulence codes. Simulations of these experiments with the DEGAS 2 Monte Carlo neutral transport code have been carried out to explore the relationship between the plasma fluctuations and the observed light emission. By imposing two-dimensional modulations on the measured time-average plasma density and temperature profiles, we demonstrate that the spatial structure of the emission cloud reflects that of the underlying turbulence. However, the photon emission rate depends on the plasma density and temperature in a complicated way, and no simple scheme for inferring the plasma parameters directly from the light emission patterns is apparent. The simulations indicate that excited atoms generated by molecular dissociation are a significant source of photons, further complicating interpretation of the gas puff imaging results

  17. THE EFFECTS OF TRANSIENT REDUCTIONS IN FUNCTIONAL LEAF AREA ON STOMATAL CONDUCTANCE: BRANCH LEVEL EXPERIMENTS ON YOUNG AND OLD TREES

    Science.gov (United States)

    As trees age and increase in size, the resistance along the water transport path has been hypothesized to increase and potentially limit the ultimate size a tree can reach. Past research has demonstrated that branches are a source of significant resistance in the transport path....

  18. The Grimsel radionuclide migration experiment - a contribution to raising confidence in the validity of solute transport models used in performance assessment

    International Nuclear Information System (INIS)

    Frick, U.

    1995-01-01

    The safety assessment of radioactive waste repositories is to provide confidence that the predictive models utilized are applicable for the specific repository systems. Nagra has carried out radionuclide migration experiments at the Grimsel underground test site (Switzerland) for testing of currently used methodologies, data bases, conceptual approaches and codes for modeling radionuclide transport through fractured host rocks. Specific objectives included: identification of the relevant transport processes, to test the extrapolation of laboratory sorption data to field conditions, and to demonstrate the applicability of currently used methodology for conceptualizing or building realistic transport models. Field tests and transport modeling work are complemented by an extensive laboratory program. The field experimental activities focused predominantly on establishing appropriate conditions for identifying relevant transport mechanisms on the scale of a few meters, aiming at full recovery of injected tracers, simple geometry and long-term stability of induced dipole flow fields. A relatively simple homogeneous, dual-porosity advection/diffusion model was built with input from a state of the art petrographic characterisation of the water conducting feature. It was possible to calibrate the model from conservative tracer breakthrough curves. (J.S.). 21 refs., 14 figs., 4 tabs

  19. Charge transport in organic light-emitting diodes. Experiments and simulations

    Energy Technology Data Exchange (ETDEWEB)

    Schober, Matthias

    2012-11-01

    . Thereby, the agreement between simulation and experiment is excellent, which demonstrates the correctness and applicability of the developed model. Finally, the complete OLED is successfully simulated on the basis of the parameters that have been obtained in the analysis of the single-carrier devices. The simulation of the OLED illustrates the transport levels of electrons and holes, and proofs that the OLED efficiency is low because of non-radiative recombination in the interlayer between the phosphorescent and fluorescent emission zones. In this context, many interesting issues are discussed, e.g. the applicability of the Langevin model in combination with the mobility models for the description of recombination and the relevance of interactions between free charge carriers and excitons.

  20. The treatment of water-conducting features in groundwater flow and transport modelling of the Borrowdale Volcanic Group in Nirex 97

    International Nuclear Information System (INIS)

    Jackson, C.P.; Norris, S.; Todman, S.J.; Watson, S.P.

    1999-01-01

    In the Nirex 97 assessment of the post-closure performance of a repository at Sellafield, the potential repository host rock was the Borrowdale Volcanic Group (BVG). The treatment of water-conducting features in groundwater flow and transport modelling of the BVG is discussed. Groundwater flow in the BVG is predominantly through a subset of the total set of discontinuities - the Flowing Features (FFs). FFs can be identified in core samples by the presence of recent calcite. In boreholes, the FFs are clustered, and the clustering appears to be significant hydro-geologically. However, there is uncertainty about the connectivity of the clusters. A range of models is possible, from the case of isolated clusters to the case where the clusters form a well-connected network. The radiological risk from the repository was determined from radionuclide transport calculations based on the groundwater flow fields obtained from the regional-scale flow calculations. For rocks, such as the BVG, in which groundwater flows predominantly through discontinuities, diffusion into immobile water int the rock matrix between the discontinuities was modelled. Data from the site characterization and research programmes could be used to develop and parameterize groundwater flow and transport models for use in repository performance assessments. (author)

  1. II. Application of field data from heater experiments conducted at Stripa, Sweden, to parameters for repository design

    International Nuclear Information System (INIS)

    Hood, M.; Carlsson, H.; Nelson, P.H.

    1979-01-01

    Current experiments are designed to yield information about both the near-field and the far-field effects of thermomechanical loading of an in-situ, granitic rock mass. Electrically heated canisters, constructed to represent high-level radioactive waste canisters, are emplaced in boreholes from excavations some 340 m below the surface. Thermally induced spalling along the heater borehole wall, a near-field effect, has been monitored and two types of spalling, one serious and one not serious, have been identified. A suggested failure criterion for the serious type of spalling is sigma/sub max/ greater than or equal to C 0 (where sigma/sub max/ is the maximum induced compressive stress at the borehole wall and C 0 is the uniaxial compressive strength of the rock). In one of these experiments this criterion was exceeded, and gross failure at the wall occurred when the equivalent power to the heater was increased beyond 5 kW. The far-field effects of the applied loading are investigated by measuring the temperature, displacement, and stress fields and then comparing the results with predictions which were made based on linear thermoelastic theory. The results show that the dominant mode of heat transfer through the rock is by conduction and, therefore, that predictions of the temperature field are made readily using simple calculations. However, displacements and stresses within the rock mass are measured to be only one-half or less of the values predicted. Two reasons for this major discrepancy are suggested. Work to verify this result is in progress

  2. An environment-dependent semi-empirical tight binding model suitable for electron transport in bulk metals, metal alloys, metallic interfaces, and metallic nanostructures. II. Application—Effect of quantum confinement and homogeneous strain on Cu conductance

    Science.gov (United States)

    Hegde, Ganesh; Povolotskyi, Michael; Kubis, Tillmann; Charles, James; Klimeck, Gerhard

    2014-03-01

    The Semi-Empirical tight binding model developed in Part I Hegde et al. [J. Appl. Phys. 115, 123703 (2014)] is applied to metal transport problems of current relevance in Part II. A systematic study of the effect of quantum confinement, transport orientation, and homogeneous strain on electronic transport properties of Cu is carried out. It is found that quantum confinement from bulk to nanowire boundary conditions leads to significant anisotropy in conductance of Cu along different transport orientations. Compressive homogeneous strain is found to reduce resistivity by increasing the density of conducting modes in Cu. The [110] transport orientation in Cu nanowires is found to be the most favorable for mitigating conductivity degradation since it shows least reduction in conductance with confinement and responds most favorably to compressive strain.

  3. An environment-dependent semi-empirical tight binding model suitable for electron transport in bulk metals, metal alloys, metallic interfaces, and metallic nanostructures. II. Application—Effect of quantum confinement and homogeneous strain on Cu conductance

    International Nuclear Information System (INIS)

    Hegde, Ganesh; Povolotskyi, Michael; Kubis, Tillmann; Charles, James; Klimeck, Gerhard

    2014-01-01

    The Semi-Empirical tight binding model developed in Part I Hegde et al. [J. Appl. Phys. 115, 123703 (2014)] is applied to metal transport problems of current relevance in Part II. A systematic study of the effect of quantum confinement, transport orientation, and homogeneous strain on electronic transport properties of Cu is carried out. It is found that quantum confinement from bulk to nanowire boundary conditions leads to significant anisotropy in conductance of Cu along different transport orientations. Compressive homogeneous strain is found to reduce resistivity by increasing the density of conducting modes in Cu. The [110] transport orientation in Cu nanowires is found to be the most favorable for mitigating conductivity degradation since it shows least reduction in conductance with confinement and responds most favorably to compressive strain

  4. An environment-dependent semi-empirical tight binding model suitable for electron transport in bulk metals, metal alloys, metallic interfaces, and metallic nanostructures. II. Application—Effect of quantum confinement and homogeneous strain on Cu conductance

    Energy Technology Data Exchange (ETDEWEB)

    Hegde, Ganesh, E-mail: ghegde@purdue.edu; Povolotskyi, Michael; Kubis, Tillmann; Charles, James; Klimeck, Gerhard, E-mail: gekco@purdue.edu [Network for Computational Nanotechnology (NCN), Department of Electrical and Computer Engineering, Purdue University, West Lafayette, Indiana 47907 (United States)

    2014-03-28

    The Semi-Empirical tight binding model developed in Part I Hegde et al. [J. Appl. Phys. 115, 123703 (2014)] is applied to metal transport problems of current relevance in Part II. A systematic study of the effect of quantum confinement, transport orientation, and homogeneous strain on electronic transport properties of Cu is carried out. It is found that quantum confinement from bulk to nanowire boundary conditions leads to significant anisotropy in conductance of Cu along different transport orientations. Compressive homogeneous strain is found to reduce resistivity by increasing the density of conducting modes in Cu. The [110] transport orientation in Cu nanowires is found to be the most favorable for mitigating conductivity degradation since it shows least reduction in conductance with confinement and responds most favorably to compressive strain.

  5. Neoclassical and gyrokinetic analysis of time-dependent helium transport experiments on MAST

    International Nuclear Information System (INIS)

    Henderson, S.S.; O'Mullane, M.; Summers, H.P.; Garzotti, L.; Casson, F.J.; Dickinson, D.; Fox, M.F.J.; Patel, A.; Roach, C.M.; Valovič, M.

    2014-01-01

    Time-dependent helium gas puff experiments have been performed on the Mega Ampère Spherical Tokamak (MAST) during a two point plasma current scan in L-mode and a confinement scan at 900 kA. An evaluation of the He II (n = 4 → 3) spectrum line induced by charge exchange suggests anomalous rates of diffusion and inward convection in the outer regions of both L-mode plasmas. Similar rates of diffusion are found in the H-mode plasma, however these rates are consistent with neoclassical predictions. The anomalous inward pinch found in the core of L-mode plasmas is also not apparent in the H-mode core. Linear gyrokinetic simulations of one flux surface in L-mode using the GS2 and GKW codes find that equilibrium flow shear is sufficient to stabilize ITG modes, consistent with beam emission spectroscopy (BES) observations, and suggest that collisionless TEMs may dominate the anomalous helium particle transport. A quasilinear estimate of the dimensionless peaking factor associated with TEMs is in good agreement with experiment. Collisionless TEMs are more stable in H-mode because the electron density gradient is flatter. The steepness of this gradient is therefore pivotal in determining the inward neoclassical particle pinch and the particle flux associated with TEM turbulence. (paper)

  6. Evaluation of water transport behavior in sodium fire experiment-II

    Energy Technology Data Exchange (ETDEWEB)

    Nakagiri, Toshio [Japan Nuclear Cycle Development Inst., Oarai, Ibaraki (Japan). Oarai Engineering Center

    2000-02-01

    Evaluation of water transport behavior in Sodium Fire-II (Run-D4) was performed. Results of other experiments performed in Oarai-Engineering Center were considered in the evaluation, and the results of the evaluation were compared with the calculated results of ASSCOPS code. The main conclusions are described below. (1) It was estimated that aerosol hydrates were not formed in the test cell in the experiment, because of high gas temperatures (200degC - 300degC), but water vapor absorption by the formation of aerosol hydrates and water vapor condensation were occurred in humility measure line, because of low gas temperature (20degC - 40degC). Therefore, it was considered appropriate that measured water vapor concentration in the humidity measure line was different from the real concentration in the test cell. (2) Water vapor concentration in the test cell was assumed to be about 35,000 ppm during sodium leak, and reached to about 70,000 ppm because of water release from heated concrete (over 100degC) walls after 190 min from sodium leak started. The assumed value of about 35,000 ppm during sodium leak almost agree with assumed value from the quantity of aerosol in the humidity measure line, but no support for the value of about 70,000 ppm after 190 min could be found. Therefore, water release rate from heated concrete walls can change with their temperature history. (author)

  7. Ion temperature gradient driven transport in a density modification experiment on the TFTR tokamak

    International Nuclear Information System (INIS)

    Horton, W.; Lindberg, D.; Kim, J.Y.; Dong, J.Q.; Hammett, G.W.; Scott, S.D.; Zarnstorff, M.C.; Hamaguchi, S.

    1991-07-01

    TFTR profiles from a supershot density-modification experiment are analyzed for their local and ballooning stability to toroidal η i -modes in order to understand the initially puzzling results showing no increase in X i when a pellet is used to produce an abrupt and large increase in the η i parameter. The local stability analysis assumes that k parallel = 1/qR and ignores the effects of shear, but makes no assumption on the magnitude of k parallel v ti /ω. The ballooning stability analysis determines a self-consistent linear spectrum of k parallel's including the effect of shear and toroidicity, but it expands in k parallel v ti /ω ≤ 1, which is a marginal assumption for this experiment. Nevertheless, the two approaches agree well and show that the mixing length estimate of the transport rate does not change appreciably during the density-modification and has a value close to or less than the observed X i , in contrast to most previous theories which predicted X i 's which were over an order-of-magnitude too large. However, we are still unable to explain the observed increase X i (r) with minor radius by adding the effects of the finite beta drift - MHD mode coupling, the slab-like mode, or the trapped electron response. The experimental tracking 0.2 e /X i i and trapped-electron driving mechanisms are operating. 4 refs., 5 figs., 5 tabs

  8. Neoclassical and gyrokinetic analysis of time-dependent helium transport experiments on MAST

    Science.gov (United States)

    Henderson, S. S.; Garzotti, L.; Casson, F. J.; Dickinson, D.; Fox, M. F. J.; O'Mullane, M.; Patel, A.; Roach, C. M.; Summers, H. P.; Valovič, M.; The MAST Team

    2014-09-01

    Time-dependent helium gas puff experiments have been performed on the Mega Ampère Spherical Tokamak (MAST) during a two point plasma current scan in L-mode and a confinement scan at 900 kA. An evaluation of the He II (n = 4 → 3) spectrum line induced by charge exchange suggests anomalous rates of diffusion and inward convection in the outer regions of both L-mode plasmas. Similar rates of diffusion are found in the H-mode plasma, however these rates are consistent with neoclassical predictions. The anomalous inward pinch found in the core of L-mode plasmas is also not apparent in the H-mode core. Linear gyrokinetic simulations of one flux surface in L-mode using the GS2 and GKW codes find that equilibrium flow shear is sufficient to stabilize ITG modes, consistent with beam emission spectroscopy (BES) observations, and suggest that collisionless TEMs may dominate the anomalous helium particle transport. A quasilinear estimate of the dimensionless peaking factor associated with TEMs is in good agreement with experiment. Collisionless TEMs are more stable in H-mode because the electron density gradient is flatter. The steepness of this gradient is therefore pivotal in determining the inward neoclassical particle pinch and the particle flux associated with TEM turbulence.

  9. TEM heat transport and fluctuations in the HSX stellarator: experiments and comparison with gyrokinetic simulation

    Science.gov (United States)

    Smoniewski, J.; Faber, B. J.; Sánchez, E.; Calvo, I.; Pueschel, M. J.; Likin, K. M.; Deng, C. B.; Talmadge, J. N.

    2017-10-01

    The Helically Symmetric eXperiment (HSX) has demonstrated reduced neoclassical transport in the plasma core with quasi-symmetry [Lore Thesis 2010], while outside this region the electron thermal diffusivity is well above the neoclassical level, likely due to the Trapped Electron Mode (TEM) [Weir PoP 2015, Faber PoP 2015]. We compare gyrokinetic simulations of the TEM to experimental heat flux and density fluctuation measurements for two configurations: Quasi-Helical Symmetry (QHS) and broken symmetry (Mirror). Both experiment and simulation show that the heat flux for Mirror is larger than for QHS by about a factor of two. Initial interferometer measurements provide evidence that density-gradient-driven TEMs are driving turbulence. Calculations of the collisionless damping of zonal flows provide another perspective into the difference between geometries. Similar to other stellarators [Monreal PPCF 2016], the zonal flow residual goes to zero at long wavelengths in both configurations. Additionally, the very short time decay of the zonal flow due to neoclassical polarization is constant between configurations. However, the collisionless damping time is longer and the zonal flow oscillation frequency is smaller in QHS than Mirror, consistent with reduced radial particle drifts. Work supported by the US DOE under Grant DE-FG02-93ER54222.

  10. Transporting ideas between marine and social sciences: experiences from interdisciplinary research programs

    Directory of Open Access Journals (Sweden)

    Lucy M. Turner

    2017-03-01

    Full Text Available The oceans comprise 70% of the surface area of our planet, contain some of the world’s richest natural resources and are one of the most significant drivers of global climate patterns. As the marine environment continues to increase in importance as both an essential resource reservoir and facilitator of global change, it is apparent that to find long-term sustainable solutions for our use of the sea and its resources and thus to engage in a sustainable blue economy, an integrated interdisciplinary approach is needed. As a result, interdisciplinary working is proliferating. We report here our experiences of forming interdisciplinary teams (marine ecologists, ecophysiologists, social scientists, environmental economists and environmental law specialists to answer questions pertaining to the effects of anthropogenic-driven global change on the sustainability of resource use from the marine environment, and thus to transport ideas outwards from disciplinary confines. We use a framework derived from the literature on interdisciplinarity to enable us to explore processes of knowledge integration in two ongoing research projects, based on analyses of the purpose, form and degree of knowledge integration within each project. These teams were initially focused around a graduate program, explicitly designed for interdisciplinary training across the natural and social sciences, at the Gothenburg Centre for Marine Research at the University of Gothenburg, thus allowing us to reflect on our own experiences within the context of other multi-national, interdisciplinary graduate training and associated research programs.

  11. A summary of the test procedures and operational details of a Delaware River and an ocean dumping pollution monitoring experiment conducted 28 August 1975

    Science.gov (United States)

    Hypes, W. D.; Ohlhorst, C. W.

    1977-01-01

    Two remote sensor evaluation experiments are discussed. One experiment was conducted at the DuPont acid-dump site off the Delaware coast. The second was conducted at an organic waste outfall in the Delaware River. The operational objective of obtaining simultaneous sea truth sampling with remote sensors overpasses was met. Descriptions of the test sites, sensors, sensor platforms, flight lines, sea truth data collected, and operational chronology are presented.

  12. Transportation of Radioactive Material Cobalt-60 is one of the Experience

    International Nuclear Information System (INIS)

    Mohd Derus Ibrahim

    2015-01-01

    During transportation of radioactive material in progress, all the procedure (SOP) must have been followed by legally and the wrappers that have been used must be not contaminated, it ensure that safety and security during transportation. (author)

  13. Defining sustainable transport in rural tourism: experiences from the New Forest

    OpenAIRE

    Dickinson, Janet E.; Smith, A.; Robbins, Derek K.

    2017-01-01

    Transport policy agendas have long sought to bring about more sustainable transport at tourism destinations. While there are examples of successes, it remains unclear what inroads have been made towards creating a sustainable transport future. Policy directions have evolved over a number of years and in many tourism destination contexts it is far from clear what a desirable transport future looks like. When translated to implementation, the aims of initiatives can be unclear and baseline meas...

  14. Clinical presentation and outcome of riboflavin transporter deficiency: mini review after five years of experience

    NARCIS (Netherlands)

    Jaeger, Bregje; Bosch, Annet M.

    2016-01-01

    Riboflavin (vitamin B2) is absorbed in the small intestine by the human riboflavin transporters RFVT1 and RFVT3. A third riboflavin transporter (RFVT2) is expressed in the brain. In 2010 it was demonstrated that mutations in the riboflavin transporter genes SLC52A2 (coding for RFVT2) and SLC52A3

  15. Urban form, transportation and greenhouse gas emissions- Experiences in the Nordic Countries

    Energy Technology Data Exchange (ETDEWEB)

    Harmaajaervi, I; Heinonen, S.; Lahti, P. [VTT, Building and Transport (Finland)

    2004-07-01

    The main objective of the project was to identify instruments to develop urban form and transportation systems in a sustainable way to decrease greenhouse gas emissions in the Nordic countries. Instruments can be found on different levels: national, regional and local. The main sectors are land use and transportation planning, land use and transportation policies, tax policy, co-operation, information dissemination, interaction, monitoring and early warning systems. Instruments concern for example control of urban development, supporting residential activities in city centres, control of location of shopping malls, preventing long commuting trips, reduction of transportation need and car dependency, promotion of walking, cycling and public transport and eco-managed telework. (au)

  16. Cyclic deformation-induced solute transport in tissue scaffolds with computer designed, interconnected, pore networks: experiments and simulations.

    Science.gov (United States)

    Den Buijs, Jorn Op; Dragomir-Daescu, Dan; Ritman, Erik L

    2009-08-01

    Nutrient supply and waste removal in porous tissue engineering scaffolds decrease from the periphery to the center, leading to limited depth of ingrowth of new tissue into the scaffold. However, as many tissues experience cyclic physiological strains, this may provide a mechanism to enhance solute transport in vivo before vascularization of the scaffold. The hypothesis of this study was that pore cross-sectional geometry and interconnectivity are of major importance for the effectiveness of cyclic deformation-induced solute transport. Transparent elastic polyurethane scaffolds, with computer-programmed design of pore networks in the form of interconnected channels, were fabricated using a 3D printing and injection molding technique. The scaffold pores were loaded with a colored tracer for optical contrast, cyclically compressed with deformations of 10 and 15% of the original undeformed height at 1.0 Hz. Digital imaging was used to quantify the spatial distribution of the tracer concentration within the pores. Numerical simulations of a fluid-structure interaction model of deformation-induced solute transport were compared to the experimental data. The results of experiments and modeling agreed well and showed that pore interconnectivity heavily influences deformation-induced solute transport. Pore cross-sectional geometry appears to be of less relative importance in interconnected pore networks. Validated computer models of solute transport can be used to design optimal scaffold pore geometries that will enhance the convective transport of nutrients inside the scaffold and the removal of waste, thus improving the cell survivability deep inside the scaffold.

  17. The use of laboratory experiments for the study of conservative solute transport in heterogeneous porous media

    Science.gov (United States)

    Silliman, S. E.; Zheng, L.; Conwell, P.

    Laboratory experiments on heterogeneous porous media (otherwise known as intermediate scale experiments, or ISEs) have been increasingly relied upon by hydrogeologists for the study of saturated and unsaturated groundwater systems. Among the many ongoing applications of ISEs is the study of fluid flow and the transport of conservative solutes in correlated permeability fields. Recent advances in ISE design have provided the capability of creating correlated permeability fields in the laboratory. This capability is important in the application of ISEs for the assessment of recent stochastic theories. In addition, pressure-transducer technology and visualization methods have provided the potential for ISEs to be used in characterizing the spatial distributions of both hydraulic head and local water velocity within correlated permeability fields. Finally, various methods are available for characterizing temporal variations in the spatial distribution (and, thereby, the spatial moments) of solute concentrations within ISEs. It is concluded, therefore, that recent developments in experimental techniques have provided an opportunity to use ISEs as important tools in the continuing study of fluid flow and the transport of conservative solutes in heterogeneous, saturated porous media. Résumé Les hydrogéologues se sont progressivement appuyés sur des expériences de laboratoire sur des milieux poreux hétérogènes (connus aussi par l'expression "Expériences àéchelle intermédiaire", ISE) pour étudier les zones saturées et non saturées des aquifères. Parmi les nombreuses applications en cours des ISE, il faut noter l'étude de l'écoulement de fluide et le transport de solutés conservatifs dans des champs aux perméabilités corrélées. Les récents progrès du protocole des ISE ont donné la possibilité de créer des champs de perméabilités corrélées au laboratoire. Cette possibilité est importante dans l'application des ISE pour l'évaluation des th

  18. Testing the equation of state and electrical conductivity of copper by the electrical wire explosion in air: Experiment and magnetohydrodynamic simulation

    International Nuclear Information System (INIS)

    Barysevich, A. E.; Cherkas, S. L.

    2011-01-01

    We perform experiments on testing the equations of state and electrical conductivity of copper in three different regimes of copper wire electrical explosion, when the inserted energy (i) is slightly exceeded, (ii) is approximately equal, and (iii) is substantially exceeded the energy needed for the wire complete evaporation. Magnetohydrodynamic simulation is performed. The results predicted by the two different equations of state are compared with the experiment. Empirical expression for the copper electrical conductivity is presented. Parameters in this expression is fit on every of two equations of state. Map of copper conductivity is plotted.

  19. Recognizing and Conducting Opportunistic Experiments in Education: A Guide for Policymakers and Researchers. REL 2014-037

    Science.gov (United States)

    Resch, Alexandra; Berk, Jillian; Akers, Lauren

    2014-01-01

    An opportunistic experiment is a type of randomized controlled trial that studies the effects of a planned intervention or policy change with minimal added disruption and cost. This guide defines opportunistic experiments and provides examples, discusses issues to consider when identifying potential opportunistic experiments, and outlines the…

  20. Neutron radiography experiments for verification of soluble boron mixing and transport modeling under natural circulation conditions

    International Nuclear Information System (INIS)

    Morlang, M.M.; Feltus, M.A.

    1996-01-01

    The use of neutron radiography for visualization of fluid flow through flow visualization modules has been very successful. Current experiments at the Penn State Breazeale Reactor serve to verify the mixing and transport of soluble boron under natural flow conditions as would be experienced in a pressurized water reactor. Different flow geometries have been modeled including holes, slots, and baffles. Flow modules are constructed of aluminum box material 1 1/2 inches by 4 inches in varying lengths. An experimental flow system was built which pumps fluid to a head tank and natural circulation flow occurs from the head tank through the flow visualization module to be radio-graphed. The entire flow system is mounted on a portable assembly to allow placement of the flow visualization module in front of the neutron beam port. A neutron-transparent fluor-inert fluid is used to simulate water at different densities. Boron is modeled by gadolinium oxide powder as a tracer element, which is placed in a mixing assembly and injected into the system a remotely operated electric valve, once the reactor is at power. The entire sequence is recorded on real-time video. Still photographs are made frame-by-frame from the video tape. Computers are used to digitally enhance the video and still photographs. The data obtained from the enhancement will be used for verification of simple geometry predictions using the TRAC and RELAP thermal-hydraulic codes. A detailed model of a reactor vessel inlet plenum, downcomer region, flow distribution area and core inlet is being constructed to model the APGOO plenum. Successive radiography experiments of each section of the model under identical conditions will provide a complete vessel / core model for comparison with the thermal-hydraulic codes

  1. Neutron radiography experiments for verification of soluble boron mixing and transport modeling under natural circulation conditions

    International Nuclear Information System (INIS)

    Feltus, M.A.; Morlang, G.M.

    1996-01-01

    The use of neutron radiography for visualization of fluid flow through flow visualization modules has been very successful. Current experiments at the Penn State Breazeale Reactor serve to verify the mixing and transport of soluble boron under natural flow conditions as would be experienced in a pressurized water reactor. Different flow geometries have been modeled including holes, slots, and baffles. Flow modules are constructed of aluminum box material 1 1/2 inches by 4 inches in varying lengths. An experimental flow system was built which pumps fluid to a head tank and natural circulation flow occurs from the head tank through the flow visualization module to be radiographed. The entire flow system is mounted on a portable assembly to allow placement of the flow visualization module in front of the neutron beam port. A neutron-transparent fluorinert fluid is used to simulate water at different densities. Boron is modeled by gadolinium oxide powder as a tracer element, which is placed in a mixing assembly and injected into the system by remote operated electric valve, once the reactor is at power. The entire sequence is recorded on real-time video. Still photographs are made frame-by-frame from the video tape. Computers are used to digitally enhance the video and still photographs. The data obtained from the enhancement will be used for verification of simple geometry predictions using the TRAC and RELAP thermal-hydraulic codes. A detailed model of a reactor vessel inlet plenum, downcomer region, flow distribution area and core inlet is being constructed to model the AP600 plenum. Successive radiography experiments of each section of the model under identical conditions will provide a complete vessel/core model for comparison with the thermal-hydraulic codes

  2. Fission Product Transport and Source Terms in HTRs: Experience from AVR Pebble Bed Reactor

    Directory of Open Access Journals (Sweden)

    Rainer Moormann

    2008-01-01

    Full Text Available Fission products deposited in the coolant circuit outside of the active core play a dominant role in source term estimations for advanced small pebble bed HTRs, particularly in design basis accidents (DBA. The deposited fission products may be released in depressurization accidents because present pebble bed HTR concepts abstain from a gas tight containment. Contamination of the circuit also hinders maintenance work. Experiments, performed from 1972 to 88 on the AVR, an experimental pebble bed HTR, allow for a deeper insight into fission product transport behavior. The activity deposition per coolant pass was lower than expected and was influenced by fission product chemistry and by presence of carbonaceous dust. The latter lead also to inconsistencies between Cs plate out experiments in laboratory and in AVR. The deposition behavior of Ag was in line with present models. Dust as activity carrier is of safety relevance because of its mobility and of its sorption capability for fission products. All metal surfaces in pebble bed reactors were covered by a carbonaceous dust layer. Dust in AVR was produced by abrasion in amounts of about 5 kg/y. Additional dust sources in AVR were ours oil ingress and peeling of fuel element surfaces due to an air ingress. Dust has a size of about 1  m, consists mainly of graphite, is partly remobilized by flow perturbations, and deposits with time constants of 1 to 2 hours. In future reactors, an efficient filtering via a gas tight containment is required because accidents with fast depressurizations induce dust mobilization. Enhanced core temperatures in normal operation as in AVR and broken fuel pebbles have to be considered, as inflammable dust concentrations in the gas phase.

  3. Dual regulation of root hydraulic conductivity and plasma membrane aquaporins by plant nitrate accumulation and high-affinity nitrate transporter NRT2.1.

    Science.gov (United States)

    Li, Guowei; Tillard, Pascal; Gojon, Alain; Maurel, Christophe

    2016-04-01

    The water status and mineral nutrition of plants critically determine their growth and development. Nitrate (NO3(-)), the primary nitrogen source of higher plants, is known to impact the water transport capacity of roots (root hydraulic conductivity, Lpr). To explore the effects and mode of action of NO3(-) on Lpr, we used an extended set of NO3(-) transport (nrt1.1, nrt1.2, nrt1.5 and nrt2.1), signaling (nrt1.1 and nrt2.1) and metabolism (nia) mutants in Arabidopsis, grown under various NO3(-) conditions. First, a strong positive relationship between Lpr and NO3(-) accumulation, in shoots rather than in roots, was revealed. Secondly, a specific 30% reduction of Lpr in nrt2.1 plants unraveled a major role for the high-affinity NO3(-) transporter NRT2.1 in increasing Lpr These results indicate that NO3(-)signaling rather than nitrogen assimilation products governs Lpr in Arabidopsis. Quantitative real-time reverse transcription-PCR and enzyme-linked immunosorbent assays (ELISAs) were used to investigate the effects of NO3(-) availability on plasma membrane aquaporin (plasma membrane intrinsic protein; PIP) expression. Whereas PIP regulation mostly occurs at the post-translational level in wild-type plants, a regulation of PIPs at both the transcriptional and translational levels was uncovered in nrt2.1 plants. In conclusion, this work reveals that control of Arabidopsis Lpr and PIP functions by NO3(-) involves novel shoot to root signaling and NRT2.1-dependent functions. © The Author 2016. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  4. Assessment of key transport parameters in a karst system under different dynamic conditions based on tracer experiments: the Jeita karst system, Lebanon

    Science.gov (United States)

    Doummar, Joanna; Margane, Armin; Geyer, Tobias; Sauter, Martin

    2018-03-01

    Artificial tracer experiments were conducted in the mature karst system of Jeita (Lebanon) under various flow conditions using surface and subsurface tracer injection points, to determine the variation of transport parameters (attenuation of peak concentration, velocity, transit times, dispersivity, and proportion of immobile and mobile regions) along fast and slow flow pathways. Tracer breakthrough curves (TBCs) observed at the karst spring were interpreted using a two-region nonequilibrium approach (2RNEM) to account for the skewness in the TBCs' long tailings. The conduit test results revealed a discharge threshold in the system dynamics, beyond which the transport parameters vary significantly. The polynomial relationship between transport velocity and discharge can be related to the variation of the conduit's cross-sectional area. Longitudinal dispersivity in the conduit system is not a constant value (α = 7-10 m) and decreases linearly with increasing flow rate because of dilution effects. Additionally, the proportion of immobile regions (arising from conduit irregularities) increases with decreasing water level in the conduit system. From tracer tests with injection at the surface, longitudinal dispersivity values are found to be large (8-27 m). The tailing observed in some TBCs is generated in the unsaturated zone before the tracer actually arrives at the major subsurface conduit draining the system. This work allows the estimation and prediction of the key transport parameters in karst aquifers. It shows that these parameters vary with time and flow dynamics, and they reflect the geometry of the flow pathway and the origin of infiltrating (potentially contaminated) recharge.

  5. Reconfigurable PCI Express cards for low-latency data transport in HEP experiments

    International Nuclear Information System (INIS)

    Ammendola, R.; Biagioni, A.; Cretaro, P.; Frezza, O.; Lo Cicero, F.; Lonardo, A.; Martinelli, M.; Paolucci, P.S.; Pastorelli, E.; Simula, F.; Vicini, P.; Lamanna, G.; Pontisso, L.

    2017-01-01

    State-of-the-art technology supports the High Energy Physics community in addressing the problem of managing an overwhelming amount of experimental data. From the point of view of communication between the detectors’ readout system and computing nodes, the critical issues are the following: latency, moving data in a deterministic and low amount of time; bandwidth, guaranteeing the maximum capability of the link and communication protocol adopted; endpoint consolidation, tight aggregation of channels on a single board. This contribution describes the status and performances of the NaNet project, whose goal is the design of a family of FPGA-based PCIe network interface cards. The efforts of the team are focused on implementing a low-latency, real-time data transport mechanism between the board network multi-channel system and CPU and GPU accelerators memories on the host. Several opportunities concerning technical solutions and scientific applications have been explored: NaNet-1 with a single GbE I/O interface, and NaNet-10, offering four 10GbE ports, for activities related to the GPU-based real-time trigger of NA62 experiment at CERN; NaNet"3, with four 2.5 Gbit optical channels, developed for the KM3NeT-ITALIA underwater neutrino telescope.

  6. Reconfigurable PCI Express cards for low-latency data transport in HEP experiments

    Science.gov (United States)

    Ammendola, R.; Biagioni, A.; Cretaro, P.; Frezza, O.; Lamanna, G.; Lo Cicero, F.; Lonardo, A.; Martinelli, M.; Paolucci, P. S.; Pastorelli, E.; Pontisso, L.; Simula, F.; Vicini, P.

    2017-01-01

    State-of-the-art technology supports the High Energy Physics community in addressing the problem of managing an overwhelming amount of experimental data. From the point of view of communication between the detectors' readout system and computing nodes, the critical issues are the following: latency, moving data in a deterministic and low amount of time; bandwidth, guaranteeing the maximum capability of the link and communication protocol adopted; endpoint consolidation, tight aggregation of channels on a single board. This contribution describes the status and performances of the NaNet project, whose goal is the design of a family of FPGA-based PCIe network interface cards. The efforts of the team are focused on implementing a low-latency, real-time data transport mechanism between the board network multi-channel system and CPU and GPU accelerators memories on the host. Several opportunities concerning technical solutions and scientific applications have been explored: NaNet-1 with a single GbE I/O interface, and NaNet-10, offering four 10GbE ports, for activities related to the GPU-based real-time trigger of NA62 experiment at CERN; NaNet ^3 , with four 2.5Gbit optical channels, developed for the KM3NeT-ITALIA underwater neutrino telescope.

  7. Short-term transport of glyphosate with erosion in Chinese loess soil--a flume experiment.

    Science.gov (United States)

    Yang, Xiaomei; Wang, Fei; Bento, Célia P M; Xue, Sha; Gai, Lingtong; van Dam, Ruud; Mol, Hans; Ritsema, Coen J; Geissen, Violette

    2015-04-15

    Repeated applications of glyphosate may contaminate the soil and water and threaten their quality both within the environmental system and beyond it through water erosion related processes and leaching. In this study, we focused on the transport of glyphosate and its metabolite aminomethylphosphonic acid (AMPA) related to soil erosion at two slope gradients (10 and 20°), two rates of pesticide with a formulation of glyphosate (Roundup®) application (360 and 720 mg m(-2)), and a rain intensity of 1.0 mm min(-1) for 1 h on bare soil in hydraulic flumes. Runoff and erosion rate were significantly different within slope gradients (psoil at the end of the experiment decreased significantly with depth (psoil layers, respectively. The risk of contamination in deep soil and the groundwater was thus low, but 5% of the initial application did reach the 2-10 cm soil layer. The risk of contamination of surface water through runoff and sedimentation, however, can be considerable, especially in regions where rain-induced soil erosion is common. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. Intense ion beam transport in magnetic quadrupoles: Experiments on electron and gas effects

    International Nuclear Information System (INIS)

    Seidl, P.A.; Molvik, A.W.; Bieniosek, F.M.; Cohen, R.H.; Faltens, A.; Friedman, A.; Kireef Covo, M.; Lund, S.M.; Prost, L.; Vay, J-L.

    2004-01-01

    Heavy-ion induction linacs for inertial fusion energy and high-energy density physics have an economic incentive to minimize the clearance between the beam edge and the aperture wall. This increases the risk from electron clouds and gas desorbed from walls. We have measured electron and gas emission from 1 MeV K + incident on surfaces near grazing incidence on the High-Current Experiment (HCX) at LBNL. Electron emission coefficients reach values >100, whereas gas desorption coefficients are near 10 4 . Mitigation techniques are being studied: A bead-blasted rough surface reduces electron emission by a factor of 10 and gas desorption by a factor of 2. We also discuss the results of beam transport (of 0.03-0.18 A K + ) through four pulsed room-temperature magnetic quadrupoles in the HCX at LBNL. Diagnostics are installed on HCX, between and within quadrupole magnets, to measure the beam halo loss, net charge and expelled ions, from which we infer gas density, electron trapping, and the effects of mitigation techniques. A coordinated theory and computational effort has made significant progress towards a self-consistent model of positive-ion beam and electron dynamics. We are beginning to compare experimental and theoretical results

  9. A planar conducting micro-loop structure for transportation of magnetic beads: An approach towards rapid sensing and quantification of biological entities

    KAUST Repository

    Gooneratne, Chinthaka Pasan

    2012-03-01

    Magnetic beads are utilized effectively in a wide variety of medical applications due to their small size, biocompatibility and large surface to volume ratio. Microfluidic lab-on-a-chip (LOC) devices, which utilize magnetic beads, are promising tools for accurate and rapid cell sorting and counting. Effective manipulation of beads is a critical factor for the performance of LOC devices. In this paper we propose a planar conducting micro-loop structure to trap, manipulate and transport magnetic beads. Current through the micro-loops produces magnetic field gradients that are proportional to the force required to manipulate the beads. Numerical analyses were performed to study the magnetic forces and their spatial distributions. Experimental results showed that magnetic beads could not only be transported towards a target region, e.g., for sensing purposes, but also the trapping rate could be increased by switching current between the different loops in the micro-loop structure. This method could lead to rapid and accurate quantification of biological entities tagged with magnetic beads. Copyright © 2012 American Scientific Publishers. All rights reserved.

  10. porewater chemistry experiment at Mont Terri rock laboratory. Reactive transport modelling including bacterial activity

    International Nuclear Information System (INIS)

    Tournassat, Christophe; Gaucher, Eric C.; Leupin, Olivier X.; Wersin, Paul

    2010-01-01

    Document available in extended abstract form only. An in-situ test in the Opalinus Clay formation, termed pore water Chemistry (PC) experiment, was run for a period of five years. It was based on the concept of diffusive equilibration whereby traced water with a composition close to that expected in the formation was continuously circulated and monitored in a packed off borehole. The main original focus was to obtain reliable data on the pH/pCO 2 of the pore water, but because of unexpected microbially- induced redox reactions, the objective was then changed to elucidate the biogeochemical processes happening in the borehole and to understand their impact on pH/pCO 2 and pH in the low permeability clay formation. The biologically perturbed chemical evolution of the PC experiment was simulated with reactive transport models. The aim of this modelling exercise was to develop a 'minimal-' model able to reproduce the chemical evolution of the PC experiment, i.e. the chemical evolution of solute inorganic and organic compounds (organic carbon, dissolved inorganic carbon etc...) that are coupled with each other through the simultaneous occurrence of biological transformation of solute or solid compounds, in-diffusion and out-diffusion of solute species and precipitation/dissolution of minerals (in the borehole and in the formation). An accurate description of the initial chemical conditions in the surrounding formation together with simplified kinetics rule mimicking the different phases of bacterial activities allowed reproducing the evolution of all main measured parameters (e.g. pH, TOC). Analyses from the overcoring and these simulations evidence the high buffer capacity of Opalinus clay regarding chemical perturbations due to bacterial activity. This pH buffering capacity is mainly attributed to the carbonate system as well as to the clay surfaces reactivity. Glycerol leaching from the pH-electrode might be the primary organic source responsible for

  11. Transporting spent fuel and reactor waste in Sweden experience from 5 years of operation

    International Nuclear Information System (INIS)

    Dybeck, P.; Gustafsson, B.

    1990-01-01

    This paper reports that since the Final Repository for Reactor Waste, SFR, was taken into operation in 1988, the SKB sea transportation system is operating at full capacity by transporting spent fuel and now also reactor waste from the 12 Swedish reactors to CLAB and SFR. Transports from the National Research Center, Studsvik to the repository has recently also been integrated in the system. CLAB, the central intermediate storage for spent fuel, has been in operation since 1985. The SKB Sea Transportation System consists today of the purpose built ship M/s Sigyn, 10 transport casks for spent fuel, 2 casks for spent core components, 27 IP-2 shielded steel containers for reactor waste and 5 terminal vehicles. During an average year about 250 tonnes of spent fuel and 3 -- 4000 m 3 of reactor waste are transported to CLAB and SFR respectively, corresponding to around 30 sea voyages

  12. Atmospheric transport simulations in support of the Carbon in Arctic Reservoirs Vulnerability Experiment (CARVE)

    Science.gov (United States)

    Henderson, J. M.; Eluszkiewicz, J.; Mountain, M. E.; Nehrkorn, T.; Chang, R. Y.-W.; Karion, A.; Miller, J. B.; Sweeney, C.; Steiner, N.; Wofsy, S. C.; Miller, C. E.

    2015-04-01

    This paper describes the atmospheric modeling that underlies the Carbon in Arctic Reservoirs Vulnerability Experiment (CARVE) science analysis, including its meteorological and atmospheric transport components (polar variant of the Weather Research and Forecasting (WRF) and Stochastic Time Inverted Lagrangian Transport (STILT) models), and provides WRF validation for May-October 2012 and March-November 2013 - the first 2 years of the aircraft field campaign. A triply nested computational domain for WRF was chosen so that the innermost domain with 3.3 km grid spacing encompasses the entire mainland of Alaska and enables the substantial orography of the state to be represented by the underlying high-resolution topographic input field. Summary statistics of the WRF model performance on the 3.3 km grid indicate good overall agreement with quality-controlled surface and radiosonde observations. Two-meter temperatures are generally too cold by approximately 1.4 K in 2012 and 1.1 K in 2013, while 2 m dewpoint temperatures are too low (dry) by 0.2 K in 2012 and too high (moist) by 0.6 K in 2013. Wind speeds are biased too low by 0.2 m s-1 in 2012 and 0.3 m s-1 in 2013. Model representation of upper level variables is very good. These measures are comparable to model performance metrics of similar model configurations found in the literature. The high quality of these fine-resolution WRF meteorological fields inspires confidence in their use to drive STILT for the purpose of computing surface influences ("footprints") at commensurably increased resolution. Indeed, footprints generated on a 0.1° grid show increased spatial detail compared with those on the more common 0.5° grid, better allowing for convolution with flux models for carbon dioxide and methane across the heterogeneous Alaskan landscape. Ozone deposition rates computed using STILT footprints indicate good agreement with observations and exhibit realistic seasonal variability, further indicating that WRF

  13. Coupled transport and chemistry in clay stone studied by advective displacement: experiments and model

    International Nuclear Information System (INIS)

    Landesman, C.; Grambow, B.; Bailly, C.; Ribet, S.; Perrigaud, K.; Baty, V.; Giffaut, E.

    2010-01-01

    Document available in extended abstract form only. Full text of publication entered in this record. For assessing the mass transfer resistance of the Callovo-Oxfordian clay rock formation in case of implementing a nuclear waste repository, various strongly coupled processes need to be understood and quantified both in near and far field: multi-species diffusion/advection, mineral/pore water interaction, interaction with the waste matrix and engineered barrier material, radionuclide retention, colloid transport, pore water chemistry evolution etc. To study many of these processes in their interrelationship simultaneously, a series of high pressure stainless steel advection cell was designed and clay cores from different locations of different calcite and clay contents were machined to fit the inner diameter of the cells with a precision of 50 μm. After assembling, simulated oxygen free clay pore water with bromine tracer was pushed by a High Pressure pump through the reactor by a pressure of up 100 bars at temperatures between 20 and 90 deg. C and the out-flowing water was collected, protected from air and analyzed by ICP-MS, COT meter and ion chromatography in regular time intervals. The water flow rate was between 0.02 and 1.2 mL/ d, corresponding to a clay rock permeabilities between 10 -12 and 10 -14 m/s at 25 deg. C. Permeabilities increase with temperature as expected due to reduction of viscosity of water. The experiments last up to 2 years. The first drops of out flowing allow estimating the initial pore water composition. This is particular useful to assess mobile natural organic matter contents, Se concentrations and temperature effect on clay water composition. Results show that only very small organic molecules are mobile. Temperature had only little effect on water composition. After few months both tritiated (HTO) water and 36 Cl were added and from the evolution of the activities in the out flowing water dispersion coefficients and accessible

  14. The effects of corona on current surges induced on conducting lines by EMP: A comparison of experiment data with results of analytic corona models

    Science.gov (United States)

    Blanchard, J. P.; Tesche, F. M.; McConnell, B. W.

    1987-09-01

    An experiment to determine the interaction of an intense electromagnetic pulse (EMP), such as that produced by a nuclear detonation above the Earth's atmosphere, was performed in March, 1986 at Kirtland Air Force Base near Albuquerque, New Mexico. The results of that experiment have been published without analysis. Following an introduction of the corona phenomenon, the reason for interest in it, and a review of the experiment, this paper discusses five different analytic corona models that may model corona formation on a conducting line subjected to EMP. The results predicted by these models are compared with measured data acquired during the experiment to determine the strengths and weaknesses of each model.

  15. Effect of Si doping on the thermal conductivity of bulk GaN at elevated temperatures – theory and experiment

    Directory of Open Access Journals (Sweden)

    P. P. Paskov

    2017-09-01

    Full Text Available The effect of Si doping on the thermal conductivity of bulk GaN was studied both theoretically and experimentally. The thermal conductivity of samples grown by Hydride Phase Vapor Epitaxy (HVPE with Si concentration ranging from 1.6×1016 to 7×1018 cm-3 was measured at room temperature and above using the 3ω method. The room temperature thermal conductivity was found to decrease with increasing Si concentration. The highest value of 245±5 W/m.K measured for the undoped sample was consistent with the previously reported data for free-standing HVPE grown GaN. In all samples, the thermal conductivity decreased with increasing temperature. In our previous study, we found that the slope of the temperature dependence of the thermal conductivity gradually decreased with increasing Si doping. Additionally, at temperatures above 350 K the thermal conductivity in the highest doped sample (7×1018 cm-3 was higher than that of lower doped samples. In this work, a modified Callaway model adopted for n-type GaN at high temperatures was developed in order to explain such unusual behavior. The experimental data was analyzed with examination of the contributions of all relevant phonon scattering processes. A reasonable match between the measured and theoretically predicted thermal conductivity was obtained. It was found that in n-type GaN with low dislocation densities the phonon-free-electron scattering becomes an important resistive process at higher temperatures. At the highest free electron concentrations, the electronic thermal conductivity was suggested to play a role in addition to the lattice thermal conductivity and compete with the effect of the phonon-point-defect and phonon-free-electron scattering.

  16. How Does Transport Policy Cope with Climate Challenges? Experiences from the UK and Other European Countries

    DEFF Research Database (Denmark)

    Gudmundsson, Henrik; Lawler, Mary; Meza, Maria Josefina Figueroa

    2011-01-01

    Transport is one of the fastest growing sources of emissions of greenhouse gases. Some European countries have adopted comprehensive “sustainable transport” policies, in which climate change is addressed. This paper looks into how sustainable transport policy frameworks deal with climate change c...

  17. STUDY OF THE EXPERIENCE OF USE OF INTERMODAL TECHNOLOGY IN THE ORGANIZATION OF PASSENGER TRANSPORTATIONS

    Directory of Open Access Journals (Sweden)

    Liudmila Andreevna Paramonova

    2017-05-01

    Full Text Available This article examines the practice of applying intermodal technology and a single transportation document in the organization of passenger transportations, contains a review of the projects on the use of intermodal technology from theoretical point of view, an analysis of the implemented models.

  18. Trans-European transport networks influence on the regional development and urban systems: Serbian experience

    Directory of Open Access Journals (Sweden)

    Maksin-Mićić Marija

    2004-01-01

    Full Text Available The trans-European transport network has different effects at macro-regional, mezzo-regional and micro-regional level, and on urban systems development, and its effectiveness rises at the lower regional levels. Possible approaches to the trans-European transport network impact and effect survey and policy options have been pointed out. The importance of increased accessibility and mobility for regional expansion and for more balanced and polycentric system of city networks has been underlined. The question is how the new major transport infrastructure affects the development of functional complementarity between cities and regions. Changes of the spatial organization, utilization and structure of cities, as well as of social benefits and losses subsequent to impacts of trans-European transport corridor "X" on urban system Ćuprija-Jagodina-Paraćin at section Belgrade-Nis have been analysed. The new trans-European or major transport infrastructure does not per se create regional and urban system network development, although it can affect the conditions for the processes that create growth and development. The effects can be increased by co-ordination of measures of regional and urban policy, land use, transport and other policies. The guidances and options of urban systems and urban centres development policies in trans-European transport corridor, as well as possibilities to improve our planning system have been given. The necessary measure is the introduction of spatial impact assessment as sectorial policy instrument for the large transport infrastructure projects.

  19. Dynamic Design of Ground Transport With the Help of Computational Experiment

    Directory of Open Access Journals (Sweden)

    Kravets Victor

    2015-05-01

    Full Text Available Objectives of ground transport (motor transport vehicle have been considered. Mathematical model of nonlinear dynamics in spatial motion of asymmetric carriage in the form of Euler-Lagrange equations represented as symmetrical block structure in quaternion matrices has been developed. Kinematic equations and partition matrices of external action in which Rodrigues-Hamilton parameters have been applied describe quaternionic matrices.

  20. Experience within international transport and direct rail services in meeting the IAEA requirement for a radiation protection programme(s)

    International Nuclear Information System (INIS)

    Billing, D.

    2003-01-01

    BNFL International Transport and Direct Rail Services have successfully developed appropriate Radiation Protection Programmes for their business. The business supports BNFL's worldwide Nuclear Fuel Services with key customer bases in Europe, Japan and the UK, utilising marine, rail and road modal transports. Experience in this business spans over 4 decades. The preparation of RPP's for each aspect of its operations has been made relatively straight forward in that the key elements within the internationally recognised model RPP (by WNTI) were already in place in BNFL's procedures to satisfy current National UK and International Regulations and supported by Management systems which comply with International Standards for Quality Assurance. (author)

  1. Inverse Porosity-Hydraulic Conductivity Relationship in Sand-and-Gravel Aquifers Determined From Analysis of Geophysical Well Logs: Implications for Transport Processes

    Science.gov (United States)

    Morin, R. H.

    2004-05-01

    It is intuitive to think of hydraulic conductivity K as varying directly and monotonically with porosity P in porous media. However, laboratory studies and field observations have documented a possible inverse relationship between these two parameters in unconsolidated deposits under certain grain-size distributions and packing arrangements. This was confirmed at two sites in sand-and-gravel aquifers on Cape Cod, Massachusetts, where sets of geophysical well logs were used to examine the interdependence of several aquifer properties. Along with K and P, the resistivity R and the natural-gamma activity G of the surrounding sediments were measured as a function of depth. Qualitative examination of field results from the first site was useful in locating a contaminant plume and inferred an inverse relation between K and P; this was substantiated by a rigorous multivariate analysis of log data collected from the second site where K and P were determined to respond in a bipolar manner among the four independent variables. Along with this result come some implications regarding our conceptual understanding of contaminant transport processes in the shallow subsurface. According to Darcy's law, the interstitial fluid velocity V is proportional to the ratio K/P and, consequently, a general inverse K-P relationship implies that values of V can extend over a much wider range than conventionally assumed. This situation introduces a pronounced flow stratification within these granular deposits that can result in large values of longitudinal dispersivity; faster velocities occur in already fast zones and slower velocities in already slow zones. An inverse K-P relationship presents a new perspective on the physical processes associated with groundwater flow and transport. Although the results of this study apply strictly to the Cape Cod aquifers, they may merit a re-evaluation of modeling approaches undertaken at other locations having similar geologic environments.

  2. Nanoclay gelation approach toward improved dye-sensitized solar cell efficiencies: an investigation of charge transport and shift in the TiO2 conduction band.

    Science.gov (United States)

    Wang, Xiu; Kulkarni, Sneha A; Ito, Bruno Ieiri; Batabyal, Sudip K; Nonomura, Kazuteru; Wong, Chee Cheong; Grätzel, Michael; Mhaisalkar, Subodh G; Uchida, Satoshi

    2013-01-23

    Nanoclay minerals play a promising role as additives in the liquid electrolyte to form a gel electrolyte for quasi-solid-state dye-sensitized solar cells, because of the high chemical stability, unique swelling capability, ion exchange capacity, and rheological properties of nanoclays. Here, we report the improved performance of a quasi-solid-state gel electrolyte that is made from a liquid electrolyte and synthetic nitrate-hydrotalcite nanoclay. Charge transport mechanisms in the gel electrolyte and nanoclay interactions with TiO(2)/electrolyte interface are discussed in detail. The electrochemical analysis reveals that the charge transport is solely based on physical diffusion at the ratio of [PMII]:[I(2)] = 10:1 (where PMII is 1-propyl-3-methylimidazolium iodide). The calculated physical diffusion coefficient shows that the diffusion of redox ions is not affected much by the viscosity of nanoclay gel. The addition of nitrate-hydrotalcite clay in the electrolyte has the effect of buffering the protonation process at the TiO(2)/electrolyte interface, resulting in an upward shift in the conduction band and a boost in open-circuit voltage (V(OC)). Higher V(OC) values with undiminished photocurrent is achieved with nitrate-hydrotalcite nanoclay gel electrolyte for organic as well as for inorganic dye (D35 and N719) systems. The efficiency for hydrotalcite clay gel electrolyte solar cells is increased by 10%, compared to that of the liquid electrolyte. The power conversion efficiency can reach 10.1% under 0.25 sun and 9.6% under full sun. This study demonstrates that nitrate-hydrotalcite nanoclay in the electrolyte not only solidifies the liquid electrolyte to prevent solvent leakage, but also facilitates the improvement in cell efficiency.

  3. Hydraulic Conductivity Distributions for Anisotropic Systems and Application to Tc Transport at the U.S. Department of Energy Hanford Site

    International Nuclear Information System (INIS)

    Hunt, A. G.

    2006-01-01

    anisotropy in K (largest ratio of horizontal to vertical values) must be provided. The data analyzed so far (received from Pacific Northwest National Laboratory Researchers, Dr. Glendon Gee and Dr. Mark Rockhold) has suggested that the majority of the finer soils in the Hanford subsurface have particularly low values of K at low moisture contents rather than particularly large values as expected by most researchers. Preliminary results suggest that about 50% of the Hanford Site subsurface may contain soils which preferentially retain water under dry conditions, however, only about 20% of these appear to be highly conductive as well. Thus only about 10% of the Hanford subsurface may actually contain soil which not only retains water preferentially under generally dry conditions, but which also has unusually high hydraulic conductivity. If this is the case, then the argument that such highly conductive regions may tend to be connected, even for short distances in the horizontal direction, may fall apart. So several alternate hypotheses have to be considered: (1) that the very small proportion (ca. 10%) of soils which retain water and are highly conductive is sufficient to percolate, even though typical percolation probabilities tend to be 15% or higher, (2) the subset of soils analyzed (from the DOE sponsored Vadose Zone Transport Study Site) is not a representative sample, (3) the horizontal transport is occurring at higher moisture contents. Further research on this particular aspect is thus required, and will be performed in the summer of 2006

  4. "Their Stories Have Changed My Life": Clinicians' Reflections on Their Experience with and Their Motivation to Conduct Asylum Evaluations.

    Science.gov (United States)

    Mishori, Ranit; Hannaford, Alisse; Mujawar, Imran; Ferdowsian, Hope; Kureshi, Sarah

    2016-02-01

    Many clinicians perform asylum evaluations yet no studies describe the motivation to perform them or their perceived rewards. The number of asylum seekers in the US is increasing and more clinicians are needed as evaluators. A survey to an asylum evaluators' network asked participants to qualitatively reflect on their experience and motivation. Answers were analyzed for themes and sentiment. Respondents cited commitment to humanistic and moral values, noted personal and family experiences, having skills, expertise, and career interests as drivers. They found the experience very rewarding personally and professionally, and in their perceived benefit to asylees. Negative sentiment was less frequent and centered on emotions related to client narratives. Process-oriented frustrations were also noted. This is the first published study describing clinicians' motivation and experience with asylum evaluations. It may illuminate clinicians' drive to volunteer, and serve as a resource for organizations for recruitment and education.

  5. AFSC/RACE/SAP/Daly:Juvenile blue king crab cannibalism experiment conducted in the Kodiak Lab in 2014

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset is part of a laboratory experiment, which evaluated how varying prey densities (year-0 blue king crabs) and habitat type (shell and sand) affect the...

  6. Effects of soil type on leaching and runoff transport of rare earth elements and phosphorous in laboratory experiments.

    Science.gov (United States)

    Wang, Lingqing; Liang, Tao; Chong, Zhongyi; Zhang, Chaosheng

    2011-01-01

    Through leaching experiments and simulated rainfall experiments, characteristics of vertical leaching of exogenous rare earth elements (REEs) and phosphorus (P) and their losses with surface runoff during simulated rainfall in different types of soils (terra nera soil, cinnamon soil, red soil, loess soil, and purple soil) were investigated. Results of the leaching experiments showed that vertical transports of REEs and P were relatively low, with transport depths less than 6 cm. The vertical leaching rates of REEs and P in the different soils followed the order of purple soil > terra nera soil > red soil > cinnamon soil > loess soil. Results of the simulated rainfall experiments (83 mm h⁻¹) revealed that more than 92% of REEs and P transported with soil particles in runoff. The loss rates of REEs and P in surface runoff in the different soil types were in the order of loess soil > terra nera soil > cinnamon soil > red soil > purple soil. The total amounts of losses of REEs and P in runoff were significantly correlated.

  7. Carbon dioxide storage in marine sediments - dissolution, transport and hydrate formation kinetics from high-pressure experiments

    Science.gov (United States)

    Bigalke, N. K.; Savy, J. P.; Pansegrau, M.; Aloisi, G.; Kossel, E.; Haeckel, M.

    2009-12-01

    By satisfying thermodynamic framework conditions for CO2 hydrate formation, pressures and temperatures of the deep marine environment are unique assets for sequestering CO2 in clathrates below the seabed. However, feasibility and safety of this storage option require an accurate knowledge of the rate constants governing the speed of physicochemical reactions following the injection of the liquefied gas into the sediments. High-pressure experiments designed to simulate the deep marine environment open the possibility to obtain the required parameters for a wide range of oceanic conditions. In an effort to constrain mass transfer coefficients and transport rates of CO2 in(to) the pore water of marine sediments first experiments were targeted at quantifying the rate of CO2 uptake by de-ionized water and seawater across a two-phase interface. The nature of the interface was controlled by selecting p and T to conditions within and outside the hydrate stability field (HSF) while considering both liquid and gaseous CO2. Concentration increase and hydrate growth were monitored by Raman spectroscopy. The experiments revealed anomalously fast transport rates of dissolved CO2 at conditions both inside and outside the HSF. While future experiments will further elucidate kinetics of CO2 transport and hydrate formation, these first results could have major significance to safety-related issues in the discussion of carbon storage in the marine environment.

  8. Romanian experience in a assessment of the risk and environmental consequences due to radioactive materials transportation

    International Nuclear Information System (INIS)

    Vieru, Gheorghe

    2006-01-01

    Full text: The transport of radioactive materials (RAM) is a very important problem taking into consideration its potential risks over the environment and the radiological consequences of this activity. Romania as a Member State of the International Atomic Energy Agency has implemented national regulations for a safe transport of RAM in complying with the Agency's recommendations as well as other international specialized organizations. The paper will present the main sources of radioactive materials in Romania, and their transportation routes with a particular focus on the radioactive wastes (very low level and mixed low-level radioactive materials), radioactive isotopes and sources, and natural uranium ore. Starting from the fact that the safety in the transport of radioactive materials is dependent on packaging appropriate for the contents being shipped, rather than operational and/or administrative actions required for the package, the paper presents, very briefly, the qualification tests for the main packages used for transport and storage of RAM in Romania. There are presented also specific problems related to the identification and evaluation of the environmental risks and impacts as well as the potential radiological consequences associated with the transport of radioactive materials, for all those three possible situations: routine transport (without incidents), normal transport (with minor incidents) and during potential accidents. As a conclusion, it is stated that the evaluated annual collective dose for the population due to RAM transport is less than those received by natural radiation sources. At the same time it is concluded that Romanian made packages are safe and prevent loss of its radioactive contents into environment. (author)

  9. Experience in the analysis of accidents and incidents involving the transport of radioactive materials

    International Nuclear Information System (INIS)

    Warner-Jones, S.M.; Hughes, J.S.; Shaw, K.B.

    2002-01-01

    Some half a million packages containing radioactive materials are transported to, from and within the UK annually. Accidents and incidents involving these shipments are rare. However, there is always the potential for such an event, which could lead to a release of the contents of a package or an increase in radiation level caused by damaged shielding. These events could result in radiological consequences for transport workers. As transport occurs in the public environment, such events could also lead to radiation exposures of members of the public. The UK Department for Transport (DfT), together with the Health and Safety Executive (HSE) have supported, for almost 20 years, work to compile, analyse and report on accidents and incidents that occur during the transport of radioactive materials. Annual reports on these events have been produced for twelve years. The details of these events are recorded in the Radioactive Materials Transport Event Database (RAMTED) maintained by the National Radiological Protection Board on behalf of the DfT and HSE. Information on accidents and incidents dates back to 1958. RAMTED currently includes information of 708 accidents and incidents, covering the period 1958 to 2000. This paper presents a summary of the data covering this period, identifying trends and lessons learned together with a discussion of some examples. It was found that, historically, the most significant exposures were received as a result of accidents involving the transport of industrial radiography sources. However, the frequency and severity of these events has decreased considerably in the later years of this study due to improvements in training, awareness and equipment. The International Atomic Energy Agency and the Nuclear Energy Agency, have established the international nuclear event scale (INES), which is described in detail in a users' guide. The INES has been revised to fully include transport events, and the information in RAMTED has been reviewed

  10. Currents, pressure, temperature, conductivity, salinity, and attenuation data collected from moorings during the Lydonia Canyon Dynamics Experiment deployed from platforms OCEANUS, LULU, and WHITEFOOT from October 24, 1980 to November 11, 1982 (NCEI Accession 0054154)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A major field experiment to determine the importance of submarine canyons in sediment transport along and across the continental margin. The experiment included...

  11. European experience in the transport of irradiated light-water reactor fuel

    International Nuclear Information System (INIS)

    Curtis, H.W.

    1979-01-01

    Various methods of transport of irradiated fuel flasks in Europe are described. While many problems in the transport of heavy flasks have been solved some remain and new ones have appeared. Some of these problems are the accumulation of crud on the surface of fuel elements, the problems of failed fuel, stringent criticality criteria, the ''sweating out'' of contaminated flasks, the access, road or rail, to reactor sites, and the maintenance of the transport vehicles. Some future trends in the direction of heavy flasks in the range of 75 to 100 tonnes are indicated

  12. Training Drug Treatment Patients to Conduct Peer-Based HIV Outreach: An Ethnographic Perspective on Peers' Experiences

    Science.gov (United States)

    Guarino, Honoria; Deren, Sherry; Mino, Milton; Kang, Sung-Yeon; Shedlin, Michele

    2010-01-01

    From 2005 to 2008, the Bienvenidos Project trained Puerto Rican patients of New York City and New Jersey methadone maintenance treatment programs to conduct peer-based community outreach to migrant Puerto Rican drug users to reduce migrants' HIV risk behaviors. Ethnographic research, including focus groups, individual interviews and observations, was conducted with a subset of the patients trained as peers (n=49; 67% male; mean age 40.3 years) to evaluate the self-perceived effects of the intervention. Results of the ethnographic component of this study are summarized. The role of ethnographic methods in implementing and evaluating this kind of intervention is also discussed. PMID:20141456

  13. Colloid-Facilitated Transport of 137Cs in Fracture-Fill Material. Experiments and Modeling

    Energy Technology Data Exchange (ETDEWEB)

    Dittrich, Timothy M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Reimus, Paul William [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-10-29

    In this study, we demonstrate how a combination of batch sorption/desorption experiments and column transport experiments were used to effectively parameterize a model describing the colloid-facilitated transport of Cs in the Grimsel granodiorite/FFM system. Cs partition coefficient estimates onto both the colloids and the stationary media obtained from the batch experiments were used as initial estimates of partition coefficients in the column experiments, and then the column experiment results were used to obtain refined estimates of the number of different sorption sites and the adsorption and desorption rate constants of the sites. The desorption portion of the column breakthrough curves highlighted the importance of accounting for adsorption-desorption hysteresis (or a very nonlinear adsorption isotherm) of the Cs on the FFM in the model, and this portion of the breakthrough curves also dictated that there be at least two different types of sorption sites on the FFM. In the end, the two-site model parameters estimated from the column experiments provided excellent matches to the batch adsorption/desorption data, which provided a measure of assurance in the validity of the model.

  14. Recent transport experiments in W7-AS on the stellarator-tokamak comparison

    Energy Technology Data Exchange (ETDEWEB)

    Stroth, U [Association Euratom-Max-Planck-Institut fuer Plasmaphysik, Garching (Germany); Branas, B [Association Euratom-Max-Planck-Institut fuer Plasmaphysik, Garching (Germany); [Association EURATOM/CIEMAT, Madrid (Spain); Estrada, T [Association Euratom-Max-Planck-Institut fuer Plasmaphysik, Garching (Germany); [Association EURATOM/CIEMAT, Madrid (Spain); Giannone, L. [Association Euratom-Max-Planck-Institut fuer Plasmaphysik, Garching (Germany); Hartfuss, H J [Association Euratom-Max-Planck-Institut fuer Plasmaphysik, Garching (Germany); Hirsch, M [Association Euratom-Max-Planck-Institut fuer Plasmaphysik, Garching (Germany); Kick, M [Association Euratom-Max-Planck-Institut fuer Plasmaphysik, Garching (Germany); Kuener, G [Association Euratom-Max-Planck-Institut fuer Plasmaphysik, Garching (Germany); Sattler, S [Association Euratom-Max-Planck-Institut fuer Plasmaphysik, Garching (Germany); Baldzuhn, J [Association Euratom-Max-Planck-Institut fuer Plasmaphysik, Garching (Germany); Brakel, R [Association Euratom-Max-Planck-Institut fuer Plasmaphysik, Garching (Germany); Erckmann, V [Association Euratom-Max-Planck-Institut fuer Plasmaphysik, Garching (Germany); Jaenicke, R [Association Euratom-Max-Planck-Institut fuer Plasmaphysik, Garching (Germany); Ringler, H [Association Euratom-Max-Planck-Institut fuer Plasmaphysik, Garching (Germany); Wagner, F [Association Euratom-Max-Planck-Institut fuer Plasmaphysik, Garching (Germany); ECRH Group; W7-AS Team

    1995-05-01

    Parameter scans in density, heating power and isotope mass have been carried out in W7-AS. ECRH at a frequency of 140 GHz has allowed to study the density scaling of the energy confinement time of ECRH plasmas up to densities of 10{sup 20} m{sup -3}. In power scans it has been tried to relate the power degradation of the energy confinement to a local plasma parameter. Transport analyses using power balance an heat wave techniques indicate that the transport coefficient does not depend on the electron temperature or related parameters. This observation can be reconciled with power degradation if the transport coefficient is formally allowed to vary with changes in the heating power on a faster than the diffusive time scale. Such a transport process describes also the observations in the dynamic phases following large changes in the heating power. (orig.).

  15. Recent transport experiments in W7-AS on the stellarator-tokamak comparison

    International Nuclear Information System (INIS)

    Stroth, U.; Branas, B.; Estrada, T.; Giannone, L.; Hartfuss, H.J.; Hirsch, M.; Kick, M.; Kuener, G.; Sattler, S.; Baldzuhn, J.; Brakel, R.; Erckmann, V.; Jaenicke, R.; Ringler, H.; Wagner, F.

    1995-01-01

    Parameter scans in density, heating power and isotope mass have been carried out in W7-AS. ECRH at a frequency of 140 GHz has allowed to study the density scaling of the energy confinement time of ECRH plasmas up to densities of 10 20 m -3 . In power scans it has been tried to relate the power degradation of the energy confinement to a local plasma parameter. Transport analyses using power balance an heat wave techniques indicate that the transport coefficient does not depend on the electron temperature or related parameters. This observation can be reconciled with power degradation if the transport coefficient is formally allowed to vary with changes in the heating power on a faster than the diffusive time scale. Such a transport process describes also the observations in the dynamic phases following large changes in the heating power. (orig.)

  16. The conceptual mismatch: transportation stressors and experiences for low-income adults.

    Science.gov (United States)

    2015-10-01

    Physical access to jobs has long been identified as a barrier to employment and earnings, with prior : research identifying the spatial mismatch between suburban entry-level jobs and low-income workers. : However, existing transportation resear...

  17. The Air Force’s Experience with Should-Cost Reviews and Options for Enhancing Its Capability to Conduct Them

    Science.gov (United States)

    2012-01-01

    contractor that will be given the opportunity to continue development into EMD.1 Competitors for these contracts have a large incentive to bid low in...and mutual financial benefits are purposes in conducting these analyses. Commercial manufacturers including Toyota , Whirlpool, and LG Electronics use

  18. Preparing Practitioners to Conduct Educational Research and Evaluation: What the Research Says and What Our Experiences Taught Us

    Science.gov (United States)

    Mansfield, Katherine Cumings; Stacy, Jaime

    2017-01-01

    The purpose of this article is to share the insights gleaned from the literature and our on-the-ground realities teaching practitioners to conduct educational research and evaluation. We focus on four areas we have found most important for teaching practitioner-scholars: (a) giving careful attention to andragogy versus pedagogy, (b) engaging the…

  19. Evaluation of long-term patient satisfaction and experience with the Baha(®) bone conduction implant

    DEFF Research Database (Denmark)

    Rasmussen, Jacob; Olsen, Steen Østergaard; Nielsen, Lars Holme

    2012-01-01

    Objective: Evaluate long-term patient satisfaction with bone-anchored hearing aids (the Baha(R), now referred to by Cochlear as a 'bone conduction implant') in our hospital clinic spanning the eighteen-year period from the inception of our Baha program. The researchers further wished to analyse t...

  20. Trans-European transport networks influence on the regional development and urban systems: Serbian experience

    OpenAIRE

    Maksin-Mićić Marija

    2004-01-01

    The trans-European transport network has different effects at macro-regional, mezzo-regional and micro-regional level, and on urban systems development, and its effectiveness rises at the lower regional levels. Possible approaches to the trans-European transport network impact and effect survey and policy options have been pointed out. The importance of increased accessibility and mobility for regional expansion and for more balanced and polycentric system of city networks has been underlined...

  1. Liability problems of international transportation of nuclear material: The Canadian experience

    International Nuclear Information System (INIS)

    Schwartz, J.A.

    1986-01-01

    Canadian law in the field of transportation of radioactive materials has largely adopted international standards. Most of the respective laws, however, are as yet untested in court. According to the author it is likely that a broad and liberal interpretation will be given to all of the provisions which entitle injured parties to seek recourse against a transporter who has negligently carried out the duties imposed upon him. (CW) [de

  2. Transport of Cryptosporidium parvum Oocysts in Charge Heterogeneous Porous Media: Microfluidics Experiment and Numerical Simulation

    Science.gov (United States)

    Liu, Y.; Meng, X.; Guo, Z.; Zhang, C.; Nguyen, T. H.; Hu, D.; Ji, J.; Yang, X.

    2017-12-01

    Colloidal attachment on charge heterogeneous grains has significant environmental implications for transport of hazardous colloids, such as pathogens, in the aquifer, where iron, manganese, and aluminium oxide minerals are the major source of surface charge heterogeneity of the aquifer grains. A patchwise surface charge model is often used to describe the surface charge heterogeneity of the grains. In the patchwise model, the colloidal attachment efficiency is linearly correlated with the fraction of the favorable patches (θ=λ(θf - θu)+θu). However, our previous microfluidic study showed that the attachment efficiency of oocysts of Cryptosporidium parvum, a waterborne protozoan parasite, was not linear correlated with the fraction of the favorable patches (λ). In this study, we developed a pore scale model to simulate colloidal transport and attachment on charge heterogeneous grains. The flow field was simulated using the LBM method and colloidal transport and attachment were simulated using the Lagrange particle tracking method. The pore scale model was calibrated with experimental results of colloidal and oocyst transport in microfluidic devices and was then used to simulate oocyst transport in charge heterogeneous porous media under a variety of environmental relative conditions, i.e. the fraction of favorable patchwise, ionic strength, and pH. The results of the pore scale simulations were used to evaluate the effect of surface charge heterogeneity on upscaling of oocyst transport from pore to continuum scale and to develop an applicable correlation between colloidal attachment efficiency and the fraction of the favorable patches.

  3. Edge-core interaction revealed with dynamic transport experiment in LHD

    International Nuclear Information System (INIS)

    Tamura, N.; Ida, K.; Inagaki, S.

    2010-11-01

    Large scale coherent structures in electron heat transport of both core and edge plasmas are clearly found in plasma with a nonlocal transport phenomenon (NTP, a core electron temperature rise in response to an edge cooling) on Large Helical Device (LHD). At the onset of the NTP, a first order transition of the electron heat transport, which is characterized by a discontinuity of electron temperature gradient, is found to take place over a wide region (at least 6 cm wide) in the periphery of the plasma. At about the same time, over a wide region (about 10 cm wide) of the plasma core, a second order transition of the electron heat transport, which is characterized by a discontinuity of the time derivative of the electron temperature gradient, appears. The both large scale coherent structures are of a scale larger than a typical micro-turbulent eddy size (a few mm in this case). In order to assess dynamic characteristics of the electron heat transport state in the core region during the NTP, a transit time distribution analysis is applied to the temporal behaviors of the electron temperature gradient. The analysis results more clearly show the existence of the large coherent structures in electron heat transport. Thus the NTP observed in LHD is considered to be invoked by the interaction of those structures. (author)

  4. Trans-European transport networks influence on the regional development and urban systems: Serbian experience

    Directory of Open Access Journals (Sweden)

    Maksin-Mićić Marija

    2004-01-01

    Full Text Available The trans-European transport network has different effects at macro regional mezzo-regional and micro-regional level, and its effectiveness rises with the lower regional levels. Possible approaches to the trans-European transport network impact and effect survey and policy options have been pointed out. The importance of increased accessibility and mobility for regional expansion and for a more balanced and polycentric system of city networks has been underlined. Changes in the spatial organization utilization and structure of cities, as well as in social benefits and losses subsequent to impacts of trans-European transport corridor "X" section Belgrade-Niš have been analyzed. The new trans-European or major transport infrastructure does not per se create regional and urban system network development, although it can affect the conditions for the processes that create growth and development. The effects can be increased by co-ordination of measures of regional, spatial and urban policy, land use transport, environmental and other policies. The necessary measure is the introduction of spatial impact assessment as sartorial policy instrument for the large transport infrastructure plans and projects.

  5. World-wide French experience in research reactor fuel cycle transportation

    International Nuclear Information System (INIS)

    Raisonnier, D.

    1997-01-01

    Since 1963 Transnucleaire has safely performed a large number of national and international transports of radioactive material. Transnucleaire has also designed and supplied suitable packagings for all types of nuclear fuel cycle radioactive material from front-end and back-end products and for power or for research reactors. Transportation of the nuclear fuel material for power reactors is made on a regular and industrial basis. The transportation of material for the research reactor fuel cycle is quite different due to the small quantities involved, the categorisation of material and the numerous places of delivery world-wide. Adapted solutions exist, which require a reactive organisation dealing with all the transportation issues for LEU and HEU products as metal, oxide, fresh fuel elements, spent fuel elements including supply of necessary transport packaging and equipment. This presentation will: - explain the choices made by Transnucleaire and its associates to provide and optimise the corresponding services, - demonstrate the capability to achieve, through reliable partnership, transport operations involving new routes, specific equipment and new political constraints while respecting sophisticated safety and security regulations. (author)

  6. Transport in the plasma edge specific connection to the wall in the Tore Supra ergodic divertor experiments

    International Nuclear Information System (INIS)

    Grosman, A.; Ghendrih, P.; DeMichelis, C.; Monier-Garbet, P.; Vallet, J.C.; Capes, H.; Chatelier, M.; Geraud, A.; Goniche, M.; Grisolia, C.; Guilhem, D.; Harris, G.; Hess, W.; Nguyen, F.; Poutchy, L.; Samain, A.

    1992-01-01

    The ergodic divertor experiments in TORE SUPRA can be analysed along two main lines. The first one refers to the change of the heat and particle transport in the ergodized zone. This is especially true for the electron heat transport which is enhanced in the edge layer. But other distinctive features give evidence of the importance of the parallel connexion length between the plasma edge and the wall. The field lines, which are stochastic in the major part of the perturbed layer (10-15 cm) are such that, in the outermost layer (3 cm), the connexion topology is regular. This has obvious effects on the particle and power deposition, but also on the plasma parameters, and consequently influences the particle recycling and impurity shielding processes. The TORE SUPRA ergodic divertor experiments are reviewed in this framework

  7. Model Simulations of a Field Experiment on Cation Exchange-affected Multicomponent Solute Transport in a Sandy Aquifer

    DEFF Research Database (Denmark)

    Bjerg, Poul Løgstrup; Ammentorp, Hans Christian; Christensen, Thomas Højlund

    1993-01-01

    A large-scale and long-term field experiment on cation exchange in a sandy aquifer has been modelled by a three-dimensional geochemical transport model. The geochemical model includes cation-exchange processes using a Gaines-Thomas expression, the closed carbonate system and the effects of ionic...... by batch experiments and by the composition of the cations on the exchange complex. Potassium showed a non-ideal exchange behaviour with K&z.sbnd;Ca selectivity coefficients indicating dependency on equivalent fraction and K+ concentration in the aqueous phase. The model simulations over a distance of 35 m...... and a period of 250 days described accurately the observed attenuation of Na and the expelled amounts of Ca and Mg. Also, model predictions of plateau zones, formed by interaction with the background groundwater, in general agreed satisfactorily with the observations. Transport of K was simulated over a period...

  8. Spent fuel storage and transport cask decontamination and modification. An overview of management requirements and applications based on practical experience

    International Nuclear Information System (INIS)

    1999-04-01

    A large increase in the number of casks required for transport and/or storage of spent fuel is forecast into the next century. The principal requirement will be for increased number of storage and dual purpose (transport/storage) casks for interim storage of spent fuel prior to reprocessing or permanent disposal in both on-site and off-site storage facilities. Through contact with radioactive materials spent fuel casks will be contaminated on both internal and external surfaces. In broad terms, cask contamination management can be defined by three components: minimisation, prevention and decontamination. This publication is a compilation of international experience with cask contamination problems and decontamination practices. The objective is to present current knowledge and experience as well as developments, trends and potential for new applications in this field. Furthermore, the report may assist in new design or modification of existing casks, cask handling systems and decontamination equipment

  9. Heights integrated model as instrument for simulation of hydrodynamic, radiation transport, and heat conduction phenomena of laser-produced plasma in EUV applications.

    Energy Technology Data Exchange (ETDEWEB)

    Sizyuk, V.; Hassanein, A.; Morozov, V.; Sizyuk, T.; Mathematics and Computer Science

    2007-01-16

    The HEIGHTS integrated model has been developed as an instrument for simulation and optimization of laser-produced plasma (LPP) sources relevant to extreme ultraviolet (EUV) lithography. The model combines three general parts: hydrodynamics, radiation transport, and heat conduction. The first part employs a total variation diminishing scheme in the Lax-Friedrich formulation (TVD-LF); the second part, a Monte Carlo model; and the third part, implicit schemes with sparse matrix technology. All model parts consider physical processes in three-dimensional geometry. The influence of a generated magnetic field on laser plasma behavior was estimated, and it was found that this effect could be neglected for laser intensities relevant to EUV (up to {approx}10{sup 12} W/cm{sup 2}). All applied schemes were tested on analytical problems separately. Benchmark modeling of the full EUV source problem with a planar tin target showed good correspondence with experimental and theoretical data. Preliminary results are presented for tin droplet- and planar-target LPP devices. The influence of three-dimensional effects on EUV properties of source is discussed.

  10. Radiation Transport

    Energy Technology Data Exchange (ETDEWEB)

    Urbatsch, Todd James [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-06-15

    We present an overview of radiation transport, covering terminology, blackbody raditation, opacities, Boltzmann transport theory, approximations to the transport equation. Next we introduce several transport methods. We present a section on Caseology, observing transport boundary layers. We briefly broach topics of software development, including verification and validation, and we close with a section on high energy-density experiments that highlight and support radiation transport.

  11. Batch and column studies of adsorption of Li, Ni and Br by a reference sand for contaminant transport experiments

    International Nuclear Information System (INIS)

    Seigel, M.D.; Ward, D.B.; Bryan, C.R.

    1995-09-01

    A processed quartz sand (Wedron 510), mined from the St. Peter sandstone, has been characterized by a variety of chemical and physical methods for use as a reference porous media in transport model validation experiments. Wedron 510 sand was used in an intermediate-scale experiment involving migration of Ni, Li and Br through a 6-m high x 3-m diameter caisson. Ni and Li adsorption/desorption, and Li/Ni site-competition experiments yielded information on the importance of the trace mineral phases to adsorption of Li and Ni by the sand. The presence of an iron hydroxide coating similar to goethite on the sand grains is suggested by visual observation and leaching experiments. Kaolinite was identified by SEM and XRD as a significant trace mineral phase in the sand and occurs as small particles coating the sand grains. Quartz, the predominant constituent of the sand by weight, does not appear to contribute significantly to the adsorption properties of the sand. Qualitatively, the adsorption properties of the sand can be adequately modeled as a two-mineral system (goethite and kaolinite). The studies described in this report should provide a basis for understanding transport of Ni, Li and Br through porous media similar to the reference sand. Techniques were developed for obtaining parameter values for surface complexation and kinetic adsorption models for the sand and its mineral components. These constants can be used directly in coupled hydrogeochemical transport codes. The techniques should be useful for characterization of other natural materials and elements in high-level nuclear waste in support of coupled hydrogeochemical transport calculations for Yucca Mountain

  12. Anisotropy, reversibility and scale dependence of transport properties in single fracture and fractured zone - Non-sorbing tracer experiment at the Kamaishi mine

    International Nuclear Information System (INIS)

    Sawada, Atushi; Uchida, Masahiro; Shimo, Michito; Yamamoto, Hajime; Takahara, Hiroyuki; Doe, T.W.

    2001-01-01

    A comprehensive set of the non-sorbing tracer experiments were run in the granodiorite of the Kamaishi mine located in the northern part of the main island of Japan-Honshu. A detailed geo-hydraulic investigation was carried out prior to performing the tracer migration experiments. The authors conducted a detailed but simple investigation in order to understand the spatial distribution of conductive fractures and the pressure field. Seven boreholes were drilled in the test area of which dimension is approximately 80 meters by 60 meters, revealing hydraulic compartmentalization and a heterogeneous distribution of conductive features. Central three boreholes which are approx. 2 to 4 meters apart form a triangle array. After identifying two hydraulically isolated fractures and one fractured zone, a comprehensive non-sorbing tracer experiments were conducted. Four different dipole fields were used to study the heterogeneity within a fracture. Firstly, anisotropy was studied using the central borehole array of three boreholes and changing injection/withdrawal wells. Secondly, dipole ratio was varied to study how prume spread could affect the result. Thirdly, reversibility was studied by switching injection/withdrawal wells. Lastly, scale dependency was studied by using outer boreholes. The tracer breakthrough curves were analyzed by using a streamline, analytical solution and numerical analysis of mass transport. Best-fit calculations of the experimental breakthrough curves were obtained by assigning apertures within the range of 1-10 times the square root of transmissivity and a dispersion length equal to 1/10 of the migration length. Different apertures and dispersion lengths were also interpreted in anisotropy case, reversibility case and scale dependency case. Fractured zone indicated an increased aperture and increased dispersivity

  13. Exploring midwifery students' views and experiences of caseload midwifery: A cross-sectional survey conducted in Victoria, Australia.

    Science.gov (United States)

    Dawson, Kate; Newton, Michelle; Forster, Della; McLachlan, Helen

    2015-02-01

    in Australia, models of maternity care that offer women continuity of care with a known midwife have been promoted. Little is known about the intentions of the future midwifery workforce to work in such models. This study aimed to explore midwifery students' views and experiences of caseload midwifery and their work intentions in relation to the caseload model following graduation. cross-sectional survey. Victoria, Australia. 129 midwifery students representing all midwifery course pathways (Post Graduate Diploma, Bachelor of Midwifery, Bachelor of Nursing/Bachelor of Midwifery) in Victoria. midwifery students from all course pathways considered that continuity of care is important to women and indicated that exposure to continuity models during their course was very positive. Two-thirds of the students (67%) considered that the continuity experiences made them want to work in a caseload model; only 5% reported that their experiences had discouraged them from continuity of care work in the future. Most wanted a period of consolidation to gain experience as a midwife prior to commencing in the caseload model. Perceived barriers to caseload work were being on-call, and challenges in regard to work/life balance and family commitments. midwifery students in this study were very positive about caseload midwifery and most would consider working in caseload after a period of consolidation. Continuity of care experiences during students' midwifery education programmes appeared to provide students with insight and understanding of continuity of care for both women and midwives. Further research should explore what factors influence students' future midwifery work, whether or not their plans are fulfilled, and whether or not the caseload midwifery workforce can be sustained. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. Quantized Majorana conductance

    Science.gov (United States)

    Zhang, Hao; Liu, Chun-Xiao; Gazibegovic, Sasa; Xu, Di; Logan, John A.; Wang, Guanzhong; van Loo, Nick; Bommer, Jouri D. S.; de Moor, Michiel W. A.; Car, Diana; Op Het Veld, Roy L. M.; van Veldhoven, Petrus J.; Koelling, Sebastian; Verheijen, Marcel A.; Pendharkar, Mihir; Pennachio, Daniel J.; Shojaei, Borzoyeh; Lee, Joon Sue; Palmstrøm, Chris J.; Bakkers, Erik P. A. M.; Sarma, S. Das; Kouwenhoven, Leo P.

    2018-04-01

    Majorana zero-modes—a type of localized quasiparticle—hold great promise for topological quantum computing. Tunnelling spectroscopy in electrical transport is the primary tool for identifying the presence of Majorana zero-modes, for instance as a zero-bias peak in differential conductance. The height of the Majorana zero-bias peak is predicted to be quantized at the universal conductance value of 2e2/h at zero temperature (where e is the charge of an electron and h is the Planck constant), as a direct consequence of the famous Majorana symmetry in which a particle is its own antiparticle. The Majorana symmetry protects the quantization against disorder, interactions and variations in the tunnel coupling. Previous experiments, however, have mostly shown zero-bias peaks much smaller than 2e2/h, with a recent observation of a peak height close to 2e2/h. Here we report a quantized conductance plateau at 2e2/h in the zero-bias conductance measured in indium antimonide semiconductor nanowires covered with an aluminium superconducting shell. The height of our zero-bias peak remains constant despite changing parameters such as the magnetic field and tunnel coupling, indicating that it is a quantized conductance plateau. We distinguish this quantized Majorana peak from possible non-Majorana origins by investigating its robustness to electric and magnetic fields as well as its temperature dependence. The observation of a quantized conductance plateau strongly supports the existence of Majorana zero-modes in the system, consequently paving the way for future braiding experiments that could lead to topological quantum computing.

  15. Compendium of NASA data base for the global tropospheric experiment's Transport and Atmospheric Chemistry Near the Equator-Atlantic (TRACE-A)

    Science.gov (United States)

    Gregory, Gerald L.; Scott, A. Donald, Jr.

    1995-01-01

    This compendium describes aircraft data that are available from NASA's Transport and Atmospheric Chemistry near the Equator - Atlantic (TRACE-A) conducted in September/October 1992. The broad objectives of TRACE-A were to study chemical processes and long-range transport associated with South American and African continental outflow during periods of widespread vegetation burning, and to understand the ozone enhancements observed from satellite data measured over the southern tropical Atlantic Ocean during the September/October time period. Flight experiments were conducted from Brazil, South Africa, Namibia, and the Ascension Island. This document provides a representation of aircraft data that are available from NASA Langley's Distributed Active Archive Center (DAAC). The data format of time series and altitude profile plots is not intended to support original analyses, but to assist the reader in identifying data that are of interest. This compendium is for only the NASA aircraft data. The DAAC data base includes numerous supporting data-meteorological products, results from surface studies, satellite observations, and data from sonde releases.

  16. Large-scale Experiment for Water and Gas Transport in Cementitious Backfill Materials (Phase 1 ): COLEX I

    International Nuclear Information System (INIS)

    Mayer, G.; Wittmann, F.H.; Moetsch, H.A.

    1998-05-01

    In the planned Swiss repository for low- and intermediate-level radioactive waste, the voids between the waste containers will be backfilled with a highly permeable mortar (NAGRA designation: mortar M1 ). As well as providing mechanical stability through filling of voids and sorbing radionuclides, the mortar must divert gases formed in the repository as a result of corrosion into the neighbouring host rock. This will prevent damage which could be caused by excess pressure on the repository structures. Water transport, which is coupled to gas transport, is also of interest. The former is responsible for the migration of radionuclides. Up till now, numerical simulations for a repository situation were carried out using transport parameters determined for small samples in the laboratory. However, the numerical simulations still had to be validated by a large-scale experiment. The investigations presented here should close this gap. Investigations into gas and water transport were carried out using a column (up to 5.4 m high) filled with backfill mortar. The column has a modular construction and can be sealed at the top end with a material of defined permeability (plug or top plug). The possibility to vary the material of the plug allows the influence of the more impermeable cavern lining or possible gas escape vents in the cavern roof to be investigated. A gas supply is connected to the bottom end and is used to simulate different gas generation rates from the waste. A total of 5 experiments were carried out in which the gas generation rate, the column height and the permeability of the plug were varied. Before the start of the experiments, the mortar in the column and the plug were saturated with water to approx. 95 %. In all the experiments, an increase in pressure with time could be observed. The higher the gas generation rate and the lower the permeability of the plug, the more quickly this occurred. At the beginning, only water flow out of the top of the column

  17. Methane and CO2 Adsorption and Transport in Carbon-based Systems from Experiments and Molecular Simulation

    Science.gov (United States)

    Wilcox, Jennifer; Firouzi, Mahnaz; Rupp, Erik; Haghapanah, Reza; Wang, Beibei

    2013-04-01

    Carbon capture and sequestration is one strategy that could potentially mitigate gigatons of CO2 emissions per year; however, technical obstacles have thus far hindered wide-scale deployment of this strategy. To design efficient and reliable strategies for either carbon capture or sequestration at the full-scale, one needs to understand the chemical and physical properties of CO2 and its interaction with its local surroundings at the molecular-scale. To investigate the chemical and physical properties of CO2 and its local surroundings at the molecular-scale, surface characterization studies are carried out alongside theoretical model efforts. Experimental investigation of CO2 interactions with organic-based porous materials ranging in complexity from functionalized graphene and activated carbon to various-rank coal and gas shale samples to create a set of realistic models that take into account both surface and pore heterogeneity. Integration of theory and experiments takes place to allow for the relevant physics at the molecular-level to be revealed. Determining adsorption and transport phenomena of CO2 (and mixtures, including H2O, and CH4) within the model pore systems can be used to understand the complex pore matrices of carbon-based sorbents, coal, and the organic components of gas shale that are crucial to determining their carbon capture or sequestration potential. Non-equilibrium molecular dynamics (NEMD) simulations of pure carbon dioxide, methane, helium and their mixtures have been carried out in carbon slit pores to investigate gas slippage and Klinkenberg effects in the organic matrices of coal and gas shale rocks. NEMD techniques are ideally suited for the experimental situation in which an external driving force, such as a chemical potential or pressure gradient, are applied on the system. Simulations have been conducted to determine the effect of pore size and exposure to an external potential on the velocity profile and slip-stick boundary

  18. Simulating surface oil transport during the Deepwater Horizon oil spill: Experiments with the BioCast system

    Science.gov (United States)

    Jolliff, Jason Keith; Smith, Travis A.; Ladner, Sherwin; Arnone, Robert A.

    2014-03-01

    The U.S. Naval Research Laboratory (NRL) is developing nowcast/forecast software systems designed to combine satellite ocean color data streams with physical circulation models in order to produce prognostic fields of ocean surface materials. The Deepwater Horizon oil spill in the Gulf of Mexico provided a test case for the Bio-Optical Forecasting (BioCast) system to rapidly combine the latest satellite imagery of the oil slick distribution with surface circulation fields in order to produce oil slick transport scenarios and forecasts. In one such sequence of experiments, MODIS satellite true color images were combined with high-resolution ocean circulation forecasts from the Coupled Ocean-Atmosphere Mesoscale Prediction System (COAMPS®) to produce 96-h oil transport simulations. These oil forecasts predicted a major oil slick landfall at Grand Isle, Louisiana, USA that was subsequently observed. A key driver of the landfall scenario was the development of a coastal buoyancy current associated with Mississippi River Delta freshwater outflow. In another series of experiments, longer-term regional circulation model results were combined with oil slick source/sink scenarios to simulate the observed containment of surface oil within the Gulf of Mexico. Both sets of experiments underscore the importance of identifying and simulating potential hydrodynamic conduits of surface oil transport. The addition of explicit sources and sinks of surface oil concentrations provides a framework for increasingly complex oil spill modeling efforts that extend beyond horizontal trajectory analysis.

  19. Healthcare professionals' self-reported experiences and preferences related to direct healthcare professional communications: a survey conducted in the Netherlands

    OpenAIRE

    Piening, Sigrid; Haaijer-Ruskamp, Flora M.; de Graeff, Pieter A.; Straus, Sabine M. J. M.; Mol, Peter G. M.

    2012-01-01

    Background: In Europe, Direct Healthcare Professional Communications (DHPCs) are important tools to inform healthcare professionals of serious, new drug safety issues. However, this tool has not always been successful in effectively communicating the desired actions to healthcare professionals. Objective: The aim of this study was to explore healthcare providers' experiences and their preferences for improvement of risk communication, comparing views of general practitioners (GPs), internists...

  20. DIRECT OBSERVATION OF THE TURBULENT emf AND TRANSPORT OF MAGNETIC FIELD IN A LIQUID SODIUM EXPERIMENT

    Energy Technology Data Exchange (ETDEWEB)

    Rahbarnia, Kian; Brown, Benjamin P.; Clark, Mike M.; Kaplan, Elliot J.; Nornberg, Mark D.; Rasmus, Alex M.; Taylor, Nicholas Zane; Forest, Cary B. [Department of Physics, University of Wisconsin-Madison, 1150 University Ave, Madison, WI 53706 (United States); Jenko, Frank; Limone, Angelo [Max-Planck-Institut fuer Plasmaphysik (IPP), EURATOM Association, D-85748 Garching (Germany); Pinton, Jean-Francois; Plihon, Nicolas; Verhille, Gautier, E-mail: kian.rahbarnia@ipp.mpg.de [Laboratoire de Physique de l' Ecole Normale Superieure de Lyon, CNRS and Universite de Lyon, F-69364 Lyon (France)

    2012-11-10

    For the first time, we have directly measured the transport of a vector magnetic field by isotropic turbulence in a high Reynolds number liquid metal flow. In analogy with direct measurements of the turbulent Reynolds stress (turbulent viscosity) that governs momentum transport, we have measured the turbulent electromotive force (emf) by simultaneously measuring three components of velocity and magnetic fields, and computed the correlations that lead to mean-field current generation. Furthermore, we show that this turbulent emf tends to oppose and cancel out the local current, acting to increase the effective resistivity of the medium, i.e., it acts as an enhanced magnetic diffusivity. This has important implications for turbulent transport in astrophysical objects, particularly in dynamos and accretion disks.

  1. A first experience with a Smart bus for improving public transportation

    Science.gov (United States)

    Tostado, R.; Rovirosa, A.; Velázquez, J. L.; Castillo, E.; Cervantes, O.

    2017-09-01

    An alternative to optimize transportation services in the city of Puebla is presented. Main problems tackled to provide advanced transport applications in a Smart City, are described and some available solutions in other countries are analyzed. As a case of study, the challenges for designing and developing a mobile application oriented to users of the buses provided by Universidad de las Américas Puebla (UDLAP) are presented. Users include students, as well as faculty members and administrative employees. The application provides an innovative way of tracking, in real time, movements of the UDLAP transportation buses through the city of Puebla in Mexico. Modeling and technical implementation solved problems are presented and future steps for extending those services to the city of Puebla are also suggested.

  2. DIRECT OBSERVATION OF THE TURBULENT emf AND TRANSPORT OF MAGNETIC FIELD IN A LIQUID SODIUM EXPERIMENT

    International Nuclear Information System (INIS)

    Rahbarnia, Kian; Brown, Benjamin P.; Clark, Mike M.; Kaplan, Elliot J.; Nornberg, Mark D.; Rasmus, Alex M.; Taylor, Nicholas Zane; Forest, Cary B.; Jenko, Frank; Limone, Angelo; Pinton, Jean-François; Plihon, Nicolas; Verhille, Gautier

    2012-01-01

    For the first time, we have directly measured the transport of a vector magnetic field by isotropic turbulence in a high Reynolds number liquid metal flow. In analogy with direct measurements of the turbulent Reynolds stress (turbulent viscosity) that governs momentum transport, we have measured the turbulent electromotive force (emf) by simultaneously measuring three components of velocity and magnetic fields, and computed the correlations that lead to mean-field current generation. Furthermore, we show that this turbulent emf tends to oppose and cancel out the local current, acting to increase the effective resistivity of the medium, i.e., it acts as an enhanced magnetic diffusivity. This has important implications for turbulent transport in astrophysical objects, particularly in dynamos and accretion disks.

  3. Some in-reactor loop experiments on corrosion product transport and water chemistry

    International Nuclear Information System (INIS)

    Balakrishnan, P.V.; Allison, G.M.

    1978-01-01

    A study of the transport of activated corrosion products in the heat transport circuit of pressurized water-cooled nuclear reactors using an in-reactor loop showed that the concentration of particulate and dissolved corrosion products in the high-temperature water depends on such chemical parameters as pH and dissolved hydrogen concentration. Transients in these parameters, as well as in temperature, generally increase the concentration of suspended corrosion products. The maximum concentration of particles observed is much reduced when high-flow, high-temperature filtration is used. Filtration also reduces the steady-state concentration of particles. Dissolved corrosion products are mainly responsible for activity accumulation on surfaces. The data obtained from this study were used to estimate the rate constants for some of the transfer processes involved in the contamination of the primary heat transport circuit in water-cooled nuclear power reactors

  4. CATHARE 2 analysis of the small break LOCA experiment SP-SB-03, conducted in SPES facility

    International Nuclear Information System (INIS)

    Meloni, P.

    1995-01-01

    SPES integral test facility is a scale model of a commercial three-loop PWR plant, making the simulation of a wide range of accident scenarios possible. A Small Break Loss of Coolant test was carried out in this facility in 1991 to serve as a counterpart of tests conducted on BETHSY (France), LSTF (Japan) and LOBI (EC) facilities. A post-test analysis of this test, performed with CATHARE 2 code was realized by ENEA in the framework of the co-operation ENEA-CEA on advanced reactors. This paper presents a survey of the results of the post-test calculation. (author). 5 refs, 11 figs, 3 tabs

  5. X-ray absorption and reflection as probes of the GaN conduction bands: Theory and experiments

    Energy Technology Data Exchange (ETDEWEB)

    Lambrecht, W.R.L.; Rashkeev, S.N.; Segall, B. [Case Western Reserve Univ., Cleveland, OH (United States)] [and others

    1997-04-01

    X-ray absorption measurements are a well-known probe of the unoccupied states in a material. The same information can be obtained by using glancing angle X-ray reflectivity. In spite of several existing band structure calculations of the group III nitrides and previous optical studies in UV range, a direct probe of their conduction band densities of states is of interest. The authors performed a joint experimental and theoretical investigation using both of these experimental techniques for wurtzite GaN.

  6. Experience with contamination protection of spent fuel transport packages in Germany since 2000/2001

    International Nuclear Information System (INIS)

    Krinninger, H.; Bach, R.; Seidel, J.; Jung, P.

    2004-01-01

    On April 30, 1998 just a few days before the PATRAM 1998 conference at Paris, the French Nuclear Installations Safety Directorate (DSIN now DGSNR) published a press release, that during the year before some 35% of the spent fuel transports to the reprocessing plant of COGEMA at La Hague have non-fixed surface contamination in excess of the regulatory standard. A few day in advance DSIN informed in French Ministries and the competent foreign authorities of the customer countries of COGEMA. The consequences of this publication were multi-fold and perceived by the public as an act negligence of the nuclear industry. Because of concerns about additional radiation exposure to the railway workers by the unions the French Railway company SNCF suspended all transports by May 6, 1998 until implementation of corrective measures. This decision of SNF interupted also the spent fuel transports from continental Europe to the reprocessing plant of BNFL at Sellafield all performed across France to the port of Dunkirk. Furthermore on May 25, 1998 the German Federal Ministry of Environment, Nature Protection and Nuclear Safety (BMU) imposed a transport ban for shipment of spent fuel from commercial power plants and for high active waste returned from La Hague to the Gorleben site. The conditions for resumption of these transports were outlined by NMU in a 10-point programme. In response to these publications on contamination findings competent German State and Federal Authorities commissioned investigations by independent experts dealing with the identification of the causes, the proposal of counter measures, the investigation of shortcomings in the transport system in general and recommendations for retification of it

  7. Tungsten impurity transport experiments in Alcator C-Mod to address high priority research and development for ITER

    Energy Technology Data Exchange (ETDEWEB)

    Loarte, A.; Polevoi, A. R.; Hosokawa, M. [ITER Organization, Route de Vinon-sur-Verdon, CS 90 046, 13067 St Paul Lez Durance Cedex (France); Reinke, M. L. [York Plasma Institute, Department of Physics, University of York, Heslington, York YO10 5DD (United Kingdom); Chilenski, M.; Howard, N.; Hubbard, A.; Hughes, J. W.; Rice, J. E.; Walk, J. [Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Köchl, F. [Technische Universität Wien, Atominstitut, Stadionallee 2, 1020 Vienna (Austria); Pütterich, T.; Dux, R. [Max-Planck-Institut für Plasmaphysik, Boltzmanstraße 2, D-85748 Garching (Germany); Zhogolev, V. E. [NRC “Kurchatov Institute,” Kurchatov Square 1, 123098 Moscow (Russian Federation)

    2015-05-15

    Experiments in Alcator C-Mod tokamak plasmas in the Enhanced D-alpha H-mode regime with ITER-like mid-radius plasma density peaking and Ion Cyclotron Resonant heating, in which tungsten is introduced by the laser blow-off technique, have demonstrated that accumulation of tungsten in the central region of the plasma does not take place in these conditions. The measurements obtained are consistent with anomalous transport dominating tungsten transport except in the central region of the plasma where tungsten transport is neoclassical, as previously observed in other devices with dominant neutral beam injection heating, such as JET and ASDEX Upgrade. In contrast to such results, however, the measured scale lengths for plasma temperature and density in the central region of these Alcator C-Mod plasmas, with density profiles relatively flat in the core region due to the lack of core fuelling, are favourable to prevent inter and intra sawtooth tungsten accumulation in this region under dominance of neoclassical transport. Simulations of ITER H-mode plasmas, including both anomalous (modelled by the Gyro-Landau-Fluid code GLF23) and neoclassical transport for main ions and tungsten and with density profiles of similar peaking to those obtained in Alcator C-Mod show that accumulation of tungsten in the central plasma region is also unlikely to occur in stationary ITER H-mode plasmas due to the low fuelling source by the neutral beam injection (injection energy ∼ 1 MeV), which is in good agreement with findings in the Alcator C-Mod experiments.

  8. How do user experiences with different transport modes affect the risk of traffic accidents? From the viewpoint of licence possession status.

    Science.gov (United States)

    Nakai, Hiroshi; Usui, Shinnosuke

    2017-02-01

    Road accidents between different modes of transport-such as between automobiles and pedestrians, automobiles and bicycles, or automobiles and motorcycles-are frequent. In such cases, it is important to consider the other side's perspective. This involves the ability to correctly judge, for every given situation, how other people on the road perceive their surroundings and what they intend to do next. In this paper, we conduct two types of studies assuming that this kind of ability to consider perspectives is higher when the person is licenced to drive the mode of transport used by the other party. For Study 1, we analysed accidents involving senior citizens between the ages of 65 and 74 years, who collided with automobiles as pedestrians or cyclists (1656 and 3192 cases respectively), in terms of the accident category and type of road at the accident spot. The results indicate that possession or non-possession of a licence was irrelevant for accidents involving cyclists, but for accidents with pedestrians, senior citizens who did not possess a licence are likely to be involved in a greater number of accidents in places that require interaction with automobiles, such as while crossing at crosswalks or at intersections. For Study 2, we reviewed 875 ordinary first-class licence practical test examinees, categorised them according to their licence possession status (motorcycle licence, moped licence, or no licence), and made a category-wise comparison of the test instructor's assessment of their ability to make a left turn. The results showed that those who had a motorcycle or moped licence tended to make a left turn more safely. Thus, the results indicate that experience with different modes of transport is likely to reduce the risk of accidents. These findings may be used to popularise educational interventions encouraging users of various transport modes to consider the perspective of others (i.e. via perspective-taking). Copyright © 2016 Elsevier Ltd. All rights

  9. A reactive transport investigation of a seawater intrusion experiment in a shallow aquifer, Skansehage Denmark

    DEFF Research Database (Denmark)

    Christensen, Flemming Damgaard; Engesgaard, Peter Knudegaard; Kipp, K.L.

    2001-01-01

    Previous investigations on seawater intrusion have mainly focused on either the physical density flow system with transport of a single non-reactive species or focused on the geochemical aspects neglecting density effects. This study focuses on both the geochemical and physical aspects of seawate...

  10. On the observability of turbulent transport rates by Argo: supporting evidence from an inversion experiment

    Directory of Open Access Journals (Sweden)

    G. Forget

    2015-10-01

    Full Text Available Although estimation of turbulent transport parameters using inverse methods is not new, there is little evaluation of the method in the literature. Here, it is shown that extended observation of the broad-scale hydrography by Argo provides a path to improved estimates of regional turbulent transport rates. Results from a 20-year ocean state estimate produced with the ECCO v4 (Estimating the Circulation and Climate of the Ocean, version 4 non-linear inverse modeling framework provide supporting evidence. Turbulent transport parameter maps are estimated under the constraints of fitting the extensive collection of Argo profiles collected through 2011. The adjusted parameters dramatically reduce misfits to in situ profiles as compared with earlier ECCO solutions. They also yield a clear reduction in the model drift away from observations over multi-century-long simulations, both for assimilated variables (temperature and salinity and independent variables (biogeochemical tracers. Despite the minimal constraints imposed specifically on the estimated parameters, their geography is physically plausible and exhibits close connections with the upper-ocean stratification as observed by Argo. The estimated parameter adjustments furthermore have first-order impacts on upper-ocean stratification and mixed layer depths over 20 years. These results identify the constraint of fitting Argo profiles as an effective observational basis for regional turbulent transport rate inversions. Uncertainties and further improvements of the method are discussed.

  11. Short-term transport of glyphosate with