WorldWideScience

Sample records for transportation study phase

  1. Quasiclassical studies of phase-coherent transport in superconducting nanostructures

    International Nuclear Information System (INIS)

    Seviour, R.F.

    1999-07-01

    In chapter two we introduce the quasiclassical technique and analysis the subgap conductance in S/N structures with barriers (zero bias and finite bias anomalies). We also analyse an Andreev interferometer. Also we present the results of studies on the Josephson effect in 4 terminal S/N/S contacts and on the possible sign reversal of the Josephson critical current (Published in Superlattices and Microstructures, Vol. 25, No. 5/6, p. 647 (1999)). In chapters three and four using the quasiclassical technique in conjunction with a numerical scattering approach (see Appendix) we consider a normal-superconducting-normal structure. In these chapters we consider the effects of the interface resistance between the Normal reservoirs and the normal film and the interface resistance between the superconductor and the normal film. This work has been published in J.Phys.Conds.Mat. 10 (1998), L615 and PHYS REV B 1 Nov 98. In Chapter 5 using the techniques discussed above we shown that for normal-superconducting-normal structure a new peek may arise in the temperature dependence of the conductance when the temperature is approximately equal to the transition temperature of the superconducting (Published PHYS. Rev.13, 1999, v.59, No.9, p. 6031). In chapter 6 we analyse the first ever experimental results showing the new peak in the conductance as discussed in chapter 5 (Submitted to PRL). Chapter 7 uses the numerical technique discussed in the appendix. to examine the phenomena of conductance suppression in 4 probe normal superconducting structures (Published Superlattices and Microstructures, Vol. 25, No.5, p. 640 (1999)). (author)

  2. Pharmacokinetic interplay of phase II metabolism and transport: a theoretical study.

    Science.gov (United States)

    Wu, Baojian

    2012-01-01

    Understanding of the interdependence of cytochrome P450 enzymes and P-glycoprotein in disposition of drugs (also termed "transport-metabolism interplay") has been significantly advanced in recent years. However, whether such "interplay" exists between phase II metabolic enzymes and efflux transporters remains largely unknown. The objective of this article is to explore the role of efflux transporters (acting on the phase II metabolites) in disposition of the parent drug in Caco-2 cells, liver, and intestine via simulations utilizing a catenary model (for Caco-2 system) and physiologically based pharmacokinetic (PBPK) models (for the liver and intestine). In all three models, "transport-metabolism interplay" (i.e., inhibition of metabolite efflux decreases the metabolism) can be observed only when futile recycling (or deconjugation) occurred. Futile recycling appeared to bridge the two processes (i.e., metabolite formation and excretion) and enable the interplay thereof. Without futile recycling, metabolite formation was independent on its downstream process excretion, thus impact of metabolite excretion on its formation was impossible. Moreover, in liver PBPK model with futile recycling, impact of biliary metabolite excretion on the exposure of parent drug [(systemic (reservoir) area under the concentration-time curve (AUC(R1))] was limited; a complete inhibition of efflux resulted in AUC(R1) increases of less than 1-fold only. In intestine PBPK model with futile recycling, even though a complete inhibition of efflux could result in large elevations (e.g., 3.5-6.0-fold) in AUC(R1), an incomplete inhibition of efflux (e.g., with a residual activity of ≥ 20% metabolic clearance) saw negligible increases (interplay between phase II enzymes and efflux transporters. Those studying such "interplay" are encouraged to adequately consider potential consequences of inhibition of efflux transporters in humans. Copyright © 2011 Wiley-Liss, Inc.

  3. Experimental studies of interaction mechanisms and phase transport processes in two-phase flow (NOVA program)

    International Nuclear Information System (INIS)

    Sauter, H.; Meyder, R.; Philipp, P.; Samstag, M.

    1995-01-01

    The NOVA program was continued with turbulent, vertical, upward two-phase flow experiments. The development of a local gas distribution along the test section was visualized by X-ray tomography. (orig.)

  4. Geographic information systems - transportation ISTEA management systems server net prototype pooled fund study : phase B - summary

    Science.gov (United States)

    1997-06-01

    The Geographic Information System-Transportation (GIS-T) ISTEA Management Systems Server Net Prototype Pooled Fund Study represents the first national cooperative effort in the transportation industry to address the management and monitoring systems ...

  5. Study of colloids transport during two-phase flow using a novel polydimethylsiloxane micro-model.

    Science.gov (United States)

    Zhang, Qiulan; Karadimitriou, N K; Hassanizadeh, S M; Kleingeld, P J; Imhof, A

    2013-07-01

    As a representation of a porous medium, a closed micro-fluidic device made of polydimethylsiloxane (PDMS), with uniform wettability and stable hydrophobic properties, was designed and fabricated. A flow network, with a mean pore size of 30 μm, was formed in a PDMS slab, covering an area of 1 mm × 10 mm. The PDMS slab was covered and bonded with a 120-μm-thick glass plate to seal the model. The glass plate was first spin-coated with a thin layer, roughly 10 μm, of PDMS. The micro-model was treated with silane in order to make it uniformly and stably hydrophobic. Fluorescent particles of 300 μm in diameter were used as colloids. It is known that more removal of colloids occurs under unsaturated conditions, compared to saturated flow in soil. At the same time, the change of saturation has been observed to cause remobilization of attached colloids. The mechanisms for these phenomena are not well understood. This is the first time that a closed micro-model, made of PDMS with uniform and stable wettability, has been used in combination with confocal microscopy to study colloid transport under transient two-phase flow conditions. With confocal microscopy, the movement of fluorescent particles and flow of two liquids within the pores can be studied. One can focus at different depths within the pores and thus determine where the particles exactly are. Thus, remobilization of attached colloids by moving fluid-fluid interfaces was visualized. In order to allow for the deposition and subsequent remobilization of colloids during two-phase flow, three micro-channels for the injection of liquids with and without colloids were constructed. An outlet channel was designed where effluent concentration breakthrough curves can be quantified by measuring the fluorescence intensity. A peak concentration also indicated in the breakthrough curve with the drainage event. The acquired images and breakthrough curve successfully confirmed the utility of the combination of such a PDMS

  6. Magneto-transport study of quantum phases in wide GaAs quantum wells

    Science.gov (United States)

    Liu, Yang

    In this thesis we study several quantum phases in very high quality two-dimensional electron systems (2DESs) confined to GaAs single wide quantum wells (QWs). In these systems typically two electric subbands are occupied. By controlling the electron density as well as the QW symmetry, we can fine tune the cyclotron and subband separation energies, so that Landau levels (LLs) belonging to different subbands cross at the Fermi energy EF. The additional subband degree of freedom enables us to study different quantum phases. Magneto-transport measurements at fixed electron density n and various QW symmetries reveal a remarkable pattern for the appearance and disappearance of fractional quantum Hall (FQH) states at LL filling factors nu = 10/3, 11/3, 13/3, 14/3, 16/3, and 17/3. These q/3 states are stable and strong as long as EF lies in a ground-state (N = 0) LL, regardless of whether that level belongs to the symmetric or the anti-symmetric subband. We also observe subtle and distinct evolutions near filling factors nu = 5/2 and 7/2, as we change the density n, or the symmetry of the charge distribution. The even-denominator FQH states are observed at nu = 5/2, 7/2, 9/2 and 11/2 when EF lies in the N= 1 LLs of the symmetric subband (the S1 levels). As we increase n, the nu = 5/2 FQH state suddenly disappears and turns into a compressible state once EF moves to the spin-up, N = 0, anti-symmetric LL (the A0 ↑ level). The sharpness of this disappearance suggests a first-order transition from a FQH to a compressible state. Moreover, thanks to the renormalization of the susbband energy separation in a well with asymmetric change distribution, two LLs can get pinned to each other when they are crossing at E F. We observe a remarkable consequence of such pinning: There is a developing FQH state when the LL filling factor of the symmetric subband nuS equals 5/2 while the antisymmetric subband has filling 1 < nuA <2. Next, we study the evolution of the nu=5/2 and 7/2 FQH

  7. Study of internal transport barriers in the initial phase of Ohmic discharges in TUMAN-3M

    International Nuclear Information System (INIS)

    Askinazi, L G; Bulanin, V V; Vildjunas, M I; Golant, V E; Gorokhov, M V; Kornev, V A; Krikunov, S V; Lebedev, S V; Petrov, A V; Rozhdestvensky, V V; Tukachinsky, A S; Zhubr, N A

    2004-01-01

    A regime with electron heat confinement improvement was recently found in the initial phase of discharges in the TUMAN-3M tokamak. An internal transport barrier (ITB) formation in this regime was confirmed by Thomson scattering measurements and by transport modelling. Two possible reasons for the ITB formation are discussed in the paper: by reduction of turbulent transport in the presence of low magnetic shear or by plasma sheared rotation. It is demonstrated that low magnetic shear formation is possible in the current ramp-up phase of the Ohmic discharge. The low magnetic shear does not seem to be the only reason for the transport reduction. Results of Doppler reflectometry measurements of poloidal rotation of density fluctuations are presented. It is found that core confinement improvement correlates with the appearance of sheared rotation of the density fluctuations and with a burst of the MHD activity. The ITB formation in the regime seems to be a result of a combined action of reduced magnetic shear and plasma sheared rotation

  8. Experimental study on interfacial area transport in downward two-phase flow

    Science.gov (United States)

    Wang, Guanyi

    In view of the importance of two group interfacial area transport equations and lack of corresponding accurate downward flow database that can reveal two group interfacial area transport, a systematic database for adiabatic, air-water, vertically downward two-phase flow in a round pipe with inner diameter of 25.4 mm was collected to gain an insight of interfacial structure and provide benchmarking data for two-group interfacial area transport models. A four-sensor conductivity probe was used to measure the local two phase flow parameters and data was collected with data sampling frequency much higher than conventional data sampling frequency to ensure the accuracy. Axial development of local flow parameter profiles including void fraction, interfacial area concentration, and Sauter mean diameter were presented. Drastic inter-group transfer of void fraction and interfacial area was observed at bubbly to slug transition flow. And the wall peaked interfacial area concentration profiles were observed in churn-turbulent flow. The importance of local data about these phenomenon on flow structure prediction and interfacial area transport equation benchmark was analyzed. Bedsides, in order to investigate the effect of inlet conditions, all experiments were repeated after installing the flow straightening facility, and the results were briefly analyzed. In order to check the accuracy of current data, the experiment results were cross-checked with rotameter measurement as well as drift-flux model prediction, the averaged error is less than 15%. Current models for two-group interfacial area transport equation were evaluated using these data. The results show that two-group interfacial area transport equations with current models can predict most flow conditions with error less than 20%, except some bubbly to slug transition flow conditions and some churn-turbulent flow conditions. The disagreement between models and experiments could result from underestimate of inter

  9. Experimental and analytical study of interfacial area transport phenomena in a vertical two-phase flow

    International Nuclear Information System (INIS)

    Huh, Byung-Gil; Euh, Dong-Jin; Yun, Byong-Jo; Youn, Young-Jung; Yoon, Han-Yeong; Song, Chul-Hwa

    2005-03-01

    The number density transport equations for various bubble groups are used to predict the void fraction and the interfacial area concentration. As the closure relations for number density transport equation, the coalescence due to random collisions and the breakup due to the impact of turbulent eddies is modified based on the previous studies and the bubble expansion term due to the pressure reduction is considered. Also, the coalescence due to a wake entrainment is modeled newly to apply to the number density transport equation. In order to predict the local experimental data, the code is developed that the two-fluid model is coupled systematically with the number density transport equation for each bubble group. As for the results of the numerical analysis, the void fraction and interfacial area concentration are predicted well by the developed code and models although some deviations exist in the values between the prediction and experiment, especially, for the high void fraction conditions

  10. Experimental and analytical study of interfacial area transport phenomena in a vertical two-phase flow

    Energy Technology Data Exchange (ETDEWEB)

    Huh, Byung-Gil; Euh, Dong-Jin; Yun, Byong-Jo; Youn, Young-Jung; Yoon, Han-Yeong; Song, Chul-Hwa

    2005-03-01

    The number density transport equations for various bubble groups are used to predict the void fraction and the interfacial area concentration. As the closure relations for number density transport equation, the coalescence due to random collisions and the breakup due to the impact of turbulent eddies is modified based on the previous studies and the bubble expansion term due to the pressure reduction is considered. Also, the coalescence due to a wake entrainment is modeled newly to apply to the number density transport equation. In order to predict the local experimental data, the code is developed that the two-fluid model is coupled systematically with the number density transport equation for each bubble group. As for the results of the numerical analysis, the void fraction and interfacial area concentration are predicted well by the developed code and models although some deviations exist in the values between the prediction and experiment, especially, for the high void fraction conditions.

  11. Electronic, optical and transport properties of {alpha}-, {beta}- and {gamma}-phases of spinel indium sulphide: An ab initio study

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, Yamini, E-mail: sharma.yamini62@gmail.com [Department of Physics, Feroze Gandhi College, Rae Bareli 229001, U.P. (India); Srivastava, Pankaj [Department of Physics, Feroze Gandhi College, Rae Bareli 229001, U.P. (India)

    2012-08-15

    Spinel indium sulphide exists in three phases. The tetragonal {beta}-phase transforms to the cubic {alpha}-phase at 420 Degree-Sign C which further transforms to the trigonal {gamma}-phase at 754 Degree-Sign C. Due to wide energy bandgap, the phases of indium sulphide have possibilities of applications in photo-electrochemical solar cell devices as a replacement of toxic CdS. The electronic, optical and transport properties of the three phases have therefore been investigated using full potential linear augmented plane wave (FP-LAPW) + local orbitals (lo) scheme, in the framework of density functional theory (DFT) with generalized gradient approximation (GGA) for the purpose of exchange-correlation energy functional. We present the structure, energy bands and density of states (DOS) for {alpha}-, {beta}- and {gamma}-phases. The partial density of states (PDOS) of {beta}-In{sub 2}S{sub 3} is in good agreement with experiment and earlier ab initio calculations. To obtain the fundamental characteristics of these phases we have analysed their linear optical properties such as the dynamic dielectric function in the energy range of 0-15 eV. From the dynamic dielectric function it is seen that there is no directional anisotropy for {alpha}-phase since the longitudinal and transverse components are almost identical, however the {beta} and {gamma}-phases show birefringence. The optical absorption profiles clearly indicate that {beta}-phase has possibility of greater multiple direct and indirect interband transitions in the visible regions compared to the other phases. To study the existence of interesting thermoelectric properties, transport properties like electrical and thermal conductivities, Seebeck and Hall coefficients etc. are also calculated. Good agreements are found with the available experimental results. -- Highlights: Black-Right-Pointing-Pointer The electronic properties of phases of In{sub 2}S{sub 3} have been investigated. Black-Right-Pointing-Pointer The

  12. Review of current results in computational studies of hydrocarbon phase and transport properties in nanoporous structures

    Science.gov (United States)

    Stroev, N.; Myasnikov, A.

    2017-12-01

    This article provides a general overview of the main simulation results on the behavior of gas/liquids under confinement conditions, namely hydrocarbons in shale formations, and current understanding of such phenomena. In addition to the key effects, which different research groups obtained and which have to be taken into account during the creation of reservoir simulation software, a list of methods is briefly covered. Comprehensive understanding of both fluid phase equilibrium and transport properties in nanoscale structures is of great importance for many scientific and technical disciplines, especially for petroleum engineering considering the hydrocarbon behavior in complex shale formations, the development of which increases with time. Recent estimations show that a significant amount of resources are trapped inside organic matter and clays, which has extremely low permeability and yet great economic potential. The issue is not only of practical importance, as the existing conventional approaches by definition are unable to capture complicated physics phenomena for effective results, but it is also of fundamental value. The research of the processes connected with such deposits is necessary for both evaluations of petroleum reservoir deposits and hydrodynamic simulators. That is why the review is divided into two major parts—equilibrium states of hydrocarbons and their transport properties in highly confined conditions.

  13. Experimental Studies of Phase Change and Microencapsulated Phase Change Materials in a Cold Storage/Transportation System with Solar Driven Cooling Cycle

    Directory of Open Access Journals (Sweden)

    Lin Zheng

    2017-11-01

    Full Text Available The paper presents the different properties of phase change material (PCM and Microencapsulated phase change material (MEPCM employed to cold storage/transportation system with a solar-driven cooling cycle. Differential Scanning Calorimeter (DSC tests have been performed to analyze the materials enthalpy, melting temperature range, and temperature range of solidification. KD2 Pro is used to test the thermal conductivities of phase change materials slurry and the results were used to compare the materials heat transfer performance. The slurry flow characteristics of MEPCM slurry also have been tested. Furthermore, in order to analyze the improvement effect on stability, the stability of MEPCM slurry with different surfactants have been tested. The researches of the PCM and MEPCM thermal properties revealed a more prospective application for phase change materials in energy storage/transportation systems. The study aims to find the most suitable chilling medium to further optimize the design of the cold storage/transportation systems with solar driven cooling cycles.

  14. Ultracold Field Gradient Magnetometry and Transport to Study Correlated Topological Phases

    Science.gov (United States)

    2016-10-01

    MIT) 77 Massachusetts Ave. NE18-901 Cambridge , MA 02139 -4307 ABSTRACT Number of Papers published in peer-reviewed journals: Number of Papers published...group of the PI and the subfield of new correlated topological phases. List of Illustrations Figure 1 – View of MBE and Glovebox System Figure... Illustrations   Figure 1 – View of MBE and Glovebox System  Figure 2 – View of Glovebox, MBE, and Dilution Refrigerator System    Statement of Problems Studied  To

  15. Future space transportation systems systems analysis study, phase 1 technical report

    Science.gov (United States)

    1975-01-01

    The requirements of projected space programs (1985-1995) for transportation vehicles more advanced than the space shuttle are discussed. Several future program options are described and their transportation needs are analyzed. Alternative systems approaches to meeting these needs are presented.

  16. Experimental Studies of Phase Change and Microencapsulated Phase Change Materials in a Cold Storage/Transportation System with Solar Driven Cooling Cycle

    OpenAIRE

    Lin Zheng; Wei Zhang; Fei Liang; Shuang Lin; Xiangyu Jin

    2017-01-01

    The paper presents the different properties of phase change material (PCM) and Microencapsulated phase change material (MEPCM) employed to cold storage/transportation system with a solar-driven cooling cycle. Differential Scanning Calorimeter (DSC) tests have been performed to analyze the materials enthalpy, melting temperature range, and temperature range of solidification. KD2 Pro is used to test the thermal conductivities of phase change materials slurry and the results were used to compar...

  17. Nonlinear transport of dynamic system phase space

    International Nuclear Information System (INIS)

    Xie Xi; Xia Jiawen

    1993-01-01

    The inverse transform of any order solution of the differential equation of general nonlinear dynamic systems is derived, realizing theoretically the nonlinear transport for the phase space of nonlinear dynamic systems. The result is applicable to general nonlinear dynamic systems, with the transport of accelerator beam phase space as a typical example

  18. The International intraval project. Phase 1, test case 13: Experimental study of brine transport in porous media

    International Nuclear Information System (INIS)

    Glasbergen, P.

    1992-01-01

    INTRAVAL is an international coordinated research program for predicting the potential radionuclide migration in the geosphere with the use of mathematical models. Such models are used to help assess the long-term safety of radioactive waste disposal systems. This report describes the findings of the project teams involved in test case 13 of INTRAVAL Phase 1. The test case is based on laboratory experiments dealing with flow and dispersion of brine in a porous medium. The purpose of these experiments was twofold : (i) to investigate some of the relevant processes in brine transport in porous media, and (ii) to provide sets of data to be used for (partial) validation of transport models. The experiments were carried out in a column packed with glass beads of diameter 0.40 to 0.52 mm. Salt water was injected through nine holes at the bottom and withdrawn through nine holes at the top. Initially a low salt concentration was used which was then displaced with higher concentrated salt water. The salt mass-fraction was detected using an array of electrodes such that breakthrough curves were obtained at five different levels in the column. The report reviews a number of conceptual models and the corresponding numerical codes employed by different modelling teams. The experiments on one- and two-dimensional flow and transport were simulated by various groups. The question underlying the experiments, namely the applicability of Fick's laws over the whole range of salt concentration, could be addressed satisfactorily. All models could simulate low-concentration experiment using a dispersivity value of 0.8 mm to 1.00 mm. However, using the same dispersivity value, it was not possible to simulate high concentration experiments. Another question intended to be studied by the experiments was the validity of Darcy's law at high concentrations. Two-dimensional experiments were carried out for this purpose. In practice, calculations were hampered by extremely high demand on

  19. Geographic Information Systems-Transportation ISTEA management systems server-net prototype pooled fund study: Phase B summary

    Energy Technology Data Exchange (ETDEWEB)

    Espinoza, J. Jr.; Dean, C.D.; Armstrong, H.M. [and others

    1997-06-01

    The Geographic Information System-Transportation (GIS-T) ISTEA Management Systems Server Net Prototype Pooled Fund Study represents the first national cooperative effort in the transportation industry to address the management and monitoring systems as well as the statewide and metropolitan transportation planning requirements of the Intermodal Surface Transportation Efficiency Act of 1991 (ISTEA). The Study was initiated in November 1993 through the Alliance for Transportation Research and under the leadership of the New Mexico State Highway and Transportation Department. Sandia National Laboratories, an Alliance partner, and Geographic Paradigm Computing. Inc. provided technical leadership for the project. In 1992, the Alliance for Transportation Research, the New Mexico State Highway and Transportation Department, Sandia National Laboratories, and Geographic Paradigm Computing, Inc., proposed a comprehensive research agenda for GIS-T. That program outlined a national effort to synthesize new transportation policy initiatives (e.g., management systems and Intelligent Transportation Systems) with the GIS-T server net ideas contained in the NCHRP project {open_quotes}Adaptation of GIS to Transportation{close_quotes}. After much consultation with state, federal, and private interests, a project proposal based on this agenda was prepared and resulted in this Study. The general objective of the Study was to develop GIS-T server net prototypes supporting the ISTEA requirements for transportation planning and management and monitoring systems. This objective can be further qualified to: (1) Create integrated information system architectures and design requirements encompassing transportation planning activities and data. (2) Encourage the development of functional GIS-T server net prototypes. (3) Demonstrate multiple information systems implemented in a server net environment.

  20. Space Transportation Engine Program (STEP), phase B

    Science.gov (United States)

    1990-01-01

    The Space Transportation Engine Program (STEP) Phase 2 effort includes preliminary design and activities plan preparation that will allow smooth and time transition into a Prototype Phase and then into Phases 3, 4, and 5. A Concurrent Engineering approach using Total Quality Management (TQM) techniques, is being applied to define an oxygen-hydrogen engine. The baseline from Phase 1/1' studies was used as a point of departure for trade studies and analyses. Existing STME system models are being enhanced as more detailed module/component characteristics are determined. Preliminary designs for the open expander, closed expander, and gas generator cycles were prepared, and recommendations for cycle selection made at the Design Concept Review (DCR). As a result of July '90 DCR, and information subsequently supplied to the Technical Review Team, a gas generator cycle was selected. Results of the various Advanced Development Programs (ADP's) for the Advanced Launch Systems (ALS) were contributive to this effort. An active vehicle integration effort is supplying the NASA, Air Force, and vehicle contractors with engine parameters and data, and flowing down appropriate vehicle requirements. Engine design and analysis trade studies are being documented in a data base that was developed and is being used to organize information. To date, seventy four trade studies were input to the data base.

  1. Advanced Concept Studies for Supersonic Commercial Transports Entering Service in the 2018-2020 Period Phase 2

    Science.gov (United States)

    Morgenstern, John; Buonanno, Michael; Yao, Jixian; Murugappan, Mugam; Paliath, Umesh; Cheung, Lawrence; Malcevic, Ivan; Ramakrishnan, Kishore; Pastouchenko, Nikolai; Wood, Trevor; hide

    2015-01-01

    Lockheed Martin Aeronautics Company (LM), working in conjunction with General Electric Global Research (GE GR) and Stanford University, executed a 19 month program responsive to the NASA sponsored "N+2 Supersonic Validation: Advanced Concept Studies for Supersonic Commercial Transports Entering Service in the 2018-2020 Period" contract. The key technical objective of this effort was to validate integrated airframe and propulsion technologies and design methodologies necessary to realize a supersonic vehicle capable of meeting the N+2 environmental and performance goals. The N+2 program is aligned with NASA's Supersonic Project and is focused on providing system level solutions capable of overcoming the efficiency, environmental, and performance barriers to practical supersonic flight. The N+2 environmental and performance goals are outlined in the technical paper, AIAA-2014-2138 (Ref. 1) along with the validated N+2 Phase 2 results. Our Phase 2 efforts built upon our Phase 1 studies (Ref. 2) and successfully demonstrated the ability to design and test realistic configurations capable of shaped sonic booms over the width of the sonic boom carpet. Developing a shaped boom configuration capable of meeting the N+2 shaped boom targets is a key goal for the N+2 program. During the LM Phase 1 effort, LM successfully designed and tested a shaped boom trijet configuration (1021) capable of achieving 85 PLdB under track (forward and aft shock) and up to 28 deg off-track at Mach 1.6. In Phase 2 we developed a refined configuration (1044-2) that extended the under 85 PLdB sonic boom level over the entire carpet of 52 deg off-track at a cruise Mach number of 1.7. Further, the loudness level of the configuration throughout operational conditions calculates to an average of 79 PLdB. These calculations rely on propagation employing Burger's (sBOOM) rounding methodology, and there are indications that the configuration average loudness would actually be 75 PLdB. We also added

  2. Nonlinear transport of accelerator beam phase space

    International Nuclear Information System (INIS)

    Xie Xi; Xia Jiawen

    1995-01-01

    Based on the any order analytical solution of accelerator beam dynamics, the general theory for nonlinear transport of accelerator beam phase space is developed by inverse transformation method. The method is general by itself, and hence can also be applied to the nonlinear transport of various dynamic systems in physics, chemistry and biology

  3. Transportation Life Cycle Assessment (LCA) Synthesis, Phase II

    Science.gov (United States)

    2018-04-24

    The Transportation Life Cycle Assessment (LCA) Synthesis includes an LCA Learning Module Series, case studies, and analytics on the use of the modules. The module series is a set of narrated slideshows on topics related to environmental LCA. Phase I ...

  4. Electrical transport in crystalline phase change materials

    International Nuclear Information System (INIS)

    Woda, Michael

    2012-01-01

    In this thesis, the electrical transport properties of crystalline phase change materials are discussed. Phase change materials (PCM) are a special class of semiconducting and metallic thin film alloys, typically with a high amount of the group five element antimony or the group six element tellurium, such as Ge 2 Sb 2 Te 5 . The unique property portfolio of this material class makes it suitable for memory applications. PCMs reveal fast switching between two stable room-temperature phases (amorphous and crystalline) realized by optical laser or electrical current pulses in memory devices. Additionally, a pronounced property contrast in form of optical reflectivity and electrical conductivity between the amorphous and crystalline phase is the characteristic fingerprint of PCMs. The emerging electrical solid state memory PCRAM is a very promising candidate to replace Flash memory in the near future or to even become a universal memory, which is non-volatile and shows the speed and cyclability of DRAM. One of the main technological challenges is the switching process into the amorphous state, which is the most power demanding step. In order to reduce the switching power, the crystalline resistivity needs to be increased at a given voltage. Thus understanding and tayloring of this property is mandatory. In this work, first the technological relevance, i.e. optical and electrical memory concepts based on PCMs are introduced. Subsequently a description of the physical properties of PCMs in four categories is given. Namely, structure, kinetics, optical properties and electrical properties are discussed. Then important recent developments such as the identification of resonant bonding in crystalline PCMs and a property predicting coordination scheme are briefly reviewed. The following chapter deals with the theoretical background of electrical transport, while the next chapter introduces the experimental techniques: Sputtering, XRR, XRD, DSC, thermal annealing

  5. Electrical transport in crystalline phase change materials

    Energy Technology Data Exchange (ETDEWEB)

    Woda, Michael

    2012-01-06

    In this thesis, the electrical transport properties of crystalline phase change materials are discussed. Phase change materials (PCM) are a special class of semiconducting and metallic thin film alloys, typically with a high amount of the group five element antimony or the group six element tellurium, such as Ge{sub 2}Sb{sub 2}Te{sub 5}. The unique property portfolio of this material class makes it suitable for memory applications. PCMs reveal fast switching between two stable room-temperature phases (amorphous and crystalline) realized by optical laser or electrical current pulses in memory devices. Additionally, a pronounced property contrast in form of optical reflectivity and electrical conductivity between the amorphous and crystalline phase is the characteristic fingerprint of PCMs. The emerging electrical solid state memory PCRAM is a very promising candidate to replace Flash memory in the near future or to even become a universal memory, which is non-volatile and shows the speed and cyclability of DRAM. One of the main technological challenges is the switching process into the amorphous state, which is the most power demanding step. In order to reduce the switching power, the crystalline resistivity needs to be increased at a given voltage. Thus understanding and tayloring of this property is mandatory. In this work, first the technological relevance, i.e. optical and electrical memory concepts based on PCMs are introduced. Subsequently a description of the physical properties of PCMs in four categories is given. Namely, structure, kinetics, optical properties and electrical properties are discussed. Then important recent developments such as the identification of resonant bonding in crystalline PCMs and a property predicting coordination scheme are briefly reviewed. The following chapter deals with the theoretical background of electrical transport, while the next chapter introduces the experimental techniques: Sputtering, XRR, XRD, DSC, thermal annealing

  6. Resonance controlled transport in phase space

    Science.gov (United States)

    Leoncini, Xavier; Vasiliev, Alexei; Artemyev, Anton

    2018-02-01

    We consider the mechanism of controlling particle transport in phase space by means of resonances in an adiabatic setting. Using a model problem describing nonlinear wave-particle interaction, we show that captures into resonances can be used to control transport in momentum space as well as in physical space. We design the model system to provide creation of a narrow peak in the distribution function, thus producing effective cooling of a sub-ensemble of the particles.

  7. ADVANCED CUTTINGS TRANSPORT STUDY

    Energy Technology Data Exchange (ETDEWEB)

    Stefan Miska; Troy Reed; Ergun Kuru

    2004-09-30

    The Advanced Cuttings Transport Study (ACTS) was a 5-year JIP project undertaken at the University of Tulsa (TU). The project was sponsored by the U.S. Department of Energy (DOE) and JIP member companies. The objectives of the project were: (1) to develop and construct a new research facility that would allow three-phase (gas, liquid and cuttings) flow experiments under ambient and EPET (elevated pressure and temperature) conditions, and at different angle of inclinations and drill pipe rotation speeds; (2) to conduct experiments and develop a data base for the industry and academia; and (3) to develop mechanistic models for optimization of drilling hydraulics and cuttings transport. This project consisted of research studies, flow loop construction and instrumentation development. Following a one-year period for basic flow loop construction, a proposal was submitted by TU to the DOE for a five-year project that was organized in such a manner as to provide a logical progression of research experiments as well as additions to the basic flow loop. The flow loop additions and improvements included: (1) elevated temperature capability; (2) two-phase (gas and liquid, foam etc.) capability; (3) cuttings injection and removal system; (4) drill pipe rotation system; and (5) drilling section elevation system. In parallel with the flow loop construction, hydraulics and cuttings transport studies were preformed using drilling foams and aerated muds. In addition, hydraulics and rheology of synthetic drilling fluids were investigated. The studies were performed under ambient and EPET conditions. The effects of temperature and pressure on the hydraulics and cuttings transport were investigated. Mechanistic models were developed to predict frictional pressure loss and cuttings transport in horizontal and near-horizontal configurations. Model predictions were compared with the measured data. Predominantly, model predictions show satisfactory agreements with the measured data. As a

  8. Nevada Transportation Options Study

    International Nuclear Information System (INIS)

    P. GEHNER; E.M. WEAVER; L. FOSSUM

    2006-01-01

    This study performs a cost and schedule analysis of three Nevada Transportation options that support waste receipt at the repository. Based on the U.S. Department of Energy preference for rail transportation in Nevada (given in the Final Environmental Impact Statement), it has been assumed that a branch rail line would be constructed to support waste receipt at the repository. However, due to potential funding constraints, it is uncertain when rail will be available. The three Nevada Transportation options have been developed to meet a varying degree of requirements for transportation and to provide cost variations used in meeting the funding constraints given in the Technical Direction Letter guidelines for this study. The options include combinations of legal-weight truck, heavy-haul truck, and rail. Option 1 uses a branch rail line that would support initial waste receipt at the repository in 2010. Rail transportation would be the primary mode, supplemented by legal weight trucks. This option provides the highest level of confidence in cost and schedule, lowest public visibility, greatest public acceptability, lowest public dose, and is the recommended option for support of waste receipt. The completion of rail by 2010 will require spending approximately $800 million prior to 2010. Option 2 uses a phased rail approach to address a constrained funding scenario. To meet funding constraints, Option 2 uses a phased approach to delay high cost activities (final design and construction) until after initial waste receipt in 2010. By doing this, approximately 95 percent of the cost associated with completion of a branch rail line is deferred until after 2010. To support waste receipt until a branch rail line is constructed in Nevada, additional legal-weight truck shipments and heavy-haul truck shipments (on a limited basis for naval spent nuclear fuel) would be used to meet the same initial waste receipt rates as in Option 1. Use of heavy-haul shipments in the absence

  9. Phase 0 and phase III transport in various organs: combined concept of phases in xenobiotic transport and metabolism.

    Science.gov (United States)

    Döring, Barbara; Petzinger, Ernst

    2014-08-01

    The historical phasing concept of drug metabolism and elimination was introduced to comprise the two phases of metabolism: phase I metabolism for oxidations, reductions and hydrolyses, and phase II metabolism for synthesis. With this concept, biological membrane barriers obstructing the accessibility of metabolism sites in the cells for drugs were not considered. The concept of two phases was extended to a concept of four phases when drug transporters were detected that guided drugs and drug metabolites in and out of the cells. In particular, water soluble or charged drugs are virtually not able to overcome the phospholipid membrane barrier. Drug transporters belong to two main clusters of transporter families: the solute carrier (SLC) families and the ATP binding cassette (ABC) carriers. The ABC transporters comprise seven families with about 20 carriers involved in drug transport. All of them operate as pumps at the expense of ATP splitting. Embedded in the former phase concept, the term "phase III" was introduced by Ishikawa in 1992 for drug export by ABC efflux pumps. SLC comprise 52 families, from which many carriers are drug uptake transporters. Later on, this uptake process was referred to as the "phase 0 transport" of drugs. Transporters for xenobiotics in man and animal are most expressed in liver, but they are also present in extra-hepatic tissues such as in the kidney, the adrenal gland and lung. This review deals with the function of drug carriers in various organs and their impact on drug metabolism and elimination.

  10. Prediction of transport phenomena in near and far field: interaction solid phase/fluid phase

    International Nuclear Information System (INIS)

    Mingarro, E.

    1995-01-01

    The prediction of transport phenomena in near and far field is presented in the present report. The study begins with the analysis of solid phases stability: solubility of storage waste: UO 2 and solubility of radionuclides the redox and sorption-desorption conditions are the last aspects studied to predict the transport phenomena

  11. Phase-averaged transport for quasiperiodic Hamiltonians

    CERN Document Server

    Bellissard, J; Schulz-Baldes, H

    2002-01-01

    For a class of discrete quasi-periodic Schroedinger operators defined by covariant re- presentations of the rotation algebra, a lower bound on phase-averaged transport in terms of the multifractal dimensions of the density of states is proven. This result is established under a Diophantine condition on the incommensuration parameter. The relevant class of operators is distinguished by invariance with respect to symmetry automorphisms of the rotation algebra. It includes the critical Harper (almost-Mathieu) operator. As a by-product, a new solution of the frame problem associated with Weyl-Heisenberg-Gabor lattices of coherent states is given.

  12. Transport reduction via shear flow modification of the cross phase

    International Nuclear Information System (INIS)

    Ware, A.S.; Terry, P.W.; Diamond, P.H.; Carreras, B.A.

    1996-01-01

    As a model example of the effect of E x B shear flow on the cross phase between electrostatic potential and pressure fluctuations, a nonlinear theory of resistive pressure gradient driven turbulence (RPGDT) in a shear flow is presented. This work builds on numerical studies of RPGDT, which have shown that both flow shear and curvature can affect the cross phase as well as the fluctuation levels. In this work, we show that the effect of shear flow on transport can be expressed through the temporal response of pressure to potential. It is shown heuristically that even in the case where the fluctuation levels are not modified, the flow shear still acts to reduce the phase angle between potential and pressure fluctuations, thereby suppressing transport. The scaling of the cross phase with flow shear and flow curvature is presented. (author)

  13. Subthreshold electrical transport in amorphous phase-change materials

    International Nuclear Information System (INIS)

    Gallo, Manuel Le; Kaes, Matthias; Sebastian, Abu; Krebs, Daniel

    2015-01-01

    Chalcogenide-based phase-change materials play a prominent role in information technology. In spite of decades of research, the details of electrical transport in these materials are still debated. In this article, we present a unified model based on multiple-trapping transport together with 3D Poole–Frenkel emission from a two-center Coulomb potential. With this model, we are able to explain electrical transport both in as-deposited phase-change material thin films, similar to experimental conditions in early work dating back to the 1970s, and in melt-quenched phase-change materials in nanometer-scale phase-change memory devices typically used in recent studies. Experimental measurements on two widely different device platforms show remarkable agreement with the proposed mechanism over a wide range of temperatures and electric fields. In addition, the proposed model is able to seamlessly capture the temporal evolution of the transport properties of the melt-quenched phase upon structural relaxation. (paper)

  14. Experimental studies of interaction mechanisms and phase transport processes in two-phase flow (NOVA program); Experimentelle Untersuchung von Wechselwirkungsmechanismen und Phasentransportprozessen in Zweiphasenstroemungen (NOVA-Vorhaben)

    Energy Technology Data Exchange (ETDEWEB)

    Sauter, H.; Meyder, R.; Philipp, P.; Samstag, M.

    1995-08-01

    The NOVA program was continued with turbulent, vertical, upward two-phase flow experiments. The development of a local gas distribution along the test section was visualized by X-ray tomography. (orig.)

  15. Impact of intercontinental pollution transport on North American ozone air pollution: an HTAP phase 2 multi-model study

    Science.gov (United States)

    The recent update on the US National Ambient Air Quality Standards (NAAQS) of the ground-level ozone (O3/ can benefit from a better understanding of its source contributions in different US regions during recent years. In the Hemispheric Transport of Air Pollution experiment phas...

  16. Recovery Of Chromium Metal (VI) Using Supported Liquid Membrane (SLM) Method, A study of Influence of NaCl and pH in Receiving Phase on Transport

    Science.gov (United States)

    Cholid Djunaidi, Muhammad; Lusiana, Retno A.; Rahayu, Maya D.

    2017-06-01

    Chromium metal(VI) is a valuable metal but in contrary has high toxicity, so the separation and recovery from waste are very important. One method that can be used for the separation and recovery of chromium (VI) is a Supported Liquid Membrane (SLM). SLM system contains of three main components: a supporting membrane, organic solvents and carrier compounds. The supported Membrane used in this research is Polytetrafluoroethylene (PTFE), organic solvent is kerosene, and the carrier compound used is aliquat 336. The supported liquid membrane is placed between two phases, namely, feed phase as the source of analyte (Cr(VI)) and the receiving phase as the result of separation. Feed phase is the electroplating waste which contains of chromium metal with pH variation about 4, 6 and 9. Whereas the receiving phase are the solution of HCl, NaOH, HCl-NaCl and NaOH-NaCl with pH variation about 1, 3, 5 and 7. The efficiency separation is determined by measurement of chromium in the feed and the receiving phase using AAS (Atomic Absorption Spectrophotometry). The experiment results show that transport of Chrom (VI) by Supported Liquid membrane (SLM) is influenced by pH solution in feed phase and receiving phase as well as NaCl in receiving phase. The highest chromium metal is transported from feed phase about 97,78%, whereas in receiving phase shows about 58,09%. The highest chromium metal transport happens on pH 6 in feed phase, pH 7 in receiving phase with the mixture of NaOH and NaCl using carrier compound aliquat 336.

  17. High pressure transport and micro-calorimetry studies on quantum phase transitions in Yb heavy fermion systems

    International Nuclear Information System (INIS)

    Colombier, E; Braithwaite, D; Lapertot, G; Salce, B; Knebel, G; Flouquet, J

    2008-01-01

    We present ac microcalorimetry and resistivity measurements under high pressure on new very pure single crystals of YbCu 2 Si 2 having residual resistivity ratios of up to 130 and residual resistivities of less than 1 μΩcm. The onset of magnetic order at high pressure has been detected by ac micro-calorimetry in a diamond anvil cell, and the phase diagram has been established showing magnetic order appearing at 7.6 GPa and 0.95K, and suggesting a possible quantum critical point at a pressure of about 6.5 GPa. The resistivity has been measured under pressure in hydrostatic conditions, but no sign of superconductivity is found close to the expected critical pressure down to T=0.05 K. We discuss these results in comparison with results on cerium based heavy fermion systems

  18. ADVANCED CUTTINGS TRANSPORT STUDY

    Energy Technology Data Exchange (ETDEWEB)

    Troy Reed; Stefan Miska; Nicholas Takach; Kaveh Ashenayi; Gerald Kane; Mark Pickell; Len Volk; Mike Volk; Barkim Demirdal; Affonso Lourenco; Evren Ozbayoglu; Paco Vieira; Lei Zhou

    2000-01-30

    This is the second quarterly progress report for Year 2 of the ACTS project. It includes a review of progress made in Flow Loop development and research during the period of time between Oct 1, 2000 and December 31, 2000. This report presents a review of progress on the following specific tasks: (a) Design and development of an Advanced Cuttings Transport Facility (Task 2: Addition of a foam generation and breaker system), (b) Research project (Task 6): ''Study of Cuttings Transport with Foam Under LPAT Conditions (Joint Project with TUDRP)'', (c) Research project (Task 7): ''Study of Cuttings Transport with Aerated Muds Under LPAT Conditions (Joint Project with TUDRP)'', (d) Research project (Task 8): ''Study of Flow of Synthetic Drilling Fluids Under Elevated Pressure and Temperature Conditions'', (e) Research project (Task 9): ''Study of Foam Flow Behavior Under EPET Conditions'', (f) Research project (Task 10): ''Study of Cuttings Transport with Aerated Mud Under Elevated Pressure and Temperature Conditions'', (g) Research on instrumentation tasks to measure: Cuttings concentration and distribution in a flowing slurry (Task 11), and Foam properties while transporting cuttings. (Task 12), (h) Development of a Safety program for the ACTS Flow Loop. Progress on a comprehensive safety review of all flow-loop components and operational procedures. (Task 1S). (i) Activities towards technology transfer and developing contacts with Petroleum and service company members, and increasing the number of JIP members. The tasks Completed During This Quarter are Task 7 and Task 8.

  19. Transport of Liquid Phase Organic Solutes in Liquid Crystalline Membranes

    OpenAIRE

    Han, Sangil

    2010-01-01

    Porous cellulose nitrate membranes were impregnated with 8CB and PCH5 LCs (liquid crystals) and separations of solutes dissolved in aqueous phases were performed while monitoring solute concentration via UV-VIS spectrometry. The diffusing organic solutes, which consist of one aromatic ring and various functional groups, were selected to exclude molecular size effects on the diffusion and sorption. We studied the effects on solute transport of solute intra-molecular hydrogen bonding and so...

  20. Multi-phase reactive transport theory

    International Nuclear Information System (INIS)

    Lichtner, P.C.

    1995-07-01

    Physicochemical processes in the near-field region of a high-level waste repository may involve a diverse set of phenomena including flow of liquid and gas, gaseous diffusion, and chemical reaction of the host rock with aqueous solutions at elevated temperatures. This report develops some of the formalism for describing simultaneous multicomponent solute and heat transport in a two-phase system for partially saturated porous media. Diffusion of gaseous species is described using the Dusty Gas Model which provides for simultaneous Knudsen and Fickian diffusion in addition to Darcy flow. A new form of the Dusty Gas Model equations is derived for binary diffusion which separates the total diffusive flux into segregative and nonsegregative components. Migration of a wetting front is analyzed using the quasi-stationary state approximation to the Richards' equation. Heat-pipe phenomena are investigated for both gravity- and capillary-driven reflux of liquid water. An expression for the burnout permeability is derived for a gravity-driven heat-pipe. Finally an estimate is given for the change in porosity and permeability due to mineral dissolution which could occur in the region of condensate formation in a heat-pipe

  1. ADVANCED CUTTINGS TRANSPORT STUDY

    Energy Technology Data Exchange (ETDEWEB)

    Ergun Kuru; Stefan Miska; Nicholas Takach; Kaveh Ashenayi; Gerald Kane; Len Volk; Mark Pickell; Evren Ozbayoglu; Barkim Demirdal; Paco Vieira; Affonso Lourenco

    1999-10-15

    This report includes a review of the progress made in ACTF Flow Loop development and research during 90 days pre-award period (May 15-July 14, 1999) and the following three months after the project approval date (July15-October 15, 1999) The report presents information on the following specific subjects; (a) Progress in Advanced Cuttings Transport Facility design and development, (b) Progress report on the research project ''Study of Flow of Synthetic Drilling Fluids Under Elevated Pressure and Temperature Conditions'', (c) Progress report on the research project ''Study of Cuttings Transport with Foam Under LPAT Conditions (Joint Project with TUDRP)'', (d) Progress report on the research project ''Study of Cuttings Transport with Aerated Muds Under LPAT Conditions (Joint Project with TUDRP)'', (e) Progress report on the research project ''Study of Foam Flow Behavior Under EPET Conditions'', (f) Progress report on the instrumentation tasks (Tasks 11 and 12) (g) Activities towards technology transfer and developing contacts with oil and service company members.

  2. A study of acute phase and transport protein synthesis in undernourished men using simulated infection and uniformly 15N-labelled Spirulina Platenses

    International Nuclear Information System (INIS)

    Kurpad, A.V.; Soares, M.J.; Sekhar, R.V.; Reeds, P.J.; Fjeld, C.R.

    1994-01-01

    This study was conducted to test the hypothesis that acute phase protein synthesis is accelerated and transport protein synthesis is decelerated in adult men in whom the stress of infection is superimposed upon undernutrition. As a pilot study, four chronically undernourished men and two well-nourished controls were studied on two occasions separated by four days; the second session was conducted 24 hours after the administration of typhoid vaccine. Basal urine and blood samples were collected and then subjects were given priming oral doses of 15 N-Spirulina (13.5mg/kg body weight) and oral doses (3.5mg/kg body weight) every 30 min for the next six hours. Meals were aliquoted during the dosing period. Blood samples were collected at four, five and six hours. 15 N enrichment in different fractions of plasma i.e., albumin, non-albumin and amino acids, was measured by combustion GC-IRMS. Total urinary nitrogen was measured by Kjeldahl. 5 refs, 2 figs, 3 tabs

  3. Evaluation of atmospheric transport models for use in Phase II of the historical public exposures studies at the Rocky Flats Plant

    Energy Technology Data Exchange (ETDEWEB)

    Rood, A.S.; Killough, G.G.; Till, J.E.

    1999-08-01

    Five atmospheric transport models were evaluated for use in Phase II of the Historical Public Exposures Studies at the Rocky Flats Plant. Models included a simple straight-line Gaussian plume model (ISCST2), several integrated puff models (RATCHET, TRIAD, and INPUFF2), and a complex terrain model (TRAC). Evaluations were based on how well model predictions compared with sulfur hexafluoride tracer measurements taken in the vicinity of Rocky Flats in February 1991. Twelve separate tracer experiments were conducted, each lasting 9 hr and measured at 140 samplers in arcs 8 and 16 km from the release point at Rocky Flats. Four modeling objectives were defined based on the endpoints of the overall study: (1) the unpaired maximum hourly average concentration, (2) paired time-averaged concentration, (3) unpaired time-averaged concentration, and (4) arc-integrated concentration. Performance measures were used to evaluate models and focused on the geometric mean and standard deviation of the predicted-to-observed ratio and the correlation coefficient between predicted and observed concentrations. No one model consistently outperformed the others in all modeling objectives and performance measures. The overall performance of the RATCHET model was somewhat better than the other models.

  4. Inactive trials of transport systems: phase II

    International Nuclear Information System (INIS)

    Haberlin, M.M.; Hardy, A.R.; Kennedy, S.T.

    1986-11-01

    Progress made during 1984-85 is reviewed in four sections: the design and installation of a stainless steel working floor in the mock-up of a crate handling and size reduction facility; the detailed evaluation of a single air pad of the type used on commercial air-transporter; an experimental programme designed to examine the problems associated with the operation of a commercial air-transporter; the design, manufacture and commissioning trials of two powered conveyor units which when combined complete a remotely operated transfer system for transporting crated waste into and within the mock-up facility. (author)

  5. Small scale laboratory studies of flow and transport phenomena in pores and fractures: Phase II. Progress report, 3rd year continuation proposal, and work plan

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, J.L.

    1994-05-01

    Small scale laboratory experiments, equipped with an ability to actually observe behavior on the pore level using microscopy, provide an economical and easily understood scientific tool to help us validate concepts and assumptions about the transport of contaminants, and offers the propensity to discover heretofore unrecognized phenomena or behavior. The main technique employs etched glass micromodels, composed of two etched glass plates, sintered together, to form a two dimensional network of three dimensional pores. Flow and transport behavior is observed on a pore or pore network level, and recorder on film and video tape. This technique is coupled with related column studies. These techniques have been used to study multiphase flow, colloid transport and most recently bacteria transport. The project has recently moved to the Bacteria Transport Subprogram, and efforts have been redirected to support that Subprogram and its collaborative field experiment. We proposed to study bacteria transport factors of relevance to the field experiment, using micromodels and other laboratory techniques. Factors that may be addressed include bacteria characteristics (eg, hydrophobicity), pore size and shape, permeability heterogeneity, surface chemistry (eg, iron oxide coatings), surface chemistry heterogeneity, active versus resting cell bacteria, and mixed bacteria populations. In other work we will continue to examine the effects of fluid-fluid interfaces on bacteria transport, and develop a new assay for bacteria hydrophobicity. Finally we will collaborate on characterization of the field site, and the design, operation, and interpretation of the field experiment.

  6. Road Transportable Analytical Laboratory system. Phase 1

    Energy Technology Data Exchange (ETDEWEB)

    Finger, S.M.; Keith, V.F.; Spertzel, R.O.; De Avila, J.C.; O`Donnell, M.; Vann, R.L.

    1993-09-01

    This developmental effort clearly shows that a Road Transportable Analytical Laboratory System is a worthwhile and achievable goal. The RTAL is designed to fully analyze (radioanalytes, and organic and inorganic chemical analytes) 20 samples per day at the highest levels of quality assurance and quality control. It dramatically reduces the turnaround time for environmental sample analysis from 45 days (at a central commercial laboratory) to 1 day. At the same time each RTAL system will save the DOE over $12 million per year in sample analysis costs compared to the costs at a central commercial laboratory. If RTAL systems were used at the eight largest DOE facilities (at Hanford, Savannah River, Fernald, Oak Ridge, Idaho, Rocky Flats, Los Alamos, and the Nevada Test Site), the annual savings would be $96,589,000. The DOE`s internal study of sample analysis needs projects 130,000 environmental samples requiring analysis in FY 1994, clearly supporting the need for the RTAL system. The cost and time savings achievable with the RTAL system will accelerate and improve the efficiency of cleanup and remediation operations throughout the DOE complex.

  7. Dual phase oxygen transport membrane for efficient oxyfuel combustion

    International Nuclear Information System (INIS)

    Ramasamy, Madhumidha

    2016-01-01

    Oxygen transport membranes (OTMs) are attracting great interest for the separation of oxygen from air in an energy efficient way. A variety of solid oxide ceramic materials that possess mixed ionic and electronic conductivity (MIEC) are being investigated for efficient oxygen separation (Betz '10, Skinner '03). Unfortunately these materials do not exhibit high degradation stability under harsh ambient conditions such as flue gas containing CO_2, SO_x, H_2O and dust, pressure gradients and high temperatures that are typical in fossil fuel power plants. For this reason, dual phase composite membranes are developed to combine the best characteristics of different compounds to achieve high oxygen permeability and sufficient chemical and mechanical stability at elevated temperatures. In this thesis, the dual phase membrane Ce_0_._8Gd_0_._2O_2_-_δ - FeCo_2O_4 (CGO-FCO) was developed after systematic investigation of various combinations of ionic and electronic conductors. The phase distribution of the composite was investigated in detail using electron microscopes and this analysis revealed the phase interaction leading to grain boundary rock salt phase and formation of perovskite secondary phase. A systematic study explored the onset of phase interactions to form perovskite phase and the role of this unintended phase as pure electronic conductor was identified. Additionally optimization of conventional sintering process to eliminate spinel phase decomposition into rock salt was identified. An elaborate study on the absolute minimum electronic conductor requirement for efficient percolation network was carried out and its influence on oxygen flux value was measured. Oxygen permeation measurements in the temperature range of 600 C - 1000 C under partial pressure gradient provided by air and argon as feed and sweep gases are used to identify limiting transport processes. The dual phase membranes are much more prone to surface exchange limitations because of the limited

  8. Dual phase oxygen transport membrane for efficient oxyfuel combustion

    Energy Technology Data Exchange (ETDEWEB)

    Ramasamy, Madhumidha

    2016-07-01

    Oxygen transport membranes (OTMs) are attracting great interest for the separation of oxygen from air in an energy efficient way. A variety of solid oxide ceramic materials that possess mixed ionic and electronic conductivity (MIEC) are being investigated for efficient oxygen separation (Betz '10, Skinner '03). Unfortunately these materials do not exhibit high degradation stability under harsh ambient conditions such as flue gas containing CO{sub 2}, SO{sub x}, H{sub 2}O and dust, pressure gradients and high temperatures that are typical in fossil fuel power plants. For this reason, dual phase composite membranes are developed to combine the best characteristics of different compounds to achieve high oxygen permeability and sufficient chemical and mechanical stability at elevated temperatures. In this thesis, the dual phase membrane Ce{sub 0.8}Gd{sub 0.2}O{sub 2-δ} - FeCo{sub 2}O{sub 4} (CGO-FCO) was developed after systematic investigation of various combinations of ionic and electronic conductors. The phase distribution of the composite was investigated in detail using electron microscopes and this analysis revealed the phase interaction leading to grain boundary rock salt phase and formation of perovskite secondary phase. A systematic study explored the onset of phase interactions to form perovskite phase and the role of this unintended phase as pure electronic conductor was identified. Additionally optimization of conventional sintering process to eliminate spinel phase decomposition into rock salt was identified. An elaborate study on the absolute minimum electronic conductor requirement for efficient percolation network was carried out and its influence on oxygen flux value was measured. Oxygen permeation measurements in the temperature range of 600 C - 1000 C under partial pressure gradient provided by air and argon as feed and sweep gases are used to identify limiting transport processes. The dual phase membranes are much more prone to surface

  9. Phase controlled rectifier study

    International Nuclear Information System (INIS)

    Bronner, G.; Murray, J.G.

    1976-03-01

    This report introduces the results of an engineering study incorporating a computer program to determine the transient and steady-state voltage and current wave shapes for a 12-pulse rectifier system. Generally, rectifier engineering studies are completed by making simplified assumptions and neglecting many circuit parameters. The studies incorporate the 3-phase AC parameters including nonlinear source or generator, 3-winding transformer impedances, and shunt and series capacitors. It includes firing angle control, and DC filter circuits with inductive loads

  10. Gas-phase transport of fission products

    International Nuclear Information System (INIS)

    Tang, I.N.; Munkelwitz, H.R.

    1982-01-01

    The paper presents the results of an experimental investigation to show the importance of nuclear aerosol formation as a mechanism for semi-volatile fission product transport under certain postulated HTGR accident conditions. Simulated fission product Sr and Ba as oxides are impregnated in H451 graphite and released at elevated temperatures into a dry helium flow. In the presence of graphite, the oxides are quantitatively reduced to metals, which subsequently vaporize at temperatures much lower than required for the oxides alone to vaporize in the absence of graphite. A substantial fraction of the released material is associated with particulate matter, which is collected on filters located downstream at ambient temperatures. Increasing carrier-gas flow rate greatly enhances the extent of particulate transport. The release and transport of simulated fission product Ag as metal are also investigated. Electron microscopic examinations of the collected Sr and Ag aerosols show large agglomerates composed of primary particles roughly 0.06 to 0.08 μm in diameter

  11. 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

  12. Stowing of radioactive materials package during land transport. Third phase

    International Nuclear Information System (INIS)

    Gilles, P.; Chevalier, G.; Pouard, M.; Jolys, J.C.; Draulans, J.; Lafontaine, I.

    1984-01-01

    Phase 3 of this study is mainly experimental. The study is based on the work performed during 2 former studies: phase 1: definition and analysis of reference accidental conditions, and phase 2: selection of some reference accidents and computation of the deceleration forces. The main goal of the study is to draw up a reference document, giving some guidances for the stowing of packages on conveyances for land transportation. The third phase includes four frontal impact tests. The reference package used is a French IL-37 container weighing about 1.3 t. The first test was performed using a truck, loaded with two IL-37 containers and launched at a speed of 50 km/h against a fixed obstacle. The deceleration curve the behaviour of each package and the behaviour of stowing systems are compared with the theoretical results. Various measurements were made during the test: vehicle impact speed; vehicle deceleration, measured at different points on the frame, package deceleration, displacement of attachment points. The impact was filmed from different angles. The second test was performed in the same impact conditions but with a waggon instead of a truck, and loaded with one container. The front of the waggon was equipped with special shock absorbers to obtain the same deceleration as recorded during the truck impact (first test). In the third test the stowing systems were reinforced by a nylon one in order to obtain information of stowing systems of that type and to increase the energy absorption capacity. In the fourth test in addition to being stowed the package was also chocked. The results obtained have shown that it is possible to maintain a package on a truck platform even during a severe frontal impact

  13. Ion transport and phase transformation in thin film intercalation electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Wunde, Fabian; Nowak, Susann; Muerter, Juliane; Hadjixenophontos, Efi; Berkemeier, Frank; Schmitz, Guido [Stuttgart Univ. (Germany). Inst. fuer Materialwissenschaft

    2017-11-15

    Thin film battery electrodes of the olivine structure LiFePO{sub 4} and the spinel phase LiMn{sub 2}O{sub 4} are deposited through ion-beam sputtering. The intercalation kinetics is studied by cyclo-voltammetry using variation of the cycling rate over 4 to 5 orders of magnitude. The well-defined layer geometry allows a detailed quantitative analysis. It is shown that LiFePO{sub 4} clearly undergoes phase separation during intercalation, although the material is nano-confined and very high charging rates are applied. We present a modified Randles-Sevcik evaluation adapted to phase-separating systems. Both the charging current and the overpotential depend on the film thickness in a systematic way. The analysis yields evidence that the grain boundaries are important short circuit paths for fast transport. They increase the electrochemical active area with increasing layer thickness. Evidence is obtained that the grain boundaries in LiFePO{sub 4} have the character of an ion-conductor of vanishing electronic conductivity.

  14. Studies of Turbulence and Transport in Alcator C-Mod H-Mode Plasmas with Phase Contrast Imaging and Comparisons with GYRO

    Science.gov (United States)

    Porkolab, M.; Lin, L.; Edlund, E. M.; Rost, J. C.; Fiore, C. L.; Greenwald, M.; Mikkelsen, D.

    2008-11-01

    We present recent experimental measurements of turbulence and transport in C-Mod H-Mode plasmas with and without internal transport barriers (ITB) using the phase contrast imaging (PCI) diagnostic and compare the results with GYRO predictions. In plasmas without ITB, the fluctuation above 300 kHz observed by PCI agrees with ITG in GYRO simulation, including the direction of propagation, wavenumber spectrum, and absolute intensity within experimental uncertainly (+/-75%). After transition to ITBs, the observed overall fluctuation intensity increases. GYRO simulation in the core shows that ITG dominates in ITBs but its intensity is lower than the overall experimental measurements which may also include contributions from the plasma edge. These results, as well as the impact of varying ∇Ti, ∇n, and ExB shear on turbulence will be discussed. C.L. Fiore et al., Fusion Sci. Technol., 51, 303 (2007). M. Porkolab et al., IEEE Trans. Plasma Sci. 34, 229 (2006). J. Candy et al., Phys. Rev. Lett., 91, 045001 (2003).

  15. Recent Advances in Understanding of Kinetic Interplay Between Phase II Metabolism and Efflux Transport.

    Science.gov (United States)

    Wang, Shuai; Xing, Huijie; Zhao, Mengjing; Lu, Danyi; Li, Zhijie; Dong, Dong; Wu, Baojian

    2016-01-01

    Mechanistic understanding of the metabolism-transport interplay assumes great importance in pharmaceutical fields because the knowledge can help to interpret drug/xenobiotic metabolism and disposition studies as well as the drug-drug interactions in vivo. About 10 years ago, it started to recognize that cellular phase II metabolism is strongly influenced by the excretion (efflux transport) of generated metabolites, a kinetic phenomenon termed "phase II metabolism-transport interplay". This interplay is believed to have significant effects on the pharmacokinetics (bioavailability) of drugs/chemicals undergoing phase II metabolism. In this article, we review the studies investigating the phase II metabolism-transport interplay using cell models, perfused rat intestine, and intact rats. The potential confounding factors in exploring such interplay is also summarized. Moreover, the mechanism underlying the phase II metabolism-transport interplay is discussed. Various studies with engineered cells and rodents have demonstrated that there is an interaction (interplay) between phase II enzymes and efflux transporters. This type of interplay mainly refers to the dependence of phase II (conjugative) metabolism on the activities of efflux transporters. In general, inhibiting efflux transporters or decreasing their expression causes the reductions in metabolite excretion, apparent excretion clearance (CLapp) and total metabolism (fmet), as well as an increase in the intracellular level of metabolite (Ci). The deconjugation mediated by hydrolase (acting as a "bridge") is essential for the interplay to play out based on pharmacokinetic modeling/simulations, cell and animal studies. The hydrolases bridge the two processes (i.e., metabolite formation and excretion) and enable the interplay thereof (a bridging effect). Without the bridge, metabolite formation is independent on its downstream process excretion, thus impact of metabolite excretion on its formation is impossible

  16. Options Study - Phase II

    Energy Technology Data Exchange (ETDEWEB)

    R. Wigeland; T. Taiwo; M. Todosow; W. Halsey; J. Gehin

    2010-09-01

    The Options Study has been conducted for the purpose of evaluating the potential of alternative integrated nuclear fuel cycle options to favorably address the issues associated with a continuing or expanding use of nuclear power in the United States. The study produced information that can be used to inform decisions identifying potential directions for research and development on such fuel cycle options. An integrated nuclear fuel cycle option is defined in this study as including all aspects of the entire nuclear fuel cycle, from obtaining natural resources for fuel to the ultimate disposal of used nuclear fuel (UNF) or radioactive wastes. Issues such as nuclear waste management, especially the increasing inventory of used nuclear fuel, the current uncertainty about used fuel disposal, and the risk of nuclear weapons proliferation have contributed to the reluctance to expand the use of nuclear power, even though it is recognized that nuclear power is a safe and reliable method of producing electricity. In this Options Study, current, evolutionary, and revolutionary nuclear energy options were all considered, including the use of uranium and thorium, and both once-through and recycle approaches. Available information has been collected and reviewed in order to evaluate the ability of an option to clearly address the challenges associated with the current implementation and potential expansion of commercial nuclear power in the United States. This Options Study is a comprehensive consideration and review of fuel cycle and technology options, including those for disposal, and is not constrained by any limitations that may be imposed by economics, technical maturity, past policy, or speculated future conditions. This Phase II report is intended to be used in conjunction with the Phase I report, and much information in that report is not repeated here, although some information has been updated to reflect recent developments. The focus in this Options Study was to

  17. ADVANCED CUTTINGS TRANSPORT STUDY

    Energy Technology Data Exchange (ETDEWEB)

    Stefan Miska; Nicholas Takach; Kaveh Ashenayi; Mengjiao Yu; Ramadan Ahmed; Mark Pickell; Len Volk; Lei Zhou; Zhu Chen; Aimee Washington; Crystal Redden

    2003-09-30

    The Quarter began with installing the new drill pipe, hooking up the new hydraulic power unit, completing the pipe rotation system (Task 4 has been completed), and making the SWACO choke operational. Detailed design and procurement work is proceeding on a system to elevate the drill-string section. The prototype Foam Generator Cell has been completed by Temco and delivered. Work is currently underway to calibrate the system. Literature review and preliminary model development for cuttings transportation with polymer foam under EPET conditions are in progress. Preparations for preliminary cuttings transport experiments with polymer foam have been completed. Two nuclear densitometers were re-calibrated. Drill pipe rotation system was tested up to 250 RPM. Water flow tests were conducted while rotating the drill pipe up to 100 RPM. The accuracy of weight measurements for cuttings in the annulus was evaluated. Additional modifications of the cuttings collection system are being considered in order to obtain the desired accurate measurement of cuttings weight in the annular test section. Cutting transport experiments with aerated fluids are being conducted at EPET, and analyses of the collected data are in progress. The printed circuit board is functioning with acceptable noise level to measure cuttings concentration at static condition using ultrasonic method. We were able to conduct several tests using a standard low pass filter to eliminate high frequency noise. We tested to verify that we can distinguish between different depths of sand in a static bed of sand. We tested with water, air and a mix of the two mediums. Major modifications to the DTF have almost been completed. A stop-flow cell is being designed for the DTF, the ACTF and Foam Generator/Viscometer which will allow us to capture bubble images without the need for ultra fast shutter speeds or microsecond flash system.

  18. ADVANCED CUTTINGS TRANSPORT STUDY

    Energy Technology Data Exchange (ETDEWEB)

    Ergun Kuru; Stefan Miska; Nicholas Takach; Kaveh Ashenayi; Gerald Kane; Mark Pickell; Len Volk; Mike Volk; Barkim Demirdal; Affonso Lourenco; Evren Ozbayoglu; Paco Vieira; Neelima Godugu

    2000-07-30

    ACTS flow loop is now operational under elevated pressure and temperature. Currently, experiments with synthetic based drilling fluids under pressure and temperature are being conducted. Based on the analysis of Fann 70 data, empirical correlations defining the shear stress as a function of temperature, pressure and the shear rate have been developed for Petrobras synthetic drilling fluids. PVT equipment has been modified for testing Synthetic oil base drilling fluids. PVT tests with Petrobras Synthetic base mud have been conducted and results are being analyzed Foam flow experiments have been conducted and the analysis of the data has been carried out to characterize the rheology of the foam. Comparison of pressure loss prediction from the available foam hydraulic models and the test results has been made. Cuttings transport experiments in horizontal annulus section have been conducted using air, water and cuttings. Currently, cuttings transport tests in inclined test section are being conducted. Foam PVT analysis tests have been conducted. Foam stability experiments have also been conducted. Effects of salt and oil concentration on the foam stability have been investigated. Design of ACTS flow loop modification for foam and aerated mud flow has been completed. A flow loop operation procedure for conducting foam flow experiments under EPET conditions has been prepared Design of the lab-scale flow loop for dynamic foam characterization and cuttings monitoring instrumentation tests has been completed. The construction of the test loop is underway. As part of the technology transport efforts, Advisory Board Meeting with ACTS-JIP industry members has been organized on May 13, 2000.

  19. Study of rural transportation issues.

    Science.gov (United States)

    2010-04-01

    This report is in response to Section 6206 of the Food, Conservation, and Energy Act of 2008 (PL : 110-246), which directs the Secretaries of Agriculture and Transportation jointly to conduct a : study of rural transportation issues. The report revie...

  20. Phase coherent transport in hybrid superconductor-topological insulator devices

    Science.gov (United States)

    Finck, Aaron

    2015-03-01

    Heterostructures of superconductors and topological insulators are predicted to host unusual zero energy bound states known as Majorana fermions, which can robustly store and process quantum information. Here, I will discuss our studies of such heterostructures through phase-coherent transport, which can act as a unique probe of Majorana fermions. We have extensively explored topological insulator Josephson junctions through SQUID and single-junction diffraction patterns, whose unusual behavior give evidence for low-energy Andreev bound states. In topological insulator devices with closely spaced normal and superconducting leads, we observe prominent Fabry-Perot oscillations, signifying gate-tunable, quasi-ballistic transport that can elegantly interact with Andreev reflection. Superconducting disks deposited on the surface of a topological insulator generate Aharonov-Bohm-like oscillations, giving evidence for unusual states lying near the interface between the superconductor and topological insulator surface. Our results point the way towards sophisticated interferometers that can detect and read out the state of Majorana fermions in topological systems. This work was done in collaboration with Cihan Kurter, Yew San Hor, and Dale Van Harlingen. We acknowledge funding from Microsoft Project Q.

  1. STOMP, Subsurface Transport Over Multiple Phases, theory guide

    International Nuclear Information System (INIS)

    White, M.D.; Oostrom, M.

    1996-10-01

    This guide describes the simulator's governing equations, constitutive functions and numerical solution algorithms of the STOMP (Subsurface Transport Over Multiple Phases) simulator, a scientific tool for analyzing multiple phase subsurface flow and transport. The STOMP simulator's fundamental purpose is to produce numerical predictions of thermal and hydrologic flow and transport phenomena in variably saturated subsurface environments, which are contaminated with volatile or nonvolatile organic compounds. Auxiliary applications include numerical predictions of solute transport processes including radioactive chain decay processes. In writing these guides for the STOMP simulator, the authors have assumed that the reader comprehends concepts and theories associated with multiple-phase hydrology, heat transfer, thermodynamics, radioactive chain decay, and nonhysteretic relative permeability, saturation-capillary pressure constitutive functions. The authors further assume that the reader is familiar with the computing environment on which they plan to compile and execute the STOMP simulator. The STOMP simulator requires an ANSI FORTRAN 77 compiler to generate an executable code. The memory requirements for executing the simulator are dependent on the complexity of physical system to be modeled and the size and dimensionality of the computational domain. Likewise execution speed depends on the problem complexity, size and dimensionality of the computational domain, and computer performance. One-dimensional problems of moderate complexity can be solved on conventional desktop computers, but multidimensional problems involving complex flow and transport phenomena typically require the power and memory capabilities of workstation or mainframe type computer systems

  2. ADVANCED CUTTINGS TRANSPORT STUDY

    Energy Technology Data Exchange (ETDEWEB)

    Stefan Miska; Nicholas Takach; Kaveh Ashenayi

    2004-01-31

    Final design of the mast was completed (Task 5). The mast is consisting of two welded plate girders, set next to each other, and spaced 14-inches apart. Fabrication of the boom will be completed in two parts solely for ease of transportation. The end pivot connection will be made through a single 2-inch diameter x 4 feet-8 inch long 316 SS bar. During installation, hard piping make-ups using Chiksan joints will connect the annular section and 4-inch return line to allow full movement of the mast from horizontal to vertical. Additionally, flexible hoses and piping will be installed to isolate both towers from piping loads and allow recycling operations respectively. Calibration of the prototype Foam Generator Cell has been completed and experiments are now being conducted. We were able to generate up to 95% quality foam. Work is currently underway to attach the Thermo-Haake RS300 viscometer and install a view port with a microscope to measure foam bubble size and bubble size distribution. Foam rheology tests (Task 13) were carried out to evaluate the rheological properties of the proposed foam formulation. After successful completion of the first foam test, two sets of rheological tests were conducted at different foam flow rates while keeping other parameters constant (100 psig, 70F, 80% quality). The results from these tests are generally in agreement with the previous foam tests done previously during Task 9. However, an unanticipated observation during these tests was that in both cases, the frictional pressure drop in 2 inch pipe was lower than that in the 3 inch and 4 inch pipes. We also conducted the first foam cuttings transport test during this quarter. Experiments on aerated fluids without cuttings have been completed in ACTF (Task 10). Gas and liquid were injected at different flow rates. Two different sets of experiments were carried out, where the only difference was the temperature. Another set of tests was performed, which covered a wide range of

  3. Non-local two phase flow momentum transport in S BWR

    International Nuclear Information System (INIS)

    Espinosa P, G.; Salinas M, L.; Vazquez R, A.

    2015-09-01

    The non-local momentum transport equations derived in this work contain new terms related with non-local transport effects due to accumulation, convection, diffusion and transport properties for two-phase flow. For instance, they can be applied in the boundary between a two-phase flow and a solid phase, or in the boundary of the transition region of two-phase flows where the local volume averaging equations fail. The S BWR was considered to study the non-local effects on the two-phase flow thermal-hydraulic core performance in steady-state, and the results were compared with the classical local averaging volume conservation equations. (Author)

  4. Non-local two phase flow momentum transport in S BWR

    Energy Technology Data Exchange (ETDEWEB)

    Espinosa P, G.; Salinas M, L.; Vazquez R, A., E-mail: gepe@xanum.uam.mx [Universidad Autonoma Metropolitana, Unidad Iztapalapa, Area de Ingenieria en Recursos Energeticos, Apdo. Postal 55-535, 09340 Ciudad de Mexico (Mexico)

    2015-09-15

    The non-local momentum transport equations derived in this work contain new terms related with non-local transport effects due to accumulation, convection, diffusion and transport properties for two-phase flow. For instance, they can be applied in the boundary between a two-phase flow and a solid phase, or in the boundary of the transition region of two-phase flows where the local volume averaging equations fail. The S BWR was considered to study the non-local effects on the two-phase flow thermal-hydraulic core performance in steady-state, and the results were compared with the classical local averaging volume conservation equations. (Author)

  5. The liquid phase epitaxy approach for the successful construction of ultra-thin and defect-free ZIF-8 membranes: Pure and mixed gas transport study

    KAUST Repository

    Shekhah, Osama; Swaidan, Raja; Belmabkhout, Youssef; Du Plessis, Marike; Jacobs, Tia; Barbour, Leonard J.; Pinnau, Ingo; Eddaoudi, Mohamed

    2014-01-01

    The liquid-phase epitaxy (LPE) method was effectively implemented to deliberately grow/construct ultrathin (0.5-1 μm) continuous and defect-free ZIF-8 membranes. Permeation properties of different gas pair systems (O 2-N2, H2-CO2, CO2-CH 4, C3H6-C3H8, CH 4-n-C4H10) were studied using the time lag technique. This journal is © The Royal Society of Chemistry.

  6. ADVANCED CUTTINGS TRANSPORT STUDY

    Energy Technology Data Exchange (ETDEWEB)

    Stefan Miska; Nicholas Takach; Kaveh Ashenayi

    2004-07-31

    We have tested the loop elevation system. We raised the mast to approximately 25 to 30 degrees from horizontal. All went well. However, while lowering the mast, it moved laterally a couple of degrees. Upon visual inspection, severe spalling of the concrete on the face of the support pillar, and deformation of the steel support structure was observed. At this time, the facility is ready for testing in the horizontal position. A new air compressor has been received and set in place for the ACTS test loop. A new laboratory has been built near the ACTS test loop Roughened cups and rotors for the viscometer (RS300) were obtained. Rheologies of aqueous foams were measured using three different cup-rotor assemblies that have different surface roughness. The relationship between surface roughness and foam rheology was investigated. Re-calibration of nuclear densitometers has been finished. The re-calibration was also performed with 1% surfactant foam. A new cuttings injection system was installed at the bottom of the injection tower. It replaced the previous injection auger. A mechanistic model for cuttings transport with aerated mud has been developed. Cuttings transport mechanisms with aerated water at various conditions were experimentally investigated. A total of 39 tests were performed. Comparisons between the model predictions and experimental measurements show a satisfactory agreement. Results from the ultrasonic monitoring system indicated that we could distinguish between different sand levels. We also have devised ways to achieve consistency of performance by securing the sensors in the caps in exactly the same manner as long as the sensors are not removed from the caps. A preliminary test was conducted on the main flow loop at 100 gpm flow rate and 20 lb/min cuttings injection rate. The measured bed thickness using the ultrasonic method showed a satisfactory agreement with nuclear densitometer readings. Thirty different data points were collected after the test

  7. Mass transport in Ti0.5Sb2Te3 phase-change nanobridge

    International Nuclear Information System (INIS)

    Ji, Xinglong; Wu, Liangcai; Lv, Shilong; Rao, Feng; Zhu, Min; Song, Zhitang; Zhou, Xilin; Feng, Songlin

    2014-01-01

    Investigation of atomic migration behavior in nanoscale phase-change material is very valuable for phase-change memory applications. In this work, Ti 0.5 Sb 2 Te 3 -based phase-change nanobridges were fabricated and mass transport by atomic migration was studied. A 3-D finite-element simulation on the electrothermal field was introduced to describe the electrothermal environment in the phase-change region. During the nanosecond operation, an obvious compositional distribution resulting from atomic migration was observed in the Ti 0.5 Sb 2 Te 3 phase-change nanobridge. Based on the mass continuity equation, a physical model for mass transport is proposed to illustrate that the density variation during the amorphous-to-crystalline structural transformation is the main reason for the atomic migration in nanoscale Ti 0.5 Sb 2 Te 3 phase-change material

  8. Generalized transport model for phase transition with memory

    International Nuclear Information System (INIS)

    Chen, Chi; Ciucci, Francesco

    2013-01-01

    A general model for phenomenological transport in phase transition is derived, which extends Jäckle and Frisch model of phase transition with memory and the Cahn–Hilliard model. In addition to including interfacial energy to account for the presence of interfaces, we introduce viscosity and relaxation contributions, which result from incorporating memory effect into the driving potential. Our simulation results show that even without interfacial energy term, the viscous term can lead to transient diffuse interfaces. From the phase transition induced hysteresis, we discover different energy dissipation mechanism for the interfacial energy and the viscosity effect. In addition, by combining viscosity and interfacial energy, we find that if the former dominates, then the concentration difference across the phase boundary is reduced; conversely, if the interfacial energy is greater then this difference is enlarged.

  9. Electronic transport in amorphous phase-change materials

    Energy Technology Data Exchange (ETDEWEB)

    Luckas, Jennifer Maria

    2012-09-14

    Phase change materials combine a pronounced contrast in resistivity and reflectivity between their disordered amorphous and ordered crystalline state with very fast crystallization kinetics. Due to this exceptional combination of properties phase-change materials find broad application in non-volatile optical memories such as CD, DVD or Bluray Disc. Furthermore, this class of materials demonstrates remarkable electrical transport phenomena in their disordered state, which have shown to be crucial for their application in electronic storage devices. The threshold switching phenomenon denotes the sudden decrease in resistivity beyond a critical electrical threshold field. The threshold switching phenomenon facilitates the phase transitions at practical small voltages. Below this threshold the amorphous state resistivity is thermally activated and is observed to increase with time. This effect known as resistance drift seriously hampers the development of multi-level storage devices. Hence, understanding the physical origins of threshold switching and resistance drift phenomena is crucial to improve non-volatile phase-change memories. Even though both phenomena are often attributed to localized defect states in the band gap, the defect state density in amorphous phase-change materials has remained poorly studied. Starting from a brief introduction of the physics of phase-change materials this thesis summarizes the most important models behind electrical switching and resistance drift with the aim to discuss the role of localized defect states. The centerpiece of this thesis is the investigation of defects state densities in different amorphous phase-change materials and electrical switching chalcogenides. On the basis of Modulated Photo Current (MPC) Experiments and Photothermal Deflection Spectroscopy, a sophisticated band model for the disordered phase of the binary phase-change alloy GeTe has been developed. By this direct experimental approach the band-model for a

  10. Electronic transport in amorphous phase-change materials

    International Nuclear Information System (INIS)

    Luckas, Jennifer Maria

    2012-01-01

    Phase change materials combine a pronounced contrast in resistivity and reflectivity between their disordered amorphous and ordered crystalline state with very fast crystallization kinetics. Due to this exceptional combination of properties phase-change materials find broad application in non-volatile optical memories such as CD, DVD or Bluray Disc. Furthermore, this class of materials demonstrates remarkable electrical transport phenomena in their disordered state, which have shown to be crucial for their application in electronic storage devices. The threshold switching phenomenon denotes the sudden decrease in resistivity beyond a critical electrical threshold field. The threshold switching phenomenon facilitates the phase transitions at practical small voltages. Below this threshold the amorphous state resistivity is thermally activated and is observed to increase with time. This effect known as resistance drift seriously hampers the development of multi-level storage devices. Hence, understanding the physical origins of threshold switching and resistance drift phenomena is crucial to improve non-volatile phase-change memories. Even though both phenomena are often attributed to localized defect states in the band gap, the defect state density in amorphous phase-change materials has remained poorly studied. Starting from a brief introduction of the physics of phase-change materials this thesis summarizes the most important models behind electrical switching and resistance drift with the aim to discuss the role of localized defect states. The centerpiece of this thesis is the investigation of defects state densities in different amorphous phase-change materials and electrical switching chalcogenides. On the basis of Modulated Photo Current (MPC) Experiments and Photothermal Deflection Spectroscopy, a sophisticated band model for the disordered phase of the binary phase-change alloy GeTe has been developed. By this direct experimental approach the band-model for a

  11. Computational methods for two-phase flow and particle transport

    CERN Document Server

    Lee, Wen Ho

    2013-01-01

    This book describes mathematical formulations and computational methods for solving two-phase flow problems with a computer code that calculates thermal hydraulic problems related to light water and fast breeder reactors. The physical model also handles the particle and gas flow problems that arise from coal gasification and fluidized beds. The second part of this book deals with the computational methods for particle transport.

  12. Study of three-phase flow vertical patterns applied to the lift and transport of heavy oil; Estudo dos padroes de fluxo trifasico vertical aplicado a elevacao e transporte de oleos pesados

    Energy Technology Data Exchange (ETDEWEB)

    Vieira, Fernando Fabris; Bannwart, Antonio C. [Universidade Estadual de Campinas, SP (Brazil)

    2003-07-01

    The E and P activity has a great importance in the oil industry. First, it assesses hydrocarbon reserves that can be recovered in order to provide the highest revenues. Second, it supplies the forecast oil and gas production through adequate lift and transportation methods. These flows become rather difficult and requires high investments for heavy oils, which can be understood as having density larger than 934 kg/m{sup 3} (API grade smaller than about 20) and viscosity higher than 100 cP at reservoir conditions. In this work, the flow of a heavy crude oil and air mixture was made viable by injecting water in the pipe, in order to lubricate the flow and reduce pressure drop, as in the core flow technique. The main objective is to observe the three-phase flow patterns formed in the vertical pipe at different mixture compositions, for application in artificial lift. The oil flow rate was measured through a mass flow meter. Water and gas flow rates were given by rotameters. A high-speed VHS camera (1000 frames/s) attached to the pipeline was used to record the experiments for the determination of the final patterns. These are described and represented in flow maps. (author)

  13. Dynamic transport study of the plasmas with transport improvement in LHD and JT-60U

    International Nuclear Information System (INIS)

    Ida, K.; Inagaki, S.; Sakamoto, R.; Tanaka, K.; Funaba, H.; Kubo, S.; Yoshinuma, M.; Shimozuma, T.; Takeiri, Y.; Ikeda, K.; Michael, C.; Tokuzawa, T.; Sakamoto, Yoshiteru; Takenaga, Hidenobu; Isayama, Akihiko; Ide, Shunsuke; Fujita, Takaaki

    2006-10-01

    A transport analysis during the transient phase of heating (a dynamic transport study) applied to the plasma with internal transport barriers (ITBs) in the Large Helical Device (LHD) heliotron and JT-60U tokamak is described. In the dynamic transport study 1) a slow transition between two transport branches is observed, 2) the time of the transition from the L-mode plasma to the ITB plasma is clearly determined by the onset of the flattening of the temperature profile in the core region and 3) a spontaneous phase transition from a weak, wide ITB to a strong, narrow ITB and its back-transition are observed. The flattening of the core region of the ITB transition and the back-transition between a wide ITB and a narrow ITB suggest the strong interaction of turbulent transport in space, where turbulence suppression at certain locations in the plasma causes the enhancement of turbulence and thermal diffusivity nearby. (author)

  14. Interfacial structures and area transport in upward and downward two-phase flow

    International Nuclear Information System (INIS)

    Paranjape, S. S.; Kim, S.; Ishii, M.; Kelly, J.

    2003-01-01

    An experimental study has been carried out for upward and downward two-phase flow to study local interfacial structures and interfacial area transport. The flow studied, is an adiabatic, air-water, co-current, two-phase flow, in 25.4 mm and 50.8 mm ID test sections. Flow regime map is obtained using the characteristic signals obtained from an impedance void meter, employing neural network based identification methodology. A four sensor conductivity probe is used to measure the local two phase flow parameters, in bubbly flow regime. The local profiles of these parameters as well as their axial development reveal the nature of the interfacial structures and the bubble interaction mechanisms occurring in the flow. Furthermore, this study provides a good database for the development of the interfacial area transport equation, which dynamically models the changes in the interfacial area along a flow field. An interfacial area transport equation is used for downward flow based on that developed for the upward flow, with certain modifications in the bubble interaction terms. The area averaged values of the interfacial area concentration are compared with those predicted by the interfacial area transport model. The differences in the interfacial structures and interfacial area transport in co-current downward and upward two-phase flows are studied

  15. Overview of TFTR transport studies

    International Nuclear Information System (INIS)

    Hawryluk, R.J.; Arunasalam, V.; Beer, M.; Bell, M.; Bell, R.; Biglari, H.; Bitter, M.; Boivin, R.; Bretz, N.L.; Budny, R.; Cheng, C.Z.; Chu, T.K.; Cohen, S.A.; Cowley, S.; Efthimion, P.C.; Fredrickson, E.; Furth, H.P.; Goldston, R.J.; Greene, G.; Grek, B.; Grisham, L.R.; Hammett, G.; Hill, K.W.; Hosea, J.; Hulse, R.A.; Hsuan, H.; Janos, A.; Jassby, D.; Jobes, F.C.; Johnson, D.W.; Johnson, L.C.; Kieras-Phillips, C.; Kilpatrick, S.J.; Kugel, H.; La Marche, P.H.; LeBlanc, B.; Manos, D.M.; Mansfield, D.K.; Mazzucato, E.; McCarthy, M.P.; McCune, D.C.; McGuire, K.M.; Meade, D.M.; Medley, S.S.; Mikkelsen, D.R.; Monticello, D.; Motley, R.; Mueller, D.; Nazikian, R.; Owens, D.K.; Park, H.; Park, W.; Paul, S.; Perkins, F.; Ramsey, A.T.; Redi, M.H.; Rewoldt, G.; Roquemore, A.L.; Rutherford, P.H.; Schilling, G.; Schivell, J.; Schmidt, G.L.; Scott, S.D.; Stevens, J.; Stratton, B.C.; Stodiek, W.; Synakowski, E.; Tang, W.; Taylor, G.; Timberlake, J.R.; Towner, H.H.; Ulrickson, M.; von Goeler, S.; Wieland, R.; Williams, M.; Wilson, J.R.; Wong, K.L.; Yamada, M.; Yoshikawa, S.; Young, K.M.; Zarnstorff, M.C.; Zweben, S.J.; Bush, C.E.; Fonck, R.J; Roberts, D.; Heidbrink, W.; Kesner, J.; Marmar, E.S.; Snipes, J.; Takase, Y.; Terry, J.; Mauel, M.; Navratil, G.A.; Sabbagh, S.; Nagayama, Y.; Pitcher, S.

    1991-10-01

    A review of TFTR plasma transport studies is presented. Parallel transport and the confinement of suprathermal ions are found to be relatively well described by theory. Cross-field transport of the thermal plasma, however, is anomalous with the momentum diffusivity being comparable to the ion thermal diffusivity and larger than the electron thermal diffusivity in neutral beam heated discharges. Perturbative experiments have studied non-linear dependencies in the transport coefficients and examined the role of possible non-local phenomena. The underlying turbulence has been studied using microwave scattering, beam emission spectroscopy and microwave reflectometry over a much broader range in k perpendicular than previously possible. Results indicate the existence of large-wavelength fluctuations correlated with enhanced transport. MHD instabilities set important operational constraints. However, by modifying the current profile using current ramp-down techniques, it has been possible to extend the operating regime to higher values of both var-epsilon β p and normalized β T . In addition, the interaction of MHD fluctuations with fast ions, of potential relevance to α-particle confinement in D-T plasmas, has been investigated. The installation of carbon-carbon composite tiles and improvements in wall conditioning, in particular the use of Li pellet injection to reduce the carbon recycling, continue to be important in the improvement of plasma performance. 96 refs., 16 figs

  16. Phase II Nuclide Partition Laboratory Study Influence of Cellulose Degradation Products on the Transport of Nuclides from SRS Shallow Land Burial Facilities; FINAL

    International Nuclear Information System (INIS)

    Serkiz, S.M.

    1999-01-01

    Degradation products of cellulosic materials (e.g., paper and wood products) can significantly influence the subsurface transport of metals and radionuclides. Codisposal of radionuclides with cellulosic materials in the E-Area slit trenches at the Savannah River Site (SRS) is, therefore, expected to influence nuclide fate and transport in the subsurface. Due to the complexities of these systems and the scarcity of site-specific data, the effects of cellulose waste loading and its subsequent influence on nuclide transport are not well established

  17. Study of underground radon transport

    International Nuclear Information System (INIS)

    Csige, I.; Hakl, J.; Lenart, L.

    1990-01-01

    The soil gas radon content measurements with solid state nuclear track detectors (SSNTDs) are widely used in geoscience, for instance in uranium exploration and earthquake prediction. In these applications the radon frequently is used as a natural tracer of underground fluid transport processes. Obviously, to get the soil radon measuring method more and more effective the study of these transport processes in deeper part of the Earth is fundamental. The Track Detector Group in the Institute of Nuclear Research of the Hungarian Academy of Sciences in Debrecen has been performing environmental radon activity concentration measurements since 1977 with alpha sensitive SSNTDs. These types of measurements were initiated and widely used by the late head of the group Dr. G. Somogyi, who devoted his life to better understanding of the nature. The measurements in caves, springs and drilled wells proved to be effective to study these underground radon transport processes. We are glad to present some results of our investigations. 7 refs, 7 figs

  18. Impacts of climate change and variability on transportation systems and infrastructure : Gulf Coast study, phase 2 : task 2 : climate variability and change in Mobile, Alabama.

    Science.gov (United States)

    2012-09-01

    Despite increasing confidence in global climate change projections in recent years, projections of : climate effects at local scales remains scarce. Location-specific risks to transportation systems : imposed by changes in climate are not yet well kn...

  19. Feasibility study on the formation of a databank of the arrangements within the European Community for transport accidents involving radioactive materials. Phase 1

    International Nuclear Information System (INIS)

    Hugues, J.S.; Shaw, K.B.

    1989-01-01

    Radioactive materials are transported throughout the European Communities (EC) by road, rail, sea and air. In case of severe accident, which could lead to the release of radioactivity into the environment, it is essential that there are pre-arranged measures which can be put into effect to minimise radiation doses to persons in the vicinity and to enable the situation to be returned to a safe condition. An essential part of emergency arrangements is the setting up of an administrative structure to establish the responsibilities of the organisations involved and this study outlines the arrangements that have been set up in each EC country. The databank should be particularly useful following an accident close to a national border or in the event of an accident in one country which involves a shipment from another. The setting up of a databank might also assist in the development of the emergency arrangements in some countries. In conclusion: - the formation of a databank of emergency arrangements is feasible. - The databank could be operated more efficiently if it were held centrally on a computed-based system and made accessible through the telephone network. - The usefulness of the databank would be enhanced by the inclusion of information on non-radiological hazards

  20. Transport Properties of the Nuclear Pasta Phase with Quantum Molecular Dynamics

    Science.gov (United States)

    Nandi, Rana; Schramm, Stefan

    2018-01-01

    We study the transport properties of nuclear pasta for a wide range of density, temperature, and proton fractions, relevant for different astrophysical scenarios adopting a quantum molecular dynamics model. In particular, we estimate the values of shear viscosity as well as electrical and thermal conductivities by calculating the static structure factor S(q) using simulation data. In the density and temperature range where the pasta phase appears, the static structure factor shows irregular behavior. The presence of a slab phase greatly enhances the peak in S(q). However, the effect of irregularities in S(q) on the transport coefficients is not very dramatic. The values of all three transport coefficients are found to have the same orders of magnitude as found in theoretical calculations for the inner crust matter of neutron stars without the pasta phase; therefore, the values are in contrast to earlier speculations that a pasta layer might be highly resistive, both thermally and electrically.

  1. Interfacial tension-induced transport of nonaqueous phase liquids in model aquifer systems

    International Nuclear Information System (INIS)

    Anderson, M.A.

    1994-01-01

    Nonaqueous phase liquids (NAPLs) such as organic solvents and fuel are common contaminants in soils and groundwater. Spills, leaking underground storage tanks, and improper disposal practices all result in the release and movement of NAPLs through soils. Movement of NAPLs through soil is considered to result from gravity- and /or capillarity-driven immiscible phase flow. Dispersive and convective transport of dissolved components, volatilization, sorption, and degradation are also considered important processes in NAPL contamination. An additional transport mechanism in which NAPLs spread on water surfaces due to differential adhesive and cohesive attractive forces is demonstrated in this study. 22 refs., 5 figs., 1 tab

  2. The International Intraval project: to study validation of geosphere transport models for performance assessment of nuclear waste disposal. Phase 1, summary report

    International Nuclear Information System (INIS)

    1993-12-01

    Intraval is an international project that addresses the validation of models of transport of radionuclides through groundwater in the geosphere. Such models are used in assessment of the long-term safety of nuclear waste disposal systems. The present report summarises the results for the test cases and presents some additional remarks

  3. Dynamic transport study of the plasmas with transport improvement in LHD and JT-60U

    International Nuclear Information System (INIS)

    Ida, K.; Inagaki, S.; Sakamoto, R.; Tanaka, K.; Fujita, T.; Funaba, H.; Kubo, S.; Yoshinuma, M.; Shimozuma, T.; Takeiri, Y.; Ikeda, K.; Michael, C.; Tokuzawa, T.; Sakamoto, Y.; Takenaga, H.; Isayama, A.; Matsunaga, G.; Ide, S.

    2009-01-01

    Transport analysis during the transient phase of heating (a dynamic transport study) applied to the plasma with internal transport barriers (ITBs) in the Large Helical Device (LHD) heliotron and the JT-60U tokamak is described. In the dynamic transport study the time of transition from the L-mode plasma to the ITB plasma is clearly determined by the onset of flattening of the temperature profile in the core region and a spontaneous phase transition from a zero curvature ITB (hyperbolic tangent shaped ITB) or a positive curvature ITB (concaved shaped ITB) to a negative curvature ITB (convex shaped ITB) and its back-transition are observed. The flattening of the core region of the ITB transition and the back-transition between a zero curvature ITB and a convex ITB suggest the strong interaction of turbulent transport in space.

  4. Intracoin - International Nuclide Transport Code Intercomparison Study

    International Nuclear Information System (INIS)

    1984-09-01

    The purpose of the project is to obtain improved knowledge of the influence of various strategies for radionuclide transport modelling for the safety assessment of final repositories for nuclear waste. This is a report of the first phase of the project which was devoted to a comparison of the numerical accuracy of the computer codes used in the study. The codes can be divided into five groups, namely advection-dispersion models, models including matrix diffusion and chemical effects and finally combined models. The results are presented as comparisons of calculations since the objective of level 1 was code verification. (G.B.)

  5. Gram-scale solution-phase synthesis of selective sodium bicarbonate co-transport inhibitor S0859: in vitro efficacy studies in breast cancer cells.

    Science.gov (United States)

    Larsen, Ann M; Krogsgaard-Larsen, Niels; Lauritzen, Gitte; Olesen, Christina W; Honoré Hansen, Steen; Boedtkjer, Ebbe; Pedersen, Stine F; Bunch, Lennart

    2012-10-01

    Na(+)-coupled HCO(3)(-) transporters (NBCs) mediate the transport of bicarbonate ions across cell membranes and are thus ubiquitous regulators of intracellular pH. NBC dysregulation is associated with a range of diseases; for instance, NBCn1 is strongly up-regulated in a model of ErbB2-dependent breast cancer, a malignant and widespread cancer with no targeted treatment options, and single-nucleotide polymorphisms in NBCn1 genetically link to breast cancer development and hypertension. The N-cyanosulfonamide S0859 has been shown to selectively inhibit NBCs, and its availability on the gram scale is therefore of significant interest to the scientific community. Herein we describe a short and efficient synthesis of S0859 with an overall yield of 45 % from commercially available starting materials. The inhibitory effect of S0859 on recovery of intracellular pH after an acid load was verified in human and murine cancer cell lines in Ringer solutions. However, S0859 binds very strongly to components in plasma, and accordingly, measurements on isolated murine tissues showed no effect of S0859 at concentrations up to 50 μM. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Multiscale Adapted Time-Splitting Technique for Nonisothermal Two-Phase Flow and Nanoparticles Transport in Heterogenous Porous Media

    KAUST Repository

    El-Amin, Mohamed F.; Kou, Jisheng; Sun, Shuyu

    2017-01-01

    This paper is devoted to study the problem of nonisothermal two-phase flow with nanoparticles transport in heterogenous porous media, numerically. For this purpose, we introduce a multiscale adapted time-splitting technique to simulate the problem

  7. Oxygen exchange and transport in dual phase ceramic composite electrodes.

    Science.gov (United States)

    Druce, John; Téllez, Helena; Ishihara, Tatsumi; Kilner, John A

    2015-01-01

    Composites consisting of a perovskite-based electronic or mixed conductor with a fluorite-structured ionic conductor are often used as electrodes in solid oxide electrochemical energy conversion devices. After sintering the materials, there is often evidence for inter-reaction between the two phases, or inter-diffusion of cations or impurities between the two phases. We studied the (18)O exchange properties of a composite consisting of CGO and LSCF in a 50 : 50 ratio. High resolution ToF-SIMS mapping reveals that the (18)O fraction at the very outer surface of grains of the CGO phase is much higher than expected from D* and k* values for the single-phase parent material. Surface compositional analysis by ToF-SIMS and low energy ion scattering (LEIS) spectroscopy suggests that the surfaces of the CGO grains in the composite do not show the impurities which typically segregate to the surface in single-phase CGO. Thus, the "cleaning" of impurities from the CGO surface by dissolution into the perovskite phase may be one explanation for the apparent enhanced surface exchange for CGO in these composites.

  8. Phase transitions and transport in anisotropic superconductors with large thermal fluctuations

    International Nuclear Information System (INIS)

    Fisher, D.S.

    1991-01-01

    Fluctuation effects in conventional superconductors such as broadening of phase transitions and flux creep tend to be very small primarily because of the large coherence lengths. Thus mean field theory, with only small fluctuation corrections, usually provides an adequate description of these systems. Regimes in which fluctuation effects cause qualitatively different physics are very difficult to study as they typically occur in very small regions of the phase diagram or, in transport, require measuring extremely small voltages. In striking contrast, in the high temperature cuprate superconductors a combination of factors - short coherence lengths, anisotropy and higher temperatures - make fluctuation effects many orders of magnitude larger. The current understanding of transport and phase transitions in the cuprate superconductors-particularly YBCO and BSCCO-is reviewed. New results are presented on the two-dimensional regimes and 2D-3D crossover in the strongly anisotropic case of BSCCO. The emphasis is on pinning and vortex glass behavior

  9. A development of multi-Species mass transport model considering thermodynamic phase equilibrium

    DEFF Research Database (Denmark)

    Hosokawa, Yoshifumi; Yamada, Kazuo; Johannesson, Björn

    2008-01-01

    ) variation in solid-phase composition when using different types of cement, (ii) physicochemical evaluation of steel corrosion initiation behaviour by calculating the molar ratio of chloride ion to hydroxide ion [Cl]/[OH] in pore solution, (iii) complicated changes of solid-phase composition caused......In this paper, a multi-species mass transport model, which can predict time dependent variation of pore solution and solid-phase composition due to the mass transport into the hardened cement paste, has been developed. Since most of the multi-species models established previously, based...... on the Poisson-Nernst-Planck theory, did not involve the modeling of chemical process, it has been coupled to thermodynamic equilibrium model in this study. By the coupling of thermodynamic equilibrium model, the multi-species model could simulate many different behaviours in hardened cement paste such as: (i...

  10. Application of neural networks to prediction of phase transport characteristics in high-pressure two-phase turbulent bubbly flows

    International Nuclear Information System (INIS)

    Yang, A.-S.; Kuo, T.-C.; Ling, P.-H.

    2003-01-01

    The phase transport phenomenon of the high-pressure two-phase turbulent bubbly flow involves complicated interfacial interactions of the mass, momentum, and energy transfer processes between phases, revealing that an enormous effort is required in characterizing the liquid-gas flow behavior. Nonetheless, the instantaneous information of bubbly flow properties is often desired for many industrial applications. This investigation aims to demonstrate the successful use of neural networks in the real-time determination of two-phase flow properties at elevated pressures. Three back-propagation neural networks, trained with the simulation results of a comprehensive theoretical model, are established to predict the transport characteristics (specifically the distributions of void-fraction and axial liquid-gas velocities) of upward turbulent bubbly pipe flows at pressures covering 3.5-7.0 MPa. Comparisons of the predictions with the test target vectors indicate that the averaged root-mean-squared (RMS) error for each one of three back-propagation neural networks is within 4.59%. In addition, this study appraises the effects of different network parameters, including the number of hidden nodes, the type of transfer function, the number of training pairs, the learning rate-increasing ratio, the learning rate-decreasing ratio, and the momentum value, on the training quality of neural networks.

  11. Thermoelectric transport of Se-rich Ag2Se in normal phases and phase transitions

    International Nuclear Information System (INIS)

    Mi, Wenlong; Lv, Yanhong; Qiu, Pengfei; Shi, Xun; Chen, Lidong; Zhang, Tiansong

    2014-01-01

    Small amount of Se atoms are used to tune the carrier concentrations (n H ) and electrical transport in Ag 2 Se. Significant enhancements in power factor and thermoelectric figure of merit (zT) are observed in the compositions of Ag 2 Se 1.06 and Ag 2 Se 1.08 . The excessive Se atoms do not change the intrinsically electron-conducting character in Ag 2 Se. The detailed analysis reveals the experiment optimum carrier concentration in Ag 2 Se is around 5 × 10 18  cm −3 . We also investigate the temperature of maximum zT and the thermoelectric transport during the first order phase transitions using the recently developed measurement system

  12. Vadose Zone Transport Field Study: Summary Report

    Energy Technology Data Exchange (ETDEWEB)

    Ward, Andy L.; Conrad, Mark E.; Daily, William D.; Fink, James B.; Freedman, Vicky L.; Gee, Glendon W.; Hoversten, Gary M.; Keller, Jason M.; Majer, Ernest L.; Murray, Christopher J.; White, Mark D.; Yabusaki, Steven B.; Zhang, Z. F.

    2006-07-31

    From FY 2000 through FY 2003, a series of vadose zone transport field experiments were conducted as part of the U.S. Department of Energy’s Groundwater/Vadose Zone Integration Project Science and Technology Project, now known as the Remediation and Closure Science Project, and managed by the Pacific Northwest National Laboratory (PNNL). The series of experiments included two major field campaigns, one at a 299-E24-11 injection test site near PUREX and a second at a clastic dike site off Army Loop Road. The goals of these experiments were to improve our understanding of vadose zone transport processes; to develop data sets to validate and calibrate vadose zone flow and transport models; and to identify advanced monitoring techniques useful for evaluating flow-and-transport mechanisms and delineating contaminant plumes in the vadose zone at the Hanford Site. This report summarizes the key findings from the field studies and demonstrates how data collected from these studies are being used to improve conceptual models and develop numerical models of flow and transport in Hanford’s vadose zone. Results of these tests have led to a better understanding of the vadose zone. Fine-scale geologic heterogeneities, including grain fabric and lamination, were observed to have a strong effect on the large-scale behavior of contaminant plumes, primarily through increased lateral spreading resulting from anisotropy. Conceptual models have been updated to include lateral spreading and numerical models of unsaturated flow and transport have revised accordingly. A new robust model based on the concept of a connectivity tensor was developed to describe saturation-dependent anisotropy in strongly heterogeneous soils and has been incorporated into PNNL’s Subsurface Transport Over Multiple Phases (STOMP) simulator. Application to field-scale transport problems have led to a better understanding plume behavior at a number of sites where lateral spreading may have dominated waste

  13. Thermodynamic and transport properties of uranium dioxide and related phases

    International Nuclear Information System (INIS)

    1965-01-01

    The high melting point of uranium dioxide and its stability under irradiation have led to its use as a fuel in a variety of types of nuclear reactors. A wide range of chemical and physical studies has been stimulated by this circumstances and by the complex nature of the uranium dioxide phase itself. The boundaries of this phase widen as the temperature is increased; at 2000 deg. K a single, homogeneous phase exists from U 2.27 to a hypostoichiometric (UO 2-x ) composition, depending on the oxygen potential of the surroundings. Since there is often an incentive to operate a reactor at the maximum practicable heat rating and, therefore, maximum thermal gradient in the fuel, the determination of the physical properties of the UO 2-x phase becomes a matter of great technological importance. In addition a complex sequence of U-O phases may be formed during the preparation of powder feed material or during the sintering process; these affect the microstructure and properties of the final product and have also received much attention. 184 refs, 33 figs, 15 tabs

  14. Kinetic studies of anomalous transport

    International Nuclear Information System (INIS)

    Tang, W.M.

    1990-11-01

    Progress in achieving a physics-based understanding of anomalous transport in toroidal systems has come in large part from investigations based on the proposition that low frequency electrostatic microinstabilities are dominant in the bulk (''confinement'') region of these plasmas. Although the presence here of drift-type modes dependent on trapped particle and ion temperature gradient driven effects appears to be consistent with a number of important observed confinement trends, conventional estimates for these instabilities cannot account for the strong current (I p ) and /or q-scaling frequently found in empirically deduced global energy confinement times for auxiliary-heated discharges. The present paper deals with both linear and nonlinear physics features, ignored in simpler estimates, which could introduce an appreciable local dependence on current. It is also pointed out that while the thermal flux characteristics of drift modes have justifiably been the focus of experimental studies assessing their relevance, other transport properties associated with these microinstabilities should additionally be examined. Accordingly, the present paper provides estimates and discusses the significance of anomalous energy exchange between ions and electrons when fluctuations are present. 19 refs., 3 figs

  15. Alternative Transportation Study : Monomoy National Wildlife Refuge.

    Science.gov (United States)

    2010-05-31

    This report provides an overview of the historic and current visitation, infrastructure, and transportation conditions related to Monomoy National Wildlife Refuge and the surrounding areas in Chatham, MA. The study defines transportation-related goal...

  16. Alternative transportation study : Wichita Mountains Wildlife Refuge

    Science.gov (United States)

    2010-08-01

    This report provides an assessment of historic and current visitation, infrastructure, and transportation conditions at the Wichita Mountains Wildlife Refuge and surrounding areas in southwest Oklahoma. The study defines transportation-related goals ...

  17. The transport phase of pyrolytic oil exiting a fast fluidized bed reactor

    Science.gov (United States)

    Daugaard, Daren Einar

    An unresolved and debated aspect in the fast pyrolysis of biomass is whether the bio-oil exits as a vapor or as an aerosol from the pyrolytic reactor. The determination of the bio-oil transport phase will have direct and significant impact on the design of fast pyrolysis systems. Optimization of both the removal of particulate matter and collection of bio-oil will require this information. In addition, the success of catalytic reforming of bio-oil to high-value chemicals will depend upon this transport phase. A variety of experimental techniques were used to identify the transport phase. Some tests were as simple as examining the catch of an inline filter while others attempted to deduce whether vapor or aerosol predominated by examining the pressure drop across a flow restriction. In supplementary testing, the effect of char on aerosol formation and the potential impact of cracking during direct contact filtering are evaluated. The study indicates that for pyrolysis of red oak approximately 90 wt-% of the collected bio-oil existed as a liquid aerosol. Conversely, the pyrolysis of corn starch produced bio-oil predominately in the vapor phase at the exit of the reactor. Furthermore, it was determined that the addition of char promotes the production of aerosols during pyrolysis of corn starch. Direct contact filtering of the product stream did not collect any liquids and the bio-oil yield was not significantly reduced indicating measurable cracking or coking did not occur.

  18. Experimental study of arsenic speciation in vapor phase to 500°C: Implications for As transport and fractionation in low-density crustal fluids and volcanic gases.

    OpenAIRE

    Pokrovski , Gleb S.; Zakirov , Ildar V.; Roux , Jacques; Testemale , Denis; Hazemann , Jean-Louis; Y. U. Bychkov , Andrew; V. Golikova , Galina

    2002-01-01

    The stoichiometry and stability of arsenic gaseous complexes were determined in the system As-H2O ± NaCl ± HCl ± H2S at temperatures up to 500°C and pressures up to 600 bar, from both measurements of As(III) and As(V) vapor-liquid and vapor-solid partitioning, and X-ray absorption fine structure (XAFS) spectroscopic study of As(III)-bearing aqueous fluids. Vapor-aqueous solution partitioning for As(III) was measured from 250 to 450°C at the saturated vapor pressure of the system (Psat) with a...

  19. Curvature and bottlenecks control molecular transport in inverse bicontinuous cubic phases

    Science.gov (United States)

    Assenza, Salvatore; Mezzenga, Raffaele

    2018-02-01

    We perform a simulation study of the diffusion of small solutes in the confined domains imposed by inverse bicontinuous cubic phases for the primitive, diamond, and gyroid symmetries common to many lipid/water mesophase systems employed in experiments. For large diffusing domains, the long-time diffusion coefficient shows universal features when the size of the confining domain is renormalized by the Gaussian curvature of the triply periodic minimal surface. When bottlenecks are widely present, they become the most relevant factor for transport, regardless of the connectivity of the cubic phase.

  20. An Eulerian two-phase flow model for sediment transport under realistic surface waves

    Science.gov (United States)

    Hsu, T. J.; Kim, Y.; Cheng, Z.; Chauchat, J.

    2017-12-01

    Wave-driven sediment transport is of major importance in driving beach morphology. However, the complex mechanisms associated with unsteadiness, free-surface effects, and wave-breaking turbulence have not been fully understood. Particularly, most existing models for sediment transport adopt bottom boundary layer approximation that mimics the flow condition in oscillating water tunnel (U-tube). However, it is well-known that there are key differences in sediment transport when comparing to large wave flume datasets, although the number of wave flume experiments are relatively limited regardless of its importance. Thus, a numerical model which can resolve the entire water column from the bottom boundary layer to the free surface can be a powerful tool. This study reports an on-going effort to better understand and quantify sediment transport under shoaling and breaking surface waves through the creation of open-source numerical models in the OpenFOAM framework. An Eulerian two-phase flow model, SedFoam (Cheng et al., 2017, Coastal Eng.) is fully coupled with a volume-of-fluid solver, interFoam/waves2Foam (Jacobsen et al., 2011, Int. J. Num. Fluid). The fully coupled model, named SedWaveFoam, regards the air and water phases as two immiscible fluids with the interfaces evolution resolved, and the sediment particles as dispersed phase. We carried out model-data comparisons with the large wave flume sheet flow data for nonbreaking waves reported by Dohmen-Janssen and Hanes (2002, J. Geophysical Res.) and good agreements were obtained for sediment concentration and net transport rate. By further simulating a case without free-surface (mimic U-tube condition), the effects of free-surface, most notably the boundary layer streaming effect on total transport, can be quantified.

  1. One-dimensional deterministic transport in neurons measured by dispersion-relation phase spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Wang Ru [Quantitative Light Imaging Laboratory, Department of Mechanical Science and Engineering, Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801 (United States); Wang Zhuo; Leigh, Joe; Popescu, Gabriel [Quantitative Light Imaging Laboratory, Department of Electrical and Computer Engineering, Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801 (United States); Sobh, Nahil [Beckman Institute for Advanced Science and Technology, Department of Civil and Environmental Engineering, and Department of Mechanical Engineering and Sciences, University of Illinois at Urbana-Champaign, Urbana, IL 61801 (United States); Millet, Larry; Gillette, Martha U [Department of Cell and Developmental Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801 (United States); Levine, Alex J, E-mail: alevine@chem.ucla.edu, E-mail: gpopescu@illinois.edu [Department of Chemistry and Biochemistry and Department of Physics and Astronomy, University of California at Los Angeles, Los Angeles, CA 90095 (United States)

    2011-09-21

    We studied the active transport of intracellular components along neuron processes using a new method developed in our laboratory: dispersion-relation phase spectroscopy. This method is able to quantitatively map spatially the heterogeneous dynamics of the concentration field of the cargos at submicron resolution without the need for tracking individual components. The results in terms of density correlation function reveal that the decay rate is linear in wavenumber, which is consistent with a narrow Lorentzian distribution of cargo velocity. (paper)

  2. Choroid plexus transport: gene deletion studies

    Directory of Open Access Journals (Sweden)

    Keep Richard F

    2011-11-01

    Full Text Available Abstract This review examines the use of transporter knockout (KO animals to evaluate transporter function at the choroid plexus (the blood-CSF barrier; BCSFB. Compared to the blood-brain barrier, there have been few such studies on choroid plexus (CP function. These have primarily focused on Pept2 (an oligopeptide transporter, ATP-binding cassette (ABC transporters, Oat3 (an organic anion transporter, Svct2 (an ascorbic acid transporter, transthyretin, ion transporters, and ion and water channels. This review focuses on the knowledge gained from such studies, both with respect to specific transporters and in general to the role of the CP and its impact on brain parenchyma. It also discusses the pros and cons of using KO animals in such studies and the technical approaches that can be used.

  3. Hydro-dynamic Solute Transport under Two-Phase Flow Conditions.

    Science.gov (United States)

    Karadimitriou, Nikolaos K; Joekar-Niasar, Vahid; Brizuela, Omar Godinez

    2017-07-26

    There are abundant examples of natural, engineering and industrial applications, in which "solute transport" and "mixing" in porous media occur under multiphase flow conditions. Current state-of-the-art understanding and modelling of such processes are established based on flawed and non-representative models. Moreover, there is no direct experimental result to show the true hydrodynamics of transport and mixing under multiphase flow conditions while the saturation topology is being kept constant for a number of flow rates. With the use of a custom-made microscope, and under well-controlled flow boundary conditions, we visualized directly the transport of a tracer in a Reservoir-on-Chip (RoC) micromodel filled with two immiscible fluids. This study provides novel insights into the saturation-dependency of transport and mixing in porous media. To our knowledge, this is the first reported pore-scale experiment in which the saturation topology, relative permeability, and tortuosity were kept constant and transport was studied under different dynamic conditions in a wide range of saturation. The critical role of two-phase hydrodynamic properties on non-Fickian transport and saturation-dependency of dispersion are discussed, which highlight the major flaws in parametrization of existing models.

  4. Sustainable transport studies in Asia

    CERN Document Server

    Zhang, Junyi

    2013-01-01

    This book aims to provide a good understanding of and perspective on sustainable transport in Asia by focusing on economic, environmental, and social sustainability. It is widely acknowledged that the current situation and trends in transport are not always sustainable in Asia, due in part to the fast-growing economy and the astounding speed of urbanization as well as least-mature governance. As essential research material, the book provides strong support for policy makers and planners by comprehensively covering three groups of strategies, characterized by the words “avoid” (e.g., urban form design and control of car ownership), “shift” (e.g., establishing comprehensive transportation systems and increasing public transportation systems for both intracity and intercity travel), and “improve” (e.g., redesign of paratransit system, low-emission vehicles, intelligent transportation systems, and eco-life). These are elaborated in the book alongside consideration of the uncertainty of policy effects ...

  5. Toroidally asymmetric particle transport caused by phase-locking of MHD modes in RFX-mod

    International Nuclear Information System (INIS)

    Lorenzini, R.; Terranova, D.; Auriemma, F.; Cavazzana, R.; Innocente, P.; Martini, S.; Serianni, G.; Zuin, M.

    2007-01-01

    The particle and energy transport in reversed field pinch experiments is affected by the locking in phase of the tearing modes, also dubbed dynamo modes, that sustain the magnetic configuration. In standard RFP pulses many m = 1 and m = 0 resonant modes have a relatively large amplitude (a spectrum dubbed MH for multiple helicity). The locking in phase of m = 1 tearing modes produces a helical deformation (locked mode (LM)) of the magnetic surfaces in a region of approximately 40 toroidal degrees. The region of the LM is characterized by a strong plasma-wall interaction and by high losses of energy and particles that account for a significant fraction of the input power and of the total particle outflux. The locking in phase of m = 0 modes modifies the plasma radius, shrinking and enlarging the plasma cross section in two wide toroidal regions of about 100 0 . The purpose of this paper is to investigate to what extent the locking in phase of m = 0 modes introduces toroidal asymmetries in the transport properties of the plasma. This study has been carried out investigating the shape of the density profile in the RFX-mod experiment. The analyses show that the profile exhibits a dependence on the toroidal angle, which is related to the deformation of the plasma column due to the locking in phase of m = 0 modes: the least steep density gradients at the edge are found in the region where the plasma column is shrunk, entailing that in this region the particle transport is enhanced. An analogous asymmetry also characterizes the density and magnetic fluctuations at the edge, which are enhanced in the same toroidal region where the particle transport also is enhanced. This result can be considered the first experimental evidence of an instability localized where the plasma column is shrunk

  6. Study of SmS properties in the low pressure phase (black phase)

    International Nuclear Information System (INIS)

    Bordier, G.

    1986-01-01

    SmS was studied for the transition from low pressure phase (black phase) to high pressure phase with an intermediate valence. But the study of the black phase is very rich. The variations of electron transport properties with pressure at low temperature show a semi-metal phase located, in the pressure-temperature diagram in the black phase for pressure over 4 kbars, corresponding to the phase B'of the doping-temperature diagram. Electron spin resonance shows a lack of sulfur and nearby this defect a samarium ion, magnetically coupled with the matrix, presents a divalent trivalent transition. Resonance lines are broadened with temperature. Conductivity relaxations occur at low pressure and low temperature by trapping a conduction electron, by magnetic exchange giving a bounded magnetic polaron. The relaxation time at null magnetic field is activated. An approximation of trapping barrier and critical field corresponding the maximum magnetoresistance is given by a model [fr

  7. STOMP Subsurface Transport Over Multiple Phases: User's guide

    International Nuclear Information System (INIS)

    White, M.D.; Oostrom, M.

    1997-10-01

    The U.S. Department of Energy, through the Office of Technology Development, has requested the demonstration of remediation technologies for the cleanup of volatile organic compounds and associated radionuclides within the soil and groundwater at arid sites. This demonstration program, called the VOC-Arid Soils Integrated Demonstration Program (Arid-ID), has been initially directed at a volume of unsaturated and saturated soil contaminated with carbon tetrachloride, on the Hanford Site near Richland, Washington. A principal subtask of the Arid-ID program involves the development of an integrated engineering simulator for evaluating the effectiveness and efficiency of various remediation technologies. The engineering simulator''s intended users include scientists and engineers who are investigating soil physics phenomena associated with remediation technologies. Principal design goals for the engineer simulator include broad applicability, verified algorithms, quality assurance controls, and validated simulations against laboratory and field-scale experiments. An important goal for the simulator development subtask involves the ability to scale laboratory and field-scale experiments to full-scale remediation technologies, and to transfer acquired technology to other arid sites. The STOMP (Subsurface Transport Over Multiple Phases) simulator has been developed by the Pacific Northwest National Laboratory for modeling remediation technologies. Information on the use, application, and theoretical basis of the STOMP simulator theory and discussions on the governing equations, constitutive relations, and numerical solution algorithms for the STOMP simulator

  8. STOMP Subsurface Transport Over Multiple Phases: Application guide

    International Nuclear Information System (INIS)

    Nichols, W.E.; Aimo, N.J.; Oostrom, M.; White, M.D.

    1997-09-01

    The U.S. Department of Energy (DOE), through the Office of Technology Development, has requested the demonstration of remediation technologies for the cleanup of volatile organic compounds and associated radionuclides within the soil and ground water at arid sites. This demonstration program, called the VOC-Arid Soils Integrated Demonstrated Program (Arid-ID), has been initially directed at a volume of unsaturated and saturated soil contaminated with carbon tetrachloride on the Hanford Site near Richland, Washington. A principal subtask of the Arid-ID program involves the development of an integrated engineering simulator for evaluating the effectiveness and efficiency of various remediation technologies. The engineering simulator''s intended users include scientists and engineers who are investigating soil physics phenomena associated with remediation technologies. Principal design goals for the engineering simulator include broad applicability, verified algorithms, quality assurance controls, and validated simulations against laboratory and field-scale experiments. An important goal for the simulator development subtask involves the ability to scale laboratory and field-scale experiments to full-scale remediation technologies, and to transfer acquired technology to other arid sites. The STOMP (Subsurface Transport Over Multiple Phases) simulator has been developed by the Pacific Northwest Laboratory for modeling remediation technologies. Information on the use, application, and theoretical basis of the STOMP simulator are documented in three companion guide guides. This document, the Application Guide, provides a suite of example applications of the STOMP simulator

  9. Coal supply and transportation markets during Phase One: Change, risk and opportunity. Final report

    International Nuclear Information System (INIS)

    Heller, J.N.; Kaplan, S.

    1996-01-01

    The Clean Air Act Amendments of 1990 (CAAA) required many utilities to sharply reduce sulfur emissions by January 1, 1995. This study describes and analyzes how the coal and transportation markets responded to this major development. The study focuses on five key coal supply regions and their associated transportation networks: the Uinta Basin (Colorado/Utah), Wyoming Powder River Basin, Illinois Basin, Monongahela region (Pittsburgh seam) and the central Appalachian region. From these regional studies, the report identifies key risk areas for future coal planning and general lessons for the fuels planning process. The study provides statistical information on coal production, demand, and transportation flows for each region. The analysis for each region focuses on developments which were generally unexpected; e.g., the relatively large volumes of medium-sulfur coal produced in the Illinois Basin and Monongahela region, the eastern penetration of Utah and Colorado coals, and the relatively modest growth in demand for central Appalachian coals. These developments generally worked to the advantage of utilities; i.e., medium- and low-sulfur coal was available at a lower price, in greater volumes and from a wider range of sources than many had expected. Utilities both took advantage of and helped to encourage these developments in the coal and transportation market. Looking ahead to Phase 11 strategies and future coal procurement, a major challenge will be to maintain the choice among supply and transportation alternatives which was so important to utility success in Phase 1. The report identifies rail transportation to be the major area of risk in most regions

  10. Transport properties and phase diagram of UNi2Si2

    International Nuclear Information System (INIS)

    Ning, Y.B.; Garrett, J.D.; Datars, W.R.; McMaster Univ., Hamilton, ON

    1992-01-01

    The resistivity and Hall coefficient of single-crystal UNi 2 Si 2 have been studied in detail for the temperature range 4.2-300 K. The resistivity of UNi 2 Si 2 is largely due to magnetic scattering and the phonon scattering contribution is estimated to be about 14% at room temperature. At low temperatures, the resistivity can be described by a gapped spin-wave model plus a T 2 term. The temperature dependence of the Hall coefficient is accounted for by a theoretical model invoking skew scattering of conduction electrons by localized magnetic moments. Among the three magnetic phase transition temperatures, the two lower ones are found to be magnetic field dependent and shift with the field applied along the tetragonal c axis. Using the resistivity measurement in an applied magnetic field, a field-temperature phase diagram of UNi 2 Si 2 is presented. (author)

  11. Plasma transport studies using transient techniques

    International Nuclear Information System (INIS)

    Simonen, T.C.; Brower, D.L.; Efthimion, P.

    1991-01-01

    Selected topics from the Transient Transport sessions of the Transport Task Force Workshop, held February 19-23, 1990, in Hilton Head, South Carolina are summarized. Presentations on sawtooth propagation, ECH modulation, particle modulation, and H-mode transitions are included. The research results presented indicated a growing theoretical understanding and experimental sophistication in the application of transient techniques to transport studies. (Author)

  12. Cold flame on Biofilm - Transport of Plasma Chemistry from Gas to Liquid Phase

    Science.gov (United States)

    Kong, Michael

    2014-10-01

    One of the most active and fastest growing fields in low-temperature plasma science today is biological effects of gas plasmas and their translation in many challenges of societal importance such as healthcare, environment, agriculture, and nanoscale fabrication and synthesis. Using medicine as an example, there are already three FDA-approved plasma-based surgical procedures for tissue ablation and blood coagulation and at least five phase-II clinical trials on plasma-assisted wound healing therapies. A key driver for realizing the immense application potential of near room-temperature ambient pressure gas plasmas, commonly known as cold atmospheric plasmas or CAP, is to build a sizeable interdisciplinary knowledge base with which to unravel, optimize, and indeed design how reactive plasma species interact with cells and their key components such as protein and DNA. Whilst a logical objective, it is a formidable challenge not least since existing knowledge of gas discharges is largely in the gas-phase and therefore not directly applicable to cell-containing matters that are covered by or embedded in liquid (e.g. biofluid). Here, we study plasma inactivation of biofilms, a jelly-like structure that bacteria use to protect themselves and a major source of antimicrobial resistance. As 60--90% of biofilm is made of water, we develop a holistic model incorporating physics and chemistry in the upstream CAP-generating region, a plasma-exit region as a buffer for as-phase transport, and a downstream liquid region bordering the gas buffer region. A special model is developed to account for rapid chemical reactions accompanied the transport of gas-phase plasma species through the gas-liquid interface and for liquid-phase chemical reactions. Numerical simulation is used to illustrate how key reactive oxygen species (ROS) are transported into the liquid, and this is supported with experimental data of both biofilm inactivation using plasmas and electron spin spectroscopy (ESR

  13. Basic equations of interfacial area transport in gas-liquid two-phase flow

    International Nuclear Information System (INIS)

    Kataoka, I.; Yoshida, K.; Naitoh, M.; Okada, H.; Morii, T.

    2011-01-01

    The rigorous and consistent formulations of basic equations of interfacial area transport were derived using correlation functions of characteristic function of each phase and velocities of each phase. Turbulent transport term of interfacial area concentration was consistently derived and related to the difference between interfacial velocity and averaged velocity of each phase. Constitutive equations of turbulent transport terms of interfacial area concentration were proposed for bubbly flow. New transport model and constitutive equations were developed for churn flow. These models and constitutive equations are validated by experimental data of radial distributions of interfacial area concentration in bubbly and churn flow. (author)

  14. Spent Fuel Transportation Package Performance Study - Experimental Design Challenges

    International Nuclear Information System (INIS)

    Snyder, A. M.; Murphy, A. J.; Sprung, J. L.; Ammerman, D. J.; Lopez, C.

    2003-01-01

    Numerous studies of spent nuclear fuel transportation accident risks have been performed since the late seventies that considered shipping container design and performance. Based in part on these studies, NRC has concluded that the level of protection provided by spent nuclear fuel transportation package designs under accident conditions is adequate. [1] Furthermore, actual spent nuclear fuel transport experience showcase a safety record that is exceptional and unparalleled when compared to other hazardous materials transportation shipments. There has never been a known or suspected release of the radioactive contents from an NRC-certified spent nuclear fuel cask as a result of a transportation accident. In 1999 the United States Nuclear Regulatory Commission (NRC) initiated a study, the Package Performance Study, to demonstrate the performance of spent fuel and spent fuel packages during severe transportation accidents. NRC is not studying or testing its current regulations, a s the rigorous regulatory accident conditions specified in 10 CFR Part 71 are adequate to ensure safe packaging and use. As part of this study, NRC currently plans on using detailed modeling followed by experimental testing to increase public confidence in the safety of spent nuclear fuel shipments. One of the aspects of this confirmatory research study is the commitment to solicit and consider public comment during the scoping phase and experimental design planning phase of this research

  15. Hierarchical transport of nanoparticles in a lyotropic lamellar phase

    International Nuclear Information System (INIS)

    Kimura, Yasuyuki; Mori, Teppei; Yamamoto, Akira; Mizuno, Daisuke

    2005-01-01

    The dynamics of nanosized colloidal particles dispersed in a hyper-swollen lyotropic lamellar phase of a nonionic surfactant has been studied by ac electrophoretic light scattering and direct tracking of particles under a microscope. The frequency spectrum of electrophoretic mobility shows two relaxation processes. These are originated from the hindrance of free diffusion of particles by the interaction between membranes and particles. By direct tracking measurement, we find that particles jump from site to site where they stay for a long time. This trap-jump process greatly decreases the mobility at low frequencies

  16. Impact of vacancy ordering on thermal transport in crystalline phase-change materials.

    Science.gov (United States)

    Siegert, K S; Lange, F R L; Sittner, E R; Volker, H; Schlockermann, C; Siegrist, T; Wuttig, M

    2015-01-01

    Controlling thermal transport in solids is of paramount importance for many applications. Often thermal management is crucial for a device's performance, as it affects both reliability and power consumption. A number of intricate concepts have been developed to address this challenge, such as diamond-like coatings to enhance the thermal conductivity or low symmetry complex super-structures to reduce it. Here, a different approach is pursued, where we explore the potential of solids with a high yet controllable degree of disorder. Recently, it has been demonstrated that an unconventionally high degree of structural disorder characterizes a number of crystalline phase-change materials (PCMs). This disorder strongly impacts electronic transport and even leads to disorder induced localization (Anderson localization). This raises the question how thermal transport is affected by such conditions. Here thermal transport in highly disordered crystalline Ge-Sb-Te (GST) based PCMs is investigated. Glass-like thermal properties are observed for several crystalline PCMs, which are attributed to strong scattering by disordered point defects. A systematic study of different compounds along the pseudo-binary line between GeTe and Sb2Te3 reveals that disordered vacancies act as point defects responsible for pronounced phonon scattering. Annealing causes a gradual ordering of the vacancies and leads to a more 'crystal-like' thermal conductivity. While both vibrational and electronic degrees of freedom are affected by disorder, the consequences differ for different stoichiometries. This opens up a pathway to tune electrical and thermal transport by controlling the degree of disorder. Materials with tailored transport properties may not only help to improve power efficiency and scaling in upcoming phase-change memories but are also of fundamental interest in the field of thermoelectric materials.

  17. Impact of vacancy ordering on thermal transport in crystalline phase-change materials

    International Nuclear Information System (INIS)

    Siegert, K S; Lange, F R L; Sittner, E R; Volker, H; Schlockermann, C; Wuttig, M; Siegrist, T

    2015-01-01

    Controlling thermal transport in solids is of paramount importance for many applications. Often thermal management is crucial for a device's performance, as it affects both reliability and power consumption. A number of intricate concepts have been developed to address this challenge, such as diamond-like coatings to enhance the thermal conductivity or low symmetry complex super-structures to reduce it. Here, a different approach is pursued, where we explore the potential of solids with a high yet controllable degree of disorder. Recently, it has been demonstrated that an unconventionally high degree of structural disorder characterizes a number of crystalline phase-change materials (PCMs). This disorder strongly impacts electronic transport and even leads to disorder induced localization (Anderson localization). This raises the question how thermal transport is affected by such conditions. Here thermal transport in highly disordered crystalline Ge–Sb–Te (GST) based PCMs is investigated. Glass-like thermal properties are observed for several crystalline PCMs, which are attributed to strong scattering by disordered point defects. A systematic study of different compounds along the pseudo-binary line between GeTe and Sb 2 Te 3 reveals that disordered vacancies act as point defects responsible for pronounced phonon scattering. Annealing causes a gradual ordering of the vacancies and leads to a more ‘crystal-like’ thermal conductivity. While both vibrational and electronic degrees of freedom are affected by disorder, the consequences differ for different stoichiometries. This opens up a pathway to tune electrical and thermal transport by controlling the degree of disorder. Materials with tailored transport properties may not only help to improve power efficiency and scaling in upcoming phase-change memories but are also of fundamental interest in the field of thermoelectric materials. (key issues review)

  18. Studies of Lanthanide Transport in Metallic Fuel

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Jinsuo; Taylor, Christopher

    2018-04-02

    result, Ln could transport to the fuel surface through pores filled with liquid cesium fission products. At the fuel slug surface, the lanthanides would undergo rapid precipitation when swamped with the large increase in liquid sodium content and cooler temperatures, which would lead to the observed sludge-like deposit. Prior PIE data also show that lanthanide deposits were found on the cold sides of closed and isolated pores, i.e., on pore surfaces directed away from the center, which can also be explained by the liquid-like transport theory. Since the total amount of lanthanides exceeds their solubility limit in liquid cesium, the small temperature gradient across a pore combined with the long durations is sufficient to drive cesium-mediated transport of lanthanides to the cold side of the pore. The liquid-like transport mechanism can qualitatively account for the migration and redistribution of lanthanides fission products in metallic fuels. The present project studied the mechanisms of lanthanide transport in metallic fuels based on the novel interpretation of ‘liquid-like’ transport mechanism experimentally and analytically. The project completed all the proposed research tasks by using an integral approach: (1) experimental studies for measurements of key parameters and first principles calculations to determine, for example, lanthanide solubility and diffusion coefficient in liquid cesium, sodium and cesium-sodium alloy; (2) theoretical model development for lanthanide transport in a non-isothermal single pore and porous medium to understand the observed behavior (deposition, dissolution and migration) in a single closed or open pore and porous medium; (3) further development of the multi-phase/physics BISON model. The key goal of the project is to develop fundamental understanding of the lanthanide fission product migration and redistribution in advanced metallic nuclear fuels, and then to provide fundamental theory/data for mitigating FCCI of advanced

  19. Molecular Transport Studies Through Unsupported Lipid Membranes

    Science.gov (United States)

    Rock, William; Parekh, Sapun; Bonn, Mischa

    2014-03-01

    Dendrimers, spherical polymeric nanoparticles made from branched monomers around a central core, show great promise as drug delivery vehicles. Dendrimer size, core contents, and surface functionality can be synthetically tuned, providing unprecedented versatility. Polyamidoamine (PAMAM) dendrimers have been shown to enter cells; however, questions remain about their biophysical interactions with the cell membrane, specifically about the presence and size of transient pores. We monitor dendrimer-lipid bilayer interactions using unsupported black lipid membranes (BLMs) as model cell membranes. Custom bilayer slides contain two vertically stacked aqueous chambers separated by a 25 μm Teflon sheet with a 120 μm aperture where the bilayer is formed. We vary the composition of model membranes (cholesterol content and lipid phase) to create biomimetic systems and study the interaction of PAMAM G6 and G3 dendrimers with these bilayers. Dendrimers, dextran cargo, and bilayers are monitored and quantified using time-lapse fluorescence imaging. Electrical capacitance measurements are simultaneously recorded to determine if the membrane is porous, and the pore size is deduced by monitoring transport of fluorescent dextrans of increasing molecular weight. These experiments shed light on the importance of cholesterol content and lipid phase on the interaction of dendrimer nanoparticles with membranes.

  20. An advanced three-phase physical, experimental and numerical method for tsunami induced boulder transport

    Science.gov (United States)

    Oetjen, Jan; Engel, Max; Prasad Pudasaini, Shiva; Schüttrumpf, Holger; Brückner, Helmut

    2017-04-01

    Coasts around the world are affected by high-energy wave events like storm surges or tsunamis depending on their regional climatological and geological settings. By focusing on tsunami impacts, we combine the abilities and experiences of different scientific fields aiming at improved insights of near- and onshore tsunami hydrodynamics. We investigate the transport of coarse clasts - so called boulders - due to tsunami impacts by a multi-methodology approach of numerical modelling, laboratory experiments, and sedimentary field records. Coupled numerical hydrodynamic and boulder transport models (BTM) are widely applied for analysing the impact characteristics of the transport by tsunami, such as wave height and flow velocity. Numerical models able to simulate past tsunami events and the corresponding boulder transport patterns with high accuracy and acceptable computational effort can be utilized as powerful forecasting models predicting the impact of a coast approaching tsunami. We have conducted small-scale physical experiments in the tilting flume with real shaped boulder models. Utilizing the structure from motion technique (Westoby et al., 2012) we reconstructed real boulders from a field study on the Island of Bonaire (Lesser Antilles, Caribbean Sea, Engel & May, 2012). The obtained three-dimensional boulder meshes are utilized for creating downscaled replica of the real boulder for physical experiments. The results of the irregular shaped boulder are compared to experiments with regular shaped boulder models to achieve a better insight about the shape related influence on transport patterns. The numerical model is based on the general two-phase mass flow model by Pudasaini (2012) enhanced for boulder transport simulations. The boulder is implemented using the immersed boundary technique (Peskin, 2002) and the direct forcing approach. In this method Cartesian grids (fluid and particle phase) and Lagrangian meshes (boulder) are combined. By applying the

  1. MAQARIN natural analogue study: phase III

    Energy Technology Data Exchange (ETDEWEB)

    Alexander, W R; Mazurek, M; Waber, H N [Univ. of Berne (Switzerland). Institutes of Geology, Mineralogy and Petrology, Rock-Water Interaction Group (GGWW); Arlinger, J; Erlandson, A C; Hallbeck, L; Pedersen, K [Goeteborg University (Sweden). Dept. of General and Marine Microbiology; Boehlmann, W; Fritz, P; Geyer, S; Geyer, W; Hanschman, G; Kopinke, F D; Poerschmann, J [Umweltforschungszentrum Leipzig-Halle (Germany); Chambers, A V; Haworth, A; Ilett, D; Linklater, C M; Tweed, C J [AEA Technology plc, Harwell (United Kingdom); Chenery, S R.N.; Kemp, S J; Milodowski, A E; Pearce, J M; Reeder, S; Rochelle, C A; Smith, B; Wetton, P D; Wragg, J [British Geological Survey, Keyworth (United Kingdom); Clark, I D [Univ. of Ottawa (Canada). Dept. of Geology; Hodginson, E; Hughes, C R [Univ. of Manchester (United Kingdom). Dept. of Earth Sciences; Hyslop, E K [British Geological Survey, Edinburgh (United Kingdom); Karlsson, F [Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden); Khoury, H N; Salameh, E [Univ. of Jordan, Amman (Jordan); Lagerblad, B [Cement Institute, Stockholm (Sweden); Longworth, G [Univ. of Manchester (United Kingdom). Dept. of Geology; Pitty, A F [Private consultant, Norwich (United Kingdom); Savage, D [QuantiSci Ltd, Melton Mowbray (United Kingdom); Smellie, J A.T. [ed.; Conterra AB, Uppsala (Sweden)

    1998-12-01

    This report represents the conclusion to Phase III of the Maqarin Natural Analogue Study. The main thrust was to establish the origin and chemistry of the Western Springs hyper alkaline groundwaters (Na/K enriched Ca(OH){sub 2} type) and to study their interaction with rocks of different compositions, as natural analogues to key processes that might occur at an early stage within the `alkali disturbed zone` of cementitious repositories in different host rocks. Whilst earlier studies at Maqarin were very much site-specific and process-oriented, Phase III provided a regional perspective to the geological evolution of the Maqarin region. This was made possible by greater field access which allowed a more systematic structural and geomorphological study of the area. This has resulted in a greater understanding of the age and spatial relationships concerning formation of the cement zones through spontaneous combustion of the Bituminous Marls, and the subsequent formation of high pH groundwaters at the Eastern and Western Springs locations. At the Western Springs locality, hydrochemical and hydrogeological evaluation of new and published data (plus access to unpublished data), together with detailed mineralogical and geochemical studies, helped to clarify the very earliest stage of cement leachate/host rock interaction. The data were used also to test coupled flow/transport codes developed to assess the long-term evolution of a cementitious repository. Additional objectives addressed include: a) rock matrix diffusion, b) the occurrence and chemical controls on zeolite composition, e) the occurrence and chemical controls on clay stability, and d) the role of microbes, organics and colloids in trace element transport. The Maqarin site now provides a consistent picture explaining the origin of the hyperalkaline groundwaters, and is therefore a unique location for the examination of the mechanisms and processes associated with cementitious repositories. Application of these

  2. MAQARIN natural analogue study: phase III

    International Nuclear Information System (INIS)

    Alexander, W.R.; Mazurek, M.; Waber, H.N.; Arlinger, J.; Erlandson, A.C.; Hallbeck, L.; Pedersen, K.; Chambers, A.V.; Haworth, A.; Ilett, D.; Linklater, C.M.; Tweed, C.J.; Chenery, S.R.N.; Kemp, S.J.; Milodowski, A.E.; Pearce, J.M.; Reeder, S.; Rochelle, C.A.; Smith, B.; Wetton, P.D.; Wragg, J.; Clark, I.D.; Karlsson, F.; Khoury, H.N.; Salameh, E.; Lagerblad, B.; Longworth, G.; Savage, D.; Smellie, J.A.T.

    1998-12-01

    This report represents the conclusion to Phase III of the Maqarin Natural Analogue Study. The main thrust was to establish the origin and chemistry of the Western Springs hyper alkaline groundwaters (Na/K enriched Ca(OH) 2 type) and to study their interaction with rocks of different compositions, as natural analogues to key processes that might occur at an early stage within the 'alkali disturbed zone' of cementitious repositories in different host rocks. Whilst earlier studies at Maqarin were very much site-specific and process-oriented, Phase III provided a regional perspective to the geological evolution of the Maqarin region. This was made possible by greater field access which allowed a more systematic structural and geomorphological study of the area. This has resulted in a greater understanding of the age and spatial relationships concerning formation of the cement zones through spontaneous combustion of the Bituminous Marls, and the subsequent formation of high pH groundwaters at the Eastern and Western Springs locations. At the Western Springs locality, hydrochemical and hydrogeological evaluation of new and published data (plus access to unpublished data), together with detailed mineralogical and geochemical studies, helped to clarify the very earliest stage of cement leachate/host rock interaction. The data were used also to test coupled flow/transport codes developed to assess the long-term evolution of a cementitious repository. Additional objectives addressed include: a) rock matrix diffusion, b) the occurrence and chemical controls on zeolite composition, e) the occurrence and chemical controls on clay stability, and d) the role of microbes, organics and colloids in trace element transport. The Maqarin site now provides a consistent picture explaining the origin of the hyperalkaline groundwaters, and is therefore a unique location for the examination of the mechanisms and processes associated with cementitious repositories. Application of these

  3. MAQARIN natural analogue study: phase III

    Energy Technology Data Exchange (ETDEWEB)

    Alexander, W R; Mazurek, M; Waber, H N [Univ. of Berne (Switzerland). Institutes of Geology, Mineralogy and Petrology, Rock-Water Interaction Group (GGWW); Arlinger, J; Erlandson, A C; Hallbeck, L; Pedersen, K [Goeteborg Univ. (Sweden). Dept. of General and Marine Microbiology; Boehlmann, W; Fritz, P; Geyer, S; Geyer, W; Hanschman, G; Kopinke, F D; Poerschmann, J [Umweltforschungszentrum Leipzig-Halle (Germany); Chambers, A V; Haworth, A; Ilett, D; Linklater, C M; Tweed, C J [AEA Technology plc, Harwell (United Kingdom); Chenery, S R.N.; Kemp, S J; Milodowski, A E; Pearce, J M; Reeder, S; Rochelle, C A; Smith, B; Wetton, P D; Wragg, J [British Geological Survey, Keyworth (United Kingdom); Clark, I D [Univ. of Ottawa (Canada). Dept. of Geology; Hodginson, E; Hughes, C R [Univ. of Manchester (United Kingdom). Dept. of Earth Sciences; Hyslop, E K [British Geological Survey, Edinburgh (United Kingdom); Karlsson, F [Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden); Khoury, H N; Salameh, E [Univ. of Jordan, Amman (Jordan); Lagerblad, B [Cement Inst., Stockholm (Sweden); Longworth, G [Univ. of Manchester (United Kingdom). Dept. of Geology; Pitty, A F [Private consultant, Norwich (United Kingdom); Savage, D [QuantiSci Ltd, Melton Mowbray (United Kingdom); Smellie, J A.T. [ed.; Conterra AB, Uppsala (Sweden)

    1998-12-01

    This report represents the conclusion to Phase III of the Maqarin Natural Analogue Study. The main thrust was to establish the origin and chemistry of the Western Springs hyper alkaline groundwaters (Na/K enriched Ca(OH){sub 2} type) and to study their interaction with rocks of different compositions, as natural analogues to key processes that might occur at an early stage within the `alkali disturbed zone` of cementitious repositories in different host rocks. Whilst earlier studies at Maqarin were very much site-specific and process-oriented, Phase III provided a regional perspective to the geological evolution of the Maqarin region. This was made possible by greater field access which allowed a more systematic structural and geomorphological study of the area. This has resulted in a greater understanding of the age and spatial relationships concerning formation of the cement zones through spontaneous combustion of the Bituminous Marls, and the subsequent formation of high pH groundwaters at the Eastern and Western Springs locations. At the Western Springs locality, hydrochemical and hydrogeological evaluation of new and published data (plus access to unpublished data), together with detailed mineralogical and geochemical studies, helped to clarify the very earliest stage of cement leachate/host rock interaction. The data were used also to test coupled flow/transport codes developed to assess the long-term evolution of a cementitious repository. Additional objectives addressed include: a) rock matrix diffusion, b) the occurrence and chemical controls on zeolite composition, e) the occurrence and chemical controls on clay stability, and d) the role of microbes, organics and colloids in trace element transport. The Maqarin site now provides a consistent picture explaining the origin of the hyperalkaline groundwaters, and is therefore a unique location for the examination of the mechanisms and processes associated with cementitious repositories. Application of these

  4. Three-dimensional two-phase mass transport model for direct methanol fuel cells

    International Nuclear Information System (INIS)

    Yang, W.W.; Zhao, T.S.; Xu, C.

    2007-01-01

    A three-dimensional (3D) steady-state model for liquid feed direct methanol fuel cells (DMFC) is presented in this paper. This 3D mass transport model is formed by integrating five sub-models, including a modified drift-flux model for the anode flow field, a two-phase mass transport model for the porous anode, a single-phase model for the polymer electrolyte membrane, a two-phase mass transport model for the porous cathode, and a homogeneous mist-flow model for the cathode flow field. The two-phase mass transport models take account the effect of non-equilibrium evaporation/ condensation at the gas-liquid interface. A 3D computer code is then developed based on the integrated model. After being validated against the experimental data reported in the literature, the code was used to investigate numerically transport behaviors at the DMFC anode and their effects on cell performance

  5. Influence of quantum phase transition on spin transport in the quantum antiferromagnet in the honeycomb lattice

    Science.gov (United States)

    Lima, L. S.

    2017-06-01

    We use the SU(3) Schwinger boson theory to study the spin transport properties of the two-dimensional anisotropic frustrated Heisenberg model in a honeycomb lattice at T = 0 with single ion anisotropy and third neighbor interactions. We have investigated the behavior of the spin conductivity for this model that presents exchange interactions J1 , J2 and J3 . We study the spin transport in the Bose-Einstein condensation regime where the bosons tz are condensed. Our results show an influence of the quantum phase transition point on the spin conductivity behavior. We also have made a diagrammatic expansion for the Green-function and did not obtain any significant change of the results.

  6. Transportation engineering advancement and mentoring program : phase I.

    Science.gov (United States)

    2010-05-01

    The numbers of female and minority students enrolled in engineering schools are increasing slowly; however, there are still : relatively small percentages drawn to the field of transportation civil engineering. As a consequence, there is a need to ed...

  7. Gearing up for transportation engineering, a summer institute : phase IX.

    Science.gov (United States)

    2009-02-01

    The numbers of female and minority students enrolled in engineering schools are increasing slowly, however there is still a relatively small percentage drawn to the field of transportation civil engineering. As a consequence, there is a need to educa...

  8. Gearing up for transportation engineering, a summer institute : phase 2

    Science.gov (United States)

    2001-12-31

    The numbers of female and minority students enrolled in engineering schools are increasing slowly; however, a relatively small percentage of these students are drawn to the field of transportation engineering. For this reason, there is a need to educ...

  9. Gearing up for transportation engineering summer program (GUTEP) : phase VIII.

    Science.gov (United States)

    2008-12-01

    The numbers of female and minority students enrolled in engineering schools are increasing slowly, however there is still a relatively small percentage drawn to the field of transportation civil engineering. As a consequence, there is a need to educa...

  10. Numerical simulation of two-phase multicomponent flow with reactive transport in porous media

    International Nuclear Information System (INIS)

    Vostrikov, Viatcheslav

    2014-01-01

    The subject of this thesis is the numerical simulation of water-gas flow in the subsurface together with chemical reactions. The subject has applications to various situations in environmental modeling, though we are mainly concerned with CO 2 storage in deep saline aquifers. In Carbon Capture and Storage studies, CO 2 is first captured from its sources of origin, transport in liquefied form and injected as gas under high pressure in deep saline aquifers. Numerical simulation is an essential tool to make sure that gaseous CO 2 will remain trapped for several hundreds or thousands of years. Several trapping mechanisms can be brought to bear to achieve this goal. Of particular interest in this thesis are solubility trapping (whereby gaseous CO 2 dissolves in the brine as it moves upward) and, on a longer term, mineral trapping (which causes CO 2 to react with the surrounding rock to form minerals such as calcite). Thus, understanding how CO 2 reacts chemically becomes an important issue for its long term fate. The thesis is composed of four chapters. The first chapter is an introduction to multicomponent two-phase flow in porous media, with or without chemical reactions. It presents a review of the existing literature, and gives an outline of the whole thesis. Chapter 2 presents a quantitative discussion of the physical and chemical phenomena involved, and of their mathematical modeling. The model we use is that of two-phase two-component flow in porous media, coupled to reactive transport. This model leads to a large set of partial differential equations, coupled to algebraic equations, describing the evolution of the concentration of each species at each grid point. A direct solution of this problem (a fully coupled solution) is possible, but presents many difficulties form the numerical point of view. Moreover, it makes it difficult to reuse codes already written, and validated, to simulate the simpler phenomena of (uncoupled) two-phase flow and reactive transport

  11. Nondimensional transport studies in TFTR

    International Nuclear Information System (INIS)

    Scott, S.D.; Mikkelsen, D.R.; Perkins, F.W.; Bell, M.G.; Bell, R.E.; Bush, C.E.; Fredrickson, E.D.; Grek, B.; Hill, K.W.; Janos, A.; Jobes, F.; Johnson, D.; Mansfield, D.K.; Owens, D.K.; Park, H.; Paul, S.; Ramsey, A.T.; Schivell, J.; Stratton, B.C.; Synakowski, E.J.; Tang, W.M.; Zarnstorff, M.C.; Ernst, D.

    1993-04-01

    The machine parameters (I p , P heat , R) required for ignition in ITER have generally been extrapolated from power-law regression fits to global τ E measurements on existing tokamaks. There remain important choices to be made in the form of the scaling relation which have not yet been resolved by theory. In particular, power flow Q(r) through a magnetic flux surface should scale as Q(r) = Q Bohm F where F = F(ρ*,β,ν*,s,T e /T i ,...) is a function of local, nondimensional plasma parameters and Q Bohm ∝ [n e T e 2 a/eB]. Projections to ITER can be reduced to establishing the dependence of F on ρ* = ρ i /a, because one can create plasmas in today's tokamaks which have similar values of the other nondimensional parameters. Two common scalings suggested by theory are Bohm (F independent of ρ*) and gyroBohm (F ∝ ρ*). Experiments have been carried out on TFTR to ascertain the dependence of F on ρ*, ν*, and β in L-mode plasmas, holding the other nondimensional parameters fixed. The observed variation of heat flow with ρ* was observed to be better described by Bohm scaling than gyroBohm. Comparisons with the critical gradient temperature transport model, which is gyroBohm in character, show that it overpredicts the temperature increase expected with increasing magnetic field. The ν* scan (remaining in the collisionless regime) revealed that the Bohm-normalized power flow is remarkably insensitive to collisionality, in agreement with ITER-P scaling. The β scan identified a deterioration of confinement with increasing β at fixed ρ* and ν*, of approximately the correct magnitude required to reconcile Bohm local transport scaling with ITER-P global scaling of τ E . This may suggest a role for electromagnetic phenomena in governing tokamak transport even at very low beta

  12. Validation of in vitro cell models used in drug metabolism and transport studies; genotyping of cytochrome P450, phase II enzymes and drug transporter polymorphisms in the human hepatoma (HepG2), ovarian carcinoma (IGROV-1) and colon carcinoma (CaCo-2, LS180) cell lines

    International Nuclear Information System (INIS)

    Brandon, Esther F.A.; Bosch, Tessa M.; Deenen, Maarten J.; Levink, Rianne; Wal, Everdina van der; Meerveld, Joyce B.M. van; Bijl, Monique; Beijnen, Jos H.; Schellens, Jan H.M.; Meijerman, Irma

    2006-01-01

    Human cell lines are often used for in vitro biotransformation and transport studies of drugs. In vivo, genetic polymorphisms have been identified in drug-metabolizing enzymes and ABC-drug transporters leading to altered enzyme activity, or a change in the inducibility of these enzymes. These genetic polymorphisms could also influence the outcome of studies using human cell lines. Therefore, the aim of our study was to pharmacogenotype four cell lines frequently used in drug metabolism and transport studies, HepG2, IGROV-1, CaCo-2 and LS180, for genetic polymorphisms in biotransformation enzymes and drug transporters. The results indicate that, despite the presence of some genetic polymorphisms, no real effects influencing the activity of metabolizing enzymes or drug transporters in the investigated cell lines are expected. However, this characterization will be an aid in the interpretation of the results of biotransformation and transport studies using these in vitro cell models

  13. Analysis of volatile phase transport in soils using natural radon gas as a tracer

    International Nuclear Information System (INIS)

    Chen, C.; Thomas, D.M.

    1992-01-01

    We have conducted a field study of soil gas transport processes using radon gas as a naturally occurring tracer. The experiment monitored soil gas radon activity, soil moisture, and soil temperature at three depths in the shallow soil column; barometric pressure, rainfall and wind speed were monitored at the soil surface. Linear and multiple regression analysis of the data sets has shown that the gas phase radon activities under natural environmental conditions are influenced by soil moisture content, barometric pressure variations, soil temperature and soil structure. The effect of wind speed on subsurface radon activities under our field conditions has not been demonstrated

  14. In Vivo Exposure of Kaempferol Is Driven by Phase II Metabolic Enzymes and Efflux Transporters.

    Science.gov (United States)

    Zheng, Liang; Zhu, Lijun; Zhao, Min; Shi, Jian; Li, Yuhuan; Yu, Jia; Jiang, Huangyu; Wu, Jinjun; Tong, Yunli; Liu, Yuting; Hu, Ming; Lu, Linlin; Liu, Zhongqiu

    2016-09-01

    Kaempferol is a well-known flavonoid; however, it lacks extensive pharmacokinetic studies. Phase II metabolic enzymes and efflux transporters play an important role in the disposition of flavonoids. This study aimed to investigate the mechanism by which phase II metabolic enzymes and efflux transporters determine the in vivo exposure of kaempferol. Pharmacokinetic analysis in Sprague-Dawley rats revealed that kaempferol was mostly biotransformed to conjugates, namely, kaempferol-3-glucuronide (K-3-G), kaempferol-7-glucuronide (K-7-G), and kaempferol-7-sulfate, in plasma. K-3-G represented the major metabolite. Compared with that in wild-type mice, pharmacokinetics in knockout FVB mice demonstrated that the absence of multidrug resistance protein 2 (MRP2) and breast cancer resistance protein (BCRP) significantly increased the area under the curve (AUC) of the conjugates. The lack of MRP1 resulted in a much lower AUC of the conjugates. Intestinal perfusion in rats revealed that the glucuronide conjugates were mainly excreted in the small intestine, but 7-sulfate was mainly excreted in the colon. In Caco-2 monolayers, K-7-G efflux toward the apical (AP) side was significantly higher than K-3-G efflux. In contrast, K-3-G efflux toward the basolateral (BL) side was significantly higher than K-7-G efflux. The BL-to-AP efflux was significantly reduced in the presence of the MRP2 inhibitor LTC4. The AP-to-BL efflux was significantly decreased in the presence of the BL-side MRPs inhibitor MK571. The BCRP inhibitor Ko143 decreased the glucuronide conjugate efflux. Therefore, kaempferol is mainly exposed as K-3-G in vivo, which is driven by phase II metabolic enzymes and efflux transporters (i.e., BCRP and MRPs).

  15. Multi-fuel reformers for fuel cells used in transportation. Phase 1: Multi-fuel reformers

    Science.gov (United States)

    1994-05-01

    DOE has established the goal, through the Fuel Cells in Transportation Program, of fostering the rapid development and commercialization of fuel cells as economic competitors for the internal combustion engine. Central to this goal is a safe feasible means of supplying hydrogen of the required purity to the vehicular fuel cell system. Two basic strategies are being considered: (1) on-board fuel processing whereby alternative fuels such as methanol, ethanol or natural gas stored on the vehicle undergo reformation and subsequent processing to produce hydrogen, and (2) on-board storage of pure hydrogen provided by stationary fuel processing plants. This report analyzes fuel processor technologies, types of fuel and fuel cell options for on-board reformation. As the Phase 1 of a multi-phased program to develop a prototype multi-fuel reformer system for a fuel cell powered vehicle, the objective of this program was to evaluate the feasibility of a multi-fuel reformer concept and to select a reforming technology for further development in the Phase 2 program, with the ultimate goal of integration with a DOE-designated fuel cell and vehicle configuration. The basic reformer processes examined in this study included catalytic steam reforming (SR), non-catalytic partial oxidation (POX) and catalytic partial oxidation (also known as Autothermal Reforming, or ATR). Fuels under consideration in this study included methanol, ethanol, and natural gas. A systematic evaluation of reforming technologies, fuels, and transportation fuel cell applications was conducted for the purpose of selecting a suitable multi-fuel processor for further development and demonstration in a transportation application.

  16. Is P-glycoprotein (ABCB1) a phase 0 or a phase 3 colchicine transporter depending on colchicine exposure conditions?

    International Nuclear Information System (INIS)

    Decleves, Xavier.; Niel, Elisabeth; Debray, Marcel; Scherrmann, Jean-Michel

    2006-01-01

    This study investigates the P-glycoprotein (Pgp)-mediated transport of its substrates in accumulation or efflux modes under steady-state conditions. The kinetics of colchicine uptake and efflux, a substrate of both Pgp and intracellular tubulin, were studied in HL60 and HL60/DNR cells; HL60/DNR cells contain 25 times more Pgp than do HL60 cells. HL60/DNR cells in a medium containing 6.25 nM colchicine, which mimics therapeutic conditions, reached steady-state twice as rapidly as did HL60 cells, and accumulated 24-times less colchicine than did HL60 cells. The Pgp inhibitor GF120918, increased colchicine uptake by HL60 cells 1.2-fold and that of HL60/DNR cells 17-fold, while it had no effect on colchicine efflux from either cell line that had been incubated with colchicine for 24 h. Colchicine kinetics fitted well a two closed-compartment model, showing that the low intracellular accumulation of colchicine in HL60/DNR cells resulted from a 11-fold decrease in colchicine uptake and a 2.3-fold increase in colchicine efflux, that could be attributed to Pgp-mediated efflux activity in HL60/DNR cells. Intracellular colchicine was mainly and similarly distributed in the cytosol in both cell lines. These data demonstrate that the kinetics of the intracellular colchicine accumulation depend on the density of Pgp and that Pgp is more a phase 0 (preventing cellular uptake) than a phase 3 (effluxing intracellular substrate) transporter under steady-state conditions, although the situation is reversed after a short incubation time (30 min), when intracellular free colchicine concentration is probably high enough for it to be removed from the cell by Pgp

  17. Hopewell Furnace NHS : alternative transportation study

    Science.gov (United States)

    2009-12-31

    This study assesses the potential for an alternative transportation system (ATS) at Hopewell Furnace National Historic Site (NHS). The Volpe Center investigated internal circulation and potential partnerships with local historic, cultural, and recrea...

  18. Energy saving opportunities in the refrigerated transport sector through Phase Change Materials (PCMs) application

    Science.gov (United States)

    Principi, P.; Fioretti, R.; Copertaro, B.

    2017-11-01

    Transportation of food products at controlled temperature is a critical task in the transport sector. In fact, whilst there is a need of ensuring both food quality and safety to the global population, its impact in terms of energy consumption and related CO2 emissions into the atmosphere is becoming increasingly evident. In this regard, Thermal Energy Storage (TES) using Phase Change Materials (PCMs) can be considered as a potential way of reducing the cooling load, energy consumption and related greenhouse gas emissions in refrigerated transport sector. In this paper two different PCM applications are investigated. Specifically, in the first study a PCM (35 °C melting temperature) layer was added to the external side of a refrigerated enclosure wall with the aim of managing the cooling peak (shifting and reducing) and reducing the daily energy rate. Outdoor experimental results showed that the added PCM layer helps to reduce (between 5.55% and 8.57%) and delay (between 4.30 h and 3.30 h) the peak load of incoming heat compared to the reference one. In the second study, the energy performance of a refrigerated chamber with an air heat exchanger containing PCM (5°C melting temperature) was investigated. The study purpose was to reduce the cooling energy consumption during steady state operating conditions and the rate of temperature increase throughout the course of a power failure event. Test results showed that using a PCM air heat exchanger addition, up to 16% of energy can be saved.

  19. COUPLED FREE AND DISSOLVED PHASE TRANSPORT: NEW SIMULATION CAPABILITIES AND PARAMETER INVERSION

    Science.gov (United States)

    The vadose zone free-phase simulation capabilities of the US EPA Hydrocarbon Spill Screening Model (HSSM) (Weaver et al., 1994) have been linked with the 3-D multi-species dissolved-phase contaminant transport simulator MT3DMS (Zheng and Wang, 1999; Zheng, 2005). The linkage pro...

  20. Transport regimes spanning magnetization-coupling phase space

    Science.gov (United States)

    Baalrud, Scott D.; Daligault, Jérôme

    2017-10-01

    The manner in which transport properties vary over the entire parameter-space of coupling and magnetization strength is explored. Four regimes are identified based on the relative size of the gyroradius compared to other fundamental length scales: the collision mean free path, Debye length, distance of closest approach, and interparticle spacing. Molecular dynamics simulations of self-diffusion and temperature anisotropy relaxation spanning the parameter space are found to agree well with the predicted boundaries. Comparison with existing theories reveals regimes where they succeed, where they fail, and where no theory has yet been developed.

  1. Studies of the neoclassical transport for CNT

    International Nuclear Information System (INIS)

    Seiwald, B; Nemov, V V; Pedersen, T Sunn; Kernbichler, W

    2007-01-01

    The original optimization of the Columbia Nonneutral Torus (CNT) considering only volume (and error field resilience) was also successful in optimizing the stored energy. To assess the general confinement properties of a device, studies of the 1/ν neoclassical transport (effective ripple ε eff ) are important. For CNT the field line tracing code NEO is used to compute ε eff . NEO is used by the code SORSSA for computation of the total stored energy based on neoclassical transport

  2. Richmond public transportation study report.

    Science.gov (United States)

    2000-05-01

    This study looked at the possible costs and benefits associated with the creation of a small deviated fixed route bus service in Richmond. It concluded that the circumstances in Richmond favor the creation of such a system. It also concluded that onl...

  3. Centrifuge workers study. Phase II, completion report

    Energy Technology Data Exchange (ETDEWEB)

    Wooten, H.D.

    1994-09-01

    Phase II of the Centrifuge Workers Study was a follow-up to the Phase I efforts. The Phase I results had indicated a higher risk than expected among centrifuge workers for developing bladder cancer when compared with the risk in the general population for developing this same type of cancer. However, no specific agent could be identified as the causative agent for these bladder cancers. As the Phase II Report states, Phase I had been limited to workers who had the greatest potential for exposure to substances used in the centrifuge process. Phase II was designed to expand the survey to evaluate the health of all employees who had ever worked in Centrifuge Program Departments 1330-1339 but who had not been interviewed in Phase I. Employees in analytical laboratories and maintenance departments who provided support services for the Centrifuge Program were also included in Phase II. In December 1989, the Oak Ridge Associated Universities (ORAU), now known as Oak Ridge Institute for Science and Education (ORISE), was contracted to conduct a follow-up study (Phase II). Phase H of the Centrifuge Workers Study expanded the survey to include all former centrifuge workers who were not included in Phase I. ORISE was chosen because they had performed the Phase I tasks and summarized the corresponding survey data therefrom.

  4. Centrifuge workers study. Phase II, completion report

    International Nuclear Information System (INIS)

    Wooten, H.D.

    1994-09-01

    Phase II of the Centrifuge Workers Study was a follow-up to the Phase I efforts. The Phase I results had indicated a higher risk than expected among centrifuge workers for developing bladder cancer when compared with the risk in the general population for developing this same type of cancer. However, no specific agent could be identified as the causative agent for these bladder cancers. As the Phase II Report states, Phase I had been limited to workers who had the greatest potential for exposure to substances used in the centrifuge process. Phase II was designed to expand the survey to evaluate the health of all employees who had ever worked in Centrifuge Program Departments 1330-1339 but who had not been interviewed in Phase I. Employees in analytical laboratories and maintenance departments who provided support services for the Centrifuge Program were also included in Phase II. In December 1989, the Oak Ridge Associated Universities (ORAU), now known as Oak Ridge Institute for Science and Education (ORISE), was contracted to conduct a follow-up study (Phase II). Phase H of the Centrifuge Workers Study expanded the survey to include all former centrifuge workers who were not included in Phase I. ORISE was chosen because they had performed the Phase I tasks and summarized the corresponding survey data therefrom

  5. Transport and fluctuation studies on RFX

    International Nuclear Information System (INIS)

    Martini, S.; Martines, E.; Carraro, L.

    2003-01-01

    The paper highlights the progress made in the modelling and understanding of the mechanisms underlying particle and energy transport in the RFP. A transport analysis has been performed on the perturbed transport coefficients for pellets of different characteristics launched both in standard RFP plasmas and in combination with pulsed poloidal current drive, this latter scenario potentially allowing an efficient fuelling and a good energy confinement. The study has confirmed the importance of large-scale MHD modes in determining the transport properties in the RFP core. As far as confinement in the edge is concerned, the analysis has been focussed on the role played by burst events on the electrostatic particle flux and to the 'intermittent events'. The intermittent events cluster during relaxation processes and such behaviour is more evident close to the magnetic reversal surface. This result confirms an interplay between the small scale edge turbulence and the large scale relaxation events driven by core-resonant tearing modes. (author)

  6. Incoherent transport for phases that spontaneously break translations

    Science.gov (United States)

    Donos, Aristomenis; Gauntlett, Jerome P.; Griffin, Tom; Ziogas, Vaios

    2018-04-01

    We consider phases of matter at finite charge density which spontaneously break spatial translations. Without taking a hydrodynamic limit we identify a boost invariant incoherent current operator. We also derive expressions for the small frequency behaviour of the thermoelectric conductivities generalising those that have been derived in a translationally invariant context. Within holographic constructions we show that the DC conductivity for the incoherent current can be obtained from a solution to a Stokes flow for an auxiliary fluid on the black hole horizon combined with specific thermodynamic quantities associated with the equilibrium black hole solutions.

  7. TRANSPORT LOCOMOTIVE AND WASTE PACKAGE TRANSPORTER ITS STANDARDS IDENTIFICATION STUDY

    International Nuclear Information System (INIS)

    Draper, K.D.

    2005-01-01

    To date, the project has established important to safety (ITS) performance requirements for structures, systems and components (SSCs) based on identification and categorization of event sequences that may result in a radiological release. These performance requirements are defined within the ''Nuclear Safety Design Basis for License Application'' (NSDB) (BSC 2005). Further, SSCs credited with performing safe functions are classified as ITS. In turn, performance confirmation for these SSCs is sought through the use of consensus code and standards. The purpose of this study is to identify applicable codes and standards for the waste package (WP) transporter and transport locomotive ITS SSCs. Further, this study will form the basis for selection and the extent of applicability of each code and standard. This study is based on the design development completed for License Application only. Accordingly, identification of ITS SSCs beyond those defined within the NSDB are based on designs that may be subject to further development during detail design. Furthermore, several design alternatives may still be under consideration to satisfy certain safety functions, and that final selection will not be determined until further design development has occurred. Therefore, for completeness, throughout this study alternative designs currently under consideration will be discussed. Further, the results of this study will be subject to evaluation as part of a follow-on gap analysis study. Based on the results of this study the gap analysis will evaluate each code and standard to ensure each ITS performance requirement is fully satisfied. When a performance requirement is not fully satisfied a ''gap'' is highlighted. Thereafter, the study will identify supplemental requirements to augment the code or standard to meet performance requirements. Further, the gap analysis will identify non-standard areas of the design that will be subject to a Development Plan. Non-standard components and

  8. The phase transport and reactions of γ-irradiated aqueous-ionic liquids

    International Nuclear Information System (INIS)

    Howett, S.; Joseph, J.; Noel, J.J.; Wren, J.C.

    2010-01-01

    A novel technology based on the transfer of chemical species across water/ionic liquid interfaces via specific complexation reactions is currently being considered for the separation and sequestration of metal ion contaminants from radioactive waste effluents in the nuclear fuel cycle. An ideal solvent for these applications should have a high intrinsic selectivity for a targeted metal or group of metals (e.g., trans-Pu actinides, lanthanides, or other fission products), an efficient switching mechanism (between complexation and decomplexation), and a high immiscibility with aqueous solutions. These characteristics must be maintained in the chemical, radiation, and mass transport environments present during the separation process. Ionic liquids (ILs) have an almost negligible vapour pressure and high thermal stability. Their ability to dissolve a wide range of substrate molecules and potential to be highly resilient in radiation fields make ILs particularly promising media. The separation efficiency of the biphasic system will depend on many parameters, including the aqueous oxidation state of the targeted metal ion, and the thermodynamics and kinetics of interfacial transport and metal-ligand complex formation at the water/IL interface or in the IL phase. The most uncertain and unstudied area for these applications is the effect of ionizing radiation on the stability and separation efficiency of the biphasic system. The present study investigates the effect of γ-radiation on gas/IL and water/IL interfacial stability and mass transfer with trihexyltetradecylphosphonium bis(trifluoromethyl-sulfonyl)imide, a phosphonium-based IL. The IL, in contact with either gas or water, was irradiated at a dose rate of 6.4 kGy·h -1 . Gas-phase samples were analyzed by gas chromatography-mass spectrometry (GC-MS) and the changes in the IL and aqueous phases were monitored by conductivity measurements and Raman spectroscopy. In this paper we discuss these observations and their

  9. Flow assurance studies for CO2 transport

    NARCIS (Netherlands)

    Veltin, J.; Belfroid, S.P.C.

    2013-01-01

    In order to compensate for the relative lack of experience of the CCTS community, Flow Assurance studies of new CO2 pipelines and networks are a very important step toward reliable operation. This report details a typical approach for Flow Assurance study of CO2 transport pipeline. Considerations to

  10. Phase-controlled localization and directed transport in an optical bipartite lattice.

    Science.gov (United States)

    Hai, Kuo; Luo, Yunrong; Lu, Gengbiao; Hai, Wenhua

    2014-02-24

    We investigate coherent control of a single atom interacting with an optical bipartite lattice via a combined high-frequency modulation. Our analytical results show that the quantum tunneling and dynamical localization can depend on phase difference between the modulation components, which leads to a different route for the coherent destruction of tunneling and a convenient phase-control method for stabilizing the system to implement the directed transport of atom. The similar directed transport and the phase-controlled quantum transition are revealed for the corresponding many-particle system. The results can be referable for experimentally manipulating quantum transport and transition of cold atoms in the tilted and shaken optical bipartite lattice or of analogical optical two-mode quantum beam splitter, and also can be extended to other optical and solid-state systems.

  11. Phase II Contaminant Transport Parameters for the Groundwater Flow and Contaminant Transport Model of Corrective Action Unit 98: Frenchman Flat, Nye County, Nevada, Rev. No.: 0

    Energy Technology Data Exchange (ETDEWEB)

    DeNovio, Nicole M.; Bryant, Nathan; King, Chrissi B.; Bhark, Eric; Drellack, Sigmund L.; Pickens, John F.; Farnham, Irene; Brooks, Keely M.; Reimus, Paul; Aly, Alaa

    2005-04-01

    This report documents pertinent transport data and data analyses as part of the Phase II Corrective Action Investigation (CAI) for Frenchman Flat (FF) Corrective Action Unit (CAU) 98. The purpose of this data compilation and related analyses is to provide the primary reference to support parameterization of the Phase II FF CAU transport model.

  12. Underground Test Area Subproject Phase I Data Analysis Task. Volume VII - Tritium Transport Model Documentation Package

    Energy Technology Data Exchange (ETDEWEB)

    None

    1996-12-01

    Volume VII of the documentation for the Phase I Data Analysis Task performed in support of the current Regional Flow Model, Transport Model, and Risk Assessment for the Nevada Test Site Underground Test Area Subproject contains the tritium transport model documentation. Because of the size and complexity of the model area, a considerable quantity of data was collected and analyzed in support of the modeling efforts. The data analysis task was consequently broken into eight subtasks, and descriptions of each subtask's activities are contained in one of the eight volumes that comprise the Phase I Data Analysis Documentation.

  13. Enhanced heat transport in environmental systems using microencapsulated phase change materials

    Science.gov (United States)

    Colvin, D. P.; Mulligan, J. C.; Bryant, Y. G.

    1992-01-01

    A methodology for enhanced heat transport and storage that uses a new two-component fluid mixture consisting of a microencapsulated phase change material (microPCM) for enhanced latent heat transport is outlined. SBIR investigations for NASA, USAF, SDIO, and NSF since 1983 have demonstrated the ability of the two-component microPCM coolants to provide enhancements in heat transport up to 40 times over that of the carrier fluid alone, enhancements of 50 to 100 percent in the heat transfer coefficient, practically isothermal operation when the coolant flow is circulated in an optimal manner, and significant reductions in pump work.

  14. Phase-space description of wave packet approach to electronic transport in nanoscale systems

    International Nuclear Information System (INIS)

    Szydłowski, D; Wołoszyn, M; Spisak, B J

    2013-01-01

    The dynamics of conduction electrons in resonant tunnelling nanosystems is studied within the phase-space approach based on the Wigner distribution function. The time evolution of the distribution function is calculated from the time-dependent quantum kinetic equation for which an effective numerical method is presented. Calculations of the transport properties of a double-barrier resonant tunnelling diode are performed to illustrate the proposed techniques. Additionally, analysis of the transient effects in the nanosystem is carried out and it is shown that for some range of the bias voltage the temporal variations of electronic current can take negative values. The explanation of this effect is based on the analysis of the time changes of the Wigner distribution function. The decay time of the temporal current oscillations in the nanosystem as a function of the bias voltage is determined. (paper)

  15. Study on the transport by superconducting elevators

    Energy Technology Data Exchange (ETDEWEB)

    Ona, K. [Technov Inc., Tokyo (Japan)

    1999-02-01

    A study on the development of a transport system using the pinning effect of a superconducting bulk structure was undertaken and a model of a flywheel for electric power storage was manufactured by introducing a bearing applying the pinning effect to investigate the feasibility through its operation. The operation behavior of vertical transport combining the superconducting bulk structure and the electromagnetic coils reproduced the predictions of simulation. As for the electric power storage via flywheel, it was confirmed that the lighting duration of a indicating lamp was elongated from the ordinary interval, 1 min., to 4 min. (H. Baba)

  16. Ion heat transport studies in JET

    DEFF Research Database (Denmark)

    Mantica, P; Angioni, C; Baiocchi, B

    2011-01-01

    Detailed experimental studies of ion heat transport have been carried out in JET exploiting the upgrade of active charge exchange spectroscopy and the availability of multi-frequency ion cyclotron resonance heating with 3He minority. The determination of ion temperature gradient (ITG) threshold a...

  17. Multiphase flow and transport caused by spontaneous gas phase growth in the presence of dense non-aqueous phase liquid.

    Science.gov (United States)

    Roy, James W; Smith, James E

    2007-01-30

    Disconnected bubbles or ganglia of trapped gas may occur below the top of the capillary fringe through a number of mechanisms. In the presence of dense non-aqueous phase liquid (DNAPL), the disconnected gas phase experiences mass transfer of dissolved gases, including volatile components from the DNAPL. The properties of the gas phase interface can also change. This work shows for the first time that when seed gas bubbles exist spontaneous gas phase growth can be expected to occur and can significantly affect water-gas-DNAPL distributions, fluid flow, and mass transfer. Source zone behaviour was observed in three different experiments performed in a 2-dimensional flow cell. In each case, a DNAPL pool was created in a zone of larger glass beads over smaller glass beads, which served as a capillary barrier. In one experiment effluent water samples were analyzed to determine the vertical concentration profile of the plume above the pool. The experiments effectively demonstrated a) a cycle of spontaneous gas phase expansion and vertical advective mobilization of gas bubbles and ganglia above the DNAPL source zone, b) DNAPL redistribution caused by gas phase growth and mobilization, and c) that these processes can significantly affect mass transport from a NAPL source zone.

  18. Studies of matrix diffusion in gas phase

    International Nuclear Information System (INIS)

    Hartikainen, K.; Timonen, J.; Vaeaetaeinen, K.; Pietarila, H.

    1994-03-01

    The diffusion of solutes from fractures into rock matrix is an important factor in the safety analysis of disposal of radioactive waste. Laboratory measurements are needed to complement field investigations for a reliable determination of the necessary transport parameters. Measurements of diffusion coefficients in tight rock samples are usually time consuming because the diffusion processes are slow. On the other hand it is well known that diffusion coefficients in the gas phase are roughly four orders of magnitude larger than those in the liquid phase. Therefore, for samples whose structures do not change much upon drying, it is possible to estimate the diffusion properties of the liquid phase when the properties of the gas phase are known. Advantages of the gas method are quick and easy measurements. In the measurements nitrogen was used as the carrier gas and helium as the tracer gas, and standard techniques have been used for helium detection. Techniques have been developed for both channel flow and through-diffusion measurements. The breakthrough curves have been measured in every experiment and all measurements have been modelled by using appropriate analytical models. As a result matrix porosities and effective diffusion coefficients in the gas phase have been determined. (12 refs., 21 figs., 6 tabs.)

  19. The influence of vertical sorbed phase transport on the fate of organic chemicals in surface soils.

    Science.gov (United States)

    McLachlan, Michael S; Czub, Gertje; Wania, Frank

    2002-11-15

    Gaseous exchange between surface soil and the atmosphere is an important process in the environmental fate of many chemicals. It was hypothesized that this process is influenced by vertical transport of chemicals sorbed to soil particles. Vertical sorbed phase transport in surface soils occurs by many processes such as bioturbation, cryoturbation, and erosion into cracks formed by soil drying. The solution of the advection/diffusion equation proposed by Jury et al. to describe organic chemical fate in a uniformly contaminated surface soil was modified to include vertical sorbed phase transport This process was modeled using a sorbed phase diffusion coefficient, the value of which was derived from soil carbon mass balances in the literature. The effective diffusivity of the chemical in a typical soil was greater in the modified model than in the model without sorbed phase transport for compounds with log K(OW) > 2 and log K(OA) > 6. Within this chemical partitioning space, the rate of volatilization from the surface soil was larger in the modified model than in the original model by up to a factor of 65. The volatilization rate was insensitive to the value of the sorbed phase diffusion coefficient throughout much of this chemical partitioning space, indicating that the surface soil layer was essentially well-mixed and that the mass transfer coefficient was determined by diffusion through the atmospheric boundary layer only. When this process was included in a non-steady-state regional multimedia chemical fate model running with a generic emissions scenario to air, the predicted soil concentrations increased by upto a factor of 25,whilethe air concentrations decreased by as much as a factor of approximately 3. Vertical sorbed phase transport in the soil thus has a major impact on predicted air and soil concentrations, the state of equilibrium, and the direction and magnitude of the chemical flux between air and soil. It is a key process influencing the environmental

  20. Debris transport evaluation during the blow-down phase of a LOCA using computational fluid dynamics

    International Nuclear Information System (INIS)

    Park, Jong Pil; Jeong, Ji Hwan; Kim, Won Tae; Kim, Man Woong; Park, Ju Yeop

    2011-01-01

    Highlights: → We conducted CFD simulation on the spreading of the coolant in the containment after a break of the hot leg. It is used to estimate the dispersion of the debris within the containment. → It was assumed that the small and fine debris is transported by the discharge flow so that a fraction of the small and fine debris transport can be estimated based on the amount of water. → The break flow was assumed to be a homogeneous two-phase mixture without phase separation. Isenthalpic expansion of the break flow was used to specify the inlet boundary condition of the break flow. → The fraction of the small and fine debris transported to the upper part is 73%; this value is close to the value calculated using 1D lumped-parameter codes by the USNRC and the KINS, respectively, while 48% more than the value shown in the NEI 04-07. - Abstract: The performance of the emergency recirculation water sump under the influence of debris accumulation following a loss-of-coolant accident (LOCA) has long been of safety concern. Debris generation and transport during a LOCA are significantly influenced by the characteristics of the ejected coolant flow. One-dimensional analyses previously have been attempted to evaluate the debris transport during the blow-down phase but the transport evaluation still has large uncertainties. In this work, a computational fluid dynamics (CFD) analysis was utilized to evaluate small and fine debris transport during the blow-down phase of a pressurized water reactor, OPR1000. The coolant ejected from the ruptured hot-leg was assumed to expand in an isenthalpic process. The transport of small and fine debris was assumed to be dominated by water-borne transport, and the transport fractions for the upper and lower parts of the containment were quantified based on the CFD analysis. It was estimated that 73% of small and fine debris is transported to the upper part of the containment. This value is close to the values estimated by nuclear

  1. Magnetoelectric and transport properties of (GaMn)Sb thin films: A ferrimagnetic phase in dilute alloys

    Energy Technology Data Exchange (ETDEWEB)

    Calderón, Jorge A. [Universidad Nacional de Colombia – Bogotá, Dpto. de Física, Grupo de Materiales Nanoestructurados y sus Aplicaciones, Cra. 30 No. 45-03 Edificio 404 Lab. 121C Ciudad Universitaria, Bogotá (Colombia); Mesa, F., E-mail: fredy.mesa@urosario.edu.co [Grupo NanoTech, Facultad de Ciencias Naturales y Matemáticas, Universidad del Rosario, Cra. 24 No. 63C-69, Bogotá (Colombia); Dussan, A. [Universidad Nacional de Colombia – Bogotá, Dpto. de Física, Grupo de Materiales Nanoestructurados y sus Aplicaciones, Cra. 30 No. 45-03 Edificio 404 Lab. 121C Ciudad Universitaria, Bogotá (Colombia)

    2017-02-28

    Highlights: • (GaMn)Sb thin films were fabricated using the direct current (DC) magnetron co-sputtering. • Presence of ferrimagnetic (Mn{sub 2}Sb) and ferromagnetic (Mn{sub 2}Sb{sub 2}) phases. • A minor difference of 1% was found with respect to percolation theory, which confirmed the validity of the diffusional model in semiconductor alloys with magnetic properties. • Increase in the localized states density (N{sub F}) with increasing substrate temperature. - Abstract: We studied the electrical, magnetic, and transport properties of (GaMn)Sb thin films fabricated by the direct current magnetron co-sputtering method. Using X-ray powder diffraction measurements, we identified the presence of ferrimagnetic (Mn{sub 2}Sb) and ferromagnetic (Mn{sub 2}Sb{sub 2}) phases within the films. We also measured the magnetization of the films versus an applied magnetic field as well as their hysteresis curves at room temperature. We determined the electrical and transport properties of the films through temperature-dependent resistivity measurements using the Van Der Pauw method. The main contribution to the transport process was variable range hopping. Hopping parameters were calculated using percolation theory and refined using the diffusional model. In addition, we determined that all samples had p type semiconductor behavior, that there was an increase in the density of localized states near the Fermi level, and that the binary magnetic phases influenced the electrical properties and transport mechanisms.

  2. Phase dependence of transport-aperture coordination variability reveals control strategy of reach-to-grasp movements.

    Science.gov (United States)

    Rand, Miya K; Shimansky, Y P; Hossain, Abul B M I; Stelmach, George E

    2010-11-01

    Based on an assumption of movement control optimality in reach-to-grasp movements, we have recently developed a mathematical model of transport-aperture coordination (TAC), according to which the hand-target distance is a function of hand velocity and acceleration, aperture magnitude, and aperture velocity and acceleration (Rand et al. in Exp Brain Res 188:263-274, 2008). Reach-to-grasp movements were performed by young adults under four different reaching speeds and two different transport distances. The residual error magnitude of fitting the above model to data across different trials and subjects was minimal for the aperture-closure phase, but relatively much greater for the aperture-opening phase, indicating considerable difference in TAC variability between those phases. This study's goal is to identify the main reasons for that difference and obtain insights into the control strategy of reach-to-grasp movements. TAC variability within the aperture-opening phase of a single trial was found minimal, indicating that TAC variability between trials was not due to execution noise, but rather a result of inter-trial and inter-subject variability of motor plan. At the same time, the dependence of the extent of trial-to-trial variability of TAC in that phase on the speed of hand transport was sharply inconsistent with the concept of speed-accuracy trade-off: the lower the speed, the larger the variability. Conversely, the dependence of the extent of TAC variability in the aperture-closure phase on hand transport speed was consistent with that concept. Taking into account recent evidence that the cost of neural information processing is substantial for movement planning, the dependence of TAC variability in the aperture-opening phase on task performance conditions suggests that it is not the movement time that the CNS saves in that phase, but the cost of neuro-computational resources and metabolic energy required for TAC regulation in that phase. Thus, the CNS

  3. Analysis of Mechanical Energy Transport on Free-Falling Wedge during Water-Entry Phase

    Directory of Open Access Journals (Sweden)

    Wen-Hua Wang

    2012-01-01

    Full Text Available For better discussing and understanding the physical phenomena and body-fluid interaction of water-entry problem, here mechanical-energy transport (wedge, fluid, and each other of water-entry model for free falling wedge is studied by numerical method based on free surface capturing method and Cartesian cut cell mesh. In this method, incompressible Euler equations for a variable density fluid are numerically calculated by the finite volume method. Then artificial compressibility method, dual-time stepping technique, and Roe's approximate Riemann solver are applied in the numerical scheme. Furthermore, the projection method of momentum equations and exact Riemann solution are used to calculate the fluid pressure on solid boundary. On this basis, during water-entry phase of the free-falling wedge, macroscopic energy conversion of overall body-fluid system and microscopic energy transformation in fluid field are analyzed and discussed. Finally, based on test cases, many useful conclusions about mechanical energy transport for water entry problem are made and presented.

  4. Impurity transport studies on the FTU tokamak

    International Nuclear Information System (INIS)

    Pacella, D.; Romanelli, F.; Gregory, B.

    1999-01-01

    In this work, the radial profile of the diffusion coefficient D and the convective velocity V in the plasma core (0 2 /s and V ∼ 100 m/s. A model for the anomalous transport induced by electrostatic turbulence is developed. With a typical fluctuation spectrum (ω = 10 5 -2x10 5 Hz), calculations can reproduce very well the experimental results. To investigate the impurity behavior in a non-stationary phase, Kr gas was injected into the plasma. It is found that the total flux of Kr gas flowing into the core is also driven by diffusion but the magnitude is much lower than the single ion fluxes derived for Mo ions. The effect of the turbulence on the single ion is very strong but it is reduced when averaged over many charge states. (author)

  5. Studying Suspended Sediment Mechanism with Two-Phase PIV

    Science.gov (United States)

    Matinpour, H.; Atkinson, J. F.; Bennett, S. J.; Guala, M.

    2017-12-01

    Suspended sediment transport affects soil erosion, agriculture and water resources quality. Turbulent diffusion is the most primary force to maintain sediments in suspension. Although extensive previous literature have been studying the interactions between turbulent motion and suspended sediment, mechanism of sediments in suspension is still poorly understood. In this study, we investigate suspension of sediments as two distinct phases: one phase of sediments and another phase of fluid with turbulent motions. We designed and deployed a state-of-the-art two-phase PIV measurement technique to discriminate these two phases and acquire velocities of each phase separately and simultaneously. The technique that we have developed is employing a computer-vision based method, which enables us to discriminate sediment particles from fluid tracer particles based on two thresholds, dissimilar particle sizes and different particle intensities. Results indicate that fluid turbulence decreases in the presence of suspended sediments. Obtaining only sediment phase consecutive images enable us to compute fluctuation sediment concentration. This result enlightens understanding of complex interaction between the fluctuation velocities and the fluctuation of associated mass and compares turbulent viscosity with turbulent eddy diffusivity experimentally.

  6. CASCADER: An m-chain gas-phase radionuclide transport and fate model

    International Nuclear Information System (INIS)

    Cawlfield, D.E.; Been, K.B.; Emer, D.F.; Lindstrom, F.T.; Shott, G.J.

    1993-06-01

    Chemicals and radionuclides move either in the gas-phase, liquid-phase, or both phases in soils. They may be acted upon by either biological or abiotic processes through advection and/or diffusion. Furthermore, parent and daughter radionuclides may decay as they are transported in the soil. This is volume two to the CASCADER series, titled CASCADR8. It embodies the concepts presented in volume one of this series. To properly understand how the CASCADR8 model works, the reader should read volume one first. This volume presents the input and output file structure for CASCADR8, and a set of realistic scenarios for buried sources of radon gas

  7. CASCADER: An M-chain gas-phase radionuclide transport and fate model

    International Nuclear Information System (INIS)

    Cawlfield, D.E.; Emer, D.F.; Lindstrom, F.T.; Shott, G.J.

    1993-09-01

    Chemicals and radionuclides move either in the gas-phase, liquid-phase, or both phases in soils. They may be acted upon by either biological or abiotic processes through advection and/or dispersion. Additionally during the transport of parent and daughter radionuclides in soil, radionuclide decay may occur. This version of CASCADER called CASCADR9 starts with the concepts presented in volumes one and three of this series. For a proper understanding of how the model works, the reader should read volume one first. Also presented in this volume is a set of realistic scenarios for buried sources of radon gas, and the input and output file structure for CASCADER9

  8. Transport and Phase Equilibria Properties for Steam Flooding of Heavy Oils

    Energy Technology Data Exchange (ETDEWEB)

    Gabitto, Jorge; Barrufet, Maria

    2002-11-20

    The objectives of this research included experimental determination and rigorous modeling and computation of phase equilibrium diagrams, volumetric, and transport properties of hydrocarbon/CO2/water mixtures at pressures and temperatures typical of steam injection processes for thermal recovery of heavy oils.

  9. On calculating phase shifts and performing fits to scattering cross sections or transport properties

    International Nuclear Information System (INIS)

    Hepburn, J.W.; Roy, R.J. Le

    1978-01-01

    Improved methods of calculating quantum mechanical phase shifts and for performing least-squares fits to scattering cross sections or transport properties, are described. Their use in a five-parameter fit to experimental differential cross sections reduces the computer time by a factor of 4-7. (Auth.)

  10. Preparation and characterization of nano-sized phase change emulsions as thermal energy storage and transport media

    International Nuclear Information System (INIS)

    Chen, J.; Zhang, P.

    2017-01-01

    Highlights: • The nano-sized phase change emulsions are prepared by using D-phase method. • The thermo-physical and transport properties are experimentally investigated. • The influence of surfactant on the melting temperature and latent heat of water is clarified. • The phase change emulsion can be used as the heat transfer fluid in a thermal energy storage system. - Abstract: Phase change emulsion (PCE) is a kind of two-phase heat transfer fluid with phase change material (PCM) dispersed in carrier fluid. It has received intensive attractions in recent years due to the fact that it can be used as both the thermal energy storage material and transport medium simultaneously in a thermal energy storage system. In the present study, nano-sized PCEs are prepared by the D-phase method with n-hexadecane and n-octadecane as PCMs. The thermo-physical and transport properties are characterized to facilitate the applications. The droplet size distribution of the PCE is measured by a Photon Correlation Spectroscopy, and the results show that the droplet size distributions are similar at different mass fractions. The rheological behavior and viscosity of the PCE are measured by a rheometer, which shows that the PCEs at mass fractions below 30.0 wt% are Newtonian fluids, and the viscosities are dependent on both the mass fraction and temperature. The differential scanning calorimetry (DSC) is employed to analyze the phase change characteristics of the PCE, and the results indicate large supercooling degree of water and PCM in the PCE. The melting temperature and latent heat of water in the PCE are much smaller than those of pure water. The thermal conductivities of the PCE with different mass fractions at different temperatures are measured by the transient hot-wire method. Furthermore, the energy transport characteristics of the PCEs are evaluated on the basis of the measured thermo-physical and transport properties. The results suggest that the PCEs show a drastic

  11. Two-phase model of hydrogen transport to optimize nanoparticle catalyst loading for hydrogen evolution reaction

    DEFF Research Database (Denmark)

    Kemppainen, Erno; Halme, Janne; Hansen, Ole

    2016-01-01

    is the evolution and transport of gaseous H2, since HER leads to the continuous formation of H2 bubbles near the electrode. We present a numerical model that includes the transport of both gaseous and dissolved H2, as well as mass exchange between them, and combine it with a kinetic model of HER at platinum (Pt......) nanoparticle electrodes. We study the effect of the diffusion layer thickness and H2 dissolution rate constant on the importance of gaseous transport, and the effect of equilibrium hydrogen coverage and Pt loading on the kinetic and mass transport overpotentials. Gaseous transport becomes significant when...

  12. Development of a multi-species mass transport model for concrete with account to thermodynamic phase equilibriums

    DEFF Research Database (Denmark)

    Hosokawa, Yoshifumi; Yamada, Kazuo; Johannesson, Björn

    2011-01-01

    different types of cements. For example, the physicochemical evaluation of steel corrosion initiation can be studied by calculating the molar ratio of chloride ion to hydroxide ion in the pore solution. The model can, further, for example, calculate changes of solid-phase composition caused......) theory alone, not involving chemical processes, have no real practical interest since the chemical action is very dominant for cement based materials. Coupled mass transport and chemical equilibrium models can be used to calculate the variation in pore solution and solid-phase composition when using...

  13. Phase diagram and transport properties for hydrogen-helium fluid planets

    International Nuclear Information System (INIS)

    Stevenson, D.J.; Salpeter, E.E.

    1977-01-01

    Hydrogen and helium are the major constituents of Jupiter and Saturn, and phase transitions can have important effects on the planetary structure. In this paper, the relevant phase diagrams and microscopic transport properties are analyzed in detail. The following paper (Paper II) applies these results to the evolution and present dynamic structure of the Jovian planets.Pure hydrogen is first discussed, especially the nature of the molecular-metallic transition and the melting curves for the two phases. It is concluded that at the temperatures and pressures of interest (Tapprox. =10 4 K, Papprox. =1--10 Mbar), both phases are fluid, but the transition between them might nevertheless be first-order. The insulator-metal transition in helium occurs at a much higher pressure (approx.70 Mbars) and is not of interest.The phase diagrams for both molecular and metallic hydrogen-helium mixtures are discussed. In the metallic mixture, calculations indicate a miscibility gap for T9 or approx. =10 4 K. Immiscibility in the molecular mixture is more difficult to predict but almost certainly occurs at much lower temperatures. A fluid-state model is constructed which predicts the likely topology of the three-dimensional phase diagram. The greater solubility of helium in the molecular phase leads to the prediction that the He/H mass ratio is typically twice as large in the molecular phase as in the coexisting metallic phase. Under these circumstances a ''density inversion'' is possible in which the molecular phase becomes more dense than the metallic phase.The partitioning of minor constituents is also considered: The deuterium/hydrogen mass ratio is essentially the same for all coexisting hydrogen-helium phases, at least for T> or approx. =5000 K. The partitioning of H 2 O, CH 4 , and NH 3 probably favors the molecular (or helium-rich) phase. Substances with high conduction electron density (e.g., Al) may partition into the metallic phase

  14. Changes in electrical transport and density of states of phase change materials upon resistance drift

    International Nuclear Information System (INIS)

    Krebs, Daniel; Bachmann, Tobias; Jonnalagadda, Prasad; Dellmann, Laurent; Raoux, Simone

    2014-01-01

    Phase-change memory technology has become more mature in recent years. But some fundamental problems linked to the electrical transport properties in the amorphous phase of phase-change materials still need to be solved. The increase of resistance over time, called resistance drift, for example, poses a major challenge for the implementation of multilevel storage, which will eventually be necessary to remain competitive in terms of high storage densities. To link structural properties with electrical transport, a broader knowledge of (i) changes in the density of states (DoS) upon structural relaxation and (ii) the influence of defects on electrical transport is required. In this paper, we present temperature-dependent conductivity and photo-conductivity measurements on the archetype phase change material GeTe. It is shown that trap-limited band transport at high temperatures (above 165 K) and variable range hopping at low temperatures are the predominating transport mechanism. Based on measurements of the temperature dependence of the optical band gap, modulated photo-conductivity and photo-thermal deflection spectroscopy, a DoS model for GeTe was proposed. Using this DoS, the temperature dependence of conductivity and photo-conductivity has been simulated. Our work shows how changes in the DoS (band gap and defect distributions) will affect the electrical transport before and after temperature-accelerated drift. The decrease in conductivity upon annealing can be explained entirely by an increase of the band gap by about 12%. However, low-temperature photo-conductivity measurements revealed that a change in the defect density may also play a role

  15. Comparative study of Waste Isolation Pilot Plant (WIPP) transportation alternatives

    International Nuclear Information System (INIS)

    1994-02-01

    WIPP transportation studies in the Final Supplement Environmental Impact Statement for WIPP are the baseline for this report. In an attempt to present the most current analysis, this study incorporates the most relevant data available. The following three transportation options are evaluated for the Disposal Phase, which is assumed to be 20 years: Truck shipments, consisting of a tractor and trailer, with three TRUPACT-IIs or one RH-72B; Regular commercial train shipments consisting of up to three railcars carrying up to 18 TRUPACT-IIs or up to six RH-72Bs; Dedicated train shipments consisting of a locomotive, an idle car, railcars carrying 18 TRUPACT-IIs or six RH-72Bs, another idle car, and a caboose or passenger car with an emergency response specialist. No other cargo is carried. This report includes: A consideration of occupational and public risks and exposures, and other environmental impacts; A consideration of emergency response capabilities; and An extimation of comparative costs

  16. Comparative study of Waste Isolation Pilot Plant (WIPP) transportation alternatives

    Energy Technology Data Exchange (ETDEWEB)

    1994-02-01

    WIPP transportation studies in the Final Supplement Environmental Impact Statement for WIPP are the baseline for this report. In an attempt to present the most current analysis, this study incorporates the most relevant data available. The following three transportation options are evaluated for the Disposal Phase, which is assumed to be 20 years: Truck shipments, consisting of a tractor and trailer, with three TRUPACT-IIs or one RH-72B; Regular commercial train shipments consisting of up to three railcars carrying up to 18 TRUPACT-IIs or up to six RH-72Bs; Dedicated train shipments consisting of a locomotive, an idle car, railcars carrying 18 TRUPACT-IIs or six RH-72Bs, another idle car, and a caboose or passenger car with an emergency response specialist. No other cargo is carried. This report includes: A consideration of occupational and public risks and exposures, and other environmental impacts; A consideration of emergency response capabilities; and An extimation of comparative costs.

  17. Comparative studies of stellarator and tokamak transport

    Energy Technology Data Exchange (ETDEWEB)

    Stroth, U; Burhenn, R; Geiger, J; Giannone, L.; Hartfuss, H J; Kuehner, G; Ledl, L; Simmet, E E; Walter, H [Max-Planck-Inst. fuer Plasmaphysik, IPP-Euratom Association, Garching (Germany); ECRH Team; W7-AS Team

    1997-09-01

    Transport properties in the W7-AS stellarator and in tokamaks are compared. The parameter dependences and the absolute values of the energy confinement time are similar. Indications are found that the density dependence, which is usually observed in stellarator confinement, can vanish above a critical density. The density dependence in stellarators seems to be similar to that in the linear ohmic confinement regime, which, in small tokamaks, extends to high density values, too. Because of the similarity in the gross confinement properties, transport in stellarators and tokamaks should not be dominated by the parameters which are very different in the two concepts, i.e. magnetic shear, major rational values of the rotational transform and plasma current. A difference in confinement is that there exists evidence for pinches in the particle and, possibly, energy transport channels in tokamaks whereas in stellarators no pinches have been observed, so far. In order to study the effect of plasma current and toroidal electric fields, stellarator discharges were carried out with an increasing amount of plasma current. From these experiments, no clear evidence of a connection of pinches with these parameters is found. The transient response in W7-AS plasmas can be described in terms of a non-local model. As in tokamaks, also cold pulse experiments in W7-AS indicate the importance of non-local transport. (author). 8 refs, 5 figs.

  18. Thermophysical and heat transfer properties of phase change material candidate for waste heat transportation system

    Science.gov (United States)

    Kaizawa, Akihide; Maruoka, Nobuhiro; Kawai, Atsushi; Kamano, Hiroomi; Jozuka, Tetsuji; Senda, Takeshi; Akiyama, Tomohiro

    2008-05-01

    A waste heat transportation system trans-heat (TH) system is quite attractive that uses the latent heat of a phase change material (PCM). The purpose of this paper is to study the thermophysical properties of various sugars and sodium acetate trihydrate (SAT) as PCMs for a practical TH system and the heat transfer property between PCM selected and heat transfer oil, by using differential scanning calorimetry (DSC), thermogravimetry-differential thermal analysis (TG-DTA) and a heat storage tube. As a result, erythritol, with a large latent heat of 344 kJ/kg at melting point of 117°C, high decomposition point of 160°C and excellent chemical stability under repeated phase change cycles was found to be the best PCM among them for the practical TH system. In the heat release experiments between liquid erythritol and flowing cold oil, we observed foaming phenomena of encapsulated oil, in which oil droplet was coated by solidification of PCM.

  19. Capillary hydrodynamics and transport processes during phase change in microscale systems

    Science.gov (United States)

    Kuznetsov, V. V.

    2017-09-01

    The characteristics of two-phase gas-liquid flow and heat transfer during flow boiling and condensing in micro-scale heat exchangers are discussed in this paper. The results of numerical simulation of the evaporating liquid film flowing downward in rectangular minichannel of the two-phase compact heat exchanger are presented and the peculiarities of microscale heat transport in annular flow with phase changes are discussed. Presented model accounts the capillarity induced transverse flow of liquid and predicts the microscale heat transport processes when the nucleate boiling becomes suppressed. The simultaneous influence of the forced convection, nucleate boiling and liquid film evaporation during flow boiling in plate-fin heat exchangers is considered. The equation for prediction of the flow boiling heat transfer at low flux conditions is presented and verified using experimental data.

  20. Study of a transportable neutron radiography system

    International Nuclear Information System (INIS)

    Souza, S.N.A. de.

    1991-05-01

    This work presents a study a transportable neutron radiography system for a 185 GBq 241 Am-Be (α, η) source with a neutron yield roughly 1,25 x 10 7 n/s. Studies about moderation, collimation and shielding are showed. In these studies, a calculation using Transport Theory was carried out by means of transport codes ANISN and DOT (3.5). Objectives were: to obtain a maximum and more homogeneous thermal neutron flux in the collimator outlet to the image plain, and an adequate radiation shielding to attend radiological protection rules. With the presented collimator, it was possible to obtain for the thermal neutron flux, at the collimator outlet and next to the image plain, a L/D ratio of 14, for neutron fluxes up to 4,09 x 10 2 n.cm -2 .s -1 . Considering the low intensity of the source, it is a good value. Studies have also been carried out for L/D ratios of 22 and 30, giving thermal neutron fluxes at the image plain of 1,27 x 10 2 n.cm -2 .s -1 and 2,65 x 10 2 n.cm -2 .s -1 , respectively. (author). 30 refs, 39 figs, 9 tabs

  1. Experimental studies of the quantum chromodynamics phase ...

    Indian Academy of Sciences (India)

    2015-05-06

    BES) ... Experimental studies of the QCD phase diagram at the STAR experiment .... However, the observed difference between v2 of particles and antiparticles could .... The grey band at the right corresponds to systematic.

  2. Two-phase optimizing approach to design assessments of long distance heat transportation for CHP systems

    International Nuclear Information System (INIS)

    Hirsch, Piotr; Duzinkiewicz, Kazimierz; Grochowski, Michał; Piotrowski, Robert

    2016-01-01

    Highlights: • New method for long distance heat transportation system effectivity evaluation. • Decision model formulation which reflects time and spatial structure of the problem. • Multi-criteria and complex approach to solving the decision-making problem. • Solver based on simulation-optimization approach with two-phase optimization method. • Sensitivity analysis of the optimization procedure elements. - Abstract: Cogeneration or Combined Heat and Power (CHP) for power plants is a method of putting to use waste heat which would be otherwise released to the environment. This allows the increase in thermodynamic efficiency of the plant and can be a source of environmental friendly heat for District Heating (DH). In the paper CHP for Nuclear Power Plant (NPP) is analyzed with the focus on heat transportation. A method for effectivity and feasibility evaluation of the long distance, high power Heat Transportation System (HTS) between the NPP and the DH network is proposed. As a part of the method the multi-criteria decision-making problem, having the structure of the mathematical programming problem, for optimized selection of design and operating parameters of the HTS is formulated. The constraints for this problem include a static model of HTS, that allows considerations of system lifetime, time variability and spatial topology. Thereby variation of annual heat demand within the DH area, variability of ground temperature, insulation and pipe aging and/or terrain elevation profile can be taken into account in the decision-making process. The HTS construction costs, pumping power, and heat losses are considered as objective functions. In general, the analyzed optimization problem is multi-criteria, hybrid and nonlinear. The two-phase optimization based on optimization-simulation framework is proposed to solve the decision-making problem. The solver introduces a number of assumptions concerning the optimization process. Methods for problem decomposition

  3. Assateague Island National Seashore alternative transportation systems planning study and business plan for alternative transportation

    Science.gov (United States)

    2012-08-31

    The purpose of this study was to (1) study the potential expansion of existing alternative transportation systems (bicycle facilities) and development of new alternative transportation systems in and around the Maryland District of Assateague Island ...

  4. Silicon transport under rotating and combined magnetic fields in liquid phase diffusion growth of SiGe

    Energy Technology Data Exchange (ETDEWEB)

    Armour, N.; Dost, S. [Crystal Growth Laboratory, University of Victoria, Victoria, BC, V8W 3P6 (Canada)

    2010-04-15

    The effect of applied rotating and combined (rotating and static) magnetic fields on silicon transport during the liquid phase diffusion growth of SiGe was experimentally studied. 72-hour growth periods produced some single crystal sections. Single and polycrystalline sections of the processed samples were examined for silicon composition. Results show that the application of a rotating magnetic field enhances silicon transport in the melt. It also has a slight positive effect on flattening the initial growth interface. For comparison, growth experiments were also conducted under combined (rotating and static) magnetic fields. The processed samples revealed that the addition of static field altered the thermal characteristics of the system significantly and led to a complete melt back of the germanium seed. Silicon transport in the melt was also enhanced under combined fields compared with experiments with no magnetic field. (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  5. Electron and impurity transport studies in the TCV Tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Wagner, D.

    2013-05-15

    are observed by detecting their radiation in the soft x-ray range. The effect of varying background plasma parameters on the soft x-ray emissivity temporal and spatial evolution is tested. Argon emissivity displays a rising emissivity signal following the injection with a time constant of about 15 ms, and a clear decay phase about ten times slower than the rise time. Neon stays considerably longer in the plasma, much longer than the expected difference in transport properties. It is shown that centrally deposited electron heating enhances impurity transport, whereas increasing plasma current leads to better argon confinement. Varying the plasma position relative to the injector and the background electron density did not result in significant effect on impurity transport. The shape scans varying the plasma elongation, triangularity and comparing limited and diverted configurations, were inconclusive and possible future experiments are proposed. It is shown that their effect are not sufficiently significant to study them separately, therefore a combined experimental campaign accounting for the various coupling is required. The experimental results are interpreted using a diffusive-advective picture. A tool chain is developed and tested providing transport coefficients for the plasma current and electron cyclotron heating experiments. The inverse diffusive-advective transport equation is solved and the obtained transport coefficients reproduce well the experimental soft x-ray emission profile evolution. It is shown, however, that the soft x-ray evolution is somewhat insensitive to variations in the advection velocity profile, that is a strongly positive (outward) or strongly negative (inward) advection result in very similar soft x-ray evolution. This is shown to be due to both the high sensitivity of SXR radiation on T{sub e} and hence of the limited range of relevance (ρ{sub ψ} ≤ 0.4) and on the sawtooth activity which acts as a large effective diffusion. (author)

  6. Electron and impurity transport studies in the TCV Tokamak

    International Nuclear Information System (INIS)

    Wagner, D.

    2013-05-01

    are observed by detecting their radiation in the soft x-ray range. The effect of varying background plasma parameters on the soft x-ray emissivity temporal and spatial evolution is tested. Argon emissivity displays a rising emissivity signal following the injection with a time constant of about 15 ms, and a clear decay phase about ten times slower than the rise time. Neon stays considerably longer in the plasma, much longer than the expected difference in transport properties. It is shown that centrally deposited electron heating enhances impurity transport, whereas increasing plasma current leads to better argon confinement. Varying the plasma position relative to the injector and the background electron density did not result in significant effect on impurity transport. The shape scans varying the plasma elongation, triangularity and comparing limited and diverted configurations, were inconclusive and possible future experiments are proposed. It is shown that their effect are not sufficiently significant to study them separately, therefore a combined experimental campaign accounting for the various coupling is required. The experimental results are interpreted using a diffusive-advective picture. A tool chain is developed and tested providing transport coefficients for the plasma current and electron cyclotron heating experiments. The inverse diffusive-advective transport equation is solved and the obtained transport coefficients reproduce well the experimental soft x-ray emission profile evolution. It is shown, however, that the soft x-ray evolution is somewhat insensitive to variations in the advection velocity profile, that is a strongly positive (outward) or strongly negative (inward) advection result in very similar soft x-ray evolution. This is shown to be due to both the high sensitivity of SXR radiation on T e and hence of the limited range of relevance (ρ ψ ≤ 0.4) and on the sawtooth activity which acts as a large effective diffusion. (author)

  7. Studies of heat transport to forced-flow He II

    International Nuclear Information System (INIS)

    Dresner, L.; Kashani, A.; Van Sciver, S.W.

    1985-01-01

    Analytical and experimental studies of heat transport to forced-flow He II are reported. The work is pertinent to the transfer of He II in space. An analytical model has been developed that establishes a condition for two-phase flow to occur in the transfer line. This condition sets an allowable limit to the heat leak into the transfer line. Experimental measurements of pressure drop and flow meter performances indicate that turbulent He II can be analyzed in terms of classical pressure drop correlations

  8. Computational studies in tokamak equilibrium and transport

    International Nuclear Information System (INIS)

    Braams, B.J.

    1986-01-01

    This thesis is concerned with some problems arising in the magnetic confinement approach to controlled thermonuclear fusion. The work address the numerical modelling of equilibrium and transport properties of a confined plasma and the interpretation of experimental data. The thesis is divided in two parts. Part 1 is devoted to some aspects of the MHD equilibrium problem, both in the 'direct' formulation (given an equation for the plasma current, the corresponding equilibrium is to be determined) and in the 'inverse' formulation (the interpretation of measurements at the plasma edge). Part 2 is devoted to numerical studies of the edge plasma. The appropriate Navier-Stokes system of fluid equations is solved in a two-dimensional geometry. The main interest of this work is to develop an understanding of particle and energy transport in the scrape-off layer and onto material boundaries, and also to contribute to the conceptual design of the NET/INTOR tokamak reactor experiment. (Auth.)

  9. CASCADER: An M-chain gas-phase radionuclide transport and fate model

    International Nuclear Information System (INIS)

    Lindstrom, F.T.; Cawlfield, D.E.; Emer, D.F.; Shott, G.J.; Donahue, M.E.

    1993-02-01

    Chemicals and radionuclides move either in the gas-phase, liquid-phase, or both phases in soils. They may be acted upon by either biological or abiotic processes through advection and diffusion. Furthermore, parent and daughter radionuclides may decay as they are transported in the soil. CASCADER is a gas-phase, one-space dimensional transport and fate model for M-chain radionuclides in very dry homogeneous or heterogeneous soil. This model contains barometric pressure-induced advection and diffusion together with linear irreversible and linear reversible sorption for each radionuclide. The advection velocity is derived from an embedded air-pumping submodel. The air-pumping submodel is based on an assumption of isothermal conditions, which is driven by barometric pressure. CASCADER allows the concentration of source radionuclides to decay via the classical Bateman chain of simple, first-order kinetic processes. The transported radionuclides also decay via first-order processes while in the soil. A mass conserving, flux-type inlet and exit set of boundary conditions are used. The user must supply the initial distribution for the parent radionuclide in the soil. The initial daughter distribution is found using equilibrium rules. The model is user friendly as it uses a prompt-driven, free-form input. The code is ANSI standard Fortran 77

  10. CASCADER: An m-chain gas-phase radionuclide transport and fate model

    International Nuclear Information System (INIS)

    Lindstrom, F.T.; Cawlfield, D.E.; Emer, D.F.; Shott, G.J.; Donahue, M.E.

    1992-06-01

    Chemicals and radionuclides move either in the gas-phase, liquid-phase, or both phases in soils. They may be acted upon by either biological or abiotic processes as they are advected and/or dispersed. Furthermore, parent and daughter radionuclides may decay as they are transported in the soil. CASCADER is a gas-phase, one space dimensional transport and fate model for an m-chain of radionuclides in very dry soil. This model contains barometric pressure-induced advection and diffusion together with linear irreversible and linear reversible sorption for each radionuclide. The advocation velocity is derived from an embedded air-pumping submodel. The airpumping submodel is based on an assumption of isothermal conditions and is barometric pressure driven. CASCADER allows the concentration of source radionuclides to decay via the classical Bateman chain of simple, first-order kinetic processes. The transported radionuclides also decay via first-order processes while in the soil. A mass conserving, flux-type inlet and exit set of boundary conditions is used. The user must supply the initial distribution for the parent radionuclide in the soil. The initial daughter distribution is found using equilibrium rules. The model is user friendly as it uses a prompt-driven, free-form input. The code is ANSI standard Fortran 77

  11. Phase-coherent transport and spin-orbit-coupling in III/V-semiconductor nanowires

    International Nuclear Information System (INIS)

    Estevez Hernandez, Sergio

    2009-01-01

    Semiconductor nanowires fabricated by a bottom-up approach are not only interesting for the realization of future nanoscaled devices but also appear to be very attractive model systems to tackle fundamental questions concerning the transport in strongly confined systems. In order to avoid the problem connected with carrier depletion, narrowband gap semiconductors, i.e., InAs or InN, or core-shell Nanowires, i.e., GaAs/AlGaAs, are preferred. The underlying reason is that in InAs or InN the Fermi-level pinning in the conduction band results in a carrier accumulation at the surface. In fact, the tubular topology of the surface electron gas opens up the possibility to observe unconventional quantum transport phenomena. When the phase-coherence length in the nanowire is comparable to its dimensions the conductance fluctuates if a magnetic field is applied or if the electron concentration is changed by means of a gate electrode. These so-called universal conductance fluctuations being in the order of e 2 /h originate from the fact that in small disordered samples, electron interference effects are not averaged out. In this work are analyzed universal conductance fluctuations to study the quantum transport properties in InN, InAs and GaAs/AlGaAs nanowires. With the use of a magnetic field and a back-gate electrode the universal conductance fluctuations and localizations effects were analyzed. Since InN and InAs are narrow band gap semiconductors, one naturally expects spin-orbit coupling effects. Because this phenomena is of importance for spin electronic applications. However, owing to the cylindrical symmetry of the InN and InAs nanowires, the latter effect was observable and actually be used to determine the strength of spin-orbit coupling. In order to clearly separate the weak antilocalization effect from the conductance fluctuations, the averaging of the magnetoconductance at different gate voltages was essential. The low-temperature quantum transport properties of

  12. Small Transport Aircraft Technology /STAT/ Propulsion Study

    Science.gov (United States)

    Heldenbrand, R. W.; Baerst, C. F.; Rowse, J. H.

    1980-01-01

    The NASA Small Transport Aircraft Technology (STAT) Propulsion Study was established to identify technology requirements and define the research and development required for new commuter aircraft. Interim results of the studies defined mission and design characteristics for 30- and 50-passenger aircraft. Sensitivities were defined that relate changes in engine specific fuel consumption (SFC), weight, and cost (including maintenance) to changes in the aircraft direct operating cost (DOC), takeoff gross weight, and empty weight. A comparison of performance and economic characteristics is presented between aircraft powered by 1980 production engines and those powered by a 1990 advanced technology baseline engine.

  13. Measurement of off-diagonal transport coefficients in two-phase flow in porous media.

    Science.gov (United States)

    Ramakrishnan, T S; Goode, P A

    2015-07-01

    The prevalent description of low capillary number two-phase flow in porous media relies on the independence of phase transport. An extended Darcy's law with a saturation dependent effective permeability is used for each phase. The driving force for each phase is given by its pressure gradient and the body force. This diagonally dominant form neglects momentum transfer from one phase to the other. Numerical and analytical modeling in regular geometries have however shown that while this approximation is simple and acceptable in some cases, many practical problems require inclusion of momentum transfer across the interface. Its inclusion leads to a generalized form of extended Darcy's law in which both the diagonal relative permeabilities and the off-diagonal terms depend not only on saturation but also on the viscosity ratio. Analogous to application of thermodynamics to dynamical systems, any of the extended forms of Darcy's law assumes quasi-static interfaces of fluids for describing displacement problems. Despite the importance of the permeability coefficients in oil recovery, soil moisture transport, contaminant removal, etc., direct measurements to infer the magnitude of the off-diagonal coefficients have been lacking. The published data based on cocurrent and countercurrent displacement experiments are necessarily indirect. In this paper, we propose a null experiment to measure the off-diagonal term directly. For a given non-wetting phase pressure-gradient, the null method is based on measuring a counter pressure drop in the wetting phase required to maintain a zero flux. The ratio of the off-diagonal coefficient to the wetting phase diagonal coefficient (relative permeability) may then be determined. The apparatus is described in detail, along with the results obtained. We demonstrate the validity of the experimental results and conclude the paper by comparing experimental data to numerical simulation. Copyright © 2015 Elsevier Inc. All rights reserved.

  14. Mechanistic analysis of solute transport in an in vitro physiological two-phase dissolution apparatus.

    Science.gov (United States)

    Mudie, Deanna M; Shi, Yi; Ping, Haili; Gao, Ping; Amidon, Gordon L; Amidon, Gregory E

    2012-10-01

    In vitro dissolution methodologies that adequately capture the oral bioperformance of solid dosage forms are critical tools needed to aid formulation development. Such methodologies must encompass important physiological parameters and be designed with drug properties in mind. Two-phase dissolution apparatuses, which contain an aqueous phase in which the drug dissolves (representing the dissolution/solubility component) and an organic phase into which the drug partitions (representing the absorption component), have the potential to provide meaningful predictions of in vivo oral bioperformance for some BCS II, and possibly some BCS IV drug products. Before such an apparatus can be evaluated properly, it is important to understand the kinetics of drug substance partitioning from the aqueous to the organic medium. A mass transport analysis was performed of the kinetics of partitioning of drug substance solutions from the aqueous to the organic phase of a two-phase dissolution apparatus. Major assumptions include pseudo-steady-state conditions, a dilute aqueous solution and diffusion-controlled transport. Input parameters can be measured or estimated a priori. This paper presents the theory and derivation of our analysis, compares it with a recent kinetic approach, and demonstrates its effectiveness in predicting in vitro partitioning profiles of three BCS II weak acids in four different in vitro two-phase dissolution apparatuses. Very importantly, the paper discusses how a two-phase apparatus can be scaled to reflect in vivo absorption kinetics and for which drug substances the two-phase dissolution systems may be appropriate tools for measuring oral bioperformance. Copyright © 2012 John Wiley & Sons, Ltd.

  15. Defense waste transportation: cost and logistics studies

    International Nuclear Information System (INIS)

    Andrews, W.B.; Cole, B.M.; Engel, R.L.; Oylear, J.M.

    1982-08-01

    Transportation of nuclear wastes from defense programs is expected to significantly increase in the 1980s and 1990s as permanent waste disposal facilities come into operation. This report uses models of the defense waste transportation system to quantify potential transportation requirements for treated and untreated contact-handled transuranic (CH-TRU) wastes and high-level defense wastes (HLDW). Alternative waste management strategies in repository siting, waste retrieval and treatment, treatment facility siting, waste packaging and transportation system configurations were examined to determine their effect on transportation cost and hardware requirements. All cost estimates used 1980 costs. No adjustments were made for future changes in these costs relative to inflation. All costs are reported in 1980 dollars. If a single repository is used for defense wastes, transportation costs for CH-TRU waste currently in surface storage and similar wastes expected to be generated by the year 2000 were estimated to be 109 million dollars. Recovery and transport of the larger buried volumes of CH-TRU waste will increase CH-TRU waste transportation costs by a factor of 70. Emphasis of truck transportation and siting of multiple repositories would reduce CH-TRU transportation costs. Transportation of HLDW to repositories for 25 years beginning in 1997 is estimated to cost $229 M in 1980 costs and dollars. HLDW transportation costs could either increase or decrease with the selection of a final canister configuration. HLDW transportation costs are reduced when multiple repositories exist and emphasis is placed on truck transport

  16. Gas Phase Transport, Adsorption and Surface Diffusion in Porous Glass Membrane

    Czech Academy of Sciences Publication Activity Database

    Yang, J.; Čermáková, Jiřina; Uchytil, Petr; Hamel, Ch.; Seidel-Morgenstern, A.

    2005-01-01

    Roč. 104, 2-4 (2005), s. 344-351 ISSN 0920-5861. [International Conference on Catalysis in Membrane Reactors /6./. Lahnstein, 06.07.2004-09.07.2004] R&D Projects: GA AV ČR(CZ) IAA4072402 Institutional research plan: CEZ:AV0Z40720504 Keywords : gas phase transport * vycor glass * adsorption Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.365, year: 2005

  17. Modeling and simulation of nanoparticles transport in a two-phase flow in porous media

    KAUST Repository

    El-Amin, Mohamed; Salama, Amgad; Sun, Shuyu

    2012-01-01

    In the current paper, a mathematical model to describe the nanoparticles transport carried by a two-phase flow in a porous medium is presented. Both capillary forces as well as Brownian diffusion are considered in the model. A numerical example of countercurrent water-oil imbibition is considered. We monitor the changing of the fluid and solid properties due to the addition of the nanoparticles using numerical experiments. Variation of water saturation, nanoparticles concentration and porosity ratio are investigated.

  18. Energy Policy Act transportation rate study: Interim report on coal transportation

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-10-01

    The primary purpose of this report is to examine changes in domestic coal distribution and railroad coal transportation rates since enactment of the Clean Air Act Amendments of 1990 (CAAA90). From 1988 through 1993, the demand for low-sulfur coal increased, as a the 1995 deadline for compliance with Phase 1 of CAAA90 approached. The shift toward low-sulfur coal came sooner than had been generally expected because many electric utilities switched early from high-sulfur coal to ``compliance`` (very low-sulfur) coal. They did so to accumulate emissions allowances that could be used to meet the stricter Phase 2 requirements. Thus, the demand for compliance coal increased the most. The report describes coal distribution and sulfur content, railroad coal transportation and transportation rates, and electric utility contract coal transportation trends from 1979 to 1993 including national trends, regional comparisons, distribution patterns and regional profiles. 14 figs., 76 tabs.

  19. 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.

  20. Separation Method for Oxygen Mass Transport Coefficient in Two Phase Porous Air Electrodes - Transport in Gas and Solid Polymer or Liquid Electrolyte Phases

    Science.gov (United States)

    2013-08-06

    of the problem studied Proton exchange membrane fuel cells ( PEMFCs ) are the most promising candidate systems for alternative electricity...characteristic. The limiting current can be used as a tool to study mass transport phenomena in PEMFC because it can provide experimental data for the...coefficient for PEMFCs under in situ conditions based on the galvanostatic discharge of a cell with an interrupted reactant supply. The results indicated

  1. Studies of energy transport in Jet H-modes

    International Nuclear Information System (INIS)

    Keilhacker, M.; Balet, B.; Cordey, J.; Gottardi, N.; Muir, D.; Thomsen, K.; Watkins, M.

    1989-01-01

    The local heat transport properties in the interior of ohmic, L- and H-phases of 2MA discharges, are determined. Time dependent energy balance code, TRANSP, and timeslice code, QFLUX are used. The global confinement properties of higher current discharges (≤ 3.8MA) are analyzed. The results indicate that during the L-phase of JET single null X-point discharges, the total heat transport coefficient in the plasma decreases to a level close to the ohmic value. Moreover, confinement during the H-phase continues to improve with current (up to 3.8MA), but degrades with increasing neutral beam power

  2. Light source distribution and scattering phase function influence light transport in diffuse multi-layered media

    Science.gov (United States)

    Vaudelle, Fabrice; L'Huillier, Jean-Pierre; Askoura, Mohamed Lamine

    2017-06-01

    Red and near-Infrared light is often used as a useful diagnostic and imaging probe for highly scattering media such as biological tissues, fruits and vegetables. Part of diffusively reflected light gives interesting information related to the tissue subsurface, whereas light recorded at further distances may probe deeper into the interrogated turbid tissues. However, modelling diffusive events occurring at short source-detector distances requires to consider both the distribution of the light sources and the scattering phase functions. In this report, a modified Monte Carlo model is used to compute light transport in curved and multi-layered tissue samples which are covered with a thin and highly diffusing tissue layer. Different light source distributions (ballistic, diffuse or Lambertian) are tested with specific scattering phase functions (modified or not modified Henyey-Greenstein, Gegenbauer and Mie) to compute the amount of backscattered and transmitted light in apple and human skin structures. Comparisons between simulation results and experiments carried out with a multispectral imaging setup confirm the soundness of the theoretical strategy and may explain the role of the skin on light transport in whole and half-cut apples. Other computational results show that a Lambertian source distribution combined with a Henyey-Greenstein phase function provides a higher photon density in the stratum corneum than in the upper dermis layer. Furthermore, it is also shown that the scattering phase function may affect the shape and the magnitude of the Bidirectional Reflectance Distribution (BRDF) exhibited at the skin surface.

  3. Mechanisms and modeling development of water transport/phase change in catalyst layers of portion exchange membrane fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Xiao, Yexiang [Dept. of Thermal Engineering, Tsinghua University Beijing (China)], email: Yexiang.Xiao@energy.lth.se; Yuan, Jinliang; Sunden, Bengt [Dept. of Energy Sciences, Faculty of Engineering, Lund University (Sweden)], email: Jinliang.yuan@energy.lth.se, email: bengt.sunden@energy.lth.se

    2011-07-01

    Research on proton exchange membrane fuel cells has shown that incorporation of nanosized catalysts can effectively increase active areas and catalyst activity and make a great contribution to development in performance and catalyst utilization. Multiphase transport processes are as significant and complicated as water generation/transfer processes which occur in nano-structured catalyst layers. A review project has been launched aimed at gaining a comprehensive understanding of the mechanisms of water generation or transport phenomena. It covers catalytic reactions and water-phase change within the catalyst layers. The review proceeds in three main stages: Firstly, it characterizes and reconstructs the nano/micro-structured pores and solid-phases; secondly, it emphasises the importance of sensitive and consistent analysis of various water-phase change and transport schemes; and thirdly, it recommends development of microscopic models for multi-phase transport processes in the pores and the solid phases.

  4. Analysis of data obtained in two-phase flow tests of primary heat transport pumps

    International Nuclear Information System (INIS)

    Currie, T.C.

    1986-06-01

    This report analyzes data obtained in two-phase flow tests of primary heat transport pumps performed during the period 1980-1983. Phenomena which have been known to cause pump-induced flow oscillations in pressurized piping systems under two-phase conditions are reviewed and the data analyzed to determine whether any of the identified phenomena could have been responsible for the instabilities observed in those tests. Tentative explanations for the most severe instabilities are given based on those analyses. It is shown that suction pipe geometry probably plays an important role in promoting instabilities, so additional experiments to investigate the effect of suction pipe geometry on the stability of flow in a closed pipe loop under two-phase conditions are recommended

  5. Study supporting the phasing out of environmentally harmful subsidies

    Energy Technology Data Exchange (ETDEWEB)

    Withana, S.; Ten Brink, P.; Franckx, L.; Hirschnitz-Garbers, M.; Mayeres, I.; Oosterhuis, F.; Porsch, L.

    2012-10-15

    The need to reform ineffective or harmful public subsidies has long been recognised and has been a contentious point of discussion for several years. The EU has a long-standing commitment to removing or phasing out environmentally harmful subsidies (EHS). Most recently, the need to phase out EHS is reiterated in the 'Roadmap for a resource efficient Europe' which includes a milestone that 'by 2020 EHS will be phased out, with due regard to the impact on people in need'. Despite several commitments, progress has been slow and subsidies remain an issue in most EU countries. This study focuses specifically on EHS at the level of EU Member States; it identifies key types of EHS and examines cases of existing EHS across a range of environmental sectors and issues, including subsidies from non-action. The study also analyses examples of good practices in the reform of EHS in EU Member States and the lessons that can be learnt from these cases. Finally, based on this analysis, it develops practical recommendations on phasing out and reforming EHS to support the objectives of the Europe 2020 Strategy and the resource efficiency agenda. The study was carried out between January and October 2012 and is based on an analysis of literature and consultation with experts and policy makers. The sectoral cases studied are listed and discussed in the annexes report: agriculture, climate and energy, fisheries, food, forestry, materials, transport, waste, and water.

  6. Transport Studies of Quantum Magnetism: Physics and Methods

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Minhyea [Univ. of Colorado, Boulder, CO (United States)

    2017-03-30

    The main goal of this project was to understand novel ground states of spin systems probed by thermal and electrical transport measurements. They are well-suited to characterize the nature of low-energy excitations as unique property of the ground state. More specifically, it was aimed to study the transverse electrical conductivity in the presence of non-collinear and non-coplanar spin ordering and the effects of gauge field as well as novel spin excitations as a coherent heat transport channel in insulating quantum magnets. Most of works done during the grant period focused on these topics. As a natural extension of the project's initial goals, the scope was broadened to include transport studies on the spin systems with strong spin-orbit coupling. One particular focus was an exploration of systems with strong magnetic anisotropy combined with non-trivial spin configuration. Magnetic anisotropy is directly related to implement the non-collinear spin ordering to the existing common geometry of planar devices and thus poses a significant potential. Work in this direction includes the comparison of the topological Hall signal under hydrostatic pressure and chemical doping, as well as the angular dependence dependence of the non-collinear spin ordered phase and their evolution up on temperature and field strength. Another focus was centered around the experimental identification of spin-originated heat carrying excitation in quasi two dimensional honeycomb lattice, where Kitaev type of quantum spin liquid phase is expected to emerge. In fact, when its long range magnetic order is destroyed by the applied field, we discovered anomalously large enhancement of thermal conductivity, for which proximate Kitaev excitations in field-induced spin liquid state are responsible for. This work, combined with further investigations in materials in the similar class may help establish the experimental characterization of new quantum spin liquid and their unique low energy

  7. Electronic transport study in PAMAM dendrimers

    International Nuclear Information System (INIS)

    Vieira, Nirton C.S.; Soares, Demetrio A.W.; Fernandes, Edson G.R.; Queiroz, Alvaro A.A. de

    2005-01-01

    Dendrimers are nanomaterials that have many potential applications in medicine, including diagnosis and therapeutic procedures. Dendrimers are isomolecular polymers, with a very well controlled architecture and a thousand times smaller than cells. Dendrimers containing biocatalysts are of great interest for clinical applications in biosensors because of the way in which their chemical and electric conduction mechanism can be tailored. In this work, the polyamidoamine dendrimer (PAMAM) of generation 4 was synthesized by divergent route and characterized by NMR spectroscopy. The electronic transport properties of PAMAM in a metal-polymer type heterojunction were studied. The electrical conduction mechanism of PAMAM studied in the temperature range of 291-323 K indicates a conduction mechanism thermally activated. (author)

  8. Pore-scale Simulation and Imaging of Multi-phase Flow and Transport in Porous Media (Invited)

    Science.gov (United States)

    Crawshaw, J.; Welch, N.; Daher, I.; Yang, J.; Shah, S.; Grey, F.; Boek, E.

    2013-12-01

    We combine multi-scale imaging and computer simulation of multi-phase flow and reactive transport in rock samples to enhance our fundamental understanding of long term CO2 storage in rock formations. The imaging techniques include Confocal Laser Scanning Microscopy (CLSM), micro-CT and medical CT scanning, with spatial resolutions ranging from sub-micron to mm respectively. First, we report a new sample preparation technique to study micro-porosity in carbonates using CLSM in 3 dimensions. Second, we use micro-CT scanning to generate high resolution 3D pore space images of carbonate and cap rock samples. In addition, we employ micro-CT to image the processes of evaporation in fractures and cap rock degradation due to exposure to CO2 flow. Third, we use medical CT scanning to image spontaneous imbibition in carbonate rock samples. Our imaging studies are complemented by computer simulations of multi-phase flow and transport, using the 3D pore space images obtained from the scanning experiments. We have developed a massively parallel lattice-Boltzmann (LB) code to calculate the single phase flow field in these pore space images. The resulting flow fields are then used to calculate hydrodynamic dispersion using a novel scheme to predict probability distributions for molecular displacements using the LB method and a streamline algorithm, modified for optimal solid boundary conditions. We calculate solute transport on pore-space images of rock cores with increasing degree of heterogeneity: a bead pack, Bentheimer sandstone and Portland carbonate. We observe that for homogeneous rock samples, such as bead packs, the displacement distribution remains Gaussian with time increasing. In the more heterogeneous rocks, on the other hand, the displacement distribution develops a stagnant part. We observe that the fraction of trapped solute increases from the beadpack (0 %) to Bentheimer sandstone (1.5 %) to Portland carbonate (8.1 %), in excellent agreement with PFG

  9. Phase Transitions, Diffraction Studies and Marginal Dimensionality

    DEFF Research Database (Denmark)

    Als-Nielsen, Jens Aage

    1985-01-01

    Continuous phase transitions and the associated critical phenomena have been one of the most active areas of research in condensed matter physics for several decades. This short review is only one cut through this huge subject and the author has chosen to emphasize diffraction studies as a basic ...

  10. Ion transport mechanisms in lamellar phases of salt-doped PS–PEO block copolymer electrolytes

    KAUST Repository

    Sethuraman, Vaidyanathan

    2017-10-23

    We use a multiscale simulation strategy to elucidate, at an atomistic level, the mechanisms underlying ion transport in the lamellar phase of polystyrene–polyethylene oxide (PS–PEO) block copolymer (BCP) electrolytes doped with LiPF6 salts. Explicitly, we compare the results obtained for ion transport in the microphase separated block copolymer melts to those for salt-doped PEO homopolymer melts. In addition, we also present results for dynamics of the ions individually in the PEO and PS domains of the BCP melt, and locally as a function of the distance from the lamellar interfaces. When compared to the PEO homopolymer melt, ions were found to exhibit slower dynamics in both the block copolymer (overall) and in the PEO phase of the BCP melt. Such results are shown to arise from the effects of slower polymer segmental dynamics in the BCP melt and the coordination characteristics of the ions. Polymer backbone-ion residence times analyzed as a function of distance from the interface indicate that ions have a larger residence time near the interface compared to that near the bulk of lamella, and demonstrates the influence of the glassy PS blocks and microphase segregation on the ion transport properties. Ion transport mechanisms in BCP melts reveal that there exist five distinct mechanisms for ion transport along the backbone of the chain and exhibit qualitative differences from the behavior in homopolymer melts. We also present results as a function of salt concentration which show that the mean-squared displacements of the ions decrease with increasing salt concentration, and that the ion residence times near the polymer backbone increase with increasing salt concentration.

  11. Ion transport mechanisms in lamellar phases of salt-doped PS–PEO block copolymer electrolytes

    KAUST Repository

    Sethuraman, Vaidyanathan; Mogurampelly, Santosh; Ganesan, Venkat

    2017-01-01

    We use a multiscale simulation strategy to elucidate, at an atomistic level, the mechanisms underlying ion transport in the lamellar phase of polystyrene–polyethylene oxide (PS–PEO) block copolymer (BCP) electrolytes doped with LiPF6 salts. Explicitly, we compare the results obtained for ion transport in the microphase separated block copolymer melts to those for salt-doped PEO homopolymer melts. In addition, we also present results for dynamics of the ions individually in the PEO and PS domains of the BCP melt, and locally as a function of the distance from the lamellar interfaces. When compared to the PEO homopolymer melt, ions were found to exhibit slower dynamics in both the block copolymer (overall) and in the PEO phase of the BCP melt. Such results are shown to arise from the effects of slower polymer segmental dynamics in the BCP melt and the coordination characteristics of the ions. Polymer backbone-ion residence times analyzed as a function of distance from the interface indicate that ions have a larger residence time near the interface compared to that near the bulk of lamella, and demonstrates the influence of the glassy PS blocks and microphase segregation on the ion transport properties. Ion transport mechanisms in BCP melts reveal that there exist five distinct mechanisms for ion transport along the backbone of the chain and exhibit qualitative differences from the behavior in homopolymer melts. We also present results as a function of salt concentration which show that the mean-squared displacements of the ions decrease with increasing salt concentration, and that the ion residence times near the polymer backbone increase with increasing salt concentration.

  12. Transport of Gas Phase Radionuclides in a Fractured, Low-Permeability Reservoir

    Science.gov (United States)

    Cooper, C. A.; Chapman, J.

    2001-12-01

    The U.S. Atomic Energy Commission (predecessor to the Department of Energy, DOE) oversaw a joint program between industry and government in the 1960s and 1970s to develop technology to enhance production from low-permeability gas reservoirs using nuclear stimulation rather than conventional means (e.g., hydraulic and/or acid fracturing). Project Rio Blanco, located in the Piceance Basin, Colorado, was the third experiment under the program. Three 30-kiloton nuclear explosives were placed in a 2134 m deep well at 1780, 1899, and 2039 m below the land surface and detonated in May 1973. Although the reservoir was extensively fractured, complications such as radionuclide contamination of the gas prevented production and subsequent development of the technology. Two-dimensional numerical simulations were conducted to identify the main transport processes that have occurred and are currently occurring in relation to the detonations, and to estimate the extent of contamination in the reservoir. Minor modifications were made to TOUGH2, the multiphase, multicomponent reservoir simulator developed at Lawrence Berkeley National Laboratories. The simulator allows the explicit incorporation of fractures, as well as heat transport, phase change, and first order radionuclide decay. For a fractured two-phase (liquid and gas) reservoir, the largest velocities are of gases through the fractures. In the gas phase, tritium and one isotope of krypton are the principle radionuclides of concern. However, in addition to existing as a fast pathway, fractures also permit matrix diffusion as a retardation mechanism. Another retardation mechanism is radionuclide decay. Simulations show that incorporation of fractures can significantly alter transport rates, and that radionuclides in the gas phase can preferentially migrate upward due to the downward gravity drainage of liquid water in the pores. This project was funded by the National Nuclear Security Administration, Nevada Operations Office

  13. Waste area Grouping 2 Phase I remedial investigation: Sediment and Cesium-137 transport modeling report

    International Nuclear Information System (INIS)

    Clapp, R.B.; Bao, Y.S.; Moore, T.D.; Brenkert, A.L.; Purucker, S.T.; Reece, D.K.; Burgoa, B.B.

    1996-06-01

    This report is one of five reports issued in 1996 that provide follow-up information to the Phase I Remedial Investigation (RI) Report for Waste Area Grouping (WAG) 2 at Oak Ridge National Laboratory (ORNL). The five reports address areas of concern that may present immediate risk to public health at the Clinch River and ecological risk within WAG 2 at ORNL. A sixth report, on groundwater, in the series documenting WAG 2 RI Phase I results were part of project activities conducted in FY 1996. The five reports that complete activities conducted as part of Phase I of the Remedial Investigation (RI) for WAG 2 are as follows: (1) Waste Area Grouping 2, Phase I Task Data Report: Seep Data Assessment, (2) Waste Area Grouping 2, Phase I Task Data Report: Tributaries Data Assessment, (3) Waste Area Grouping 2, Phase I Task Data Report: Ecological Risk Assessment, (4) Waste Area Grouping 2, Phase I Task Data Report: Human Health Risk Assessment, (5) Waste Area Grouping 2, Phase I Task Data Report: Sediment and 137 Cs Transport Modeling In December 1990, the Remedial Investigation Plan for Waste Area Grouping 2 at Oak Ridge National Laboratory was issued (ORNL 1990). The WAG 2 RI Plan was structured with a short-term component to be conducted while upgradient WAGs are investigated and remediated, and a long-term component that will complete the RI process for WAG 2 following remediation of upgradient WAGs. RI activities for the short-term component were initiated with the approval of the Environmental Protection Agency, Region IV (EPA), and the Tennessee Department of Environment and Conservation (TDEC). This report presents the results of an investigation of the risk associated with possible future releases of 137 Cs due to an extreme flood. The results are based on field measurements made during storms and computer model simulations

  14. Gene expression of transporters and phase I/II metabolic enzymes in murine small intestine during fasting

    Directory of Open Access Journals (Sweden)

    van der Meijde Jolanda

    2007-08-01

    Full Text Available Abstract Background Fasting has dramatic effects on small intestinal transport function. However, little is known on expression of intestinal transport and phase I/II metabolism genes during fasting and the role the fatty acid-activated transcription factor PPARα may play herein. We therefore investigated the effects of fasting on expression of these genes using Affymetrix GeneChip MOE430A arrays and quantitative RT-PCR. Results After 24 hours of fasting, expression levels of 33 of the 253 analyzed transporter and phase I/II metabolism genes were changed. Upregulated genes were involved in transport of energy-yielding molecules in processes such as glycogenolysis (G6pt1 and mitochondrial and peroxisomal oxidation of fatty acids (Cact, Mrs3/4, Fatp2, Cyp4a10, Cyp4b1. Other induced genes were responsible for the inactivation of the neurotransmitter serotonin (Sert, Sult1d1, Dtd, Papst2, formation of eicosanoids (Cyp2j6, Cyp4a10, Cyp4b1, or for secretion of cholesterol (Abca1 and Abcg8. Cyp3a11, typically known because of its drug metabolizing capacity, was also increased. Fasting had no pronounced effect on expression of phase II metabolic enzymes, except for glutathione S-transferases which were down-regulated. Time course studies revealed that some genes were acutely regulated, whereas expression of other genes was only affected after prolonged fasting. Finally, we identified 8 genes that were PPARα-dependently upregulated upon fasting. Conclusion We have characterized the response to fasting on expression of transporters and phase I/II metabolic enzymes in murine small intestine. Differentially expressed genes are involved in a variety of processes, which functionally can be summarized as a increased oxidation of fat and xenobiotics, b increased cholesterol secretion, c increased susceptibility to electrophilic stressors, and d reduced intestinal motility. This knowledge increases our understanding of gut physiology, and may be of relevance

  15. Real time quantitative phase microscopy based on single-shot transport of intensity equation (ssTIE) method

    Science.gov (United States)

    Yu, Wei; Tian, Xiaolin; He, Xiaoliang; Song, Xiaojun; Xue, Liang; Liu, Cheng; Wang, Shouyu

    2016-08-01

    Microscopy based on transport of intensity equation provides quantitative phase distributions which opens another perspective for cellular observations. However, it requires multi-focal image capturing while mechanical and electrical scanning limits its real time capacity in sample detections. Here, in order to break through this restriction, real time quantitative phase microscopy based on single-shot transport of the intensity equation method is proposed. A programmed phase mask is designed to realize simultaneous multi-focal image recording without any scanning; thus, phase distributions can be quantitatively retrieved in real time. It is believed the proposed method can be potentially applied in various biological and medical applications, especially for live cell imaging.

  16. Molecular structure of the discotic liquid crystalline phase of hexa-peri-hexabenzocoronene/oligothiophene hybrid and their charge transport properties

    International Nuclear Information System (INIS)

    Bag, Saientan; Maingi, Vishal; Maiti, Prabal K.; Yelk, Joe; Glaser, Matthew A.; Clark, Noel A.; Walba, David M.

    2015-01-01

    Using atomistic molecular dynamics simulation, we study the discotic columnar liquid crystalline (LC) phases formed by a new organic compound having hexa-peri-Hexabenzocoronene (HBC) core with six pendant oligothiophene units recently synthesized by Nan Hu et al. [Adv. Mater. 26, 2066 (2014)]. This HBC core based LC phase was shown to have electric field responsive behavior and has important applications in organic electronics. Our simulation results confirm the hexagonal arrangement of columnar LC phase with a lattice spacing consistent with that obtained from small angle X-ray diffraction data. We have also calculated various positional and orientational correlation functions to characterize the ordering of the molecules in the columnar arrangement. The molecules in a column are arranged with an average twist of 25° having an average inter-molecular separation of ∼5 Å. Interestingly, we find an overall tilt angle of 43° between the columnar axis and HBC core. We also simulate the charge transport through this columnar phase and report the numerical value of charge carrier mobility for this liquid crystal phase. The charge carrier mobility is strongly influenced by the twist angle and average spacing of the molecules in the column

  17. German risk study, phase (DRS-B)

    International Nuclear Information System (INIS)

    Werner, W.

    1992-01-01

    The first risk investigations were primarily intended to estimate the risk of accidents in nuclear power plants and to compare it with other natural risk and civilization risks. The American reactor safety study WASH 1400 and the German risk study phase A (DRS-A) gave a detailed analyses of the offsite consequences of accidents, especially the magnitude and frequency of health damage for the population. Risk investigations today are primarily used to examine the design of safety systems and to further develop the entire safety concept. Safety investigations have shown that nuclear power plants still possess safety reserves if safety systems do not operate as planned. These safety reserves can be exploited in the sense of a further development of safety by plant internal emergency measures. One purpose of risk analyses is to identify such measures and to evaluate their feasibility and effectiveness. The most important goals of the investigations in DRS-B were: Identification of vulnerabilities and possible safety improvements; determination of safety reserves during accident sequences exceeding the design limits; evaluation of plant internal emergency measures. Thus, goals in phase B compared with phase A have changed from investigations of the magnitude of damage to detailed analysis of the plant systems response under accident conditions. The magnitude of possible fission product releases is also determined in phase B. However, no new accident consequence calculations are performed. Figs and tabs

  18. Spectroscopic transport studies at the stellerator Wendelstein 7-AS

    International Nuclear Information System (INIS)

    Unger, E.

    1995-11-01

    The following topics were dealt with: Magnetic confinement experiments with toroidal geometry, foundations of particle transport theory, code calculations (SITAR), gaseous oscillation method for impurity transport study and results

  19. MacMillan Pier Transportation Center Feasibility Study.

    Science.gov (United States)

    2006-06-01

    The MacMillan Pier Transportation Center Feasibility Study examines two potential sites (landside and waterside) for a transportation center that provides a range of tourist and traveler information. It would serve as a gateway for Provincetown and t...

  20. A two-dimensional, two-phase mass transport model for liquid-feed DMFCs

    International Nuclear Information System (INIS)

    Yang, W.W.; Zhao, T.S.

    2007-01-01

    A two-dimensional, isothermal two-phase mass transport model for a liquid-feed direct methanol fuel cell (DMFC) is presented in this paper. The two-phase mass transport in the anode and cathode porous regions is formulated based on the classical multiphase flow in porous media without invoking the assumption of constant gas pressure in the unsaturated porous medium flow theory. The two-phase flow behavior in the anode flow channel is modeled by utilizing the drift-flux model, while in the cathode flow channel the homogeneous mist-flow model is used. In addition, a micro-agglomerate model is developed for the cathode catalyst layer. The model also accounts for the effects of both methanol and water crossover through the membrane. The comprehensive model formed by integrating those in the different regions is solved numerically using a home-written computer code and validated against the experimental data in the literature. The model is then used to investigate the effects of various operating and structural parameters, such as methanol concentration, anode flow rate, porosities of both anode and cathode electrodes, the rate of methanol crossover, and the agglomerate size, on cell performance

  1. Development of a central data warehouse for statewide ITS and transportation data in Florida phase III : final report.

    Science.gov (United States)

    2009-12-15

    This report documents Phase III of the development and operation of a prototype for the Statewide Transportation : Engineering Warehouse for Archived Regional Data (STEWARD). It reflects the progress on the development and : operation of STEWARD sinc...

  2. Imaging the Spatial Distribution of Transport Currents and the Phenomenon of Nanoscale Phase Separation Phenomenon in CMR Materials

    National Research Council Canada - National Science Library

    Banerjee, Satyajit

    2007-01-01

    ... by transport currents sent through materials. Based on the above objective it was planned to apply this technique to investigate fundamental issues like magnetic phase separation in colossal magneto resistive materials as well as to investigate...

  3. Plasma transport properties at the L-H transition and high performance phase of JET discharges

    Energy Technology Data Exchange (ETDEWEB)

    Balet, B; Cordey, J G; Erba, M; Jones, T T.C.; Lomas, P J; Smeulders, P; Springmann, E M; Stubberfield, P M; Taroni, A; Thomsen, K [Commission of the European Communities, Abingdon (United Kingdom). JET Joint Undertaking; Parail, V V [Kurchatov Institute, Moscow (Russian Federation)

    1994-07-01

    Numerical analysis are performed which show that both electron and ion thermal diffusivities are reduced by one order of magnitude everywhere, not only in a narrow region near separatrix during the L-H transition. There is no separate H-VH transition on JET, this transition coincides with the cessation of ELMs. In the ELM free phase ion transport in the core is close to its neoclassical value, but probably rises towards plasma edge (however still remaining much less than it was in L-mode). The best agreement with experiment is obtained with the model which simultaneously takes into account both the global reduction of Bohm type anomalous transport in plasma core and formation of temperature pedestal near plasma edge. (authors). 6 refs., 5 figs.

  4. An Iterative Implicit Scheme for Nanoparticles Transport with Two-Phase Flow in Porous Media

    KAUST Repository

    El-Amin, Mohamed

    2016-06-01

    In this paper, we introduce a mathematical model to describe the nanoparticles transport carried by a two-phase flow in a porous medium including gravity, capillary forces and Brownian diffusion. Nonlinear iterative IMPES scheme is used to solve the flow equation, and saturation and pressure are calculated at the current iteration step and then the transport equation is solved implicitly. Therefore, once the nanoparticles concentration is computed, the two equations of volume of the nanoparticles available on the pore surfaces and the volume of the nanoparticles entrapped in pore throats are solved implicitly. The porosity and the permeability variations are updated at each time step after each iteration loop. Numerical example for regular heterogenous permeability is considered. We monitor the changing of the fluid and solid properties due to adding the nanoparticles. Variation of water saturation, water pressure, nanoparticles concentration and porosity are presented graphically.

  5. Study of nonequilibrium dispersed two phase flow

    International Nuclear Information System (INIS)

    Reyes, J.N. Jr.

    1986-01-01

    Understanding the behavior of liquid droplets in a superheated steam environment is essential to the accurate prediction of nuclear fuel rod surface temperatures during the blowdown and reflood phase of a loss-of-coolant-accident (LOCA). In response to this need, this treatise presents several original and significant contributions to the field of thermofluid physics. The research contained herein presents a statistical derivation of the two-phase mass, momentum, and energy-conservation equations using a droplet continuity equation analogous to that used in the Kinetic Theory of Gases. Unlike the Eulerian volume and time-averaged conservation equations generally used to describe dispersed two-phase flow behavior, this statistical averaging approach results in an additional mass momentum or energy term in each of the respective conservation equations. Further, this study demonstrates that current definitions of the volumetric vapor generation rate used in the mass conservation equation are inappropriate results under certain circumstances. The mass conservation equation derived herein is used to obtain a new definition for the volumetric vapor-generation rate. Last, a simple two phase phenomenological model, based on the statistically averaged conservation equations, is presented and solved analytically. It is shown that the actual quality and vapor temperature, under these circumstances, depend on a single dimensionless group

  6. Simulation studies of GST phase change alloys

    Science.gov (United States)

    Martyna, Glenn

    2008-03-01

    In order to help drive post-Moore's Law technology development, switching processes involving novel materials, in particular, GeSbTe (GST) alloys are being investigated for use in memory and eFuse applications. An anneal/quench thermal process crystallizes/amorphosizes a GST alloy which then has a low/high resistance and thereby forms a readable/writeable bit; for example, a ``one'' might be the low resistance, conducting crystalline state and a ``zero'' might be the high resistance, glassy state. There are many open questions about the precise nature of the structural transitions and the coupling to electronic structure changes. Computational and experimental studies of the effect of pressure on the GST materials were initiated in order to probe the physics behind the thermal switching process. A new pathway to reversible phase change involving pressure-induced structural metal insulator transitions was discovered. In a binary GS system, a room-temperature, direct, pressure-induced transformation from the high resistance amorphous phase to the low resistance crystalline phase was observed experimentally while the reverse process under tensile load was demonstrated via ab initio MD simulations performed on IBM's Blue Gene/L enabled by massively parallel software. Pressure induced transformations of the ternary material GST-225 (Ge2Sb2Te5) were, also, examined In the talk, the behavior of the two systems will be compared and insight into the nature of the phase change given.

  7. Transport Studies and Modeling in PEM Fuel Cells

    Energy Technology Data Exchange (ETDEWEB)

    Mittelsteadt, Cortney K. [Giner, Inc., Auburndale, MA (United States); Xu, Hui [Giner, Inc., Auburndale, MA (United States); Brawn, Shelly [Giner, Inc., Auburndale, MA (United States)

    2014-07-30

    This project’s aim was to develop fuel cell components (i.e. membranes, gas-diffusion media (GDM), bipolar plates and flow fields) that possess specific properties (i.e. water transport and conductivity). A computational fluid dynamics model was developed to elucidate the effect of certain parameters on these specific properties. Ultimately, the model will be used to determine sensitivity of fuel cell performance to component properties to determine limiting components and to guide research. We have successfully reached our objectives and achieved most of the milestones of this project. We have designed and synthesized a variety of hydrocarbon block polymer membranes with lower equivalent weight, structure, chemistry, phase separation and process conditions. These membranes provide a broad selection with optimized water transport properties. We have also designed and constructed a variety of devices that are capable of accurately measuring the water transport properties (water uptake, water diffusivity and electro-osmatic drag) of these membranes. These transport properties are correlated to the membranes’ structures derived from X-ray and microscopy techniques to determine the structure-property relationship. We successfully integrated hydrocarbon membrane MEAs with a current distribution board (CBD) to study the impact of hydrocarbon membrane on water transport in fuel cells. We have designed and fabricated various GDM with varying substrate, diffusivity and micro-porous layers (MPL) and characterized their pore structure, tortuosity and hydrophobicity. We have derived a universal chart (MacMullin number as function of wet proofing and porosity) that can be used to characterize various GDM. The abovementioned GDMs have been evaluated in operating fuel cells; their performance is correlated to various pore structure, tortuosity and hydrophobicity of the GDM. Unfortunately, determining a universal relationship between the MacMullin number and these properties

  8. Multiscale Adapted Time-Splitting Technique for Nonisothermal Two-Phase Flow and Nanoparticles Transport in Heterogenous Porous Media

    KAUST Repository

    El-Amin, Mohamed F.

    2017-05-05

    This paper is devoted to study the problem of nonisothermal two-phase flow with nanoparticles transport in heterogenous porous media, numerically. For this purpose, we introduce a multiscale adapted time-splitting technique to simulate the problem under consideration. The mathematical model consists of equations of pressure, saturation, heat, nanoparticles concentration in the water–phase, deposited nanoparticles concentration on the pore–walls, and entrapped nanoparticles concentration in the pore–throats. We propose a multiscale time splitting IMplicit Pressure Explicit Saturation–IMplicit Temperature Concentration (IMPES-IMTC) scheme to solve the system of governing equations. The time step-size adaptation is achieved by satisfying the stability Courant–Friedrichs–Lewy (CFL<1) condition. Moreover, numerical test of a highly heterogeneous porous medium is provided and the water saturation, the temperature, the nanoparticles concentration, the deposited nanoparticles concentration, and the permeability are presented in graphs.

  9. Transepithelial transport of aliphatic carboxylic acids studied in Madin Darby canine kidney (MDCK) cell monolayers

    International Nuclear Information System (INIS)

    Cho, M.J.; Adson, A.; Kezdy, F.J.

    1990-01-01

    Transport of 14C-labeled acetic, propionic (PA), butyric, valeric, heptanoic (HA), and octanoic (OA) acids across the Madin Darby canine kidney (MDCK) epithelial cell monolayer grown on a porous polycarbonate membrane was studied in Hanks' balanced salt solution (HBSS) at 37 degrees C in both apical-to-basolateral and basolateral-to-apical directions. At micromolar concentrations of solutes, metabolic decomposition was significant as evidenced by [14C]CO2 production during the OA transport. The apparent permeability (Pe) indicates that as lipophilicity increases, diffusion across the unstirred boundary layer becomes rate limiting. In support of this notion, transport of OA and HA was enhanced by agitation, showed an activation energy of 3.7 kcal/mol for OA, and resulted in identical Pe values for both transport directions. Analysis of Pe changes with varying alkyl chain length resulted in a delta G of -0.68 +/- 0.09 kcal/mol for -CH2-group transfer from an aqueous phase to the MDCK cells. When the intercellular tight junctions were opened by the divalent chelator EGTA in Ca2+/Mg2(+)-free HBSS, transport of the fluid-phase marker Lucifer yellow greatly increased because of paracellular leakage. PA transport also showed a significant increase, but OA transport was independent of EGTA. Although albumin also undergoes paracellular transport in the presence of EGTA and OA binds strongly to albumin, OA transport in EGTA solution was unchanged by albumin. These observations indicate that transmembrane transport is the major mechanism for lipophilic substances. The present study, together with earlier work on the transport of polar substances, shows that the MDCK cell monolayer is an excellent model of the transepithelial transport barrier

  10. Phase behavior and reactive transport of partial melt in heterogeneous mantle model

    Science.gov (United States)

    Jordan, J.; Hesse, M. A.

    2013-12-01

    The reactive transport of partial melt is the key process that leads to the chemical and physical differentiation of terrestrial planets and smaller celestial bodies. The essential role of the lithological heterogeneities during partial melting of the mantle is increasingly recognized. How far can enriched melts propagate while interacting with the ambient mantle? Can the melt flow emanating from a fertile heterogeneity be localized through a reactive infiltration feedback in a model without exogenous factors or contrived initial conditions? A full understanding of the role of heterogeneities requires reactive melt transport models that account for the phase behavior of major elements. Previous work on reactive transport in the mantle focuses on trace element partitioning; we present the first nonlinear chromatographic analysis of reactive melt transport in systems with binary solid solution. Our analysis shows that reactive melt transport in systems with binary solid solution leads to the formation of two separate reaction fronts: a slow melting/freezing front along which enthalpy change is dominant and a fast dissolution/precipitation front along which compositional changes are dominated by an ion-exchange process over enthalpy change. An intermediate state forms between these two fronts with a bulk-rock composition and enthalpy that are not necessarily bounded by the bulk-rock composition and enthalpy of either the enriched heterogeneity or the depleted ambient mantle. The formation of this intermediate state makes it difficult to anticipate the porosity changes and hence the stability of reaction fronts. Therefore, we develop a graphical representation for the solution that allows identification of the intermediate state by inspection, for all possible bulk-rock compositions and enthalpies of the heterogeneity and the ambient mantle. We apply the analysis to the partial melting of an enriched heterogeneity. This leads to the formation of moving precipitation

  11. Probing exotic magnetic phases and electrical transport in Cr-rich γ-NiFeCr alloys

    Energy Technology Data Exchange (ETDEWEB)

    Pal, Pampa [S. N. Bose National Centre for Basic Sciences, Block JD, Sector III, Salt Lake, Kolkata 700098 (India); Majumdar, A.K., E-mail: akm@bose.res.in [S. N. Bose National Centre for Basic Sciences, Block JD, Sector III, Salt Lake, Kolkata 700098 (India); Ramakrishna Mission Vivekananda University, PO Belur Math, Howrah 711202 (India); Nigam, A.K. [Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400005 (India)

    2015-05-01

    We have identified ferromagnetic, antiferromagnetic, and re-entrant spin-glass-like phases in Cr-rich γ-NiFeCr alloys and studied their critical magnetic behavior. Their electrical resistivity exhibits distinct minima between 10 and 24 K with ρ∞−√T due to electron–electron interaction effects. Electron–phonon and electron–magnon contributions to ρ are isolated. The magnetoresistance shows hysteresis effects, a signature of spin-glass-like phases and a sign reversal with change of magnetic states. We have also observed that the nature of magnetic states strongly depends on the concentration of Fe and Cr. In this system, even a small amount of Fe enhances ferromagnetism a lot while addition of a little bit of Cr suppresses ferromagnetism and takes the system to the antiferromagnetic regime. The correlation between the magnetic and the electrical properties are more meaningful here since both studies were done on the same set of samples which have rather high melting points. - Highlights: • Identified ferro, antiferro, and re-entrant spin-glass phases in Ni–Fe–Cr alloys. • Resistivity ρ~−√T shows minima from 10–24 K due to electron–electron interaction. • Electron–phonon and electron–magnon contributions to ρ are isolated. • Magneto-transport measurements strengthened the magnetic phases identified. • Correlation in magnetic/electrical properties more meaningful if same samples used.

  12. Nanoscale phase engineering of thermal transport with a Josephson heat modulator

    Science.gov (United States)

    Fornieri, Antonio; Blanc, Christophe; Bosisio, Riccardo; D'Ambrosio, Sophie; Giazotto, Francesco

    2016-03-01

    Macroscopic quantum phase coherence has one of its pivotal expressions in the Josephson effect, which manifests itself both in charge and energy transport. The ability to master the amount of heat transferred through two tunnel-coupled superconductors by tuning their phase difference is the core of coherent caloritronics, and is expected to be a key tool in a number of nanoscience fields, including solid-state cooling, thermal isolation, radiation detection, quantum information and thermal logic. Here, we show the realization of the first balanced Josephson heat modulator designed to offer full control at the nanoscale over the phase-coherent component of thermal currents. Our device provides magnetic-flux-dependent temperature modulations up to 40 mK in amplitude with a maximum of the flux-to-temperature transfer coefficient reaching 200 mK per flux quantum at a bath temperature of 25 mK. Foremost, it demonstrates the exact correspondence in the phase engineering of charge and heat currents, breaking ground for advanced caloritronic nanodevices such as thermal splitters, heat pumps and time-dependent electronic engines.

  13. Improving road transport operations through lean thinking: A case study

    OpenAIRE

    Villarreal, B.; Garza-Reyes, J. A.; Kumar, V.; Lim, M. K.

    2017-01-01

    Traditionally, logistics and transportation problems have been addressed through mathematical modelling, operations research, and simulation methods. This paper documents a case study where the road transport operations of a leading Mexican brewery organisation have been improved through lean thinking and waste reduction. Two lean-based principles and tools were combined; the Seven Transportation Extended Wastes (STEWs) and Transportation Value Stream Mapping (TVSM), and three systematic step...

  14. Experimental evaluation of the ‘transport-of-intensity’ equation for magnetic phase reconstruction in Lorentz transmission electron microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Kohn, Amit, E-mail: akohn@post.tau.ac.il [Department of Materials Science and Engineering, Faculty of Engineering, Tel Aviv University, 69978 Tel Aviv (Israel); Habibi, Avihay; Mayo, Martin [Department of Materials Engineering, Ben-Gurion University of the Negev, 84105 Beer Sheva (Israel)

    2016-01-15

    The ‘transport-of-intensity’ equation (TIE) is a general phase reconstruction methodology that can be applied to Lorentz transmission electron microscopy (TEM) through the use of Fresnel-contrast (defocused) images. We present an experimental study to test the application of the TIE for quantitative magnetic mapping in Lorentz TEM without aberration correction by examining sub-micrometer sized Ni{sub 80}Fe{sub 20} (Permalloy) elements. For a JEOL JEM 2100F adapted for Lorentz microscopy, we find that quantitative magnetic phase reconstructions are possible for defoci distances ranging between approximately 200 μm and 800 μm. The lower limit originates from competing sources of image intensity variations in Fresnel-contrast images, namely structural defects and diffraction contrast. The upper defocus limit is due to a numerical error in the estimation of the intensity derivative based on three images. For magnetic domains, we show quantitative reconstructions of the product of the magnetic induction vector and thickness in element sizes down to approximately 100 nm in lateral size and 5 nm thick resulting in a minimal detection of 5 T nm. Three types of magnetic structures are tested in terms of phase reconstruction: vortex cores, domain walls, and element edges. We quantify vortex core structures at a diameter of 12 nm while the structures of domain walls and element edges are characterized qualitatively. Finally, we show by image simulations that the conclusions of this experimental study are relevant to other Lorentz TEM in which spherical aberration and defocus are dominant aberrations. - Highlights: • Testing TIE for quantitative magnetic phase reconstruction in Lorentz TEM. • Quantitative magnetic phase reconstructions for defoci distances in 200–800 μm range. • Minimal detection of the product of the magnetic induction and thickness is 5 T nm. • Quantitative phase reconstruction for vortex core structures at 12 nm diameter. • Observations

  15. Transport Studies in Alcator C-Mod ITB Plasmas

    Science.gov (United States)

    Fiore, C. L.; Bonoli, P. T.; Ernst, D.; Greenwald, M. J.; Ince-Cushman, A.; Lin, L.; Marmar, E. S.; Porkolab, M.; Rice, J. E.; Wukitch, S.; Rowan, W.; Bespamyatnov, I.; Phillips, P.

    2008-11-01

    Internal transport barriers occur in C-Mod plasmas that have off-axis ICRF heating and also in Ohmic H-mode plasmas. These ITBs are marked by highly peaked density and pressure profiles, as they rely on a reduction of particle and thermal flux in the barrier region which allows the neoclassical pinch to peak the central density without reducing the central temperature. Enhancement of several core diagnostics has resulted in increased understanding of C-Mod ITBs. Ion temperature profile measurements have been obtained using an innovative design for x-ray crystal spectrometry and clearly show a barrier forming in the ion temperature profile. The phase contrast imaging (PCI) provides limited localization of the ITB related fluctuations that increase in strength as the central density increases. Simulation of triggering conditions, integrated simulations with fluctuation measurements, parametric studies, and transport implications of fully ionized boron impurity profiles in the plasma are under study. A summary of these results will be presented.

  16. Case studies of transport for London.

    Science.gov (United States)

    2009-01-01

    This project was motivated by the election of Ken Livingston as Mayor of London in : 2000. Mayor Livingston campaigned on a platform of improving transportation service through : such innovative means as congestion pricing. Mayor Livingston relied on...

  17. State transportation liaison funded positions study

    Science.gov (United States)

    2009-10-01

    The Safe, Accountable, Flexible, Efficient Transportation Equity Act: A Legacy for Users (SAFETEA-LU), which was signed into law in August 2005, contained several provisions focused on streamlining the environmental review process. One of these provi...

  18. A Thermomechanical Transport Approach and Application in Soil-Water System of Polluted Mining Areas considering the Three-Phase Coupling

    Directory of Open Access Journals (Sweden)

    Xuan Guo

    2016-01-01

    Full Text Available The thermomechanical transport approach includes the process of diffusing or the condition of being diffused, absorption/desorption, swell/shrink, equilibrium/nonequilibrium, and thermomechanical transport of contaminant in three phases of polluted mining soil which are discussed. The thermomechanical transport model of the contaminants transport in polluted soil is established, and its basic equations are given. Based on that, the distribution regularities of the contaminant seepage in water-soil system are discussed in detail and the sensitivities of parameters are analyzed. The study shows that the parameter has important influence on the contamination distribution and transportation in polluted soil-water system. The influence degree is also related to the action of seepage force directly.

  19. INTRAVAL phase 2, test case 8. Alligator Rivers Natural Analogue - Modelling of uranium transport in the weathered zone at Koongarra (Australia). Progress report

    NARCIS (Netherlands)

    van der Weerd H; Hassanizadeh SM; Richardson-van der Poel MA; LBG

    1993-01-01

    A study of uranium transport in the Koongarra site of Alligator Rivers Uranium deposit (Australia) is carried out. The analysis of the solid phase uranium concentration measured at various depths provides a useful picture of the dispersion process. Results of this analysis seem to support the

  20. Studies and research concerning BNFP. Nuclear spent fuel transportation studies

    International Nuclear Information System (INIS)

    Anderson, R.T.; Maier, J.B.

    1979-11-01

    Currently, there are a number of institutional problems associated with the shipment of spent fuel assemblies from commercial nuclear power plants: new and conflicting regulations, embargoing of certain routes, imposition of transport safeguards, physical security in-transit, and a lack of definition of when and where the fuel will be moved. This report presents a summary of these types and kinds of problems. It represents the results of evaluations performed relative to fuel receipt at the Barnwell Nuclear Fuel Plant. Case studies were made which address existing reactor sites with near-term spent fuel transportation needs. Shipment by either highway, rail, water, or intermodal water-rail was considered. The report identifies the impact of new regulations and uncertainty caused by indeterminate regulatory policy and lack of action on spent fuel acceptance and storage. This stagnant situation has made it impossible for industry to determine realistic transportation scenarios for business planning and financial risk analysis. A current lack of private investment in nuclear transportation equipment is expected to further prolong the problems associated with nuclear spent fuel and waste disposition. These problems are expected to intensify in the 1980's and in certain cases will make continuing reactor plant operation difficult or impossible

  1. Diagnostic needs for fluctuations and transport studies

    International Nuclear Information System (INIS)

    Carreras, B.A.

    1992-01-01

    The identification of fundamental transport mechanisms in magnetically confined plasmas is a critical issue for the magnetic fusion program. Recent progress in understanding fluctuations and transport is well correlated with the development and use of new diagnostics, but there a great deal of information is still missing. Some of the required measurements are well beyond our present diagnostic capabilities, but some are within reach and could answer critical questions in this area of research. Some of these critical issues are discussed

  2. Yinchenhao Decoction Ameliorates Alpha-Naphthylisothiocyanate Induced Intrahepatic Cholestasis in Rats by Regulating Phase II Metabolic Enzymes and Transporters

    Directory of Open Access Journals (Sweden)

    Ya-Xiong Yi

    2018-05-01

    Full Text Available Yinchenhao Decoction (YCHD, a famous traditional Chinese formula, has been used for treating cholestasis for 1000s of years. The cholagogic effect of YCHD has been widely reported, but its pharmacodynamic material and underlying therapeutic mechanism remain unclear. By using ultra-high-performance liquid chromatography (UHPLC-quadrupole time-of-flight mass spectrometry, 11 original active components and eight phase II metabolites were detected in rats after oral administration of YCHD, including three new phase II metabolites. And it indicated that phase II metabolism was one of the major metabolic pathway for most active components in YCHD, which was similar to the metabolism process of bilirubin. It arouses our curiosity that whether the metabolism process of YCHD has any relationship with its cholagogic effects. So, a new method for simultaneous quantitation of eight active components and four phase II metabolites of rhein, emodin, genipin, and capillarisin has been developed and applied for their pharmacokinetic study in both normal and alpha-naphthylisothiocyanate (ANIT-induced intrahepatic cholestasis rats. The results indicated the pharmacokinetic behaviors of most components of YCHD were inhibited, which was hypothesized to be related to different levels of metabolic enzymes and transporters in rat liver. So dynamic changes of intrahepatic enzyme expression in cholestasis and YCHD treated rats have been monitored by an UHPLC-tandem mass spectrometry method. The results showed expression levels of UDP-glucuronosyltransferase 1-1 (UGT1A1, organic anion-transporting polypeptide 1A4 (OATP1A4, multidrug resistance-associated protein 2 (MRP2, multidrug resistance protein 1, sodium-dependent taurocholate cotransporter, and organic anion-transporting polypeptide 1A2 were significantly inhibited in cholestasis rats, which would account for reducing the drug absorption and the metabolic process of YCHD in cholestatic rats. A high dose (12 g/kg of

  3. Ionic diffusion in quartz studied by transport measurements, SIMS and atomistic simulations

    International Nuclear Information System (INIS)

    Sartbaeva, Asel; Wells, Stephen A; Redfern, Simon A T; Hinton, Richard W; Reed, Stephen J B

    2005-01-01

    Ionic diffusion in the quartz-β-eucryptite system is studied by DC transport measurements, SIMS and atomistic simulations. Transport data show a large transient increase in ionic current at the α-β phase transition of quartz (the Hedvall effect). The SIMS data indicate two diffusion processes, one involving rapid Li + motion and the other involving penetration of Al and Li atoms into quartz at the phase transition. Atomistic simulations explain why the fine microstructure of twin domain walls in quartz near the transition does not hinder Li + diffusion

  4. Technology for the storage of radioactive materials packagings during maritime transport. Phase 1

    International Nuclear Information System (INIS)

    Ringot, C.; Chevalier, G.; Tomachevski, E.G.

    1989-01-01

    Following the accident of the M/S Mont Louis on August 25, 1984 carrying UF 6 cylinders, this report is a preliminary study of bibliographic data to help to define recommendations on packaging stowing for sea transport. Data on acceleration to take into account for normal or accidental transport conditions, safe areas on board that should be reserved for radioactive materials and accidents statistics are collected. Main information concerns: number of serious casualities or total losses to ships in European waters, accident causes, collision probability in function of mean distance between ships in the British Channel, selection of 8 reference accidents for future studies

  5. Transportable and vibration-free full-field low-coherent quantitative phase microscope

    Science.gov (United States)

    Yamauchi, Toyohiko; Yamada, Hidenao; Goto, Kentaro; Matsui, Hisayuki; Yasuhiko, Osamu; Ueda, Yukio

    2018-02-01

    We developed a transportable Linnik-type full-field low-coherent quantitative phase microscope that is able to compensate for optical path length (OPL) disturbance due to environmental mechanical noises. Though two-beam interferometers such as Linnik ones suffer from unstable OPL difference, we overcame this problem with a mechanical feedback system based on digital signal-processing that controls the OPL difference in sub-nanometer resolution precisely with a feedback bandwidth of 4 kHz. The developed setup has a footprint of 200 mm by 200 mm, a height of 500 mm, and a weight of 4.5 kilograms. In the transmission imaging mode, cells were cultured on a reflection-enhanced glass-bottom dish, and we obtained interference images sequentially while performing stepwise quarter-wavelength phase-shifting. Real-time image processing, including retrieval of the unwrapped phase from interference images and its background correction, along with the acquisition of interference images, was performed on a laptop computer. Emulation of the phase contrast (PhC) images and the differential interference contrast (DIC) images was also performed in real time. Moreover, our setup was applied for full-field cell membrane imaging in the reflection mode, where the cells were cultured on an anti-reflection (AR)-coated glass-bottom dish. The phase and intensity of the light reflected by the membrane revealed the outer shape of the cells independent of the refractive index. In this paper, we show imaging results on cultured cells in both transmission and reflection modes.

  6. Urban transport energy consumption: Belgrade case study

    Directory of Open Access Journals (Sweden)

    Jovanović Miomir M.

    2015-01-01

    Full Text Available More than half of the global population now lives in towns and cities. At the same time, transport has become the highest single energy-consuming human activity. Hence, one of the major topics today is the reduction of urban transport demand and of energy consumption in cities. In this article we focused on the whole package of instruments that can reduce energy consumption and transport demand in Belgrade, a city that is currently at a major crossroad. Belgrade can prevent a dramatic increase in energy consumption and CO2 emissions (and mitigate the negative local environmental effects of traffic congestion, traffic accidents and air pollution, only if it: 1 implements a more decisive strategy to limit private vehicles use while its level of car passenger km (PKT is still relatively low; 2 does not try to solve its transport problems only by trying to build urban road infrastructure (bridges and ring roads; and 3 if it continues to provide priority movement for buses (a dominant form of public transport, while 4 at the same time developing urban rail systems (metro or LRT with exclusive tracks, immune to the traffic congestion on urban streets. [Projekat Ministarstva nauke Republike Srbije, br. 37010

  7. Tritium environmental transport studies at TFTR

    International Nuclear Information System (INIS)

    Ritter, P.D.; Dolan, T.J.; Longhurst, G.R.

    1993-01-01

    Environmental tritium concentrations will be measured near the Tokamak Fusion Test Reactor (TFTR) to help validate dynamic models of tritium transport in the environment. For model validation the database must contain sequential measurements of tritium concentrations in key environmental compartments. Since complete containment of tritium is an operational goal, the supplementary monitoring program should be able to glean useful data from an unscheduled acute release. Portable air samplers will be used to take samples automatically every 4 hours for a weak after an acute release, thus obtaining the time resolution needed for code validation. Samples of soil, vegetation, and foodstuffs will be gathered daily at the same locations as the active air monitors. The database may help validate the plant/soil/air part of tritium transport models and enhance environmental tritium transport understanding for the International Thermonuclear Experimental Reactor (ITER)

  8. Tritium environmental transport studies at TFTR

    Science.gov (United States)

    Ritter, P. D.; Dolan, T. J.; Longhurst, G. R.

    1993-06-01

    Environmental tritium concentrations will be measured near the Tokamak Fusion Test Reactor (TFTR) to help validate dynamic models of tritium transport in the environment. For model validation the database must contain sequential measurements of tritium concentrations in key environmental compartments. Since complete containment of tritium is an operational goal, the supplementary monitoring program should be able to glean useful data from an unscheduled acute release. Portable air samplers will be used to take samples automatically every 4 hours for a week after an acute release, thus obtaining the time resolution needed for code validation. Samples of soil, vegetation, and foodstuffs will be gathered daily at the same locations as the active air monitors. The database may help validate the plant/soil/air part of tritium transport models and enhance environmental tritium transport understanding for the International Thermonuclear Experimental Reactor (ITER).

  9. Transportation studies: 40-MM collider dipole magnets

    International Nuclear Information System (INIS)

    Daly, E.

    1992-01-01

    Several fully functional 40-mm Collider Dipole Magnets (CDM) were instrumented with accelerometers to monitor shock and vibration loads during transport. The magnets were measured with optical tooling telescopes before and after transport. Changes in mechanical alignment due to shipping and handling were determined. The mechanical stability of the cryogen lines were checked using the same method. Field quality and dipole angle were measured warm before and after transport to determine changes in these parameters. Power spectra were calculated for accelerometers located on the cold mass, vacuum vessel, and trailer bed. Where available, plots of field quality and dipole roll both before and after were created. Shipping loads measured were largest in the vertical direction, where most of the structural deformation of the magnet was evident. It was not clear that magnetic performance was affected by the shipping and handling environment

  10. Interfacial area transport of vertical upward air-water two-phase flow in an annulus at elevated pressures

    International Nuclear Information System (INIS)

    Ozar, Basar; Hibiki, Takashi; Ishii, Mamoru; Euh, Dong-Jin

    2009-01-01

    The interfacial area transport of vertical, upward, air-water two-phase flows in an annular channel has been investigated at different system pressures. The inner and outer diameters of the annular channel were 19.1 mm and 38.1 mm, respectively. Twenty three inlet flow conditions were selected, which coverED bubbly, cap-slug, and churn-turbulent flows. These flow conditions also overlapped with twelve conditions of our previous study for comparison. The local flow parameters, such as void fractions, interfacial area concentrations (IAC), and bubble interface velocities, were measured at nine radial positions for the three axial locations (z/D h =52, 149 and 230) and converted into area-averaged parameters. The axial evolutions of local flow structure was interpreted in terms of bubble coalescence, breakup, expansion of the gas-phase due to pressure drop and system pressure. An assessment of interfacial area transport equation (IATE) was made and compared with the experimental data. A discussion of the comparison between model prediction and the experimental results were made. (author)

  11. Transportation properties of amorphous state InSb and its metastable middle phase

    International Nuclear Information System (INIS)

    Cao Xiaowen

    1990-09-01

    The variation of the substrate temperature induces the metal-semiconductor transition in the condensation InSb films at low temperatrue. The electron conduction is dominant in the metal-type amorphous InSb and the hole in semiconductor-type one. In the metal-type amorphous InSb the electron-electron is correlated under the field above 0.1T in the temperature region of liquid nitrogen. The structure relaxation leads to not only the increase of the short range order but also the change of electron structure in metal-type amorphous InSb. The first conductance jump originates mainly from the increase of Hall mobility of the carrier, i.e. the increase of the short range order, and the system relaxes from the liquid-like to the lattice-like amorphous state. The three types of the crystallization phase transition for the metal-type amorphous InSb present obviously different transportation behaviours. Both metal-type amorphous state and metastable middle phase of InSb all are one of superconducting system with the lowest carrier concentration (n 0 ∼10 18 cm -3 ). Superconducting T c of the metastable middle phase is related to the state density near Fermi surface, i.e. the higher T c corresponds to the higher state density. The quasi-two-dimensional structure is favourable to superconductivity

  12. Feasibility study on embedded transport core calculations

    International Nuclear Information System (INIS)

    Ivanov, B.; Zikatanov, L.; Ivanov, K.

    2007-01-01

    The main objective of this study is to develop an advanced core calculation methodology based on embedded diffusion and transport calculations. The scheme proposed in this work is based on embedded diffusion or SP 3 pin-by-pin local fuel assembly calculation within the framework of the Nodal Expansion Method (NEM) diffusion core calculation. The SP 3 method has gained popularity in the last 10 years as an advanced method for neutronics calculation. NEM is a multi-group nodal diffusion code developed, maintained and continuously improved at the Pennsylvania State University. The developed calculation scheme is a non-linear iteration process, which involves cross-section homogenization, on-line discontinuity factors generation, and boundary conditions evaluation by the global solution passed to the local calculation. In order to accomplish the local calculation, a new code has been developed based on the Finite Elements Method (FEM), which is capable of performing both diffusion and SP 3 calculations. The new code will be used in the framework of the NEM code in order to perform embedded pin-by-pin diffusion and SP 3 calculations on fuel assembly basis. The development of the diffusion and SP 3 FEM code is presented first following by its application to several problems. Description of the proposed embedded scheme is provided next as well as the obtained preliminary results of the C3 MOX benchmark. The results from the embedded calculations are compared with direct pin-by-pin whole core calculations in terms of accuracy and efficiency followed by conclusions made about the feasibility of the proposed embedded approach. (authors)

  13. 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

  14. U.S. DOT roadway transportation data business plan (phase 2) : data business plan.

    Science.gov (United States)

    2013-06-01

    In 2011, the FHWA Office of Operations, Office of Transportation Management commissioned a study to address needs and gaps related to the operation and coordination of U.S. DOT Data Capture and Management Programs. The development of the Data Busines...

  15. Clinton River Sediment Transport Modeling Study

    Science.gov (United States)

    The U.S. ACE develops sediment transport models for tributaries to the Great Lakes that discharge to AOCs. The models developed help State and local agencies to evaluate better ways for soil conservation and non-point source pollution prevention.

  16. Transport Network Technologies – Study and Testing

    DEFF Research Database (Denmark)

    Bozorgebrahimi, K.; Channegowda, M.; Colmenero, A.

    Following on from the theoretical research into Carrier Class Transport Network Technologies (CCTNTs) documented in DJ1.1.1, this report describes the extensive testing performed by JRA1 Task 1. The tests covered EoMPLS, Ethernet OAM, Synchronous Ethernet, PBB-TE, MPLS-TP, OTN and GMPLS...

  17. Study of transport coefficients of nanodiamond nanofluids

    Science.gov (United States)

    Pryazhnikov, M. I.; Minakov, A. V.; Guzei, D. V.

    2017-09-01

    Experimental data on the thermal conductivity coefficient and viscosity coefficient of nanodiamond nanofluids are presented. Distilled water and ethylene glycol were used as the base fluid. Dependences of transport coefficients on concentration are obtained. It was shown that the thermal conductivity coefficient increases with increasing nanodiamonds concentration. It was shown that base fluids properties and nanodiamonds concentration affect on the rheology of nanofluids.

  18. Perturbative analysis of transport and fluctuation studies on RFX

    International Nuclear Information System (INIS)

    Martini, S.

    2002-01-01

    On the RFX reversed field pinch different transport mechanisms govern the centre and the edge of the plasma. Core transport is driven by parallel transport in a stochastic magnetic field, giving rise to an outward directed particle convection velocity. At the edge, roughly corresponding to the region outside the toroidal field reversal surface (where q=0), electrostatic fluctuations are an important loss channel, but more than 50% of the power losses have been associated to localized plasma-wall interaction due to the non-axisymmetric magnetic perturbations caused by locked modes. In the paper we present the most recent progress made in the modeling and understanding of the above mechanisms underlying particle and energy transport. The paper also discusses the correlations between core and edge transport phenomena. The main tools are perturbative transport studies by pellet injection and the analysis of the contribution of intermittency processes to particle transport in the edge. (author)

  19. Numerical studies of transport processes in Tokamak plasma

    International Nuclear Information System (INIS)

    Spineanu, F.; Vlad, M.

    1984-09-01

    The paper contains the summary of a set of studies of the transport processes in tokamak plasma, performed with a one-dimensional computer code. The various transport models (which are implemented by the expressions of the transport coefficients) are presented in connection with the regimes of the dynamical development of the discharge. Results of studies concerning the skin effect and the large scale MHD instabilities are also included

  20. W transport and accumulation control in the termination phase of JET H-mode discharges and implications for ITER

    Science.gov (United States)

    Köchl, F.; Loarte, A.; de la Luna, E.; Parail, V.; Corrigan, G.; Harting, D.; Nunes, I.; Reux, C.; Rimini, F. G.; Polevoi, A.; Romanelli, M.; Contributors, JET

    2018-07-01

    Tokamak operation with W PFCs is associated with specific challenges for impurity control, which may be particularly demanding in the transition from stationary H-mode to L-mode. To address W control issues in this phase, dedicated experiments have been performed at JET including the variation of the decrease of the power and current, gas fuelling and central ion cyclotron heating (ICRH), and applying active ELM control by vertical kicks. The experimental results obtained demonstrate the key role of maintaining ELM control to control the W concentration in the exit phase of H-modes with slow (ITER-like) ramp-down of the neutral beam injection power in JET. For these experiments, integrated fully predictive core+edge+SOL transport modelling studies applying discrete models for the description of transients such as sawteeth and ELMs have been performed for the first time with the JINTRAC suite of codes for the entire transition from stationary H-mode until the time when the plasma would return to L-mode focusing on the W transport behaviour. Simulations have shown that the existing models can appropriately reproduce the plasma profile evolution in the core, edge and SOL as well as W accumulation trends in the termination phase of JET H-mode discharges as function of the applied ICRH and ELM control schemes, substantiating the ambivalent effect of ELMs on W sputtering on one side and on edge transport affecting core W accumulation on the other side. The sensitivity with respect to NB particle and momentum sources has also been analysed and their impact on neoclassical W transport has been found to be crucial to reproduce the observed W accumulation characteristics in JET discharges. In this paper the results of the JET experiments, the comparison with JINTRAC modelling and the adequacy of the models to reproduce the experimental results are described and conclusions are drawn regarding the applicability of these models for the extrapolation of the applied W

  1. Paddle-wheel versus percolation mechanism for cation transport in some sulphate phases

    DEFF Research Database (Denmark)

    Andersen, N.H.; Bandaranyake, P.W.S.K.; Careem, M.A.

    1992-01-01

    in these phases. A single-crystal neutron diffraction study has been performed for cubic lithium sulphate. The refinement of the data gives a very complex model for the location of the lithium ions. There is definitely a void at and near the octahedral (1/2, 1/2, 1/2) position. 90% of the lithium ions are located...... and interdiffusion, all studied mono- and divalent cations are very mobile in the rotor phases, which lack the pronounced correlation with ionic radii that is characteristic for diffusion in other classes of solid electrolytes. The quoted studies are to be considered as strong evidence against a percolation model...

  2. Quantitative phase microscopy for cellular dynamics based on transport of intensity equation.

    Science.gov (United States)

    Li, Ying; Di, Jianglei; Ma, Chaojie; Zhang, Jiwei; Zhong, Jinzhan; Wang, Kaiqiang; Xi, Teli; Zhao, Jianlin

    2018-01-08

    We demonstrate a simple method for quantitative phase imaging of tiny transparent objects such as living cells based on the transport of intensity equation. The experiments are performed using an inverted bright field microscope upgraded with a flipping imaging module, which enables to simultaneously create two laterally separated images with unequal defocus distances. This add-on module does not include any lenses or gratings and is cost-effective and easy-to-alignment. The validity of this method is confirmed by the measurement of microlens array and human osteoblastic cells in culture, indicating its potential in the applications of dynamically measuring living cells and other transparent specimens in a quantitative, non-invasive and label-free manner.

  3. Topological spin transport of photons: the optical Magnus effect and Berry phase

    International Nuclear Information System (INIS)

    Bliokh, K.Yu.; Bliokh, Yu.P.

    2004-01-01

    The Letter develops a modified geometrical optics (GO) of smoothly inhomogeneous isotropic medium, which takes into account two topological phenomena: Berry phase and the optical Magnus effect. Taking into account the correspondence between a quasi-classical motion of a quantum particle with a spin and GO of an electromagnetic wave in smoothly inhomogeneous media, we have introduced the standard gauge potential associated with the degeneracy in the wave momentum space. This potential corresponds to the magnetic-monopole-like field (Berry curvature), which causes the topological spin (polarization) transport of photons. The deviations of waves of right-hand and left-hand polarization occur in the opposite directions and orthogonally to the principal direction of motion. This produces a spin current directed across the principal motion. The situation is similar to the anomalous Hall effect for electrons. In addition, a simple scheme of the experiment allowing one to observe the topological spin splitting of photons has been suggested

  4. Single-phase pump model for analysis of LMFBR heat transport systems

    International Nuclear Information System (INIS)

    Madni, I.K.; Cazzoli, E.

    1978-05-01

    A single-phase pump model for transient and steady-state analysis of LMFBR heat transport systems is presented. Fundamental equations of the model are angular momentum balance to determine transient impeller speed and mass balance (including thermal expansion effects) to determine the level of sodium in the pump tank. Pump characteristics are modeled by homologous head and torque relations. All regions of pump operation are represented with reverse rotation allowed. The model also includes option for enthalpy rise calculations and pony motor operation. During steady state, the pump operating speed is determined by matching required head with total load in the circuit. Calculated transient results are presented for pump coastdown and double-ended pipe break accidents. The report examines the influence of frictional torque and specific speed on predicted response for the pump coastdown to natural circulation transient. The results for a double-ended pipe break accident indicate the necessity of including all regions of operation for pump characteristics

  5. Direct disposal of spent fuel. Simulation of shaft transport. Phase III. Final report

    International Nuclear Information System (INIS)

    Filbert, W.; Heda, M.; Khamis, M.; Neydek, J.; Niehues, N.; Rissel, J.; Schrimpf, C.; Weber, W.; Fuchs, D.; Gerlach, A.; Langebrake, F.; Sindern, W.; Gasch, A.; Leicht, R.; Schwab, B.; Hecke, R. van; Kipka, P.; Simmich, K.; Weber, H.

    1994-01-01

    The aim of these demonstration tests was to verify the technical feasibility of a shaft hoisting equipment with a payload of 85 t as well as the safe transport of POLLUX-casks. In phase III of the project the components and the test stand were built, their proper functioning and reliability were tested to demonstrate that they are state-of-the-art. The following additional investigations were carried out: - Tests to fix operational disturbances and simulation tests for the new components to demonstrate their licensibility -Selection and lifetime tests of ropes and investigation of the present state-of-the-art of rope slighting under the conditions of the conceptual design of the shaft hoisting facility - Execution of a probabilistic safety analysis e.g. the determination of the release of radioactive material (result: probability [de

  6. A pumped, two-phase flow heat transport system for orbiting instrument payloads

    Science.gov (United States)

    Fowle, A. A.

    1981-01-01

    A pumped two-phase (heat absorption/heat rejection) thermal transport system for orbiting instrument payloads is investigated. The thermofluid characteristics necessary for the system design are discussed. A preliminary design with a series arrangement of four instrument heat stations and six radiators in a single loop is described in detail, and the total mass is estimated to be 134 kg, with the radiators, instrument heat stations, and fluid reservoir accounting for approximately 86, 24, and 12 kg, respectively. The evaluation of preliminary test results shows that the system has potential advantages; however, further research is necessary in the areas of one-g and zero-g heat transfer coefficients/fluid regimes, fluid by-pass temperature control, and reliability of small pumps.

  7. Approximated transport-of-intensity equation for coded-aperture x-ray phase-contrast imaging.

    Science.gov (United States)

    Das, Mini; Liang, Zhihua

    2014-09-15

    Transport-of-intensity equations (TIEs) allow better understanding of image formation and assist in simplifying the "phase problem" associated with phase-sensitive x-ray measurements. In this Letter, we present for the first time to our knowledge a simplified form of TIE that models x-ray differential phase-contrast (DPC) imaging with coded-aperture (CA) geometry. The validity of our approximation is demonstrated through comparison with an exact TIE in numerical simulations. The relative contributions of absorption, phase, and differential phase to the acquired phase-sensitive intensity images are made readily apparent with the approximate TIE, which may prove useful for solving the inverse phase-retrieval problem associated with these CA geometry based DPC.

  8. STUDY OF TCP PHASE PRECIPITATING IN GH4199 SUPERALLOY

    Institute of Scientific and Technical Information of China (English)

    T.Cui; Y.S.Zhang; S.W.Guo; L.Wang; H.C.Yang

    2004-01-01

    The precipitating regulation and mechanism of TCP phasephase and σ phase) are studied, using electron hole number (EHN) theory, phase analysis technology and TEM observation. The results indicate that the EHN in studied alloy is 2.311-2.348 which is higher than that of critical EHN of μ phase precipitate (2.30), so μ phase could precipitate if there is enough thermo-exposition. In contrast, the calculated EHN is less than that of critical EHN of σ phase precipitate (2.52). However the σ phase is also observed by TEM.Enrich of Cr and Mo around γ phase after γ' phase precipitated leads to σ phase precipitated.

  9. Mass transport aspects of polymer electrolyte fuel cells under two-phase flow conditions

    Energy Technology Data Exchange (ETDEWEB)

    Kramer, D.

    2007-03-27

    This work deals with selected aspects of mass transport phenomena in PEFCs and DMFCs. Emphasis is placed on the implications originating from the occurrence of two-phase flow within these devices. Optimality of supply, distribution, and removal of the fuel, the oxidant, and the reaction products is of utmost importance for the stability, efficiency, and durability of the devices. Being a prerequisite for high current densities while maintaining sufficient voltage, mass transport optimization contributes to the development of cost effective as well as compact designs and hence competitive fuel cells. [German] Die Visualisierung und Quantifizierung von Fluessigwasseransammlungen in Polymerelektrolytmembran-Brennstoffzellen konnte mittels Neutronenradiographie erreicht werden. Dank dieser neuartigen diagnostischen Methode konnte erstmals die Fluessigwasseransammlung in den poroesen Gasdiffusionsschichten direkt nachgewiesen und quantifiziert werden. Die Kombination von Neutronenradiographie mit ortsaufgeloesten Stromdichtemessungen bzw. lokaler Impedanzspektroskopie erlaubte die Korrelation des inhomogenen Fluessigwasseranfalls mit dem lokalen elektrochemischen Leistungsverhalten. Systematische Untersuchungen an Polymerelektrolyt- und Direkt-Methanol-Brennstoffzellen verdeutlichen sowohl den Einfluss von Betriebsbedingungen als auch die Auswirkung von Materialeigenschaften auf die Ausbildung zweiphasiger Stroemungen.

  10. Investigation of one-dimensional interfacial area transport for vertical upward air–water two-phase flow in an annular channel at elevated pressures

    International Nuclear Information System (INIS)

    Ozar, B.; Brooks, C.S.; Euh, D.J.; Hibiki, T.; Ishii, M.

    2013-01-01

    Highlights: • Interfacial area transport equation (IATE) for a rectangular duct is modified for an annulus. • IATE predicts interfacial area transport in bubbly-to-churn flow. • Scalability of IATE to elevated pressure conditions is validated. • Detailed 1D interfacial area transport data are presented. • Detailed interfacial area transport mechanisms are discussed. -- Abstract: The interfacial area transport of vertical, upward, air–water two-phase flows in an annular channel has been investigated at different system pressures. The inner and outer diameters of the annular channel were 19.1 mm and 38.1 mm, respectively. Twenty three inlet flow conditions were selected, which covered bubbly, cap-bubbly, and churn-turbulent flows. These flow conditions also overlapped with twelve conditions of a previous study for comparison. The local flow parameters, such as void fractions, interfacial area concentrations (IAC), and bubble interface velocities, were measured at nine radial positions for the three axial locations and converted into area-averaged parameters. The axial evolutions of local flow structure were interpreted in terms of bubble coalescence, breakup, expansion of the gas-phase due to pressure drop and system pressure. An assessment of interfacial area transport equation (IATE) was made and compared with the experimental data. A discussion of the comparison between model prediction and the experimental results were made

  11. Investigation of one-dimensional interfacial area transport for vertical upward air–water two-phase flow in an annular channel at elevated pressures

    Energy Technology Data Exchange (ETDEWEB)

    Ozar, B., E-mail: ozar@fauske.com [School of Nuclear Engineering, Purdue University, 400 Central Drive, West Lafayette, IN 47907-2017 (United States); Brooks, C.S. [School of Nuclear Engineering, Purdue University, 400 Central Drive, West Lafayette, IN 47907-2017 (United States); Euh, D.J. [Korea Atomic Energy Research Institute, 150 Deokjin, Yuseong, Daejeon 305-353 (Korea, Republic of); Hibiki, T.; Ishii, M. [School of Nuclear Engineering, Purdue University, 400 Central Drive, West Lafayette, IN 47907-2017 (United States)

    2013-10-15

    Highlights: • Interfacial area transport equation (IATE) for a rectangular duct is modified for an annulus. • IATE predicts interfacial area transport in bubbly-to-churn flow. • Scalability of IATE to elevated pressure conditions is validated. • Detailed 1D interfacial area transport data are presented. • Detailed interfacial area transport mechanisms are discussed. -- Abstract: The interfacial area transport of vertical, upward, air–water two-phase flows in an annular channel has been investigated at different system pressures. The inner and outer diameters of the annular channel were 19.1 mm and 38.1 mm, respectively. Twenty three inlet flow conditions were selected, which covered bubbly, cap-bubbly, and churn-turbulent flows. These flow conditions also overlapped with twelve conditions of a previous study for comparison. The local flow parameters, such as void fractions, interfacial area concentrations (IAC), and bubble interface velocities, were measured at nine radial positions for the three axial locations and converted into area-averaged parameters. The axial evolutions of local flow structure were interpreted in terms of bubble coalescence, breakup, expansion of the gas-phase due to pressure drop and system pressure. An assessment of interfacial area transport equation (IATE) was made and compared with the experimental data. A discussion of the comparison between model prediction and the experimental results were made.

  12. Modeling quiescent phase transport of air bubbles induced by breaking waves

    Science.gov (United States)

    Shi, Fengyan; Kirby, James T.; Ma, Gangfeng

    Simultaneous modeling of both the acoustic phase and quiescent phase of breaking wave-induced air bubbles involves a large range of length scales from microns to meters and time scales from milliseconds to seconds, and thus is computational unaffordable in a surfzone-scale computational domain. In this study, we use an air bubble entrainment formula in a two-fluid model to predict air bubble evolution in the quiescent phase in a breaking wave event. The breaking wave-induced air bubble entrainment is formulated by connecting the shear production at the air-water interface and the bubble number intensity with a certain bubble size spectra observed in laboratory experiments. A two-fluid model is developed based on the partial differential equations of the gas-liquid mixture phase and the continuum bubble phase, which has multiple size bubble groups representing a polydisperse bubble population. An enhanced 2-DV VOF (Volume of Fluid) model with a k - ɛ turbulence closure is used to model the mixture phase. The bubble phase is governed by the advection-diffusion equations of the gas molar concentration and bubble intensity for groups of bubbles with different sizes. The model is used to simulate air bubble plumes measured in laboratory experiments. Numerical results indicate that, with an appropriate parameter in the air entrainment formula, the model is able to predict the main features of bubbly flows as evidenced by reasonable agreement with measured void fraction. Bubbles larger than an intermediate radius of O(1 mm) make a major contribution to void fraction in the near-crest region. Smaller bubbles tend to penetrate deeper and stay longer in the water column, resulting in significant contribution to the cross-sectional area of the bubble cloud. An underprediction of void fraction is found at the beginning of wave breaking when large air pockets take place. The core region of high void fraction predicted by the model is dislocated due to use of the shear

  13. Phase distribution studies in metallic alloy SIMFUEL

    International Nuclear Information System (INIS)

    Kolay, S.; Basu, M.; Kaity, S.; Das, D.

    2014-01-01

    Utilization of U-Pu based alloy fuel in the three stage nuclear power generation program in India is one of the important mandate due to shorter doubling time for breeding of the fissile isotopes ( 239 Pu and 233 U) to be used in Th based driver fuel in the 3rd stage. Reported information shows successful performance of fuel with porous alloy matrix in achieving 10-15 atom % burn-up. The porosity and microstructure of this alloy are strongly dependent on the composition and phases of the fission products incorporated in the matrix. The porosity influences the extent of fuel swelling and fission gas release, which affects the performance and integrity of the fuel. This study addresses to these issues taking the base alloy U-10wt% Zr

  14. Study of incommensurable phases in quantum chains

    International Nuclear Information System (INIS)

    Vollmer, J.

    1990-12-01

    The phases of quantum chains with spin-1/2 and spin-1-respresentations of the SU(2) algebra and the phases of a mixed spin-1/2 / spin-1 chain are reported and investigated. These chains are models with an XX-interaction in a magnetic field. In a certain range of the magnetic field the groundstate magnetisation depends continuously on the magnetic field and the energy gaps vanish, this is a so called 'floating phase'. Within this phase the energy spectrum is a conformal spectrum, comparable to the spectrum of the Gauss-model, but the momenta have a macroscopic part. These macroscopic momenta are connected to oscillating correlation functions, whose periods are determined by the magnetic field. The transition from the floating phase to an existing phase with constant groundstate magnetisation is a Pokrovsky-Talapov-transition, it is a universal transition in all three models. (orig.) [de

  15. National Waterways Study. Commercial Water Transportation Users.

    Science.gov (United States)

    1981-08-01

    green and stored in covered or pit silos for feed. When corn in used for its grain only, the ears are picked off the plant and the corn is shelled from...among -egions creates a need for the domestic transportation of products and crude to satisfy 206 net demand. The actual behavor of the regions may...distributed as follows: 531 million tons of reserves in the Green River-Hams Fork region (Idaho, Wyoming, Utah, and Colorado); 109 million tons in the Uinta

  16. Growth of Cd0.96Zn0.04Te single crystals by vapor phase gas transport method

    Directory of Open Access Journals (Sweden)

    S. H. Tabatabai Yazdi

    2006-03-01

    Full Text Available   Cd0.96Zn0.04Te crystals were grown using vapor phase gas transport method (VPGT. The results show that dendritic crystals with grain size up to 3.5 mm can be grown with this technique. X-ray diffraction and Laue back-reflection patterns show that dendritic crystals are single-phase, whose single crystal grains are randomly oriented with respect to the gas-transport axis. Electrical measurements, carried out using Van der Pauw method, show that the as-grown crystals have resistivity of about 104 Ω cm and n-type conductivity.

  17. Phase-coherent transport and spin-orbit-coupling in III/V-semiconductor nanowires; Phasenkohaerenter Transport und Spin-Bahn-Wechselwirkung in III/V-Halbleiternanodraehten

    Energy Technology Data Exchange (ETDEWEB)

    Estevez Hernandez, Sergio

    2009-10-16

    Semiconductor nanowires fabricated by a bottom-up approach are not only interesting for the realization of future nanoscaled devices but also appear to be very attractive model systems to tackle fundamental questions concerning the transport in strongly confined systems. In order to avoid the problem connected with carrier depletion, narrowband gap semiconductors, i.e., InAs or InN, or core-shell Nanowires, i.e., GaAs/AlGaAs, are preferred. The underlying reason is that in InAs or InN the Fermi-level pinning in the conduction band results in a carrier accumulation at the surface. In fact, the tubular topology of the surface electron gas opens up the possibility to observe unconventional quantum transport phenomena. When the phase-coherence length in the nanowire is comparable to its dimensions the conductance fluctuates if a magnetic field is applied or if the electron concentration is changed by means of a gate electrode. These so-called universal conductance fluctuations being in the order of e{sup 2}/h originate from the fact that in small disordered samples, electron interference effects are not averaged out. In this work are analyzed universal conductance fluctuations to study the quantum transport properties in InN, InAs and GaAs/AlGaAs nanowires. With the use of a magnetic field and a back-gate electrode the universal conductance fluctuations and localizations effects were analyzed. Since InN and InAs are narrow band gap semiconductors, one naturally expects spin-orbit coupling effects. Because this phenomena is of importance for spin electronic applications. However, owing to the cylindrical symmetry of the InN and InAs nanowires, the latter effect was observable and actually be used to determine the strength of spin-orbit coupling. In order to clearly separate the weak antilocalization effect from the conductance fluctuations, the averaging of the magnetoconductance at different gate voltages was essential. The low-temperature quantum transport properties

  18. SEP-225289 serotonin and dopamine transporter occupancy: a PET study.

    Science.gov (United States)

    DeLorenzo, Christine; Lichenstein, Sarah; Schaefer, Karen; Dunn, Judith; Marshall, Randall; Organisak, Lisa; Kharidia, Jahnavi; Robertson, Brigitte; Mann, J John; Parsey, Ramin V

    2011-07-01

    SEP-225289 is a novel compound that, based on in vitro potencies for transporter function, potentially inhibits reuptake at dopamine, norepinephrine, and serotonin transporters. An open-label PET study was conducted during the development of SEP-225289 to investigate its dopamine and serotonin transporter occupancy. Different single doses of SEP-225289 were administered to healthy volunteers in 3 cohorts: 8 mg (n = 7), 12 mg (n = 5), and 16 mg (n = 7). PET was performed before and approximately 24 h after oral administration of SEP-225289, to assess occupancy at trough levels. Dopamine and serotonin transporter occupancies were estimated from PET using (11)C-N-(3-iodoprop-2E-enyl)-2β-carbomethoxy-3β-(4-methylphenyl)nortropane ((11)C-PE2I) and (11)C-N,N-dimethyl-2-(2-amino-4-cyanophenylthio)benzylamine ((11)C-DASB), respectively. Plasma concentration of SEP-225289 was assessed before ligand injection, and subjects were monitored for adverse events. Average dopamine and serotonin transporter occupancies increased with increasing doses of SEP-225289. Mean dopamine and serotonin transporter occupancies were 33% ± 11% and 2% ± 13%, respectively, for 8 mg; 44% ± 4% and 9% ± 10%, respectively, for 12 mg; and 49% ± 7% and 14% ± 15%, respectively, for 16 mg. On the basis of the relationship between occupancy and plasma concentration, dopamine transporter IC(50) (the plasma concentration of drug at 50% occupancy) was determined (4.5 ng/mL) and maximum dopamine transporter occupancy was extrapolated (85%); however, low serotonin transporter occupancy prevented similar serotonin transporter calculations. No serious adverse events were reported. At the doses evaluated, occupancy of the dopamine transporter was significantly higher than that of the serotonin transporter, despite similar in vitro potencies, confirming that, in addition to in vitro assays, PET occupancy studies can be instrumental to the drug development process by informing early decisions about

  19. Outsourcing of logistics transport: A Brazilian leather industry case study.

    Directory of Open Access Journals (Sweden)

    Pedro Domingos Antoniolli

    2015-09-01

    Full Text Available This study aims to analyze the transport sector in Brazil and the criteria for outsourcing of business transport through a case study in a Brazilian industry of leather sector, which outsourced its transport distribution process. As a result of this process, this company could save 60% of its transport costs and improved its service level, which generated an additional 3.5% on its revenue. These research findings are relevant in terms of transportation outsourcing decision criteria, being a strategic decision in operations; thus, in managerial terms, this outsourcing process could make the company’s distribution transportation capability more flexible and agile. RESUMEN: Este estudio tiene como objetivo analizar el sector del transporte en Brasil y los criterios de subcontratación de transporte comercial a través de un estudio de caso, en una empresa brasileña del sector de cuero que subcontrató su proceso de transporte de distribución. Como resultado de este proceso, la empresa pudo ahorrar 60% de sus costes de transporte y mejoró su nivel de servicio, lo que generó un 3.5% adicional en sus ingresos. Estos resultados de la investigación son relevantes en cuanto a los criterios de subcontratación de transporte, como una decisión estratégica en las operaciones; así, en materia de gestión, este proceso de subcontratación podría hacer el transporte de distribución de la empresa más flexible y ágil.

  20. Best practices in road transport: An exploratory study

    Directory of Open Access Journals (Sweden)

    Mar Fernández Vázquez-Noguerol

    2018-04-01

    Full Text Available Purpose: Road transport aspects are becoming increasingly important due to their high impact on economic, environmental and social sustainability. Considering the triple bottom line approach, best practices play a fundamental role within organisations. The purpose of this paper is to analyse several sustainable initiatives in road transport adopted by companies. Design/methodology/approach: The findings were developed and evaluated based on empirical data captured through a survey of 98 professionals involved in logistics and transport activities. Additionally, key literature on transport initiatives was reviewed to supplement the framework for the implementation of best practices in road transport. Findings: The exploratory study shows the importance of each best practice and determines the level of implementation of each initiative, comparing the results among different dealers (retailers, wholesalers, carriers and manufacturers, type of transport fleet and companies’ revenues. Research limitations/implications: The sample of 98 companies was based on simple search filters and the group is not wholly representative of all sectors. Respondents were mainly managers from Spain involved in logistics and transport activities. Surveyed companies included manufacturing, retailers, wholesalers and third-party logistics providers. Practical implications: The most common best practices in road transport are identified, including initiatives related to: efficiency, reusability, safety, optimization, emissions, waste and recycling. Initiatives that influence road transport are ranked by their degree of implementation in the companies analysed.  Social implications: Implementation of some of these best practices may help lessen negative impacts of road transport on society and the environment. Originality/value: The study results indicate which practices are most frequently used and their level of implementation depending on companies’ roles in the

  1. Interference and k-point sampling in the supercell approach to phase-coherent transport - art. no. 0333401

    DEFF Research Database (Denmark)

    Thygesen, Kristian Sommer; Jacobsen, Karsten Wedel

    2005-01-01

    We present a systematic study of interference and k-point sampling effects in the supercell approach to phase-coherent electron transport. We use a representative tight-binding model to show that interference between the repeated images is a small effect compared to the error introduced by using...... only the Gamma-point for a supercell containing (3,3) sites in the transverse plane. An insufficient k-point sampling can introduce strong but unphysical features in the transmission function which can be traced to the presence of van Hove singularities in the lead. We present a first......-principles calculation of the transmission through a Pt contact which shows that the k-point sampling is also important for realistic systems....

  2. 5-D simulation study of suprathermal electron transport in non-axisymmetric plasmas

    International Nuclear Information System (INIS)

    Murakami, S.; Idei, H.; Kubo, S.; Nakajima, N.; Okamoto, M.; Gasparino, U.; Maassberg, H.; Rome, M.; Marushchenko, N.

    2000-01-01

    ECRH driven transport of suprathermal electrons is studied in non-axisymmetric plasmas using a new Monte Carlo simulation technique in 5-D phase space. Two different phases of the ECRH driven transport of suprathermal electrons can be seen. The first is a rapid convective phase due to the direct radial motion of trapped electrons and the second is a slower phase due to the collisional transport. The important role of the radial transport of suprathermal electrons in the broadening of the ECRH deposition profile in W7-AS is clarified. The ECRH driven flux is also evaluated and considered in relation to the 'electron root' feature recently observed in W7-AS. It is found that, at low collisionalities, the ECRH driven flux due to the suprathermal electrons can play a dominant role in the condition of ambipolarity, and thus the observed electron root feature in W7-AS is thought to be driven by the radial (convective) flux of ECRH generated suprathermal electrons. A possible scenario for this type of electron root is considered for the LHD plasma. (author)

  3. 5D simulation study of suprathermal electron transport in non-axisymmetric plasmas

    International Nuclear Information System (INIS)

    Murakami, S.; Idei, H.; Kubo, S.; Nakajima, N.; Okamoto, M.; Gasparino, U.; Maassberg, H.; Rome, M.; Marushchenko, N.

    1999-01-01

    ECRH-driven transport of suprathermal electrons is studied in non-axisymmetric plasmas using a new Monte Carlo simulation technique in 5D phase space. Two different phases of the ECRH-driven transport of suprathermal electrons can be seen; one is a rapid convective phase due to the direct radial motion of trapped electrons and the other is a slower phase due to the collisional transport. The important role of the radial transport of suprathermal electrons in the broadening of the ECRH deposition profile is clarified in W7-AS. The ECRH driven flux is also evaluated and put in relation with the 'electron root' feature recently observed in W7-AS. It is found that, at low collisionalities, the ECRH driven flux due to the suprathermal electrons can play a dominant role in the condition of ambipolarity and, thus, the observed 'electron root' feature in W7-AS is thought to be driven by the radial (convective) flux of ECRH generated suprathermal electrons. The possible scenario of this 'ECRH-driven electron root' is considered in the LHD plasma. (author)

  4. 5D simulation study of suprathermal electron transport in non-axisymmetric plasmas

    International Nuclear Information System (INIS)

    Murakami, S.; Idei, H.; Kubo, S.; Nakajima, N.; Okamoto, M.; Gasparino, U.; Maassberg, H.; Rome, M.; Marushchenko, N.

    2001-01-01

    ECRH-driven transport of is studied in using a new Monte Carlo simulation technique in 5D phase space. Two different phases of the ECRH-driven transport of suprathermal electrons can be seen; one is a rapid convective phase due to the direct radial motion of trapped electrons and the other is a slower phase due to the collisional transport. The important role of the radial transport of suprathermal electrons in the broadening of the ECRH deposition profile is clarified in W7-AS. The ECRH driven flux is also evaluated and put in relation with the ''electron root'' feature recently observed in W7-AS. It is found that, at low collisionalities, the ECRH driven flux due to the suprathermal electrons can play a dominant role in the condition of ambipolarity and, thus, the observed ''electron root'' feature in W7-AS is thought to be driven by the radial (convective) flux of ECRH generated suprathermal electrons. The possible scenario of this ''ECRH-driven electron root'' is considered in the LHD plasma. (author)

  5. Effect of nephrotoxicants on renal membrane transport: In vitro studies

    International Nuclear Information System (INIS)

    Ansari, R.A.; Berndt, W.O.

    1990-01-01

    It is possible to study the effects of nephrotoxicants on membrane function free of other cellular influences. By the use of Percoll gradient centrifugation, highly purified preparations of right-side-out basolateral (BL) and brush border (BB) membrane vesicles can be obtained from rat (male, Sprague-Dawley) renal cortex. Membrane function can be monitored by evaluation of sodium driven transport: 14 C-p-aminohippurate (PAH) for BL and 14 C-glucose for BB. Transport was measured by the rapid filtration technique. Each vesicle preparation was preincubated with the nephrotoxicant for five minutes before initiation of transport. Control vesicles showed a prominant overshoot 1 to 2 minutes after start of transport. Mercuric ion (Hg) had no effect on transport by BB at concentrations as high as 10μM. Transport by BL was reduced significantly at Hg concentrations as low as 100 nM. Chromate (Cr) also reduced BL transport at 100 nM and had no effect on BB transport. Citrinin significantly reduced both BB and BL transport, but the sensitivity of the membrane preparations differed. These data are consistent with the hypothesis that some nephrotoxicants may act on either side of the renal tubular cell membrane

  6. STOMP Subsurface Transport Over Multiple Phases, Version 4.0, User’s Guide

    Energy Technology Data Exchange (ETDEWEB)

    White, Mark D.; Oostrom, Martinus

    2006-06-09

    This guide describes the general use, input file formatting, compilation and execution of the STOMP (Subsurface Transport Over Multiple Phases) simulator, a scientific tool for analyzing single and multiple phase subsurface flow and transport. A description of the simulator’s governing equations, constitutive functions and numerical solution algorithms are provided in a companion theory guide. In writing these guides for the STOMP simulator, the authors have assumed that the reader comprehends concepts and theories associated with multiple-phase hydrology, heat transfer, thermodynamics, radioactive chain decay, and relative permeability-saturation-capillary pressure constitutive relations. The authors further assume that the reader is familiar with the computing environment on which they plan to compile and execute the STOMP simulator. Source codes for the sequential versions of the simulator are available in pure FORTRAN 77 or mixed FORTRAN 77/90 forms. The pure FORTRAN 77 source code form requires a parameters file to define the memory requirements for the array elements. The mixed FORTRAN 77/90 form of the source code uses dynamic memory allocation to define memory requirements, based on a FORTRAN 90 preprocessor STEP, that reads the input files. The simulator utilizes a variable source code configuration, which allows the execution memory and speed to be tailored to the problem specifics, and essentially requires that the source code be assembled and compiled through a software maintenance utility. The memory requirements for executing the simulator are dependent on the complexity of physical system to be modeled and the size and dimensionality of the computational domain. Likewise execution speed depends on the problem complexity, size and dimensionality of the computational domain, and computer performance. Selected operational modes of the STOMP simulator are available for scalable execution on multiple processor (i.e., parallel) computers. These versions

  7. Electronic and magnetic phase separation in EuB6. Fluctuation spectroscopy and nonlinear transport

    International Nuclear Information System (INIS)

    Amyan, Adham

    2013-01-01

    The main topics of this thesis are electrical, stationary, and time-resolved transport measurements on EuB 6 as well as the further development of measuring methods and analysis procedures of the fluctuation spectroscopy. The first part of this thesis was dedicated to the further development of the already known measuring methods under application of a fast data-acquisition card. The second part deals with the electrical transport properties of EuB 6 and the understanding of the coupling between charge and magnetic degrees of freedom. By means of resistance and nonlinear-transport measurements as well as fluctuation spectroscopy hypotheses of other scientists were systematically verified as well as new knowledge obtained. The magnetoresistance was studied as function of the temperature in small external magnetic fields between 1 mT and 700 mT. Measurements of the third harmonic resistance as function of the temperature show maxima at T MI and T C . Electrical-resistance fluctuations were measured without external magnetic field between 5 and 100 K as well in presence of a magnetic field between 18 K and 32 K. At constant temperature measurements of the spectral power density in external magnetic fields were performed in the temperature range from 18 K to 32 K. Highly resolving measurements of the thermal expansion coefficient showed a very strong coupling of the magnetic (polaronic) degrees of freedom to the crystal lattice.

  8. Computational analysis of interfacial attachment kinetics and transport phenomena during liquid phase epitaxy of mercury cadmium telluride

    Energy Technology Data Exchange (ETDEWEB)

    Rasin, Igal; Brandon, Simon [Dept. of Chemical Engineering, Technion, Haifa 32000 (Israel); Ben Dov, Anne; Grimberg, Ilana; Klin, Olga; Weiss, Eliezer [SCD-Semi-Conductor Devices, P.O. Box 2250/99, Haifa 31021 (Israel)

    2010-07-01

    Deposition of mercury cadmium telluride (MCT) thin films, on lattice matched cadmium zinc telluride substrates, is often achieved via Liquid Phase Epitaxy (LPE). The yield and quality of these films, required for the production of infrared detector devices, is to a large extent limited by lack of knowledge regarding details of physical phenomena underlying the deposition process. Improving the understanding of these phenomena and their impact on the quality of the resultant films is therefore an important goal which can be achieved through relevant computational and/or experimental studies. We present a combined computational and experimental effort aimed at elucidating physical phenomena underlying the LPE of MCT via a slider growth process. The focus of the presentation will be results generated by a time-dependent three-dimensional model of mass transport, fluid flow, and interfacial attachment kinetics, which we have developed and applied in the analysis of this LPE process. These results, combined with experimental analyses, lead to an improved understanding of the role of different transport and kinetic phenomena underlying this growth process.

  9. Studies on phase kinetics of new superalloys

    International Nuclear Information System (INIS)

    Weisbrodt, A.; Penkalla, H.J.; Schubert, F.; Nickel, H.

    1990-08-01

    At the development of new ODS (Oxide-Dispersion-Strengthened) alloys for components being exposed to hot-gas temperatures nickel-base alloys and ODS alloys have been investigated. The experimental work mainly referred to phase investigations of thermally loaded samples. The addition of alloying elements will have a decisive influence on the γ'-phase fraction, γ'-lattice parameter, the morphology as well as the coarsening behaviour of the γ'-phase under temperature load. The main characteristics of ODS alloys are Y,Al-mixed oxides and microstructural inhomogenities. As for MA6000 a Time-Temperature-Precipitation diagram has been elaborated. By means of the improved computer programme PHASCALC for phase and N v (= average electron vacancy concentration) - value calculation many microstructural parameters such as the γ/γ'-misfit, the solution of the γ'-phase and melting temperatures can be determined. Tensile tests made at temperatures above 900deg C have shown that the strengthening parameters are dependent on alloy composition, temperature conditions, γ'-phase fraction and oxide dispersion content. (orig.) [de

  10. Fundamental study on interfacial area transport model (I) (contract research)

    International Nuclear Information System (INIS)

    Mishima, Kaichiro; Nakamura, Hideo

    2001-03-01

    Recently, improvement in the best-estimate (BE) code predictive capability is attempted by incorporating the interfacial area transport model (IATM) into a one-dimensional two-fluid model to represent gas-liquid two-phase flows in detail with less uncertainty in the flow predictions. Internationally, the nuclear regulatory commission (NRC) and Purdue University in the U.S.A. and CEA in France have promoted the renewal of their BE codes such as TRAC, RELAP5 and CATHARE, by introducing the IATM in cooperative manner. In Japan, JAERI is underway to develop a one-dimensional code based primarily on the IATM against the licensing procedures of next-generation nuclear reactors. The IATM has a possibility to correctly predict flow transient along flow path for such flows as developing flows, multi-dimensional flows, transitional flows, boiling flows, which are difficult to accurately predict by the two-fluid models employed in the current BE codes. The newly developed code with the IATM would dramatically improve the accuracy in the flow prediction. The model, however, is under development and needs great effort to overcome many difficulties with plenty of theoretical considerations based on much of data bases to be acquired further. This study attempts to measure interfacial area in air-water two-phase flows in a large-diameter tube to understand the characteristic of multi-dimensional flows that usually appear in large-diameter tube flows, and provide data bases, to contribute the development of the IATM. The results obtained by such institutes as Purdue University and CEA France were reviewed first. Clarified are the current status and problems of the IATM, basics and practical methods to measure the interfacial area using multi-sensor miniature local probes; metal needle electro-resistance probe and fiber-optic probe. It was found that the applicability of the IATM is limited mostly to a one-dimensional bubbly flow, and is far from satisfactory for multi

  11. Programme of research into the management and storage of radioactive waste. Aqueous phase transport through granitic rocks

    International Nuclear Information System (INIS)

    Bradbury, M.H.; Green, A.

    1984-01-01

    Three aspects of work on aqueous phase transport by diffusion through porous granites are considered (1) The formation factor and long range connectivity of pore structure. (2) The effect of degraded fissure surfaces on diffusion into the main pore structure. (3) Effect of overburden pressures at depth on diffusion rates. Experiments were conducted on Cornish carnmenellis granite. (U.K.)

  12. Meta-Analytical Studies in Transport Economics. Methodology and Applications

    Energy Technology Data Exchange (ETDEWEB)

    Brons, M.R.E.

    2006-05-18

    Vast increases in the external costs of transport in the late twentieth century have caused national and international governmental bodies to worry about the sustainability of their transport systems. In this thesis we use meta-analysis as a research method to study various topics in transport economics that are relevant for sustainable transport policymaking. Meta-analysis is a research methodology that is based on the quantitative summarisation of a body of previously documented empirical evidence. In several fields of economic, meta-analysis has become a well-accepted research tool. Despite the appeal of the meta-analytical approach, there are methodological difficulties that need to be acknowledged. We study a specific methodological problem which is common in meta-analysis in economics, viz., within-study dependence caused by multiple sampling techniques. By means of Monte Carlo analysis we investigate the effect of such dependence on the performance of various multivariate estimators. In the applied part of the thesis we use and develop meta-analytical techniques to study the empirical variation in indicators of the price sensitivity of demand for aviation transport, the price sensitivity of demand for gasoline, the efficiency of urban public transport and the valuation of the external costs of noise from rail transport. We focus on the estimation of mean values for these indicators and on the identification of the impact of conditioning factors.

  13. A study on the formation and transport of radioactive colloids in porous media

    International Nuclear Information System (INIS)

    Chung, Jin Yop

    1992-02-01

    Colloid particles, which may be supplied naturally by groundwater, are shown to be important potential vehicles for the transport of radionuclides in geologic media. Colloid particles have also large available sites for adsorption because small particles have high surface areas per unit mass. This possibility leads us to investigate the controlling factors of colloids in groundwater to simulate the radionuclide behavior at the repository. Analytical models that can be generalized for the purpose, however, are not available yet. Therefore, in this study the mechanisms that affect the colloid transport were reviewed carefully and, also in order to evaluate the extent of their effects, general and analytical model combined with modified filtration equation was developed. This modified filtration equation including colloidal particle size effect was solved as a function of colloidal particle size, which is a important factor affecting the colloidal transport, grain diameter of porous media, groundwater velocity, distance, and time. Also, as another measure to estimate colloidal particle size effect, analytical method to calculate the adsorption of radionuclides on the colloid, concepts of transport velocity and migration distance were introduced. To evaluate the relative contribution of colloid to the radionuclide transport quatitatively, colloidal transport was compared with the corresponding solute transport under same conditions. Finally, the three phase analysis was proposed to treat the radionuclide transport more practically. A good agreement was obtained between the predicted result by modified filtration equation and the corresponding published experimental data. As the colloidal size is increased, the effect of diffusional velocity on the mobility decreases and that of gravitational settling increases, respectively, whereas the mobility reduction due to filtration increases when interception and gravitational settling dominate. Results of case studies about

  14. Measurements of Two-Phase Suspended Sediment Transport in Breaking Waves Using Volumetric Three-Component Velocimetry

    Science.gov (United States)

    Ting, F. C. K.; LeClaire, P.

    2016-02-01

    Understanding the mechanisms of sediment pickup and distribution in breaking waves is important for modeling sediment transport in the surf zone. Previous studies were mostly concerned with bulk sediment transport under specific wave conditions. The distribution of suspended sediments in breaking waves had not been measured together with coherent flow structures. In this study, two-phase flow measurements were obtained under a train of plunging regular waves on a plane slope using the volumetric three-component velocimetry (V3V) technique. The measurements captured the motions of sediment particles simultaneously with the three-component, three-dimensional (3C3D) velocity fields of turbulent coherent structures (large eddies) induced by breaking waves. Sediment particles (solid glass spheres diameter 0.125 to 0.15 mm, specific gravity 2.5) were separated from fluid tracers (mean diameter 13 µm, specific gravity 1.3) based on a combination of particle spot size and brightness in the two-phase images. The interactions between the large eddies and glass spheres were investigated for plunger vortices generated at incipient breaking and for splash-up vortices generated at the second plunge point. The measured data show that large eddies impinging on the bottom was the primary mechanism which lift sediment particles into suspension and momentarily increased near-bed suspended sediment concentration. Although eddy impingement events were sporadic in space and time, the distributions of suspended sediments in the large eddies were not uniform. High suspended sediment concentration and vertical sediment flux were found in the wall-jet region where the impinging flow was deflected outward and upward. Sediment particles were also trapped and carried around by counter-rotating vortices (Figure 1). Suspended sediment concentration was significantly lower in the impingement region where the fluid velocity was downward, even though turbulent kinetic energy in the down flow was

  15. Incorporating transportation network modeling tools within transportation economic impact studies of disasters

    Directory of Open Access Journals (Sweden)

    Yi Wen

    2014-08-01

    Full Text Available Transportation system disruption due to a disaster results in "ripple effects" throughout the entire transportation system of a metropolitan region. Many researchers have focused on the economic costs of transportation system disruptions in transportation-related industries, specifïcally within commerce and logistics, in the assessment of the regional economic costs. However, the foundation of an assessment of the regional economic costs of a disaster needs to include the evaluation of consumer surplus in addition to the direct cost for reconstruction of the regional transportation system. The objective of this study is to propose a method to estimate the regional consumer surplus based on indirect economic costs of a disaster on intermodal transportation systems in the context of diverting vehicles and trains. The computational methods used to assess the regional indirect economic costs sustained by the highway and railroad system can utilize readily available state departments of transportation (DOTs and metropolitan planning organizations (MPOs traffic models allowing prioritization of regional recovery plans after a disaster and strengthening of infrastructure before a disaster. Hurricane Katrina is one of the most devastating hurricanes in the history of the United States. Due to the significance of Hurricane Katrina, a case study is presented to evaluate consumer surplus in the Gulf Coast Region of Mississippi. Results from the case study indicate the costs of rerouting and congestion delays in the regional highway system and the rent costs of right-of-way in the regional railroad system are major factors of the indirect costs in the consumer surplus.

  16. Growth kinetics and mass transport mechanisms of GaN columns by selective area metal organic vapor phase epitaxy

    Science.gov (United States)

    Wang, Xue; Hartmann, Jana; Mandl, Martin; Sadat Mohajerani, Matin; Wehmann, Hergo-H.; Strassburg, Martin; Waag, Andreas

    2014-04-01

    Three-dimensional GaN columns recently have attracted a lot of attention as the potential basis for core-shell light emitting diodes for future solid state lighting. In this study, the fundamental insights into growth kinetics and mass transport mechanisms of N-polar GaN columns during selective area metal organic vapor phase epitaxy on patterned SiOx/sapphire templates are systematically investigated using various pitch of apertures, growth time, and silane flow. Species impingement fluxes on the top surface of columns Jtop and on their sidewall Jsw, as well as, the diffusion flux from the substrate Jsub contribute to the growth of the GaN columns. The vertical and lateral growth rates devoted by Jtop, Jsw and Jsub are estimated quantitatively. The diffusion length of species on the SiOx mask surface λsub as well as on the sidewall surfaces of the 3D columns λsw are determined. The influences of silane on the growth kinetics are discussed. A growth model is developed for this selective area metal organic vapor phase epitaxy processing.

  17. A Study of Transport Airplane Crash-Resistant Fuel Systems

    National Research Council Canada - National Science Library

    Robertson, S

    2002-01-01

    ...), of transport airplane crash-resistant fuel system (CRFS). The report covers the historical studies related to aircraft crash fires and fuel containment concepts undertaken by the FAA, NASA, and the U.S...

  18. ZnO Nanowires Synthesized by Vapor Phase Transport Deposition on Transparent Oxide Substrates

    Directory of Open Access Journals (Sweden)

    Taylor Curtis

    2010-01-01

    Full Text Available Abstract Zinc oxide nanowires have been synthesized without using metal catalyst seed layers on fluorine-doped tin oxide (FTO substrates by a modified vapor phase transport deposition process using a double-tube reactor. The unique reactor configuration creates a Zn-rich vapor environment that facilitates formation and growth of zinc oxide nanoparticles and wires (20–80 nm in diameter, up to 6 μm in length, density <40 nm apart at substrate temperatures down to 300°C. Electron microscopy and other characterization techniques show nanowires with distinct morphologies when grown under different conditions. The effect of reaction parameters including reaction time, temperature, and carrier gas flow rate on the size, morphology, crystalline structure, and density of ZnO nanowires has been investigated. The nanowires grown by this method have a diameter, length, and density appropriate for use in fabricating hybrid polymer/metal oxide nanostructure solar cells. For example, it is preferable to have nanowires no more than 40 nm apart to minimize exciton recombination in polymer solar cells.

  19. 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...

  20. Phase-coherent electron transport in (Zn, Al)Ox thin films grown by atomic layer deposition

    Science.gov (United States)

    Saha, D.; Misra, P.; Ajimsha, R. S.; Joshi, M. P.; Kukreja, L. M.

    2014-11-01

    A clear signature of disorder induced quantum-interference phenomena leading to phase-coherent electron transport was observed in (Zn, Al)Ox thin films grown by atomic layer deposition. The degree of static-disorder was tuned by varying the Al concentration through periodic incorporation of Al2O3 sub-monolayer in ZnO. All the films showed small negative magnetoresistance due to magnetic field suppressed weak-localization effect. The temperature dependence of phase-coherence length ( l φ ∝ T - 3 / 4 ), as extracted from the magnetoresistance measurements, indicated electron-electron scattering as the dominant dephasing mechanism. The persistence of quantum-interference at relatively higher temperatures up to 200 K is promising for the realization of ZnO based phase-coherent electron transport devices.

  1. Phase-coherent electron transport in (Zn, Al)O{sub x} thin films grown by atomic layer deposition

    Energy Technology Data Exchange (ETDEWEB)

    Saha, D., E-mail: sahaphys@gmail.com, E-mail: pmisra@rrcat.gov.in; Misra, P., E-mail: sahaphys@gmail.com, E-mail: pmisra@rrcat.gov.in; Ajimsha, R. S.; Joshi, M. P.; Kukreja, L. M. [Laser Materials Processing Division, Raja Ramanna Centre for Advanced Technology, Indore 452 013 (India)

    2014-11-24

    A clear signature of disorder induced quantum-interference phenomena leading to phase-coherent electron transport was observed in (Zn, Al)O{sub x} thin films grown by atomic layer deposition. The degree of static-disorder was tuned by varying the Al concentration through periodic incorporation of Al{sub 2}O{sub 3} sub-monolayer in ZnO. All the films showed small negative magnetoresistance due to magnetic field suppressed weak-localization effect. The temperature dependence of phase-coherence length (l{sub φ}∝T{sup −3/4}), as extracted from the magnetoresistance measurements, indicated electron-electron scattering as the dominant dephasing mechanism. The persistence of quantum-interference at relatively higher temperatures up to 200 K is promising for the realization of ZnO based phase-coherent electron transport devices.

  2. Spectral Cascade-Transport Turbulence Model Development for Two-Phase Flows

    Science.gov (United States)

    Brown, Cameron Scott

    Turbulence modeling remains a challenging problem in nuclear reactor applications, particularly for the turbulent multiphase flow conditions in nuclear reactor subchannels. Understanding the fundamental physics of turbulent multiphase flows is crucial for the improvement and further development of multiphase flow models used in reactor operation and safety calculations. Reactor calculations with Reynolds-averaged Navier-Stokes (RANS) approach continue to become viable tools for reactor analysis. The on-going increase in available computational resources allows for turbulence models that are more complex than the traditional two-equation models to become practical choices for nuclear reactor computational fluid dynamic (CFD) and multiphase computational fluid dynamic (M-CFD) simulations. Similarly, increased computational capabilities continue to allow for higher Reynolds numbers and more complex geometries to be evaluated using direct numerical simulation (DNS), thus providing more validation and verification data for turbulence model development. Spectral turbulence models are a promising approach to M-CFD simulations. These models resolve mean flow parameters as well as the turbulent kinetic energy spectrum, reproducing more physical details of the turbulence than traditional two-equation type models. Previously, work performed by other researchers on a spectral cascade-transport model has shown that the model behaves well for single and bubbly twophase decay of isotropic turbulence, single and two-phase uniform shear flow, and single-phase flow in a channel without resolving the near-wall boundary layer for relatively low Reynolds number. Spectral models are great candidates for multiphase RANS modeling since bubble source terms can be modeled as contributions to specific turbulence scales. This work focuses on the improvement and further development of the spectral cascadetransport model (SCTM) to become a three-dimensional (3D) turbulence model for use in M

  3. A desk study of surface diffusion and mass transport in clay

    International Nuclear Information System (INIS)

    Cook, A.J.

    1989-01-01

    Research into the properties of clays as barrier materials for nuclear waste disposal has led to the realization that they have important transport properties which are relatively insignificant in most other geological materials. Sorption has always been regarded as a purely retarding mechanism, but laboratory experiments over the past decade have indicated that surface diffusion of sorbed cations is a potentially significant transport mechanism in both compacted montmorillonite, and biotite gneiss. The present desk study about these issues was part of the CEC coordinated project Mirage-Second phase, research area Natural analogues

  4. A novel image database analysis system for maintenance of transportation facility : phase I.

    Science.gov (United States)

    2010-06-01

    Transportation is critical to the global economy and plays a particularly vital role in this regions economic growth. Transportation infrastructures such as highways, streets, and bridges represent one of the largest public investments of many gov...

  5. A kinetic study of mercury(II transport through a membrane assisted by new transport reagent

    Directory of Open Access Journals (Sweden)

    Görgülü Ahmet

    2011-07-01

    Full Text Available Abstract Background A new organodithiophosphorus derivative, namely O-(1,3-Bispiperidino-2-propyl-4-methoxy phenyldithiophosphonate, was synthesized and then the kinetic behavior of the transport process as a function of concentration, temperature, stirring rate and solvents was investigated. Results The compound 1 was characterized by elemental analysis, IR, 1H and 31P NMR spectroscopies. The transport of mercury(II ion by a zwitterionic dithiophosphonate 1 in the liquid membrane was studied and the kinetic behavior of the transport process as a function of concentration, temperature, stirring rate and solvents was investigated. The compound 1 is expected to serve as a model liquid membrane transport with mercury(II ions. Conclusion A kinetic study of mercury(II transport through a membrane assisted by O-(1,3-Bispiperidino-2-propyl-4-methoxy phenyldithiophosphonate was performed. It can be concluded that the compound 1 can be provided a general and straightforward route to remove toxic metals ions such as mercury(II ion from water or other solution.

  6. 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.)

  7. Transient particle transport studies at the W7-AS stellarator

    International Nuclear Information System (INIS)

    Koponen, J.

    2000-01-01

    One of the crucial problems in fusion research is the understanding of the transport of particles and heat in plasmas relevant for energy production. Extensive experimental transport studies have unraveled many details of heat transport in tokamaks and stellarators. However, due to larger experimental difficulties, the properties of particle transport have remained much less known. In particular, very few particle transport studies have been carried out in stellarators. This thesis summarises the transient particle transport experiments carried out at the Wendelstein 7-Advanced Stellarator (W7-AS). The main diagnostics tool was a 10-channel microwave interferometer. A technique for reconstructing the electron density profiles from the multichannel interferometer data was developed and implemented. The interferometer and the reconstruction software provide high quality electron density measurements with high temporal and sufficient spatial resolution. The density reconstruction is based on regularization methods studied during the development work. An extensive program of transient particle transport studies was carried out with the gas modulation method. The experiments resulted in a scaling expression for the diffusion coefficient. Transient inward convection was found in the edge plasma. The role of convection is minor in the core plasma, except at higher heating power, when an outward directed convective flux is observed. Radially peaked density profiles were found in discharges free of significant central density sources. Such density profiles are usually observed in tokamaks, but never before in W7-AS. Existence of an inward pinch is confirmed with two independent transient transport analysis methods. The density peaking is possible if the plasma is heated with extreme off-axis Electron Cyclotron Heating (ECH), when the temperature gradient vanishes in the core plasma, and if the gas puffing level is relatively low. The transport of plasma particles and heat

  8. Simulation study of burning control with internal transport barrier

    Energy Technology Data Exchange (ETDEWEB)

    Tateishi, Gonta [Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, Fukuoka (Japan); Yagi, Masatoshi; Itoh, S.I. [Kyushu Univ., Fukuoka (Japan). Research Inst. for Applied Mechanics

    2000-02-01

    Dynamics of burning plasma with internal transport barrier is studied by use of a one dimensional transport simulation code. Two possible mechanisms are modeled for internal transport barrier collapse. One is the collapse, which occurs above the critical pressure gradient, the impact of which is modeled by the enhancement of thermal conductivity. The other is the collapse, which occurs due to the sawtooth trigger. The extended Kadomtsev type reconnection model with multiple resonant surfaces is introduced. Both models are examined for the analysis of long time sustainment of burning. A test of profile control to mitigate the collapse is investigated. The additional circulating power to suppress thermal quench (collapse) is evaluated. (author)

  9. A study on the radionuclide transport by bacteria in geologic media

    International Nuclear Information System (INIS)

    Han, Byoung Sub

    1997-02-01

    The purpose of this paper is to provide a methodology to develop a predictive model based on a conceptual three phase system and to investigate the influence of bacteria and their generation on the transport of radionuclide in porous and fractured media. The mass balance for bacteria, substrate and radionuclide were formulated. To illustrate the model simply, an equilibrium condition was assumed to partition the substrate, bacteria and radionuclide concentrations between the solid soil matrix, aqueous phase, rock matrix and bacterial surface. From the numerical calculation of the radionuclide transport in the presence of bacteria, it was found that the growth of bacteria and supplied primary substrate as limiting or stimulating growth factor of bacteria are the most important factors of the radionuclide transport. We also found that, depend on the transport of bacteria the temporal and spatial distribution of radionuclide concentration was significantly altered. The model proposed in this study will improve the evaluation of the role of the bacteria in the transport of radionuclide in groundwater systems. Furthermore, this model would be usefully utilized in analyzing the important role of colloidal particulate on the overall performance of radioactive waste safety

  10. A review of some geocolloid transport studies in the Farfield relevant to radioactive waste disposal

    International Nuclear Information System (INIS)

    Longworth, G.; Ivanovich, M.

    1990-01-01

    The major pathway for the spread of radionuclides within the geosphere surrounding a radioactive waste repository is the groundwater. Since ground waters contain colloidal particles which can sorb radionuclides and may be mobile, it is important to assess whether the presence of colloids will significantly change the radionuclide burden carried by the groundwater. Groundwater colloids from a variety of aquifers have been characterized in terms of their physical, chemical, and actinide compositions. The partition of natural series actinides has been measured using isotope dilution alpha spectrometry, between the particulate, colloid and solution phases. When the colloids are inorganic in character the fraction of total actinide activities on the colloid phase is less than one per cent for uranium and <10% for thorium. In the case of organic colloids/complexes, however, 80-90% of the uranium or thorium load is carried by the colloid phase. In addition, measurements of daughter/parent isotopic activity ratio demonstrate that the uranium associated with the colloid phase is not in chemical equilibrium with that in the groundwater. The transport of colloids is being studied using labelled synthetic colloids in a shallow glacial sand aquifer in which a set of ordered boreholes over a scale of several meters has been established by the British Geological Survey. The stability and transport behavior of these colloids has been established in laboratory column experiments before their use in a field tracer experiment. The implications of this work for modeling radionuclide transport in the geosphere is discussed. 8 refs., 3 tabs

  11. An environmentally sustainable transport system in Sweden. A scenario study

    Energy Technology Data Exchange (ETDEWEB)

    Brokking, P.; Emmelin, L.; Engstroem, M-G.; Nilsson, Jan-Evert; Eriksson, Gunnar; Wikberg, O.

    1997-02-01

    This is a short version of a scenario study concerning the possibilities to reach an Environmentally Sustainable Transport system in Sweden in a perspective of 30 years. The aim of the scenario study has been to describe one of several possible paths from today`s transport system to an environmentally adopted one. However, this does not imply that the task is to predict how such a transformation can be accomplished. The aim is rather to illustrate what such transformation require in the form of political decisions. The transformation of the transport system in to an environmentally adopted one, is primarily treated as a political problem, and a political perspective has accordingly been chosen for the study. In this English version of the scenario, the carbon dioxide problem is used to illuminate the many conflicts in goals and other problem that will attend an environmental adoption of the Swedish transport system, and to highlight the analytical points of departure for the scenario study. The analysis shows that it is possible to reach the national environmental goals that characterise, with given definitions, an environmentally sustainable transport system. However, this implies many severe political decisions over a long period of time, which in turn, implies a long term national consensus about the importance to reach the overall goal. Other results the scenario points out, is the risk that a policy focused on one sector leads to `solving` a problem by moving it outside systems limitations, and the limitations on a national environmental policy: Being able to count on assistance from other countries through an environmental adoption of the transport system in the European Union or globally, would drastically facilitate the environmental adoption of the Swedish transport system, through, among other things, a more rapid technological development. This indicates the necessity of promoting issues involving transportation and the environment in international

  12. Dispersed catalysts for transforming extra heavy crude oil into transportable upgraded crude: phase identification

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, S.; Canizales, E.; Machin, I. [Gerencia Depttal de Investigacion Estrategica en Refinacion PDVSA Intevep (Venezuela); Segovia, X.; Rivas, A.; Lopez, E.; Pena, J.P.; Rojas, J.D.; Sardella, R. [Gerencia Depttal de Infraestructura y Mejoramiento en Faja Petrolifera PDVSA Intevep (Venezuela)

    2011-07-01

    A new technology to convert extra heavy crude oil into transportable upgraded crude has been developed. A water/oil emulsion composed of steam and catalyst precursors is introduced in the feed which then generates unsupported dispersed catalyst in situ under thermal decomposition. The aim of this paper is to characterize the particles. The study was conducted in a laboratory and on a pilot scale on three different vacuum residues using high resolution transmission electron microscopy and a transmission electron microscope. Results showed that the particles were formed by oxides and inorganic sulphur based in transition metals and their sizes ranged between 5 and 120 nm; in addition, good dispersion was observed. This study demonstrated that the process involved in the generation of dispersed catalyst is extremely complex and showed that further work with heavy crude oils and its residua is required to understand the mechanisms involved.

  13. Electrical transport and temperature coefficient of resistance in polycrystalline La0.7−xAgxCa0.3MnO3 pellets: Analysis in terms of a phase coexistence transport model and phase separation model

    International Nuclear Information System (INIS)

    Phong, P.T.; Nguyen, L.H.; Manh, D.H.; Phuc, N.X.; Lee, I.-J.

    2013-01-01

    The temperature dependent resistivity and temperature coefficient of resistance of Ag doped La 0.7−x Ag x Ca 0.3 MnO 3 polycrystalline pellets (x=0, 0.05, 0.10, 0.15, and 0.20) are investigated. Ag substitution enhances the conductivity of this system. The Curie temperature also increases from 260 to 283 K with increasing Ag content. Using phase-coexistence transport model and phase separation model, we calculated the resistivity as a function of temperature and the temperature coefficient of resistivity (TCR) behavior. Comparing the calculated maximum TCR, we found that it is related to activation energy, transition temperature, and disorder in doped manganites. The relationship between the proposed TCR behavior and the transport parameters can suggest conditions improving TCR max of doped manganites for the use of the bolometric infrared detectors

  14. Center for Transportation Studies 24th annual transportation research conference, May 22-23, 2013, Saint Paul, Minnesota.

    Science.gov (United States)

    2013-05-01

    The University of Minnesotas Center for Transportation : Studies is pleased to present its 24th Annual Transportation : Research Conference, May 22-23, 2013. The conference will : be held at the Saint Paul RiverCentre, 175 West Kellogg : Boulevard...

  15. Building Enclosure Hygrothermal Performance Study, Phase 1

    Energy Technology Data Exchange (ETDEWEB)

    Karagiozis, A.N.

    2002-08-08

    The moisture performance of three different classes of wall systems has been investigated in the context of the preliminary hygrothermal analysis of walls in Seattle. The results reported in this phase specifically address the moisture performance of walls designed with loads that have some unintentional water penetration. The results have been developed in a manner to present the relative performance of the walls in the same climate with similar water penetration effects. The analysis was performed with the best available input data. Several limitations should be recognized within the context of this study. Results showed that selection of wooden sheathing boards on interior vapor-tight assemblies does not significantly influence the performance of stucco-clad walls. A larger effect was observed when the interior vapor control is made vapor open. When continuous cavity ventilation is employed, the effect of the selection of the type of sheathing board on the hygrothermal performance of the wall was found to be negligible. When comparing oriented strand board sheathing performance against the performance of exterior grade gypsum, the differences are very significant in terms of the amount of moisture content present in the walls. Moisture content alone does not indicate their respective durability as durability is directly related to the combination of relative humidity and temperature, mechanical, chemical, and biological properties of the substrates. This study did not investigate the durability performance of either sheathing. In terms of interior vapor control, inhabitant behavior must be considered during the wall hygrothermal design stage. If interior relative humidity is maintained below 60%, then a latex primer and paint may perform better than the use of PVA or even a polyethylene sheet. When the interior environment is maintained at a higher relative humidity, then stricter vapor control is needed. Multilayered building paper was experimentally shown to

  16. 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...

  17. Shuttle Transportation System Case-Study Development

    Science.gov (United States)

    Ransom, Khadijah

    2012-01-01

    A case-study collection was developed for NASA's Space Shuttle Program. Using lessons learned and documented by NASA KSC engineers, analysts, and contractors, decades of information related to processing and launching the Space Shuttle was gathered into a single database. The goal was to provide educators with an alternative means to teach real-world engineering processes and to enhance critical thinking, decision making, and problem solving skills. Suggested formats were created to assist both external educators and internal NASA employees to develop and contribute their own case-study reports to share with other educators and students. Via group project, class discussion, or open-ended research format, students will be introduced to the unique decision making process related to Shuttle missions and development. Teaching notes, images, and related documents will be made accessible to the public for presentation of Space Shuttle reports. Lessons investigated included the engine cutoff (ECO) sensor anomaly which occurred during mission STS-114. Students will be presented with general mission infom1ation as well as an explanation of ECO sensors. The project will conclude with the design of a website that allows for distribution of information to the public as well as case-study report submissions from other educators online.

  18. Quantitative evaluation of a thrust vector controlled transport at the conceptual design phase

    Science.gov (United States)

    Ricketts, Vincent Patrick

    The impetus to innovate, to push the bounds and break the molds of evolutionary design trends, often comes from competition but sometimes requires catalytic political legislature. For this research endeavor, the 'catalyzing legislation' comes in response to the rise in cost of fossil fuels and the request put forth by NASA on aircraft manufacturers to show reduced aircraft fuel consumption of +60% within 30 years. This necessitates that novel technologies be considered to achieve these values of improved performance. One such technology is thrust vector control (TVC). The beneficial characteristic of thrust vector control technology applied to the traditional tail-aft configuration (TAC) commercial transport is its ability to retain the operational advantage of this highly evolved aircraft type like cabin evacuation, ground operation, safety, and certification. This study explores if the TVC transport concept offers improved flight performance due to synergistically reducing the traditional empennage size, overall resulting in reduced weight and drag, and therefore reduced aircraft fuel consumption. In particular, this study explores if the TVC technology in combination with the reduced empennage methodology enables the TAC aircraft to synergistically evolve while complying with current safety and certification regulation. This research utilizes the multi-disciplinary parametric sizing software, AVD Sizing, developed by the Aerospace Vehicle Design (AVD) Laboratory. The sizing software is responsible for visualizing the total system solution space via parametric trades and is capable of determining if the TVC technology can enable the TAC aircraft to synergistically evolve, showing marked improvements in performance and cost. This study indicates that the TVC plus reduced empennage methodology shows marked improvements in performance and cost.

  19. Transient electro-magneto-hydrodynamic two-phase blood flow and thermal transport through a capillary vessel.

    Science.gov (United States)

    Mirza, I A; Abdulhameed, M; Vieru, D; Shafie, S

    2016-12-01

    Therapies with magnetic/electromagnetic field are employed to relieve pains or, to accelerate flow of blood-particles, particularly during the surgery. In this paper, a theoretical study of the blood flow along with particles suspension through capillary was made by the electro-magneto-hydrodynamic approach. Analytical solutions to the non-dimensional blood velocity and non-dimensional particles velocity are obtained by means of the Laplace transform with respect to the time variable and the finite Hankel transform with respect to the radial coordinate. The study of thermally transfer characteristics is based on the energy equation for two-phase thermal transport of blood and particles suspension with viscous dissipation, the volumetric heat generation due to Joule heating effect and electromagnetic couple effect. The solution of the nonlinear heat transfer problem is derived by using the velocity field and the integral transform method. The influence of dimensionless system parameters like the electrokinetic width, the Hartman number, Prandtl number, the coefficient of heat generation due to Joule heating and Eckert number on the velocity and temperature fields was studied using the Mathcad software. Results are presented by graphical illustrations. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  20. Small transport aircraft technology propeller study

    Science.gov (United States)

    Black, B. M.; Magliozzi, B.; Rohrbach, C.

    1983-01-01

    A study to define potential benefits of advanced technology propeller for 1985-1990 STAT commuter airplanes was completed. Two baselines, a Convair, 30 passenger, 0.47 Mach number airplane and a Lockheed, 50 passenger, 0.70 Mach number airplane, were selected from NASA-Ames sponsored airframe contracts. Parametric performance, noise level, weight and cost trends for propellers with varying number of blades, activity factor, camber and diameter incorporating blade sweep, tip proplets, advanced composite materials, advanced airfoils, advanced prevision synchrophasing and counter-rotation are presented. The resulting DOC, fuel burned, empty weight and acquisition cost benefits are presented for resizings of the two baseline airplanes. Six-bladed propeller having advanced composite blades, advanced airfoils, tip proplets and advanced prevision synchrophasers provided the maximum DOC improvements for both airplanes. DOC and fuel burned were reduced by 8.3% and 17.0% respectively for the Convair airplane and by 24.9% and 41.2% respectively for the Lockheed airplane. The larger reductions arose from a baseline definition with very heavy fuselage acoustic treatment. An alternate baseline, with a cabin noise 13dB in excess of the objective, was also studied.

  1. Performance of a neutron transport code with full phase space decomposition on the Cray Research T3D

    International Nuclear Information System (INIS)

    Dorr, M.R.; Salo, E.M.

    1995-01-01

    We present performance results obtained on a 128-node Cray Research T3D computer by a neutron transport code implementing a standard mtiltigroup, discrete ordinates algorithm on a three-dimensional Cartesian grid. After summarizing the implementation strategy used to obtain a full decomposition of phase space (i.e., simultaneous parallelization of the neutron energy, directional and spatial variables), we investigate the scalability of the fundamental source iteration step with respect to each phase space variable. We also describe enhancements that have enabled performance rates approaching 10 gigaflops on the full 128-node machine

  2. Transport studies in p-type double quantum well samples

    International Nuclear Information System (INIS)

    Hyndman, R.J.

    2000-01-01

    The motivation for the study of double quantum well samples is that the extra spatial degree of freedom can modify the ground state energies of the system, leading to new and interesting many body effects. Electron bi-layers have been widely studied but the work presented here is the first systematic study of transport properties of a p-type, double quantum well system. The samples, grown on the 311 plane, consisted of two 100A GaAs wells separated by a 30A AlAs barrier. The thin barrier in our structures, gives rise to very strong inter-layer Coulombic interactions but in contrast to electron double quantum well samples, tunnelling between the two wells is very weak. This is due to the large effective mass of holes compared with electrons. It is possible to accurately control the total density of a sample and the relative occupancy of each well using front and back gates. A systematic study of the magnetoresistance properties of the p-type bi-layers, was carried out at low temperatures and in high magnetic fields, for samples covering a range of densities. Considerable care was required to obtain reliable results as the samples were extremely susceptible to electrical shock and were prone to drift in density slowly over time. With balanced wells, the very low tunnelling in the p-type bi-layer leads to a complete absence of all odd integers in both resistance and thermopower except for the v=1 state, ( v 1/2 in each layer) where v is the total Landau level filling factor. Unlike other FQHE features the v=1 state strengthens with increased density as inter-layer interactions increase in strength over intra-layer interactions. The state is also destroyed at a critical temperature, which is much lower than the measured activation temperature. This is taken as evidence for a finite temperature phase transition predicted for the bi-layer v=1. From the experimental observations, we construct a phase diagram for the state, which agree closely with theoretical predictions

  3. TRANSPORT MECHANISM STUDIES OF CHITOSAN ELECTROLYTE SYSTEMS

    International Nuclear Information System (INIS)

    Navaratnam, S.; Ramesh, K.; Ramesh, S.; Sanusi, A.; Basirun, W.J.; Arof, A.K.

    2015-01-01

    ABSTRACT: Knowledge of ion-conduction mechanisms in polymers is important for designing better polymer electrolytes for electrochemical devices. In this work, chitosan-ethylene carbonate/propylene carbonate (chitosan-EC/PC) system with lithium acetate (LiCH 3 COO) and lithium triflate (LiCF 3 SO 3 ) as salts were prepared and characterized using electrochemical impedance spectroscopy to study the ion-conduction mechanism. It was found that the electrolyte system using LiCF 3 SO 3 salt had a higher ionic conductivity, greater dielectric constant and dielectric loss value compared to system using LiCH 3 COO at room temperature. Hence, it may be inferred that the system incorporated with LiCF 3 SO 3 dissociated more readily than LiCH 3 COO. Conductivity mechanism for the systems, 42 wt.% chitosan- 28 wt.% LiCF 3 SO 3 -30 wt.% EC/PC (CLT) and 42 wt.% chitosan-28 wt.% LiCH 3 COO-30 wt.% EC/PC (CLA) follows the overlapping large polaron tunneling (OLPT) model. Results show that the nature of anion size influences the ionic conduction of chitosan based polymer electrolytes. The conductivity values of the CLA system are found to be higher than that of CLT system at higher temperatures. This may be due to the vibration of bigger triflate anions would have hindered the lithium ion movements. FTIR results show that lithium ions can form complexation with polymer host which would provide a platform for ion hopping

  4. High-Fidelity Kinetics and Radiation Transport for NLTE Hypersonic Flows, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The modeling of NLTE hypersonic flows combines several disciplines: chemistry, kinetics, radiation transport, fluid mechanics, and surface science. No single code or...

  5. Subsurface Access, Characterization, Acquisition, Transport, Storage and Delivery in Microgravity, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — This project will develop geotechnical measurements, sample extraction and transport equipment for subsurface regolith on NEOs, asteroids, moons and planets,...

  6. Studies on the transport of actinides and lanthanides through DHDECMPO based supported liquid membranes (SLM)

    Energy Technology Data Exchange (ETDEWEB)

    Dudwadkar, N.L.; Tripathi, S.C.; Gandhi, P.M. [Bhabha Atomic Research Centre, Trombay, Mumbai (India). Fuel Reprocessing Div.

    2013-07-01

    This paper describes our studies on the partitioning of actinides from high level liquid waste of PUREX origin employing a supported liquid membrane technique. The process uses a solution of DHDECMPO in n-dodecane as a carrier with poly tetra fluoro ethylene support and a mixture of citric acid, formic acid and hydrazine hydrate as a receiving phase. Transport studies are carried out for {sup 241}Am under different experimental conditions to optimize the transport parameters such as feed acidity, carrier concentration and effect of uranium, Nd(III) and salt concentration in the feed. Studies indicated good transport of neptunium, americium and plutonium across the membrane from a nitric acid medium. Under the optimized conditions the transport of {sup 241}Am has been studied for uranium depleted synthetic PHWR-HLW and finally the technique is used for the partitioning of alpha emitters from an actual HLW after reprocessing. A high concentration of uranium in the feed is found to retard the transport of americium, suggesting the need of prior removal of uranium from the waste. Separation of actinides from uranium-lean simulated as well as actual HLW has been found to be feasible using the above described technique. (orig.)

  7. Evaluating health effects of transport interventions methodologic case study.

    Science.gov (United States)

    Ogilvie, David; Mitchell, Richard; Mutrie, Nanette; Petticrew, Mark; Platt, Stephen

    2006-08-01

    There is little evidence about the effects of environmental interventions on population levels of physical activity. Major transport projects may promote or discourage physical activity in the form of walking and cycling, but researching the health effects of such "natural experiments" in transport policy or infrastructure is challenging. Case study of attempts in 2004-2005 to evaluate the effects of two major transport projects in Scotland: an urban congestion charging scheme in Edinburgh, and a new urban motorway (freeway) in Glasgow. These interventions are typical of many major transport projects. They are unique to their context. They cannot easily be separated from the other components of the wider policies within which they occur. When, where, and how they are implemented are political decisions over which researchers have no control. Baseline data collection required for longitudinal studies may need to be planned before the intervention is certain to take place. There is no simple way of defining a population or area exposed to the intervention or of defining control groups. Changes in quantitative measures of health-related behavior may be difficult to detect. Major transport projects have clear potential to influence population health, but it is difficult to define the interventions, categorize exposure, or measure outcomes in ways that are likely to be seen as credible in the field of public health intervention research. A final study design is proposed in which multiple methods and spatial levels of analysis are combined in a longitudinal quasi-experimental study.

  8. Pain and Joy of a Panel Survey on Transport Studies

    Energy Technology Data Exchange (ETDEWEB)

    Comendador Arquero, María Eugenia López-Lambas

    2016-07-01

    Over ten years ago, it was established that the most frequent reason that motivates a panel survey on transport studies is the evaluation of a change in the transportation system, or a specific transportation-planning project, especially when the project involves novel elements. From a statistical viewpoint, a panel survey has the definite advantage to offer more accurate estimatesof changes than cross-sectional surveys for the same sample size. Observing travel patterns of individuals and households overseveral consecutive days, has offered insights into activity scheduling and travel planning. Variability in travel patterns has important policy implications as well, but how much effort is worth to design a panel survey? To evaluate the effects of the transport policies introduced in Madrid during the last five years, a ‘short-long’ panel survey wasbuilt, based on a sample of a Madrid-worker subpopulation most affected by those recent changes in transport policy. The paper describes both the design and construction of the panel based on GPS technology, and presents some results based on an analysis of its two waves; for example, it registered an increment of public transport use and walking trips in 10%. The panel overcomes the known attrition problem thanks to providing incentives, maintaining contact, using the same interviewer for the same respondents, and conducting face-to-face interviews. (Author)

  9. Phase transition behavior of sediment transport at the sand-mud interface, across scales from flumes to the large rivers

    Science.gov (United States)

    Ma, H.; Nittrouer, J. A.; Wu, B.; Zhang, Y.; Mohrig, D. C.; Lamb, M. P.; Wang, Y.; Fu, X.; Moodie, A. J.; Naito, K.; Parker, G.

    2017-12-01

    Sediment dispersal and deposition creates deltaic landscapes, establishes coastlines, and produces fertile floodplains, all of which serve as critical landforms inhabited by a large proportion of humankind. If poorly managed, sediment loads in these environments can elevate and clog channels, thereby enhancing hazards such as severe flooding. Predictive descriptions of sediment loads, however, are not well constrained, especially for fine-grained (silt and very-fine sand) dispersal systems, which often include river deltas and coastlines. Here, we show efforts to collect and analyze an extensive sediment load database for fine-grained channels, spanning from small flume experiments to large rivers, in order to evaluate the nature of sediment flux. Our analyses determined that sediment transport exhibits two distinct transport phases, separated by a discontinuous transition, whereby sediment flux differs by one to two orders of magnitude. It is determined that the transition responds to the bed material grain size, and we propose a phase diagram based on this metric alone. These findings help elucidate why previous theories of sediment transport at the sand-silt interface, which are typically continuous, are not able to give satisfactory predictions across different scales and environments. Our work serves to help evaluate anthropic influences on rivers, deltas, and coastlines, and can be applied to better constrain sediment flux of paleo-fluvial systems found on Earth and Mars. For example, in situ measurements of sediment flux for the silty-sandy bed of the lower Yellow River, China, validate the aforementioned phase transition behavior, and illustrate that the channel resides near the transition of high to low efficiency transport modes. Recent dam construction and resulting downstream coarsening of the bed via armoring, however, might lead to the unintended consequence of enhancing flood risk by driving the system to a low efficiency transport mode with high

  10. Global well-posedness for passively transported nonlinear moisture dynamics with phase changes

    Science.gov (United States)

    Hittmeir, Sabine; Klein, Rupert; Li, Jinkai; Titi, Edriss S.

    2017-10-01

    We study a moisture model for warm clouds that has been used by Klein and Majda (2006 Theor. Comput. Fluid Dyn. 20 525-551) as a basis for multiscale asymptotic expansions for deep convective phenomena. These moisture balance equations correspond to a bulk microphysics closure in the spirit of Kessler (1969 Meteorol. Monogr. 10 1-84) and Grabowski and Smolarkiewicz (1996 Mon. Weather Rev. 124 487-97), in which water is present in the gaseous state as water vapor and in the liquid phase as cloud water and rain water. It thereby contains closures for the phase changes condensation and evaporation, as well as the processes of autoconversion of cloud water into rainwater and the collection of cloud water by the falling rain droplets. Phase changes are associated with enormous amounts of latent heat and therefore provide a strong coupling to the thermodynamic equation. In this work we assume the velocity field to be given and prove rigorously the global existence and uniqueness of uniformly bounded solutions of the moisture model with viscosity, diffusion and heat conduction. To guarantee local well-posedness we first need to establish local existence results for linear parabolic equations, subject to the Robin boundary conditions on the cylindric type of domains under consideration. We then derive a priori estimates, for proving the maximum principle, using the Stampacchia method, as well as the iterative method by Alikakos (1979 J. Differ. Equ. 33 201-25) to obtain uniform boundedness. The evaporation term is of power law type, with an exponent in general less or equal to one and therefore making the proof of uniqueness more challenging. However, these difficulties can be circumvented by introducing new unknowns, which satisfy the required cancellation and monotonicity properties in the source terms.

  11. Use of probabilistic design methods for NASA applications. [to be used in design phase of Space Transportation Main Engine

    Science.gov (United States)

    Safie, Fayssal M.

    1992-01-01

    This paper presents a reliability evaluation process designed to improve the reliability of advanced launch systems. The work performed includes the development of a reliability prediction methodology to be used in the design phase of the Space Transportation Main Engine (STME). This includes prediction techniques which use historical data bases as well as deterministic and probabilistic engineering models for predicting design reliability. In summary, this paper describes a probabilistic design approach for the next-generation liquid rocket engine, the STME.

  12. Quasi-three dimensional dynamic modeling of a proton exchange membrane fuel cell with consideration of two-phase water transport through a gas diffusion layer

    International Nuclear Information System (INIS)

    Kang, Sanggyu

    2015-01-01

    Water management is one of the challenging issues for low-temperature PEMFCs (proton exchange membrane fuel cells). When liquid water is formed at the GDL (gas diffusion layer), the pathway of reactant gas can be blocked, which inhibits the electrochemical reaction of PEMFC. Thus, liquid water transport through GDL is a critical factor determining the performance of a PEMFC. In present study, quasi-three dimensional dynamic modeling of PEMFC with consideration of two-phase water transport through GDL is developed. To investigate the distributions of PEMFC characteristics, including current density, species mole fraction, and membrane hydration, the PEMFC was discretized into twenty control volumes along the anode channel. To resolve the mass and energy conservation, the PEMFC is discretized into eleven and fifteen control volumes in the perpendicular direction, respectively. The dynamic variation of PEMFC characteristics of cell voltage, overvoltage of activation and ohmic, liquid water saturation through a GDL, and oxygen concentration were captured during transient behavior. - Highlights: • A quasi-three dimensional two-phase dynamic model of PEMFC is developed. • Presented model is validated by comparison with experimental data. • Two-phase model is compared with one-phase model at steady-states and transients.

  13. Policy study: energy conservation in transportation in Puerto Rico

    Energy Technology Data Exchange (ETDEWEB)

    Mayda, J

    1978-09-01

    The present study is an initial effort to apply social system analysis to transportation energy conservation, in order to prepare the ground for a team effort of transportation and energy specialists, regional planners, policy analysis and generalists, and government administrators - with additional imputs from commerce, industry and the community at large. The task of this study has been to inventory the principal factors and inputs in the field of transportation energy demand and possible conservation, estimate their magnitudes and relations, and arrange in a tentative but reasoned pattern - where there were before only so many scattered data, technical studies with a limited focus, sectoral programs and decisions, and vague impressions about the serviceability, the impacts and the social value of the product.

  14. SedFoam-2.0: a 3-D two-phase flow numerical model for sediment transport

    Directory of Open Access Journals (Sweden)

    J. Chauchat

    2017-11-01

    Full Text Available In this paper, a three-dimensional two-phase flow solver, SedFoam-2.0, is presented for sediment transport applications. The solver is extended from twoPhaseEulerFoam available in the 2.1.0 release of the open-source CFD (computational fluid dynamics toolbox OpenFOAM. In this approach the sediment phase is modeled as a continuum, and constitutive laws have to be prescribed for the sediment stresses. In the proposed solver, two different intergranular stress models are implemented: the kinetic theory of granular flows and the dense granular flow rheology μ(I. For the fluid stress, laminar or turbulent flow regimes can be simulated and three different turbulence models are available for sediment transport: a simple mixing length model (one-dimensional configuration only, a k − ε, and a k − ω model. The numerical implementation is demonstrated on four test cases: sedimentation of suspended particles, laminar bed load, sheet flow, and scour at an apron. These test cases illustrate the capabilities of SedFoam-2.0 to deal with complex turbulent sediment transport problems with different combinations of intergranular stress and turbulence models.

  15. SedFoam-2.0: a 3-D two-phase flow numerical model for sediment transport

    Science.gov (United States)

    Chauchat, Julien; Cheng, Zhen; Nagel, Tim; Bonamy, Cyrille; Hsu, Tian-Jian

    2017-11-01

    In this paper, a three-dimensional two-phase flow solver, SedFoam-2.0, is presented for sediment transport applications. The solver is extended from twoPhaseEulerFoam available in the 2.1.0 release of the open-source CFD (computational fluid dynamics) toolbox OpenFOAM. In this approach the sediment phase is modeled as a continuum, and constitutive laws have to be prescribed for the sediment stresses. In the proposed solver, two different intergranular stress models are implemented: the kinetic theory of granular flows and the dense granular flow rheology μ(I). For the fluid stress, laminar or turbulent flow regimes can be simulated and three different turbulence models are available for sediment transport: a simple mixing length model (one-dimensional configuration only), a k - ɛ, and a k - ω model. The numerical implementation is demonstrated on four test cases: sedimentation of suspended particles, laminar bed load, sheet flow, and scour at an apron. These test cases illustrate the capabilities of SedFoam-2.0 to deal with complex turbulent sediment transport problems with different combinations of intergranular stress and turbulence models.

  16. Evaluation of storage/transportation options to support criteria development for the Phase I MRS

    International Nuclear Information System (INIS)

    Sorenson, K.B.; Brown, N.N.; Bennett, P.C.; Lake, W.

    1991-01-01

    The DOE's Office of Civilian Waste Management (OCRWM) plans to develop an interim storage facility to enable acceptance of spent fuel in 1998. It is estimated that this interim storage facility would be needed for about two years. A Monitored Retrievable Storage (MRS) facility is anticipated in 2000 and a repository in 2010. Acceptance and transport of spent fuel by DOE/OCRWM in 1998 will require an operating transportation system. Because this interim storage facility is not yet defined, development of an optimally compatible transportation system is not a certainty. In order to assure a transport capability for 1998 acceptance of spent fuel, it was decided that the OCRWM transportation program had to identify likely options for an interim storage facility, including identification of the components needed for compatibility between likely interim storage facility options and transportation. Primary attention was given to existing hardware, although conceptual designs were also considered. A systems-based probabilistic decision model was suggested by Sandia National Labs. and accepted by DOE/OCRWM's transportation program. Performance of the evaluation task involved several elements of the transportation program. This paper describes the decision model developed to accomplish this task, along with some of the results and conclusions

  17. A study on contaminant transport in indoor air

    International Nuclear Information System (INIS)

    Pujala, Usha; Sen, Soubhadra; Subramanian, V.; Srinivas, C.V.; Baskaran, R.; Venkatraman, B.

    2016-01-01

    In case of an accidental release of radioactive contaminant inside a well-ventilated room, the same will be transported to the different parts of the room due to the circulation of indoor air. To ensure safety of the operating personnel, it is important to identify the ideal locations for keeping the warning alarm systems. To address the problem, a detailed study is required where numerical simulation has to be supported by experimental verification. A computational methodology has already been verified for this purpose (IGC report-no.323). In this work, a study on the transport of an inert aerosol inside a well-ventilated isolated room has been carried out

  18. Field studies of radionuclide transport at the Chalk River Laboratories

    International Nuclear Information System (INIS)

    Champ, D.R.; Killey, R.W.D.; Moltyaner, G.L.

    1991-01-01

    In this paper the authors summarize the results of: in situ field column experiments to study the transport behaviour of several long-lived radionuclides, 4 natural gradient non-reactive radiotracer injection experiments at the Chalk River Laboratories (CRL) Twin Lake Tracer Test Site, and a model validation study that used data for 90 Sr from two well-defined contaminated groundwater flow systems at CRL. The paper also describes a current re-evaluation of radionuclide release and transport from a 1960 experimental burial (in a CRL sand aquifer) of glass blocks containing fission and activation products. (J.P.N.)

  19. Magmatic Vapor Phase Transport of Copper in Reduced Porphyry Copper-Gold Deposits: Evidence From PIXE Microanalysis of Fluid Inclusions

    Science.gov (United States)

    Rowins, S. M.; Yeats, C. J.; Ryan, C. G.

    2002-05-01

    Nondestructive proton-induced X-ray emission (PIXE) studies of magmatic fluid inclusions in granite-related Sn-W deposits [1] reveal that copper transport out of reduced felsic magmas is favored by low-salinity vapor and not co-existing high-salinity liquid (halite-saturated brine). Copper transport by magmatic vapor also has been documented in oxidized porphyry Cu-Au deposits, but the magnitude of Cu partitioning into the vapor compared to the brine generally is less pronounced than in the reduced magmatic Sn-W systems [2]. Consideration of these microanalytical data leads to the hypothesis that Cu and, by inference, Au in the recently established "reduced porphyry copper-gold" (RPCG) subclass should partition preferentially into vapor and not high-salinity liquid exsolving directly from fluid-saturated magmas [3-4]. To test this hypothesis, PIXE microanalysis of primary fluid inclusions in quartz-sulfide (pyrite, pyrrhotite & chalcopyrite) veins from two RPCG deposits was undertaken using the CSIRO-GEMOC nuclear microprobe. PIXE microanalysis for the ~30 Ma San Anton deposit (Mexico) was done on halite-saturated aqueous brine (deposit (W. Australia) was done on halite-saturated "aqueous" inclusions, which contain a small (deposits of the new RPCG subclass demonstrate the greater potential of these systems, compared to the classically oxidized porphyry Cu-Au systems, to transport Cu and probably precious metals in a magmatic aqueous vapor phase. These PIXE data also support the possibility that Cu partitions preferentially into an immiscible CO2-rich magmatic fluid. References: [1] Heinrich, C.A. et al. (1992) Econ. Geol., 87, 1566-1583. [2] Heinrich, C.A. et al. (1999) Geology, 27, 755-758. [3] Rowins, S.M. (2000) Geology, 28, 491-494. [4] Rowins, S.M. (2000) The Gangue, GAC-MDD Newsletter, 67, 1-7 (www.gac.ca). [5] Rowins, S.M. et al. (1993) Geol. Soc. Australia Abs., 34, 68-70.

  20. Radioimmuoassay study of antidigitoxin antibodies in liquid phase and after coupling on a solid phase

    International Nuclear Information System (INIS)

    Collignon, A.; German, A.; Scherrmann, J.M.; Bourdon, R.

    1983-01-01

    Antidigitoxin antibodies prepared by immunizing rabbits with a digitoxin-bovine serum albumin conjugate have been studied by radioimmunoassay in the native serum (homogeneous phase antibodies) and after coupling on glass beads (heterogeneous phase antibodies). Homogeneous phase antibodies present a satisfactory titer and affinity constant and react very specifically with digitoxin. Fixation of antibodies on a solid phase induce a loss of their immunoreactivity as it is showed by modification of the inhibition curves, by a greater sensitivity to the chemical structure of the tracer and by a decrease of the affinity constant. Reactionnal kinetic and sensitivity to the incubation temperature are not modified. Heterogeneous phase antibodies present a greater stability. Both antibodies types can be used for a digitoxin radioimmunoassay [fr

  1. A STUDY OF SYMBOLIC RELATIONS IN PUBLIC TRANSPORT

    Directory of Open Access Journals (Sweden)

    ANDREI BALAN

    2011-04-01

    Full Text Available This paper presents an anthropological, exploratory study of the microsocial world of public transport. Our research focuses on the symbolic relations that are being established (verbally or nonverbally between urban transport travellers that do not know each other and the consequences these relations create. Modern urban configuration forces large numbers of individuals to share public space every day. When this space becomes restrictive, symbolic relations and interpersonal behaviors such as territoriality and personal space management become clearer. Due to overcrowding, public transport is the scene of one of the most restrictive public spaces in a city. The challenge was to observe and interpret daily, casual behaviors through a sociological and psychological scheme, following the methodological tradition established by Erving Goffman and the other symbolic interactionists. Finally, our study generates a number of hypotheses and explanatory models for common practices and behaviors in trams and metros regarded from a symbolic perspective.

  2. Konrad transport study: Safety analysis of the transportation of radioactive waste to the Konrad waste disposal site

    International Nuclear Information System (INIS)

    Lange, F.; Gruendler, D.; Schwarz, G.

    1992-05-01

    For the purpose of the study the anticipated waste transport volume and the waste properties were analysed in detail. This included information on the transport containers, waste product properties, activity inventories and local dose rates of the waste packages being transported. The envisaged practical implementation, i.e. the transport arrangements including shunting operations at the Braunschweig marshalling yard and the Beddingen interchange station, were also included. The two shipping scenarios 100% transportation by rail and 80% transportation by rail, 20% by road, which could be considered to bound the real conditions, were analysed. The relevant transport regulations contain the requirements to be met by the transport of shipping units carrying radioactive waste. In addition, the ''Konrad preliminary waste acceptance criteria'' contain activity limits for waste packages being disposed of in conjunction with further requirements relating to the properties of waste products and waste containers. (orig./DG)

  3. Modeling of the Transport Phenomena in Passive Direct Methanol Fuel Cells Using a Two-Phase Anisotropic Model

    Directory of Open Access Journals (Sweden)

    Zheng Miao

    2014-04-01

    Full Text Available The transport phenomena in a passive direct methanol fuel cell (DMFC were numerically simulated by the proposed two-dimensional two-phase nonisothermal mass transport model. The anisotropic transport characteristic and deformation of the gas diffusion layer (GDL were considered in this model. The natural convection boundary conditions were adopted for the transport of methanol, oxygen, and heat at the GDL outer surface. The effect of methanol concentration in the reservoir on cell performance was examined. The distribution of multiphysical fields in the membrane electrode assembly (MEA, especially in the catalyst layers (CLs, was obtained and analyzed. The results indicated that transport resistance for the methanol mainly existed in the MEA while that for oxygen and heat was primarily due to natural convection at the GDL outer surface. Because of the relatively high methanol concentration, the local reaction rate in CLs was mainly determined by the overpotential. Methanol concentration between 3 M and 4 M was recommended for passive liquid feed DMFC in order to achieve a balance between the cell performance and the methanol crossover.

  4. Lunar Transportation Facilities and Operations Study, option 1

    Science.gov (United States)

    1991-05-01

    Throughout the Option I period of the Lunar Transportation Facilities and Operations Study (LTFOS), McDonnell Douglas Space Systems Company - Kennedy Space Center (MDSSC-KSC) provided support to both the Planetary Surface Systems (PSS) Office at the National Aeronautics and Space Administration (NASA) at the Johnson Space Center and to the Flight and Ground Systems Projects Office (Payload Projects Management) at the Kennedy Space Center. The primary objective of the Option I phase of the study was to assist the above NASA centers in developing Space Exploration Initiative (SEI) concepts. MDSSC-KSC conducted three analyses which provided launch and landing detail to the proposed exploration concepts. One analysis, the Lunar Ejecta Assessment, was conducted to determine the effects of launch and landing a vehicle in a dusty environment. A second analysis, the Thermal/Micrometeoroid Protection Trade Study, was refined to determine the impacts that Reference Architecture Option 5A would have on thermal/micrometeoroid protection approaches. The third analysis, the Centaur Prelaunch Procedure Analysis, used a Centaur prelaunch test and checkout flow to identify key considerations that would be important if a Lunar Excursion Vehicle (LEV) was to use an expander cycle liquid oxygen-liquid hydrogen engine. Several 'quick look' assessments were also conducted. One quick look assessment, the Storable Propellant Quick Look Assessment, was conducted to identify design considerations that should be made if storable propellants were to be used instead of liquid oxygen and liquid hydrogen. The LEV Servicer Maintenance Analysis provided an early look at the effort required to maintain an LEV Servicer on the lunar surface. Also, support was provided to the PSS Logistics Manager to develop initial LEV Servicer cost inputs. Consideration was given to the advanced development that must be provided to accomplish a lunar and/or Mars mission. MDSS-KSC also provided support to both MASE

  5. Emergence of Quantum Phase-Slip Behaviour in Superconducting NbN Nanowires: DC Electrical Transport and Fabrication Technologies

    Directory of Open Access Journals (Sweden)

    Nicolas G. N. Constantino

    2018-06-01

    Full Text Available Superconducting nanowires undergoing quantum phase-slips have potential for impact in electronic devices, with a high-accuracy quantum current standard among a possible toolbox of novel components. A key element of developing such technologies is to understand the requirements for, and control the production of, superconducting nanowires that undergo coherent quantum phase-slips. We present three fabrication technologies, based on using electron-beam lithography or neon focussed ion-beam lithography, for defining narrow superconducting nanowires, and have used these to create nanowires in niobium nitride with widths in the range of 20–250 nm. We present characterisation of the nanowires using DC electrical transport at temperatures down to 300 mK. We demonstrate that a range of different behaviours may be obtained in different nanowires, including bulk-like superconducting properties with critical-current features, the observation of phase-slip centres and the observation of zero conductance below a critical voltage, characteristic of coherent quantum phase-slips. We observe critical voltages up to 5 mV, an order of magnitude larger than other reports to date. The different prominence of quantum phase-slip effects in the various nanowires may be understood as arising from the differing importance of quantum fluctuations. Control of the nanowire properties will pave the way for routine fabrication of coherent quantum phase-slip nanowire devices for technology applications.

  6. A computational study of the effect of capillary network anastomoses and tortuosity on oxygen transport.

    Science.gov (United States)

    Goldman, D; Popel, A S

    2000-09-21

    The objective of this study was to investigate the effects of capillary network anastomoses and tortuosity on oxygen transport in skeletal muscle, as well as the importance of muscle fibers in determining the arrangement of parallel capillaries. Countercurrent flow and random capillary blockage (e.g. by white blood cells) were also studied. A general computational model was constructed to simulate oxygen transport from a network of blood vessels within a rectangular volume of tissue. A geometric model of the capillary network structure, based on hexagonally packed muscle fibers, was constructed to produce networks of straight unbranched capillaries, capillaries with anastomoses, and capillaries with tortuosity, in order to examine the effects of these geometric properties. Quantities examined included the tissue oxygen tension and the capillary oxyhemoglobin saturation. The computational model included a two-phase simulation of blood flow. Appropriate parameters were chosen for working hamster cheek-pouch retractor muscle. Our calculations showed that the muscle-fiber geometry was important in reducing oxygen transport heterogeneity, as was countercurrent flow. Tortuosity was found to increase tissue oxygenation, especially when combined with anastomoses. In the absence of tortuosity, anastomoses had little effect on oxygen transport under normal conditions, but significantly improved transport when vessel blockages were present. Copyright 2000 Academic Press.

  7. Evaluation of results of Phase B of the German Risk Study for Nuclear Power Plants

    International Nuclear Information System (INIS)

    Fischer, B.; Hahn, L.; Sailer, M.

    1989-01-01

    The expert opinion summarizes and discusses the intermediate and the final results of Phase B of the German Risk Study. Emphasis is placed on systems analyses and event scenarios, core melt-down scenarios and effects on the containment, failure of the containment and resulting source terms, radioactivity transport and consequences of accidents, multi-system emergencies and external disturbances, accident management and means of mitigation of damage. (DG) [de

  8. Feasibility study: Assess the feasibility of siting a monitored retrievable storage facility. Phase 1

    Energy Technology Data Exchange (ETDEWEB)

    King, J.W.

    1993-08-01

    The purpose of phase one of this study are: To understand the waste management system and a monitored retrievable storage facility; and to determine whether the applicant has real interest in pursuing the feasibility assessment process. Contents of this report are: Generating electric power; facts about exposure to radiation; handling storage, and transportation techniques; description of a proposed monitored retrievable storage facility; and benefits to be received by host jurisdiction.

  9. Initial Studies of Core and Edge Transport of NSTX Plasmas

    International Nuclear Information System (INIS)

    Synakowski, E.J.; Bell, M.G.; Bell, R.E.; Bush, C.E.; Bourdelle, C.; Darrow, D.; Dorland, W.; Ejiri, A.; Fredrickson, E.D.; Gates, D.A.; Kaye, S.M.; Kubota, S.; Kugel, H.W.; LeBlanc, B.P.; Maingi, R.; Maqueda, R.J.; Menard, J.E.; Mueller, D.; Rosenberg, A.; Sabbagh, S.A.; Stutman, D.; Taylor, G.; Johnson, D.W.; Kaita, R.; Ono, M.; Paoletti, F.; Peebles, W.; Peng, Y-K.M.; Roquemore, A.L.; Skinner, C.H.; Soukhanovskii, V.A.

    2001-01-01

    Rapidly developing diagnostic, operational, and analysis capability is enabling the first detailed local physics studies to begin in high-beta plasmas of the National Spherical Torus Experiment (NSTX). These studies are motivated in part by energy confinement times in neutral-beam-heated discharges that are favorable with respect to predictions from the ITER-89P scaling expression. Analysis of heat fluxes based on profile measurements with neutral-beam injection (NBI) suggest that the ion thermal transport may be exceptionally low, and that electron thermal transport is the dominant loss channel. This analysis motivates studies of possible sources of ion heating not presently accounted for by classical collisional processes. Gyrokinetic microstability studies indicate that long wavelength turbulence with k(subscript ''theta'') rho(subscript ''i'') ∼ 0.1-1 may be suppressed in these plasmas, while modes with k(subscript ''theta'') rho(subscript ''i'') ∼ 50 may be robust. High-harmonic fast-wave (HHFW) heating efficiently heats electrons on NSTX, and studies have begun using it to assess transport in the electron channel. Regarding edge transport, H-mode [high-confinement mode] transitions occur with either NBI or HHFW heating. The power required for low-confinement mode (L-mode) to H-mode transitions far exceeds that expected from empirical edge-localized-mode-free H-mode scaling laws derived from moderate aspect ratio devices. Finally, initial fluctuation measurements made with two techniques are permitting the first characterizations of edge turbulence

  10. Transport studies of radon in limestone underlying houses

    International Nuclear Information System (INIS)

    Gammage, R.B.; Dudney, C.S.; Wilson, D.L.; Saultz, R.J.

    1990-01-01

    In hilly limestone terrains of the southern Appalachians, subterranean networks of solution cavities and fissures present circulatory systems facilitating convective and advective transport of radon-bearing gas. Evidence suggests that the primary driving forces for transport are aerostatic pressure differentials created by the difference between the underground and the outside air temperatures. Examples are presented of houses experiencing elevated indoor radon levels as a consequence of communicating with such subsurface transportation systems. The location of a house near the upper or lower end of a subterranean-circulatory system seems to produce amplification of indoor radon levels in winter or summer, respectively. The transport mechanism for radon-bearing air in karst and its impact on indoor radon need better understanding, both in regard to evaluating the geographical prevalence of the phenomenon and the induced spatial and temporal effects that are possible. This paper reports field studies made at houses in karst regions at Oak Ridge, Tennessee, and Huntsville, Alabama. A primary radon-transport mechanism is advocated of ascending or descending subsurface columns of air whose flows are largely driven by aerostatic pressure gradients created by the inground-outdoor air temperature differentials. 5 refs., 5 figs., 1 tab

  11. Runaway electron transport studies in the HL-1M tokamak

    International Nuclear Information System (INIS)

    Zheng Yongzhen; Qi Changwei; Ding Xuantong; Li Wenzhong

    2002-01-01

    The transport of runaway electrons in a hot plasma has been studied in four experiments, which provide the runaway diffusivity D r The first experiment obtained runaway electrons using a steady state approach for values of the runaway confinement time τ r , deduced from hard X-ray bremsstrahlung spectra. In the second experiment, diffusion has been interpreted in terms of the magnetic fluctuation, from which a electron thermal diffusivity can be deduced. Runaway electro diffusion coefficient is determined by intrinsic magnetic fluctuations, rather than electrostatic fluctuations because of the high energy involved. The results presented here demonstrate the efficiency of using runaway transport techniques for determining intrinsic magnetic fluctuations

  12. Study of transport in unsaturated sands using radioactive tracers

    International Nuclear Information System (INIS)

    Merritt, W.F.; Pickens, J.F.; Allison, G.B.

    1979-01-01

    A laboratory experiment was conducted to investigate the mixing that occurs as a series of labelled pulses of water are transported by gravity drainage down through a sand filled column having a water table imposed at the bottom. It also demonstrated the utility of gamma-ray emitting radioactive tracers in studying transport in unsaturated or saturated porous media. The motivation for pursuing this topic was developed from observing that the content of oxygen-18, deuterium and tritium in rainwater shows marked temporal variations whereas their concentrations below the water table in shallow ground water flow systems are generally found to show much less variation. (auth)

  13. COMMERCIAL SUPERSONIC TRANSPORT PROGRAM. PHASE II-C REPORT. HIGH STRENGTH STEEL EVALUATION FOR SUPERSONIC AIRCRAFT.

    Science.gov (United States)

    JET TRANSPORT AIRCRAFT, *AIRFRAMES, SUPERSONIC AIRCRAFT, STEEL , STRUCTURAL PROPERTIES, FRACTURE(MECHANICS), FATIGUE(MECHANICS), STRESS CORROSION...MICROPHOTOGRAPHY, HIGH TEMPERATURE, NICKEL ALLOYS, COBALT ALLOYS, CARBON, BAINITE , COMMERCIAL AIRCRAFT.

  14. Turbulent Scalar Transport Model Validation for High Speed Propulsive Flows, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — This effort entails the validation of a RANS turbulent scalar transport model (SFM) for high speed propulsive flows, using new experimental data sets and...

  15. Developing an interdisciplinary certificate program in transportation planning, phase 2 : the eCertificate.

    Science.gov (United States)

    2011-11-01

    This proposal extends the delivery of the recently developed graduate Certificate in Transportation : Planning to a wider audience through the establishment of an Executive Certificate Program by distance : (eCertificate). While the need for an inter...

  16. Graphical User Interface for High Energy Multi-Particle Transport, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Computer codes such as MCNPX now have the capability to transport most high energy particle types (34 particle types now supported in MCNPX) with energies extending...

  17. Graphical User Interface for High Energy Multi-Particle Transport, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Computer codes such as MCNPX now have the capability to transport most high energy particle types (34 particle types now supported in MCNPX) with energies extending...

  18. Feasibility study for a transportation operations system cask maintenance facility

    Energy Technology Data Exchange (ETDEWEB)

    Rennich, M.J.; Medley, L.G.; Attaway, C.R.

    1991-01-01

    The US Department of Energy (DOE), Office of Civilian Radioactive Waste Management (OCRWM) is responsible for the development of a waste management program for the disposition of spent nuclear fuel (SNF) and high-level waste (HLW). The program will include a transportation system for moving the nuclear waste from the sources to a geologic repository for permanent disposal. Specially designed casks will be used to safely transport the waste. The cask systems must be operated within limits imposed by DOE, the Nuclear Regulatory Commission (NRC), and the Department of Transportation (DOT). A dedicated facility for inspecting, testing, and maintaining the cask systems was recommended by the General Accounting Office (in 1979) as the best means of assuring their operational effectiveness and safety, as well as regulatory compliance. In November of 1987, OCRWM requested a feasibility study be made of a Cask Maintenance Facility (CMF) that would perform the required functions. 46 refs., 16 figs., 13 tabs.

  19. Preliminary Study of RFID System for the LILW Transportation

    International Nuclear Information System (INIS)

    Kim, Dohyung; Lee, Unjang; Choi, Kyusup

    2008-01-01

    Radio-Frequency Identification (RFID) is an automatic identification method, relying on storing and remotely retrieving data using devices called RFID tags or transponders. In Korea, Low-to-Intermediate Level Radioactive Wastes (LILW) are planed to be disposed at Kyeonju disposal repository, and 100,000 LILW drums will be disposed for the first 10 years of disposal. Tracking of these LILW drums is one of the important parts for safe transportation. To track the LILW drums during the transport as well as storage and disposal, RFID can be the prospective method for tracking the LILW drums. In this report, RFID system is introduced to the LILW transport from the generation site to disposal site, and one possible RFID system is suggested as a preliminary study

  20. Studies of cesium permeability of potassium transporter from Arabidopsis

    International Nuclear Information System (INIS)

    Kobayashi, Daisuke; Yamagami, Mutsumi; Hisamatsu, Shun'ichi; Inaba, Jiro; Uozumi, Nobuyuki; Hazama, Akihiro

    2007-01-01

    Cs-137 is an important radionuclide for safety assessment of nuclear facilities, and its transfer via plants is an important route from the environment to humans. Studies of Cs uptake mechanisms by plants are essential for understanding 137 Cs movement in soil-to-plant systems and in plants. Since uptake of Cs is considered to be mediated by K transport protein, we investigated Cs + permeability of two Arabidopsis K + transporters, AKT2 and AtHKT1, by using Xenopus oocytes expression systems and two-electrode voltage-clamp technique under various pH conditions. The data showed AKT2 and AtHKT1 did not transport Cs + at external pH in the 5.5-7.5 range. These results indicated that AKT2 and AtHKT1 did not contribute to Cs + influx into cells under physiological conditions in plants. (author)

  1. Feasibility study for a transportation operations system cask maintenance facility

    International Nuclear Information System (INIS)

    Rennich, M.J.; Medley, L.G.; Attaway, C.R.

    1991-01-01

    The US Department of Energy (DOE), Office of Civilian Radioactive Waste Management (OCRWM) is responsible for the development of a waste management program for the disposition of spent nuclear fuel (SNF) and high-level waste (HLW). The program will include a transportation system for moving the nuclear waste from the sources to a geologic repository for permanent disposal. Specially designed casks will be used to safely transport the waste. The cask systems must be operated within limits imposed by DOE, the Nuclear Regulatory Commission (NRC), and the Department of Transportation (DOT). A dedicated facility for inspecting, testing, and maintaining the cask systems was recommended by the General Accounting Office (in 1979) as the best means of assuring their operational effectiveness and safety, as well as regulatory compliance. In November of 1987, OCRWM requested a feasibility study be made of a Cask Maintenance Facility (CMF) that would perform the required functions. 46 refs., 16 figs., 13 tabs

  2. Experimental study of the longitudinal instability for beam transport

    International Nuclear Information System (INIS)

    Reiser, M.; Wang, J.G.; Guo, W.M.; Wang, D.X.

    1990-01-01

    Theoretical model for beam longitudinal instability in a transport pipe with general wall impedance is considered. The result shows that a capacitive wall tends to stabilize the beam. The experimental study of the instability for a pure resistive-wall is presented, including the design parameters, setup and components for the experiment. 6 refs., 3 figs

  3. Robust optimisation of forest transportation networks: a case study ...

    African Journals Online (AJOL)

    Forest transportation costs are the major cost component for many forest product supply chains. In order to minimise these costs, many organisations have turned ... The simulation results are then evaluated for robustness by means of seven robustness performance measures. For our case study, the results show that (1) the ...

  4. ULTRATHIN SILICON MEMBRANES TO STUDY SUPERCURRENT TRANSPORT IN CRYSTALLINE SEMICONDUCTORS

    NARCIS (Netherlands)

    VANHUFFELEN, WM; DEBOER, MJ; KLAPWIJK, TM

    1991-01-01

    We have developed a two-step anisotropic etching process to fabricate thin silicon membranes, used to study supercurrent transport in semiconductor coupled weak links. The process uses a shallow BF2+ implantation, and permits easy control of membrane thickness less-than-or-equal-to 100 nm.

  5. Investigation of diffusional transport of heat and its enhancement in phase-change thermal energy storage systems

    International Nuclear Information System (INIS)

    Saraswat, Amit; Bhattacharjee, Rajdeep; Verma, Ankit; Das, Malay K.; Khandekar, Sameer

    2017-01-01

    Thermal energy storage in general, and phase-change materials (PCMs) in particular, have been a major topic of research for the last thirty years. Due to their favorable thermo-dynamical characteristics, such as high density, specific heat and latent heat of fusion, PCMs are usually employed as working fluids for thermal storage. However, low thermal conductivities of organic PCMs have posed a continuous challenge in its large scale deployment. This study focuses on experimental and numerical investigation of the melting process of industrial grade paraffin wax inside a semi-cylindrical enclosure with a heating strip attached axially along the center of semi-cylinder. During the first part of the study, the solid-liquid interface location, the liquid flow patterns in the melt pool, and the spatial and temporal variation of PCM temperature were recorded. For numerical simulation of the system, open source library OpenFOAM® was used in order to solve the coupled Navier-Stokes and energy equations in the considered system. It is seen that the enthalpy-porosity technique implemented on OpenFOAM® is reasonably well suited for handling melting/solidification problems and can be employed for system level design. Next, to overcome the inherent thermal limitations of PCM storage material, the study further explored the potential of coupling the existing heat source with copper-water heat pipes, so as to help augment the rate of heat dissipation within the medium by increasing the effective system-level thermal conductivity. Integration of heat pipes led to enhanced transport, and hence, a substantial decrease in the total required melting time. The study provides a framework for designing of large systems with integration of heat pipes with PCM based thermal storage systems.

  6. Transport of Gas-Phase Anthropogenic VOCs to the Remote Troposphere During the NASA ATom Mission

    Science.gov (United States)

    Hornbrook, R. S.; Apel, E. C.; Hills, A. J.; Asher, E. C. C.; Emmons, L. K.; Blake, D. R.; Blake, N. J.; Simpson, I. J.; Barletta, B.; Meinardi, S.; Montzka, S. A.; Moore, F. L.; Miller, B. R.; Sweeney, C.; McKain, K.; Wofsy, S. C.; Daube, B. C.; Commane, R.; Bui, T. V.; Hanisco, T. F.; Wolfe, G. M.; St Clair, J. M.; Ryerson, T. B.; Thompson, C. R.; Peischl, J.; Ray, E. A.

    2017-12-01

    The NASA Atmospheric Tomography (ATom) project aims to study the impact of human-produced air pollution on greenhouse gases and on chemically reactive gases in the atmosphere. During the first two deployments, ATom-1 and ATom-2, which took place August 2016 and February 2017, respectively, a suite of trace gas measurement instruments were deployed on the NASA DC-8 which profiled the atmosphere between 0.2 and 13 km from near-pole to near-pole around the globe, sampling in the most remote regions of the atmosphere over the Arctic, Pacific, Southern, and Atlantic Oceans. Volatile organic compounds (VOCs) with a range of lifetimes from days to decades quantified using the Trace Organic Gas Analyzer (TOGA), Whole Air Sampler (WAS) and Programmable Flask Packages (PFPs) demonstrate a significant impact on the remote atmosphere from urban and industrial sources. Comparisons between the transport and fate of pollutants during Northern Hemisphere summer and winter will be presented. Observations of the distributions of anthropogenic VOCs will be compared with simulations using the Community Atmosphere Model with chemistry (CAM-chem).

  7. In vitro placental model optimization for nanoparticle transport studies

    Directory of Open Access Journals (Sweden)

    Cartwright L

    2012-01-01

    Full Text Available Laura Cartwright1, Marie Sønnegaard Poulsen2, Hanne Mørck Nielsen3, Giulio Pojana4, Lisbeth E Knudsen2, Margaret Saunders1, Erik Rytting2,51Bristol Initiative for Research of Child Health (BIRCH, Biophysics Research Unit, St Michael's Hospital, UH Bristol NHS Foundation Trust, Bristol, UK; 2University of Copenhagen, Faculty of Health Sciences, Department of Public Health, 3University of Copenhagen, Faculty of Pharmaceutical Sciences, Department of Pharmaceutics and Analytical Chemistry, Copenhagen, Denmark; 4Department of Environmental Sciences, Informatics and Statistics, University Ca' Foscari Venice, Venice, Italy; 5Department of Obstetrics and Gynecology, University of Texas Medical Branch, Galveston, Texas, USABackground: Advances in biomedical nanotechnology raise hopes in patient populations but may also raise questions regarding biodistribution and biocompatibility, especially during pregnancy. Special consideration must be given to the placenta as a biological barrier because a pregnant woman's exposure to nanoparticles could have significant effects on the fetus developing in the womb. Therefore, the purpose of this study is to optimize an in vitro model for characterizing the transport of nanoparticles across human placental trophoblast cells.Methods: The growth of BeWo (clone b30 human placental choriocarcinoma cells for nanoparticle transport studies was characterized in terms of optimized Transwell® insert type and pore size, the investigation of barrier properties by transmission electron microscopy, tight junction staining, transepithelial electrical resistance, and fluorescein sodium transport. Following the determination of nontoxic concentrations of fluorescent polystyrene nanoparticles, the cellular uptake and transport of 50 nm and 100 nm diameter particles was measured using the in vitro BeWo cell model.Results: Particle size measurements, fluorescence readings, and confocal microscopy indicated both cellular uptake of

  8. Effect of isochronal annealing on phase transformation studies of ...

    Indian Academy of Sciences (India)

    The mixed phase sample shows higher value of magnetization because of the presence of ferromagnetic γ-Fe2O3 ... 1. Introduction. The study of particle size, phase transformation and micros- ..... The results are in qualitative agreement with ...

  9. Study of Strange Quark Mass in CFL Phase

    Institute of Scientific and Technical Information of China (English)

    LI Xin; L(U) Xiao-Fu

    2006-01-01

    In this paper we introduce bilocal fields in the global color symmetry model and consider color and electrical neutrality conditions simultaneously to study the effect of strange quark mass Ms for the momentum-dependent condensate of color-flavor locked phase. Consequently we find that there will be a quantum phase transition occurring.

  10. Small modular biopower initiative Phase 1 feasibility studies executive summaries

    Energy Technology Data Exchange (ETDEWEB)

    Bain, R.

    2000-03-06

    The Phase 1 objective is a feasibility study that includes a market assessment, resource assessment, preliminary system design, and assessment of relevant environmental and safety considerations, and evaluation of financial and cost issues, and a preliminary business plan and commercialization strategy. Each participating company will share at least 20% of the cost of the first phase.

  11. Study of heat transfer and particle transport in Tore Supra and HL-2A tokamaks

    International Nuclear Information System (INIS)

    Song, S.

    2011-12-01

    This thesis reports on experimental studies of heat and particles transport performed on 2 large tokamaks: Tore Supra (based at CEA/Cadarache, France) and HL-2A (based at the Southwestern Institute of Physics, Chengdu, China). The modulated source is the Electron Cyclotron Resonance Heating (ECRH) for the heat pinch and density pump-out studies, while the non-local transport experiments use the Supersonic Molecular Beam Injection (SMBI) as source of modulation. The emphasis is put on the inward heat pinch. In the off-axis ECRH modulation experiments on Tore Supra with low frequency (1 Hz), strong heat inward transport has been observed, in particular for low density. Two transport models have been applied in order to analyze the experimental behavior. The first one is the linear pinch model (LPM) and the second one is an empirical model based on micro-instabilities theory, named Critical Gradient Model (CGM). Good agreement has been found for all harmonics between the experimental data and the simulation using LPM. On the other hand, good agreement has not been achieved using CGM. The density pump-out with large particles and energy losses during ECRH is commonly observed in tokamaks. A new dynamic approach using the modulation technique has been used in HL-2A for analyzing the transient phase of the density pump-out. A correlation between the turbulence increase and the density pump-out has been found. The non-local transport phenomenon, characterized by a fast transient process compared to the normal diffusive response to the perturbation is observed. Both phenomena, i.e., pump-out and non-locality, show as simultaneous variation of density and temperature. This can be an inspiration for the usage of a transport matrix which considers the density and temperature evolution together. Simulations with a simple transport matrix, with non-diagonal terms coupling temperature and density qualitatively reproduce the non-local and pump-out effects qualitatively

  12. Numerical Study of the Influence of Cavity on Immiscible Liquid Transport in Varied-Wettability Fractures

    Directory of Open Access Journals (Sweden)

    Zhi Dou

    2015-01-01

    Full Text Available Field evidence indicates that cavities often occur in fractured rocks, especially in a Karst region. Once the immiscible liquid flows into the cavity, the cavity has the immiscible liquid entrapped and results in a low recovery ratio. In this paper, the immiscible liquid transport in cavity-fractures was simulated by Lattice Boltzmann Method (LBM. The interfacial and surface tensions were incorporated by Multicomponent Shan-Chen (MCSC model. Three various fracture positions were generated to investigate the influence on the irreducible nonwetting phase saturation and displacement time. The influences of fracture aperture and wettability on the immiscible liquid transport were discussed and analyzed. It was found that the cavity resulted in a long displacement time. Increasing the fracture aperture with the corresponding decrease in displacement pressure led to the long displacement time. This consequently decreased the irreducible nonwetting phase saturation. The fracture positions had a significant effect on the displacement time and irreducible saturation. The distribution of the irreducible nonwetting phase was strongly dependent on wettability and fracture position. Furthermore, this study demonstrated that the LBM was very effective in simulating the immiscible two-phase flow in the cavity-fracture.

  13. Study of the low pressure (Black Phase) SmS properties

    International Nuclear Information System (INIS)

    Bordier, G.

    1987-03-01

    SmS has been studied for its transition from the low pressure black phase to the high pressure intermediate valence phase; but the black phase properties seem to be very rich. The variations which pressure of the low-temperature electronic transport properties show the existence of a semi-metallic phase within the black phase domain in a pressure-temperature diagram, for a pressure above 4 kbar, which corresponds to the so-called B'phase. We study the insulating low pressure phase with a model involving acceptor like states. Using electronic paramagnetic resonance experiments we observe a square symmetry trivalent samarium ion neighbour of a sulfure defect, and magnetically coupled with the lattice. This defect exists in two nearly symmetric configurations and the resonance line broadens with temperature in an actived way. It gives rise to metastable effects yielding conductivity relaxations, analysed with stretched exponential laws, because the defect traps magnetically conduction electrons forming a bound magnetic polaron. The relaxation time at zero field is temperature actived. We develop a phenomenological model that gives the good orders of magnitude for the trapping barrier and for the critical field corresponding to the maximum of the low temperature magnetoresistance [fr

  14. Histological studies on the telencephalon of Hynobius leechii at the metamorphosis phase and the adult phase.

    Science.gov (United States)

    Zhou, Ying-Ying; Shao, Ran; Liang, Chuan-Cheng; Wang, Yong; Wang, Li-Wen

    2009-08-01

    To investigate the telencephalon developmental characteristics of Hynobius leehii, and enrich the research data of comparable neurobiology and nervous system development of amphibian. HE staining and Nissl staining methods were used to study the telencephalon histological structure of Hynobius leechii at both the metamorphosis and the adult phases, and to explore the developmental phases of telencephalon. The olfactory bulb could be roughly divided into 6 layers from lateral to medial. The lateral cerebral ventricles at the metamorphosis phase were smaller than those at the adult phase, and there were no clear borderlines between the primordial pallium and the primordial hippocampus, or between the primordial pallium and the primordial piriform area. Moreover, the cells in the primordial piriform area were more closely distributed than those in the primordial hippocampus or the primordial pallium. Compared with those at the adult phase, cells in nucleuses at the metamorphosis phase were larger in number and more closely distributed. The telencephalon of Hynobius leehii at the metamorphosis phase has generally formed the adult structure. However, it is still at a transition state of differentiation to maturity during the development of Hynobius leehii.

  15. Characterization of Single Phase and Two Phase Heat and Momentum Transport in a Spiraling Radial Inow Microchannel Heat Sink

    Science.gov (United States)

    Ruiz, Maritza

    Thermal management of systems under high heat fluxes on the order of hundreds of W/cm2 is important for the safety, performance and lifetime of devices, with innovative cooling technologies leading to improved performance of electronics or concentrating solar photovoltaics. A novel, spiraling radial inflow microchannel heat sink for high flux cooling applications, using a single phase or vaporizing coolant, has demonstrated enhanced heat transfer capabilities. The design of the heat sink provides an inward swirl flow between parallel, coaxial disks that form a microchannel of 1 cm radius and 300 micron channel height with a single inlet and a single outlet. The channel is heated on one side through a conducting copper surface, and is essentially adiabatic on the opposite side to simulate a heat sink scenario for electronics or concentrated photovoltaics cooling. Experimental results on the heat transfer and pressure drop characteristics in the heat sink, using single phase water as a working fluid, revealed heat transfer enhancements due to flow acceleration and induced secondary flows when compared to unidirectional laminar fully developed flow between parallel plates. Additionally, thermal gradients on the surface are small relative to the bulk fluid temperature gain, a beneficial feature for high heat flux cooling applications. Heat flux levels of 113 W/cm2 at a surface temperature of 77 deg C were reached with a ratio of pumping power to heat rate of 0.03%. Analytical models on single phase flow are used to explore the parametric trends of the flow rate and passage geometry on the streamlines and pressure drop through the device. Flow boiling heat transfer and pressure drop characteristics were obtained for this heat sink using water at near atmospheric pressure as the working fluid for inlet subcooling levels ranging from 20 to 80 deg C and mean mass flux levels ranging from 184-716 kg/m. 2s. Flow enhancements similar to singlephase flow were expected, as well

  16. Three-dimensional multi-phase flow computational fluid dynamics model for analysis of transport phenomena and thermal stresses in PEM fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Maher, A.R.; Al-Baghdadi, S. [International Technological Univ., London (United Kingdom). Dept. of Mechanical Engineering; Haroun, A.K.; Al-Janabi, S. [Babylon Univ., Babylon (Iraq). Dept. of Mechanical Engineering

    2007-07-01

    Fuel cell technology is expected to play an important role in meeting the growing demand for distributed generation because it can convert the chemical energy of a clean fuel directly into electrical energy. An operating fuel cell has varying local conditions of temperature, humidity, and power generation across the active area of the fuel cell in 3D. This paper presented a model that was developed to improve the basic understanding of the transport phenomena and thermal stresses in PEM fuel cells, and to investigate the behaviour of polymer membrane under hygro and thermal stresses during the cell operation. This comprehensive 3D, multiphase, non-isothermal model accounts for the major transport phenomena in a PEM fuel cell, notably convective and diffusive heat and mass transfer; electrode kinetics; transport and phase change mechanism of water; and potential fields. The model accounts for the liquid water flux inside the gas diffusion layers by viscous and capillary forces and can therefore predict the amount of liquid water inside the gas diffusion layers. This study also investigated the key parameters affecting fuel cell performance including geometry, materials and operating conditions. The model considers the many interacting, complex electrochemical, transport phenomena, thermal stresses and deformation that cannot be studied experimentally. It was concluded that the model can provide a computer-aided tool for the design and optimization of future fuel cells with much higher power density and lower cost. 21 refs., 2 tabs., 14 figs.

  17. Microscopic studies of nonlocal spin dynamics and spin transport (invited)

    Energy Technology Data Exchange (ETDEWEB)

    Adur, Rohan; Du, Chunhui; Cardellino, Jeremy; Scozzaro, Nicolas; Wolfe, Christopher S.; Wang, Hailong; Herman, Michael; Bhallamudi, Vidya P.; Pelekhov, Denis V.; Yang, Fengyuan; Hammel, P. Chris, E-mail: hammel@physics.osu.edu [Department of Physics, The Ohio State University, Columbus, Ohio 43210 (United States)

    2015-05-07

    Understanding the behavior of spins coupling across interfaces in the study of spin current generation and transport is a fundamental challenge that is important for spintronics applications. The transfer of spin angular momentum from a ferromagnet into an adjacent normal material as a consequence of the precession of the magnetization of the ferromagnet is a process known as spin pumping. We find that, in certain circumstances, the insertion of an intervening normal metal can enhance spin pumping between an excited ferromagnetic magnetization and a normal metal layer as a consequence of improved spin conductance matching. We have studied this using inverse spin Hall effect and enhanced damping measurements. Scanned probe magnetic resonance techniques are a complementary tool in this context offering high resolution magnetic resonance imaging, localized spin excitation, and direct measurement of spin lifetimes or damping. Localized magnetic resonance studies of size-dependent spin dynamics in the absence of lithographic confinement in both ferromagnets and paramagnets reveal the close relationship between spin transport and spin lifetime at microscopic length scales. Finally, detection of ferromagnetic resonance of a ferromagnetic film using the photoluminescence of nitrogen vacancy spins in neighboring nanodiamonds demonstrates long-range spin transport between insulating materials, indicating the complexity and generality of spin transport in diverse, spatially separated, material systems.

  18. Microscopic studies of nonlocal spin dynamics and spin transport (invited)

    Science.gov (United States)

    Adur, Rohan; Du, Chunhui; Cardellino, Jeremy; Scozzaro, Nicolas; Wolfe, Christopher S.; Wang, Hailong; Herman, Michael; Bhallamudi, Vidya P.; Pelekhov, Denis V.; Yang, Fengyuan; Hammel, P. Chris

    2015-05-01

    Understanding the behavior of spins coupling across interfaces in the study of spin current generation and transport is a fundamental challenge that is important for spintronics applications. The transfer of spin angular momentum from a ferromagnet into an adjacent normal material as a consequence of the precession of the magnetization of the ferromagnet is a process known as spin pumping. We find that, in certain circumstances, the insertion of an intervening normal metal can enhance spin pumping between an excited ferromagnetic magnetization and a normal metal layer as a consequence of improved spin conductance matching. We have studied this using inverse spin Hall effect and enhanced damping measurements. Scanned probe magnetic resonance techniques are a complementary tool in this context offering high resolution magnetic resonance imaging, localized spin excitation, and direct measurement of spin lifetimes or damping. Localized magnetic resonance studies of size-dependent spin dynamics in the absence of lithographic confinement in both ferromagnets and paramagnets reveal the close relationship between spin transport and spin lifetime at microscopic length scales. Finally, detection of ferromagnetic resonance of a ferromagnetic film using the photoluminescence of nitrogen vacancy spins in neighboring nanodiamonds demonstrates long-range spin transport between insulating materials, indicating the complexity and generality of spin transport in diverse, spatially separated, material systems.

  19. Microscopic studies of nonlocal spin dynamics and spin transport (invited)

    International Nuclear Information System (INIS)

    Adur, Rohan; Du, Chunhui; Cardellino, Jeremy; Scozzaro, Nicolas; Wolfe, Christopher S.; Wang, Hailong; Herman, Michael; Bhallamudi, Vidya P.; Pelekhov, Denis V.; Yang, Fengyuan; Hammel, P. Chris

    2015-01-01

    Understanding the behavior of spins coupling across interfaces in the study of spin current generation and transport is a fundamental challenge that is important for spintronics applications. The transfer of spin angular momentum from a ferromagnet into an adjacent normal material as a consequence of the precession of the magnetization of the ferromagnet is a process known as spin pumping. We find that, in certain circumstances, the insertion of an intervening normal metal can enhance spin pumping between an excited ferromagnetic magnetization and a normal metal layer as a consequence of improved spin conductance matching. We have studied this using inverse spin Hall effect and enhanced damping measurements. Scanned probe magnetic resonance techniques are a complementary tool in this context offering high resolution magnetic resonance imaging, localized spin excitation, and direct measurement of spin lifetimes or damping. Localized magnetic resonance studies of size-dependent spin dynamics in the absence of lithographic confinement in both ferromagnets and paramagnets reveal the close relationship between spin transport and spin lifetime at microscopic length scales. Finally, detection of ferromagnetic resonance of a ferromagnetic film using the photoluminescence of nitrogen vacancy spins in neighboring nanodiamonds demonstrates long-range spin transport between insulating materials, indicating the complexity and generality of spin transport in diverse, spatially separated, material systems

  20. Oak Ridge Health Studies phase 1 report, Volume 1: Oak Ridge Phase 1 overview

    Energy Technology Data Exchange (ETDEWEB)

    Yarbrough, M.I.; Van Cleave, M.L.; Turri, P.; Daniel, J.

    1993-09-01

    In July 1991, the State of Tennessee initiated the Health Studies Agreement with the United States Department of Energy to carry out independent studies of possible adverse health effects in people living in the vicinity of the Oak Ridge Reservation. The health studies focus on those effects that could have resulted or could result from exposures to chemicals and radioactivity released at the Reservation since 1942. The major focus of the first phase was to complete a Dose Reconstruction Feasibility Study. This study was designed to find out if enough data exist about chemical and radionuclide releases from the Oak Ridge Reservation to conduct a second phase. The second phase will lead to estimates of the actual amounts or the ``doses`` of various contaminants received by people as a result of off-site releases. Once the doses of various contaminants have been estimated, scientists and physicians will be better able to evaluate whether adverse health effects could have resulted from the releases.

  1. Oak Ridge Health Studies phase 1 report, Volume 1: Oak Ridge Phase 1 overview

    International Nuclear Information System (INIS)

    Yarbrough, M.I.; Van Cleave, M.L.; Turri, P.; Daniel, J.

    1993-09-01

    In July 1991, the State of Tennessee initiated the Health Studies Agreement with the United States Department of Energy to carry out independent studies of possible adverse health effects in people living in the vicinity of the Oak Ridge Reservation. The health studies focus on those effects that could have resulted or could result from exposures to chemicals and radioactivity released at the Reservation since 1942. The major focus of the first phase was to complete a Dose Reconstruction Feasibility Study. This study was designed to find out if enough data exist about chemical and radionuclide releases from the Oak Ridge Reservation to conduct a second phase. The second phase will lead to estimates of the actual amounts or the ''doses'' of various contaminants received by people as a result of off-site releases. Once the doses of various contaminants have been estimated, scientists and physicians will be better able to evaluate whether adverse health effects could have resulted from the releases

  2. Crime Self-Reporting Study: Phase 1

    National Research Council Canada - National Science Library

    Buck, Kelly

    2004-01-01

    The PERSEREC Crime Self-Reporting Study covers criminal record checks conducted in CY00 on 14,470 subjects of DoD security clearance investigations, including uniformed military, civilian, and contractor personnel...

  3. Modelling the effect of acoustic waves on the thermodynamics and kinetics of phase transformation in a solution: Including mass transportation.

    Science.gov (United States)

    Haqshenas, S R; Ford, I J; Saffari, N

    2018-01-14

    Effects of acoustic waves on a phase transformation in a metastable phase were investigated in our previous work [S. R. Haqshenas, I. J. Ford, and N. Saffari, "Modelling the effect of acoustic waves on nucleation," J. Chem. Phys. 145, 024315 (2016)]. We developed a non-equimolar dividing surface cluster model and employed it to determine the thermodynamics and kinetics of crystallisation induced by an acoustic field in a mass-conserved system. In the present work, we developed a master equation based on a hybrid Szilard-Fokker-Planck model, which accounts for mass transportation due to acoustic waves. This model can determine the kinetics of nucleation and the early stage of growth of clusters including the Ostwald ripening phenomenon. It was solved numerically to calculate the kinetics of an isothermal sonocrystallisation process in a system with mass transportation. The simulation results show that the effect of mass transportation for different excitations depends on the waveform as well as the imposed boundary conditions and tends to be noticeable in the case of shock waves. The derivations are generic and can be used with any acoustic source and waveform.

  4. German risk study on nuclear power stations. Phase B

    International Nuclear Information System (INIS)

    1989-11-01

    The German Risk Study on Nuclear Power Stations is concerned with investigations of accidents in nuclear facilities and their associated risks. These investigations are undertaken on behalf of the federal Minister of Research and Technology. They have been broken down into two phases (Phase A and Phase B). The results of Phase A were published in 1979 (GRS 79). This report contains a summary of the investigations relating to Phase B. After an introduction setting out the basic principles and aim of the study, a general review will be given of the most important results. The course of the investigations and the results have already been published in a Technical Report (GRS 89). (author)

  5. Current transport properties and phase diagram of a Kitaev chain with long-range pairing

    Science.gov (United States)

    Giuliano, Domenico; Paganelli, Simone; Lepori, Luca

    2018-04-01

    We describe a method to probe the quantum phase transition between the short-range topological phase and the long-range topological phase in the superconducting Kitaev chain with long-range pairing, both exhibiting subgap modes localized at the edges. The method relies on the effects of the finite mass of the subgap edge modes in the long-range regime (which survives in the thermodynamic limit) on the single-particle scattering coefficients through the chain connected to two normal leads. Specifically, we show that, when the leads are biased at a voltage V with respect to the superconducting chain, the Fano factor is either zero (in the short-range correlated phase) or 2 e (in the long-range correlated phase). As a result, we find that the Fano factor works as a directly measurable quantity to probe the quantum phase transition between the two phases. In addition, we note a remarkable "critical fractionalization effect" in the Fano factor, which is exactly equal to e along the quantum critical line. Finally, we note that a dual implementation of our proposed device makes it suitable as a generator of large-distance entangled two-particle states.

  6. OSPW contamination transport through peat soils : laboratory and greenhouse study

    Energy Technology Data Exchange (ETDEWEB)

    Rezanezhad, F.; Price, J.S. [Waterloo Univ., ON (Canada). Dept. of Geography; Rochefort, L.; Pouliot, R. [Laval Univ., Quebec City, PQ (Canada). Dept. of Phytology; Andersen, R. [Laval Univ., Quebec City, PQ (Canada). Dept. of Phytology; Macaulay Land Use Research Inst., Aberdeen (United Kingdom); Daly, C. [Suncor Energy, Fort McMurray, AB (Canada)

    2010-07-01

    Large portions of northern Canada are covered by peatlands, and the majority of post-mined landscapes have increased salinity, heavy metals and naphthenic acids (NA). This PowerPoint presentation discussed laboratory and greenhouse studies conducted to determine oil sands process water (OSPW) contamination transport through peat soils. Peat is a highly complex porous media. The presence of sodium and NA has a toxic effect on aquatic life. Greenhouse studies were conducted to determine the changes caused by OSPW in the microbial community of a peat matrix over 2 growing seasons. The study showed that peat has an exceptional ability to absorb the contaminants in OSPW water. NA and sodium transport through peat was significantly delayed by sorption, and by diffusion into immobile water contained in the peat matrix. The vegetation in the study was healthy and tolerant to the contaminants in the OSPW. tabs., figs.

  7. NMR studies of transmembrane electron transport in human erythrocytes

    International Nuclear Information System (INIS)

    Kennett, E.C.; Bubb, W.A.; Kuchel, P.W.

    2002-01-01

    Full text: Electron transport systems exist in the plasma membranes of all cells. These systems appear to play a role in cell growth and proliferation, intracellular signalling, hormone responses, apoptotic events, cell defence and perhaps most importantly they enable the cell to respond to changes in the redox state of both the intra- and extracellular environments. Previously, 13 C NMR has been used to study transmembrane electron transport in human erythrocytes, specifically the reduction of extracellular 13 C-ferricyanide. NMR is a particularly useful tool for studying such systems as changes in the metabolic state of the cell can be observed concomitantly with extracellular reductase activity. We investigated the oxidation of extracellular NADH by human erythrocytes using 1 H and 31 P NMR spectroscopy. Recent results for glucose-starved human erythrocytes indicate that, under these conditions, extracellular NADH can be oxidised at the plasma membrane with the electron transfer across the membrane resulting in reduction of intracellular NAD + . The activity is inhibited by known trans-plasma membrane electron transport inhibitors (capsaicin and atebrin) and is unaffected by inhibition of the erythrocyte Band 3 anion transporter. These results suggest that electron import from extracellular NADH allows the cell to re-establish a reducing environment after the normal redox balance is disturbed

  8. Modeling Phase Equilibria for Acid Gas Mixtures using the Cubic-Plus-Association Equation of State. 3. Applications Relevant to Liquid or Supercritical CO2 Transport

    DEFF Research Database (Denmark)

    Tsivintzelis, Ioannis; Ali, Shahid; Kontogeorgis, Georgios

    2014-01-01

    density data for both CO2 and CO2–water and for vapor–liquid equilibrium for mixtures of CO2 with various compounds present in transport systems. In all of these cases we consider various possibilities for modeling CO2 (inert, self-associating using two-, three-, and four sites) and the possibility......The CPA (cubic-plus-association) equation of state is applied in this work to a wide range of systems of relevance to CO2 transport. Both phase equilibria and densities over extensive temperature and pressure ranges are considered. More specifically in this study we first evaluate CPA against......” for applying CPA to acid gas mixtures. The overall conclusion is that CPA performs satisfactorily; the model in most cases correlates well binary data and predicts with good accuracy multicomponent vapor–liquid equilibria. Among the various approaches investigated, the best ones are when cross association...

  9. Integration of computational modeling with membrane transport studies reveals new insights into amino acid exchange transport mechanisms

    Science.gov (United States)

    Widdows, Kate L.; Panitchob, Nuttanont; Crocker, Ian P.; Please, Colin P.; Hanson, Mark A.; Sibley, Colin P.; Johnstone, Edward D.; Sengers, Bram G.; Lewis, Rohan M.; Glazier, Jocelyn D.

    2015-01-01

    Uptake of system L amino acid substrates into isolated placental plasma membrane vesicles in the absence of opposing side amino acid (zero-trans uptake) is incompatible with the concept of obligatory exchange, where influx of amino acid is coupled to efflux. We therefore hypothesized that system L amino acid exchange transporters are not fully obligatory and/or that amino acids are initially present inside the vesicles. To address this, we combined computational modeling with vesicle transport assays and transporter localization studies to investigate the mechanisms mediating [14C]l-serine (a system L substrate) transport into human placental microvillous plasma membrane (MVM) vesicles. The carrier model provided a quantitative framework to test the 2 hypotheses that l-serine transport occurs by either obligate exchange or nonobligate exchange coupled with facilitated transport (mixed transport model). The computational model could only account for experimental [14C]l-serine uptake data when the transporter was not exclusively in exchange mode, best described by the mixed transport model. MVM vesicle isolates contained endogenous amino acids allowing for potential contribution to zero-trans uptake. Both L-type amino acid transporter (LAT)1 and LAT2 subtypes of system L were distributed to MVM, with l-serine transport attributed to LAT2. These findings suggest that exchange transporters do not function exclusively as obligate exchangers.—Widdows, K. L., Panitchob, N., Crocker, I. P., Please, C. P., Hanson, M. A., Sibley, C. P., Johnstone, E. D., Sengers, B. G., Lewis, R. M., Glazier, J. D. Integration of computational modeling with membrane transport studies reveals new insights into amino acid exchange transport mechanisms. PMID:25761365

  10. Phase I clinical studies with WR-2721

    International Nuclear Information System (INIS)

    Kligerman, M.M.; Shaw, M.T.; Slavik, M.; Yuhas, J.M.

    1980-01-01

    Toxicity studies of S-2-(3 aminopropylamino)-ethylphosphorothioic acid (WR-2721) access patients in remission following radiation therapy. The dose has been escalated from 25 to 250 mg/m2 without significant symptoms. Inconsistent variation in the systolic blood pressure in some patients has been observed over an 8-10-point range without producing any symptoms. Combining WR-2721 with conventional radiotherapy is contemplated by intravenous injection the drug 20 to 30 minutes before irradiation. This will start as weekly injections, and the number of weekly injections will be increased progessively. Animal studies suggest that the level already safely reached could give significant protection to the normal tissues without protecting tumor

  11. Study of two-phase foam flow

    Energy Technology Data Exchange (ETDEWEB)

    Gurbanov, R S; Guliev, B B; Mekhtiev, K G; Kerimov, R G

    1970-01-01

    The objectives of this study were to determine characteristics of aqueous foam flow through porous media and to estimate the depth of foam penetration into a formation. Foam was generated by mixing air and 1% solution of surfactant PO-1. Foam density was maintained at 0.14 g/cc in all experiments. The foam was passed through sand columns (800 mm long x 30 mm diam) of permeabilities 26, 39, 80, 111, and 133 darcys. Flow rates were measured at various pressure drops and the relationship between system parameters was expressed analytically and graphically. From the data, distance of foam penetration into a formation as a function of pressure drop and permeability was calculated. The data indicate that under most conditions, foam will penetrate the formation to a negligible distance. This study indicates that when foam is used to remove sand from a well, a negligible loss of foam to the formation occurs.

  12. Investigation of Single Phase NanoCellulose Transport through Porous Media

    Science.gov (United States)

    Dziuba, Carter Jordan

    The application of nanotechnology to the petroleum industry has seen many recent advancements. Nanocellulose is an emerging nanoparticle at the forefront of research. Before nanocellulose can be injected into petroleum reservoirs, further understanding is needed as to the retention mechanisms that occur during nanocellulose transport through porous media. A series of unconsolidated sandpack floods were preformed with nanocellulose and the resulting retention and permeability reduction were measured. The experimental variables include nanocellulose type, sand grain size, flowrate, and salinity. It was found that all types of nanocellulose tested showed significantly different transport properties. Retention and permeability reduction increased as grain size decreased or flowrate decreased. As a general trend, the larger the size of aggregates in bulk solution, the greater the retention and permeability reduction. Salinity was found to be the primary parameter affecting transport. Increased salinity caused additional aggregation which resulted in increased straining and filter cake formation.

  13. Planning level assessment of greenhouse gas emissions for alternative transportation construction projects : carbon footprint estimator, phase II, volume I - GASCAP model.

    Science.gov (United States)

    2014-03-01

    The GASCAP model was developed to provide a software tool for analysis of the life-cycle GHG : emissions associated with the construction and maintenance of transportation projects. This phase : of development included techniques for estimating emiss...

  14. Self-regulated transport in photonic crystals with phase-changing defects

    Science.gov (United States)

    Thomas, Roney; Ellis, Fred M.; Vitebskiy, Ilya; Kottos, Tsampikos

    2018-01-01

    Phase-changing materials (PCMs) are widely used for optical data recording, sensing, all-optical switching, and optical limiting. Our focus here is on the case when the change in transmission characteristics of the optical material is caused by the input light itself. Specifically, the light-induced heating triggers the phase transition in the PCM. In this paper, using a numerical example, we demonstrate that the incorporation of the PCM in a photonic structure can lead to a dramatic modification of the effects of light-induced phase transition, as compared to a stand-alone sample of the same PCM. Our focus is on short pulses. We discuss some possible applications of such phase-changing photonic structures for optical sensing and limiting.

  15. Study on the transport behavior of uranyl nitrate in aqueous and non-aqueous systems

    International Nuclear Information System (INIS)

    Roesel, B.

    1985-01-01

    The analytical ultracentrifuge has proven itself through diffusion measurements to be well suited for studying radioactive compounds. In the framework of this paper the extent to which the UV and schlieren optics of an analytical ultracentrifuge can be used for extraction-kinetic tests was tested. With this method there is also the possibility of determining the distribution coefficients right at the phase boundary. The results show the good possibility of application of the absorption and schlieren optics to the study of the transport behavior of uranyl nitrate in practice oriented solutions. (orig.) [de

  16. Advanced supersonic propulsion study, phase 4

    Science.gov (United States)

    Howlett, R. A.

    1977-01-01

    Installation characteristics for a Variable Stream Control Engine (VSCE) were studied for three advanced supersonic airplane designs. Sensitivity of the VSCE concept to change in technology projections was evaluated in terms of impact on overall installed performance. Based on these sensitivity results, critical technology requirements were reviewed, resulting in the reaffirmation of the following requirements: low-noise nozzle system; a high performance, low emissions duct burner and main burner; hot section technology; variable geometry components; and propulsion integration features, including an integrated electronic control system.

  17. 2009 South American benchmarking study: natural gas transportation companies

    Energy Technology Data Exchange (ETDEWEB)

    Jordan, Nathalie [Gas TransBoliviano S.A. (Bolivia); Walter, Juliana S. [TRANSPETRO, Rio de Janeiro, RJ (Brazil)

    2009-07-01

    In the current business environment large corporations are constantly seeking to adapt their strategies. Benchmarking is an important tool for continuous improvement and decision-making. Benchmarking is a methodology that determines which aspects are the most important to be improved upon, and it proposes establishing a competitive parameter in an analysis of the best practices and processes, applying continuous improvement driven by the best organizations in their class. At the beginning of 2008, GTB (Gas TransBoliviano S.A.) contacted several South American gas transportation companies to carry out a regional benchmarking study in 2009. In this study, the key performance indicators of the South American companies, whose reality is similar, for example, in terms of prices, availability of labor, and community relations, will be compared. Within this context, a comparative study of the results, the comparative evaluation among natural gas transportation companies, is becoming an essential management instrument to help with decision-making. (author)

  18. Western Wind and Solar Integration Study: Phase 2 (Presentation)

    Energy Technology Data Exchange (ETDEWEB)

    Lew, D.; Brinkman, G.; Ibanez, E.; Lefton, S.; Kumar, N.; Venkataraman, S.; Jordan, G.

    2013-09-01

    This presentation summarizes the scope and results of the Western Wind and Solar Integration Study Phase 2, which examined operational impacts of high penetrations of variable renewable generation in the West.

  19. Nevada potential repository preliminary transportation strategy: Study 1

    International Nuclear Information System (INIS)

    1995-04-01

    Limited feasible options exist when considering the shipment of spent nuclear fuel and high-level radioactive waste. These options are rail or truck; because of the weight associated with transportation casks (68.0 to 113.4 tonnes/75 to 125 tons), heavy-haul trucks are also considered. Yucca Mountain currently lacks rail service or an existing right-of-way for rail; it also lacks a dedicated highway suitable for heavy-haul trucks. Approximately 11,230 shipments by rail are planned from waste producer sites to Nevada, with an additional 1,041 shipments by legal-weight truck from four reactor sites not capable of upgrading for rail shipment. This study identifies the reasonable alternatives for waste transport to the potential repository site, describes the evaluation process performed to identify those alternatives, and discusses the reasons for elimination of transportation routes deemed to be not reasonable. The study concluded that heavy haul truck transportation is feasible-cost is very favorable when compared to rail-but route restrictions must be further evaluated. In addition to restrictions due to seasonal weather conditions, specific routes have additional restrictions, including no travel on holidays or weekends, and travel during daylight hours only. Further restrictions will be imposed by the U.S. Department of Transportation based on routing of radioactive materials by highway. Operation and maintenance costs for heavy-haul over a 24-year period, based on preliminary information, were calculated on an estimated operational cost of $15,000 per trip, with an estimated 468 trips per year average (11,230 total trips), for an estimated cost of $171 million to $173 million, depending on the route used. Because the initial costs and the total system life cycle costs of heavy-haul are approximately 50 percent lower than the lowest rail cost, this option will continue to be evaluated

  20. Nevada potential repository preliminary transportation strategy: Study 1

    Energy Technology Data Exchange (ETDEWEB)

    None,

    1995-04-01

    Limited feasible options exist when considering the shipment of spent nuclear fuel and high-level radioactive waste. These options are rail or truck; because of the weight associated with transportation casks (68.0 to 113.4 tonnes/75 to 125 tons), heavy-haul trucks are also considered. Yucca Mountain currently lacks rail service or an existing right-of-way for rail; it also lacks a dedicated highway suitable for heavy-haul trucks. Approximately 11,230 shipments by rail are planned from waste producer sites to Nevada, with an additional 1,041 shipments by legal-weight truck from four reactor sites not capable of upgrading for rail shipment. This study identifies the reasonable alternatives for waste transport to the potential repository site, describes the evaluation process performed to identify those alternatives, and discusses the reasons for elimination of transportation routes deemed to be not reasonable. The study concluded that heavy haul truck transportation is feasible-cost is very favorable when compared to rail-but route restrictions must be further evaluated. In addition to restrictions due to seasonal weather conditions, specific routes have additional restrictions, including no travel on holidays or weekends, and travel during daylight hours only. Further restrictions will be imposed by the U.S. Department of Transportation based on routing of radioactive materials by highway. Operation and maintenance costs for heavy-haul over a 24-year period, based on preliminary information, were calculated on an estimated operational cost of $15,000 per trip, with an estimated 468 trips per year average (11,230 total trips), for an estimated cost of $171 million to $173 million, depending on the route used. Because the initial costs and the total system life cycle costs of heavy-haul are approximately 50 percent lower than the lowest rail cost, this option will continue to be evaluated.

  1. The effect of a micro bubble dispersed gas phase on hydrogen isotope transport in liquid metals under nuclear irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Fradera, J., E-mail: jfradera@ubu.es; Cuesta-López, S., E-mail: scuesta@ubu.es

    2013-12-15

    The present work intend to be a first step towards the understanding and quantification of the hydrogen isotope complex phenomena in liquid metals for nuclear technology. Liquid metals under nuclear irradiation in, e.g., breeding blankets of a nuclear fusion reactor would generate tritium which is to be extracted and recirculated as fuel. At the same time that tritium is bred, helium is also generated and may precipitate in the form of nano bubbles. Other liquid metal systems of a nuclear reactor involve hydrogen isotope absorption processes, e.g., tritium extraction system. Hence, hydrogen isotope absorption into gas bubbles modelling and control may have a capital importance regarding design, operation and safety. Here general models for hydrogen isotopes transport in liquid metal and absorption into gas phase, that do not depend on the mass transfer limiting regime, are exposed and implemented in OpenFOAM® CFD tool for 0D–3D simulations. Results for a 0D case show the impact of a He dispersed phase of nano bubbles on hydrogen isotopes inventory at different temperatures as well as the inventory evolution during a He nucleation event. In addition, 1D and 2D axisymmetric cases are exposed showing the effect of a He dispersed gas phase on hydrogen isotope permeation through a lithium lead eutectic alloy and the effect of vortical structures on hydrogen isotope transport at a backward facing step. Exposed results give a valuable insight on current nuclear technology regarding the importance of controlling hydrogen isotope transport and its interactions with nucleation event through gas absorption processes.

  2. Basic Studies of Non-Diffusive Transport in Plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Morales, George J. [University of California, Los Angeles, CA (United States); Maggs, James E. [University of California, Los Angeles, CA (United States)

    2014-10-25

    The project expanded and developed mathematical descriptions, and corresponding numerical modeling, of non-diffusive transport to incorporate new perspectives derived from basic transport experiments performed in the LAPD device at UCLA, and at fusion devices throughout the world. By non-diffusive it is meant that the transport of fundamental macroscopic parameters of a system, such as temperature and density, does not follow the standard diffusive behavior predicted by a classical Fokker-Planck equation. The appearance of non-diffusive behavior is often related to underlying microscopic processes that cause the value of a system parameter, at one spatial position, to be linked to distant events, i.e., non-locality. In the LAPD experiments the underlying process was traced to large amplitude, coherent drift-waves that give rise to chaotic trajectories. Significant advances were made in this project. The results have lead to a new perspective about the fundamentals of edge transport in magnetically confined plasmas; the insight has important consequences for worldwide studies in fusion devices. Progress was also made in advancing the mathematical techniques used to describe fractional diffusion.

  3. Transportation fuel from plastic: Two cases of study.

    Science.gov (United States)

    Faussone, Gian Claudio

    2018-03-01

    Synthesis of liquid fuels from waste is a promising pathway for reducing the carbon footprint of transportation industry and optimizing waste management towards zero landfilling. The study of commercial plants that conduct pyrolysis of plastics from post-consumer recycled materials and directly mine from old landfills without any pre-treatment has revealed two cases that show the feasibility of manufacturing transportation fuels via these methods. Pyrolysis oil, consisting of almost 26% hydrocarbons within the gasoline range and almost 70% within the diesel range, is upgraded to transportation fuel in the existing refinery. A batch operating plant is able to deliver relatively good quality pyrolysis oil from post-consumer plastic waste, owing to the catalyst employed. Simple distillation was also evaluated as an alternative and cheaper upgrading process into transportation fuels, meeting EN590 diesel and ISO8217 marine fuel standards. Even though the two installations are outside the European Union, they represent good examples of the "circular economy" concept envisaged by the European Union via its ambitious "Circular Economy Package [1]", providing real world data for comparison with other experimental and lab results. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. External fuel vaporization study, phase 2

    Science.gov (United States)

    Szetela, E. J.; Chiappetta, L.

    1981-01-01

    An analytical study was conducted to evaluate the effect of variations in fuel properties on the design of an external fuel vaporizaton system. The fuel properties that were considered included thermal stability, critical temperature, enthalpy a critical conditions, volatility, and viscosity. The design parameters that were evaluated included vaporizer weight and the impact on engine requirement such as maintenance, transient response, performance, and altitude relight. The baseline fuel properties were those of Jet A. The variation in thermal stability was taken as the thermal stability variation for Experimental Referee Broad Specification (ERBS) fuel. The results of the analysis indicate that a change in thermal stability equivalent to that of ERBS would increase the vaporization system weight by 20 percent, decrease oprating time between cleaning by 40 percent and make altitude relight more difficult. An increase in fuel critical temperature of 39 K would require a 40 percent increase in vaporization system weight. The assumed increase in enthalpy and volatility would also increase vaporizer weight by 40 percent and make altitude relight extremely difficult. The variation in fuel viscosity would have a negligible effect on the design parameters.

  5. U.S. DOT roadway transportation data business plan (phase 1) : data business plan.

    Science.gov (United States)

    2013-01-01

    In 2010 the FHWA Office of Operations, Office of Transportation Management (HOTM) commissioned the development of a white paper, Data Capture and Management: Needs and Gaps in the Operation and Coordination of U.S. DOT Data Capture and Management Pro...

  6. Shared Freight Transportation and Energy Commodities Phase One: Coal, Crude Petroleum, & Natural Gas Flows

    Energy Technology Data Exchange (ETDEWEB)

    Chin, Shih-Miao [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Hwang, Ho-Ling [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Davidson, Diane [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-07-01

    The Freight Analysis Framework (FAF) integrates data from a variety of sources to create a comprehensive picture of nationwide freight movements among states and major metropolitan areas for all modes of transportation. It provides a national picture of current freight flows to, from, and within the United States, assigns selected flows to the transportation network, and projects freight flow patterns into the future. The latest release of FAF is known as FAF4 with a base year of 2012. The FAF4 origin-destination-commodity-mode (ODCM) matrix is provided at national, state, major metropolitan areas, and major gateways with significant freight activities (e.g., El Paso, Texas). The U.S. Department of Energy (DOE) is interested in using FAF4 database for its strategic planning and policy analysis, particularly in association with the transportation of energy commodities. However, the geographic specification that DOE requires is a county-level ODCM matrix. Unfortunately, the geographic regions in the FAF4 database were not available at the DOE desired detail. Due to this limitation, DOE tasked Oak Ridge National Laboratory (ORNL) to assist in generating estimates of county-level flows for selected energy commodities by mode of transportation.

  7. Revenue sources for financing transportation safety activities in Virginia : phase two, state sources.

    Science.gov (United States)

    1980-01-01

    Senate Bill 85, an action of the 1978 General Assembly, amended the Code of Virginia to provide, in part, that the Division of Highway Safety be succeeded by the newly created Department of Transportation Safety effective July 1, 1978. In its Declara...

  8. Value of ITS information for congestion avoidance in inter-modal transportation systems : phase II.

    Science.gov (United States)

    2010-03-01

    Our project has four major mile-stones for the second year: : Mile-stone #1: Develop Dynamic Inter-modal Transportation Optimization Models: For : mostly air-road network and inter-modal networks significant to OHIO : MICHIGAN regions and our col...

  9. Heavy ion inertial fusion: interface between target gain, accelerator phase space and reactor beam transport revisited

    International Nuclear Information System (INIS)

    Barletta, W.A.; Fawley, W.M.; Judd, D.L.; Mark, J.W.K.; Yu, S.S.

    1984-01-01

    Recently revised estimates of target gain have added additional optimistic inputs to the interface between targets, accelerators and fusion chamber beam transport. But it remains valid that neutralization of the beams in the fusion chamber is useful if ion charge state Z > 1 or if > 1 kA per beamlet is to be propagated. Some engineering and economic considerations favor higher currents

  10. Tuning the electronic transport anisotropy in α-phase phosphorene through superlattice design

    Science.gov (United States)

    He, Yuanyuan; Xiong, Shiyun; Xia, Feifei; Shao, Zhibin; Zhao, Jianwei; Zhang, Xiujuan; Jie, Jiansheng; Zhang, Xiaohong

    2018-02-01

    Rational tuning the anisotropic electronic properties of monolayer phosphorene is essential to their applications in electronic and optoelectronic devices. By combining the density functional theory and the nonequilibrium Green's function method, we developed a strategy to tune the anisotropic transport properties of phosphorene by designing stable arsenic-phosphorene (A sxP1 -x ) superlattice (SL). It was found that, with a careful design of As:P ratio and atomic arrangement, the anisotropic transport properties could be tuned in a wide range. The transport current along the zigzag direction, which is very low in pristine phosphorene, was gradually enhanced by increasing the As:P ratio, and even became larger than that along armchair direction when the As:P ratio achieved 1:1 under a given arrangement of As atoms in A sxP1 -x SL. The tunable anisotropic transport properties of A sxP1 -x SL are attributed to the interplay between the different scattering rates related to the number and orientation of As-P interfaces. This finding demonstrates that the A sxP1 -x SL design could be an effective approach to tune the anisotropic electronic properties of monolayer phosphorene, which is important for the development of high-performance electronic and optoelectronic devices based on phosphorene.

  11. Molecular response to imatinib & its correlation with mRNA expression levels of imatinib influx & efflux transporters in patients with chronic myeloid leukaemia in chronic phase

    Directory of Open Access Journals (Sweden)

    Hemant Malhotra

    2015-01-01

    Full Text Available Background & objectives: Imatinib is the standard first-line treatment for chronic myeloid leukaemia (CML patients. About 20 to 30 per cent patients develop resistance to imatinib and fail imatinib treatment. One of the mechanisms proposed is varying expression levels of the drug transporters. This study was aimed to determine the expression levels of imatinib transporter genes (OCT1, ABCB1, ABCG2 in CML patients and to correlate these levels with molecular response. Methods: Sixty three CML chronic phase patients who were on 400 mg/day imatinib for more than two years were considered for gene expression analysis study for OCT1, ABCB1 and ABCG2 genes. These were divided into responders and non-responders. The relative transcript expression levels of the three genes were compared between these two categories. The association between the expression values of these three genes was also determined. Results: No significant difference in the expression levels of OCT1, ABCB1 and ABCG2 was found between the two categories. The median transcript expression levels of OCT1, ABCB1 and ABCG2 genes in responders were 26.54, 10.78 and 0.64 versus 33.48, 7.09 and 0.53 in non-responders, respectively. A positive association was observed between the expression of the ABCB1 and ABCG2 transporter genes (r=0.407, P<0.05 while no association was observed between the expression of either of the ABC transporter genes with the OCT1 gene. Interpretation & conclusions: Our findings demonstrated that the mRNA expression levels of imatinib transporter genes were not correlated with molecular response in CML patients. Further studies need to be done on a large sample of CML patients to confirm these findings.

  12. Contribution to the theoretical study of transient two-phase flows

    International Nuclear Information System (INIS)

    Achard, J.L.

    1978-12-01

    The work presented in this paper has been given rise from the existence of violent boiling phenomena of the coolant that have been revealed by reactor safety studies with water and sodium. The aim as to describe in a basic mammer, one of these phenomena called ''chugging'' or ''choucage''. The experimental part of this work concerns two original works concerning the temperature measurement at the wall; a device is proposed to evaluate the contact resistance and the thermal inertia of the thermocouple; from the measurements that have been obtained, the flux the wall transfers to the flow and the temperature of the internal wall surface are deduced. A statistical method is developed for dispersed two-phase flow study, to establish: 1) a mass transfer law, 2) a law of change of the flow configuration. The proposed model contains: 1) for the dispersed phase (vapor bubbles), the basic momentum transport equations; 2) for the continuous phase (liquid), the transport equations of the classical formulation. The statistical formulation introduces the interaction phenomenon between the phases before applying the operation of the average (homogenization method); it allows to introduce the coalescence phenomena of bubbles. Finally, structures of exchange laws for transient laminar flows are proposed: transient linear momentum exchange law; possible structures of heat exchange laws [fr

  13. Metropolitan transportation management center concepts of operation : a cross-cutting study : improving transportation network efficiency

    Science.gov (United States)

    1999-10-01

    The implementor and operator of a regional transportation management center (TMC) face a challenging task. Operators of TMCsthe primary point of coordination for managing transportation resourcestypically control millions of dollars of intellig...

  14. Laboratory studies of radionuclide transport in fractured Climax granite

    International Nuclear Information System (INIS)

    Failor, R.; Isherwood, D.; Raber, E.; Vandergraaf, T.

    1982-06-01

    This report documents our laboratory studies of radionuclide transport in fractured granite cores. To simulate natural conditions, our laboratory studies used naturally fractured cores and natural ground water from the Climax Granite Stock at the Nevada Test Site. For comparison, additional tests used artificially fractured granite cores or distilled water. Relative to the flow of tritiated water, 85 Sr and /sup 95m/Tc showed little or no retardation, whereas 137 Cs was retarded. After the transport runs the cores retained varying amounts of the injected radionuclides along the fracture. Autoradiography revealed some correlation between sorption and the fracture fill material. Strontium and cesium retention increased when the change was made from natural ground water to distilled water. Artificial fractures retained less 137 Cs than most natural fractures. Estimated fracture apertures from 18 to 60 μm and hydraulic conductivities from 1.7 to 26 x 10 -3 m/s were calculated from the core measurements

  15. A Density Functional Theory Study of the Ionic and Electronic Transport Mechanisms in LiFeBO3 Battery Electrodes

    DEFF Research Database (Denmark)

    Loftager, Simon; García Lastra, Juan Maria; Vegge, Tejs

    2016-01-01

    electrochemical effects can be explained by an intrinsically low Li-ion and electron/hole-polaron mobility in Li0.5FeBO3 due to high activation barriers for both the ionic and electronic transport. These studies include the effects of the experimentally reported commensurate modulation. We have also investigated...... with the formation of intermediate phases is linked to the intrinsically poor properties of the Li0.5FeBO3 phase rather than to the presence of interfaces between different phases....

  16. Pore scale study of multiphase multicomponent reactive transport during CO2 dissolution trapping

    Science.gov (United States)

    Chen, Li; Wang, Mengyi; Kang, Qinjun; Tao, Wenquan

    2018-06-01

    Solubility trapping is crucial for permanent CO2 sequestration in deep saline aquifers. For the first time, a pore-scale numerical method is developed to investigate coupled scCO2-water two-phase flow, multicomponent (CO2(aq), H+, HCO3-, CO32- and OH-) mass transport, heterogeneous interfacial dissolution reaction, and homogeneous dissociation reactions. Pore-scale details of evolutions of multiphase distributions and concentration fields are presented and discussed. Time evolutions of several variables including averaged CO2(aq) concentration, scCO2 saturation, and pH value are analyzed. Specific interfacial length, an important variable which cannot be determined but is required by continuum models, is investigated in detail. Mass transport coefficient or efficient dissolution rate is also evaluated. The pore-scale results show strong non-equilibrium characteristics during solubility trapping due to non-uniform distributions of multiphase as well as slow mass transport process. Complicated coupling mechanisms between multiphase flow, mass transport and chemical reactions are also revealed. Finally, effects of wettability are also studied. The pore-scale studies provide deep understanding of non-linear non-equilibrium multiple physicochemical processes during CO2 solubility trapping processes, and also allow to quantitatively predict some important empirical relationships, such as saturation-interfacial surface area, for continuum models.

  17. Study on flow and mass transport through fractured sedimentary rocks (2)

    International Nuclear Information System (INIS)

    Shimo, Michito; Kumamoto, Sou; Karasaki, Kenzi; Sato, Hisashi; Sawada, Atsushi

    2009-03-01

    It is important for safety assessment of HLW geological disposal to understand hydro-geological conditions at the investigation area, and to evaluate groundwater flow and mass transport model and parameters, at each investigation phase. Traditionally, for Neogene sedimentary rock, the grain spacing of sediments has been considered as the dominant migration path. However, fractures of sedimentary rock could act as dominant paths, although they were soft sedimentary rocks. In this study, as part of developing groundwater flow and mass transport evaluation methodologies of such a fractured sedimentary rock' distributed area, we conducted two different scale of studies; 1) core rock sample scale and 2) several kilometer scale. For the core rock sample scale, some of laboratory hydraulic and tracer experiments have conducted using the rock cores with tailored parallel fracture, obtained at pilot borehole drilled in the vicinity of ventilation shaft. From the test results, hydraulic conductivity, diffusion coefficient, transport aperture, dispersion length and etc. was evaluated. Based on these test results, the influence of these parameters onto mass transport behavior of fractures sedimentary rocks was examined. For larger scale, such as several kilometer scale, the regional scale groundwater flow was examined using temperature data observed along the boreholes at Horonobe site. The results show that the low permeable zone between the boreholes might be estimated. (author)

  18. Integrated thermal treatment system study -- Phase 2 results. Revision 1

    Energy Technology Data Exchange (ETDEWEB)

    Feizollahi, F.; Quapp, W.J.

    1996-02-01

    This report presents the second phase of a study on thermal treatment technologies. The study consists of a systematic assessment of nineteen thermal treatment alternatives for the contact-handled mixed low-level waste (MLLW) currently stored in the US Department of Energy complex. The treatment alternatives consist of widely varying technologies for safely destroying the hazardous organic components, reducing the volume, and preparing for final disposal of the MLLW. The alternatives considered in Phase 2 were innovative thermal treatments with nine types of primary processing units. Other variations in the study examined the effect of combustion gas, air pollution control system design, and stabilization technology for the treatment residues. The Phase 1 study examined ten initial thermal treatment alternatives. The Phase 2 systems were evaluated in essentially the same manner as the Phase 1 systems. The alternatives evaluated were: rotary kiln, slagging kiln, plasma furnace, plasma gasification, molten salt oxidation, molten metal waste destruction, steam gasification, Joule-heated vitrification, thermal desorption and mediated electrochemical oxidation, and thermal desorption and supercritical water oxidation. The quantities, and physical and chemical compositions, of the input waste used in the Phase 2 systems differ from those in the Phase 1 systems, which were based on a preliminary waste input database developed at the onset of the Integrated Thermal Treatment System study. The inventory database used in the Phase 2 study incorporates the latest US Department of Energy information. All systems, both primary treatment systems and subsystem inputs, have now been evaluated using the same waste input (2,927 lb/hr). 28 refs., 88 figs., 41 tabs.

  19. Integrated thermal treatment system study -- Phase 2 results. Revision 1

    International Nuclear Information System (INIS)

    Feizollahi, F.; Quapp, W.J.

    1996-02-01

    This report presents the second phase of a study on thermal treatment technologies. The study consists of a systematic assessment of nineteen thermal treatment alternatives for the contact-handled mixed low-level waste (MLLW) currently stored in the US Department of Energy complex. The treatment alternatives consist of widely varying technologies for safely destroying the hazardous organic components, reducing the volume, and preparing for final disposal of the MLLW. The alternatives considered in Phase 2 were innovative thermal treatments with nine types of primary processing units. Other variations in the study examined the effect of combustion gas, air pollution control system design, and stabilization technology for the treatment residues. The Phase 1 study examined ten initial thermal treatment alternatives. The Phase 2 systems were evaluated in essentially the same manner as the Phase 1 systems. The alternatives evaluated were: rotary kiln, slagging kiln, plasma furnace, plasma gasification, molten salt oxidation, molten metal waste destruction, steam gasification, Joule-heated vitrification, thermal desorption and mediated electrochemical oxidation, and thermal desorption and supercritical water oxidation. The quantities, and physical and chemical compositions, of the input waste used in the Phase 2 systems differ from those in the Phase 1 systems, which were based on a preliminary waste input database developed at the onset of the Integrated Thermal Treatment System study. The inventory database used in the Phase 2 study incorporates the latest US Department of Energy information. All systems, both primary treatment systems and subsystem inputs, have now been evaluated using the same waste input (2,927 lb/hr). 28 refs., 88 figs., 41 tabs

  20. California air transportation study: A transportation system for the California Corridor of the year 2010

    Science.gov (United States)

    1989-01-01

    To define and solve the problems of transportation in the California Corrider in the year 2010, the 1989 California Polytechnic State University Aeronautical Engineering Senior Design class determined future corridor transportation needs and developed a system to meet the requirements. A market study, which included interpreting travel demand and gauging the future of regional and national air travel in and out of the corridor, allowed the goals of the project to be accurately refined. Comprehensive trade-off studies of several proposed transporation systems were conducted to determine which components would form the final proposed system. Preliminary design and further analysis were performed for each resulting component. The proposed system consists of three vehicles and a special hub or mode mixer, the Corridor Access Port (CAP). The vehicles are: (1) an electric powered aircraft to serve secondary airports and the CAP; (2) a high speed magnetic levitation train running through the CAP and the high population density areas of the corridor; and (3) a vertical takeoff and landing tilt rotor aircraft to serve both intercity and intrametropolitan travelers from the CAP and city vertiports. The CAP is a combination and an extension of the hub, mode mixer, and Wayport concepts. The CAP is an integrated part of the system which meets the travel demands in the corridor, and interfaces with interstate and international travel.

  1. Intercity passenger transportation: energy efficiency and conservation case study

    Energy Technology Data Exchange (ETDEWEB)

    Khan, A.M.

    1981-01-01

    To demonstrate a methodology for energy analysis and to advance technical knowledge on the energy conservation potential in intercity passenger transportation, this paper reports findings of a case study of the Toronto-Ottawa-Montreal multimodal system. From a total (direct and indirect) energy perspective for origin-destination travel, energy efficiency and conservation potential of technological improvements, modal shifts and increased load factors are reported. 11 refs.

  2. Integrating transportation and production: an international study case

    OpenAIRE

    L Bertazzi; O Zappa

    2012-01-01

    The problem we study is inspired by the real case of Mesdan S.p.A., an Italian company worldwide leader in the textile machinery sector, which has two production units with two warehouses, one located in Italy (Brescia) and the other in China (Foshan). The critical point in this logistic system is the integration between production and transportation management, given the long distance between Brescia and Foshan. Shipments are performed by the means of different types of vehicles with differe...

  3. In vitro placental model optimization for nanoparticle transport studies

    DEFF Research Database (Denmark)

    Cartwright, Laura; Poulsen, Marie Sønnegaard; Nielsen, Hanne Mørck

    2012-01-01

    Background: Advances in biomedical nanotechnology raise hopes in patient populations but may also raise questions regarding biodistribution and biocompatibility, especially during pregnancy. Special consideration must be given to the placenta as a biological barrier because a pregnant woman...... placental choriocarcinoma cells for nanoparticle transport studies was characterized in terms of optimized Transwell® insert type and pore size, the investigation of barrier properties by transmission electron microscopy, tight junction staining, transepithelial electrical resistance, and fluorescein sodium...

  4. Development of Novel active transport membrane devices. Phase I. Final report, 31 October 1988--31 January 1994

    Energy Technology Data Exchange (ETDEWEB)

    Laciak, D.V.; Quinn, R.; Choe, G.S.; Cook, P.J.; Tsai, Fu-Jya

    1994-08-01

    The main objective of this program was to identify and develop a technique for fabricating Active Transport Materials (ATM) into lab-scale membrane devices. Air Products met this objective by applying thin film, multilayer fabrication techniques to support the AT material on a substrate membrane. In Phase IA, spiral-wound hollow fiber membrane modules were fabricated and evaluated. These nonoptimized devices were used to demonstrate the AT-based separation of carbon dioxide from methane, hydrogen sulfide from methane, and ammonia from hydrogen. It was determined that a need exists for a more cost efficient and less energy intensive process for upgrading subquality natural gas. Air Products estimated the effectiveness of ATM for this application and concluded that an optimized ATM system could compete effectively with both conventional acid gas scrubbing technology and current membrane technology. In addition, the optimized ATM system would have lower methane loss and consume less energy than current alternative processes. Air Products made significant progress toward the ultimate goal of commercializing an advanced membrane for upgrading subquality natural gas. The laboratory program focused on developing a high performance hollow fiber substrate and fabricating and evaluating ATM-coated lab-scale hollow fiber membrane modules. Selection criteria for hollow fiber composite membrane supports were developed and used to evaluate candidate polymer compositions. A poly(amide-imide), PAI, was identified for further study. Conditions were identified which produced microporous PAI support membrane with tunable surface porosity in the range 100-1000{Angstrom}. The support fibers exhibited good hydrocarbon resistance and acceptable tensile strength though a higher elongation may ultimately be desirable. ATM materials were coated onto commercial and PAI substrate fiber. Modules containing 1-50 fibers were evaluated for permselectivity, pressure stability, and lifetime.

  5. Wave Tank Studies of Phase Velocities of Short Wind Waves

    Science.gov (United States)

    Ermakov, S.; Sergievskaya, I.; Shchegolkov, Yu.

    Wave tank studies of phase velocities of short wind waves have been carried out using Ka-band radar and an Optical Spectrum Analyser. The phase velocities were retrieved from measured radar and optical Doppler shifts, taking into account measurements of surface drift velocities. The dispersion relationship was studied in centimetre (cm)- and millimetre(mm)-scale wavelength ranges at different fetches and wind speeds, both for a clean water surface and for water covered with surfactant films. It is ob- tained that the phase velocities do not follow the dispersion relation of linear capillary- gravity waves, increasing with fetch and, therefore, depending on phase velocities of dominant decimetre (dm)-centimetre-scale wind waves. One thus can conclude that nonlinear cm-mm-scale harmonics bound to the dominant wind waves and propagat- ing with the phase velocities of the decimetric waves are present in the wind wave spectrum. The resulting phase velocities of short wind waves are determined by re- lation between free and bound waves. The relative intensity of the bound waves in the spectrum of short wind waves is estimated. It is shown that this relation depends strongly on the surfactant concentration, because the damping effect due to films is different for free and bound waves; this results to changes of phase velocities of wind waves in the presence of surfactant films. This work was supported by MOD, UK via DERA Winfrith (Project ISTC 1774P) and by RFBR (Project 02-05-65102).

  6. Research and technology strategy to help overcome the environmental problems in relation to transport. Resource uses study

    International Nuclear Information System (INIS)

    Billings, R.; Crowley, J.; Moran, R.

    1992-04-01

    This report concerns the environmental impact of resource utilization in the transport sector. The first phase of the study involved a dissection of transport into its different modes, its operational components, and its existing patterns of resource usage. The second phase was an investigation of existing environmental impacts. Since in principle a significant environmental impact may occur anywhere along the extraction-to-disposal life cycle of a material, it was necessary to investigate a range of environmental phenomena upstream and downstream from the transport sector, as well as within the sector itself. In this development of a holistic perspective of resource usage, particular attention was paid to depletion, disposal, and re-cycling questions. The third phase involved the examination of possible innovations in transport technology. Of particular interest was the resource usage implications of these innovations, and their potential for ameliorating negative environmental impacts. In the final phase of the study, are addressed questions of the net costs and benefits of the various technologies, and of the most appropriate policy options for the Community

  7. A hydro-geochemical study of Nahr-Ibrahim catchment area: Fluvial metal transport

    International Nuclear Information System (INIS)

    Korfali, Samira

    2004-01-01

    Author.Metals enter water bodies geological weathering, soil erosion, industrial and domestic waste discharges, as well as atmospheric deposition. The metal content in sediments is a reflection of the nature of their background whether of geologic and/or anthropogenic origin. The depositional process of metals in sediment are controlled by river discharge, turbulence of river, morphology and river geometry, as well as the geochemical phases of sediment and soils. Thus a study of metal content in river and /or metal transport with a water body should include a hydrological study of the river, types of minerals in sediment and soil, sediment and soil textures, and metal speciation in the different geochemical phases of sediment, bank and soils. A contaminated flood plain is a temporary storage system for pollutants and an understanding of soil-sediment-interactions is important prerequisite for modeling fluvial pollutant transport. The determination of metal speciation in sediment and soil chemical fraction can provide information on the way in which these metals are bound to sediment and soil, their mobilization potential, bioavailability and possible mechanism of fluvial pollutant transport. Sequential extraction techniques yielding operationally defined chemical pools have been used by many workers to examine the partitioning of metals among the various geochemical phases of sediment or soil. The sequential extraction method specifies metals in sediment fractions as: exchangeable, specifically sorbed, easily reducible, moderately reducible, organic, residual. Previously, I have conducted a study on speciation of metals (Fe, Mn, Zn, Cu, Pb and Cd) in the dry season bed-load sediments only at five sites 13 km stretch upstream from the mouth of Nahr Ibrahim. The reported data revealed that the specifically sorbed sediment fraction was the prime fraction for deposition of Mn, Z, CU, Pb and Cd metals in sediments. X-ray diffraction analysis of bed sediments showed

  8. Advanced transportation system study: Manned launch vehicle concepts for two way transportation system payloads to LEO

    Science.gov (United States)

    Duffy, James B.

    1993-01-01

    The purpose of the Advanced Transportation System Study (ATSS) task area 1 study effort is to examine manned launch vehicle booster concepts and two-way cargo transfer and return vehicle concepts to determine which of the many proposed concepts best meets NASA's needs for two-way transportation to low earth orbit. The study identified specific configurations of the normally unmanned, expendable launch vehicles (such as the National Launch System family) necessary to fly manned payloads. These launch vehicle configurations were then analyzed to determine the integrated booster/spacecraft performance, operations, reliability, and cost characteristics for the payload delivery and return mission. Design impacts to the expendable launch vehicles which would be required to perform the manned payload delivery mission were also identified. These impacts included the implications of applying NASA's man-rating requirements, as well as any mission or payload unique impacts. The booster concepts evaluated included the National Launch System (NLS) family of expendable vehicles and several variations of the NLS reference configurations to deliver larger manned payload concepts (such as the crew logistics vehicle (CLV) proposed by NASA JSC). Advanced, clean sheet concepts such as an F-1A engine derived liquid rocket booster (LRB), the single stage to orbit rocket, and a NASP-derived aerospace plane were also included in the study effort. Existing expendable launch vehicles such as the Titan 4, Ariane 5, Energia, and Proton were also examined. Although several manned payload concepts were considered in the analyses, the reference manned payload was the NASA Langley Research Center's HL-20 version of the personnel launch system (PLS). A scaled up version of the PLS for combined crew/cargo delivery capability, the HL-42 configuration, was also included in the analyses of cargo transfer and return vehicle (CTRV) booster concepts. In addition to strictly manned payloads, two-way cargo

  9. Structural and phase studies of stainless wire after electroplastic drawing

    International Nuclear Information System (INIS)

    Troitskij, O.A.; Baldokhin, Yu.V.; Kir'yanchev, N.E.; Ryzhkov, V.G.; Kalugin, V.D.; Sokolov, N.V.; Klekovkin, A.A.; Klevtsur, S.A.

    1983-01-01

    Structural and phase properties of the 12Kh18N10T steel wire are studied after usual and electroplastic drawing from 0.40 up to 0.11 mm with 18-22% reduction per pass with passing 250 A/mm 2 electric current. The earlier made observation on a sharp decrease in content of deformation-induced martensite of α-phase takes place in the wire from stainless metastable austenitic steel as a result of electroplastic drawing. Distribution of the remained α-phase by the wire cross section is established

  10. Neutron scattering studies of pretransitional phenomena in structural phase transformations

    International Nuclear Information System (INIS)

    Shapiro, S.M.

    1979-03-01

    Materials exhibiting structural phase transformations are well known to possess pretransitional phenomena. Below the transition temperature, T/sub c/, an order parameter appears and the pretransitional effects are associated with the fluctuations of the order parameter. Neutron scattering techniques have proved invaluable in studying the temporal and spatial dependence of these fluctuations. SrTiO 3 is the prototypical example of a structural phase transformation exhibiting features observable in other transformations such as martensitic and order-disorder. The experimental evolution of the understanding of the phase transformation in SrTiO 3 will be reviewed and the features observed will be shown to typify other systems

  11. Active transportation and public transportation use to achieve physical activity recommendations? A combined GPS, accelerometer, and mobility survey study.

    Science.gov (United States)

    Chaix, Basile; Kestens, Yan; Duncan, Scott; Merrien, Claire; Thierry, Benoît; Pannier, Bruno; Brondeel, Ruben; Lewin, Antoine; Karusisi, Noëlla; Perchoux, Camille; Thomas, Frédérique; Méline, Julie

    2014-09-27

    Accurate information is lacking on the extent of transportation as a source of physical activity, on the physical activity gains from public transportation use, and on the extent to which population shifts in the use of transportation modes could increase the percentage of people reaching official physical activity recommendations. In 2012-2013, 234 participants of the RECORD GPS Study (French Paris region, median age = 58) wore a portable GPS receiver and an accelerometer for 7 consecutive days and completed a 7-day GPS-based mobility survey (participation rate = 57.1%). Information on transportation modes and accelerometry data aggregated at the trip level [number of steps taken, energy expended, moderate to vigorous physical activity (MVPA), and sedentary time] were available for 7,644 trips. Associations between transportation modes and accelerometer-derived physical activity were estimated at the trip level with multilevel linear models. Participants spent a median of 1 h 58 min per day in transportation (8.2% of total time). Thirty-eight per-cent of steps taken, 31% of energy expended, and 33% of MVPA over 7 days were attributable to transportation. Walking and biking trips but also public transportation trips with all four transit modes examined were associated with greater steps, MVPA, and energy expenditure when compared to trips by personal motorized vehicle. Two simulated scenarios, implying a shift of approximately 14% and 33% of all motorized trips to public transportation or walking, were associated with a predicted 6 point and 13 point increase in the percentage of participants achieving the current physical activity recommendation. Collecting data with GPS receivers, accelerometers, and a GPS-based electronic mobility survey of activities and transportation modes allowed us to investigate relationships between transportation modes and physical activity at the trip level. Our findings suggest that an increase in active transportation

  12. Theoretical study of titanium phases; Etude theorique des phases du titane

    Energy Technology Data Exchange (ETDEWEB)

    Trinite, V

    2006-10-15

    The aim of this work is to obtain a good understanding of the phase diagram of titanium within density functional theory. This diagram is composed of the alpha phase, the high pressure omega phase and the high temperature beta phase. This requires the differences in total energy to be predicted with a great precision, because these differences are around 50 meV. I find the omega phase to be the most stable one by ab initio calculation at zero temperature and pressure, in contradiction to the experimental results. I find this inversion of the stability also appears in titanium dioxide and zirconium. I have analyzed all the approximations brought into play in the ab initio approach. I have estimated the zero point energy and studied the impact of including the semi-core states as well as the effect of the exchange-correlation functionals. The conclusion is that the usual approximations for the exchange-correlation generate the biggest part of the error. A possible correction is to take into account the electronic self-interaction. I have apply this correction to the semi-core states and find a systematic improvement of the cell parameters, but no improvement on the phase stability. So I can conclude that a better description of the exchange interaction on the localized 3d states is needed. Although the standard functionals of exchange-correlation are not accurate enough to predict the phase diagrams of titanium, they perform well in describing physical properties less demanding in terms of precision, like elastic constants. However, I find important that the predicted equilibrium volume must be precise, as these properties are found strongly dependent on the volume. (author)

  13. A novel method for trace tritium transport studies

    International Nuclear Information System (INIS)

    Bonheure, Georges; Mlynar, Jan; Murari, A.; Giroud, C.; Popovichev, S.; Belo, P.; Bertalot, L.

    2009-01-01

    A new method combining a free-form solution for the neutron emissivity and the ratio method (Bonheure et al 2006 Nucl. Fusion 46 725-40) is applied to the investigation of tritium particle transport in JET plasmas. The 2D neutron emissivity is calculated using the minimum Fisher regularization method (MFR) (Anton et al 1996 Plasma Phys. Control. Fusion 38 1849, Mlynar et al 2003 Plasma Phys. Control. Fusion 45 169). This method is being developed and studied alongside other methods at JET. The 2D neutron emissivity was significantly improved compared with the first MFR results by constraining the emissivity along the magnetic flux surfaces. 1D profiles suitable for transport analysis are then obtained by subsequent poloidal integration. In methods on which previous JET publications are based (Stork et al 2005 Nucl. Fusion 45 S181, JET Team (prepared by Zastrow) 1999 Nucl. Fusion 39 1891, Zastrow et al 2004 Plasma Phys. Control. Fusion 46 B255, Adams et al 1993 Nucl. Instrum. Methods A 329 277, Jarvis et al 1997 Fusion Eng. Des. 34-35 59, Jarvis et al 1994 Plasma Phys. Control. Fusion 36 219), the 14.07 MeV D-T neutron line integrals measurements were simulated and the transport coefficients varied until good fits were obtained. In this novel approach, direct knowledge of tritium concentration or the fuel ratio n T /n D is obtained using all available neutron profile information, e.g both 2.45 MeV D-D neutron profiles and 14.07 MeV D-T neutron profiles (Bonheure et al 2006 Nucl.Fusion 46 725-40). Tritium particle transport coefficients are then determined using a linear regression from the dynamic response of the tritium concentration n T /n D profile. The temporal and spatial evolution of tritium particle concentration was studied for a set of JET discharges with tritium gas puffs from the JET trace tritium experiments. Local tritium transport coefficients were derived from the particle flux equation Γ = -D∇n T + Vn T , where D is the particle diffusivity and V

  14. Phase-coherent electron transport through metallic atomic-sized contacts and organic molecules

    Energy Technology Data Exchange (ETDEWEB)

    Pauly, F.

    2007-02-02

    This work is concerned with the theoretical description of systems at the nanoscale, in particular the electric current through atomic-sized metallic contacts and organic molecules. In the first part, the characteristic peak structure in conductance histograms of different metals is analyzed within a tight-binding model. In the second part, an ab-initio method for quantum transport is developed and applied to single-atom and single-molecule contacts. (orig.)

  15. Experimental study of the thermal characteristics of phase change slurries for active cooling

    International Nuclear Information System (INIS)

    Lu, W.; Tassou, S.A.

    2012-01-01

    Highlights: ► Tween 60 and hexadecanol can be employed to produce paraffin-in-water emulsions. ► Paraffin with longer carbon chain than the paraffin in the emulsion can act as nucleate agent to reduce supercooling. ► Increasing the quantity of paraffin increases the viscosity of the emulsion. ► Antifreeze and traces of thickener can cause a significant increase to the viscosity of the emulsion. ► Well prepared emulsions are stable with storage and thermal cycles. -- Abstract: Phase change materials (PCMs) are increasingly being used for thermal energy storage in buildings and industry to produce energy savings and reduce carbon dioxide emissions. PCM slurries are also being investigated for active thermal energy storage or as alternatives to conventional single phase fluids because they are pumpable and have advanced heat transport performance with phase change. The present study investigates several types of phase change materials for the preparation of PCM slurries which have potential for cooling applications. The thermophysical properties of paraffin in water emulsions, such as latent heat of fusion, melting and freezing temperature ranges, viscosity and the effect of surfactants, have been tested using appropriate experimental techniques. It has been identified that the use of small quantities of higher melting temperature paraffin and surfactants in the emulsion can reduce the effect of supercooling and increase the useful heat of fusion. However there are negative impacts on viscosity which should be considered in heat transport applications.

  16. Lateral electron transport in monolayers of short chains at interfaces: A Monte Carlo study

    International Nuclear Information System (INIS)

    George, Christopher B.; Szleifer, Igal; Ratner, Mark A.

    2010-01-01

    Graphical abstract: Electron hopping between electroactive sites in a monolayer composed of redox-active and redox-passive molecules. - Abstract: Using Monte Carlo simulations, we study lateral electronic diffusion in dense monolayers composed of a mixture of redox-active and redox-passive chains tethered to a surface. Two charge transport mechanisms are considered: the physical diffusion of electroactive chains and electron hopping between redox-active sites. Results indicate that by varying the monolayer density, the mole fraction of electroactive chains, and the electron hopping range, the dominant charge transport mechanism can be changed. For high density monolayers in a semi-crystalline phase, electron diffusion proceeds via electron hopping almost exclusively, leading to static percolation behavior. In fluid monolayers, the diffusion of chains may contribute more to the overall electronic diffusion, reducing the observed static percolation effects.

  17. Aging of snubbers in nuclear service: Phase I study results and Phase II plans

    International Nuclear Information System (INIS)

    Goodman, R.L.; Bush, S.H.; Page, R.E.

    1988-01-01

    Two major research areas were investigated in the Phase I snubber aging studies. The first area involved a preliminary evaluation of the effects of various aging mechanisms on snubber operation; failure modes of mechanisms were identified and their contributions to aging degradation were assessed relative to other failure modes. The second area involved estimating the efficacy of existing tests and examinations that are intended to determine the effects of aging and degradation. Available data on snubber behavior and operating experience were reviewed, using licensee event reports and other historical data for the 10-year period from 1973 through 1983. Value-impact was considered in terms of (1) exposure of workers to radioactive environments for examination/testing and (2) the cost for expansion of the snubber testing program due to failed snubbers. Results from the Phase I studies identified the need to modify or improve examination and testing procedures to enhance snubber reliability. Based on the results of the Phase I snubber studies, the seals and fluids were identified as the two principal elements affected by aging degradation in hydraulic snubbers. Phase II work, which was initiated in FY 1987, will develop cooperative activities between PNL and operating utilities through the Snubber Utility Group (SNUG), who will work to establish a strong data and experience base for both hydraulic and mechanical snubbers based on actual operating and maintenance history at nuclear power plants. Application guidelines for snubbers will be recommended based on the study results

  18. Conceptual design study of 1985 commercial tilt rotor transports. Volume 3. STOL design summary. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Sambell, K.W.

    1976-04-01

    A conceptual design study is presented of 1,985 commercial tilt rotor STOL transports for a NASA 200 n. mi. (370 km) STOL Mission. A 100-passenger STOL Variant (Bell D313) of the Phase I VTOL Tilt Rotor Aircraft is defined. Aircraft characteristics are given; with the aircraft redesigned to meet 2,000-foot (610 m) field criteria, with emphasis on low fuel consumption and low direct operating cost. The 100-passenger STOL Tilt Rotor Aircraft was analyzed for performance, weights, economics, handling qualities, noise footprint and aeroelastic stability. (GRA)

  19. Classified study and clinical value of the phase imaging features

    International Nuclear Information System (INIS)

    Dang Yaping; Ma Aiqun; Zheng Xiaopu; Yang Aimin; Xiao Jiang; Gao Xinyao

    2000-01-01

    445 patients with various heart diseases were examined by the gated cardiac blood pool imaging, and the phase was classified. The relationship between the seven types with left ventricular function index, clinical heart function, different heart diseases as well as electrocardiograph was studied. The results showed that the phase image classification could match with the clinical heart function. It can visually, directly and accurately indicate clinical heart function and can be used to identify diagnosis of heart disease

  20. Considerations of stationary-phase interactions in groundwater pollution studies

    International Nuclear Information System (INIS)

    Hall, E.S.

    1980-01-01

    Studies of groundwater pollution are complicated by retention of both pollutant and tracers as static phases associated with the rock matrix. Three types of static phase are considered: (1) immobile pore water, (2) equilibrium adsorbed layers and (3) bulk precipitates, including biological systems. A brief discussion of the systems is given with examples from the work of the Water Research Centre on the problems encountered in quantifying groundwater pollution where static contamination may occur. (author)

  1. Phase equilibrium study on system uranium-plutonium-tungsten-carbon

    International Nuclear Information System (INIS)

    Ugajin, Mitsuhiro

    1976-11-01

    Metallurgical properties of the U-Pu-W-C system have been studied with emphasis on phases and reactions. Free energy of compound formation, carbon activity and U/Pu segregation in the W-doped carbide fuel are estimated using phase diagram data. The results indicate that tungsten metal is useful as a thermochemical stabilizer of the carbide fuel. Tungsten has high temperature stability in contact with uranium carbide and mixed uranium-plutonium carbide. (auth.)

  2. Radiotracer and Sealed Source Applications in Sediment Transport Studies

    International Nuclear Information System (INIS)

    2014-01-01

    The investigation of sediment transport in seas and rivers is crucial for civil engineering and littoral protection and management. Coastlines and seabeds are dynamic regions, with sediments undergoing periods of erosion, transport, sedimentation and consolidation. The main causes for erosion in beaches include storms and human actions such as the construction of seawalls, jetties and the dredging of stream mouths. Each of these human actions disrupts the natural flow of sand. Current policies and practices are accelerating the beach erosion process. However, there are viable options available to mitigate this damage and to provide for sustainable coastlines. Radioactive methods can help in investigating sediment dynamics, providing important parameters for better designing, maintaining and optimizing civil engineering structures. Radioisotopes as tracers and sealed sources have been useful and often irreplaceable tools for sediment transport studies. The training course material is based on lecture notes and practical works delivered by many experts in IAEA supported activities. Lectures and case studies were reviewed by a number of specialists in this field

  3. Radiotracer application in bedload transport: case studies at Calcutta port

    International Nuclear Information System (INIS)

    Pendharkar, A.S.; Yelgoankar, V.N.; Pant, H.J.; Saravana Kumar, U.; Mendhekar, G.N.; Navada, S.V.

    1994-01-01

    Radioactive isotopes as tracers are widely used to study the dynamic behaviour of sediments in navigation channels in harbours, estuaries and in rivers. Four radioactive tracer experiments were carried out in Calcutta Port during 1985-1992, to investigate the suitability of the dumping sites for the dredged sediments. Two experiments were carried out off Sagar island and the other two were carried out off Haldia river buoy. For all the experiments radiotracers used was 46 Sc labelled 1% scandium glass powder having the same specific gravity and particle size distribution as the natural sediment in the areas of investigation. About 370 GBq (10 Ci) each off Sagar island and 185 GBq (5 Ci) each off Haldia river buoy was used. An extensive background survey of the area was carried out using waterproof scintillation detectors to measure the natural radiation level prior to the experiments. The tracer was released on to the sea bed and its movement was followed by waterproof scintillation detector. The studies indicate the general direction of movement of sediment in the area of interest and it is found to be away from the shipping channels. The velocity of transport is calculated from transport diagrams of two successive trackings. The transport thickness E, estimated for the experiments off Haldia river buoy, is about 2 to 3 cm. (author). 3 refs., 7 figs., 2 tabs

  4. Online slug detection in multi-phase transportation pipelines using electrical tomography

    DEFF Research Database (Denmark)

    Pedersen, Simon; Mai, Christian; Hansen, Leif

    2015-01-01

    in the pipelines is a highly investigated topic. To eliminate the slug in an online manner real-time slug detection methods are often required. Traditionally topside pressure transmitters upstream a 3-phase separator have been used as the controlled variable. In this paper Electrical Resistivity Tomography (ERT...

  5. Online Slug Detection in Multi-phase Transportation Pipelines Using Electrical Tomography

    DEFF Research Database (Denmark)

    Pedersen, Simon; Mai, Christian; Hansen, Leif

    2015-01-01

    in the pipelines is a highly investigated topic. To eliminate the slug in an online manner real-time slug detection methods are often required. Traditionally topside pressure transmitters upstream a 3-phase separator have been used as the controlled variable. In this paper Electrical Resistivity Tomography (ERT...

  6. Controlling Microstructure-Transport Interplay in Highly Phase-Separated Perfluorosulfonated Aromatic Multiblock Ionomers via Molecular Architecture Design.

    Science.gov (United States)

    Nguyen, Huu-Dat; Assumma, Luca; Judeinstein, Patrick; Mercier, Regis; Porcar, Lionel; Jestin, Jacques; Iojoiu, Cristina; Lyonnard, Sandrine

    2017-01-18

    Proton-conducting multiblock polysulfones bearing perfluorosulfonic acid side chains were designed to encode nanoscale phase-separation, well-defined hydrophilic/hydrophobic interfaces, and optimized transport properties. Herein, we show that the superacid side chains yield highly ordered morphologies that can be tailored by best compromising ion-exchange capacity and block lengths. The obtained microstructures were extensively characterized by small-angle neutron scattering (SANS) over an extended range of hydration. Peculiar swelling behaviors were evidenced at two different scales and attributed to the dilution of locally flat polymer particles. We evidence the direct correlation between the quality of interfaces, the topology and connectivity of ionic nanodomains, the block superstructure long-range organization, and the transport properties. In particular, we found that the proton conductivity linearly depends on the microscopic expansion of both ionic and block domains. These findings indicate that neat nanoscale phase-separation and block-induced long-range connectivity can be optimized by designing aromatic ionomers with controlled architectures to improve the performances of polymer electrolyte membranes.

  7. Experimental study of the transport limits of intense heavy ion beams in the HCX

    International Nuclear Information System (INIS)

    Prost, L.R.; Bieniosek, F.M.; Celata, C.M.; Dugan, C.C.; Faltens, A.; Seidl, P.A.; Waldron, W.L.; Cohen, R.; Friedman, A.; Kireeff Covo, M.; Lund, S.M.; Molvik, A.W.; Haber, I.

    2004-01-01

    The High Current Experiment (HCX) at Lawrence Berkeley National Laboratory is part of the US 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 space-charge intensity (line charge density up to ∼ 0.2 (micro)C/m) over long pulse durations (4 (micro)s) in alternating gradient focusing lattices of electrostatic or magnetic quadrupoles. The experiment also contributes to the practical baseline knowledge of intense beam manipulations necessary for the design, construction and operation of a heavy ion driver for inertial fusion. This experiment is testing transport issues resulting from nonlinear space-charge effects and collective modes, beam centroid alignment and beam steering, matching, image charges, halo, electron cloud effects, and longitudinal bunch control. We first present the results for a coasting 1 MeV K + ion beam transported through the first ten electrostatic transport quadrupoles, measured with optical beam-imaging and double-slit phase-space diagnostics. This includes studies at two different radial fill factors (60% and 80%), for which the beam transverse distribution was characterized in detail. Additionally, beam energy measurements will be shown. We then discuss the first results of beam transport through four pulsed room-temperature magnetic quadrupoles (located downstream of the electrostatic quadrupoles), where the beam dynamics become more sensitive to the presence of secondary electrons

  8. Application of tracer techniques in studies of sediment transport in Vietnam

    International Nuclear Information System (INIS)

    Hai, P.S.; Quang, N.H.; Xuan, N.M.; Chuong, P.N.; Hien, P.Z.

    1997-01-01

    As a consequence of intensive erosion processes typical of the humid tropical one, as well as of human activities destroying tropical forests, grasslands and protective mangrove swamps, etc, most navigable estuaries in Vietnam suffer seriously from sedimentation. In order to maintain the necessary depth for the 7.000 ton vessels entering and leaving ports, a large amount of money is spent annually on dredging operation. A lot of hydraulic and sedimentary surveys were carried out in the past by different groups of researchers. However, owing to the complexity of sediment processes in estuarine areas under the hydrometeorological conditions typical of the southwest Pacific, the use of just any modelling approach is not suitable. In many cases, the conclusions inferred from mathematical models have been the controversial matter. The tracer techniques, which have been employed in the country since 1991, have provided a very efficient tool to obtain a dynamic idea of sediment transport. Many investigations of bedload transport using Sc-46 labelled glass and Ir-192 glass as radioactive tracers were carried out from 1992 to 1996 at Haiphong harbour area. Bedload transport rates under effect of northeast monsoon and southeast monsoon at 5 zones located on both sides of the navigation channel were estimated. In bedload transport studies, apart from conventional methods for assessment of transport thickness, a new method using the ratio of photoelectric peak to Compton region of spectra acquired directly on the sea bed was put forward and applied. The influence of dredging materials at two dumping sites under different tidal phases on in fill rate in the access channel was assessed by radioactive tracers. The qualitative and quantitative information on sediment transport at some experimental sites given by tracers was used by modelling specialists who have undertaken hydraulic and sedimentary surveys in this region

  9. A new δf method for neoclassical transport studies

    International Nuclear Information System (INIS)

    Wang, W.X.; Nakajima, N.; Okamoto, M.; Murakami, S.

    1999-01-01

    A new δf method is presented in detail to solve the drift kinetic equation for the simulation study of neoclassical transport. It is demonstrated that valid results essentially rely on the correct evaluation of the marker density g in the weight calculation. A new weighting scheme is developed without assuming g in the weight equation for advancing particle weights, unlike previous schemes. This scheme employs an additional weight function to directly solve g from its kinetic equation based on the δf method itself. Therefore, the severe constraint that the real marker distribution must be consistent with the initially assumed g is relaxed. An improved like-particle collision scheme is also presented. By compensating for momentum, energy and particle losses, the conservations of all three quantities are greatly improved during collisions. With the improvement in both the like-particle collision scheme and the weighting scheme, the δf simulation shows a significantly improved performance. The new δf method is applied to the study of ion neoclassical transports due to self-collisions, taking the effect of finite orbit width into account. The ion thermal transport near the magnetic axis is shown to be greatly reduced from its conventional neoclassical level, like that of previous δf simulations. On the other hand, the direct particle loss from the confinement region may strongly increase the ion thermal transport near the edge. It is found that the ion parallel flow near the axis is also largely reduced due to non-standard orbit topology. (author)

  10. Phase II Transport Model of Corrective Action Unit 98: Frenchman Flat, Nevada Test Site, Nye County, Nevada, Revision 1

    Energy Technology Data Exchange (ETDEWEB)

    Gregg Ruskuaff

    2010-01-01

    This document, the Phase II Frenchman Flat transport report, presents the results of radionuclide transport simulations that incorporate groundwater radionuclide transport model statistical and structural uncertainty, and lead to forecasts of the contaminant boundary (CB) for a set of representative models from an ensemble of possible models. This work, as described in the Federal Facility Agreement and Consent Order (FFACO) Underground Test Area (UGTA) strategy (FFACO, 1996; amended 2010), forms an essential part of the technical basis for subsequent negotiation of the compliance boundary of the Frenchman Flat corrective action unit (CAU) by Nevada Division of Environmental Protection (NDEP) and National Nuclear Security Administration Nevada Site Office (NNSA/NSO). Underground nuclear testing via deep vertical shafts was conducted at the Nevada Test Site (NTS) from 1951 until 1992. The Frenchman Flat area, the subject of this report, was used for seven years, with 10 underground nuclear tests being conducted. The U.S. Department of Energy (DOE), NNSA/NSO initiated the UGTA Project to assess and evaluate the effects of underground nuclear tests on groundwater at the NTS and vicinity through the FFACO (1996, amended 2010). The processes that will be used to complete UGTA corrective actions are described in the “Corrective Action Strategy” in the FFACO Appendix VI, Revision No. 2 (February 20, 2008).

  11. Experimental study of particle transport and density fluctuation in LHD

    International Nuclear Information System (INIS)

    Tanaka, K.; Michael, C.; Sanin, A.

    2005-01-01

    A variety of electron density (n e ) profiles have been observed in Large Helical Device (LHD). The density profiles change dramatically with heating power and toroidal magnetic field (B t ) under the same line averaged density. The particle transport coefficients, i.e., diffusion coefficient (D) and convection velocity (V) are experimentally obtained in the standard configuration from density modulation experiments. The values of D and V are estimated separately in the core and edge. The diffusion coefficients are found to be a strong function of electron temperature (T e ) and are proportional to T e 1.7±0.9 in the core and T e 1.1±0.14 in the edge. Edge diffusion coefficients are proportional to B t -2.08 . It is found that the scaling of D in the edge is close to gyro-Bohm-like in nature. Non-zero V is observed and it is found that the electron temperature gradient can drive particle convection, particularly in the core region. The convection velocity in the core reverses direction from inward to outward as the T e gradient increases. In the edge, convection is inward directed in most cases of the present data set. It shows a modest tendency, being proportional to T e gradient and remaining inward directed. However, the toroidal magnetic field also significantly affects the value and direction of V. The density fluctuation spectrum varies with heating power suggesting that it has an influence on particle transport. The value of K sub(perpendicular) ρ i is around 0.1, as expected for gyro-Bohm diffusion. Fluctuations are localized in both positive and negative density gradient regions of the hollow density profiles. The fluctuation power in each region is clearly distinguished having different phase velocity profiles. (author)

  12. Study on a phase space representation of quantum theory

    International Nuclear Information System (INIS)

    Ranaivoson, R.T.R; Raoelina Andriambololona; Hanitriarivo, R.; Raboanary, R.

    2013-01-01

    A study on a method for the establishment of a phase space representation of quantum theory is presented. The approach utilizes the properties of Gaussian distribution, the properties of Hermite polynomials, Fourier analysis and the current formulation of quantum mechanics which is based on the use of Hilbert space and linear operators theory. Phase space representation of quantum states and wave functions in phase space are introduced using properties of a set of functions called harmonic Gaussian functions. Then, new operators called dispersion operators are defined and identified as the operators which admit as eigenstates the basis states of the phase space representation. Generalization of the approach for multidimensional cases is shown. Examples of applications are given.

  13. Preliminary Studies Of A Phase Modulation Technique For Measuring Chromaticity

    International Nuclear Information System (INIS)

    Tan, C.-Y.

    2006-01-01

    The classical method for measuring chromaticity is to slowly modulate the RF frequency and then measure the betatron tune excursion. The technique that is discussed in this paper instead modulates the phase of the RF and then the chromaticity is obtained by phase demodulating the betatron tune. This technique requires knowledge of the betatron frequency in real time in order for the phase to be demodulated. Fortunately, the Tevatron has a tune tracker based on the phase locked loop principle which fits this requirement. A preliminary study with this technique has showed that it is a promising method for doing continuous chromaticity measurement and raises the possibility of doing successful chromaticity feedback with it

  14. A real case study on transportation scenario comparison

    Directory of Open Access Journals (Sweden)

    Tsoukiás A.

    2002-01-01

    Full Text Available This paper presents a real case study dealing with the comparison of transport scenarios. The study is conducted within a larger project concerning the establishment of the maritime traffic policy in Greece. The paper presents the problem situation and an appropriate problem formulation. Moreover a detailed version of the evaluation model is presented in the paper. The model consists of a complex hierarchy of evaluation models enabling us to take into account the multiple dimensions and points of view of the actors involved in the evaluations.

  15. Transportation capabilities study of DOE-owned spent nuclear fuel

    Energy Technology Data Exchange (ETDEWEB)

    Clark, G.L.; Johnson, R.A.; Smith, R.W. [Packaging Technology, Inc., Tacoma, WA (United States); Abbott, D.G.; Tyacke, M.J. [Lockheed Idaho Technologies Co., Idaho Falls, ID (United States)

    1994-10-01

    This study evaluates current capabilities for transporting spent nuclear fuel owned by the US Department of Energy. Currently licensed irradiated fuel shipping packages that have the potential for shipping the spent nuclear fuel are identified and then matched against the various spent nuclear fuel types. Also included are the results of a limited investigation into other certified packages and new packages currently under development. This study is intended to support top-level planning for the disposition of the Department of Energy`s spent nuclear fuel inventory.

  16. Plutonium disposition study phase 1b final report

    International Nuclear Information System (INIS)

    1993-01-01

    This report provides the results of the Westinghouse activities performed as part of the Plutonium Disposition Study Phase 1b. These activities, which took place from May 16, 1993 to September 15, 1993, build upon the work completed in Phase 1a, which concluded on May 15, 1993. In Phase 1a, three Plutonium Disposal Reactor (PDR) options were developed for the disposal of excess weapons grade plutonium from returned and dismantled nuclear weapons. This report documents the results of several tasks that were performed to further knowledge in specific areas leading up to Phase 2 of the PDR Study. The Westinghouse activities for Phase 1b are summarized as follows: (1) resolved technical issues concerning reactor physics including equilibrium cycle calculations, use of gadolinium, moderator temperature coefficient, and others as documented in Section 2.0; (2) analyzed large Westinghouse commercial plants for plutonium disposal; (3) reactor safety issues including the steam line break were resolved, and are included in Section 2.0; (4) several tasks related to the PDR Fuel Cycle were examined; (5) cost and deployment options were examined to determine optimal configuration for both plutonium disposal and tritium production; (6) response to questions from DOE and National Academy of Scientists (NAS) reviewers concerning the PDR Phase 1a report are included in Appendix A

  17. Fast electron transport study for inertial confinement fusion

    International Nuclear Information System (INIS)

    Touati, Michael

    2015-01-01

    A new hybrid reduced model for relativistic electron beam transport in solids and dense plasmas is presented. It is based on the two first angular moments of the relativistic kinetic equation completed with the Minerbo maximum angular entropy closure. It takes into account collective effects with the self-generated electromagnetic fields as well as collisional effects with the slowing down of the electrons in collisions with plasmons, bound and free electrons and their angular scattering on both ions and electrons. This model allows for fast computations of relativistic electron beam transport while describing the kinetic distribution function evolution. Despite the loss of information concerning the angular distribution of the electron beam, the model reproduces analytical estimates in the academic case of a collimated and monoenergetic electron beam propagating through a warm and dense Hydrogen plasma and hybrid PIC simulation results in a realistic laser-generated electron beam transport in a solid target. The model is applied to the study of the emission of Kα photons in laser-solid experiments and to the generation of shock waves. (author) [fr

  18. Characterization of single crystalline ZnTe and ZnSe grown by vapor phase transport

    Energy Technology Data Exchange (ETDEWEB)

    Trigubo, A B; Di Stefano, M C [FRBA-UTN, (1179) Buenos Aires (Argentina); Aguirre, M H [Dpto de Quim Inorg, Fac de Cs Quim, Univ Complutense, (28040) Madrid (Spain); Martinez, A M; D' Elia, R; Canepa, H; Heredia, E, E-mail: atrigubo@citefa.gov.a [CINSO-CITEFA: (1603) Villa Martelli, Pcia de Buenos Aires (Argentina)

    2009-05-01

    Tubular furnaces were designed and built to obtain single crystalline ZnTe and ZnSe ingots using respectively physical and chemical transport methods. Different temperature profiles and growth rates were analyzed in order to optimize the necessary crystalline quality for device development. Optical and scanning electron micrographs of the corrosion figures produced by chemical etching were used to obtain the dislocation density and the misorientation between adjacent subgrains in ZnTe and ZnSe wafers. Structural quality of the single crystalline material was determined by transmission electronic microscopy. Optical transmittance was measured by infrared transmission spectrometry and the resulting values were compared to commercial samples.

  19. Metropolitan transportation management center : a case study : Michigan intelligent transportation system : improving safety and air quality while reducing stress for motorists

    Science.gov (United States)

    1999-10-01

    The following case study provides a snapshot of Michigan's Intelligent Transportation Systems transportation management center (MITSC). It follows the outline provided in the companion document, Metropolitan Transportation Management Center Concepts ...

  20. Charge Transport and Phase Behavior of Imidazolium-Based Ionic Liquid Crystals from Fully Atomistic Simulations.

    Science.gov (United States)

    Quevillon, Michael J; Whitmer, Jonathan K

    2018-01-02

    Ionic liquid crystals occupy an intriguing middle ground between room-temperature ionic liquids and mesostructured liquid crystals. Here, we examine a non-polarizable, fully atomistic model of the 1-alkyl-3-methylimidazolium nitrate family using molecular dynamics in the constant pressure-constant temperature ensemble. These materials exhibit a distinct "smectic" liquid phase, characterized by layers formed by the molecules, which separate the ionic and aliphatic moieties. In particular, we discuss the implications this layering may have for electrolyte applications.

  1. [11]Cocaine: PET studies of cocaine pharmacokinetics, dopamine transporter availability and dopamine transporter occupancy

    International Nuclear Information System (INIS)

    Fowler, Joanna S.; Volkow, Nora D.; Wang, Gene-Jack; Gatley, S. John; Logan, Jean

    2001-01-01

    Cocaine was initially labeled with carbon-11 in order to track the distribution and pharmacokinetics of this powerful stimulant and drug of abuse in the human brain and body. It was soon discovered that [ 11 C]cocaine was not only useful for measuring cocaine pharmacokinetics and its relationship to behavior but that it is also a sensitive radiotracer for dopamine transporter (DAT) availability. Measures of DAT availability were facilitated by the development of a graphical analysis method (Logan Plot) for reversible systems which streamlined kinetic analysis. This expanded the applications of [ 11 C]cocaine to studies of DAT availability in the human brain and allowed the first comparative measures of the degree of DAT occupancy by cocaine and another stimulant drug methylphenidate. This article will summarize preclinical and clinical research with [ 11 C]cocaine

  2. CHARLES HORTON COOLEY'S THEORY OF TRANSPORTATION: TOWARDS AN INTERACTIONIST APPROACH FOR TRANSPORTATION STUDIES

    Science.gov (United States)

    Nakano, Takeshi

    The aim of this paper is to interpret Charles Horton Cooley's "Theory of Transportation", situating it in his interactionist sociology of communication and social process. Cooley defines transportation as a spatial and physical form of communication. He also develops a interactionist theory of valuation and articulates that value as an end of action is shaped an d transformed by communication and interaction. These insights suggest that transportation as a form of communication will change and develop economic society through transforming personal desires and values so as to change behaviours. Cooley's theory implies that an interactionist approach is useful for understanding the subjective side of phenomena of transportation.

  3. Transport and first-principles study of novel thermoelectric materials

    Science.gov (United States)

    Chi, Hang

    Thermoelectric materials can recover waste industrial heat and convert it to electricity as well as provide efficient local cooling of electronic devices. The efficiency of such environmentally responsible and exceptionally reliable solid state energy conversion is determined by the dimensionless figure-of-merit ZT = alpha2 sigmaT/kappa, where alpha is the Seebeck coefficient, sigma is the electrical conductivity, kappa is the thermal conductivity, and T is the absolute temperature. The goal of the thesis is to (i) illustrate the physics to achieve high ZT of advanced thermoelectric materials and (ii) explore fundamental structure and transport properties in novel condensed matter systems, via an approach combining comprehensive experimental techniques and state-of-the-art first-principles simulation methods. Thermo-galvanomagnetic transport coefficients are derived from Onsager's reciprocal relations and evaluated via solving Boltzmann transport equation using Fermi-Dirac statistics, under the relaxation time approximation. Such understanding provides insights on enhancing ZT through two physically intuitive and very effective routes: (i) improving power factor PF = alpha2sigma; and (ii) reducing thermal conductivity kappa, as demonstrated in the cases of Mg2Si1-xSnx solid solution and Ge/Te double substituted skutterudites CoSb3(1-x)Ge1.5x Te1.5x, respectively. Motivated by recent theoretical predictions of enhanced thermoelectric performance in highly mismatched alloys, ZnTe:N molecular beam epitaxy (MBE) films deposited on GaAs (100) substrates are carefully examined, which leads to a surprising discovery of significant phonon-drag thermopower (reaching 1-2 mV/K-1) at ~13 K. Further systematic study in Bi2Te3 MBE thin films grown on sapphire (0001) and/or BaF2 (111) substrates, reveal that the peak of phonon drag can be tuned by the choice of substrates with different Debye temperatures. Moreover, the detailed transport and structure studies of Bi2-xTl xTe3

  4. A Review of Study on Thermal Energy Transport System by Synthesis and Decomposition Reactions of Methanol

    Science.gov (United States)

    Liu, Qiusheng; Yabe, Akira; Kajiyama, Shiro; Fukuda, Katsuya

    The study on thermal energy transport system by synthesis and decomposition reactions of methanol was reviewed. To promote energy conservation and global environment protection, a two-step liquid-phase methanol synthesis process, which starts with carbonylation of methanol to methyl formate, then followed by the hydrogenolysis of the formate, was studied to recover wasted or unused discharged heat from industrial sources for the thermal energy demands of residential and commercial areas by chemical reactions. The research and development of the system were focused on the following three points. (1) Development of low-temperature decomposition and synthetic catalysts, (2) Development of liquid phase reactor (heat exchanger accompanying chemical reaction), (3) Simulation of the energy transport efficiency of entire system which contains heat recovery and supply sections. As the result of the development of catalyst, promising catalysts which agree with the development purposes for the methyl formate decomposition reaction and the synthetic reaction are being developed though some studies remain for the methanol decomposition and synthetic reactions. In the fundamental development of liquid phase reactor, the solubilities of CO and H2 gases in methanol and methyl formate were measured by the method of total pressure decrease due to absorption under pressures up to 1500kPa and temperatures up to 140°C. The diffusivity of CO gas in methanol was determined by measuring the diameter and solution time of single CO bubbles in methanol. The chemical reaction rate of methanol synthesis by hydrogenolysis of methyl formate was measured using a plate-type of Raney copper catalyst in a reactor with rectangular channel and in an autoclave reactor. The reaction characteristics were investigated by carrying out the experiments at various temperatures, flow rates and at various catalyst development conditions. We focused on the effect of Raney copper catalyst thickness on the liquid-phase

  5. Phase field model for the study of boiling

    International Nuclear Information System (INIS)

    Ruyer, P.

    2006-07-01

    This study concerns both the modeling and the numerical simulation of boiling flows. First we propose a review concerning nucleate boiling at high wall heat flux and focus more particularly on the current understanding of the boiling crisis. From this analysis we deduce a motivation for the numerical simulation of bubble growth dynamics. The main and remaining part of this study is then devoted to the development and analyze of a phase field model for the liquid-vapor flows with phase change. We propose a thermodynamic quasi-compressible formulation whose properties match the one required for the numerical study envisaged. The system of governing equations is a thermodynamically consistent regularization of the sharp interface model, that is the advantage of the di use interface models. We show that the thickness of the interface transition layer can be defined independently from the thermodynamic description of the bulk phases, a property that is numerically attractive. We derive the kinetic relation that allows to analyze the consequences of the phase field formulation on the model of the dissipative mechanisms. Finally we study the numerical resolution of the model with the help of simulations of phase transition in simple configurations as well as of isothermal bubble dynamics. (author)

  6. Two-phase, mass-transport model for direct methanol fuel cells with effect of non-equilibrium evaporation and condensation

    Science.gov (United States)

    Yang, W. W.; Zhao, T. S.

    A two-phase, mass-transport model for liquid-feed direct methanol fuel cells (DMFCs) is developed by taking into account the effect of non-equilibrium evaporation and condensation of methanol and water. The comparison between the present model and other models indicates that the present model yields more reasonable predictions of cell performance. Particularly, it is shown that the models that invoke a thermodynamic-equilibrium assumption between phases will overestimate mass-transport rates of methanol and water, thereby resulting in an inaccurate prediction of cell performance. The parametric study using the present model reveals that the gas coverage at the flow channel-diffusion-layer interface is directly related to the gas-void fraction inside the anode porous region; increasing the gas-void fraction will increase the mass-transfer resistance of methanol and thus lower cell performance. The effects of the geometric dimensions of the cell structure, such as channel width and rib width, on cell performance are also investigated with the model developed in this work.

  7. Electrical properties and transport mechanisms in phase change memory thin films of quasi-binary-line GeTe–Sb{sub 2}Te{sub 3} chalcogenide semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Sherchenkov, A. A. [National Research University of Electronic Technology (Russian Federation); Kozyukhin, S. A., E-mail: sergkoz@igic.ras.ru [Russian Academy of Sciences, Kurnakov Institute of General and Inorganic Chemistry (Russian Federation); Lazarenko, P. I.; Babich, A. V. [National Research University of Electronic Technology (Russian Federation); Bogoslovskiy, N. A. [Russian Academy of Sciences, Ioffe Physical–Technical Institute (Russian Federation); Sagunova, I. V.; Redichev, E. N. [National Research University of Electronic Technology (Russian Federation)

    2017-02-15

    The temperature dependences of the resistivity and current–voltage (I–V) characteristics of phase change memory thin films based on quasi-binary-line GeTe–Sb{sub 2}Te{sub 3} chalcogenide semiconductors Ge{sub 2}Sb{sub 2}Te{sub 5}, GeSb{sub 2}Te{sub 5}, and GeSb{sub 4}Te{sub 7} are investigated. The effect of composition variation along the quasibinary line on the electrical properties and transport mechanisms of the thin films is studied. The existence of three ranges with different I–V characteristics is established. The position and concentration of energy levels controlling carrier transport are estimated. The results obtained show that the electrical properties of the thin films can significantly change during a shift along the quasi-binary line GeTe–Sb{sub 2}Te{sub 3}, which is important for targeted optimization of the phase change memory technology.

  8. Ion transport property studies on PEO-PVP blended solid polymer electrolyte membranes

    International Nuclear Information System (INIS)

    Chandra, Angesh; Agrawal, R C; Mahipal, Y K

    2009-01-01

    The ion transport property studies on Ag + ion conducting PEO-PVP blended solid polymer electrolyte (SPE) membranes, (1 - x)[90PEO : 10AgNO 3 ] : xPVP, where x = 0, 1, 2, 3, 5, 7, 10 (wt%), are reported. SPE films were caste using a novel hot-press technique instead of the traditional solution cast method. The conventional solid polymeric electrolyte (SPE) film, (90PEO : 10AgNO 3 ), also prepared by the hot-press method and identified as the highest conducting composition at room temperature on the basis of PEO-AgNO 3 -salt concentration dependent conductivity studies, was used as the first-phase polymer electrolyte host into which PVP were dispersed as second-phase dispersoid. A two-fold conductivity enhancement from that of the PEO host could be achieved at room temperature for PVP blended SPE film composition: 98(90PEO : 10AgNO 3 ) : 2PVP. This has been referred to as optimum conducting composition (OCC). The formation of SPE membranes and material characterizations were done with the help of the XRD and DSC techniques. The ion transport mechanism in this SPE OCC has been characterized with the help of basic ionic parameters, namely ionic conductivity (σ), ionic mobility (μ), mobile ion concentration (n) and ionic transference number (t ion ). Solid-state polymeric batteries were fabricated using OCC as electrolyte and the cell-potential discharge characteristics were studied under different load conditions.

  9. Western Wind and Solar Integration Study Phase 2 (Presentation)

    Energy Technology Data Exchange (ETDEWEB)

    Lew, D.; Brinkman, G.; Ibanez, E.; Kumar, N.; Lefton, S.; Jordan, G.; Venkataraman, S.; King, J.

    2013-06-01

    This presentation accompanies Phase 2 of the Western Wind and Solar Integration Study, a follow-on to Phase 1, which examined the operational impacts of high penetrations of variable renewable generation on the electric power system in the West and was one of the largest variable generation studies to date. High penetrations of variable generation can induce cycling of fossil-fueled generators. Cycling leads to wear-and-tear costs and changes in emissions. Phase 2 calculated these costs and emissions, and simulated grid operations for a year to investigate the detailed impact of variable generation on the fossil-fueled fleet. The presentation highlights the scope of the study and results.

  10. Study of thermodynamic and transport properties of strongly interacting matter in a color string percolation model at RHIC

    International Nuclear Information System (INIS)

    Sahoo, Pragati; Tiwari, Swatantra Kumar; De, Sudipan; Sahoo, Raghunath

    2017-01-01

    The main perspectives of Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory are to study the properties of the strongly interacting matter and to explore the conjectured Quantum Chromodynamics (QCD) phase diagram. Lattice QCD (lQCD) predicts a smooth crossover at vanishing baryon chemical potential (μ B ) and other QCD based theoretical models predicts first order phase transition at large μB. Searching of the Critical Point in the QCD phase diagram, finding the evidence and nature of phase transition, studying the properties of the matter formed in nuclear collisions as a function of √sNN are the main goals of RHIC. To investigate the nature of the matter produced at heavy-ion collisions, the thermodynamical and transport quantities like: energy density, shear viscosity etc. are studied. It is expected that the ratio of shear viscosity (η) to entropy density (s) would exhibit a minimum value near the QCD critical point

  11. A new method to describe two-phase solvent extraction based on net transport potential derived as linear combinations of forward and reverse constituents

    International Nuclear Information System (INIS)

    Nabeshima, Masahiro

    1998-01-01

    With the view to avoiding the difficulties encountered in estimating thermodynamic activities of the multiple chemical species in two-phase liquid system, a set of forward, reverse, net and total transport potentials are defined to represent the chemical state of a transferring solute during transient using bulk concentrations. The net transport potential corresponds to that in the conventional two-film model of diffusion-controlled processes. The overall driving forces of mass transport are redefined as the derivatives of the relevant transport potentials differentiated with respect to a state variable newly defined in terms of the bulk concentrations of the solute contained in both phases. Net and total quantities, i.e. transport potentials, overall driving forces and the molar fluxes are obtained as linear combinations of those for forward and reverse directions. The topical features presented by these quantities and their mutual relations are discussed in detail. The experimental new overall transport coefficient for U(VI) varied in accord with the changes in the theoretical net transport potential and overall driving force. The present method permits describing the extractive mass transport consistently both to forward and reverse directions of transport. (author)

  12. Comparative divertor-transport study for helical devices

    International Nuclear Information System (INIS)

    Feng, Y.; Sardei, F.; Kobayashi, M.

    2008-10-01

    Using the island divertors (ID) of W7-AS and W7-X and the helical divertor (HD) of LHD as examples, the paper presents a comparative divertor transport study for three typical helical devices of different machine-size following two distinct divertor concepts, aiming at identifying common physics issues/effects for mutual validation and combined studies. Based on EMC3/EIRENE simulations supported by experimental results, the paper first reviews and compares the essential transport features of the W7-AS ID and the LHD HD in order to build a base and framework for a predictive study of W7-X. Revealed is the fundamental role of the low-order magnetic islands in both divertor concepts. Preliminary EMC3/EIRENE simulation results for W7-X are presented and discussed with respect to W7-AS and LHD in order to show how the individual field and divertor topologies affect the divertor transport and performance. For instance, a high recycling regime which is absent from W7-AS and LHD is expected for W7-X. Topics addressed are restricted to the basic function elements of a divertor such as particle flux enhancement and impurity retention. In particular, the divertor function on reducing the influx of intrinsic impurities is examined for all the three devices under different divertor plasma conditions. Special attention is paid to examining the island screening potential of intrinsic impurities which has been predicted for all the three devices under high divertor collisionality conditions. The results are discussed in conjunction with the experimental observations for high density divertor plasmas in W7-AS and LHD. (author)

  13. Electronic transport in mixed-phase hydrogenated amorphous/nanocrystalline silicon thin films

    Science.gov (United States)

    Wienkes, Lee Raymond

    Interest in mixed-phase silicon thin film materials, composed of an amorphous semiconductor matrix in which nanocrystalline inclusions are embedded, stems in part from potential technological applications, including photovoltaic and thin film transistor technologies. Conventional mixed-phase silicon films are produced in a single plasma reactor, where the conditions of the plasma must be precisely tuned, limiting the ability to adjust the film and nanoparticle parameters independently. The films presented in this thesis are deposited using a novel dual-plasma co-deposition approach in which the nanoparticles are produced separately in an upstream reactor and then injected into a secondary reactor where an amorphous silicon film is being grown. The degree of crystallinity and grain sizes of the films are evaluated using Raman spectroscopy and X-ray diffraction respectively. I describe detailed electronic measurements which reveal three distinct conduction mechanisms in n-type doped mixed-phase amorphous/nanocrystalline silicon thin films over a range of nanocrystallite concentrations and temperatures, covering the transition from fully amorphous to ~30% nanocrystalline. As the temperature is varied from 470 to 10 K, we observe activated conduction, multiphonon hopping (MPH) and Mott variable range hopping (VRH) as the nanocrystal content is increased. The transition from MPH to Mott-VRH hopping around 100K is ascribed to the freeze out of the phonon modes. A conduction model involving the parallel contributions of these three distinct conduction mechanisms is shown to describe both the conductivity and the reduced activation energy data to a high accuracy. Additional support is provided by measurements of thermal equilibration effects and noise spectroscopy, both done above room temperature (>300 K). This thesis provides a clear link between measurement and theory in these complex materials.

  14. Single-phase and two phase bubbly flow in a T connection: theoretical and experimental study

    International Nuclear Information System (INIS)

    Hervieu, Eric

    1988-01-01

    The objective of this research thesis is to highlight the driving factors of the separation of phases of a bubbly flow in a T junction, and to develop a prediction model. In a first part, the author reports the rigorous formulation of equations averaged on the T volume. He shows that it's not possible to solve globally the problem with these equations. Then, he reports a bibliographical study on the modelling of a bubbly flow, and, based upon this study, highlights intrinsic characteristics of the flow, and explains its dynamic mechanisms. He reports the development of the theoretical model, and describes the experimental installation used to validate it. In the third part, he reports the study of the liquid-gas interaction, and presents the adopted approach: study of the behaviour of an isolated bubble within a single-phase flow. Experimentation is used to check theoretical predictions. Results are used to compute phase separation. The obtained results are again compared with experimental results to validate the global relevance of the model [fr

  15. Role of hot electron transport in scintillators: A theoretical study

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Huihui [SZU-NUS Collaborative Innovation Center for Optoelectronic Science and Technology, Key Lab. of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Optoelectronic Engineering, Shenzhen Univ. (China); Li, Qi [Physical Sciences Division, IBM TJ Watson Research Center, Yorktown Heights, NY (United States); Department of Computer Science, University of Illinois at Urbana-Champaign, Urbana, IL (United States); Lu, Xinfu; Williams, R.T. [Department of Physics, Wake Forest University, Winston Salem, NC (United States); Qian, Yiyang [College of Engineering and Applied Science, Nanjing University (China); Wu, Yuntao [Scintillation Materials Research Center, University of Tennessee, Knoxville, TN (United States)

    2016-10-15

    Despite recent intensive study on scintillators, several fundamental questions on scintillator properties are still unknown. In this work, we use ab-initio calculations to determine the energy dependent group velocity of the hot electrons from the electronic structures of several typical scintillators. Based on the calculated group velocities and optical phonon frequencies, a Monte-Carlo simulation of hot electron transport in scintillators is carried out to calculate the thermalization time and diffusion range in selected scintillators. Our simulations provide physical insights on a recent trend of improved proportionality and light yield from mixed halide scintillators. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  16. Study of quiet turbofan STOL aircraft for short haul transportation

    Science.gov (United States)

    Higgins, T. P.; Stout, E. G.; Sweet, H. S.

    1973-01-01

    Conceptual designs of Quiet Turbofan STOL Short-Haul Transport Aircraft for the mid-1980 time period are developed and analyzed to determine their technical, operational, and economic feasibility. A matrix of aircraft using various high-lift systems and design parameters are considered. Variations in aircraft characteristics, airport geometry and location, and operational techniques are analyzed systematically to determine their effects on the market, operating economics, and community acceptance. In these studies, the total systems approach is considered to be critically important in analyzing the potential of STOL aircraft to reduce noise pollution and alleviate the increasing air corridor and airport congestion.

  17. Mass transport aspects of polymer electrolyte fuel cells under two-phase flow conditions

    Energy Technology Data Exchange (ETDEWEB)

    Kramer, D.

    2007-03-15

    This well-illustrated, comprehensive dissertation by Dr. Ing. Denis Kramer takes an in-depth look at polymer electrolyte fuel cells (PEFC) and the possibilities for their application. First of all, the operating principles of polymer electrolyte fuel cells are described and discussed, whereby thermodynamics aspects and loss mechanisms are examined. The mass transport diagnostics made with respect to the function of the cells are discussed. Field flow geometry, gas diffusion layers and, amongst other things, liquid distribution, the influence of flow direction and the low-frequency behaviour of air-fed PEFCs are discussed. Direct methanol fuel cells are examined, as are the materials chosen. The documentation includes comprehensive mathematical and graphical representations of the mechanisms involved.

  18. The use of a diffuse interface model to estimate effective transport properties for two-phase flows in porous media

    International Nuclear Information System (INIS)

    Fichot, Floriana; Duval, Fabiena; Garcia, Aureliena; Belloni, Julien; Quintard, Michel

    2005-01-01

    Full text of publication follows: In the framework of its research programme on severe nuclear reactor accidents, IRSN investigates the water flooding of an overheated porous bed, where complex two-phase flows are likely to exist. The goal is to describe the flow with a general model, covering rods and debris beds regions in the vessel. A better understanding of the flow at the pore level appears to be necessary in order to justify and improve closure laws of macroscopic models. Although the Direct Numerical Simulation (DNS) of two-phase flows is possible with several methods, applications are now limited to small computational domains, typically of the order of a few centimeters. Therefore, numerical solutions at the reactor scale can only be obtained by using averaged models. Volume averaging is the most traditional way of deriving such models. For nuclear safety codes, a control volume must include a few rods or a few debris particles, with a characteristic dimension of a few centimeters. The difficulty usually met with averaged models is the closure of several transport or source terms which appear in the averaged conservation equations (for example the interfacial drag or the heat transfers between phases) [2]. In the past, the closure of these terms was obtained, when possible, from one-dimensional experiments that allowed measurements of heat flux or pressure drops. For more complex flows, the experimental measurement of local parameters is often impossible and the effective properties cannot be determined easily. An alternative way is to perform 'numerical experiments' with numerical simulations of the local flow. As mentioned above, the domain of application of DNS corresponds to the size of control volumes necessary to derive averaged models. Therefore DNS appears as a powerful tool to investigate the local features of a two-phase flow in complex geometries. Diffuse interface methods provide a way to model flows with interfacial phenomena through an

  19. Quantification of glacial effects on radionuclide transport: transport sensitivity studies for SKI's SITE-94

    International Nuclear Information System (INIS)

    King-Clayton, L.M.; Smith, P.A.; Dverstorp, B.

    1996-01-01

    with ice sheet coverage), and correspond to periods of high groundwater discharge at the margin of the modelled ice sheets. These short-term flux maxima may exceed the corresponding fluxes from the near-field and represent a relatively rapid 'flushing out' of radionuclides from the repository host rock. Fluxes to the biosphere may, for limited periods (∼2000 years or less), be 3 times higher than those from the near-field. The occurrence of these peak fluxes requires careful consideration in any performance assessment which wishes to take account of future changes in groundwater flow conditions. The study has provided a quantitative way of illustrating the possible effects of future glaciations on radionuclide transport from a repository. Such effects are likely to be significant in any potential siting area predicted to be affected by future periods of ice cover. (author)

  20. Self-consistent quasi-static radial transport during the substorm growth phase

    Science.gov (United States)

    Le Contel, O.; Pellat, R.; Roux, A.

    2000-06-01

    We develop a self-consistent description of the slowly changing magnetic configuration of the near-Earth plasma sheet (NEPS) during substorm growth phase. This new approach is valid for quasi-static fluctuations ωcurrent. The quasi-neutrality condition (QNC) is solved via an expansion in the small parameter Te/Ti (Te/Ti is the ratio between the electronic and ionic temperatures). To the lowest order in Te/Ti, we find that the enforcement of QNC implies the presence of a global electrostatic potential which is constant for a given magnetic field line but varies across the magnetic field. The corresponding electric field shields the effect of the inductive component of the electric field, thereby producing a partial reduction of the motion that would correspond to the inductive electric field. Furthermore, we show that enforcing the QNC implies a field-aligned potential drop which is computed to the next order in Te/Ti in a companion paper [Le Contel et al., this issue]. In the present paper, we show that the direction of the azimuthal electric field varies along the field line, thus the equatorial electric field cannot be mapped onto the ionosphere. Furthermore during the growth phase, the (total) azimuthal electric field is directed eastward, close to the equator, and westward, off-equator. Thus large equatorial pitch angle particles drift tailward, whereas small pitch angle particles drift earthward.

  1. Aerodynamic study of state transport bus using computational fluid dynamics

    Science.gov (United States)

    Kanekar, Siddhesh; Thakre, Prashant; Rajkumar, E.

    2017-11-01

    The main purpose of this study was to develop the aerodynamic study of a Maharashtra state road transport bus. The rising fuel price and strict government regulations makes the road transport uneconomical now days. With the objective of increasing fuel efficiency and reducing the emission of harmful exhaust gases. It has been proven experimentally that vehicle consumes almost 40% of the available useful engine power to overcome the drag resistance. This provides us a huge scope to study the influence of aerodynamic drag. The initial of the project was to identify the drag coefficient of the existing ordinary type model called “Parivartan” from ANSYS fluent. After preliminary analysis of the existing model corresponding changes are made in such a way that their implementation should be possible at workshop level. The simulation of the air flow over the bus was performed in two steps: design on SolidWorks CAD and ANSYS (FLUENT) is used as a virtual analysis tool to estimate the drag coefficient of the bus. We have used the turbulence models k-ε Realizable having a better approximation of the actual result. Around 28% improvement in the drag coefficient is achieved by CFD driven changes in the bus design. Coefficient of drag is improved by 28% and fuel efficiency increased by 20% by CFD driven changes.

  2. Efficient C1-continuous phase-potential upwind (C1-PPU) schemes for coupled multiphase flow and transport with gravity

    Science.gov (United States)

    Jiang, Jiamin; Younis, Rami M.

    2017-10-01

    In the presence of counter-current flow, nonlinear convergence problems may arise in implicit time-stepping when the popular phase-potential upwinding (PPU) scheme is used. The PPU numerical flux is non-differentiable across the co-current/counter-current flow regimes. This may lead to cycles or divergence in the Newton iterations. Recently proposed methods address improved smoothness of the numerical flux. The objective of this work is to devise and analyze an alternative numerical flux scheme called C1-PPU that, in addition to improving smoothness with respect to saturations and phase potentials, also improves the level of scalar nonlinearity and accuracy. C1-PPU involves a novel use of the flux limiter concept from the context of high-resolution methods, and allows a smooth variation between the co-current/counter-current flow regimes. The scheme is general and applies to fully coupled flow and transport formulations with an arbitrary number of phases. We analyze the consistency property of the C1-PPU scheme, and derive saturation and pressure estimates, which are used to prove the solution existence. Several numerical examples for two- and three-phase flows in heterogeneous and multi-dimensional reservoirs are presented. The proposed scheme is compared to the conventional PPU and the recently proposed Hybrid Upwinding schemes. We investigate three properties of these numerical fluxes: smoothness, nonlinearity, and accuracy. The results indicate that in addition to smoothness, nonlinearity may also be critical for convergence behavior and thus needs to be considered in the design of an efficient numerical flux scheme. Moreover, the numerical examples show that the C1-PPU scheme exhibits superior convergence properties for large time steps compared to the other alternatives.

  3. Laboratory and numerical investigations of kinetic interface sensitive tracers transport for immiscible two-phase flow porous media systems

    Science.gov (United States)

    Tatomir, Alexandru Bogdan A. C.; Sauter, Martin

    2017-04-01

    A number of theoretical approaches estimating the interfacial area between two fluid phases are available (Schaffer et al.,2013). Kinetic interface sensitive (KIS) tracers are used to describe the evolution of fluid-fluid interfaces advancing in two phase porous media systems (Tatomir et al., 2015). Initially developed to offer answers about the supercritical (sc)CO2 plume movement and the efficiency of trapping in geological carbon storage reservoirs, KIS tracers are tested in dynamic controlled laboratory conditions. N-octane and water, analogue to a scCO2 - brine system, are used. The KIS tracer is dissolved in n-octane, which is injected as the non-wetting phase in a fully water saturated porous media column. The porous system is made up of spherical glass beads with sizes of 100-250 μm. Subsequently, the KIS tracer follows a hydrolysis reaction over the n-octane - water interface resulting in an acid and phenol which are both water soluble. The fluid-fluid interfacial area is described numerically with the help of constitutive-relationships derived from the Brooks-Corey model. The specific interfacial area is determined numerically from pore scale calculations, or from different literature sources making use of pore network model calculations (Joekar-Niasar et al., 2008). This research describes the design of the laboratory setup and compares the break-through curves obtained with the forward model and in the laboratory experiment. Furthermore, first results are shown in the attempt to validate the immiscible two phase flow reactive transport numerical model with dynamic laboratory column experiments. Keywords: Fluid-fluid interfacial area, KIS tracers, model validation, CCS, geological storage of CO2

  4. Nevada potential repository preliminary transportation strategy Study 2. Volume 1

    International Nuclear Information System (INIS)

    1996-02-01

    The objectives of this study were to build on the findings of the Nevada Potential Repository Preliminary Transportation Strategy Study 1 (CRWMS M ampersand O 1995b), and to provide additional information for input to the repository environmental impact statement (EIS) process. In addition, this study supported the future selection of a preferred rail corridor and/or heavy haul route based on defensible data, methods, and analyses. Study research did not consider proposed legislation. Planning was conducted according to the Civilian Radioactive Waste Management Program Plan (DOE 1994a). The specific objectives of Study 2 were to: eliminate or reduce data gaps, inconsistencies, and uncertainties, and strengthen the analysis performed in Study 1; develop a preliminary list of rail route evaluation criteria that could be used to solicit input from stakeholders during scoping meetings. The evaluation criteria will be revised based on comments received during scoping; restrict and refine the width of the four rail corridors identified in Study 1 to five miles or less, based on land use constraints and engineering criteria identified and established in Study 2; evaluate national-level effects of routing spent nuclear fuel and high-level waste to the four identified branch lines, including the effects of routing through or avoiding Las Vegas; continue to gather published land use information and environmental data to support the repository EIS; continue to evaluate heavy haul truck transport over three existing routes as an alternative to rail and provide sufficient information to support the repository EIS process; and evaluate secondary uses for rail (passenger use, repository construction, shared use)

  5. Study supporting the phasing out of environmentally harmful subsidies. Annexes to Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Withana, S.; Ten Brink, P.; Franckx, L.; Hirschnitz-Garbers, M.; Mayeres, I.; Oosterhuis, F.; Porsch, L.

    2012-10-15

    The need to reform ineffective or harmful public subsidies has long been recognised and has been a contentious point of discussion for several years. The EU has a long-standing commitment to removing or phasing out environmentally harmful subsidies (EHS). Most recently, the need to phase out EHS is reiterated in the 'Roadmap for a resource efficient Europe' which includes a milestone that 'by 2020 EHS will be phased out, with due regard to the impact on people in need'. Despite several commitments, progress has been slow and subsidies remain an issue in most EU countries. This study focuses specifically on EHS at the level of EU Member States; it identifies key types of EHS and examines cases of existing EHS across a range of environmental sectors and issues, including subsidies from non-action. The study also analyses examples of good practices in the reform of EHS in EU Member States and the lessons that can be learnt from these cases. Finally, based on this analysis, it develops practical recommendations on phasing out and reforming EHS to support the objectives of the Europe 2020 Strategy and the resource efficiency agenda. The study was carried out between January and October 2012 and is based on an analysis of literature and consultation with experts and policy makers. The sectoral cases studied are listed and discussed in this annex report: agriculture, climate and energy, fisheries, food, forestry, materials, transport, waste, and water.

  6. Seismic risk analysis in the German risk study phase B

    International Nuclear Information System (INIS)

    Hasser, D.; Liemersdorf, J.

    1989-01-01

    The paper discusses some aspects of the seismic risk part of the German risk study for nuclear power plants, phase B. First simplified analyses in phase A of the study allowed a rough classification of structures and systems of the PWR reference plant according to their seismic risk contribution. These studies were extended in phase B using improved models for the dynamic analyses of buildings, structures and components as well as for the probabilistic analyses of seismic loading, failure probabilities and event trees. The methodology of deriving probabilistic seismic load descriptions is explained and compared with the methods in phase A of the study and in other studies. Some details of the linear and nonlinear dynamic analyses of structures are reported, in order to demonstrate the influence of different assumptions for material behavior and failure criteria. The probabilistic structural and event tree analyses are discussed with respect to the distribution assumptions, acceptable simplifications, special results for the PWR reference plant and, finally, the influence of model uncertainties

  7. Seismic risk analyses in the German Risk Study, phase B

    International Nuclear Information System (INIS)

    Hosser, D.; Liemersdorf, H.

    1991-01-01

    The paper discusses some aspects of the seismic risk part of the German Risk Study for Nuclear Power Plants, Phase B. First simplified analyses in Phase A of the study allowed only a rough classification of structures and systems of the PWR reference plant according to their seismic risk contribution. These studies were extended in Phase B using improved models for the dynamic analyses of buildings, structures and components as well as for the probabilistic analyses of seismic loading, failure probabilities and event trees. The methodology of deriving probabilistic seismic load descriptions is explained and compared with the methods in Phase A of the study and in other studies. Some details of the linear and nonlinear dynamic analyses of structures are reported in order to demonstrate the influence of different assumptions for material behaviour and failure criteria. The probabilistic structural and event tree analyses are discussed with respect to distribution assumptions, acceptable simplifications and model uncertainties. Some results for the PWR reference plant are given. (orig.)

  8. Auxiliary analyses in support of performance assessment of a hypothetical low-level waste facility: Two-phase flow and contaminant transport in unsaturated soils with application to low-level radioactive waste disposal. Volume 2

    International Nuclear Information System (INIS)

    Binning, P.; Celia, M.A.; Johnson, J.C.

    1995-05-01

    A numerical model of multiphase air-water flow and contaminant transport in the unsaturated zone is presented. The multiphase flow equations are solved using the two-pressure, mixed form of the equations with a modified Picard linearization of the equations and a finite element spatial approximation. A volatile contaminant is assumed to be transported in either phase, or in both phases simultaneously. The contaminant partitions between phases with an equilibrium distribution given by Henry's Law or via kinetic mass transfer. The transport equations are solved using a Galerkin finite element method with reduced integration to lump the resultant matrices. The numerical model is applied to published experimental studies to examine the behavior of the air phase and associated contaminant movement under water infiltration. The model is also used to evaluate a hypothetical design for a low-level radioactive waste disposal facility. The model has been developed in both one and two dimensions; documentation and computer codes are available for the one-dimensional flow and transport model

  9. Study of neoclassical transport in LHD plasmas by applying the DCOM/NNW neoclassical transport database

    International Nuclear Information System (INIS)

    Wakasa, Arimitsu; Oikawa, Shun-ichi; Murakami, Sadayoshi

    2008-01-01

    In helical systems, neoclassical transport is one of the important issues in addition to anomalous transport, because of a strong temperature dependency of heat conductivity and an important role in the radial electric field determination. Therefore, the development of a reliable tool for the neoclassical transport analysis is necessary for the transport analysis in Large Helical Device (LHD). We have developed a neoclassical transport database for LHD plasmas, DCOM/NNW, where mono-energetic diffusion coefficients are evaluated by the Monte Carlo method, and the diffusion coefficient database is constructed by a neural network technique. The input parameters of the database are the collision frequency, radial electric field, minor radius, and configuration parameters (R axis , beta value, etc). In this paper, database construction including the plasma beta is investigated. A relatively large Shafranov shift occurs in the finite beta LHD plasma, and the magnetic field configuration becomes complex leading to rapid increase in the number of the Fourier modes in Boozer coordinates. DCOM/NNW can evaluate neoclassical transport accurately even in such a configuration with a large number of Fourier modes. The developed DCOM/NNW database is applied to a finite-beta LHD plasma, and the plasma parameter dependences of neoclassical transport coefficients and the ambipolar radial electric field are investigated. (author)

  10. Development of ANC-type empirical two-phase pump model for full size CANDU primary heat transport pump

    International Nuclear Information System (INIS)

    Chan, A.M.C.; Huynh, H.M.

    2004-01-01

    The development of an ANC-type empirical two-phase pump model for CANDU (Canadian Deuterium) reactor primary heat transport pumps is described in the present paper. The model was developed based on Ontario Hydro Technologies' full scale Darlington pump first quadrant test data. The functional form of the ANC model which is widely used was chosen to facilitate the implementation of the model into existing computer codes. The work is part of a bigger test program with the aims: (1) to produce high quality pump performance data under off-normal operating conditions using both full-size and model scale pumps; (2) to advance our basic understanding of the dominant mechanisms affecting pump performance based on more detailed local measurements; and (3) to develop a 'best-estimate' or improved pump model for use in reactor licensing and safety analyses. (author)

  11. Effect of a static magnetic field on silicon transport in liquid phase diffusion growth of SiGe

    Energy Technology Data Exchange (ETDEWEB)

    Armour, N.; Dost, S. [Crystal Growth Laboratory, University of Victoria, Victoria, BC V8W 3P6 (Canada)

    2010-03-15

    Liquid phase diffusion experiments have been performed without and with the application of a 0.4 T static magnetic field using a three-zone DC furnace system. SiGe crystals were grown from the germanium side for a period of 72 h. Experiments have led to the growth of single crystal sections varying from 0 to 10 mm thicknesses. Examination of the processed samples (single and polycrystalline sections) has shown that the effect of the applied static magnetic field is significant. It alters the temperature distribution in the system, reduces mass transport in the melt, and leads to a much lower growth rate. The initial curved growth interface was slightly flattened under the effect of magnetic field. There were no growth striations in the single crystal sections of the samples. (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  12. Purification of a Multidrug Resistance Transporter for Crystallization Studies

    Directory of Open Access Journals (Sweden)

    Kamela O. Alegre

    2015-03-01

    Full Text Available Crystallization of integral membrane proteins is a challenging field and much effort has been invested in optimizing the overexpression and purification steps needed to obtain milligram amounts of pure, stable, monodisperse protein sample for crystallography studies. Our current work involves the structural and functional characterization of the Escherichia coli multidrug resistance transporter MdtM, a member of the major facilitator superfamily (MFS. Here we present a protocol for isolation of MdtM to increase yields of recombinant protein to the milligram quantities necessary for pursuit of structural studies using X-ray crystallography. Purification of MdtM was enhanced by introduction of an elongated His-tag, followed by identification and subsequent removal of chaperonin contamination. For crystallization trials of MdtM, detergent screening using size exclusion chromatography determined that decylmaltoside (DM was the shortest-chain detergent that maintained the protein in a stable, monodispersed state. Crystallization trials of MdtM performed using the hanging-drop diffusion method with commercially available crystallization screens yielded 3D protein crystals under several different conditions. We contend that the purification protocol described here may be employed for production of high-quality protein of other multidrug efflux members of the MFS, a ubiquitous, physiologically and clinically important class of membrane transporters.

  13. Fabrication and transport studies of graphene-superconductor heterostructures

    Science.gov (United States)

    Hu, Jiuning; Wu, Tailung; Tian, Jifa; Chen, Yong

    2014-03-01

    Recently, graphene based stacked heterostructures, e.g., graphene and boron nitride (BN) multi-layers, have attracted much attention as a system to study novel interaction-driven physics (e.g., excitonic condensation) and perform interesting measurements (eg. Coulomb drag and tunneling). The realm of graphene-superconductor heterostructures remains less unexplored, while such a system offers various interesting prospects (effects of superconductor vortices lattices on over-layering graphene and quantum Hall states, where novel phenomena such as anionic excitations have been predicted). We have used polyvinyl alcohol (PVA) based carrier films and a micro-manipulator to transfer mechanically exfoliated flakes and fabricated graphene/BN/NbSe2 structures to study the transport properties of graphene in close proximity to electrically isolated superconducting NbSe2 films. The NbSe2 film shows the superconducting transition temperature of ~7 K and upper critical field of ~3.5 T after device fabrication. We will present results from magneto-transport in graphene and graphene-NbSe2 Coulomb drag and tunneling measurements.

  14. Structure and ionic transport studies of sodium borophosphate glassy system

    International Nuclear Information System (INIS)

    Anantha, P.S.; Hariharan, K.

    2005-01-01

    Sodium borophosphate glasses of composition (mol%) 50Na 2 O-50[xB 2 O 3 -(1-x)P 2 O 5 ], 0 ≤ x ≤ 0.8 have been prepared by melt quenching method and characterized through XRD, DSC, FTIR and impedance spectroscopy techniques. The glass transition temperature increases with the substitution of B 2 O 3 due to the cross-linking of the network and the FTIR study shows the presence of different structural units in the network. The ionic conductivity study as a function of composition of B 2 O 3 shows increment in conductivity with two conductivity maxima at 10 and 30 mol% of B 2 O 3 and conductivity variations with temperature follow an Arrhenius type behaviour. Transport numbers evaluated for ions and electrons show that Na + ions are the mobile species in the investigated systems. The frequency dependence of the electric conductivity follows a simple power law feature. The analysis of various electrical parameters as a function of temperature in different complex planes shows that the charge transport occurs by the hopping mechanism

  15. Electrical transport and phase stability in silver iodide-cadmium iodide

    International Nuclear Information System (INIS)

    Brightwell, J.W.; Buckley, C.N.; Miller, L.S.; Ray, B.

    1983-01-01

    A form of the equilibrium diagram for the system AgI-CdI 2 is proposed on the basis of thermal, X-ray diffractometer, and electrical conductivity data. Only one intermediate equilibrium phase, of composition Ag 2 CdI 4 , of tetragonal form with a 0 = 6.35 A and c 0 = 12.7 A is apparent; the previously reported hexagonal form of this composition being metastable. Low levels of CdI 2 are found to enhance the formation of the cubic, #betta#-form, af AgI and to increase the electrical conductivity. For various levels of CdI 2 inclusion in AgI, the principal increase in conductivity occurs in the region of 110 0 C instead of at 146 0 C as in pure AgI. (author)

  16. Electrical transport and phase stability in silver iodide-cadmium iodide

    Energy Technology Data Exchange (ETDEWEB)

    Brightwell, J.W.; Buckley, C.N.; Miller, L.S.; Ray, B. (Lanchester Polytechnic, Coventry (UK))

    1983-03-16

    A form of the equilibrium diagram for the system AgI-CdI/sub 2/ is proposed on the basis of thermal, X-ray diffractometer, and electrical conductivity data. Only one intermediate equilibrium phase, of composition Ag/sub 2/CdI/sub 4/, of tetragonal form with a/sub 0/ = 6.35 A and c/sub 0/ = 12.7 A is apparent; the previously reported hexagonal form of this composition being metastable. Low levels of CdI/sub 2/ are found to enhance the formation of the cubic, ..gamma..-form, af AgI and to increase the electrical conductivity. For various levels of CdI/sub 2/ inclusion in AgI, the principal increase in conductivity occurs in the region of 110 /sup 0/C instead of at 146 /sup 0/C as in pure AgI.

  17. The use of scans for impact studies of transportation packages

    International Nuclear Information System (INIS)

    Mok, G.C.; Witte, M.C.

    1988-01-01

    This paper presents the results of an impact study using the computer program SCANS (Shipping Cask ANalysis System), which was developed by Lawrence Livermore National Laboratory (LLNL) for the US Nuclear Regulatory Commission (NRC) and the Department of Energy (DOE) for structural analysis of transportation packages of radioactive materials. The program operates on IBM PC and compatible microcomputers. It has capabilities for other analysis such as heat transfer, pressure and thermal stress analysis. However, this study uses only the impact analysis capability, which includes a quasi-static and a dynamic analysis option. It is shown that the program produces reasonable results for a wide range of impact conditions. The results are in agreement with existing information on impact analysis and phenomenon. In view of its simplicity in modelling and convenience in usage, the SCANS program can be effectively used for confirmatory analysis, preliminary design study, and quick assessment of the need for detailed impact analysis. 2 refs., 7 figs., 2 tabs

  18. An investigation on near wall transport characteristics in an adiabatic upward gas-liquid two-phase slug flow

    Science.gov (United States)

    Zheng, Donghong; Che, Defu

    2007-08-01

    The near-wall transport characteristics, inclusive of mass transfer coefficient and wall shear stress, which have a great effect on gas-liquid two-phase flow induced internal corrosion of low alloy pipelines in vertical upward oil and gas mixing transport, have been both mechanistically and experimentally investigated in this paper. Based on the analyses on the hydrodynamic characteristics of an upward slug unit, the mass transfer in the near wall can be divided into four zones, Taylor bubble nose zone, falling liquid film zone, Taylor bubble wake zone and the remaining liquid slug zone; the wall shear stress can be divided into two zones, the positive wall shear stress zone associated with the falling liquid film and the negative wall shear stress zone associated with the liquid slug. Based on the conventional mass transfer and wall shear stress characteristics formulas of single phase liquid full-pipe turbulent flow, corrected normalized mass transfer coefficient formula and wall shear stress formula are proposed. The calculated results are in good agreement with the experimental data. The shear stress and the mass transfer coefficient in the near wall zone are increased with the increase of superficial gas velocity and decreased with the increase of superficial liquid velocity. The mass transfer coefficients in the falling liquid film zone and the wake zone of leading Taylor bubble are lager than those in the Taylor bubble nose zone and the remaining liquid slug zone, and the wall shear stress associated falling liquid film is larger than that associated the liquid slug. The mass transfer coefficient is within 10-3 m/s, and the wall shear stress below 103 Pa. It can be concluded that the alternate wall shear stress due to upward gas-liquid slug flow is considered to be the major cause of the corrosion production film fatigue cracking.

  19. Phase conjugation of gap solitons: A numerical study

    Indian Academy of Sciences (India)

    We study the effect of a nearby phase-conjugate mirror (PCM) on the gap soliton of a. Kerr non-linear ... They are characterized by a sech field distribution corresponding to the ... It is a generalization of the earlier model proposed by Jose et.

  20. Study of effect of chromium on titanium dioxide phase transformation ...

    Indian Academy of Sciences (India)

    Administrator

    Study of effect of chromium on titanium dioxide phase transformation by A Bellifa (pp 669–677). Figure S1. Structural ... 4 × 1⋅9486; 2 × 1⋅9799. Octahedral packing. 2 × 2 shared edges. 8 free edges. 3 shared edges. 4 corners. 5 free edges. 2 parallel shared edges. 2 corners. 10 free edges. O. O. Coordination scheme.