WorldWideScience

Sample records for underlying transport physics

  1. Transport, boundary physics

    International Nuclear Information System (INIS)

    Romanelli, F.

    2001-01-01

    In this paper the contributions presented at the 18 th IAEA Fusion Energy Conference in the field of transport and boundary physics will be summarised with reference to the following distinct issues: H-mode physics, Internal Transport Barrier formation, transport studies, Radiative Improved modes and impurity seeding, divertor and He exhaust, new configurations. (author)

  2. Analysis of physical mechanisms underlying density-dependent transport in porous media

    NARCIS (Netherlands)

    Landman, A.J.

    2005-01-01

    In this thesis, the interaction between (large) density gradients and flow and transport in porous media is studied. Large gradients in the density of groundwater exist for example near deep salt rock formations, which are considered as possible long-term storage sites for radioactive waste.

  3. Transports under surveillance

    International Nuclear Information System (INIS)

    Jouette, I.

    2016-01-01

    Each year 770.000 nuclear transports are performed in France representing less than 3% of the transport of dangerous materials. This article review various aspects of nuclear transport: modes of transportation, packages, current legislation, safety and surveillance. A map presents the transport route of vitrified wastes from Sellafield plant to the Zwilag storing center in Switzerland at one moment this transport crosses France and another map presents the transport routes involved in the nuclear fuel cycle in France. (A.C.)

  4. Physical protection of radioactive material in transport

    International Nuclear Information System (INIS)

    1975-01-01

    Safety in the transport of radioactive material is ensured by enclosing the material, when necessary, in packaging which prevents its dispersal and which absorbs to any adequate extent any radiation emitted by the material. Transport workers, the general public and the environment are thus protected against the harmful effects of the radioactive material. The packaging also serves the purpose of protecting its contents against the effects of rough handling and mishaps under normal transport conditions, and against the severe stresses and high temperatures that could be encountered in accidents accompanied by fires. If the radioactive material is also fissile, special design features are incorporated to prevent any possibility of criticality under normal transport conditions and in accidents. The safe transport requirements are designed to afford protection against unintentional opening of packages in normal handling and transport conditions and against damage in severe accident conditions; whereas the physical protection requirements are designed to prevent intentional opening of packages and deliberate damage. This clearly illustrates the difference in philosophical approach underlying the requirements for safe transport and for physical protection during transport. This difference in approach is, perhaps, most easily seen in the differing requirements for marking of consignments. While safety considerations dictate that packages be clearly labelled, physical protection considerations urge restraint in the use of special labels. Careful consideration must be given to such differences in approach in any attempt to harmonize the safety and physical protection aspects of transport. (author)

  5. Numerical modeling of solute transport in a sand tank physical model under varying hydraulic gradient and hydrological stresses

    Science.gov (United States)

    Atlabachew, Abunu; Shu, Longcang; Wu, Peipeng; Zhang, Yongjie; Xu, Yang

    2018-03-01

    This laboratory study improves the understanding of the impacts of horizontal hydraulic gradient, artificial recharge, and groundwater pumping on solute transport through aquifers. Nine experiments and numerical simulations were carried out using a sand tank. The variable-density groundwater flow and sodium chloride transport were simulated using the three-dimensional numerical model SEAWAT. Numerical modelling results successfully reproduced heads and concentrations observed in the sand tank. A higher horizontal hydraulic gradient enhanced the migration of sodium chloride, particularly in the groundwater flow direction. The application of constant artificial recharge increased the spread of the sodium chloride plume in both the longitudinal and lateral directions. In addition, groundwater pumping accelerated spreading of the sodium chloride plume towards the pumping well. Both higher hydraulic gradient and pumping rate generated oval-shaped plumes in the horizontal plane. However, the artificial recharge process produced stretched plumes. These effects of artificial recharge and groundwater pumping were greater under higher hydraulic gradient. The concentration breakthrough curves indicated that emerging solutions never attained the concentration of the originally injected solution. This is probably because of sorption of sodium chloride onto the silica sand and/or the exchange of sodium chloride between the mobile and immobile liquid domains. The fingering and protruding plume shapes in the numerical models constitute instability zones produced by buoyancy-driven flow. Overall, the results have substantiated the influences of hydraulic gradient, boundary condition, artificial recharge, pumping rate and density differences on solute transport through a homogeneous unconfined aquifer. The implications of these findings are important for managing liquid wastes.

  6. Physical System Requirements: Transport Waste

    International Nuclear Information System (INIS)

    1992-04-01

    The Nuclear Waste Policy Act (NWPA) of 1982 assigned to the Department of Energy (DOE) the responsibility for managing the disposal of spent nuclear fuel and high-level radioactive waste and established the Office of Civilian Radioactive Waste Management (OCRWM) for that purpose. The Secretary of Energy, in his November 1989 report to Congress (DOE/RW-0247), announced three new initiatives for the conduct of the Civilian Radioactive Waste Management (CRWM) program. One of these initiatives was to establish improved management structure and procedures. In response, OCRWM performed a management study and the Director subsequently issued the Management Systems Improvement Strategy (MSIS) on August 10, 1990, calling for a rigorous implementation of systems engineering principles with a special emphasis on functional analysis. The functional analysis approach establishes a framework for integrating the program management efforts with the technical requirements analysis into a single, unified, and consistent program. This approach recognizes that just as the facilities and equipment comprising the physical waste management system must perform certain functions, so must certain programmatic and management functions be performed within the program in order to successfully bring the physical system into being. The objective of this document is to establish the essential functions, requirements, interfaces, and system architecture for the Transport Waste mission. Based upon the Nuclear Waste Policy Act, the mission of the Waste Transportation System is to transport SNF and/or HLW from the purchaser's/producer's facilities to, and between, NWMS facilities in a manner that protects the health and safety of the public and of workers and the quality of the environment makes effective use of financial and other resources, and to the fullest extent possible uses the private sector

  7. Radionuclide Transport Models Under Ambient Conditions

    Energy Technology Data Exchange (ETDEWEB)

    G. Moridis; Q. Hu

    2000-03-12

    The purpose of this Analysis/Model Report (AMR) is to evaluate (by means of 2-D semianalytical and 3-D numerical models) the transport of radioactive solutes and colloids in the unsaturated zone (UZ) under ambient conditions from the potential repository horizon to the water table at Yucca Mountain (YM), Nevada. This is in accordance with the ''AMR Development Plan U0060, Radionuclide Transport Models Under Ambient Conditions'' (CRWMS M and O 1999a). This AMR supports the UZ Flow and Transport Process Model Report (PMR). This AMR documents the UZ Radionuclide Transport Model (RTM). This model considers: the transport of radionuclides through fractured tuffs; the effects of changes in the intensity and configuration of fracturing from hydrogeologic unit to unit; colloid transport; physical and retardation processes and the effects of perched water. In this AMR they document the capabilities of the UZ RTM, which can describe flow (saturated and/or unsaturated) and transport, and accounts for (a) advection, (b) molecular diffusion, (c) hydrodynamic dispersion (with full 3-D tensorial representation), (d) kinetic or equilibrium physical and/or chemical sorption (linear, Langmuir, Freundlich or combined), (e) first-order linear chemical reaction, (f) radioactive decay and tracking of daughters, (g) colloid filtration (equilibrium, kinetic or combined), and (h) colloid-assisted solute transport. Simulations of transport of radioactive solutes and colloids (incorporating the processes described above) from the repository horizon to the water table are performed to support model development and support studies for Performance Assessment (PA). The input files for these simulations include transport parameters obtained from other AMRs (i.e., CRWMS M and O 1999d, e, f, g, h; 2000a, b, c, d). When not available, the parameter values used are obtained from the literature. The results of the simulations are used to evaluate the transport of radioactive

  8. Radionuclide Transport Models Under Ambient Conditions

    International Nuclear Information System (INIS)

    Moridis, G.; Hu, Q.

    2000-01-01

    The purpose of this Analysis/Model Report (AMR) is to evaluate (by means of 2-D semianalytical and 3-D numerical models) the transport of radioactive solutes and colloids in the unsaturated zone (UZ) under ambient conditions from the potential repository horizon to the water table at Yucca Mountain (YM), Nevada. This is in accordance with the ''AMR Development Plan U0060, Radionuclide Transport Models Under Ambient Conditions'' (CRWMS M and O 1999a). This AMR supports the UZ Flow and Transport Process Model Report (PMR). This AMR documents the UZ Radionuclide Transport Model (RTM). This model considers: the transport of radionuclides through fractured tuffs; the effects of changes in the intensity and configuration of fracturing from hydrogeologic unit to unit; colloid transport; physical and retardation processes and the effects of perched water. In this AMR they document the capabilities of the UZ RTM, which can describe flow (saturated and/or unsaturated) and transport, and accounts for (a) advection, (b) molecular diffusion, (c) hydrodynamic dispersion (with full 3-D tensorial representation), (d) kinetic or equilibrium physical and/or chemical sorption (linear, Langmuir, Freundlich or combined), (e) first-order linear chemical reaction, (f) radioactive decay and tracking of daughters, (g) colloid filtration (equilibrium, kinetic or combined), and (h) colloid-assisted solute transport. Simulations of transport of radioactive solutes and colloids (incorporating the processes described above) from the repository horizon to the water table are performed to support model development and support studies for Performance Assessment (PA). The input files for these simulations include transport parameters obtained from other AMRs (i.e., CRWMS M and O 1999d, e, f, g, h; 2000a, b, c, d). When not available, the parameter values used are obtained from the literature. The results of the simulations are used to evaluate the transport of radioactive solutes and colloids, and

  9. Physical security during transportation, 1976

    International Nuclear Information System (INIS)

    Edlow, J.; Rudolph, D.

    1976-01-01

    The U.S. government is in the process of quietly taking over the transportation of strategic special nuclear material. ERDA is beginning to transport ERDA-owned SSNM between contractor/license plants. This paper discusses the evolution of this program and the attendant security hysteria impinging on the nuclear industry. The history of Edlow International transport security operations for nuclear materials is presented. The need for government intervention is questioned

  10. Sediment transport under breaking waves

    DEFF Research Database (Denmark)

    Christensen, Erik Damgaard; Hjelmager Jensen, Jacob; Mayer, Stefan

    2000-01-01

    generated at the surface where the wave breaks as well as the turbulence generated near the bed due to the wave-motion and the undertow. In general, the levels of turbulent kinetic energy are found to be higher than experiments show. This results in an over prediction of the sediment transport. Nevertheless...

  11. Physics of transport in Tokamaks

    International Nuclear Information System (INIS)

    Garbet, X.; Asp, E.; Bourdelle, C.; Hoang, T.; Imbeaux, F.; Joffrin, E.; Litaudon, X.; Angioni, C.; Manini, A.; Peeter, A.; Ryter, F.; Baranov, Y.; Cordey, G.; McDonald, D.C.; Parail, V.; Valovic, M.; Thyagaraja, A.; Voitsekhovitch, I.; Budny, R.; Kirneva, N.; Hogeweij, D.; Nordman, H.; Weilland, J.; Tala, T.; Weisen, H.; Zabolotsky, A.

    2004-01-01

    This paper is an overview of recent results related to turbulent particle and heat transport, and triggering of Internal Transport Barriers. Particle transport is characterised by a pinch velocity that is found to be larger than the value predicted by theory of collisional transport (Ware pinch) in L-mode plasmas. Also it increases with magnetic shear. In H-mode, density peaking decreases with collisionality. Pinch velocity reaches the Ware value for large collision frequencies. Heat transport has made progress along two directions: dimensionless scaling laws and analysis of modulation experiments. Dimensionless scaling law of thermal confinement agrees with the prediction for electrostatic turbulence. Dependence with collisionality remains to be understood. Heat modulation experiments have been investigated in several devices using a critical gradient model, micro-stability analysis and predictive modelling. Thresholds and stiffness are correctly reproduced by stability analysis and modelling with Weiland model. Analysis with a critical gradient model leads to a large variability of stiffness. Finally the question of triggering Internal Transport Barriers has been addressed by analysing electron transport barriers. It is confirmed that negative magnetic shear combined with Shafranov shift is a robust stabilizing mechanism. However, some well established features of internal barriers are hardly explained by theory, in particular the role of low order rational values of the minimum safety factor, and the existence of multiple barriers. (authors)

  12. Physics of transport in Tokamaks

    Energy Technology Data Exchange (ETDEWEB)

    Garbet, X.; Asp, E.; Bourdelle, C.; Hoang, T.; Imbeaux, F.; Joffrin, E.; Litaudon, X. [Association Euratom-CEA Cadarache (DSM/DRFC), 13 - Saint-Paul-lez-Durance (France). Dept. de Recherches sur la Fusion Controlee; Mantica, P.; Sozzi, C. [Euratom-ENEA/CNR, Istituto di Fisica del Plasma, Milano (Italy); Angioni, C.; Manini, A.; Peeter, A.; Ryter, F. [Euratom Association, MPI fur Plasmaphysik, Garchin bei Munchen (Germany); Baranov, Y.; Cordey, G.; McDonald, D.C.; Parail, V.; Valovic, M.; Thyagaraja, A.; Voitsekhovitch, I. [Euratom-UKAEA, Culham Science Centre, Abingdon OX (United Kingdom); Budny, R. [Princeton Univ., NJ (United States). Plasma Physics Lab; Crisati, F. [Association Euratom-ENEA sulla Fusione, Frascati (Italy); Kirneva, N. [Kurchatov Institute, RRC, Moscow (Russian Federation); Hogeweij, D. [Association Euratom-FOM Institute voor Plasmafysica, Nieuwegein (Netherlands); Nordman, H.; Weilland, J. [Chalmers Univ. of Technology and Euratom-VR Association, Goeteborg (Sweden); Tala, T. [Association Euratom-Tekes, VTT Processes (Finland); Weisen, H.; Zabolotsky, A. [Association Euratom-Confederation Suisse, CRPP, EPFL, Lausanne (Switzerland)

    2004-07-01

    This paper is an overview of recent results related to turbulent particle and heat transport, and triggering of Internal Transport Barriers. Particle transport is characterised by a pinch velocity that is found to be larger than the value predicted by theory of collisional transport (Ware pinch) in L-mode plasmas. Also it increases with magnetic shear. In H-mode, density peaking decreases with collisionality. Pinch velocity reaches the Ware value for large collision frequencies. Heat transport has made progress along two directions: dimensionless scaling laws and analysis of modulation experiments. Dimensionless scaling law of thermal confinement agrees with the prediction for electrostatic turbulence. Dependence with collisionality remains to be understood. Heat modulation experiments have been investigated in several devices using a critical gradient model, micro-stability analysis and predictive modelling. Thresholds and stiffness are correctly reproduced by stability analysis and modelling with Weiland model. Analysis with a critical gradient model leads to a large variability of stiffness. Finally the question of triggering Internal Transport Barriers has been addressed by analysing electron transport barriers. It is confirmed that negative magnetic shear combined with Shafranov shift is a robust stabilizing mechanism. However, some well established features of internal barriers are hardly explained by theory, in particular the role of low order rational values of the minimum safety factor, and the existence of multiple barriers. (au0011tho.

  13. Fundamental aspects of plasma chemical physics transport

    CERN Document Server

    Capitelli, Mario; Laricchiuta, Annarita

    2013-01-01

    Fundamental Aspects of Plasma Chemical Physics: Tranpsort develops basic and advanced concepts of plasma transport to the modern treatment of the Chapman-Enskog method for the solution of the Boltzmann transport equation. The book invites the reader to consider actual problems of the transport of thermal plasmas with particular attention to the derivation of diffusion- and viscosity-type transport cross sections, stressing the role of resonant charge-exchange processes in affecting the diffusion-type collision calculation of viscosity-type collision integrals. A wide range of topics is then discussed including (1) the effect of non-equilibrium vibrational distributions on the transport of vibrational energy, (2) the role of electronically excited states in the transport properties of thermal plasmas, (3) the dependence of transport properties on the multitude of Saha equations for multi-temperature plasmas, and (4) the effect of the magnetic field on transport properties. Throughout the book, worked examples ...

  14. Transport processes in space physics and astrophysics

    CERN Document Server

    Zank, Gary P

    2014-01-01

    Transport Processes in Space Physics and Astrophysics' is aimed at graduate level students to provide the necessary mathematical and physics background to understand the transport of gases, charged particle gases, energetic charged particles, turbulence, and radiation in an astrophysical and space physics context. Subjects emphasized in the work include collisional and collisionless processes in gases (neutral or plasma), analogous processes in turbulence fields and radiation fields, and allows for a simplified treatment of the statistical description of the system. A systematic study that addresses the common tools at a graduate level allows students to progress to a point where they can begin their research in a variety of fields within space physics and astrophysics. This book is for graduate students who expect to complete their research in an area of plasma space physics or plasma astrophysics. By providing a broad synthesis in several areas of transport theory and modeling, the work also benefits resear...

  15. RADIONUCLIDE TRANSPORT MODELS UNDER AMBIENT CONDITIONS

    Energy Technology Data Exchange (ETDEWEB)

    S. Magnuson

    2004-11-01

    The purpose of this model report is to document the unsaturated zone (UZ) radionuclide transport model, which evaluates, by means of three-dimensional numerical models, the transport of radioactive solutes and colloids in the UZ, under ambient conditions, from the repository horizon to the water table at Yucca Mountain, Nevada.

  16. Computer codes in particle transport physics

    International Nuclear Information System (INIS)

    Pesic, M.

    2004-01-01

    is given. Importance of validation and verification of data and computer codes is underlined briefly. Examples of applications of the MCNPX, FLUKA and SHIELD codes to simulation of some of processes in nature, from reactor physics, ion medical therapy, cross section calculations, design of accelerator driven sub-critical systems to astrophysics and shielding of spaceships, are shown. More reliable and more frequent cross sections data in intermediate and high- energy range for particles transport and interactions with mater are expected in near future, as a result of new experimental investigations that are under way with the aim to validate theoretical models applied currently in the codes. These new data libraries are expected to be much larger and more comprehensive than existing ones requiring more computer memory and faster CPUs. Updated versions of the codes to be developed in future, beside sequential computation versions, will also include the MPI or PVM options to allow faster ru: ming of the code at acceptable cost for an end-user. A new option to be implemented in the codes is expected too - an end-user written application for particular problem could be added relatively simple to the general source code script. Initial works on full implementation of graphic user interface for preparing input and analysing output of codes and ability to interrupt and/or continue code running should be upgraded to user-friendly level. (author)

  17. Radionuclide Transport Models Under Ambient Conditions

    Energy Technology Data Exchange (ETDEWEB)

    G. Moridis; Q. Hu

    2001-12-20

    The purpose of Revision 00 of this Analysis/Model Report (AMR) is to evaluate (by means of 2-D semianalytical and 3-D numerical models) the transport of radioactive solutes and colloids in the unsaturated zone (UZ) under ambient conditions from the potential repository horizon to the water table at Yucca Mountain (YM), Nevada.

  18. Radionuclide Transport Models Under Ambient Conditions

    International Nuclear Information System (INIS)

    Moridis, G.; Hu, Q.

    2001-01-01

    The purpose of Revision 00 of this Analysis/Model Report (AMR) is to evaluate (by means of 2-D semianalytical and 3-D numerical models) the transport of radioactive solutes and colloids in the unsaturated zone (UZ) under ambient conditions from the potential repository horizon to the water table at Yucca Mountain (YM), Nevada

  19. The German Physical Society Under National Socialism

    Science.gov (United States)

    Hoffmann, Dieter; Walker, Mark

    2004-12-01

    The history of the German Physical Society from 1933 to 1945 is not the same as a comprehensive history of physics under Adolf Hitler, but it does reflect important aspects of physicists' work and life during the Third Reich.

  20. 77 FR 15114 - Extension of Agency Information Collection Activity Under OMB Review: Transportation Security...

    Science.gov (United States)

    2012-03-14

    ... SECURITY Transportation Security Administration Extension of Agency Information Collection Activity Under... Evaluation, Diabetes Further Evaluation, Drug or Alcohol Use Further Evaluation, General Medical Further... evaluation forms evaluate a candidate's physical and medical qualifications to be a TSO, including visual and...

  1. An evaluation of transport mode shift policies on transport-related physical activity through simulations based on random forests.

    Science.gov (United States)

    Brondeel, Ruben; Kestens, Yan; Chaix, Basile

    2017-10-23

    Physical inactivity is widely recognized as one of the leading causes of mortality, and transport accounts for a large part of people's daily physical activity. This study develops a simulation approach to evaluate the impact of the Ile-de-France Urban Mobility Plan (2010-2020) on physical activity, under the hypothesis that the intended transport mode shifts are realized. Based on the Global Transport Survey (2010, n = 21,332) and on the RECORD GPS Study (2012-2013, n = 229) from the French capital region of Paris (Ile-de-France), a simulation method was designed and tested. The simulation method used accelerometer data and random forest models to predict the impact of the transport mode shifts anticipated in the Mobility Plan on transport-related moderate-to-vigorous physical activity (T-MVPA). The transport mode shifts include less private motorized trips in favor of more public transport, walking, and biking trips. The simulation model indicated a mean predicted increase of 2 min per day of T-MVPA, in case the intended transport mode shifts in the Ile-de-France Urban Mobility Plan were realized. The positive effect of the transport mode shifts on T-MVPA would, however, be larger for people with a higher level of education. This heterogeneity in the positive effect would further increase the existing inequality in transport-related physical activity by educational level. The method presented in this paper showed a significant increase in transport-related physical activity in case the intended mode shifts in the Ile-de-France Urban Mobility Plan were realized. This simulation method could be applied on other important health outcomes, such as exposure to noise or air pollution, making it a useful tool to anticipate the health impact of transport interventions or policies.

  2. MC++ and a transport physics framework

    International Nuclear Information System (INIS)

    Lee, S.R.; Cummings, J.C.; Nolen, S.D.; Keen, N.D.

    1997-01-01

    The Department of Energy has launched the Accelerated Strategic Computing Initiative (ASCI) to address a pressing need for more comprehensive computer simulation capabilities in the area of nuclear weapons safety and reliability. In light of the decision by the US Government to abandon underground nuclear testing, the Science-Based Stockpile Stewardship (SBSS) program is focused on using computer modeling to assure the continued safety and effectiveness of the nuclear stockpile. The authors believe that the utilization of object-oriented design and programming techniques can help in this regard. Object-oriented programming (OOP) has become a popular model in the general software community for several reasons. MC++ is a specific ASCI-relevant application project which demonstrates the effectiveness of the object-oriented approach. It is a Monte Carlo neutron transport code written in C++. It is designed to be simple yet flexible, with the ability to quickly introduce new numerical algorithms or representations of the physics into the code. MC++ is easily ported to various types of Unix workstations and parallel computers such as the three new ASCI platforms, largely because it makes extensive use of classes from the Parallel Object-Oriented Methods and Applications (POOMA) C++ class library. The MC++ code has been successfully benchmarked using some simple physics test problems, has been shown to provide comparable serial performance and a parallel efficiency superior to that of a well-known Monte Carlo neutronics package written in Fortran, and was the first ASCI-relevant application to run in parallel on all three ASCI computing platforms

  3. Overview. Department of Environmental and Radiation Transport Physics. Section 6

    Energy Technology Data Exchange (ETDEWEB)

    Loskiewicz, J. [Institute of Nuclear Physics, Cracow (Poland)

    1995-12-31

    Research activities in the Department of Environmental and Radiation Transport Physics are carried out by three Laboratories: Laboratory of Environmental Physics, Laboratory of Neutron Transport Physics and Laboratory of Physics and Modeling of Radiation Transport. The researches provided in 1994 cover: tracer transport and flows in porous media, studies on pollution in atmospheric air, physics of molecular phenomena in chromatographic detectors, studies on neutron transport in heterogenous media, studies on evaluation of neutron cross-section in the thermal region, studies on theory and utilization of neural network in data evaluation, numerical modelling of particle cascades for particle accelerator shielding purpose. In this section the description of mentioned activities as well as the information about personnel employed in the Department, papers and reports published in 1994, contribution to conferences and grants is also given.

  4. Strategic planning for transportation under the NWPA

    International Nuclear Information System (INIS)

    Larson, D.; Miernyk, J.

    1992-01-01

    This paper reports that the western states have found strategic planning to be an effective approach for identifying activities, and the appropriate sequencing of activities, that should be undertaken in the development of a transportation system for shipping high-level waste and spent nuclear fuel to a repository or monitored retrievable storage (MRS) facility. The Western Interstate Energy Board's High-Level Radioactive Waste Committee works with the U.S. Department of Energy pursuant to a cooperative agreement on the development of a safe, publicly-acceptable transportation system. The Committee has developed a Strategic Plan and Schedule which: guides the scheduling and prioritization of the Committee's work; enhances understanding of the complex and interrelated activities that states believe should be undertaken in developing a transportation system for high-level radioactive materials; and provides states with an appropriate structure for evaluating DOE's responsiveness to state needs

  5. Intracellular transport: from physics to ... biology.

    Science.gov (United States)

    Roux, Aurélien; Cuvelier, Damien; Bassereau, Patricia; Goud, Bruno

    2008-03-01

    Considerable effort over the past three decades has allowed the identification of the protein families that control the cellular machinery responsible for intracellular transport within eukaryotic cells. These proteins are estimated to represent about 10-20% of the human "proteome." The complexity of intracellular transport makes useful the development of model membranes. We describe here experimental systems based on lipid giant unilamellar vesicles (GUVs), which are attached to kinesin molecules. These systems give rise to thin membrane tubes and to complex tubular networks when incubated in vitro with microtubules and ATP. This type of assay, which mimics key events occurring during intracellular transport, allows physicists and biologists to understand how the unique mechanical properties of lipid membranes could be involved in the budding process, the sorting of cargo proteins and lipids, and the separation of the buds from a donor membrane.

  6. Simultaneous transport of water and solutes under transient ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Earth System Science; Volume 117; Issue 4. Simultaneous transport of water and solutes under transient unsaturated flow conditions – A case study ... Keywords. Hydraulic conductivity; infiltration; leaching; Malaprabha; modeling; permeability; salinity; solute transport; SWIM model; water flow.

  7. Assessment of Physical Activity and Active Transport Among School ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Assessment of Physical Activity and Active Transport Among School Children in Kenya, Nigeria, and Mozambique ... presented during the Global Summit on Physical Activity of Children in 2014; - To modify the Neighbourhood Environment Walkability Scale instrument (NEWS) for use in African countries, assess its reliability ...

  8. Particle acceleration, transport and turbulence in cosmic and heliospheric physics

    Science.gov (United States)

    Matthaeus, W.

    1992-01-01

    In this progress report, the long term goals, recent scientific progress, and organizational activities are described. The scientific focus of this annual report is in three areas: first, the physics of particle acceleration and transport, including heliospheric modulation and transport, shock acceleration and galactic propagation and reacceleration of cosmic rays; second, the development of theories of the interaction of turbulence and large scale plasma and magnetic field structures, as in winds and shocks; third, the elucidation of the nature of magnetohydrodynamic turbulence processes and the role such turbulence processes might play in heliospheric, galactic, cosmic ray physics, and other space physics applications.

  9. Internal Transport Barrier Physics in Helical Systems

    International Nuclear Information System (INIS)

    Yokoyama, M.; Maassberg, H.; Ida, K.; Estrada, T.; Castejon, F.; Minami, T.; Fujisawa, A.; Yamagishi, O.; Shats, M. G.; Dinklage, A.; Tribaldos, V.; Beidler, C. D.; Shimozuma, T.; Takeiri, Y.; Herranz, J.; Murakami, S.; Yamada, H.

    2005-01-01

    The characteristics of electron internal transport barriers (eITBs) in helical systems are reviewed. The common features are highly peaked Te profile with strongly positive Er in the core region. The transition nature of Er based on neoclassical (NC) ambipolarity, with the clear threshold feature such as ECH power and Ohmic current, is the common mechanism for the eITB formation. The electron heat confinement improvement has been revealed within the eITB region. The ECH power threshold can be lowered in the presence of ripple-trapped electrons-induced convective flux, and rational surfaces at the core region. The gyrokinetic calculations, for example eITB in LHD, have shown that the ETG mode is unstable in eITB region due to the large Te gradient. A larger zonal flow amplitude has been observed in eITB phase in CHS. The geodesic transfer of energy from stationary zonal flow to oscillatory modes (GAMs) recognized in H-1 implies that the stationary zonal flows can be maintained at a higher level by reducing the geodesic curvature in helical systems. This is the first report of the eITB branch in the framework of the International Stellarator Profile DataBase (ISPDB). (Author)

  10. Strontium and caesium transport in unsaturated soil from Chernobyl Pilot Site under steady flow conditions

    International Nuclear Information System (INIS)

    Szenknect, St.

    2003-10-01

    This work is devoted to the quantification and the identification of the predominant processes involved in strontium and caesium transport in unsaturated soil from Chernobyl Pilot Site under steady flow conditions. The transport and fate of radionuclides in the subsurface is affected by various physical and chemical processes including advective and diffusive transport as well as chemical and biological transformations. Laboratory experiments and the use of a multiple tracer approach allow to isolate the contributions of each elementary process and to control the physico-chemical conditions in the system. To be more representative of the field conditions, we decided to perform column miscible displacement experiments. We perform batch and flow-through reactor experiments to characterize the radionuclides sorption mechanisms. Miscible displacement experiments within homogeneous columns and modeling allow to characterize the hydrodynamic properties of the soil and to describe the radionuclides behaviour under dynamic conditions at different water contents. We show that the water content of porous media affect the transport behaviour of inert and strongly sorbing radionuclides. Our results demonstrate that a parametrized transport model that was calibrated under completely saturated conditions was not able to describe the advective-dispersive transport of reactive solutes under unsaturated steady state conditions. Under our experimental conditions, there is no effect of a decrease of the mean water content on the sorption model parameters, but the transport parameters are modified. We established for the studied soil the relation between hydrodynamic dispersion and water content and the relation between pore water velocity and water content. (author)

  11. Prediction of transport and other physical properties of fluids

    CERN Document Server

    Bretsznajder, S

    1971-01-01

    Prediction of Transport and Other Physical Properties of Fluids reviews general methods for predicting the transport and other physical properties of fluids such as gases and liquids. Topics covered range from the theory of corresponding states and methods for estimating the surface tension of liquids to some basic concepts of the kinetic theory of gases. Methods of estimating liquid viscosity based on the principle of additivity are also described. This volume is comprised of eight chapters and opens by presenting basic information on gases and liquids as well as intermolecular forces and con

  12. Tariff Policy and Transport Costs under Reciprocal Dumping

    OpenAIRE

    Jun Oshiro

    2011-01-01

    This paper analyzes tariff competition by investigating the strategic interactions among firms that are highly mobile across national boundaries. Although high transport costs yield a geographic dispersion of the industry, sufficiently low transport costs result in a core-periphery location where nobody bears tariff burdens. In any case, the world economy would be in a much better position under an international coordination scheme. An economy is only required to enforce a weak international ...

  13. A quasilinear model for solute transport under unsaturated flow

    International Nuclear Information System (INIS)

    Houseworth, J.E.; Leem, J.

    2009-01-01

    We developed an analytical solution for solute transport under steady-state, two-dimensional, unsaturated flow and transport conditions for the investigation of high-level radioactive waste disposal. The two-dimensional, unsaturated flow problem is treated using the quasilinear flow method for a system with homogeneous material properties. Dispersion is modeled as isotropic and is proportional to the effective hydraulic conductivity. This leads to a quasilinear form for the transport problem in terms of a scalar potential that is analogous to the Kirchhoff potential for quasilinear flow. The solutions for both flow and transport scalar potentials take the form of Fourier series. The particular solution given here is for two sources of flow, with one source containing a dissolved solute. The solution method may easily be extended, however, for any combination of flow and solute sources under steady-state conditions. The analytical results for multidimensional solute transport problems, which previously could only be solved numerically, also offer an additional way to benchmark numerical solutions. An analytical solution for two-dimensional, steady-state solute transport under unsaturated flow conditions is presented. A specific case with two sources is solved but may be generalized to any combination of sources. The analytical results complement numerical solutions, which were previously required to solve this class of problems.

  14. Reliability and validity of the transport and physical activity questionnaire (TPAQ) for assessing physical activity behaviour.

    Science.gov (United States)

    Adams, Emma J; Goad, Mary; Sahlqvist, Shannon; Bull, Fiona C; Cooper, Ashley R; Ogilvie, David

    2014-01-01

    No current validated survey instrument allows a comprehensive assessment of both physical activity and travel behaviours for use in interdisciplinary research on walking and cycling. This study reports on the test-retest reliability and validity of physical activity measures in the transport and physical activity questionnaire (TPAQ). The TPAQ assesses time spent in different domains of physical activity and using different modes of transport for five journey purposes. Test-retest reliability of eight physical activity summary variables was assessed using intra-class correlation coefficients (ICC) and Kappa scores for continuous and categorical variables respectively. In a separate study, the validity of three survey-reported physical activity summary variables was assessed by computing Spearman correlation coefficients using accelerometer-derived reference measures. The Bland-Altman technique was used to determine the absolute validity of survey-reported time spent in moderate-to-vigorous physical activity (MVPA). In the reliability study, ICC for time spent in different domains of physical activity ranged from fair to substantial for walking for transport (ICC = 0.59), cycling for transport (ICC = 0.61), walking for recreation (ICC = 0.48), cycling for recreation (ICC = 0.35), moderate leisure-time physical activity (ICC = 0.47), vigorous leisure-time physical activity (ICC = 0.63), and total physical activity (ICC = 0.56). The proportion of participants estimated to meet physical activity guidelines showed acceptable reliability (k = 0.60). In the validity study, comparison of survey-reported and accelerometer-derived time spent in physical activity showed strong agreement for vigorous physical activity (r = 0.72, ptravel behaviours and may be suitable for wider use. Its physical activity summary measures have comparable reliability and validity to those of similar existing questionnaires.

  15. Underlying Mechanisms of Improving Physical Activity Behavior after Rehabilitation

    NARCIS (Netherlands)

    van der Ploeg, Hidde P.; Streppel, Kitty R.M.; van der Beek, Allard J.; Woude, Luc H.V.; van Harten, Willem H.; Vollenbroek-Hutten, Miriam Marie Rosé; van Mechelen, Willem

    2008-01-01

    Background: Regular physical activity is beneficial for the health and functioning of people with a disability. Effective components of successful physical activity promotion interventions should be identified and disseminated. Purpose: To study the underlying mechanisms of the combined sport

  16. Preliminary Results on Sediment Sorting Under Intense Bedload Transport

    Science.gov (United States)

    Hernandez Moreira, R. R.; Vautin, D.; Mathews, S. L.; Kuprenas, R.; Viparelli, E.

    2014-12-01

    Previous experiments show that parallel-laminated deposits are emplaced under upper plane bed regime by the migration of small-amplitude, long-wavelength bedforms. The present research focuses on how sediment is sorted under upper plane bed and sheet flow transport regimes, and whether parallel-lamination is inhibited during sheet flow transport. The problem of studying the sorting of sediment under so intense transport conditions is plagued by the uncertainties related to flow resistances and bedload transport rates. We simplify the problem by first running the experiments with uniform sediment, to establish a baseline that will aid in the design of the experiments with poorly sorted material. We are running experiments at the Hydraulics Laboratory of the Department of Civil and Environmental Engineering at the University of South Carolina in Columbia, in a unidirectional sediment-feed flume, 9 meters long by 0.2 meters wide, of which 7 meters are used as test section. During the experiments, water surface and bed elevations are periodically measured to characterize the global parameters of the flow, e.g. mean flow velocity and bed shear stress. When the flow and the sediment transport reach conditions of mobile bed equilibrium, bed elevation fluctuations are measured with ultrasonic transducer systems at six fixed locations. Channel bed aggradation is then induced by slowly raising the tail gate of the flume such that there is no change in transport regime, as confirmed by additional measurements of water surface and bed elevation and bed elevation fluctuations. Preliminary observations under upper plane bed regime show the formation of the small-amplitude and long-wavelength bedforms, as well as hints of parallel lamination in the deposits. In the near future we aim to achieve sheet flow transport conditions with both uniform and non-uniform grain size distributions to look at the internal structure of the emplaced deposit.

  17. Transport processes in space physics and astrophysics problems and solutions

    CERN Document Server

    Dosch, Alexander

    2016-01-01

     This is the problems and solution manual for the graduate text with the same title and published as Lecture Notes in Physics Vol 877 which provides the necessary mathematical and physics background to understand the transport of gases, charged particle gases, energetic charged particles, turbulence, and radiation in an astrophysical and space physics context. The very detailed and self-contained problems and solutions will be an essential part of the training of any graduate student wishing to enter and pursuing research in this field. .

  18. Physical and transportation requirements for a FLIP fueled TRIGA

    International Nuclear Information System (INIS)

    Johnson, A.G.; Ringle, J.C.; Anderson, T.V.

    1977-01-01

    Several major changes to the OSTR Physical Security Plan were required by the NRC prior to the August 1976 receipt and installation of a new core consisting entirely of FLIP fuel. The general nature of these changes will be reviewed along with several decisions we faced during their implementation. At the previous TRIGA Owners' Conference in Salt Lake City, Utah, we reported on Oregon's regulatory program for research reactor emergency response planning and physical security. The latter program was of particular interest to us in light of the projected FLIP fuel shipments. The impact of the State's program for physical security of FLIP fuel during transportation will be presented. (author)

  19. A Boltzmann Transport Simulation Using Open Source Physics

    Science.gov (United States)

    Hasbun, Javier

    2004-03-01

    The speed of a charged particle, under an applied electric field, in a conducting media, is, usually, simply modelled by writing Newton's 2nd law in the form mfrac ddtv=qE-mfrac vτ ; (1), where v is the speed, E is the applied electric field, q is the charge, m is the mass, and τ is the scattering time between collisions. Here, we simulate a numerical solution of the Boltzmann transport equation,frac partial partial tf+ vot nabla _rf+Fot nabla _pf=frac partial partial tf|_coll (2), where in general the Boltzmann distribution function f=f(r,p,t) depends on position, momentum, and time. Our numerical solution is made possible by neglecting the 2nd term on the LHS, and by modelling the RHS collision term as fracpartial partial tf|_coll=-frac 1τ . With these approximations, in addition to considering only one dimension, we find, our numerical solution of (2). The average velocity numerically obtained through the resulting distribution is compared to that obtained by the analytic solution of (1). An efficient method of carrying out the numerical solution of (2) due to P. Drallos and M. Wadehra [Journal of Applied Physics 63, 5601(1988)] is incorporated here. A final version of an applet that performs the full Java simulation will be located at http://www.westga.edu/ jhasbun/osp/osp.htm.

  20. Neutron Stars: Laboratories for Fundamental Physics Under ...

    Indian Academy of Sciences (India)

    DEBADES BANDYOPADHYAY

    2017-09-07

    Sep 7, 2017 ... American Physical Society in 1933, Baade & Zwicky ... of pulsars and black holes using the SKA and LIGO-. India along with other ..... a black hole. Different groups investigated the problem of stability of a PNS for short times. When a PNS is made up of nucleons and leptons, it has a slightly smaller max-.

  1. Collaboration between physical activity researchers and transport planners

    DEFF Research Database (Denmark)

    Crist, Katie; Bolling, Khalisa; Schipperijn, Jasper

    2018-01-01

    sources. Informants believed that research collaboration could increase capacity by providing unbiased data and access to students to assist with targeted research. Collaboration could also increase the relevance of academic research in applied settings. Identified barriers included: setting up contracts...... the benefits and barriers of researcher and transport agency collaboration, and 4) identify the facilitators to collaboration for these groups. Semi-structured interviews were conducted with 17 transport modeling, planning or engineering professionals, transport agency directors, and academics with relevant...... expertise in health or transport planning. A thematic analysis was conducted following structural coding by two researchers. The analysis revealed that geographic and physical activity data that are current, local, objective and specific to individual AT trips would improve upon currently available data...

  2. Sixth Microgravity Fluid Physics and Transport Phenomena Conference Abstracts

    Science.gov (United States)

    Singh, Bhim (Compiler)

    2002-01-01

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

  3. Advanced physical protection systems for facilities and transportation

    International Nuclear Information System (INIS)

    Jones, O.E.

    1976-01-01

    Sandia Laboratories is developing advanced physical protection safeguards in order to improve the security of special nuclear materials, facilities, and transportation. Computer models are being used to assess the cost-effectiveness of alternative systems for protecting facilities against external attack which may include internal assistance, and against internal theft or sabotage. Physical protection elements such as admittance controls, portals and detectors, perimeter and interior intrusion alarms, fixed and remotely activated barriers, and secure communications are being evaluated, adapted, and where required, developed. New facilities safeguards concepts which involve ''control loops'' between physical protection and materials control elements are being evolved jointly between Sandia Laboratories and Los Alamos Scientific Laboratory. Special vehicles and digital communications equipment have been developed for the ERDA safe-secure transportation system. The current status and direction of these activities are surveyed

  4. Structural Evaluation on HIC Transport Packaging under Accident Conditions

    International Nuclear Information System (INIS)

    Chung, Sung Hwan; Kim, Duck Hoi; Jung, Jin Se; Yang, Ke Hyung; Lee, Heung Young

    2005-01-01

    HIC transport packaging to transport a high integrity container(HIC) containing dry spent resin generated from nuclear power plants is to comply with the regulatory requirements of Korea and IAEA for Type B packaging due to the high radioactivity of the content, and to maintain the structural integrity under normal and accident conditions. It must withstand 9 m free drop impact onto an unyielding surface and 1 m drop impact onto a mild steel bar in a position causing maximum damage. For the conceptual design of a cylindrical HIC transport package, three dimensional dynamic structural analysis to ensure that the integrity of the package is maintained under all credible loads for 9 m free drop and 1 m puncture conditions were carried out using ABAQUS code.

  5. Simultaneous transport of water and solutes under transient ...

    Indian Academy of Sciences (India)

    Simultaneous transport of water and solutes under transient unsaturated flow conditions – A case study. B K Purandara. ∗. , N Varadarajan and B Venkatesh. National Institute of Hydrology, Hard Rock Regional Center, Belgaum 590 001, Karnataka, India. ∗ e-mail: purandarabk@yahoo.com. The imbalance between ...

  6. Integrative Analysis of the Physical Transport Network into Australia.

    Directory of Open Access Journals (Sweden)

    Robert C Cope

    Full Text Available Effective biosecurity is necessary to protect nations and their citizens from a variety of threats, including emerging infectious diseases, agricultural or environmental pests and pathogens, and illegal wildlife trade. The physical pathways by which these threats are transported internationally, predominantly shipping and air traffic, have undergone significant growth and changes in spatial distributions in recent decades. An understanding of the specific pathways and donor-traffic hotspots created by this integrated physical transport network is vital for the development of effective biosecurity strategies into the future. In this study, we analysed the physical transport network into Australia over the period 1999-2012. Seaborne and air traffic were weighted to calculate a "weighted cumulative impact" score for each source region worldwide, each year. High risk source regions, and those source regions that underwent substantial changes in risk over the study period, were determined. An overall risk ranking was calculated by integrating across all possible weighting combinations. The source regions having greatest overall physical connectedness with Australia were Singapore, which is a global transport hub, and the North Island of New Zealand, a close regional trading partner with Australia. Both those regions with large amounts of traffic across multiple vectors (e.g., Hong Kong, and those with high levels of traffic of only one type (e.g., Bali, Indonesia with respect to passenger flights, were represented among high risk source regions. These data provide a baseline model for the transport of individuals and commodities against which the effectiveness of biosecurity controls may be assessed, and are a valuable tool in the development of future biosecurity policy.

  7. Reliability and validity of the transport and physical activity questionnaire (TPAQ for assessing physical activity behaviour.

    Directory of Open Access Journals (Sweden)

    Emma J Adams

    Full Text Available No current validated survey instrument allows a comprehensive assessment of both physical activity and travel behaviours for use in interdisciplinary research on walking and cycling. This study reports on the test-retest reliability and validity of physical activity measures in the transport and physical activity questionnaire (TPAQ.The TPAQ assesses time spent in different domains of physical activity and using different modes of transport for five journey purposes. Test-retest reliability of eight physical activity summary variables was assessed using intra-class correlation coefficients (ICC and Kappa scores for continuous and categorical variables respectively. In a separate study, the validity of three survey-reported physical activity summary variables was assessed by computing Spearman correlation coefficients using accelerometer-derived reference measures. The Bland-Altman technique was used to determine the absolute validity of survey-reported time spent in moderate-to-vigorous physical activity (MVPA.In the reliability study, ICC for time spent in different domains of physical activity ranged from fair to substantial for walking for transport (ICC = 0.59, cycling for transport (ICC = 0.61, walking for recreation (ICC = 0.48, cycling for recreation (ICC = 0.35, moderate leisure-time physical activity (ICC = 0.47, vigorous leisure-time physical activity (ICC = 0.63, and total physical activity (ICC = 0.56. The proportion of participants estimated to meet physical activity guidelines showed acceptable reliability (k = 0.60. In the validity study, comparison of survey-reported and accelerometer-derived time spent in physical activity showed strong agreement for vigorous physical activity (r = 0.72, p<0.001, fair but non-significant agreement for moderate physical activity (r = 0.24, p = 0.09 and fair agreement for MVPA (r = 0.27, p = 0.05. Bland-Altman analysis showed a mean

  8. Upscaling of adsorptive transport under unsaturated conditions (Invited)

    Science.gov (United States)

    Raoof, A.; Hassanizadeh, S. M.

    2010-12-01

    Understanding of colloid transport mechanisms in unsaturated porous media has recently attracted significant attention, especially in the case of groundwater polluted by contaminants that could adsorb to colloids. In general, the transport mechanisms of colloids in saturated porous media have been studied in detail. However, the mechanisms of colloid transport in the unsaturated porous media needed to be understood in greater detail. This is especially the case for the upscaling issues, which relate the adsorptive behavior of the system at the macro scale to the transport processes happening at the scale of individual pores (i.e., pore scale). Under unsaturated conditions, existence of the non-wetting phase causes a greater velocity variation and thus more dispersion, since only a fraction of the pore space is involved in the flow processes. So, dispersion coefficient varies with Darcy velocity and saturation. Flow mechanisms in the unsaturated zone could be dominated by preferential flows causes by the saturated pore system. Under unsaturated conditions, the system contains three phases: air, water, and solid. The principal interaction usually occurs at the solid-water interfaces (SWI) and air-water interfaces (AWI), thus greatly influenced by water content. In this study, we have investigated the adsorptive transport process under unsaturated conditions. We have considered absorption to the solid-water interfaces (SWI) as well as air-water interfaces (AWI). We modeled porous medium with a network of pore bodies and pore throats of finite volumes. The pore space was modeled using a Multi-Directional Pore Network (MDPN) which allows a distribution of coordination number ranging between zero and 26. This topological property together with geometrical distributions was used to reconstruct the microstructure of real porous media. Upon construction of pore network, adsorptive transport parameters have been calculated by solving mass balance equations with adsorption

  9. Physics of turbulence control and transport barrier formation in DIII-D

    International Nuclear Information System (INIS)

    Doyle, E.J.; Burrell, K.H.; Carlstrom, T.N.

    1996-10-01

    This paper describes the physical mechanisms responsible for turbulence control and transport barrier formation on DIII-D as determined from a synthesis of results from different enhanced confinement regimes, including quantitative and qualitative comparisons to theory. A wide range of DIII-D data support the hypothesis that a single underlying physical mechanism, turbulence suppression via E x B shear flow is playing an essential, though not necessarily unique, role in reducing turbulence and transport in all of the following improved confinement regimes: H-mode, VH-mode, high-ell i modes, improved performance counter-injection L-mode discharges and high performance negative central shear (NCS) discharges. DIII-D data also indicate that synergistic effects are important in some cases, as in NCS discharges where negative magnetic shear also plays a role in transport barrier formation. This work indicates that in order to control turbulence and transport it is important to focus on understanding physical mechanisms, such as E x B shear, which can regulate and control entire classes of turbulent modes, and thus control transport. In the highest performance DIII-D discharges, NCS plasmas with a VH-mode like edge, turbulence is suppressed at all radii, resulting in neoclassical levels of ion transport over most of the plasma volume

  10. Physical and chemical mechanisms underlying hematoma evolution

    International Nuclear Information System (INIS)

    Cho, K.J.; Fanders, B.L.; Smid, A.R.; McLaughlin, P.

    1986-01-01

    Angiostat, a new collagen embolic material supplied at a concentration of 35 mg/ml (Target Therapeutics, Los Angeles) was used for flow-directed hepatic artery embolization in a series of rabbits to examine its acute effects on hepatic microcirculation. Arteriograms were obtained both before and after embolization. The aorta and portal vein were perfused with two different colors of Microfil after the animals were killed,. Cleared liver specimens were examined under a dissection microscope. Extent of dearterialization, status of portal sinusoidal perfusion, and collateral formation after embolization with Angiostat were evaluated. Results will be compared with results achieved using other liquid and particulate embolic agents

  11. Effect of moisture transport on microclimate under T-shirts.

    Science.gov (United States)

    Dai, Xiao-Qun; Imamura, Ritsuko; Liu, Guo-Lian; Zhou, Fu-Ping

    2008-09-01

    Water transport through garments has influence on the microclimate between the garments and the body beneath; thus the thermal comfort feeling for the wearer. Soybean protein fiber (SPF), a new type environmental fiber, which has been reported to be superior in water transfer, is often blended with cotton to improve the water transport property. In this paper, T-shirts made of this SPF/cotton blended fabric were focused in comparison with T-shirts made of cotton fabric. Wicking and immersion tests were carried out on the two types of fabrics to investigate the water transport and absorption properties, respectively; wear trials of T-shirts made of the fabrics were also conducted. Comparing with the cotton fabric which had better water absorptive property, it was found that the blended fabric with superior wicking ability could not only delay the increase of the vapor pressure under the T-shirt at the beginning of the exercise, but also help to keep it lower through the exercise significantly, and also kept the skin temperature under the T-shirt lower. It was made clear that it is the water transfer property rather than the water absorption property helps to take away sweat quickly and prevents the increase of the humidity and temperature at skin surface, thus maintaining a comfort microclimate under garments.

  12. Department of Environmental and Radiation Transport Physics - Overview

    International Nuclear Information System (INIS)

    Woznicka, U.

    2001-01-01

    Full text: We deal with environmental physics and the radiation transport physics, both theoretically and experimentally. Some results find their way to practical applications. Our environmental physics research encompasses hydrogeological problems as well as measurements of trace elements in the atmosphere and in the water. Theoretical (analytical and numerical) and experimental issues of the radiation transport and radiation fields are our main field of research. The interest in radiation transport phenomena is stimulated by their importance for the environmental physics, industrial and nuclear facilities and methods of geophysical. Environmental isotopes and noble gases are used in the investigation of water-bearing geological formations in order to determine the origin and age of groundwater. The papers listed below and three ''Reports on research'' present recent achievements in this field. The gas chromatography methods are used for monitoring the anthropogenic trace gases (SF 6 and freons), which participate in the Earth green-house effect. A very high detection level of SF 6 in water, 0.0028 fg/cm 3 H 2 0, has been reached as required for hydrogeological purposes. A preliminary verification of the SF 6 tracer method for dating young groundwaters by the tritium method has been carried out. We carried on the work on a method of radon measurement in soil in connection with geological conditions. The national seminar ''Radon in Environment'' organized at the INP aroused an interest of Polish scientific centres in that field. The seminar gathered 60 participants who presented 24 oral reports and 8 posters. Within the scope of the radiation transport physics we studied thermal neutron transport in finite hydrogenous media. Advantages and limitations of a Monte Carlo code (MCNP) in thermal neutron transport simulations have been examined by both the analytical solution and the experiment on the INP pulsed neutron generator. An interesting contribution to the

  13. Mixed Transportation Network Design under a Sustainable Development Perspective

    Directory of Open Access Journals (Sweden)

    Jin Qin

    2013-01-01

    Full Text Available A mixed transportation network design problem considering sustainable development was studied in this paper. Based on the discretization of continuous link-grade decision variables, a bilevel programming model was proposed to describe the problem, in which sustainability factors, including vehicle exhaust emissions, land-use scale, link load, and financial budget, are considered. The objective of the model is to minimize the total amount of resources exploited under the premise of meeting all the construction goals. A heuristic algorithm, which combined the simulated annealing and path-based gradient projection algorithm, was developed to solve the model. The numerical example shows that the transportation network optimized with the method above not only significantly alleviates the congestion on the link, but also reduces vehicle exhaust emissions within the network by up to 41.56%.

  14. Strategies for optical transport network recovery under epidemic network failures

    DEFF Research Database (Denmark)

    Ruepp, Sarah Renée; Fagertun, Anna Manolova; Kosteas, Vasileios

    2015-01-01

    are evaluated under multiple correlated large-scale failures. We employ the Susceptible–Infected– Disabled epidemic failure spreading model and look into possible trade-offs between resiliency and resource effi- ciency. Via extensive simulations, we show that source rerouting outperforms on-site rerouting......The current trend in deploying automatic control plane solutions for increased flexibility in the optical transport layer leads to numerous advantages for both the operators and the customers, but also pose challenges related to the stability of the network and its ability to operate in a robust......, and that there exist a clear trade-off between policy performance and network resource consumption, which must be addressed by network operators for improved robustness of their transport infrastructures. Applying proactive methods for avoiding areas where epidemic failures spread results in 50% less connections...

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

    Science.gov (United States)

    Gavert, R.

    2000-01-01

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

  16. Ionic transport properties in AgCl under high pressures

    Science.gov (United States)

    Wang, Jia; Zhang, Guozhao; Liu, Hao; Wang, Qinglin; Shen, Wenshu; Yan, Yalan; Liu, Cailong; Han, Yonghao; Gao, Chunxiao

    2017-07-01

    Ionic transport behaviors of silver chloride (AgCl) have been revealed with impedance spectra measurement under high pressures up to 20.4 GPa. AgCl always presented ionic conducting under experimental pressures, but electronic conduction can coexist with ionic conduction within the pressure range from 6.7 to 9.3 GPa. The ionic conductivity of AgCl decreases by three orders of magnitude under compression, indicating that Ag+ ion migrations are suppressed by high pressure. A parameter, fW, was defined as the starting frequency at which Ag+ ions begin to show obvious long-distance diffusion in AgCl. fW showed a similar trend with the ionic conductivity under high pressures, indicating that the speed of Ag+ ion diffusion slows down as the pressure increases. Unlike AgI, Ag+ ion diffusion in AgCl is controlled by the indirect-interstitial mechanism. Due to stronger ionic bonds and larger lattice deformation, Ag+ ion diffusion in the rigid Cl- lattice is more difficult than in the I- lattice under high pressures.

  17. 76 FR 73020 - Agency Information Collection (Request for Transportation Expense Reimbursement): Activity Under...

    Science.gov (United States)

    2011-11-28

    ... AFFAIRS Agency Information Collection (Request for Transportation Expense Reimbursement): Activity Under... INFORMATION: Title: Request for Transportation Expense Reimbursement (38 CFR 21.8370). OMB Control Number... reimbursement for transportation expenses. To be eligible, the child must provide supportive documentation of...

  18. Physical nutrient transport in the North Atlantic Subtropical Gyre

    Science.gov (United States)

    Jenkins, W.; Lott, D. E.

    2009-04-01

    Use of the helium-3 flux gauge to estimate the physically mediated flux of new nutrients to the euphotic zone of the North Atlantic subtropical gyre broadly suggests a pathway whereby inorganic nutrients that have been remineralized within the main thermocline may be returned to the seasonally accessible layer in the Sargasso Sea: the so-called "Nutrient Spiral" (Jenkins and Doney (2003), Glob. Biog. Cyc., 17(4), doi:1110.1029/2003GB002085.) The challenge, however, is identifying the exact mechanism whereby this occurs. One possible process is that of "obduction", whereby the combination of strong advection and rapidly deepening winter mixed layers result in the effective outcropping of substantial amounts of thermocline nutrients and tritiugenic helium-3. We present here a quantitative estimate based on hydrographic sections and geostrophic transports of the fluxes and transformations of both tritugenic helium-3 and nitrate within the basin, and attempt to relate these estimates to the specific shallow-water behaviors of these tracers, and their global and regional physical transports. An important constraint for these estimates lies in the evolving distributions of the transient tracers tritium and helium-3. We compare these results with other tracer-based estimates of new, net-community, and export production.

  19. Particle transport and deposition: basic physics of particle kinetics.

    Science.gov (United States)

    Tsuda, Akira; Henry, Frank S; Butler, James P

    2013-10-01

    The human body interacts with the environment in many different ways. The lungs interact with the external environment through breathing. The enormously large surface area of the lung with its extremely thin air-blood barrier is exposed to particles suspended in the inhaled air. The particle-lung interaction may cause deleterious effects on health if the inhaled pollutant aerosols are toxic. Conversely, this interaction can be beneficial for disease treatment if the inhaled particles are therapeutic aerosolized drugs. In either case, an accurate estimation of dose and sites of deposition in the respiratory tract is fundamental to understanding subsequent biological response, and the basic physics of particle motion and engineering knowledge needed to understand these subjects is the topic of this article. A large portion of this article deals with three fundamental areas necessary to the understanding of particle transport and deposition in the respiratory tract. These are: (i) the physical characteristics of particles, (ii) particle behavior in gas flow, and (iii) gas-flow patterns in the respiratory tract. Other areas, such as particle transport in the developing lung and in the diseased lung are also considered. The article concludes with a summary and a brief discussion of areas of future research. © 2013 American Physiological Society. Compr Physiol 3:1437-1471, 2013.

  20. Physics models in the toroidal transport code PROCTR

    Energy Technology Data Exchange (ETDEWEB)

    Howe, H.C.

    1990-08-01

    The physics models that are contained in the toroidal transport code PROCTR are described in detail. Time- and space-dependent models are included for the plasma hydrogenic-ion, helium, and impurity densities, the electron and ion temperatures, the toroidal rotation velocity, and the toroidal current profile. Time- and depth-dependent models for the trapped and mobile hydrogenic particle concentrations in the wall and a time-dependent point model for the number of particles in the limiter are also included. Time-dependent models for neutral particle transport, neutral beam deposition and thermalization, fusion heating, impurity radiation, pellet injection, and the radial electric potential are included and recalculated periodically as the time-dependent models evolve. The plasma solution is obtained either in simple flux coordinates, where the radial shift of each elliptical, toroidal flux surface is included to maintain an approximate pressure equilibrium, or in general three-dimensional torsatron coordinates represented by series of helical harmonics. The detailed coupling of the plasma, scrape-off layer, limiter, and wall models through the neutral transport model makes PROCTR especially suited for modeling of recycling and particle control in toroidal plasmas. The model may also be used in a steady-state profile analysis mode for studying energy and particle balances starting with measured plasma profiles.

  1. Radionuclide Transport in Fractured Tuff under Episodic Flow Conditions

    Science.gov (United States)

    Hu, Q.; Sun, Y.; Ewing, R. P.

    2005-12-01

    The current conceptual model of radionuclide transport in unsaturated fractured rock includes water movement in fractures, with migration of the entrained radionuclides being retarded by diffusion into and sorption within the rock matrix. Water infiltration and radionuclide transport through low-permeability unsaturated fractured rock are episodic and intermittent in nature, at least at local scales. Under episodic flow conditions, the matrix is constantly imbibing or draining, and this fluctuating wetness both drives two-way advective movement of radionuclides, and forces changes in the matrix diffusivity. This work is intended to examine, both experimentally and numerically, how radionuclide transport under episodic flow conditions is affected by the interacting processes of imbibition and drainage, diffusion, and matrix sorption. Using Topopah Spring welded volcanic tuff, collected from the potential repository geologic unit at Yucca Mountain for storing high-level nuclear waste, we prepared a saw-cut fracture core (length 10.2 cm, diameter 4.4 cm, and fracture aperture 100 microns). The dry core was packed into a flow reactor, flushed with CO2, then saturated via slow pumping (0.01 mL/min) of synthetic groundwater. The fractured core was then flushed with air at 97% relative humidity (to simulate in situ unsaturated fractured rock conditions at Yucca Mountain), then the episodic transport experiment was conducted. Episodic flow involved 4 cycles of tracer solution flow within the fracture, followed by flushing with high humidity air. Each flow episode contained a different suite of non-sorbing and sorbing tracers, which included 3H, ReO4- (a chemical analog for 99TcO4-), I- (for 129I-), Sr and Cs (for 90Sr and 137Cs), plus the radionuclides 235U, 237Np, and 241Pu. These radionuclides span a variety of sorption strengths and represent a large fraction of the radionuclides of concern at the potential Yucca Mountain repository. Meanwhile, the non-sorbing 3H and Re

  2. Effects of Solutally Dominant Convection on Physical Vapor Transport for a Mixture of Hg{sub 2}Br{sub 2} and Br{sub 2} under Microgravity Environments

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Geug-Tae [Hannam University, Daejeon (Korea, Republic of); Kown, Moo Hyun [Woosuk University, Wanju (Korea, Republic of)

    2014-02-15

    The convective flow structures in the vapor phase on earth are shown to be single unicellular, indicating the solutally dominant convection is important. These findings reflect that the total molar fluxes show asymmetrical patterns in a viewpoint of interfacial distributions. With decreasing the gravitational level form 1 g{sub 0} down to 1.0x10{sup -4} g{sub 0}, the total molar fluxes decay first order exponentially. It is also found that the total molar fluxes decay first order exponentially with increasing the partial pressure of component B, PB (Torr) form 5 Torr up to 400 Torr.. Under microgravity environments less than 1 g{sub 0}, a diffusive-convection mode is dominant and, results in much uniformity in front of the crystal regions in comparisons with a normal gravity acceleration of 1 g{sub 0}.

  3. Physics basis of Multi-Mode anomalous transport module

    Energy Technology Data Exchange (ETDEWEB)

    Rafiq, T.; Kritz, A. H.; Luo, L. [Department of Physics, Lehigh University, Bethlehem, Pennsylvania 18015 (United States); Weiland, J. [Departments of Applied Physics, Chalmers University of Technology and Euratom-VR Assoc., S41296 Gothenburg (Sweden); Pankin, A. Y. [Tech-X Corporation, Boulder, Colorado (United States)

    2013-03-15

    The derivation of Multi-Mode anomalous transport module version 8.1 (MMM8.1) is presented. The MMM8.1 module is advanced, relative to MMM7.1, by the inclusion of peeling modes, dependence of turbulence correlation length on flow shear, electromagnetic effects in the toroidal momentum diffusivity, and the option to compute poloidal momentum diffusivity. The MMM8.1 model includes a model for ion temperature gradient, trapped electron, kinetic ballooning, peeling, collisionless and collision dominated magnetohydrodynamics modes as well as model for electron temperature gradient modes, and a model for drift resistive inertial ballooning modes. In the derivation of the MMM8.1 module, effects of collisions, fast ion and impurity dilution, non-circular flux surfaces, finite beta, and Shafranov shift are included. The MMM8.1 is used to compute thermal, particle, toroidal, and poloidal angular momentum transports. The fluid approach which underlies the derivation of MMM8.1 is expected to reliably predict, on an energy transport time scale, the evolution of temperature, density, and momentum profiles in plasma discharges for a wide range of plasma conditions.

  4. Electrical transport properties of manganite powders under pressure

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez, M.G. [Laboratorio de Bajas Temperaturas, Departamento de Fisica, FCEyN, UBA, and IFIBA (CONICET), Ciudad Universitaria, (C1428EHA) Buenos Aires (Argentina); Leyva, A.G. [Gerencia de Investigacion y Aplicaciones, CAC, Comision Nacional de Energia Atomica, Gral Paz 1499, 1650 San Martin, Buenos Aires (Argentina); Acha, C., E-mail: acha@df.uba.ar [Laboratorio de Bajas Temperaturas, Departamento de Fisica, FCEyN, UBA, and IFIBA (CONICET), Ciudad Universitaria, (C1428EHA) Buenos Aires (Argentina)

    2012-08-15

    We have measured the electrical resistance of micrometric to nanometric powders of the La{sub 5/8-y}Pr{sub y}Ca{sub 3/8}MnO{sub 3} (LPCMO with y=0.3) manganite for hydrostatic pressures up to 4 kbar. By applying different final thermal treatments to samples synthesized by a microwave assisted denitration process, we obtained two particular grain characteristic dimensions (40 nm and 1000 nm) which allowed us to analyze the grain size sensitivity of the electrical conduction properties of both the metal electrode interface with manganite (Pt/LPCMO) and the intrinsic intergranular interfaces formed by the LPCMO powder, conglomerate under the only effect of external pressure. We also analyzed the effects of pressure on the phase diagram of these powders. Our results indicate that different magnetic phases coexist at low temperatures and that the electrical transport properties are related to the intrinsic interfaces, as we observe evidences of a granular behavior and an electronic transport dominated by the Space Charge limited Current mechanism.

  5. Modelling transport phenomena in a multi-physics context

    Science.gov (United States)

    Marra, Francesco

    2015-01-01

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

  6. Modelling transport phenomena in a multi-physics context

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-01-22

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

  7. Modelling transport phenomena in a multi-physics context

    International Nuclear Information System (INIS)

    Marra, Francesco

    2015-01-01

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

  8. Some Physics and Applications for DNA Transport Through Single Nanopores

    Science.gov (United States)

    Kasianowicz, J. J.

    2002-03-01

    In an effort to understand macromolecular transport in living systems, we are studying the ability of a single-stranded DNA (ssDNA) to thread through single nanometer-scale pores. Some six years ago it was shown that an applied electrostatic potential can drive individual negatively charged molecules of ssDNA through a single Staphylococcus aureus a-hemolysin (aHL) protein ionic channel(Kasianowicz, J.J., et al. 1996. Proc. Natl. Acad. Sci. (USA) 93, 13770). We also demonstrated that the mean rate at which polynucleotides enter this pore depends on the magnitude of the applied potential and the side through which the polymer enters. Although the flux of polynucleotides into the pore can be described by a simple Van't-Hoff rate law(Henrickson, S.E., et al. 2000. Phys. Rev. Lett. 85, 3057), detailed models provide more physical insight into both this process and polymer translocation(Konkoli, Z., et al. submitted)/footnoteAmbjörnsson, T., et al. submitted. We show that modified polynucleotides can be used to probe the structure of channels formed by native aHL and modified aHL mutants(Henrickson, et al., submitted). These experimental results suggest that both the location of energy barriers to polymer transport and the channel's geometric properties can be determined. We discuss several potential biotechnological applications based on these findings(Kasianowicz, J.J. et al., Anal. Chem. 73, 2268)(Stanford, V. and J.J. Kasianowicz, submitted.)

  9. KAMCCO, a reactor physics Monte Carlo neutron transport code

    International Nuclear Information System (INIS)

    Arnecke, G.; Borgwaldt, H.; Brandl, V.; Lalovic, M.

    1976-06-01

    KAMCCO is a 3-dimensional reactor Monte Carlo code for fast neutron physics problems. Two options are available for the solution of 1) the inhomogeneous time-dependent neutron transport equation (census time scheme), and 2) the homogeneous static neutron transport equation (generation cycle scheme). The user defines the desired output, e.g. estimates of reaction rates or neutron flux integrated over specified volumes in phase space and time intervals. Such primary quantities can be arbitrarily combined, also ratios of these quantities can be estimated with their errors. The Monte Carlo techniques are mostly analogue (exceptions: Importance sampling for collision processes, ELP/MELP, Russian roulette and splitting). Estimates are obtained from the collision and track length estimators. Elastic scattering takes into account first order anisotropy in the center of mass system. Inelastic scattering is processed via the evaporation model or via the excitation of discrete levels. For the calculation of cross sections, the energy is treated as a continuous variable. They are computed by a) linear interpolation, b) from optionally Doppler broadened single level Breit-Wigner resonances or c) from probability tables (in the region of statistically distributed resonances). (orig.) [de

  10. Effects of hydration and physical therapy on tracheal transport velocity

    International Nuclear Information System (INIS)

    Chopra, S.K.; Taplin, G.V.; Simmons, D.H.; Coulson, A.; Elam, D.

    1976-01-01

    A new tracer method for quantitative measurements of tracheal transport velocity (TTV) in mm/min in dogs has been described recently. Using the same technique, the effects of dehydration, hydration, postural drainage and physical therapy on TTV were studied. There was a significant (p < 0.05) reduction in TTV following dehydration and these values reverted to normal with hydration in all ten dogs. Tracheal transport velocity increased on the average of 39.7 percent with a mean change of 7.7 mm/min (p < 0.01) following postural drainage in seven dogs. On the other hand, TTV increased on the average of 51 percent with a mean change of 8.2 mm/min (p <0.01) following chest percussion in six dogs. Postural drainage and chest percussion each increased TTV significantly beyond the base-line values. However, hydration only restored TTV to base-line values when applied to dogs in the hydropenic state. These therapeutic measures have been used empirically in the past. The present study gives objective evidence of their beneficial effects in dogs and suggests that such treatments may have a definite scientific basis for clinical application in chronic obstructive airways disease

  11. Pedometer-determined physical activity and active transport in girls

    Directory of Open Access Journals (Sweden)

    Schofield Grant

    2008-01-01

    Full Text Available Abstract Background It is well established that the risk of insufficient physical activity is greater in girls than in boys, especially during the adolescent years. The promotion of active transport (AT to and from school has been posited as a practical and convenient solution for increasing girls' total daily activity. However, there is limited information describing the associations between AT choices and girls' physical activity across a range of age, ethnic, and socioeconomic groups. The objectives of this study were to (1 investigate physical activity patterns in a large multiethnic sample of female children and adolescents, and to (2 estimate the physical activity associated with AT to and from school. Methods A total of 1,513 girls aged 5–16 years wore sealed multiday memory (MDM pedometers for three weekdays and two weekend days. The ethnic composition of this sample was 637 European (42.1%, 272 Pacific Island (18.0%, 207 East Asian (13.7%, 179 Maori (11.8%, 142 South Asian (9.4%, and 76 from other ethnic groups (5%. Pedometer compliance and school-related AT were assessed by questionnaire. Results Mean weekday step counts (12,597 ± 3,630 were higher and less variable than mean weekend steps (9,528 ± 4,407. A consistent decline in daily step counts was observed with age: after adjustment for ethnicity and SES, girls in school years 9–10 achieved 2,469 (weekday and 4,011 (weekend fewer steps than girls in years 1–2. Daily step counts also varied by ethnicity, with Maori girls the most active and South Asian girls the least active. Overall, 44.9% of participants used AT for school-related travel. Girls who used AT to and from school averaged 1,052 more weekday steps than those who did not use AT. However, the increases in steps associated with AT were significant only in older girls (school years 5–10 and in those of Maori or European descent. Conclusion Our data suggest that adolescent-aged girls and girls of Asian descent are

  12. 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

  13. Three dimensional computational fluid dynamic analysis of debris transport under emergency cooling water recirculation

    International Nuclear Information System (INIS)

    Park, Jong Woon

    2010-01-01

    This paper provides a computational fluid dynamic (CFD) analysis method on the evaluation of debris transport under emergency recirculation mode after loss of coolant accident of a nuclear power plant. Three dimensional reactor building floor geometrical model is constructed including flow obstacles larger than 6 inches such as mechanical components and equipments and considering various inlet flow paths from the upper reactor building such as break and spray flow. In the modeling of the inlet flows from the upper floors, effect of gravitational force was also reflected. For the precision of the analysis, 3 millions of tetrahedral-shaped meshes were generated. Reference calculation showed physically reasonable results. Sensitivity studies for mesh type and turbulence model showed very similar results to the reference case. This study provides useful information on the application of CFD to the evaluation of debris transport fraction for the design of new emergency sump filters. (orig.)

  14. Physical processes that control droplet transport in rock fracture systems

    Science.gov (United States)

    Hay, Katrina Moran

    Aquifer recharge is generally driven by fluids that move from the Earths surface to groundwater through the unsaturated zone, also known as the vadose zone. When the vadose zone is fractured, fluids, which may include contaminants, can move through the fracture network as well as the porous matrix. Such a network of fractures can provide a more rapid path, thereby reducing contact time between the fluid and the matrix. Contact time allows for exchange of solutes between the fluid and the porous matrix, thus being able to quantify contact time is important. In addition, the behavior of fluids within a fracture network has been found to be very complex; large-scale models are yet not able to predict transport paths or flux rates. Because, small-scale flow phenomena can strongly influence the large-scale behavior of fluid movement through systems of fractures, it is important that small-scale dynamics be properly understood in order to improve our predictive capabilities in these complex systems. Relevant flow dynamics includes the impact of boundary conditions, fluid modes that evolve in time and space and transitions between modes. This thesis presents three investigations aimed at understanding the physical processes governing fluid movement in unsaturated fractures, with the ultimate goal of improving predictive relationships for fluid transport in rock fracture systems. These investigations include a theoretical analysis of the wetting of a rough surface, an experimental study of the dynamics of fluid droplets (or liquid bridges) moving in a single fracture and a theoretical analysis of the movement of a fluid droplet encountering a fracture intersection. Each investigation is motivated by environmental applications. Development of an analytical equation for the wetting of a rough surface is based on a balance between capillary forces and frictional resistive forces. The resulting equation predicts movement of the liquid invasion front driven solely by the

  15. Thermal analysis on NAC-STC spent fuel transport cask under different transport conditions

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Yumei [Institute of Process Equipment, Zhejiang University, Hangzhou (China); Yang, Jian, E-mail: zdhjkz@zju.edu.cn [Institute of Process Equipment, Zhejiang University, Hangzhou (China); Xu, Chao; Wang, Weiping [Institute of Process Equipment, Zhejiang University, Hangzhou (China); Ma, Zhijun [Department of Material Engineering, South China University of Technology, Guangzhou (China)

    2013-12-15

    Highlights: • Spent fuel cask was investigated as a whole instead of fuel assembly alone. • The cask was successfully modeled and meshed after several simplifications. • Equivalence method was used to calculate the properties of parts. • Both the integral thermal field and peak values are captured to verify safety. • The temperature variations of key parts were also plotted. - Abstract: Transport casks used for conveying spent nuclear fuel are inseparably related to the safety of the whole reprocessing system for spent nuclear fuel. Thus they must be designed according to rigorous safety standards including thermal analysis. In this paper, for NAC-STC cask, a finite element model is established based on some proper simplifications on configurations and the heat transfer mechanisms. Considering the complex components and gaps, the equivalence method is presented to define their material properties. Then an equivalent convection coefficient is introduced to define boundary conditions. Finally, the temperature field is captured and analyzed under both normal and accident transport conditions by using ANSYS software. The validity of numerical calculation is given by comparing its results with theoretical calculation. Obtaining the integral distribution laws of temperature and peak temperature values of all vital components, the security of the cask can be evaluated and verified.

  16. 76 FR 41510 - Extension of Agency Information Collection Activity Under OMB Review; Transportation Worker...

    Science.gov (United States)

    2011-07-14

    ...] Extension of Agency Information Collection Activity Under OMB Review; Transportation Worker Identification... Title: Transportation Worker Identification Credential (TWIC) Program. Type of Request: Extension of a... verify their biographic information and provide identity documentation, biometric information, and proof...

  17. 78 FR 59364 - Revision of Agency Information Collection Activity Under OMB Review: Transportation Worker...

    Science.gov (United States)

    2013-09-26

    ...] Revision of Agency Information Collection Activity Under OMB Review: Transportation Worker Identification.... Information Collection Requirement Title: Transportation Worker Identification Credential (TWIC) Program. Type... documentation, biometric information, and proof of immigration status (if required). This information allows TSA...

  18. Heat transport and afterheat removal for gas cooled reactors under accident conditions

    International Nuclear Information System (INIS)

    2001-01-01

    The Co-ordinated Research Project (CRP) on Heat Transport and Afterheat Removal for Gas Cooled Reactors Under Accident Conditions was organized within the framework of the International Working Group on Gas Cooled Reactors (IWGGCR). This International Working Group serves as a forum for exchange of information on national programmes, provides advice to the IAEA on international co-operative activities in advanced technologies of gas cooled reactors (GCRs) and supports the conduct of these activities. Advanced GCR designs currently being developed are predicted to achieve a high degree of safety through reliance on inherent safety features. Such design features should permit the technical demonstration of exceptional public protection with significantly reduced emergency planning requirements. For advanced GCRs, this predicted high degree of safety largely derives from the ability of the ceramic coated fuel particles to retain the fission products under normal and accident conditions, the safe neutron physics behaviour of the core, the chemical stability of the core and the ability of the design to dissipate decay heat by natural heat transport mechanisms without reaching excessive temperatures. Prior to licensing and commercial deployment of advanced GCRs, these features must first be demonstrated under experimental conditions representing realistic reactor conditions, and the methods used to predict the performance of the fuel and reactor must be validated against these experimental data. Within this CRP, the participants addressed the inherent mechanisms for removal of decay heat from GCRs under accident conditions. The objective of this CRP was to establish sufficient experimental data at realistic conditions and validated analytical tools to confirm the predicted safe thermal response of advance gas cooled reactors during accidents. The scope includes experimental and analytical investigations of heat transport by natural convection conduction and thermal

  19. Prediction of physical properties of water under extremely supercritical conditions: A molecular dynamics study

    Science.gov (United States)

    Sakuma, Hiroshi; Ichiki, Masahiro; Kawamura, Katsuyuki; Fuji-ta, Kiyoshi

    2013-04-01

    The physical properties of water under a wide range of pressure and temperature conditions are important in fundamental physics, chemistry, and geoscience. Molecular simulations are useful for predicting and understanding the physical properties of water at phases extremely different from ambient conditions. In this study, we developed a new five-site flexible induced point charge model to predict the density, static dielectric constant, and transport properties of water in the extremely supercritical phase at high temperatures and pressures of up to 2000 K and 2000 MPa. The model satisfactorily reproduced the density, radial distribution function, static dielectric constant, reorientation time, and self-diffusion coefficients of water above the critical points. We also developed a database of the static dielectric constant, which is useful for discussing the electrical conductivity of aqueous fluids in the earth's crust and mantle.

  20. Decision-making in Sport under Mental and Physical Stress

    Directory of Open Access Journals (Sweden)

    Teri J. Hepler

    2015-10-01

    Full Text Available Background: Successful decision-making in sport requires good decisions to be made quickly, but little is understood about the decision process under stress. Objective: The purpose of this study was to compare decision outcomes and the Take the First (TTF heuristic under conditions of mental, physical, and no stress.  Method:  Participants (N=112 were divided into 3 stress groups:  mental stress (mental serial subtraction, physical stress (running on treadmill at 60-70% of maximum effort, and no stress (counting backwards by 1. Participants were exposed to 30 seconds of stress and then watched a video depicting an offensive situation in basketball requiring them to decide what the player with the ball should do next. Each participant performed 10 trials of the video decision-making task.  Results: No differences were found between the 3 stress groups on decision quality, TTF frequency, number of options generated, or quality of first generated option.  However, participants in the no stress and physical stress conditions were faster in generating their first option and making their final decision as compared to the mental stress group.  Conclusion: Overall, results suggest that mental stress impairs decision speed and that TTF is an ecologically rationale heuristic in dynamic, time-pressured situations.  Keywords: Take the first, Heuristic, Pressure, Cognitive performance

  1. Exergy performance of human body under physical activities

    International Nuclear Information System (INIS)

    Mady, Carlos Eduardo Keutenedjian; Albuquerque, Cyro; Fernandes, Tiago Lazzaretti; Hernandez, Arnaldo José; Saldiva, Paulo Hilário Nascimento; Yanagihara, Jurandir Itizo; Oliveira, Silvio de

    2013-01-01

    The aim of this work is to apply performance indicators for individuals under physical activity based on the concepts of exergy destroyed and exergy efficiency. The cardiopulmonary exercise test is one of the most used tests to assess the functional capacity of individuals with varying degrees of physical training. To perform the exergy analysis during the test, it is necessary to calculate heat and mass flow rates, associated with radiation, convection, vaporization and respiration, determined from the measurements and some relations found in the literature. The energy balance allowed the determination of the internal temperature over time and the exergy variation of the body along the experiment. Eventually, it was possible to calculate the destroyed exergy and the exergy efficiency from the exergy analysis. The exergy rates and flow rates are dependent of the exercise level and the body metabolism. The results show that the relation between the destroyed exergy and the metabolism is almost constant during the test, furthermore its value has a great dependence of the subject age. From the exergy analysis it was possible to divide the subjects according to their training level, for the same destroyed exergy, subjects with higher lactate threshold can perform more work. - Highlights: • Exergy analysis was applied to the human body under physical activities. • Concept of maximum available work from ATP hydrolysis was compared with exergy analysis results. • For the same destroyed exergy, subjects with higher lactate threshold can perform more work. • Runners during physical activities tend to a state of minimum destroyed exergy and maximum exergy efficiency

  2. Physics and modelling of scrape-off layer transport

    Energy Technology Data Exchange (ETDEWEB)

    Cohen, R.H.; Allen, S.L.; Crotinger, J.A.; Kaiser, T.B.; Milovich, J.L.; Mattor, N.; Nevins, W.M.; Porter, G.D.; Rensink, M.E.; Rognlien, T.D. [Lawrence Livermore National Lab., CA (United States); Berk, H.L. [Texas Univ., Austin, TX (United States). Inst. for Fusion Studies; Campbell, R.B. [Sandia National Labs., Albuquerque, NM (United States); Diamond, P.H.; Rosenbluth, M.N. [California Univ., San Diego, CA (United States); Hinton, F.L.; Staebler, G.M. [General Atomics, San Diego, CA (United States); Knoll, D.A. [EG and G Idaho, Inc., Idaho Falls, ID (United States); Modi, B.; Xu, X.Q. [California Univ., Berkeley, CA (United States); Prinja, A.K. [New Mexico Univ., Albuquerque, NM (United States); Ryutov, D.D.; Tsidulko, Y.A. [Budker Institute of Nuclear Physics, Novosibirsk (Russia)

    1992-12-31

    We present studies of three schemes for reducing the peak heat flux on divertor plates, divertor biasing, impurity injection (``radiative divertor``) and neutral gas injection (``gas target divertor``). We report on theoretical analysis of a likely source of turbulent transport in the SOL and incorporation of the resultant transport coefficients into self-consistent models.

  3. Physics and modelling of scrape-off layer transport

    Energy Technology Data Exchange (ETDEWEB)

    Cohen, R.H.; Allen, S.L.; Crotinger, J.A.; Kaiser, T.B.; Milovich, J.L.; Mattor, N.; Nevins, W.M.; Porter, G.D.; Rensink, M.E.; Rognlien, T.D. (Lawrence Livermore National Lab., CA (United States)); Berk, H.L. (Texas Univ., Austin, TX (United States). Inst. for Fusion Studies); Campbell, R.B. (Sandia National Labs., Albuquerque, NM (United States)); Diamond, P.H.; Rosenbluth, M.N. (California Univ., San Di

    1992-01-01

    We present studies of three schemes for reducing the peak heat flux on divertor plates, divertor biasing, impurity injection ( radiative divertor'') and neutral gas injection ( gas target divertor''). We report on theoretical analysis of a likely source of turbulent transport in the SOL and incorporation of the resultant transport coefficients into self-consistent models.

  4. Physics and modelling of scrape-off layer transport

    International Nuclear Information System (INIS)

    Cohen, R.H.; Allen, S.L.; Crotinger, J.A.; Kaiser, T.B.; Milovich, J.L.; Mattor, N.; Nevins, W.M.; Porter, G.D.; Rensink, M.E.; Rognlien, T.D.; Berk, H.L.; Diamond, P.H.; Rosenbluth, M.N.; Hinton, F.L.; Staebler, G.M.; Knoll, D.A.; Modi, B.; Xu, X.Q.; Prinja, A.K.; Ryutov, D.D.; Tsidulko, Y.A.

    1992-01-01

    We present studies of three schemes for reducing the peak heat flux on divertor plates, divertor biasing, impurity injection (''radiative divertor'') and neutral gas injection (''gas target divertor''). We report on theoretical analysis of a likely source of turbulent transport in the SOL and incorporation of the resultant transport coefficients into self-consistent models

  5. Origin of life and the underlying physics of the universe.

    Science.gov (United States)

    Conrad, M

    1997-01-01

    The thesis is put forward that the non-linear self-organizing dynamics of biological systems are inherent in any physical theory that satisfies the requirements of both quantum mechanics and general relativity. Biological life is viewed as an extension of these underlying dynamics rather than as an emergent property of systems that reached a requisite threshold of complexity at a definite point in time. The underlying dynamics are based on interactions between manifest material organizations and an unmanifest vacuum sea whose density structure is isomorphic to the metric structure of space-time. These interactions possess an intrinsic self-corrective character, due to the fact that quantum processes lead to changes in particle states that have a random aspect, while general relativity requires that the distribution of manifest and unmanifest particles be self-consistent. The model implies vacuum hysteretic effects that would bear on nanobiological phenomena and that might be detected through nanobiological techniques.

  6. Laboratory studies on bedload transport under unsteady flow conditions

    OpenAIRE

    Mrokowska Magdalena M.; Rowiński Paweł M.; Książek Leszek; Strużyński Andrzej; Wyrębek Maciej; Radecki-Pawlik Artur

    2018-01-01

    Two sets of triangular hydrographs were generated in a 12-m-long laboratory flume for two sets of initial bed conditions: intact and water-worked gravel bed. Flowrate ranging from 0.0013 m3 s-1 to 0.0456 m3 s-1, water level ranging from 0.02 m to 0.11 m, and cumulative mass of transported sediment ranging from 4.5 kg to 14.2 kg were measured. Then, bedload transport rate, water surface slope, bed shear stress, and stream power were evaluated. The results indicated the impact of initial bed co...

  7. Mechanistic logic underlying the axonal transport of cytosolic proteins

    Science.gov (United States)

    Scott, David A.; Das, Utpal; Tang, Yong; Roy, Subhojit

    2011-01-01

    Proteins vital to presynaptic function are synthesized in the neuronal perikarya and delivered into synapses via two modes of axonal transport. While membrane-anchoring proteins are conveyed in fast axonal transport via motor-driven vesicles, cytosolic proteins travel in slow axonal transport; via mechanisms that are poorly understood. We found that in cultured axons, populations of cytosolic proteins tagged to photoactivable-GFP (PA-GFP) move with a slow motor-dependent anterograde bias; distinct from vesicular-trafficking or diffusion of untagged PA-GFP. The overall bias is likely generated by an intricate particle-kinetics involving transient assembly and short-range vectorial spurts. In-vivo biochemical studies reveal that cytosolic proteins are organized into higher-order structures within axon-enriched fractions that are largely segregated from vesicles. Data-driven biophysical modeling best predicts a scenario where soluble molecules dynamically assemble into mobile supra-molecular structures. We propose a model where cytosolic proteins are transported by dynamically assembling into multi-protein complexes that are directly/indirectly conveyed by motors. PMID:21555071

  8. CO2-ECBM related coupled physical and mechanical transport processes

    Science.gov (United States)

    Gensterblum, Yves; Satorius, Michael; Busch, Andreas; Krooß, Bernhard

    2013-04-01

    The interrelation of cleat transport processes and mechanical properties was investigated by permeability tests at different stress levels (60% to 130% of in-situ stress) with sorbing (CH4, CO2) and inert gases (N2, Ar, He) on a sub bituminous A coal from the Surat Basin, Queensland Australia. From the flow tests under controlled triaxial stress conditions the Klinkenberg-corrected "true" permeability coefficients and the Klinkenberg slip factors were derived. The "true"-, absolute or Klinkenberg corrected permeability shows a gas type dependence. Following the approach of Seidle et al. (1992) the cleat volume compressibility (cf) was calculated from observed changes in apparent permeability upon variation of external stress (at equal mean gas pressures). The observed effects also show a clear dependence on gas type. Due to pore or cleat compressibility the cleat aperture decreases with increasing effective stress. Vice versa we observe with increasing mean pressure at lower confining pressure an increase in permeability which we attribute to a cleat aperture widening. The cleat volume compressibility (cf) also shows a dependence on the mean pore pressure. Non-sorbing gases like helium and argon show higher apparent permeabilities than sorbing gases like methane. Permeability coefficients measured with successively increasing mean gas pressures were consistently lower than those determined at decreasing mean gas pressures. This permeability hysteresis is in accordance with results reported by Harpalani and McPherson (1985). The kinetics of matrix transport processes were studied by sorption tests on different particle sizes at various moisture contents and temperatures (cf. Busch et al., 2006). Methane uptake rates were determined from the pressure decline curves recorded for each particle-size fraction, and "diffusion coefficients" were calculated using several unipore and bidisperse diffusion models. While the CH4 sorption capacity of moisture-equilibrated coals

  9. On Runaway Transport under Magnetic Turbulence in Tokamaks

    Energy Technology Data Exchange (ETDEWEB)

    Castejon, F.; Equilior, S.; Rodriguez-Rodrigo, L. [CIEMAT. Madrid (Spain)

    2001-07-01

    The influence of magnetic turbulence on runaway transport has been studied. The evolution of runaway distribution function has been calculated using Electra a 2D code in momentum space and 1D in radius coordinate. The code considers the effect of averaging the turbulence by runaway orbits. Then Hard X-Ray emission spectrum is estimated and compared with experimental results of TJ-1 tokamak, obtaining a remarkable agreement. (Author) 15 refs.

  10. Robust Evaluation for Transportation Network Capacity under Demand Uncertainty

    Directory of Open Access Journals (Sweden)

    Muqing Du

    2017-01-01

    Full Text Available As more and more cities in worldwide are facing the problems of traffic jam, governments have been concerned about how to design transportation networks with adequate capacity to accommodate travel demands. To evaluate the capacity of a transportation system, the prescribed origin and destination (O-D matrix for existing travel demand has been noticed to have a significant effect on the results of network capacity models. However, the exact data of the existing O-D demand are usually hard to be obtained in practice. Considering the fluctuation of the real travel demand in transportation networks, the existing travel demand is represented as uncertain parameters which are defined within a bounded set. Thus, a robust reserve network capacity (RRNC model using min–max optimization is formulated based on the demand uncertainty. An effective heuristic approach utilizing cutting plane method and sensitivity analysis is proposed for the solution of the RRNC problem. Computational experiments and simulations are implemented to demonstrate the validity and performance of the proposed robust model. According to simulation experiments, it is showed that the link flow pattern from the robust solutions to network capacity problems can reveal the probability of high congestion for each link.

  11. Network Performance Improvement under Epidemic Failures in Optical Transport Networks

    DEFF Research Database (Denmark)

    Fagertun, Anna Manolova; Ruepp, Sarah Renée

    2013-01-01

    In this paper we investigate epidemic failure spreading in large- scale GMPLS-controlled transport networks. By evaluating the effect of the epidemic failure spreading on the network, we design several strategies for cost-effective network performance improvement via differentiated repair times....... First we identify the most vulnerable and the most strategic nodes in the network. Then, via extensive simulations we show that strategic placement of resources for improved failure recovery has better performance than randomly assigning lower repair times among the network nodes. Our OPNET simulation...... model can be used during the network planning process for facilitating cost- effective network survivability design....

  12. Network Performance Improvement under Epidemic Failures in Optical Transport Networks

    DEFF Research Database (Denmark)

    Fagertun, Anna Manolova; Ruepp, Sarah Renée

    2013-01-01

    In this paper we investigate epidemic failure spreading in large- scale GMPLS-controlled transport networks. By evaluating the effect of the epidemic failure spreading on the network, we design several strategies for cost-effective network performance improvement via differentiated repair times....... First we identify the most vulnerable and the most strategic nodes in the network. Then, via extensive simulations we show that strategic placement of resources for improved failure recovery has better performance than randomly assigning lower repair times among the network nodes. Our OPNET simulation...

  13. Soil Quality and Colloid Transport under Biodegradable Mulches

    Science.gov (United States)

    Sintim, Henry; Bandopadhyay, Sreejata; Ghimire, Shuresh; Flury, Markus; Bary, Andy; Schaeffer, Sean; DeBruyn, Jennifer; Miles, Carol; Inglis, Debra

    2016-04-01

    Polyethylene (PE) mulch is commonly used in agriculture to increase water use efficiency, to control weeds, manage plant diseases, and maintain a favorable micro-climate for plant growth. However, producers need to retrieve and safely dispose PE mulch after usage, which creates enormous amounts of plastic waste. Substituting PE mulch with biodegradable plastic mulches could alleviate disposal needs. However, repeated applications of biodegradable mulches, which are incorporated into the soil after the growing season, may cause deterioration of soil quality through breakdown of mulches into colloidal fragments, which can be transported through soil. Findings from year 1 of a 5-year field experiment will be presented.

  14. Physical protection in the transport of nuclear materials (Legal aspects of the domestic system)

    International Nuclear Information System (INIS)

    Novais, F.J.G.

    1978-04-01

    A study of the physical protection system is made. Emphasis is given to some considerations in the nuclear material transport area, mainly the details of the domestic system, from a juridic pont of view. (Author) [pt

  15. Physical Activity through Sustainable Transport Approaches (PASTA): a study protocol for a multicentre project.

    Science.gov (United States)

    Gerike, Regine; de Nazelle, Audrey; Nieuwenhuijsen, Mark; Panis, Luc Int; Anaya, Esther; Avila-Palencia, Ione; Boschetti, Florinda; Brand, Christian; Cole-Hunter, Tom; Dons, Evi; Eriksson, Ulf; Gaupp-Berghausen, Mailin; Kahlmeier, Sonja; Laeremans, Michelle; Mueller, Natalie; Orjuela, Juan Pablo; Racioppi, Francesca; Raser, Elisabeth; Rojas-Rueda, David; Schweizer, Christian; Standaert, Arnout; Uhlmann, Tina; Wegener, Sandra; Götschi, Thomas

    2016-01-07

    Only one-third of the European population meets the minimum recommended levels of physical activity (PA). Physical inactivity is a major risk factor for non-communicable diseases. Walking and cycling for transport (active mobility, AM) are well suited to provide regular PA. The European research project Physical Activity through Sustainable Transport Approaches (PASTA) pursues the following aims: (1) to investigate correlates and interrelations of AM, PA, air pollution and crash risk; (2) to evaluate the effectiveness of selected interventions to promote AM; (3) to improve health impact assessment (HIA) of AM; (4) to foster the exchange between the disciplines of public health and transport planning, and between research and practice. PASTA pursues a mixed-method and multilevel approach that is consistently applied in seven case study cities. Determinants of AM and the evaluation of measures to increase AM are investigated through a large scale longitudinal survey, with overall 14,000 respondents participating in Antwerp, Barcelona, London, Örebro, Rome, Vienna and Zurich. Contextual factors are systematically gathered in each city. PASTA generates empirical findings to improve HIA for AM, for example, with estimates of crash risks, factors on AM-PA substitution and carbon emissions savings from mode shifts. Findings from PASTA will inform WHO's online Health Economic Assessment Tool on the health benefits from cycling and/or walking. The study's wide scope, the combination of qualitative and quantitative methods and health and transport methods, the innovative survey design, the general and city-specific analyses, and the transdisciplinary composition of the consortium and the wider network of partners promise highly relevant insights for research and practice. Ethics approval has been obtained by the local ethics committees in the countries where the work is being conducted, and sent to the European Commission before the start of the survey. The PASTA website

  16. Promoting physical activity and reducing climate change: opportunities to replace short car trips with active transportation.

    Science.gov (United States)

    Maibach, Edward; Steg, Linda; Anable, Jillian

    2009-10-01

    Automobile use is a significant contributor to climate change, local air pollution, pedestrian injuries and deaths, declines in physical activity and obesity. A significant proportion of car use is for short trips that can relatively easily be taken with active transportation options--walking or cycling--or with public transportation. In this commentary, we review a number of immediate, practical opportunities to implement policies and programs that reduce short car trips and increase active transportation.

  17. Physical and Temporal Characteristics of Under 19, Under 21 and Senior Male Beach Volleyball Players

    Directory of Open Access Journals (Sweden)

    Alexandre Medeiros, Rui Marcelino, Isabel Mesquita, José Manuel Palao

    2014-09-01

    Full Text Available This study aimed to assess the effects of age groups and players’ role (blocker vs. defender specialist in beach volleyball in relation to physical and temporal variables, considering quality of opposition. 1101 rallies from Under 19 (U19, 933 rallies from Under 21 (U21, and 1480 rallies from senior (senior (Men’s Swatch World Championships, 2010-2011 were observed using video match analysis. Cluster analysis was used to set teams’ competitive levels and establish quality of opposition as “balanced”, “moderate balanced” and “unbalanced” games. The analyzed variables were: temporal (duration of set, total rest time, total work time, duration of rallies, rest time between rallies and physical (number of jumps and number of hits done by defenders and blockers characteristics. A one-way ANOVA, independent samples t-test and multinomial logistic regression were performed to analyze the variables studied. The analysis of temporal and physical characteristics showed differences considering age group, player’s role and quality of opposition. The duration of set, total rest time, and number of jumps done by defenders significantly increased from the U19 to senior category. Multinomial logistic regression showed that in: a balanced games, rest time between rallies was higher in seniors than in U19 or U21; number of jumps done by defenders was higher in seniors than in U19 and U21; b moderate balanced games, number of jumps done by defenders was higher in seniors than in U21 and number of jumps done by blockers was smaller in U19 than U21 or seniors; c unbalanced games, no significant findings were shown. This study suggests differences in players’ performances according to age group and players’ role in different qualities of opposition. The article provides reference values that can be useful to guide training and create scenarios that resemble a competition, taking into account physical and temporal characteristics.

  18. A novel two-dimensional model for colloid transport in physically and geochemically heterogeneous porous media.

    Science.gov (United States)

    Sun, N; Elimelech, M; Sun, N Z; Ryan, J N

    2001-06-01

    A two-dimensional model for colloid transport in geochemically and physically heterogeneous porous media is presented. The model considers patchwise geochemical heterogeneity, which is suitable to describe the chemical variability of many surficial aquifers with ferric oxyhydroxide-coated porous matrix, as well as spatial variability of hydraulic conductivity, which results in heterogeneous flow field. The model is comprised of a transient fluid flow equation, a transient colloid transport equation, and an equation for the dynamics of colloid deposition and release. Numerical simulations were carried out with the model to investigate the colloid transport behavior in layered and randomly heterogeneous porous media. Results demonstrate that physical and geochemical heterogeneities markedly affect the colloid transport behavior. Layered physical or geochemical heterogeneity can result in distinct preferential flow paths of colloidal particles. Furthermore, the combined effect of layered physical and geochemical heterogeneity may result in enhanced or reduced preferential flow of colloids. Random distribution of physical heterogeneity (hydraulic conductivity) results in a random flow field and an irregularly distributed colloid concentration profile in the porous medium. Contrary to random physical heterogeneity, the effect of random patchwise geochemical heterogeneity on colloid transport behavior is not significant. It is mostly the mean value of geochemical heterogeneity rather than its distribution that governs the colloid transport behavior.

  19. Physical and temporal characteristics of under 19, under 21 and senior male beach volleyball players.

    Science.gov (United States)

    Medeiros, Alexandre; Marcelino, Rui; Mesquita, Isabel; Palao, José Manuel

    2014-09-01

    This study aimed to assess the effects of age groups and players' role (blocker vs. defender specialist) in beach volleyball in relation to physical and temporal variables, considering quality of opposition. 1101 rallies from Under 19 (U19), 933 rallies from Under 21 (U21), and 1480 rallies from senior (senior) (Men's Swatch World Championships, 2010-2011) were observed using video match analysis. Cluster analysis was used to set teams' competitive levels and establish quality of opposition as "balanced", "moderate balanced" and "unbalanced" games. The analyzed variables were: temporal (duration of set, total rest time, total work time, duration of rallies, rest time between rallies) and physical (number of jumps and number of hits done by defenders and blockers) characteristics. A one-way ANOVA, independent samples t-test and multinomial logistic regression were performed to analyze the variables studied. The analysis of temporal and physical characteristics showed differences considering age group, player's role and quality of opposition. The duration of set, total rest time, and number of jumps done by defenders significantly increased from the U19 to senior category. Multinomial logistic regression showed that in: a) balanced games, rest time between rallies was higher in seniors than in U19 or U21; number of jumps done by defenders was higher in seniors than in U19) and U21; b) moderate balanced games, number of jumps done by defenders was higher in seniors than in U21 and number of jumps done by blockers was smaller in U19 than U21 or seniors; c) unbalanced games, no significant findings were shown. This study suggests differences in players' performances according to age group and players' role in different qualities of opposition. The article provides reference values that can be useful to guide training and create scenarios that resemble a competition, taking into account physical and temporal characteristics. Key PointsPlayer roles, quality of opposition

  20. Evaluation of atrazine transport in soils under different agricultural managements

    OpenAIRE

    Correia, Fabio Veríssimo; Langenbach, Tomaz; Campos, Tácio Mauro

    2010-01-01

    A pouca informação sobre o movimento de pesticidas em solos brasileiros com manejo de plantio direto torna o conhecimento desse assunto de grande relevância na avaliação de risco de contaminação do solo e de lençóis de água. Os experimentos simularam chuvas intensas com fluxo contínuo por meio de uma nova técnica para a determinação simultânea das propriedades de advecção, difusão e sorção, representando o transporte de contaminantes ao longo do perfil de solo estudado. Os resultados mostrara...

  1. Physics of gas breakdown for ion beam transport in gas

    International Nuclear Information System (INIS)

    Olson, C.L.; Poukey, J.W.; Hinshelwood, D.D.; Rose, D.V.; Hubbard, R.F.; Lampe, M.; Neri, J.M.; Ottinger, P.F.; Slinker, S.P.; Stephanakis, S.J.; Young, F.C.; Welch, D.R.

    1993-01-01

    Detailed analysis, experiments, and computer simulations are producing a new understanding of gas breakdown during intense ion beam transport in neutral gas. Charge neutralization of beam micro clumps is shown to limit the net clump potentials to a non-zero value π min , which can lead to divergence growth and axial energy spreading. At pressures approx-gt 1 Torr, plasma shielding should substantially reduce this effect Current neutralization has been studied in experiments on the GAMBLE II accelerator. The importance of fast electrons (knockons and runaways) has been established in IPROP simulations, which are in agreement with the experiments. For light ion fusion parameters with pressures approx-gt 1 Torr, very small net current fractions (much-lt 1%) appear feasible, permitting ballistic transport in gas. Self-pinched requires higher net current fractions (≥ 2%) and preliminary IPROP code results indicate that this appears achievable for small-radius intense beams in lower pressure gases (approx-gt Torr). Several self-pinched transport concepts look promising. The importance of these results for both light ion fusion and heavy ion fusion is discussed

  2. USEFUL: Ultrasound Exam for Underlying Lesions Incorporated into Physical Exam

    Directory of Open Access Journals (Sweden)

    Jon Steller

    2014-05-01

    Full Text Available Introduction: The Ultrasound Screening Exam for Underlying Lesions (USEFUL was developed in an attempt to establish a role for bedside ultrasound in the primary and preventive care setting. It is the purpose of our pilot study to determine if students were first capable of performing all of the various scans required of our USEFUL while defining such an ultrasound-assisted physical exam that would supplement the standard hands-on physical exam in the same head-to-toe structure. We also aimed to assess the time needed for an adequate exam and analyze if times improved with repetition and previous ultrasound training. Methods: Medical students with ranging levels of ultrasound training received a 25-minute presentation on our USEFUL followed by a 30-minute hands-on session. Following the hands-on session, the students were asked to perform a timed USEFUL on 2-3 standardized subjects. All images were documented as normal or abnormal with the understanding that an official detailed exam would be performed if an abnormality were to be found. All images were read and deemed adequate by board eligible emergency medicine ultrasound fellows. Results: Twenty-six exams were performed by 9 students. The average time spent by all students per USEFUL was 11 minutes and 19 seconds. Students who had received the University of California, Irvine School of Medicine’s integrated ultrasound curriculum performed the USEFUL significantly faster (p< 0.0025. The time it took to complete the USEFUL ranged from 6 minutes and 32 seconds to 17 minutes, and improvement was seen with each USEFUL performed. The average time to complete the USEFUL on the first standardized patient was 13 minutes and 20 seconds, while 11 minutes and 2 seconds, and 9 minutes and 20 seconds were spent performing the exam on the second and third patient, respectively. Conclusion: Students were able to effectively complete all scans required by the USEFUL in a timely manner. Students who have

  3. Device physics underlying silicon heterojunction and passivating-contact solar cells: A topical review

    KAUST Repository

    Chavali, Raghu V. K.

    2018-01-15

    The device physics of commercially dominant diffused-junction silicon solar cells is well understood, allowing sophisticated optimization of this class of devices. Recently, so-called passivating-contact solar cell technologies have become prominent, with Kaneka setting the world\\'s silicon solar cell efficiency record of 26.63% using silicon heterojunction contacts in an interdigitated configuration. Although passivating-contact solar cells are remarkably efficient, their underlying device physics is not yet completely understood, not in the least because they are constructed from diverse materials that may introduce electronic barriers in the current flow. To bridge this gap in understanding, we explore the device physics of passivating contact silicon heterojunction (SHJ) solar cells. Here, we identify the key properties of heterojunctions that affect cell efficiency, analyze the dependence of key heterojunction properties on carrier transport under light and dark conditions, provide a self-consistent multiprobe approach to extract heterojunction parameters using several characterization techniques (including dark J-V, light J-V, C-V, admittance spectroscopy, and Suns-Voc), propose design guidelines to address bottlenecks in energy production in SHJ cells, and develop a process-to-module modeling framework to establish the module\\'s performance limits. We expect that our proposed guidelines resulting from this multiscale and self-consistent framework will improve the performance of future SHJ cells as well as other passivating contact-based solar cells.

  4. Hydrogen transport through stainless steel under plasma irradiation

    Science.gov (United States)

    Airapetov, A. A.; Begrambekov, L. B.; Kaplevsky, A. S.; Sadovskiy, Ya A.

    2016-01-01

    The paper presents the results of investigation of gas exchange through stainless steel surface of the plasma chamber under irradiation with hydrogen atoms in oxygen atmosphere or oxygen contaminated hydrogen plasma. Dependence of this process on various irradiation parameters, such as the metal temperature, energy of irradiating ions, gas composition of plasma are studied. It is shown, that desorption from stainless steel is activated with the increase of the plasma chamber walls temperature and energy of irradiating ions. Hydrogen release occurs also under irradiation of the walls by helium and argon plasmas added with oxygen, however the amount of released hydrogen is several times lower than in the case of irradiation with oxygen contaminated deuterium plasma.

  5. School physical activity policies and active transport to school among pupils in the Czech Republic

    NARCIS (Netherlands)

    Hollein, Tomas; Vasickova, Jana; Bucksch, Jens; Kalman, Michal; Sigmundova, Dagmar; van Dijk, Jitse P.

    Background: Previous studies indicate that the level of physical activity (PA) significantly affects children's health. Active transport to school is PA on a daily basis that may contribute substantially to the overall volume of moderate to vigorous physical activity (MVPA). Aim of our study was to

  6. Physical Activity Energy Expenditure in Dutch Adolescents: Contribution of Active Transport to School, Physical Education, and Leisure Time Activities

    Science.gov (United States)

    Slingerland, Menno; Borghouts, Lars B.; Hesselink, Matthijs K. C.

    2012-01-01

    Background: Detailed knowledge about physical activity energy expenditure (PAEE) can guide the development of school interventions aimed at reducing overweight in adolescents. However, relevant components of PAEE have never been objectively quantified in this population. This study investigated the contribution of active transport to and from…

  7. 76 FR 68257 - Letters of Interest for Credit Assistance Under the Transportation Infrastructure Finance and...

    Science.gov (United States)

    2011-11-03

    ... Under the Transportation Infrastructure Finance and Innovation Act (TIFIA) Program AGENCY: Federal... Transportation Infrastructure Finance and Innovation Act of 1998 (TIFIA), authorizing the U.S. Department of... letter and detailed plan of finance). Letters of Interest submitted pursuant to this notice of funding...

  8. Modeling colloid transport and retention in saturated porous media under unfavorable attachment conditions

    Science.gov (United States)

    A mathematical model is presented for colloid transport and retention in saturated porous media under unfavorable attachment conditions. The model accounts for colloid transport in the bulk aqueous phase and adjacent to the solid surface, and rates of colloid collision, interaction, release and imm...

  9. Sixth Microgravity Fluid Physics and Transport Phenomena Conference: Exposition Topical Areas 1-6. Volume 2

    Science.gov (United States)

    Singh, Bhim (Compiler)

    2002-01-01

    The Sixth Microgravity Fluid Physics and Transport Phenomena Conference provides the scientific community the opportunity to view the current scope of the Microgravity Fluid Physics and Transport Phenomena Program, current research opportunities, and plans for the near future. The conference focuses not only on fundamental research but also on applications of this knowledge towards enabling future space exploration missions. A whole session dedicated to biological fluid physics shows increased emphasis that the program has placed on interdisciplinary research. The conference includes invited plenary talks, technical paper presentations, poster presentations, and exhibits. This CP (conference proceeding) is a compilation of the abstracts, presentations, and posters presented at the conference.

  10. The impacts of pore-scale physical and chemical heterogeneities on the transport of radionuclide-carrying colloids

    Energy Technology Data Exchange (ETDEWEB)

    WU, Ning

    2018-04-24

    Independent of the methods of nuclear waste disposal, the degradation of packaging materials could lead to mobilization and transport of radionuclides into the geosphere. This process can be significantly accelerated due to the association of radionuclides with the backfill materials or mobile colloids in groundwater. The transport of these colloids is complicated by the inherent coupling of physical and chemical heterogeneities (e.g., pore space geometry, grain size, charge heterogeneity, and surface hydrophobicity) in natural porous media that can exist on the length scale of a few grains. In addition, natural colloids themselves are often heterogeneous in their surface properties (e.g., clay platelets possess opposite charges on the surface and along the rim). Both physical and chemical heterogeneities influence the transport and retention of radionuclides under various groundwater conditions. However, the precise mechanisms how these coupled heterogeneities influence colloidal transport are largely elusive. This knowledge gap is a major source of uncertainty in developing accurate models to represent the transport process and to predict distribution of radionuclides in the geosphere.

  11. Solute transport in a well under slow-purge and no-purge conditions

    Science.gov (United States)

    Plummer, M. A.; Britt, S. L.; Martin-Hayden, J. M.

    2010-12-01

    Non-purge sampling techniques, such as diffusion bags and in-situ sealed samplers, offer reliable and cost-effective groundwater monitoring methods that are a step closer to the goal of real-time monitoring without pumping or sample collection. Non-purge methods are, however, not yet completely accepted because questions remain about how solute concentrations in an unpurged well relate to concentrations in the adjacent formation. To answer questions about how undisturbed well water samples compare to formation concentrations, and to provide the information necessary to interpret results from non-purge monitoring systems, we have conducted a variety of physical experiments and numerical simulations of flow and transport in and through monitoring wells under low-flow and ambient flow conditions. Previous studies of flow and transport in wells used a Darcy’s law - based continuity equation for flow, which is often justified under the strong, forced-convection flow caused by pumping or large vertical hydraulic potential gradients. In our study, we focus on systems with weakly forced convection, where density-driven free convection may be of similar strength. We therefore solved Darcy’s law for porous media domains and the Navier Stokes equations for flow in the well, and coupled solution of the flow equations to that of solute transport. To illustrate expected in-well transport behavior under low-flow conditions, we present results of three particular studies: (1) time-dependent effluent concentrations from a well purged at low-flow pumping rates, (2) solute-driven density effects in a well under ambient horizontal flow and (3) temperature-driven mixing in a shallow well subject to seasonal temperature variations. Results of the first study illustrate that assumptions about the nature of in-well flow have a significant impact on effluent concentration curves even during pumping, with Poiseuille-type flow producing more rapid removal of concentration differences

  12. Physical considerations relevant to HZE-particle transport in matter.

    Science.gov (United States)

    Schimmerling, W

    1988-06-01

    High-energy, highly charged (HZE) heavy nuclei may seem at first sight to be an exotic type of radiation, only remotely connected with nuclear power generation. On closer examination it becomes evident that heavy-ion accelerators are being seriously considered for driving inertial confinement fusion reactors, and high-energy heavy nuclei in the cosmic radiation are likely to place significant constraints on satellite power system deployment and space-based power generation. The use of beams of heavy nuclei in an increasing number of current applications, as well as their importance for the development of the state of the art of the future, makes it necessary to develop at the same time a good understanding of their transport through matter.

  13. Physics of Lightning under Control of Big Scale Experiments

    Czech Academy of Sciences Publication Activity Database

    Mrázek, Josef

    2007-01-01

    Roč. 52, č. 2 (2007), s. 173-186 ISSN 0001-7043 Institutional research plan: CEZ:AV0Z20570509 Keywords : gas discharges * physics of lightning * long air gaps Subject RIV: BL - Plasma and Gas Discharge Physics

  14. Neutralisation and transport of negative ion beams: physics and diagnostics

    Science.gov (United States)

    Serianni, G.; Agostinetti, P.; Agostini, M.; Antoni, V.; Aprile, D.; Baltador, C.; Barbisan, M.; Brombin, M.; Cavenago, M.; Chitarin, G.; Dalla Palma, M.; Delogu, R.; Fellin, F.; Fonnesu, N.; Marconato, N.; Pasqualotto, R.; Pimazzoni, A.; Sartori, E.; Spagnolo, S.; Spolaore, M.; Veltri, P.; Zaniol, B.; Zaupa, M.

    2017-04-01

    Neutral beam injection is one of the most important methods of plasma heating in thermonuclear fusion experiments, allowing the attainment of fusion conditions as well as driving the plasma current. Neutral beams are generally produced by electrostatically accelerating ions, which are neutralised before injection into the magnetised plasma. At the particle energy required for the most advanced thermonuclear devices and particularly for ITER, neutralisation of positive ions is very inefficient so that negative ions are used. The present paper is devoted to the description of the phenomena occurring when a high-power multi-ampere negative ion beam travels from the beam source towards the plasma. Simulation of the trajectory of the beam and of its features requires various numerical codes, which must take into account all relevant phenomena. The leitmotiv is represented by the interaction of the beam with the background gas. The main outcome is the partial neutralisation of the beam particles, but ionisation of the background gas also occurs, with several physical and technological consequences. Diagnostic methods capable of investigating the beam properties and of assessing the relevance of the various phenomena will be discussed. Examples will be given regarding the measurements collected in the small flexible NIO1 source and regarding the expected results of the prototype of the neutral beam injectors for ITER. The tight connection between measurements and simulations in view of the operation of the beam is highlighted.

  15. Summary report on transportation of nuclear fuel materials in Japan : transportation infrastructure, threats identified in open literature, and physical protection regulations.

    Energy Technology Data Exchange (ETDEWEB)

    Cochran, John Russell; Ouchi, Yuichiro (Japan Atomic Energy Agency, Japan); Furaus, James Phillip; Marincel, Michelle K.

    2008-03-01

    This report summarizes the results of three detailed studies of the physical protection systems for the protection of nuclear materials transport in Japan, with an emphasis on the transportation of mixed oxide fuel materials1. The Japanese infrastructure for transporting nuclear fuel materials is addressed in the first section. The second section of this report presents a summary of baseline data from the open literature on the threats of sabotage and theft during the transport of nuclear fuel materials in Japan. The third section summarizes a review of current International Atomic Energy Agency, Japanese and United States guidelines and regulations concerning the physical protection for the transportation of nuclear fuel materials.

  16. 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.

  17. Directed evolution of a cellodextrin transporter for improved biofuel production under anaerobic conditions in Saccharomyces cerevisiae.

    Science.gov (United States)

    Lian, Jiazhang; Li, Yanglin; HamediRad, Mohammad; Zhao, Huimin

    2014-08-01

    Introduction of a cellobiose utilization pathway consisting of a cellodextrin transporter and a β-glucosidase into Saccharomyces cerevisiae enables co-fermentation of cellobiose and xylose. Cellodextrin transporter 1 (CDT1) from Neurospora crassa has been established as an effective transporter for the engineered cellobiose utilization pathways. However, cellodextrin transporter 2 (CDT2) from the same species is a facilitator and has the potential to be more efficient than CDT1 under anaerobic conditions due to its energetic benefits. Currently, CDT2 has a very low activity and is considered rate-limiting in cellobiose fermentation. Here, we report the directed evolution of CDT2 with an increased cellobiose uptake activity, which results in improved cellobiose fermentation under anaerobic conditions. After three rounds of directed evolution, the cellobiose uptake activity of CDT2 was increased by 2.2-fold, which resulted from both increased specific activity and transporter expression level. Using high cell density fermentation under anaerobic conditions, the evolved mutant conferred 4.0- and 4.4-fold increase in the cellobiose consumption rate and ethanol productivity, respectively. In addition, although the cellobiose uptake activity was still lower than that of CDT1, the engineered CDT2 showed significantly improved cellobiose consumption and ethanol production under anaerobic conditions, representing the energetic benefits of a sugar facilitator for anaerobic cellobiose fermentation. This study demonstrated that anaerobic biofuel production could be significantly improved via directed evolution of a sugar transporter protein in yeast. © 2014 Wiley Periodicals, Inc.

  18. Physical Activity through Sustainable Transport Approaches (PASTA): protocol for a multi-centre, longitudinal study.

    Science.gov (United States)

    Dons, Evi; Götschi, Thomas; Nieuwenhuijsen, Mark; de Nazelle, Audrey; Anaya, Esther; Avila-Palencia, Ione; Brand, Christian; Cole-Hunter, Tom; Gaupp-Berghausen, Mailin; Kahlmeier, Sonja; Laeremans, Michelle; Mueller, Natalie; Orjuela, Juan Pablo; Raser, Elisabeth; Rojas-Rueda, David; Standaert, Arnout; Stigell, Erik; Uhlmann, Tina; Gerike, Regine; Int Panis, Luc

    2015-11-14

    Physical inactivity is one of the leading risk factors for non-communicable diseases, yet many are not sufficiently active. The Physical Activity through Sustainable Transport Approaches (PASTA) study aims to better understand active mobility (walking and cycling for transport solely or in combination with public transport) as an innovative approach to integrate physical activity into individuals' everyday lives. The PASTA study will collect data of multiple cities in a longitudinal cohort design to study correlates of active mobility, its effect on overall physical activity, crash risk and exposure to traffic-related air pollution. A set of online questionnaires incorporating gold standard approaches from the physical activity and transport fields have been developed, piloted and are now being deployed in a longitudinal study in seven European cities (Antwerp, Barcelona, London, Oerebro, Rome, Vienna, Zurich). In total, 14000 adults are being recruited (2000 in each city). A first questionnaire collects baseline information; follow-up questionnaires sent every 13 days collect prospective data on travel behaviour, levels of physical activity and traffic safety incidents. Self-reported data will be validated with objective data in subsamples using conventional and novel methods. Accelerometers, GPS and tracking apps record routes and activity. Air pollution and physical activity are measured to study their combined effects on health biomarkers. Exposure-adjusted crash risks will be calculated for active modes, and crash location audits are performed to study the role of the built environment. Ethics committees in all seven cities have given independent approval for the study. The PASTA study collects a wealth of subjective and objective data on active mobility and physical activity. This will allow the investigation of numerous correlates of active mobility and physical activity using a data set that advances previous efforts in its richness, geographical coverage

  19. Propulsion Physics Under the Changing Density Field Model

    Science.gov (United States)

    Robertson, Glen A.

    2011-01-01

    To grow as a space faring race, future spaceflight systems will requires new propulsion physics. Specifically a propulsion physics model that does not require mass ejection without limiting the high thrust necessary to accelerate within or beyond our solar system and return within a normal work period or lifetime. In 2004 Khoury and Weltman produced a density dependent cosmology theory they called Chameleon Cosmology, as at its nature, it is hidden within known physics. This theory represents a scalar field within and about an object, even in the vacuum. Whereby, these scalar fields can be viewed as vacuum energy fields with definable densities that permeate all matter; having implications to dark matter/energy with universe acceleration properties; implying a new force mechanism for propulsion physics. Using Chameleon Cosmology, the author has developed a new propulsion physics model, called the Changing Density Field (CDF) Model. This model relates to density changes in these density fields, where the density field density changes are related to the acceleration of matter within an object. These density changes in turn change how an object couples to the surrounding density fields. Whereby, thrust is achieved by causing a differential in the coupling to these density fields about an object. Since the model indicates that the density of the density field in an object can be changed by internal mass acceleration, even without exhausting mass, the CDF model implies a new propellant-less propulsion physics model

  20. Physical quality of an oxisol under different uses

    Directory of Open Access Journals (Sweden)

    Francisco Ocian Bastos Mota

    2012-12-01

    Full Text Available The use of a soil induces changes in the physical properties according to the management, tillage intensity and type of crop. The objective of this work was to measure the alterations of some of the soil physical properties and evaluate the physical quality by the S index, an indicator proposed by Dexter (2004, comparing the land uses: eucalyptus plantations at different ages, grazing pasture, annual crops, and an area of preserved secondary vegetation with an area of preserved native forest (National Forest Araripe - NFA as control. The study was carried out on an Oxisol on the Fazenda Redenção, in Jardim, State of Ceará, Brazil. The experiment was arranged in a completely randomized design with seven treatments and three replications in the layers 0-0.1 and 0.1-0.2 m. The soil was analyzed for the following physical properties: bulk density, particle density, total pore volume, micro and macroporosity, soil water retention curves and water availability. Based on the S index, the hypothesis that the use of a soil deteriorates the physical quality was accepted. Clearly, native forest (NFA was the land use with the best conditions in all physical properties studied, followed closely by the area reforested with 20 year-old eucalyptus. The use as grazing pasture affected the soil physical conditions most, especially in the surface layer (0-0.1 m, as evidenced by increased bulk density and a substantial reduction in soil porosity, mainly in macroporosity. Microporosity was not influenced by any of the uses and in any layer studied.

  1. Applying GPS to enhance understanding of transport-related physical activity.

    Science.gov (United States)

    Duncan, Mitch J; Badland, Hannah M; Mummery, W Kerry

    2009-09-01

    The purpose of the paper is to review the utility of the global positioning system (GPS) in the study of health-related physical activity. The paper draws from existing literature to outline the current work performed using GPS to examine transport-related physical activity, with a focus on the relative utility of the approach when combined with geographic information system (GIS) and other data sources including accelerometers. The paper argues that GPS, especially when used in combination with GIS and accelerometery, offers great promise in objectively measuring and studying the relationship of numerous environmental attributes to human behaviour in terms of physical activity and transport-related activity. Limitations to the use of GPS for the purpose of monitoring health-related physical activity are presented, and recommendations for future avenues of research are discussed.

  2. Visualization of Fuel Cell Water Transport and Performance Characterization under Freezing Conditions

    Energy Technology Data Exchange (ETDEWEB)

    Kandlikar, Satish G. [Rochester Inst. of Technology, Rochester, NY (United States); Lu, Zijie [Rochester Inst. of Technology, Rochester, NY (United States); Rao, Navalgund [Rochester Inst. of Technology, Rochester, NY (United States); Sergi, Jacqueline [Rochester Inst. of Technology, Rochester, NY (United States); Rath, Cody [Rochester Inst. of Technology, Rochester, NY (United States); McDade, Christopher [Rochester Inst. of Technology, Rochester, NY (United States); Trabold, Thomas [General Motors, Honeoye Falls, NY (United States); Owejan, Jon [General Motors, Honeoye Falls, NY (United States); Gagliardo, Jeffrey [General Motors, Honeoye Falls, NY (United States); Allen, Jeffrey [Michigan Technological Univ., Houghton, MI (United States); Yassar, Reza S. [Michigan Technological Univ., Houghton, MI (United States); Medici, Ezequiel [Michigan Technological Univ., Houghton, MI (United States); Herescu, Alexandru [Michigan Technological Univ., Houghton, MI (United States)

    2010-05-30

    In this program, Rochester Institute of Technology (RIT), General Motors (GM) and Michigan Technological University (MTU) have focused on fundamental studies that address water transport, accumulation and mitigation processes in the gas diffusion layer and flow field channels of the bipolar plate. These studies have been conducted with a particular emphasis on understanding the key transport phenomena which control fuel cell operation under freezing conditions.

  3. Electronic structure and thermoelectric transport properties of the golden Th2S3-type Ti2O3 under pressure

    Directory of Open Access Journals (Sweden)

    Bin Xu

    2016-05-01

    Full Text Available A lot of physical properties of Th2S3-type Ti2O3 have investigated experimentally, hence, we calculated electronic structure and thermoelectric transport properties by the first-principles calculation under pressure. The increase of the band gaps is very fast from 30GP to 35GP, which is mainly because of the rapid change of the lattice constants. The total density of states becomes smaller with increasing pressure, which shows that Seebeck coefficient gradually decreases. Two main peaks of Seebeck coefficients always decrease and shift to the high doping area with increasing temperature under pressure. The electrical conductivities always decrease with increasing temperature under pressure. The electrical conductivity can be improved by increasing pressure. Electronic thermal conductivity increases with increasing pressure. It is noted that the thermoelectric properties is reduced with increasing temperature.

  4. Physical activity during work, transport and leisure in Germany--prevalence and socio-demographic correlates.

    Directory of Open Access Journals (Sweden)

    Birgit Wallmann-Sperlich

    Full Text Available BACKGROUND: This study aimed 1 to provide data estimates concerning overall moderate- and vigorous-intensity physical activity (MVPA as well as MVPA during work, transport and leisure in Germany and 2 to investigate MVPA and possible associations with socio-demographic correlates. METHODS: A cross-sectional telephone survey interviewed 2248 representative participants in the age of 18-65 years (1077 men; 42.4 ± 13.4 years; body mass index: 25.3 ± 4.5 kg • m(-2 regarding their self-reported physical activity across Germany. The Global Physical Activity Questionnaire was applied to investigate MVPA during work, transport and leisure and questions were answered concerning their demographics. MVPA was stratified by gender, age, body mass index, residential setting, educational and income level. To identify socio-demographic correlates of overall MVPA as well as in the domains, we used a series of linear regressions. RESULTS: 52.8% of the sample achieved physical activity recommendations (53.7% men/52.1% women. Overall MVPA was highest in the age group 18-29 years (p < .05, in participants with 10 years of education (p < .05 and in participants with lowest income levels < 1.500 € (p < .05. Regression analyses revealed that age, education and income were negatively associated with overall and work MVPA. Residential setting and education was positively correlated with transport MVPA, whereas income level was negatively associated with transport MVPA. Education was the only correlate for leisure MVPA with a positive association. CONCLUSIONS: The present data underlines the importance of a comprehensive view on physical activity engagement according to the different physical activity domains and discloses a need for future physical activity interventions that consider socio-demographic variables, residential setting as well as the physical activity domain in Germany.

  5. Monte Carlo 2000 Conference : Advanced Monte Carlo for Radiation Physics, Particle Transport Simulation and Applications

    CERN Document Server

    Baräo, Fernando; Nakagawa, Masayuki; Távora, Luis; Vaz, Pedro

    2001-01-01

    This book focusses on the state of the art of Monte Carlo methods in radiation physics and particle transport simulation and applications, the latter involving in particular, the use and development of electron--gamma, neutron--gamma and hadronic codes. Besides the basic theory and the methods employed, special attention is paid to algorithm development for modeling, and the analysis of experiments and measurements in a variety of fields ranging from particle to medical physics.

  6. Parents' perception of neighbourhood environment as a determinant of screen time, physical activity and active transport.

    Science.gov (United States)

    Carson, Valerie; Kuhle, Stefan; Spence, John C; Veugelers, Paul J

    2010-01-01

    To study the importance of parents' perception of neighbourhood environment for health behaviours such as screen time, physical activity, and active transport in a Canadian context. As part of the REAL Kids Alberta project, 3,421 grade five students from 148 randomly selected schools in Alberta and their parents were surveyed in the spring of 2008. Physical activity was assessed by self-report using an adapted version of the Physical Activity Questionnaire for Older Children (PAQ-C). Screen time and active transport (walking and biking) was assessed by parent proxy reports. Parents were also surveyed on their perception of their neighbourhoods. These responses were reduced to three components (satisfaction/services, safety, sidewalks/parks) through principal component analysis. Subsequent multilevel logistic regression analyses were conducted to quantify the associations of these principal neighbourhood components with screen time, physical activity, and active transport. Children residing in neighbourhoods with good satisfaction/services and sidewalks/parks were significantly more likely to engage in 2 hours or less of screen time and to be physically active. Children in neighbourhoods with good sidewalks/parks were also more likely to engage in active transport to and from school. However, perceived neighbourhood safety had little impact on activity. The findings suggest physical activity and active transport may be increased and sedentary behaviours reduced through 1) increasing access to parks, playgrounds, and play spaces, 2) increasing access to sports and recreation programs, and 3) provision of sidewalks such that children and youth can walk or bike to school.

  7. Soil physical and hydraulic properties modification under Arachis ...

    African Journals Online (AJOL)

    Reductions in soil water evaporation were 44.5%, 41.1% and 34.7% under SAMNUT 21, PINTOI and SAMNUT 10 respectively. Significant (p= 0.05) improvement on soil structure and hydraulic conductivity was observed under Arachis varieties. Plant density of 66667 plants/ha showed the best positive effect on the ...

  8. Light-Emitting Diodes: Exploration of Underlying Physics

    Science.gov (United States)

    Etkina, Eugenia; Planinšic, Gorazd

    2014-01-01

    This paper is the second in the series of LED-dedicated papers that have a goal to systematically investigate the use of LEDs in a general physics course. The first paper, published in the February 2014 issue, provided an overview of the course units where LEDs can be used and suggested three different ways of utilizing LEDs in an introductory…

  9. US physics begins to crumble under budget strain

    CERN Multimedia

    2008-01-01

    The reality of the US budget cuts to particle physics has hit home. The Stanford Linear Accelerator Center (SLAC) in California, US, has just announced a trio of painful consequences: the end of work on the International Linear Collider, the imminent closure of its BaBar antimatter experiment, and the layoff of 125 workers.

  10. Physical and Chemical Properties of Soils under Contrasting Land ...

    African Journals Online (AJOL)

    The soil chemical properties studied were soil pH, organic carbon, total nitrogen, available P, exchangeable base (Ca2+, Mg2+, K+ and Na+) and exchangeable acidity (H+ and Al3+). The physical properties were aggregate stability, mean weight diameter, water dispersible clay and clay flocculation index. Two fractions of ...

  11. The Association Between the Physical Environment of Primary Schools and Active School Transport

    NARCIS (Netherlands)

    Kann, D.H.H. van; Kremers, S.P.J.; Gubbels, J.S.; Bartelink, N.H.M.; Vries, S.I. de; Vries, N.K. de; Jansen, M.W.J.

    2015-01-01

    This study examined the relationship between the physical environment characteristics of primary schools and active school transport among 3,438 5- to 12-year-old primary school children in the Netherlands. The environmental characteristics were categorized into four theory-based clusters (function,

  12. Associations between the Physical, Sociocultural, and Safety Environments and Active Transportation to School

    Science.gov (United States)

    Ross, Allison; Rodríguez, Ariel; Searle, Mark

    2017-01-01

    Background: Understanding why youth actively transport to school (ATS) has important health, programming, and policy implications. A growing body of research has revealed that there are common factors that influence this behavior. Collectively, these influences can be categorized into 3 domains: the physical environment (PE), sociocultural…

  13. Promoting physical activity and reducing climate change : Opportunities to replace short car trips with active transportation

    NARCIS (Netherlands)

    Maibach, E.; Steg, L.; Anable, J.

    2009-01-01

    Automobile use is a significant contributor to climate change, local air pollution, pedestrian injuries and deaths, declines in physical activity and obesity. A significant proportion of car use is for short trips that can relatively easily be taken with active transportation options - walking or

  14. Adult active transport in the Netherlands: an analysis of its contribution to physical activity requirements.

    Directory of Open Access Journals (Sweden)

    Elliot Fishman

    Full Text Available Modern, urban lifestyles have engineered physical activity out of everyday life and this presents a major threat to human health. The Netherlands is a world leader in active travel, particularly cycling, but little research has sought to quantify the cumulative amount of physical activity through everyday walking and cycling.Using data collected as part of the Dutch National Travel Survey (2010 - 2012, this paper determines the degree to which Dutch walking and cycling contributes to meeting minimum level of physical activity of 150 minutes of moderate intensity aerobic activity throughout the week. The sample includes 74,465 individuals who recorded at least some travel on the day surveyed. As physical activity benefits are cumulative, all walking and cycling trips are analysed, including those to and from public transport. These trips are then converted into an established measure of physical activity intensity, known as metabolic equivalents of tasks. Multivariate Tobit regression models were performed on a range of socio-demographic, transport resources, urban form and meteorological characteristics.The results reveal that Dutch men and women participate in 24 and 28 minutes of daily physical activity through walking and cycling, which is 41% and 55% more than the minimum recommended level. It should be noted however that some 57% of the entire sample failed to record any walking or cycling, and an investigation of this particular group serves as an important topic of future research. Active transport was positively related with age, income, bicycle ownership, urban density and air temperature. Car ownership had a strong negative relationship with physically active travel.The results of this analysis demonstrate the significance of active transport to counter the emerging issue of sedentary lifestyle disease. The Dutch experience provides other countries with a highly relevant case study in the creation of environments and cultures that

  15. Experimental quantification of solute transport through the vadose zone under dynamic boundary conditions with dye tracers and optical methods.

    Science.gov (United States)

    Cremer, Clemens; Neuweiler, Insa

    2017-04-01

    Knowledge of subsurface solute transport processes is vital to investigate e.g. groundwater contamination, nutrient uptake by plant roots and to implement remediation strategies. Beside field measurements and numerical simulations, physical laboratory experiments represent a way to establish process understanding and furthermore validate numerical schemes. Atmospheric forcings, such as erratically varying infiltration and evaporation cycles, subject the shallow subsurface to local and temporal variations in water content and associated hydraulic conductivity of the prevailing porous media. Those variations in material properties can cause flow paths to differ between upward and downward flow periods. Thereby, the unsaturated subsurface presents a highly complicated, dynamic system. Following an extensive systematical numerical investigation of flow and transport through bimodal, unsaturated porous media under dynamic boundary conditions (Cremer et al., 2016), we conduct physical laboratory experiments in a 22 cm x 8 cm x 1 cm flow cell where we introduce structural heterogeneity in the form sharp material interfaces between different porous media. In all experiments, a constant pressure head is implemented at the lower boundary, while cyclic infiltration-evaporation phases are applied at the soil surface. As a reference case a stationary infiltration with a rate corresponding to the cycle-averaged infiltration rate is applied. By initial application of dye tracers, solute transport within the domain is visualized such that transport paths and redistribution processes can be observed in a qualitative manner. Solute leaching is quantified at the bottom outlet, where breakthrough curves are obtained via spectroscopy. Liquid and vapor flow in and out of the domain is obtained from multiple balances. Thereby, the interplay of material structural heterogeneity and alternating flow (transport) directions and flow (transport) paths is investigated. Results show lateral

  16. Physical protection of export/import and transportation of nuclear material in the Slovak Republic

    International Nuclear Information System (INIS)

    Vaclav, J

    2002-01-01

    Full text: The paper contains short overview about average amount of nuclear materials transported on the territory of the Slovak Republic in a year, and the physical protection of these nuclear materials. There are several types of transportation and export/import of nuclear materials in the SR: fresh fuel import; import of other unirradiated nuclear materials (e.g. depleted uranium, natural uranium); export of unirradiated nuclear materials (e.g. natural uranium); internal transportation of fresh fuel; internal transportation of other unirradiated nuclear materials; internal transportation of spent fuel. The main objective of the nuclear regulatory authority SR is to supervise observation of the national legislation as follows: the act no. 130 / 1998 on peaceful use of nuclear energy; UJD SR's regulation no. 186/1999 which details the physical protection of the nuclear facilities, nuclear materials, and radioactive waste (following requirements of INFCIRC 225 / Rev. 4); UJD SR's regulation no. 284 / 1999 which details conditions of nuclear material and radioactive wastes transportation. (author)

  17. Physical control of carrier-mediated ion-transporters by entrainment of their turnover rate

    Science.gov (United States)

    Chen, Wei; Mathis, Clausell; Fang, Zhihui; Mast, Jason; Hamidi, Karim; Kelly, Patrick; Eve, Max

    2012-02-01

    In the past, tremendous efforts have been made to physically activate carrier-mediated ion-transporters, such as Na/K pumps. However, the outcome is not significant. Recently, we developed a new technique which can effectively and efficiently control the pumping rate by introducing a concept of an electronic synchrotron accelerator to the biological system. The approach consists of two steps. First, a specially designed oscillating electric field is used to force or synchronize individual pump molecules to run at the same turnover rate and phase as the field oscillation frequency. Then, by gradually changing the field frequency and carefully keeping the pump synchronization we can entrain the pump molecules so that their pumping rate can be progressively modulated, either decelerated or accelerated, following the field frequency to a defined value. Based on theoretical analysis of the underlying mechanisms involved in the technique, computer simulation of the entrainment process, and intensive experimental studies we have realized significant activation of the Na/K pumping rate up to ten-folds quickly in less than ten seconds.

  18. The birth of the blues: how physics underlies music

    International Nuclear Information System (INIS)

    Gibson, J M

    2009-01-01

    Art and science have intimate connections, although these are often underappreciated. Western music provides compelling examples. The sensation of harmony and related melodic development are rooted in physical principles that can be understood with simple mathematics. The focus of this review is not the better known acoustics of instruments, but the structure of music itself. The physical basis of the evolution of Western music in the last half millennium is discussed, culminating with the development of the 'blues'. The paper refers to a number of works which expand the connections, and introduces material specific to the development of the 'blues'. Several conclusions are made: (1) that music is axiomatic like mathematics and that to appreciate music fully listeners must learn the axioms; (2) that this learning does not require specific conscious study but relies on a linkage between the creative and quantitative brain and (3) that a key element of the musical 'blues' comes from recreating missing notes on the modern equal temperament scale. The latter is an example of 'art built on artifacts'. Finally, brief reference is made to the value of music as a tool for teaching physics, mathematics and engineering to non-scientists.

  19. The birth of the blues: how physics underlies music

    Science.gov (United States)

    Gibson, J. M.

    2009-07-01

    Art and science have intimate connections, although these are often underappreciated. Western music provides compelling examples. The sensation of harmony and related melodic development are rooted in physical principles that can be understood with simple mathematics. The focus of this review is not the better known acoustics of instruments, but the structure of music itself. The physical basis of the evolution of Western music in the last half millennium is discussed, culminating with the development of the 'blues'. The paper refers to a number of works which expand the connections, and introduces material specific to the development of the 'blues'. Several conclusions are made: (1) that music is axiomatic like mathematics and that to appreciate music fully listeners must learn the axioms; (2) that this learning does not require specific conscious study but relies on a linkage between the creative and quantitative brain and (3) that a key element of the musical 'blues' comes from recreating missing notes on the modern equal temperament scale. The latter is an example of 'art built on artifacts'. Finally, brief reference is made to the value of music as a tool for teaching physics, mathematics and engineering to non-scientists.

  20. The birth of the blues: how physics underlies music

    Energy Technology Data Exchange (ETDEWEB)

    Gibson, J M [Argonne National Laboratory, 9700 Cass Avenue, Argonne IL 60439 (United States)], E-mail: jmgibson@aps.anl.gov

    2009-07-15

    Art and science have intimate connections, although these are often underappreciated. Western music provides compelling examples. The sensation of harmony and related melodic development are rooted in physical principles that can be understood with simple mathematics. The focus of this review is not the better known acoustics of instruments, but the structure of music itself. The physical basis of the evolution of Western music in the last half millennium is discussed, culminating with the development of the 'blues'. The paper refers to a number of works which expand the connections, and introduces material specific to the development of the 'blues'. Several conclusions are made: (1) that music is axiomatic like mathematics and that to appreciate music fully listeners must learn the axioms; (2) that this learning does not require specific conscious study but relies on a linkage between the creative and quantitative brain and (3) that a key element of the musical 'blues' comes from recreating missing notes on the modern equal temperament scale. The latter is an example of 'art built on artifacts'. Finally, brief reference is made to the value of music as a tool for teaching physics, mathematics and engineering to non-scientists.

  1. The birth of the blues : how physics underlies music.

    Energy Technology Data Exchange (ETDEWEB)

    Gibson, J. M.

    2009-07-01

    Art and science have intimate connections, although these are often underappreciated. Western music provides compelling examples. The sensation of harmony and related melodic development are rooted in physical principles that can be understood with simple mathematics. The focus of this review is not the better known acoustics of instruments, but the structure of music itself. The physical basis of the evolution of Western music in the last half millennium is discussed, culminating with the development of the 'blues'. The paper refers to a number of works which expand the connections, and introduces material specific to the development of the 'blues'. Several conclusions are made: (1) that music is axiomatic like mathematics and that to appreciate music fully listeners must learn the axioms; (2) that this learning does not require specific conscious study but relies on a linkage between the creative and quantitative brain and (3) that a key element of the musical 'blues' comes from recreating missing notes on the modern equal temperament scale. The latter is an example of 'art built on artifacts'. Finally, brief reference is made to the value of music as a tool for teaching physics, mathematics and engineering to non-scientists.

  2. Body Composition, Physical Activity and Active Transportation in Adolescents of Metropolitan Region of Curitiba, Brazil

    Directory of Open Access Journals (Sweden)

    Leandra Ulbrict

    2014-06-01

    Full Text Available Background: Physical activity is a part of a healthy lifestyle, however sed entary habits are currently prevalent among adolescents which impacts rates of overweight and obesity in this group. This study aims to describe the relationship of physical activity with the use of active transportation to school (ATS and its relationshi p with body composition in adolescents. Materials and Methods: Information about physical activity, sedentary behavior and active transportation were collected through two survey instruments, one completed by a responsible parent/guardian and other by the adolescent. Body composition was assessed by dual - energy x - ray absorptiometry (DXA. Excess body fat was defined as ≥ 25% in male and ≥ 30% among female adolescents. Less than 60 minutes of moderate to vigorous daily physical activity defined one as sede ntary and greater than 2 hours of screen time per day was defined as excessive. Results: The prevalence of excess body fat was 46.5%. Only 24.7% of the sample performed recommended amounts of physical activity and 92.3% engaged in excess screen time. Appro ximately one - fifth of our sample (19.2% used ATS. The main barriers to active transport were traffic, distance and safety. Those that used ATS had lower body fat and fewer hours of sedentary behavior.

  3. Effect of physical training on glucose transporter protein and mRNA levels in rat adipocytes

    DEFF Research Database (Denmark)

    Stallknecht, B; Andersen, P H; Vinten, J

    1993-01-01

    Physical training increases insulin-stimulated glucose transport and the number of glucose transporters in adipocytes measured by cytochalasin B binding. In the present study we used immunoblotting to measure the abundance of two glucose transporters (GLUT-4, GLUT-1) in white adipocytes from...... trained rats. Furthermore, the abundance of the mRNAs for these proteins and glucose transport was measured. Rats were swim-trained for 10 wk, and adipocytes were isolated from epididymal fat pads. The amount of GLUT-4/adipocyte volume unit was significantly higher in trained animals compared with both...... age- and cell size-matched animals. The amount of GLUT-4 mRNA was also increased by training and it decreased with increasing age. Furthermore, young age as well as training was accompanied by relatively low GLUT-4 protein/mRNA and relatively high overall GLUT-4 efficiency (recruitability and...

  4. Discrete nodal integral transport-theory method for multidimensional reactor physics and shielding calculations

    International Nuclear Information System (INIS)

    Lawrence, R.D.; Dorning, J.J.

    1980-01-01

    A coarse-mesh discrete nodal integral transport theory method has been developed for the efficient numerical solution of multidimensional transport problems of interest in reactor physics and shielding applications. The method, which is the discrete transport theory analogue and logical extension of the nodal Green's function method previously developed for multidimensional neutron diffusion problems, utilizes the same transverse integration procedure to reduce the multidimensional equations to coupled one-dimensional equations. This is followed by the conversion of the differential equations to local, one-dimensional, in-node integral equations by integrating back along neutron flight paths. One-dimensional and two-dimensional transport theory test problems have been systematically studied to verify the superior computational efficiency of the new method

  5. Academic Training - The use of Monte Carlo radiation transport codes in radiation physics and dosimetry

    CERN Multimedia

    Françoise Benz

    2006-01-01

    2005-2006 ACADEMIC TRAINING PROGRAMME LECTURE SERIES 27, 28, 29 June 11:00-12:00 - TH Conference Room, bldg. 4 The use of Monte Carlo radiation transport codes in radiation physics and dosimetry F. Salvat Gavalda,Univ. de Barcelona, A. FERRARI, CERN-AB, M. SILARI, CERN-SC Lecture 1. Transport and interaction of electromagnetic radiation F. Salvat Gavalda,Univ. de Barcelona Interaction models and simulation schemes implemented in modern Monte Carlo codes for the simulation of coupled electron-photon transport will be briefly reviewed. Different schemes for simulating electron transport will be discussed. Condensed algorithms, which rely on multiple-scattering theories, are comparatively fast, but less accurate than mixed algorithms, in which hard interactions (with energy loss or angular deflection larger than certain cut-off values) are simulated individually. The reliability, and limitations, of electron-interaction models and multiple-scattering theories will be analyzed. Benchmark comparisons of simu...

  6. Physical and logistical considerations of using ultrasonic anemometers in aeolian sediment transport research

    Science.gov (United States)

    Walker, Ian J.

    2005-05-01

    Recently, ultrasonic anemometers (UAs) have become available for precise, high-frequency measurement of three-dimensional velocity and turbulence properties. Except for a few wind tunnel and computational fluid dynamics (CFD) simulations, advances in aeolian sediment transport and bedform research have been limited to field studies using instrumentation that is either incapable of measuring turbulence (e.g., cup anemometers) or unable to withstand sediment-laden airflow (e.g., hotfilms). In contrast, extensive progress has occurred in fluvial research where turbulence instrumentation has been available for some time. This paper provides a pragmatic discussion on using UAs in aeolian research. Recent advances using this technology are reviewed and key physical and logistical considerations for measuring airflow properties and near-surface shear stress using UAs over complex terrain are discussed. Physical considerations include limitations of applying boundary layer theory to flow over natural surfaces such as non-logarithmic velocity profiles resulting from roughness- and topographically induced effects and the inability of instrumentation to measure within the thin constant-stress region. These constraints hinder accurate shear velocity ( u*), shear stress and sand transport estimation. UAs allow measurement of turbulent Reynolds stress (RS) that, in theory, should equal profile-derived shear stress. Discrepancies often exist between these quantities however due to three-dimensional (spanwise) flow components and rapid distortion effects (i.e., unbalanced production and dissipation of turbulence) common in flow over complex terrain. While the RS approach yields information on turbulent contributions to near-surface stress generation, little evidence exists showing that RS is a better measure of forces responsible for sediment transport. Consequently, predictive equations for sediment transport using RS do not exist. There is also a need to identify the role of

  7. Peristaltic transport of Johnson-Segalman fluid under effect of a magnetic field

    Directory of Open Access Journals (Sweden)

    Moustafa Elshahed

    2005-01-01

    Full Text Available The peristaltic transport of Johnson-Segalman fluid by means of an infinite train of sinusoidal waves traveling along the walls of a two-dimensional flexible channel is investigated. The fluid is electrically conducted by a transverse magnetic field. A perturbation solution is obtained for the case in which amplitude ratio is small. Numerical results are reported for various values of the physical parameters of interest.

  8. Ultra High Intensity laser produced fast electron transport in under-dense and over-dense matter

    International Nuclear Information System (INIS)

    Manclossi, Mauro

    2006-01-01

    This thesis is related to inertial fusion research, and particularly concerns the approach to fast ignition, which is based on the use of ultra-intense laser pulses to ignite the thermonuclear fuel. Until now, the feasibility of this scheme has not been proven and depends on many fundamental aspects of the underlying physics, which are not yet fully understood and which are also very far from controls. The main purpose of this thesis is the experimental study of transport processes in the material over-dense (solid) and under-dense (gas jet) of a beam of fast electrons produced by pulse laser at a intensity of some 10 19 Wcm -2 . (author)

  9. The under-critical reactors physics for the hybrid systems

    International Nuclear Information System (INIS)

    Schapira, J.P.; Vergnes, J.; Zaetta, A.

    1998-01-01

    This day, organized by the SFEN, took place at Paris the 12 march 1998. Nine papers were presented. They take stock on the hybrid systems and more specifically the under-critical reactors. One of the major current preoccupation of nuclear industry is the problems of the increase of radioactive wastes produced in the plants and the destruction of the present stocks. To solve these problems a solution is the utilisation of hybrid systems: the coupling of a particle acceleration to an under-critical reactor. Historical aspects, advantages and performances of such hybrid reactors are presented in general papers. More technical papers are devoted to the spallation, the MUSE and the TARC experiments. (A.L.B.)

  10. Underlying Event Studies and Forward Physics at CMS

    International Nuclear Information System (INIS)

    Krammer, Manfred; Bartalini, Paolo

    2010-01-01

    Studies of the underlying event and forward processes are important tests of the standard model and inputs for Monte Carlo tuning. By selecting regions transverse and parallel to the hard parton-parton scatter, different aspects of non-perturbative QCD are enhanced and allow fine tuning of different Monte Carlo models. The underlying event in pp interactions, recorded by the CMS detector, is studied measuring the charged multiplicity density and the charged energy density in a region perpendicular to the plane of the hard 2-to-2 scattering. Two different methodologies are adopted to identify the direction and the energy scale of the hard scattering in Minimum Bias events that rely on the leading charged track and on the leading charged jet. The study allows to discriminate between various QCD Monte Carlo models with different multiple parton interaction schemes. In addition, we present the measurement of the underlying event using the jet area/ median approach. We demonstrate its sensitivity to different underlying event scenarios and tunes on generator level after applying detector specific cuts and thresholds. In the forward direction, the first measurement of forward energy flow in 3 35 GeV and compare to model with different multi-parton interaction schemes. In addition, the absence of energy deposition in the forward region is used to observe diffractive events. We compare our results with predictions from Monte Carlo event generators including a simulation of multi-parton scattering. All four measurements can be used to determine the parameters of multi-parton interaction models in a extended region of phase space. (author)

  11. Chemical and physical reactions under thermal plasmas conditions

    International Nuclear Information System (INIS)

    Fauchais, P.; Vardelle, A.; Vardelle, M.; Coudert, J.F.

    1987-01-01

    Basic understanding of the involved phenomena lags far behind industrial development that requires now a better knowledge of the phenomena to achieve a better control of the process allowing to improve the quality of the products. Thus the authors try to precise what is their actual knowledge in the fields of: plasma generators design; plasma flow models with the following key points: laminar or turbulent flow, heat transfer to walls, 2D or 3D models, non equilibrium effects, mixing problems when chemical reactions are to be taken into account with very fast kinetics, electrode regions, data for transport properties and kinetic rates; nucleation problems; plasma flow characteristics measurements: temperature or temperatures and population of excited states (automatized emission spectroscopy, LIF, CARS) as well as flow velocity (LDA with small particles, Doppler effects...); plasma and particles momentum and heat transfer either with models taking into account particles size and injection velocity distributions, heat propagation, vaporization, Kundsen effect, turbulences ... or with measurements: particles velocity and flux distributions (Laser Anemometry) as well as surface temperature distributions (two colour pyrometry in flight statistical or not)

  12. Genetic and environmental transactions underlying the association between physical fitness/physical exercise and body composition

    DEFF Research Database (Denmark)

    Johnson, Wendy; de Ruiter, Ingrid; Kyvik, Kirsten Ohm

    2015-01-01

    We examined mean effects and variance moderating effects of measures of physical activity and fitness on six measures of adiposity and their reciprocal effects in a subsample of the population-representative Danish Twin Registry. Consistent with prior studies, higher levels of physical activity...... these reciprocal effects are uniform. Some variance moderating effects also appeared due to biases in individual measures of adiposity, as well as to differences and inaccuracies in measures of physical activity. This suggests a need to avoid reliance on single measures of both physical activity and adiposity...... in attempting to understand the pathways involved in their linkages, and constraint in interpreting results if only single measures are available. Future research indications include identifying which physical activity-related environmental circumstances have relatively uniform effects on adiposity in everyone...

  13. Proceedings of the Fourth Microgravity Fluid Physics and Transport Phenomena Conference

    Science.gov (United States)

    Singh, Bhim S. (Editor)

    1999-01-01

    This conference presents information to the scientific community on research results, future directions, and research opportunities in microgravity fluid physics and transport phenomena within NASA's microgravity research program. The conference theme is "The International Space Station." Plenary sessions provide an overview of the Microgravity Fluid Physics Program, the International Space Station and the opportunities ISS presents to fluid physics and transport phenomena researchers, and the process by which researchers may become involved in NASA's program, including information about the NASA Research Announcement in this area. Two plenary lectures present promising areas of research in electrohydrodynamics/electrokinetics in the movement of particles and in micro- and meso-scale effects on macroscopic fluid dynamics. Featured speakers in plenary sessions present results of recent flight experiments not heretofore presented. The conference publication consists of this book of abstracts and the full Proceedings of the 4th Microgravity Fluid Physics and Transport Phenomena Conference on CD-ROM, containing full papers presented at the conference (NASA/CP-1999-208526/SUPPL1).

  14. The importance of Active Transportation to and from school for daily physical activity among children.

    Science.gov (United States)

    Pabayo, Roman; Maximova, Katerina; Spence, John C; Vander Ploeg, Kerry; Wu, Biao; Veugelers, Paul J

    2012-09-01

    To investigate if students who use of Active Transportation (AT) to and from school among urban and rural Canadian children are more likely to meet physical activity recommendations. The Raising healthy Eating and Active Living in Alberta (REAL Kids Alberta) study is a population-based health survey among Grade 5 students. In 2009, physical activity levels were measured using time-stamped pedometers (number of steps/hour) among 688 children. Parents reported mode of transportation to and from school (AT/non-AT). Multilevel multiple linear regression analyses with corresponding β coefficients were conducted to quantify the relationship between mode of transportation to and from school with (1) overall step count, and (2) the likelihood of achieving at least 13,500 steps per day recommended for optimal growth and development. Among urban children, those who used AT to and from school accumulated more steps [β=1124(95% CI=170,2077)] and although not significant, were more likely to achieve the recommended 13,500 steps/day compared to those not using AT to and from school [OR=1.61(95% CI=0.93,2.81)]. Using AT to and from school appears to be beneficial to children by supplementing their physical activity, particularly those living in urban regions. Strategies to promote physical activity are needed, particular for children residing in rural regions and smaller towns. Copyright © 2012 Elsevier Inc. All rights reserved.

  15. Computerized transportation model for the NRC Physical Protection Project. Versions I and II

    International Nuclear Information System (INIS)

    Anderson, G.M.

    1978-01-01

    Details on two versions of a computerized model for the transportation system of the NRC Physical Protection Project are presented. The Version I model permits scheduling of all types of transport units associated with a truck fleet, including truck trailers, truck tractors, escort vehicles and crews. A fixed-fleet itinerary construction process is used in which iterations on fleet size are required until the service requirements are satisfied. The Version II model adds an aircraft mode capability and provides for a more efficient non-fixed-fleet itinerary generation process. Test results using both versions are included

  16. Progress in integrated 2-D models for analysis of scrape-off layer transport physics

    Energy Technology Data Exchange (ETDEWEB)

    Rognlien, T.D. [Lawrence Livermore National Lab., CA (United States); Braams, B.J. [New York Univ., NY (United States); Knoll, D.A. [Idaho National Engineering Lab., Idaho Falls (United States)

    1996-08-01

    We present the status of comprehensive two-dimensional (2-D) transport modeling for the tokamak scrape-off layer (SOL) using the UEDGE and B2.5 codes. These codes are now able to integrate a variety of physics, including coupling of plasma and neutral transport leading to detachment, complicated diverto-plate geometries, multispecies impurities, and currents and E x B drifts. These new models are outlined and the capabilities are illustrated by a number of examples that emphasize the importance of including the 2-D geometry. (orig.)

  17. Silicon transport in sputter-deposited tantalum layers grown under ion bombardment

    International Nuclear Information System (INIS)

    Gallais, P.; Hantzpergue, J.J.; Remy, J.C.; Roptin, D.

    1988-01-01

    Tantalum was sputter deposited on (111) Si substrate under low-energy ion bombardment in order to study the effects of the ion energy on the silicon transport into the Ta layer. The Si substrate was heated up to 500 0 C during growth. For ion energies up to 180 eV silicon is not transported into tantalum and the growth temperature has no effect. An ion bombardment energy of 280 eV enhances the transport of silicon throughout the tantalum layer. Growth temperatures up to 300 0 C have no effect on the silicon transport which is mainly enhanced by the ion bombardment. For growth temperatures between 300 and 500 0 C, the silicon transport is also enhanced by the thermal diffusion. The experimental depth distribution of silicon is similar to the theoretical depth distribution calculated for the case of an interdiffusion. The ion-enhanced process of silicon transport is characterized by an activation energy of 0.4 eV. Silicon into the layers as-grown at 500 0 C is in both states, amorphous silicide and microcrystalline cubic silicon

  18. A Bingham-plastic model for fluid mud transport under waves and currents

    Science.gov (United States)

    Liu, Chun-rong; Wu, Bo; Huhe, Ao-de

    2014-04-01

    Simplified equations of fluid mud motion, which is described as Bingham-Plastic model under waves and currents, are presented by order analysis. The simplified equations are non-linear ordinary differential equations which are solved by hybrid numerical-analytical technique. As the computational cost is very low, the effects of wave current parameters and fluid mud properties on the transportation velocity of the fluid mud are studied systematically. It is found that the fluid mud can move toward one direction even if the shear stress acting on the fluid mud bed is much smaller than the fluid mud yield stress under the condition of wave and current coexistence. Experiments of the fluid mud motion under current with fluctuation water surface are carried out. The fluid mud transportation velocity predicted by the presented mathematical model can roughly match that measured in experiments.

  19. Advancing solar energy forecasting through the underlying physics

    Science.gov (United States)

    Yang, H.; Ghonima, M. S.; Zhong, X.; Ozge, B.; Kurtz, B.; Wu, E.; Mejia, F. A.; Zamora, M.; Wang, G.; Clemesha, R.; Norris, J. R.; Heus, T.; Kleissl, J. P.

    2017-12-01

    As solar power comprises an increasingly large portion of the energy generation mix, the ability to accurately forecast solar photovoltaic generation becomes increasingly important. Due to the variability of solar power caused by cloud cover, knowledge of both the magnitude and timing of expected solar power production ahead of time facilitates the integration of solar power onto the electric grid by reducing electricity generation from traditional ancillary generators such as gas and oil power plants, as well as decreasing the ramping of all generators, reducing start and shutdown costs, and minimizing solar power curtailment, thereby providing annual economic value. The time scales involved in both the energy markets and solar variability range from intra-hour to several days ahead. This wide range of time horizons led to the development of a multitude of techniques, with each offering unique advantages in specific applications. For example, sky imagery provides site-specific forecasts on the minute-scale. Statistical techniques including machine learning algorithms are commonly used in the intra-day forecast horizon for regional applications, while numerical weather prediction models can provide mesoscale forecasts on both the intra-day and days-ahead time scale. This talk will provide an overview of the challenges unique to each technique and highlight the advances in their ongoing development which come alongside advances in the fundamental physics underneath.

  20. Physical-chemical quality of onion analyzed under drying temperature

    Science.gov (United States)

    Djaeni, M.; Arifin, U. F.; Sasongko, S. B.

    2017-03-01

    Drying is one of conventional processes to enhance shelf life of onion. However, the active compounds such as vitamin and anthocyanin (represented in red color), degraded due to the introduction of heat during the process. The objective of this research was to evaluate thiamine content as well as color in onion drying under different temperature. As an indicator, the thiamine and color was observed every 30 minutes for 2 hours. Results showed that thiamine content and color were sensitvely influenced by the temperature change. For example, at 50°C for 2 hours drying process, the thiamine degradation was 55.37 %, whereas, at 60°C with same drying time, the degradation was 74.01%. The quality degradation also increased by prolonging drying time.

  1. Soil physical properties of high mountain fields under bauxite mining

    Directory of Open Access Journals (Sweden)

    Dalmo Arantes de Barros

    2013-10-01

    Full Text Available Mining contributes to the life quality of contemporary society, but can generate significant impacts, these being mitigated due to environmental controls adopted. This study aimed to characterize soil physical properties in high-altitude areas affected by bauxite mining, and to edaphic factors responses to restoration techniques used to recover mined areas in Poços de Caldas plateau, MG, Brazil. The experiment used 3 randomized block design involving within 2 treatments (before mining intervention and after environmental recovery, and 4 replicates (N=24. In each treatment, soil samples with deformed structures were determined: granulometry, water-dispersible clay content, flocculation index, particle density, stoniness level, water aggregate stability, and organic matter contend. Soil samples with preserved structures were used to determine soil density and the total volume of pores, macropores, and micropores. Homogenization of stoniness between soil layers as a result of soil mobilization was observed after the mined area recovery. Stoniness decreased in 0.10-0.20 m layer after recovery, but was similar in the 0-0.10 m layer in before and after samples. The recovery techniques restored organic matter levels to pre-mining levels. However, changes in soil, including an increase in soil flocculation degree and a decrease in water-dispersible clays, were still apparent post-recovery. Furthermore, mining operations caused structural changes to the superficial layer of soil, as demonstrated by an increase in soil density and a decrease in total porosity and macroporosity. Decreases in the water stability of aggregates were observed after mining operations.

  2. A Methodology for Physical Interconnection Decisions of Next Generation Transport Networks

    DEFF Research Database (Denmark)

    Gutierrez Lopez, Jose Manuel; Riaz, M. Tahir; Madsen, Ole Brun

    2011-01-01

    The physical interconnection for optical transport networks has critical relevance in the overall network performance and deployment costs. As telecommunication services and technologies evolve, the provisioning of higher capacity and reliability levels is becoming essential for the proper...... of possibilities when designing the physical network interconnection. This paper develops and presents a methodology in order to deal with aspects related to the interconnection problem of optical transport networks. This methodology is presented as independent puzzle pieces, covering diverse topics going from...... development of Next Generation Networks. Currently, there is a lack of specific procedures that describe the basic guidelines to design such networks better than "best possible performance for the lowest investment". Therefore, the research from different points of view will allow a broader space...

  3. Effects of a Danish multicomponent physical activity intervention on active school transport

    DEFF Research Database (Denmark)

    Breum, Lars; Toftager, Mette; Ersbøll, Annette K.

    2014-01-01

    AbstractIntroduction Walking and bicycling to school yields great potential in increasing the physical activity levels of adolescents, but to date very few intervention studies have been evaluated. The aim of this study was to evaluate the effect of a multicomponent school-based physical activity...... intervention on adolescent active school transport (AST) and three intermediate outcomes: perceived school route safety, parent support and attitude towards bicycling. Methods In total, 1014 adolescents at 14 schools filled in a transport diary at baseline and at a two-year follow-up and were included...... between the intervention and the comparison schools after the intervention, but more students perceived parental encouragement and had a positive attitude towards bicycling at the intervention schools. This difference was however only borderline significant. Conclusion The prevalence of AST was high...

  4. Nonequilibrium thermodynamics transport and rate processes in physical, chemical and biological systems

    CERN Document Server

    Demirel, Yasar

    2014-01-01

    Natural phenomena consist of simultaneously occurring transport processes and chemical reactions. These processes may interact with each other and may lead to self-organized structures, fluctuations, instabilities, and evolutionary systems. Nonequilibrium Thermodynamics, 3rd edition emphasizes the unifying role of thermodynamics in analyzing the natural phenomena. This third edition updates and expands on the first and second editions by focusing on the general balance equations for coupled processes of physical, chemical, and biological systems. The new edition contains a new chapte

  5. Impact of New Transport Infrastructure on Walking, Cycling, and Physical Activity.

    Science.gov (United States)

    Panter, Jenna; Heinen, Eva; Mackett, Roger; Ogilvie, David

    2016-02-01

    Walking and cycling bring health and environmental benefits, but there is little robust evidence that changing the built environment promotes these activities in populations. This study evaluated the effects of new transport infrastructure on active commuting and physical activity. Quasi-experimental analysis nested within a cohort study. Four hundred and sixty-nine adult commuters, recruited through a predominantly workplace-based strategy, who lived within 30 kilometers of Cambridge, United Kingdom and worked in areas of the city to be served by the new transport infrastructure. The Cambridgeshire Guided Busway opened in 2011 and comprised a new bus network and a traffic-free walking and cycling route. Exposure to the intervention was defined using the shortest distance from each participant's home to the busway. Change in weekly time spent in active commuting between 2009 and 2012, measured by validated 7-day recall instrument. Secondary outcomes were changes in total weekly time spent walking and cycling and in recreational and overall physical activity, measured using the validated Recent Physical Activity Questionnaire. Data were analyzed in 2014. In multivariable multinomial regression models--adjusted for potential sociodemographic, geographic, health, and workplace confounders; baseline active commuting; and home or work relocation-exposure to the busway was associated with a significantly greater likelihood of an increase in weekly cycle commuting time (relative risk ratio=1.34, 95% CI=1.03, 1.76) and with an increase in overall time spent in active commuting among the least active commuters at baseline (relative risk ratio=1.76, 95% CI=1.16, 2.67). The study found no evidence of changes in recreational or overall physical activity. Providing new sustainable transport infrastructure was effective in promoting an increase in active commuting. These findings provide new evidence to support reconfiguring transport systems as part of public health improvement

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

    Science.gov (United States)

    Singh, Bhim S.

    1999-01-01

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

  7. The 26th International Physics Olympiad: On top down under!

    Science.gov (United States)

    1996-01-01

    As they opened the plane door on arrival at Canberra it was like stepping inside a freezer. I had escaped from the heatwave in Britain to experience winter in Australia. I have not found anyone who believes that there was really frost! The Australian welcome did its best to combat the cold, however, and Professor Rod Jury had soon introduced our guides and got us settled in on the campus of Canberra University. The British team of five students, selected through the British Physics Olympiad, were: Alan Bain of Birkenhead School, Chris Blake of King Edward VI School, Southampton, Richard Davies of Dulwich College, Tom Down of Embley Park School, Romsey and Chris Webb of Royal Grammar School, Worcester. The two Leaders of the party were Cyril Isenberg of the University of Kent and Guy Bagnall of Harrow School. Chris Robson of St Bee's School and myself from Stoke on Trent Sixth form College were interested Observers and Guy's wife, Jenny, completed the party. For the old hands there were many friendships stretching back years to renew, and with 51 countries this year many new ones to be made. Â Photo Figure 1. Photograph taken by C Robson of the British Physics Team immediately after the Awards Ceremony in Canberra in July 1995. From left to right: Chris Webb, Richard Davies, Tom Down, Alan Bain and Chris Blake. In addition to the confusion caused by the Sun being in the North and the Moon appearing to lie on its back, we had to get used to the flocks of chattering parrots browsing on the lawns and the kangaroos on campus! Everyone was presented with a boomerang and there were several sessions introducing the art of throwing them, even in the dark! The Opening Ceremony was colourful and a good mix of ceremony and fun with the Aboriginal entertainment and the Flame of Science to be lit. This was followed by my first examiners' meeting. Once the questions have been introduced no one is allowed to leave the group until ten hours later when the students are in bed! The

  8. Fringe-controlled biodegradation under dynamic conditions: Quasi 2-D flow-through experiments and reactive-transport modeling

    Science.gov (United States)

    Eckert, Dominik; Kürzinger, Petra; Bauer, Robert; Griebler, Christian; Cirpka, Olaf A.

    2015-01-01

    Biodegradation in contaminated aquifers has been shown to be most pronounced at the fringe of contaminant plumes, where mixing of contaminated water and ambient groundwater, containing dissolved electron acceptors, stimulates microbial activity. While physical mixing of contaminant and electron acceptor by transverse dispersion has been shown to be the major bottleneck for biodegradation in steady-state plumes, so far little is known on the effect of flow and transport dynamics (caused, e.g., by a seasonally fluctuating groundwater table) on biodegradation in these systems. Towards this end we performed experiments in quasi-two-dimensional flow-through microcosms on aerobic toluene degradation by Pseudomonas putida F1. Plume dynamics were simulated by vertical alteration of the toluene plume position and experimental results were analyzed by reactive-transport modeling. We found that, even after disappearance of the toluene plume for two weeks, the majority of microorganisms stayed attached to the sediment and regained their full biodegradation potential within two days after reappearance of the toluene plume. Our results underline that besides microbial growth, also maintenance and dormancy are important processes that affect biodegradation performance under transient environmental conditions and therefore deserve increased consideration in future reactive-transport modeling.

  9. Simplified calculation method for radiation dose under normal condition of transport

    International Nuclear Information System (INIS)

    Watabe, N.; Ozaki, S.; Sato, K.; Sugahara, A.

    1993-01-01

    In order to estimate radiation dose during transportation of radioactive materials, the following computer codes are available: RADTRAN, INTERTRAN, J-TRAN. Because these codes consist of functions for estimating doses not only under normal conditions but also in the case of accidents, when nuclei may leak and spread into the environment by air diffusion, the user needs to have special knowledge and experience. In this presentation, we describe how, with a view to preparing a method by which a person in charge of transportation can calculate doses in normal conditions, the main parameters upon which the value of doses depends were extracted and the dose for a unit of transportation was estimated. (J.P.N.)

  10. Local charge transport properties of hydrazine reduced monolayer graphene oxide sheets prepared under pressure condition

    DEFF Research Database (Denmark)

    Ryuzaki, Sou; Meyer, Jakob Abild Stengaard; Petersen, Søren Vermehren

    2014-01-01

    Charge transport properties of chemically reduced graphene oxide (RGO) sheets prepared by treatment with hydrazine were examined using conductive atomic force microscopy. The current-voltage (I-V) characteristics of monolayer RGO sheets prepared under atmospheric pressure followed an exponentially...... increase due to 2D variable-range hopping conduction through small graphene domains in an RGO sheet containing defect regions of residual sp3carbon clusters bonded to oxygen groups, whereas RGO sheets prepared in a closed container under moderate pressure showed linear I-V characteristics...... with a conductivity of 267.2-537.5S/m. It was found that the chemical reduction under pressure results in larger graphene domains (sp2networks) in the RGO sheets when compared to that prepared under atmospheric pressure, indicating that the present reduction of GO sheets under the pressure is one of the effective...

  11. Central Hemodynamics and Oxygen Transport in Various Activation of Patients Operated On Under Extracorporeal Circulation

    Directory of Open Access Journals (Sweden)

    Ye. V. Dzybinskaya

    2009-01-01

    Full Text Available Objective: to study central hemodynamics, the determinants of myocardial oxygen balance, and the parameters of oxygen transport in various activation of patients after surgery under extracorporeal circulation. Subjects and methods. Thirty-four patients aged 57.8±2.5 years who had coronary heart disease were divided into 2 groups: 1 those with late activation (artificial ventilation time 157±9 min and 2 those with immediate activation (artificial ventilation time 33±6 min. Group 2 patients were, if required, given fentanyl, midazolam, or myorelaxants. Results. During activation, there were no intergroup differences in the mean levels of the major parameters of cardiac pump function, in the determinants of coronary blood flow (coronary perfusion gradients and myocardial oxygen demand (the product of heart rate by systolic blood pressure, and in the parameters of oxygen transport, including arterial lactatemia. After tracheal extubation, the left ventricular pump coefficient was increased considerably (up to 3.8±0.2 and 4.4±0.2 gm/mm Hg/m2 in Groups 1 and 2, respectively; p<0.05 with minimum inotropic support (dopamine and/or dobutamine being used at 2.7±0.3 and 2.4±0.3 mg/kg/min, respectively. In both groups, there were no close correlations between the indices of oxygen delivery and consumption at all stages of the study, which was indicative of no transport-dependent oxygen uptake. Conclusion. When the early activation protocol was followed up, the maximum acceleration of early activation, including that using specific antagonists of anesthetics, has no negative impact on central hemodynamics, the determinants of myocardial oxygen balance and transport in patients operated on under extracorporeal circulation. Key words: early activation, surgery under extracorporeal circulation, tracheal extubation in the operating-room, central hemodynamics, oxygen transport.

  12. Influence of Humic Acid on the Transport and Deposition of Colloidal Silica under Different Hydrogeochemical Conditions

    Directory of Open Access Journals (Sweden)

    Jingjing Zhou

    2016-12-01

    Full Text Available The transport and deposition of colloids in aquifers plays an important role in managed aquifer recharge (MAR schemes. Here, the processes of colloidal silica transport and deposition were studied by displacing groundwater with recharge water. The results showed that significant amounts of colloidal silica transport occurred when native groundwater was displaced by HA solution. Solution contains varying conditions of ionic strength and ion valence. The presence of humic acid could affect the zeta potential and size of the colloidal silica, which led to obvious colloidal silica aggregation in the divalent ion solution. Humic acid increased colloidal silica transport by formation of non-adsorbing aqueous phase silica–HA complexes. The experimental and modeling results showed good agreement, indicating that the essential physics were accurately captured by the model. The deposition rates were less than 10−8 s−1 in deionized water and monovalent ion solution. Moreover, the addition of Ca2+ and increase of IS resulted in the deposition rates increasing by five orders of magnitude to 10−4 s−1. In all experiments, the deposition rates decreased in the presence of humic acid. Overall, the promotion of humic acid in colloidal silica was strongly associated with changes in water quality, indicating that they should receive greater attention during MAR.

  13. 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

  14. Connection Management and Recovery Strategies under Epidemic Network Failures in Optical Transport Networks

    DEFF Research Database (Denmark)

    Fagertun, Anna Manolova; Ruepp, Sarah Renée

    2014-01-01

    The current trend in deploying automatic control plane solutions for increased flexibility in the optical transport layer leads to numerous advantages for both the operators and the customers, but also pose challenges related to the stability of the network and its ability to operate in a robust ...... of their transport infrastructures. Applying proactive methods for avoiding areas where epidemic failures spread results in 50% less connections requiring recovery, which translates in improved quality of service to customers....... manner under attacks. This work proposes four policies for failure handling in a connection-oriented optical transport network, under Generalized MultiProtocol Label Switching control plane, and evaluates their performance under multiple correlated large-scale failures. We employ the Susceptible......-Infected-Disabled epidemic failure spreading model and look into possible tradeoffs between resiliency and resource efficiency. Via extensive simulations we show that there exist a clear tradeoff between policy performance and network resource consumption, which must be addressed by network operators for improved robustness...

  15. Nitrate and colloid transport through coarse Hanford sediments under steady state, variably saturated flow

    Science.gov (United States)

    Cherrey, Kelly D.; Flury, Markus; Harsh, James B.

    2003-06-01

    At the U.S. Department of Energy's Hanford Reservation, colloid-facilitated transport is a potential mechanism for accelerated movement of radionuclides like Cs-137. Here we investigate the transport of colloids through Hanford sediments under steady state, unsaturated flow conditions. We isolated colloids from Hanford sediments by dispersion and sedimentation and determined colloid breakthrough curves in packed sediment columns. A column system was developed with which we could control volumetric water contents with accuracy better than 0.01 effective saturation and the water potentials to better than 0.06 cm-H2O. Inflow and outflow boundary conditions had to be meticulously controlled to ensure uniformity of water contents and water potentials inside the column. Colloid breakthrough curves were determined under a series of water contents ranging from 0.2 to 1.0 effective saturation. Colloids were mobile under all water saturations, but the total amount of colloids transported decreased with decreasing water saturation. Colloid behavior was described with the mobile-immobile model concept, including first-order deposition from the mobile phase only.

  16. Advective-diffusive transport of D2O in unsaturated media under evaporation condition

    International Nuclear Information System (INIS)

    Koarashi, Jun; Atarashi-Andoh, Mariko; Amano, Hikaru; Yamazawa, Hiromi; Iida, Takao

    2003-01-01

    Advective-diffusive transport of HTO in unsaturated media was investigated empirically using deuterated water (D 2 O) and columns filled with glass beads. The tortuosity factor was evaluated by numerical model calculations corresponding to first experiment for diffusion under no-evaporation condition. Temporal variations in depth profiles of D 2 O concentrations in the columns were observed by second experiment, which considers the transferring and spreading of D 2 O by pore-water flow caused by evaporation. Measurements and model calculations indicated that diffusion was about two times more efficient than dispersion for D 2 O spreading process under this evaporation condition. (author)

  17. Combined physical and chemical nonequilibrium transport model: analytical solution, moments, and application to colloids.

    Science.gov (United States)

    Leij, Feike J; Bradford, Scott A

    2009-11-20

    The transport of solutes and colloids in porous media is influenced by a variety of physical and chemical nonequilibrium processes. A combined physical-chemical nonequilibrium (PCNE) model was therefore used to describe general mass transport. The model partitions the pore space into "mobile" and "immobile" flow regions with first-order mass transfer between these two regions (i.e, "physical" nonequilibrium or PNE). Partitioning between the aqueous and solid phases can either proceed as an equilibrium or a first-order process (i.e, "chemical" nonequilibrium or CNE) for both the mobile and immobile regions. An analytical solution for the PCNE model is obtained using iterated Laplace transforms. This solution complements earlier semi-analytical and numerical approaches to model solute transport with the PCNE model. The impact of selected model parameters on solute breakthrough curves is illustrated. As is well known, nonequilibrium results in earlier solute breakthrough with increased tailing. The PCNE model allows greater flexibility to describe this trend; for example, a closer resemblance between solute input and effluent pulse. Expressions for moments and transfer functions are presented to facilitate the analytical use of the PCNE model. Contours of mean breakthrough time, variance, and spread of the colloid breakthrough curves as a function of PNE and CNE parameters demonstrate the utility of a model that accounts for both physical and chemical nonequilibrium processes. The model is applied to describe representative colloid breakthrough curves in Ottawa sands reported by Bradford et al. (2002). An equilibrium model provided a good description of breakthrough curves for the bromide tracer but could not adequately describe the colloid data. A considerably better description was provide by the simple CNE model but the best description, especially for the larger 3.2-microm colloids, was provided by the PCNE model.

  18. Determination of O₂ Mass Transport at the Pt | PFSA Ionomer Interface under Reduced Relative Humidity.

    Science.gov (United States)

    Novitski, David; Holdcroft, Steven

    2015-12-16

    Oxygen mass transport resistance through the ionomer component in the cathode catalyst layer is considered to contribute overpotential losses in polymer electrolyte membrane fuel cells. Whereas it is known that water uptake, water transport, and proton conductivity are reduced upon reducing relative humidity, the effect on oxygen mass transport remains unknown. We report a two-electrode approach to determine mass transport coefficients for the oxygen reduction reaction in air at the Pt/perfluorosulfonic acid ionomer membrane interface between 90 and 30% RH at 70 °C using a Pt microdisk in a solid state electrochemical cell. Potential-step chronoamperometry was performed at specific mass-transport limiting potentials to allow for the elucidation of the oxygen diffusion coefficient (D(bO2)) and oxygen concentration (c(bO2)). In our efforts, novel approaches in data acquisition, as well as analysis, were examined because of the dynamic nature of the membrane under lowered hydration conditions. Linear regression analysis reveals a decrease in oxygen permeability (D(bO2c(bO2)) by a factor of 1.7 and 3.4 from 90 to 30% RH for Nafion 211 membrane and membranes cast from Nafion DE2020 ionomer solutions, respectively. Additionally, nonlinear curve fitting by way of the Shoup-Szabo equation is employed to analyze the entire current transient during potential step controlled ORR. We also report on the presence of an RH dependence of our previously reported time-dependency measurements for O2 mass transport coefficients.

  19. Microbial transport from dairying under two spray-irrigation systems in Canterbury, New Zealand.

    Science.gov (United States)

    Close, Murray; Noonan, Mike; Hector, Ross; Bright, John

    2010-01-01

    Transport through the soil and vadose zone to groundwater of Escherichia coli, fecal coliforms, and Campylobacter spp. from pasturing of dairy cows was studied on two working dairy farms under a traveling irrigator and a center pivot system. Leachate was collected from 1.5 m depth using a large linear lysimeter over a period of 4 yr after rainfall or irrigation applied using a traveling irrigator. There was little transport of fecal coliforms or Campylobacter from irrigation applications of 55 mm. There was some transport of fecal coliforms at applications of 80 mm (corresponding to irrigation plus heavy rainfall) but no detectable Campylobacter. When fresh cow pats were placed on half of the lysimeter plots with an 80-mm water application, there was transport of fecal coliforms and Campylobacter, but levels of Campylobacter were low (spray irrigation was monitored monthly from September 2001 to June 2007, with 60% of samples being collected from downgradient wells. Escherichia coli were detected in 5.4 and 2.8% of samples from upgradient and downgradient wells, respectively, at concentrations of >or=1 cfu 100 mL(-1). Campylobacter was detected in 0.7% of samples over the study period, with equal percentages from up- and downgradient wells. The results indicate minimal impact of dairying at these sites on microbial quality of groundwater as a result of spray irrigation using traveling irrigators at rates of approximately 55 mm every 2 wk or center pivot irrigators at 18 mm every 3 to 4 d.

  20. Novel instrument for characterizing comprehensive physical properties under multi-mechanical loads and multi-physical field coupling conditions

    Science.gov (United States)

    Liu, Changyi; Zhao, Hongwei; Ma, Zhichao; Qiao, Yuansen; Hong, Kun; Ren, Zhuang; Zhang, Jianhai; Pei, Yongmao; Ren, Luquan

    2018-02-01

    Functional materials represented by ferromagnetics and ferroelectrics are widely used in advanced sensor and precision actuation due to their special characterization under coupling interactions of complex loads and external physical fields. However, the conventional devices for material characterization can only provide a limited type of loads and physical fields and cannot simulate the actual service conditions of materials. A multi-field coupling instrument for characterization has been designed and implemented to overcome this barrier and measure the comprehensive physical properties under complex service conditions. The testing forms include tension, compression, bending, torsion, and fatigue in mechanical loads, as well as different external physical fields, including electric, magnetic, and thermal fields. In order to offer a variety of information to reveal mechanical damage or deformation forms, a series of measurement methods at the microscale are integrated with the instrument including an indentation unit and in situ microimaging module. Finally, several coupling experiments which cover all the loading and measurement functions of the instrument have been implemented. The results illustrate the functions and characteristics of the instrument and then reveal the variety in mechanical and electromagnetic properties of the piezoelectric transducer ceramic, TbDyFe alloy, and carbon fiber reinforced polymer under coupling conditions.

  1. Performance Evaluation of Survivability Strategies for Elastic Optical Networks under Physical Layer Impairments

    Directory of Open Access Journals (Sweden)

    Jurandir Lacerda Jr

    2017-08-01

    Full Text Available This paper carried out a performance evaluation study that compares two survivability strategies (DPP and SM-RSA for elastic optical networks with and without physical layer impairments. The evaluated scenarios include three representative topologies for elastic optical network, NSFNET, EON and USA. It also analyzes the increase of blocking probability when the survivability strategies are evaluated under the realistic scenario that assumes physical layer impairments. For all studied topologies under physical layer impairments, the survivability strategies achieved blocking probability above 80%.

  2. Multi-scale nitrate transport in a sandstone aquifer system under intensive agriculture

    Science.gov (United States)

    Paradis, Daniel; Ballard, Jean-Marc; Lefebvre, René; Savard, Martine M.

    2018-03-01

    Nitrate transport in heterogeneous bedrock aquifers is influenced by mechanisms that operate at different spatial and temporal scales. To understand these mechanisms in a fractured sandstone aquifer with high porosity, a groundwater-flow and nitrate transport model—reproducing multiple hydraulic and chemical targets—was developed to explain the actual nitrate contamination observed in groundwater and surface water in a study area on Prince Edward Island, Canada. Simulations show that nitrate is leached to the aquifer year-round, with 61% coming from untransformed and transformed organic sources originating from fertilizers and manure. This nitrate reaches the more permeable shallow aquifer through fractures in weathered sandstone that represent only 1% of the total porosity (17%). Some of the nitrate reaches the underlying aquifer, which is less active in terms of groundwater flow, but most of it is drained to the main river. The river-water quality is controlled by the nitrate input from the shallow aquifer. Groundwater in the underlying aquifer, which has long residence times, is also largely influenced by the diffusion of nitrate in the porous sandstone matrix. Consequently, following a change of fertilizer application practices, water quality in domestic wells and the river would change rapidly due to the level of nitrate found in fractures, but a lag time of up to 20 years would be necessary to reach a steady level due to diffusion. This demonstrates the importance of understanding nitrate transport mechanisms when designing effective agricultural and water management plans to improve water quality.

  3. A theoretical model for oxygen transport in skeletal muscle under conditions of high oxygen demand.

    Science.gov (United States)

    McGuire, B J; Secomb, T W

    2001-11-01

    Oxygen transport from capillaries to exercising skeletal muscle is studied by use of a Krogh-type cylinder model. The goal is to predict oxygen consumption under conditions of high demand, on the basis of a consideration of transport processes occurring at the microvascular level. Effects of the decline in oxygen content of blood flowing along capillaries, intravascular resistance to oxygen diffusion, and myoglobin-facilitated diffusion are included. Parameter values are based on human skeletal muscle. The dependence of oxygen consumption on oxygen demand, perfusion, and capillary density are examined. When demand is moderate, the tissue is well oxygenated and consumption is slightly less than demand. When demand is high, capillary oxygen content declines rapidly with axial distance and radial oxygen transport is limited by diffusion resistance within the capillary and the tissue. Under these conditions, much of the tissue is hypoxic, consumption is substantially less than demand, and consumption is strongly dependent on capillary density. Predicted consumption rates are comparable with experimentally observed maximal rates of oxygen consumption.

  4. Leakage current transport mechanism under reverse bias in Au/Ni/GaN Schottky barrier diode

    Science.gov (United States)

    Peta, Koteswara Rao; Kim, Moon Deock

    2018-01-01

    The leakage current transport mechanism under reverse bias of Au/Ni/GaN Schottky diode is studied using temperature dependent current-voltage (I-V-T) and capacitance-voltage (C-V) characteristics. I-V measurement in this study is in the range of 140 K-420 K in steps of 10 K. A reduction in voltage dependent barrier height and a strong internal electric field in depletion region under reverse bias suggested electric field enhanced thermionic emission in carrier transport via defect states in Au/Ni/GaN SBD. A detailed analysis of reverse leakage current revealed two different predominant transport mechanisms namely variable-range hopping (VRH) and Poole-Frenkel (PF) emission conduction at low (260 K) temperatures respectively. The estimated thermal activation energies (0.20-0.39 eV) from Arrhenius plot indicates a trap assisted tunneling of thermally activated electrons from a deep trap state into a continuum of states associated with each conductive threading dislocation.

  5. Physical Layer Secret-Key Generation Scheme for Transportation Security Sensor Network.

    Science.gov (United States)

    Yang, Bin; Zhang, Jianfeng

    2017-06-28

    Wireless Sensor Networks (WSNs) are widely used in different disciplines, including transportation systems, agriculture field environment monitoring, healthcare systems, and industrial monitoring. The security challenge of the wireless communication link between sensor nodes is critical in WSNs. In this paper, we propose a new physical layer secret-key generation scheme for transportation security sensor network. The scheme is based on the cooperation of all the sensor nodes, thus avoiding the key distribution process, which increases the security of the system. Different passive and active attack models are analyzed in this paper. We also prove that when the cooperative node number is large enough, even when the eavesdropper is equipped with multiple antennas, the secret-key is still secure. Numerical results are performed to show the efficiency of the proposed scheme.

  6. A physical model describing the interaction of nuclear transport receptors with FG nucleoporin domain assemblies.

    Science.gov (United States)

    Zahn, Raphael; Osmanović, Dino; Ehret, Severin; Araya Callis, Carolina; Frey, Steffen; Stewart, Murray; You, Changjiang; Görlich, Dirk; Hoogenboom, Bart W; Richter, Ralf P

    2016-04-08

    The permeability barrier of nuclear pore complexes (NPCs) controls bulk nucleocytoplasmic exchange. It consists of nucleoporin domains rich in phenylalanine-glycine motifs (FG domains). As a bottom-up nanoscale model for the permeability barrier, we have used planar films produced with three different end-grafted FG domains, and quantitatively analyzed the binding of two different nuclear transport receptors (NTRs), NTF2 and Importin β, together with the concomitant film thickness changes. NTR binding caused only moderate changes in film thickness; the binding isotherms showed negative cooperativity and could all be mapped onto a single master curve. This universal NTR binding behavior - a key element for the transport selectivity of the NPC - was quantitatively reproduced by a physical model that treats FG domains as regular, flexible polymers, and NTRs as spherical colloids with a homogeneous surface, ignoring the detailed arrangement of interaction sites along FG domains and on the NTR surface.

  7. Systems Models for Transportation Problems : Part 2. The Social Physics for Modern Societies - the Role of the Cities

    Science.gov (United States)

    1977-09-01

    The objective of the research was to make use of a physically based social systems model, developed earlier, to study the determinants of city sizes and their national interactions. In particular, information on the role of a transportation system in...

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

    Science.gov (United States)

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

    2016-04-01

    Coasts are crucial areas for living, economy, recreation, transportation, and various sectors of industry. Many of them are exposed to high-energy wave events. With regard to the ongoing population growth in low-elevation coastal areas, the urgent need for developing suitable management measures, especially for hazards like tsunamis, becomes obvious. These measures require supporting tools which allow an exact estimation of impact parameters like inundation height, inundation area, and wave energy. Focussing on tsunamis, geological archives can provide essential information on frequency and magnitude on a longer time scale in order to support coastal hazard management. While fine-grained deposits may quickly be altered after deposition, multi-ton coarse clasts (boulders) may represent an information source on past tsunami events with a much higher preservation potential. Applying numerical hydrodynamic coupled boulder transport models (BTM) is a commonly used approach to analyse characteristics (e.g. wave height, flow velocity) of the corresponding tsunami. Correct computations of tsunamis and the induced boulder transport can provide essential event-specific information, including wave heights, runup and direction. Although several valuable numerical models for tsunami-induced boulder transport exist (e. g. Goto et al., 2007; Imamura et al., 2008), some important basic aspects of both tsunami hydrodynamics and corresponding boulder transport have not yet been entirely understood. Therefore, our project aims at these questions in four crucial aspects of boulder transport by a tsunami: (i) influence of sediment load, (ii) influence of complex boulder shapes other than idealized rectangular shapes, (iii) momentum transfers between multiple boulders, and (iv) influence of non-uniform bathymetries and topographies both on tsunami and boulder. The investigation of these aspects in physical experiments and the correct implementation of an advanced model is an urgent need

  9. Electronic transport in armchair graphene nanoribbon under double magnetic barrier modulation

    Science.gov (United States)

    Wang, Haiyan; Wu, Chao; Xie, Fang; Zhang, Xiaojiao; Zhou, Guanghui

    2018-03-01

    We present a theoretical investigation of the transport properties and the magnetoresistance effect in armchair graphene nanoribbons (AGNRs) under modulation by two magnetic barriers. The energy levels are found to be degenerate for a metallic AGNR but are not degenerate for a semiconducting AGNR. However, the conductance characteristics show quantized plateaus in both the metallic and semiconducting cases. When the magnetization directions of the barriers change from parallel to antiparallel, the conductance plateau in the metallic AGNR shows a degenerate feature due to matching between the transport modes in different regions. As the barrier height increases, the conductance shows more oscillatory behavior with sharp peaks and troughs. Specifically, the initial position of nonzero conductance for the metallic AGNR system moves towards a higher energy regime, which indicates that an energy gap has been opened. In addition, the magnetoresistance ratio also shows plateau structures in certain specific energy regions. These results may be useful in the design of electron devices based on AGNR nanostructures.

  10. Underlying Physics of Conductive Polymer Composites and Force Sensing Resistors (FSRs) under Static Loading Conditions.

    Science.gov (United States)

    Paredes-Madrid, Leonel; Palacio, Carlos A; Matute, Arnaldo; Parra Vargas, Carlos A

    2017-09-14

    Conductive polymer composites are manufactured by randomly dispersing conductive particles along an insulating polymer matrix. Several authors have attempted to model the piezoresistive response of conductive polymer composites. However, all the proposed models rely upon experimental measurements of the electrical resistance at rest state. Similarly, the models available in literature assume a voltage-independent resistance and a stress-independent area for tunneling conduction. With the aim of developing and validating a more comprehensive model, a test bench capable of exerting controlled forces has been developed. Commercially available sensors-which are manufactured from conductive polymer composites-have been tested at different voltages and stresses, and a model has been derived on the basis of equations for the quantum tunneling conduction through thin insulating film layers. The resistance contribution from the contact resistance has been included in the model together with the resistance contribution from the conductive particles. The proposed model embraces a voltage-dependent behavior for the composite resistance, and a stress-dependent behavior for the tunneling conduction area. The proposed model is capable of predicting sensor current based upon information from the sourcing voltage and the applied stress. This study uses a physical (non-phenomenological) approach for all the phenomena discussed here.

  11. Reactive transport under stress: Permeability evolution by chemo-mechanical deformation

    Science.gov (United States)

    Roded, R.; Holtzman, R.

    2017-12-01

    The transport of reactive fluids in porous media is important in many natural and engineering processes. Reaction with the solid matrix—e.g. dissolution—changes the transport properties, which in turn affect the rate of reagent transport and hence the reaction. The importance of this highly nonlinear problem has motivated intensive research. Specifically, there have been numerous studies concerning the permeability evolution, especially the process of "wormholing", where preferential dissolution of the most conductive regions leads to a runaway permeability increase. Much less attention, however, has been given to the effect of geomechanics; that is, how the fact that the medium is under stress changes the permeability evolution. Here, we present a novel, mechanistic pore-scale model, simulating the interplay between pore opening by matrix dissolution and pore closure by mechanical compaction, facilitated by weakening caused by the very same process of dissolution. We combine a pore network model of reactive transport with a block-spring model that captures the effect of geomechanics through the update of the network properties. Our simulations show that permeability enhancement is inhibited by stress concentration downstream, in the less dissolved (hence stiffer) regions. Higher stresses lead to stronger inhibition, in agreement with experiments. The effect of stress also depends on the Damkohler number (Da)—the ratio between the flow and the reaction rate. At rapid injection (small Da), where dissolution is relatively uniform, stress has a significant effect on permeability. At slower flow rates (high Da, wormholing regime), stress affects the permeability evolution mostly in early stages, with a much smaller effect on the injected volume required for a significant permeability increase (breakthrough) than at low Da. Interestingly, at higher Da, stress concentration downstream induced by the more heterogeneous dissolution leads to a more homogeneous reagent

  12. Applied Physics of Carbon Nanotubes Fundamentals of Theory, Optics and Transport Devices

    CERN Document Server

    Rotkin, Slava V

    2005-01-01

    The book describes the state-of-the-art in fundamental, applied and device physics of nanotubes, including fabrication, manipulation and characterization for device applications; optics of nanotubes; transport and electromechanical devices and fundamentals of theory for applications. This information is critical to the field of nanoscience since nanotubes have the potential to become a very significant electronic material for decades to come. The book will benefit all all readers interested in the application of nanotubes, either in their theoretical foundations or in newly developed characterization tools that may enable practical device fabrication.

  13. Carbon dioxide sequestration: Modeling the diffusive and convective transport under a CO2 cap

    KAUST Repository

    Allen, Rebecca

    2012-01-01

    A rise in carbon dioxide levels from industrial emissions is contributing to the greenhouse effect and global warming. CO2 sequestration in saline aquifers is a strategy to reduce atmospheric CO2 levels. Scientists and researchers rely on numerical simulators to predict CO2 storage by modeling the fluid transport behaviour. Studies have shown that after CO2 is injected into a saline aquifer, undissolved CO2 rises due to buoyant forces and will spread laterally away from the injection site under an area of low permeability. CO2 from this ‘capped\\' region diffuses into the fluid underlying it, and the resulting CO2-fluid mixture increases in density. This increase in density leads to gravity-driven convection. Accordingly, diffusive-convective transport is important to model since it predicts an enhanced storage capacity of the saline aquifer. This work incorporates the diffusive and convective transport processes into the transport modeling equation, and uses a self-generated code. Discretization of the domain is done with a cell-centered finite difference method. Cases are set up using similar parameters from published literature in order to compare results. Enhanced storage capacity is predicted in this work, similar to work done by others. A difference in the onset of convective transport between this work and published results is noticed and discussed in this paper. A sensitivity analysis is performed on the density model used in this work, and on the diffusivity value assumed. The analysis shows that the density model and diffusivity value is a key component on simulation results. Also, perturbations are added to porosity and permeability in order to see the effect of perturbations on the onset of convection, and results agree with similar findings by others. This work provides a basis for studying other cases, such as the impact of heterogeneity on the diffusion-convective transport. An extension of this work may involve the use of an equation of state to

  14. Acute physical exercise under hypoxia improves sleep, mood and reaction time.

    Science.gov (United States)

    de Aquino-Lemos, Valdir; Santos, Ronaldo Vagner T; Antunes, Hanna Karen Moreira; Lira, Fabio S; Luz Bittar, Irene G; Caris, Aline V; Tufik, Sergio; de Mello, Marco Tulio

    2016-02-01

    This study aimed to assess the effect of two sessions of acute physical exercise at 50% VO2peak performed under hypoxia (equivalent to an altitude of 4500 m for 28 h) on sleep, mood and reaction time. Forty healthy men were randomized into 4 groups: Normoxia (NG) (n = 10); Hypoxia (HG) (n = 10); Exercise under Normoxia (ENG) (n = 10); and Exercise under Hypoxia (EHG) (n = 10). All mood and reaction time assessments were performed 40 min after awakening. Sleep was reassessed on the first day at 14 h after the initiation of hypoxia; mood and reaction time were measured 28 h later. Two sessions of acute physical exercise at 50% VO2peak were performed for 60 min on the first and second days after 3 and 27 h, respectively, after starting to hypoxia. Improved sleep efficiency, stage N3 and REM sleep and reduced wake after sleep onset were observed under hypoxia after acute physical exercise. Tension, anger, depressed mood, vigor and reaction time scores improved after exercise under hypoxia. We conclude that hypoxia impairs sleep, reaction time and mood. Acute physical exercise at 50% VO2peak under hypoxia improves sleep efficiency, reversing the aspects that had been adversely affected under hypoxia, possibly contributing to improved mood and reaction time.

  15. The effect of pre-plasma formation under nonlocal transport conditions for ultra-relativistic laser-plasma interaction

    Science.gov (United States)

    Holec, M.; Nikl, J.; Vranic, M.; Weber, S.

    2018-04-01

    Interaction of high-power lasers with solid targets is in general strongly affected by the limited contrast available. The laser pre-pulse ionizes the target and produces a pre-plasma which can strongly modify the interaction of the main part of the laser pulse with the target. This is of particular importance for future experiments which will use laser intensities above 1021 W cm-2 and which are subject to the limited contrast. As a consequence the main part of the laser pulse will be modified while traversing the pre-plasma, interacting with it partially. A further complication arises from the fact that the interaction of a high-power pre-pulse with solid targets very often takes place under nonlocal transport conditions, i.e. the characteristic mean-free-path of the particles and photons is larger than the characteristic scale-lengths of density and temperature. The classical diffusion treatment of radiation and heat transport in the hydrodynamic model is then insufficient for the description of the pre-pulse physics. These phenomena also strongly modify the formation of the pre-plasma which in turn affects the propagation of the main laser pulse. In this paper nonlocal radiation-hydrodynamic simulations are carried out and serve as input for subsequent kinetic simulations of ultra-high intensity laser pulses interacting with the plasma in the ultra-relativistic regime. It is shown that the results of the kinetic simulations differ considerably whether a diffusive or nonlocal transport is used for the radiation-hydrodynamic simulations.

  16. Testing ZigBee Motes for Monitoring Refrigerated Vegetable Transportation under Real Conditions

    Directory of Open Access Journals (Sweden)

    Luis Ruiz-Garcia

    2010-05-01

    Full Text Available Quality control and monitoring of perishable goods during transportation and delivery services is an increasing concern for producers, suppliers, transport decision makers and consumers. The major challenge is to ensure a continuous ‘cold chain’ from producer to consumer in order to guaranty prime condition of goods. In this framework, the suitability of ZigBee protocol for monitoring refrigerated transportation has been proposed by several authors. However, up to date there was not any experimental work performed under real conditions. Thus, the main objective of our experiment was to test wireless sensor motes based in the ZigBee/IEEE 802.15.4 protocol during a real shipment. The experiment was conducted in a refrigerated truck traveling through two countries (Spain and France which means a journey of 1,051 kilometers. The paper illustrates the great potential of this type of motes, providing information about several parameters such as temperature, relative humidity, door openings and truck stops. Psychrometric charts have also been developed for improving the knowledge about water loss and condensation on the product during shipments.

  17. Bacteria transport and retention in intact calcareous soil columns under saturated flow conditions

    Directory of Open Access Journals (Sweden)

    Farrokhian Firouzi Ahmad

    2015-06-01

    Full Text Available Study of bacterial transport and retention in soil is important for various environmental applications such as groundwater contamination and bioremediation of soil and water. The main objective of this research was to quantitatively assess bacterial transport and deposition under saturated conditions in calcareous soil. A series of leaching experiments was conducted on two undisturbed soil columns. Breakthrough curves of Pseudomonas fluorescens and Cl were measured. After the leaching experiment, spatial distribution of bacteria retention in the soil columns was determined. The HYDRUS-1D one- and two-site kinetic models were used to predict the transport and deposition of bacteria in soil. The results indicated that the two-site model fits the observed data better than one-site kinetic model. Bacteria interaction with the soil of kinetic site 1 revealed relatively fast attachment and slow detachment, whereas attachment to and detachment of bacteria from kinetic site 2 was fast. Fast attachment and slow detachment of site 1 can be attributed to soil calcium carbonate that has favorable attachment sites for bacteria. The detachment rate was less than 0.02 of the attachment rate, indicating irreversible attachment of bacteria. High reduction rate of bacteria was also attributed to soil calcium carbonate.

  18. A Transporter of Ibuprofen is Upregulated in MDCK I Cells under Hyperosmotic Culture Conditions

    DEFF Research Database (Denmark)

    Nielsen, Carsten Uhd; Rasmussen, Rune N; Mo, Junying

    2016-01-01

    Ibuprofen is a widely used drug. It has been identified as an inhibitor of several transporters, but it is not clear if ibuprofen is a substrate of any transporter itself. In the present work, we have characterized a transporter of ibuprofen, which is upregulated by hyperosmotic culture conditions...... in Madin-Darby canine kidney I (MDCK I) renal cells. [(3)H]-Ibuprofen uptake rate was measured in MDCK I cell cultured under normal (300 mOsm) and hyperosmotic (500 mOsm) conditions. Hyperosmotic conditions were obtained by supplementing urea, NaCl, mannitol, or raffinose to culture medium. The effect...... of increased osmolarity was investigated for different incubation times. [(3)H]-Ibuprofen uptake in MDCK I cells was upregulated by hyperosmotic culture condition, and was saturable with a Km value of 0.37 ± 0.08 μM and a Vmax of 233.1 ± 17.2 pmol· cm(-2)· min(-1). Racemic [(3)H]-ibuprofen uptake could...

  19. On the Way to Future's High Energy Particle Physics Transport Code

    CERN Document Server

    Bíró, Gábor; Futó, Endre

    2015-01-01

    High Energy Physics (HEP) needs a huge amount of computing resources. In addition data acquisition, transfer, and analysis require a well developed infrastructure too. In order to prove new physics disciplines it is required to higher the luminosity of the accelerator facilities, which produce more-and-more data in the experimental detectors. Both testing new theories and detector R&D are based on complex simulations. Today have already reach that level, the Monte Carlo detector simulation takes much more time than real data collection. This is why speed up of the calculations and simulations became important in the HEP community. The Geant Vector Prototype (GeantV) project aims to optimize the most-used particle transport code applying parallel computing and to exploit the capabilities of the modern CPU and GPU architectures as well. With the maximized concurrency at multiple levels the GeantV is intended to be the successor of the Geant4 particle transport code that has been used since two decades succe...

  20. Physics-based hybrid method for multiscale transport in porous media

    Science.gov (United States)

    Yousefzadeh, Mehrdad; Battiato, Ilenia

    2017-09-01

    Despite advancements in the development of multiscale models for flow and reactive transport in porous media, the accurate, efficient and physics-based coupling of multiple scales in hybrid models remains a major theoretical and computational challenge. Improving the predictivity of macroscale predictions by means of multiscale algorithms relative to classical at-scale models is the primary motivation for the development of multiscale simulators. Yet, very few are the quantitative studies that explicitly address the predictive capability of multiscale coupling algorithms as it is still generally not possible to have a priori estimates of the errors that are present when complex flow processes are modeled. We develop a nonintrusive pore-/continuum-scale hybrid model whose coupling error is bounded by the upscaling error, i.e. we build a predictive tightly coupled multiscale scheme. This is accomplished by slightly enlarging the subdomain where continuum-scale equations are locally invalid and analytically defining physics-based coupling conditions at the interfaces separating the two computational sub-domains, while enforcing state variable and flux continuity. The proposed multiscale coupling approach retains the advantages of domain decomposition approaches, including the use of existing solvers for each subdomain, while it gains flexibility in the choice of the numerical discretization method and maintains the coupling errors bounded by the upscaling error. We implement the coupling in finite volumes and test the proposed method by modeling flow and transport through a reactive channel and past an array of heterogeneously reactive cylinders.

  1. Proceedings of the Fifth Microgravity Fluid Physics and Transport Phenomena Conference

    Science.gov (United States)

    Singh, Bhim S. (Editor)

    2000-01-01

    The Fifth Microgravity Fluid Physics and Transport Phenomena Conference provided the scientific community the opportunity to view the current scope of the Microgravity Fluid Physics and Transport Phenomena Program and research opportunities and plans for the near future. Consistent with the conference theme "Microgravity Research an Agency-Wide Asset" the conference focused not only on fundamental research but also on applications of this knowledge towards enabling future space exploration missions. The conference included 14 invited plenary talks, 61 technical paper presentations, 61 poster presentations, exhibits and a forum on emerging research themes focusing on nanotechnology and biofluid mechanics. This web-based proceeding includes the presentation and poster charts provided by the presenters of technical papers and posters that were scanned at the conference site. Abstracts of all the papers and posters are included and linked to the presentations charts. The invited and plenary speakers were not required to provide their charts and are generally not available for scanning and hence not posted. The conference program is also included.

  2. ARES: A Parallel Discrete Ordinates Transport Code for Radiation Shielding Applications and Reactor Physics Analysis

    Directory of Open Access Journals (Sweden)

    Yixue Chen

    2017-01-01

    Full Text Available ARES is a multidimensional parallel discrete ordinates particle transport code with arbitrary order anisotropic scattering. It can be applied to a wide variety of radiation shielding calculations and reactor physics analysis. ARES uses state-of-the-art solution methods to obtain accurate solutions to the linear Boltzmann transport equation. A multigroup discretization is applied in energy. The code allows multiple spatial discretization schemes and solution methodologies. ARES currently provides diamond difference with or without linear-zero flux fixup, theta weighted, directional theta weighted, exponential directional weighted, and linear discontinuous finite element spatial differencing schemes. Discrete ordinates differencing in angle and spherical harmonics expansion of the scattering source are adopted. First collision source method is used to eliminate or mitigate the ray effects. Traditional source iteration and Krylov iterative method preconditioned with diffusion synthetic acceleration are applied to solve the linear system of equations. ARES uses the Koch-Baker-Alcouffe parallel sweep algorithm to obtain high parallel efficiency. Verification and validation for the ARES transport code system have been done by lots of benchmarks. In this paper, ARES solutions to the HBR-2 benchmark and C5G7 benchmarks are in excellent agreement with published results. Numerical results are presented which demonstrate the accuracy and efficiency of these methods.

  3. Health Impacts of Increased Physical Activity from Changes in Transportation Infrastructure: Quantitative Estimates for Three Communities.

    Science.gov (United States)

    Mansfield, Theodore J; MacDonald Gibson, Jacqueline

    2015-01-01

    Recently, two quantitative tools have emerged for predicting the health impacts of projects that change population physical activity: the Health Economic Assessment Tool (HEAT) and Dynamic Modeling for Health Impact Assessment (DYNAMO-HIA). HEAT has been used to support health impact assessments of transportation infrastructure projects, but DYNAMO-HIA has not been previously employed for this purpose nor have the two tools been compared. To demonstrate the use of DYNAMO-HIA for supporting health impact assessments of transportation infrastructure projects, we employed the model in three communities (urban, suburban, and rural) in North Carolina. We also compared DYNAMO-HIA and HEAT predictions in the urban community. Using DYNAMO-HIA, we estimated benefit-cost ratios of 20.2 (95% C.I.: 8.7-30.6), 0.6 (0.3-0.9), and 4.7 (2.1-7.1) for the urban, suburban, and rural projects, respectively. For a 40-year time period, the HEAT predictions of deaths avoided by the urban infrastructure project were three times as high as DYNAMO-HIA's predictions due to HEAT's inability to account for changing population health characteristics over time. Quantitative health impact assessment coupled with economic valuation is a powerful tool for integrating health considerations into transportation decision-making. However, to avoid overestimating benefits, such quantitative HIAs should use dynamic, rather than static, approaches.

  4. Efficacy of adjusting working height and mechanizing of transport on physical work demands and local discomfort in construction work

    NARCIS (Netherlands)

    van der Molen, Henk F.; Grouwstra, Robin; Kuijer, P. Paul F. M.; Sluiter, Judith K.; Frings-Dresen, Monique H. W.

    2004-01-01

    The efficacy of ergonomics measures to reduce physical work demands in a real working situation is often assumed, but seldom studied. In this study, the effect of adjusting working height and mechanization of transport on physical work demands and local discomfort of bricklayers' work was evaluated

  5. Biomass Energy for Transport and Electricity: Large scale utilization under low CO2 concentration scenarios

    Energy Technology Data Exchange (ETDEWEB)

    Luckow, Patrick; Wise, Marshall A.; Dooley, James J.; Kim, Son H.

    2010-01-25

    This paper examines the potential role of large scale, dedicated commercial biomass energy systems under global climate policies designed to stabilize atmospheric concentrations of CO2 at 400ppm and 450ppm. We use an integrated assessment model of energy and agriculture systems to show that, given a climate policy in which terrestrial carbon is appropriately valued equally with carbon emitted from the energy system, biomass energy has the potential to be a major component of achieving these low concentration targets. The costs of processing and transporting biomass energy at much larger scales than current experience are also incorporated into the modeling. From the scenario results, 120-160 EJ/year of biomass energy is produced by midcentury and 200-250 EJ/year by the end of this century. In the first half of the century, much of this biomass is from agricultural and forest residues, but after 2050 dedicated cellulosic biomass crops become the dominant source. A key finding of this paper is the role that carbon dioxide capture and storage (CCS) technologies coupled with commercial biomass energy can play in meeting stringent emissions targets. Despite the higher technology costs of CCS, the resulting negative emissions used in combination with biomass are a very important tool in controlling the cost of meeting a target, offsetting the venting of CO2 from sectors of the energy system that may be more expensive to mitigate, such as oil use in transportation. The paper also discusses the role of cellulosic ethanol and Fischer-Tropsch biomass derived transportation fuels and shows that both technologies are important contributors to liquid fuels production, with unique costs and emissions characteristics. Through application of the GCAM integrated assessment model, it becomes clear that, given CCS availability, bioenergy will be used both in electricity and transportation.

  6. Entropy analysis in a cilia transport of nanofluid under the influence of magnetic field

    Directory of Open Access Journals (Sweden)

    Muhammad N. Abrar

    2017-12-01

    Full Text Available In this study, analysis is performed on entropy generation during cilia transport of water based titanium dioxide nanoparticles in the presence of viscous dissipation. Moreover, thermal heat flux is considered at the surface of a channel with ciliated walls. Mathematical formulation is constructed in the form of nonlinear partial differential equations. Making use of suitable variables, the set of partial differential equations is reduced to coupled nonlinear ordinary differential equations. Closed form exact solutions are obtained for velocity, temperature, and pressure gradient. Graphical illustrations for emerging flow parameters, such as Hartmann number (Ha, Brinkmann number (Br, radiation parameter (Rn, and flow rate, have been prepared in order to capture the physical behavior of these parameters. The main goal (i.e., the minimizing of entropy generation of the second law of thermodynamics can be achieved by decreasing the magnitude of Br, Ha and Λ parameters.

  7. Physical investigation of square cylinder array dynamical response under single-phase cross-flow

    International Nuclear Information System (INIS)

    Longatte, E.; Baj, F.

    2014-01-01

    Fluid structure interaction and flow-induced vibration in square cylinder arrangement under single-phase incompressible laminar cross flow are investigated in the present paper. Dynamic instability governed by damping generation is studied without any consideration about mixing with turbulence effects. Conservative and non-conservative effects are pointed out and dynamical stability limit sensitivity to physical parameters is analyzed. Finally the influence of key physical parameters on fluid solid dynamics interaction is quantified. (authors)

  8. The implications of megatrends in information and communication technology and transportation for changes in global physical activity.

    Science.gov (United States)

    Pratt, Michael; Sarmiento, Olga L; Montes, Felipe; Ogilvie, David; Marcus, Bess H; Perez, Lilian G; Brownson, Ross C

    2012-07-21

    Physical inactivity accounts for more than 3 million deaths per year, most from non-communicable diseases in low-income and middle-income countries. We used reviews of physical activity interventions and a simulation model to examine how megatrends in information and communication technology and transportation directly and indirectly affect levels of physical activity across countries of low, middle, and high income. The model suggested that the direct and potentiating eff ects of information and communication technology, especially mobile phones, are nearly equal in magnitude to the mean eff ects of planned physical activity interventions. The greatest potential to increase population physical activity might thus be in creation of synergistic policies in sectors outside health including communication and transportation. However, there remains a glaring mismatch between where studies on physical activity interventions are undertaken and where the potential lies in low-income and middle-income countries for population-level effects that will truly affect global health.

  9. 19 CFR 18.4a - Containers or road vehicles accepted for transport under customs seal; requirements.

    Science.gov (United States)

    2010-04-01

    ... the container or road vehicle without obvious damage to it or without breaking the seal. A container... 19 Customs Duties 1 2010-04-01 2010-04-01 false Containers or road vehicles accepted for transport... General Provisions § 18.4a Containers or road vehicles accepted for transport under customs seal...

  10. The effects of physical and geochemical heterogeneities on hydro-geochemical transport and effective reaction rates

    Science.gov (United States)

    Atchley, Adam L.; Navarre-Sitchler, Alexis K.; Maxwell, Reed M.

    2014-09-01

    The role of coupled physical and geochemical heterogeneities in hydro-geochemical transport is investigated by simulating three-dimensional transport in a heterogeneous system with kinetic mineral reactions. Ensembles of 100 physically heterogeneous realizations were simulated for three geochemical conditions: 1) spatially homogeneous reactive mineral surface area, 2) reactive surface area positively correlated to hydraulic heterogeneity, and 3) reactive surface area negatively correlated to hydraulic heterogeneity. Groundwater chemistry and the corresponding effective reaction rates were calculated at three transverse planes to quantify differences in plume evolution due to heterogeneity in mineral reaction rates and solute residence time (τ). The model is based on a hypothetical CO2 intrusion into groundwater from a carbon capture utilization and storage (CCUS) operation where CO2 dissolution and formation of carbonic acid created geochemical dis-equilibrium between fluids and the mineral galena that resulted in increased aqueous lead (Pb2 +) concentrations. Calcite dissolution buffered the pH change and created conditions of galena oversaturation, which then reduced lead concentrations along the flow path. Near the leak kinetic geochemical reactions control the release of solutes into the fluid, but further along the flow path mineral solubility controls solute concentrations. Simulation results demonstrate the impact of heterogeneous distribution of geochemical reactive surface area in coordination with physical heterogeneity on the effective reaction rate (Krxn,eff) and Pb2 + concentrations within the plume. Dissimilarities between ensemble Pb2 + concentration and Krxn,eff are attributed to how geochemical heterogeneity affects the time (τeq) and therefore advection distance (Leq) required for the system to re-establish geochemical equilibrium. Only after geochemical equilibrium is re-established, Krxn,eff and Pb2 + concentrations are the same for all three

  11. The effects of physical and geochemical heterogeneities on hydro-geochemical transport and effective reaction rates.

    Science.gov (United States)

    Atchley, Adam L; Navarre-Sitchler, Alexis K; Maxwell, Reed M

    2014-09-01

    The role of coupled physical and geochemical heterogeneities in hydro-geochemical transport is investigated by simulating three-dimensional transport in a heterogeneous system with kinetic mineral reactions. Ensembles of 100 physically heterogeneous realizations were simulated for three geochemical conditions: 1) spatially homogeneous reactive mineral surface area, 2) reactive surface area positively correlated to hydraulic heterogeneity, and 3) reactive surface area negatively correlated to hydraulic heterogeneity. Groundwater chemistry and the corresponding effective reaction rates were calculated at three transverse planes to quantify differences in plume evolution due to heterogeneity in mineral reaction rates and solute residence time (τ). The model is based on a hypothetical CO2 intrusion into groundwater from a carbon capture utilization and storage (CCUS) operation where CO2 dissolution and formation of carbonic acid created geochemical dis-equilibrium between fluids and the mineral galena that resulted in increased aqueous lead (Pb(2+)) concentrations. Calcite dissolution buffered the pH change and created conditions of galena oversaturation, which then reduced lead concentrations along the flow path. Near the leak kinetic geochemical reactions control the release of solutes into the fluid, but further along the flow path mineral solubility controls solute concentrations. Simulation results demonstrate the impact of heterogeneous distribution of geochemical reactive surface area in coordination with physical heterogeneity on the effective reaction rate (Krxn,eff) and Pb(2+) concentrations within the plume. Dissimilarities between ensemble Pb(2+) concentration and Krxn,eff are attributed to how geochemical heterogeneity affects the time (τeq) and therefore advection distance (Leq) required for the system to re-establish geochemical equilibrium. Only after geochemical equilibrium is re-established, Krxn,eff and Pb(2+) concentrations are the same for all

  12. Comparisons of physical and chemical sputtering in high density divertor plasmas with the Monte Carlo Impurity (MCI) transport model

    International Nuclear Information System (INIS)

    Evans, T.E.; Loh, Y.S.; West, W.P.; Finkenthal, D.F.

    1997-11-01

    The MCI transport model was used to compare chemical and physical sputtering for a DIII-D divertor plasma near detachment. With physical sputtering alone the integrated carbon influx was 8.4 x 10 19 neutral/s while physical plus chemical sputtering produced an integrated carbon influx of 1.7 x 10 21 neutrals/s. The average carbon concentration in the computational volume increased from 0.012% with only physical sputtering to 0.182% with both chemical and physical sputtering. This increase in the carbon inventory produced more radiated power which is in better agreement with experimental measurements

  13. Distance From Public Transportation and Physical Activity in Japanese Older Adults: The Moderating Role of Driving Status.

    Science.gov (United States)

    Harada, Kazuhiro; Lee, Sangyoon; Lee, Sungchul; Bae, Seongryu; Anan, Yuya; Harada, Kenji; Shimada, Hiroyuki

    2018-01-25

    Although previous studies have shown that good access to public transportation is positively related with physical activity, the moderators of this relationship have not been explored sufficiently in older adults. It is possible that driving status could moderate this relationship. The present study examined whether the objectively measured distance between public transportation and the home was associated with physical activity levels, and whether this association was moderated by driving status among Japanese older adults. In this cross-sectional study, participants (n = 2,878) completed questionnaires and wore accelerometers for at least 7 days, to measure their average daily step counts and minutes spent engaging in moderate-to-vigorous physical activity. Road network distances between the home and the nearest bus stop or train station were measured using geographic information systems. Driving status was assessed using questionnaires. Multiple regression analyses stratified by driving status revealed that, among nondrivers, living further away from public transportation was associated with higher step counts (β = 0.08, p transportation was significantly associated with higher moderate-to-vigorous physical activity levels (β = -0.05, p = .042). Despite the small effect sizes, the direction of the association between distance from public transportation and physical activity was different for current drivers and nondrivers. These findings imply that good access to public transportation does not positively relate with greater engagement in physical activity among nondriving older adults. Shorter distances to public transportation might reduce opportunities for engaging in physical activity for them. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

  14. Analysis of corrosion product transport in PWR primary system under non-convective condition

    International Nuclear Information System (INIS)

    Han, Byoung Sub

    1992-02-01

    The increase of occupational radiation exposure (ORE) due to the increase of the operational period at existing nuclear power plant and also the publication of the new version of ICRP recommendation (ICRP publication No. 60) for radiological protection require much more strict reduction of radiation buildup in the nuclear power plant. The major sources of the radiation, i.e. the radioactive corrosion-products, are generated by the neutron activation of the corrosion products at the reactor core, and then the radioactive corrosion products are transported to the outside of the core, and accumulated near the steam generator side at PWR. Major radioactive corrosion-products of interest in PWR are Cr 51 ,: Mn 54 ,: Co 58 ,: Fe 59 and Co 60 . Among them Co 58 and Co 60 are known to contribute approximately more than 70% of the total ORE. Thus our main concerns are focused on predicting the transport and deposition of the Co radionuclides and suggesting the optimizing method which can minimize and control the ORE of the nuclear power plant. It is well known that Co-source is most effectively controlled by pH-solubility radiation control, and also some complex computer codes such as CORA and PACTOLE have been developed and revised to predict the corrosion product behavior. However these codes still imply some intrisic problems in simulating the real behavior of corrosion products in the reactor because of 1) the lack of important experimental data, coefficients and parameters of the transport and reactions under actual high temperature and pressure conditions, 2) no general theoretical modelling which can describe such many different mechanisms involved in the corrosion product movements, 3) the newly developed and measured behavior of the corrosion product transport mechanism. Since no sufficient and detailed information is available from the above-mentioned codes (also due to propriority problems), we concentrate on developing a new computer code, CP-TRAN (Corrosion

  15. The Role of Partially-Saturated Conditions, Physical Heterogeneity, and Desorption Kinetics on Colloid-Facilitated Transport of Cesium and Strontium by Illite in Quartz Sand

    Science.gov (United States)

    Dittrich, T. M.; Ryan, J. N.; Saiers, J. E.

    2009-12-01

    In many soil and groundwater systems, colloids are present, mobile, and capable of enhancing the transport of some contaminants if the rate of contaminant desorption from the contaminants is slow relative to the rate of colloid and contaminant transport. The importance of contaminant desorption kinetics has been well illustrated in saturated porous media systems, but not in partially-saturated systems. The goal of this research project was to examine and quantify the effects of contaminant desorption kinetics on colloid-facilitated transport under partially-saturated conditions. Laboratory breakthrough experiments were conducted using a column (12.7 cm diameter and 33.5 cm length) packed with (1) quartz sand of uniform size and (2) quartz sand of two different sizes packed as a central tube simulating a macropore (coarse sand) and surrounding matrix (fine sand). Illite was used as the colloids. Cesium and strontium were chosen as model contaminants because their mechanisms of adsorption to illite result in slower desorption of cesium than of strontium and because these cations are found in their radioactive forms at contaminated Department of Energy sites. In the partially saturated columns of uniform sand, the illite colloids facilitated the transport of both cesium and strontium; however, the transport of cesium was facilitated to a greater extent than strontium because cesium binds strongly to the frayed edge sites on the illite colloids. Compared to saturated conditions, partially-saturated conditions increased the transport of cesium and strontium due to the decreased effective surface area of the quartz sand. At moisture contents near saturation, addition of a macropore increased transport of cesium and strontium due to increased porewater movement through the macropore. At lower moisture contents, less porewater was transported through the macropore and cesium and strontium transport was similar to the uniform sand experiments. A model for colloid

  16. Upscaling of nanoparticle transport in porous media under unfavorable conditions: Pore scale to Darcy scale

    Science.gov (United States)

    Seetha, N.; Raoof, Amir; Mohan Kumar, M. S.; Majid Hassanizadeh, S.

    2017-05-01

    Transport and deposition of nanoparticles in porous media is a multi-scale problem governed by several pore-scale processes, and hence, it is critical to link the processes at pore scale to the Darcy-scale behavior. In this study, using pore network modeling, we develop correlation equations for deposition rate coefficients for nanoparticle transport under unfavorable conditions at the Darcy scale based on pore-scale mechanisms. The upscaling tool is a multi-directional pore-network model consisting of an interconnected network of pores with variable connectivities. Correlation equations describing the pore-averaged deposition rate coefficients under unfavorable conditions in a cylindrical pore, developed in our earlier studies, are employed for each pore element. Pore-network simulations are performed for a wide range of parameter values to obtain the breakthrough curves of nanoparticle concentration. The latter is fitted with macroscopic 1-D advection-dispersion equation with a two-site linear reversible deposition accounting for both equilibrium and kinetic sorption. This leads to the estimation of three Darcy-scale deposition coefficients: distribution coefficient, kinetic rate constant, and the fraction of equilibrium sites. The correlation equations for the Darcy-scale deposition coefficients, under unfavorable conditions, are provided as a function of measurable Darcy-scale parameters, including: porosity, mean pore throat radius, mean pore water velocity, nanoparticle radius, ionic strength, dielectric constant, viscosity, temperature, and surface potentials of the particle and grain surfaces. The correlation equations are found to be consistent with the available experimental results, and in qualitative agreement with Colloid Filtration Theory for all parameters, except for the mean pore water velocity and nanoparticle radius.

  17. Upscaling of nanoparticle transport in porous media under unfavorable conditions: Pore scale to Darcy scale.

    Science.gov (United States)

    Seetha, N; Raoof, Amir; Mohan Kumar, M S; Majid Hassanizadeh, S

    2017-05-01

    Transport and deposition of nanoparticles in porous media is a multi-scale problem governed by several pore-scale processes, and hence, it is critical to link the processes at pore scale to the Darcy-scale behavior. In this study, using pore network modeling, we develop correlation equations for deposition rate coefficients for nanoparticle transport under unfavorable conditions at the Darcy scale based on pore-scale mechanisms. The upscaling tool is a multi-directional pore-network model consisting of an interconnected network of pores with variable connectivities. Correlation equations describing the pore-averaged deposition rate coefficients under unfavorable conditions in a cylindrical pore, developed in our earlier studies, are employed for each pore element. Pore-network simulations are performed for a wide range of parameter values to obtain the breakthrough curves of nanoparticle concentration. The latter is fitted with macroscopic 1-D advection-dispersion equation with a two-site linear reversible deposition accounting for both equilibrium and kinetic sorption. This leads to the estimation of three Darcy-scale deposition coefficients: distribution coefficient, kinetic rate constant, and the fraction of equilibrium sites. The correlation equations for the Darcy-scale deposition coefficients, under unfavorable conditions, are provided as a function of measurable Darcy-scale parameters, including: porosity, mean pore throat radius, mean pore water velocity, nanoparticle radius, ionic strength, dielectric constant, viscosity, temperature, and surface potentials of the particle and grain surfaces. The correlation equations are found to be consistent with the available experimental results, and in qualitative agreement with Colloid Filtration Theory for all parameters, except for the mean pore water velocity and nanoparticle radius. Copyright © 2017. Published by Elsevier B.V.

  18. Combining geoelectrical and advanced lysimeter methods to characterize heterogeneous flow and transport under unsaturated transient conditions

    Science.gov (United States)

    Wehrer, M.; Skowronski, J.; Binley, A. M.; Slater, L. D.

    2013-12-01

    driven by textural heterogeneities. As a consequence, preferential transport of the conservative tracer also occurred. However, tracer displacement is subject not only to preferential flow but also to dilution, which complicates the interpretation of the imaging results by ERT. The novelty of our approach includes spatially and temporally highly resolved measurements under transient boundary conditions in combination with a multicompartment suction plate. Through systematic variation of boundary conditions we were able to overcome interpretation bias in the ERT data resulting from simultaneous changes of water content and pore fluid conductivity. We consider this an important step towards field applications of ERT for process identification and model parameterization.

  19. Physical and genetic interaction between ammonium transporters and the signaling protein Rho1 in the plant pathogen Ustilago maydis.

    Science.gov (United States)

    Paul, Jinny A; Barati, Michelle T; Cooper, Michael; Perlin, Michael H

    2014-10-01

    Dimorphic transitions between yeast-like and filamentous forms occur in many fungi and are often associated with pathogenesis. One of the cues for such a dimorphic switch is the availability of nutrients. Under conditions of nitrogen limitation, fungal cells (such as those of Saccharomyces cerevisiae and Ustilago maydis) switch from budding to pseudohyphal or filamentous growth. Ammonium transporters (AMTs) are responsible for uptake and, in some cases, for sensing the availability of ammonium, a preferred nitrogen source. Homodimer and/or heterodimer formation may be required for regulating the activity of the AMTs. To investigate the potential interactions of Ump1 and Ump2, the AMTs of the maize pathogen U. maydis, we first used the split-ubiquitin system, followed by a modified split-YFP (yellow fluorescent protein) system, to validate the interactions in vivo. This analysis showed the formation of homo- and hetero-oligomers by Ump1 and Ump2. We also demonstrated the interaction of the high-affinity ammonium transporter, Ump2, with the Rho1 GTPase, a central protein in signaling, with roles in controlling polarized growth. This is the first demonstration in eukaryotes of the physical interaction in vivo of an ammonium transporter with the signaling protein Rho1. Moreover, the Ump proteins interact with Rho1 during the growth of cells in low ammonium concentrations, a condition required for the expression of the Umps. Based on these results and the genetic evidence for the interaction of Ump2 with both Rho1 and Rac1, another small GTPase, we propose a model for the role of these interactions in controlling filamentation, a fundamental aspect of development and pathogenesis in U. maydis. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  20. Finite element computation of multi-physical micropolar transport phenomena from an inclined moving plate in porous media

    Science.gov (United States)

    Shamshuddin, MD.; Anwar Bég, O.; Sunder Ram, M.; Kadir, A.

    2018-02-01

    Non-Newtonian flows arise in numerous industrial transport processes including materials fabrication systems. Micropolar theory offers an excellent mechanism for exploring the fluid dynamics of new non-Newtonian materials which possess internal microstructure. Magnetic fields may also be used for controlling electrically-conducting polymeric flows. To explore numerical simulation of transport in rheological materials processing, in the current paper, a finite element computational solution is presented for magnetohydrodynamic, incompressible, dissipative, radiative and chemically-reacting micropolar fluid flow, heat and mass transfer adjacent to an inclined porous plate embedded in a saturated homogenous porous medium. Heat generation/absorption effects are included. Rosseland's diffusion approximation is used to describe the radiative heat flux in the energy equation. A Darcy model is employed to simulate drag effects in the porous medium. The governing transport equations are rendered into non-dimensional form under the assumption of low Reynolds number and also low magnetic Reynolds number. Using a Galerkin formulation with a weighted residual scheme, finite element solutions are presented to the boundary value problem. The influence of plate inclination, Eringen coupling number, radiation-conduction number, heat absorption/generation parameter, chemical reaction parameter, plate moving velocity parameter, magnetic parameter, thermal Grashof number, species (solutal) Grashof number, permeability parameter, Eckert number on linear velocity, micro-rotation, temperature and concentration profiles. Furthermore, the influence of selected thermo-physical parameters on friction factor, surface heat transfer and mass transfer rate is also tabulated. The finite element solutions are verified with solutions from several limiting cases in the literature. Interesting features in the flow are identified and interpreted.

  1. Assessment of bridge abutment scour and sediment transport under various flow conditions

    Science.gov (United States)

    Gilja, Gordon; Valyrakis, Manousos; Michalis, Panagiotis; Bekić, Damir; Kuspilić, Neven; McKeogh, Eamon

    2017-04-01

    Safety of bridges over watercourses can be compromised by flow characteristics and bridge hydraulics. Scour process around bridge foundations can develop rapidly during low-recurrence interval floods when structural elements are exposed to increased flows. Variations in riverbed geometry, as a result of sediment removal and deposition processes, can increase flood-induced hazard at bridge sites with catastrophic failures and destructive consequences for civil infrastructure. The quantification of flood induced hazard on bridge safety generally involves coupled hydrodynamic and sediment transport models (i.e. 2D numerical or physical models) for a range of hydrological events covering both high and low flows. Modelled boundary conditions are usually estimated for their probability of occurrence using frequency analysis of long-term recordings at gauging stations. At smaller rivers gauging station records are scarce, especially in upper courses of rivers where weirs, drops and rapids are common elements of river bathymetry. As a result, boundary conditions that accurately represent flow patterns on modelled river reach cannot be often reliably acquired. Sediment transport process is also more complicated to describe due to its complexity and dependence to local flow field making scour hazard assessment a particularly challenging issue. This study investigates the influence of flow characteristics to the development of scour and sedimentation processes around bridge abutments of a single span masonry arch bridge in south Ireland. The impact of downstream weirs on bridge hydraulics through variation of downstream model domain type is also considered in this study. The numerical model is established based on detailed bathymetry data surveyed along a rectangular grid of 50cm spacing. Acquired data also consist of riverbed morphology and water level variations which are monitored continuously on bridge site. The obtained data are then used to compare and calibrate

  2. Controlled traffic and soil physical quality of an Oxisol under sugarcane cultivation

    Directory of Open Access Journals (Sweden)

    Gustavo Soares de Souza

    2015-06-01

    Full Text Available Machinery traffic in sugarcane (Saccharumsp. plantations reduces soil physical quality, and hinders both root development and crop yield. We evaluated the physical quality of an Oxisol and the development of sugarcane roots under controlled traffic. The treatments assessed were: without controlled machinery traffic (WCT, controlled traffic by adjusting the tractor and infield wagons to a 3.0 m track width with the operator guiding the machinery (CT1 and the previous treatment using real time kinematic / global positioning system (RTK / GPS precision auto steer (CT2. Soil samples were collected from the planting rows, seedbed and inter-row center to determine the least limiting water range (LLWR and soil porosity from scanned 2-D images. The root dry mass was sampled from monoliths, separated from the soil by washing through a 2-mm sieve and dried in an oven. A higher LLWR was observed in the planting row under CT1 and CT2 than under WCT. The planting row had a predominance of complex pores with a diameter > 500 µm in the 0.15-0.27 m depth layer under CT1 and CT2. In the planting rows under WCT, the root dry mass was only 44 % of that measured under CT2. Benefits regarding soil physical quality and growth roots were observed when the tractor-wagon track width was adjusted based on the sugarcane spacing using either precision auto steering or manual operation of the machinery.

  3. PREFACE: 11th IAEA Technical Meeting on H-mode Physics and Transport Barriers

    Science.gov (United States)

    Takizuka, Tomonori

    2008-07-01

    This volume of Journal of Physics: Conference Series contains papers based on invited talks and contributed posters presented at the 11th IAEA Technical Meeting on H-mode Physics and Transport Barriers. This meeting was held at the Tsukuba International Congress Center in Tsukuba, Japan, on 26-28 September 2007, and was organized jointly by the Japan Atomic Energy Agency and the University of Tsukuba. The previous ten meetings in this series were held in San Diego (USA) 1987, Gut Ising (Germany) 1989, Abingdon (UK) 1991, Naka (Japan) 1993, Princeton (USA) 1995, Kloster Seeon (Germany) 1997, Oxford (UK) 1999, Toki (Japan) 2001, San Diego (USA) 2003, and St Petersburg (Russia) 2005. The purpose of the eleventh meeting was to present and discuss new results on H-mode (edge transport barrier, ETB) and internal transport barrier, ITB, experiments, theory and modeling in magnetic fusion research. It was expected that contributions give new and improved insights into the physics mechanisms behind high confinement modes of H-mode and ITBs. Ultimately, this research should lead to improved projections for ITER. As has been the tradition at the recent meetings of this series, the program was subdivided into six topics. The topics selected for the eleventh meeting were: H-mode transition and the pedestal-width Dynamics in ETB: ELM threshold, non-linear evolution and suppression, etc Transport relations of various quantities including turbulence in plasmas with ITB: rotation physics is especially highlighted Transport barriers in non-axisymmetric magnetic fields Theory and simulation on transport barriers Projections of transport barrier physics to ITER For each topic there was an invited talk presenting an overview of the topic, based on contributions to the meeting and on recently published external results. The six invited talks were: A Leonard (GA, USA): Progress in characterization of the H-mode pedestal and L-H transition N Oyama (JAEA, Japan): Progress and issues in

  4. Proteomic analysis of Ketogulonicigenium vulgare under glutathione reveals high demand for thiamin transport and antioxidant protection.

    Directory of Open Access Journals (Sweden)

    Qian Ma

    Full Text Available Ketogulonicigenium vulgare, though grows poorly when mono-cultured, has been widely used in the industrial production of the precursor of vitamin C with the coculture of Bacillus megaterium. Various efforts have been made to clarify the synergic pattern of this artificial microbial community and to improve the growth and production ability of K. vulgare, but there is still no sound explanation. In previous research, we found that the addition of reduced glutathione into K. vulgare monoculture could significantly improve its growth and productivity. By performing SEM and TEM, we observed that after adding GSH into K. vulgare monoculture, cells became about 4-6 folds elongated, and formed intracytoplasmic membranes (ICM. To explore the molecular mechanism and provide insights into the investigation of the synergic pattern of the co-culture system, we conducted a comparative iTRAQ-2-D-LC-MS/MS-based proteomic analysis of K. vulgare grown under reduced glutathione. Principal component analysis of proteomic data showed that after the addition of glutathione, proteins for thiamin/thiamin pyrophosphate (TPP transport, glutathione transport and the maintenance of membrane integrity, together with several membrane-bound dehydrogenases had significant up-regulation. Besides, several proteins participating in the pentose phosphate pathway and tricarboxylic acid cycle were also up-regulated. Additionally, proteins combating intracellular reactive oxygen species were also up-regulated, which similarly occurred in K. vulgare when the co-cultured B. megaterium cells lysed from our former research results. This study reveals the demand for transmembrane transport of substrates, especially thiamin, and the demand for antioxidant protection of K. vulgare.

  5. Transport Calculations for the reference configuration under neutral bean injection in TJ-II

    International Nuclear Information System (INIS)

    Guasp, J.; Castejon, F.; Liniers, M.

    1999-01-01

    Transport calculations for the Reference Configuration under Neutral Beam Injection in TJ-II are discussed. For all these analysis the Transport Code PROCTR has been used but, in reason of the complex geometry of TJ-II, some modifications to the code have been needed, not only for the absorption, losses and deposition radial profile evaluations, but also for the treatment of the transition between ECRH and NBI or the fit of Transport Coefficients to the different Scaling Laws. The attained centralβ values for high density ( central value around 11 x 10''13 cm''3), in steady, range between a minimum of 1.9% for the GRB law up to 3.6% or 4.2% for those laws that show an explicit dependence with the rotational transform (ISS and LGS), with an intermediate value of 2.8% for the LHD case. Global energy confinement times range between 3.9 and 8.8 ms for the two extreme cases and 5.6 ms for LHD. As well ions as electrons are clearly in the plateau regime, in contrast to the ECRH phase where the electrons are well inside the 1/ν regime, dominated by helical ripple effects. The effect of impurities is to decrease slightly the absorption and the attainable β levels, but only for Zeff values higher than 4 this degradation becomes important. For the stationary state the density remains always below the semiempirical limit, independently of the Zeff value. Even along the first stages of injection, where absorption can be rather low, the limit is not reached, at least for Zeff < 4, so that radioactive collapse along this critical phase should not to be expected. (Author) 14 refs

  6. Mechanisms underlying food-drug interactions: inhibition of intestinal metabolism and transport.

    Science.gov (United States)

    Won, Christina S; Oberlies, Nicholas H; Paine, Mary F

    2012-11-01

    Food-drug interaction studies are critical to evaluate appropriate dosing, timing, and formulation of new drug candidates. These interactions often reflect prandial-associated changes in the extent and/or rate of systemic drug exposure. Physiologic and physicochemical mechanisms underlying food effects on drug disposition are well-characterized. However, biochemical mechanisms involving drug metabolizing enzymes and transport proteins remain underexplored. Several plant-derived beverages have been shown to modulate enzymes and transporters in the intestine, leading to altered pharmacokinetic (PK) and potentially negative pharmacodynamic (PD) outcomes. Commonly consumed fruit juices, teas, and alcoholic drinks contain phytochemicals that inhibit intestinal cytochrome P450 and phase II conjugation enzymes, as well as uptake and efflux transport proteins. Whereas myriad phytochemicals have been shown to inhibit these processes in vitro, translation to the clinic has been deemed insignificant or undetermined. An overlooked prerequisite for elucidating food effects on drug PK is thorough knowledge of causative bioactive ingredients. Substantial variability in bioactive ingredient composition and activity of a given dietary substance poses a challenge in conducting robust food-drug interaction studies. This confounding factor can be addressed by identifying and characterizing specific components, which could be used as marker compounds to improve clinical trial design and quantitatively predict food effects. Interpretation and integration of data from in vitro, in vivo, and in silico studies require collaborative expertise from multiple disciplines, from botany to clinical pharmacology (i.e., plant to patient). Development of more systematic methods and guidelines is needed to address the general lack of information on examining drug-dietary substance interactions prospectively. Copyright © 2012 Elsevier Inc. All rights reserved.

  7. Physical Modelling of Bucket Foundation Under Long-Term Cyclic Lateral Loading

    DEFF Research Database (Denmark)

    Foglia, Aligi; Ibsen, Lars Bo; Andersen, Lars Vabbersgaard

    2012-01-01

    functioning. In this article a 1g physical model of bucket foundation under horizontal and moment cyclic loading is described. A testing program including four tests was carried out. Every test was conducted for at least 30000 cycles, each with different loading features. The capability of the model...

  8. Analysis of EBR-II neutron and photon physics by multidimensional transport-theory techniques

    International Nuclear Information System (INIS)

    Jacqmin, R.P.; Finck, P.J.; Palmiotti, G.

    1994-01-01

    This paper contains a review of the challenges specific to the EBR-II core physics, a description of the methods and techniques which have been developed for addressing these challenges, and the results of some validation studies relative to power-distribution calculations. Numerical tests have shown that the VARIANT nodal code yields eigenvalue and power predictions as accurate as finite difference and discrete ordinates transport codes, at a small fraction of the cost. Comparisons with continuous-energy Monte Carlo results have proven that the errors introduced by the use of the diffusion-theory approximation in the collapsing procedure to obtain broad-group cross sections, kerma factors, and photon-production matrices, have a small impact on the EBR-II neutron/photon power distribution

  9. Silicon nanopore membrane (SNM) for islet encapsulation and immunoisolation under convective transport

    Science.gov (United States)

    Song, Shang; Faleo, Gaetano; Yeung, Raymond; Kant, Rishi; Posselt, Andrew M; Desai, Tejal A; Tang, Qizhi; Roy, Shuvo

    2016-01-01

    Problems associated with islet transplantation for Type 1 Diabetes (T1D) such as shortage of donor cells, use of immunosuppressive drugs remain as major challenges. Immune isolation using encapsulation may circumvent the use of immunosuppressants and prolong the longevity of transplanted islets. The encapsulating membrane must block the passage of host’s immune components while providing sufficient exchange of glucose, insulin and other small molecules. We report the development and characterization of a new generation of semipermeable ultrafiltration membrane, the silicon nanopore membrane (SNM), designed with approximately 7 nm-wide slit-pores to provide middle molecule selectivity by limiting passage of pro-inflammatory cytokines. Moreover, the use of convective transport with a pressure differential across the SNM overcomes the mass transfer limitations associated with diffusion through nanometer-scale pores. The SNM exhibited a hydraulic permeability of 130 ml/hr/m2/mmHg, which is more than 3 fold greater than existing polymer membranes. Analysis of sieving coefficients revealed 80% reduction in cytokines passage through SNM under convective transport. SNM protected encapsulated islets from infiltrating cytokines and retained islet viability over 6 hours and remained responsive to changes in glucose levels unlike non-encapsulated controls. Together, these data demonstrate the novel membrane exhibiting unprecedented hydraulic permeability and immune-protection for islet transplantation therapy. PMID:27009429

  10. Quadrupole beam-transport experiment for heavy ions under extreme space charge conditions

    International Nuclear Information System (INIS)

    Chupp, W.; Faltens, A.; Hartwig, E.C.

    1983-03-01

    A Cs ion-beam-transport experiment is in progress to study beam behavior under extreme space-charge conditions. A five-lens section matches the beam into a periodic electrostatic quadrupole FODO channel and its behavior is found to agree with predictions. With the available parameters (less than or equal to 200 keV, less than or equal to 20 mA, πepsilon/sub n/ greater than or equal to 10 - 7 π rad-m, up to 41 periods) the transverse (betatron) occillation frequency (nu) can be depressed down to one-tenth of its zero current value (nu/sub 0/), where nu/sup 2/ = nu/sub 0//sup 2/ -#betta#/sub p/ 2 /2, and #betta#/sub p/ is the beam plasma frequency. The current can be controlled by adjustment of the gun and the emittance can be controlled independently by means of a set of charged grids

  11. A numerical study of the nanoribbon field-effect transistors under the ballistic and dissipative transport

    Science.gov (United States)

    Ghoreishi, Seyed Saleh; Yousefi, Reza; Saghafi, Kamyar; Aderang, Habib

    2017-08-01

    In this article, a detailed performance comparison is made between ballistic and dissipative quantum transport of metal oxide semicondutor-like graphene nanoribbon field-effect transistor, in ON and OFF-state conditions. By the self-consistent mode-space non-equilibrium Green's function approach, inter- and intraband scattering is accounted and the role of acoustic and optical phonon scattering on the performance of the devices is evaluated. We found that in this structure the dominant mechanism of scattering changes according to the ranges of voltage bias. Under large biasing conditions, the influence of optical phonon scattering becomes important. Also, the ambipolar and OFF-current are impressed by the phonon-assisted band-to-band tunneling and increased considerably compared to the ballistic conditions, although sub-threshold swing degrades due to optical phonon scattering.

  12. Electronic transport in Thue-Morse gapped graphene superlattice under applied bias

    Science.gov (United States)

    Wang, Mingjing; Zhang, Hongmei; Liu, De

    2018-04-01

    We investigate theoretically the electronic transport properties of Thue-Morse gapped graphene superlattice under an applied electric field. The results indicate that the combined effect of the band gap and the applied bias breaks the angular symmetry of the transmission coefficient. The zero-averaged wave-number gap can be greatly modulated by the band gap and the applied bias, but its position is robust against change of the band gap. Moreover, the conductance and the Fano factor are strongly dependent not only on the Fermi energy but also on the band gap and the applied bias. In the vicinity of the new Dirac point, the minimum value of the conductance obviously decreases and the Fano factor gradually forms a Poissonian value plateau with increasing of the band gap.

  13. Crystal growth of ZnSe and related ternary compound semiconductors by physical vapor transport

    Science.gov (United States)

    Su, Ching-Hua

    1993-01-01

    The materials to be investigated are ZnSe and related ternary semiconducting alloys (e.g., ZnS(x)Se(1-x), ZnTe(x)Se(1-x), and Zn(1-x)Cd(x)Se). These materials are useful for opto-electronic applications such as high efficient light emitting diodes and low power threshold and high temperature lasers in the blue-green region of the visible spectrum. The recent demonstration of its optical bistable properties also makes ZnSe a possible candidate material for digital optical computers. The investigation consists of an extensive ground-based study followed by flight experimentation, and involves both experimental and theoretical work. The objectives of the ground-based work are to establish the characteristics of the crystals grown on Earth as a basis for subsequent comparative evaluations of the crystals grown in a low gravity environment and to obtain the experimental data and perform the analyses required to define the optimum parameters for the flight experiments. During the six months of the Preliminary Definition Phase, the research efforts were concentrated on the binary compound ZnSe - the purification of starting materials of Se by zone refining, the synthesis of ZnSe starting materials, the heat treatments of the starting materials, the vapor transport rate measurements, the vapor partial pressure measurements of ZnSe, the crystal growth of ZnSe by physical vapor transport, and various characterization on the grown ZnSe crystals.

  14. Proposal for guidelines for the physical protection of nuclear materials, plants and transports in Denmark

    International Nuclear Information System (INIS)

    1978-03-01

    The guidelines are based on recommendations in the IAEA's ''Physical Protection of Nuclear Material,'' INFCIRC/225/rev.1. In accordance with practice in other countries, the guidelines give more detailed requirements for the protection of reactor plants than those given in the IAEA's present recommendations, which put more emphasis on the protection of nuclear materials. The measures to be taken for nuclear plants, or nuclear transports, are proposed made to fit the potential risk that the more closely defined actions imply. It is suggested that the more detailed rules for the scope of the protection of plants or materials should be laid down by the National Agency on the basis of recommendations made by the Inspectorate of Nuclear Installations, which in turn are based on the safety documentation of the plant/material owners. It is further proposed that the National Agency, again on a recommendation from the Inspectorate, should lay down more detailed guidelines for the reporting of changes in stocks or transports of nuclear materials. (author)

  15. Physical properties evaluation of roselle extract-egg white mixture under various drying temperatures

    Science.gov (United States)

    Triyastuti, M. S.; Kumoro, A. C.; Djaeni, M.

    2017-03-01

    Roselle contains anthocyanin that is potential for food colorant. Occasionally, roselle extract is provided in dry powder prepared under high temperature. In this case, the anthocyanin color degrades due to the intervention of heat. The foammat drying with egg white is a potential method to speed up the drying process as well as minimize color degradation. This research aims to study the physical properties of roselle extract under foam mat drying. As indicators, the powder size and color intensity were observed. The result showed that at high temperatures, roselle powder under foam mat drying has the fine size with porous structure. However, at the higher the drying temperature the color retention decreased.

  16. Biogeochemical Processes Responsible for the Enhanced Transport of Plutonium Under transient Unsaturated Ground Water Conditions

    Energy Technology Data Exchange (ETDEWEB)

    Fred J. Molz, III

    2010-05-28

    to Pu uptake by corn roots and xylem transport. Plants were started in wet paper wrapped around each corn seed. When the tap roots were sufficiently long, the seedlings were transplanted to a soil container with the tap root extending out the container bottom. The soil container was then placed over a nutrient solution container, and the solution served as an additional medium for root growth. To conduct an uptake study, a radioactive substance, such as Pu complexed with the bacterial siderophore DFOB, was added to the nutrient solution. After a suitable elapsed time, the corn plant was sacrificed, cut into 10 cm lengths, and the activity distribution measured. Experimental results clarified the basic nature of Pu uptake and transport in corn plants, and resulting simulations suggested that each growing season Pu in the SRS lysimeters would move into the plant shoots and be deposited on the soil surface during the Fall dieback. Subsequent isotope ratio analyses showed that this did happen. OVERALL RESULTS AND CONCLUSIONS - (1) Pu transport downward from the source is controlled by advection, dispersion and adsorption, along with surface-mediated REDOX reactions. (2) Hysteresis, extreme root distribution functions, air-content dependent oxidation rate constants, and large evaporation rates from the soil surface were not able to explain the observed upward migration of Pu. (3) Small amounts of Pu uptake by plant roots and translocation in the transpiration stream creates a realistic mechanism for upward Pu migration (4) Realistic xylem cross-sectional areas imply high flow velocities under hot, wet conditions. Such flow velocities produce the correct shape for the observed activity distributions in the top 20 cm of the lysimeter soil. (5) Simulations imply that Pu should have moved into the above-ground grass tissue each year during the duration of the experiments, resulting in an activity residual accumulating on the soil surface. An isotope ratio analysis showed that

  17. Biogeochemical Processes Responsible for the Enhanced Transport of Plutonium Under transient Unsaturated Ground Water Conditions

    International Nuclear Information System (INIS)

    Molz, Fred J. III

    2010-01-01

    to Pu uptake by corn roots and xylem transport. Plants were started in wet paper wrapped around each corn seed. When the tap roots were sufficiently long, the seedlings were transplanted to a soil container with the tap root extending out the container bottom. The soil container was then placed over a nutrient solution container, and the solution served as an additional medium for root growth. To conduct an uptake study, a radioactive substance, such as Pu complexed with the bacterial siderophore DFOB, was added to the nutrient solution. After a suitable elapsed time, the corn plant was sacrificed, cut into 10 cm lengths, and the activity distribution measured. Experimental results clarified the basic nature of Pu uptake and transport in corn plants, and resulting simulations suggested that each growing season Pu in the SRS lysimeters would move into the plant shoots and be deposited on the soil surface during the Fall dieback. Subsequent isotope ratio analyses showed that this did happen. OVERALL RESULTS AND CONCLUSIONS - (1) Pu transport downward from the source is controlled by advection, dispersion and adsorption, along with surface-mediated REDOX reactions. (2) Hysteresis, extreme root distribution functions, air-content dependent oxidation rate constants, and large evaporation rates from the soil surface were not able to explain the observed upward migration of Pu. (3) Small amounts of Pu uptake by plant roots and translocation in the transpiration stream creates a realistic mechanism for upward Pu migration (4) Realistic xylem cross-sectional areas imply high flow velocities under hot, wet conditions. Such flow velocities produce the correct shape for the observed activity distributions in the top 20 cm of the lysimeter soil. (5) Simulations imply that Pu should have moved into the above-ground grass tissue each year during the duration of the experiments, resulting in an activity residual accumulating on the soil surface. An isotope ratio analysis showed that

  18. 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.)

  19. Biogeochemical Attributes That Affect the Fate and Transport of Military Relevant Contaminants Under Freeze-thaw Conditions

    Science.gov (United States)

    LeMonte, J.; Price, C. L.; Seiter, J.; Crocker, F. H.; Douglas, T.; Chappell, M. A.

    2017-12-01

    The roles and missions that the U.S. Department of Defense (DoD) undertakes in the Arctic are being reshaped by significant changes in the operational environment as a result of rising global temperatures and increased development of the vast training ranges available in Alaska. The Arctic is warming faster than any other region on Earth resulting in changing seasonality and precipitation patterns that, in turn, are leading to alterations in above ground vegetation, permafrost stability and summer sea ice extent. Collectively, these poorly defined ecosystem changes play critical roles in affecting the transport and eventual fate of persistent military relevant contaminants through unique Arctic and Subarctic terrestrial environments. As a result, management of military contaminants in a changing Arctic represents a unique and potentially significant liability to the Army and the DoD. The United States footprint in the Arctic region falls within the state of Alaska and U.S. Army Alaska manages 10% of all active Army training lands worldwide, which cover nearly 2,500 square miles in total land area. Primary recalcitrant contaminants of concern at active training ranges and at legacy sites include energetics (i.e. RDX and 2,4-dinitrotoluene) and heavy metals (i.e. antimony and lead). Through a series of field sampling and laboratory experiments, the objectives of this work are to: 1) quantify soil biogeochemical attributes that effect the physical fate and transport of military relevant contaminants in Arctic and subarctic soils under freeze-thaw conditions with a focus on near surface processes, and 2) quantify microbial diversity in Arctic and subarctic soils and the environmental constraints on community activity while exploring the effects of amendments on community function as they relate to contaminant transformation.

  20. Growth of ZnO crystals by vapour transport: Some ways to act on physical properties

    Energy Technology Data Exchange (ETDEWEB)

    Tena-Zaera, R.; Martinez-Tomas, C.; Munoz-Sanjose, V. [Dept. Fisica Aplicada i Electromagnetisme, Universitat de Valencia, C/ Dr. Moliner 50, 46100 Burjassot (Spain); Gomez-Garcia, C.J. [Instituto de Ciencia Molecular, Universitat de Valencia, C/ Dr. Moliner 50, 46100 Burjassot (Spain)

    2006-08-15

    Nowadays, the growth of ZnO by vapor transport in silica ampoules is generally made in presence of graphite. As it has been already shown, this means that the growth process is carried out in presence of a Zn excess. In order to control that and act, as a consequence, on the physical properties of crystals we have performed a systematic study of the growth process in a wide range of Zn excess compositions using well defined experimental conditions. As a preliminary characterization, optical absorption and electrical properties have been analyzed at room temperature. The results show how some physical properties of as-grown ZnO crystals can be changed in a controlled way by an adequate combination of different growth conditions such as graphite covering of inner ampoule walls, thermal difference between source material and crystallization zone and additional gas (composition and pressure). In this frame some post-growth annealing processes can be avoided reducing the time and cost of processes. (copyright 2006 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  1. Physical activity at home, at leisure, during transportation and at work in French adults with type 2 diabetes: the ENTRED physical activity study.

    Science.gov (United States)

    Cloix, L; Caille, A; Helmer, C; Bourdel-Marchasson, I; Fagot-Campagna, A; Fournier, C; Lecomte, P; Oppert, J M; Jacobi, D

    2015-02-01

    Our study assessed the distribution of physical activity during various typical tasks of daily life in adults with type 2 diabetes (T2D), a population typified by low physical activity. We investigated the duration and intensity of physical activity in four domains (work, leisure, transportation and domestic), and how individual determinants might influence the repartition. The long-form International Physical Activity Questionnaire (IPAQ) was administered to participants from the échantillon national témoin représentatif des personnes diabétiques (ENTRED), a study of French adults with T2D (n=724, 65% men, age 62±10y, BMI 29±5kg.m(-2), HbA1c 7.1±1.1%), and the associations between sociodemographic/clinical characteristics and categories of physical activity intensity (low, moderate or high) were examined by logistic regression. The median total physical activity was 2079 [Q1=893, Q3=3915]MET-min·week(-1). The main contributors to total physical activity were domestic chores, followed by leisure-time activities and transportation (median: 630, 347 and 198MET-min·week(-1), respectively). Absence of cardiovascular complications (OR=1.87, 95% CI=1.01-3.47), agephysical activity. In all patient subgroups (defined by category of physical activity intensity or stratified by determinants of physical activity level), domestic chores were always the main contributor to total physical activity (Pphysical activity. This emphasizes the vast potential for promoting voluntary leisure-time physical activity in this population. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  2. Learning Physics-based Models in Hydrology under the Framework of Generative Adversarial Networks

    Science.gov (United States)

    Karpatne, A.; Kumar, V.

    2017-12-01

    Generative adversarial networks (GANs), that have been highly successful in a number of applications involving large volumes of labeled and unlabeled data such as computer vision, offer huge potential for modeling the dynamics of physical processes that have been traditionally studied using simulations of physics-based models. While conventional physics-based models use labeled samples of input/output variables for model calibration (estimating the right parametric forms of relationships between variables) or data assimilation (identifying the most likely sequence of system states in dynamical systems), there is a greater opportunity to explore the full power of machine learning (ML) methods (e.g, GANs) for studying physical processes currently suffering from large knowledge gaps, e.g. ground-water flow. However, success in this endeavor requires a principled way of combining the strengths of ML methods with physics-based numerical models that are founded on a wealth of scientific knowledge. This is especially important in scientific domains like hydrology where the number of data samples is small (relative to Internet-scale applications such as image recognition where machine learning methods has found great success), and the physical relationships are complex (high-dimensional) and non-stationary. We will present a series of methods for guiding the learning of GANs using physics-based models, e.g., by using the outputs of physics-based models as input data to the generator-learner framework, and by using physics-based models as generators trained using validation data in the adversarial learning framework. These methods are being developed under the broad paradigm of theory-guided data science that we are developing to integrate scientific knowledge with data science methods for accelerating scientific discovery.

  3. Transport properties of Lu.sub.2./sub.Fe.sub.17./sub. single crystals under extreme conditions

    Czech Academy of Sciences Publication Activity Database

    Skorokhod, Yuriy; Arnold, Zdeněk; Kamarád, Jiří; Andreev, Alexander V.

    2004-01-01

    Roč. 11, č. 3 (2004), s. 471-475 ISSN 1027-5495 R&D Projects: GA ČR(CZ) GA106/02/0943 Institutional research plan: CEZ:AV0Z1010914 Keywords : transport properties * magnetotransport properties * pressure effect * single crystals * intermetallic compounds Subject RIV: BM - Solid Matter Physics ; Magnetism

  4. Strontium and caesium transport in unsaturated soil from Chernobyl Pilot Site under steady flow conditions; Transfert de radioelements en zone non saturee. Etude experimentale et modelisation appliquees au Site Pilote de Tchernobyl

    Energy Technology Data Exchange (ETDEWEB)

    Szenknect, St

    2003-10-15

    This work is devoted to the quantification and the identification of the predominant processes involved in strontium and caesium transport in unsaturated soil from Chernobyl Pilot Site under steady flow conditions. The transport and fate of radionuclides in the subsurface is affected by various physical and chemical processes including advective and diffusive transport as well as chemical and biological transformations. Laboratory experiments and the use of a multiple tracer approach allow to isolate the contributions of each elementary process and to control the physico-chemical conditions in the system. To be more representative of the field conditions, we decided to perform column miscible displacement experiments. We perform batch and flow-through reactor experiments to characterize the radionuclides sorption mechanisms. Miscible displacement experiments within homogeneous columns and modeling allow to characterize the hydrodynamic properties of the soil and to describe the radionuclides behaviour under dynamic conditions at different water contents. We show that the water content of porous media affect the transport behaviour of inert and strongly sorbing radionuclides. Our results demonstrate that a parametrized transport model that was calibrated under completely saturated conditions was not able to describe the advective-dispersive transport of reactive solutes under unsaturated steady state conditions. Under our experimental conditions, there is no effect of a decrease of the mean water content on the sorption model parameters, but the transport parameters are modified. We established for the studied soil the relation between hydrodynamic dispersion and water content and the relation between pore water velocity and water content. (author)

  5. Disorder effects on helical edge transport in graphene under a strong tilted magnetic field

    Science.gov (United States)

    Huang, Chunli; Cazalilla, Miguel A.

    2015-10-01

    In a recent experiment, Young et al. [Nature (London) 505, 528 (2014), 10.1038/nature12800] observed a metal to insulator transition as well as transport through helical edge states in monolayer graphene under a strong, tilted magnetic field. Under such conditions, the bulk is a magnetic insulator which can exhibit metallic conduction through helical edges. It was found that the two-terminal conductance of the helical channels deviates from the expected quantized value (=e2/h per edge, at zero temperature). Motivated by this observation, we study the effect of disorder on the conduction through the edge channels. We show that, unlike for helical edges of topological insulators in semiconducting quantum wells, a disorder Rashba spin-orbit coupling does not lead to backscattering, at least to leading order. Instead, we find that the lack of perfect antialignment of the electron spins in the helical channels to be the most likely cause for backscattering arising from scalar (i.e., spin-independent) impurities. The intrinsic spin-orbit coupling and other time-reversal symmetry-breaking and/or sublattice parity-breaking potentials also lead to (subleading) corrections to the channel conductance.

  6. [Comparative analysis of the physical status of students living under different conditions of environmental pollution].

    Science.gov (United States)

    Musalimova, R S; Valiakhmetov, R M

    2010-01-01

    The physical status was comparatively studied in students living under different conditions of environmental pollution. The anthropometric and some physiometric (vital capacity) parameters were established to be lower in students from polluted areas than in those from relatively pure ones. The students from polluted areas were observed to have higher hemodynamic parameters (heart rate, stroke volume, cardiac output). The results of the study improve and supplement knowledge of the physical development of the students living in the areas with varying environmental pollution levels and reflect the morphofunctional status that is an indicator in the evaluation of the body's functional tension, which may suggest the suppressing action of environmental pollution on the students' body.

  7. Denaturation of collagen structures and their transformation under the physical and chemical effects

    Science.gov (United States)

    Ivankin, A.; Boldirev, V.; Fadeev, G.; Baburina, M.; Kulikovskii, A.; Vostrikova, N.

    2017-11-01

    The process of denaturation of collagen structures under the influence of physical and chemical factors play an important role in the manufacture of food technology and the production of drugs for medicine and cosmetology. The paper discussed the problem of the combined effects of heat treatment, mechanical dispersion and ultrasonic action on the structural changes of the animal collagen in the presence of weak protonated organic acids. Algorithm combined effects of physical and chemical factors as a result of the formation of the technological properties of products containing collagen has been shown.

  8. Silicon Transporters and Effects of Silicon Amendments in Strawberry under High Tunnel and Field Conditions

    Directory of Open Access Journals (Sweden)

    Samuel Ouellette

    2017-06-01

    Full Text Available Together with longer production periods, the commercial transition to day-neutral strawberry (Fragaria × ananassa varieties has favored the development of diseases such as powdery mildew (Podosphaera aphanis that thrives in late summer-early fall. In an attempt to find alternative solutions to fungicides currently employed to curb the disease, we wanted to investigate the potential of silicon (Si amendments that have been associated with prophylactic properties against powdery mildews. To this end, our first objective was to determine if strawberry was a Si-competent species following the recent characterization of the properties of Si transporters that plants must carry to uptake silicic acid. Based on genomic data, we were able to conclude that strawberry contained both functional influx (Lsi1 and efflux (Lsi2 transporters for Si uptake. Subsequently commercial experiments under high tunnel and field conditions were conducted with different Si fertilization regimes: constant soluble Si feeding in high tunnel, and bi-weekly soluble Si feeding or three concentrations of calcium silicate fertilization in the field. Results from high tunnel experiments showed that strawberry could accumulate as much as 3% Si on a dry-weight basis, the highest concentration ever reported for this species. All six tested cultivars contained roughly the same concentration, thereby confirming the limited genetic variability, also observed in other species, associated with the trait. Silicon fertilization under high tunnel led to a significant reduction of powdery mildew severity in both years and on all cultivars, and a significant increase in yield of marketable fruits reaching as much as 300% with cv. Monterey. By contrast, Si fertilization under field conditions in soils deficient in plant available Si, either in soluble or solid form, did not result in significant accumulation of Si in plants, regardless of the cultivars, year or concentrations. Our results have

  9. Renal excretion of water in men under hypokinesia and physical exercise with fluid and salt supplementation

    Science.gov (United States)

    Zorbas, Yan G.; Federenko, Youri F.; Togawa, Mitsui N.

    It has been suggested that under hypokinesia (reduced number of steps/day) and intensive physical exercise, the intensification of fluid excretion in men is apparently caused as a result of the inability of the body to retain optimum amounts of water. Thus, to evaluate this hypothesis, studies were performed with the use of fluid and sodium chloride (NaCl) supplements on 12 highly trained physically healthy male volunteers aged 19-24 years under 364 days of hypokinesis (HK) and a set of intensive physical exercises (PE). They were divided into two groups with 6 volunteers per group. The first group of subjects were submitted to HK and took daily fluid and salt supplements in very small doses and the second group of volunteers were subjected to intensive PE and fluid-salt supplements. For the simulation of the hypokinetic effect, both groups of subjects were kept under an average of 4000 steps/day. During the prehypokinetic period of 60 days and under the hypokinetic period of 364 days water consumed and eliminated in urine by the men, water content in blood, plasma volume, rate of glomerular filtration, renal blood flow, osmotic concentration of urine and blood were measured. Under HK, the rate of renal excretion of water increased considerably in both groups. The additional fluid and salt intake failed to normalize water balance adequately under HK and PE. It was concluded that negative water balance evidently resulted not from shortage of water in the diet but from the inability of the body to retain optimum amounts of fluid under HK and a set of intensive PEs.

  10. Predicting Nitrate Transport under Future Climate Scenarios beneath the Nebraska Management Systems Evaluation Area (MSEA) site

    Science.gov (United States)

    Li, Y.; Akbariyeh, S.; Gomez Peña, C. A.; Bartlet-Hunt, S.

    2017-12-01

    Understanding the impacts of future climate change on soil hydrological processes and solute transport is crucial to develop appropriate strategies to minimize adverse impacts of agricultural activities on groundwater quality. The goal of this work is to evaluate the direct effects of climate change on the fate and transport of nitrate beneath a center-pivot irrigated corn field in Nebraska Management Systems Evaluation Area (MSEA) site. Future groundwater recharge rate and actual evapotranspiration rate were predicted based on an inverse modeling approach using climate data generated by Weather Research and Forecasting (WRF) model under the RCP 8.5 scenario, which was downscaled from global CCSM4 model to a resolution of 24 by 24 km2. A groundwater flow model was first calibrated based on historical groundwater table measurement and was then applied to predict future groundwater table in the period 2057-2060. Finally, predicted future groundwater recharge rate, actual evapotranspiration rate, and groundwater level, together with future precipitation data from WRF, were used in a three-dimensional (3D) model, which was validated based on rich historic data set collected from 1993-1996, to predict nitrate concentration in soil and groundwater from the year 2057 to 2060. Future groundwater recharge was found to be decreasing in the study area compared to average groundwater recharge data from the literature. Correspondingly, groundwater elevation was predicted to decrease (1 to 2 ft) over the five years of simulation. Predicted higher transpiration data from climate model resulted in lower infiltration of nitrate concentration in subsurface within the root zone.

  11. A risk analysis for gas transport network planning expansion under regulatory uncertainty in Western Europe

    International Nuclear Information System (INIS)

    Pelletier, C.; Wortmann, J.C.

    2009-01-01

    The natural gas industry in Western Europe went through drastic changes induced by the unbundling of the national companies, followed by the liberalization of gas trade and the regulation of gas transmission. Natural gas transmission is operated through a network of interconnected grids, and is capacity constrained. Each of the grids is locally regulated in terms of price limits on transportation services. Local tariff differences may induce unnatural gas routing within a network, creating congestion in some part of it. This phenomena is referred to as the Jepma effect. Following Jepma [2001. Gaslevering onder druk. Stichting JIN. Available at: (www.jiqweb.org) (52pp) (in Dutch)] this may lead to misguided investment decisions. In this paper a multi-stage linear program is used to simulate the repartition of the natural gas flow in an interconnected grid system on a succession of contracting periods. By this simulation, the risk linked to infrastructure investment is assessed. The risk measured can be seen as the probability of a negative present net value for the investment. The model is applied on an example of two grids that are on alternative routes serving same destinations. When applied to a specific situation of North-West Europe (Germany and The Netherlands), the model clearly demonstrates that the risks turn out to be too high to invest: there are hardly any scenarios under which an acceptable ROI will be realized. Given the current tariff policy and current publicly available forecasts of demand and supply, it is unlikely that market forces will attract additional investments in transportation capacity. This reluctance to invest can be prohibitive for further growth of supply if the demand would increase significantly

  12. Safety Evaluation of Radioactive Material Transport Package under Stacking Test Condition

    International Nuclear Information System (INIS)

    Lee, Ju Chan; Seo, Ki Seog; Yoo, Seong Yeon

    2012-01-01

    Radioactive waste transport package was developed to transport eight drums of low and intermediate level waste(LILW) in accordance with the IAEA and domestic related regulations. The package is classified with industrial package IP-2. IP-2 package is required to undergo a free drop test and a stacking test. After free drop and stacking tests, it should prevent the loss or dispersal of radioactive contents, and loss of shielding integrity which would result in more than 20 % increase in the radiation level at any external surface of the package. The objective of this study is to establish the safety test method and procedure for stacking test and to prove the structural integrities of the IP-2 package. Stacking test and analysis were performed with a compressive load equal to five times the weight of the package for a period of 24 hours using a full scale model. Strains and displacements were measured at the corner fitting of the package during the stacking test. The measured strains and displacements were compared with the analysis results, and there were good agreements. It is very difficult to measure the deflection at the container base, so the maximum deflection of the container base was calculated by the analysis method. The maximum displacement at the corner fitting and deflection at the container base were less than their allowable values. Dimensions of the test model, thickness of shielding material and bolt torque were measured before and after the stacking test. Throughout the stacking test, it was found that there were no loss or dispersal of radioactive contents and no loss of shielding integrity. Thus, the package was shown to comply with the requirements to maintain structural integrity under the stacking condition.

  13. 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, Douglas; 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...

  14. Bengal Fan sediment transport activity and response to climate forcing inferred from sediment physical properties

    Science.gov (United States)

    Weber, M. E.; Wiedicke-Hombach, M.; Kudrass, H. R.; Erlenkeuser, H.

    2003-02-01

    We obtained sediment physical properties and geochemical data from 47 piston and gravity cores located in the Bay of Bengal, to study the complex history of the Late Pleistocene run-off from the Ganges and Brahmaputra rivers and its imprint on the Bengal Fan. Grain-size parameters were predicted from core logs of density and velocity to infer sediment transport energy and to distinguish different environments along the 3000-km-long transport path from the delta platform to the lower fan. On the shelf, 27 cores indicate rapidly prograding delta foresets today that contain primarily mud, whereas outer shelf sediment has 25% higher silt contents, indicative of stronger and more stable transport regime, which prevent deposition and expose a Late Pleistocene relic surface. Deposition is currently directed towards the shelf canyon 'Swatch of No Ground', where turbidites are released to the only channel-levee system that is active on the fan during the Holocene. Active growth of the channel-levee system occurred throughout sea-level rise and highstand with a distinct growth phase at the end of the Younger Dryas. Coarse-grained material bypasses the upper fan and upper parts of the middle fan, where particle flow is enhanced as a result of flow-restriction in well-defined channels. Sandier material is deposited mainly as sheet-flow deposits on turbidite-dominated plains at the lower fan. The currently most active part of the fan with 10-40-cm-thick turbidites is documented for the central channel including inner levees (e.g., site 40). Site 47 from the lower fan far to the east of the active channel-levee system indicates the end of turbidite sedimentation at 300 ka for that location. That time corresponds to the sea-level lowering during late isotopic stage 9 when sediment supply to the fan increased and led to channel avulsion farther upstream, probably indicating a close relation of climate variability and fan activity. Pelagic deep-sea sites 22 and 28 contain a 630

  15. Contribution of raindrop impact to the change of soil physical properties and water erosion under semi-arid rainfalls.

    Science.gov (United States)

    Vaezi, Ali Reza; Ahmadi, Morvarid; Cerdà, Artemi

    2017-04-01

    Soil erosion by water is a three-phase process that consists of detachment of soil particles from the soil mass, transportation of detached particles either by raindrop impact or surface water flow, and sedimentation. Detachment by raindrops is a key component of the soil erosion process. However, little information is available on the role of raindrop impact on soil losses in the semi-arid regions where vegetation cover is often poor and does not protect the soil from rainfall. The objective of this study is to determine the contribution of raindrop impact to changes in soil physical properties and soil losses in a semiarid weakly-aggregated agricultural soil. Soil losses were measured under simulated rainfalls of 10, 20, 30, 40, 50, 60 and 70mmh -1 , and under two conditions: i) with raindrop impact; and, ii) without raindrop impact. Three replications at each rainfall intensity and condition resulted in a total of 42 microplots of 1m×1.4m installed on a 10% slope according to a randomized complete block design. The contribution of raindrop impact to soil loss was computed using the difference between soil loss with raindrop impact and without raindrop impact at each rainfall intensity. Soil physical properties (aggregate size, bulk density and infiltration rate) were strongly damaged by raindrop impact as rainfall intensity increased. Soil loss was significantly affected by rainfall intensity under both soil surface conditions. The contribution of raindrop impact to soil loss decreased steadily with increasing rainfall intensity. At the lower rainfall intensities (20-30mmh -1 ), raindrop impact was the dominant factor controlling soil loss from the plots (68%) while at the higher rainfall intensities (40-70mmh -1 ) soil loss was mostly affected by increasing runoff discharge. At higher rainfall intensities the sheet flow protected the soil from raindrop impact. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Electronic transport in semiconductor nanowires: physics studies and possible device applications

    Science.gov (United States)

    Samuelson, Lars

    2007-03-01

    Semiconductor nanowires are attractive for physics as well as for applications due to the highly ideal character of their electronic and structural properties. We grow our III-V nanowires by what can be described as guided self-assembly, by which we can accurately control location as well as dimensions of epitaxially nucleated nanowires. The level of control of growth allows controlled formation of axial as well as radial heterostructures. I will describe studies of charge transport via single, double and multiple quantum dots positioned inside InAs/InP nanowires. Such studies have allowed detailed studies of the addition of electrons one-by-one, from the very first electron into an empty quantum dot to the addition of up to 50 electrons. By replacing the one-dimensional emitter by a small quantum dot in a double-dot configuration, the discrete character of the injecting state allows ever more detailed spectroscopic studies of the charge additions to the second dot. Comparisons will be made with transport through quantum dots defined by tunnel barriers induced via gating techniques. Finally, a recently developed technique for the formation vertical wrap-gate field-effect transistors around InAs nanowires will be described, suggesting interesting opportunities for the realization of high-speed and low-power transistors and circuits. The geometrical design of such nanowire wrap-gate field-effect transistors, offers exciting ways of formation of ultra-short transistor gate-lengths as well as the use of heterostructures to further enhance the performance of such devices.

  17. Colloidal and physical transport textures exhibited by electrum and naumannite in bonanza epithermal veins from western USA, and their significance

    Science.gov (United States)

    Saunders, James A.; Vikre, Peter G.; Unger, Derick L.; Beasley, Lee

    2010-01-01

    It is reasonably clear that disequilibrium or “far-from equilibrium” conditions lead to the formation of silica colloids and their deposition in many epithermal deposits. This implies ore-forming solutions had elevated concentrations of dissolved silica, well in excess of amorphous silica saturation. We have previously demonstrated that such colloidal silica particles were deposited in epithermal veins as silica gels and opal, which may later progress along a path to crystallize into more thermodynamically favored (less-soluble) silica phases such as quartz and chalcedony. Also, in some deposits, amorphous silica is co-deposited with precious-metal minerals, such as electrum in the banded super-bonanza ores of the Sleeper deposit (NV). Ore-mineral textures from some western USA bonanza epithermal ores indicate that two precious-metal phases (electrum and naumannite, Ag2Se) form colloidal particles that are transported by ore-forming fluids and are deposited either by aggregation (by sticking to other precious metal-particles) to make dendrites, or are deposited on the “lee” side of protrusion along vein walls (or perhaps by both processes). We can infer by analogy to silica that this also implies that ore-forming solutions contained elevated (supersaturated) dissolved concentrations of both gold and silver that formed colloidal particles under disequilibrium (often chaotic) conditions. Thus physical transport and deposition textures seem to indicate the presence of strongly precious-metal-enriched ore forming fluids, which led to (not surprisingly) the bonanza grades of these remarkable ores. What causes such a precious-metal-rich solution is debatable, but that is the subject of our continued investigations.

  18. Expression of genes involved in fatty acid transport and insulin signaling is altered by physical inactivity and exercise training in human skeletal muscle.

    Science.gov (United States)

    Lammers, Gerwen; Poelkens, Fleur; van Duijnhoven, Noortje T L; Pardoel, Elisabeth M; Hoenderop, Joost G; Thijssen, Dick H J; Hopman, Maria T E

    2012-11-15

    Physical deconditioning is associated with the development of chronic diseases, including type 2 diabetes and cardiovascular disease. Exercise training effectively counteracts these developments, but the underlying mechanisms are largely unknown. To gain more insight into these mechanisms, muscular gene expression levels were assessed after physical deconditioning and after exercise training of the lower limbs in humans by use of gene expression microarrays. To exclude systemic effects, we used human models for local physical inactivity (3 wk of unilateral limb suspension) and for local exercise training (6 wk of functional electrical stimulation exercise of the extremely deconditioned legs of individuals with a spinal cord injury). The most interesting subset of genes, those downregulated after deconditioning as well as upregulated after exercise training, contained 18 genes related to both the "insulin action" and "adipocytokine signaling" pathway. Of these genes, the three with strongest up/downregulation were the muscular fatty acid-binding protein-3 (FABP3), the fatty acid oxidizing enzyme hydroxyacyl-CoA dehydrogenase (HADH), and the mitochondrial fatty acid transporter solute carrier 25 family member A20 (SLC25A20). The expression levels of these genes were confirmed using RT-qPCR. The results of the present study indicate an important role for a decreased transport and metabolism of fatty acids, which provides a link between physical activity levels and insulin signaling.

  19. Soil physical and microbiological attributes cultivated with the common bean under two management systems

    Directory of Open Access Journals (Sweden)

    Lorena Adriana De Gennaro

    Full Text Available Agricultural management systems can alter the physical and biological soil quality, interfering with crop development. The objective of this study was to evaluate the physical and microbiological attributes of a Red Latosol, and its relationship to the biometric parameters of the common bean (Phaseolus vulgaris, irrigated and grown under two management systems (conventional tillage and direct seeding, in Campinas in the state of São Paulo, Brazil. The experimental design was of randomised blocks, with a split-plot arrangement for the management system and soil depth, analysed during the 2006/7 and 2007/8 harvest seasons, with 4 replications. The soil physical and microbiological attributes were evaluated at depths of 0.00-0.05, 0.05-0.10, 0.10-0.20 and 0.20-0.40 m. The following were determined for the crop: density, number of pods per plant, number of beans per pod, thousand seed weight, total weight of the shoots and harvest index. Direct seeding resulted in a lower soil physical quality at a depth of 0.00-0.05 m compared to conventional tillage, while the opposite occurred at a depth of 0.05-0.10 m. The direct seeding showed higher soil biological quality, mainly indicated by the microbial biomass nitrogen, basal respiration and metabolic quotient. The biometric parameters in the bean were higher under the direct seeding compared to conventional tillage.

  20. Colloid-Facilitated Transport of Cations in an Unsaturated Fractured Soil Under Transient Conditions

    Energy Technology Data Exchange (ETDEWEB)

    Ryan, Joseph [Univ. of Colorado, Boulder, CO (United States)

    2015-01-31

    Rainfall experiments were conducted using intact soil cores and an instrumented soil pedon to examine the effect of physical heterogeneity and rainfall characteristics on the mobilization of colloids, organic matter, cesium, and strontium in a fractured soil. To measure the spatial variability of infiltration of colloids and contaminants, samples were collected through a 19-port grid placed below the soil core in laboratory study and in 27 samplers at multiple depths in the soil pedon in the field study. Cesium and strontium were applied to the soil cores and the soil pedon prior to mobilization experiments. Rainwater solutions of multiple ionic strengths and organic matter concentrations were applied to the soil cores and soil pedon to mobilize in situ colloids, cesium, and strontium. The mobilization of colloids and metal cations occurred through preferential flow paths in the soil cores. Compared to steady rainfall, greater amounts of colloids were mobilized during rainfall interrupted by pauses, which indicates that the supply of colloids to be mobilized was replenished during the pauses. A maximum in the amount of mobilized colloids were mobilized during a rainfall following a pause of 2.5 d. Pauses of shorter or longer duration resulted in less colloid mobilization. Freeze-thaw cycles, a transient condition in winter, enhanced colloid mobilization and colloid-facilitated transport of cesium and strontium in the soil cores. The exchange of solutes between the soil matrix and macropores caused a hysteretic mobilization of colloids, cesium, and strontium during changes in ionic strength. Colloid-facilitated mobilization of cesium and strontium was important at low ionic strength in fractures where slow flow allowed greater exchange of flow between the fractures and the surrounding matrix. The release of cesium and strontium by cation exchange occurred at high ionic strength in fractures where there is a little exchange of pore water with the surrounding matrix

  1. Climate change and larval transport in the ocean: fractional effects from physical and physiological factors.

    Science.gov (United States)

    Kendall, Matthew S; Poti, Matt; Karnauskas, Kristopher B

    2016-04-01

    Changes in larval import, export, and self-seeding will affect the resilience of coral reef ecosystems. Climate change will alter the ocean currents that transport larvae and also increase sea surface temperatures (SST), hastening development, and shortening larval durations. Here, we use transport simulations to estimate future larval connectivity due to: (1) physical transport of larvae from altered circulation alone, and (2) the combined effects of altered currents plus physiological response to warming. Virtual larvae from islands throughout Micronesia were moved according to present-day and future ocean circulation models. The Hybrid Coordinate Ocean Model (HYCOM) spanning 2004-2012 represented present-day currents. For future currents, we altered HYCOM using analysis from the National Center for Atmospheric Research Community Earth System Model, version 1-Biogeochemistry, Representative Concentration Pathway 8.5 experiment. Based on the NCAR model, regional SST is estimated to rise 2.74 °C which corresponds to a ~17% decline in larval duration for some taxa. This reduction was the basis for a separate set of simulations. Results predict an increase in self-seeding in 100 years such that 62-76% of islands experienced increased self-seeding, there was an average domainwide increase of ~1-3% points in self-seeding, and increases of up to 25% points for several individual islands. When changed currents alone were considered, approximately half (i.e., random) of all island pairs experienced decreased connectivity but when reduced PLD was added as an effect, ~65% of connections were weakened. Orientation of archipelagos relative to currents determined the directional bias in connectivity changes. There was no universal relationship between climate change and connectivity applicable to all taxa and settings. Islands that presently export large numbers of larvae but that also maintain or enhance this role into the future should be the focus of conservation

  2. Cycling and walking for transport: Estimating net health effects from comparison of different transport mode users' self-reported physical activity.

    Science.gov (United States)

    Veisten, Knut; Flügel, Stefan; Ramjerdi, Farideh; Minken, Harald

    2011-07-20

    There is comprehensive evidence of the positive health effects of physical activity, and transport authorities can enable this by developing infrastructure for cycling and walking. In particular, cycling to work or to school can be a relatively high intensity activity that by itself might suffice for maximum health gain. In this paper, we present estimates of net health effects that can be assumed for demand responses to infrastructure development. The estimation was based on comparing current cyclists/pedestrians against potential cyclists/pedestrians, applying the international physical activity questionnaire, which is a survey-based method for estimating metabolic equivalent task levels from self-reported types of physical activity, and their frequency, duration and level of intensity (moderate or vigorous).. By comparing between shares of individuals with medium or high intensity levels, within the segments of current cyclists/pedestrians and potential cyclists/pedestrians, we estimate the possible net health effects of potential new users of improved cycling/walking infrastructure. For an underpinning of the estimates, we also include the respondents' assessments of the extent to which cycling/walking for transport replaces other physical activity, and we carry out a regression of cycling/walking activity levels on individual characteristics and cycle/walk facility features. The estimated share of new regular cyclists obtaining net health gains was ca. 30%, while for new regular pedestrians this was only ca. 15%. These estimates are based on the assumption that the new users of improved cycle/walk facilities are best represented by self-declared potential users of such improved facilities. For potential cyclists/pedestrians, exercise was stated as the main motivation for physical active transport, but among current regular cyclists "fast and flexible" was just as important as exercising. Measured intensity levels from physically active transport increased with

  3. The implications of megatrends in information and communication technology and transportation for changes in global physical activity

    DEFF Research Database (Denmark)

    Pratt, Michael; Sarmiento, Olga L; Montes, Felipe

    2012-01-01

    Physical inactivity accounts for more than 3 million deaths per year, most from non-communicable diseases in low-income and middle-income countries. We used reviews of physical activity interventions and a simulation model to examine how megatrends in information and communication technology...... and transportation directly and indirectly aff ect levels of physical activity across countries of low, middle, and high income. The model suggested that the direct and potentiating eff ects of information and communication technology, especially mobile phones, are nearly equal in magnitude to the mean eff ects...

  4. Particle Tracking Model for Suspended Sediment Transport and Streambed Clogging Under Losing and Gaining Conditions

    Science.gov (United States)

    Preziosi-Ribero, A.; Fox, A.; Packman, A. I.; Escobar-Vargas, J.; Donado-Garzon, L. D.; Li, A.; Arnon, S.

    2017-12-01

    Exchange of mass, momentum and energy between surface water and groundwater is a driving factor for the biology, ecology and chemistry of rivers and water bodies in general. Nonetheless, this exchange is dominated by different factors like topography, bed morphology, and large-scale hydraulic gradient. In the particular case of fine sediments like clay, conservative tracer modeling is impossible because they are trapped in river beds for long periods, thus the normal advection dispersion approach leads to errors and results do not agree with reality. This study proposes a numerical particle tracking model that represents the behavior of kaolinite in a sand flume, and how its deposition varies according to different flow conditions, namely losing and gaining flow. Since fine particles do not behave like solutes, kaolinite dynamics are represented using settling velocity and a filtration coefficient allowing the particles to be trapped in the bed. This approach allows us to use measurable parameters directly related with the fine particle features as size and shape, and hydraulic parameters. Results are then compared with experimental results from lab experiments obtained in a recirculating flume, in order to assess the impact of losing and gaining conditions on sediment transport and deposition. Furthermore, our model is able to identify the zones where kaolinite deposition concentrates over the flume due to the bed geometry, and later relate these results with clogging of the bed and hence changes in the bed's hydraulic conductivity. Our results suggest that kaolinite deposition is higher under losing conditions since the vertical velocity of the flow is added to the deposition velocity of the particles modeled. Moreover, the zones where kaolinite concentrates varies under different flow conditions due to the difference in pressure and velocity in the river bed.

  5. The buckling of fuel rods in transportation casks under hypothetical accident conditions

    International Nuclear Information System (INIS)

    Bjorkman, G.S.

    2004-01-01

    The buckling analysis of fuel rods during an end drop impact of a spent fuel transportation cask has traditionally been performed to demonstrate the structural integrity of the fuel rod cladding or the integrity of the fuel geometry in criticality evaluations following a cask drop event. The actual calculation of the fuel rod buckling load, however, has been the subject of some controversy, with estimates of the critical buckling load differing by as much as a factor of 5. Typically, in the buckling analysis of a fuel rod, assumptions are made regarding the percentage of fuel mass that is bonded to or participates with the cladding during the buckling process, with estimates ranging from 0 to 100%. The greater the percentage of fuel mass that is assumed to be bonded to the cladding the higher the inertia loads on the cladding, and, therefore, the lower the ''g'' value at which buckling occurs. Current published solutions do not consider displacement compatibility between the fuel and the cladding. By invoking displacement compatibility between the fuel column and the cladding column, this paper presents an exact solution for the buckling of fuel rods under inertia loading. The results show that the critical inertia load magnitude for the buckling of a fuel rod depends on the weight of the cladding and the total weight of the fuel, regardless of the percentage of fuel mass that is assumed to be attached to or participate with the cladding in the buckling process. Therefore, 100% of the fuel always participates in the buckling of a fuel rod under inertia loading

  6. Percolation and transport in a sandy soil under a natural hydraulic gradient

    Science.gov (United States)

    Green, C.T.; Stonestrom, David A.; Bekins, B.A.; Akstin, K.C.; Schulz, M.S.

    2005-01-01

    [1] Unsaturated flow and transport under a natural hydraulic gradient in a Mediterranean climate were investigated with a field tracer experiment combined with laboratory analyses and numerical modeling. Bromide was applied to the surface of a sandy soil during the dry season. During the subsequent rainy season, repeated sediment sampling tracked the movement of bromide through the profile. Analysis of data on moisture content, matric pressure, unsaturated hydraulic conductivity, bulk density, and soil texture and structure provides insights into parameterization and use of the advective-dispersive modeling approach. Capturing the gross features of tracer and moisture movement with model simulations required an order-of-magnitude increase in laboratory-measured hydraulic conductivity. Wetting curve characteristics better represented field results, calling into question the routine estimation of hydraulic characteristics based only on drying conditions. Measured increases in profile moisture exceeded cumulative precipitation in early winter, indicating that gains from dew drip can exceed losses from evapotranspiration during periods of heavy ("Tule") fog. A single-continuum advective-dispersive modeling approach could not reproduce a peak of bromide that was retained near the soil surface for over 3 years. Modeling of this feature required slow exchange of solute at a transfer rate of 0.5-1 ?? 10-4 d-1 with an immobile volume approaching the residual moisture content.

  7. Carbohydrate production and transport in cotton cultivars grown under boron deficiency

    Directory of Open Access Journals (Sweden)

    Julio Cesar Bogiani

    2013-12-01

    Full Text Available An adequate supply of boron (B is required for the optimal growth and development of cotton (Gossypium hirsutum L. plants, but the low phloem mobility of B limits the possibilities of correcting B deficiency. There are indications that different cotton cultivars could have different responses to B deficiency. The differences in responses of cotton cultivars to B regarding photoassimilate production and transport were studied in a greenhouse experiment with nutrient solution. Treatments consisted of three cotton cultivars (FMT 701, DP 604BG and FMX 993 and five concentrations of B (0.0, 2.5, 5.0, 10.0 and 20.0 µmol L−1. Sampling began at the phenological stage B1 (first square and continued for four weeks. The leaf area and the number of reproductive branches and structures decreased due to B deficiency. A higher level of abortion of reproductive structures was observed under B deficiency. Boron deficiency increased the internal CO2 concentration but decreased the transpiration rate, stomatal conductance and photosynthesis. Despite the decrease in photosynthesis, nonstructural carbohydrates accumulated in the leaves due to decreased export to bolls in B-deficient plants. The response to B deficiency is similar among cotton cultivars, which shows that the variability for this trait is low even for cultivars with different genetic backgrounds.

  8. Optimization of the transporting beam for the CMS Barrel under a displacement constraint

    CERN Document Server

    AUTHOR|(CDS)2139604; Spadinger, Markus

    The aim of this research was to find the optimal solution for the design of the new transporting beam for the Compact Muon Solenoid (CMS) Barrel. Once the new crane in the experimental cavern is installed, the previous design of the beam will become obsolete due to its weight. The current beam is made from steel and has four air-pads to support it. The new design of the beam, which will be presented in this thesis, will be made of aluminium alloy and will have only two air-pads supporting it. Two main issues that guided the direction of this research were the concentrations of stresses and the displacements due to bending. At the beginning of the research, all of the focus will be on the beam. This approach will prove to be limited, which will lead to the gradual inclusion of other interfacing components in the analysis. In order to correctly mimic the behaviour of the beam under such loads, representative models of the air-pads will be introduced into the Finite Element Analysis (FEA). Part of the original B...

  9. Experimental and Numerical Investigations of Silver Nanoparticle Transport under Variable Flow and Ionic Strength in Soil.

    Science.gov (United States)

    Makselon, Joanna; Zhou, Dan; Engelhardt, Irina; Jacques, Diederik; Klumpp, Erwin

    2017-02-21

    Unsaturated column experiments were conducted with an undisturbed loamy sand soil to investigate the influence of flow interruption (FI) and ionic strength (IS) on the transport and retention of surfactant-stabilized silver nanoparticles (AgNP) and the results were compared to those obtained under continuous flow conditions. AgNP concentrations for breakthrough curves (BTCs) and retention profiles (RPs) were analyzed by ICP-MS. Experimental results were simulated by the numerical code HP1 (Hydrus-PhreeqC) with the DLVO theory, extended colloid filtration theory and colloid release model. BTCs of AgNP showed a dramatic drop after FI compared to continuous flow conditions. Evaporation increased due to FI, resulting in increased electrical conductivity of the soil solution, which led to a totally reduced mobility of AgNP. A reduction of IS after FI enhanced AgNP mobility slightly. Here the strongly increased Al and Fe concentration in the effluent suggested that soil colloids facilitated the release of AgNP (cotransport). The numerical model reproduced the measured AgNP BTCs and indicated that attachment to the air-water interface (AWI) occurring during FI was the key process for AgNP retention.

  10. Solute and colloid transport in karst conduits under low- and high-flow conditions.

    Science.gov (United States)

    Göppert, Nadine; Goldscheider, Nico

    2008-01-01

    Solute and colloid transport in karst aquifers under low and high flows was investigated by tracer tests using fluorescent dyes (uranine) and microspheres of the size of pathogenic bacteria (1 microm) and Cryptosporidium cysts (5 microm), which were injected into a cave stream and sampled at a spring 2.5 km away. The two types of microspheres were analyzed using an epifluorescence microscope or a novel fluorescence particle counter, respectively. Uranine breakthrough curves (BTCs) were regular shaped and recovery approached 100%. Microsphere recoveries ranged between 27% and 75%. During low flow, the 1-microm spheres displayed an irregular BTC preceding the uranine peak. Only a very few 5-microm spheres were recovered. During high flow, the 1-microm-sphere BTC was regular and more similar to the uranine curve. BTCs were modeled analytically with CXTFIT using a conventional advection dispersion model (ADM) and a two-region nonequilibrium model (2RNE). The results show that (1) colloids travel at higher velocities than solutes during low flow; (2) colloids and solutes travel at similar velocities during high flow; (3) higher maximum concentrations occur during high flow; and (4) the 2RNE achieves a better fit, while the ADM is more robust, as it requires less parameters.

  11. First-principles calculation of transport property in nano-devices under an external magnetic field

    International Nuclear Information System (INIS)

    Chen Jingzhe; Zhang Jin; Han Rushan

    2008-01-01

    The mesoscopic quantum interference phenomenon (QIP) can be observed and behaves as the oscillation of conductance in nano-devices when the external magnetic field changes. Excluding the factor of impurities or defects, specific QIP is determined by the sample geometry. We have improved a first-principles method based on the matrix Green's function and the density functional theory to simulate the transport behaviour of such systems under a magnetic field. We have studied two kinds of QIP: universal conductance fluctuation (UCF) and Aharonov–Bohm effect (A–B effect). We find that the amplitude of UCF is much smaller than the previous theoretical prediction. We have discussed the origin of difference and concluded that due to the failure of ergodic hypothesis, the ensemble statistics is not applicable, and the conductance fluctuation is determined by the flux-dependent density of states (DOSs). We have also studied the relation between the UCF and the structure of sample. For a specific structure, an atomic circle, the A–B effect is observed and the origin of the oscillation is also discussed

  12. Electrical characterization of 6H-SiC grown by physical vapor transport method

    Energy Technology Data Exchange (ETDEWEB)

    Zaremba, G., E-mail: gzaremba@ite.waw.p [Institute of Electron Technology, Department of Analysis of Semiconductor Nanostructures, Al. Lotnikow 32/46, 02-668 Warsaw (Poland); Kaniewska, M.; Jung, W. [Institute of Electron Technology, Department of Analysis of Semiconductor Nanostructures, Al. Lotnikow 32/46, 02-668 Warsaw (Poland); Guziewicz, M. [Institute of Electron Technology, Department of Semiconductor Processing for Photonics, Al. Lotnikow 32/46, 02-668 Warsaw (Poland); Grasza, K. [Institute of Physics, Polish Academy of Sciences, Al. Lotnikow 32/46, 02-668 Warsaw (Poland); Institute of Electronic Materials Technology, ul. Wolczynska 133, 01-919 Warsaw (Poland)

    2009-11-25

    Deep level transient spectroscopy (DLTS) and capacitance versus voltage (C-V) measurements have been used to study the electrical properties of electron traps in n-type 6H-silicon carbide (SiC) grown by physical vapor transport (PVT) technique, designed as Schottky diodes. Ir Schottky- and Ni ohmic-contacts were deposited by sputtering. Current versus voltage (I-V) measurements showed that sputter deposition of the Schottky contact yields diodes with a reduced barrier height and poor rectification characteristics. Four main electron traps revealed in DLTS spectra have activation energies at 0. 39, 0.41, 0,66, and 0.74 eV below the conduction band. Based on a comparison made with electron traps reported in the literature, we conclude that three of them are well-known traps found in the as-grown or irradiated material. There was no emission signature in the literature to make such a correspondence for the trap at 0.74 eV. Strongly nonhomogenous spatial distribution with a tendency of the trap to accumulation at the surface was found by DLTS and C-V profiling. This together with the fact that the trap at 0.74 eV has not been previously reported in as-grown or processed material makes it possible that the trap is sputter deposition induced defect.

  13. Purification and Crystal Growth of Lead Iodide by Physical Vapor Transport Method

    Science.gov (United States)

    Wright, G. W.; Cole, M.; Chen, Y.-F.; Chen, K.-T.; Chen, H.; Chattopadhyay, K.; Burger, A.

    1998-01-01

    Lead iodide (PbI2) is a layered compound semiconductor being developed as room temperature x- and gamma-ray detector. Compared to the more studied material, mercuric iodide, PbI2 has a higher melting temperature and no phase transition until liquid phase which are indications of better mechanical properties. In this study, the source material was purified by the zone-refining process, and the purest section was extracted from center of the the zone-refined ingot to be grown by physical vapor transport (PVT) method. The zone-refined material and as-grown crystals were characterized by optical microscopy and differential scanning calorimetry (DSC) to reveal the surface morphology, purity and stoichiometry. The results shows that both materials are near-stoichiometric composition, with the purity of the as-grown crystals higher than zone-refined materials. The resistivity of the as-grown crystal (10" Omega-cm) was derived from current-voltage (I-V) measurement, and is 10 times higher than the zone-refined materials. Detail results will be presented and discussed.

  14. Formation and development of a breaker bar under regular waves. Part 2: Sediment transport and morphology

    DEFF Research Database (Denmark)

    Jacobsen, Niels Gjøl; Fredsøe, Jørgen

    2014-01-01

    In Part 2 of this work, the hydrodynamic model described in Part 1 is applied for the simulation of sediment transport and the associated morphological development of breaker bars. The sediment description is split into bed load and suspended load, and like the hydrodynamics the sediment transport...... is phase-resolved in order to get on- and offshore directed contributions to the sediment transport from phase lags between the suspended sediment and the hydrodynamics.First, the sediment transport over a morphologically fixed bed of a constant slope is considered, and the transport rates are discussed......) is discussed relative to the reference simulation.The coupling between sediment transport rate and morphology is analysed and discussed. © 2014 Elsevier B.V....

  15. Mineralization of human bone tissue under hypokinesia and physical exercise with calcium supplements

    Science.gov (United States)

    Zorbas, Yan G.; Verentsov, Grigori E.; Abratov, Nikolai I.

    It has been suggested that physical exercise and calcium supplements may be used to prevent demineralization of bone tissue under hypokinesia (diminished muscular activity). Thus, the aim of this study was to determine mineral content of bones of 12 physically healthy men aged 19-24 years under 90 days of hypokinesia and intensive physical exercise (PE) with calcium lactate (C) supplements. They were divided into experimental and control groups with 6 men in each. The experimental group of men were subjected to hypokinesia (HK) and intensive PE and took 650 mg C 6 times per day; the control group was placed under pure HK, i.e. without the use of any preventive measures. The mineral content of different bone tissues was measured with a densitometric X-ray method in milligrams of calcium per 1 mm 3 before and after exposure to HK. The level of bone density of the examined bone tissues decreased by 7-9% and 5-7% for the control and experimental groups of men, respectively. A statistical analysis revealed that the reduction of bone mineralization was significant with P physical exercise with calcium supplements. Experimental studies of hypokinetic physiology are generally based on the assumption that diminished muscular activity (progressive reduction of number of steps per day) is detrimental to animal and human organisms, since the entire animal kingdom had been formed in an environment of high motor activity which left its imprint on the evolution, structure, function and behaviour of animals and men. The impossibility of the body tissues to retain optimum amounts of fluid and electrolytes is the dominant hypokinetic effect.

  16. Suitability of Commercial Transport Media for Biological Pathogens under Nonideal Conditions

    Science.gov (United States)

    2011-01-01

    water and was made in-house. For the liquid transport media, one milliliter of each was added to sterile transport tubes containing a sponge (kindly...for microorganisms capable of sporulation in nutrient-poor transport media. Unfortunately, if a sample slowly converts from the vegetative to the...Efficient methods for large-area surface sampling of sites contaminated with pathogenic microorgan - isms and other hazardous agents: current state, needs

  17. Transport Sector CO(2) Emissions Growth in Asia : Underlying Factors and Policy Options

    OpenAIRE

    Timilsina, G. R.; Shrestha, A.

    2009-01-01

    This study analyze the potential factors influencing the growth of transport sector carbon dioxide (CO(2)) emissions in selected Asian countries during the 1980-2005 period by decomposing annual emissions growth into components representing changes in fuel mix, modal shift, per capita gross domestic product (GDP) and population, as well as changes in emission coefficients and transportation energy intensity. We find that changes in per capita GDP, population growth and transportation energy i...

  18. Transport sector CO2 emissions growth in Asia: Underlying factors and policy options

    International Nuclear Information System (INIS)

    Timilsina, Govinda R.; Shrestha, Ashish

    2009-01-01

    This study analyze the potential factors influencing the growth of transport sector carbon dioxide (CO 2 ) emissions in selected Asian countries during the 1980-2005 period by decomposing annual emissions growth into components representing changes in fuel mix, modal shift, per capita gross domestic product (GDP) and population, as well as changes in emission coefficients and transportation energy intensity. We find that changes in per capita GDP, population growth and transportation energy intensity are the main factors driving transport sector CO 2 emission growth in the countries considered. While growth in per capita income and population are responsible for the increasing trend of transport sector CO 2 emissions in China, India, Indonesia, Republic of Korea, Malaysia, Pakistan, Sri Lanka and Thailand; the decline of transportation energy intensity is driving CO 2 emissions down in Mongolia. Per capita GDP, population and transportation energy intensity effects are all found responsible for transport sector CO 2 emissions growth in Bangladesh, the Philippines and Vietnam. The study also reviews existing government policies to limit CO 2 emissions growth, such as fiscal instruments, fuel economy standards and policies to encourage switching to less emission intensive fuels and transportation modes.

  19. Regulation of ethanol intake under chronic mild stress: roles of dopamine receptors and transporters

    Science.gov (United States)

    Delis, Foteini; Rombola, Christina; Bellezza, Robert; Rosko, Lauren; Grandy, David K.; Volkow, Nora D.; Thanos, Panayotis K.

    2015-01-01

    Studies have shown that exposure to chronic mild stress decreases ethanol intake and preference in dopamine D2 receptor wild-type mice (Drd2+/+), while it increases intake in heterozygous (Drd2+/−) and knockout (Drd2−/−) mice. Dopaminergic neurotransmission in the basal forebrain plays a major role in the reinforcing actions of ethanol as well as in brain responses to stress. In order to identify neurochemical changes associated with the regulation of ethanol intake, we used in vitro receptor autoradiography to measure the levels and distribution of dopamine D1 and D2 receptors and dopamine transporters (DAT). Receptor levels were measured in the basal forebrain of Drd2+/+, Drd2+/−, and Drd2−/− mice belonging to one of four groups: control (C), ethanol intake (E), chronic mild stress exposure (S), and ethanol intake under chronic mild stress (ES). D2 receptor levels were higher in the lateral and medial striatum of Drd2+/+ ES mice, compared with Drd2+/+ E mice. Ethanol intake in Drd2+/+ mice was negatively correlated with striatal D2 receptor levels. D2 receptor levels in Drd2+/− mice were the same among the four treatment groups. DAT levels were lower in Drd2+/− C and Drd2−/− C mice, compared with Drd2+/+ C mice. Among Drd2+/− mice, S and ES groups had higher DAT levels compared with C and E groups in most regions examined. In Drd2−/− mice, ethanol intake was positively correlated with DAT levels in all regions studied. D1 receptor levels were lower in Drd2+/− and Drd2−/− mice, compared with Drd2+/+, in all regions examined and remained unaffected by all treatments. The results suggest that in normal mice, ethanol intake is associated with D2 receptor-mediated neurotransmission, which exerts a protective effect against ethanol overconsumption under stress. In mice with low Drd2 expression, where DRD2 levels are not further modulated, ethanol intake is associated with DAT function which is upregulated under stress leading to ethanol

  20. Advanced Monte Carlo for radiation physics, particle transport simulation and applications. Proceedings

    International Nuclear Information System (INIS)

    Kling, A.; Barao, F.J.C.; Nakagawa, M.; Tavora, L.

    2001-01-01

    The following topics were dealt with: Electron and photon interactions and transport mechanisms, random number generation, applications in medical physisc, microdosimetry, track structure, radiobiological modeling, Monte Carlo method in radiotherapy, dosimetry, and medical accelerator simulation, neutron transport, high-energy hadron transport. (HSI)

  1. Soil physical and hydrological properties under three biofuel crops in Ohio

    Energy Technology Data Exchange (ETDEWEB)

    Bonin, Catherine [Ohio State University; Lal, Dr. Rattan [Ohio State University; Schmitz, Matthias [Rheinsche Friedrich/Wilhelms Universitaet Boon; Wullschleger, Stan D [ORNL

    2012-01-01

    While biofuel crops are widely studied and compared for their energy and carbon footprints, less is known about their effects on other soil properties, particularly hydrologic characteristics. Soils under three biofuel crops, corn (Zea mays), switchgrass (Panicum virgatum), and willow (Salix spp.), were analyzed seven years after establishment to assess the effects on soil bulk density ({rho}{sub b}), penetration resistance (PR), water-holding capacity, and infiltration characteristics. The PR was the highest under corn, along with the lowest associated water content, while PR was 50-60% lower under switchgrass. In accordance with PR data, surface (0-10 cm) bulk density also tended to be lower under switchgrass. Both water infiltration rates and cumulative infiltration amounts varied widely among and within the three crops. Because the Philip model did not fit the data, results were analyzed using the Kostiakov model instead. Switchgrass plots had an average cumulative infiltration of 69 cm over 3 hours with a constant infiltration rate of 0.28 cm min{sup -1}, compared with 37 cm and 0.11 cm min{sup -1} for corn, and 26 cm and 0.06 cm min{sup -1} for willow, respectively. Results suggest that significant changes in soil physical and hydrologic properties may require more time to develop. Soils under switchgrass may have lower surface bulk density, higher field water capacity, and a more rapid water infiltration rate than those under corn or willow.

  2. Physical properties of a rhodic haplustox under two sugarcane harvesting systems

    Directory of Open Access Journals (Sweden)

    Walquíria Machado

    2010-12-01

    Full Text Available This study had the purpose of evaluating the effects of two management types of sugarcane: harvesting of burnt cane (BCH and mechanized harvesting of unburnt green cane (MCH, on some soil physical properties of a dystrophic Rhodic Haplustox. The data were then compared with results for the same soil type under native forest. A completely randomized design was used, with three treatments and 20 replications. The following characteristics were determined: organic matter, aggregate stability, soil bulk density, and porosity at depths of 0-0.20 m and soil penetration resistance. After 15 years of cultivation, there were some alterations in the soil under cane burnt before harvesting, evidenced by a drop in the weighted average diameter of stable aggregates in water and increased soil bulk density. Significant changes were also detected in total porosity and pore distribution under both harvesting systems. Critical values for penetration resistance were observed in the area under mechanized sugar cane harvesting, with a value of 4.5 MPa in the 40-55 cm layer. This value is considered high and could indicate compaction and restriction of root growth. Soil properties under the green cane (unburned management system were closest to those of the soil under native forest.

  3. Soil physical and hydrological properties under three biofuel crops in Ohio

    Energy Technology Data Exchange (ETDEWEB)

    Bonin, Catherine; Lal, Rattan [The Ohio State Univ., School of Environment and Natural Resources, Carbon Management and Sequestration Center, Columbus, OH (United States); Schmitz, Matthias [Rheinische Friedrich/Wilhelms-Universitaet Bonn, Steinmann Institut fuer Geologie, Mineralogie und Palaeontologie, Bonn (Germany); Wullschleger, S. [The Oakridge National Lab., Oakridge, TN (United States)

    2012-10-15

    While biofuel crops are widely studied and compared for their energy and carbon footprints, less is known about their effects on other soil properties, particularly hydrologic characteristics. Soils under three biofuel crops, corn (Zea mays), switchgrass (Panicum virgatum), and willow (Salix spp.), were analyzed seven years after establishment to assess the effects on soil bulk density ({rho}{sub b}), penetration resistance (PR), water-holding capacity, and infiltration characteristics. The PR was the highest under corn, along with the lowest associated water content, while PR was 50-60 % lower under switchgrass. In accordance with PR data, surface (0-10 cm) bulk density also tended to be lower under switchgrass. Both water infiltration rates and cumulative infiltration amounts varied widely among and within the three crops. Because the Philip model did not fit the data, results were analyzed using the Kostiakov model instead. Switchgrass plots had an average cumulative infiltration of 69 cm over 3 hours with a constant infiltration rate of 0.28 cm min{sup -1}, compared with 37 cm and 0.11 cm min{sup -1} for corn, and 26 cm and 0.06 cm min{sup -1} for willow, respectively. Results suggest that significant changes in soil physical and hydrologic properties may require more time to develop. Soils under switchgrass may have lower surface bulk density, higher field water capacity, and a more rapid water infiltration rate than those under corn or willow.

  4. Investigation of soil physical properties under Shorea peltata sym in Tengaroh Forest Reserve, Johor Bahru, Malaysia

    Directory of Open Access Journals (Sweden)

    Musalam Mohammed Abdalmoula

    2016-01-01

    Full Text Available Soil properties of tropical rain forest in Southeast Asia have been characterized by several researchers. However, empirical data on soil characteristics under rehabilitation program are still limited or even lacking. A study was conducted to characterize the soil physical properties under different densities of Shorea peltata species. The objective of the research was to determine the relationship between Shorea peltata species and soil physical properties. Twenty observational plots, 50 X 50 m namely, rare (A, low (B, moderate (C and high (D densities were established. Each plot was divided into 10 subplots. Five subplots were selected randomly. Soil samples were collected using auger at 0 - 15 cm, and core-ring at 0 - 10 cm depth. The results show that there was a significant difference among the groups. Analysis of the relationship between soil physical properties and site variables showed that moisture content, bulk density, particle density, silt and clay were the important factors in the distribution of Shorea peltata species in the study sites.

  5. Radial Continuous Time Random Walks for Non-Fickian Solute Transport under Forced Flow Conditions and Different Heterogeneity Scenarios

    Science.gov (United States)

    Dentz, Marco; Kang, Peter K.; Le Borgne, Tanguy

    2015-04-01

    Solute transport in heterogeneous porous media is characterized by features that do not conform to advection-dispersion models characterized by equivalent transport parameters. This has been observed in tracer experiments under forced and natural flow conditions. Key questions are (i) how non-Fickian solute transport can be quantified under radial flow conditions, and (ii) how different heterogeneity sources of non-Fickian behavior manifest in non-Fickian radial transport models. In order to approach these questions, we develop a radial continuous time random walk (CTRW) formulation for the quantification and interpretation of non-Fickian solute transport under forced flow conditions and different heterogeneity scenarios. The derived radial CTRW approaches model anomalous behavior induced by heterogeneous flow distributions and mobile-immobile mass transfer processes (matrix diffusion). We start by establishing a general CTRW framework in radial coordinates on the basis of the random walk equations for radial particle positions and times. The evolution of solute concentration is governed by a non-local radial advection-dispersion equation. Unlike in CTRWs for uniform flow scenarios, particle transition times here depend on the radial particle position, which renders the CTRW non-stationary. We then derive radial CTRW implementations that (i) emulate non-local radial transport due to heterogeneous advection, (ii) model multirate mass transfer (MRMT) between mobile and immobile continua, and (iii) quantify both heterogeneous advection in a mobile and mass transfer between mobile and immobile regions. We analyze the transport signatures for the distinct CTRW models in terms of solute breakthrough curves and their dependence on the heterogeneity scenarios.

  6. 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.)

  7. Transport of Silica Colloid through Saturated Porous Media under Different Hydrogeochemical and Hydrodynamic Conditions Considering Managed Aquifer Recharge

    OpenAIRE

    Zhuo Wang; Wenjing Zhang; Shuo Li; Jingjing Zhou; Dan Liu

    2016-01-01

    Colloids may have an important role in regulating the structure and function of groundwater ecosystems, and may influence the migration of low solubility contaminants in groundwater. There is, however, a degree of uncertainty about how colloids behave under the variable hydrogeochemical and hydrodynamic conditions that occur during managed aquifer recharge. We used an online monitoring system to monitor the transport of silica colloid in saturated porous media under different hydrogeochemical...

  8. Effects of heat and water transport on the performance of polymer electrolyte membrane fuel cell under high current density operation

    International Nuclear Information System (INIS)

    Tabuchi, Yuichiro; Shiomi, Takeshi; Aoki, Osamu; Kubo, Norio; Shinohara, Kazuhiko

    2010-01-01

    Key challenges to the acceptance of polymer electrolyte membrane fuel cells (PEMFCs) for automobiles are the cost reduction and improvement in its power density for compactness. In order to get the solution, the further improvement in a fuel cell performance is required. In particular, under higher current density operation, water and heat transport in PEMFCs has considerable effects on the cell performance. In this study, the impact of heat and water transport on the cell performance under high current density was investigated by experimental evaluation of liquid water distribution and numerical validation. Liquid water distribution in MEA between rib and channel area is evaluated by neutron radiography. In order to neglect the effect of liquid water in gas channels and reactant species concentration distribution in the flow direction, the differential cell was used in this study. Experimental results suggested that liquid water under the channel was dramatically changed with rib/channel width. From the numerical study, it is found that the change of liquid water distribution was significantly affected by temperature distribution in MEA between rib and channel area. In addition, not only heat transport but also water transport through the membrane also significantly affected the cell performance under high current density operation.

  9. Transportable activation facility for preparation of radioactive sodium under industrial conditions to study boreholes by isotope methods

    International Nuclear Information System (INIS)

    Kostin, Yu.I.; Zajchenkov, B.D.; Ibatullin, R.A.; Gulin, Yu.A.; Tugarinov, L.N.

    1981-01-01

    A method of short-living isotope production at the place their application is proposed. A transportable activation facility for the preparation of radioactive sodium under industrial conditions was developed to radioactive tracer logging. Facility specifications and its application results are given [ru

  10. Transportable activation facility for preparation of radioactive sodium under industrial conditions to study boreholes by isotope methods

    Energy Technology Data Exchange (ETDEWEB)

    Kostin, Yu.I.; Zajchenkov, B.D.; Ibatullin, R.A.; Gulin, Yu.A.; Tugarinov, L.N. (Vsesoyuznyj Nauchno-Issledovatel' skij i Proektno-Konstruktorskij Inst. Geofizicheskikh Issledovanij Geologorazvedochnykh Skvazhin, Oktyabr' skij (USSR))

    1981-01-01

    A method of short-living isotope production at the place their application is proposed. A transportable activation facility for the preparation of radioactive sodium under industrial conditions was developed to radioactive tracer logging. Facility specifications and its application results are given.

  11. Influence of physical and chemical dispersion on the biodegradation of oil under simulated marine conditions

    International Nuclear Information System (INIS)

    Swannell, R. P. J.; Daniel, F.; Croft, B. C.; Engelhardt, M. A.; Wilson, S.; Mitchell, D. J.; Lunel, T.

    1997-01-01

    Dispersion and biodegradation of oil was studied in marine microcosms designed to simulate oil dispersion at sea. Dispersion was studied using both Phase Doppler Particle Analyser and a Chamber Slide technique. In both natural and artificial seawater, oil addition was observed to encourage the growth of hydrocarbon-degrading bacteria in the presence of sufficient nitrogen and phosphorus. Results showed that microorganisms enhanced oil dispersion by colonizing physically-dispersed oil droplets and preventing re-coalescence with the surface slick. The addition of dispersants increased the rate of colonization as well as the number of degraded droplets. These results suggest that stimulation of physical dispersion by chemical means increase the rate of oil biodegradation under natural conditions. 25 refs., 3 tabs., 14 figs

  12. Serving the Reich the struggle for the soul of physics under Hitler

    CERN Document Server

    Ball, Philip

    2013-01-01

    Serving the Reich tells the story of physics under Hitler. While some scientists tried to create an Aryan physics that excluded any 'Jewish ideas', many others made compromises and concessions as they continued to work under the Nazi regime. Among them were three world-renowned physicists: Max Planck, pioneer of quantum theory, regarded it as his moral duty to carry on under the regime. Peter Debye, a Dutch physicist, rose to run the Reich's most important research institute before leaving for the United States in 1940. Werner Heisenberg, discovered the Uncertainty Principle, and became the leading figure in Germany's race for the atomic bomb. After the war most scientists in Germany maintained they had been apolitical or even resisted the regime: Debye claimed that he had gone to America to escape Nazi interference in his research; Heisenberg and others argued that they had deliberately delayed production of the atomic bomb. Mixing history, science and biography, Serving the Reich is a gripping exploration o...

  13. Ability of sat-1 to transport sulfate, bicarbonate, or oxalate under physiological conditions.

    Science.gov (United States)

    Krick, Wolfgang; Schnedler, Nina; Burckhardt, Gerhard; Burckhardt, Birgitta C

    2009-07-01

    Tubular reabsorption of sulfate is achieved by the sodium-dependent sulfate transporter, NaSi-1, located at the apical membrane, and the sulfate-anion exchanger, sat-1, located at the basolateral membrane. To delineate the physiological role of rat sat-1, [(35)S]sulfate and [(14)C]oxalate uptake into sat-1-expressing oocytes was determined under various experimental conditions. Influx of [(35)S]sulfate was inhibited by bicarbonate, thiosulfate, sulfite, and oxalate, but not by sulfamate and sulfide, in a competitive manner with K(i) values of 2.7 +/- 1.3 mM, 101.7 +/- 9.7 microM, 53.8 +/- 10.9 microM, and 63.5 +/- 38.7 microM, respectively. Vice versa, [(14)C]oxalate uptake was inhibited by sulfate with a K(i) of 85.9 +/- 9.5 microM. The competitive type of inhibition indicates that these compounds are most likely substrates of sat-1. Physiological plasma bicarbonate concentrations (25 mM) reduced sulfate and oxalate uptake by more than 75%. Simultaneous application of sulfate, bicarbonate, and oxalate abolished sulfate as well as oxalate uptake. These data and electrophysiological studies using a two-electrode voltage-clamp device provide evidence that sat-1 preferentially works as an electroneutral sulfate-bicarbonate or oxalate-bicarbonate exchanger. In kidney proximal tubule cells, sat-1 likely completes sulfate reabsorption from the ultrafiltrate across the basolateral membrane in exchange for bicarbonate. In hepatocytes, oxalate extrusion is most probably mediated either by an exchange for sulfate or bicarbonate.

  14. Used Nuclear Fuel Loading and Structural Performance Under Normal Conditions of Transport - Modeling, Simulation and Experimental Integration RD&D Plan

    Energy Technology Data Exchange (ETDEWEB)

    Adkins, Harold E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2013-04-01

    Under current U.S. Nuclear Regulatory Commission regulation, it is not sufficient for used nuclear fuel (UNF) to simply maintain its integrity during the storage period, it must maintain its integrity in such a way that it can withstand the physical forces of handling and transportation associated with restaging the fuel and moving it to treatment or recycling facilities, or a geologic repository. Hence it is necessary to understand the performance characteristics of aged UNF cladding and ancillary components under loadings stemming from transport initiatives. Researchers would like to demonstrate that enough information, including experimental support and modeling and simulation capabilities, exists to establish a preliminary determination of UNF structural performance under normal conditions of transport (NCT). This research, development and demonstration (RD&D) plan describes a methodology, including development and use of analytical models, to evaluate loading and associated mechanical responses of UNF rods and key structural components. This methodology will be used to provide a preliminary assessment of the performance characteristics of UNF cladding and ancillary components under rail-related NCT loading. The methodology couples modeling and simulation and experimental efforts currently under way within the Used Fuel Disposition Campaign (UFDC). The methodology will involve limited uncertainty quantification in the form of sensitivity evaluations focused around available fuel and ancillary fuel structure properties exclusively. The work includes collecting information via literature review, soliciting input/guidance from subject matter experts, performing computational analyses, planning experimental measurement and possible execution (depending on timing), and preparing a variety of supporting documents that will feed into and provide the basis for future initiatives. The methodology demonstration will focus on structural performance evaluation of

  15. Physics of non-diffusive turbulent transport of momentum and the origins of spontaneous rotation in tokamaks

    DEFF Research Database (Denmark)

    Diamond, P.H.; McDevitt, C.J.; Güran, Ö.D.

    2009-01-01

    Recent results in the theory of turbulent momentum transport and the origins of intrinsic rotation are summarized. Special attention is focused on aspects of momentum transport critical to intrinsic rotation, namely the residual stress and the edge toroidal flow velocity pinch. Novel results...... include a systematic decomposition of the physical processes which drive intrinsic rotation, a calculation of the critical external torque necessary to hold the plasma stationary against the intrinsic residual stress, a simple model of net velocity scaling which recovers the salient features...

  16. Uptake, transport and distribution of molybdenum in two oilseed rape (Brassica napus L.) cultivars under different nitrate/ammonium ratios.

    Science.gov (United States)

    Qin, Shi-Yu; Sun, Xue-Cheng; Hu, Cheng-Xiao; Tan, Qi-Ling; Zhao, Xiao-Hu

    2017-06-01

    To investigate the effects of different nitrate sources on the uptake, transport, and distribution of molybdenum (Mo) between two oilseed rape (Brassica napus L.) cultivars, L0917 and ZS11. A hydroponic culture experiment was conducted with four nitrate/ammonium (NO 3 - :NH 4 + ) ratios (14:1, 9:6, 7.5:7.5, and 1:14) at a constant nitrogen concentration of 15 mmol/L. We examined Mo concentrations in roots, shoots, xylem and phloem sap, and subcellular fractions of leaves to contrast Mo uptake, transport, and subcellular distribution between ZS11 and L0917. Both the cultivars showed maximum biomass and Mo accumulation at the 7.5:7.5 ratio of NO 3 - :NH 4 + while those were decreased by the 14:1 and 1:14 treatments. However, the percentages of root Mo (14.8% and 15.0% for L0917 and ZS11, respectively) were low under the 7.5:7.5 treatment, suggesting that the equal NO 3 - :NH 4 + ratio promoted Mo transportation from root to shoot. The xylem sap Mo concentration and phloem sap Mo accumulation of L0917 were lower than those of ZS11 under the 1:14 treatment, which suggests that higher NO 3 - :NH 4 + ratio was more beneficial for L0917. On the contrary, a lower NO 3 - :NH 4 + ratio was more beneficial for ZS11 to transport and remobilize Mo. Furthermore, the Mo concentrations of both the cultivars' leaf organelles were increased but the Mo accumulations of the cell wall and soluble fraction were reduced significantly under the 14:1 treatment, meaning that more Mo was accumulated in organelles under the highest NO 3 - :NH 4 + ratio. This investigation demonstrated that the capacities of Mo absorption, transportation and subcellular distribution play an important role in genotype-dependent differences in Mo accumulation under low or high NO 3 - :NH 4 + ratio conditions.

  17. Essential concepts and underlying theories from physics, chemistry, and mathematics for "biochemistry and molecular biology" majors.

    Science.gov (United States)

    Wright, Ann; Provost, Joseph; Roecklein-Canfield, Jennifer A; Bell, Ellis

    2013-01-01

    Over the past two years, through an NSF RCN UBE grant, the ASBMB has held regional workshops for faculty members from around the country. The workshops have focused on developing lists of Core Principles or Foundational Concepts in Biochemistry and Molecular Biology, a list of foundational skills, and foundational concepts from Physics, Chemistry, and Mathematics that all Biochemistry or Molecular Biology majors must understand to complete their major coursework. The allied fields working group created a survey to validate foundational concepts from Physics, Chemistry, and Mathematics identified from participant feedback at various workshops. One-hundred twenty participants responded to the survey and 68% of the respondents answered yes to the question: "We have identified the following as the core concepts and underlying theories from Physics, Chemistry, and Mathematics that Biochemistry majors or Molecular Biology majors need to understand after they complete their major courses: 1) mechanical concepts from Physics, 2) energy and thermodynamic concepts from Physics, 3) critical concepts of structure from chemistry, 4) critical concepts of reactions from Chemistry, and 5) essential Mathematics. In your opinion, is the above list complete?" Respondents also delineated subcategories they felt should be included in these broad categories. From the results of the survey and this analysis the allied fields working group constructed a consensus list of allied fields concepts, which will help inform Biochemistry and Molecular Biology educators when considering the ASBMB recommended curriculum for Biochemistry or Molecular Biology majors and in the development of appropriate assessment tools to gauge student understanding of how these concepts relate to biochemistry and molecular biology. © 2013 by The International Union of Biochemistry and Molecular Biology.

  18. Physical scale modeling of single free head piles under lateral loading in cohesive soils

    Directory of Open Access Journals (Sweden)

    Edgar Leonardo Salamanca-Medina

    2017-06-01

    Full Text Available This paper presents the results of the small scale modeling of free head wood piles under horizontal loading in cohesive soils, tested in order to compare the results with analytical models proposed by various authors. Characteristic Load (CLM and P-Y Curves methods were used for the prediction of lateral deflections at the head of the piles and the method proposed by Broms for estimating the ultimate lateral load. These predictions were compared with the results of the physical modeling, obtaining a good approximation between them.

  19. Rhabdomyolysis Occurring under Statins after Intense Physical Activity in a Marathon Runner

    Directory of Open Access Journals (Sweden)

    Éric Toussirot

    2015-01-01

    Full Text Available Statins are widely used in the treatment of hypercholesterolemia and their side effects on muscles are well established. Conversely, data are sparse regarding the safety of this class of drugs in subjects who engage in sports, particularly those who have intense sports activity. We report the case of a marathon runner who presented with acute rhabdomyolysis during competition while being under rosuvastatin treatment. This case raises the question of the need for temporary discontinuation of statin therapy when intense physical activity is planned.

  20. Thermo-Physical Properties of Ammonium Azide under High Pressure from First-Principles

    Science.gov (United States)

    Landerville, Aaron; Steele, Brad; Oleynik, Ivan

    2013-03-01

    Polynitrogen compounds offer tremendous promise for use as insensitive high-explosives or propellants. While the existence of such compounds have been observed in Diamond Anvil Cells (DAC) under high pressure, recovery to ambient pressure and temperature has proven problematic. A current thrust towards the recovery, and ultimate manufacture, of materials rich in polymeric nitrogen has brought renewed attention to various nitrogen-rich compounds, particularly crystalline azides, as possible precursors. We investigate the thermo-physical properties and Raman spectra of one azide candidate - ammonium azide - under hydrostatic compression using density functional theory with an empirical van der Waals correction. Additionally, we perform structural minima searches to discern possible polymorphs that may help to elucidate dynamical processes leading to the production of a material rich in polymeric nitrogen, as well as its recovery from DAC.

  1. Macrocrack propagation in concrete specimens under sustained loading: Study of the physical mechanisms

    International Nuclear Information System (INIS)

    Rossi, Pierre; Boulay, Claude; Tailhan, Jean-Louis; Martin, Eric; Desnoyers, Dominic

    2014-01-01

    This study presents a series of 4-point bending tests performed to describe the delayed behavior of unreinforced pre-cracked beams under low, moderate and high sustained loading levels. The deflection creep rate, the failure time and the load level were assessed. A linear relation, in a semi-log scale, was found for the deflection creep rate at high load levels. In addition, a linear relation, in a log–log scale, between the secondary deflection creep rate and failure time was observed. Besides, it was shown that the secondary creep deflection rate increases with the sustained loading level and the macrocrack propagation rate when macrocrack propagation occurs during the sustained loading. Physical mechanisms are proposed to explain these results and may be summarized as follows: the delayed behavior of an unreinforced cracked concrete specimen under sustained loading is mainly due to the cracking evolution, thus the creation of microcracks and/or the propagation of a macrocrack

  2. Presynaptic transporter-mediated release of glutamate evoked by the protonophore FCCP increases under altered gravity conditions

    Science.gov (United States)

    Borisova, T. A.; Krisanova, N. V.

    2008-12-01

    High-affinity Na +-dependent glutamate transporters of the plasma membrane mediate the glutamate uptake into neurons, and thus maintain low levels of extracellular glutamate in the synaptic cleft. The study focused on the release of glutamate by reversal of Na +-dependent glutamate transporters from rat brain nerve terminals (synaptosomes) under conditions of centrifuge-induced hypergravity. Flow cytometric analysis revealed similarity in the size and cytoplasmic granularity between synaptosomal preparations obtained from control and G-loaded animals (10 G, 1 h). The release of cytosolic L-[ 14C]glutamate from synaptosomes was evaluated using the protonophore FCCP, which dissipated synaptic vesicle proton gradient, thus synaptic vesicles were not able to keep glutamate inside and the latter enriched cytosol. FCCP per se induced the greater release of L-[ 14C]glutamate in hypergravity as compared to control (4.8 ± 1.0% and 8.0 ± 1.0% of total label). Exocytotic release of L-[ 14C]glutamate evoked by depolarization was reduced down to zero after FCCP application under both conditions studied. Depolarization stimulated release of cytosolic L-[ 14C]glutamate from synaptosomes preliminary treated with FCCP was considerably increased from 27.0 ± 2.2% of total label in control to 35.0 ± 2.3% in hypergravity. Non-transportable inhibitor of glutamate transporter DL-threo-β-benzyloxyaspartate was found to significantly inhibit high-KCl and FCCP-stimulated release of L-[ 14C]glutamate, confirming the release by reversal of glutamate transporters. The enhancement of transporter-mediated release of glutamate in hypergravity was found to result at least partially from the inhibition of the activity of Na/K-ATPase in the plasma membrane of synaptosomes. We suggested that hypergravity-induced alteration in transporter-mediated release of glutamate indicated hypoxic injury of neurons.

  3. Crystallization and Thermoelectric Transport in Semiconductor Micro- and Nanostructures Under Extreme Conditions

    Energy Technology Data Exchange (ETDEWEB)

    Gokirmak, Ali [Univ. of Connecticut, Storrs, CT (United States); Silva, Helena [Univ. of Connecticut, Storrs, CT (United States)

    2017-08-30

    This project focused on thermoelectric transport in semiconductor micro and nanostructures where moderate and typical operating voltages and currents lead to extreme thermal gradients and current densities. Models that describe behavior of semiconducting materials typically assume an equilibrium condition or slight deviations from it. In these cases the generation-recombination processes are assumed to have reached a local equilibrium for a given temperature. Hence, free carrier concentrations and their mobilities, band-gap, thermal conductivity, thermoelectric properties, mobility of atoms and mechanical properties of the material, can be described as a function of temperature. In the case of PN junctions under electrical bias, carrier concentrations can change up to ~ 1020 cm-3 and a drift-diffusion approximation is typically used to obtain the carrier concentrations while assuming that the material properties do not change. In non-equilibrium conditions, the assumption that the material properties remain the same may not be valid. While the increased conduction-band electron concentration may not have a drastic effect on the material, large hole concentration is expected to soften the material as ‘a hole’ comes into existence as a broken bond in the lattice. As the hole density approaches 1022 cm-3, the number of bonds holding the lattice together is significantly reduced, making it easier to break additional bonds, reduce band-gap and inhibit phonon transport. As these holes move away from where they were generated, local properties are expected to deviate significantly from the equilibrium case. Hence, temperature alone is not sufficient to describe the behavior of the material. The behavior of the solid material close to a molten region (liquid-solid interfaces) is also expected to deviate from the equilibrium case as a function of hole injection rate, which can be drastically increased or decreased in the presence of an electric field. In the past years

  4. Comparison of transports expected under different waste management concepts: determination of basic data for application in risk analyses

    International Nuclear Information System (INIS)

    Alter, U.; Mielke, H.G.; Wehner, G.

    1983-01-01

    According to the Atomic Act, article 9a, paragraph 1, the licensees of nuclear power plants in the Federal Republic of Germany are obliged to provide for the management of radioactive wastes resulting from the operation of these plants. Concerning the provisions to be made for the management of such wastes, two concepts are discussed: nuclear reprocessing and final waste disposal center (Nukleares Entsorgungszentrum, NEZ); and the integrated spent fuel and waste management concept (Integriertes Entsorgungskonzept, IEK). Unlike the NEZ, the IEK-concept may have different sites for the following fuel cycle facilities: intermediate spent fuel storage, reprocessing, waste conditioning and final disposal, and uranium and plutonium fuel element fabrication facilities. The fundamental differences of the pertinent transports are presented. Transport scenarios expected under the two alternatives NEZ and IEK have been elaborated for the purpose of a data collection covering the following aspects: materials to be shipped, number of packages shipped, number of packages shipped per transport, transport by rail or by road, transport routes and distances, and duration of transports

  5. Bacterial biofilm under flow: First a physical struggle to stay, then a matter of breathing.

    Directory of Open Access Journals (Sweden)

    Philippe Thomen

    Full Text Available Bacterial communities attached to surfaces under fluid flow represent a widespread lifestyle of the microbial world. Through shear stress generation and molecular transport regulation, hydrodynamics conveys effects that are very different by nature but strongly coupled. To decipher the influence of these levers on bacterial biofilms immersed in moving fluids, we quantitatively and simultaneously investigated physicochemical and biological properties of the biofilm. We designed a millifluidic setup allowing to control hydrodynamic conditions and to monitor biofilm development in real time using microscope imaging. We also conducted a transcriptomic analysis to detect a potential physiological response to hydrodynamics. We discovered that a threshold value of shear stress determined biofilm settlement, with sub-piconewton forces sufficient to prevent biofilm initiation. As a consequence, distinct hydrodynamic conditions, which set spatial distribution of shear stress, promoted distinct colonization patterns with consequences on the growth mode. However, no direct impact of mechanical forces on biofilm growth rate was observed. Consistently, no mechanosensing gene emerged from our differential transcriptomic analysis comparing distinct hydrodynamic conditions. Instead, we found that hydrodynamic molecular transport crucially impacts biofilm growth by controlling oxygen availability. Our results shed light on biofilm response to hydrodynamics and open new avenues to achieve informed design of fluidic setups for investigating, engineering or fighting adherent communities.

  6. Modeling of water and solute transport under variably saturated conditions: state of the art

    International Nuclear Information System (INIS)

    Lappala, E.G.

    1980-01-01

    This paper reviews the equations used in deterministic models of mass and energy transport in variably saturated porous media. Analytic, quasi-analytic, and numerical solution methods to the nonlinear forms of transport equations are discussed with respect to their advantages and limitations. The factors that influence the selection of a modeling method are discussed in this paper; they include the following: (1) the degree of coupling required among the equations describing the transport of liquids, gases, solutes, and energy; (2) the inclusion of an advection term in the equations; (3) the existence of sharp fronts; (4) the degree of nonlinearity and hysteresis in the transport coefficients and boundary conditions; (5) the existence of complex boundaries; and (6) the availability and reliability of data required by the models

  7. Proactive approach to transportation resource allocation under severe winter weather emergencies.

    Science.gov (United States)

    2012-01-01

    Severe winter weather dramatically reduces road transportation infrastructure : serviceability and decreases safety throughout Oklahoma. Although it has relatively mild winters : when compared with northern regions of the United States, Oklahoma has ...

  8. Columnar to equiaxed transition in a refined Al-Cu alloy under diffusive and convective transport conditions

    Energy Technology Data Exchange (ETDEWEB)

    Dupouy, M.D.; Camel, D.; Mazille, J.E. [CEA Centre d' Etudes et de Recherches sur les Materiaux, 38 - Grenoble (France); Hugon, I. [Lab. de Metallographie, DCC/DTE/SIM, CEA Valrho (France)

    2000-07-01

    The columnar-equiaxed transition under diffusive transport conditions was studied in microgravity (EUROMIR95 and spacelab-LMS96) by solidifying four Al-4wt%Cu alloys refined at different levels, with a constant cooling rate (1 K/min), both under nearly isothermal conditions and under a decreasing temperature gradient. Isothermal samples showed a homogeneous equiaxed structure with no fading of the refiner efficiency. Gradient samples revealed a continuous transition consisting of an orientation of the microsegregation parallel to the solidification direction, without any grain selection effect. For comparison, ground samples evidence the influence of the motion of both refiner particles and growing equiaxed grains. (orig.)

  9. Competitiveness of the Air and the Sea Cargo Transport of Mexico under the International Trade Frame

    OpenAIRE

    America I. Zamora Torres; Jose Cesar Lenin Navarro Chavez; Joel Bonales Valencia

    2015-01-01

    International trade trends have changed the cost structure, pricing, logistics, supply chain and hence comparative advantages. Such trends have similarly defined the trade competitiveness of countries becoming more relevant with the level of integration of global transport networks as a driver of international trade. In this paper we evaluate through Principal Component Analysis methodology the international transport competitiveness considering the most important variables that affect this s...

  10. Expression of Saccharomyces cerevisiae α-glucoside transporters under different growth conditions

    OpenAIRE

    S. L. Alves Jr.; J. M. Thevelein; B. U. Stambuk

    2014-01-01

    Important biotechnological processes depend on the efficient fermentation by Saccharomyces cerevisiae yeasts of starch hydrolysates rich in maltose and maltotriose. The rate-limiting step for fermentation of these α-glucosides is the transport across the plasma membrane of the cells. In order to contribute to a better understanding of maltose and maltotriose metabolism by S. cerevisiae, we analyzed the expression of the main α glucoside transporter genes in two different yeast strains grown o...

  11. 32P uptake and transport to shoots in Pinus serotina seedlings under aerobic and hypoxic growth conditions

    International Nuclear Information System (INIS)

    Topa, M.A.; Cheeseman, J.M.

    1993-01-01

    We examined the effects of long-term hypoxic growth conditions on net uptake and transport of P to shoots of pond pine (Pinus serotina Michx.), a moderately flood-tolerant southern pine. Seedlings were grown under aerobic or hypoxic solution conditions for 4-5 weeks in continuously flowing solution culture containing 100 muM P. Short- and long-term P-32 experiments were then conducted with intact seedlings to determine rates of P-32 influx, efflux and net transport to the shoot. Shoot fresh weight/root fresh weight ratios were significantly higher under hypoxic growth conditions, reflecting the larger reduction in root growth than shoot growth, despite extensive aerechyma formation in roots. Estimates for the unidirectional influx of P-32 in aerobic and hypoxic seedlings were 1.43 and 3.20 mumol P (g(FW) root)-1 h-1, respectively. However, P-32 accumulation between the two treatments became similar within 8 h, suggesting that efflux was also higher in seedlings from the hypoxic treatment. Indeed, in a separate experiment, hypoxic growth conditions increased efflux by over 60%. Transport of P-32 to shoots was significantly reduced under hypoxic growth conditions. despite higher root P concentrations and lower shoot P concentrations. After 48 h, P-32 accumulation in roots was similar between the two treatments, yet total accumulation of seedling P-32 decreased by 31% under the hypoxic treatment, largely because of reduced transport of P-32 to the shoot. The lower accumulation of P-32 by shoots of seedlings in the hypoxic treatment may be the result of a direct inhibition on the transport process in O2-deficient tissues, but could also reflect a slower turnover or labeling of the pool available for transport. Indeed, the percentage of total P-32 in roots present in the soluble P(i) (or transportable form of P) was about 33% lower in seedlings from the hypoxic treatment, probably reflecting increased assimilation into organic compounds as well as chelation with iron

  12. Effects of chromium and chromium + vitamin C combination on metabolic, oxidative, and fear responses of broilers transported under summer conditions

    Science.gov (United States)

    Perai, A. H.; Kermanshahi, H.; Moghaddam, H. Nassiri; Zarban, A.

    2015-04-01

    A total of 240 female broilers (42 days old) were randomly assigned to four groups with six replicates and fed either a basal diet (two control groups) or a basal diet supplemented with either 1,200 μg Cr+3 from chromium (Cr) methionine/kg (Cr group) or 1,200 μg Cr+3 from Cr methionine plus 800 mg vitamin C (Vit C)/kg of diet (Cr + Vit C group). After 7 days on the dietary treatment, all groups except one of the controls were transported for 3 h under the summer conditions. Performance parameters were not influenced by dietary treatments. The plasma concentrations of insulin, triiodothyronine, triglyceride, and the ratio of triiodothyronine/thyroxin were decreased and the ratio of glucose/insulin was increased due to transport process. Road transportation also increased the plasma concentrations of protein, cholesterol, aspartate aminotransferase, and creatine kinase and decreased the concentration of low-density lipoprotein cholesterol in the Cr + Vit C group. The pretransport concentrations of insulin and triiodothyronine were highest in the Cr + Vit C group. The concentration of phosphorous was lower in the Cr group than that in the other groups after transport. No significant effects of dietary treatments were observed on the other biochemical parameters. Transport increased malondialdehyde concentration in the control group and did not change plasma total antioxidant capacity and erythrocyte glutathione peroxidase activity. Either in combination or alone, Cr increased plasma total antioxidant capacity (before transport P ≤ 0.05, after transport P = 0.07) but did not affect the concentration of malondialdehyde and activity of glutathione peroxidase. The duration of tonic immobility (TI) was similar between nontransported control chicks and transported chicks without any supplements. Pretreatment with Cr + Vit C significantly reduced the duration of TI.

  13. PETher - Physical Properties of Thermal Water under In-situ-Conditions

    Science.gov (United States)

    Herfurth, Sarah; Schröder, Elisabeth

    2016-04-01

    The objective of PETher, a research project funded by the German Federal Ministry for Economic Affairs and Energy (BMWi), is to experimentally determine thermo-physical properties (specific isobaric heat capacity, kinematic viscosity, density and thermal conductivity) of geothermal water in-situ-conditions (pressure, temperature, chemical composition including gas content of the brine) present in geothermal applications. Knowing these thermo-physical properties reduces the uncertainties with respect to estimating the thermal output and therefore the economic viability of the power plant. Up to now, only a limited number of measurements of selected physical properties have been made, usually under laboratory conditions and for individual geothermal plants. In-situ measured parameters, especially in the temperature range of 120°C and higher, at pressures of 20 bar and higher, as well as with a salinity of up to 250 g/l, are sparse to non-existing. Therefore, pure water properties are often used as reference data and for designing the power plant and its components. Currently available numerical models describing the thermo-physical properties are typically not valid for the conditions in geothermal applications and do not consider the substantial influence of the chemical composition of the thermal water. Also, actual geothermal waters have not been subject of detailed measurements systematically performed under operational conditions on a large-scale basis. Owing to the lack of reliable data, a validation of numerical models for investigating geothermal systems is not possible. In order to determine the dependency of the thermo-physical properties of geothermal water on temperature, pressure and salinity in-situ measurements are conducted. The measurements are taking place directly at several geothermal applications located in Germany's hydrogeothermal key regions. In order to do this, a mobile testing unit was developed and refined with instruments specifically

  14. Patterns and perceptions of physical activity and sedentary time in male transport drivers working in regional Australia.

    Science.gov (United States)

    Wong, Jason Y L; Gilson, Nicholas D; Bush, Robert A; Brown, Wendy J

    2014-08-01

    To objectively measure physical activity (PA) patterns and sedentary time, and explore perceptions of workplace PA opportunities in regional male transport workers. A multi-method study involving 28 drivers (52.4±9.69 years) working at a bus company in South-East Queensland, Australia. PA was measured using accelerometers (n=23) to determine the proportion of time spent in sedentary (take advantage of existing workplace-related PA opportunities. © 2014 Public Health Association of Australia.

  15. The use of Monte Carlo radiation transport codes in radiation physics and dosimetry

    CERN Multimedia

    CERN. Geneva; Ferrari, Alfredo; Silari, Marco

    2006-01-01

    Transport and interaction of electromagnetic radiation Interaction models and simulation schemes implemented in modern Monte Carlo codes for the simulation of coupled electron-photon transport will be briefly reviewed. In these codes, photon transport is simulated by using the detailed scheme, i.e., interaction by interaction. Detailed simulation is easy to implement, and the reliability of the results is only limited by the accuracy of the adopted cross sections. Simulations of electron and positron transport are more difficult, because these particles undergo a large number of interactions in the course of their slowing down. Different schemes for simulating electron transport will be discussed. Condensed algorithms, which rely on multiple-scattering theories, are comparatively fast, but less accurate than mixed algorithms, in which hard interactions (with energy loss or angular deflection larger than certain cut-off values) are simulated individually. The reliability, and limitations, of electron-interacti...

  16. Physical, Hydraulic, and Transport Properties of Sediments and Engineered Materials Associated with Hanford Immobilized Low-Activity Waste

    Energy Technology Data Exchange (ETDEWEB)

    Rockhold, Mark L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Zhang, Z. F. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Meyer, Philip D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Thomle, Jonathan N. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-02-28

    Current plans for treatment and disposal of immobilized low-activity waste (ILAW) from Hanford’s underground waste storage tanks include vitrification and storage of the glass waste form in a nearsurface disposal facility. This Integrated Disposal Facility (IDF) is located in the 200 East Area of the Hanford Central Plateau. Performance assessment (PA) of the IDF requires numerical modeling of subsurface flow and reactive transport processes over very long periods (thousands of years). The models used to predict facility performance require parameters describing various physical, hydraulic, and transport properties. This report provides updated estimates of physical, hydraulic, and transport properties and parameters for both near- and far-field materials, intended for use in future IDF PA modeling efforts. Previous work on physical and hydraulic property characterization for earlier IDF PA analyses is reviewed and summarized. For near-field materials, portions of this document and parameter estimates are taken from an earlier data package. For far-field materials, a critical review is provided of methodologies used in previous data packages. Alternative methods are described and associated parameters are provided.

  17. Contribution of Physical Education and Active Transport to Energy Expenditure in Dutch Adolescents

    NARCIS (Netherlands)

    drs Menno Slingerland; dr. Lars B. Borghouts

    2010-01-01

    Introduction: It has been suggested that physical education (PE) can make a meaningful contribution to children's physical activity (PA) levels. The amount of moderate-to-vigorous physical activity (MVPA) in PE has been quantified in various manners, including heart rate monitoring and direct

  18. Turbulence and Fluid Flow: Perspectives. Physical Processes in Terrestrial and Aquatic Ecosystems, Transport Processes.

    Science.gov (United States)

    Simpson, James R.

    This module is part of a series on Physical Processes in Terrestrial and Aquatic Ecosystems. The materials were designed to be used by life science students for instruction in the application of physical theory to ecosystem operation. Most modules contain computer programs which are built around a particular application of a physical process.…

  19. Survival of Ucides cordatus (Decapoda: Ocypodidae megalopae during transport under different conditions of density and duration

    Directory of Open Access Journals (Sweden)

    Robson Ventura

    2010-01-01

    Full Text Available Target areas for Ucides cordatus (Linnaeus, 1763 restocking programs are often located far from the laboratory where larval rearing is developed. During translocation, the larvae are submitted to highly stressful conditions due to handling, packing, and transport activities. The aim of the present study was to assess the mortality rates of U. cordatus megalopae caused by different transportation procedures. Megalopae at loading densities of 50, 150, and 300 ind.L-1 were packed in double polyethylene 12 x 25 cm plastic bags with 200 ml of marine water at salinity 30. The bags were filled with oxygen at a proportion of 1:2 parts of water and sealed tightly. The trepidations during transport were simulated by the use of a shaker device (800 vibrations/minute over periods of three and six hours inside a dark container. The survivorship rates of larvae after simulation were compared to those obtained in control groups, which consisted of plastic vials with megalopae at a loading density of 50 ind.L-1 maintained at rest. Immediately after the two transport simulations, there was no significant difference in survivorship between the treatments and the control. However, 24 hours after simulation some of the tested densities resulted in significantly lower survivorships. The results demonstrated that U. cordatus megalopae can tolerate six hours of shaking during transportation, at high densities with minimal mortality.

  20. Modeling and simulation of multi-physics multi-scale transport phenomenain bio-medical applications

    International Nuclear Information System (INIS)

    Kenjereš, Saša

    2014-01-01

    We present a short overview of some of our most recent work that combines the mathematical modeling, advanced computer simulations and state-of-the-art experimental techniques of physical transport phenomena in various bio-medical applications. In the first example, we tackle predictions of complex blood flow patterns in the patient-specific vascular system (carotid artery bifurcation) and transfer of the so-called 'bad' cholesterol (low-density lipoprotein, LDL) within the multi-layered artery wall. This two-way coupling between the blood flow and corresponding mass transfer of LDL within the artery wall is essential for predictions of regions where atherosclerosis can develop. It is demonstrated that a recently developed mathematical model, which takes into account the complex multi-layer arterial-wall structure, produced LDL profiles within the artery wall in good agreement with in-vivo experiments in rabbits, and it can be used for predictions of locations where the initial stage of development of atherosclerosis may take place. The second example includes a combination of pulsating blood flow and medical drug delivery and deposition controlled by external magnetic field gradients in the patient specific carotid artery bifurcation. The results of numerical simulations are compared with own PIV (Particle Image Velocimetry) and MRI (Magnetic Resonance Imaging) in the PDMS (silicon-based organic polymer) phantom. A very good agreement between simulations and experiments is obtained for different stages of the pulsating cycle. Application of the magnetic drug targeting resulted in an increase of up to ten fold in the efficiency of local deposition of the medical drug at desired locations. Finally, the LES (Large Eddy Simulation) of the aerosol distribution within the human respiratory system that includes up to eight bronchial generations is performed. A very good agreement between simulations and MRV (Magnetic Resonance Velocimetry) measurements is

  1. Aerosol optical and physical properties during winter monsoon pollution transport in an urban environment.

    Science.gov (United States)

    Verma, S; Bhanja, S N; Pani, S K; Misra, A

    2014-04-01

    We analysed aerosol optical and physical properties in an urban environment (Kolkata) during winter monsoon pollution transport from nearby and far-off regions. Prevailing meteorological conditions, viz. low temperature and wind speed, and a strong downdraft of air mass, indicated weak dispersion and inhibition of vertical mixing of aerosols. Spectral features of WinMon aerosol optical depth (AOD) showed larger variability (0.68-1.13) in monthly mean AOD at short-wavelength (SW) channels (0.34-0.5 μm) compared to that (0.28-0.37) at long-wavelength (LW) channels (0.87-1.02 μm), thereby indicating sensitivity of WinMon AOD to fine aerosol constituents and the predominant contribution from fine aerosol constituents to WinMon AOD. WinMon AOD at 0.5 μm (AOD 0. 5) and Angstrom parameter ( α) were 0.68-0.82 and 1.14-1.32, respectively, with their highest value in December. Consistent with inference from spectral features of AOD, surface aerosol loading was primarily constituted of fine aerosols (size 0.23-3 μm) which was 60-70 % of aerosol 10- μm (size 0.23-10 μm) concentration. Three distinct modes of aerosol distribution were obtained, with the highest WinMon concentration at a mass median diameter (MMD) of 0.3 μm during December, thereby indicating characteristics of primary contribution related to anthropogenic pollutants that were inferred to be mostly due to contribution from air mass originating in nearby region having predominant emissions from biofuel and fossil fuel combustion. A relatively higher contribution from aerosols in the upper atmospheric layers than at the surface to WinMon AOD was inferred during February compared to other months and was attributed to predominant contribution from open burning emissions arising from nearby and far-off regions. A comparison of ground-based measurements with Moderate Resolution Imaging Spectroradiometer (MODIS) data showed an underestimation of MODIS AOD and α values for most of the days. Discrepancy in

  2. Addressing the Safety of Transportation Cyber-Physical Systems: Development and Validation of a Verbal Warning Utility Scale for Intelligent Transportation Systems

    Directory of Open Access Journals (Sweden)

    Yiqi Zhang

    2015-01-01

    Full Text Available As an important application of Cyber-Physical Systems (CPS, advances in intelligent transportation systems (ITS improve driving safety by informing drivers of hazards with warnings in advance. The evaluation of the warning effectiveness is an important issue in facilitating communication of ITS. The goal of the present study was to develop a scale to evaluate the warning utility, namely, the effectiveness of a warning in preventing accidents in general. A driving simulator study was conducted to validate the Verbal Warning Utility Scale (VWUS in a simulated driving environment. The reliability analysis indicated a good split-half reliability for the VWUS with a Spearman-Brown Coefficient of 0.873. The predictive validity of VWUS in measuring the effectiveness of the verbal warnings was verified by the significant prediction of safety benefits indicated by variables, including reduced kinetic energy and collision rate. Compared to conducting experimental studies, this scale provides a simpler way to evaluate overall utility of verbal warnings in communicating associated hazards in intelligent transportation systems. This scale can be further applied to improve the design of warnings of ITS in order to improve transportation safety. The applications of the scale in nonverbal warning situations and limitations of the current scale are also discussed.

  3. Thermal Transport in Single-Walled Carbon Nanotubes Under Pure Bending

    Science.gov (United States)

    Ma, Jihong; Ni, Yuxiang; Volz, Sebastian; Dumitricǎ, Traian

    2015-02-01

    The carbon nanotubes' resilience to mechanical deformation is a potentially important feature for imparting tunable properties at the nanoscale. Using nonequilibrium molecular dynamics and empirical interatomic potentials, we examine the thermal conductivity variations with bending in the thermal transport regime where both ballistic and diffusive effects coexist. These simulations are enabled by the realistic atomic-scale descriptions of uniformly curved and buckled nanotube morphologies obtained by imposing objective boundary conditions. We uncover a contrasting behavior. At shorter lengths, the phonon propagation is affected significantly by the occurrence of localized structural buckling. As the nanotube length becomes comparable with the phonon mean free path, heat transport becomes insensitive to the buckling deformations. Our result settles the controversy around the differences between the current experimental and molecular-dynamics measurements of the thermal transport in bent nanotubes.

  4. Photosystem II cycle activity and alternative electron transport in the diatom Phaeodactylum tricornutum under dynamic light conditions and nitrogen limitation.

    Science.gov (United States)

    Wagner, Heiko; Jakob, Torsten; Lavaud, Johann; Wilhelm, Christian

    2016-05-01

    Alternative electron sinks are an important regulatory mechanism to dissipate excessively absorbed light energy particularly under fast changing dynamic light conditions. In diatoms, the cyclic electron transport (CET) around Photosystem II (PS II) is an alternative electron transport pathway (AET) that contributes to avoidance of overexcitation under high light illumination. The combination of nitrogen limitation and high-intensity irradiance regularly occurs under natural conditions and is expected to force the imbalance between light absorption and the metabolic use of light energy. The present study demonstrates that under N limitation, the amount of AET and the activity of CETPSII in the diatom Phaeodactylum tricornutum were increased. Thereby, the activity of CETPSII was linearly correlated with the amount of AET rates. It is concluded that CETPSII significantly contributes to AET in P. tricornutum. Surprisingly, CETPSII was found to be activated already at the end of the dark period under N-limited conditions. This coincided with a significantly increased degree of reduction of the plastoquinone (PQ) pool. The analysis of the macromolecular composition of cells of P. tricornutum under N-limited conditions revealed a carbon allocation in favor of carbohydrates during the light period and their degradation during the dark phase. A possible linkage between the activity of CETPSII and degree of reduction of the PQ pool on the one side and the macromolecular changes on the other is discussed.

  5. Temporal Variability of Physical Properties on an Aquic Argiudoll under no Tillage

    Science.gov (United States)

    Castiglione, M. G.; Sasal, M. C.; Wilson, M. G.; Paz González, A.; Oszust, J. D.

    2012-04-01

    Practices for the implementation and development of crops affect soil properties and processes in space and time with consequences for the accumulation and movement of water, nutrients and pollutants, which affects plant growth. The aim of this study was to determine the temporal variability of soil physical properties and its link with the infiltration process, on an Aquic Argiudoll of the Argentine Pampas under no-till cultivation. Sampling was performed during six dates in the INTA EEA Paraná (Entre Ríos, Argentina), in the course of the succession of wheat/ soybean-corn. In each of those dates, rain simulations were performed under covered and uncovered soil. From these results it was determined the saturated hydraulic conductivity (Ks), the runoff coefficient (EC), the accumulated rainfall up to ponding (Tp), the accumulated rainfall to reach the steady state infiltration rate (TI) and the decline slope of the infiltration rate (Pd). Also we determine: the initial soil water content (HI), bulk density (Dap), volume occupied by pores larger than 50 µm (> 50), volume occupied by pores between 10 and 50 µm (10-50), soil physical quality index (S) and structural stability (CDMP). On three dates HI was approximately 11%, two were between 22 and 27% and in the remaining time HI was 36%. Despite these variations we don't observed significant changes in most soil physical properties associated with the structure and pore size. However, we could prove significant differences between dates in Ks and EC, both on bare and cover soil. At the same time, differences in these parameters between coverage degrees were significant only in two dates. The HI affected the variability of Ks results. Also Ks ratio between covered and uncovered soil improved with HI increment, except for HI equal to 36%. We found highly significant linkage between Ks, CE and Pd with HI. This study reveals the importance of the temporal dynamics of water movement in this Aquic Argiudoll, although

  6. On the problem of studying physical properties of rock collectors under conditions modelling layer ones

    Energy Technology Data Exchange (ETDEWEB)

    Petkevich, G.I.

    1972-01-01

    A review is given of the state in studying physical properties of rock collectors under conditions modelling the layer ones. From the theoretical point of view, this direction is determined as petrophysics of multiphase systems and from the practical, as oil field petrophysics. The following aspects of the problem are considered: models of porous media, thermodynamic conditions of deformation process, parameters of stressed state of porous deformed media, and analysis of experimental data. To describe collector behavior under thermodynamic conditions of natural occurrence, it is necessary to construct the model of the porous deformed medium. In connection with heterogeneity and multiphase character of rock collectors, they may be considered as differential-elastic media, and to characterize the stressed state such indices as coefficients of compressibility of skeleton, solid and liquid phase, as well as coefficients of pore compressibility, relaxation, structural parameter, etc. may be used. It is emphasized that only reversable (elastic) parameter changes are studied under laboratory conditions. The results of laboratory measurements of collector parameters are summarized on the basis of different researcher data. (54 refs.)

  7. Which physical and social environmental factors are most important for adolescents' cycling for transport? An experimental study using manipulated photographs.

    Science.gov (United States)

    Verhoeven, Hannah; Ghekiere, Ariane; Van Cauwenberg, Jelle; Van Dyck, Delfien; De Bourdeaudhuij, Ilse; Clarys, Peter; Deforche, Benedicte

    2017-08-17

    Ecological models emphasize that cycling for transport is determined by an interplay between individual, physical and social environmental factors. The current study investigated (a) which physical and social environmental factors determine adolescents' preferences towards cycling for transport and (b) which individual, physical and social environmental factors are associated with their intention to actually cycle for transport. An online questionnaire consisting of questions on individual and social environmental variables, and 15 choice-based conjoint tasks with manipulated photographs was completed by 882 adolescents (55.3% male; 13.9 ± 1.6 years). Within the choice tasks, participants were asked to indicate which of two situations they would prefer to cycle to a friend's house. The manipulated photographs were all modified versions of one semi-urban street which differed in the following physical micro-environmental attributes (separation of cycle path, evenness of cycle path, speed limit, speed bump, traffic density, amount of vegetation and maintenance). In addition, each photograph was accompanied by two sentences which described varying cycling distances and co-participation in cycling (i.e. cycling alone or with a friend). After each choice task participants were also asked if they would actually cycle in that situation in real life (i.e. intention). Hierarchical Bayes analyses were performed to calculate relative importances and part-worth utilities of environmental attributes. Logistic regression analyses were performed to investigate which individual, physical and social environmental factors were associated with adolescents' intention to actually cycle for transport. Adolescents' preference to cycle for transport was predominantly determined by separation of cycle path, followed by shorter cycling distance and co-participation in cycling. Higher preferences were observed for a separation between the cycle path and motorized traffic by means of a

  8. Investigation of the Multi-Physics of Laser-Induced Ignition of Transportation Fuels

    Science.gov (United States)

    Peters, Nathan D.

    Cleaner and more efficient combustion systems are expected to operate at conditions where successful spark ignition is difficult to achieve. Laser ignition is a proposed alternative ignition system capable of stable engine performance under these conditions. Fundamental studies are needed to fully characterize the complex, multi-physics nature of the laser ignition process. This thesis is a contribution in that direction, also characterizing the ignition and flame behavior of some engine-relevant fuels. This work investigates experimentally the early stages of the laser ignition process, characterizing breakdown and laser-induced shock waves. It then explores self-sustained flame behavior from early flame emergence to complete propagation or quenching. Regarding the early stages of laser ignition, the influence of focusing optics, thermodynamic conditions, and chemical structure of fuels on optical breakdown threshold is examined. These results are presented in a universal representation of the breakdown threshold, facilitating their comparison. The results agree with previous studies and new data sets are generated. Thermomechanical differences between breakdown in non-reactive and reactive mixtures are quantified, isolating the effect of exothermicity on plasma and shock wave propagation. The thermodynamic conditions of the gas near the focal volume are investigated and quantified using two-color interferometry. This information is applied toward developing accurate initial conditions for simulations based on absorbed laser energy and early kernel geometry. With respect to flame propagation, schlieren and interferometric imaging techniques are used to examine early flame behavior, especially near flammability limits. This provides insight into the mechanisms controlling quenching of fuel-lean laser ignited flames as well as the time-scales involved. Four fuels (methane, biogas, iso-octane, and E85) are characterized, highlighting thermochemical effects which

  9. Selected soil physical and hydraulic properties for different crop successions under no tillage

    Science.gov (United States)

    Sasal, M. C.; Castiglioni, M.; Paz-Ferreiro, J.; Wilson, M. G.; Oszust, J.

    2009-04-01

    No tillage is now widely widespread in Argentina in response to several circumstances, including limited runoff and a drop in soil erosion. Crop residues left on the soil surface help both natural rainfall and irrigation water infiltrate and also limits evaporation, conserving water for plant growth. This notwithstanding, wide differences in runoff rates between crop succession have been observed under no tillage. The aim of this work was to assess the effect of the main crop successions of Entre Ríos province, Argentina on selected soil physic and hydraulic properties. Results obtained on no-till plots were compared with those recorded on a 10-years old grassland plot and on a conventionally tilled plot left bare, both of them taken as references. The study soil was classified as an Aquic Argiudoll. Treatments were: maize and soybean, both cropped as monoculture, succession wheat/soybean or wheat/maize, grassland and conventionally tilled soil left bare. Soil runoff was recorded on experimental plots 100 m2 in surface. Saturated hydraulic conductivity (Khc) and sorptivity were measured in field conditions using a disc permeameter. Bulk density (Bd), saturated hydraulic conductivity (Kh) total porosity (TP) and pore size distributions were determined on undisturbed cores sampled at the 0-4 and 4-8 cm depth with five replications. Maximum water losses were recorded in bare soils conventionally tilled. Under maize and soybean monocultures water losses were six time higher than under grassland. Water losses under successions wheat/soybean-maize were lower than under monoculture but not significantly different. Field saturated hydraulic conductivity (Khc) was highest under grassland and the remaining treatments don't showed significant differences. Differences in sorptivity between plots were not significantly different. A significant relationship was found between saturated hydraulic conductivity measured in field conditions (Khc) and determined in soil cores (Kh

  10. Quantitative gene expression of somatostatin receptors and noradrenaline transporter underlying scintigraphic results in patients with neuroendocrine tumors

    DEFF Research Database (Denmark)

    Binderup, Tina; Knigge, Ulrich; Mellon Mogensen, Anne

    2008-01-01

    AIM: To measure, by a quantitative approach, the gene expression underlying the results of somatostatin receptor (sst) scintigraphy ((111)In-DTPA-octreotide) and noradrenaline transporter (NAT) scintigraphy ((123)I-MIBG) in patients with neuroendocrine (NE) tumors. METHODS: The gene expression of...... to achieve a better understanding of the link between them, which in turn could aid in planning and development of noninvasive molecular imaging of key molecular processes....

  11. Unusual Sediment Transportation Processes Under Low Pressure Environments and Implications For Gullies and Recurring Slope Lineae (RSL)

    Science.gov (United States)

    Raack, J.; Herny, C.; Conway, S. J.; Balme, M. R.; Carpy, S.; Patel, M.

    2017-12-01

    Recently and presently active mass wasting features such as gullies and recurring slope lineae (RSL) are common on the surface of Mars, but their origin and triggering mechanisms are under intense debate. While several active mass wasting features have been linked to sublimation of CO2ice, dry granular flows (avalanches), or a combination of both effects, others have been more closely linked to liquid water or briny outflows (e.g. for RSL). However, liquid water on the surface of Mars is unstable under present-day low pressures and surface temperatures. Nevertheless, numerical modeling and remote sensing data have shown that maximum surface temperatures can exceed the frost point of water and that liquid water could exist on the surface of actual Mars in a transient state. But to explain the observed spatial extent of RSL and recent modification of gullies, it is estimated that relatively large amounts of liquid water are necessary. It is proving challenging to generate such quantities from the atmosphere. In this contribution we explore the potential effects of boiling water (boiling occurs at martian pressures slightly above the frost point of 273 K) on sediment transport. We will present the outcomes of a series of experiments under low surface and water temperatures (between 278 and 297 K, analogous to surface temperatures observed near RSL) and low pressures (between 8 and 11 mbar). We simulate sediment transport by boiling liquid water over a sloping bed of unconsolidated sediment. Our results reveal a suite of unusual and very reactive sediment transportation processes, which are not produced under terrestrial pressures. We will discuss the impact of these unusual sediment transport processes on estimates of water budgets for active mass wasting processes.

  12. Mass transport in low permeability rocks under the influence of coupled thermomechanical and hydrochemical effects - an overview

    International Nuclear Information System (INIS)

    Tsang, C.F.

    1984-10-01

    The present paper gives a general overview of mass transport in low permeability rocks under the coupled thermomechanical and hydrochemical effects associated with a nuclear waste repository. A classification of coupled processes is given. Then an ess is presented. example of a coupled process is presented. Discussions of coupled processes based on a recent LBL Panel meeting are summarized. 5 references, 3 figures, 4 tables

  13. The effect of mineral dust transport on PM10 concentrations and physical properties in Istanbul during 2007-2014

    Science.gov (United States)

    Flores, Rosa M.; Kaya, Nefel; Eşer, Övgü; Saltan, Şehnaz

    2017-11-01

    Mineral dust is the most significant source of natural particulate matter. In urban regions, where > 50% of the world population is currently living, local emissions of particulate matter are further aggravated by mineral dust loadings from deserts. The megacity of Istanbul is located in an area sensitive to local pollution due to transportation (i.e., private cars, public transportation, aircrafts, ships, heavy diesel trucks, etc.), industrial emissions, residential heating, and long-range transport from Europe, Asia, and deserts. In this work, the effect of desert dust transport on PM10 concentrations and physical properties was investigated for the period of 2007-2014 in the touristic area of Aksaray, Istanbul. The Dust Regional Atmospheric Model (DREAM8b) was used to predict dust loading in Istanbul during dust transport events. Variations on surface PM10 concentrations were investigated according to seasons and during dust transport events. Cluster analysis of air mass backward trajectories was useful to understand frequency analysis and air mass trajectory dependence of PM10 concentrations on dust loadings. The effect of desert dust transport on aerosol optical depths was also investigated. It was observed that PM10 concentrations exceeded the air quality standard of 50 μg m- 3 50% of the time during the study period. The largest number of exceedances in air quality standard occurred during the spring and winter seasons. Approximately 40-60% of the dust loading occurs during the spring. Desert dust and non-desert dust sources contribute to 22-72% and 48-81% of the ground-level PM10 concentrations in Aksaray, Istanbul during the study period. Averaged AOD observed during dust transport events in spring and summer ranged 0.35-0.55. Cluster analysis resolved over 82% the variability of individual air mass backward trajectories into 5 clusters. Overall, air masses arriving to Istanbul at 500 m are equally distributed into northern (52%) and southern (48

  14. Weather is not significantly correlated with destination-specific transport-related physical activity among adults: A large-scale temporally matched analysis.

    Science.gov (United States)

    Durand, Casey P; Zhang, Kai; Salvo, Deborah

    2017-08-01

    Weather is an element of the natural environment that could have a significant effect on physical activity. Existing research, however, indicates only modest correlations between measures of weather and physical activity. This prior work has been limited by a failure to use time-matched weather and physical activity data, or has not adequately examined the different domains of physical activity (transport, leisure, occupational, etc.). Our objective was to identify the correlation between weather variables and destination-specific transport-related physical activity in adults. Data were sourced from the California Household Travel Survey, collected in 2012-3. Weather variables included: relative humidity, temperature, wind speed, and precipitation. Transport-related physical activity (walking) was sourced from participant-recorded travel diaries. Three-part hurdle models were used to analyze the data. Results indicate statistically or substantively insignificant correlations between the weather variables and transport-related physical activity for all destination types. These results provide the strongest evidence to date that transport-related physical activity may occur relatively independently of weather conditions. The knowledge that weather conditions do not seem to be a significant barrier to this domain of activity may potentially expand the universe of geographic locations that are amenable to environmental and programmatic interventions to increase transport-related walking. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. Study of heat transport in structured soil under grass cover. Dual-continuum approach

    Czech Academy of Sciences Publication Activity Database

    Votrubová, J.; Dohnal, M.; Tesař, Miroslav; Vogel, T.

    2011-01-01

    Roč. 13, - (2011), s. 7414 ISSN 1607-7962. [European Geosciences Union General Assembly 2011. 03.04.2011-08.04.2011, Vienna] R&D Projects: GA ČR GA205/08/1174 Institutional research plan: CEZ:AV0Z20600510 Keywords : water and heat transport * model S1D * Sumava Mts. Subject RIV: DA - Hydrology ; Limnology

  16. Trypanosoma cruzi Polyamine Transporter: Its Role on Parasite Growth and Survival Under Stress Conditions.

    Science.gov (United States)

    Reigada, Chantal; Sayé, Melisa; Vera, Edward Valera; Balcazar, Darío; Fraccaroli, Laura; Carrillo, Carolina; Miranda, Mariana R; Pereira, Claudio A

    2016-08-01

    Trypanosoma cruzi is the etiological agent of Chagas disease, a major health problem in Latin America. Polyamines are polycationic compounds that play a critical role as regulators of cell growth and differentiation. In contrast with other protozoa, T. cruzi is auxotrophic for polyamines because of its inability to synthesize putrescine due to the lack of both, arginine and ornithine decarboxylase; therefore, the intracellular availability of polyamines depends exclusively on transport processes. In this work, the polyamine transporter TcPAT12 was overexpressed in T. cruzi epimastigotes demonstrating that growth rates at different concentrations of polyamines strongly depend on the regulation of the polyamine transport. In addition, parasites overexpressing TcPAT12 showed a highly increased resistance to hydrogen peroxide and the trypanocidal drugs nifurtimox and benznidazole, which act by oxidative stress and interfering the synthesis of polyamine derivatives, respectively. Finally, the presence of putative polyamine transporters was analyzed in T. cruzi, Trypanosoma brucei, and Leishmania major genomes identifying 3-6 genes in these trypanosomatids.

  17. Thinking on Sichuan-Chongqing gas pipeline transportation system reform under market-oriented conditions

    Science.gov (United States)

    Duan, Yanzhi

    2017-01-01

    The gas pipeline networks in Sichuan and Chongqing (Sichuan-Chongqing) region have formed a fully-fledged gas pipeline transportation system in China, which supports and promotes the rapid development of gas market in Sichuan-Chongqing region. In the circumstances of further developed market-oriented economy, it is necessary to carry out further the pipeline system reform in the areas of investment/financing system, operation system and pricing system to lay a solid foundation for improving future gas production and marketing capability and adapting itself to the national gas system reform, and to achieve the objectives of multiparty participated pipeline construction, improved pipeline transportation efficiency and fair and rational pipeline transportation prices. In this article, main thinking on reform in the three areas and major deployment are addressed, and corresponding measures on developing shared pipeline economy, providing financial support to pipeline construction, setting up independent regulatory agency to enhance the industrial supervision for gas pipeline transportation, and promoting the construction of regional gas trade market are recommended.

  18. Decay characteristics and erosion-related transport of glyphosate in Chinese loess soil under field conditions

    NARCIS (Netherlands)

    Yang, X.; Wang, Fei; Martins Bento, Celia; Meng, L.; Dam, van R.C.J.; Mol, J.G.J.; Liu, Guobin; Ritsema, C.J.; Geissen, V.

    2015-01-01

    The decay characteristics and erosion-related transport of glyphosate and aminomethylphosphonic acid (AMPA) were monitored for 35 d at different slope gradients and rates of application in plots with loess soil on the Loess Plateau, China. The initial glyphosate decayed rapidly (half-life of 3.5 d)

  19. Investing in CO2 transport infrastructure under uncertainty : A comparison between ships and pipelines

    NARCIS (Netherlands)

    Knoope, M. M J; Ramírez, A.; Faaij, A. P C

    2015-01-01

    The aim of this study is to assess whether the value of flexibility can influence the investment decision between CO2 ship and pipeline transport and, therefore, the way the infrastructure develops. For this, the value of a carbon capture and storage project are calculated with the

  20. Interaction of Physical and Chemical Processes Controlling the Environmental Fate and Transport of Lampricides Through Stream-Hyporheic Systems

    Science.gov (United States)

    Hixson, J.; Ward, A. S.; Schmadel, N.; McConville, M.; Remucal, C.

    2016-12-01

    The transport and fate of contaminants of emerging concern through the environment is complicated by the heterogeneity of natural systems and the unique reaction pathways of individual compounds. Our current evaluation of risk is often simplified to controls assumed to be homogeneous in space and time. However, we know spatial heterogeneity and time-variable reaction rates complicate predictions of environmental transport and fate, and therefore risk. These complications are the result of the interactions between the physical and chemical systems and the time-variable equilibrium that exists between the two. Compounds that interact with both systems, such as photolytic compounds, require that both components are fully understood in order to predict transport and fate. Release of photolytic compounds occurs through both unintentional releases and intentional loadings. Evaluating risks associated with unintentional releases and implementing best management practices for intentional releases requires an in-depth understanding of the sensitivity of photolytic compounds to external controls. Lampricides, such as 3-trifluoromethyl-4-nitrophenol (TFM), are broadly applied in the Great Lakes system to control the population of invasive sea lamprey. Over-dosing can yield fish kills and other detrimental impacts. Still, planning accounts for time of passage and dilution, but not the interaction of the physical and chemical systems (i.e., storage in the hyporheic zone and time-variable decay rates). In this study, we model a series of TFM applications to test the efficacy of dosing as a function of system characteristics. Overall, our results demonstrate the complexity associated with photo-sensitive compounds through stream-hyporheic systems, and highlight the need to better understand how physical and chemical systems interact to control transport and fate in the environment.

  1. Poleward energy transport: is the standard definition physically relevant at all time scales?

    Science.gov (United States)

    Liang, Minyi; Czaja, Arnaud; Graversen, Rune; Tailleux, Remi

    2018-03-01

    Poleward energy transport in the atmosphere and oceans constitutes an important branch of the global energy budget, and its role in the climate system has been the subject of many studies. In the atmosphere, the transport is affected by "eddies" and large scale meridional cells, both with zero net mass transport across latitude circles, but also partly by processes associated with a net transport of mass across latitude circles. The latter must cease to operate in steady state, but they may be significant when time variability of the heat budget is considered. Indeed, examination of reanalysis data on short (daily to monthly) timescales shows that mass variations on these timescales result in surprisingly large fluctuations (in excess of 10^{15} W = 1 PW) in the poleward heat transport. These fluctuations are referred to as "extensive", for they primarily alter the mass integrated energy of the region considered, but not its averaged value. It is suggested that extensive fluctuations mask more meaningful climate signals present in the heat transport variability on monthly and interannual timescales, and a new formulation is proposed to isolate the latter. This new formulation is applied successfully to reanalysis data and climate model simulations.

  2. How do soil physical conditions for crop growth vary over time under established contrasting tillage regimes?

    Science.gov (United States)

    Hallett, Paul; Stobart, Ron; Valentine, Tracy; George, Timothy; Morris, Nathan; Newton, Adrian; McKenzie, Blair

    2014-05-01

    When plant breeders develop modern cereal varieties for the sustainable intensification of agriculture, insufficient thought is given to the impact of tillage on soil physical conditions for crop production. In earlier work, we demonstrated that barley varieties that perform best in ploughed soil (the approach traditionally used for breeding trials) were not the same as those performing best under shallow non-inversion or zero-tillage. We also found that the Quantitative Trait Loci (QTL) associated with improved phosphorus uptake, and hence useful for marker assisted breeding, were not robust between different tillage regimes. The impact of the soil environment had greater impact than the genetics in GxE interactions. It is obvious that soil tillage should be considered when breeding the next generation of crops. Tillage may also have important impacts on carbon storage, but we found that despite greater soil carbon at shallow depths under non-inversion tillage, the carbon stored throughout the soil profile was not affected by tillage. Studies on soil tillage impacts to crop productivity and soil quality are often performed in one season, on single sites that have had insufficient time to develop. Our current research explores multiple sites, on different soils, with temporal measurements of soil physical conditions under contrasting tillage regimes. We use the oldest established contemporary tillage experiments in the United Kingdom, with all sites sharing ploughed and shallow (7cm) non-inversion tillage treatments. In eastern Scotland (Mid Pilmore), the site also has zero tillage and deep ploughing (40 cm) treatments, and was established 11 years ago. In east England there are two sites, both also having a deep non-inversion tillage treatment, and they were established 6 (New Farm Systems) and 8 (STAR) years ago. We measure a range of crop and soil properties at sowing, one month after sowing and post-harvest, including rapid lab based assays that allow high

  3. Induced Sporicidal Activity of Chlorhexidine against Clostridium difficile Spores under Altered Physical and Chemical Conditions

    Science.gov (United States)

    Nerandzic, Michelle M.; Donskey, Curtis J.

    2015-01-01

    Background Chlorhexidine is a broad-spectrum antimicrobial commonly used to disinfect the skin of patients to reduce the risk of healthcare-associated infections. Because chlorhexidine is not sporicidal, it is not anticipated that it would have an impact on skin contamination with Clostridium difficile, the most important cause of healthcare-associated diarrhea. However, although chlorhexidine is not sporicidal as it is used in healthcare settings, it has been reported to kill spores of Bacillus species under altered physical and chemical conditions that disrupt the spore’s protective barriers (e.g., heat, ultrasonication, alcohol, or elevated pH). Here, we tested the hypothesis that similarly altered physical and chemical conditions result in enhanced sporicidal activity of chlorhexidine against C. difficile spores. Principal Findings C. difficile spores became susceptible to heat killing at 80°C within 15 minutes in the presence of chlorhexidine, as opposed to spores suspended in water which remained viable. The extent to which the spores were reduced was directly proportional to the concentration of chlorhexidine in solution, with no viable spores recovered after 15 minutes of incubation in 0.04%–0.0004% w/v chlorhexidine solutions at 80°C. Reduction of spores exposed to 4% w/v chlorhexidine solutions at moderate temperatures (37°C and 55°C) was enhanced by the presence of 70% ethanol. However, complete elimination of spores was not achieved until 3 hours of incubation at 55°C. Elevating the pH to ≥9.5 significantly enhanced the killing of spores in either aqueous or alcoholic chlorhexidine solutions. Conclusions Physical and chemical conditions that alter the protective barriers of C. difficile spores convey sporicidal activity to chlorhexidine. Further studies are necessary to identify additional agents that may allow chlorhexidine to reach its target within the spore. PMID:25861057

  4. Contribution of underlying processes to improved visuospatial working memory associated with physical activity.

    Science.gov (United States)

    Ji, Qingchun; Wang, Yingying; Guo, Wei; Zhou, Chenglin

    2017-01-01

    Working memory is critical for various cognitive processes and can be separated into two stages: short-term memory storage and manipulation processing. Although previous studies have demonstrated that increased physical activity (PA) improves working memory and that males outperform females on visuospatial working memory tasks, few studies have determined the contribution of the two underlying stages to the visuospatial working memory improvement associated with PA. Thus, the aims of the present study were to verify the relationship between physical activity and visuospatial working memory, determine whether one or both stages were affected by PA, and investigate any sex differences. A total of 56 undergraduate students were recruited for this study. Their scores on the International Physical Activity Questionnaire (IPAQ) were used to separate them into either a lower PA ( n  = 26; IPAQ score ≤3,000 metabolic equivalent [MET]-min/week) or higher PA ( n  = 30; IPAQ score >3,000 MET-min/week) group. Participants were required to complete three tasks: a visuospatial working memory task, a task that examines the short-term memory storage stage, and a mental rotation task that examines the active manipulation stage. Participants in the higher PA group maintained similar accuracy but displayed significantly faster reaction times (RT) than those in the lower PA group on the visuospatial working memory and manipulation tasks. By contrast, no difference was observed between groups on the short-term memory storage task. In addition, no effects of sex were detected. Our results confirm that PA was positively to visuospatial working memory and that this positive relationship was associated with more rapid cognitive processing during the manipulation stage, with little or no relationship between PA and the memory storage stage of visuospatial working memory.

  5. E-COURSE BASED ON THE PLATFORM MOODLE IN TEACHING PHYSICS TO FUTURE SPECIALISTS OF RIVER AND SEA TRANSPORT

    Directory of Open Access Journals (Sweden)

    Cherniavskyі V.

    2017-03-01

    Full Text Available The article considers that the fastest way to include Ukraine into the global educational system is to create conditions for widespread use of the Internet for training purposes, which is considered the most perfect model of communication in the global information society. It is stated that one of the most common and most convenient forms of distance learning for marine institutions of higher education is electronic courses. Their main advantage over traditional forms of education is to provide the conditions for productive individual work of the students. It is shown that the problem of individual work is particularly relevant for marine education, due to the specific schedule of the educational process, including the presence of long-term shipboard training. It is defined the peculiarities of usage of e-learning courses in Physics for training of the specialists of river and sea transport. It is proposed the interpretation of the term "e-learning course in Physics" as an information model of a specific topic or section of "Physics", which displays the oriented basis of cognitive activity of the student, it provides organic and natural formation, regulates mental and emotional processes, predicts the opportunities for educational tasks solving by offered means for stimulating the development of personal cognitive capabilities. The requirements for e-learning courses in Physics are determined and their advantages over other innovative teaching methods towards the realization of methodological features of the educational process are highlighted. The structure of e-learning courses in Physics is proposed and the experience of e-courses using in Physics for bachelors of specialty "River and Sea transport" is described.

  6. THE DEVELOPMENT OF STUDENTS’ MOTIVATIONAL DIMENSIONS UNDER THE PHYSICAL EDUCATION EXPERIMENTAL PROGRAMME

    Directory of Open Access Journals (Sweden)

    Said Hasanbegović

    2014-04-01

    Full Text Available This study shows the development of some motivational dimensions of secondary school students when they are treated by the experimental way of teaching. The study was conducted on a sample of 240 pupils of The Secondary School Banovici, out of which 124 males and 116 females. The pupils were divided into two groups. The first group consisted of 120 pupils divided into four sections, out of which 73 males and 47 females. This is the control group. The second group also consisted of 120 pupils divided into four sections, out of which 51 male and 69 females. This group was subjected to the experimental way of teaching and thus represents the experimental group. Results show the changes in pupils’ motivational characteristics under the influence of innovative educational content that are reflected through their activities and final attitudes on the physical education value. The discriminate analysis revealed the statistically important differences between pupils that are treated by the experimental program compared to students treated by traditional program in terms of motivation in physical education classes (PE classes. However, the study, in some way, solves the problem of inactivity and pupils’ lack of interest for the PE classes, i.e. it suggests the pupils’ possible development of motivation for work using the appropriate educational contents.

  7. [Physics of materials and female stress urinary continence: New concepts: I) Elasticity under bladder].

    Science.gov (United States)

    Guerquin, B

    2015-09-01

    Improving the understanding of the adaptation to stress of urinary continence. A transversal analysis between physics of materials and the female anatomy. Laws of physics of the materials and of their viscoelastic behavior are applied to the anatomy of the anterior vaginal wall. The anterior vaginal wall may be divided into two segments of different viscoelastic behavior, the vertical segment below the urethra and the horizontal segment below the bladder. If the urethra gets crushed on the first segment according to the hammock theory, the crushing of the bladder on the second segment is, on the other hand, damped by its important elasticity. The importance of this elasticity evokes an unknown function: damping under the bladder that moderates and delays the increase of intravesical pressure. This damping function below the bladder is increased in the cystocele, which is therefore a continence factor; on the other hand, it is impaired in obesity, which is therefore a factor of SUI. It is necessary to include in the theory of stress continence, the notion of a damping function below the bladder. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  8. Sociospatial distribution of access to facilities for moderate and vigorous intensity physical activity in Scotland by different modes of transport

    Directory of Open Access Journals (Sweden)

    Lamb Karen E

    2012-07-01

    Full Text Available Abstract Background People living in neighbourhoods of lower socioeconomic status have been shown to have higher rates of obesity and a lower likelihood of meeting physical activity recommendations than their more affluent counterparts. This study examines the sociospatial distribution of access to facilities for moderate or vigorous intensity physical activity in Scotland and whether such access differs by the mode of transport available and by Urban Rural Classification. Methods A database of all fixed physical activity facilities was obtained from the national agency for sport in Scotland. Facilities were categorised into light, moderate and vigorous intensity activity groupings before being mapped. Transport networks were created to assess the number of each type of facility accessible from the population weighted centroid of each small area in Scotland on foot, by bicycle, by car and by bus. Multilevel modelling was used to investigate the distribution of the number of accessible facilities by small area deprivation within urban, small town and rural areas separately, adjusting for population size and local authority. Results Prior to adjustment for Urban Rural Classification and local authority, the median number of accessible facilities for moderate or vigorous intensity activity increased with increasing deprivation from the most affluent or second most affluent quintile to the most deprived for all modes of transport. However, after adjustment, the modelling results suggest that those in more affluent areas have significantly higher access to moderate and vigorous intensity facilities by car than those living in more deprived areas. Conclusions The sociospatial distributions of access to facilities for both moderate intensity and vigorous intensity physical activity were similar. However, the results suggest that those living in the most affluent neighbourhoods have poorer access to facilities of either type that can be reached on foot

  9. Synchronized mammalian cell culture: part I--a physical strategy for synchronized cultivation under physiological conditions.

    Science.gov (United States)

    Barradas, Oscar Platas; Jandt, Uwe; Becker, Max; Bahnemann, Janina; Pörtner, Ralf; Zeng, An-Ping

    2015-01-01

    Conventional analysis and optimization procedures of mammalian cell culture processes mostly treat the culture as a homogeneous population. Hence, the focus is on cell physiology and metabolism, cell line development, and process control strategy. Impact on cultivations caused by potential variations in cellular properties between different subpopulations, however, has not yet been evaluated systematically. One main cause for the formation of such subpopulations is the progress of all cells through the cell cycle. The interaction of potential cell cycle specific variations in the cell behavior with large-scale process conditions can be optimally determined by means of (partially) synchronized cultivations, with subsequent population resolved model analysis. Therefore, it is desirable to synchronize a culture with minimal perturbation, which is possible with different yield and quality using physical selection methods, but not with frequently used chemical or whole-culture methods. Conventional nonsynchronizing methods with subsequent cell-specific, for example, flow cytometric analysis, can only resolve cell-limited effects of the cell cycle. In this work, we demonstrate countercurrent-flow centrifugal elutriation as a useful physical method to enrich mammalian cell populations within different phases of a cell cycle, which can be further cultivated for synchronized growth in bioreactors under physiological conditions. The presented combined approach contrasts with other physical selection methods especially with respect to the achievable yield, which makes it suitable for bioreactor scale cultivations. As shown with two industrial cell lines (CHO-K1 and human AGE1.HN), synchronous inocula can be obtained with overall synchrony degrees of up to 82% in the G1 phase, 53% in the S phase and 60% in the G2/M phase, with enrichment factors (Ysync) of 1.71, 1.79, and 4.24 respectively. Cells are able to grow with synchrony in bioreactors over several cell cycles. This

  10. Microbial and physical properties as indicators of sandy soil quality under cropland and grassland

    Science.gov (United States)

    Frac, Magdalena; Lipiec, Jerzy; Usowicz, Boguslaw; Oszust, Karolina; Brzezinska, Malgorzata

    2017-04-01

    Land use is one of the key factor driving changes in soil properties influencing on soil health and quality. Microbial diversity and physical properties are sensitive indicators for assessing soil health and quality. The alterations of microbial diversity and physical properties following land use changes have not been sufficiently elucidated, especially for sandy soils. We investigated microbial diversity indicators including fungal communities composition and physical properties of sandy acid soil under cropland and more than 20-yr-old grassland (after cropland) in Trzebieszów, Podlasie Region, Poland (N 51° 59' 24", E 22° 33' 37"). The study included four depths within 0-60 cm. Microbial genetic diversity was assessed by terminal restriction fragment length polymorphism (t-RFLP) analysis, fungal community composition was evaluated by next generation sequencing (NGS) analysis and functional diversity was determined by Biolog EcoPlate method. Overall microbial activity was assessed by soil enzymes (dehydrogenases, β-glucosidase) and respiration test. At the same places soil texture, organic carbon content, pH, bulk density, water holding capacity were determined. Our results showed that grassland soil was characterized by higher activity of soil enzymes than cropland. The average well color development of soil microorganisms, the microbial functional diversity and the number of carbon source utilization were significantly affected by land use type and were differentiated among soil depths. In grassland compared to cropland soil a significant increase of carboxylic acids and decrease of amino acids utilization was observed. The quantitative and qualitative differences were found in community of ammonia oxidizing archaea in cropland and grassland soil. The results of fungal community composition help to explain the soil health of grassland and cropland based on the appearance of phytopathogenic and antagonistic fungi. In general bulk density and field water

  11. Suitability of Commercial Transport Media for Biological Pathogens under Nonideal Conditions

    Directory of Open Access Journals (Sweden)

    Kyle Hubbard

    2011-01-01

    Full Text Available There is extensive data to support the use of commercial transport media as a stabilizer for known clinical samples; however, there is little information to support their use outside of controlled conditions specified by the manufacturer. Furthermore, there is no data to determine the suitability of said media for biological pathogens, specifically those of interest to the US military. This study evaluates commercial off-the-shelf (COTS transport media based on sample recovery, viability, and quality of nucleic acids and peptides for nonpathogenic strains of Bacillus anthracis, Yersinia pestis, and Venezuelan equine encephalitis virus, in addition to ricin toxin. Samples were stored in COTS, PBST, or no media at various temperatures over an extended test period. The results demonstrate that COTS media, although sufficient for the preservation of nucleic acid and proteinaceous material, are not capable of maintaining an accurate representation of biothreat agents at the time of collection.

  12. Electron transport in bulk GaN under ultrashort high-electric field transient

    Science.gov (United States)

    Korotyeyev, V. V.; Kochelap, V. A.; Kim, K. W.

    2011-10-01

    We have investigated nonlinear electron transport in GaN induced by high-electric field transients by analyzing the temporal dependence of the electron drift velocity and temperature. For picosecond transients, our calculations have established that the electron dynamics retain almost all the features of the steady-state velocity-field characteristics including the portion with negative differential conductivity. It was also found that transient currents in GaN samples give rise to the THz re-emission effect—radiation of electromagnetic field, temporal and spectral properties of which directly relate to the velocity-field characteristics of the sample. The results clearly indicate that existing methods for the generation of high-electric field transients and subpicosecond signal measurements can be applied to the characterization of hot electron transport at ultrahigh fields while avoiding Joule self-heating, hot phonon accumulation and other undesirable effects.

  13. Magnetic Shear and Transport in ECRH Discharges of the TJ-II under Ohmic Induction

    Energy Technology Data Exchange (ETDEWEB)

    Lopez-Bruna, D.; Castejon, F.; Romero, J. A.; Estrada, T.; Medina, F.; Ochando, M.; Lopez-Fraguas, A.; Ascasibar, E.; Herranz, J.; Sanchez, E.; Luna, E. de la; Pastor, I.

    2006-07-01

    TJ-II is ha heliac type stellarator characterised by high, but almost constant, vacuum rotational transform throughout the confining volume. In ECRH plasmas, moderate induced ohmic currents (negligible heating and modification of the magnetic field nodules) are enough to disregard the bootstrap contribution, which allows us performing a fair calculation of the evolution of the rotational transform. We use the loop voltage diagnostic to estimate the plasma electrical conductivity. Then the evolution of the rotational transform and shear is related to changes in the profiles of electron and thermal diffusivities: negative shear correlates with decreasing diffusivities in the region of steepest density gradient; transport increases toward zero shear but the achieved positive values are too small to draw conclusions. The radial sweeping of lowest order rational magnetic surfaces does not determine the observed trends in transport. (Author)43 refs.

  14. Magnetic Shear and Transport in ECRH Discharges of the TJ-II under Ohmic Induction

    International Nuclear Information System (INIS)

    Lopez-Bruna, D.; Castejon, F.; Romero, J. A.; Estrada, T.; Medina, F.; Ochando, M.; Lopez-Fraguas, A.; Ascasibar, E.; Herranz, J.; Sanchez, E.; Luna, E. de la; Pastor, I.

    2006-01-01

    TJ-II is ha heliac type stellarator characterised by high, but almost constant, vacuum rotational transform throughout the confining volume. In ECRH plasmas, moderate induced ohmic currents (negligible heating and modification of the magnetic field nodules) are enough to disregard the bootstrap contribution, which allows us performing a fair calculation of the evolution of the rotational transform. We use the loop voltage diagnostic to estimate the plasma electrical conductivity. Then the evolution of the rotational transform and shear is related to changes in the profiles of electron and thermal diffusivities: negative shear correlates with decreasing diffusivities in the region of steepest density gradient; transport increases toward zero shear but the achieved positive values are too small to draw conclusions. The radial sweeping of lowest order rational magnetic surfaces does not determine the observed trends in transport. (Author)43 refs

  15. Fluid Dynamics Applied to Streams. Physical Processes in Terrestrial and Aquatic Ecosystems, Transport Processes.

    Science.gov (United States)

    Cowan, Christina E.

    This module is part of a series designed to be used by life science students for instruction in the application of physical theory to ecosystem operation. Most modules contain computer programs which are built around a particular application of a physical process. This module deals specifically with concepts that are basic to fluid flow and…

  16. Transpiration and Leaf Temperature. Physical Processes in Terrestrial and Aquatic Ecosystems, Transport Processes.

    Science.gov (United States)

    Gates, David M.

    These materials were designed to be used by life science students for instruction in the application of physical theory to ecosystem operation. Most modules contain computer programs which are built around a particular application of a physical process. This report introduces two models of the thermal energy budget of a leaf. Typical values for…

  17. Pressure and Buoyancy in Aquatic Ecosystems. Physical Processes in Terrestrial and Aquatic Ecosystems, Transport Processes.

    Science.gov (United States)

    Cowan, Christina E.

    This module is part of a series designed to be used by life science students for instruction in the application of physical theory to ecosystem operation. Most modules contain computer programs which are built around a particular application of a physical process. This module explores some of the characteristics of aquatic organisms which can be…

  18. Thermodynamics of Irreversible Processes. Physical Processes in Terrestrial and Aquatic Ecosystems, Transport Processes.

    Science.gov (United States)

    Levin, Michael; Gallucci, V. F.

    These materials were designed to be used by life science students for instruction in the application of physical theory to ecosystem operation. Most modules contain computer programs which are built around a particular application of a physical process. This module describes the application of irreversible thermodynamics to biology. It begins with…

  19. Secure Fusion Estimation for Bandwidth Constrained Cyber-Physical Systems Under Replay Attacks.

    Science.gov (United States)

    Chen, Bo; Ho, Daniel W C; Hu, Guoqiang; Yu, Li

    2017-07-03

    State estimation plays an essential role in the monitoring and supervision of cyber-physical systems (CPSs), and its importance has made the security and estimation performance a major concern. In this case, multisensor information fusion estimation (MIFE) provides an attractive alternative to study secure estimation problems because MIFE can potentially improve estimation accuracy and enhance reliability and robustness against attacks. From the perspective of the defender, the secure distributed Kalman fusion estimation problem is investigated in this paper for a class of CPSs under replay attacks, where each local estimate obtained by the sink node is transmitted to a remote fusion center through bandwidth constrained communication channels. A new mathematical model with compensation strategy is proposed to characterize the replay attacks and bandwidth constrains, and then a recursive distributed Kalman fusion estimator (DKFE) is designed in the linear minimum variance sense. According to different communication frameworks, two classes of data compression and compensation algorithms are developed such that the DKFEs can achieve the desired performance. Several attack-dependent and bandwidth-dependent conditions are derived such that the DKFEs are secure under replay attacks. An illustrative example is given to demonstrate the effectiveness of the proposed methods.

  20. Interface traps contribution on transport mechanisms under illumination in metal-oxide-semiconductor structures based on silicon nanocrystals

    Science.gov (United States)

    Chatbouri, S.; Troudi, M.; Kalboussi, A.; Souifi, A.

    2018-02-01

    The transport phenomena in metal-oxide-semiconductor (MOS) structures having silicon nanocrystals (Si-NCs) inside the dielectric layer have been investigated, in dark condition and under visible illumination. At first, using deep-level transient spectroscopy (DLTS), we find the presence of series electron traps having very close energy levels (comprised between 0.28 and 0.45 eV) for ours devices (with/without Si-NCs). And a single peak appears at low temperature only for MOS with Si-NCs related to Si-NCs DLTS response. In dark condition, the conduction mechanism is dominated by the thermionic fast emission/capture of charge carriers from the highly doped polysilicon layer to Si-substrate through interface trap states for MOS without Si-NCs. The tunneling of charge carriers from highly poly-Si to Si substrate trough the trapping/detrapping mechanism in the Si-NCs, at low temperature, contributed to the conduction mechanism for MOS with Si-NCs. The light effect on transport mechanisms has been investigated using current-voltage ( I- V), and high frequency capacitance-voltage ( C- V) methods. We have been marked the photoactive trap effect in inversion zone at room temperature in I- V characteristics, which confirm the contribution of photo-generated charge on the transport mechanisms from highly poly-Si to Si substrate trough the photo-trapping/detrapping mechanism in the Si-NCs and interfaces traps levels. These results have been confirmed by an increasing about 10 pF in capacity's values for the C- V characteristics of MOS with Si-NCs, in the inversion region for inverse high voltage applied under photoexcitation at low temperature. These results are helpful to understand the principle of charge transport in dark condition and under illumination, of MOS structures having Si-NCs in the SiO x = 1.5 oxide matrix.

  1. Transport of titanium dioxide nanoparticles in saturated porous media under various solution chemistry conditions

    International Nuclear Information System (INIS)

    Wang Yu; Gao Bin; Morales, Verónica L.; Tian Yuan; Wu Lei; Gao Jie; Bai Wei; Yang Liuyan

    2012-01-01

    Because of its wide applications, nanosized titanium dioxide may become a potential environmental risk to soil and groundwater system. It is therefore important to improve current understanding of the environmental fate and transport of titanium oxides nanoparticles (TONPs). In this work, the effect of solution chemistry (i.e., pH, ionic strength, and natural organic matter (NOM) concentration) on the deposition and transport of TONPs in saturated porous media was examined in detail. Laboratory columns packed with acid-cleaned quartz sand were used in the experiment as porous media. Transport experiments were conducted with various chemistry combinations, including four ionic strengths, three pH levels, and two NOM concentrations. The results showed that TONP mobility increased with increasing solution pH, but decreased with increasing solution ionic strength. It is also found that the presence of NOM in the system enhanced the mobility of TONPs in the saturated porous media. The Derjaguin–Landau–Verwey–Overbeek (DLVO) theory was used to justify the mobility trends observed in the experimental data. Predictions from the theory agreed excellently with the experimental data.

  2. Electrical transport properties of AlAs under compression: reversible boundary effect.

    Science.gov (United States)

    Yan, Jiejuan; Ke, Feng; Liu, Cailong; Wang, Qinglin; Zhang, Junkai; Wang, Li; Peng, Gang; Han, Yonghao; Ma, Yanzhang; Gao, Chunxiao

    2015-10-21

    Herein, we report on the intriguing electrical transport properties of compressed AlAs. The relative permittivity and the resistances of both the grain and bulk boundaries vary abnormally at ∼10.9 GPa, accompanied by the cubic-hexagonal structural transition of AlAs. With further compression, the boundary effect becomes undistinguished, and subsequently, the electrical transport mechanism converts from boundary- to bulk-dominated, which gives rise to a significant reduction in the total resistance of AlAs. After being quenched to ambient pressure, resistances recover to the initial values followed by the re-emergence of the boundary effect. Eg decreases with pressure and its pressure dependence changes at ∼14.0 GPa, which rationalizes the anomalous variation of the electrical transport properties. The experimental results indicate that the boundary effect can be modulated by compression and increases the resistance difference between the two states. This opens up a new possible basis for optimizing the performance of AlAs-based applications, including multilevel phase-change memories.

  3. Analytical and experimental investigations of the passive heat transport in HTRs under severe accident conditions

    International Nuclear Information System (INIS)

    Rehm, W.; Barthels, H.; Jahn, W.; Cleveland, J.C.; Ishihara, M.

    1992-01-01

    Thermodynamic accident analyses have been performed with computer simulation models to investigate core heatup sequences, sensitivity analyses, power variations, anticipated transients without scram, and core displacement considerations for probabilistic safety analyses (PSA) of small gas-cooled high-temperature reactors (e.g. HTR-Module). In worst case considerations where not only a loss of the active heat removal system is assumed but also a loss of the vessel cooling system, the heat would be transported into the surrounding concrete structure. In such a case the concrete would act as a natural long-term intermediate heat storage dissipating the heat through the concrete surface. Large scale and reactor safety experiments have been performed to investigate passive heat transport mechanisms -- which can cooldown a HIR core during severe accident conditions -- for validation basis of computer simulation codes used for accident analyses. In general, the comparisons of experimental and analytical results with computer calculations of the heat transport codes are in good agreement

  4. The climatological mean atmospheric transport under weakened Atlantic thermohaline circulation climate scenario

    Energy Technology Data Exchange (ETDEWEB)

    Erukhimova, T. [Texas A and M University, Department of Physics, College Station, TX (United States); Zhang, R. [GFDL/NOAA, Princeton, NJ (United States); Bowman, K.P. [Texas A and M University, Department of Atmospheric Sciences, College Station, TX (United States)

    2009-02-15

    Global atmospheric transport in a climate subject to a substantial weakening of the Atlantic thermohaline circulation (THC) is studied by using climatological Green's functions of the mass conservation equation for a conserved, passive tracer. Two sets of Green's functions for the perturbed climate and for the present climate are evaluated from 11-year atmospheric trajectory calculations, based on 3-D winds simulated by GFDL's newly developed global coupled ocean-atmosphere model (CM2.1). The Green's function analysis reveals pronounced effects of the climate change on the atmospheric transport, including seasonally modified Hadley circulation with a stronger Northern Hemisphere cell in DJF and a weaker Southern Hemisphere cell in JJA. A weakened THC is also found to enhance mass exchange rates through mixing barriers between the tropics and the two extratropical zones. The response in the tropics is not zonally symmetric. The 3-D Green's function analysis of the effect of THC weakening on transport in the tropical Pacific shows a modified Hadley cell in the eastern Pacific, confirming the results of our previous studies, and a weakening (strengthening) of the upward and eastward motion to the south (north) of the Equator in the western Pacific in the perturbed climate as compared to the present climate. (orig.)

  5. Dynamical transition of heat transport in a physical gel near the sol-gel transition

    Science.gov (United States)

    Kobayashi, Kazuya U.; Oikawa, Noriko; Kurita, Rei

    2015-12-01

    We experimentally study heat transport in a gelatin solution near a reversible sol-gel transition point where viscosity strongly depends on temperature. We visualize the temperature field and velocity field using thermochromic liquid crystals and polystyrene latex particles, respectively. During the initial stages of heating, we find that heat transport undergoes a dynamical transition from conductive to convective. Subsequently, during later stages, we observe that the transport dynamics are much more complex than conventional thermal convections. At the sample’s surface we observe the formation of stagnant domains, which lack fluid flow. Their formation is not due to the effects of local cooling. We determine that it is the dynamics of these stagnant domains that induce convective-conductive-convective transitions.

  6. Avoiding transport bottlenecks in an expanding root system: xylem vessel development in fibrous and pioneer roots under field conditions.

    Science.gov (United States)

    Bagniewska-Zadworna, Agnieszka; Byczyk, Julia; Eissenstat, David M; Oleksyn, Jacek; Zadworny, Marcin

    2012-09-01

    Root systems develop to effectively absorb water and nutrients and to rapidly transport these materials to the transpiring shoot. In woody plants, roots can be born with different functions: fibrous roots are primarily used for water and nutrient absorption, whereas pioneer roots have a greater role in transport. Because pioneer roots extend rapidly in the soil and typically quickly produce fibrous roots, they need to develop transport capacity rapidly so as to avoid becoming a bottleneck to the absorbed water of the developing fibrous roots and, as we hypothesized, immediately activate a specific type of autophagy at a precise time of their development. Using microscopy techniques, we monitored xylem development in Populus trichocarpa roots in the first 7 d after emergence under field conditions. Newly formed pioneer roots contained more primary xylem poles and had larger diameter tracheary elements than fibrous roots. While xylogenesis started later in pioneer roots than in fibrous, it was completed at the same time, resulting in functional vessels on the third to fourth day following root emergence. Programmed cell death was responsible for creating the water conducting capacity of xylem. Although the early xylogenesis processes were similar in fibrous and pioneer roots, secondary vascular development proceeded much more rapidly in pioneer roots. Compared to fibrous roots, rapid development of transport capacity in pioneer roots is not primarily caused by accelerated xylogenesis but by larger and more numerous tracheary elements and by rapid initiation of secondary growth.

  7. SELECTED DESIGNING ISSUES OF INNOVATIVE MEANS OF TRANSPORT ADAPTED TO PEOPLE WITH LIMITED PHYSICAL ABILITY

    Directory of Open Access Journals (Sweden)

    Iwona GRABAREK

    2014-06-01

    Full Text Available Nowadays, the challenge for transport designers is to ensure more mobility and participation in social life of elderly and disabled people, because of the systematic increase of this group. The selected issues regarding designing of the two new public means of transport construction, completely adjusted to the elderly and disabled people have been presented in this paper. The research work has been carried out within the Eco Mobility Project that is co-financed by the European Regional Development Fund/Operational Programme for Innovative Economy. The innovative solution of eco-car and PRT vehicle have been presented.

  8. The effect of exogenous calcium on mitochondria, respiratory metabolism enzymes and ion transport in cucumber roots under hypoxia.

    Science.gov (United States)

    He, Lizhong; Li, Bin; Lu, Xiaomin; Yuan, Lingyun; Yang, Yanjuan; Yuan, Yinghui; Du, Jing; Guo, Shirong

    2015-08-25

    Hypoxia induces plant stress, particularly in cucumber plants under hydroponic culture. In plants, calcium is involved in stress signal transmission and growth. The ultimate goal of this study was to shed light on the mechanisms underlying the effects of exogenous calcium on the mitochondrial antioxidant system, the activity of respiratory metabolism enzymes, and ion transport in cucumber (Cucumis sativus L. cv. Jinchun No. 2) roots under hypoxic conditions. Our experiments revealed that exogenous calcium reduces the level of reactive oxygen species (ROS) and increases the activity of antioxidant enzymes in mitochondria under hypoxia. Exogenous calcium also enhances the accumulation of enzymes involved in glycolysis and the tricarboxylic acid (TCA) cycle. We utilized fluorescence and ultrastructural cytochemistry methods to observe that exogenous calcium increases the concentrations of Ca(2+) and K(+) in root cells by increasing the activity of plasma membrane (PM) H(+)-ATPase and tonoplast H(+)-ATPase and H(+)-PPase. Overall, our results suggest that hypoxic stress has an immediate and substantial effect on roots. Exogenous calcium improves metabolism and ion transport in cucumber roots, thereby increasing hypoxia tolerance in cucumber.

  9. Anisotropic transport properties of quasiballistic InAs nanowires under high magnetic field

    Science.gov (United States)

    Vigneau, Florian; Zeng, Zaiping; Escoffier, Walter; Caroff, Philippe; Leturcq, Renaud; Niquet, Yann-Michel; Raquet, Bertrand; Goiran, Michel

    2018-03-01

    The magnetoconductance of a long channel InAs nanowire based field effect transistor in the quasiballistic regime under large magnetic field is investigated. The quasi-1D nanowire is fully characterized by a bias voltage spectroscopy and measurements under magnetic field up to 50 T applied either perpendicular or parallel to the nanowire axis lifting the spin and orbital degeneracies of the subbands. Under normal magnetic field, the conductance shows quantized steps due to the backscattering reduction and a decrease due to depopulation of the 1D modes. Under axial magnetic field, a quasioscillatory behavior is evidenced due to the coupling of the magnetic field with the angular momentum of the wave function. In addition the formation of cyclotron orbits is highlighted under high magnetic field. The experimental results are compared with theoretical calculation of the 1D band structure and related parameters.

  10. A Hitch-hiker's Guide to Stochastic Differential Equations. Solution Methods for Energetic Particle Transport in Space Physics and Astrophysics

    Science.gov (United States)

    Strauss, R. Du Toit; Effenberger, Frederic

    2017-10-01

    In this review, an overview of the recent history of stochastic differential equations (SDEs) in application to particle transport problems in space physics and astrophysics is given. The aim is to present a helpful working guide to the literature and at the same time introduce key principles of the SDE approach via "toy models". Using these examples, we hope to provide an easy way for newcomers to the field to use such methods in their own research. Aspects covered are the solar modulation of cosmic rays, diffusive shock acceleration, galactic cosmic ray propagation and solar energetic particle transport. We believe that the SDE method, due to its simplicity and computational efficiency on modern computer architectures, will be of significant relevance in energetic particle studies in the years to come.

  11. Survey of ABC transporter and metallothionein genes expressions in tall fescue inoculated with Funneliformis intraradices under Nickel toxicity

    Directory of Open Access Journals (Sweden)

    Massomeh Rafiei-Demneh

    2016-09-01

    Full Text Available In plants, there are complex network of transport, chelation, and sequestration processes that functions in maintaining concentrations of essential metal ions in different cellular compartments, thus minimizing the damage caused by entry of non-essential metal ions into the cytosol. In the presence of toxic ones, arbuscular mycorrhizal (AM fungi are able to alleviate metal toxicity in the plant. In this study the effect of an arbuscular mycorrhizal fungi Funneliformis intraradices on growth, Nickel tolerance, and ABC transporter and metallothionein expression in leaves and roots of tall fescue (Festuca arundinacea plants cultivated in Ni polluted soil were evaluated. The fungi infected (M+ and uninfected (M- fescue plants were cultivated in soil under different Ni concentrations (0, 30, 90 and 180 ppm for 3 months. Results demonstrated the positive effect of fungi colonization on the increase in growth and reduction in Ni uptake (90 and 180 ppm and Ni translocation from roots to shoot of tall fescue under Ni stress. The results also demonstrated that the level of ABC transporterand metallothionein transcripts accumulation in roots was considerably higher for both M- and M+ plants compared to the control. Also, M+ plants showed less ABC and MET expression compared to the M- plants. These results demonstrated the importance of mycorrhizal colonization of F. intraradices in reduction of Ni transport from root to shoot of tall fescue which alleviates Ni-induced stress.

  12. Meteorology, physical oceanography, transport of water, biogeochemistry, and other parameters collected at fixed locations in the open ocean from the OceanSITES network

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This collection comprises data covering meteorology, physical oceanography, transport of water, biogeochemistry, and parameters relevant to the carbon cycle, ocean...

  13. On the physics of upgradient momentum transport in unstable eastward jets

    NARCIS (Netherlands)

    Dijkstra, H.A.; Vaart, P.C.F. van der

    1998-01-01

    The weakly nonlinear finite amplitude evolution of mixed baro-clinic / barotropic instabilities of an eastward zonal jet is considered in a two-layer QG-model on a midlatitude beta-plane. Linear friction is included and is essential to the momentum transport. The focus is two parameter regimes,

  14. Test-Retest Reliability of a Survey to Measure Transport-Related Physical Activity in Adults

    Science.gov (United States)

    Badland, Hannah; Schofield, Grant

    2006-01-01

    The present research details test-retest reliability of a newly developed, telephone-administered TPA survey for adults. This instrument examines barriers, perceptions, and current travel behaviors to place of work/study and local convenience shops. Demonstrated test-retest reliability of the Active Friendly Environments-Transport-Related Physical…

  15. Influence of Physical Properties of Liquids on Transport Velocity through Wood and Its Dimensional Analysis

    NARCIS (Netherlands)

    Kojima, Kazuo; Ohta, Masamitsu

    2010-01-01

    An apparent diffusion coefficient was defined as an index of transport rate of liquids through wood by analogy to Fick's diffusion coefficient, even though the entire processes of penetration into wood would be different from those of actual diffusion. All measurements were carried out on Western

  16. Ion transport in roots of cotton seedlings under the effect of gamma-radiation

    International Nuclear Information System (INIS)

    Kasymov, A.K.

    1976-01-01

    It has been found that small doses (0.1 to 0.5kR) increase the ion transport (K + and Na + ) in seedling roots, and relatively high radiation doses (25 to 100 kR) markedly decrease it. ATPase activity varied with the dose. Mgsup(++)-, Na + - and K + -activated ATPases were more sensitive than a background ATPase. It is suggested that high radiation doses destroy the work of the sodium-potassium pump of cotton root cells inhibiting the activity of the transfer ATPase

  17. Electron transport in nanometer GaAs structure under radiation exposure

    CERN Document Server

    Demarina, N V

    2002-01-01

    One investigates into effect of neutron and proton irradiation on electron transport in nanometer GaAs structures. Mathematical model takes account of radiation defects via introduction of additional mechanisms od scattering of carriers at point defects and disordered regions. To investigate experimentally into volt-ampere and volt-farad characteristics one used a structure based on a field-effect transistor with the Schottky gate and a built-in channel. Calculation results of electron mobility, drift rate of electrons, time of energy relaxation and electron pulse are compared with the experimental data

  18. The transport properties of BSCCO superconducting tapes under cyclic stress/strain conditions

    International Nuclear Information System (INIS)

    Oduleye, O.O.

    1999-01-01

    Current research on high temperature superconducting (HTS) ceramics is concerned with the optimisation of the mechanical, physiochemical and electromagnetic properties of multifilamentary structures with cores of either yttrium-based cuprates, thallium-based cuprates or bismuth-based cuprates. Owing to their superior intergrain transport current carrying capacity and the relative success in the manufacture of tapes, the bismuth-based cuprates, collectively known as BSCCO, have shown the most promise for practical engineering applications. Silver clad (Bi,Pb) 2 Sr 2 Ca 2 Cu 3 O 10 , (Ag/BSCCO-2223) tapes prepared by the powder in method (PIT) have been investigated

  19. Water transport by the Na+/glucose cotransporter under isotonic conditions

    DEFF Research Database (Denmark)

    Zeuthen, T; Meinild, A K; Klaerke, D A

    1997-01-01

    Solute cotransport in the Na+/glucose cotransporter is directly coupled to significant water fluxes. The water fluxes are energized by the downhill fluxes of the other substrates by a mechanism within the protein itself. In the present paper we investigate the Na+/glucose cotransporter expressed ...... of water molecules and the number of Na+ ions transported, equivalent to 390 water molecules per glucose molecule. Unstirred layer effects are ruled out on the basis of experiments on native oocytes incubated with the ionophores gramicidin D or nystatin....

  20. Conjugate problems of transport phenomena under quasi-steady microaccelerations in realistic spaceflight.

    Science.gov (United States)

    Polezhaev, V I; Nikitin, S A

    2009-04-01

    A new model for spatial convective transport processes conjugated with the measured or calculated realistic quasi-steady microaccelerations is presented. Rotation around the mass center, including accelerated rotation, gravity gradient, and aerodynamical drag are taken into account. New results of the effect on mixing and concentration inhomogeneities of the elementary convective processes are presented. The mixing problem in spacecraft enclosures, concentration inhomogeneities due to convection induced by body forces in realistic spaceflight, and the coupling of this kind of convection with thermocapillary convection on the basis of this model are discussed.

  1. Nutrient transports in the Baltic Sea - results from a 30-year physical-biogeochemical reanalysis

    Science.gov (United States)

    Liu, Ye; Meier, H. E. Markus; Eilola, Kari

    2017-04-01

    Long-term oxygen and nutrient transports in the Baltic Sea are reconstructed using the Swedish Coastal and Ocean Biogeochemical model (SCOBI) coupled to the Rossby Centre Ocean model (RCO). Two simulations with and without data assimilation covering the period 1970-1999 are carried out. Here, the weakly coupled scheme with the Ensemble Optimal Interpolation (EnOI) method is adopted to assimilate observed profiles in the reanalysis system. The reanalysis shows considerable improvement in the simulation of both oxygen and nutrient concentrations relative to the free run. Further, the results suggest that the assimilation of biogeochemical observations has a significant effect on the simulation of the oxygen-dependent dynamics of biogeochemical cycles. From the reanalysis, nutrient transports between sub-basins, between the coastal zone and the open sea, and across latitudinal and longitudinal cross sections are calculated. Further, the spatial distributions of regions with nutrient import or export are examined. Our results emphasize the important role of the Baltic proper for the entire Baltic Sea, with large net transport (export minus import) of nutrients from the Baltic proper into the surrounding sub-basins (except the net phosphorus import from the Gulf of Riga and the net nitrogen import from the Gulf of Riga and Danish Straits). In agreement with previous studies, we found that the Bothnian Sea imports large amounts of phosphorus from the Baltic proper that are retained in this sub-basin. For the calculation of sub-basin budgets, the location of the lateral borders of the sub-basins is crucial, because net transports may change sign with the location of the border. Although the overall transport patterns resemble the results of previous studies, our calculated estimates differ in detail considerably.

  2. Integrating supply and demand aspects of transportation for mass evacuation under disasters.

    Science.gov (United States)

    2009-10-15

    This study seeks to address real-time operational needs in the context of the evacuation response problem by providing a capability to dynamically route vehicles under evacuation, thereby being responsive to the actual conditions unfolding in real-ti...

  3. 49 CFR 1.74 - Delegations to the Under Secretary for Transportation Policy.

    Science.gov (United States)

    2010-10-01

    ... Equity Act: A Legacy for Users” to manage the day-to-day activities associated with implementation of section 11143 regarding tax-exempt financing of highway projects and rail-truck facilities. The Under...

  4. 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.

  5. Dynamics of herbicide transport and partitioning under event flow conditions in the lower Burdekin region, Australia

    International Nuclear Information System (INIS)

    Davis, Aaron M.; Lewis, Stephen E.; Bainbridge, Zoë T.; Glendenning, Lionel; Turner, Ryan D.R.; Brodie, Jon E.

    2012-01-01

    This study examined the temporal variability in herbicide delivery to the Great Barrier Reef (GBR) lagoon (Australia) from one of the GBR catchment’s major sugarcane growing regions. Annual loads of measured herbicides were consistently in the order of 200+ kg. Atrazine, it’s degradate desethylatrazine, and diuron contributed approximately 90% of annual herbicide load, with early ‘first-flush’ events accounting for the majority of herbicide loads leaving the catchment. Assessment of herbicide water–sediment partitioning in flood runoff highlighted the majority of herbicides were transported in predominantly dissolved form, although a considerable fraction of diuron was transported in particulate-bound form (ca. 33%). Diuron was also the herbicide demonstrating the highest concentrations and frequency of detection in sediments collected from catchment waterways and adjacent estuarine–marine environments, an outcome aligning with previous research. Herbicide physico-chemical properties appear to play a crucial role in partitioning between water column and sediment habitat types in GBR receiving ecosystems.

  6. A binomial modeling approach for upscaling colloid transport under unfavorable conditions: organic prediction of extended tailing

    Science.gov (United States)

    Hilpert, Markus; Rasmuson, Anna; Johnson, William

    2017-04-01

    Transport of colloids in saturated porous media is significantly influenced by colloidal interactions with grain surfaces. Near-surface fluid domain colloids experience relatively low fluid drag and relatively strong colloidal forces that slow their down-gradient translation relative to colloids in bulk fluid. Near surface fluid domain colloids may re-enter into the bulk fluid via diffusion (nanoparticles) or expulsion at rear flow stagnation zones, they may immobilize (attach) via strong primary minimum interactions, or they may move along a grain-to-grain contact to the near surface fluid domain of an adjacent grain. We introduce a simple model that accounts for all possible permutations of mass transfer within a dual pore and grain network. The primary phenomena thereby represented in the model are mass transfer of colloids between the bulk and near-surface fluid domains and immobilization onto grain surfaces. Colloid movement is described by a sequence of trials in a series of unit cells, and the binomial distribution is used to calculate the probabilities of each possible sequence. Pore-scale simulations provide mechanistically-determined likelihoods and timescales associated with the above pore-scale colloid mass transfer processes, whereas the network-scale model employs pore and grain topology to determine probabilities of transfer from up-gradient bulk and near-surface fluid domains to down-gradient bulk and near-surface fluid domains. Inter-grain transport of colloids in the near surface fluid domain can cause extended tailing.

  7. Adherent diamond film deposited on Cu substrate by carbon transport from nanodiamond buried under Pt interlayer

    International Nuclear Information System (INIS)

    Liu Xuezhang; Wei Qiuping; Yu Zhiming; Yang Taiming; Zhai Hao

    2013-01-01

    Highlights: ► Adherent polycrystalline diamond films were grown on copper substrate by carbon transport. ► The nucleation density was increased to 10 11 cm −2 . ► Diamond films were a composite structure of nano-crystalline diamond layer and micro-crystalline diamond layer. ► Diamond nucleation was based by carbon dissolving from UDDs to Pt interlayer and formation of sp 3 -bonded diamond clusters at the Pt surface. - Abstract: Diamond film deposited on Cu suffered from poor adhesion mainly due to the large mismatch of thermal expansion coefficients and the lack of affinity between carbon and Cu. Enhancing diamond nucleation by carbon transport from buried nanodiamond through a Pt ultrathin interlayer, adherent diamond film was then deposited on Cu substrate without distinctly metallic interlayer. This novel nucleation mechanism increased diamond nucleation density to 10 11 cm −2 , and developed diamond film with a composite structure of nano-crystalline diamond (NCD) layer and micro-crystalline diamond layer. Diamond film was characterized by the scanning electron microscope (SEM) and Raman spectroscope, respectively. The composition of diamond film/Cu substrate interface was examined by electron probe microanalysis (EPMA). The adhesion of diamond film was evaluated by indentation test. Those results show that a Pt ultrathin interlayer provides stronger chemically bonded interfaces and improve film adhesion.

  8. Role of hybrid forecasting techniques for transportation planning of broiler meat under uncertain demand in thailand

    Directory of Open Access Journals (Sweden)

    Thoranin Sujjaviriyasup

    2014-12-01

    Full Text Available One of numerous problems experiencing in supply chain management is the demand. Most demands are appeared in terms of uncertainty. The broiler meat industry is inevitably encountering the same problem. In this research, hybrid forecasting model of ARIMA and Support Vector Machine (SVMs are developed to forecast broiler meat export. In addition, ARIMA, SVMs, and Moving Average (MA are chosen for comparing the forecasting efficiency. All the forecasting models are tested and validated using the data of Brazil’s export, Canada’s export, and Thailand’s export. The hybrid model provides accuracy of the forecasted values that are 98.71%, 97.50%, and 93.01%, respectively. In addition, the hybrid model presents the least error of all MAE, RMSE, and MAPE comparing with other forecasting models. As forecasted data are applied to transportation planning, the mean absolute percentage error (MAPE of optimal value of forecasted value and actual value is 14.53%. The hybrid forecasting model shows an ability to reduce risk of total cost of transportation when broiler meat export is forecasted by using MA(2, MA(3, ARIMA, and SVM are 50.59%, 60.18%, 68.01%, and 46.55%, respectively. The results indicate that the developed forecasting model is recommended to broiler meat industries’ supply chain decision.

  9. Adherent diamond film deposited on Cu substrate by carbon transport from nanodiamond buried under Pt interlayer

    Energy Technology Data Exchange (ETDEWEB)

    Liu Xuezhang [School of Materials Science and Engineering, Central South University, Changsha, 410083 (China); Wei Qiuping, E-mail: qiupwei@csu.edu.cn [School of Materials Science and Engineering, Central South University, Changsha, 410083 (China); State Key Laboratory of Powder Metallurgy, Central South University, Changsha, 410083 (China); Yu Zhiming, E-mail: zhiming@csu.edu.cn [School of Materials Science and Engineering, Central South University, Changsha, 410083 (China); State Key Laboratory of Powder Metallurgy, Central South University, Changsha, 410083 (China); Yang Taiming; Zhai Hao [School of Materials Science and Engineering, Central South University, Changsha, 410083 (China)

    2013-01-15

    Highlights: Black-Right-Pointing-Pointer Adherent polycrystalline diamond films were grown on copper substrate by carbon transport. Black-Right-Pointing-Pointer The nucleation density was increased to 10{sup 11} cm{sup -2}. Black-Right-Pointing-Pointer Diamond films were a composite structure of nano-crystalline diamond layer and micro-crystalline diamond layer. Black-Right-Pointing-Pointer Diamond nucleation was based by carbon dissolving from UDDs to Pt interlayer and formation of sp{sup 3}-bonded diamond clusters at the Pt surface. - Abstract: Diamond film deposited on Cu suffered from poor adhesion mainly due to the large mismatch of thermal expansion coefficients and the lack of affinity between carbon and Cu. Enhancing diamond nucleation by carbon transport from buried nanodiamond through a Pt ultrathin interlayer, adherent diamond film was then deposited on Cu substrate without distinctly metallic interlayer. This novel nucleation mechanism increased diamond nucleation density to 10{sup 11} cm{sup -2}, and developed diamond film with a composite structure of nano-crystalline diamond (NCD) layer and micro-crystalline diamond layer. Diamond film was characterized by the scanning electron microscope (SEM) and Raman spectroscope, respectively. The composition of diamond film/Cu substrate interface was examined by electron probe microanalysis (EPMA). The adhesion of diamond film was evaluated by indentation test. Those results show that a Pt ultrathin interlayer provides stronger chemically bonded interfaces and improve film adhesion.

  10. [Response of Sediment Micro Environment and Micro Interface to Physical Disturbance Intensity Under the Disturbance of Chironomus plumosus].

    Science.gov (United States)

    Shi, Xiao-dan; Li, Yong; Li, Da-peng; Wang, Ren; Deng, Meng; Huang, Yong

    2015-05-01

    The response of sediment micro environment and micro intertace to physical disturbance intensity under the physical and Chironomus plumosus disturbance was investigated by means of sediment Rhizon samplers and Unisense micro sensor system. The sediment and overlying water were taken from Meiliang bay of Taihu Lake. The results showed that the OPD reached up to 12.1 mm under the high intensity (240 r · min(-1)), while it was higher than 3. 8. mm under low intensity (60 r · min(-1)). The TOE, the difference of TOE and DOE, OPD, ORP and the difference of DO spatial distribution were all positively correlated with the physical disturbance intensity. The increasing magnitude and range of pH as well as the decreasing magnitude and range of ferrous followed the same response tendency. Within the 0-6 cm sediment, the water content and porosity as well as the microbial activity at the same depth increased with the increase of physical disturbance intensity. In addition, the degree of response of the above parameters to the physical disturbance intensity was weakened with the increase of sediment depth. It was suggested that Chironomus plumosus dug more and deeper galleries under high intensity physical disturbance. Therefore, the sediment micro environment and micro interface were transformed in the vertical direction of the sediment.

  11. Physical-chemical and microbiological changes in Cerrado Soil under differing sugarcane harvest management systems.

    Science.gov (United States)

    Rachid, Caio T C C; Piccolo, Marisa C; Leite, Deborah Catharine A; Balieiro, Fabiano C; Coutinho, Heitor Luiz C; van Elsas, Jan Dirk; Peixoto, Raquel S; Rosado, Alexandre S

    2012-08-08

    Sugarcane cultivation plays an important role in Brazilian economy, and it is expanding fast, mainly due to the increasing demand for ethanol production. In order to understand the impact of sugarcane cultivation and management, we studied sugarcane under different management regimes (pre-harvest burn and mechanical, unburnt harvest, or green cane), next to a control treatment with native vegetation. The soil bacterial community structure (including an evaluation of the diversity of the ammonia oxidizing (amoA) and denitrifying (nirK) genes), greenhouse gas flow and several soil physicochemical properties were evaluated. Our results indicate that sugarcane cultivation in this region resulted in changes in several soil properties. Moreover, such changes are reflected in the soil microbiota. No significant influence of soil management on greenhouse gas fluxes was found. However, we did find a relationship between the biological changes and the dynamics of soil nutrients. In particular, the burnt cane and green cane treatments had distinct modifications. There were significant differences in the structure of the total bacterial, the ammonia oxidizing and the denitrifying bacterial communities, being that these groups responded differently to the changes in the soil. A combination of physical and chemical factors was correlated to the changes in the structures of the total bacterial communities of the soil. The changes in the structures of the functional groups follow a different pattern than the physicochemical variables. The latter might indicate a strong influence of interactions among different bacterial groups in the N cycle, emphasizing the importance of biological factors in the structuring of these communities. Sugarcane land use significantly impacted the structure of total selected soil bacterial communities and ammonia oxidizing and denitrifier gene diversities in a Cerrado field site in Central Brazil. A high impact of land use was observed in soil under

  12. Physical-chemical and microbiological changes in Cerrado Soil under differing sugarcane harvest management systems

    Directory of Open Access Journals (Sweden)

    Rachid Caio TCC

    2012-08-01

    Full Text Available Abstract Background Sugarcane cultivation plays an important role in Brazilian economy, and it is expanding fast, mainly due to the increasing demand for ethanol production. In order to understand the impact of sugarcane cultivation and management, we studied sugarcane under different management regimes (pre-harvest burn and mechanical, unburnt harvest, or green cane, next to a control treatment with native vegetation. The soil bacterial community structure (including an evaluation of the diversity of the ammonia oxidizing (amoA and denitrifying (nirK genes, greenhouse gas flow and several soil physicochemical properties were evaluated. Results Our results indicate that sugarcane cultivation in this region resulted in changes in several soil properties. Moreover, such changes are reflected in the soil microbiota. No significant influence of soil management on greenhouse gas fluxes was found. However, we did find a relationship between the biological changes and the dynamics of soil nutrients. In particular, the burnt cane and green cane treatments had distinct modifications. There were significant differences in the structure of the total bacterial, the ammonia oxidizing and the denitrifying bacterial communities, being that these groups responded differently to the changes in the soil. A combination of physical and chemical factors was correlated to the changes in the structures of the total bacterial communities of the soil. The changes in the structures of the functional groups follow a different pattern than the physicochemical variables. The latter might indicate a strong influence of interactions among different bacterial groups in the N cycle, emphasizing the importance of biological factors in the structuring of these communities. Conclusion Sugarcane land use significantly impacted the structure of total selected soil bacterial communities and ammonia oxidizing and denitrifier gene diversities in a Cerrado field site in Central Brazil

  13. Effect of L-carnitine Supplementation on Nutritional Status and Physical Performance Under Calorie Restriction.

    Science.gov (United States)

    Jain, Swati; Singh, Som Nath

    2015-04-01

    L-carnitine is popular as a potential ergogenic aid because of its role in the conversion of fat into energy. The present study was undertaken to investigate the effect of short term supplementation of L-carnitine on metabolic markers and physical efficiency tests under short term calorie restriction. Male albino rats were divided into four groups (n = 12 in each)-control, calorie restricted (CR for 5 days, 25 % of basal food intake), L-carnitine supplemented (CAR, given orally for 5 days at a dose of 100 mg/kg), CR with L-carnitine supplementation (CR + CAR). Food intake and body weight of the rats were measured along with biochemical variables like blood glucose, tissue glycogen, plasma and muscle protein and enzymatic activities of CPT-1 (carnitine palmitoyl transferase-1) and AMP kinase. Results demonstrated that L-carnitine caused marked increase in muscle glycogen, plasma protein, CPT-1 activity and swim time of rats (P supplementation. In addition to the substantive effects caused by CR alone, L-carnitine under CR significantly affected muscle glycogen, plasma protein, CPT-1 activity and AMP kinase (P < 0.05). Short term CR along with L-carnitine also resulted in increased swim time of rats than control, CR and L-carnitine treated rats (P < 0.05). The present study was an attempt towards developing an approach for better adherence to dietary restriction regimen, with the use of L-carnitine.

  14. Soil Physical Characteristics and Biological Indicators of Soil Quality Under Different Biodegradable Mulches

    Science.gov (United States)

    Schaeffer, S. M.; Flury, M.; Sintim, H.; Bandopadhyay, S.; Ghimire, S.; Bary, A.; DeBruyn, J.

    2015-12-01

    Application of conventional polyethylene (PE) mulch in crop production offers benefits of increased water use efficiency, weed control, management of certain plant diseases, and maintenance of a micro-climate conducive for plant growth. These factors improve crop yield and quality, but PE must be retrieved and safely disposed of after usage. Substituting PE with biodegradable plastic mulches (BDM) would alleviate disposal needs, and is potentially a more sustainable practice. However, knowledge of potential impacts of BDMs on agricultural soil ecosystems is needed to evaluate sustainability. We (a) monitored soil moisture and temperature dynamics, and (b) assessed soil quality upon usage of different mulches, with pie pumpkin (Cucurbita pepo) as the test crop. Experimental field trials are ongoing at two sites, one at Northwestern Washington Research and Extension Center, Mount Vernon, WA, and the other at East Tennessee Research and Education Center, Knoxville, TN. The treatments constitute four different commercial BDM products, one experimental BDM; no mulch and PE served as the controls. Soil quality parameters being examined include: organic matter content, aggregate stability, water infiltration rate, CO2 flux, pH, and extracellular enzyme activity. In addition, lysimeters were installed to examine the soil water and heat flow dynamics. We present baseline and the first field season results from this study. Mulch cover appeared to moderate soil temperatures, but biodegradable mulches also appeared to lose water more quickly than PE. All mulch types, with the exception of cellulose, reduced the diurnal fluctuations in soil temperature at 10cm depth from 1 to 4ºC. However, volumetric water content ranged from 0.10 to 0.22 m3 m-3 under the five biodegradable mulches compared to 0.22 to 0.28 m3 m-3 under conventional PE. Results from the study will be useful for management practices by providing knowledge on how different mulches impact soil physical and

  15. Study on cultural innovation of Shanghai physical education under international perspective—on the role of physical education teachers

    Directory of Open Access Journals (Sweden)

    WANG Ziqing

    2013-08-01

    Full Text Available Shanghai school sports culture is formed in the process of accumulation and inherited after years of school physical education reform and practice in Shanghai,with Shanghai local characteristics of the physical education culture.Its innovation will help the majority of Shanghai young students to meet their needs of culture and to promote their identity to cultural of Shanghai city to make Shanghai school sports achieve the power of sustainable development.The innovation of Shanghai school sports culture includes the innovation in ideas of school sports,school sports system,contains of school sports activities etc.Shanghai school sports culture innovative ways includes communication with the school′s sports culture,integration,the original innovation.Currently Shanghai school sports culture innovation level is not high, the incentive to innovate is accumulating.Innovation mechanisms is not yet perfect,it is needed to improve the mechanism,to optimize the environment for innovation.Further efforts are paid to stimulate innovation,giving full play to the main role of physical education teachers in order to further enhance the innovation level of Shanghai school sports culture.

  16. The Numerical Tokamak Project (NTP) simulation of turbulent transport in the core plasma: A grand challenge in plasma physics

    International Nuclear Information System (INIS)

    1993-12-01

    The long-range goal of the Numerical Tokamak Project (NTP) is the reliable prediction of tokamak performance using physics-based numerical tools describing tokamak physics. The NTP is accomplishing the development of the most advanced particle and extended fluid model's on massively parallel processing (MPP) environments as part of a multi-institutional, multi-disciplinary numerical study of tokamak core fluctuations. The NTP is a continuing focus of the Office of Fusion Energy's theory and computation program. Near-term HPCC work concentrates on developing a predictive numerical description of the core plasma transport in tokamaks driven by low-frequency collective fluctuations. This work addresses one of the greatest intellectual challenges to our understanding of the physics of tokamak performance and needs the most advanced computational resources to progress. We are conducting detailed comparisons of kinetic and fluid numerical models of tokamak turbulence. These comparisons are stimulating the improvement of each and the development of hybrid models which embody aspects of both. The combination of emerging massively parallel processing hardware and algorithmic improvements will result in an estimated 10**2--10**6 performance increase. Development of information processing and visualization tools is accelerating our comparison of computational models to one another, to experimental data, and to analytical theory, providing a bootstrap effect in our understanding of the target physics. The measure of success is the degree to which the experimentally observed scaling of fluctuation-driven transport may be predicted numerically. The NTP is advancing the HPCC Initiative through its state-of-the-art computational work. We are pushing the capability of high performance computing through our efforts which are strongly leveraged by OFE support

  17. Myosin VI as a transporter and an anchor: A model for kinetics of the motor under load

    Science.gov (United States)

    Chuan, Peiying; Spudich, James; Dunn, Alexander

    2010-03-01

    Myosin VI is an actin-based motor that is thought to function both as a transporter and an anchor in vivo. In an earlier study (Altman et al, Cell 2004), inhibition of myosin VI stepping kinetics by load applied using an optical trap was observed at saturating ATP and low ADP concentrations (ADP binding increases exponentially with load was proposed. This model predicts that myosin VI functions primarily as an anchor at loads greater than ˜0.5 pN under physiological nucleotide conditions, which is potentially inconsistent with its roles in vivo. Here we present myosin VI stepping data taken at a variety of applied loads and ADP concentrations, and show that the Altman model only holds at low ADP concentrations. At higher, physiologically relevant ADP concentrations under load we observe dwell times that are an order of magnitude smaller than predicted by the Altman model. We present a modified model in which applied load alters the equilibrium between two myosin VI states with different nucleotide affinities. This new kinetic scheme accurately describes myosin VI behavior at various nucleotide conditions under a large range of loads, and explains how the motor is able to carry out its roles in vivo, both as a force-generating transporter and as an anchor.

  18. Two-dimensional numerical modeling of 90Sr transport in an unsaturated Chinese loess under artificial sprinkling

    International Nuclear Information System (INIS)

    Qian Tianwei; Li, Shushen; Ding Qingwei; Wu Guibin; Zhao Dongye

    2009-01-01

    90 Sr is a fission byproduct of uranium and plutonium, and it presents a major health problem in the environment. A field test on the transport of various radionuclides including 90 Sr in an unsaturated Chinese loess was conducted under artificial rain conditions from July 1997 to August 2000. The vertical concentration distribution of 90 Sr displayed an unusual profile of double concentration peaks, which were separated by a thin (0.7 cm) source layer. In order to interpret the double-peak concentration profile, the transport of 3 H and 90 Sr in the unsaturated Chinese loess under artificial sprinkling conditions was simulated using WATERM, a numerical code for simulating flow field, and NESOR, also a numerical code but for simulating nuclide migration. The models were able to adequately simulate the double-peak concentration profile. The observation suggested that the fine arenaceous quartz layer, though 0.7 cm thick, formed a capillary barrier together with the local loess, which prevented water from penetrating. A significant discrepancy was observed between the model-fitted distribution coefficient (K d ) of 90 Sr and that determined from independent laboratory experiments, which can be attributed to a number of factors such as the capillary barrier effect, solution-to-solid ratio and soil water content. Therefore, when the model is used for predictive purposes where K d is used as an input parameter, K d must be determined under well controlled conditions by taking into account these factors as well as the heterogeneity in the field.

  19. Structural analysis of deformations in the seal region of a radioactive material transport cask under thermal loadings

    International Nuclear Information System (INIS)

    Turula, P.; Wang, Z.

    1991-01-01

    In the design of casks for the transport of highly radioactive materials, a major concern is preventing leakage under both the normal conditions of transport and the hypothetical accident conditions specified in the federal regulations. The designs must accommodate various loadings, including thermal loadings. The latter are particularly difficult to withstand because thermal considerations require exceptional structural flexibility, while other design considerations require structural stiffness. To guarantee a design that will be leaktight, the designer needs to quantify and limit the range of possible movement between the cask body and the lid under all conditions. This paper first shows the deformations obtained from a simplified model of the basic configuration of a sample design under selected normal and hypothetical thermal loading conditions. The design is then modified and re-analyzed to evaluate the effectiveness of two configuration modifications intended to reduce relative movement at the closure interface between cask body and the lid. Comparisons of required bolting forces demonstrate that accommodating the thermal loadings must be a primary consideration in designing the cask. 5 refs., 6 figs., 1 tab

  20. The physics of W transport illuminated by recent progress in W density diagnostics at ASDEX Upgrade

    Science.gov (United States)

    Odstrcil, T.; Pütterich, T.; Angioni, C.; Bilato, R.; Gude, A.; Odstrcil, M.; ASDEX Upgrade Team; the EUROfusion MST1 Team

    2018-01-01

    Due to the high mass and charge of the heavy ions, centrifugal and electrostatic forces cause a significant variation in their poloidal density. The impact of these forces on the poloidal density profile of tungsten was investigated utilizing the detailed two-dimensional SXR emissivity profiles from the ASDEX Upgrade tokamak. The perturbation in the electrostatic potential generated by magnetic trapping of the non-thermal ions from neutral beam injection was found to be responsible for significant changes in the poloidal distribution of tungsten ions. An excellent match with the results from fast particle modeling was obtained, validating the model for the poloidal fast particle distribution. Additionally, an enhancement of the neoclassical transport due to an outboard side impurity localization was measured in the experiment when analyzing the tungsten flux between sawtooth crashes. A qualitative match with neoclassical modeling was found, demonstrating the possibility of minimizing neoclassical transport by an optimization of the poloidal asymmetry profile of the impurity.

  1. Thermal transport in low dimensions from statistical physics to nanoscale heat transfer

    CERN Document Server

    2016-01-01

    Understanding non-equilibrium properties of classical and quantum many-particle systems is one of the goals of contemporary statistical mechanics. Besides its own interest for the theoretical foundations of irreversible thermodynamics(e.g. of the Fourier's law of heat conduction), this topic is also relevant to develop innovative ideas for nanoscale thermal management with possible future applications to nanotechnologies and effective energetic resources. The first part of the volume (Chapters 1-6) describes the basic models, the phenomenology and the various theoretical approaches to understand heat transport in low-dimensional lattices (1D e 2D). The methods described will include equilibrium and nonequilibrium molecular dynamics simulations, hydrodynamic and kinetic approaches and the solution of stochastic models. The second part (Chapters 7-10) deals with applications to nano and microscale heat transfer, as for instance phononic transport in carbon-based nanomaterials, including the prominent case of na...

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

    CERN Document Server

    Heikkila, Tero T

    2013-01-01

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

  3. Physical attributes of ultisol of Brazil's northeastern semiarid under organic farming of wine grapes

    Directory of Open Access Journals (Sweden)

    Jardenia R. Feitosa

    2015-03-01

    Full Text Available The purpose of this study was to evaluate the effects of organic farming of wine grapes under physical and chemical characteristics of Ultisol Brazil's northeastern semiarid region. The samples of soil were collected from the row and interrow of the farming and from the fallow area, at the depths of 0.0-0.10, 0.10-0.20, 0.20-0.30 and 0.30-0.60 m. The samples were collected at six and twelve months after the culture implementation to evaluate the state of aggregation, bulk density and total soil porosity, flocculation index and organic matter contents, calcium, magnesium, and sodium. The results were submitted to statistical analysis. The adoption of organic farming contributed to the soil aggregation process. The bulk density and total soil porosity did not differ significantly between the evaluations, but were within the critical limits for sandy soils. The index flocculation did not have a great influence on the aggregates formation, being this process influenced by organic matter. The period of one year was considered short to obtain conclusive results in improving the soil quality by organic farming, since there are difficulties in tropical soils in promoting significant increases in organic matter content in short time.

  4. Physical attributes of Ultisol of Brazil's northeastern semiarid under organic farming of wine grapes.

    Science.gov (United States)

    Feitosa, Jardenia R; Mendes, Alessandra M S; Olszevski, Nelci; Cunha, Tony J F; Cortez, Jorge W; Giongo, Vanderlise

    2015-03-01

    The purpose of this study was to evaluate the effects of organic farming of wine grapes under physical and chemical characteristics of Ultisol Brazil's northeastern semiarid region. The samples of soil were collected from the row and interrow of the farming and from the fallow area, at the depths of 0.0-0.10, 0.10-0.20, 0.20-0.30 and 0.30-0.60 m. The samples were collected at six and twelve months after the culture implementation to evaluate the state of aggregation, bulk density and total soil porosity, flocculation index and organic matter contents, calcium, magnesium, and sodium. The results were submitted to statistical analysis. The adoption of organic farming contributed to the soil aggregation process. The bulk density and total soil porosity did not differ significantly between the evaluations, but were within the critical limits for sandy soils. The index flocculation did not have a great influence on the aggregates formation, being this process influenced by organic matter. The period of one year was considered short to obtain conclusive results in improving the soil quality by organic farming, since there are difficulties in tropical soils in promoting significant increases in organic matter content in short time.

  5. Evaluating the soil physical quality under long-term field experiments in Southern Italy

    Science.gov (United States)

    Castellini, Mirko; Stellacci, Anna Maria; Iovino, Massimo; Rinaldi, Michele; Ventrella, Domenico

    2017-04-01

    Long-term field experiments performed in experimental farms are important research tools to assess the soil physical quality (SPQ) given that relatively stable conditions can be expected in these soils. However, different SPQ indicators may sometimes provide redundant or conflicting results, making difficult an SPQ evaluation (Castellini et al., 2014). As a consequence, it is necessary to apply appropriate statistical procedures to obtain a minimum set of key indicators. The study was carried out at the Experimental Farm of CREA-SCA (Foggia) in two long-term field experiments performed on durum wheat. The first long-term experiment is aiming at evaluating the effects of two residue management systems (burning, B or soil incorporation of crop residues, I) while the second at comparing the effect of tillage (conventional tillage, CT) and sod-seeding (direct drilling, DD). In order to take into account both optimal and non-optimal soil conditions, five SPQ indicators were monitored at 5-6 sampling dates during the crop season (i.e., between November and June): soil bulk density (BD), macroporosity (PMAC), air capacity (AC), plant available water capacity (PAWC) and relative field capacity (RFC). Two additional data sets, collected on DD plot in different cropping seasons and in Sicilian soils differing for texture, depth and land use (N=140), were also used with the aim to check the correlation among indicators. Impact of soil management was assessed by comparing SPQ evaluated under different management systems with optimal reference values reported in literature. Two techniques of multivariate analysis (principal component analysis, PCA and stepwise discriminant analysis, SDA) were applied to select the most suitable indicator to facilitate the judgment on SPQ. Regardless of the considered management system, sampling date or auxiliary data set, correlation matrices always showed significant negative relationships between RFC and AC. Decreasing RFC at increasing AC is

  6. using fuzzy-robust approach for minimizing transportation and fuel costs in location problem under uncertainty

    Directory of Open Access Journals (Sweden)

    hasan hosseini nasab

    2016-02-01

    Full Text Available Operations research is a commonly used method in many subjects nowadays. One applicable domain of operation research is the problem of facility layout and location. In this paper, a new mathematical programing model is developed for an optimal facility location and assignment. The model includes two objective functions. The first one minimizes the total material handling and fixed costs of facility location. Because of the importance of energy and the main role of fossil fuel in transportation, the second objective function, minimizes the total cost of fuel consumption. To consider the real condition in the proposed model, the cost of fuel, is considered to increase stepwise gradually. In the proposed model the coefficients of objective function are considered to be probabilistic and some of constraints to be fuzzy variables. Using a new approach, this model can be changed to a robust model. To prove the applicability of the model, it is examined for a real condition of facility location.

  7. 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.

  8. Nuclear data physics issues in Monte Carlo simulations of neutron and photon transport in the Indian context

    International Nuclear Information System (INIS)

    Ganesan, S.

    2009-01-01

    In this write-up, some of the basic issues of nuclear data physics in Monte Carlo simulation of neutron transport in the Indian context are dealt with. In this lecture, some of the aspects associated with usage of the ENDF/B system, and of the PREPRO code system developed by D.E. Cullen and distributed by the IAEA Nuclear Data Section are briefly touched upon. Some aspects of the SIGACE code system which was developed by the author in collaboration with IPR, Ahmedabad and the IAEA Nuclear Data Section are also briefly covered. The validation of the SIGACE package included investigations using the NJOY and the MCNP compatible ACE files. Appendix-1 of the paper provides some useful discussions pointing out that voluminous and high-quality nuclear physics data required for nuclear applications usually evolve from a national effort to provide state-of-the-art data that are based upon established needs and uncertainties. Appendix-2 deals with some interesting work that was carried out using the SIGACE Code for Generating High Temperature ACE Files. Appendix-3 mentions briefly Integral nuclear data validation studies and use of Monte Carlo codes and nuclear data. Appendix-4 provides a brief summary report on selected Indian nuclear data physics activities for the interested reader in the light of BARC/DAE treating the subject area of nuclear data physics as a thrust area in our atomic energy programme

  9. Fat gain with physical detraining is correlated with increased glucose transport and oxidation in periepididymal white adipose tissue in rats

    Energy Technology Data Exchange (ETDEWEB)

    Sertié, R.A.L.; Andreotti, S. [Departamento de Fisiologia e Biofísica, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, SP (Brazil); Proença, A.R.G. [Laboratório de Biotecnologia, Faculdade de Ciências Aplicadas, Universidade Estadual de Campinas, Limeira, SP (Brazil); Campaña, A.B.; Lima, F.B. [Departamento de Fisiologia e Biofísica, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, SP (Brazil)

    2015-05-26

    As it is a common observation that obesity tends to occur after discontinuation of exercise, we investigated how white adipocytes isolated from the periepididymal fat of animals with interrupted physical training transport and oxidize glucose, and whether these adaptations support the weight regain seen after 4 weeks of physical detraining. Male Wistar rats (45 days old, weighing 200 g) were divided into two groups (n=10): group D (detrained), trained for 8 weeks and detrained for 4 weeks; and group S (sedentary). The physical exercise was carried out on a treadmill for 60 min/day, 5 days/week for 8 weeks, at 50-60% of the maximum running capacity. After the training protocol, adipocytes isolated from the periepididymal adipose tissue were submitted to glucose uptake and oxidation tests. Adipocytes from detrained animals increased their glucose uptake capacity by 18.5% compared with those from sedentary animals (P<0.05). The same cells also showed a greater glucose oxidation capacity in response to insulin stimulation (34.55%) compared with those from the S group (P<0.05). We hypothesize that, owing to the more intense glucose entrance into adipose cells from detrained rats, more substrate became available for triacylglycerol synthesis. Furthermore, this increased glucose oxidation rate allowed an increase in energy supply for triacylglycerol synthesis. Thus, physical detraining might play a role as a possible obesogenic factor for increasing glucose uptake and oxidation by adipocytes.

  10. A binomial modeling approach for upscaling colloid transport under unfavorable conditions: Emergent prediction of extended tailing

    Science.gov (United States)

    Hilpert, Markus; Rasmuson, Anna; Johnson, William P.

    2017-07-01

    Colloid transport in saturated porous media is significantly influenced by colloidal interactions with grain surfaces. Near-surface fluid domain colloids experience relatively low fluid drag and relatively strong colloidal forces that slow their downgradient translation relative to colloids in bulk fluid. Near-surface fluid domain colloids may reenter into the bulk fluid via diffusion (nanoparticles) or expulsion at rear flow stagnation zones, they may immobilize (attach) via primary minimum interactions, or they may move along a grain-to-grain contact to the near-surface fluid domain of an adjacent grain. We introduce a simple model that accounts for all possible permutations of mass transfer within a dual pore and grain network. The primary phenomena thereby represented in the model are mass transfer of colloids between the bulk and near-surface fluid domains and immobilization. Colloid movement is described by a Markov chain, i.e., a sequence of trials in a 1-D network of unit cells, which contain a pore and a grain. Using combinatorial analysis, which utilizes the binomial coefficient, we derive the residence time distribution, i.e., an inventory of the discrete colloid travel times through the network and of their probabilities to occur. To parameterize the network model, we performed mechanistic pore-scale simulations in a single unit cell that determined the likelihoods and timescales associated with the above colloid mass transfer processes. We found that intergrain transport of colloids in the near-surface fluid domain can cause extended tailing, which has traditionally been attributed to hydrodynamic dispersion emanating from flow tortuosity of solute trajectories.

  11. Dynamics of cardiovascular parameters in combined aortic malformations under the influence of a physical therapy program during the rehabilitation process

    Directory of Open Access Journals (Sweden)

    Serhii Kalmykov

    2017-12-01

    Full Text Available Purpose: to study hemodynamic parameters and the reaction of the cardiovascular system to the dosed physical load of patients combined aortic defect with heart failure of the I degree under the influence of the complex physical therapy program developed by us during the rehabilitation process. Material & Methods: the study involved 26 middle-aged men with a diagnosis: combined aortic valve disease, HF I st. Result: dynamics of functional parameters of the cardiovascular system of patients under the influence of the physical therapy program is analyzed. Conclusion: the combination of morning hygienic gymnastics, therapeutic gymnastics, independent activities and dosed walking with a therapeutic massage contributes to the normalization of vascular tone, motor-vascular reflexes and blood pressure, increasing the tolerance of the cardiovascular system to physical activity.

  12. Metribuzin transport in undisturbed soil cores under controlled water potential conditions: experiments and modelling to evaluate the risk of leaching in a sandy loam soil profile.

    Science.gov (United States)

    Pot, Valérie; Benoit, Pierre; Le Menn, Mona; Eklo, Ole-Martin; Sveistrup, Tore; Kvaerner, Jens

    2011-04-01

    Mobility of pesticides in soils is often evaluated and characterised in the surface soil layers rather than at different depths where soil characteristics such as soil organic matter, microbial biomass or clay contents can strongly change pesticide behaviour. The objective of this work was to characterise the reactivity of the herbicide metribuzin in three main soil horizons found in the 0-80 cm profile of an alluvial soil of southern Norway under dynamic transport conditions. A laboratory infiltrometer was used to perform percolation experiments in soil cores sampled in the three horizons Ap, Bw and Bw/C, at a fixed matric potential of -10 cm, thus preventing pores of equivalent radii higher than 0.015 cm from contributing to water flow. The physical equilibrium transport model correctly described the transport of water tracer (bromide). The distribution coefficient K(d) values were estimated to be 0.29, 0.17 ± 0.02 and 0.15 ± 0.00 L kg(-1) for horizons Ap, Bw and Bw/C respectively, in close agreement with batch sorption data. Degradation was found only for the surface horizon with a short half-life of about 5 days, in disagreement with longer half-lives found in batch and field degradation data. For all horizons, a kinetic sorption model was needed for better description of metribuzin leaching. Chemical non-equilibrium was greatest in the Bw horizon and lowest in the Bw/C horizon. Overall, metribuzin exhibited a greater mobility in the deeper horizons. The risk of metribuzin transfer to groundwater in such alluvial soils should therefore be considered. Copyright © 2011 Society of Chemical Industry.

  13. The specification and testing of radioactive sources designated as ''special form'' under the IAEA transport regulations

    International Nuclear Information System (INIS)

    Aston, D.; Bodimeade, A.H.; Hall, E.G.; Taylor, C.B.G.

    1982-01-01

    The object of this study is to remove some of the uncertainties associated with the application of the IAEA Regulations insofar as they apply to Special Form materials. The first part of this project involved a comparison of the ISO and IAEA Regulations. An analysis of the physical tests has been carried out. The second and most important part of the project involved an assessment of the leakage tests used to evaluate the capsules after each of the physical tests. The work has defined and confirmed by experiment the relationship between the IAEA and ISO impact and percussion tests. The practical application of the tests particularly with regard to specimen orientation will be aided by the data now available. The work has established the sensitivities of the primary volumetric leak test methods and practical procedures are outlined. Volumetric leak test methods, with sentivities approximately 10 - 5 mbar l/s, are considered to be more reliable in detecting leakage paths in capsules than methods using solid leachable or non-leachable radioactive contents. The work reported should assist in the updating and clarification and harmonisation of IAEA Safety Series Nos 6 and 37 and ISO 4919 and ISO TR 4826

  14. Physical parameter estimation in spatial heat transport models with an application to food storage

    NARCIS (Netherlands)

    van Mourik, S.; Vries, Dirk; Ploegaert, Johan P. M.; Zwart, Heiko J.; Keesman, Karel J.

    Parameter estimation plays an important role in physical modelling, but can be problematic due to the complexity of spatiotemporal models that are used for analysis, control and design in industry. In this paper we aim to circumvent these problems by using a methodology that approximates a model, or

  15. Physical parameter estimation in spatial heat transport models with an application to food storage

    NARCIS (Netherlands)

    Mourik, van S.; Vries, D.; Ploegaert, J.P.M.; Zwart, H.; Keesman, K.J.

    2012-01-01

    Parameter estimation plays an important role in physical modelling, but can be problematic due to the complexity of spatiotemporal models that are used for analysis, control and design in industry. In this paper we aim to circumvent these problems by using a methodology that approximates a model, or

  16. Assurance of risk assessment and protection distant transportation and fall out of pollutants under large anthropogenic on nuclear power stations due to mountainous regional peculiarities

    International Nuclear Information System (INIS)

    Tsitskishvili, M.; Tsitskishvili, N.; Kordzakhia, G.; Valiaev, A.; Kazakov, S.; Aitmatov, I.; Petrov, V.

    2005-01-01

    Full text: All types of industrial activities require the norms of protection, assessment of corresponding risks to preserve the pollution and degradation of corresponding areas. To make available the sustainable development of the country the risk assessment of possible accidents on the big enterprises is foreseen that provides preparedness of the country and possibility of the prevention measures and mitigation of the accidents. While big anthropogenic accidents in mountainous countries - the main paths for transportation of the pollution are the rivers and sea basins. Due to overpopulation of these areas assessment of the pollution risks are very important. Problem of forecast and distant atmospheric transportation of the toxic products and corresponding risk assessment under anthropogenic damages is multi-component and depends on meteorological conditions and frontier layer of atmosphere. Generally, for real relief and basic fields the problem is not solved yet especially taking into consideration the big level and shortest time of the process being of the natural anthropogenic accidents in mountainous regions. Usually, geostropic drawing for determined relief is used. Integral differential equations taking into consideration a physical- chemical characteristic of the pollutants, their transformations, fall out, coagulations, washing out and self rectification in general cannot be solved. In last time essential success in formalization of above-mentioned equations i.e. carrying out some simplifications give possibility to establish necessary modeling on the basis of numerical calculations. In the most general case forecasting model is essentially limited because of bulky size of accounting schemes and necessity of powerful and high-speed computers. Main ways of achievement of further success is connected with so called 'seasonal typification' with applied a priory calculation of probabilistic picture of the pollutants concentration fields, as well as

  17. Quantification of chemical and physical processes influencing ozone during long-range transport using a trajectory ensemble

    Directory of Open Access Journals (Sweden)

    M. Cain

    2012-08-01

    Full Text Available During long-range transport, many distinct processes – including photochemistry, deposition, emissions and mixing – contribute to the transformation of air mass composition. Partitioning the effects of different processes can be useful when considering the sensitivity of chemical transformation to, for example, a changing environment or anthropogenic influence. However, transformation is not observed directly, since mixing ratios are measured, and models must be used to relate changes to processes. Here, four cases from the ITCT-Lagrangian 2004 experiment are studied. In each case, aircraft intercepted a distinct air mass several times during transport over the North Atlantic, providing a unique dataset and quantifying the net changes in composition from all processes. A new framework is presented to deconstruct the change in O3 mixing ratio (Δ O3 into its component processes, which were not measured directly, taking into account the uncertainty in measurements, initial air mass variability and its time evolution.

    The results show that the net chemical processing (Δ O3chem over the whole simulation is greater than net physical processing (Δ O3phys in all cases. This is in part explained by cancellation effects associated with mixing. In contrast, each case is in a regime of either net photochemical destruction (lower tropospheric transport or production (an upper tropospheric biomass burning case. However, physical processes influence O3 indirectly through addition or removal of precursor gases, so that changes to physical parameters in a model can have a larger effect on Δ O3chem than Δ O3phys. Despite its smaller magnitude, the physical processing distinguishes the lower tropospheric export cases, since the net photochemical O3 change is −5 ppbv per day in all three cases.

    Processing is quantified using a Lagrangian

  18. Dispersal and population connectivity in the deep North Atlantic estimated from physical transport processes

    Science.gov (United States)

    Etter, Ron J.; Bower, Amy S.

    2015-10-01

    Little is known about how larvae disperse in deep ocean currents despite how critical estimates of population connectivity are for ecology, evolution and conservation. Estimates of connectivity can provide important insights about the mechanisms that shape patterns of genetic variation. Strong population genetic divergence above and below about 3000 m has been documented for multiple protobranch bivalves in the western North Atlantic. One possible explanation for this congruent divergence is that the Deep Western Boundary Current (DWBC), which flows southwestward along the slope in this region, entrains larvae and impedes dispersal between the upper/middle slope and the lower slope or abyss. We used Lagrangian particle trajectories based on an eddy-resolving ocean general circulation model (specifically FLAME - Family of Linked Atlantic Model Experiments) to estimate the nature and scale of dispersal of passive larvae released near the sea floor at 4 depths across the continental slope (1500, 2000, 2500 and 3200 m) in the western North Atlantic and to test the potential role of the DWBC in explaining patterns of genetic variation on the continental margin. Passive particles released into the model DWBC followed highly complex trajectories that led to both onshore and offshore transport. Transport averaged about 1 km d-1 with dispersal kernels skewed strongly right indicating that some larvae dispersed much greater distances. Offshore transport was more likely than onshore and, despite a prevailing southwestward flow, some particles drifted north and east. Dispersal trajectories and estimates of population connectivity suggested that the DWBC is unlikely to prevent dispersal among depths, in part because of strong cross-slope forces induced by interactions between the DWBC and the deeper flows of the Gulf Stream. The strong genetic divergence we find in this region of the Northwest Atlantic is therefore likely driven by larval behaviors and/or mortality that limit

  19. Applicability of DLVO Approach to Predict Trends in Iron Oxide Colloid Mobility Under Various Physical And Chemical Soil Conditions

    Science.gov (United States)

    Florian Carstens, Jannis; Bachmann, Jörg; Neuweiler, Insa

    2014-05-01

    In soil and groundwater, highly mobile iron oxide colloids can act as "shuttles" for transport of adsorbed contaminants such as heavy metals and radionuclides. Artificial iron oxide colloids are injected into polluted porous media to accelerate bacterial degradation of pollutants in the context of bioremediation purposes. The mobility of iron oxide colloids is strongly affected by the hydraulic, physical and chemical conditions of the pore space, the solid particle surface properties, the fluid phase, and the colloids themselves. Most pioneering studies focused on iron oxide colloid transport and retention in simplified model systems. The aim of this study is to investigate iron oxide colloid mobility under more complex, soil-typical conditions that have as yet only been applied for model microspheres, i.e. functionalized latex colloids. Among these conditions is the pivotal impact of organic matter, either dissolved or adsorbed onto solid particles, modifying wettability properties. Of particular importance was to determine if effective chemical surface parameters derived from contact angle and zeta potential measurements can be used as a tool to predict general tendencies for iron oxide colloid mobility in porous media. In column breakthrough experiments, goethite colloids (particle size: 200-900 nm) were percolated through quartz sand (grain size: 100-300 µm) at pH 5. The impact of a multitude of conditions on colloid mobility was determined: dissolved organic matter (DOM) concentration, ionic strength, flow velocity, flow interruption, partial saturation, and drying with subsequent re-wetting. The solid matrix consisted of either clean sand, organic matter-coated sand, goethite-coated sand, or sand hydrophobized with dichlorodimethylsilane. Additionally, contact angles and zeta potentials of the materials applied in the column experiments were measured. By means of these surface parameters, traditional DLVO interaction energies based on zeta potential as well

  20. A new nuclide transport model in soil in the GENII-LIN health physics code

    Science.gov (United States)

    Teodori, F.

    2017-11-01

    The nuclide soil transfer model, originally included in the GENII-LIN software system, was intended for residual contamination from long term activities and from waste form degradation. Short life nuclides were supposed absent or at equilibrium with long life parents. Here we present an enhanced soil transport model, where short life nuclide contributions are correctly accounted. This improvement extends the code capabilities to handle incidental release of contaminant to soil, by evaluating exposure since the very beginning of the contamination event, before the radioactive decay chain equilibrium is reached.

  1. Survey and alignment of high energy physics accelerators and transport lines

    International Nuclear Information System (INIS)

    Ruland, R.E.

    1992-11-01

    This talk summarizes the survey and alignment processes of accelerators and transport lines and discusses the propagation of errors associated with these processes. The major geodetic principles governing the survey and alignment measurement space are revisited and their relationship to a lattice coordinate system shown. The paper continues with a broad overview about the activities involved in the step by step sequence from initial absolute alignment to final smoothing. Emphasis is given to the relative alignment of components, in particular to the importance of incorporating methods to remove residual systematic effects in surveying and alignment operations

  2. Transport properties of finite carbon nanotubes under electric and magnetic fields

    International Nuclear Information System (INIS)

    Li, T S; Lin, M F

    2006-01-01

    Electronic and transport properties of finite carbon nanotubes subject to the influences of a transverse electric field and a magnetic field with varying polar angles are studied by the tight-binding model. The external fields will modify the state energies, destroy the state degeneracy, and modulate the energy gap. Both the state energy and the energy gap exhibit rich dependence on the field strength, the magnetic field direction, and the types of carbon nanotubes. The semiconductor-metal transition would be allowed for certain field strengths and magnetic field directions. The variations of state energies with the external fields will also be reflected in the electrical and thermal conductance. The number, the heights, and the positions of the conductance peaks are strongly dependent on the external fields. The heights of the electrical and thermal conductance peaks display a quantized behaviour, while that of the Peltier coefficient does not. Finally, it is found that the validity of the Wiedemann-Franz law depends upon the temperature, the field strength, the electronic structure, and the chemical potential

  3. Fission Product Transport in TRISO Particle Layers under Operating and Off-Normal Conditions

    Energy Technology Data Exchange (ETDEWEB)

    Van der Ven, Anton [Univ. of Michigan, Ann Arbor, MI (United States); Was, Gary [Univ. of Michigan, Ann Arbor, MI (United States); Wang, Lumin [Univ. of Michigan, Ann Arbor, MI (United States); Taheri, Mitra [Drexel Univ., Philadelphia, PA (United States)

    2014-04-26

    The objective of this project is to determine the diffusivity and chemical behavior of key fission products (ag, Cs, I. Te, Eu and Sr) through SiC and PyC both thermally, under irradiation, and under stress using FP introduction techniques that avoid the pitfalls of past experiments. The experimental approach is to create thin PyC-SiC couples containing the fission product to be studied embedded in the PyC layer. These samples will then be subjected to high temperature exposures in a vacuum and also to irradiation at high temperature, and last, to irradiation under stress at high temperature. The PyC serves as a host layer, providing a means of placing the fission product close to the SiC without damaging the SiC layer by its introduction or losing the FP during heating. Experimental measurements of grain boundary structure and distribution (EBSD, HRTEM, APT) will be used in the modeling effort to determine the qualitative dependence of FP diffusion coefficients on grain boundary orientation, temperature and stress.

  4. Chemical and physical fractions of soil organic matter under various management regimes in Roraima, Brazil

    Directory of Open Access Journals (Sweden)

    Marden Daniel Espinoza Guardiola

    2017-08-01

    Full Text Available The crop-livestock integration (CLI and crop-livestock-forest integration (CLFI management systems, have been shown to be viable approaches for increasing carbon sequestration in soils, resulting in the improvement of physical and chemical soil attributes. The objective of this study was to evaluate the chemical attributes and organic matter in soils under Natural Forest (NF converted to different uses and managed differently: rotational pasture area (PAST, crop-livestock integration (CLI, and crop-livestock-forest integration (CLIF. The research was conducted at the São Paulo farm, in Iracema, located in the south-central region of the state of Roraima, Brazil. The studied soil type was classified as Ultisol. Soil samples were taken by opening ditches and examining layers at 0.1-m depth intervals from surface to 0.60-m depth. Total organic carbon (TOC, chemical and granulometric fractionation of soil organic matter (SOM, oxidizable fractions, and light organic matter in water were analyzed. Our results showed low levels of the analyzed chemical elements, a characteristic of a soil with low natural fertility. This matches conditions inherent in source material, weathered by high rainfall, a warm and humid climate, and flat topographic relief. In the 0-0.1 m layer, the PAST and CLI systems had the highest TOC contents relative to the other systems studied. At other depths, there were no statistical differences among TOC levels. The highest concentration of C in the particulate fraction (POC was noted in the surface layer in all management systems. The pasture system had the highest concentration POC in the top 0.10 m. Our results also showed that the upper 0.10 m of soil in NF contained the lowest content of organic carbon associated with mineral (MOC relative to the managed agrosystems. In addition, humin provided the largest contribution to SOM in all evaluated management systems. The crop-livestock integration (CLI and crop

  5. Oil Droplet Transport under Non-Breaking Waves: An Eulerian RANS Approach Combined with a Lagrangian Particle Dispersion Model

    Directory of Open Access Journals (Sweden)

    Roozbeh Golshan

    2018-01-01

    Full Text Available Oil droplet transport under a non-breaking deep water wave field is investigated herein using Computational Fluid dynamics (CFD. The Reynolds-averaged Navier–Stokes (RANS equations were solved to simulate regular waves in the absence of wind stress, and the resulting water velocities agreed with Stokes theory for waves. The RANS velocity field was then used to predict the transport of buoyant particles representing oil droplets under the effect of non-locally generated turbulence. The RANS eddy viscosity exhibited an increase with depth until reaching a maximum at approximately a wave height below the mean water level. This was followed by a gradual decrease with depth. The impact of the turbulence was modeled using the local value of eddy diffusivity in a random walk framework with the added effects of the gradient of eddy diffusivity. The vertical gradient of eddy viscosity increased the residence time of droplets in the water column region of high diffusivity; neglecting the gradient of eddy diffusivity resulted in a deviation of the oil plume centroid by more than a half a wave height after 10 wave periods.

  6. Flux-pinning-induced stress and magnetostriction in a superconducting strip under combination of transport current and magnetic field

    Science.gov (United States)

    Yang, Yumei; Wang, Xingzhe

    2017-09-01

    The magnetoelastic properties and behaviors arising from the flux-pinning effect are investigated for a long rectangular superconducting strip subject to a combination of applied transport current and magnetic field. Based on the Bean critical state model and linear elastic theory, the flux-pinning-induced stress in the superconducting strip is analytically obtained under the zero-field cooling condition. In particular, the magnetostriction performance for the strip with a one-sided restraint condition is then investigated. The results show that the trapped magnetic flux is distributed asymmetrically along the y-direction. A non-zero resultant force is consequently observed from the magnetization arising from the applied transport current and magnetic field. An obvious tension stress emerges around the constrained side of the strip along which the highest probability for cracking occurs and leads to a structural instability. The analytical results give insight into the flux-pinning-induced stress and magnetostriction response of the superconducting strip under both complex carrying-current and applied magnetic field conditions. These results may also provide helpful guidance in avoiding the breakdown of high-temperature superconductors.

  7. Predictions of Separated and Transitional Boundary Layers Under Low-Pressure Turbine Airfoil Conditions Using an Intermittency Transport Equation

    Science.gov (United States)

    Suzen, Y. B.; Huang, P. G.; Hultgren, Lennart S.; Ashpis, David E.

    2003-01-01

    A new transport equation for the intermittency factor was proposed to predict separated and transitional boundary layers under low-pressure turbine airfoil conditions. The intermittent behavior of the transitional flows is taken into account and incorporated into computations by modifying the eddy viscosity, t , with the intermittency factor, y. Turbulent quantities are predicted by using Menter s two-equation turbulence model (SST). The intermittency factor is obtained from a transport equation model, which not only can reproduce the experimentally observed streamwise variation of the intermittency in the transition zone, but also can provide a realistic cross-stream variation of the intermittency profile. In this paper, the intermittency model is used to predict a recent separated and transitional boundary layer experiment under low pressure turbine airfoil conditions. The experiment provides detailed measurements of velocity, turbulent kinetic energy and intermittency profiles for a number of Reynolds numbers and freestream turbulent intensity conditions and is suitable for validation purposes. Detailed comparisons of computational results with experimental data are presented and good agreements between the experiments and predictions are obtained.

  8. The Effect of Suspended Sediment Transport and Deposition on Streambed Clogging Under Losing and Gaining Flow Conditions

    Science.gov (United States)

    Fox, A.; Packman, A. I.; Preziosi-Ribero, A.; Li, A.; Arnon, S.

    2017-12-01

    Sediment transport and deposition in streams can affect streambed hydraulic characteristics due to clogging, reduce water fluxes through the hyporheic zone, and thus expected to affect biogeochemical processes. Processes affecting deposition of suspended particles were systematically studied under various overlying velocities but without taking into account the interactions with groundwater. This is despite the fact that the interaction with groundwater were shown to play an important role in deposition patterns of fine sediments in field studies. The objective of this study was to evaluate the effect of losing and gaining fluxes on suspended sediment depositional patterns and on hyporheic exchange fluxes. Experiments were conducted in a laboratory flume system (640 cm long and 30 cm wide) that has a capacity to enforce losing or gaining flow conditions. The flume was packed with homogenous sand, while suspended sediment deposition was evaluated by adding kaolinite particles to the water and following the deposition rate by particle disappearance from the bulk water. Consecutive additions of kaolinite were done, while hyporheic exchange fluxes were evaluated by conducting NaCl tracer experiments between each kaolinite additions. Furthermore, dye injections were used to visualize the flow patterns in the streambed using time-lapse photography through the transparent sidewalls of the flume. Hyporheic exchange and particle tracking simulations were done to assess the results of particle deposition and feedbacks between hyporheic flow, particle transport, and streambed clogging. Experimental results showed that the deposition of clay decreases with increasing amount of clay concentration in the sediment. Hyporheic exchange flux decreases linearly with increasing amount of clay added to the system and the region of active hyporheic exchange was confined to the upper part of the sediment. Understanding the particle deposition mechanisms under losing and gaining flow

  9. Physics based Degradation Modeling and Prognostics of Electrolytic Capacitors under Electrical Overstress Conditions

    Data.gov (United States)

    National Aeronautics and Space Administration — This paper proposes a physics based degradation modeling and prognostics approach for electrolytic capacitors. Electrolytic capacitors are critical components in...

  10. German physical protection concept for the storage of spent fuel elements in transport and storage casks

    International Nuclear Information System (INIS)

    Weil, L.; Maier, R.

    2005-01-01

    Full text: In Germany, the legal regulations and requirements derived from rules and guidelines for the protection of storage facilities for spent fuel elements from disruptive action or other inference by third parties are structured hierarchically. The Atomic Energy Act constitutes the top level. It is supported by federal ordinances. The next level down is formed by the rules and guidelines. The storage of nuclear fuels may only be authorized, according to the provisions of the Atomic Energy Act, if the required protection from disruptive action or other interference by third parties can be guaranteed as following: it must be possible to prevent any danger to life and health due to a substantial amount of direct radiation or due to the release of a substantial amount of radioactive material; it must be possible to prevent singular or repeated acts of stealing nuclear fuels in such amounts that a critical accumulation can be produced directly without reprocessing and enrichment. Knowing that nuclear installations cannot be protected from every possible interference, physical protection is focused on basic security standards, the so-called design basic threat (DBT), departing from the assumed interference. DBT is regularly reviewed by the competent federal authorities and authorities of the states and are revised on the basis of newly gained knowledge, if necessary, such as in the wake of the terrorist attacks in the U.S. on September 11, 2001. The operator must guarantee and give proof of a sufficient level of physical protection of the plant. The sole physical protection measures implemented by the operator cannot ensure the required protection from other interference by third parties for an unlimited time span. The concept therefore requires additional physical protection measures by the police. (author)

  11. The coupling of the neutron transport application RATTLESNAKE to the nuclear fuels performance application BISON under the MOOSE framework

    Energy Technology Data Exchange (ETDEWEB)

    Gleicher, Frederick N.; Williamson, Richard L.; Ortensi, Javier; Wang, Yaqi; Spencer, Benjamin W.; Novascone, Stephen R.; Hales, Jason D.; Martineau, Richard C.

    2014-10-01

    The MOOSE neutron transport application RATTLESNAKE was coupled to the fuels performance application BISON to provide a higher fidelity tool for fuel performance simulation. This project is motivated by the desire to couple a high fidelity core analysis program (based on the self-adjoint angular flux equations) to a high fidelity fuel performance program, both of which can simulate on unstructured meshes. RATTLESNAKE solves self-adjoint angular flux transport equation and provides a sub-pin level resolution of the multigroup neutron flux with resonance treatment during burnup or a fast transient. BISON solves the coupled thermomechanical equations for the fuel on a sub-millimeter scale. Both applications are able to solve their respective systems on aligned and unaligned unstructured finite element meshes. The power density and local burnup was transferred from RATTLESNAKE to BISON with the MOOSE Multiapp transfer system. Multiple depletion cases were run with one-way data transfer from RATTLESNAKE to BISON. The eigenvalues are shown to agree well with values obtained from the lattice physics code DRAGON. The one-way data transfer of power density is shown to agree with the power density obtained from an internal Lassman-style model in BISON.

  12. Neighbourhood walkability, leisure-time and transport-related physical activity in a mixed urban-rural area.

    Science.gov (United States)

    de Sa, Eric; Ardern, Chris I

    2014-01-01

    Objectives. To develop a walkability index specific to mixed rural/suburban areas, and to explore the relationship between walkability scores and leisure time physical activity. Methods. Respondents were geocoded with 500 m and 1,000 m buffer zones around each address. A walkability index was derived from intersections, residential density, and land-use mix according to built environment measures. Multivariable logistic regression models were used to quantify the association between the index and physical activity levels. Analyses used cross-sectional data from the 2007-2008 Canadian Community Health Survey (n = 1158; ≥18 y). Results. Respondents living in highly walkable 500 m buffer zones (upper quartiles of the walkability index) were more likely to walk or cycle for leisure than those living in low-walkable buffer zones (quartile 1). When a 1,000 m buffer zone was applied, respondents in more walkable neighbourhoods were more likely to walk or cycle for both leisure-time and transport-related purposes. Conclusion. Developing a walkability index can assist in exploring the associations between measures of the built environment and physical activity to prioritize neighborhood change.

  13. Design retrofit to prevent damage due to heat transport pump operation under conditions of significant void

    International Nuclear Information System (INIS)

    Lam, K.F.

    1991-01-01

    The purpose of this paper is to provide a general review of certain key design areas which address the safety concerns of HT pump operation under conditions of significant void. To illustrate the challenges confronting designers and analysts, some of the highlights during the design of a protective system to prevent damage to HT piping and pump supports at Bruce NGS 'A' are outlined. The effects of this protective system on reactor safety are also discussed. HI pump operation under conditions of significant void offers a major challenge to designers and analysts to ensure that pump induced vibration and its effects on pump and piping are addressed. For an in-service station the search for a practical solution is often limited by existing. station equipment design and Layout. The diversity of design verification process requires a major commitment of engineering resources to ensure all. safety aspects meet the requirements of regulatory body. Work currently undertaken at Ontario Hydro Research Pump Test Complex on two-phase flow in pumps and piping may provide better prediction of vibration characteristics so that inherent conservativeness in fatigue Life prediction of HI system components can be reduced

  14. PHYSICS

    CERN Multimedia

    P. Sphicas

    There have been three physics meetings since the last CMS week: “physics days” on March 27-29, the Physics/ Trigger week on April 23-27 and the most recent physics days on May 22-24. The main purpose of the March physics days was to finalize the list of “2007 analyses”, i.e. the few topics that the physics groups will concentrate on for the rest of this calendar year. The idea is to carry out a full physics exercise, with CMSSW, for select physics channels which test key features of the physics objects, or represent potential “day 1” physics topics that need to be addressed in advance. The list of these analyses was indeed completed and presented in the plenary meetings. As always, a significant amount of time was also spent in reviewing the status of the physics objects (reconstruction) as well as their usage in the High-Level Trigger (HLT). The major event of the past three months was the first “Physics/Trigger week” in Apri...

  15. Underlying Dimensions of the "Physical Educators' Judgments about Inclusion" Instrument: Brazilian-Version

    Science.gov (United States)

    Hodge, Samuel R.; Gutierres Filho, Paulo José Barbosa; Haegele, Justin A.; Kozub, Francis M.

    2015-01-01

    Background/Objective: The available information pertaining to the attitudes of Brazilian physical education teachers about teaching students with disabilities is limited in the extant literature base. Rationally, however, scholars argue that determining, analyzing, and theorizing about the attitudes of physical education teachers is important in…

  16. [Insulation characteristics of transport containers for organ cultured donor corneas under different ambient temperatures].

    Science.gov (United States)

    Schroeter, J; Meltendorf, C

    2009-08-01

    The aim of this study was to evaluate the ability of different transport containers to maintain an inside temperature between +10 and +40 degrees C, which is supposed to be safe for organ cultured donor corneas in dextran containing culture media, for a period of 24 hours at ambient temperatures of -10, 0, +10 and +50 degrees C. 3 containers were tested: 1. Styrofoam box with 2.5 cm thick walls (Graft-tec, AL.CHI.MI.A., Padova, Italy). 2. Thermos jug 0.5 litre (Primus, Solna, Sweden), a double walled metal jug. 3. ThempShell-22 degrees (VWR International, Darmstadt, Germany), a box of gel filled plastic elements. The containers were exposed to -10, 0, +10 and +50 degrees C for 24 hours each. A continuous temperature recording of the ambient and internal environments was performed using electronic thermometers (Mini Intelligent Logger, Escort). The inside temperature of the styrofoam box reached the outside temperature level after 80 - 230 min for all tested settings. The Thermos jug reached the outside temperature approximately after 5 hours. In contrast, the inside temperature of the TempShell-22 degrees CC was at -10 degrees C outside temperature 21 degrees C after 6 hours, 19 degrees C after 12 hours and 12 degrees C after 24 hours. At an ambient temperature of 0 and +10 degrees C the inside temperature of the TempShell-22 degrees C was 19.2 and 17.8 degrees C respectively after 24 hours. An ambient temperature of + 50 degrees C led to an inside temperature of the TempShell-22 degrees C of 30.5 degrees C after 6, 38.3 degrees C after 12 hours and 47.0 degrees C after 24 hours. A standard Styrofoam box with 2.5 cm thick walls and the tested thermos jug are not suitable to assure a safe temperature range. The TempShell-22 degrees C assures a safe temperature range for low ambient temperatures (-10 to +10 degrees C) for at least 24 hours and for an ambient temperature of +50 degrees C for at least 10 hours. Georg Thieme Verlag KG Stuttgart.New York.

  17. Understanding unusual thermal transport behavior in soft materials under mechanical strain - A molecular dynamics study

    Science.gov (United States)

    Murad, Sohail; Puri, Ishwar K.

    2015-04-01

    Experiments have shown a dependence of the thermal conductivity of soft polymer materials on shear stress, which is common to several applications, such as film processing, fiber spinning, blow molding, and vacuum forming. Experiments reveal that the conductivity initially decreases with shear, but then increases as additional shear rate is applied. Based on molecular principles, we hypothesize that when molecules are initially placed under tension and extended, they disentangle, which reduces the number of points of interaction and diminishes the heat flux. Further molecular stretching increases this flux because the molecules are now better axially aligned. Molecular dynamics simulations confirm this competition and reproduce the inflection in the flux-strain relationship, which has not been previously explained.

  18. Fate and transport of oil sand process-affected water into the underlying clay till: A field study

    Science.gov (United States)

    Abolfazlzadehdoshanbehbazari, Mostafa; Birks, S. Jean; Moncur, Michael C.; Ulrich, Ania C.

    2013-08-01

    The South Tailings Pond (STP) is a ~ 2300-ha tailing pond operated by Suncor Energy Inc. that has received oil sand process-affected (PA) water and mature fine tailings since 2006. The STP is underlain by a clay till, which is in turn underlain by the Wood Creek Sand Channel (WCSC). The sandy deposits of the WCSC provide greater geotechnical stability but could act as a potential flow pathway for PA water to migrate off site and into the Athabasca River. Preliminary modeling of the STP suggests that PA water from the pond will infiltrate into the underlying sand channel, but the extent and development of this impact is still poorly understood. Suncor Energy Inc. built interception wells and a cut-off-wall to control any potential seepage. Here we present the results of an investigation of the fate and transport of PA water in clay till underlying a 10 m × 10 m infiltration pond that was constructed on the southeastern portion of the STP. The geochemistry of pore water in the till underlying the infiltration pond was determined prior to filling with process-affected water (2008) and two years after the infiltration pond was filled with PA waters (2010). Pore water was analyzed for metals, cations, anions, and isotopes (2H and 18O). The distribution of conservative tracers (18O and chloride) indicated migration of the PA waters to approximately 0.9 m, but the migrations of major ions and metals were significantly delayed relative to this depth. Uptake of Na and Mo and release of Ca, Mg, Mn, Ba, and Sr suggest that adsorption and ion exchange reactions are the foremost attenuation processes controlling inorganic solutes transport.

  19. Manual transportation within the plot and physical damages to bananas Transporte manual no interior do talhão e danos físicos em bananas

    Directory of Open Access Journals (Sweden)

    Mário Jorge Maia de Magalhães

    2004-02-01

    Full Text Available The manual transportation of banana bunches within plots provokes physical damages to fruits compromising their quality. To assess the influence of the distance banana bunches travel on the shoulders of harvesters within the plot, on the incidence of physical damages present on the peel of fruits of the Nanicão cultivar, two experiments were carried out in the Vale do Ribeira region (SP, in sites with slope O transporte manual de cachos de banana no interior do talhão provoca danos físicos aos frutos que comprometem sua qualidade. Este trabalho objetivou avaliar a influência da distância percorrida pelo cacho de banana no ombro do carregador, no interior do talhão, na incidência de danos físicos na superfície de frutos do cultivar Nanicão. Foram conduzidos dois experimentos na Região do Vale do Ribeira - SP. Os experimentos foram realizados em terreno plano (declividade 0-1%. Em cada experimento dividiu-se o talhão em duas faixas de distâncias distintas: uma situada mais distante do carreador e uma intermediária. No 1° experimento, as faixas de distância foram 30-50 m e 80-100 m, e no 2º, foram 70-80 m e 130-150 m. Para cada faixa de distância foram amostrados, aleatoriamente, seis cachos de banana com frutos de calibre 36 mm. De cada cacho retiraram-se quatro pencas da região mediana para a avaliação de 10 frutos por penca, totalizando 240 frutos por tratamento, somando-se ao final dos dois experimentos 1440 frutos avaliados. Para testemunha, colheram-se cachos no mesmo grau de maturação e não se efetuou o transporte dos mesmos. A avaliação dos danos físicos na superfície dos frutos foi feita através de uma escala com 6 divisões de área: 0-0,25 cm²; 0,25-0,5 cm²; 0,5-1,0 cm²; 1,0-1,5 cm²; 1,5-2,0 cm²; 2,0-2,5 cm². Os cachos transportados no ombro do operador por distâncias maiores que 70 m, sofreram um aumento (P < 0,01 na área lesionada nos frutos. A maioria das lesões apresentou área de até 0,5 cm².

  20. On the physics of dispersive electron transport characteristics in SnO2 nanoparticle-based dye sensitized solar cells

    Science.gov (United States)

    Ashok, Aditya; Vijayaraghavan, S. N.; Unni, Gautam E.; Nair, Shantikumar V.; Shanmugam, Mariyappan

    2018-04-01

    The present study elucidates dispersive electron transport mediated by surface states in tin oxide (SnO2) nanoparticle-based dye sensitized solar cells (DSSCs). Transmission electron microscopic studies on SnO2 show a distribution of ∼10 nm particles exhibiting (111) crystal planes with inter-planar spacing of 0.28 nm. The dispersive transport, experienced by photo-generated charge carriers in the bulk of SnO2, is observed to be imposed by trapping and de-trapping processes via SnO2 surface states present close to the band edge. The DSSC exhibits 50% difference in performance observed between the forward (4%) and reverse (6%) scans due to the dispersive transport characteristics of the charge carriers in the bulk of the SnO2. The photo-generated charge carriers are captured and released by the SnO2 surface states that are close to the conduction band-edge resulting in a very significant variation; this is confirmed by the hysteresis observed in the forward and reverse scan current–voltage measurements under AM1.5 illumination. The hysteresis behavior assures that the charge carriers are accumulated in the bulk of electron acceptor due to the trapping, and released by de-trapping mediated by surface states observed during the forward and reverse scan measurements.

  1. Physical, chemical, and biological properties of soil under soybean cultivation and at an adjacent rainforest in Amazonia

    Science.gov (United States)

    T.P. Beldini; R.C. Oliveira Junior; Michael Keller; P.B. de Camargo; P.M. Crill; A. Damasceno da Silva; D. Bentes dos Santos; D. Rocha de Oliveira

    2015-01-01

    Land-use change in the Amazon basin has occurred at an accelerated pace during the last decade, and it is important that the effects induced by these changes on soil properties are better understood. This study investigated the chemical, physical, and biological properties of soil in a field under cultivation of soy and rice, and at an adjacent primary rain forest....

  2. Proximity under Threat: The Role of Physical Distance in Intergroup Relations

    Science.gov (United States)

    Wohl, Michael J. A.; Van Bavel, Jay J.

    2016-01-01

    Throughout human history, social groups have invested immense amounts of wealth and time to keep threatening out-groups at a distance. In the current research, we explored the relationship between intergroup threat, physical distance, and discrimination. Specifically, we examined how intergroup threat alters estimates of physical distance to out-groups and how physical proximity affects intergroup relations. Previous research has found that people judge threatening out-groups as physically close. In Studies 1 and 2, we examined ways to attenuate this bias. In Study 1 a secure (vs. permeable) US-Mexico border reduced the estimated proximity to Mexico City among Americans who felt threatened by Mexican immigration. In Study 2, intergroup apologies reduced estimates of physical proximity to a threatening cross-town rival university, but only among participants with cross-group friendships. In Study 3, New York Yankees fans who received an experimental induction of physical proximity to a threatening out-group (Boston Red Sox) had a stronger relationship between their collective identification with the New York Yankees and support for discriminatory policies toward members of the out-group (Red Sox fans) as well as how far they chose to sit from out-group members (Red Sox fans). Together, these studies suggest that intergroup threat alters judgment of physical properties, which has important implications for intergroup relations. PMID:27467267

  3. Transport Properties of EuNi2Ge2 under High Pressure

    Science.gov (United States)

    Wada, Hirofumi; Goki, Yusuke; Mitsuda, Akihiro

    2018-03-01

    Transverse magnetoresistance (MR) and Hall effect have been measured for EuNi2Ge2 single crystals under high pressures up to 2.0 GPa. The compound undergoes a valence transition from a nearly trivalent state to a divalent state with increasing temperature above 1.6 GPa. It was found that the transverse MR of EuNi2Ge2 is negative at low temperatures in the nearly trivalent state, although the compound is nonmagnetic. The origin of the negative MR is discussed. In the temperature dependence of the Hall resistivity ρH, large jumps associated with the valence transition were observed at the valence transition temperature. We also examined the field-induced valence transition by the MR and ρH measurements. A marked change in the Hall coefficient was observed at the valence transition field. Our analyses suggest that the ordinary Hall effect plays a dominant role in the changes in ρH at the valence transition.

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

    KAUST Repository

    French, William R.

    2013-01-01

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

  5. The environment of nature reserves under anthropogenic load: air transport of pollution to the North of European Russia

    Science.gov (United States)

    Vinogradova, A. A.; Ivanova, Yu. A.; Veremeychik, A. O.

    2012-04-01

    Nature reserves are created to keep in their original states natural environment, flora and fauna of various ecological systems, territories, climatic zones, etc. Now natural objects everywhere exist under anthropogenic loading from man-made activities. It is impossible to avoid atmospheric or river transport of pollution to the environment of reserved territories. The main idea of the work is to analyze atmospheric transport of anthropogenic metals (Ni, Cu, Pb, Fe, Al), as well as of soot (black carbon - BC) from Russian large industrial areas (source-regions) to the territories of nature reserves at the North of European Russia - the Kostomukshsky reserve (KR) in Karelia (64.57°N, 30.67°E) and the Nenetzky reserve (NR) at the Pechora River mouth (68,5°N, 53,5°E). The basic data for these 2 points were back trajectories of air mass transport calculated for every day of January, April, July, and October during 10 years from 2001 to 2010. We used NCEP/NCAR Reanalysis Data Files with HYSPLIT 4 model and two approaches for analyzing the trajectories. The main source-regions were chosen for each reserve. The annual source emissions for the last decade are generalized from the data published by Roshydromet of Russia (http://www.nii-atmosphere.ru/files/PUBL/Eg_2008.doc). The deposition velocity was a sum of dry and wet components. The equal values of deposition velocities onto the surface were assumed for all impurities because they are mainly on submicron aerosol particles under atmospheric transport for a long distance. The seasonal and spatial variations of averaged deposition velocity were accounted in accordance with surface properties and precipitation regimes. As a result, the maximal air concentrations of aerosol pollutants are observed in cold seasons, whereas the maximal fluxes onto the surface occur in warm period. Thus, it's possible that the cleanest air does not indicate the same surface. Fe and Al are the crust (dust or soil) elements. Thus, their main

  6. Physically-Based Rendering of Particle-Based Fluids with Light Transport Effects

    Science.gov (United States)

    Beddiaf, Ali; Babahenini, Mohamed Chaouki

    2018-03-01

    Recent interactive rendering approaches aim to efficiently produce images. However, time constraints deeply affect their output accuracy and realism (many light phenomena are poorly or not supported at all). To remedy this issue, in this paper, we propose a physically-based fluid rendering approach. First, while state-of-the-art methods focus on isosurface rendering with only two refractions, our proposal (1) considers the fluid as a heterogeneous participating medium with refractive boundaries, and (2) supports both multiple refractions and scattering. Second, the proposed solution is fully particle-based in the sense that no particles transformation into a grid is required. This interesting feature makes it able to handle many particle types (water, bubble, foam, and sand). On top of that, a medium with different fluids (color, phase function, etc.) can also be rendered.

  7. Soil organic carbon loss and selective transportation under field simulated rainfall events.

    Directory of Open Access Journals (Sweden)

    Xiaodong Nie

    Full Text Available The study on the lateral movement of soil organic carbon (SOC during soil erosion can improve the understanding of global carbon budget. Simulated rainfall experiments on small field plots were conducted to investigate the SOC lateral movement under different rainfall intensities and tillage practices. Two rainfall intensities (High intensity (HI and Low intensity (LI and two tillage practices (No tillage (NT and Conventional tillage (CT were maintained on three plots (2 m width × 5 m length: HI-NT, LI-NT and LI-CT. The rainfall lasted 60 minutes after the runoff generated, the sediment yield and runoff volume were measured and sampled at 6-min intervals. SOC concentration of sediment and runoff as well as the sediment particle size distribution were measured. The results showed that most of the eroded organic carbon (OC was lost in form of sediment-bound organic carbon in all events. The amount of lost SOC in LI-NT event was 12.76 times greater than that in LI-CT event, whereas this measure in HI-NT event was 3.25 times greater than that in LI-NT event. These results suggest that conventional tillage as well as lower rainfall intensity can reduce the amount of lost SOC during short-term soil erosion. Meanwhile, the eroded sediment in all events was enriched in OC, and higher enrichment ratio of OC (ERoc in sediment was observed in LI events than that in HI event, whereas similar ERoc curves were found in LI-CT and LI-NT events. Furthermore, significant correlations between ERoc and different size sediment particles were only observed in HI-NT event. This indicates that the enrichment of OC is dependent on the erosion process, and the specific enrichment mechanisms with respect to different erosion processes should be studied in future.

  8. Mitigating Vadose Zone Nitrogen Transport Under Land Use Change and Urbanization

    Science.gov (United States)

    Parratt, R. T.; Menon, M.; Tyler, S.; Kropf, C.

    2008-12-01

    The discovery of large accumulations of nitrate within the vadose zones of many desert ecosystems coupled with land use change from urbanization in these areas may be having a detrimental effect on the ground water quality, often the source of public water supplies of these regions. Land use change can result in the initiation or increase in aquifer recharge (from over-irrigation, leaking pipes, wastewater discharge, etc.) and has the potential to mobilize the observed stores of accumulated nitrate in the vadose zone. This research focuses on mitigation options to reduce mobilization of nitrate in the vadose zone by stimulating denitrification reactions during transit through the vadose zone prior to reaching the underlying aquifers. Laboratory experiments using typical vadose zone materials from Spanish Springs, Nevada, conducted in 1 meter columns have been prepared with a nitrate rich soil layer (1000 ppm KNO3, labeled with 2% KNO3 - N15 isotopic tracer) designed to simulate a nitrate accumulation zone. All columns are irrigated with treated wastewater (effluent) at a rate of 0.5 cm/day to simulate excess irrigation of urbanized parklands. In addition to a control column, one column's irrigation is augmented with dextrose (C6H12O6) designed to provide sufficient carbon sources, when combined with higher water content, to promote microbial denitrification. A third column is treated with a compost and soil mixture at the surface of the soil to provide an alternative method of producing dissolved organic carbon to be advected with the infiltration to the nitrogen storage regions within the column. All columns are instrumented with volumetric water content probes, tensiometers, and soil solution samplers. Initial results from soil solution analysis indicate the possibility of nitrate reduction by as much as 50 % of the initial concentration, after only 14 days of residence time within the dextrose amended column. Analysis will be presented comparing the treatments

  9. Modeling transport of nutrients & sediment loads into Lake Tahoe under climate change

    Science.gov (United States)

    Riverson, John; Coats, Robert; Costa-Cabral, Mariza; Dettinger, Mike; Reuter, John; Sahoo, Goloka; Schladow, Geoffrey

    2013-01-01

    The outputs from two General Circulation Models (GCMs) with two emissions scenarios were downscaled and bias-corrected to develop regional climate change projections for the Tahoe Basin. For one model—the Geophysical Fluid Dynamics Laboratory or GFDL model—the daily model results were used to drive a distributed hydrologic model. The watershed model used an energy balance approach for computing evapotranspiration and snowpack dynamics so that the processes remain a function of the climate change projections. For this study, all other aspects of the model (i.e. land use distribution, routing configuration, and parameterization) were held constant to isolate impacts of climate change projections. The results indicate that (1) precipitation falling as rain rather than snow will increase, starting at the current mean snowline, and moving towards higher elevations over time; (2) annual accumulated snowpack will be reduced; (3) snowpack accumulation will start later; and (4) snowmelt will start earlier in the year. Certain changes were masked (or counter-balanced) when summarized as basin-wide averages; however, spatial evaluation added notable resolution. While rainfall runoff increased at higher elevations, a drop in total precipitation volume decreased runoff and fine sediment load from the lower elevation meadow areas and also decreased baseflow and nitrogen loads basin-wide. This finding also highlights the important role that the meadow areas could play as high-flow buffers under climatic change. Because the watershed model accounts for elevation change and variable meteorological patterns, it provided a robust platform for evaluating the impacts of projected climate change on hydrology and water quality.

  10. PHYSICS

    CERN Multimedia

    D. Acosta

    2010-01-01

    A remarkable amount of progress has been made in Physics since the last CMS Week in June given the exponential growth in the delivered LHC luminosity. The first major milestone was the delivery of a variety of results to the ICHEP international conference held in Paris this July. For this conference, CMS prepared 15 Physics Analysis Summaries on physics objects and 22 Summaries on new and interesting physics measurements that exploited the luminosity recorded by the CMS detector. The challenge was incorporating the largest batch of luminosity that was delivered only days before the conference (300 nb-1 total). The physics covered from this initial running period spanned hadron production measurements, jet production and properties, electroweak vector boson production, and even glimpses of the top quark. Since then, the accumulated integrated luminosity has increased by a factor of more than 100, and all groups have been working tremendously hard on analysing this dataset. The September Physics Week was held ...

  11. Physical analysis and modelling of aerosols transport. implementation in a finite elements code. Experimental validation in laminar and turbulent flows

    International Nuclear Information System (INIS)

    Armand, Patrick

    1995-01-01

    The aim of this work consists in the Fluid Mechanics and aerosol Physics coupling. In the first part, the order of magnitude analysis of the particle dynamics is done. This particle is embedded in a non-uniform unsteady flow. Flow approximations around the inclusion are described. Corresponding aerodynamic drag formulae are expressed. Possible situations related to the problem data are extensively listed. In the second part, one studies the turbulent particles transport. Eulerian approach which is particularly well adapted to industrial codes is preferred in comparison with the Lagrangian methods. One chooses the two-fluid formalism in which career gas-particles slip is taken into account. Turbulence modelling gets through a k-epsilon modulated by the inclusions action on the flow. The model is implemented In a finite elements code. Finally, In the third part, one validates the modelling in laminar and turbulent cases. We compare simulations to various experiments (settling battery, inertial impaction in a bend, jets loaded with glass beads particles) which are taken in the literature or done by ourselves at the laboratory. The results are very close. It is a good point when it is thought of the particles transport model and associated software future use. (author) [fr

  12. Present status on the ion collective acceleration and high-current beam transport in the Lebedev's Physical Institute USSR

    International Nuclear Information System (INIS)

    Kolomenskij, A.A.

    1982-01-01

    The results of investigations into the ion collective acceleration and transport of high-current electron beams (HCEB) in vacuum channels with dielectric walls (VCDW) are presented. The physical principle of transport is in the partial neutralization of spatial charge of electrons with ions escaped from the prewall plasma and the compression of the beam with its own magnetic field. A problem of obtaining the intensive beams of negative ions in diode with magnetic isolation is considered. The mechanism of ion acceleration in VCDW is considered. It is shown that there are two regions with different mechanisms of acceleration. In the first region (''plasma'') ion acceleration in the quasipotential HCEB field up to energy of the order of the electron energy takes place. In the second region (''beam'') the acceleration takes place in the wave fields that can be excited due to the mechanism of the two-beam type instability. The mechanism of ion acceleration in direct electron beams is considered. This mechanism is based on the concept of relaxation oscillations of the virtual cathode and corresponding the reconstruction of the spatial charge distribution

  13. Heat transport in two-dimensional materials by directly solving the phonon Boltzmann equation under Callaway's dual relaxation model

    Science.gov (United States)

    Guo, Yangyu; Wang, Moran

    2017-10-01

    The single mode relaxation time approximation has been demonstrated to greatly underestimate the lattice thermal conductivity of two-dimensional materials due to the collective effect of phonon normal scattering. Callaway's dual relaxation model represents a good approximation to the otherwise ab initio solution of the phonon Boltzmann equation. In this work we develop a discrete-ordinate-method (DOM) scheme for the numerical solution of the phonon Boltzmann equation under Callaway's model. Heat transport in a graphene ribbon with different geometries is modeled by our scheme, which produces results quite consistent with the available molecular dynamics, Monte Carlo simulations, and experimental measurements. Callaway's lattice thermal conductivity model with empirical boundary scattering rates is examined and shown to overestimate or underestimate the direct DOM solution. The length convergence of the lattice thermal conductivity of a rectangular graphene ribbon is explored and found to depend appreciably on the ribbon width, with a semiquantitative correlation provided between the convergence length and the width. Finally, we predict the existence of a phonon Knudsen minimum in a graphene ribbon only at a low system temperature and isotope concentration so that the average normal scattering rate is two orders of magnitude stronger than the intrinsic resistive one. The present work will promote not only the methodology for the solution of the phonon Boltzmann equation but also the theoretical modeling and experimental detection of hydrodynamic phonon transport in two-dimensional materials.

  14. PHYSICS

    CERN Multimedia

    P. Sphicas

    The CPT project came to an end in December 2006 and its original scope is now shared among three new areas, namely Computing, Offline and Physics. In the physics area the basic change with respect to the previous system (where the PRS groups were charged with detector and physics object reconstruction and physics analysis) was the split of the detector PRS groups (the old ECAL-egamma, HCAL-jetMET, Tracker-btau and Muons) into two groups each: a Detector Performance Group (DPG) and a Physics Object Group. The DPGs are now led by the Commissioning and Run Coordinator deputy (Darin Acosta) and will appear in the correspond¬ing column in CMS bulletins. On the physics side, the physics object groups are charged with the reconstruction of physics objects, the tuning of the simulation (in collaboration with the DPGs) to reproduce the data, the provision of code for the High-Level Trigger, the optimization of the algorithms involved for the different physics analyses (in collaboration with the analysis gr...

  15. PHYSICS

    CERN Multimedia

    J. Incandela

    There have been numerous developments in the physics area since the September CMS week. The biggest single event was the Physics/Trigger week in the end of Octo¬ber, whereas in terms of ongoing activities the “2007 analyses” went into high gear. This was in parallel with participation in CSA07 by the physics groups. On the or¬ganizational side, the new conveners of the physics groups have been selected, and a new database for man¬aging physics analyses has been deployed. Physics/Trigger week The second Physics-Trigger week of 2007 took place during the week of October 22-26. The first half of the week was dedicated to working group meetings. The ple¬nary Joint Physics-Trigger meeting took place on Wednesday afternoon and focused on the activities of the new Trigger Studies Group (TSG) and trigger monitoring. Both the Physics and Trigger organizations are now focused on readiness for early data-taking. Thus, early trigger tables and preparations for calibr...

  16. National transportation statistics 2011

    Science.gov (United States)

    2011-04-01

    Compiled and published by the U.S. Department of Transportation's Bureau of Transportation Statistics (BTS), National Transportation Statistics presents information on the U.S. transportation system, including its physical components, safety record, ...

  17. Pharmacology of smac mimetics; chemotype differentiation based on physical association with caspase regulators and cellular transport.

    Science.gov (United States)

    Talbott, Randy L; Borzilleri, Robert M; Chaudhry, Charu; Fargnoli, Joseph; Shen, Henry; Fairchild, Craig; Barnhart, Bryan; Ortega, Marie; McDonagh, Thomas E; Vuppugalla, Ragini; Vite, Gregory D; Hunt, John T; Gottardis, Marco; Naglich, Joseph G

    2015-11-01

    Cellular levels of inhibitor of apoptosis (IAP) proteins are elevated in multiple human cancers and their activities often play a part in promoting cancer cell survival by blocking apoptotic pathways, controlling signal transduction pathways and contributing to resistance. These proteins function through interactions of their BIR (baculoviral IAP repeat) protein domains with pathway components and these interactions are endogenously antagonized by Smac/Diablo (second mitochondrial activator of caspases/direct IAP binding protein with low isoelectric point). This report describes development of synthetic smac mimetics (SM) and compares their binding, antiproliferative and anti-tumor activities. All dimeric antagonists inhibit in vitro smac tetrapeptide binding to recombinant IAP proteins, rescue IAP-bound caspase-3 activity and show anti-proliferative activity against human A875 melanoma cells. One heterodimeric SM, SM3, binds tightly to IAP proteins in vitro and slowly dissociates (greater than two hours) from these protein complexes compared to the other antagonists. In addition, in vitro SM anti-proliferation potency is influenced by ABCB1 transporter (ATP-binding cassette, sub-family B; MDR1, P-gp) activities and one antagonist, SM5, does not appear to be an ABCB1 efflux pump substrate. All dimeric smac mimetics inhibit the growth of human melanoma A875 tumors implanted in athymic mice at well-tolerated doses. One antagonist, SM4, shows broad spectrum in vivo anti-tumor activity and modulates known pharmacodynamic markers of IAP antagonism. These data taken together demonstrate the range of diverse dimeric IAP antagonist activities and supports their potential as anticancer agents. Copyright © 2015 Elsevier Inc. All rights reserved.

  18. Semi-analytical solution of land-derived solute transport under tidal fluctuation in a confined aquifer

    Science.gov (United States)

    Suk, Heejun

    2017-11-01

    A one-dimensional semi-analytical solution of land-derived solute transport, subject to tidal fluctuation in a coastal confined aquifer, was derived using the generalized integral-transform technique (GITT). To investigate the plume migration of land-derived contaminants within a tidally influenced aquifer, both spatially and temporally varying expressions of the Darcy velocity and dispersion coefficients obtained from the analytical solution of the groundwater head response, which were subject to sinusoidal boundary conditions due to tidal fluctuation, were considered. This new semi-analytical solution was verified against a numerical solution, as well as the peak location trajectory obtained using the Predictor-Corrector method. Sensitivity analyses of tidal amplitude, hydraulic conductivity, and storage coefficient using the proposed solution were performed to understand plume behavior with regard to plume shape, plume spatial moments, and macrodispersion coefficients to gain a better understanding of the transport mechanisms. As the tidal amplitude, hydraulic conductivity, and storage coefficient were increased, the peaks were travelled faster, and peak concentrations were decreased. In addition, an increase in tidal amplitude, hydraulic conductivity, and storage coefficient caused an increase in variance as well as the macrodispersion coefficient. It was observed that negative macrodispersion appeared when the storage coefficient was largest, as well as when the difference between landward-directed advective velocity at the leading and trailing edges of the plume was greatest. This newly developed semi-analytical solution provides a useful mathematical tool for validating numerical models and understanding the physical mechanism of the migration of plume discharge to the sea or estuaries within a tidally influenced aquifer.

  19. Cross sectional analysis of the association between mode of school transportation and physical fitness in children and adolescents.

    Science.gov (United States)

    Ostergaard, Lars; Kolle, Elin; Steene-Johannessen, Jostein; Anderssen, Sigmund A; Andersen, Lars Bo

    2013-07-17

    To investigate the associations between body composition, cardiorespiratory and muscular fitness in relation to travel mode to school in children and adolescents. Children and adolescents from 40 elementary schools and 23 high schools representing all regions in Norway were invited to participate in the study. Anthropometry, cardiorespiratory and muscular fitness were tested at the school location. Questionnaires were used in order to register mode of transport to school, age, gender and levels of leisure time physical activity. A total of 1694 (i.e. 60% of all invited participants) children and adolescents at a mean age of 9.6 and 15.6 respectively (SD = 0.4 for both groups) were analyzed for associations with physical fitness variables. Males cycling to school had lower sum of skin folds than adolescents walking to school. Higher cardiorespiratory fitness in adolescents and male cyclists compared to walkers and passive commuters were observed. Among children, cycling and walking to school, higher isometric muscle endurance in the back extensors compared to passive commuters was observed. Based on this national representative cross-sectional examination of randomly selected children and adolescents there is evidence that active commuting, especially cycling, is associated with a favourable body composition and better cardiorespiratory and muscular fitness as compared to passive commuting.

  20. Sulfur deposition changes under sulfate geoengineering conditions: quasi-biennial oscillation effects on the transport and lifetime of stratospheric aerosols

    Science.gov (United States)

    Visioni, Daniele; Pitari, Giovanni; Tuccella, Paolo; Curci, Gabriele

    2018-02-01

    Sustained injection of sulfur dioxide (SO2) in the tropical lower stratosphere has been proposed as a climate engineering technique for the coming decades. Among several possible environmental side effects, the increase in sulfur deposition deserves additional investigation. In this study we present results from a composition-climate coupled model (University of L'Aquila Composition-Chemistry Model, ULAQ-CCM) and a chemistry-transport model (Goddard Earth Observing System Chemistry-Transport Model, GEOS-Chem), assuming a sustained lower-stratospheric equatorial injection of 8 Tg SO2 yr-1. Total S deposition is found to globally increase by 5.2 % when sulfate geoengineering is deployed, with a clear interhemispheric asymmetry (+3.8 and +10.3 % in the Northern Hemisphere (NH) and the Southern Hemisphere (SH), due to +2.2 and +1.8 Tg S yr-1, respectively). The two models show good consistency, both globally and on a regional scale under background and geoengineering conditions, except for S-deposition changes over Africa and the Arctic. The consistency exists with regard to time-averaged values but also with regard to monthly and interannual deposition changes. The latter is driven essentially by the variability in stratospheric large-scale transport associated with the quasi-biennial oscillation (QBO). Using an externally nudged QBO, it is shown how a zonal wind E shear favors aerosol confinement in the tropical pipe and a significant increase in their effective radius (+13 % with respect to W shear conditions). The net result is an increase in the downward cross-tropopause S flux over the tropics with dominant E shear conditions with respect to W shear periods (+0.61 Tg S yr-1, +42 %, mostly due to enhanced aerosol gravitational settling) and a decrease over the extratropics (-0.86 Tg S yr-1, -35 %, mostly due to decreased large-scale stratosphere-troposphere exchange of geoengineering sulfate). This translates into S-deposition changes that are significantly

  1. Development of Physical Protection Regulations for Rosatom State Corporation Sites under the U.S.-Russian MPC&A Program

    Energy Technology Data Exchange (ETDEWEB)

    Izmaylov, Alexander; Babkin, Vladimir; Shemigon, Nikolai N.; O' Brien, Patricia; Wright, Troy L.; Hazel, Michael J.; Tuttle, John D.; Cunningham, Mitchel E.; Lane, Melinda; Kovchegin, Dmitry

    2012-07-14

    This paper describes issues related to upgrading the physical protection regulatory basis for Rosatom State Corporation sites. It is underlined that most of the regulatory and methodological documents for this subject area have been developed under the U.S.-Russian MPC&A Program. According to the joint management plan developed and agreed upon by the parties in 2005, nearly 50 physical protection documents were identified to be developed, approved and implemented at Rosatom sites by 2012. It is also noted that, on the whole, the plans have been fulfilled.

  2. PHYSICS

    CERN Document Server

    Submitted by

    Physics Week: plenary meeting on physics groups plans for startup (14–15 May 2008) The Physics Objects (POG) and Physics Analysis (PAG) Groups presented their latest developments at the plenary meeting during the Physics Week. In the presentations particular attention was given to startup plans and readiness for data-taking. Many results based on the recent cosmic run were shown. A special Workshop on SUSY, described in a separate section, took place the day before the plenary. At the meeting, we had also two special DPG presentations on “Tracker and Muon alignment with CRAFT” (Ernesto Migliore) and “Calorimeter studies with CRAFT” (Chiara Rovelli). We had also a report from Offline (Andrea Rizzi) and Computing (Markus Klute) on the San Diego Workshop, described elsewhere in this bulletin. Tracking group (Boris Mangano). The level of sophistication of the tracking software increased significantly over the last few months: V0 (K0 and Λ) reconstr...

  3. The Physics of Traffic Congestion and Road Pricing in Transportation Planning

    Science.gov (United States)

    Levinson, David

    2010-03-01

    This presentation develops congestion theory and congestion pricing theory from its micro- foundations, the interaction of two or more vehicles. Using game theory, with a two- player game it is shown that the emergence of congestion depends on the players' relative valuations of early arrival, late arrival, and journey delay. Congestion pricing can be used as a cooperation mechanism to minimize total costs (if returned to the players). The analysis is then extended to the case of the three- player game, which illustrates congestion as a negative externality imposed on players who do not themselves contribute to it. A multi-agent model of travelers competing to utilize a roadway in time and space is presented. To realize the spillover effect among travelers, N-player games are constructed in which the strategy set includes N+1 strategies. We solve the N-player game (for N = 7) and find Nash equilibria if they exist. This model is compared to the bottleneck model. The results of numerical simulation show that the two models yield identical results in terms of lowest total costs and marginal costs when a social optimum exists. Moving from temporal dynamics to spatial complexity, using consistent agent- based techniques, we model the decision-making processes of users and infrastructure owner/operators to explore the welfare consequence of price competition, capacity choice, and product differentiation on congested transportation networks. Component models include: (1) An agent-based travel demand model wherein each traveler has learning capabilities and unique characteristics (e.g. value of time); (2) Econometric facility provision cost models; and (3) Representations of road authorities making pricing and capacity decisions. Different from small-network equilibrium models in prior literature, this agent- based model is applicable to pricing and investment analyses on large complex networks. The subsequent economic analysis focuses on the source, evolution

  4. Diffusion behaviors of fluorescence probe molecules through the stratum corneum layer under physical stress.

    Science.gov (United States)

    Lee, Ho; Kim, Jin Woong

    2013-04-01

    This study experimentally demonstrates how application of an external physical stress onto the skin membrane affects the permeation of penetrating molecules. As a proxy of active compounds, in this study, a series of fluorescence probe molecules were utilized. We observed that skin permeation could be enhanced by imparting vertical strokes from a tapping head consisting of projections onto the skin. This was confirmed with consistency from in vitro and in vivo transdermal permeation studies. After an effective physical stress was applied to the skin, the permeation depth of probe molecules remarkably increased, which was comparable to the case of topical treatment. This seems to arise from temporal disordering of the stratum corneum layer in response to the applied physical stress.

  5. How inflammation underlies physical and organ function in acutely admitted older medical patients

    DEFF Research Database (Denmark)

    Klausen, Henrik Hedegaard; Bodilsen, Ann Christine; Petersen, Janne

    2017-01-01

    OBJECTIVES: To investigate whether systemic inflammation in acutely admitted older medical patients (age >65 years) is associated with physical performance and organ dysfunction. Organ dysfunction´s association with physical performance, and whether these associations are mediated by systemic...... inflammation, was also investigated. METHODS: A cross-sectional study in an Emergency Department. Physical performance was assessed by handgrip strength and de Morton Mobility Index (DEMMI), and organ dysfunction by FI-OutRef, the number of standard blood tests outside the reference range. Systemic...... inflammation was assessed by suPAR, TNFα, and IL-6. Associations were investigated by regression analyses adjusted for age, sex, cognitive impairment, CRP, and VitalPAC Modified Early Warning Score. RESULTS: A total of 369 patients were evaluated. In adjusted analyses, suPAR and TNFα was associated with both...

  6. Embrittlement of steels for hydrogen transport and storage under high pressure; Fragilisation des aciers destines au transport et au stockage de l'hydrogene sous haute pression

    Energy Technology Data Exchange (ETDEWEB)

    Jouinot, P.; Gantchenko, V.; Katundi, D. [Institut Superieur de Mecanique de Paris (ISMEP-Sumeca), 93 - Saint-Ouen (France)

    2007-07-01

    This work deals with gaseous hydrogen embrittlement of steels for pipelines having a relatively high mechanical resistance (elasticity limit: 550 MPa, Grade 80). The studied materials come from 5 tube steels batch already used for hydrocarbons transport. Plates have been obtained by continuous casting followed by a hot controlled rolling: the rolling temperature is adjusted for obtaining a strain hardening in order to increase the mechanical resistance of the steel. These materials have been tested under hydrogen pressure and the resistance to hydrogen has been measured for each of them. The results show that the hydrogen embrittlement decreases when the mechanical resistance of the plate (or its hardness) increases. The inclusion state of the different steels has been quantified by images analysis at different depths in the plates. These steels contain only globular oxides or aligned aluminates. The hydrogen embrittlement increases with the amount of the globular oxides (or with the length of the aligned aluminates). Micrographic and fractographic analyses show that even small globular inclusions ({phi}=1 {mu}m) concentrate enough hydrogen to induce a crack in the material or to lead to a crack propagation. In order to estimate the homogeneity of the ferrito-perlitic structure, the thickness of ferrite bands have been measured. The hydrogen embrittlement increases as the thickness of the ferrite bands, that is to say, as the heterogeneity of the structure. Micrographs have shown that the hydrogen cracking is initiated on perlite aggregates; the crack propagates then in ferrite and joins then others perlitic areas. This study shows that relatively resistant steels (Grade 80, elasticity limit: 550 MPa) can be used for manufacturing pipelines submitted to high hydrogen pressure. (O.M.)

  7. Resilience Evaluation of Demand Response as Spinning Reserve under Cyber-Physical Threats

    Directory of Open Access Journals (Sweden)

    Anas AlMajali

    2016-12-01

    Full Text Available In the future, automated demand response mechanisms will be used as spinning reserve. Demand response in the smart grid must be resilient to cyber-physical threats. In this paper, we evaluate the resilience of demand response when used as spinning reserve in the presence of cyber-physical threats. We quantify this evaluation by correlating the stability of the system in the presence of attacks measured by system frequency (Hz and attack level measured by the amount of load (MW that responds to the demand response event. The results demonstrate the importance of anticipating the dependability of demand response before it can be relied upon as spinning reserve.

  8. Magnetic and transport properties of PrRu.sub.2./sub.Si.sub.2./sub. single crystal under high pressure

    Czech Academy of Sciences Publication Activity Database

    Vejpravová, J.; Kamarád, Jiří; Prchal, J.; Sechovsky, V.

    2007-01-01

    Roč. 76, suppl. A (2007), s. 49-50 ISSN 0031-9015 Institutional research plan: CEZ:AV0Z10100521 Keywords : pressure effect * magnetic properties * transport properties * single crystal Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.212, year: 2007

  9. Essential Concepts and Underlying Theories from Physics, Chemistry, and Mathematics for "Biochemistry and Molecular Biology" Majors

    Science.gov (United States)

    Wright, Ann; Provost, Joseph; Roecklein-Canfield, Jennifer A.; Bell, Ellis

    2013-01-01

    Over the past two years, through an NSF RCN UBE grant, the ASBMB has held regional workshops for faculty members from around the country. The workshops have focused on developing lists of Core Principles or Foundational Concepts in Biochemistry and Molecular Biology, a list of foundational skills, and foundational concepts from Physics, Chemistry,…

  10. Sensitivity analyses of biodiesel thermo-physical properties under diesel engine conditions

    DEFF Research Database (Denmark)

    Cheng, Xinwei; Ng, Hoon Kiat; Gan, Suyin

    2016-01-01

    This reported work investigates the sensitivities of spray and soot developments to the change of thermo-physical properties for coconut and soybean methyl esters, using two-dimensional computational fluid dynamics fuel spray modelling. The choice of test fuels made was due to their contrasting s...

  11. Transport of Silica Colloid through Saturated Porous Media under Different Hydrogeochemical and Hydrodynamic Conditions Considering Managed Aquifer Recharge

    Directory of Open Access Journals (Sweden)

    Zhuo Wang

    2016-11-01

    Full Text Available Colloids may have an important role in regulating the structure and function of groundwater ecosystems, and may influence the migration of low solubility contaminants in groundwater. There is, however, a degree of uncertainty about how colloids behave under the variable hydrogeochemical and hydrodynamic conditions that occur during managed aquifer recharge. We used an online monitoring system to monitor the transport of silica colloid in saturated porous media under different hydrogeochemical conditions, including a range of pH values (5, 7, and 9, ionic strengths (<0.0005, 0.02, and 0.05 M, cation valences (Na+, Ca2+, flow rates (0.1, 0.2, and 0.4 mL/min. The results showed that silica colloid was more likely to deposit on the surface of porous media in acidic conditions (pH = 5 than in alkaline conditions (pH = 9, indicating that the risks of pollution from colloidal interactions would be higher when the pH of the recharge water was higher. Colloid deposition occurred when the ionic strength of the colloidal suspension increased, and bivalent cations had a greater effect than monovalent cations. This suggests that bivalent cation-rich recharge water might affect the porosity of the porous medium because of colloid deposition during the managed aquifer recharge process. As the flow rate increased, the migration ability of silica colloid increased. We simulated the migration of silica colloid in porous media with the COMSOL Multiphysics model.

  12. A review on ab initio studies of static, transport, and optical properties of polystyrene under extreme conditions for inertial confinement fusion applications

    Science.gov (United States)

    Hu, S. X.; Collins, L. A.; Boehly, T. R.; Ding, Y. H.; Radha, P. B.; Goncharov, V. N.; Karasiev, V. V.; Collins, G. W.; Regan, S. P.; Campbell, E. M.

    2018-05-01

    Polystyrene (CH), commonly known as "plastic," has been one of the widely used ablator materials for capsule designs in inertial confinement fusion (ICF). Knowing its precise properties under high-energy-density conditions is crucial to understanding and designing ICF implosions through radiation-hydrodynamic simulations. For this purpose, systematic ab initio studies on the static, transport, and optical properties of CH, in a wide range of density and temperature conditions (ρ = 0.1 to 100 g/cm3 and T = 103 to 4 × 106 K), have been conducted using quantum molecular dynamics (QMD) simulations based on the density functional theory. We have built several wide-ranging, self-consistent material-properties tables for CH, such as the first-principles equation of state, the QMD-based thermal conductivity (κQMD) and ionization, and the first-principles opacity table. This paper is devoted to providing a review on (1) what results were obtained from these systematic ab initio studies; (2) how these self-consistent results were compared with both traditional plasma-physics models and available experiments; and (3) how these first-principles-based properties of polystyrene affect the predictions of ICF target performance, through both 1-D and 2-D radiation-hydrodynamic simulations. In the warm dense regime, our ab initio results, which can significantly differ from predictions of traditional plasma-physics models, compared favorably with experiments. When incorporated into hydrocodes for ICF simulations, these first-principles material properties of CH have produced significant differences over traditional models in predicting 1-D/2-D target performance of ICF implosions on OMEGA and direct-drive-ignition designs for the National Ignition Facility. Finally, we will discuss the implications of these studies on the current small-margin ICF target designs using a CH ablator.

  13. Suppression of the Neoclassical Tearing Modes in Tokamaks under Anomalous Transverse Transport Conditions when the Magnetic Well Effect Predominates over the Bootstrap Drive

    International Nuclear Information System (INIS)

    Konovalov, S.V.; Mikhailovskii, A.B.; Shirokov, M.S.; Ozeki, T.; Tsypin, V.S.

    2005-01-01

    A study is made of the suppression of neoclassical tearing modes in tokamaks under anomalous transverse transport conditions when the magnetic well effect predominates over the bootstrap drive. It is stressed that the corresponding effect, which is called the compound suppression effect, depends strongly on the profiles of the electron and ion temperature perturbations. Account is taken of the fact that the temperature profile can be established as a result of the competition between anomalous transverse heat transport, on the one hand, and longitudinal collisional heat transport, longitudinal heat convection, longitudinal inertial transport, and transport due to the rotation of magnetic islands, on the other hand. The role of geodesic effects is discussed. The cases of competition just mentioned are described by the model sets of reduced transport equations, which are called, respectively, collisional, convective, inertial, and rotational plasmophysical models. The magnetic well is calculated with allowance for geodesic effects. It is shown that, for strong anomalous heat transport conditions, the contribution of the magnetic well to the generalized Rutherford equation for the island width W is independent of W not only in the collisional model (which has been investigated earlier) but also in the convective and inertial models and depends very weakly (logarithmically) on W in the rotational model. It is this weak dependence that gives rise to the compound effect, which is the subject of the present study. A criterion for the stabilization of neoclassical tearing modes by the compound effect at an arbitrary level of the transverse heat transport by electrons and ions is derived and is analyzed for two cases: when the electron heat transport and ion heat transport are both strong, and when the electron heat transport is strong and the ion heat transport is weak

  14. The behaviour of transport from the fission products caesium and strontium in coated particles for high temperature reactors under irradiation conditions

    International Nuclear Information System (INIS)

    Zoller, P.

    1976-07-01

    At first survey is given about existing knowledge of the behaviour of caesium and strontium fission product transport in coated particles. In order to describe the complicated fission product transport mechanisms under irradiation conditions a suitable calculating model (SLIPPER) is taken over and modified to the special problems of an irradiation experiment. Fundamentally, the fission product transport is represented by the two contributions of diffusion and recoil, at which the diffusion is described by effective diffusion coefficients. In difference of that the possibility of a two-phase-diffusion is examined for the Cs diffusion in the fuel kernel. The model application on measuring results from irradiation experiments of KFA-Juelich and Mol-Belgien allowed the explanation from the characteristic of fission product transport in coated particles under irradiation conditions and produced effective diffusion coefficients for the fission products Cs and Sr. (orig.) [de

  15. Physical, Chemical, and Biological Properties of Soil under Decaying Wood in a Tropical Wet Forest in Puerto Rico

    Science.gov (United States)

    Marcela Zalamea; Grizelle Gonzalez; D. Jean Lodge

    2016-01-01

    Decaying wood is related to nutrient cycling through its role as either a sink or source of nutrients. However, at micro scales, what is the effect of decaying logs on the physical, chemical,and biotic characteristics of the soil underneath? We took samples from a 0 to 5 cm depth under and a 50 cm distance away from decaying logs (Dacryodes excelsa and Swietenia...

  16. PHYSICS

    CERN Multimedia

    D. Futyan

    A lot has transpired on the “Physics” front since the last CMS Bulletin. The summer was filled with preparations of new Monte Carlo samples based on CMSSW_3, the finalization of all the 10 TeV physics analyses [in total 50 analyses were approved] and the preparations for the Physics Week in Bologna. A couple weeks later, the “October Exercise” commenced and ran through an intense two-week period. The Physics Days in October were packed with a number of topics that are relevant to data taking, in a number of “mini-workshops”: the luminosity measurement, the determination of the beam spot and the measurement of the missing transverse energy (MET) were the three main topics.  Physics Week in Bologna The second physics week in 2009 took place in Bologna, Italy, on the week of Sep 7-11. The aim of the week was to review and establish how ready we are to do physics with the early collisions at the LHC. The agenda of the week was thus pac...

  17. PHYSICS

    CERN Multimedia

    D. Futyan

    A lot has transpired on the “Physics” front since the last CMS Bulletin. The summer was filled with preparations of new Monte Carlo samples based on CMSSW_3, the finalization of all the 10 TeV physics analyses [in total 50 analyses were approved] and the preparations for the Physics Week in Bologna. A couple weeks later, the “October Exercise” commenced and ran through an intense two-week period. The Physics Days in October were packed with a number of topics that are relevant to data taking, in a number of “mini-workshops”: the luminosity measurement, the determination of the beam spot and the measurement of the missing transverse energy (MET) were the three main topics.   Physics Week in Bologna The second physics week in 2009 took place in Bologna, Italy, on the week of Sep 7-11. The aim of the week was to review and establish (we hoped) the readiness of CMS to do physics with the early collisions at the LHC. The agenda of the...

  18. Personal transportation plan pilot program phase 1 : exploring the transportation behaviors and needs of veterans and people with physical disabilities and mobility constraints.

    Science.gov (United States)

    2017-06-01

    This report summarizes the initial phase of the Personal Transportation Plan Pilot Program (PTP3). The purpose of the PTP3 initiative is to develop a personal transportation planning tool that can be used by disabled Vermonters and Vermont veterans t...

  19. Distinct effects of reminding mortality and physical pain on the default-mode activity and activity underlying self-reflection.

    Science.gov (United States)

    Shi, Zhenhao; Han, Shihui

    2018-06-01

    Behavioral research suggests that reminding both mortality and negative affect influences self-related thoughts. Using functional magnetic resonance imaging (MRI), we tested the hypothesis that reminders of mortality and physical pain decrease brain activity underlying self-related thoughts. Three groups of adults underwent priming procedures during which they answered questions pertaining to mortality, physical pain, or leisure time, respectively. Before and after priming, participants performed personality trait judgments on oneself or a celebrity, identified the font of words, or passively viewed a fixation. The default-mode activity and neural activity underlying self-reflection were identified by contrasting viewing a fixation vs. font judgment and trait judgments on oneself vs. a celebrity, respectively. The analyses of the pre-priming functional MRI (fMRI) data identified the default-mode activity in the posterior cingulate cortex (PCC), ventral medial prefrontal cortex (MPFC), and parahippocampal gyrus, and the activity underlying instructed self-reflection in both the ventral and dorsal regions of the MPFC. The analyses of the post-priming fMRI data revealed that, relative to leisure time priming, reminding mortality significantly reduced the default-mode PCC activity, and reminding physical pain significantly decreased the dorsal MPFC activity during instructed self-reflection. Our findings suggest distinct neural underpinnings of the effect of reminding morality and aversive emotion on default-mode and instructed self-reflection.

  20. Changes in physical fitness profilogramach women aged 60 - 75 years under training health

    Directory of Open Access Journals (Sweden)

    Kortas Jakub

    2011-10-01

    Full Text Available The growing awareness of the society with regards to the positive influence of physical activity, and the ageing of world population are two facts that promote the need to develop qualified personnel of instructors. Individual approach to each group of training attendants is the principle of effective health training at every level of sport activity. This individual approach should be reflected in both the selection of training program, and the perceived effect of the activity. In the present work, I present personal analysis of influence of general keep-fit training performed in a gym. 36 women were enrolled in the study, for whom profilograms were created, which reflected the results of five measurements of physical fitness.

  1. Flight Experiments of Physical Vapor Transport of ZnSe: Growth of Crystals in Various Convective Conditions

    Science.gov (United States)

    Su, Ching-Hua

    2015-01-01

    A low gravity material experiment will be performed in the Material Science Research Rack (MSRR) on International Space Station (ISS). The flight experiment will conduct crystal growths of ZnSe and related ternary compounds, such as ZnSeS and ZnSeTe, by physical vapor transport (PVT). The main objective of the project is to determine the relative contributions of gravity-driven fluid flows to the compositional distribution, incorporation of impurities and defects, and deviation from stoichiometry observed in the grown crystals as results of buoyancy-driven convection and growth interface fluctuations caused by irregular fluid-flows on Earth. The investigation consists of extensive ground-based experimental and theoretical research efforts and concurrent flight experimentation. The objectives of the ground-based studies are (1) obtain the experimental data and conduct the analyses required to define the optimum growth parameters for the flight experiments, (2) perfect various characterization techniques to establish the standard procedure for material characterization, (3) quantitatively establish the characteristics of the crystals grown on Earth as a basis for subsequent comparative evaluations of the crystals grown in a low-gravity environment and (4) develop theoretical and analytical methods required for such evaluations. ZnSe and related ternary compounds have been grown by vapor transport technique with real time in-situ non-invasive monitoring techniques. The grown crystals have been characterized extensively by various techniques to correlate the grown crystal properties with the growth conditions. This talk will focus on the ground-based studies on the PVT crystal growth of ZnSe and related ternary compounds, especially the effects of different growth orientations related to gravity direction on the grown crystals.

  2. Laboratory Experiments to Simulate and Investigate the Physics Underlying the Dynamics of Merging Solar Corona Structures

    Science.gov (United States)

    2016-06-05

    described analytic Grad-Shafranov toroidal equilibria where the pressure on the magnetic axis is lower than the pres- sure external to the toroid so...2015. Magnetic axis safety factor of finite beta spheromaks and transition from spheromaks to toroidal magnetic bubbles. Physics of Plasmas, 22(2...Paccagnella, Roberto. 2015. Magnetic axis safety factor of finite beta spheromaks and transition from spheromaks to toroidal magnetic bubbles

  3. A large data base on a small computer. Neutron Physics data and bibliography under IDMS

    International Nuclear Information System (INIS)

    Schofield, A.; Pellegrino, L.; Tubbs, N.

    1978-01-01

    The transfer of three associated files to an IDMS data base is reported: the CINDA bibliographic index to neutron physics publications, the cumulated EXFOR exchange tapes used for maintaining parallel data collections at all four centres and the CCDN's internal data storage and retrieval system NEUDADA. With associated dictionaries and inter-file conversion tables the corresponding IDMS data base will be about 160 Mbytes. The main characteristics of the three files are shown

  4. Soil physical properties under different soil managements for the cultivation of sweet potato

    Directory of Open Access Journals (Sweden)

    Amarílis Beraldo Rós

    2014-02-01

    Full Text Available This study aimed to assess the impact of tillage systems on physical properties of an Alfissol type soil and on the growth of sweet potato tuberous roots. To assess the soil physical properties, an experiment was conducted in randomized blocks design, in split-plot scheme. The plots consisted of the treatments conventional tillage with making mounds and straw incorporated, conventional tillage with making mounds and without straw, reduced tillage with straw on the soil surface and reduced tillage without straw; and the subplots, to collect periods. The soil physical properties evaluated were soil bulk density, total soil porosity, soil macroporosity and soil microporosity, soil resistance to penetration and gravimetric soil water. For the assessment of the growth of sweet potato tuberous roots, it was adopted an experiment where the plots corresponded to the soil management forms and subplots to four collect periods: 90, 120, 150 and 180 (DAP. The length / roots diameter of individual roots relations were avaluated. It was concluded that the reduced tillage gives greater soil resistance to penetration of roots, by reducing the vertical growth of roots, and the presence of straw incorporated in the conventional tillage favors maintenance of lowest soil bulk density and highest soil macroporosity along the time.

  5. Transport properties of LiF under strong compression: modeling using advanced electronic structure methods and classical molecular dynamics

    Science.gov (United States)

    Mattsson, Thomas R.; Jones, Reese; Ward, Donald; Spataru, Catalin; Shulenburger, Luke; Benedict, Lorin X.

    2015-06-01

    Window materials are ubiquitous in shock physics and with high energy density drivers capable of reaching multi-Mbar pressures the use of LiF is increasing. Velocimetry and temperature measurements of a sample through a window are both influenced by the assumed index of refraction and thermal conductivity, respectively. We report on calculations of index of refraction using the many-body theory GW and thermal ionic conductivity using linear response theory and model potentials. The results are expected to increase the accuracy of a broad range of high-pressure shock- and ramp compression experiments. 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. Department of Energy's National Nuclear Security Administration under Contract DE-AC04-94AL85000.

  6. PHYSICS

    CERN Multimedia

    J. Incandela

    The all-plenary format of the CMS week in Cyprus gave the opportunity to the conveners of the physics groups to present the plans of each physics analysis group for tackling early physics analyses. The presentations were complete, so all are encouraged to browse through them on the Web. There is a wealth of information on what is going on, by whom and on what basis and priority. The CMS week was followed by two CMS “physics events”, the ICHEP08 days and the physics days in July. These were two weeks dedicated to either the approval of all the results that would be presented at ICHEP08, or to the review of all the other Monte-Carlo based analyses that were carried out in the context of our preparations for analysis with the early LHC data (the so-called “2008 analyses”). All this was planned in the context of the beginning of a ramp down of these Monte Carlo efforts, in anticipation of data.  The ICHEP days are described below (agenda and talks at: http://indic...

  7. PHYSICS

    CERN Multimedia

    Joe Incandela

    There have been two plenary physics meetings since the December CMS week. The year started with two workshops, one on the measurements of the Standard Model necessary for “discovery physics” as well as one on the Physics Analysis Toolkit (PAT). Meanwhile the tail of the “2007 analyses” is going through the last steps of approval. It is expected that by the end of January all analyses will have converted to using the data from CSA07 – which include the effects of miscalibration and misalignment. January Physics Days The first Physics Days of 2008 took place on January 22-24. The first two days were devoted to comprehensive re¬ports from the Detector Performance Groups (DPG) and Physics Objects Groups (POG) on their planning and readiness for early data-taking followed by approvals of several recent studies. Highlights of POG presentations are included below while the activities of the DPGs are covered elsewhere in this bulletin. January 24th was devo...

  8. The utility industry's perspective on OCRWM's plans for developing the system for transporting spent fuel under the Nuclear Waste Policy Act

    International Nuclear Information System (INIS)

    Brodnick, D.A.

    1988-01-01

    The electric utility industry has a vital interest in the transport program to be developed by the Department of Energy's Office of Civilian Radioactive Waste Management under the Nuclear Waste Policy Act. The industry's interest stems in part from the fact that the DOE's transportation program is financed by the Nuclear Waste Fund which is made up of ratepayer funds. However, the industry is also vitally interested in the DOE's transportation program because it could impact the ongoing transportation operations of all nuclear utilities, and, perhaps most importantly, without the utility industry's input, DOE is not able to develop an optimal transportation program. The NWPA contemplates that the DOE conducts its transportation program in accordance with the existing federal and state regulatory structure. DOE has significant discretion, however, in creating and implementing the business, operational and institutional aspects of its NWPA transportation program. The utility industry intends to ensure that the DOE meets the challenge to develop a safe, efficient and economically sound program to transport spent fuel and high-level waste to the appropriate federal facilities

  9. Physical and Transport Property Variations Within Carbonate-Bearing Fault Zones: Insights From the Monte Maggio Fault (Central Italy)

    Science.gov (United States)

    Trippetta, F.; Carpenter, B. M.; Mollo, S.; Scuderi, M. M.; Scarlato, P.; Collettini, C.

    2017-11-01

    The physical characterization of carbonate-bearing normal faults is fundamental for resource development and seismic hazard. Here we report laboratory measurements of density, porosity, Vp, Vs, elastic moduli, and permeability for a range of effective confining pressures (0.1-100 MPa), conducted on samples representing different structural domains of a carbonate-bearing fault. We find a reduction in porosity from the fault breccia (11.7% total and 6.2% connected) to the main fault plane (9% total and 3.5% connected), with both domains showing higher porosity compared to the protolith (6.8% total and 1.1% connected). With increasing confining pressure, P wave velocity evolves from 4.5 to 5.9 km/s in the fault breccia, is constant at 5.9 km/s approaching the fault plane and is low (4.9 km/s) in clay-rich fault domains. We find that while the fault breccia shows pressure sensitive behavior (a reduction in permeability from 2 × 10-16 to 2 × 10-17 m2), the cemented cataclasite close to the fault plane is characterized by pressure-independent behavior (permeability 4 × 10-17 m2). Our results indicate that the deformation processes occurring within the different fault structural domains influence the physical and transport properties of the fault zone. In situ Vp profiles match well the laboratory measurements demonstrating that laboratory data are valuable for implications at larger scale. Combining the experimental values of elastic moduli and frictional properties it results that at shallow crustal levels, M ≤ 1 earthquakes are less favored, in agreement with earthquake-depth distribution during the L'Aquila 2009 seismic sequence that occurred on carbonates.

  10. Physics

    CERN Document Server

    Cullen, Katherine

    2005-01-01

    Defined as the scientific study of matter and energy, physics explains how all matter behaves. Separated into modern and classical physics, the study attracts both experimental and theoretical physicists. From the discovery of the process of nuclear fission to an explanation of the nature of light, from the theory of special relativity to advancements made in particle physics, this volume profiles 10 pioneers who overcame tremendous odds to make significant breakthroughs in this heavily studied branch of science. Each chapter contains relevant information on the scientist''s childhood, research, discoveries, and lasting contributions to the field and concludes with a chronology and a list of print and Internet references specific to that individual.

  11. Effects of four-month handbike training under free-living conditions on physical fitness and health in wheelchair users.

    Science.gov (United States)

    Hoekstra, Sven; Valent, Linda; Gobets, David; van der Woude, Lucas; de Groot, Sonja

    2017-08-01

    Recognizing the encouraging effect of challenging events, the HandbikeBattle (HBB) was created to promote exercise among wheelchair users. The purpose of this study was to reveal the effects on physical fitness and health outcomes of four-month handbike training under free-living conditions in preparation for the event. In this prospective cohort study, 59 relatively inexperienced handyclists participated in the HBB of 2013 or 2014. Incremental exercise tests were conducted, respiratory function was tested and anthropometrics were measured before and after the preparation period. Main outcome measures were peak power output (POpeak), peak oxygen uptake (VO2peak) and waist circumference, of which the changes were tested using repeated measures ANOVA. To detect possible determinants of changes in physical fitness, a linear regression analysis was conducted with personal characteristics, executed training volume and upper-extremity complaints during the training period as independent variables. POpeak, VO2peak and waist circumference improved significantly with 17%, 7% and 4.1%, respectively. None of the included variables were significant determinants for the changes in POpeak found as a result of the training. A challenging event such as the HBB provokes training regimes among participants of sufficient load to realize substantial improvements in physical fitness and health outcomes. Implications for Rehabilitation Due to the often impaired muscle function in the lower-limbs and an inactive lifestyle, wheelchair users generally show considerably lower levels of fitness compared to able-bodied individuals. This prospective cohort study showed that four months of handbike training under free-living conditions in preparation for this event resulted in substantial improvements in physical fitness and health outcomes in wheelchair users. The creation of a challenging event such as the HandbikeBattle as part of a follow-up rehabilitation practice can therefore be a useful

  12. Restorability on 3-connected WDM Networks Under Single and Dual Physical Link Failures

    DEFF Research Database (Denmark)

    Gutierrez Lopez, Jose Manuel; Jensen, Michael; Riaz, Tahir

    2013-01-01

    This work studies the influence the network interconnection has over restoration techniques. The way physical links are distributed to interconnect network nodes has a great impact on parameters such as path distances when failures occur and restoration is applied. The work focuses on single and ...... to network planning, the trade-off network length vs. performance of the different topological options is studied. The results show how 3-connected graphs could provide a reasonable trade-off between costs, link failure rates, and restored path parameters....

  13. Under the spell of Landau when theoretical physics was shaping destinies

    CERN Document Server

    2013-01-01

    This invaluable collection of memoirs and reviews on scientific activities of the most prominent theoretical physicists belonging to the Landau School - Landau, Anselm, Gribov, Zeldovich, Kirzhnits, Migdal, Ter-Martirosyan and Larkin - are being published in English for the first time. The main goal is to acquaint readers with the life and work of outstanding Soviet physicists who, to a large extent, shaped theoretical physics in the 1950s - 70s. Many intriguing details have remained unknown beyond the "Iron Curtain" which was dismantled only with the fall of the USSR.

  14. Analysis of Physics Processes in the AC Plasma Torch Discharge under High Pressure

    International Nuclear Information System (INIS)

    Safronov, A A; Vasilieva, O B; Dudnik, J D; Kuznetsov, V E; Kuchina, J A; Shiryaev, V N; Pavlov, A V

    2017-01-01

    The paper is devoted to investigation of electrophysical processes in the electric discharge generated by a three-phase AC plasma torch whe