Optimum ratio of main mechanized operations for direct-flow fertilizers introduction

Directory of Open Access Journals (Sweden)

V. P. Uvarov

2016-01-01

Full Text Available Use of transport and technological means is carried out according to the direct-flow scheme and includes stage-by-stage performance as the main standard-setting operations (fertilizers transportation, movement and their distribution across a field, and auxiliary (return from a field and loading of fertilizers. The method of comparison of main types of operations at fertilizers application is given. An estimation criterion is a ratio of cargo movements on a road and across a field, proportionality coefficient between movement of freight and a fertilizers distribution area across the field. These indicators depend on transportation distances and doses of fertilizers application, and also on technology factor that is freight moving frequency across the field. The last characteristic is taken as the optimized parameter. An extremum of this indicator was searched due to a classical method. Optimum values of estimated indicators with the accounting of a variation of a ratio of load capacity and operating width of technical means are received. Concrete combinations of transportation distances and doses of fertilizers application are specified. The authors defined conditions of effective use of tractor and perspective automobile transport and technological means. They recommended to use the automeans allowing to change operating width. Realization of the stated methodological approach will make it possible to select an optimum ratio of the mechanized operations at direct-flow fertilizers application, to exclude additional cargo movements across the field, to cut fuel consumption, to increase productivity. Productivity of transport and technological means increases by 2.0; 1.3 and 1.15 times respectively to length of furrow 3; 9 and 27 km at fertilizers application by a dose of 0.06 kg per sq.m.

New trends in mechanics and transport

CERN Document Server

Uhl, Tadeusz

2007-01-01

Nowadays, one of the most rapidly growing sectors of industry is that of the infrastructure and vehicles of transportation systems. This discipline needs new, innovative and economically proven initiatives.The domain of transport is an interdisciplinary one which brings together many different scientific and engineering strands. The synergy between mechanics and transportation science offers the possibility of finding new and effective solutions to design, manufacturing and servicing problems. Due to globalization of the market-place, international cooperation in applied research is very fruitful and expedient.This collection of 13 refereed papers is the result of a unique opportunity offered to the scientific and technical communities for them to interact and to consolidate the application of current achievements in mechanical science as applied to transport. It covers topics which include theoretical, numerical and experimental studies of transport-related areas. All-in-all, it represents a succinct state-o...

Operations Research in PassengerRaiway Transportation

NARCIS (Netherlands)

D. Huisman (Dennis); L.G. Kroon (Leo); R.M. Lentink (Ramon); M.J.C.M. Vromans (Michiel)

2005-01-01

textabstractIn this paper we give an overview of state-of-the-art Operations Research models and techniques used in passenger railway transportation. For each planning phase (strategic, tactical and operational), we describe the planning problems arising there and discuss some models and algorithms

SDDOT transportation systems management & operations program plan.

Science.gov (United States)

2016-06-01

The objective of this project is the development of a comprehensive Transportation Systems Management and : Operations (TSM&O) Program Plan for the South Dakota Department of Transportation. This plan guides : business planning and strategic decision...

Mechanism for Particle Transport and Size Sorting via Low-Frequency Vibrations

Science.gov (United States)

Sherrit, Stewart; Scott, James S.; Bar-Cohen, Yoseph; Badescu, Mircea; Bao, Xiaoqi

2010-01-01

There is a need for effective sample handling tools to deliver and sort particles for analytical instruments that are planned for use in future NASA missions. Specifically, a need exists for a compact mechanism that allows transporting and sieving particle sizes of powdered cuttings and soil grains that may be acquired by sampling tools such as a robotic scoop or drill. The required tool needs to be low mass and compact to operate from such platforms as a lander or rover. This technology also would be applicable to sample handling when transporting samples to analyzers and sorting particles by size.

The PTFE-nanocomposites mechanical properties for transport systems dynamic sealing devices elements

Science.gov (United States)

Mashkov, Y. K.; Egorova, V. A.; Chemisenko, O. V.; Maliy, O. V.

2017-06-01

The mechanical properties study results of polymer nanocomposites based on polytetrafluoroethylene with modifiers in the form of micro- and nanoscale cryptocrystalline graphite and silicon dioxide powders are determined. The nanocomposites mechanical properties determined values provide high sealing degree of transport systems dynamic sealing devices elements. When the temperature changes from cryogenic to high positive then the elastic modulus, tensile strength decrease significantly and nonlinearly, the latter limits the composite usage in heavily loaded tribosystems operating at elevated temperatures.

Operating control techniques for maglev transport systems

Energy Technology Data Exchange (ETDEWEB)

Kraft, K H; Schnieder, E

1984-06-01

The technical and operational possibilities of magnetic levitation transport systems can only be fully exploited by introducing 'intelligent' control systems which ensure automatic and trouble-free train running. The solution of exacting requirements in the fields of traction dynamics, security and control as well as information gathering transmission and processing is an important prior condition in that respect. The authors report here on the present state of research and development in operating control techniques applicable to maglev transport systems.

Metropolitan transportation management center concepts of operation : a cross-cutting study : improving transportation network efficiency

Science.gov (United States)

1999-10-01

The implementor and operator of a regional transportation management center (TMC) face a challenging task. Operators of TMCsthe primary point of coordination for managing transportation resourcestypically control millions of dollars of intellig...

Transportation operations functions of the federal waste management system

International Nuclear Information System (INIS)

Shappert, L.B.; Klimas, M.J.

1989-01-01

This paper documents the functions that are necessary to operate the OCRWM transportation system. OCRWM's mission is to accept and transport spent fuel and high-level waste from waste generators to FWMS facilities. The emphasis is on transportation operations and assumes that all necessary facilities are in place and equipment designs and specifications are available to permit the system to operate properly. The information reported in this paper was developed for TOPO and is compatible with the draft revision of the Waste Management System Requirements and Description (SRD). 5 refs

Electrochemical-mechanical coupled modeling and parameterization of swelling and ionic transport in lithium-ion batteries

Science.gov (United States)

Sauerteig, Daniel; Hanselmann, Nina; Arzberger, Arno; Reinshagen, Holger; Ivanov, Svetlozar; Bund, Andreas

2018-02-01

The intercalation and aging induced volume changes of lithium-ion battery electrodes lead to significant mechanical pressure or volume changes on cell and module level. As the correlation between electrochemical and mechanical performance of lithium ion batteries at nano and macro scale requires a comprehensive and multidisciplinary approach, physical modeling accounting for chemical and mechanical phenomena during operation is very useful for the battery design. Since the introduced fully-coupled physical model requires proper parameterization, this work also focuses on identifying appropriate mathematical representation of compressibility as well as the ionic transport in the porous electrodes and the separator. The ionic transport is characterized by electrochemical impedance spectroscopy (EIS) using symmetric pouch cells comprising LiNi1/3Mn1/3Co1/3O2 (NMC) cathode, graphite anode and polyethylene separator. The EIS measurements are carried out at various mechanical loads. The observed decrease of the ionic conductivity reveals a significant transport limitation at high pressures. The experimentally obtained data are applied as input to the electrochemical-mechanical model of a prismatic 10 Ah cell. Our computational approach accounts intercalation induced electrode expansion, stress generation caused by mechanical boundaries, compression of the electrodes and the separator, outer expansion of the cell and finally the influence of the ionic transport within the electrolyte.

Designing for transportation management and operations : a primer.

Science.gov (United States)

2013-02-01

This primer is focused on the collaborative and systematic consideration of management and operations during transportation : project design and development. This is termed designing for operations. Effectively designing for operations involves...

Improving road transport operations through lean thinking: A case study

OpenAIRE

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

2017-01-01

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

Design considerations for CRBRP heat transport system piping operating at elevated temperatures

International Nuclear Information System (INIS)

Pollono, L.P.; Mello, R.M.

1979-01-01

The heat transport system sodium piping for the Clinch River Breeder Reactor Plant (CRBRP) within the reactor containment building must withstand high temperatures for long periods of time. Each phase of the mechanical design process of the piping system is influenced by elevated temperature considerations which include material thermal creep effects, ratchetting caused by rapid temperature transients and stress relaxation, and material degradation effects. The structural design philosophy taken to design the CRBRP piping operating in a high temperature environment is described. The resulting design of the heat transport system piping is presented along with a discussion of special features that resulted from the elevated temperature considerations

Device for the simultaneous operation of the closing valve of a vessel and the closing valve of a transport container

International Nuclear Information System (INIS)

Tellier, Claude; Surriray, Michel.

1982-01-01

This device includes mechanisms for unlatching the closing valve of the vessel and securing it to the closing valve of the transport container and other mechanisms for vertically raising the assembly of valves, pivoting it and bringing it into a vertical position in a bulge provided in the bottom of the transport container. For example the first containment is a nuclear reactor vessel and the transport container is used for carrying an item from the vessel to an external area (for instance, a defective pump to the repair area) and for the return transport operation [fr

Membrane-traversing mechanism of thyroid hormone transport by monocarboxylate transporter 8.

Science.gov (United States)

Protze, Jonas; Braun, Doreen; Hinz, Katrin Manuela; Bayer-Kusch, Dorothea; Schweizer, Ulrich; Krause, Gerd

2017-06-01

Monocarboxylate transporter 8 (MCT8) mediates thyroid hormone (TH) transport across the plasma membrane in many cell types. In order to better understand its mechanism, we have generated three new MCT8 homology models based on sugar transporters XylE in the intracellular opened (PDB ID: 4aj4) and the extracellular partly occluded (PDB ID: 4gby) conformations as well as FucP (PDB ID: 3o7q) and GLUT3 (PDB ID: 4zwc) in the fully extracellular opened conformation. T 3 -docking studies from both sides revealed interactions with His192, His415, Arg445 and Asp498 as previously identified. Selected mutations revealed further transport-sensitive positions mainly at the discontinuous transmembrane helices TMH7 and 10. Lys418 is potentially involved in neutralising the charge of the TH substrate because it can be replaced by charged, but not by uncharged, amino acids. The side chain of Thr503 was hypothesised to stabilise a helix break at TMH10 that undergoes a prominent local shift during the transport cycle. A T503V mutation accordingly affected transport. The aromatic Tyr419, the polar Ser313 and Ser314 as well as the charged Glu422 and Glu423 lining the transport channel have been studied. Based on related sugar transporters, we suggest an alternating access mechanism for MCT8 involving a series of amino acid positions previously and newly identified as critical for transport.

Mechanism of realization economic strategy of transport organization

Science.gov (United States)

Palkina, E. S.

2017-10-01

In modern conditions of economic globalization, high dynamism of external environment, economic strategy of transport organization plays an important role in maintaining its competitive advantages, long-term development. For effective achievement of set strategic goals it is necessary to use an adequate mechanism based on completeness and interrelation of its constituent instruments. The main objective of the study presented in this paper is to develop methodological provisions on formation the mechanism of realization economic strategy for transport organizations. The principles of its construction have been proposed, the key components have been defined. Finally, an attempt to implementation this mechanism into the transport organization management system has been realized.

Membrane transport mechanism 3D structure and beyond

CERN Document Server

Ziegler, Christine

2014-01-01

This book provides a molecular view of membrane transport by means of numerous biochemical and biophysical techniques. The rapidly growing number of atomic structures of transporters in different conformations and the constant progress in bioinformatics have recently added deeper insights.   The unifying mechanism of energized solute transport across membranes is assumed to consist of the conformational cycling of a carrier protein to provide access to substrate binding sites from either side of a cellular membrane. Due to the central role of active membrane transport there is considerable interest in deciphering the principles of one of the most fundamental processes in nature: the alternating access mechanism.   This book brings together particularly significant structure-function studies on a variety of carrier systems from different transporter families: Glutamate symporters, LeuT-like fold transporters, MFS transporters and SMR (RND) exporters, as well as ABC-type importers.   The selected examples im...

Concept of Operations for Waste Transport, Emplacement, and Retrieval

International Nuclear Information System (INIS)

Raczka, Norman T.

2001-01-01

The preparation of this technical report has two objectives. The first objective is to discuss the base case concepts of waste transport, emplacement, and retrieval operations and evaluate these operations relative to a lower-temperature repository design. Aspects of the operations involved in waste transport, emplacement and retrieval may be affected by the lower-temperature operating schemes. This report evaluates the effects the lower-temperature alternatives may have on the operational concepts involved in emplacing and retrieving waste. The second objective is to provide backup material for the design description, in a traceable and defensible format, for Section 2 of the Waste Emplacement/Retrieval System Description Document

Advanced Transport Operating Systems Program

Science.gov (United States)

White, John J.

1990-01-01

NASA-Langley's Advanced Transport Operating Systems Program employs a heavily instrumented, B 737-100 as its Transport Systems Research Vehicle (TRSV). The TRSV has been used during the demonstration trials of the Time Reference Scanning Beam Microwave Landing System (TRSB MLS), the '4D flight-management' concept, ATC data links, and airborne windshear sensors. The credibility obtainable from successful flight test experiments is often a critical factor in the granting of substantial commitments for commercial implementation by the FAA and industry. In the case of the TRSB MLS, flight test demonstrations were decisive to its selection as the standard landing system by the ICAO.

Big data's implications for transportation operations : an exploration.

Science.gov (United States)

The purpose of this white paper is to expand the understanding of big data for transportation operations, the value it could provide, and the implications for the : future direction of the U.S. Department of Transportation (USDOT) Connected Vehicle R...

Transport equations, Level Set and Eulerian mechanics. Application to fluid-structure coupling

International Nuclear Information System (INIS)

Maitre, E.

2008-11-01

My works were devoted to numerical analysis of non-linear elliptic-parabolic equations, to neutron transport equation and to the simulation of fabrics draping. More recently I developed an Eulerian method based on a level set formulation of the immersed boundary method to deal with fluid-structure coupling problems arising in bio-mechanics. Some of the more efficient algorithms to solve the neutron transport equation make use of the splitting of the transport operator taking into account its characteristics. In the present work we introduced a new algorithm based on this splitting and an adaptation of minimal residual methods to infinite dimensional case. We present the case where the velocity space is of dimension 1 (slab geometry) and 2 (plane geometry) because the splitting is simpler in the former

IMPROVEMENT OF FREIGHT TRANSPORTATION PROCESS AND THEIR MANAGEMENT MECHANISM

Directory of Open Access Journals (Sweden)

L. V. Martsenyuk

2014-03-01

Full Text Available Purpose. For Ukraine as for a post-socialist state there is an objective need of reforming on railway transport. In order to meet the requirements of consumers both within the country and outside of it, it is necessary to solve transport problems in time and to introduce new technologies, without lagging behind the developed European states. The purpose of this article is identification of problems in the process of freight transportations and development of ways of their overcoming, formation of the principles of economic efficiency increase for the use of freight cars using the improvement of management mechanism of freight transportations in the conditions of reforming. Methodology. Methods of strategic planning, system approach for research on improvement of the management mechanism of freight transportations, as well as the organizational-administrative method for structure of management construction were used in this research. Findings. Authors have explored the problems arising in the process of transportation of goods and measures, which will increase the efficiency of goods transportation. Advanced mechanism of freight transportation management for its application in the conditions of the railway transport reforming was developed. It is based on management centralization. Originality. The major factors, which slow down process of cargo transportations, are investigated in the article. The principles of management mechanism improvement of freight transportations are stated. They are based on association of commercial and car-repair activity of depots. All this will allow reducing considerably a car turn by decrease in duration of idle times on railway transport, increasing the speed of freight delivery and cutting down a transport component in the price of delivered production. Practical value. The offered measures will improve the efficiency of rolling stock use and increase cargo volumes turnover, promote links of Ukraine with

Urban Transport Services in Sub-Saharan Africa : Improving Vehicle Operations

OpenAIRE

World Bank

2003-01-01

The report presents findings, and the way forward in respect of the Knowledge and Research (KAR) Project on vehicle operations in Sub-Saharan Africa, basically undertaken in Uganda and Ghana. In the first phase, the study identified problems faced by transport operators in both countries, and analyzed their impact on vehicle operating costs, as well as examining transport regulations, and ...

14 CFR 135.397 - Small transport category airplane performance operating limitations.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Small transport category airplane... PERSONS ON BOARD SUCH AIRCRAFT Airplane Performance Operating Limitations § 135.397 Small transport category airplane performance operating limitations. (a) No person may operate a reciprocating engine...

Charge Carrier Transport Mechanism Based on Stable Low Voltage Organic Bistable Memory Device.

Science.gov (United States)

Ramana, V V; Moodley, M K; Kumar, A B V Kiran; Kannan, V

2015-05-01

A solution processed two terminal organic bistable memory device was fabricated utilizing films of polymethyl methacrylate PMMA/ZnO/PMMA on top of ITO coated glass. Electrical characterization of the device structure showed that the two terminal device exhibited favorable switching characteristics with an ON/OFF ratio greater than 1 x 10(4) when the voltage was swept between - 2 V and +3 V. The device maintained its state after removal of the bias voltage. The device did not show degradation after a 1-h retention test at 120 degrees C. The memory functionality was consistent even after fifty cycles of operation. The charge transport switching mechanism is discussed on the basis of carrier transport mechanism and our analysis of the data shows that the charge carrier trans- port mechanism of the device during the writing process can be explained by thermionic emission (TE) and space-charge-limited-current (SCLC) mechanism models while erasing process could be explained by the FN tunneling mechanism. This demonstration provides a class of memory devices with the potential for low-cost, low-power consumption applications, such as a digital memory cell.

Identification of facility constraints that impact transportation operations

International Nuclear Information System (INIS)

Peterson, R.W.; Pope, R.B.

1990-01-01

As Federal waste Management Systems (FWMS) receiving facilities become available, the US Department of Energy (DOE) intends to begin accepting spent nuclear fuel from US utilities for eventual permanent disposal. Transporting the radioactive spent fuel to the repository will require development of a complex network of equipment, services, and operations personnel that will comprise the Transportation Operations System. This paper identifies and discusses, in a qualitative manner, the key reactor facility constraints that will eventually need to be assessed in detail on a site-specific basis to guide the development of the FWMS transportation cask fleet. This evaluation of constraints is needed to assess their impact on the size, composition, availability, and use of the cask fleet and to assist in the development of the transportation system support facilities such as a cask maintenance facility. Such assessment will also be needed to support decisions on modifying shipping facilities (i.e., reactors), identification and design of interface hardware, and on the designs of receiving facilities

Reshaping transport operations to overcome new challenges

International Nuclear Information System (INIS)

Harari, F.; Blachet, L.

2004-01-01

After more than 30 years of Spent Fuel Nuclear Fuel (SFN) and High Level Waste (HLW) casks shipments to and from the COGEMA reprocessing factories in LA HAGUE, COGEMA LOGISTICS has demonstrated a unique outstanding performance in transportation for the benefit of its international customers and has integrated all feed-back from past successful operations. While maintaining the highest safety and security records, the last 5 years have been a major challenge to overcome the increase in transport throughputs, regulatory requirements, specific customer demands and new environmental approach (both COGEMA-La Hague and COGEMA LOGISTICS have been certified ISO14001 since 2003). Improvements in procedures, equipments, controls, inspection and organization have been undertaken. Additional important logistics means such as cranes, lifting devices, spreaders were put in operations in the dedicated workshop of our road and maritime facilities as well as in our rail terminals. Thus COGEMA LOGISTICS has developed and improved important logistics means in the Cherbourg area for the loading and unloading operations of heavy casks (i.e. whose weight is between 25 and 120 tons) among three modes of freight (road, railway or maritime transportation). In Valognes, which is currently the most important railway terminal in the world for the transfer of nuclear materials, about 1200 transfers of heavy casks were performed in 2003. New transport equipment and assets were integrated successfully to answer the new requirements for the best interest of our customers. This paper will provide information about equipments and management system developed to overcome these challenges

Reshaping transport operations to overcome new challenges

Energy Technology Data Exchange (ETDEWEB)

Harari, F.; Blachet, L. [COGEMA Logistics, (AREVA Group) (France)

2004-07-01

After more than 30 years of Spent Fuel Nuclear Fuel (SFN) and High Level Waste (HLW) casks shipments to and from the COGEMA reprocessing factories in LA HAGUE, COGEMA LOGISTICS has demonstrated a unique outstanding performance in transportation for the benefit of its international customers and has integrated all feed-back from past successful operations. While maintaining the highest safety and security records, the last 5 years have been a major challenge to overcome the increase in transport throughputs, regulatory requirements, specific customer demands and new environmental approach (both COGEMA-La Hague and COGEMA LOGISTICS have been certified ISO14001 since 2003). Improvements in procedures, equipments, controls, inspection and organization have been undertaken. Additional important logistics means such as cranes, lifting devices, spreaders were put in operations in the dedicated workshop of our road and maritime facilities as well as in our rail terminals. Thus COGEMA LOGISTICS has developed and improved important logistics means in the Cherbourg area for the loading and unloading operations of heavy casks (i.e. whose weight is between 25 and 120 tons) among three modes of freight (road, railway or maritime transportation). In Valognes, which is currently the most important railway terminal in the world for the transfer of nuclear materials, about 1200 transfers of heavy casks were performed in 2003. New transport equipment and assets were integrated successfully to answer the new requirements for the best interest of our customers. This paper will provide information about equipments and management system developed to overcome these challenges.

Issues in tokamak/stellarator transport and confinement enhancement mechanisms

International Nuclear Information System (INIS)

Perkins, F.W.

1990-08-01

At present, the mechanism for anomalous energy transport in low-β toroidal plasmas -- tokamaks and stellarators -- remains unclear, although transport by turbulent E x B velocities associated with nonlinear, fine-scale microinstabilities is a leading candidate. This article discusses basic theoretical concepts of various transport and confinement enhancement mechanisms as well as experimental ramifications which would enable one to distinguish among them and hence identify a dominant transport mechanism. While many of the predictions of fine-scale turbulence are born out by experiment, notable contradictions exist. Projections of ignition margin rest both on the scaling properties of the confinement mechanism and on the criteria for entering enhanced confinement regimes. At present, the greatest uncertainties lie with the basis for scaling confinement enhancement criteria. A series of questions, to be answered by new experimental/theoretical work, is posed to resolve these outstanding contradictions (or refute the fine-scale turbulence model) and to establish confinement enhancement criteria. 73 refs., 4 figs., 5 tabs

Problem Sets: Fundamentals Of Transportation And Traffic Operations

OpenAIRE

Daganzo, Carlos F.

1998-01-01

These problem sets comprise a supplement to Fundamentals of Transportation and Traffic Operations (C. Daganzo, Pergamon, 1997). Academicians can also obtain a companion set of solutions by writing to "Institute of Transportation Studies, Publications Office, 109 McLaughlin Hall, University of California, Berkeley, CA 94720" or by sending e-mail to .

Charge carrier transport mechanisms in nanocrystalline indium oxide

International Nuclear Information System (INIS)

Forsh, E.A.; Marikutsa, A.V.; Martyshov, M.N.; Forsh, P.A.; Rumyantseva, M.N.; Gaskov, A.M.; Kashkarov, P.K.

2014-01-01

The charge transport properties of nanocrystalline indium oxide (In 2 O 3 ) are studied. A number of nanostructured In 2 O 3 samples with various nanocrystal sizes are prepared by sol–gel method and characterized using various techniques. The mean nanocrystals size varies from 7–8 nm to 18–20 nm depending on the conditions of their preparation. Structural characterizations of the In 2 O 3 samples are performed by means of transmission electron microscopy and X-ray diffraction. The analysis of dc and ac conductivity in a wide temperature range (T = 50–300 K) shows that at high temperatures charge carrier transport takes place over conduction band and at low temperatures a variable range hopping transport mechanism can be observed. We find out that the temperature of transition from one mechanism to another depends on nanocrystal size: the transition temperature rises when nanocrystals are bigger in size. The average hopping distance between two sites and the activation energy are calculated basing on the analysis of dc conductivity at low temperature. Using random barrier model we show a uniform hopping mechanism taking place in our samples and conclude that nanocrystalline In 2 O 3 can be regarded as a disordered system. - Highlights: • In 2 O 3 samples with various nanocrystal sizes are prepared by sol–gel method. • The mean nanocrystal size varies from 7–8 nm to 18–20 nm. • At high temperatures charge carrier transport takes place over conduction band. • At low temperatures a variable range hopping transport mechanism can be observed. • We show a uniform hopping mechanism taking place in our samples

Equivalent mechanical parameters of oscillating rotary motors used in transport equipment

Directory of Open Access Journals (Sweden)

A. Andziulis

2006-12-01

Full Text Available In various appliances and equipment of sundry transport means there is a lot of diverse mechanisms of periodical movement. So, the various piston or membrane pumps of fuel feeding and lubrication systems, circulation pumps, air and refrigerating coolant compressors, etc. are the typical examples of innovative and well promising application of the oscillating motors. In these cases the moving part of a motor can be directly connected to the working body of driven mechanism without the additional gears. Consequently, the drive can be simplified in design and improved in efficiency and reliability. Application of the oscillating rotary motors, if used in the aforesaid devices, strictly depends on specific properties of mechanical system of a motor aggregated with the driven mechanism and considered as the one-piece unit on the whole. So, this study analyses how the properties of mechanical system, comprised of two moving parts interconnected eccentrically or centrically, can be evaluated by the equivalent rotational inertia, equivalent mass and by equivalent mechanical power factor which, in turn, determine the operating characteristics and basic possibilities of the motor.

Polar transport in plants mediated by membrane transporters: focus on mechanisms of polar auxin transport.

Science.gov (United States)

Naramoto, Satoshi

2017-12-01

Directional cell-to-cell transport of functional molecules, called polar transport, enables plants to sense and respond to developmental and environmental signals. Transporters that localize to plasma membranes (PMs) in a polar manner are key components of these systems. PIN-FORMED (PIN) auxin efflux carriers, which are the most studied polar-localized PM proteins, are implicated in the polar transport of auxin that in turn regulates plant development and tropic growth. In this review, the regulatory mechanisms underlying polar localization of PINs, control of auxin efflux activity, and PIN abundance at PMs are considered. Up to date information on polar-localized nutrient transporters that regulate directional nutrient movement from soil into the root vasculature is also discussed. Copyright © 2017 Elsevier Ltd. All rights reserved.

Dynamic response analysis as a tool for investigating transport mechanisms

International Nuclear Information System (INIS)

Dudok de Wit, Th.; Joye, B.; Lister, J.B.; Moret, J.M.

1990-01-01

Dynamic response analysis provides an attractive method for studying transport mechanisms in tokamak plasmas. The analysis of the radial response has already been widely used for heat and particle transport studies. The frequency dependence of the dynamic response, which is often omitted, reveals further properties of the dominant transport mechanisms. Extended measurements of the soft X-ray emission were carried out on the TCA tokamak in order to determine the underlying transport processes. (author) 5 refs., 2 figs

Small Aircraft Transportation System, Higher Volume Operations Concept: Normal Operations

Science.gov (United States)

Abbott, Terence S.; Jones, Kenneth M.; Consiglio, Maria C.; Williams, Daniel M.; Adams, Catherine A.

2004-01-01

This document defines the Small Aircraft Transportation System (SATS), Higher Volume Operations (HVO) concept for normal conditions. In this concept, a block of airspace would be established around designated non-towered, non-radar airports during periods of poor weather. Within this new airspace, pilots would take responsibility for separation assurance between their aircraft and other similarly equipped aircraft. Using onboard equipment and procedures, they would then approach and land at the airport. Departures would be handled in a similar fashion. The details for this operational concept are provided in this document.

Driverless operation for public passenger transport systems

Energy Technology Data Exchange (ETDEWEB)

Kehl, R. [Siemens AG, Erlangen (Germany). Bereich Verkehrstechnik

2001-07-01

The author presents the automation of new and existing lines as a possible solution to the twin problems of the growing need for public transport and the threat of collapse facing many public transport systems in the big conurbations as they wrestle against overloading. It emerges that automatic, driverless operation is a suitable approach to making systems more flexible and more attractive. Automation can increase the capacities of existing systems significantly and thus help them gain more passengers. (orig.)

Transportation Safety Excellence in Operations Through Improved Transportation Safety Document

International Nuclear Information System (INIS)

Dr. Michael A. Lehto; MAL

2007-01-01

A recent accomplishment of the Idaho National Laboratory (INL) Materials and Fuels Complex (MFC) Nuclear Safety analysis group was to obtain DOE-ID approval for the inter-facility transfer of greater-than-Hazard-Category-3 quantity radioactive/fissionable waste in Department of Transportation (DOT) Type A drums at MFC. This accomplishment supported excellence in operations through safety analysis by better integrating nuclear safety requirements with waste requirements in the Transportation Safety Document (TSD); reducing container and transport costs; and making facility operations more efficient. The MFC TSD governs and controls the inter-facility transfer of greater-than-Hazard-Category-3 radioactive and/or fissionable materials in non-DOT approved containers. Previously, the TSD did not include the capability to transfer payloads of greater-than-Hazard-Category-3 radioactive and/or fissionable materials using DOT Type A drums. Previous practice was to package the waste materials to less-than-Hazard-Category-3 quantities when loading DOT Type A drums for transfer out of facilities to reduce facility waste accumulations. This practice allowed operations to proceed, but resulted in drums being loaded to less than the Waste Isolation Pilot Plant (WIPP) waste acceptance criteria (WAC) waste limits, which was not cost effective or operations friendly. An improved and revised safety analysis was used to gain DOE-ID approval for adding this container configuration to the MFC TSD safety basis. In the process of obtaining approval of the revised safety basis, safety analysis practices were used effectively to directly support excellence in operations. Several factors contributed to the success of MFC's effort to obtain approval for the use of DOT Type A drums, including two practices that could help in future safety basis changes at other facilities. (1) The process of incorporating the DOT Type A drums into the TSD at MFC helped to better integrate nuclear safety

The alternating access mechanism of transport as observed in the sodium-hydantoin transporter Mhp1

International Nuclear Information System (INIS)

Weyand, Simone; Shimamura, Tatsuro; Beckstein, Oliver; Sansom, Mark S. P.; Iwata, So; Henderson, Peter J. F.; Cameron, Alexander D.

2011-01-01

Crystal structures of a membrane protein transporter in three different conformational states provide insights into the transport mechanism. Secondary active transporters move molecules across cell membranes by coupling this process to the energetically favourable downhill movement of ions or protons along an electrochemical gradient. They function by the alternating access model of transport in which, through conformational changes, the substrate binding site alternately faces either side of the membrane. Owing to the difficulties in obtaining the crystal structure of a single transporter in different conformational states, relatively little structural information is known to explain how this process occurs. Here, the structure of the sodium-benzylhydantoin transporter, Mhp1, from Microbacterium liquefaciens, has been determined in three conformational states; from this a mechanism is proposed for switching from the outward-facing open conformation through an occluded structure to the inward-facing open state

Operational analysis supporting the definition of the repository/transportation interface

International Nuclear Information System (INIS)

Peterson, R.W.; Smith, L.A.; Wampler, J.A.

1985-06-01

This report discusses progress made to date in an on-going effort to analyze operations at the repository-transportation interface of the Mined Geologic Disposal System of the Salt Repository Project (SRP). The interface is where the two systems actually are in physical contact with one another. The overall intent of the on-going effort is to to evaluate several interface design concepts for the extent to which workers are exposed to radiation, for the time required to receive and process transportation casks, and for the associated capital and operating costs. The design criteria report will outline interface functional requirements, which when incorporated into the interfacing systems (transportation-repository receiving), will ensure their physical compatibility, their optimal operation, and their compliance with performance standards. The final design criteria report will subsequently serve as an input to the receiving facility design portions of the SRP System Design Description (SDD), and System Requirements Specifications (SRS), and to the transportation cask design specifications. 6 refs., 13 figs., 6 tabs

14 CFR 203.5 - Compliance as condition on operations in air transportation.

Science.gov (United States)

2010-01-01

... air transportation. 203.5 Section 203.5 Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF... DEFENSES § 203.5 Compliance as condition on operations in air transportation. It shall be a condition on the authority of all direct U.S. and foreign carriers to operate in air transportation that they have...

Modified random hinge transport mechanics and multiple scattering step-size selection in EGS5

International Nuclear Information System (INIS)

Wilderman, S.J.; Bielajew, A.F.

2005-01-01

The new transport mechanics in EGS5 allows for significantly longer electron transport step sizes and hence shorter computation times than required for identical problems in EGS4. But as with all Monte Carlo electron transport algorithms, certain classes of problems exhibit step-size dependencies even when operating within recommended ranges, sometimes making selection of step-sizes a daunting task for novice users. Further contributing to this problem, because of the decoupling of multiple scattering and continuous energy loss in the dual random hinge transport mechanics of EGS5, there are two independent step sizes in EGS5, one for multiple scattering and one for continuous energy loss, each of which influences speed and accuracy in a different manner. Further, whereas EGS4 used a single value of fractional energy loss (ESTEPE) to determine step sizes at all energies, to increase performance by decreasing the amount of effort expended simulating lower energy particles, EGS5 permits the fractional energy loss values which are used to determine both the multiple scattering and continuous energy loss step sizes to vary with energy. This results in requiring the user to specify four fractional energy loss values when optimizing computations for speed. Thus, in order to simplify step-size selection and to mitigate step-size dependencies, a method has been devised to automatically optimize step-size selection based on a single material dependent input related to the size of problem tally region. In this paper we discuss the new transport mechanics in EGS5 and describe the automatic step-size optimization algorithm. (author)

Study on modeling of operator's learning mechanism

International Nuclear Information System (INIS)

Yoshimura, Seichi; Hasegawa, Naoko

1998-01-01

One effective method to analyze the causes of human errors is to model the behavior of human and to simulate it. The Central Research Institute of Electric Power Industry (CRIEPI) has developed an operator team behavior simulation system called SYBORG (Simulation System for the Behavior of an Operating Group) to analyze the human errors and to establish the countermeasures for them. As an operator behavior model which composes SYBORG has no learning mechanism and the knowledge of a plant is fixed, it cannot take suitable actions when unknown situations occur nor learn anything from the experience. However, considering actual operators, learning is an essential human factor to enhance their abilities to diagnose plant anomalies. In this paper, Q learning with 1/f fluctuation was proposed as a learning mechanism of an operator and simulation using the mechanism was conducted. The results showed the effectiveness of the learning mechanism. (author)

Transport mechanism and regulatory properties of the human amino acid transporter ASCT2 (SLC1A5).

Science.gov (United States)

Scalise, Mariafrancesca; Pochini, Lorena; Panni, Simona; Pingitore, Piero; Hedfalk, Kristina; Indiveri, Cesare

2014-11-01

The kinetic mechanism of the transport catalyzed by the human glutamine/neutral amino acid transporter hASCT2 over-expressed in P. pastoris was determined in proteoliposomes by pseudo-bi-substrate kinetic analysis of the Na(+)-glutamineex/glutaminein transport reaction. A random simultaneous mechanism resulted from the experimental analysis. Purified functional hASCT2 was chemically cross-linked to a stable dimeric form. The oligomeric structure correlated well with the kinetic mechanism of transport. Half-saturation constants (Km) of the transporter for the other substrates Ala, Ser, Asn and Thr were measured both on the external and internal side. External Km were much lower than the internal ones confirming the asymmetry of the transporter. The electric nature of the transport reaction was determined imposing a negative inside membrane potential generated by K(+) gradients in the presence of valinomycin. The transport reaction resulted to be electrogenic and the electrogenicity originated from external Na(+). Internal Na(+) exerted a stimulatory effect on the transport activity which could be explained by a regulatory, not a counter-transport, effect. Native and deglycosylated hASCT2 extracted from HeLa showed the same transport features demonstrating that the glycosyl moiety has no role in transport function. Both in vitro and in vivo interactions of hASCT2 with the scaffold protein PDZK1 were revealed.

Nonequilibrium statistical operator in hot-electron transport theory

International Nuclear Information System (INIS)

Xing, D.Y.; Liu, M.

1991-09-01

The Nonequilibrium Statistical Operator method developed by Zubarev is generalized and applied to the study of hot-electron transport in semiconductors. The steady-state balance equations for momentum and energy are derived to the lowest order in the electron-lattice coupling. We show that the derived balance equations are exactly the same as those obtained by Lei and Ting. This equivalence stems from the fact that to the linear order in the electron-lattice coupling, two statistical density matrices have identical effect when they are used to calculate the average value of a dynamical operator. The application to the steady-state and transient hot-electron transport in multivalley semiconductors is also discussed. (author). 28 refs, 1 fig

Feline hepatic biotransformation and transport mechanisms

NARCIS (Netherlands)

van Beusekom, C.D. van

2015-01-01

Hepatic biotransformation and drug transport mechanisms vary significantly between species. While these processes that determine largely the kinetic behavior of drugs have been studied abundantly in dogs, corresponding investigations in cats are hardly available, despite the increasing role of cats

Transport mechanisms in Schottky diodes realized on GaN

Science.gov (United States)

Amor, Sarrah; Ahaitouf, Ali; Ahaitouf, Abdelaziz; Salvestrini, Jean Paul; Ougazzaden, Abdellah

2017-03-01

This work is focused on the conducted transport mechanisms involved on devices based in gallium nitride GaN and its alloys. With considering all conduction mechanisms of current, its possible to understanded these transport phenomena. Thanks to this methodology the current-voltage characteristics of structures with unusual behaviour are further understood and explain. Actually, the barrier height (SBH) is a complex problem since it depends on several parameters like the quality of the metal-semiconductor interface. This study is particularly interesting as solar cells are made on this material and their qualification is closely linked to their transport properties.

Dealing with Uncertainty in Operational Transport Planning

NARCIS (Netherlands)

Zutt, J.; Van Gemund, A.J.C.; De Weerdt, M.M.; Witteveen, C.

2010-01-01

An important problem in transportation is how to ensure efficient operational route planning when several vehicles share a common road infrastructure with limited capacity. Examples of such a problem are route planning for automated guided vehicles in a terminal and route planning for aircraft

Mechanisms involved in the transport of mercuric ions in target tissues

Science.gov (United States)

Bridges, Christy C.; Zalups, Rudolfs K.

2016-01-01

Mercury exists in the environment in various forms, all of which pose a risk to human health. Despite guidelines regulating the industrial release of mercury into the environment, humans continue to be exposed regularly to various forms of this metal via inhalation or ingestion. Following exposure, mercuric ions are taken up by and accumulate in numerous organs, including brain, intestine, kidney, liver, and placenta. In order to understand the toxicological effects of exposure to mercury, a thorough understanding of the mechanisms that facilitate entry of mercuric ions into target cells must first be obtained. A number of mechanisms for the transport of mercuric ions into target cells and organs have been proposed in recent years. However, the ability of these mechanisms to transport mercuric ions and the regulatory features of these carriers have not been characterized completely. The purpose of this review is to summarize the current findings related to the mechanisms that may be involved in the transport of inorganic and organic forms of mercury in target tissues and organs. This review will describe mechanisms known to be involved in the transport of mercury and will also propose additional mechanisms that may potentially be involved in the transport of mercuric ions into target cells. PMID:27422290

Cell Membrane Transport Mechanisms: Ion Channels and Electrical Properties of Cell Membranes.

Science.gov (United States)

Kulbacka, Julita; Choromańska, Anna; Rossowska, Joanna; Weżgowiec, Joanna; Saczko, Jolanta; Rols, Marie-Pierre

2017-01-01

Cellular life strongly depends on the membrane ability to precisely control exchange of solutes between the internal and external (environmental) compartments. This barrier regulates which types of solutes can enter and leave the cell. Transmembrane transport involves complex mechanisms responsible for passive and active carriage of ions and small- and medium-size molecules. Transport mechanisms existing in the biological membranes highly determine proper cellular functions and contribute to drug transport. The present chapter deals with features and electrical properties of the cell membrane and addresses the questions how the cell membrane accomplishes transport functions and how transmembrane transport can be affected. Since dysfunctions of plasma membrane transporters very often are the cause of human diseases, we also report how specific transport mechanisms can be modulated or inhibited in order to enhance the therapeutic effect.

Primary heat transport pump mechanical seal replacement strategy for Pickering B

International Nuclear Information System (INIS)

Chacinsi, V.

1995-01-01

Pickering Nuclear Generating Station is a CANDU PHWR eight unit station located on Lake Ontario. The station is divided into Pickering A (Units 1 to 4) and Pickering B (Units 5 to 8). Pickering B is the focus of this paper. Each unit is rated at 540 MWe. The Primary Heat Transport (PHT) system, which is used to cool the fuel, is divided into four quadrants. Each quadrant has four vertical Byron Jackson PHT main circulation pumps. Three pumps in each quadrant are required for normal operation, leaving one pump in each quadrant as a spare. Each Pickering PHT pump has a Byron Jackson Type SU two stage mechanical seal. The typical pressure breakdown across the seal is 8.7-4.5-1.0 MPa. Certain features of seal operation and the PHT system which influence seal replacement are discussed below. (author)

Transport operations and closure notification

CERN Multimedia

2007-01-01

Please note that the car parks for the following buildings will be closed owing to transport operations involving an exceptional load: 228 110 192, 191, 190 182 582 279 584 609 The car parks will be closed from 5.30 p.m. on Friday 2 February 2007 until the evening of Tuesday 6 February 2007. Traffic on the Routes SCHRODINGER, BORN, POWEL, PERRIN, and GREGORY will be disrupted on Tuesday 6 February 2007. Thank you for your cooperation and understanding. Group TS-IC - Tel. 163012 - 160319

properties of the SN - equivalent integral transport operator in slab geometry and the iterative acceleration of neutron transport methods

International Nuclear Information System (INIS)

Massimiliano, Rosa; Azmy, Y.Y.; Morel, J.E.

2005-01-01

The general expressions for the matrix elements of the discrete Sn-equivalent integral transport operator have been derived in slab geometry. Their asymptotic behavior has been investigated both for a homogeneous slab and for a heterogeneous slab characterized by a periodic material discontinuity wherein each optically thick cell is surrounded by two optically thin cells in a repeating pattern. In the case of a homogeneous slab, the asymptotic analysis conducted in a diffusive limit obtained as the thick limit of computational cell size for a highly scattering medium, has shown that the discretized integral transport operator is approximated by a sparse matrix characterized by a tri-diagonal diffusion-like coupling stencil. Also, the tri-diagonal matrix structure, characteristic of the diffusion coupling stencil, is approached at a fast exponential rate. In the case of periodically heterogeneous slab configurations, the asymptotic behavior investigated is that in which the cells' optical thicknesses are pushed apart, i.e. the thick is made thicker while the thin is made thinner at a prescribed rate. It has been shown that in this limit the discretized integral transport operator is approximated by a penta-diagonal structure. Notwithstanding, the discrete operator is amenable to algebraic transformations leading to a matrix representation still asymptotically approaching a tri-diagonal structure at a fast exponential rate. The existence of a low order tri-diagonal approximation to the full discrete integral transport operator in the case of a periodically heterogeneous slab might provide a basic understanding of the superior convergence properties of diffusion-based acceleration schemes observed in slab geometry, even in the presence of sharp material discontinuities. The obtained results also suggest that a sparse approximation to the S n -equivalent integral transport operator might itself be used as the low-order operator in an acceleration scheme for the

49 CFR 236.809 - Signal, slotted mechanical.

Science.gov (United States)

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Signal, slotted mechanical. 236.809 Section 236.809 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD... § 236.809 Signal, slotted mechanical. A mechanically operated signal with an electromagnetic device...

Molecular mechanisms of water transport in the eye

DEFF Research Database (Denmark)

Hamann, Steffen

2002-01-01

The four major sites for ocular water transport, the corneal epithelium and endothelium, the ciliary epithelium, and the retinal pigment epithelium, are reviewed. The cornea has an inherent tendency to swell, which is counteracted by its two surface cell layers, the corneal epithelium...... and endothelium. The bilayered ciliary epithelium secretes the aqueous humor into the posterior chamber, and the retinal pigment epithelium transports water from the retinal to the choroidal site. For each epithelium, ion transport mechanisms are associated with fluid transport, but the exact molecular coupling...... sites between ion and water transport remain undefined. In the retinal pigment epithelium, a H+-lactate cotransporter transports water. This protein could be the site of coupling between salt and water in this epithelium. The distribution of aquaporins does not suggest a role for these proteins...

Operations Research In Maritime Transport And Freight Logistics

Directory of Open Access Journals (Sweden)

Shubham Tuslyan

2017-11-01

Full Text Available Todays globalization would be impossible without modern cost-effective merchant ships crossing the seas. World trade was 17 times as high at the end of the 20th century as it was 50 years previously. A shipping industry that has steadily lowered its costs has been a prerequisite of this development and there are no signs that the world economy will rely any less heavily on sea transport in the future. The current decade has witnessed a remarkable growth in container transportation and vessel sizes India is the 20th largest maritime country in the world. Its strategic location of a long coastline that flanks important global shipping routes makes it a major maritime nation. The maritime sector in India comprises of ports shipping shipbuilding and ship repair as well as inland water transport systems. About 95 of the countrys trade by volume and 70 by value is moved through maritime transport.Among the problems to be solved there are the spatial allocation of containers on the terminal yard optimization of shipping routes allocation of ships to berths and cranes allocation of cargo to ships scheduling priorities and operations in order to maximize performances based on some economic indicators. During the evaluation of the identified studies it becomes clear that the existing literature can be further subdivided into analytical simulation and combined approaches. The majority of the papers 212 out of 243 or 87 adopted analytical approaches that exclusively apply optimization algorithms to optimize container terminal operations. However in order to optimize the entire container terminal operations the use of this approach to simultaneously deal with different types of problems is difficult although not impossible especially in regard to stand-alone components. This is a major limitation of the widely used analytical approaches in traditional literature.

Advanced Transport Operating System (ATOPS) control display unit software description

Science.gov (United States)

Slominski, Christopher J.; Parks, Mark A.; Debure, Kelly R.; Heaphy, William J.

1992-01-01

The software created for the Control Display Units (CDUs), used for the Advanced Transport Operating Systems (ATOPS) project, on the Transport Systems Research Vehicle (TSRV) is described. Module descriptions are presented in a standardized format which contains module purpose, calling sequence, a detailed description, and global references. The global reference section includes subroutines, functions, and common variables referenced by a particular module. The CDUs, one for the pilot and one for the copilot, are used for flight management purposes. Operations performed with the CDU affects the aircraft's guidance, navigation, and display software.

Small Aircraft Transportation System, Higher Volume Operations Concept: Off-Nominal Operations

Science.gov (United States)

Abbott, Terence S.; Consiglio, Maria C.; Baxley, Brian T.; Williams, Daniel M.; Conway, Sheila R.

2005-01-01

This document expands the Small Aircraft Transportation System, (SATS) Higher Volume Operations (HVO) concept to include off-nominal conditions. The general philosophy underlying the HVO concept is the establishment of a newly defined area of flight operations called a Self-Controlled Area (SCA). During periods of poor weather, a block of airspace would be established around designated non-towered, non-radar airports. Aircraft flying enroute to a SATS airport would be on a standard instrument flight rules flight clearance with Air Traffic Control providing separation services. Within the SCA, pilots would take responsibility for separation assurance between their aircraft and other similarly equipped aircraft. Previous work developed the procedures for normal HVO operations. This document provides details for off-nominal and emergency procedures for situations that could be expected to occur in a future SCA.

Critical Care Air Transport Team severe traumatic brain injury short-term outcomes during flight for Operation Iraqi Freedom/Operation Enduring Freedom.

Science.gov (United States)

Boyd, L Renee; Borawski, J; Lairet, J; Limkakeng, A T

2017-10-01

Our understanding of the expertise and equipment required to air transport injured soldiers with severe traumatic brain injuries (TBIs) continue to evolve. We conducted a retrospective chart review of characteristics, interventions required and short-term outcomes of patients with severe TBI managed by the US Air Force Critical Care Air Transport Teams (CCATTs) deployed in support of Operation Iraqi Freedom and Operation Enduring Freedom between 1 June 2007 and 31 August 2010. Patients were cared for based on guidelines given by the Brain Trauma Foundation and the Joint Theater Trauma System by non-neurosurgeon physicians with dedicated neurocritical care training. We report basic characteristics, injuries, interventions required and complications during transport. Intracranial haemorrhage was the most common diagnosis in this cohort. Most injuries were weapon related. During this study, there were no reported in-flight deaths. The majority of patients were mechanically ventilated. There were 45 patients who required at least one vasopressor to maintain adequate tissue perfusion, including four patients who required three or more. Some patients required intracranial pressure (ICP) management, treatment of diabetes insipidus and/or seizure prophylaxis medications. Air transport personnel must be prepared to provide standard critical care but also care specific to TBIs, including ICP control and management of diabetes insipidus. Although these patients and their potential complications are traditionally managed by neurosurgeons, those providers without neurosurgical backgrounds can be provided this training to help fill a wartime need. This study provides data for the future development of air transport guidelines for validating and clearing flight surgeons. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Structure, mechanism and cooperation of bacterial multidrug transporters.

Science.gov (United States)

Du, Dijun; van Veen, Hendrik W; Murakami, Satoshi; Pos, Klaas M; Luisi, Ben F

2015-08-01

Cells from all domains of life encode energy-dependent trans-membrane transporters that can expel harmful substances including clinically applied therapeutic agents. As a collective body, these transporters perform as a super-system that confers tolerance to an enormous range of harmful compounds and consequently aid survival in hazardous environments. In the Gram-negative bacteria, some of these transporters serve as energy-transducing components of tripartite assemblies that actively efflux drugs and other harmful compounds, as well as deliver virulence agents across the entire cell envelope. We draw together recent structural and functional data to present the current models for the transport mechanisms for the main classes of multi-drug transporters and their higher-order assemblies. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Direct visualization of glutamate transporter elevator mechanism by high-speed AFM.

Science.gov (United States)

Ruan, Yi; Miyagi, Atsushi; Wang, Xiaoyu; Chami, Mohamed; Boudker, Olga; Scheuring, Simon

2017-02-14

Glutamate transporters are essential for recovery of the neurotransmitter glutamate from the synaptic cleft. Crystal structures in the outward- and inward-facing conformations of a glutamate transporter homolog from archaebacterium Pyrococcus horikoshii , sodium/aspartate symporter Glt Ph , suggested the molecular basis of the transporter cycle. However, dynamic studies of the transport mechanism have been sparse and indirect. Here we present high-speed atomic force microscopy (HS-AFM) observations of membrane-reconstituted Glt Ph at work. HS-AFM movies provide unprecedented real-space and real-time visualization of the transport dynamics. Our results show transport mediated by large amplitude 1.85-nm "elevator" movements of the transport domains consistent with previous crystallographic and spectroscopic studies. Elevator dynamics occur in the absence and presence of sodium ions and aspartate, but stall in sodium alone, providing a direct visualization of the ion and substrate symport mechanism. We show unambiguously that individual protomers within the trimeric transporter function fully independently.

76 FR 16654 - Austin Western Railroad, L.L.C.-Lease and Operation Exemption-Capital Metropolitan Transportation...

Science.gov (United States)

2011-03-24

... DEPARTMENT OF TRANSPORTATION Surface Transportation Board [Docket No. FD 35456] Austin Western Railroad, L.L.C.--Lease and Operation Exemption-- Capital Metropolitan Transportation Authority Austin... be leased since 2007, pursuant to an operating agreement. See Austin W. R.R.--Operation Exemption...

Small Aircraft Transportation System Higher Volume Operations Concept

Science.gov (United States)

Abbott, Terence S.; Consiglio, Maria C.; Baxley, Brian T.; Williams, Daniel M.; Jones, Kenneth M.; Adams, Catherine A.

2006-01-01

This document defines the Small Aircraft Transportation System (SATS) Higher Volume Operations concept. The general philosophy underlying this concept is the establishment of a newly defined area of flight operations called a Self-Controlled Area (SCA). Within the SCA, pilots would take responsibility for separation assurance between their aircraft and other similarly equipped aircraft. This document also provides details for a number of off-nominal and emergency procedures which address situations that could be expected to occur in a future SCA. The details for this operational concept along with a description of candidate aircraft systems to support this concept are provided.

MOPITT Mechanisms 16 Years In-Orbit Operation on TERRA

Science.gov (United States)

Gibson, Andrew S.; Nichitiu, Florian; Caldwell, Dwight

2016-01-01

The 16th anniversary of the launch of NASA's Terra Spacecraft was marked on December 18, 2015, with the Measurements of Pollution in the Troposphere (MOPITT) instrument being a successful contributor to the NASA EOS flagship. MOPITT has been enabled by a large suite of mechanisms, allowing the instrument to perform long-duration monitoring of atmospheric carbon monoxide, providing global measurements of this important greenhouse gas for 16 years. Mechanisms have been successfully employed for scanning, cooling of detectors, and to optically modulate the gas path length within the instrument by means of pressure and gas cell length variation. The instrument utilizes these devices to perform correlation spectroscopy, enabling measurements with vertical resolution from the nadir view, and has thereby furthered understanding of source and global transport effects of carbon monoxide. Given the design requirement for a 5.25-year lifetime, the stability and performance of the majority of mechanisms have far surpassed design goals. With 16 continuously operating mechanisms in service on MOPITT, including 12 rotating mechanisms and 4 with linear drive elements, the instrument was an ambitious undertaking. The long life requirements combined with demands for cleanliness and optical stability made for difficult design choices including that of the selection of new lubrication processes. Observations and lessons learned with regards to many aspects of the mechanisms and associated monitoring devices are discussed here. Mechanism behaviors are described, including anomalies, long-term drive current/power, fill pressure, vibration and cold-tip temperature trends. The effectiveness of particular lubrication formulations and the screening method implemented is discussed in relation to continuous rotating mechanisms and stepper motors, which have exceeded 15 billon rotations and 2.5 billion steps respectively. Aspects of gas cell hermeticity, optical cleanliness, heater problems

Small substrate transport and mechanism of a molybdate ATP binding cassette transporter in a lipid environment.

Science.gov (United States)

Rice, Austin J; Harrison, Alistair; Alvarez, Frances J D; Davidson, Amy L; Pinkett, Heather W

2014-05-23

Embedded in the plasma membrane of all bacteria, ATP binding cassette (ABC) importers facilitate the uptake of several vital nutrients and cofactors. The ABC transporter, MolBC-A, imports molybdate by passing substrate from the binding protein MolA to a membrane-spanning translocation pathway of MolB. To understand the mechanism of transport in the biological membrane as a whole, the effects of the lipid bilayer on transport needed to be addressed. Continuous wave-electron paramagnetic resonance and in vivo molybdate uptake studies were used to test the impact of the lipid environment on the mechanism and function of MolBC-A. Working with the bacterium Haemophilus influenzae, we found that MolBC-A functions as a low affinity molybdate transporter in its native environment. In periods of high extracellular molybdate concentration, H. influenzae makes use of parallel molybdate transport systems (MolBC-A and ModBC-A) to take up a greater amount of molybdate than a strain with ModBC-A alone. In addition, the movement of the translocation pathway in response to nucleotide binding and hydrolysis in a lipid environment is conserved when compared with in-detergent analysis. However, electron paramagnetic resonance spectroscopy indicates that a lipid environment restricts the flexibility of the MolBC translocation pathway. By combining continuous wave-electron paramagnetic resonance spectroscopy and substrate uptake studies, we reveal details of molybdate transport and the logistics of uptake systems that employ multiple transporters for the same substrate, offering insight into the mechanisms of nutrient uptake in bacteria. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

Environmental management system for transportation maintenance operations : [technical brief].

Science.gov (United States)

2014-04-01

This report provides the framework for the environmental management system to analyze : greenhouse gas emissions from transportation maintenance operations. The system enables user : to compare different scenarios and make informed decisions to minim...

Transporting spent fuel and reactor waste in Sweden experience from 5 years of operation

International Nuclear Information System (INIS)

Dybeck, P.; Gustafsson, B.

1990-01-01

This paper reports that since the Final Repository for Reactor Waste, SFR, was taken into operation in 1988, the SKB sea transportation system is operating at full capacity by transporting spent fuel and now also reactor waste from the 12 Swedish reactors to CLAB and SFR. Transports from the National Research Center, Studsvik to the repository has recently also been integrated in the system. CLAB, the central intermediate storage for spent fuel, has been in operation since 1985. The SKB Sea Transportation System consists today of the purpose built ship M/s Sigyn, 10 transport casks for spent fuel, 2 casks for spent core components, 27 IP-2 shielded steel containers for reactor waste and 5 terminal vehicles. During an average year about 250 tonnes of spent fuel and 3 -- 4000 m 3 of reactor waste are transported to CLAB and SFR respectively, corresponding to around 30 sea voyages

Drug transport mechanism of the AcrB efflux pump.

Science.gov (United States)

Pos, Klaas M

2009-05-01

In Gram-negative bacteria such as Escherichia coli and Pseudomonas aeruginosa, tripartite multidrug efflux systems extrude cytotoxic substances from the cell directly into the medium bypassing periplasm and the outer membrane. In E. coli, the tripartite efflux system AcrA/AcrB/TolC is the pump that extrudes multiple antibiotics, dyes, bile salts and detergents. The inner membrane component AcrB, a member of the Resistance Nodulation cell Division (RND) family, is the major site for substrate recognition and energy transduction of the entire tripartite system. The drug/proton antiport processes in this secondary transporter are suggested to be spatially separated, a feature frequently observed for primary transporters like membrane-bound ATPases. The recently elucidated asymmetric structure of the AcrB trimer reveals three different monomer conformations proposed to represent consecutive states in a directional transport cycle. Each monomer shows a distinct tunnel system with entrances located at the boundary of the outer leaflet of the inner membrane and the periplasm through the periplasmic porter (pore) domain towards the funnel of the trimer and TolC. In one monomer a hydrophobic pocket is present which has been shown to bind the AcrB substrates minocyclin and doxorubicin. The energy conversion from the proton motive force into drug efflux includes proton binding in (and release from) the transmembrane part. The conformational changes observed within a triad of essential, titratable residues (D407/D408/K940) residing in the hydrophobic transmembrane domain appear to be transduced by transmembrane helix 8 and associated with the conformational changes seen in the periplasmic domain. From the asymmetric structure a possible peristaltic pump transport mechanism based on a functional rotation of the AcrB trimer has been postulated. The novel drug transport model combines the alternate access pump mechanism with the rotating site catalysis of F(1)F(o) ATPase as

Safety relevant failure mechanisms in the post-operational phase

International Nuclear Information System (INIS)

Mayer, Gerhard; Stiller, Jan Christopher; Roemer, Sarah

2017-03-01

When the 13"t"h amendment of the Atomic Energy Act came into force, eight Germ an nuclear power plant units had their power operating licences revoked and are now in the so-called post operation phase. Of the remaining nuclear power plants, one have by now also entered the post operation phase, with those left in operation bound for entering this phase sometime between now and the end of 2022. Therefore, failure mechanisms that are particularly relevant for post operation were to be identified and described in the frame of the present project. To do so, three major steps were taken: Firstly, recent national and international pertinent literature was evaluated to obtain indications of failure mechanisms in the post operation phase. It turned out that most of the national and international literature deals with the general procedure of the transition from power operation to decommissioning and dismantling. However, there were also some documents providing detailed indications of possible failure mechanisms in post operation. This includes e.g. the release of radioactive materials caused by the drop of containers, chemical impacts on systems important to safety in connection with decontamination work, and corrosion in connection with the storage of the core in the spent fuel pool, with the latter leading to the jamming of the fuel assemblies in the storage racks and a possible reduction of coolant circulation. In a second step, three safety analyses of pressurised water reactors prepared by the respective plant operators were evaluated to identify failure mechanisms based on systems engineering. The failure mechanisms that were found here include e.g. faults in the boric acid concentration of the reactor coolant, damage to the equipment airlock upon the unloading of Castor casks, leakages in connection with primary system decontamination, and the drop of packages holding radioactive residual materials or waste with subsequent mobilisation of radioactive aerosols

Transportable Xenon Laboratory (TXL-1) Operations Manual

Energy Technology Data Exchange (ETDEWEB)

Thompson, Robert C.; Stewart, Timothy L.; Willett, Jesse A.; Woods, Vincent T.

2011-03-07

The Transportable Xenon Laboratory Operations Manual is a guide to set up and shut down TXL, a fully contained laboratory made up of instruments to identify and measure concentrations of the radioactive isotopes of xenon by taking air samples and analyzing them. The TXL is housed in a standard-sized shipping container. TXL can be shipped to and function in any country in the world.

Effectiveness and efficiency of the two trolley system as an infection control mechanism in the operating theatre.

Science.gov (United States)

Tuisawana, Viliame

2009-11-01

A good infection control manager understands the need to prevent a complete cycle of infection. The Infection Control Working Group Manual of Fiji, emphasised that the Cycle of Infection is the series of stage in which infection is spread. Operating theatres have infection control protocols. Most equipments and instruments used in operating theatre circulate within the theatre. The theatre trolleys are a main component in managing an operating theatre but the least recognised. This paper reviews the effectiveness and efficiency of the current two-trolley system as an infection control mechanism in theatre. The paper will discuss infection control using the current trolley system in relation to the layout of Labasa Hospital operating theatre, human resource, equipment standard and random swab results. The following are random swab results of theatre equipments taken by the Infection Control Nurse from 2006 to 2008. The Labasa Hospital Infection Committee have discouraged random swab sample from mid 2008 based on new guidelines on infection control. The two trolley system, in which an allocated outside trolley transports patients from the ward to a semi-sterile area in theatre. The inside trolley which transports the patient to the operating table. The two trolley system means more trolleys, extra staffs for lifting, additional handling of very sick patients, congestion and delay in taking patients to operating table in theatres should be considered. The one-trolley system in theatre greatly reduces the chances of manually lifting patients, thus reducing the risk of patient injury from fall and risk of back injuries to nurses. There are other evident based practices which can compliment the one trolley system for an effective infection control mechanism in theatres. The Fiji Infection Control Manual (2002) emphases the importance of regularly cleaning the environment and equipments in theatre but there is never a mention about using a two trolley system as an

Hepatobiliary transporter expression and post-operative jaundice in patients undergoing partial hepatectomy.

Science.gov (United States)

Bernhardt, Gerwin A; Zollner, Gernot; Cerwenka, Herwig; Kornprat, Peter; Fickert, Peter; Bacher, Heinz; Werkgartner, Georg; Müller, Gabriele; Zatloukal, Kurt; Mischinger, Hans-Jörg; Trauner, Michael

2012-01-01

Post-operative hyperbilirubinaemia in patients undergoing liver resections is associated with high morbidity and mortality. Apart from different known factors responsible for the development of post-operative jaundice, little is known about the role of hepatobiliary transport systems in the pathogenesis of post-operative jaundice in humans after liver resection. Two liver tissue samples were taken from 14 patients undergoing liver resection before and after Pringle manoeuvre. Patients were retrospectively divided into two groups according to post-operative bilirubin serum levels. The two groups were analysed comparing the results of hepatobiliary transporter [Na-taurocholate cotransporter (NTCP); multidrug resistance gene/phospholipid export pump(MDR3); bile salt export pump (BSEP); canalicular bile salt export pump (MRP2)], heat shock protein 70 (HSP70) expression as well as the results of routinely taken post-operative liver chemistry tests. Patients with low post-operative bilirubin had lower levels of NTCP, MDR3 and BSEP mRNA compared to those with high bilirubin after Pringle manoeuvre. HSP70 levels were significantly higher after ischaemia-reperfusion (IR) injury in both groups resulting in 4.5-fold median increase. Baseline median mRNA expression of all four transporters prior to Pringle manoeuvre tended to be lower in the low bilirubin group whereas expression of HSP70 was higher in the low bilirubin group compared to the high bilirubin group. Higher mRNA levels of HSP70 in the low bilirubin group could indicate a possible protective effect of high HSP70 levels against IR injury. Although the exact role of hepatobiliary transport systems in the development of post-operative hyper bilirubinemia is not yet completely understood, this study provides new insights into the molecular aspects of post-operative jaundice after liver surgery. © 2011 John Wiley & Sons A/S.

Integration of computational modeling with membrane transport studies reveals new insights into amino acid exchange transport mechanisms

Science.gov (United States)

Widdows, Kate L.; Panitchob, Nuttanont; Crocker, Ian P.; Please, Colin P.; Hanson, Mark A.; Sibley, Colin P.; Johnstone, Edward D.; Sengers, Bram G.; Lewis, Rohan M.; Glazier, Jocelyn D.

2015-01-01

Uptake of system L amino acid substrates into isolated placental plasma membrane vesicles in the absence of opposing side amino acid (zero-trans uptake) is incompatible with the concept of obligatory exchange, where influx of amino acid is coupled to efflux. We therefore hypothesized that system L amino acid exchange transporters are not fully obligatory and/or that amino acids are initially present inside the vesicles. To address this, we combined computational modeling with vesicle transport assays and transporter localization studies to investigate the mechanisms mediating [14C]l-serine (a system L substrate) transport into human placental microvillous plasma membrane (MVM) vesicles. The carrier model provided a quantitative framework to test the 2 hypotheses that l-serine transport occurs by either obligate exchange or nonobligate exchange coupled with facilitated transport (mixed transport model). The computational model could only account for experimental [14C]l-serine uptake data when the transporter was not exclusively in exchange mode, best described by the mixed transport model. MVM vesicle isolates contained endogenous amino acids allowing for potential contribution to zero-trans uptake. Both L-type amino acid transporter (LAT)1 and LAT2 subtypes of system L were distributed to MVM, with l-serine transport attributed to LAT2. These findings suggest that exchange transporters do not function exclusively as obligate exchangers.—Widdows, K. L., Panitchob, N., Crocker, I. P., Please, C. P., Hanson, M. A., Sibley, C. P., Johnstone, E. D., Sengers, B. G., Lewis, R. M., Glazier, J. D. Integration of computational modeling with membrane transport studies reveals new insights into amino acid exchange transport mechanisms. PMID:25761365

Feasibility study for a transportation operations system cask maintenance facility

Energy Technology Data Exchange (ETDEWEB)

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

1991-01-01

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

Feasibility study for a transportation operations system cask maintenance facility

International Nuclear Information System (INIS)

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

1991-01-01

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

Structure and Mechanism of the S Component of a Bacterial ECF Transporter

Energy Technology Data Exchange (ETDEWEB)

P Zhang; J Wang; Y Shi

2011-12-31

The energy-coupling factor (ECF) transporters, responsible for vitamin uptake in prokaryotes, are a unique family of membrane transporters. Each ECF transporter contains a membrane-embedded, substrate-binding protein (known as the S component), an energy-coupling module that comprises two ATP-binding proteins (known as the A and A' components) and a transmembrane protein (known as the T component). The structure and transport mechanism of the ECF family remain unknown. Here we report the crystal structure of RibU, the S component of the ECF-type riboflavin transporter from Staphylococcus aureus at 3.6-{angstrom} resolution. RibU contains six transmembrane segments, adopts a previously unreported transporter fold and contains a riboflavin molecule bound to the L1 loop and the periplasmic portion of transmembrane segments 4-6. Structural analysis reveals the essential ligand-binding residues, identifies the putative transport path and, with sequence alignment, uncovers conserved structural features and suggests potential mechanisms of action among the ECF transporters.

Weather information integration in transportation management center (TMC) operations.

Science.gov (United States)

2011-01-02

This report presents the results of the third phase of an on-going FHWA study on weather integration in Transportation Management Center (TMC) operations. The report briefly describes the earlier phases of the integration study, summarizes the findin...

Decision support systems for transportation system management and operations (TSM&O).

Science.gov (United States)

2015-12-01

There is a need for the development of tools and methods to support off-line and real-time : planning and operation decisions associated with the Transportation System Management and : Operations (TSM&O) program. The goal of this proposed project is ...

Temperature-dependent charge transport mechanisms in carbon sphere/polyaniline composite

Science.gov (United States)

Nieves, Cesar A.; Martinez, Luis M.; Meléndez, Anamaris; Ortiz, Margarita; Ramos, Idalia; Pinto, Nicholas J.; Zimbovskaya, Natalya

2017-12-01

Charge transport in the temperature range 80 K electrons between polymeric chains in PANi-filled gaps between CS is the predominant transport mechanism through CS/PANi composites. The high conductivity of the CS/PANi composite makes the material attractive for the fabrication of devices and sensors.

The transport mechanism DC arcs in advanced spectroanalysis

International Nuclear Information System (INIS)

Moeller, H.; Mazurkiewicz, M.; Nickel, H.

1977-08-01

This report presents some basic investigations concerning the emission spectroanalysis of powder specimens with application of a new type of advanced DC arcs which operate in horizontally arranged graphite cylinders. The extremely low detection limits found by experiment for various elements (Be, Cd, In, Pb, Sn) suggest a beneficial and reflector like effect of the graphite cylinder on the transport process in the arc plasma. Experiments in detail and by using radioactive tracers (Ag-110, Cd-115, Co-56, Fe-59, Zn-65) lead to an element specific modified model of the effective mechanism of the new arc arrangement. Elements of favourable thermochemical properties produce about three times as much of the average particle density in the arc plasma with the effect of the graphite cylinder. Besides these effects the element specific properties of the graphite cylinder are remarkably invariable towards magnetic fields (1,24 . 10 -2 T bzw. 2,6 . 10 -4 T) and various additives (Ga 2 O 3 , Li 2 Co 3 , NaCl) to the test specimens. (orig.) [de

Chemical and mechanical control of corrosion product transport

Energy Technology Data Exchange (ETDEWEB)

Hede Larsen, O; Blum, R [I/S Fynsvaerket, Faelleskemikerne, Odense (Denmark); Daucik, K [I/S Skaerbaekvaerket, Faelleskemikerne, Fredericia (Denmark)

1996-12-01

The corrosion products formed in the condensate and feedwater system of once-through boilers are precipitated and deposited inside the evaporator tubes mainly in the burner zone at the highest heat flux. Depositions lead to increased oxidation rate and increased metal temperature of the evaporator tubes, hereby decreasing tube lifetime. This effect is more important in the new high efficiency USC boilers due to increased feedwater temperature and hence higher thermal load on the evaporator tubes. The only way to reduce the load on the evaporator tubes is to minimise corrosion product transport to the boiler. Two general methods for minimising corrosion product transport to the boiler have been evaluated through measurement campaigns for Fe in the water/steam cycle in supercritical boilers within the ELSAM area. One method is to reduce corrosion in the low temperature condensate system by changing conditioning mode from alkaline volatile treatment (AVT) to oxygenated treatment (OT). The other method is to filtrate part of the condensate with a mechanical filter at the deaerator. The results show, that both methods are effective at minimising Fe-transport to the boiler, but changing to OT has the highest effect and should always be used, whenever high purity condensate is maintained. Whether mechanical filtration also is required, depends on the boiler, specifically the load on the evaporator. A simplified calculation model for lifetime evaluation of evaporator tubes has been developed. This model has been used for evaluating the effect of corrosion product transport to the boiler on evaporator tube lifetime. Conventional supercritical boilers generally can achieve sufficient lifetime by AVT and even better by OT, whereas all measures to reduce Fe-content of feedwater, including OT and mechanical filtration, should be taken, to ensure sufficient lifetime for the new boilers with advanced steam data - 290 bar/580 deg. C and above. (au)

Ergonomic Aspects of Transport of Patient through the Operating Theatre

Science.gov (United States)

Janowicz, Rafał

2017-10-01

One of the most crucial decisions to be made while designing and re-modernizing an operating theatre is selecting a method of transporting the patient through the hospital’s spatial arrangement. This decision, while irrelevant at first thought, implies numerous project and functional consequences. Designing an operating theatre within a hospital is related to numerous specialist requirements with an aim of minimizing the risk of microbiological contamination. Surgeries conducted on the operating theatre take place within sterile areas, usually within a protection area provided with laminar air flow. Furthermore, currently in Poland, there are applicable rules requiring to have entrances secured with tract locks leading towards the operational rooms for hospital personnel, patients as well as hospital equipment and materials. Such construction of an operating theatre provides the necessity of applying detailed procedures of transporting the patient, who in most cases is not able to reach the surgery on his or her own. In operating theatres functioning during the last decades, the operating tables were most often fixed to the floor. This resulted in the need to relocate the patient, who is ready for surgery, for several times. The consequences of this included risks related shock due to the relocations for the patient as well as physical overload for the medical staff. The aim of hereby article is to present modern designer solutions providing the opportunity to enhance ergonomics of using the operating theatre.

TRANSMISSION OF IMPACTS DURING MECHANICAL GRAPE HARVESTING AND TRANSPORTATION

Directory of Open Access Journals (Sweden)

Fabio Pezzi

2008-09-01

Full Text Available The aim of the research was to study vibrational stress on grapes during mechanical harvesting, transfer and delivery to the winery, in order to identify the most critical stages and the consequent effects on the winemaking. An instrumented sphere was used to evaluate and memorise the impacts in the grape harvester and means of transport. Three treatments, obtained by differing harvesting method (manual and mechanical and transport type (short and long distance, were compared. A correlation was sought between the transmitted stresses and characteristics of the harvested product. The effects on product quality were evaluated by chemical analyses of the musts and sensorial analysis of the end-product, vinified using the same procedure.

Using operations research to plan improvement of the transport of critically ill patients.

Science.gov (United States)

Chen, Jing; Awasthi, Anjali; Shechter, Steven; Atkins, Derek; Lemke, Linda; Fisher, Les; Dodek, Peter

2013-01-01

Operations research is the application of mathematical modeling, statistical analysis, and mathematical optimization to understand and improve processes in organizations. The objective of this study was to illustrate how the methods of operations research can be used to identify opportunities to reduce the absolute value and variability of interfacility transport intervals for critically ill patients. After linking data from two patient transport organizations in British Columbia, Canada, for all critical care transports during the calendar year 2006, the steps for transfer of critically ill patients were tabulated into a series of time intervals. Statistical modeling, root-cause analysis, Monte Carlo simulation, and sensitivity analysis were used to test the effect of changes in component intervals on overall duration and variation of transport times. Based on quality improvement principles, we focused on reducing the 75th percentile and standard deviation of these intervals. We analyzed a total of 3808 ground and air transports. Constraining time spent by transport personnel at sending and receiving hospitals was projected to reduce the total time taken by 33 minutes with as much as a 20% reduction in standard deviation of these transport intervals in 75% of ground transfers. Enforcing a policy of requiring acceptance of patients who have life- or limb-threatening conditions or organ failure was projected to reduce the standard deviation of air transport time by 63 minutes and the standard deviation of ground transport time by 68 minutes. Based on findings from our analyses, we developed recommendations for technology renovation, personnel training, system improvement, and policy enforcement. Use of the tools of operations research identifies opportunities for improvement in a complex system of critical care transport.

Decision support systems for transportation system management and operations (TSM&O) : [summary].

Science.gov (United States)

2016-01-01

The Transportation System Management and Operations (TSM&O) program of the Florida : Department of Transportation (FDOT) has seven objectives, which are listed in the TSM&O : Tier 2 business plan. Two important objectives of the program are to con...

Conceptual designs of radioactive canister transporters

International Nuclear Information System (INIS)

1978-02-01

This report covers conceptual designs of transporters for the vertical, horizontal, and inclined installation of canisters containing spent-fuel elements, high-level waste, cladding waste, and intermediate-level waste (low-level waste is not discussed). Included in the discussion are cask concepts; transporter vehicle designs; concepts for mechanisms for handling and manipulating casks, canisters, and concrete plugs; transporter and repository operating cycles; shielding calculations; operator radiation dosages; radiation-resistant materials; and criteria for future design efforts

Preliminary definition of the DOE/OCRWM transportation operating system: Final report

International Nuclear Information System (INIS)

Rawl, R.R.; Kline, S.C.

1988-01-01

This paper is based on the report ''Preliminary Definition of the Transportation Operations System'' and presents a summary of the preliminary definition of transportation operations activities for the cask shipment cycle, commencing with the dispatch of an empty cask, to loading and unloading of cask contents, and preparation of the empty cask for redispatch. It first presents a high-level description of the transportation cycle and then further describes each of the major activities in greater detail. For simplicity of presentation, the highway mode of transport is most often used to describe activities. The reader should keep in mind that the use of other modes will slightly alter the activities and possibly the sequences. Major activities and functions of the system are organized into a first cut of how they could be allocated to specific facilities. The reader should keep in mind that the assignment of functions and the aggregation of these into specific facilities are tasks which have yet to be performed. This paper simply presents a first look at possible groupings of the functions on a facility basis. 12 figs

Implementation of an operator model with error mechanisms for nuclear power plant control room operation

International Nuclear Information System (INIS)

Suh, Sang Moon; Cheon, Se Woo; Lee, Yong Hee; Lee, Jung Woon; Park, Young Taek

1996-01-01

SACOM(Simulation Analyser with Cognitive Operator Model) is being developed at Korea Atomic Energy Research Institute to simulate human operator's cognitive characteristics during the emergency situations of nuclear power plans. An operator model with error mechanisms has been developed and combined into SACOM to simulate human operator's cognitive information process based on the Rasmussen's decision ladder model. The operational logic for five different cognitive activities (Agents), operator's attentional control (Controller), short-term memory (Blackboard), and long-term memory (Knowledge Base) have been developed and implemented on blackboard architecture. A trial simulation with a scenario for emergency operation has been performed to verify the operational logic. It was found that the operator model with error mechanisms is suitable for the simulation of operator's cognitive behavior in emergency situation

Rupture mechanics of metallic alloys for hydrogen transport

International Nuclear Information System (INIS)

Moro, I.; Briottet, L.; Lemoine, P.; Andrieu, E.; Blanc, C.

2007-01-01

With the aim to establish a cheap hydrogen distribution system, the transport by pipelines is a solution particularly interesting. Among the high limit of elasticity steels, the X80 has been chosen for hydrogen transport. Its chemical composition and microstructure are given. Important microstructural changes have been revealed in the sheet thickness: the microstructure is thinner and richer in perlite in surface than in bulk. In parallel to this microstructural evolution, a microhardness gradient has been observed: the material microhardness is stronger in surface than in bulk of the sheet. The use of this material for hydrogen transport requires to study its resistance to hydrogen embrittlement. The main aim of this work is to develop an easy rupture mechanics test allowing to qualify the studied material in a gaseous hydrogen environment, to determine the sensitivity of the studied material to the hydrogen embrittlement and to better understand the mechanisms of the hydrogen embrittlement for ferritic materials. Two experimental tests have been used for: the first one is a traction machine coupled to an autoclave; the second one allows to carry out disk rupture tests. The toughness of the material in a gaseous hydrogen environment has thus been determined. The resistance of the material to hydrogen embrittlement has been characterized and by simulation, it has been possible to identify the areas with a strong concentration in hydrogen. The second aim of this work is to study the influence of the steel microstructure on the hydrogen position in the material and on the resistance of the material to the hydrogen embrittlement. The preferential trapping sites on the material not mechanically loaded have at first been identified, as well as the hydrogen position on the different phases and at the ferrite/cementite interface. The interaction between the mechanical loads, the position and the trapping of the hydrogen have been studied then. At last, has been

Gyrokinetic simulations of neoclassical transport using a minimal collision operator

International Nuclear Information System (INIS)

Dif-Pradalier, G.; Grandgirard, V.; Sarazin, Y.; Garbet, X.; Ghendrih, Ph.; Angelino, P.

2008-01-01

Conventional neoclassical predictions are successfully recovered within a gyrokinetic framework using a minimal Fokker-Planck collision operator. This operator is shown to accurately describe some essential features of neoclassical theory, namely the neoclassical transport, the poloidal rotation and the linear damping of axisymmetric flows while interestingly preserving a high numerical efficiency. Its form makes it especially adapted to Eulerian or Semi-Lagrangian schemes.

Structure and elevator mechanism of the Na+-citrate transporter CitS.

Science.gov (United States)

Lolkema, Juke S; Slotboom, Dirk Jan

2017-08-01

The recently determined crystal structure of the bacterial Na + -citrate symporter CitS provides unexpected structural and mechanistic insights. The protein has a fold that has not been seen in other proteins, but the oligomeric state, domain organization and proposed transport mechanism strongly resemble those of the sodium-dicarboxylate symporter vcINDY, and the putative exporters YdaH and MtrF, thus hinting at convergence in structure and function. CitS and the related proteins are predicted to translocate their substrates by an elevator-like mechanism, in which a compact transport domain slides up and down through the membrane while the dimerization domain is stably anchored. Here we review the large body of available biochemical data on CitS in the light of the new crystal structure. We show that the biochemical data are fully consistent with the proposed elevator mechanism, but also demonstrate that the current structural data cannot explain how strict coupling of citrate and Na + transport is achieved. We propose a testable model for the coupling mechanism. Copyright © 2016 Elsevier Ltd. All rights reserved.

Design features and operational characteristics of the PEP beam-transport and injection system

International Nuclear Information System (INIS)

Peterson, J.M.; Brown, K.L.; Truher, J.B.

1981-03-01

The PEP beam-transport system was designed to transmit 4-to-15 GeV electron and positron beams from the SLAC linac within a +- 0.8% momentum band, to have flexible tuning of the betatron and off-momentum functions for matching into the PEP storage ring, and to have convenient operating characteristics. The transport lines were brought into operation quickly and have operated well. Electron injection has been consistent and efficient and relatively easy to accomplish. Positron injection also has been satisfactory but is variable and more sensitive to ring conditions

Comparison of mechanical and manual ventilation during transport of patients to the intensive care unit after cardiac surgery

Directory of Open Access Journals (Sweden)

Atilla Canbulat

2012-12-01

Full Text Available Objectives: We compared effects of mechanical andmanual ventilation during transport to the intensive careunit(ICU in cardiac surgeries.Materials and methods: After ethical approval, 66 patients(ASAgrade II and III, 20-80years were assignedrandomly. Ventilation during transport to ICU was performedmanual (Group EV; n=36 or mechanical ventilation(Group MV; n=30. Measurements were recorded:operation room (A, during transport (T and in ICU (YB.Systolic, diastolic pressures (SAP, DAP, pulmonary arterialpressure (PAP, pulmonary capillary wedge pressure(PCWP, central venous pressure (CVP, heart rate (HR,cardiac output (CO, blood gases (pH, PCO2, PO2, BEand peripheral oxygen saturation (SpO2 were recorded.Stroke volume index (SVI, systemic and pulmonary vascularresistance indices (SVRI, PVRI and mean arterialpressures(MAP were calculated.Results: Patients were similar. Duration of transportwas shorter in Group MV (p< 0.01. The alterations inHR, MAP, DAP, CVP, PAP, PCWP, PVRI, SVRI, SVI, CO,SpO2 were similar, the increase in SAP during T periodwas higher in Group MV (p<0.05. Pulmonary arterial pHin Group MV was lower (p< 0.05. Arterial and pulmonaryarterial pO2, pCO2 decreased in Group MV, there was increasein Group EV during ICU (p< 0.001, p< 0.01, p<0.01, p< 0.05. During T period hypotension and tachycardiain Group EV, and hypertension in Group MV wereobserved.Conclusions: Mechanical ventilation had short transporttime, less alterations in hemodynamic and respiration valuesand less complication rates. We concluded that theuse of mechanical ventilation is a safer method for theintrahospital transport of critical patients. J Clin Exp Invest2012; 3(4: 521-528Key words: Cardiac surgery, patient transport, mechanicalventilator, manual ventilator, hemodynamia

Ion transport restriction in mechanically strained separator membranes

Science.gov (United States)

Cannarella, John; Arnold, Craig B.

2013-03-01

We use AC impedance methods to investigate the effect of mechanical deformation on ion transport in commercial separator membranes and lithium-ion cells as a whole. A Bruggeman type power law relationship is found to provide an accurate correlation between porosity and tortuosity of deformed separators, which allows the impedance of a separator membrane to be predicted as a function of deformation. By using mechanical compression to vary the porosity of the separator membranes during impedance measurements it is possible to determine both the α and γ parameters from the modified Bruggeman relation for individual separator membranes. From impedance testing of compressed pouch cells it is found that separator deformation accounts for the majority of the transport restrictions arising from compressive stress in a lithium-ion cell. Finally, a charge state dependent increase in the impedance associated with charge transfer is observed with increasing cell compression.

Versatile cable handling mechanisms for remote operator control

Energy Technology Data Exchange (ETDEWEB)

Collie, A.A.; White, T.S.; Christopher, M.D.; Hewer, N.D. [Portech Ltd., Portsmouth (United Kingdom)

1996-12-31

This paper describes a system of cable management for keeping the umbilical cables of remote operating vehicles and manipulators tidy and contained without direct intervention by operators. Two distinct types of winding mechanism have been designed. One mechanism is a fixed reel type where the cable is wound onto the reel by a rotating bail arm. The other mechanism consists of a pair of curved belts held against each other between which cable is passed. The complete system includes tension measuring and slack loop take-up devices. The whole system is controlled by a servo system in conjunction with a PC based visual graphic environment which allows a variety of mechanisms to be built up into a system able to handle up to four umbilical cables simultaneously. The control system provides additional tension sensors and cable odometers connected to the control system so that the operator has immediate perception of all the cable parameters, and by defining rules, can set up a variety of alarm situations. (Author).

Versatile cable handling mechanisms for remote operator control

International Nuclear Information System (INIS)

Collie, A.A.; White, T.S.; Christopher, M.D.; Hewer, N.D.

1996-01-01

This paper describes a system of cable management for keeping the umbilical cables of remote operating vehicles and manipulators tidy and contained without direct intervention by operators. Two distinct types of winding mechanism have been designed. One mechanism is a fixed reel type where the cable is wound onto the reel by a rotating bail arm. The other mechanism consists of a pair of curved belts held against each other between which cable is passed. The complete system includes tension measuring and slack loop take-up devices. The whole system is controlled by a servo system in conjunction with a PC based visual graphic environment which allows a variety of mechanisms to be built up into a system able to handle up to four umbilical cables simultaneously. The control system provides additional tension sensors and cable odometers connected to the control system so that the operator has immediate perception of all the cable parameters, and by defining rules, can set up a variety of alarm situations. (Author)

Versatile cable handling mechanisms for remote operator control

International Nuclear Information System (INIS)

Collie, A.A.; White, T.S.; Christopher, M.D.; Hewer, N.D.

1996-01-01

This paper describes a system of cable management for keeping the umbilical cables of remote operating vehicles and manipulators tidy and contained without direct intervention by operators. Two distinct types of winding mechanism have been designed. One mechanism is a fixed reel type where the cable is wound onto the reel by a rotating bail arm. The other mechanism consists of a pair of curved belts held against each other, between which cable is passed. The complete system includes tension measuring and slack loop take-up devices. The whole system is controlled by a servo system in conjunction with a PC based visual graphic environment which allows a variety of mechanisms to be built up into a system able to handle up to four umbilical cables simultaneously. The control system provides additional tension sensors and cable odometers connected to the control system so that the operator has immediate perception of all the cable parameters, and by defining rules, can set up a variety of alarm situations. (UK)

Alternatives for implementing burnup credit in the design and operation of spent fuel transport casks

International Nuclear Information System (INIS)

Sanders, T.L.; Lake, W.H.

1989-01-01

It is possible to develop an optimal strategy for implementing burnup credit in spent fuel transport casks. For transport, the relative risk is rapidly reduced if additional pre-transport controls such as a cavity dryness verifications are conducted prior to transport. Some other operational and design features that could be incorporated into a burnup credit cask strategy are listed. These examples represent many of the system features and alternatives already available for use in developing a broadly based criticality safety strategy for implementing burnup credit in the design and operation of spent fuel transport casks. 4 refs., 1 tab

A minimal collision operator for implementing neoclassical transport in gyrokinetic simulations

International Nuclear Information System (INIS)

Garbet, X.; Dif-Pradalier, G.; Nguyen, C.; Angelino, P.; Sarazin, Y.; Grandgirard, V.; Ghendrih, P.; Samain, A.

2008-01-01

This paper presents a class of collision operators, which reproduce neoclassical transport and comply with the constraints of a full-f global gyrokinetic code. The assessment of these operators is based on a variational entropy method, which allows a fast calculation of the neoclassical diffusivity and poloidal velocity.

Continuity of operations/continuity of government for state-level transportation organizations : brief.

Science.gov (United States)

2011-09-01

As a result of a federal requirement, all non-federal entities that own or operate critical : infrastructure are required to develop Continuity of Operations/Continuity of Government : (COOP/COG) Plans. Transportation is a critical infrastructure com...

Identification of a transport mechanism for NH₄⁺ in the symbiosome membrane of pea root nodules

DEFF Research Database (Denmark)

Mouritzen, P.; Rosendahl, L.

1997-01-01

Symbiosome membrane vesicles, facing bacteroid-side-out, were purified from pea (Pisum sativum L.) root nodules and used to study NH4+ transport across the membrane by recording vesicle uptake of the NH4+ analog [C-14]methylamine (MA). Membrane potentials (Delta psi) were imposed on the vesicles...... of the pH gradient indicated that uptake of MA was not related to the presence of a pH gradient. The MA-uptake mechanism appeared to have a large capacity for transport, and saturation was not observed at MA concentrations in the range of 25 mu M to 150 mM. MA uptake could be inhibited by NH4+, which...... indicates that NH4+ and MA compete for the same uptake mechanism. The observed fluxes suggest that voltage-driven channels are operating in the wsymbiosome membrane and that these are capable of transporting NH4+ at high rates from the bacteroid side of the membrane to the plant cytosol. The p...

Transport mechanisms acting in toroidal devices: a theoretician's view

International Nuclear Information System (INIS)

Carreras, B.A.

1992-01-01

Understanding the basic mechanisms of transport in toroidal confinement devices remains one of the more challenging scientific issues in magnetic confinement. At the same time, it is a critical issue for the magnetic fusion program. Recent progress in understanding fluctuations and transport has been fostered by the development and use of new diagnostics, bringing new perspectives on these studies. This has stimulated new theoretical developments. A view of the most recent issues and progress in this area is given. The role of long wavelengths in core transport and the relation between shear flows and turbulence at the plasma edge are the primary topics considered. (Author)

Mechanical transport in two-dimensional networks of fractures

International Nuclear Information System (INIS)

Endo, H.K.

1984-04-01

The objectives of this research are to evaluate directional mechanical transport parameters for anisotropic fracture systems, and to determine if fracture systems behave like equivalent porous media. The tracer experiments used to measure directional tortuosity, longitudinal geometric dispersivity, and hydraulic effective porosity are conducted with a uniform flow field and measurements are made from the fluid flowing within a test section where linear length of travel is constant. Since fluid flow and mechanical transport are coupled processes, the directional variations of specific discharge and hydraulic effective porosity are measured in regions with constant hydraulic gradients to evaluate porous medium equivalence for the two processes, respectively. If the fracture region behaves like an equivalent porous medium, the system has the following stable properties: (1) specific discharge is uniform in any direction and can be predicted from a permeability tensor; and (2) hydraulic effective porosity is directionally stable. Fracture systems with two parallel sets of continuous fractures satisfy criterion 1. However, in these systems hydraulic effective porosity is directionally dependent, and thus, criterion 2 is violated. Thus, for some fracture systems, fluid flow can be predicted using porous media assumptions, but it may not be possible to predict transport using porous media assumptions. Two discontinuous fracture systems were studied which satisfied both criteria. Hydraulic effective porosity for both systems has a value between rock effective porosity and total porosity. A length-density analysis (LDS) of Canadian fracture data shows that porous media equivalence for fluid flow and transport is likely when systems have narrow aperture distributions. 54 references, 90 figures, 7 tables

Early metabolic effects and mechanism of ammonium transport in yeast

International Nuclear Information System (INIS)

Pena, A.; Pardo, J.P.; Ramirez, J.

1987-01-01

Studies were performed to define the effects and mechanism of NH+4 transport in yeast. The following results were obtained. Glucose was a better facilitator than ethanol-H 2 O 2 for ammonium transport; low concentrations of uncouplers or respiratory inhibitors could inhibit the transport with ethanol as the substrate. With glucose, respiratory inhibitors showed only small inhibitory effects, and only high concentrations of azide or trifluoromethoxy carbonylcyanide phenylhydrazone could inhibit ammonium transport. Ammonium in the free state could be concentrated approximately 200-fold by the cells. Also, the addition of ammonium produced stimulation of both respiration and fermentation; an increased rate of H+ extrusion and an alkalinization of the interior of the cell; a decrease of the membrane potential, as monitored by fluorescent cyanine; an immediate decrease of the levels of ATP and an increase of ADP, which may account for the stimulation of both fermentation and respiration; and an increase of the levels of inorganic phosphate. Ammonium was found to inhibit 86Rb+ transport much less than K+. Also, while K+ produced a competitive type of inhibition, that produced by NH4+ was of the noncompetitive type. From the distribution ratio of ammonium and the pH gradient, an electrochemical potential gradient of around -180 mV was calculated. The results indicate that ammonium is transported in yeast by a mechanism similar to that of monovalent alkaline cations, driven by a membrane potential. The immediate metabolic effects of this cation seem to be due to an increased [H+]ATPase, to which its transport is coupled. However, the carriers seem to be different. The transport system studied in this work was that of low affinity

Quantum-mechanical transport equation for atomic systems.

Science.gov (United States)

Berman, P. R.

1972-01-01

A quantum-mechanical transport equation (QMTE) is derived which should be applicable to a wide range of problems involving the interaction of radiation with atoms or molecules which are also subject to collisions with perturber atoms. The equation follows the time evolution of the macroscopic atomic density matrix elements of atoms located at classical position R and moving with classical velocity v. It is quantum mechanical in the sense that all collision kernels or rates which appear have been obtained from a quantum-mechanical theory and, as such, properly take into account the energy-level variations and velocity changes of the active (emitting or absorbing) atom produced in collisions with perturber atoms. The present formulation is better suited to problems involving high-intensity external fields, such as those encountered in laser physics.

The Small Aircraft Transportation System (SATS), Higher Volume Operations (HVO) Off-Nominal Operations

Science.gov (United States)

Baxley, B.; Williams, D.; Consiglio, M.; Conway, S.; Adams, C.; Abbott, T.

2005-01-01

The ability to conduct concurrent, multiple aircraft operations in poor weather, at virtually any airport, offers an important opportunity for a significant increase in the rate of flight operations, a major improvement in passenger convenience, and the potential to foster growth of charter operations at small airports. The Small Aircraft Transportation System, (SATS) Higher Volume Operations (HVO) concept is designed to increase traffic flow at any of the 3400 nonradar, non-towered airports in the United States where operations are currently restricted to one-in/one-out procedural separation during Instrument Meteorological Conditions (IMC). The concept's key feature is pilots maintain their own separation from other aircraft using procedures, aircraft flight data sent via air-to-air datalink, cockpit displays, and on-board software. This is done within the Self-Controlled Area (SCA), an area of flight operations established during poor visibility or low ceilings around an airport without Air Traffic Control (ATC) services. The research described in this paper expands the HVO concept to include most off-nominal situations that could be expected to occur in a future SATS environment. The situations were categorized into routine off-nominal operations, procedural deviations, equipment malfunctions, and aircraft emergencies. The combination of normal and off-nominal HVO procedures provides evidence for an operational concept that is safe, requires little ground infrastructure, and enables concurrent flight operations in poor weather.

Charge transport model in nanodielectric composites based on quantum tunneling mechanism and dual-level traps

Energy Technology Data Exchange (ETDEWEB)

Li, Guochang; Chen, George, E-mail: gc@ecs.soton.ac.uk, E-mail: sli@mail.xjtu.edu.cn [State Key Laboratory of Electrical Insulation and Power Equipment, Xi' an Jiaotong University, Xi' an 710049 (China); School of Electronic and Computer Science, University of Southampton, Southampton SO17 1BJ (United Kingdom); Li, Shengtao, E-mail: gc@ecs.soton.ac.uk, E-mail: sli@mail.xjtu.edu.cn [State Key Laboratory of Electrical Insulation and Power Equipment, Xi' an Jiaotong University, Xi' an 710049 (China)

2016-08-08

Charge transport properties in nanodielectrics present different tendencies for different loading concentrations. The exact mechanisms that are responsible for charge transport in nanodielectrics are not detailed, especially for high loading concentration. A charge transport model in nanodielectrics has been proposed based on quantum tunneling mechanism and dual-level traps. In the model, the thermally assisted hopping (TAH) process for the shallow traps and the tunnelling process for the deep traps are considered. For different loading concentrations, the dominant charge transport mechanisms are different. The quantum tunneling mechanism plays a major role in determining the charge conduction in nanodielectrics with high loading concentrations. While for low loading concentrations, the thermal hopping mechanism will dominate the charge conduction process. The model can explain the observed conductivity property in nanodielectrics with different loading concentrations.

Expanding transportation systems management and operations (TSM&O) from planning to construction primer.

Science.gov (United States)

2015-12-01

The Florida Department of Transportation (FDOT) has initiated business plans to promote the Transportation : Systems Management and Operations (TSM&O) program throughout the State. TSM&O is traditionally managed : by traffic engineers that focus on o...

A Hybrid Dynamic Programming for Solving Fixed Cost Transportation with Discounted Mechanism

OpenAIRE

Farhad Ghassemi Tari

2016-01-01

The problem of allocating different types of vehicles for transporting a set of products from a manufacturer to its depots/cross docks, in an existing transportation network, to minimize the total transportation costs, is considered. The distribution network involves a heterogeneous fleet of vehicles, with a variable transportation cost and a fixed cost in which a discount mechanism is applied on the fixed part of the transportation costs. It is assumed that the number of available vehicles i...

Structures of the fractional spaces generated by the difference neutron transport operator

International Nuclear Information System (INIS)

Ashyralyev, Allaberen; Taskin, Abdulgafur

2015-01-01

The initial boundary value problem for the neutron transport equation is considered. The first, second and third order of accuracy difference schemes for the approximate solution of this problem are presented. Highly accurate difference schemes for neutron transport equation based on Padé approximation are constructed. In applications, stability estimates for solutions of difference schemes for the approximate solution of the neutron transport equation are obtained.The positivity of the neutron transport operator in Slobodeckij spaces is proved. Numerical techniques are developed and algorithms are tested on an example in MATLAB

Psychostimulants affect dopamine transmission through both dopamine transporter-dependent and independent mechanisms

Science.gov (United States)

dela Peña, Ike; Gevorkiana, Ruzanna; Shi, Wei-Xing

2015-01-01

The precise mechanisms by which cocaine and amphetamine-like psychostimulants exert their reinforcing effects are not yet fully defined. It is widely believed, however, that these drugs produce their effects by enhancing dopamine neurotransmission in the brain, especially in limbic areas such as the nucleus accumbens, by inducing dopamine transporter-mediated reverse transport and/or blocking dopamine reuptake though the dopamine transporter. Here, we present the evidence that aside from dopamine transporter, non-dopamine transporter-mediated mechanisms also participate in psychostimulant-induced dopamine release and contribute to the behavioral effects of these drugs, such as locomotor activation and reward. Accordingly, psychostimulants could increase norepinephrine release in the prefrontal cortex, the latter then alters the firing pattern of dopamine neurons resulting in changes in action potential-dependent dopamine release. These alterations would further affect the temporal pattern of dopamine release in the nucleus accumbens, thereby modifying information processing in that area. Hence, a synaptic input to a nucleus accumbens neuron may be enhanced or inhibited by dopamine depending on its temporal relationship to dopamine release. Specific temporal patterns of dopamine release may also be required for certain forms of synaptic plasticity in the nucleus accumbens. Together, these effects induced by psychostimulants, mediated through a non-dopamine transporter-mediated mechanism involving norepinephrine and the prefrontal cortex, may also contribute importantly to the reinforcing properties of these drugs. PMID:26209364

One-Loop Operation of Primary Heat Transport System in MONJU During Heat Transport System Modifications

International Nuclear Information System (INIS)

Goto, T.; Tsushima, H.; Sakurai, N.; Jo, T.

2006-01-01

MONJU is a prototype fast breeder reactor (FBR). Modification work commenced in March 2005. Since June 2004, MONJU has changed to one-loop operation of the primary heat transport system (PHTS) with all of the secondary heat transport systems (SHTS) drained of sodium. The purposes of this change are to shorten the modification period and to reduce the cost incurred for circuit trace heating electrical consumption. Before changing condition, the following issues were investigated to show that this mode of operation was possible. The heat loss from the reactor vessel and the single primary loop must exceed the decay heat by an acceptable margin but the capacity of pre-heaters to keep the sodium within the primary vessel at about 200 deg. C must be maintained. With regard to the heat loss and the decay heat, the estimated heat loss in the primary system was in the range of 90-170 kW in one-loop operation, and the calculated decay heat was 21.2 kW. Although the heat input of the primary pump was considered, it was clear that circuit heat loss greatly exceeded the decay heat. As for pre-heaters, effective capacity was less than the heat loss. Therefore, the temperature of the reactor vessel room was raised to reduce the heat loss. One-loop operation of the PHTS was able to be executed by means of these measures. The cost of electrical consumption in the power plant has been reduced by one-loop operation of the PHTS and the modification period was shortened. (authors)

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

International Nuclear Information System (INIS)

Bailey, W.J.

1983-01-01

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

Evaluation Of The Advanced Operating System Of The Ann Arbor Transportation Authority : Driver And Dispatcher Perceptions Of AATA'S Advanced Operating System

Science.gov (United States)

1999-01-01

In 1997, the Ann Arbor (Michigan) Transportation Authority began deploying advanced public transportation systems (APTS) technologies in its fixed route and paratransit operations. The project's concept is the integration of a range of such technolog...

Sources of expertise in transportation planning, management, and operations: Information received as of September 25, 1987

International Nuclear Information System (INIS)

1987-01-01

The DOE Office of Storage and Transportation Systems is responsible for the development and management of a transportation system to provide all the necessary services for the transportation of the spent fuel and wastes from reactor sites to repositories. DOE/ORO has requested Oak Ridge Associated Universities (ORAU) to assist DOE in developing rosters of sources of transportation expertise in: (1) carrier operations; (2) transportation management, planning, and logistics; (3) transportation equipment; (4) transportation facilities design and operation; (5) vehicle safety; and (6) transportation operations quality assurance; as related to truck, rail, barge, and intermodal transportation. Persons or organizations with experience in shipping of non-hazardous materials, spent nuclear fuel, other radioactive materials, and/or other hazardous materials were included in the information system. A mailed inquiry was sent to over 2300 potential sources of transportation expertise. Responses were received from 207 persons and 254 organizations. Section 1 contains the identification numbers of the individuals and organizations that responded. Section 2 contains identification codes, names, addresses, and phone numbers of each of the individual and organization respondents. The reader can refer to Section 2 for the name and address of the respondents for the identification codes listed for each technical area/experience base in Section 1

Mechanical transport and dissemination of soil-transmitted helminth ...

African Journals Online (AJOL)

In previous studies, helminth eggs were isolated from wild-caught Musca domestica L. (Diptera: Muscidae). This laboratory study investigated the potential of the fly for mechanical transport and transmission of soil-transmitted helminths. Naïve, 2-3 day old, laboratory-reared adult flies were exposed to a mixture of Ascaris ...

The bacterial dicarboxylate transporter VcINDY uses a two-domain elevator-type mechanism.

Science.gov (United States)

Mulligan, Christopher; Fenollar-Ferrer, Cristina; Fitzgerald, Gabriel A; Vergara-Jaque, Ariela; Kaufmann, Desirée; Li, Yan; Forrest, Lucy R; Mindell, Joseph A

2016-03-01

Secondary transporters use alternating-access mechanisms to couple uphill substrate movement to downhill ion flux. Most known transporters use a 'rocking bundle' motion, wherein the protein moves around an immobile substrate-binding site. However, the glutamate-transporter homolog GltPh translocates its substrate-binding site vertically across the membrane, through an 'elevator' mechanism. Here, we used the 'repeat swap' approach to computationally predict the outward-facing state of the Na(+)/succinate transporter VcINDY, from Vibrio cholerae. Our model predicts a substantial elevator-like movement of VcINDY's substrate-binding site, with a vertical translation of ~15 Å and a rotation of ~43°. Our observation that multiple disulfide cross-links completely inhibit transport provides experimental confirmation of the model and demonstrates that such movement is essential. In contrast, cross-links across the VcINDY dimer interface preserve transport, thus revealing an absence of large-scale coupling between protomers.

Operating systems in the air transportation environment.

Science.gov (United States)

Cherry, G. W.

1971-01-01

Consideration of the problems facing air transport at present, and to be expected in the future. In the Northeast Corridor these problems involve community acceptance, airway and airport congestion and delays, passenger acceptance, noise reduction, and improvements in low-density short-haul economics. In the development of a superior short-haul operating system, terminal-configured vs cruise-configured vehicles are evaluated. CTOL, STOL, and VTOL aircraft of various types are discussed. In the field of noise abatement, it is shown that flight procedural techniques are capable of supplementing ?quiet engine' technology.

Calculating the C operator in PT-symmetric quantum mechanics

International Nuclear Information System (INIS)

Bender, C.M.

2004-01-01

It has recently been shown that a non-Hermitian Hamiltonian H possessing an unbroken PT-symmetry (i) has a real spectrum that is bounded below, and (ii) defines a unitary theory of quantum mechanics with positive norm. The proof of unitarity requires a linear operator C, which was originally defined as a sum over the eigenfunctions of H. However, using this definition it is cumbersome to calculate C in quantum mechanics and impossible in quantum field theory. An alternative method is devised here for calculating C directly in terms of the operator dynamical variables of the quantum theory. This new method is general and applies to a variety of quantum mechanical systems having several degrees of freedom. More importantly, this method can be used to calculate the C operator in quantum field theory. The C operator is a new time-independent observable in PT-symmetric quantum field theory. (author)

Two Differential Binding Mechanisms of FG-Nucleoporins and Nuclear Transport Receptors

Directory of Open Access Journals (Sweden)

Piau Siong Tan

2018-03-01

Full Text Available Summary: Phenylalanine-glycine-rich nucleoporins (FG-Nups are intrinsically disordered proteins, constituting the selective barrier of the nuclear pore complex (NPC. Previous studies showed that nuclear transport receptors (NTRs were found to interact with FG-Nups by forming an “archetypal-fuzzy” complex through the rapid formation and breakage of interactions with many individual FG motifs. Here, we use single-molecule studies combined with atomistic simulations to show that, in sharp contrast, FG-Nup214 undergoes a coupled reconfiguration-binding mechanism when interacting with the export receptor CRM1. Association and dissociation rate constants are more than an order of magnitude lower than in the archetypal-fuzzy complex between FG-Nup153 and NTRs. Unexpectedly, this behavior appears not to be encoded selectively into CRM1 but rather into the FG-Nup214 sequence. The same distinct binding mechanisms are unperturbed in O-linked β-N-acetylglucosamine-modified FG-Nups. Our results have implications for differential roles of distinctly spatially distributed FG-Nup⋅NTR interactions in the cell. : Archetypal-fuzzy complexes found in most FG-Nucleoporin⋅nuclear transport receptor complexes allow fast yet specific nuclear transport. Tan et al. show that FG-Nup214, located at the periphery of the nuclear pore complex, binds to CRM1⋅RanGTP via a coupled reconfiguration-binding mechanism, which can enable different functionalities e.g., cargo release. Keywords: intrinsically disordered protein, glycosylation, FG-Nup, nuclear transport receptors, binding mechanism, single-molecule FRET, molecular dynamics simulations

Third-order differential ladder operators and supersymmetric quantum mechanics

International Nuclear Information System (INIS)

Mateo, J; Negro, J

2008-01-01

Hierarchies of one-dimensional Hamiltonians in quantum mechanics admitting third-order differential ladder operators are studied. Each Hamiltonian has associated three-step Darboux (pseudo)-cycles and Painleve IV equations as a closure condition. The whole hierarchy is generated applying some operations on the cycles. These operations are investigated in the frame of supersymmetric quantum mechanics and mainly involve algebraic manipulations. A consistent geometric representation for the hierarchy and cycles is built that also helps in understanding the operations. Three kinds of hierarchies are distinguished and a realization based on the harmonic oscillator Hamiltonian is supplied, giving an interpretation for the spectral properties of the Hamiltonians of each hierarchy

Private–public partnerships: A mechanism for freight transport infrastructure delivery?

Directory of Open Access Journals (Sweden)

Hans W. Ittmann

2017-02-01

Full Text Available Background: Freight transport infrastructure is an indispensable requirement for economic growth, development and prosperity. Public–private partnerships (PPPs, as a mechanism to fund and construct freight transport infrastructure, have been suggested by many in private and public sectors. Objectives: The concept of PPPs is dealt with, and the relevance of this mechanism is expanded upon. It is clear that PPPs in the rail environment present huge challenges and complexities. The objective was to determine whether PPPs are a viable mechanism to fund freight transport infrastructure in South Africa. Method: Experiences with rail PPPs worldwide have shown that many failures occurred implementing these. The challenges and complexities of PPPs, in the freight rail environment, are highlighted together with the benefits, risks and best practices of PPPs. It is shown that suitable policies, legislation and regulations concerning PPPs are in place in South Africa. Results: A proper framework and methodology to proceed should be in place. PPPs take time and are complex. Government involvement remains essential. Firm contractual agreements between parties are essential. Risk handling, risk sharing and the magnitude of risks should be clarified with agreement on where the risks reside. Financial viability, with value for money (VfM and financial benefits for private sector role players are non-negotiable. Conclusion: Appropriate legislation for implementing PPPs must be in place while two further important elements are economic circumstances and proper project execution. Taking all these factors into consideration, the freight transport sector can only benefit from successfully negotiated and implemented PPPs.

Transportation system modeling and simulation in support of logistics and operations

International Nuclear Information System (INIS)

Yoshimura, R.H.; Kjeldgaard, E.A.; Turnquist, M.A.; List, G.F.

1997-12-01

Effective management of DOE's transportation operations requires better data than are currently available, a more integrated management structure for making transportation decisions, and decision support tools to provide needed analysis capabilities. This paper describes a vision of an advanced logistics management system for DOE, and the rationale for developing improved modeling and simulation capability as an integral part of that system. The authors illustrate useful types of models through four examples, addressing issues of transportation package allocation, fleet sizing, routing/scheduling, and emergency responder location. The overall vision for the advanced logistics management system, and the specific examples of potential capabilities, provide the basis for a conclusion that such a system would meet a critical DOE need in the area of radioactive material and waste transportation

Transportation system modeling and simulation in support of logistics and operations

International Nuclear Information System (INIS)

Yoshimura, R.H.; Kjeldgaard, E.A.; Turnquist, M.A.; List, G.F.

1998-01-01

Effective management of DOE's transportation operations requires better data than are currently available, a more integrated management structure for making transportation decisions, and decision support tools to provide needed analysis capabilities. This paper describes a vision of an advanced logistics management system for DOE, and the rationale for developing improved modeling and simulation capability as an integral part of that system. We illustrate useful types of models through four examples, addressing issues of transportation package allocation, fleet sizing, routing/Scheduling, and emergency responder location. The overall vision for the advanced logistics management system, and the specific examples of potential capabilities, provide the basis for a conclusion that such a system would meet a critical DOE need in the area of radioactive material and waste transportation. (authors)

Contaminant Attenuation and Transport Characterization of 200-DV-1 Operable Unit Sediment Samples

Energy Technology Data Exchange (ETDEWEB)

Truex, Michael J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Szecsody, James E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Qafoku, Nikolla [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Strickland, Christopher E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Moran, James J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Lee, Brady D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Snyder, Michelle M.V. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Lawter, Amanda R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Resch, Charles T. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Gartman, Brandy N. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Zhong, Lirong [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Nims, Megan K. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Saunders, Danielle L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Williams, Benjamin D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Horner, Jacob A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Leavy, Ian I. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Baum, Steven R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Christiansen, Beren B. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Clayton, Ray E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); McElroy, Erin M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Appriou, Delphine [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Tyrrell, Kimberly J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Striluk, Miranda L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

2017-05-15

A laboratory study was conducted to quantify contaminant attenuation processes and associated contaminant transport parameters that are needed to evaluate transport of contaminants through the vadose zone to the groundwater. The laboratory study information, in conjunction with transport analyses, can be used as input to evaluate the feasibility of Monitored Natural Attenuation and other remedies for the 200-DV-1 Operable Unit at the Hanford Site.

Dissecting the molecular mechanisms of intraflagellar transport in Chlamydomonas

DEFF Research Database (Denmark)

Pedersen, L. B.; Geimer, S.; Rosenbaum, J. L.

2006-01-01

Background The assembly and maintenance of eukaryotic cilia and flagella are mediated by intraflagellar transport (IFT), a bidirectional microtubule (MT)-based transport system. The IFT system consists of anterograde (kinesin-2) and retrograde (cDynein1b) motor complexes and IFT particles...... comprising two complexes, A and B. In the current model for IFT, kinesin-2 carries cDynein1b, IFT particles, and axonemal precursors from the flagellar base to the tip, and cDynein1b transports kinesin-2, IFT particles, and axonemal turnover products from the tip back to the base. Most of the components...... of the IFT system have been identified and characterized, but the mechanisms by which these different components are coordinated and regulated at the flagellar base and tip are unclear. Results Using a variety of Chlamydomonas mutants, we confirm that cDynein1b requires kinesin-2 for transport toward the tip...

The direction of water transport on Mars: A possible pumping mechanism

Science.gov (United States)

James, P. B.

1987-01-01

It is suggested that an atmospheric pumping mechanism might be at work in which water is preferentially transported into the north by a mass outflow wind (due to sublimation from polar cap) that is stronger during southern spring than it is during northern spring. The mechanism is provided by the asymmetric seasonal temperature distribution produced by the eccentric martial orbit and by the associated seasonal asymmetry in the carbon dioxide cycle. The alternating condensation and sublimation of CO2 at the poles produces condensation winds which, in turn, contribute to the meridional transport of water vapor.

Projection operator techniques in nonequilibrium statistical mechanics

International Nuclear Information System (INIS)

Grabert, H.

1982-01-01

This book is an introduction to the application of the projection operator technique to the statistical mechanics of irreversible processes. After a general introduction to the projection operator technique and statistical thermodynamics the Fokker-Planck and the master equation approach are described together with the response theory. Then, as applications the damped harmonic oscillator, simple fluids, and the spin relaxation are considered. (HSI)

Driverless operation for local transport systems; Fahrerloser Betrieb in Nahverkehrssystemen

Energy Technology Data Exchange (ETDEWEB)

Kehl, R. [Siemens AG, Erlangen (Germany)

1999-10-01

With the increasing need for local public transport on the one hand and the overloading and threatening collapse of many local transport systems in the conurbations on the other, the automation of new and existing lines is seen as a possible solution. It has been shown that driverless automatic operation can make systems more flexible and attractive. Existing passenger capacity can be significantly increased by automation and more passengers attracted. Driverless operation offers potential for cost savings, which can offset the higher investment for the automation systems. Possibilities for reducing investment and operating costs are also shown. In addition to discussing the prospects for automation the article considers the technical realization of the concept from the standpoint of the vehicle manufacturer. Specially described are those components that have to meet the special safety requirements. (orig.) [Deutsch] Unter dem Eindruck der steigenden Notwendigkeit des oeffentlichen Nahverkehrs einerseits und der Ueberlastung und dem drohenden Kollaps vieler Nahverkehrssysteme in Ballungszentren andererseits wird die Automatisierung neuer und bestehender Strecken als moegliche Loesung vorgestellt. Es zeigt sich, dass der fahrerlose automatische Betrieb sich dazu eignet, Systeme flexibler und attraktiver zu gestalten. Bestehende Befoerderungskapazitaeten koennen durch Automatisierung signifikant erhoeht und somit Fahrgaeste gewonnen werden. (orig.)

Simple collision operators for direct Vlasov simulations of laser plasma interaction and transport

International Nuclear Information System (INIS)

Arber, T D; Sircombe, N J

2010-01-01

Non-local electron transport effects have a direct influence on the compression of cryogenic targets in laser driven ICF and target heating in high energy density experiments. There is a growing need for self-consistent models of laser plasma interactions coupled to nonlocal transport. We present a direct Vlasov solver that includes multiple species and a simple collision operator. This BGK model operator - which conserves particle density, energy and momentum - is fully implicit. For collisionless plasmas it has been shown that a double layer may be formed in which an accelerated, kinetic ion population satisfies the zero current condition. Here we extend this result to collisionalities of interest to laser driven ignition to assess the validity of nonlocal electron transport models based on fluid ions.

Thermodynamic secrets of multidrug resistance: A new take on transport mechanisms of secondary active antiporters.

Science.gov (United States)

Zhang, Xuejun C; Liu, Min; Lu, Guangyuan; Heng, Jie

2018-03-01

Multidrug resistance (MDR) presents a growing challenge to global public health. Drug extrusion transporters play a critical part in MDR; thus, their mechanisms of substrate recognition are being studied in great detail. In this work, we review common structural features of key transporters involved in MDR. Based on our membrane potential-driving hypothesis, we propose a general energy-coupling mechanism for secondary-active antiporters. This putative mechanism provides a common framework for understanding poly-specificity of most-if not all-MDR transporters. © 2017 The Protein Society.

Tuning transport properties of graphene three-terminal structures by mechanical deformation

Science.gov (United States)

Torres, V.; Faria, D.; Latgé, A.

2018-04-01

Straintronic devices made of carbon-based materials have been pushed up due to the graphene high mechanical flexibility and the possibility of interesting changes in transport properties. Properly designed strained systems have been proposed to allow optimized transport responses that can be explored in experimental realizations. In multiterminal systems, comparisons between schemes with different geometries are important to characterize the modifications introduced by mechanical deformations, especially if the deformations are localized at a central part of the system or extended in a large region. Then, in the present analysis, we study the strain effects on the transport properties of triangular and hexagonal graphene flakes, with zigzag and armchair edges, connected to three electronic terminals, formed by semi-infinite graphene nanoribbons. Using the Green's function formalism with circular renormalization schemes, and a single band tight-binding approximation, we find that resonant tunneling transport becomes relevant and is more affected by localized deformations in the hexagonal graphene flakes. Moreover, triangular systems with deformation extended to the leads, like longitudinal three-folded type, are shown as an interesting scenario for building nanoscale waveguides for electronic current.

46 CFR 113.35-13 - Mechanical engine order telegraph systems; operation.

Science.gov (United States)

2010-10-01

... 46 Shipping 4 2010-10-01 2010-10-01 false Mechanical engine order telegraph systems; operation...) ELECTRICAL ENGINEERING COMMUNICATION AND ALARM SYSTEMS AND EQUIPMENT Engine Order Telegraph Systems § 113.35-13 Mechanical engine order telegraph systems; operation. If more than one transmitter operates a...

Moderation control in low enriched 235U uranium hexafluoride packaging operations and transportation

International Nuclear Information System (INIS)

Dyer, R.H.; Kovac, F.M.; Pryor, W.A.

1993-01-01

Moderation control is the basic parameter for ensuring nuclear criticality safety during the packaging and transport of low 235 U enriched uranium hexafluoride before its conversion to nuclear power reactor fuel. Moderation control has permitted the shipment of bulk quantities in large cylinders instead of in many smaller cylinders and, therefore, has resulted in economies without compromising safety. Overall safety and uranium accountability have been enhanced through the use of the moderation control. This paper discusses moderation control and the operating procedures to ensure that moderation control is maintained during packaging operations and transportation

Solution structure and elevator mechanism of the membrane electron transporter CcdA.

Science.gov (United States)

Zhou, Yunpeng; Bushweller, John H

2018-02-01

Membrane oxidoreductase CcdA plays a central role in supplying reducing equivalents from the bacterial cytoplasm to the envelope. It transports electrons across the membrane using a single pair of cysteines by a mechanism that has not yet been elucidated. Here we report an NMR structure of the Thermus thermophilus CcdA (TtCcdA) in an oxidized and outward-facing state. CcdA consists of two inverted structural repeats of three transmembrane helices (2 × 3-TM). We computationally modeled and experimentally validated an inward-facing state, which suggests that CcdA uses an elevator-type movement to shuttle the reactive cysteines across the membrane. CcdA belongs to the LysE superfamily, and thus its structure may be relevant to other LysE clan transporters. Structure comparisons of CcdA, semiSWEET, Pnu, and major facilitator superfamily (MFS) transporters provide insights into membrane transporter architecture and mechanism.

Water transport mechanisms across inorganic membranes in rad waste treatment by electro dialysis

International Nuclear Information System (INIS)

Andalaft, E.; Labayru, R.

1992-01-01

The work described in this paper deals with effects and mechanisms of water transport across an inorganic membrane, as related to some studied on the concentration of caesium, strontium, plutonium and other cations of interest to radioactive waste treatment. Several different water transport mechanisms are analysed and assessed as to their individual contribution towards the total transference of water during electro-dialysis using inorganic membranes. Water transfer assisted by proton jump mechanism, water of hydration transferred along with the ions, water related to thermo-osmotic effect, water transferred by concentration gradient and water transferred electrolytically under zeta potential surface charge drive are some of the different mechanism discussed. (author)

The operational and regulatory outlook for the transport of radioactive material

International Nuclear Information System (INIS)

Sousselier, Y.

1983-05-01

Future actions to achieve overall optimization with reasonable economic constraints are discussed in this paper. The knowledge of data used for design calculations of packaging should be improved. Another sector is that of taking into consideration the whole interlinked series of operations involved and not just the transport. Future regulations need not be more and more restrictive and detailed, but more and more effective. In the administrative aspects of regulations the documents should be simplified and their number reduced but checklists should be more detailed to show that operations have been done corectly. Optimum conditions should be pursued in quality control. These recommendations can only be put in practice if the general public is convinced that transporting radioactive materials is perfectly safe and that optimum conditions are in their interest

Critical review: Radionuclide transport, sediment transport, and water quality mathematical modeling; and radionuclide adsorption/desorption mechanisms

Energy Technology Data Exchange (ETDEWEB)

Onishi, Y.; Serne, R.J.; Arnold, E.M.; Cowan, C.E.; Thompson, F.L. [Pacific Northwest Lab., Richland, WA (United States)

1981-01-01

This report describes the results of a detailed literature review of radionuclide transport models applicable to rivers, estuaries, coastal waters, the Great Lakes, and impoundments. Some representatives sediment transport and water quality models were also reviewed to evaluate if they can be readily adapted to radionuclide transport modeling. The review showed that most available transport models were developed for dissolved radionuclide in rivers. These models include the mechanisms of advection, dispersion, and radionuclide decay. Since the models do not include sediment and radionuclide interactions, they are best suited for simulating short-term radionuclide migration where: (1) radionuclides have small distribution coefficients; (2) sediment concentrations in receiving water bodies are very low. Only 5 of the reviewed models include full sediment and radionuclide interactions: CHMSED developed by Fields; FETRA SERATRA, and TODAM developed by Onishi et al, and a model developed by Shull and Gloyna. The 5 models are applicable to cases where: (1) the distribution coefficient is large; (2) sediment concentrations are high; or (3) long-term migration and accumulation are under consideration. The report also discusses radionuclide absorption/desorption distribution ratios and addresses adsorption/desorption mechanisms and their controlling processes for 25 elements under surface water conditions. These elements are: Am, Sb, C, Ce, Cm, Co, Cr, Cs, Eu, I, Fe, Mn, Np, P, Pu, Pm, Ra, Ru, Sr, Tc, Th, {sup 3}H, U, Zn and Zr.

Human and veterinary pharmaceutical abundance and transport in a rural central Indiana stream influenced by confined animal feeding operations (CAFOs).

Science.gov (United States)

Bernot, Melody J; Smith, Lora; Frey, Jeff

2013-02-15

Previous research has documented the ubiquity of human and veterinary pharmaceuticals and personal care products (PPCPs) in freshwater, though their persistence and transport is relatively unknown. The objective of this study was to quantify the abundance and transport of human and veterinary PPCPs in a rural, central Indiana stream influenced by confined animal feeding operations (CAFOs). Research objectives also aimed to identify mechanisms controlling abundance and transport. PPCP concentrations and stream physicochemical characteristics were measured monthly over one year at multiple sites along a 60 km reach. Overall, human PPCPs were more abundant and measured at higher concentrations than veterinary pharmaceuticals. Veterinary pharmaceutical concentrations (lincomycin, sulfamethazine) were greatest in stream reaches adjacent to CAFOs. No distinct spatial variation was observed for human PPCPs. However, caffeine and paraxanthine had significant temporal variation with higher concentrations in winter. In contrast, DEET had higher concentrations in summer. Pharmaceutical load (μg/s) ranged fromcaffeine are transported farther than triclosan though had lower loss velocities (loss relative to abundance). Loss rate of PPCPs was an order of magnitude lower than nitrate-N loss rate. Human PPCPs were more abundant than veterinary pharmaceuticals in this rural watershed influenced by CAFOs. Further, concentrations had significant temporal and spatial variation highlighting differential sources and fates. Thus, mechanisms driving PPCP retention and transport need to be identified to aid management of these emerging contaminants. Copyright © 2012 Elsevier B.V. All rights reserved.

Receptor-mediated mechanism for the transport of prolactin from blood to cerebrospinal fluid

International Nuclear Information System (INIS)

Walsh, R.J.; Slaby, F.J.; Posner, B.I.

1987-01-01

Prolactin (PRL) interacts with areas of the central nervous system which reside behind the blood-brain barrier. While vascular PRL does not cross this barrier, it is readily accessible to the cerebrospinal fluid (CSF) from which it may gain access to the PRL-responsive areas of the brain. Studies were undertaken to characterize the mechanism responsible for the translocation of PRL from blood to CSF. Rats were given external jugular vein injections of [ 125 -I]iodo-PRL in the presence or absence of an excess of unlabeled ovine PRL (oPRL), human GH, bovine GH, or porcine insulin. CSF and choroid plexus were removed 60 min later. CSF samples were electrophoresed on sodium dodecyl sulfate-polyacrylamide slab gels and resultant autoradiographs were analyzed with quantitative microdensitometry. The data revealed that unlabeled lactogenic hormones, viz. oPRL and human GH, caused a statistically significant inhibition of [ 125 I]iodo-PRL transport from blood to CSF. In contrast, nonlactogenic hormones, viz bovine GH and insulin, had no effect on [ 125 I]iodo-PRL transport into the CSF. An identical pattern of competition was observed in the binding of hormone to the choroid plexus. Furthermore, vascular injections of [ 125 I]iodo-PRL administered with a range of concentrations of unlabeled oPRL revealed a dose-response inhibition in the transport of [ 125 I]iodo-PRL from blood to CSF. The study demonstrates that PRL enters the CSF by a specific, PRL receptor-mediated transport mechanism. The data is consistent with the hypothesis that the transport mechanism resides at the choroid plexus. The existence of this transport mechanism reflects the importance of the cerebroventricular system in PRL-brain interactions

Spatial and temporal variations of the callus mechanical properties during bone transport

Energy Technology Data Exchange (ETDEWEB)

Mora-Macias, J.; Reina-Romo, E.; Pajares, A.; Miranda, P.; Dominguez, J.

2016-07-01

Nanoindentation allows obtaining the elastic modulus and the hardness of materials point by point. This technique has been used to assess the mechanical propeties of the callus during fracture healing. However, as fas as the authors know, the evaluation of mechanical properties by this technique of the distraction and the docking-site calluses generated during bone transport have not been reported yet. Therefore, the aim of this work is using nanoindentation to assess the spatial and temporal variation of the elastic modulus of the woven bone generated during bone transport. Nanoindentation measurements were carried out using 6 samples from sheep sacrificed at different stages of the bone transport experiments. The results obtained show an important heterogeneity of the elastic modulus of the woven bone without spatial trends. In the case of temporal variation, a clear increase of the mean elastic modulus with time after surgery was observed (from 7±2GPa 35 days after surgery to 14±2GPa 525 days after surgery in the distraction callus and a similar increase in the docking site callus). Comparison with the evolution of the elastic modulus in the woven bone generated during fracture healing shows that mechanical properties increase slower in the case of the woven bone generated during bone transport. (Author)

Single-vesicle imaging reveals different transport mechanisms between glutamatergic and GABAergic vesicles.

Science.gov (United States)

Farsi, Zohreh; Preobraschenski, Julia; van den Bogaart, Geert; Riedel, Dietmar; Jahn, Reinhard; Woehler, Andrew

2016-02-26

Synaptic transmission is mediated by the release of neurotransmitters, which involves exo-endocytotic cycling of synaptic vesicles. To maintain synaptic function, synaptic vesicles are refilled with thousands of neurotransmitter molecules within seconds after endocytosis, using the energy provided by an electrochemical proton gradient. However, it is unclear how transmitter molecules carrying different net charges can be efficiently sequestered while maintaining charge neutrality and osmotic balance. We used single-vesicle imaging to monitor pH and electrical gradients and directly showed different uptake mechanisms for glutamate and γ-aminobutyric acid (GABA) operating in parallel. In contrast to glutamate, GABA was exchanged for protons, with no other ions participating in the transport cycle. Thus, only a few components are needed to guarantee reliable vesicle filling with different neurotransmitters. Copyright © 2016, American Association for the Advancement of Science.

Unraveling fatty acid transport and activation mechanisms in Yarrowia lipolytica.

Science.gov (United States)

Dulermo, Rémi; Gamboa-Meléndez, Heber; Ledesma-Amaro, Rodrigo; Thévenieau, France; Nicaud, Jean-Marc

2015-09-01

Fatty acid (FA) transport and activation have been extensively studied in the model yeast species Saccharomyces cerevisiae but have rarely been examined in oleaginous yeasts, such as Yarrowia lipolytica. Because the latter begins to be used in biodiesel production, understanding its FA transport and activation mechanisms is essential. We found that Y. lipolytica has FA transport and activation proteins similar to those of S. cerevisiae (Faa1p, Pxa1p, Pxa2p, Ant1p) but mechanism of FA peroxisomal transport and activation differs greatly with that of S. cerevisiae. While the ScPxa1p/ScPxa2p heterodimer is essential for growth on long-chain FAs, ΔYlpxa1 ΔYlpxa2 is not impaired for growth on FAs. Meanwhile, ScAnt1p and YlAnt1p are both essential for yeast growth on medium-chain FAs, suggesting they function similarly. Interestingly, we found that the ΔYlpxa1 ΔYlpxa2 ΔYlant1 mutant was unable to grow on short-, medium-, or long-chain FAs, suggesting that YlPxa1p, YlPxa2p, and YlAnt1p belong to two different FA degradation pathways. We also found that YlFaa1p is involved in FA storage in lipid bodies and that FA remobilization largely depended on YlFat1p, YlPxa1p and YlPxa2p. This study is the first to comprehensively examine FA intracellular transport and activation in oleaginous yeast. Copyright © 2015. Published by Elsevier B.V.

Transport mechanism of an initially spherical droplet on a combined hydrophilic/hydrophobic surface

Energy Technology Data Exchange (ETDEWEB)

Myong, Hyon Kook; Kwon, Young Hoo [Dept. of Mechanical Engineering, Kookmin University, Seoul (Korea, Republic of)

2015-11-15

Fluid transport is a key issue in the development of microfluidic systems. Recently, Myong (2014) has proposed a new concept for droplet transport without external power sources, and numerically validated the results for a hypothetical 2D shape, initially having a hemicylindrical droplet shape. Myong and Kwon (2015) have also examined the transport mechanism for an actual water droplet, initially having a 3D hemispherical shape, on a horizontal hydrophilic/hydrophobic surface, based on the numerical results of the time evolution of the droplet shape, as well as the total kinetic, gravitational, pressure and surface free energies inside the droplet. In this study, a 3D numerical analysis of an initially spherical droplet is carried out to establish a new concept for droplet transport. Further, the transport mechanism of an actual water droplet is examined in detail from the viewpoint of the capillarity force imbalance through the numerical results of droplet shape and various energies inside the droplet.

Advanced Transport Operating System (ATOPS) utility library software description

Science.gov (United States)

Clinedinst, Winston C.; Slominski, Christopher J.; Dickson, Richard W.; Wolverton, David A.

1993-01-01

The individual software processes used in the flight computers on-board the Advanced Transport Operating System (ATOPS) aircraft have many common functional elements. A library of commonly used software modules was created for general uses among the processes. The library includes modules for mathematical computations, data formatting, system database interfacing, and condition handling. The modules available in the library and their associated calling requirements are described.

Transportation-Driven Mars Surface Operations Supporting an Evolvable Mars Campaign

Science.gov (United States)

Toups, Larry; Brown, Kendall; Hoffman, Stephen J.

2015-01-01

This paper describes the results of a study evaluating options for supporting a series of human missions to a single Mars surface destination. In this scenario the infrastructure emplaced during previous visits to this site is leveraged in following missions. The goal of this single site approach to Mars surface infrastructure is to enable "Steady State" operations by at least 4 crew for up to 500 sols at this site. These characteristics, along with the transportation system used to deliver crew and equipment to and from Mars, are collectively known as the Evolvable Mars Campaign (EMC). Information in this paper is presented in the sequence in which it was accomplished. First, a logical buildup sequence of surface infrastructure was developed to achieve the desired "Steady State" operations on the Mars surface. This was based on a concept of operations that met objectives of the EMC. Second, infrastructure capabilities were identified to carry out this concept of operations. Third, systems (in the form of conceptual elements) were identified to provide these capabilities. This included top-level mass, power and volume estimates for these elements. Fourth, the results were then used in analyses to evaluate three options (18t, 27t, and 40t landed mass) of Mars Lander delivery capability to the surface. Finally, Mars arrival mass estimates were generated based upon the entry, descent, and landing requirements for inclusion in separate assessments of in-space transportation capabilities for the EMC.

Active zone proteins are transported via distinct mechanisms regulated by Par-1 kinase.

Directory of Open Access Journals (Sweden)

Kara R Barber

2017-02-01

Full Text Available Disruption of synapses underlies a plethora of neurodevelopmental and neurodegenerative disease. Presynaptic specialization called the active zone plays a critical role in the communication with postsynaptic neuron. While the role of many proteins at the active zones in synaptic communication is relatively well studied, very little is known about how these proteins are transported to the synapses. For example, are there distinct mechanisms for the transport of active zone components or are they all transported in the same transport vesicle? Is active zone protein transport regulated? In this report we show that overexpression of Par-1/MARK kinase, a protein whose misregulation has been implicated in Autism spectrum disorders (ASDs and neurodegenerative disorders, lead to a specific block in the transport of an active zone protein component- Bruchpilot at Drosophila neuromuscular junctions. Consistent with a block in axonal transport, we find a decrease in number of active zones and reduced neurotransmission in flies overexpressing Par-1 kinase. Interestingly, we find that Par-1 acts independently of Tau-one of the most well studied substrates of Par-1, revealing a presynaptic function for Par-1 that is independent of Tau. Thus, our study strongly suggests that there are distinct mechanisms that transport components of active zones and that they are tightly regulated.

An Operational evaluation of head up displays for civil transport operations. NASA/FAA phase 3 report

Science.gov (United States)

Lauber, J. K.; Bray, R. S.; Harrison, R. L.; Hemingway, J. C.; Scott, B. C.

1982-01-01

The advantages and disadvantages of head-up displays (HUDs) in commercial jet transport approach and landing operations was evaluated. Ten airline captains currently qualified in the B-727 aircraft flew a series of instrument landing system (ILS) and nonprecision approaches in a motion base simulator using both a flight director HUD concept and a flightpath HUD concept as well as conventional head-down instruments under a variety of environmental and operational conditions to assess: (1) the potential benefits of these HUDs in airline operations; (2) problems which might be associated with their use; and (3) flight crew training requirements and flight crew operating procedures suitable for use with the HUDs. Results are presented in terms of objective simulator based performance measures, subject pilot opinion and rating data, and observer data.

SUBTASK 2.19 – OPERATIONAL FLEXIBILITY OF CO2 TRANSPORT AND STORAGE

Energy Technology Data Exchange (ETDEWEB)

Jensen, Melanie; Schlasner, Steven; Sorensen, James; Hamling, John

2014-12-31

Carbon dioxide (CO2) is produced in large quantities during electricity generation and by industrial processes. These CO2 streams vary in terms of both composition and mass flow rate, sometimes substantially. The impact of a varying CO2 stream on pipeline and storage operation is not fully understood in terms of either operability or infrastructure robustness. This study was performed to summarize basic background from the literature on the topic of operational flexibility of CO2 transport and storage, but the primary focus was on compiling real-world lessons learned about flexible operation of CO2 pipelines and storage from both large-scale field demonstrations and commercial operating experience. Modeling and pilot-scale results of research in this area were included to illustrate some of the questions that exist relative to operation of carbon capture and storage (CCS) projects with variable CO2 streams. It is hoped that this report’s real-world findings provide readers with useful information on the topic of transport and storage of variable CO2 streams. The real-world results were obtained from two sources. The first source consisted of five full-scale, commercial transport–storage projects: Sleipner, Snøhvit, In Salah, Weyburn, and Illinois Basin–Decatur. These scenarios were reviewed to determine the information that is available about CO2 stream variability/intermittency on these demonstration-scale projects. The five projects all experienced mass flow variability or an interruption in flow. In each case, pipeline and/or injection engineers were able to accommodate any issues that arose. Significant variability in composition has not been an issue at these five sites. The second source of real- world results was telephone interviews conducted with experts in CO2 pipeline transport, injection, and storage during which commercial anecdotal information was acquired to augment that found during the literature search of the five full-scale projects. The

Optimizing Public Transport Planning and Operations Using Automatic Vehicle Location Data: The Dutch Example

NARCIS (Netherlands)

van Oort, N.; Sparing, D.; Brands, Ties; Goverde, R.M.P.; Albrecht, Thomas; Jaekel, Birgit; Lehnert, Martin

2013-01-01

There is a growing pressure on urban public transport companies and authorities to improve efficiency, stemming from reduced budgets, political expectations and competition between operators. In order to find inefficiencies, bottlenecks and potentials in the public transport service, it is useful to

The planning and management system of the low level radioactive waste transportation

International Nuclear Information System (INIS)

Tanaka, K.; Yoshida, K.; Miyamoto, J.; Sanui, T.; Noura, T.; Kitanishi, K.; Nara, S.

1993-01-01

Nuclear Fuel Transport Co, Ltd. (hereafter called NFT) was the first in Japan to transport low-level radioactive waste (LLW). It is now engaged in preparatory operations with the slogan 'Improved Safety and Reliability' and is introducing advanced mechanization systems to provide safety and reliability in software management such as transportation planning and transportation information management. The following is an introduction of these systems, which provide overall support in transportation planning determination and transportation management operations related to the LLW transportation cycle. (J.P.N.)

Mechanism for transporting used resin

International Nuclear Information System (INIS)

Sugimoto, Yoshikazu; Yusa, Hideo; Kamiya, Kunio.

1975-01-01

Object: In the operation of a light water reactor type atomic power plant, to permit transport and reuse of used ion exchange resin used for the filtering or cleaning of cooling water or the desalting of radioactive exhaust liquid through an ejector. Structure: Used ion exchange resin within a desalter having high radioactivity is withdrawn through the action of an ejector and led to a solid-liquid separator for separation into used resin and water. The separated resin is directly collected in a storage tank while the separated water is forced through a circulating pump to a gas-liquid separator for separation into gas having radioactivity and water. The separated gas is led to a radioactive gas treatment station while the water deprived of the gas is recirculated by a drive water pump for repeated use. (Kamimura, M.)

Mechanism for transporting used resin

Energy Technology Data Exchange (ETDEWEB)

Sugimoto, Y; Yusa, H; Kamiya, K

1975-01-16

In the operation of a light water reactor type atomic power plant the objectives is to permit transport and reuse of used ion exchange resin used for the filtering or cleaning of cooling water or the desalting of radioactive exhaust liquid through an ejector. Used ion exchange resin within a desalter having high radioactivity is withdrawn through the action of an ejector and led to a solid-liquid separator for separation into used resin and water. The separated resin is directly collected in a storage tank while the separated water is forced through a circulating pump to a gas-liquid separator for separation into gas having radioactivity and water. The separated gas is led to a radioactive gas treatment station while the water deprived of the gas is recirculated by a drive water pump for repeated use.

Mechanism of travelling-wave transport of particles

International Nuclear Information System (INIS)

Kawamoto, Hiroyuki; Seki, Kyogo; Kuromiya, Naoyuki

2006-01-01

Numerical and experimental investigations have been carried out on transport of particles in an electrostatic travelling field. A three-dimensional hard-sphere model of the distinct element method was developed to simulate the dynamics of particles. Forces applied to particles in the model were the Coulomb force, the dielectrophoresis force on polarized dipole particles in a non-uniform field, the image force, gravity and the air drag. Friction and repulsion between particle-particle and particle-conveyer were included in the model to replace initial conditions after mechanical contacts. Two kinds of experiments were performed to confirm the model. One was the measurement of charge of particles that is indispensable to determine the Coulomb force. Charge distribution was measured from the locus of free-fallen particles in a parallel electrostatic field. The averaged charge of the bulk particle was confirmed by measurement with a Faraday cage. The other experiment was measurements of the differential dynamics of particles on a conveyer consisting of parallel electrodes to which a four-phase travelling electrostatic wave was applied. Calculated results agreed with measurements, and the following characteristics were clarified. (1) The Coulomb force is the predominant force to drive particles compared with the other kinds of forces, (2) the direction of particle transport did not always coincide with that of the travelling wave but changed partially. It depended on the frequency of the travelling wave, the particle diameter and the electric field, (3) although some particles overtook the travelling wave at a very low frequency, the motion of particles was almost synchronized with the wave at the low frequency and (4) the transport of some particles was delayed to the wave at medium frequency; the majority of particles were transported backwards at high frequency and particles were not transported but only vibrated at very high frequency

Increased coordination in public transport – which mechanisms are available?

DEFF Research Database (Denmark)

Sørensen, Claus Hedegaard; Longva, Frode

2011-01-01

After several years of New Public Management reforms within public transport, coordination seems to receive increased attention. With examples of actual as well as suggested changes taken from Denmark, Sweden and the UK the aim of the article is to analyse and classify the mechanisms utilized...... mechanism has its strengths and failures. The article also debates to what extent the mechanisms conflict with three core characteristics of New Public Management: Unbundling of the public sector into corporatized units; more contract-based competitive provision; and greater emphasis on output controls....

A Preliminary Evaluation of Supersonic Transport Category Vehicle Operations in the National Airspace System

Science.gov (United States)

Underwood, Matthew C.; Guminsky, Michael D.

2015-01-01

Several public sector businesses and government agencies, including the National Aeronautics and Space Administration are currently working on solving key technological barriers that must be overcome in order to realize the vision of low-boom supersonic flights conducted over land. However, once these challenges are met, the manner in which this class of aircraft is integrated in the National Airspace System may become a potential constraint due to the significant environmental, efficiency, and economic repercussions that their integration may cause. Background research was performed on historic supersonic operations in the National Airspace System, including both flight deck procedures and air traffic controller procedures. Using this information, an experiment was created to test some of these historic procedures in a current-day, emerging Next Generation Air Transportation System (NextGen) environment and observe the interactions between commercial supersonic transport aircraft and modern-day air traffic. Data was gathered through batch simulations of supersonic commercial transport category aircraft operating in present-day traffic scenarios as a base-lining study to identify the magnitude of the integration problems and begin the exploration of new air traffic management technologies and architectures which will be needed to seamlessly integrate subsonic and supersonic transport aircraft operations. The data gathered include information about encounters between subsonic and supersonic aircraft that may occur when supersonic commercial transport aircraft are integrated into the National Airspace System, as well as flight time data. This initial investigation is being used to inform the creation and refinement of a preliminary Concept of Operations and for the subsequent development of technologies that will enable overland supersonic flight.

Cellular phone interference with the operation of mechanical ventilators.

Science.gov (United States)

Shaw, Cheryl I; Kacmarek, Robert M; Hampton, Rickey L; Riggi, Vincent; El Masry, Ashraf; Cooper, Jeffrey B; Hurford, William E

2004-04-01

To determine whether a cellular phone would interfere with the operation of mechanical ventilators. Laboratory study. University medical center. Fourteen mechanical ventilators. We evaluated change in operation and malfunction of the mechanical ventilators. The cellular phone (Nokia 6120i) was computer controlled, operating at 828.750 MHz analog modulation. It was operated at 16, 40, 100, 250, and 600 mW, 30 cm from the floor and 30, 15, and ventilator. Six of the 14 ventilators tested malfunctioned when a cellular phone at maximum power output was placed ventilating when the cellular phone at maximum power output was placed ventilator. One ventilator doubled the ventilatory rate and another increased the displayed tidal volume from 350 to 1033 mL. In one of the infant ventilators, displayed tidal volume increased from 21 to 100 mL. In another ventilator, the high respiratory rate alarm sounded but the rate had not changed. In a controlled laboratory setting, cellular phones placed in close proximity to some commercially available intensive care ventilators can cause malfunctions, including irrecoverable cessation of ventilation. This is most likely to occur if the cellular phone is or =3 feet from all medical devices. The current electromagnetic compatibility standards for mechanical ventilators are inadequate to prevent malfunction. Manufacturers should ensure that their products are not affected by wireless technology even when placed immediately next to the device.

Regional transportation operations collaboration and coordination : a primer for working together to improve transportation safety, reliability, and security

Science.gov (United States)

2002-01-01

This primer was written for transportation professionals and public safety officials from cities, counties, and States who are responsible for day-to-day management and operations within a metropolitan region. It is intended to help agencies and orga...

Chronic blockade or constitutive deletion of the serotonin transporter reduces operant responding for food reward.

Science.gov (United States)

Sanders, Amy Cecilia; Hussain, Ali J; Hen, René; Zhuang, Xiaoxi

2007-11-01

The therapeutic effects of chronic selective serotonin reuptake inhibitors (SSRIs) are well documented, yet the elementary behavioral processes that are affected by such treatment have not been fully investigated. We report here the effects of chronic fluoxetine treatment and genetic deletion of the serotonin transporter (SERT) on food reinforced behavior in three paradigms: the progressive ratio operant task, the concurrent choice operant task, and the Pavlovian-to-Instrumental transfer task. We consistently find that chronic pharmacological blockade or genetic deletion of SERT result in similar behavioral consequences: reduced operant responding for natural reward. This is in line with previous studies reporting declines in operant responding for drugs and intracranial self-stimulation with fluoxetine treatment, suggesting that the effect of SERT blockade can be generalized to different reward types. Detailed analyses of behavioral parameters indicate that this reduction in operant responding affect both goal-directed and non-goal-directed behaviors without affecting the Pavlovian cue-triggered excessive operant responding. In addition, both pharmacological and genetic manipulations reduce locomotor activity in the open field novel environment. Our data contrast with the effect of dopamine in increasing operant responding for natural reward specifically in goal-directed behaviors and in increasing Pavlovian cue-triggered excessive operant responding. Serotonin and dopamine have been proposed to serve opposing functions in motivational processes. Our data suggest that their interactions do not result in simple opponency. The fact that pharmacological blockade and genetic deletion of SERT have similar behavioral consequences reinforces the utility of the SERT null mice for investigation of the mechanisms underlying chronic SSRIs treatment.

On the definition of time operator in quantum mechanics

International Nuclear Information System (INIS)

Nowicki, A.A.

1974-01-01

Different approaches to the quantum-mechanical definition of time operator T are briefly discussed. In particular we define the analytic continuation of the time operator and show that one can construct its exact eigenstates. We consider also the case of a relativistic free scalar particle and discuss the notion of proper time operator S. (author)

Integrated model of port oil piping transportation system safety including operating environment threats

Directory of Open Access Journals (Sweden)

Kołowrocki Krzysztof

2017-06-01

Full Text Available The paper presents an integrated general model of complex technical system, linking its multistate safety model and the model of its operation process including operating environment threats and considering variable at different operation states its safety structures and its components safety parameters. Under the assumption that the system has exponential safety function, the safety characteristics of the port oil piping transportation system are determined.

Integrated model of port oil piping transportation system safety including operating environment threats

OpenAIRE

Kołowrocki, Krzysztof; Kuligowska, Ewa; Soszyńska-Budny, Joanna

2017-01-01

The paper presents an integrated general model of complex technical system, linking its multistate safety model and the model of its operation process including operating environment threats and considering variable at different operation states its safety structures and its components safety parameters. Under the assumption that the system has exponential safety function, the safety characteristics of the port oil piping transportation system are determined.

Time Operator in Relativistic Quantum Mechanics

Science.gov (United States)

Khorasani, Sina

2017-07-01

It is first shown that the Dirac’s equation in a relativistic frame could be modified to allow discrete time, in agreement to a recently published upper bound. Next, an exact self-adjoint 4 × 4 relativistic time operator for spin-1/2 particles is found and the time eigenstates for the non-relativistic case are obtained and discussed. Results confirm the quantum mechanical speculation that particles can indeed occupy negative energy levels with vanishingly small but non-zero probablity, contrary to the general expectation from classical physics. Hence, Wolfgang Pauli’s objection regarding the existence of a self-adjoint time operator is fully resolved. It is shown that using the time operator, a bosonic field referred here to as energons may be created, whose number state representations in non-relativistic momentum space can be explicitly found.

Assessment and validation of CT scanogram to compare per-operative and post-operative mechanical axis after navigated total knee replacement

Science.gov (United States)

Jain, Sunil

2008-01-01

Our objective was to assess and validate low-dose computed tomography (CT) scanogram as a post-operative imaging modality to measure the mechanical axis after navigated total knee replacement. A prospective study was performed to compare intra-operative and post-operative mechanical axis after navigated total knee replacements. All consecutive patients who underwent navigated total knee replacement between May and December 2006 were included. The intra-operative final axis was recorded, and post-operatively a CT scanogram of lower limbs was performed. The mechanical axis was measured and compared against the intra-operative measurement. There were 15 patients ranging in age from 57 to 80 (average 70) years. The average final intra-operative axis was 0.56° varus (4° varus to 1.5° valgus) and post-operative CT scanogram axis was 0.52° varus (3.1° varus to 1.8° valgus). The average deviation from final axes to CT scanogram axes was 0.12° valgus with a correlation coefficient of 0.9. Our study suggests that CT scanogram is an imaging modality with reasonable accuracy for measuring mechanical axis despite significantly low radiation. It also confirms a high level of correlation between intra-operative and post-operative mechanical axis after navigated total knee replacement. PMID:18696064

Tape transport mechanism

International Nuclear Information System (INIS)

Groh, E.F.; McDowell, W.; Modjeski, N.S.; Keefe, D.J.; Groer, P.

1979-01-01

A device is provided for transporting, in a stepwise manner, tape between a feed reel and takeup reel. An indexer moves across the normal path of the tape displacing it while the tape on the takeup reel side of the indexer is braked. After displacement, the takeup reel takes up the displaced tape while the tape on the feed reel side of the indexer is braked, providing stepwise tape transport in precise intervals determined by the amount of displacement caused by the indexer

A Model to Couple Flow, Thermal and Reactive Chemical Transport, and Geo-mechanics in Variably Saturated Media

Science.gov (United States)

Yeh, G. T.; Tsai, C. H.

2015-12-01

This paper presents the development of a THMC (thermal-hydrology-mechanics-chemistry) process model in variably saturated media. The governing equations for variably saturated flow and reactive chemical transport are obtained based on the mass conservation principle of species transport supplemented with Darcy's law, constraint of species concentration, equation of states, and constitutive law of K-S-P (Conductivity-Degree of Saturation-Capillary Pressure). The thermal transport equation is obtained based on the conservation of energy. The geo-mechanic displacement is obtained based on the assumption of equilibrium. Conventionally, these equations have been implicitly coupled via the calculations of secondary variables based on primary variables. The mechanisms of coupling have not been obvious. In this paper, governing equations are explicitly coupled for all primary variables. The coupling is accomplished via the storage coefficients, transporting velocities, and conduction-dispersion-diffusion coefficient tensor; one set each for every primary variable. With this new system of equations, the coupling mechanisms become clear. Physical interpretations of every term in the coupled equations will be discussed. Examples will be employed to demonstrate the intuition and superiority of these explicit coupling approaches. Keywords: Variably Saturated Flow, Thermal Transport, Geo-mechanics, Reactive Transport.

The molecular mechanism for overcoming the rate-limiting step in monoamine neurotransmitter transport

DEFF Research Database (Denmark)

Sinning, Steffen; Said, Saida; Malinauskaite, Lina

The monoamine transporter family consists of dopamine (DAT), norepinephrine (NET) and serotonin transporters (SERT) that mediate the reuptake of the monoamine neurotransmitters after their release during neurotransmission. These transporters play prominent roles in psychiatric disorders and are t......The monoamine transporter family consists of dopamine (DAT), norepinephrine (NET) and serotonin transporters (SERT) that mediate the reuptake of the monoamine neurotransmitters after their release during neurotransmission. These transporters play prominent roles in psychiatric disorders...... membrane. The rate-limiting step in monoamine reuptake is the return of the empty transporter from an inward-facing to an outward-facing conformation without neurotransmitter and sodium bound. The molecular mechanism underlying this important conformational transition has not been described. Crystal...

Optimation of Operation System Integration between Main and Feeder Public Transport (Case Study: Trans Jakarta-Kopaja Bus Services)

Science.gov (United States)

Miharja, M.; Priadi, Y. N.

2018-05-01

Promoting a better public transport is a key strategy to cope with urban transport problems which are mostly caused by a huge private vehicle usage. A better public transport service quality not only focuses on one type of public transport mode, but also concerns on inter modes service integration. Fragmented inter mode public transport service leads to a longer trip chain as well as average travel time which would result in its failure to compete with a private vehicle. This paper examines the optimation process of operation system integration between Trans Jakarta Bus as the main public transport mode and Kopaja Bus as feeder public transport service in Jakarta. Using scoring-interview method combined with standard parameters in operation system integration, this paper identifies the key factors that determine the success of the two public transport operation system integrations. The study found that some key integration parameters, such as the cancellation of “system setoran”, passenger get in-get out at official stop points, and systematic payment, positively contribute to a better service integration. However, some parameters such as fine system, time and changing point reliability, and information system reliability are among those which need improvement. These findings are very useful for the authority to set the right strategy to improve operation system integration between Trans Jakarta and Kopaja Bus services.

Long Length Contaminated Equipment Retrieval System Receiver Trailer and Transport Trailer Operations and Maintenance Manual

International Nuclear Information System (INIS)

DALE, R.N.

2000-01-01

A system to accommodate the removal of long-length contaminated equipment (LLCE) from Hanford underground radioactive waste storage tanks was designed, procured, and demonstrated, via a project activity during the 1990s. The system is the Long Length Contaminated Equipment Removal System (LLCERS). LLCERS will be maintained and operated by Tank Farms Engineering and Operations organizations and other varied projects having a need for the system. The responsibility for the operation and maintenance of the LLCERS Receiver Trailer (RT) and Transport Trailer (TT) resides with the RPP Characterization Project Operations organization. The purpose of this document is to provide vendor supplied operating and maintenance (O and M) information for the RT and TT in a readily retrievable form. This information is provided this way instead of in a vendor information (VI) file to maintain configuration control of the operations baseline as described in RPP-6085, ''Configuration Management Plan for Long Length Contaminated Equipment Receiver and Transport Trailers''. Additional Operations Baseline documents are identified in RPP-6085

Mechanism of Transport Modulation by an Extracellular Loop in an Archaeal Excitatory Amino Acid Transporter (EAAT) Homolog*

Science.gov (United States)

Mulligan, Christopher; Mindell, Joseph A.

2013-01-01

Secondary transporters in the excitatory amino acid transporter family terminate glutamatergic synaptic transmission by catalyzing Na+-dependent removal of glutamate from the synaptic cleft. Recent structural studies of the aspartate-specific archaeal homolog, GltPh, suggest that transport is achieved by a rigid body, piston-like movement of the transport domain, which houses the substrate-binding site, between the extracellular and cytoplasmic sides of the membrane. This transport domain is connected to an immobile scaffold by three loops, one of which, the 3–4 loop (3L4), undergoes substrate-sensitive conformational change. Proteolytic cleavage of the 3L4 was found to abolish transport activity indicating an essential function for this loop in the transport mechanism. Here, we demonstrate that despite the presence of fully cleaved 3L4, GltPh is still able to sample conformations relevant for transport. Optimized reconstitution conditions reveal that fully cleaved GltPh retains some transport activity. Analysis of the kinetics and temperature dependence of transport accompanied by direct measurements of substrate binding reveal that this decreased transport activity is not due to alteration of the substrate binding characteristics but is caused by the significantly reduced turnover rate. By measuring solute counterflow activity and cross-link formation rates, we demonstrate that cleaving 3L4 severely and specifically compromises one or more steps contributing to the movement of the substrate-loaded transport domain between the outward- and inward-facing conformational states, sparing the equivalent step(s) during the movement of the empty transport domain. These results reveal a hitherto unknown role for the 3L4 in modulating an essential step in the transport process. PMID:24155238

Transactional approach in assessment of operational performance of companies in transport infrastructure

Energy Technology Data Exchange (ETDEWEB)

Dubrovsky, V.; Yaroshevich, N.; Kuzmin, E.

2016-07-01

Offer an alternative method to assess operational performance of companies in transport infrastructure of a region by making a comparison between transaction costs. The method is supposed to be a cross-functional and possibly applied to an analysis of economic entities of a different order (country, region, sector, companies) while evaluating “viscosity” / complexity of the outside and the inside. The paper includes an analysis of various methodological approaches to assess a development level of the transport infrastructure in a region. Within the author's approach and for purposed of the research, an index of transaction capacity or the transactionalness index is proposed, which determines a level of transaction costs calculated against the cost of production and revenue. The approach is piloted using the region-wise consolidated financial data of companies involved in the Russian transport infrastructure for 2005/2013. The proposed alternative way to measure corporate operating efficiency has proved its academic consistency. A specific comparison between the transaction costs using the transactionalness index allows first to identify companies or regions/sectors, where there is excess complexity of economical communication in bargaining. Secondly, the index does not only point out indirectly to a degree of development in the institutional environment, but also the infrastructure (the transport one in the example given). Third, the transactionalness level may say of uncertainty and risks. As an addition to theoretical and methodological aspects of transaction costs, the authors justify an approach to their size estimation, as well as their differentiation dividing them into two groups: those of a natural type and a background type. In a course of their discussion, the authors have concluded that there are such transaction costs in place, which are standard in a manner of speaking. There is a discussion whether it is scientifically reasonable to use an

A proposal for operator team behavior model and operator's thinking mechanism

International Nuclear Information System (INIS)

Yoshimura, Seiichi; Takano, Kenichi; Sasou, Kunihide

1995-01-01

Operating environment in huge systems like nuclear power plants or airplanes is changing rapidly with the advance of computer technology. It is necessary to elucidate thinking process of operators and decision-making process of an operator team in abnormal situations, in order to prevent human errors under such environment. The Central Research Institute of Electric Power Industry is promoting a research project to establish human error prevention countermeasures by modeling and simulating the thinking process of operators and decision-making process of an operator team. In the previous paper, application of multilevel flow modeling was proposed to a mental model which conducts future prediction and cause identification, and the characteristics were verified by experienced plant operators. In this paper, an operator team behavior model and a fundamental operator's thinking mechanism especially 'situation understanding' are proposed, and the proposals are evaluated by experiments using a full-scale simulator. The results reveal that some assumptions such as 'communication is done between a leader and a follower' are almost appropriate and that the situation understanding can be represented by 'probable candidates for cause, determination of a parameter which changes when an event occurs, determination of parameters which are influenced by the change of the previous parameter, determination of a principal parameter and future prediction of the principal parameter'. (author)

Reliability evaluation of a port oil transportation system in variable operation conditions

International Nuclear Information System (INIS)

Soszynska, Joanna

2006-01-01

The semi-Markov model of the system operation processes is proposed and its selected parameters are determined. The series 'm out of k n ' multi-state system is considered and its reliability and risk characteristics are found. Next, the joint model of the system operation process and the system multi-state reliability and risk is constructed. Moreover, reliability and risk evaluation of the multi-state series 'm out of k n ' system in its operation process is applied to the port oil transportation system

The transportation institutional plan: Cooperative planning for NWPA transportation

International Nuclear Information System (INIS)

Denny, S.H.; Livingston-Behan, E.A.

1987-01-01

The Transportation Institutional Plan, published in 1986 by the U.S. Department of Energy's Office of Civilian Radioactive Waste Management (OCRWM), defines a process for effective interaction among those who may be affected by transportation activities conducted under provisions of the Nuclear Waste Policy Act of 1982 (NWPA). The Plan describes formal mechanisms for identifying, addressing, and resolving specific transportation issues. An appendix to the Plan includes detailed discussion of the following transportation issues: (1) the transportation of defense waste; (2) prenotification; (3) physical and rail shipments; (4) highway routing; (5) rail routing; (6) inspection and enforcement for highway and rail shipments; (7) emergency response; (8) liability coverage for transportation to NWPA facilities; (9) cask design and testing; (10) overweight truck shipments; (11) rail service analysis; (12) mixture of transportation modes; (13) transportation infrastructure improvements; (14) OCRWM training standards; (15) transportation operational procedures; and (16) State, Tribal, and local regulation of transportation. The OCRWM's intent is to provide an open accounting of planning, to identify opportunities for public involvement in program activities, and to foster communication and negotiation in the cooperative development of a safe, efficient, and cost-effective NWPA transportation program

A proposed new mechanism for research and development co-operation

International Nuclear Information System (INIS)

Dolan, T.

2001-01-01

Scientists in developing countries sometimes lack knowledge of recent developments, co-operation with advanced countries, and government appreciation of the importance and quality of their work. The present IAEA mechanisms like CRPs and TC projects are very helpful but do not fully meet R and D co-operation needs of these scientists. A new complementary mechanism of co-operation among the Member States is proposed that would utilize IAEA services through a suitable agreement. The IAEA could help to evaluate joint R and D proposals, to provide an example legal agreement, to monitor progress, to disseminate the results, and, in some cases, to administer joint funds. This new mechanism would be similar to ITER, but on a smaller scale, and applicable to all fields of nuclear R and D. (author)

How LeuT shapes our understanding of the mechanisms of sodium-coupled neurotransmitter transporters.

Science.gov (United States)

Penmatsa, Aravind; Gouaux, Eric

2014-03-01

Neurotransmitter transporters are ion-coupled symporters that drive the uptake of neurotransmitters from neural synapses. In the past decade, the structure of a bacterial amino acid transporter, leucine transporter (LeuT), has given valuable insights into the understanding of architecture and mechanism of mammalian neurotransmitter transporters. Different conformations of LeuT, including a substrate-free state, inward-open state, and competitive and non-competitive inhibitor-bound states, have revealed a mechanistic framework for the transport and transport inhibition of neurotransmitters. The current review integrates our understanding of the mechanistic and pharmacological properties of eukaryotic neurotransmitter transporters obtained through structural snapshots of LeuT.

Improvement of water transport mechanisms during potato drying by applying ultrasound.

Science.gov (United States)

Ozuna, César; Cárcel, Juan A; García-Pérez, José V; Mulet, Antonio

2011-11-01

The drying rate of vegetables is limited by internal moisture diffusion and convective transport mechanisms. The increase of drying air temperature leads to faster water mobility; however, it provokes quality loss in the product and presents a higher energy demand. Therefore, the search for new strategies to improve water mobility during convective drying constitutes a topic of relevant research. The aim of this work was to evaluate the use of power ultrasound to improve convective drying of potato and quantify the influence of the applied power in the water transport mechanisms. Drying kinetics of potato cubes were increased by the ultrasonic application. The influence of power ultrasound was dependent on the ultrasonic power (from 0 to 37 kW m(-3) ), the higher the applied power, the faster the drying kinetic. The diffusion model considering external resistance to mass transfer provided a good fit of drying kinetics. From modelling, it was observed a proportional and significant (P mass transfer coefficient. The ultrasonic application during drying represents an interesting alternative to traditional convective drying by shortening drying time, which may involve an energy saving concerning industrial applications. In addition, the ultrasonic effect in the water transport is based on mechanical phenomena with a low heating capacity, which is highly relevant for drying heat sensitive materials and also for obtaining high-quality dry products. Copyright © 2011 Society of Chemical Industry.

Evaporation as the transport mechanism of metals in arid regions

KAUST Repository

Lima, Ana T.

2014-09-01

Soils of arid regions are exposed to drought and drastic temperature oscillations throughout the year. Transport mechanisms in these soils are therefore very different from the ones in temperate regions, where rain dictates the fate of most elements in soils. Due to the low rainfall and high evaporation rates in arid regions, groundwater quality is not threatened and all soil contamination issues tend to be overlooked. But if soil contamination happens, where do contaminants go? This study tests the hypothesis of upward metal movement in soils when evaporation is the main transport mechanism. Laboratory evaporation tests were carried out with heavy metal spiked Saudi soil, using circulation of air as the driving force (Fig. 1). Main results show that loamy soil retains heavy metals quite well while evaporation drives heavy metals to the surface of a sandy soil. Evaporation transports heavy metals upward in sandy soils of arid regions, making them accumulate at the soil surface. Sand being the dominating type of soil in arid regions, soils can then be a potential source of contaminated aerosols and atmospheric pollution - a transboundary problem. Some other repercussions for this problem are foreseen, such as the public ingestion or inhalation of dust. © 2014 Elsevier Ltd.

The gBL transport equations

International Nuclear Information System (INIS)

Mynick, H.E.

1989-05-01

The transport equations arising from the ''generalized Balescu- Lenard'' (gBL) collision operator are obtained, and some of their properties examined. The equations contain neoclassical and turbulent transport as two special cases, having the same structure. The resultant theory offers potential explanation for a number of results not well understood, including the anomalous pinch, observed ratios of Q/ΓT on TFTR, and numerical reproduction of ASDEX profiles by a model for turbulent transport invoked without derivation, but by analogy to neoclassical theory. The general equations are specialized to consideration of a number of particular transport mechanisms of interest. 10 refs

Double internal transport barrier triggering mechanism in tokamak plasmas

International Nuclear Information System (INIS)

Dong, Jiaqi; Mou, Zongze; Long, Yongxing; Mahajan, Swadesh M.

2004-01-01

Sheared flow layers created by energy released in magnetic reconnection processes are studied with the magneto hydrodynamics (MHD), aimed at internal transport barrier (ITB) dynamics. The double tearing mode induced by electron viscosity is investigated and proposed as a triggering mechanism for double internal transport barrier (DITB) observed in tokamak plasmas with non-monotonic safety factor profiles. The quasi-linear development of the mode is simulated and the emphasis is placed on the structure of sheared poloidal flow layers formed in the vicinity of the magnetic islands. For viscosity double tearing modes, it is shown that the sheared flows induced by the mode may reach the level required by the condition for ITB formation. Especially, the flow layers are found to form just outside the magnetic islands. The scaling of the generated velocity with plasma parameters is given. Possible explanation for the experimental observations that the preferential formation of transport barriers in the proximity of low order rational surface is discussed. (author)

Reliability evaluation of a port oil transportation system in variable operation conditions

Energy Technology Data Exchange (ETDEWEB)

Soszynska, Joanna [Department of Mathematics, Gdynia Maritime University, ul. Morska 83, 81-225 Gdynia (Poland)]. E-mail: joannas@am.gdynia.pl

2006-04-15

The semi-Markov model of the system operation processes is proposed and its selected parameters are determined. The series 'm out of k {sub n}' multi-state system is considered and its reliability and risk characteristics are found. Next, the joint model of the system operation process and the system multi-state reliability and risk is constructed. Moreover, reliability and risk evaluation of the multi-state series 'm out of k {sub n}' system in its operation process is applied to the port oil transportation system.

Operator methods in quantum mechanics

CERN Document Server

Schechter, Martin

2003-01-01

This advanced undergraduate and graduate-level text introduces the power of operator theory as a tool in the study of quantum mechanics, assuming only a working knowledge of advanced calculus and no background in physics. The author presents a few simple postulates describing quantum theory, gradually introducing the mathematical techniques that help answer questions important to the physical theory; in this way, readers see clearly the purpose of the method and understand the accomplishment. The entire book is devoted to the study of a single particle moving along a straight line. By posing q

Optimal Operation of Interdependent Power Systems and Electrified Transportation Networks

Directory of Open Access Journals (Sweden)

M. Hadi Amini

2018-01-01

Full Text Available Electrified transportation and power systems are mutually coupled networks. In this paper, a novel framework is developed for interdependent power and transportation networks. Our approach constitutes solving an iterative least cost vehicle routing process, which utilizes the communication of electrified vehicles (EVs with competing charging stations, to exchange data such as electricity price, energy demand, and time of arrival. The EV routing problem is solved to minimize the total cost of travel using the Dijkstra algorithm with the input from EVs battery management system, electricity price from charging stations, powertrain component efficiencies and transportation network traffic conditions. Through the bidirectional communication of EVs with competing charging stations, EVs’ charging demand estimation is done much more accurately. Then the optimal power flow problem is solved for the power system, to find the locational marginal price at load buses where charging stations are connected. Finally, the electricity prices were communicated from the charging stations to the EVs, and the loop is closed. Locational electricity price acts as the shared parameter between the two optimization problems, i.e., optimal power flow and optimal routing problem. Electricity price depends on the power demand, which is affected by the charging of EVs. On the other hand, location of EV charging stations and their different pricing strategies might affect the routing decisions of the EVs. Our novel approach that combines the electrified transportation with power system operation, holds tremendous potential for solving electrified transportation issues and reducing energy costs. The effectiveness of the proposed approach is demonstrated using Shanghai transportation network and IEEE 9-bus test system. The results verify the cost-savings for both power system and transportation networks.

Evaporation as the transport mechanism of metals in arid regions

NARCIS (Netherlands)

Lima, A.T.; Safar, Z.; Loch, J.P.G.

Soils of arid regions are exposed to drought and drastic temperature oscillations throughout the year. Transport mechanisms in these soils are therefore very different from the ones in temperate regions, where rain dictates the fate of most elements in soils. Due to the low rainfall and high

On the mechanism of charge transport in low density polyethylene

Science.gov (United States)

Upadhyay, Avnish K.; Reddy, C. C.

2017-08-01

Polyethylene based polymeric insulators, are being increasingly used in the power industry for their inherent advantages over conventional insulation materials. Specifically, modern power cables are almost made with these materials, replacing the mass-impregnated oil-paper cable technology. However, for ultra-high dc voltage applications, the use of these polymeric cables is hindered by ununderstood charge transport and accumulation. The conventional conduction mechanisms (Pool-Frenkel, Schottky, etc.) fail to track high-field charge transport in low density polyethylene, which is semi-crystalline in nature. Until now, attention was devoted mainly to the amorphous region of the material. In this paper, authors propose a novel mechanism for conduction in low density polyethylene, which could successfully track experimental results. As an implication, a novel, substantial relationship is established for electrical conductivity that could be effectively used for understanding conduction and breakdown in polyethylene, which is vital for successful development of ultra-high voltage dc cables.

Experimental Evaluation of the Transport Mechanisms of PoIFN-α in Caco-2 Cells

Directory of Open Access Journals (Sweden)

Xin Liu

2017-11-01

Full Text Available For the development of an efficient intestinal delivery system for Porcine interferon-α (PoIFN-α, the understanding of transport mechanisms of which in the intestinal cell is essential. In this study, we investigated the absorption mechanisms of PoIFN-α in intestine cells. Caco-2 cells and fluorescein isothiocyanate-labeled (FITC-PoIFN-α were used to explore the whole transport process, including endocytosis, intracellular trafficking, exocytosis, and transcytosis. Via various techniques, the transport pathways of PoIFN-α in Caco-2 cells and the mechanisms were clarified. Firstly, the endocytosis of PoIFN-α by Caco-2 cells was time, concentration and temperature dependence. And the lipid raft/caveolae endocytosis was the most likely endocytic pathway for PoIFN-α. Secondly, both Golgi apparatus and lysosome were involved in the intracellular trafficking of PoIFN-α. Thirdly, the treatment of indomethacin resulted in a significant decrease of exocytosis of PoIFN-α, indicating the participation of cyclooxygenase. Finally, to evaluate the efficiency of PoIFN-α transport, the transepithelial electrical resistance (TEER value was measured to investigate the tight junctional integrity of the cell monolayers. The fluorescence microscope results revealed that the transport of PoIFN-α across the Caco-2 cell monolayers was restricted. In conclusion, this study depicts a probable picture of PoIFN-α transport in Caco-2 cells characterized by non-specificity, partial energy-dependency and low transcytosis.

Regulatory mechanisms for iron transport across the blood-brain barrier.

Science.gov (United States)

Duck, Kari A; Simpson, Ian A; Connor, James R

2017-12-09

Many critical metabolic functions in the brain require adequate and timely delivery of iron. However, most studies when considering brain iron uptake have ignored the iron requirements of the endothelial cells that form the blood-brain barrier (BBB). Moreover, current models of BBB iron transport do not address regional regulation of brain iron uptake or how neurons, when adapting to metabolic demands, can acquire more iron. In this study, we demonstrate that both iron-poor transferrin (apo-Tf) and the iron chelator, deferoxamine, stimulate release of iron from iron-loaded endothelial cells in an in vitro BBB model. The role of the endosomal divalent metal transporter 1 (DMT1) in BBB iron acquisition and transport has been questioned. Here, we show that inhibition of DMT1 alters the transport of iron and Tf across the endothelial cells. These data support an endosome-mediated model of Tf-bound iron uptake into the brain and identifies mechanisms for local regional regulation of brain iron uptake. Moreover, our data provide an explanation for the disparity in the ratio of Tf to iron transport into the brain that has confounded the field. Copyright © 2017 Elsevier Inc. All rights reserved.

As if Kyoto mattered: The clean development mechanism and transportation

International Nuclear Information System (INIS)

Christopher Zegras, P.

2007-01-01

Transportation is a major source of greenhouse gas (GHG) emissions and the most rapidly growing anthropogenic source. In the future, the developing world will account for the largest share of transport GHG increases. Four basic components drive transportation energy consumption and GHG emissions: activities (A), mode share (S), fuel intensity (I) and fuel choice (F) (ASIF). Currently, the Kyoto Protocol's clean development mechanism (CDM) serves as the main international market-based tool designed to reduce GHG emissions from the developing world. Theoretically, the CDM has the dual purpose of helping developing countries achieve 'sustainable development' goals and industrialized countries meet their Kyoto emissions reduction commitments. This paper reviews overall CDM activities and transportation CDM activities to date and then presents findings from three case studies of transportation CDM possibilities examined with the ASIF framework in Santiago de Chile. The analysis suggests that bus technology switch (I) provides a fairly good project fit for the CDM, while options aimed at inducing mode share (S) to bicycle, or modifying travel demand via land use changes (ASI) face considerable challenges. The implications of the findings for the CDM and the 'post-Kyoto' world are discussed

Long Length Contaminated Equipment Retrieval System Receiver Trailer and Transport Trailer Operations and Maintenance Manual

Energy Technology Data Exchange (ETDEWEB)

DALE, R.N.

2000-05-01

A system to accommodate the removal of long-length contaminated equipment (LLCE) from Hanford underground radioactive waste storage tanks was designed, procured, and demonstrated, via a project activity during the 1990s. The system is the Long Length Contaminated Equipment Removal System (LLCERS). LLCERS will be maintained and operated by Tank Farms Engineering and Operations organizations and other varied projects having a need for the system. The responsibility for the operation and maintenance of the LLCERS Receiver Trailer (RT) and Transport Trailer (TT) resides with the RPP Characterization Project Operations organization. The purpose of this document is to provide vendor supplied operating and maintenance (O & M) information for the RT and TT in a readily retrievable form. This information is provided this way instead of in a vendor information (VI) file to maintain configuration control of the operations baseline as described in RPP-6085, ''Configuration Management Plan for Long Length Contaminated Equipment Receiver and Transport Trailers''. Additional Operations Baseline documents are identified in RPP-6085.

EXPRESSION OF THE TRANSPORT SECTOR OPERATIONAL EFFICIENCY EVALUATION METHODOLOGY (TRENDS AT DIFFERENT STAGES OF THE ECONOMIC CYCLE

Directory of Open Access Journals (Sweden)

Deimena KIYAK

2017-12-01

Full Text Available It is important to evaluate the impact of economic fluctuations on the transport sector operational efficiency, since such an analysis is a source of economic information which contributes to the identification of the sector's potential and advantages, the establishment of the risky areas of activity, and the exploration of the opportunities to increase its effectiveness. The aim of the study was to apply mathematical evaluation methods to the exploration of the operational efficiency of the Lithuanian transport sector companies and, based on the outcomes, to validate the opportunity of predicting a potential change of the economic cycle. The operational efficiency of the Lithuanian transport sector was analysed in the context of the cyclical national economy, and not in individual economic boom or recession periods, as that allowed for more detailed evaluation of the specific activities of the sector and its impact on Lithuanian economy. To achieve the aim, three different stages of the economic cycle in Lithuania were identified, and calculations were made during them. Based on the aggregate financial data, four different economic efficiency indicators were developed that reflected the efficiency level of the entire transport sector, and the sensitivity of the transport sector to economic fluctuations was identified. The comparison of the changes in the transport sector and in Lithuanian economy made it obvious that the level of the sector's operational efficiency could be regarded as a leading indicator of the economic cycle.

New York State intelligent transportation system commercial vehicle operations (CVO) : business plan

Science.gov (United States)

1998-07-01

The purpose of this Business Plan is to describe the major Intelligent Transportation System (ITS) initiatives and projects in the area of Commercial Vehicle Operations (CVO) that have recently been or are planned to be undertaken in New York State b...

Risk assessment for transport operations

International Nuclear Information System (INIS)

Appleton, P.R.; Miles, J.C.

1990-01-01

The world-wide safety of the transport of radioactive material is based on the IAEA Transport Regulations. Risk assessment can provide quantitative data to help in the demonstration, understanding and improvement of the effectiveness of the Regulations in assuring safety. In this Paper the methodology, data and computer codes necessary and available for transport risk assessment are reviewed. Notable examples of assessments carried out over the past 15 years are briefly described along with current research, and the benefits and limitations of the techniques are discussed. (author)

Quasi-Compact Perturbations of the Weyl Essential Spectrum and Application to Singular Transport Operators

Directory of Open Access Journals (Sweden)

Leila Mebarki

2015-11-01

Full Text Available This paper is devoted to the investigation of the stability of the Weyl essential spectrum of closed densely dened linear operator A subjected to additive perturbation K such that (lambda-A-K^{-1}K or K(lambda-A-K^{-1} is a quasi-compact operator. The obtained results are used to describe the Weyl essential spectrum of singular neutron transport operator.

Operation, Safety and Human: Critical Factors for the Success of Railway Transportation

NARCIS (Netherlands)

Rajabali Nejad, Mohammadreza; Martinetti, Alberto; van Dongen, Leonardus Adriana Maria

2016-01-01

This paper focuses on three categories of performance indicators for railway transportation: the excellence of operation, system safety and human factors. These are among the most critical indicators for delivering high quality services. This paper discusses the main issues, challenges and future

Interagency mechanical operations group numerical systems group

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-09-01

This report consists of the minutes of the May 20-21, 1971 meeting of the Interagency Mechanical Operations Group (IMOG) Numerical Systems Group. This group looks at issues related to numerical control in the machining industry. Items discussed related to the use of CAD and CAM, EIA standards, data links, and numerical control.

A continuum mechanics-based musculo-mechanical model for esophageal transport

Science.gov (United States)

Kou, Wenjun; Griffith, Boyce E.; Pandolfino, John E.; Kahrilas, Peter J.; Patankar, Neelesh A.

2017-11-01

In this work, we extend our previous esophageal transport model using an immersed boundary (IB) method with discrete fiber-based structural model, to one using a continuum mechanics-based model that is approximated based on finite elements (IB-FE). To deal with the leakage of flow when the Lagrangian mesh becomes coarser than the fluid mesh, we employ adaptive interaction quadrature points to deal with Lagrangian-Eulerian interaction equations based on a previous work (Griffith and Luo [1]). In particular, we introduce a new anisotropic adaptive interaction quadrature rule. The new rule permits us to vary the interaction quadrature points not only at each time-step and element but also at different orientations per element. This helps to avoid the leakage issue without sacrificing the computational efficiency and accuracy in dealing with the interaction equations. For the material model, we extend our previous fiber-based model to a continuum-based model. We present formulations for general fiber-reinforced material models in the IB-FE framework. The new material model can handle non-linear elasticity and fiber-matrix interactions, and thus permits us to consider more realistic material behavior of biological tissues. To validate our method, we first study a case in which a three-dimensional short tube is dilated. Results on the pressure-displacement relationship and the stress distribution matches very well with those obtained from the implicit FE method. We remark that in our IB-FE case, the three-dimensional tube undergoes a very large deformation and the Lagrangian mesh-size becomes about 6 times of Eulerian mesh-size in the circumferential orientation. To validate the performance of the method in handling fiber-matrix material models, we perform a second study on dilating a long fiber-reinforced tube. Errors are small when we compare numerical solutions with analytical solutions. The technique is then applied to the problem of esophageal transport. We use two

Controlling the transport of an ion: classical and quantum mechanical solutions

International Nuclear Information System (INIS)

Fürst, H A; Poschinger, U G; Schmidt-Kaler, F; Singer, K; Goerz, M H; Koch, C P; Murphy, M; Montangero, S; Calarco, T

2014-01-01

The accurate transport of an ion over macroscopic distances represents a challenging control problem due to the different length and time scales that enter and the experimental limitations on the controls that need to be accounted for. Here, we investigate the performance of different control techniques for ion transport in state-of-the-art segmented miniaturized ion traps. We employ numerical optimization of classical trajectories and quantum wavepacket propagation as well as analytical solutions derived from invariant based inverse engineering and geometric optimal control. The applicability of each of the control methods depends on the length and time scales of the transport. Our comprehensive set of tools allows us make a number of observations. We find that accurate shuttling can be performed with operation times below the trap oscillation period. The maximum speed is limited by the maximum acceleration that can be exerted on the ion. When using controls obtained from classical dynamics for wavepacket propagation, wavepacket squeezing is the only quantum effect that comes into play for a large range of trapping parameters. We show that this can be corrected by a compensating force derived from invariant based inverse engineering, without a significant increase in the operation time. (paper)

Operation analysis of a Chebyshev-Pantograph leg mechanism for a single DOF biped robot

Science.gov (United States)

Liang, Conghui; Ceccarelli, Marco; Takeda, Yukio

2012-12-01

In this paper, operation analysis of a Chebyshev-Pantograph leg mechanism is presented for a single degree of freedom (DOF) biped robot. The proposed leg mechanism is composed of a Chebyshev four-bar linkage and a pantograph mechanism. In contrast to general fully actuated anthropomorphic leg mechanisms, the proposed leg mechanism has peculiar features like compactness, low-cost, and easy-operation. Kinematic equations of the proposed leg mechanism are formulated for a computer oriented simulation. Simulation results show the operation performance of the proposed leg mechanism with suitable characteristics. A parametric study has been carried out to evaluate the operation performance as function of design parameters. A prototype of a single DOF biped robot equipped with two proposed leg mechanisms has been built at LARM (Laboratory of Robotics and Mechatronics). Experimental test shows practical feasible walking ability of the prototype, as well as drawbacks are discussed for the mechanical design.

Design, operation, and evaluation of the transportable vitrification system

International Nuclear Information System (INIS)

Zamecnik, J.R.; Young, S.R.; Hansen, E.K.; Whitehouse, J.C.

1997-01-01

The Transportable Vitrification System (TVS) is a transportable melter system designed to demonstrate the treatment of low-level and mixed hazardous and radioactive wastes such as wastewater treatment sludges, contaminated soils and incinerator ash. The TVS is a large-scale, fully integrated vitrification system consisting of melter feed preparation, melter, offgas, service, and control modules. The TVS was tested with surrogate waste at the Clemson University Environmental Systems Engineering Department's (ESED) DOE/Industry Center for Vitrification Research prior to being shipped to the DOE Oak Ridge Reservation (ORR) K-25 site for treatment of mixed waste. This testing, along with additional testing at ORR, proved that the TVS would be able to successfully treat mixed waste. These surrogate tests consistently produced glass that met the EPA Toxicity Characteristic Leaching Procedure (TCLP). Performance of the system resulted in acceptable emissions of regulated metals from the offgas system. The TVS is scheduled to begin mixed waste operations at ORR in June 1997

A low-frequency wave motion mechanism enables efficient energy transport in carbon nanotubes at high heat fluxes.

Science.gov (United States)

Zhang, Xiaoliang; Hu, Ming; Poulikakos, Dimos

2012-07-11

The great majority of investigations of thermal transport in carbon nanotubes (CNTs) in the open literature focus on low heat fluxes, that is, in the regime of validity of the Fourier heat conduction law. In this paper, by performing nonequilibrium molecular dynamics simulations we investigated thermal transport in a single-walled CNT bridging two Si slabs under constant high heat flux. An anomalous wave-like kinetic energy profile was observed, and a previously unexplored, wave-dominated energy transport mechanism is identified for high heat fluxes in CNTs, originated from excited low frequency transverse acoustic waves. The transported energy, in terms of a one-dimensional low frequency mechanical wave, is quantified as a function of the total heat flux applied and is compared to the energy transported by traditional Fourier heat conduction. The results show that the low frequency wave actually overtakes traditional Fourier heat conduction and efficiently transports the energy at high heat flux. Our findings reveal an important new mechanism for high heat flux energy transport in low-dimensional nanostructures, such as one-dimensional (1-D) nanotubes and nanowires, which could be very relevant to high heat flux dissipation such as in micro/nanoelectronics applications.

Structure and elevator mechanism of the Na(+)-citrate transporter CitS

NARCIS (Netherlands)

Lolkema, Juke S; Slotboom, Dirk Jan

2016-01-01

The recently determined crystal structure of the bacterial Na(+)-citrate symporter CitS provides unexpected structural and mechanistic insights. The protein has a fold that has not been seen in other proteins, but the oligomeric state, domain organization and proposed transport mechanism strongly

Study on the control mechanism of China aerospace enterprises' binary multinational operation

Institute of Scientific and Technical Information of China (English)

Wang Jian; Li Hanling; Wu Weiwei

2008-01-01

China's aerospace enterprises carry on the multinational operation and participate in the international competition and the international division of labor and cooperation positively.This article first analyzs China aerospace enterprises' binary multinational business control objective and constructes its model.Then the article analyzes the tangible and intangible control mechanism of China aerospace enterprises' binary multinational operation respectively.Finally,the article constructs the model of China aerospace enterprises' binary multinational operation mechanisms.

Modeling of Gas Production from Shale Reservoirs Considering Multiple Transport Mechanisms.

Directory of Open Access Journals (Sweden)

Chaohua Guo

Full Text Available Gas transport in unconventional shale strata is a multi-mechanism-coupling process that is different from the process observed in conventional reservoirs. In micro fractures which are inborn or induced by hydraulic stimulation, viscous flow dominates. And gas surface diffusion and gas desorption should be further considered in organic nano pores. Also, the Klinkenberg effect should be considered when dealing with the gas transport problem. In addition, following two factors can play significant roles under certain circumstances but have not received enough attention in previous models. During pressure depletion, gas viscosity will change with Knudsen number; and pore radius will increase when the adsorption gas desorbs from the pore wall. In this paper, a comprehensive mathematical model that incorporates all known mechanisms for simulating gas flow in shale strata is presented. The objective of this study was to provide a more accurate reservoir model for simulation based on the flow mechanisms in the pore scale and formation geometry. Complex mechanisms, including viscous flow, Knudsen diffusion, slip flow, and desorption, are optionally integrated into different continua in the model. Sensitivity analysis was conducted to evaluate the effect of different mechanisms on the gas production. The results showed that adsorption and gas viscosity change will have a great impact on gas production. Ignoring one of following scenarios, such as adsorption, gas permeability change, gas viscosity change, or pore radius change, will underestimate gas production.

DARHT-II Downstream Transport Beamline

International Nuclear Information System (INIS)

Westenskow, G A; Bertolini, L R; Duffy, P T; Paul, A C

2001-01-01

This paper describes the mechanical design of the downstream beam transport line for the second axis of the Dual Axis Radiographic Hydrodynamic Test (DARHT II) Facility. The DARHT-II project is a collaboration between LANL, LBNL and LLNL. DARHT II is a 18.4-MeV, 2000-Amperes, 2-(micro)sec linear induction accelerator designed to generate short bursts of x-rays for the purpose of radiographing dense objects. The downstream beam transport line is approximately 22-meter long region extending from the end of the accelerator to the bremsstrahlung target. Within this proposed transport line there are 12 conventional solenoid, quadrupole and dipole magnets; as well as several specialty magnets, which transport and focus the beam to the target and to the beam dumps. There are two high power beam dumps, which are designed to absorb 80-kJ per pulse during accelerator start-up and operation. Aspects of the mechanical design of these elements are presented

Calcium transport mechanism in molting crayfish revealed by microanalysis

International Nuclear Information System (INIS)

Mizuhira, V.; Ueno, M.

1983-01-01

Crayfish provide a good model in which to study the transport mechanism of Ca ions. During the molting stage, decalcified Ca ions are transferred into the blood and accumulate in the gastrolith epithelium, after which a gastrolith is formed on the surface of the epithelium. The gastrolith is dissolved in the stomach after molting, and the Ca is reabsorbed and redistributed throughout the newly formed exoskeleton. We studied the mechanism of Ca transport by cytochemical precipitation of Ca ions and by electron microanalysis, including X-ray microanalysis (EDX) and electron energy-loss spectroscopy (EELS), with a computer. In EDX analysis, the fine precipitates of K-antimonate in the gastrolith mitochondria clearly defined Ca with antimony; we also observed a large amount of Ca-oxalate in the mitochondria, and Ca-K X-ray pulses were clearly defined. Ca-K X-rays were also detected from fresh freeze-substituted mitochondria. Finally, we succeeded in taking a Ca-L EELS image from the mitochondria of fresh freeze-substituted thin sections. Only a very small amount of Ca was detected from the cell membrane and other organelles. Ca-adenosine triphosphatase (ATPase) and Mg-ATPase activity was also very clearly demonstrated in the mitochondria. These enzymes may play an important role in Ca metabolism

Transuranic package transporter (TRUPACT) system design status and operational support equipment

International Nuclear Information System (INIS)

Johanson, N.W.; Meyer, R.J.; Romesberg, L.E.; Pope, R.B.

1983-01-01

A program was initiated in the late 1970's at Sandia National Laboratories to develop an efficient, safe, reliable, and cost-effective transportation packaging system for the carriage of contact-handled transuranic (CH-TRU) waste within the Department of Energy (DOE) complex. It is anticipated that eventually a family of TRUPACT (TRansUranic PACKage Transporter) systems having varied dimensions and weight/volume capacities will be needed by the DOE to transport different CH-TRU waste forms. Each TRUPACT system will be a Type B packaging. Large quantities of CH-TRU wastes having many different forms, isotopic contents, and contained in a variety of waste containers have been, are being, and will continue to be produced and stored for ultimate disposal. Packaging design is being closely coordinated with facility designs to ensure the rapid and economic integration of the TRUPACT system. The first packaging developed for transport by truck or rail (bimodal) is designated TRUPACT-I and will become operational in 1984. This paper provides an overview of progress on the TRUPACT-I design and details of equipment to be used for interfacing with users

Modal Testing of Mechanical Structures subject to Operational Excitation Forces

DEFF Research Database (Denmark)

Møller, N.; Brincker, Rune; Herlufsen, H.

2001-01-01

Operational Modal Analysis also known as Output Only Modal Analysis has in the recent years been used for extracting modal parameters of civil engineering structures and is now becoming popular for mechanical structures. The advantage of the method is that no artificial excitation need to be appl......Operational Modal Analysis also known as Output Only Modal Analysis has in the recent years been used for extracting modal parameters of civil engineering structures and is now becoming popular for mechanical structures. The advantage of the method is that no artificial excitation need...

Information sharing guidebook for transportation management centers, emergency operations centers, and fusion centers

Science.gov (United States)

2010-06-01

This guidebook provides an overview of the mission and functions of transportation management centers, emergency operations centers, and fusion centers. The guidebook focuses on the types of information these centers produce and manage and how the sh...

Information sharing guidebook for transportation management centers, emergency operations centers, and fusion centers.

Science.gov (United States)

2010-06-01

This guidebook provides an overview of the mission and functions of transportation management centers, emergency operations centers, and fusion centers. The guidebook focuses on the types of information these centers produce and manage and how the sh...

Modeling of glycerol-3-phosphate transporter suggests a potential 'tilt' mechanism involved in its function.

Science.gov (United States)

Tsigelny, Igor F; Greenberg, Jerry; Kouznetsova, Valentina; Nigam, Sanjay K

2008-10-01

Many major facilitator superfamily (MFS) transporters have similar 12-transmembrane alpha-helical topologies with two six-helix halves connected by a long loop. In humans, these transporters participate in key physiological processes and are also, as in the case of members of the organic anion transporter (OAT) family, of pharmaceutical interest. Recently, crystal structures of two bacterial representatives of the MFS family--the glycerol-3-phosphate transporter (GlpT) and lac-permease (LacY)--have been solved and, because of assumptions regarding the high structural conservation of this family, there is hope that the results can be applied to mammalian transporters as well. Based on crystallography, it has been suggested that a major conformational "switching" mechanism accounts for ligand transport by MFS proteins. This conformational switch would then allow periodic changes in the overall transporter configuration, resulting in its cyclic opening to the periplasm or cytoplasm. Following this lead, we have modeled a possible "switch" mechanism in GlpT, using the concept of rotation of protein domains as in the DynDom program17 and membranephilic constraints predicted by the MAPAS program.(23) We found that the minima of energies of intersubunit interactions support two alternate positions consistent with their transport properties. Thus, for GlpT, a "tilt" of 9 degrees -10 degrees rotation had the most favorable energetics of electrostatic interaction between the two halves of the transporter; moreover, this confirmation was sufficient to suggest transport of the ligand across the membrane. We conducted steered molecular dynamics simulations of the GlpT-ligand system to explore how glycerol-3-phosphate would be handled by the "tilted" structure, and obtained results generally consistent with experimental mutagenesis data. While biochemical data remain most consistent with a single-site alternating access model, our results raise the possibility that, while the

Alternating access mechanisms of LeuT-fold transporters: trailblazing towards the promised energy landscapes.

Science.gov (United States)

Kazmier, Kelli; Claxton, Derek P; Mchaourab, Hassane S

2017-08-01

Secondary active transporters couple the uphill translocation of substrates to electrochemical ion gradients. Transporter conformational motion, generically referred to as alternating access, enables a central ligand binding site to change its orientation relative to the membrane. Here we review themes of alternating access and the transduction of ion gradient energy to power this process in the LeuT-fold class of transporters where crystallographic, computational and spectroscopic approaches have converged to yield detailed models of transport cycles. Specifically, we compare findings for the Na + -coupled amino acid transporter LeuT and the Na + -coupled hydantoin transporter Mhp1. Although these studies have illuminated multiple aspects of transporter structures and dynamics, a number of questions remain unresolved that so far hinder understanding transport mechanisms in an energy landscape perspective. Copyright © 2016 Elsevier Ltd. All rights reserved.

Mechanical Fatigue Testing of High Burnup Fuel for Transportation Applications

Energy Technology Data Exchange (ETDEWEB)

Wang, Jy-An John [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Wang, Hong [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

2015-05-01

This report describes testing designed to determine the ability of high burnup (HBU) (>45 GWd/MTU) spent fuel to maintain its integrity under normal conditions of transportation. An innovative system, Cyclic Integrated Reversible-bending Fatigue Tester (CIRFT), has been developed at Oak Ridge National Laboratory (ORNL) to test and evaluate the mechanical behavior of spent nuclear fuel (SNF) under conditions relevant to storage and transportation. The CIRFT system is composed of a U-frame equipped with load cells for imposing the pure bending loads on the SNF rod test specimen and measuring the in-situ curvature of the fuel rod during bending using a set up with three linear variable differential transformers (LVDTs).

Mechanical Fatigue Testing of High-Burnup Fuel for Transportation Applications

Energy Technology Data Exchange (ETDEWEB)

Wang, Jy-An John [ORNL; Wang, Hong [ORNL

2015-05-01

This report describes testing designed to determine the ability of high burnup (HBU) (>45 GWd/MTU) spent fuel to maintain its integrity under normal conditions of transportation. An innovative system, Cyclic Integrated Reversible-bending Fatigue Tester (CIRFT), has been developed at Oak Ridge National Laboratory (ORNL) to test and evaluate the mechanical behavior of spent nuclear fuel (SNF) under conditions relevant to storage and transportation. The CIRFT system is composed of a U-frame equipped with load cells for imposing the pure bending loads on the SNF rod test specimen and measuring the in-situ curvature of the fuel rod during bending using a set up with three linear variable differential transformers (LVDTs).

PC-aided scheduling of transportation truck in utility operations; PC-unterstuetzte Einsatzplanung der Transport-Lkw im EVU-Betrieb

Energy Technology Data Exchange (ETDEWEB)

Dreele, H. von; Hartwich, D.; Rolke, D. [RWE Energie AG, Regionalversorgung Nike, Osnabrueck (Germany); Leidig, R. [PLS Unternehmensberatung GmbH, Duesseldorf (Germany)

1998-02-23

The DP software system Plantour is used to optimize truck operations meeting the transportation needs of a regional supply utility taking into account the specific operational requirements. The chance to centralized scheduling was based on logistic principles. New practice-oriented software had to be developed using standards. (orig.) [Deutsch] Mit Hilfe des DV-Software-Systems Plantour werden die Einsaetze der Lkw fuer das Transportwesen einer Regionalversorgung unter Beruecksichtigung der spezifischen betrieblichen Belange optimiert. Dabei wurde die Umstellung auf eine zentrale Einsatzplanung unter Beruecksichtigung logistischer Prinzipien vorgenommen. Die erforderliche Software musste neu unter Verwendung von Standards praxisnah entwickelt werden. (orig.)

Exploring Concepts of Operations for On-Demand Passenger Air Transportation

Science.gov (United States)

Nneji, Victoria Chibuogu; Stimpson, Alexander; Cummings, Mary; Goodrich, Kenneth H.

2017-01-01

In recent years, a surge of interest in "flying cars" for city commutes has led to rapid development of new technologies to help make them and similar on-demand mobility platforms a reality. To this end, this paper provides analyses of the stakeholders involved, their proposed operational concepts, and the hazards and regulations that must be addressed. Three system architectures emerged from the analyses, ranging from conventional air taxi to revolutionary fully autonomous aircraft operations, each with vehicle safety functions allocated differently between humans and machines. Advancements for enabling technologies such as distributed electric propulsion and artificial intelligence have had major investments and initial experimental success, but may be some years away from being deployed for on-demand passenger air transportation at scale.

A Hybrid Dynamic Programming for Solving Fixed Cost Transportation with Discounted Mechanism

Directory of Open Access Journals (Sweden)

Farhad Ghassemi Tari

2016-01-01

Full Text Available The problem of allocating different types of vehicles for transporting a set of products from a manufacturer to its depots/cross docks, in an existing transportation network, to minimize the total transportation costs, is considered. The distribution network involves a heterogeneous fleet of vehicles, with a variable transportation cost and a fixed cost in which a discount mechanism is applied on the fixed part of the transportation costs. It is assumed that the number of available vehicles is limited for some types. A mathematical programming model in the form of the discrete nonlinear optimization model is proposed. A hybrid dynamic programming algorithm is developed for finding the optimal solution. To increase the computational efficiency of the solution algorithm, several concepts and routines, such as the imbedded state routine, surrogate constraint concept, and bounding schemes, are incorporated in the dynamic programming algorithm. A real world case problem is selected and solved by the proposed solution algorithm, and the optimal solution is obtained.

Flux-based transport enhancement as a plausible unifying mechanism for auxin transport in meristem development.

Directory of Open Access Journals (Sweden)

Szymon Stoma

2008-10-01

Full Text Available Plants continuously generate new organs through the activity of populations of stem cells called meristems. The shoot apical meristem initiates leaves, flowers, and lateral meristems in highly ordered, spiralled, or whorled patterns via a process called phyllotaxis. It is commonly accepted that the active transport of the plant hormone auxin plays a major role in this process. Current hypotheses propose that cellular hormone transporters of the PIN family would create local auxin maxima at precise positions, which in turn would lead to organ initiation. To explain how auxin transporters could create hormone fluxes to distinct regions within the plant, different concepts have been proposed. A major hypothesis, canalization, proposes that the auxin transporters act by amplifying and stabilizing existing fluxes, which could be initiated, for example, by local diffusion. This convincingly explains the organised auxin fluxes during vein formation, but for the shoot apical meristem a second hypothesis was proposed, where the hormone would be systematically transported towards the areas with the highest concentrations. This implies the coexistence of two radically different mechanisms for PIN allocation in the membrane, one based on flux sensing and the other on local concentration sensing. Because these patterning processes require the interaction of hundreds of cells, it is impossible to estimate on a purely intuitive basis if a particular scenario is plausible or not. Therefore, computational modelling provides a powerful means to test this type of complex hypothesis. Here, using a dedicated computer simulation tool, we show that a flux-based polarization hypothesis is able to explain auxin transport at the shoot meristem as well, thus providing a unifying concept for the control of auxin distribution in the plant. Further experiments are now required to distinguish between flux-based polarization and other hypotheses.

Fracture mechanics based design for radioactive material transport packagings -- Historical review

International Nuclear Information System (INIS)

Smith, J.A.; Salzbrenner, D.; Sorenson, K.; McConnell, P.

1998-04-01

The use of a fracture mechanics based design for the radioactive material transport (RAM) packagings has been the subject of extensive research for more than a decade. Sandia National Laboratories (SNL) has played an important role in the research and development of the application of this technology. Ductile iron has been internationally accepted as an exemplary material for the demonstration of a fracture mechanics based method of RAM packaging design and therefore is the subject of a large portion of the research discussed in this report. SNL's extensive research and development program, funded primarily by the U. S. Department of Energy's Office of Transportation, Energy Management and Analytical Services (EM-76) and in an auxiliary capacity, the office of Civilian Radioactive Waste Management, is summarized in this document along with a summary of the research conducted at other institutions throughout the world. In addition to the research and development work, code and standards development and regulatory positions are also discussed

Investigating the effects of ABC transporter-based acquired drug resistance mechanisms at the cellular and tissue scale.

Science.gov (United States)

Liu, Cong; Krishnan, J; Xu, Xiao Yun

2013-03-01

In this paper we systematically investigate the effects of acquired drug resistance at the cellular and tissue scale, with a specific focus on ATP-binding cassette (ABC) transporter-based mechanisms and contrast this with other representative intracellular resistance mechanisms. This is done by developing in silico models wherein the drug resistance mechanism is overlaid on a coarse-grained description of apoptosis; these cellular models are coupled with interstitial drug transport, allowing for a transparent examination of the effect of acquired drug resistances at the tissue level. While ABC transporter-mediated resistance mechanisms counteract drug effect at the cellular level, its tissue-level effect is more complicated, revealing unexpected trends in tissue response as drug stimuli are systematically varied. Qualitatively different behaviour is observed in other drug resistance mechanisms. Overall the paper (i) provides insight into the tissue level functioning of a particular resistance mechanism, (ii) shows that this is very different from other resistance mechanisms of an apparently similar type, and (iii) demonstrates a concrete instance of how the functioning of a negative feedback based cellular adaptive mechanism can have unexpected higher scale effects.

Operational range and transport barrier of the H-mode in the stellarator W7-AS

International Nuclear Information System (INIS)

Hirsch, M.; Amadeo, P.; Anton, M.; Baldzuhn, J.; Brakel, R.; Bleuel, J.; Fiedler, S.; Geist, T.; Grigull, P.; Hartfuss, H.J.; Jaenicke, R.; Kick, M.; Kisslinger, J.; Koponen, J.; Wagner, F.; Weller, A.; Wobig, H.; Zoletnik, S.; Holzhauer, E.

1998-01-01

In W7-AS the H-mode is characterized by an edge transport barrier localized in the first 3-4 cm inside the separatrix. In the ELMy H-mode preceding the quiescent state ELMs appear as a sudden breakdown of the edge transport barrier in coincidence with bursts of fluctuations. Between ELMs fluctuations are identical to those of the quiescent H-mode. The operational range of the quiescent H-mode is determined by narrow windows of the edge rotational transform and a threshold edge electron density. In contrast, ELM-like events are observed for a variety of plasma conditions by far exceeding the narrow operational windows for the quiescent state. (author)

The 'generalized Balescu-Lenard' transport equations

International Nuclear Information System (INIS)

Mynick, H.E.

1990-01-01

The transport equations arising from the 'generalized Balescu-Lenard' collision operator are obtained and some of their properties examined. The equations contain neoclassical and turbulent transport as two special cases having the same structure. The resultant theory offers a possible explanation for a number of results not well understood, including the anomalous pinch, observed ratios of Q/ΓT on TFTR, and numerical reproduction of ASDEX profiles by a model for turbulent transport invoked without derivation, but by analogy with neoclassical theory. The general equations are specialized to consideration of a number of particular transport mechanisms of interest. (author). Letter-to-the-editor. 10 refs

Urban poverty and informal motorcycle transport services in a Nigerian intermediate settlement: a synthesis of operative motives and satisfaction

Directory of Open Access Journals (Sweden)

Abubakar Zakariyya Al-Hasan

2015-01-01

Full Text Available The paper aims at examining operations motives and satisfaction in motorcycle taxi operators in Auchi. Primary data were sourced using structured questionnaires. Of the 148 questionnaires administered, 135 were found analysable. SPSS software version 17.0 was used for data analysis. The frequency distribution result of the demographic information of the respondents revealed that males, aged 21–30 year (58%, are predominantly involved in the operation. The education level of the majority of operators was in the secondary cohort (62.2%. Among operators, 56% operate motorcycle taxis for self-employment, whilst 34.1% was for augmenting income. A test of hypothesis result suggested that operator satisfaction based on the motive behind operation is statistically significant at 1%. The findings also strengthen previous studies. In terms of sustainability, informal motorcycle taxis are considered by the study to be unrealistic given the efficient transport system and enabling economic situation. Moreover, their operation impacts negatively on the environment, health, social and human capital development. Government and transport policy-makers should pursue efficient integrated modal transport system. Poverty alleviation machinery by government should explore viable initiatives that will engage the urban poor, especially youths, to divest their massive involvements in motorcycle taxi operation in Nigeria.

Advanced Transport Operating System (ATOPS) color displays software description microprocessor system

Science.gov (United States)

Slominski, Christopher J.; Plyler, Valerie E.; Dickson, Richard W.

1992-01-01

This document describes the software created for the Sperry Microprocessor Color Display System used for the Advanced Transport Operating Systems (ATOPS) project on the Transport Systems Research Vehicle (TSRV). The software delivery known as the 'baseline display system', is the one described in this document. Throughout this publication, module descriptions are presented in a standardized format which contains module purpose, calling sequence, detailed description, and global references. The global reference section includes procedures and common variables referenced by a particular module. The system described supports the Research Flight Deck (RFD) of the TSRV. The RFD contains eight cathode ray tubes (CRTs) which depict a Primary Flight Display, Navigation Display, System Warning Display, Takeoff Performance Monitoring System Display, and Engine Display.

Program of assessment of mechanical and corrosion mechanical properties of reactor internals materials due to operation conditions in WWERs

International Nuclear Information System (INIS)

Ruscak, M.; Zamboch, M.

1998-01-01

Reactor internals are subject to three principle operation influences: neutron and gamma irradiation, mechanical stresses, both static and dynamic, and coolant chemistry. Several cases of damage have been reported in previous years in both boiling and pressure water reactors. They are linked with the term of irradiation assisted stress corrosion cracking as a possible damage mechanism. In WWERs, the principal material used for reactor internals is austenitic titanium stabilized stainless steel 08Kh18N10T, however high strength steels are used as well. To assess the changes of mechanical properties and to determine whether sensitivity to intergranular cracking can be increased by high neutron fluences, the experimental program has been started. The goal is to assure safe operation of the internals as well as life management for all planned operation period. The program consists of tests of material properties, both mechanical and corrosion-mechanical. Detailed neutron fluxes calculation as well as stress and deformation calculations are part of the assessment. Model of change will be proposed in order to plan inspections of the facility. In situ measurements of internals will be used to monitor exact status of structure during operation. Tensile specimens manufactured from both base metal and model weld joint have been irradiated to the total fluences of 3-20 dpa. Changes of mechanical properties are tested by the tensile test, stress corrosion cracking tests are performed in the autoclave with water loop and active loading. Operation temperature, pressure and water chemistry are chosen for the tests. (author)

Modification and Performance Evaluation of a Low Cost Electro-Mechanically Operated Creep Testing Machine

OpenAIRE

John J. MOMOH; Lanre Y. SHUAIB-BABATA; Gabriel O. ADELEGAN

2010-01-01

Existing mechanically operated tensile and creep testing machine was modified to a low cost, electro-mechanically operated creep testing machine capable of determining the creep properties of aluminum, lead and thermoplastic materials as a function of applied stress, time and temperature. The modification of the testing machine was necessitated by having an electro-mechanically operated creep testing machine as a demonstration model ideal for use and laboratory demonstrations, which will prov...

Extending helicopter operations to meet future integrated transportation needs.

Science.gov (United States)

Stanton, Neville A; Plant, Katherine L; Roberts, Aaron P; Harvey, Catherine; Thomas, T Glyn

2016-03-01

Helicopters have the potential to be an integral part of the future transport system. They offer a means of rapid transit in an overly populated transport environment. However, one of the biggest limitations on rotary wing flight is their inability to fly in degraded visual conditions in the critical phases of approach and landing. This paper presents a study that developed and evaluated a Head up Display (HUD) to assist rotary wing pilots by extending landing to degraded visual conditions. The HUD was developed with the assistance of the Cognitive Work Analysis method as an approach for analysing the cognitive work of landing the helicopter. The HUD was tested in a fixed based flight simulator with qualified helicopter pilots. A qualitative analysis to assess situation awareness and workload found that the HUD enabled safe landing in degraded conditions whilst simultaneously enhancing situation awareness and reducing workload. Continued development in this area has the potential to extend the operational capability of helicopters in the future. Copyright © 2015 Elsevier Ltd and The Ergonomics Society. All rights reserved.

The development of an operations system for the transport of spent nuclear fuel in the United States Civilian Radioactive Waste Management Program

International Nuclear Information System (INIS)

Best, R.E.; Danese, F.L.; Peterson, R.W.; Joy, D.S.; Pope, R.B.; Ratledge, J.E.; Shappert, L.B.; Wankerl, M.W.; Klimas, M.J.; Darrough, M.E.

1990-01-01

In order to support the development of a Transportation Operations System for the Federal Waste Management System (FWMS) by the Office of Civilian Radioactive Waste Management, the United States Department of Energy formed the Transportation Project Office at its field office in Chicago. Planning and development activities are being performed in a number of areas including a major effort in operations support, providing the planning and assessment necessary for developing the future transportation operations capability needed by the FWMS. The purpose of this paper is to review significant planning and development accomplishments, and outline expected future efforts for the continued development, acquisition, test, and startup of the transportation operations component of the FWMS. 2 refs

Fundamental transport mechanisms, fabrication and potential applications of nanoporous atomically thin membranes.

Science.gov (United States)

Wang, Luda; Boutilier, Michael S H; Kidambi, Piran R; Jang, Doojoon; Hadjiconstantinou, Nicolas G; Karnik, Rohit

2017-06-06

Graphene and other two-dimensional materials offer a new approach to controlling mass transport at the nanoscale. These materials can sustain nanoscale pores in their rigid lattices and due to their minimum possible material thickness, high mechanical strength and chemical robustness, they could be used to address persistent challenges in membrane separations. Here we discuss theoretical and experimental developments in the emerging field of nanoporous atomically thin membranes, focusing on the fundamental mechanisms of gas- and liquid-phase transport, membrane fabrication techniques and advances towards practical application. We highlight potential functional characteristics of the membranes and discuss applications where they are expected to offer advantages. Finally, we outline the major scientific questions and technological challenges that need to be addressed to bridge the gap from theoretical simulations and proof-of-concept experiments to real-world applications.

Fundamental transport mechanisms, fabrication and potential applications of nanoporous atomically thin membranes

Science.gov (United States)

Wang, Luda; Boutilier, Michael S. H.; Kidambi, Piran R.; Jang, Doojoon; Hadjiconstantinou, Nicolas G.; Karnik, Rohit

2017-06-01

Graphene and other two-dimensional materials offer a new approach to controlling mass transport at the nanoscale. These materials can sustain nanoscale pores in their rigid lattices and due to their minimum possible material thickness, high mechanical strength and chemical robustness, they could be used to address persistent challenges in membrane separations. Here we discuss theoretical and experimental developments in the emerging field of nanoporous atomically thin membranes, focusing on the fundamental mechanisms of gas- and liquid-phase transport, membrane fabrication techniques and advances towards practical application. We highlight potential functional characteristics of the membranes and discuss applications where they are expected to offer advantages. Finally, we outline the major scientific questions and technological challenges that need to be addressed to bridge the gap from theoretical simulations and proof-of-concept experiments to real-world applications.

Electric generation and ratcheted transport of contact-charged drops

Science.gov (United States)

Cartier, Charles A.; Graybill, Jason R.; Bishop, Kyle J. M.

2017-10-01

We describe a simple microfluidic system that enables the steady generation and efficient transport of aqueous drops using only a constant voltage input. Drop generation is achieved through an electrohydrodynamic dripping mechanism by which conductive drops grow and detach from a grounded nozzle in response to an electric field. The now-charged drops are transported down a ratcheted channel by contact charge electrophoresis powered by the same voltage input used for drop generation. We investigate how the drop size, generation frequency, and transport velocity depend on system parameters such as the liquid viscosity, interfacial tension, applied voltage, and channel dimensions. The observed trends are well explained by a series of scaling analyses that provide insight into the dominant physical mechanisms underlying drop generation and ratcheted transport. We identify the conditions necessary for achieving reliable operation and discuss the various modes of failure that can arise when these conditions are violated. Our results demonstrate that simple electric inputs can power increasingly complex droplet operations with potential opportunities for inexpensive and portable microfluidic systems.

Administrative mechanics of research fuel transportation

International Nuclear Information System (INIS)

Harmon, Diane W.

1983-01-01

This presentation contains the discussion on the multitude of administrative mechanics that have to be meshed for the successful completion of a shipment of spent fuel, HEU or LEU in the research reactors fuel cycle. The costs associated with transportation may be the equivalent of 'a black hole', so an overview of cost factors is given. At the end one could find that this black hole factor in the budget is actually a bargain. The first step is the quotation phase. The cost variables in the quotation contain the cost of packaging i.e. containers; the complete routing of the packages and the materials. Factors that are of outmost importance are the routing restrictions and regulations, physical security regulations. All of this effort is just to provide a valid quotation not to accomplish the goal of completing a shipment. Public relations cannot be omitted either

Administrative mechanics of research fuel transportation

Energy Technology Data Exchange (ETDEWEB)

Harmon, Diane W [Edlow International Company, Washington, DC (United States)

1983-09-01

This presentation contains the discussion on the multitude of administrative mechanics that have to be meshed for the successful completion of a shipment of spent fuel, HEU or LEU in the research reactors fuel cycle. The costs associated with transportation may be the equivalent of 'a black hole', so an overview of cost factors is given. At the end one could find that this black hole factor in the budget is actually a bargain. The first step is the quotation phase. The cost variables in the quotation contain the cost of packaging i.e. containers; the complete routing of the packages and the materials. Factors that are of outmost importance are the routing restrictions and regulations, physical security regulations. All of this effort is just to provide a valid quotation not to accomplish the goal of completing a shipment. Public relations cannot be omitted either.

Transport mechanisms of soil-bound mercury in the erosion process during rainfall-runoff events.

Science.gov (United States)

Zheng, Yi; Luo, Xiaolin; Zhang, Wei; Wu, Xin; Zhang, Juan; Han, Feng

2016-08-01

Soil contamination by mercury (Hg) is a global environmental issue. In watersheds with a significant soil Hg storage, soil erosion during rainfall-runoff events can result in nonpoint source (NPS) Hg pollution and therefore, can extend its environmental risk from soils to aquatic ecosystems. Nonetheless, transport mechanisms of soil-bound Hg in the erosion process have not been explored directly, and how different fractions of soil organic matter (SOM) impact transport is not fully understood. This study investigated transport mechanisms based on rainfall-runoff simulation experiments. The experiments simulated high-intensity and long-duration rainfall conditions, which can produce significant soil erosion and NPS pollution. The enrichment ratio (ER) of total mercury (THg) was the key variable in exploring the mechanisms. The main study findings include the following: First, the ER-sediment flux relationship for Hg depends on soil composition, and no uniform ER-sediment flux function exists for different soils. Second, depending on soil composition, significantly more Hg could be released from a less polluted soil in the early stage of large rainfall events. Third, the heavy fraction of SOM (i.e., the remnant organic matter coating on mineral particles) has a dominant influence on the enrichment behavior and transport mechanisms of Hg, while clay mineral content exhibits a significant, but indirect, influence. The study results imply that it is critical to quantify the SOM composition in addition to total organic carbon (TOC) for different soils in the watershed to adequately model the NPS pollution of Hg and spatially prioritize management actions in a heterogeneous watershed. Copyright © 2016 Elsevier Ltd. All rights reserved.

Comparative economic efficiency, operating costs and fuel consumption rates of freight transport modes between the largest industrial cities and seaports in South Africa

Directory of Open Access Journals (Sweden)

W J (Wessel Pienaar

2013-09-01

Full Text Available The paper deals with aspects of efficiency within the five modes of freight transport, with special reference to the operating cost and fuel consumption rates between South Africa’s largest industrial cities and seaports. In particular, the paper deals with (a the opportunities that exist for the achievement of efficiency in freight transport; (b the subgroups of economies that can enhance efficiency attainment in the freight transport industry; (c prevailing cost structures, operating cost and fuel consumption rates within the five modes of freight transport; and (d the salient economic features of the freight transport market. The research approach and methodology combine (a a literature survey; (b empiric research, (c an analysis of the cost structures of freight transport operators from different modes of transport; and (d interviews conducted with specialists in the freight transport industry.

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

KAUST Repository

Sethuraman, Vaidyanathan; Mogurampelly, Santosh; Ganesan, Venkat

2017-01-01

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

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

KAUST Repository

Sethuraman, Vaidyanathan

2017-10-23

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

The generalized Balescu-Lenard collision operator: A unifying concept for tokamak transport

International Nuclear Information System (INIS)

Mynick, H.E.

1987-08-01

The generalization of the Balescu-Lenard collision operator to its fully electromagnetic counterpart in Kaufman's action-angle formalism is derived and its properties investigated. The general form may be specialized to any particular geometry where the unperturbed particle motion is integrable, and thus includes cylindrical plasmas, inhomogeneous slabs with nonuniform magnetic fields, tokamaks, and the particularly simple geometry of the standard operator as special cases. The general form points to the commonality between axisymmetric, turbulent, and ripple transport, and implies properties (e.g., intrinsic ambipolarity) which should be shared by them, under appropriate conditions. Along with a turbulent ''anomalous diffusion coefficient'' calculated for tokamaks in previous work, an ''anomalous pinch'' term of closely related structure and scaling is also implied by the generalized operator. 20 refs

Modeling of Glycerol-3-Phosphate Transporter Suggests a Potential ‘Tilt’ Mechanism involved in its Function

Science.gov (United States)

Tsigelny, Igor F.; Greenberg, Jerry; Kouznetsova, Valentina; Nigam, Sanjay K.

2009-01-01

Many major facilitator superfamily (MFS) transporters have similar 12-transmembrane α-helical topologies with two six-helix halves connected by a long loop. In humans, these transporters participate in key physiological processes and are also, as in the case of members of the organic anion transporter (OAT) family, of pharmaceutical interest. Recently, crystal structures of two bacterial representatives of the MFS family — the glycerol-3-phosphate transporter (GlpT) and lac-permease (LacY) — have been solved and, because of assumptions regarding the high structural conservation of this family, there is hope that the results can be applied to mammalian transporters as well. Based on crystallography, it has been suggested that a major conformational “switching” mechanism accounts for ligand transport by MFS proteins. This conformational switch would then allow periodic changes in the overall transporter configuration, resulting in its cyclic opening to the periplasm or cytoplasm. Following this lead, we have modeled a possible “switch” mechanism in GlpT, using the concept of rotation of protein domains as in the DynDom program17 and membranephilic constraints predicted by the MAPAS program.23 We found that the minima of energies of intersubunit interactions support two alternate positions consistent with their transport properties. Thus, for GlpT, a “tilt” of 9°–10° rotation had the most favorable energetics of electrostatic interaction between the two halves of the transporter; moreover, this confirmation was sufficient to suggest transport of the ligand across the membrane. We conducted steered molecular dynamics simulations of the GlpT-ligand system to explore how glycerol-3-phosphate would be handled by the “tilted” structure, and obtained results generally consistent with experimental mutagenesis data. While biochemical data remain most consistent with a single-site alternating access model, our results raise the possibility that, while

Grasping and Placing Operation for Labware Transportation in Life Science Laboratories using Mobile Robots

Directory of Open Access Journals (Sweden)

Mohammed Myasar Ali

2017-07-01

Full Text Available In automated working environments, mobile robots can be used for different purposes such as material handling, domestic services, and objects transportation. This work presents a grasping and placing operation for multiple labware and tube racks in life science laboratories using the H20 mobile robots. The H20 robot has dual arms where each arm consists of 6 revolute joints with 6-DOF and 2-DOF grippers. The labware, which have to be manipulated and transported, contain chemical and biological components. Therefore, an accurate approach for object recognition and position estimation is required. The recognition and pose estimation of the desired objects are very essential to guide the robotic arm in the manipulation tasks. In this work, the problem statement of H20 transportation system with the proposed methodology are presented. Different strategies (visual and non-visual of labware manipulation using mobile robots are described. The H20 robot is equipped with a Kinect V2 sensor to identify and estimate the position of the target. The local features recognition based on SURF algorithm (Speeded-Up Robust Features is used. The recognition process is performed for the required labware and holder to perform the grasping and placing operation. A strategy is proposed to find the required holder and to check its emptiness for the placing tasks. Different styles of grippers and labware containers are used to manipulate different weights of labware and to realize a safe transportation. The parts of mobile robot transportation system are communicated with each other using Asynchronous socket Channels.

Turbulent particle transport in streams: can exponential settling be reconciled with fluid mechanics?

Science.gov (United States)

McNair, James N; Newbold, J Denis

2012-05-07

Most ecological studies of particle transport in streams that focus on fine particulate organic matter or benthic invertebrates use the Exponential Settling Model (ESM) to characterize the longitudinal pattern of particle settling on the bed. The ESM predicts that if particles are released into a stream, the proportion that have not yet settled will decline exponentially with transport time or distance and will be independent of the release elevation above the bed. To date, no credible basis in fluid mechanics has been established for this model, nor has it been rigorously tested against more-mechanistic alternative models. One alternative is the Local Exchange Model (LEM), which is a stochastic advection-diffusion model that includes both longitudinal and vertical spatial dimensions and is based on classical fluid mechanics. The LEM predicts that particle settling will be non-exponential in the near field but will become exponential in the far field, providing a new theoretical justification for far-field exponential settling that is based on plausible fluid mechanics. We review properties of the ESM and LEM and compare these with available empirical evidence. Most evidence supports the prediction of both models that settling will be exponential in the far field but contradicts the ESM's prediction that a single exponential distribution will hold for all transport times and distances. Copyright © 2012 Elsevier Ltd. All rights reserved.

Flexural resonance mechanism of thermal transport across graphene-SiO2 interfaces

Science.gov (United States)

Ong, Zhun-Yong; Qiu, Bo; Xu, Shanglong; Ruan, Xiulin; Pop, Eric

2018-03-01

Understanding the microscopic mechanism of heat dissipation at the dimensionally mismatched interface between a two-dimensional (2D) crystal and its substrate is crucial for the thermal management of devices based on 2D materials. Here, we study the lattice contribution to thermal (Kapitza) transport at graphene-SiO2 interfaces using molecular dynamics (MD) simulations and non-equilibrium Green's functions (NEGF). We find that 78 percent of the Kapitza conductance is due to sub-20 THz flexural acoustic modes, and that a resonance mechanism dominates the interfacial phonon transport. MD and NEGF estimate the classical Kapitza conductance to be hK ≈ 10 to 16 MW K-1 m-2 at 300 K, respectively, consistent with existing experimental observations. Taking into account quantum mechanical corrections, this value is approximately 28% lower at 300 K. Our calculations also suggest that hK scales as T2 at low temperatures (T < 100 K) due to the linear frequency dependence of phonon transmission across the graphene-SiO2 interface at low frequencies. Our study sheds light on the role of flexural acoustic phonons in heat dissipation from graphene to its substrate.

The mechanism of transport of pollution from industrial accidents

International Nuclear Information System (INIS)

Bagelova, A.; Takacova, A.

2015-01-01

During industrial accidents pollution may penetrate through the unsaturated zone to groundwater. Penetration depends on the characteristics of the contaminant, leaked pollution amount as well as rock composition. If the pollution reaches the groundwater level it is drifted by flowing water. The flowing water can carry it to greater distances, where may be water sources. During accidents it is necessary to take positions quickly and propose appropriate protective measures. It is necessary to know the management processes of pollution transport. Without knowledge of these processes the measures may not be effective. Aim of this paper is to review the mechanism of transport of pollution and the main processes influencing the change in pollutant concentrations. On concrete and fictitious examples there will be shown properties that influence the spread of contamination especially in his direction because its determination is crucial to the draft measures. Researching of other processes in natural conditions depends on its correct specification.

Operators and representation theory canonical models for algebras of operators arising in quantum mechanics

CERN Document Server

Jorgensen, Palle E T

1987-01-01

Historically, operator theory and representation theory both originated with the advent of quantum mechanics. The interplay between the subjects has been and still is active in a variety of areas.This volume focuses on representations of the universal enveloping algebra, covariant representations in general, and infinite-dimensional Lie algebras in particular. It also provides new applications of recent results on integrability of finite-dimensional Lie algebras. As a central theme, it is shown that a number of recent developments in operator algebras may be handled in a particularly e

Transport mechanism of lipid covered saquinavir pure drug nanoparticles in intestinal epithelium

DEFF Research Database (Denmark)

Xia, Dengning; He, Yuan; Li, Qiuxia

2018-01-01

are transported. To improve cellular uptake and transport of pure nanodrug in cells, here, a lipid covered saquinavir (SQV) pure drug NP (Lipo@nanodrug) was designed by modifying a pure SQV NP (nanodrug) with a phospholipid bilayer. We studied their endocytosis, intracellular trafficking mechanism using Caco-2...... their intracellular processing, helping to improve drug transport across intestinal epithelium. To our knowledge, this is the first presentation of the novel phospholipid bilayer covered SQV pure drug NP design, and a mechanistic study on intracellular trafficking in in vitro cell models has been described......Pure drug nanoparticles (NPs) represent a promising formulation for improved drug solubility and controlled dissolution velocity. However, limited absorption by the intestinal epithelium remains challenge to their clinical application, and little is known about how these NPs within the cells...

A fully resolved active musculo-mechanical model for esophageal transport

Science.gov (United States)

Kou, Wenjun; Bhalla, Amneet Pal Singh; Griffith, Boyce E.; Pandolfino, John E.; Kahrilas, Peter J.; Patankar, Neelesh A.

2015-10-01

Esophageal transport is a physiological process that mechanically transports an ingested food bolus from the pharynx to the stomach via the esophagus, a multi-layered muscular tube. This process involves interactions between the bolus, the esophagus, and the neurally coordinated activation of the esophageal muscles. In this work, we use an immersed boundary (IB) approach to simulate peristaltic transport in the esophagus. The bolus is treated as a viscous fluid that is actively transported by the muscular esophagus, and the esophagus is modeled as an actively contracting, fiber-reinforced tube. Before considering the full model of the esophagus, however, we first consider a standard benchmark problem of flow past a cylinder. Next a simplified version of our model is verified by comparison to an analytic solution to the tube dilation problem. Finally, three different complex models of the multi-layered esophagus, which differ in their activation patterns and the layouts of the mucosal layers, are extensively tested. To our knowledge, these simulations are the first of their kind to incorporate the bolus, the multi-layered esophagus tube, and muscle activation into an integrated model. Consistent with experimental observations, our simulations capture the pressure peak generated by the muscle activation pulse that travels along the bolus tail. These fully resolved simulations provide new insights into roles of the mucosal layers during bolus transport. In addition, the information on pressure and the kinematics of the esophageal wall resulting from the coordination of muscle activation is provided, which may help relate clinical data from manometry and ultrasound images to the underlying esophageal motor function.

Fractional power operation of tokamak reactors

International Nuclear Information System (INIS)

Mau, T.K.; Vold, E.L.; Conn, R.W.

1986-01-01

Methods to operate a tokamak fusion reactor at fractions of its rated power, identify the more effective control knobs and assess the impact of the requirements of fractional power operation on full power reactor design are explored. In particular, the role of burn control in maintaining the plasma at thermal equilibrium throughout these operations is studied. As a prerequisite to this task, the critical physics issues relevant to reactor performance predictions are examined and some insight into their impact on fractional power operation is offered. The basic tool of analysis consists of a zero-dimensional (0-D) time-dependent plasma power balance code which incorporates the most advanced data base and models in transport and burn plasma physics relevant to tokamaks. Because the plasma power balance is dominated by the transport loss and given the large uncertainty in the confinement model, the authors have studied the problem for a wide range of energy confinement scalings. The results of this analysis form the basis for studying the temporal behavior of the plasma under various thermal control mechanisms. Scenarios of thermally stable full and fractional power operations have been determined for a variety of transport models, with either passive or active feedback burn control. Important power control parameters, such as gas fueling rate, auxiliary power and other plasma quantities that affect transport losses, have also been identified. The results of these studies vary with the individual transport scaling used and, in particular, with respect to the effect of alpha heating power on confinement

Molecular mechanism of ligand recognition by membrane transport protein, Mhp1

Science.gov (United States)

Simmons, Katie J; Jackson, Scott M; Brueckner, Florian; Patching, Simon G; Beckstein, Oliver; Ivanova, Ekaterina; Geng, Tian; Weyand, Simone; Drew, David; Lanigan, Joseph; Sharples, David J; Sansom, Mark SP; Iwata, So; Fishwick, Colin WG; Johnson, A Peter; Cameron, Alexander D; Henderson, Peter JF

2014-01-01

The hydantoin transporter Mhp1 is a sodium-coupled secondary active transport protein of the nucleobase-cation-symport family and a member of the widespread 5-helix inverted repeat superfamily of transporters. The structure of Mhp1 was previously solved in three different conformations providing insight into the molecular basis of the alternating access mechanism. Here, we elucidate detailed events of substrate binding, through a combination of crystallography, molecular dynamics, site-directed mutagenesis, biochemical/biophysical assays, and the design and synthesis of novel ligands. We show precisely where 5-substituted hydantoin substrates bind in an extended configuration at the interface of the bundle and hash domains. They are recognised through hydrogen bonds to the hydantoin moiety and the complementarity of the 5-substituent for a hydrophobic pocket in the protein. Furthermore, we describe a novel structure of an intermediate state of the protein with the external thin gate locked open by an inhibitor, 5-(2-naphthylmethyl)-L-hydantoin, which becomes a substrate when leucine 363 is changed to an alanine. We deduce the molecular events that underlie acquisition and transport of a ligand by Mhp1. PMID:24952894

Modeling and Mechanisms of Intercontinental Transport of Biomass-Burning Plumes

Science.gov (United States)

Reid, J. S.; Westphal, D. L.; Christopher, S. A.; Prins, E. M.; Justice, C. O.; Richardson, K. A.; Reid, E. A.; Eck, T. F.

2003-12-01

With the aid of fire products from GOES and MODIS, the NRL Aerosol Analysis and Prediction System (NAAPS) successfully monitors and predicts the formation and transport of massive smoke plumes between the continents in near real time. The goal of this system, formed under the joint Navy, NASA, and NOAA sponsored Fire Locating and Modeling of Burning Emissions (FLAMBE) project, is to provide 5 day forecasts of large biomass burning plumes and evaluate impacts on air quality, visibility, and regional radiative balance. In this paper we discuss and compare the mechanisms of intercontinental transport from the three most important sources in the world prone to long range advection: Africa, South/Central America, and Siberia. We demonstrate how these regions impact neighboring continents. As the meteorology of these three regions are distinct, differences in transport phenomenon subsequently result, particularly with respect to vertical distribution. Specific examples will be given on prediction and the impact of Siberian and Central American smoke plumes on the United States as well as transport phenomena from Africa to Australia. We present rules of thumb for radiation and air quality impacts. We also model clear sky bias (both positive and negative) with respect to MODIS data, and show the frequency to which frontal advection of smoke plumes masks remote sensing retrievals of smoke optical depth.

Cellular interactions of a lipid-based nanocarrier model with human keratinocytes: Unravelling transport mechanisms.

Science.gov (United States)

Silva, Elisabete; Barreiros, Luísa; Segundo, Marcela A; Costa Lima, Sofia A; Reis, Salette

2017-04-15

Knowledge of delivery system transport through epidermal cell monolayer is vital to improve skin permeation and bioavailability. Recently, nanostructured lipid carriers (NLCs) have gained great attention for transdermal delivery due to their biocompatibility, high drug payload, occlusive properties and skin hydration effect. However, the nanocarriers transport related mechanisms in epidermal epithelial cells are not yet understood. In this research, the internalization and transport pathways of the NLCs across the epidermal epithelial cell monolayer (HaCaT cells) were investigated. The 250nm sized witepsol/miglyol NLCs, prepared by hot homogenization had reduced cytotoxicity and no effect on the integrity of cell membrane in human HaCaT keratinocytes. The internalization was time-, concentration- and energy-dependent, and the uptake of NLCs was a vesicle-mediated process by macropinocytosis and clathrin-mediated pathways. 3% of NLCs were found at the apical membrane side of the HaCaT monolayer through exocytosis mechanism. Additionally, the endoplasmic reticulum, Golgi apparatus and microtubules played crucial roles in the transport of NLCs out of HaCaT cells. NLCs were transported intact across the human keratinocytes monolayer, without disturbing the tight junction's structure. From the transcytosis data only approximately 12% of the internalized NLCs were passed from the apical to the basolateral side. The transcytosis of NLCs throughout the HaCaT cell monolayer towards the basolateral membrane side requires the involvement of the endoplasmic reticulum, Golgi apparatus and microtubules. Our findings may contribute to a systematic understanding of NLCs transport across epidermal epithelial cell monolayers and their optimization for clinical transdermal application. Transdermal drug delivery is a challenging and growing area of clinical application. Lipid nanoparticles such as nanostructured lipid carriers (NLCs) have gained wide interest for transdermal drug

Analog performance of vertical nanowire TFETs as a function of temperature and transport mechanism

Science.gov (United States)

Martino, Marcio Dalla Valle; Neves, Felipe; Ghedini Der Agopian, Paula; Martino, João Antonio; Vandooren, Anne; Rooyackers, Rita; Simoen, Eddy; Thean, Aaron; Claeys, Cor

2015-10-01

The goal of this work is to study the analog performance of tunnel field effect transistors (TFETs) and its susceptibility to temperature variation and to different dominant transport mechanisms. The experimental input characteristic of nanowire TFETs with different source compositions (100% Si and Si1-xGex) has been presented, leading to the extraction of the Activation Energy for each bias condition. These first results have been connected to the prevailing transport mechanism for each configuration, namely band-to-band tunneling (BTBT) or trap assisted tunneling (TAT). Afterward, this work analyzes the analog behavior, with the intrinsic voltage gain calculated in terms of Early voltage, transistor efficiency, transconductance and output conductance. Comparing the results for devices with different source compositions, it is interesting to note how the analog trends vary depending on the source characteristics and the prevailing transport mechanisms. This behavior results in a different suitability analysis depending on the working temperature. In other words, devices with full-Silicon source and non-abrupt junction profile present the worst intrinsic voltage gain at room temperature, but the best results for high temperatures. This was possible since, among the 4 studied devices, this configuration was the only one with a positive intrinsic voltage gain dependence on the temperature variation.

Transport mechanisms through PE-CVD coatings: influence of temperature, coating properties and defects on permeation of water vapour

International Nuclear Information System (INIS)

Kirchheim, Dennis; Jaritz, Montgomery; Hopmann, Christian; Dahlmann, Rainer; Mitschker, Felix; Awakowicz, Peter; Gebhard, Maximilian; Devi, Anjana; Brochhagen, Markus; Böke, Marc

2017-01-01

Gas transport mechanisms through plastics are usually described by the temperature-dependent Arrhenius-model and compositions of several plastic layers are represented by the CLT. When it comes to thin films such as plasma-enhanced chemical vapour deposition (PE-CVD) or plasma-enhanced atomic layer deposition (PE-ALD) coatings on substrates of polymeric material, a universal model is lacking. While existing models describe diffusion through defects, these models presume that permeation does not occur by other means of transport mechanisms. This paper correlates the existing transport models with data from water vapour transmission experiments. (paper)

Bioturbation as a mechanism for radionuclide transport in soil: relevance of earthworms

International Nuclear Information System (INIS)

Mueller-Lemans, H.; Dorp, F. van

1996-01-01

In the context of safety analyses performed for radioactive waste repositories, one important group of scenarios assumes that radionuclides escaping from a repository will reach the biosphere via groundwater. Consequently, when calculating radionuclide migration in the biosphere, most of the models used to date concentrate on transport in the liquid phase. In the soil, however, transport in the solid phase can also be important, particularly when burrowing animals displace the soil together with sorbed and low-solubility radionuclides. Given the conditions prevailing in agricultural areas of central Europe, it is mainly earthworms which play a significant role in material displacement and these will be the subject of this report. A numerical example is used to present the equations which, for given distribution coefficients, can be applied to calculate the portions of the transfer coefficient which can be attributed to transport in the liquid and solid phases. The results demonstrate that material transport by soil fauna, and particularly by earthworms, is a relevant mechanism in many cases, especially for the upward transport of strongly sorbing radionuclides. It should therefore be considered in biosphere models. (Author)

Safety relevant failure mechanisms in the post-operational phase; Sicherheitstechnisch relevante Fehlermechanismen in der Nachbetriebsphase

Energy Technology Data Exchange (ETDEWEB)

Mayer, Gerhard; Stiller, Jan Christopher; Roemer, Sarah

2017-03-15

When the 13{sup th} amendment of the Atomic Energy Act came into force, eight Germ an nuclear power plant units had their power operating licences revoked and are now in the so-called post operation phase. Of the remaining nuclear power plants, one have by now also entered the post operation phase, with those left in operation bound for entering this phase sometime between now and the end of 2022. Therefore, failure mechanisms that are particularly relevant for post operation were to be identified and described in the frame of the present project. To do so, three major steps were taken: Firstly, recent national and international pertinent literature was evaluated to obtain indications of failure mechanisms in the post operation phase. It turned out that most of the national and international literature deals with the general procedure of the transition from power operation to decommissioning and dismantling. However, there were also some documents providing detailed indications of possible failure mechanisms in post operation. This includes e.g. the release of radioactive materials caused by the drop of containers, chemical impacts on systems important to safety in connection with decontamination work, and corrosion in connection with the storage of the core in the spent fuel pool, with the latter leading to the jamming of the fuel assemblies in the storage racks and a possible reduction of coolant circulation. In a second step, three safety analyses of pressurised water reactors prepared by the respective plant operators were evaluated to identify failure mechanisms based on systems engineering. The failure mechanisms that were found here include e.g. faults in the boric acid concentration of the reactor coolant, damage to the equipment airlock upon the unloading of Castor casks, leakages in connection with primary system decontamination, and the drop of packages holding radioactive residual materials or waste with subsequent mobilisation of radioactive aerosols

Application of PolyHIPE Membrane with Tricaprylmethylammonium Chloride for Cr(VI) Ion Separation: Parameters and Mechanism of Transport Relating to the Pore Structure.

Science.gov (United States)

Chen, Jyh-Herng; Le, Thi Tuyet Mai; Hsu, Kai-Chung

2018-03-02

The structural characteristics of membrane support directly affect the performance of carrier facilitated transport membrane. A highly porous PolyHIPE impregnated with Aliquat 336 is proposed for Cr(VI) separation. PolyHIPE consisting of poly(styrene- co -2-ethylhexyl acrylate) copolymer crosslinked with divinylbenzene has the pore structure characteristic of large pore spaces interconnected with small window throats. The unique pore structure provides the membrane with high flux and stability. The experimental results indicate that the effective diffusion coefficient D* of Cr(VI) through Aliquat 336/PolyHIPE membrane is as high as 1.75 × 10 -11 m² s -1 . Transport study shows that the diffusion of Cr(VI) through Aliquat 336/PolyHIPE membrane can be attributed to the jumping transport mechanism. The hydraulic stability experiment shows that the membrane is quite stable, with recovery rates remaining at 95%, even after 10 consecutive cycles of operation. The separation study demonstrates the potential application of this new type of membrane for Cr(VI) recovery.

The molecular mechanism of ion-dependent gating in secondary transporters.

Directory of Open Access Journals (Sweden)

Chunfeng Zhao

2013-10-01

Full Text Available LeuT-like fold Na-dependent secondary active transporters form a large family of integral membrane proteins that transport various substrates against their concentration gradient across lipid membranes, using the free energy stored in the downhill concentration gradient of sodium ions. These transporters play an active role in synaptic transmission, the delivery of key nutrients, and the maintenance of osmotic pressure inside the cell. It is generally believed that binding of an ion and/or a substrate drives the conformational dynamics of the transporter. However, the exact mechanism for converting ion binding into useful work has yet to be established. Using a multi-dimensional path sampling (string-method followed by all-atom free energy simulations, we established the principal thermodynamic and kinetic components governing the ion-dependent conformational dynamics of a LeuT-like fold transporter, the sodium/benzyl-hydantoin symporter Mhp1, for an entire conformational cycle. We found that inward-facing and outward-facing states of Mhp1 display nearly the same free energies with an ion absent from the Na2 site conserved across the LeuT-like fold transporters. The barrier separating an apo-state from inward-facing or outward-facing states of the transporter is very low, suggesting stochastic gating in the absence of ion/substrate bound. In contrast, the binding of a Na2 ion shifts the free energy stabilizing the outward-facing state and promoting substrate binding. Our results indicate that ion binding to the Na2 site may also play a key role in the intracellular thin gate dynamics modulation by altering its interactions with the transmembrane helix 5 (TM5. The Potential of Mean Force (PMF computations for a substrate entrance displays two energy minima that correspond to the locations of the main binding site S1 and proposed allosteric S2 binding site. However, it was found that substrate's binds to the site S1 ∼5 kcal/mol more favorable

Structure of Pioncare covariant tensor operators in quantum mechanical models

International Nuclear Information System (INIS)

Polyzou, W.N.; Klink, W.H.

1988-01-01

The structure of operators that transform covariantly in Poincare invariant quantum mechanical models is analyzed. These operators are shown to have an interaction dependence that comes from the geometry of the Poincare group. The operators can be expressed in terms of matrix elements in a complete set of eigenstates of the mass and spin operators associated with the dynamical representation of the Poincare group. The matrix elements are factored into geometrical coefficients (Clebsch--Gordan coefficients for the Poincare group) and invariant matrix elements. The geometrical coefficients are fixed by the transformation properties of the operator and the eigenvalue spectrum of the mass and spin. The invariant matrix elements, which distinguish between different operators with the same transformation properties, are given in terms of a set of invariant form factors. copyright 1988 Academic Press, Inc

Feedback from operational experience in front-end transportation

International Nuclear Information System (INIS)

Mondonel, J.L.; Parison, C.

1998-01-01

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

Modal Testing of Mechanical Structures Subject to Operational Excitation Forces

DEFF Research Database (Denmark)

Møller, N.; Brincker, Rune; Herlufsen, H.

2000-01-01

to the Operational Modal Analysis. For Operational Modal Analysis two different estimation techniques are used: a non-parametric technique based on Frequency Domain Decomposition (FDD), and a parametric technique working on the raw data in time domain, a data driven Stochastic Subspace Identification (SSI) algorithm......Operational Modal Analysis also known as Output Only Modal Analysis has in the recent years been used for extracting modal parameters of civil engineering structures and is now becoming popular for mechanical structures. The advantage of the method is that no artificial excitation need...

Advanced Transport Operating System (ATOPS) color displays software description: MicroVAX system

Science.gov (United States)

Slominski, Christopher J.; Plyler, Valerie E.; Dickson, Richard W.

1992-01-01

This document describes the software created for the Display MicroVAX computer used for the Advanced Transport Operating Systems (ATOPS) project on the Transport Systems Research Vehicle (TSRV). The software delivery of February 27, 1991, known as the 'baseline display system', is the one described in this document. Throughout this publication, module descriptions are presented in a standardized format which contains module purpose, calling sequence, detailed description, and global references. The global references section includes subroutines, functions, and common variables referenced by a particular module. The system described supports the Research Flight Deck (RFD) of the TSRV. The RFD contains eight Cathode Ray Tubes (CRTs) which depict a Primary Flight Display, Navigation Display, System Warning Display, Takeoff Performance Monitoring System Display, and Engine Display.

Competitiveness of the railway transportation in the conditions of functioning of the infrastructure new organizational-economic mechanism

Directory of Open Access Journals (Sweden)

M.I. Mishchenko

2012-08-01

Full Text Available The transport infrastructure of railways of the countries of EU-27 in the conditions of functioning new organizational-economic mechanism, and also dynamics of level of competitiveness of a railway transportation as result of reforming of railways of the countries of EU-27, in the conditions of realisation of the European transport legislation is investigated.

Advanced Transport Operating System (ATOPS) Flight Management/Flight Controls (FM/FC) software description

Science.gov (United States)

Wolverton, David A.; Dickson, Richard W.; Clinedinst, Winston C.; Slominski, Christopher J.

1993-01-01

The flight software developed for the Flight Management/Flight Controls (FM/FC) MicroVAX computer used on the Transport Systems Research Vehicle for Advanced Transport Operating Systems (ATOPS) research is described. The FM/FC software computes navigation position estimates, guidance commands, and those commands issued to the control surfaces to direct the aircraft in flight. Various modes of flight are provided for, ranging from computer assisted manual modes to fully automatic modes including automatic landing. A high-level system overview as well as a description of each software module comprising the system is provided. Digital systems diagrams are included for each major flight control component and selected flight management functions.

Molecular Simulation and Biochemical Studies Support an Elevator-type Transport Mechanism in EIIC.

Science.gov (United States)

Lee, Jumin; Ren, Zhenning; Zhou, Ming; Im, Wonpil

2017-06-06

Enzyme IIC (EIIC) is a membrane-embedded sugar transport protein that is part of the phosphoenolpyruvate-dependent phosphotransferases. Crystal structures of two members of the glucose EIIC superfamily, bcChbC in the inward-facing conformation and bcMalT in the outward-facing conformation, were previously solved. Comparing the two structures led us to the hypothesis that sugar translocation could be achieved by an elevator-type transport mechanism in which a transport domain binds to the substrate and, through rigid body motions, transports it across the membrane. To test this hypothesis and to obtain more accurate descriptions of alternate conformations of the two proteins, we first performed collective variable-based steered molecular dynamics (CVSMD) simulations starting with the two crystal structures embedded in model lipid bilayers, and steered their transport domain toward their own alternative conformation. Our simulations show that large rigid-body motions of the transport domain (55° in rotation and 8 Å in translation) lead to access of the substrate binding site to the alternate side of the membrane. H-bonding interactions between the sugar and the protein are intact, although the side chains of the binding-site residues were not restrained in the simulation. Pairs of residues in bcMalT that are far apart in the crystal structure become close to each other in the simulated model. Some of these pairs can be cross-linked by a mercury ion when mutated to cysteines, providing further support for the CVSMD-generated model. In addition, bcMalT binds to maltose with similar affinities before and after the cross-linking, suggesting that the binding site is preserved after the conformational change. In combination, these results support an elevator-type transport mechanism in EIIC. Copyright © 2017 Biophysical Society. Published by Elsevier Inc. All rights reserved.

Transport mechanisms in low-resistance ohmic contacts to p-InP formed by rapid thermal annealing

DEFF Research Database (Denmark)

Clausen, Thomas; Leistiko, Otto

1993-01-01

process is related to interdiffusion and compound formation between the metal elements and the InP. The onset of low specific contact resistance is characterized by a change in the dominant transport mechanism; from predominantly a combination of thermionic emission and field emission to purely thermionic......Thermionic emission across a very small effective Schottky barrier (0-0.2 eV) are reported as being the dominant transport process mechanism in very low-resistance ohmic contacts for conventional AuZn(Ni) metallization systems top-InP formed by rapid thermal annealing. The barrier modulation...

Improving transportation systems management and operations (TSM&O), capability maturity model workshop white paper : culture.

Science.gov (United States)

2015-04-01

Research done through the Second Strategic Highway Research Program (SHRP 2) determined : that agencies with the most effective transportation systems management and operations : (TSM&O) activities were differentiated not by budgets or technical skil...

Improving transportation systems management and operations (TSM&O), capability maturity model workshop white paper : collaboration.

Science.gov (United States)

2015-04-01

Research done through the Second Strategic Highway Research Program (SHRP 2) determined : that agencies with the most effective transportation systems management and operations : (TSM&O) activities were differentiated not by budgets or technical skil...

Automatic braking system modification for the Advanced Transport Operating Systems (ATOPS) Transportation Systems Research Vehicle (TSRV)

Science.gov (United States)

Coogan, J. J.

1986-01-01

Modifications were designed for the B-737-100 Research Aircraft autobrake system hardware of the Advanced Transport Operating Systems (ATOPS) Program at Langley Research Center. These modifications will allow the on-board flight control computer to control the aircraft deceleration after landing to a continuously variable level for the purpose of executing automatic high speed turn-offs from the runway. A bread board version of the proposed modifications was built and tested in simulated stopping conditions. Test results, for various aircraft weights, turnoff speed, winds, and runway conditions show that the turnoff speeds are achieved generally with errors less than 1 ft/sec.

On the pull: periplasmic trapping of sugars before transport.

Science.gov (United States)

Thomas, Gavin H

2017-06-01

Bacteria have evolved many routes for taking up nutrients, demonstrating great versatility in the types and mechanism of uptake used in different physiological conditions. The discovery of a single transporter in the bacterium Advenella mimigardefordensis for the uptake of five different sugars, including L-glucose and D-xylose, is described in this issue (Meinert et al., ), providing yet another example of the surprising adaptability of bacterial transport strategies. The transporter identified is a tripartite ATP-independent (TRAP) transporter, not previously associated with sugar transport, and in fact does not transport the sugars directly at all, rather requiring them to be converted in the periplasm to their respective sugar acid forms before transport through what appears to be a novel general sugar acid transporter. In this commentary, I describe how this process is consistent with the known mechanisms of TRAP transporters and consider how the role of sugar oxidation, or oxidative fermentation, operates with multiple hexose and pentose sugars. Finally I suggest that the periplasmic conversion of nutrients acquired across the outer membrane, before transport across the inner membrane, could have potentially useful biological functions in Gram negative bacteria. © 2017 John Wiley & Sons Ltd.

Vitamin A Transport Mechanism of the Multitransmembrane Cell-Surface Receptor STRA6

Directory of Open Access Journals (Sweden)

Riki Kawaguchi

2015-08-01

Full Text Available Vitamin A has biological functions as diverse as sensing light for vision, regulating stem cell differentiation, maintaining epithelial integrity, promoting immune competency, regulating learning and memory, and acting as a key developmental morphogen. Vitamin A derivatives have also been used in treating human diseases. If vitamin A is considered a drug that everyone needs to take to survive, evolution has come up with a natural drug delivery system that combines sustained release with precise and controlled delivery to the cells or tissues that depend on it. This “drug delivery system” is mediated by plasma retinol binding protein (RBP, the principle and specific vitamin A carrier protein in the blood, and STRA6, the cell-surface receptor for RBP that mediates cellular vitamin A uptake. The mechanism by which the RBP receptor absorbs vitamin A from the blood is distinct from other known cellular uptake mechanisms. This review summarizes recent progress in elucidating the fundamental molecular mechanism mediated by the RBP receptor and multiple newly discovered catalytic activities of this receptor, and compares this transport system with retinoid transport independent of RBP/STRA6. How to target this new type of transmembrane receptor using small molecules in treating diseases is also discussed.

Charge trapping and carrier transport mechanism in silicon-rich silicon oxynitride

International Nuclear Information System (INIS)

Yu Zhenrui; Aceves, Mariano; Carrillo, Jesus; Lopez-Estopier, Rosa

2006-01-01

The charge-trapping and carrier transport properties of silicon-rich silicon oxynitride (SRO:N) were studied. The SRO:N films were deposited by low pressure chemical vapor deposition. Infrared (IR) and transmission electron microscopic (TEM) measurements were performed to characterize their structural properties. Capacitance versus voltage and current versus voltage measurements (I-V) were used to study the charge-trapping and carrier transport mechanism. IR and TEM measurements revealed the existence of Si nanodots in SRO:N films. I-V measurements revealed that there are two conduction regimes divided by a threshold voltage V T . When the applied voltage is smaller than V T , the current is dominated by the charge transfer between the SRO:N and substrate; and in this regime only dynamic charging/discharging of the SRO:N layer is observed. When the voltage is larger than V T , the current increases rapidly and is dominated by the Poole-Frenkel mechanism; and in this regime, large permanent trapped charge density is obtained. Nitrogen incorporation significantly reduced the silicon nanodots or defects near the SRO:N/Si interface. However, a significant increase of the density of silicon nanodot in the bulk of the SRO:N layer is obtained

Structure of Bor1 supports an elevator transport mechanism for SLC4 anion exchangers.

Science.gov (United States)

Thurtle-Schmidt, Bryan H; Stroud, Robert M

2016-09-20

Boron is essential for plant growth because of its incorporation into plant cell walls; however, in excess it is toxic to plants. Boron transport and homeostasis in plants is regulated in part by the borate efflux transporter Bor1, a member of the solute carrier (SLC) 4 transporter family with homology to the human bicarbonate transporter Band 3. Here, we present the 4.1-Å resolution crystal structure of Arabidopsis thaliana Bor1. The structure displays a dimeric architecture in which dimerization is mediated by centralized Gate domains. Comparisons with a structure of Band 3 in an outward-open state reveal that the Core domains of Bor1 have rotated inwards to achieve an occluded state. Further structural comparisons with UapA, a xanthine transporter from the nucleobase-ascorbate transporter family, show that the downward pivoting of the Core domains relative to the Gate domains may access an inward-open state. These results suggest that the SLC4, SLC26, and nucleobase-ascorbate transporter families all share an elevator transport mechanism in which alternating access is provided by Core domains that carry substrates across a membrane.

Proton movement and coupling in the POT family of peptide transporters.

Science.gov (United States)

Parker, Joanne L; Li, Chenghan; Brinth, Allete; Wang, Zhi; Vogeley, Lutz; Solcan, Nicolae; Ledderboge-Vucinic, Gregory; Swanson, Jessica M J; Caffrey, Martin; Voth, Gregory A; Newstead, Simon

2017-12-12

POT transporters represent an evolutionarily well-conserved family of proton-coupled transport systems in biology. An unusual feature of the family is their ability to couple the transport of chemically diverse ligands to an inwardly directed proton electrochemical gradient. For example, in mammals, fungi, and bacteria they are predominantly peptide transporters, whereas in plants the family has diverged to recognize nitrate, plant defense compounds, and hormones. Although recent structural and biochemical studies have identified conserved sites of proton binding, the mechanism through which transport is coupled to proton movement remains enigmatic. Here we show that different POT transporters operate through distinct proton-coupled mechanisms through changes in the extracellular gate. A high-resolution crystal structure reveals the presence of ordered water molecules within the peptide binding site. Multiscale molecular dynamics simulations confirm proton transport occurs through these waters via Grotthuss shuttling and reveal that proton binding to the extracellular side of the transporter facilitates a reorientation from an inward- to outward-facing state. Together these results demonstrate that within the POT family multiple mechanisms of proton coupling have likely evolved in conjunction with variation of the extracellular gate. Copyright © 2017 the Author(s). Published by PNAS.

Mechanical Design Features of PGSFR NSSS

International Nuclear Information System (INIS)

Park, Chang-Gyu; Koo, Gyeong-Hoi; Cho, Jae-Hun; Kim, Sung-Kyun

2016-01-01

The NSSS(Nuclear Steam Supply System) is composed of PHTS(Primary Heat Transport System), IHTS (Intermediate Heat Transport System), and SGS(Steam Generation System). And, DHRS(Decay Heat Removal System) adopts both the active and passive systems for diversity. The structures including components and piping should be designed to ensure the structural integrity for their design life against mechanical and operational loads. In this study, the mechanical design features for the structures and components that make up PGSFR NSSS are described. The mechanical design features of structures and components for a PGSFR NSSS are described. The structures are being designed to maintain the structural integrity for their design lifetime by considering the high temperature operating condition. The decay heat removal system(DHRS) removes all reactor decay heat in two ways; active type(ADHRS) and passive type(PDHRS). ADHRS consists of DHX, blower, FHX, circulation pump, and expansion tank. But PDHRS consists of DHX, AHX, and expansion tank. FHX is a finned-tube-type sodium-to-air heat exchanger whereas AHX is a helical-type sodium-to-air heat exchanger

Mechanical Design Features of PGSFR NSSS

Energy Technology Data Exchange (ETDEWEB)

Park, Chang-Gyu; Koo, Gyeong-Hoi; Cho, Jae-Hun; Kim, Sung-Kyun [KAERI, Daejeon (Korea, Republic of)

2016-05-15

The NSSS(Nuclear Steam Supply System) is composed of PHTS(Primary Heat Transport System), IHTS (Intermediate Heat Transport System), and SGS(Steam Generation System). And, DHRS(Decay Heat Removal System) adopts both the active and passive systems for diversity. The structures including components and piping should be designed to ensure the structural integrity for their design life against mechanical and operational loads. In this study, the mechanical design features for the structures and components that make up PGSFR NSSS are described. The mechanical design features of structures and components for a PGSFR NSSS are described. The structures are being designed to maintain the structural integrity for their design lifetime by considering the high temperature operating condition. The decay heat removal system(DHRS) removes all reactor decay heat in two ways; active type(ADHRS) and passive type(PDHRS). ADHRS consists of DHX, blower, FHX, circulation pump, and expansion tank. But PDHRS consists of DHX, AHX, and expansion tank. FHX is a finned-tube-type sodium-to-air heat exchanger whereas AHX is a helical-type sodium-to-air heat exchanger.

Operator algebras for general one-dimensional quantum mechanical potentials with discrete spectrum

International Nuclear Information System (INIS)

Wuensche, Alfred

2002-01-01

We define general lowering and raising operators of the eigenstates for one-dimensional quantum mechanical potential problems leading to discrete energy spectra and investigate their associative algebra. The Hamilton operator is quadratic in these lowering and raising operators and corresponding representations of operators for action and angle are found. The normally ordered representation of general operators using combinatorial elements such as partitions is derived. The introduction of generalized coherent states is discussed. Linear laws for the spacing of the energy eigenvalues lead to the Heisenberg-Weyl group and general quadratic laws of level spacing to unitary irreducible representations of the Lie group SU(1, 1) that is considered in detail together with a limiting transition from this group to the Heisenberg-Weyl group. The relation of the approach to quantum deformations is discussed. In two appendices, the classical and quantum mechanical treatment of the squared tangent potential is presented as a special case of a system with quadratic level spacing

Mechanisms of calcium transport in small intestine. Final report

International Nuclear Information System (INIS)

DeLuca, H.F.

1982-01-01

The vitamin D hormone, 1,25-dihydroxyvitamin D 3 , was demonstrated to be the prime hormonal agent regulating intestinal absorption of divalent cations. Production of the vitamin D hormone is, in turn, regulated by parathyroid hormone, low dietary calcium, low plasma phosphorus, and is suppressed by 1,25-dihydroxyvitamin D 3 , by high plasma phosphorus, high plasma calcium, and the absence of parathyroid hormone. A variety of analogs of the vitamin D hormone were prepared. In addition, the preparation of radiolabeled vitamin D hormone was accomplished using chemical synthesis, and this highly radioactive substance was found to localize in the nuclei of the intestinal villus cells that promote intestinal absorption of calcium. A receptor for the vitamin D hormone was also located, and the general mechanism of response to the vitamin D hormone included the binding to a receptor molecule, transfer to the nucleus, transcription of specific genes followed by translation to transport proteins. Methods were developed for the discovery of the appropriate gene products that play a role in calcium transport

Mechanical environmental transport of actinides and ¹³⁷Cs from an arid radioactive waste disposal site.

Science.gov (United States)

Snow, Mathew S; Clark, Sue B; Morrison, Samuel S; Watrous, Matthew G; Olson, John E; Snyder, Darin C

2015-10-01

Aeolian and pluvial processes represent important mechanisms for the movement of actinides and fission products at the Earth's surface. Soil samples taken in the early 1970's near a Department of Energy radioactive waste disposal site (the Subsurface Disposal Area, SDA, located in southeastern Idaho) provide a case study for studying the mechanisms and characteristics of environmental actinide and (137)Cs transport in an arid environment. Multi-component mixing models suggest actinide contamination within 2.5 km of the SDA can be described by mixing between 2 distinct SDA end members and regional nuclear weapons fallout. The absence of chemical fractionation between (241)Am and (239+240)Pu with depth for samples beyond the northeastern corner and lack of (241)Am in-growth over time (due to (241)Pu decay) suggest mechanical transport and mixing of discrete contaminated particles under arid conditions. Occasional samples northeast of the SDA (the direction of the prevailing winds) contain anomalously high concentrations of Pu with (240)Pu/(239)Pu isotopic ratios statistically identical to those in the northeastern corner. Taken together, these data suggest flooding resulted in mechanical transport of contaminated particles into the area between the SDA and a flood containment dike in the northeastern corner, following which subsequent contamination spreading in the northeastern direction resulted from wind transport of discrete particles. Copyright © 2015 Elsevier Ltd. All rights reserved.

Lead transport in intra-oceanic subduction zones: 2D geochemical-thermo-mechanical modeling of isotopic signatures

NARCIS (Netherlands)

Baitsch-Ghirardello, B.; Stracke, A.; Connolly, J.A.D.; Nikolaeva, K.M.; Gerya, T.V.

2014-01-01

Understanding the physical-chemical mechanisms and pathways of geochemical transport in subduction zones remains a long-standing goal of subduction-related research. In this study, we perform fully coupled geochemical-thermo-mechanical (GcTM) numerical simulations to investigate Pb isotopic

Implementation and Reconfiguration of Robot Operating System on Human Follower Transporter Robot

Directory of Open Access Journals (Sweden)

Addythia Saphala

2015-10-01

Full Text Available Robotic Operation System (ROS is an im- portant platform to develop robot applications. One area of applications is for development of a Human Follower Transporter Robot (HFTR, which  can  be  considered  as a custom mobile robot utilizing differential driver steering method and equipped with Kinect sensor. This study discusses the development of the robot navigation system by implementing Simultaneous Localization and Mapping (SLAM.

Transportation Institutional Plan

Energy Technology Data Exchange (ETDEWEB)

1986-08-01

This Institutional Plan is divided into three chapters. Chapter 1 provides background information, discusses the purposes of the Plan and the policy guidance for establishing the transportation system, and describes the projected system and the plans for its integrated development. Chapter 2 discusses the major participants who must interact to build the system. Chapter 3 suggests mechanisms for interaction that will foster wide participation in program planning and implementation and provides a framework for managing and resolving the issues related to development and operation of the transportation system. A list of acronyms and a glossary are included for the reader's convenience. Also included in this Plan are four appendices. Of particular importance is Appendix A, which includes detailed discussion of specific transportation issues. Appendices B, C, and D provide supporting material to assist the reader in understanding the roles of the involved institutions.

Origami-based tunable truss structures for non-volatile mechanical memory operation.

Science.gov (United States)

Yasuda, Hiromi; Tachi, Tomohiro; Lee, Mia; Yang, Jinkyu

2017-10-17

Origami has recently received significant interest from the scientific community as a method for designing building blocks to construct metamaterials. However, the primary focus has been placed on their kinematic applications by leveraging the compactness and auxeticity of planar origami platforms. Here, we present volumetric origami cells-specifically triangulated cylindrical origami (TCO)-with tunable stability and stiffness, and demonstrate their feasibility as non-volatile mechanical memory storage devices. We show that a pair of TCO cells can develop a double-well potential to store bit information. What makes this origami-based approach more appealing is the realization of two-bit mechanical memory, in which two pairs of TCO cells are interconnected and one pair acts as a control for the other pair. By assembling TCO-based truss structures, we experimentally verify the tunable nature of the TCO units and demonstrate the operation of purely mechanical one- and two-bit memory storage prototypes.Origami is a popular method to design building blocks for mechanical metamaterials. Here, the authors assemble a volumetric origami-based structure, predict its axial and rotational movements during folding, and demonstrate the operation of mechanical one- and two-bit memory storage.

Transportable Payload Operations Control Center reusable software: Building blocks for quality ground data systems

Science.gov (United States)

Mahmot, Ron; Koslosky, John T.; Beach, Edward; Schwarz, Barbara

1994-01-01

The Mission Operations Division (MOD) at Goddard Space Flight Center builds Mission Operations Centers which are used by Flight Operations Teams to monitor and control satellites. Reducing system life cycle costs through software reuse has always been a priority of the MOD. The MOD's Transportable Payload Operations Control Center development team established an extensive library of 14 subsystems with over 100,000 delivered source instructions of reusable, generic software components. Nine TPOCC-based control centers to date support 11 satellites and achieved an average software reuse level of more than 75 percent. This paper shares experiences of how the TPOCC building blocks were developed and how building block developer's, mission development teams, and users are all part of the process.

Charge transport mechanisms of graphene/semiconductor Schottky barriers: A theoretical and experimental study

International Nuclear Information System (INIS)

Zhong, Haijian; Liu, Zhenghui; Xu, Gengzhao; Shi, Lin; Fan, Yingmin; Yang, Hui; Xu, Ke; Wang, Jianfeng; Ren, Guoqiang

2014-01-01

Graphene has been proposed as a material for semiconductor electronic and optoelectronic devices. Understanding the charge transport mechanisms of graphene/semiconductor Schottky barriers will be crucial for future applications. Here, we report a theoretical model to describe the transport mechanisms at the interface of graphene and semiconductors based on conventional semiconductor Schottky theory and a floating Fermi level of graphene. The contact barrier heights can be estimated through this model and be close to the values obtained from the experiments, which are lower than those of the metal/semiconductor contacts. A detailed analysis reveals that the barrier heights are as the function of the interface separations and dielectric constants, and are influenced by the interfacial states of semiconductors. Our calculations show how this behavior of lowering barrier heights arises from the Fermi level shift of graphene induced by the charge transfer owing to the unique linear electronic structure

Bessel equation as an operator identity's matrix element in quantum mechanics

International Nuclear Information System (INIS)

Fan Hongyi; Li Chao

2004-01-01

We study the well-known Bessel equation itself in the framework of quantum mechanics. We show that the Bessel equation is a spontaneous result of an operator identity's matrix element in some definite entangled state representations, which is a fresh look. Application of this operator formalism in the Hankel transform of Laplace equation is presented

Collisional transport in nonneutral plasmas

International Nuclear Information System (INIS)

Dubin, D.H.E.

1999-01-01

Classical transport theory grossly underestimates collisionally-driven cross-field transport for plasmas in the parameter regime of r c D , where r c ≡ v-bar/Ω c , λ D 2 ≡ T/4πe 2 n. In current experiments operating in this regime, cross-field test particle transport is observed to be a factor of 10 larger than the prediction of classical theory. Heat conduction is enhanced by up to 300 times over classical theory, and viscosity is up to 10 4 times larger. New guiding center theories of transport due to long-range collisions have been developed that agree with the measurements. Theory also predicts that emission and absorption of plasma waves may further enhance the thermal conduction and viscosity, providing a possible mechanism for anomalous thermal conductivity in the electron channel of fusion plasmas. (author)

Reform of refined oil product pricing mechanism and energy rebound effect for passenger transportation in China

International Nuclear Information System (INIS)

Lin, Boqiang; Liu, Xia

2013-01-01

Improving energy efficiency is the primary method adopted by the Chinese government in an effort to achieve energy conservation target in the transport sector. However, the offsetting effect of energy rebound would greatly reduce its real energy-saving potentials. We set up a Linear Approximation of the Almost Ideal Demand System Model (LA-AIDS model) to estimate the rebound effect for passenger transportation in China. Real energy conservation effect of improving energy efficiency can also be obtained in the process. The result shows that the rebound effect is approximately 107.2%. This figure signifies the existence of ‘backfire effect’, indicating that efficiency improvement in practice does not always lead to energy-saving. We conclude that one important factor leading to the rebound effect, is the refined oil pricing mechanism. China's refined oil pricing mechanism has been subjected to criticism in recent years. The results of simulation analysis show that the rebound could be reduced to approximately 90.7% if the refined oil pricing mechanism is reformed. In this regard, we suggest further reforms in the current refined oil pricing mechanism. - Highlights: ► We set up the LA-AIDS model to estimate traffic service demand for urban residents. ► The size of the rebound effect for passenger transportation in China is evaluated. ► The rebound effect for passenger transportation in China is 107.2%. ► Reform of oil pricing could reduced the rebound to 90.7%. ► Reform of oil pricing might be an effective method for mitigating rebound effect

Post-operative atrial fibrillation: a maze of mechanisms

Science.gov (United States)

Maesen, Bart; Nijs, Jan; Maessen, Jos; Allessie, Maurits; Schotten, Ulrich

2012-01-01

Post-operative atrial fibrillation (POAF) is one of the most frequent complications of cardiac surgery and an important predictor of patient morbidity as well as of prolonged hospitalization. It significantly increases costs for hospitalization. Insights into the pathophysiological factors causing POAF have been provided by both experimental and clinical investigations and show that POAF is ‘multi-factorial’. Facilitating factors in the mechanism of the arrhythmia can be classified as acute factors caused by the surgical intervention and chronic factors related to structural heart disease and ageing of the heart. Furthermore, some proarrhythmic mechanisms specifically occur in the setting of POAF. For example, inflammation and beta-adrenergic activation have been shown to play a prominent role in POAF, while these mechanisms are less important in non-surgical AF. More recently, it has been shown that atrial fibrosis and the presence of an electrophysiological substrate capable of maintaining AF also promote the arrhythmia, indicating that POAF has some proarrhythmic mechanisms in common with other forms of AF. The clinical setting of POAF offers numerous opportunities to study its mechanisms. During cardiac surgery, biopsies can be taken and detailed electrophysiological measurements can be performed. Furthermore, the specific time course of POAF, with the delayed onset and the transient character of the arrhythmia, also provides important insight into its mechanisms. This review discusses the mechanistic interaction between predisposing factors and the electrophysiological mechanisms resulting in POAF and their therapeutic implications. PMID:21821851

Leakage current transport mechanisms of La 0.67 Sr 0.33 MnO 3 ...

Indian Academy of Sciences (India)

limited current mechanism under forward bias while thermionic emission model under reverse bias. Analysis indicates that a modulating Schottky barrier exists at the LSMO/BTO interface, which dominates the leakage current transport properties ...

Mechanical behaviour of PEM fuel cell catalyst layers during regular cell operation

OpenAIRE

Maher A.R. Sadiq Al-Baghdadi

2010-01-01

Damage mechanisms in a proton exchange membrane fuel cell are accelerated by mechanical stresses arising during fuel cell assembly (bolt assembling), and the stresses arise during fuel cell running, because it consists of the materials with different thermal expansion and swelling coefficients. Therefore, in order to acquire a complete understanding of the mechanical behaviour of the catalyst layers during regular cell operation, mechanical response under steady-state hygro-thermal stresses s...

Extended SUSY quantum mechanics, intertwining operators and coherent states

International Nuclear Information System (INIS)

Bagarello, F.

2008-01-01

We propose an extension of supersymmetric quantum mechanics which produces a family of isospectral Hamiltonians. Our procedure slightly extends the idea of intertwining operators. Several examples of the construction are given. Further, we show how to build up vector coherent states of the Gazeau-Klauder type associated to our Hamiltonians

Mechanism of ochratoxin A transport in kidney

International Nuclear Information System (INIS)

Sokol, P.P.; Ripich, G.; Holohan, P.D.; Ross, C.R.

1988-01-01

The effect of the fungal metabolite (mycotoxin) Ochratoxin A (OTA) on the transport of p-amino[ 3 H]hippurate (PAH), a prototypic organic anion, was examined in renal brush border (BBMV) and basolateral membrane vesicles (BLMV). OTA was as effective an inhibitor of PAH uptake in both membranes as probenecid. The dose response curves for OTA in BBMV and BLMV gave IC50 values of 20 +/- 6 and 32 +/- 7 microM, respectively. The effect was specific since the transport of the organic cation N1-methylnicotinamide was not affected. The phenomenon of counterflow was studied to establish that OTA is translocated. OTA produced trans stimulation of PAH transport in both BBMV and BLMV, demonstrating that OTA is transported across both these membranes. The data suggest that OTA interacts with the PAH transport system in both BBMV and BLMV. We conclude that OTA transport in the kidney is mediated via the renal organic anion transport system

UFD Storage and Transportation - Transportation Working Group Report

International Nuclear Information System (INIS)

Maheras, Steven J.; Ross, Steven B.

2011-01-01

The Used Fuel Disposition (UFD) Transportation Task commenced in October 2010. As its first task, Pacific Northwest National Laboratory (PNNL) compiled a list of structures, systems, and components (SSCs) of transportation systems and their possible degradation mechanisms during extended storage. The list of SSCs and the associated degradation mechanisms (known as features, events, and processes (FEPs)) were based on the list of used nuclear fuel (UNF) storage system SSCs and degradation mechanisms developed by the UFD Storage Task (Hanson et al. 2011). Other sources of information surveyed to develop the list of SSCs and their degradation mechanisms included references such as Evaluation of the Technical Basis for Extended Dry Storage and Transportation of Used Nuclear Fuel (NWTRB 2010), Transportation, Aging and Disposal Canister System Performance Specification, Revision 1 (OCRWM 2008), Data Needs for Long-Term Storage of LWR Fuel (EPRI 1998), Technical Bases for Extended Dry Storage of Spent Nuclear Fuel (EPRI 2002), Used Fuel and High-Level Radioactive Waste Extended Storage Collaboration Program (EPRI 2010a), Industry Spent Fuel Storage Handbook (EPRI 2010b), and Transportation of Commercial Spent Nuclear Fuel, Issues Resolution (EPRI 2010c). SSCs include items such as the fuel, cladding, fuel baskets, neutron poisons, metal canisters, etc. Potential degradation mechanisms (FEPs) included mechanical, thermal, radiation and chemical stressors, such as fuel fragmentation, embrittlement of cladding by hydrogen, oxidation of cladding, metal fatigue, corrosion, etc. These degradation mechanisms are discussed in Section 2 of this report. The degradation mechanisms have been evaluated to determine if they would be influenced by extended storage or high burnup, the need for additional data, and their importance to transportation. These categories were used to identify the most significant transportation degradation mechanisms. As expected, for the most part, the

Gravitational Mass, Its Mechanics - What It Is; How It Operates

OpenAIRE

Ellman, Roger

1999-01-01

The earlier paper, Inertial Mass, Its Mechanics - What It Is; How It Operates, developed the mechanics of inertial mass. The present paper is for the purpose of equivalently developing gravitation. The behavior of gravitation is well known, as described by Newton's Law of Gravitation. But just what gravitational mass is, how gravitational behavior comes about, what in material reality produces the effects of gravitational mass, has been little understood. The only extant hypotheses involve th...

Risk assessment of maintenance operations: the analysis of performing task and accident mechanism.

Science.gov (United States)

Carrillo-Castrillo, Jesús A; Rubio-Romero, Juan Carlos; Guadix, Jose; Onieva, Luis

2015-01-01

Maintenance operations cover a great number of occupations. Most small and medium-sized enterprises lack the appropriate information to conduct risk assessments of maintenance operations. The objective of this research is to provide a method based on the concepts of task and accident mechanisms for an initial risk assessment by taking into consideration the prevalence and severity of the maintenance accidents reported. Data were gathered from 11,190 reported accidents in maintenance operations in the manufacturing sector of Andalusia from 2003 to 2012. By using a semi-quantitative methodology, likelihood and severity were evaluated based on the actual distribution of accident mechanisms in each of the tasks. Accident mechanisms and tasks were identified by using those variables included in the European Statistics of Accidents at Work methodology. As main results, the estimated risk of the most frequent accident mechanisms identified for each of the analysed tasks is low and the only accident mechanisms with medium risk are accidents when lifting or pushing with physical stress on the musculoskeletal system in tasks involving carrying, and impacts against objects after slipping or stumbling for tasks involving movements. The prioritisation of public preventive actions for the accident mechanisms with a higher estimated risk is highly recommended.

Transport mechanisms in capillary condensation of water at a single-asperity nanoscopic contact.

Science.gov (United States)

Sirghi, Lucel

2012-02-07

Transport mechanisms involved in capillary condensation of water menisci in nanoscopic gaps between hydrophilic surfaces are investigated theoretically and experimentally by atomic force microscopy (AFM) measurements of capillary force. The measurements showed an instantaneous formation of a water meniscus by coalescence of the water layers adsorbed on the AFM tip and sample surfaces, followed by a time evolution of meniscus toward a stationary state corresponding to thermodynamic equilibrium. This dynamics of the water meniscus is indicated by time evolution of the meniscus force, which increases with the contact time toward its equilibrium value. Two water transport mechanisms competing in this meniscus dynamics are considered: (1) Knudsen diffusion and condensation of water molecules in the nanoscopic gap and (2) adsorption of water molecules on the surface region around the contact and flow of the surface water toward the meniscus. For the case of very hydrophilic surfaces, the dominant role of surface water transportation on the meniscus dynamics is supported by the results of the AFM measurements of capillary force of water menisci formed at sliding tip-sample contacts. These measurements revealed that fast movement of the contact impedes on the formation of menisci at thermodynamic equilibrium because the flow of the surface water is too slow to reach the moving meniscus.

Influence of surface wettability on transport mechanisms governing water droplet evaporation.

Science.gov (United States)

Pan, Zhenhai; Weibel, Justin A; Garimella, Suresh V

2014-08-19

Prediction and manipulation of the evaporation of small droplets is a fundamental problem with importance in a variety of microfluidic, microfabrication, and biomedical applications. A vapor-diffusion-based model has been widely employed to predict the interfacial evaporation rate; however, its scope of applicability is limited due to incorporation of a number of simplifying assumptions of the physical behavior. Two key transport mechanisms besides vapor diffusion-evaporative cooling and natural convection in the surrounding gas-are investigated here as a function of the substrate wettability using an augmented droplet evaporation model. Three regimes are distinguished by the instantaneous contact angle (CA). In Regime I (CA ≲ 60°), the flat droplet shape results in a small thermal resistance between the liquid-vapor interface and substrate, which mitigates the effect of evaporative cooling; upward gas-phase natural convection enhances evaporation. In Regime II (60 ≲ CA ≲ 90°), evaporative cooling at the interface suppresses evaporation with increasing contact angle and counterbalances the gas-phase convection enhancement. Because effects of the evaporative cooling and gas-phase convection mechanisms largely neutralize each other, the vapor-diffusion-based model can predict the overall evaporation rates in this regime. In Regime III (CA ≳ 90°), evaporative cooling suppresses the evaporation rate significantly and reverses entirely the direction of natural convection induced by vapor concentration gradients in the gas phase. Delineation of these counteracting mechanisms reconciles previous debate (founded on single-surface experiments or models that consider only a subset of the governing transport mechanisms) regarding the applicability of the classic vapor-diffusion model. The vapor diffusion-based model cannot predict the local evaporation flux along the interface for high contact angle (CA ≥ 90°) when evaporative cooling is strong and the

Mass transport mechanism in the collision of sulphur on medium-weight nuclei

International Nuclear Information System (INIS)

Lejeune, A.; Richert, J.

1980-01-01

The reactions of 32 S on 59 Co, 65 Cu, 74 Ge, 79 Br, 85 Rb, 89 Y are studied. An explanation for the specific shape of the double differential cross sections as a function of the scattering angle and the mass asymmetry is given in the framework of a transport model. Conclusions about the reaction mechanism are drawn

Multi-Drug Resistance Transporters and a Mechanism-Based Strategy for Assessing Risks of Pesticide Combinations to Honey Bees.

Science.gov (United States)

Guseman, Alex J; Miller, Kaliah; Kunkle, Grace; Dively, Galen P; Pettis, Jeffrey S; Evans, Jay D; vanEngelsdorp, Dennis; Hawthorne, David J

2016-01-01

Annual losses of honey bee colonies remain high and pesticide exposure is one possible cause. Dangerous combinations of pesticides, plant-produced compounds and antibiotics added to hives may cause or contribute to losses, but it is very difficult to test the many combinations of those compounds that bees encounter. We propose a mechanism-based strategy for simplifying the assessment of combinations of compounds, focusing here on compounds that interact with xenobiotic handling ABC transporters. We evaluate the use of ivermectin as a model substrate for these transporters. Compounds that increase sensitivity of bees to ivermectin may be inhibiting key transporters. We show that several compounds commonly encountered by honey bees (fumagillin, Pristine, quercetin) significantly increased honey bee mortality due to ivermectin and significantly reduced the LC50 of ivermectin suggesting that they may interfere with transporter function. These inhibitors also significantly increased honey bees sensitivity to the neonicotinoid insecticide acetamiprid. This mechanism-based strategy may dramatically reduce the number of tests needed to assess the possibility of adverse combinations among pesticides. We also demonstrate an in vivo transporter assay that provides physical evidence of transporter inhibition by tracking the dynamics of a fluorescent substrate of these transporters (Rhodamine B) in bee tissues. Significantly more Rhodamine B remains in the head and hemolymph of bees pretreated with higher concentrations of the transporter inhibitor verapamil. Mechanism-based strategies for simplifying the assessment of adverse chemical interactions such as described here could improve our ability to identify those combinations that pose significantly greater risk to bees and perhaps improve the risk assessment protocols for honey bees and similar sensitive species.

Contraction-stimulated glucose transport in muscle is controlled by AMPK and mechanical stress but not sarcoplasmatic reticulum Ca2+ release

DEFF Research Database (Denmark)

Jensen, Thomas Elbenhardt; Sylow, Lykke; Rose, Adam John

2014-01-01

signals through proteins such as AMPK. Here, we demonstrate in incubated mouse muscle that Ca(2+) release is neither sufficient nor strictly necessary to increase glucose transport. Rather, the glucose transport response is associated with metabolic feedback signals through AMPK, and mechanical stress......-activated signals. Furthermore, artificial stimulation of AMPK combined with passive stretch of muscle is additive and sufficient to elicit the full contraction glucose transport response. These results suggest that ATP-turnover and mechanical stress feedback are sufficient to fully increase glucose transport...

Aero-Mechanical Design Methodology for Subsonic Civil Transport High-Lift Systems

Science.gov (United States)

vanDam, C. P.; Shaw, S. G.; VanderKam, J. C.; Brodeur, R. R.; Rudolph, P. K. C.; Kinney, D.

2000-01-01

In today's highly competitive and economically driven commercial aviation market, the trend is to make aircraft systems simpler and to shorten their design cycle which reduces recurring, non-recurring and operating costs. One such system is the high-lift system. A methodology has been developed which merges aerodynamic data with kinematic analysis of the trailing-edge flap mechanism with minimum mechanism definition required. This methodology provides quick and accurate aerodynamic performance prediction for a given flap deployment mechanism early on in the high-lift system preliminary design stage. Sample analysis results for four different deployment mechanisms are presented as well as descriptions of the aerodynamic and mechanism data required for evaluation. Extensions to interactive design capabilities are also discussed.

Water transport mechanisms across inorganic membranes in rad waste treatment by electro dialysis. Mecanismos de transporte de agua atraves de membranas inorganicas en tratamiento de desechos radiactivos por electrodialisis

Energy Technology Data Exchange (ETDEWEB)

Andalaft, E; Labayru, R [Comision Chilena de Energia Nuclear, Santiago (Chile)

1992-12-01

The work described in this paper deals with effects and mechanisms of water transport across an inorganic membrane, as related to some studied on the concentration of caesium, strontium, plutonium and other cations of interest to radioactive waste treatment. Several different water transport mechanisms are analysed and assessed as to their individual contribution towards the total transference of water during electro-dialysis using inorganic membranes. Water transfer assisted by proton jump mechanism, water of hydration transferred along with the ions, water related to thermo-osmotic effect, water transferred by concentration gradient and water transferred electrolytically under zeta potential surface charge drive are some of the different mechanism discussed. (author).

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

International Nuclear Information System (INIS)

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

2000-01-01

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

An Improved Cuckoo Search for a Patient Transportation Problem with Consideration of Reducing Transport Emissions

Directory of Open Access Journals (Sweden)

Liyang Xiao

2018-03-01

Full Text Available Many government agencies and business organizations have realized that it is necessary to consider not only the economic cost but also the road transport emissions when they determine the transport policies and operations. In this study, a patient transportation problem with the aim of reducing transport emissions has been formulated by implementing CVRP model. In order to determine the routes of patient transportation with optimized emissions for targeted hospital, an improved Cuckoo Search (ICS algorithm is proposed. In this study, a ‘split’ procedure has been implemented to simplify the individual’s representation. A new category of cuckoos has been introduced to improve the ICS’s search ability. Two heuristics have been applied to improve the quality of initial population. A local search mechanism has been embedded in the search procedure to improve the quality of solutions obtained at the end of each iteration. The computational results were encouraging and demonstrated the effectiveness of the proposed solution method.

TRANSPORT/HANDLING REQUESTS

CERN Multimedia

Groupe ST/HM

2002-01-01

A new EDH document entitled 'Transport/Handling Request' will be in operation as of Monday, 11th February 2002, when the corresponding icon will be accessible from the EDH desktop, together with the application instructions. This EDH form will replace the paper-format transport/handling request form for all activities involving the transport of equipment and materials. However, the paper form will still be used for all vehicle-hire requests. The introduction of the EDH transport/handling request form is accompanied by the establishment of the following time limits for the various services concerned: 24 hours for the removal of office items, 48 hours for the transport of heavy items (of up to 6 metric tons and of standard road width), 5 working days for a crane operation, extra-heavy transport operation or complete removal, 5 working days for all transport operations relating to LHC installation. ST/HM Group, Logistics Section Tel: 72672 - 72202

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

Directory of Open Access Journals (Sweden)

Wen-Hua Wang

2012-01-01

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

Ageing degradation mechanisms in nuclear power plants: lessons learned from operating experience

International Nuclear Information System (INIS)

Bieth, M.; Zerger, B.; Duchac, A.

2014-01-01

This paper presents main results of a comprehensive study performed by the European Clearinghouse on Operating Experience Feedback of Nuclear Power Plants (NPP) with the support of IRSN (Institut de Surete Nucleaire et de Radioprotection) and GRS (Gesellschaft fuer Anlagen und Reaktorsicherheit mbH). Physical ageing mechanisms of Structures, Systems and Components (SSC) that eventually lead to ageing related systems and components failures at nuclear power plants were the main focus of this study. The analysis of ageing related events involved operating experience reported by NPP operators in France, Germany, USA and to the IAEA/NEA International Reporting System on operating experience for the past 20 years. A list of relevant ageing related events was populated. Each ageing related event contained in the list was analyzed and results of analysis were summarized for each ageing degradation mechanism which appeared to be the dominant contributor or direct cause. This paper provides insights into ageing related operating experience as well as recommendations to deal with the physical ageing of nuclear power plant SSC important to safety. (authors)

Transport, mechanical and global migration data of multilayer copolyamide nanocomposite films with different layouts.

Science.gov (United States)

Scarfato, P; Garofalo, E; Di Maio, L; Incarnato, L

2017-06-01

Transport, mechanical and global migration data concern multilayer food packaging films with different layouts, all incorporating a layered silicate/polyamide nanocomposite as oxygen barrier layer, and a low-density polyethylene (LDPE) as moisture resistant layer in direct contact with food. The data are related to "Tuning of co-extrusion processing conditions and film layout to optimize the performances of PA/PE multilayer nanocomposite films for food packaging" by Garofalo et al. (2017) [1]. Nanocomposite multilayer films, with different relative layer thicknesses and clay types, were produced using a laboratory scale co-extrusion blown-film equipment and were analyzed in terms of transport to oxygen and water vapor, mechanical properties and overall migration. The results have shown that all the multilayer hybrid films, based on the copolyamide layer filled with Cloisite 30B, displayed the most significant oxygen barrier improvements and the best mechanical properties compared to the unfilled films. No significant alteration of the overall migration values was observed, as expectable [2], [3], [4]. The performance improvement was more relevant in the case of the film with the thinner nanocomposite layer.

Organizational and financial mechanism of development of services of railway transport through public-private partnership

OpenAIRE

Fedorko, I.

2014-01-01

The paper developed organizational and financial mechanism development of railway transport services, which, unlike the existing ones, includes participants of investment and transportation process, the state target program, a list of potential private and public sources of financing of investment projects, the system of state financial control, which allows to provide the necessary storage the volume of investment funds, effective funding for the achievement of strategic, technical and techn...

Organization and mechanization of maintenance operations at NPPs with the WWER type reactors

International Nuclear Information System (INIS)

Titov, A.A.

1983-01-01

The structure of capital investments defining organization and mechanization of maintepance operations at NPPs with the WWER type reactors is analyzed. The trends in development of optimum decisions for organization and mechanization of repair obs at NPPs being designed taking into account the prospects of nuclear powep enginerning development, the system of NPP maintenance servicing, as well as the structure of repair-productive capacities are discussed. On the basis of the analysis of the data obtained in designing the Zaporozhskaya NPP it is shown that the capital investments for organizing and mechanization of maintenance operations at the unified NPP site with four WWER-1000 reactors reach nearly 18 roubles/kW. A conclusion is drawn that at present the design of an NPP with the WWER-1000 reactor totally meets the requirements of realization of periodic maintenance operations. It is advisable to cooperate the NPP management with that of a thermal power station from the viewpoint of using manpower, which would improve the operating conditions and labour productivity of workers engaged in repair and, consequently, reduce the capital investments and repair expenditures

Energy study of rail passenger transportation. Volume 2. Description of operating systems. Final report

Energy Technology Data Exchange (ETDEWEB)

Henderson, C.; Ellis, H. T.; Wilhelm, J. P.

1979-08-01

The rail passenger systems of the US are described in terms of selected physical, operating, and economic characteristics, and relates services rendered to energy usage and costs. Rail passenger transportation exists in 4 distinct forms: intercity railroads, suburban railroads, heavy-rail transit, and light-rail transit. Each form varies in technical equipment, design of facilities, operating practices, size of systems. Specific data for the national rail passenger network and the Boston, Chicago, Cleveland, New York, Philadelphia, Pittsburgh, and San Francisco regions and the Washington Metropolitan area transit authority are presented.

Driverless transport systems. Globally and versatility in operation; Fahrerlose Transportsysteme. Global und vielseitig im Einsatz

Energy Technology Data Exchange (ETDEWEB)

Irrgang Reinhard

2013-05-10

Driverless transport systems enjoy a strong international demand and just versatile applications. The application possibilities are across all industries and include applications in the automotive industry, the pharmaceutical industry as well as banks, clinics and mechanical engineering.

CLUB FORMATION MECHANISM FOR TRANSPORT-COMMUNITY CREDIT CARDS

Science.gov (United States)

Ding, Yue; Kobayashi, Kiyoshi; Nishida, Junji; Yoshida, Mamoru

In this paper, the roles of transport-community cards jointly issued by a public transport firm and retails are investigated as a means to vitalize an obsolescence shopping center located in a middle of a city. When both the price of goods supplied by the retails and the transport fares affect the consumers' behavior, there exist pecuniary externality between the behaviors of the retails and transport firms. The introduction of a transport-community cards system enables to integrate a basket of goods and transport service into a single commodity; thus, the pecuniary externality can be internalized by price coordination. In addition, the paper clarifies theoretically that the transport firm initiatively decides the price of the transportation service and the retails transfer their incomes to the transport firm so that they are induced to jointly issue the transport-community cards.

Better-Than-Visual Technologies for Next Generation Air Transportation System Terminal Maneuvering Area Operations

Science.gov (United States)

Prinzel, Lawrence J., III; Bailey, Randall E.; Shelton, Kevin J.; Jones, Denise R.; Kramer, Lynda J.; Arthur, Jarvis J., III; Williams, Steve P.; Barmore, Bryan E.; Ellis, Kyle E.; Rehfeld, Sherri A.

2011-01-01

A consortium of industry, academia and government agencies are devising new concepts for future U.S. aviation operations under the Next Generation Air Transportation System (NextGen). Many key capabilities are being identified to enable NextGen, including the concept of Equivalent Visual Operations (EVO) replicating the capacity and safety of today's visual flight rules (VFR) in all-weather conditions. NASA is striving to develop the technologies and knowledge to enable EVO and to extend EVO towards a Better-Than-Visual (BTV) operational concept. The BTV operational concept uses an electronic means to provide sufficient visual references of the external world and other required flight references on flight deck displays that enable VFR-like operational tempos and maintain and improve the safety of VFR while using VFR-like procedures in all-weather conditions. NASA Langley Research Center (LaRC) research on technologies to enable the concept of BTV is described.

Draft Transportation Institutional Plan

International Nuclear Information System (INIS)

1985-09-01

The Department of Energy recognizes that the success of its program to develop and implement a national system for nuclear waste management and disposal depends on broad-based public understanding and acceptance. While each program element has its particular sensitivity, the transportation of the waste may potentially affect the greatest number of people, and accordingly is highly visible and potentially issue-laden. Therefore, the Office of Civilian Radioactive Waste Management has developed this Transportation Institutional Plan to lay the foundation for interaction among all interested parties for the purpose of identifying and resolving issues of concern. The Plan is divided into four chapters. Chapter 1 provides bachground information and discusses the purpose of the Plan and the policy guidance for establishing the transportation system. Chapter 2 introduces the major participants who must interact to build both the system itself and the consensus philosophy that is essential for effective operations. Chapter 3 suggests mechanisms for interaction that will ensure wide participation in program planning and implementation. And, finally, Chapter 4 suggests a framework for managing and resolving the issues related to development and operation of the transportation system. A list of acronyms and a glossary are included for the reader's convenience. The Plan's appendices provide supporting material to assist the reader in understanding the roles of the involved institutions. 4 figs., 1 tab

Contraction-stimulated glucose transport in muscle is controlled by AMPK and mechanical stress but not sarcoplasmatic reticulum Ca2+ release

Directory of Open Access Journals (Sweden)

Thomas E. Jensen

2014-10-01

Full Text Available Understanding how muscle contraction orchestrates insulin-independent muscle glucose transport may enable development of hyperglycemia-treating drugs. The prevailing concept implicates Ca2+ as a key feed forward regulator of glucose transport with secondary fine-tuning by metabolic feedback signals through proteins such as AMPK. Here, we demonstrate in incubated mouse muscle that Ca2+ release is neither sufficient nor strictly necessary to increase glucose transport. Rather, the glucose transport response is associated with metabolic feedback signals through AMPK, and mechanical stress-activated signals. Furthermore, artificial stimulation of AMPK combined with passive stretch of muscle is additive and sufficient to elicit the full contraction glucose transport response. These results suggest that ATP-turnover and mechanical stress feedback are sufficient to fully increase glucose transport during muscle contraction, and call for a major reconsideration of the established Ca2+ centric paradigm.

Amino Acid Metabolism and Transport Mechanisms as Potential Antifungal Targets

Directory of Open Access Journals (Sweden)

Matthew W. McCarthy

2018-03-01

Full Text Available Discovering new drugs for treatment of invasive fungal infections is an enduring challenge. There are only three major classes of antifungal agents, and no new class has been introduced into clinical practice in more than a decade. However, recent advances in our understanding of the fungal life cycle, functional genomics, proteomics, and gene mapping have enabled the identification of new drug targets to treat these potentially deadly infections. In this paper, we examine amino acid transport mechanisms and metabolism as potential drug targets to treat invasive fungal infections, including pathogenic yeasts, such as species of Candida and Cryptococcus, as well as molds, such as Aspergillus fumigatus. We also explore the mechanisms by which amino acids may be exploited to identify novel drug targets and review potential hurdles to bringing this approach into clinical practice.

The molecular mechanism of Zinc acquisition by the neisserial outer-membrane transporter ZnuD

Science.gov (United States)

Calmettes, Charles; Ing, Christopher; Buckwalter, Carolyn M.; El Bakkouri, Majida; Chieh-Lin Lai, Christine; Pogoutse, Anastassia; Gray-Owen, Scott D.; Pomès, Régis; Moraes, Trevor F.

2015-01-01

Invading bacteria from the Neisseriaceae, Acinetobacteriaceae, Bordetellaceae and Moraxellaceae families express the conserved outer-membrane zinc transporter zinc-uptake component D (ZnuD) to overcome nutritional restriction imposed by the host organism during infection. Here we demonstrate that ZnuD is required for efficient systemic infections by the causative agent of bacterial meningitis, Neisseria meningitidis, in a mouse model. We also combine X-ray crystallography and molecular dynamics simulations to gain insight into the mechanism of zinc recognition and transport across the bacterial outer-membrane by ZnuD. Because ZnuD is also considered a promising vaccine candidate against N. meningitidis, we use several ZnuD structural intermediates to map potential antigenic epitopes, and propose a mechanism by which ZnuD can maintain high sequence conservation yet avoid immune recognition by altering the conformation of surface-exposed loops. PMID:26282243

Adenoviral-mediated placental gene transfer of IGF-1 corrects placental insufficiency via enhanced placental glucose transport mechanisms.

Directory of Open Access Journals (Sweden)

Helen N Jones

Full Text Available Previous work in our laboratory demonstrated that over-expression of human insulin-like growth factor -1 (hIGF-1 in the placenta corrects fetal weight deficits in mouse, rat, and rabbit models of intrauterine growth restriction without changes in placental weight. The underlying mechanisms of this effect have not been elucidated. To investigate the effect of intra-placental IGF-1 over-expression on placental function we examined glucose transporter expression and localization in both a mouse model of IUGR and a model of human trophoblast, the BeWo Choriocarcinoma cell line.At gestational day 18, animals were divided into four groups; sham-operated controls, uterine artery branch ligation (UABL, UABL+Ad-hIGF-1 (10(8 PFU, UABL+Ad-LacZ (10(8 PFU. At gestational day 20, pups and placentas were harvested by C-section. For human studies, BeWo choriocarcinoma cells were grown in F12 complete medium +10%FBS. Cells were incubated in serum-free control media ± Ad-IGF-1 or Ad-LacZ for 48 hours. MOIs of 10∶1 and 100∶1 were utilized. The RNA, protein expression and localization of glucose transporters GLUT1, 3, 8, and 9 were analyzed by RT-PCR, Western blot and immunohistochemistry.In both the mouse placenta and BeWo, GLUT1 regulation was linked to altered protein localization. GLUT3, localized to the mouse fetal endothelial cells, was reduced in placental insufficiency but maintained with Ad-I GF-1 treatment. Interestingly, GLUT8 expression was reduced in the UABL placenta but up-regulated following Ad-IGF-1 in both mouse and human systems. GLUT9 expression in the mouse was increased by Ad-IGF-1 but this was not reflected in the BeWo, where Ad-IGF-1 caused moderate membrane relocalization.Enhanced GLUT isoform transporter expression and relocalization to the membrane may be an important mechanism in Ad-hIGF-1mediated correction of placental insufficiency.

Improving transportation systems management and operations (TSM&O), capability maturity model workshop white paper : performance measurement.

Science.gov (United States)

2015-04-01

Research done through the Second Strategic Highway Research Program (SHRP 2) determined : that agencies with the most effective transportation systems management and operations : (TSM&O) activities were differentiated not by budgets or technical skil...

A novel bacterial transport mechanism of Acinetobacter baumannii via activated human neutrophils through interleukin-8.

Science.gov (United States)

Kamoshida, Go; Tansho-Nagakawa, Shigeru; Kikuchi-Ueda, Takane; Nakano, Ryuichi; Hikosaka, Kenji; Nishida, Satoshi; Ubagai, Tsuneyuki; Higashi, Shouichi; Ono, Yasuo

2016-12-01

Hospital-acquired infections as a result of Acinetobacter baumannii have become problematic because of high rates of drug resistance. Although neutrophils play a critical role in early protection against bacterial infection, their interactions with A. baumannii remain largely unknown. To elucidate the interactions between A. baumannii and human neutrophils, we cocultured these cells and analyzed them by microscopy and flow cytometry. We found that A. baumannii adhered to neutrophils. We next examined neutrophil and A. baumannii infiltration into Matrigel basement membranes by an in vitro transmigration assay. Neutrophils were activated by A. baumannii, and invasion was enhanced. More interestingly, A. baumannii was transported together by infiltrating neutrophils. Furthermore, we observed by live cell imaging that A. baumannii and neutrophils moved together. In addition, A. baumannii-activated neutrophils showed increased IL-8 production. The transport of A. baumannii was suppressed by inhibiting neutrophil infiltration by blocking the effect of IL-8. A. baumannii appears to use neutrophils for transport by activating these cells via IL-8. In this study, we revealed a novel bacterial transport mechanism that A. baumannii exploits human neutrophils by adhering to and inducing IL-8 release for bacterial portage. This mechanism might be a new treatment target. © Society for Leukocyte Biology.

Current transport mechanism in graphene/AlGaN/GaN heterostructures with various Al mole fractions

Science.gov (United States)

Pandit, Bhishma; Seo, Tae Hoon; Ryu, Beo Deul; Cho, Jaehee

2016-06-01

The current transport mechanism of graphene formed on AlxGa1-xN/GaN heterostructures with various Al mole fractions (x = 0.15, 0.20, 0.30, and 0.40) is investigated. The current-voltage measurement from graphene to AlGaN/GaN shows an excellent rectifying property. The extracted Schottky barrier height of the graphene/AlGaN/GaN contacts increases with the Al mole fraction in AlGaN. However, the current transport mechanism deviates from the Schottky-Mott theory owing to the deterioration of AlGaN crystal quality at high Al mole fractions confirmed by reverse leakage current measurement.

Current transport mechanism in graphene/AlGaN/GaN heterostructures with various Al mole fractions

Directory of Open Access Journals (Sweden)

Bhishma Pandit

2016-06-01

Full Text Available The current transport mechanism of graphene formed on AlxGa1−xN/GaN heterostructures with various Al mole fractions (x = 0.15, 0.20, 0.30, and 0.40 is investigated. The current–voltage measurement from graphene to AlGaN/GaN shows an excellent rectifying property. The extracted Schottky barrier height of the graphene/AlGaN/GaN contacts increases with the Al mole fraction in AlGaN. However, the current transport mechanism deviates from the Schottky-Mott theory owing to the deterioration of AlGaN crystal quality at high Al mole fractions confirmed by reverse leakage current measurement.

An Assessment of Civil Tiltrotor Concept of Operations in the Next Generation Air Transportation System

Science.gov (United States)

Chung, William W.; Salvano, Dan; Rinehart, David; Young, Ray; Cheng, Victor; Lindsey, James

2012-01-01

Based on a previous Civil Tiltrotor (CTR) National Airspace System (NAS) performance analysis study, CTR operations were evaluated over selected routes and terminal airspace configurations assuming noninterference operations (NIO) and runway-independent operations (RIO). This assessment aims to further identify issues associated with these concepts of operations (ConOps), and their dependency on the airspace configuration and interaction with conventional fixed-wing traffic. Safety analysis following a traditional Safety Management System (SMS) methodology was applied to CTR-unique departure and arrival failures in the selected airspace to identify any operational and certification issues. Additional CTR operational cases were then developed to get a broader understanding of issues and gaps that will need to be addressed in future CTR operational studies. Finally, needed enhancements to National Airspace System performance analysis tools were reviewed, and recommendations were made on improvements in these tools that are likely to be required to support future progress toward CTR fleet operations in the Next Generation Air Transportation System (NextGen).

Maritime transport operation in conditions of globalization

Directory of Open Access Journals (Sweden)

Tomasz Nowosielski

2011-06-01

Full Text Available The contemporary world economy is subject to dynamic integration processes that cause the most open countries in the free import and export goods. Intensive trade relations requires intercontinental free access to well-functioning transport systems. In the case of trade with distant partners, especially on other continents, an important criterion for the organization of cargo handling is a long range. Technological development of means of transport has meant that transport services have become a cheap and highly accessible to passengers and cargo.

Low-energy beam transport studies supporting the spallation neutron source 1-MW beam operation.

Science.gov (United States)

Han, B X; Kalvas, T; Tarvainen, O; Welton, R F; Murray, S N; Pennisi, T R; Santana, M; Stockli, M P

2012-02-01

The H(-) injector consisting of a cesium enhanced RF-driven ion source and a 2-lens electrostatic low-energy beam transport (LEBT) system supports the spallation neutron source 1 MW beam operation with ∼38 mA beam current in the linac at 60 Hz with a pulse length of up to ∼1.0 ms. In this work, two important issues associated with the low-energy beam transport are discussed: (1) inconsistent dependence of the post-radio frequency quadrupole accelerator beam current on the ion source tilt angle and (2) high power beam losses on the LEBT electrodes under some off-nominal conditions compromising their reliability.

Rupture mechanics of metallic alloys for hydrogen transport; Mecanique de la rupture des alliages metalliques pour le transport de l'hydrogene

Energy Technology Data Exchange (ETDEWEB)

Moro, I.; Briottet, L.; Lemoine, P. [CEA Grenoble (DRT/LITEN/DTH/LEV), 38 (France); Andrieu, E.; Blanc, C. [Centre Interuniversitaire de Recherche et d' Ingenierie des Materiaux (ENSIACET/CIRIMAT), 31 - Toulouse (France)

2007-07-01

With the aim to establish a cheap hydrogen distribution system, the transport by pipelines is a solution particularly interesting. Among the high limit of elasticity steels, the X80 has been chosen for hydrogen transport. Its chemical composition and microstructure are given. Important microstructural changes have been revealed in the sheet thickness: the microstructure is thinner and richer in perlite in surface than in bulk. In parallel to this microstructural evolution, a microhardness gradient has been observed: the material microhardness is stronger in surface than in bulk of the sheet. The use of this material for hydrogen transport requires to study its resistance to hydrogen embrittlement. The main aim of this work is to develop an easy rupture mechanics test allowing to qualify the studied material in a gaseous hydrogen environment, to determine the sensitivity of the studied material to the hydrogen embrittlement and to better understand the mechanisms of the hydrogen embrittlement for ferritic materials. Two experimental tests have been used for: the first one is a traction machine coupled to an autoclave; the second one allows to carry out disk rupture tests. The toughness of the material in a gaseous hydrogen environment has thus been determined. The resistance of the material to hydrogen embrittlement has been characterized and by simulation, it has been possible to identify the areas with a strong concentration in hydrogen. The second aim of this work is to study the influence of the steel microstructure on the hydrogen position in the material and on the resistance of the material to the hydrogen embrittlement. The preferential trapping sites on the material not mechanically loaded have at first been identified, as well as the hydrogen position on the different phases and at the ferrite/cementite interface. The interaction between the mechanical loads, the position and the trapping of the hydrogen have been studied then. At last, has been

Improving transportation systems management and operations (TSM&O), capability maturity model workshop white paper : business processes.

Science.gov (United States)

2015-04-01

Research done through the Second Strategic Highway Research Program (SHRP 2) determined that agencies with the most effective transportation systems management and operations (TSM&O) activities were differentiated not by budgets or technical skills a...

Logistic Core Operations with SAP Inventory Management, Warehousing, Transportation, and Compliance

CERN Document Server

Kappauf, Jens; Koch, Matthias

2012-01-01

“Logistic Core Operations with SAP” not only provides an overview of core logistics processes and functionality—it also shows how SAP’s Business Suite covers logistic core operations, what features are supported, and which systems can be used to implement end-to-end processes in the following logistic core disciplines: Procurement, Distribution, Transportation, Warehouse Logistics and Inventory Management, and Compliance and Reporting. In this context the authors not only explain their integration, the organizational set-up, and master data, but also which solution fits best for a particular business need.   This book serves as a solid foundation for understanding SAP software. No matter whether you are a student or a manager involved in an SAP implementation, the authors go far beyond traditional function and feature descriptions, helping you ask the right questions, providing answers, and making recommendations. The book assists you in understanding SAP terminology, concepts and technological compo...

Monte Carlo study of the mechanisms of transport of fast neutrons in various media

International Nuclear Information System (INIS)

Ku, L.

1976-01-01

The technique of analyzing Monte Carlo histories was used to study the details of neutron transport and slowing down mechanisms. The statistical properties of life histories of ''exceptional'' neutrons, i.e., those staying closer to the source or penetrating to larger distances from the source, were compared to those of the general population. The macroscopic behavior of ''exceptional'' neutrons was also related to the interaction mechanics and to the microscopic properties of the medium

Concept Layout Model of Transportation Terminals

Directory of Open Access Journals (Sweden)

Li-ya Yao

2012-01-01

Full Text Available Transportation terminal is the key node in transport systems. Efficient terminals can improve operation of passenger transportation networks, adjust the layout of public transportation networks, provide a passenger guidance system, and regulate the development of commercial forms, as well as optimize the assembly and distribution of modern logistic modes, among others. This study aims to clarify the relationship between the function and the structure of transportation terminals and establish the function layout design. The mapping mechanism of demand, function, and structure was analyzed, and a quantitative relationship between function and structure was obtained from a design perspective. Passenger demand and terminal structure were decomposed into several demand units and structural elements following the principle of reverse engineering. The relationship maps between these two kinds of elements were then analyzed. Function-oriented concept layout model of transportation terminals was established using the previous method. Thus, a technique in planning and design of transportation structures was proposed. Meaningful results were obtained from the optimization of transportation terminal facilities, which guide the design of the functional layout of transportation terminals and improve the development of urban passenger transportation systems.

A comprehensive detailed kinetic mechanism for the simulation of transportation fuels

KAUST Repository

Mehl, Marco; Zhang, Kuiwen; Wagnon, Scott; Kukkadapu, Goutham; Westbrook, Charles K.; Pitz, William J.; Zhang, Yinjia; Curran, Henry J.; Al Rachidi, Mariam; Atef, Nour; Sarathy, Mani; Ahmed, Ahfaz

2017-01-01

This work presents a recently compiled comprehensive model for transportations fuels resulting from the collaboration of three research groups: LLNL, NUI Galway and KAUST. In the past 5 years new fundamental calculations led to significant improvements in the fidelity of detailed kinetic models of important surrogate components (e.g. n-heptane, iso-octane, toluene…) improving predictions of the combustion behavior of pure components and mixtures. By extending the newly adopted reaction rate rules, mechanisms for components that were not included in the previous LLNL gasoline and diesel surrogate mechanisms were developed (e.g. polyalkylated aromatics, cycloalkanes, components from bio-logical sources…). The major features of this updated and extended model are presented together with validation comparisons, examples of applications and future directions.

A comprehensive detailed kinetic mechanism for the simulation of transportation fuels

KAUST Repository

Mehl, Marco

2017-02-27

This work presents a recently compiled comprehensive model for transportations fuels resulting from the collaboration of three research groups: LLNL, NUI Galway and KAUST. In the past 5 years new fundamental calculations led to significant improvements in the fidelity of detailed kinetic models of important surrogate components (e.g. n-heptane, iso-octane, toluene…) improving predictions of the combustion behavior of pure components and mixtures. By extending the newly adopted reaction rate rules, mechanisms for components that were not included in the previous LLNL gasoline and diesel surrogate mechanisms were developed (e.g. polyalkylated aromatics, cycloalkanes, components from bio-logical sources…). The major features of this updated and extended model are presented together with validation comparisons, examples of applications and future directions.

Transport package maintenance requirements and operations

International Nuclear Information System (INIS)

Tyacke, M.J.; Ball, L.J.; Ayers, A.L. Jr.; Hayes, G.R.; Anselmo, A.A.

1988-01-01

The NuPac 125-B rail cask, which transports the damaged core debris from Three Mile Island Unit 2 (TMI-2) to the Idaho National Engineering Laboratory (INEL), is the only new spent-fuel rail shipping cask to be licensed in the United States within the last decade. EG ampersand G Idaho, Inc. (EG ampersand G), acting on behalf of the US Department of Energy, is responsible for ensuring that those new casks and rail cars are properly maintained per regulatory requirements. Both the casks and rail cars have comprehensive in-service inspection and preventive maintenance programs, which are more involved than implied by the requirements. The TMI-2 shipping campaign is the most ambitious spent-fuel transport activity being conducted in the nuclear industry. The experience gained in this campaign, as it relates to maintenance of a transport system, should be of interest and have direct applicability to similar shipping activities planned in the years ahead

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.

Design and operational parameters of transportable supercritical water oxidation waste destruction unit

International Nuclear Information System (INIS)

McFarland, R.D.; Brewer, G.R.; Rofer, C.K.

1991-12-01

Supercritical water oxidation (SCWO) is the destruction of hazardous waste by oxidation in the presence of water at temperatures and pressures above its critical point. A 1 gal/h SCWO waste destruction unit (WDU) has been designed, built, and operated at Los Alamos National Laboratory. This unit is transportable and is intended to demonstrate the SCWO technology on wastes at Department of Energy sites. This report describes the design of the WDU and the preliminary testing phase leading to demonstration

Dual and Direction-Selective Mechanisms of Phosphate Transport by the Vesicular Glutamate Transporter

Directory of Open Access Journals (Sweden)

Julia Preobraschenski

2018-04-01

Full Text Available Summary: Vesicular glutamate transporters (VGLUTs fill synaptic vesicles with glutamate and are thus essential for glutamatergic neurotransmission. However, VGLUTs were originally discovered as members of a transporter subfamily specific for inorganic phosphate (Pi. It is still unclear how VGLUTs accommodate glutamate transport coupled to an electrochemical proton gradient ΔμH+ with inversely directed Pi transport coupled to the Na+ gradient and the membrane potential. Using both functional reconstitution and heterologous expression, we show that VGLUT transports glutamate and Pi using a single substrate binding site but different coupling to cation gradients. When facing the cytoplasm, both ions are transported into synaptic vesicles in a ΔμH+-dependent fashion, with glutamate preferred over Pi. When facing the extracellular space, Pi is transported in a Na+-coupled manner, with glutamate competing for binding but at lower affinity. We conclude that VGLUTs have dual functions in both vesicle transmitter loading and Pi homeostasis within glutamatergic neurons. : Preobraschenski et al. show that the vesicular glutamate transporter functions as a bi-directional phosphate transporter that is coupled with different cations in each direction and hence may play a key role in neuronal phosphate homeostasis. Keywords: VGLUT, SLC17 family, type I Na+-dependent inorganic phosphate transporter, ATPase, proteoliposomes, hybrid vesicles, anti-VGLUT1 nanobody

Transport coefficients and mechanical response in hard-disk colloidal suspensions

International Nuclear Information System (INIS)

Zhang Bo-Kai; Ma Yu-Qiang; Li Jian; Chen Kang; Tian Wen-De

2016-01-01

We investigate the transport properties and mechanical response of glassy hard disks using nonlinear Langevin equation theory. We derive expressions for the elastic shear modulus and viscosity in two dimensions on the basis of thermal-activated barrier-hopping dynamics and mechanically accelerated motion. Dense hard disks exhibit phenomena such as softening elasticity, shear-thinning of viscosity, and yielding upon deformation, which are qualitatively similar to dense hard-sphere colloidal suspensions in three dimensions. These phenomena can be ascribed to stress-induced “landscape tilting”. Quantitative comparisons of these phenomena between hard disks and hard spheres are presented. Interestingly, we find that the density dependence of yield stress in hard disks is much more significant than in hard spheres. Our work provides a foundation for further generalizing the nonlinear Langevin equation theory to address slow dynamics and rheological behavior in binary or polydisperse mixtures of hard or soft disks. (rapid communication)

Operation and maintenance of spent fuel storage and transportation casks/containers

International Nuclear Information System (INIS)

2007-01-01

Member States have a growing need for casks for spent fuel storage and transportation. A variety of casks has been developed and is in use at an increasing number of sites. This has resulted in an accumulation of experience that will provide valuable information for other projects in spent fuel management. This publication provides a comprehensive review of information on the cask operation and maintenance associated with spent fuel storage. It draws upon generic knowledge from industrial experience and applications and is intended to serve as a basis for better planning and implementation in future projects

An electron counting mechanism for the open counter operated in air

International Nuclear Information System (INIS)

Noguchi, T.; Nagashima, S.; Uda, M.

1994-01-01

An electron counting mechanism for an open or air filled counter has been explicitly explained for the first time. Electrons emitted from a solid surface or formed in air by radiations are transported to the neighborhood of the anode in the counter in the form of O 2 - ions, and are detached from the ions and multiplied in the proximity to the anode through electronic avalanche process. The estimation of the number of the emitted electrons from observed count rates has successively been performed by expressing the dead time as the sum of time intervals necessary for quenching using an external circuit and for drifting of the O 2 - ions, and also by taking into account the reduction in the number of electrons during transportation, which is due to scattering of the O 2 - ions in air. (orig.)

Synthesis, characterization and charge transport mechanism of CdZnO nanorods

International Nuclear Information System (INIS)

Mahmoud, Waleed E.; Al-Ghamdi, A.A.; El-Tantawy, F.; Al-Heniti, S.

2009-01-01

ZnO and Cd-doped ZnO nanostructures were prepared by new facile method at 80 deg. C. XRD measurement indicated that both samples had typical hexagonal wurtzite structures. Transmission electron microscopy (TEM) measurement shows that rod-like crystals have been formed. EDX measurement confirms the incorporation of the cadmium ion into the crystalline lattice of ZnO and indicated that cadmium ions uniformly distributed on the surface of the rods. The doping with cadmium ions has a great influence on the optical properties of the ZnO. The electrical measurements of Cd-doped ZnO nanorod were measured. The current-voltage (I-V) characteristic curve revealed that the charge transport above 4 V is mainly non-linear due to grain boundary contribution. The complex impedance spectroscopy was confirmed that the grain boundary effect controls the charge transport mechanism through CdZnO ceramic material.

Probabilistic transport models for plasma transport in the presence of critical thresholds: Beyond the diffusive paradigm

International Nuclear Information System (INIS)

Sanchez, R.; Milligen, B.Ph. van; Carreras, B.A.

2005-01-01

It is argued that the modeling of plasma transport in tokamaks may benefit greatly from extending the usual local paradigm to accommodate scale-free transport mechanisms. This can be done by combining Levy distributions and a nonlinear threshold condition within the continuous time random walk concept. The advantages of this nonlocal, nonlinear extension are illustrated by constructing a simple particle density transport model that, as a result of these ideas, spontaneously exhibits much of nondiffusive phenomenology routinely observed in tokamaks. The fluid limit of the system shows that the kind of equations that are appropriate to capture these dynamics are based on fractional differential operators. In them, effective diffusivities and pinch velocities are found that are dynamically set by the system in response to the specific characteristics of the fueling source and external perturbations. This fact suggests some dramatic consequences for the extrapolation of these transport properties to larger size systems

Investigation of sediment transport and optimization of dredging operations in Indian ports using radiotracer technique

International Nuclear Information System (INIS)

Pant, H.J.

2012-01-01

India has a long coastline of about 7,515 km and there are twelve major ports situated on the coastline. Out of them, six are situated on the West Coast whereas other six are situated on the East Coast. In addition to this, there are more than 140 minor ports and other marine establishments situated along the coastline. Each port and marine project has a navigation channel and depth of this navigation channel needs to be maintained to a level of at least 12-15 meters for smooth sailing of ships. Sediments continuously move along the coast due to alongshore currents generated by the waves and tides; and get deposited in navigation channels. For maintaining the required depth of the channels, the dredging operation is carried out. throughout the year or as and when required. Development of a new port or harbour also involves huge capital dredging. The dredged sediments generated during maintenance or capital dredging needs to be dumped at a suitable location, so that it does not find its way back to the channel and obstruct sailing of ships. Moreover the selected site should be such that the turn around time of the dredger is kept minimum to economize the dredging operation. In order to meet the above requirements, the knowledge of transport parameters such as the general direction of movement, extent of lateral and longitudinal movement, transport velocity, transport thickness and bed load movement rate is required. Radiotracer techniques are commonly used to investigate sediment transport on seabed and evaluate the suitability of the proposed dumping sites. Scandium-46 (half-life: 84 days, Gamma energies: 0.89 MeV (100%), 1.12 MeV (100%)) in the form of scandium glass powder is the most suitable radiotracer for tracing sediments on seabed. The activity used in an investigation ranges from 75-300 GBq (2-8 Ci). The suitably prepared particulate radiotracer is injected on seabed at the proposed site using a specially designed injection system and its movement is

Cellular Transport Mechanisms of Cytotoxic Metallodrugs: An Overview beyond Cisplatin

Directory of Open Access Journals (Sweden)

Sarah Spreckelmeyer

2014-09-01

Full Text Available The field of medicinal inorganic chemistry has grown consistently during the past 50 years; however, metal-containing coordination compounds represent only a minor proportion of drugs currently on the market, indicating that research in this area has not yet been thoroughly realized. Although platinum-based drugs as cancer chemotherapeutic agents have been widely studied, exact knowledge of the mechanisms governing their accumulation in cells is still lacking. However, evidence suggests active uptake and efflux mechanisms are involved; this may be involved also in other experimental metal coordination and organometallic compounds with promising antitumor activities in vitro and in vivo, such as ruthenium and gold compounds. Such knowledge would be necessary to elucidate the balance between activity and toxicity profiles of metal compounds. In this review, we present an overview of the information available on the cellular accumulation of Pt compounds from in vitro, in vivo and clinical studies, as well as a summary of reports on the possible accumulation mechanisms for different families of experimental anticancer metal complexes (e.g., Ru Au and Ir. Finally, we discuss the need for rationalization of the investigational approaches available to study metallodrug cellular transport.

The operational efficiency of waterway transport of forest chips on Finland's Lake Saimaa

Energy Technology Data Exchange (ETDEWEB)

Karttunen, K.; Ranta, T. [Lappeenranta Univ. of Technology, LUT Savo Sustainable Technologies, Mikkeli (Finland); Vaatainen, K.; Asikainen, A. [The Finnish Forest Research Inst., Joensuu (Finland)], E-mail: kalle.karttunen@lut.fi

2012-11-01

New and cost-efficient methods for use in supply chains for energy wood should be found, to reach the targets of the renewable energy utilisation set by the European Union. The long-distance waterway transportation of forest fuels should be thoroughly investigated, especially in areas where the transport distance is long and waterways could provide a feasible method of conveying forest fuel. In comparison to transport of forest chips by truck, barge-based waterway transport shows a competitive advantage due to the larger loads and higher bulk density of chips it allows. The cost-efficiency of waterway transportation operations related to forest chips in Finland's Lake Saimaa region was studied using practical demonstrations and discrete-event simulation. The varying demand for fuel wood in three separate bio-power plants on the Saimaa lakeside (near the cities of Varkaus, Mikkeli, and Savonlinna) was addressed in several barge transportation scenarios. Finally, the economy of barge transportation was compared to the economy of truck transportation as a function of transportation distance and in terms of the annual performance of the transportation methods examined. The waterway supply chain of forest chips was cost-competitive to road transport by truck after 100-150 km. According to the simulation study, the most economical waterway transport options were based on fixed barge system and shift-independent harbor logistics where loading and unloading of barges were carried-out with a wheeled loader and a belt conveyor. Total supply chain costs including the best waterway logistics from road side storage to power plant ranged from 10.75 euros to 11.64 euros/MWh in distances of 100-150 km by waterways. The energy-density of forest chips in the barge load was found to be, on average, 25% higher than that in truck hauling, because of the better compaction of chips. Waterway transport is a viable option for long-distance transportation of forest chips in Eastern

Computer-aided operations engineering with integrated models of systems and operations

Science.gov (United States)

Malin, Jane T.; Ryan, Dan; Fleming, Land

1994-01-01

CONFIG 3 is a prototype software tool that supports integrated conceptual design evaluation from early in the product life cycle, by supporting isolated or integrated modeling, simulation, and analysis of the function, structure, behavior, failures and operation of system designs. Integration and reuse of models is supported in an object-oriented environment providing capabilities for graph analysis and discrete event simulation. Integration is supported among diverse modeling approaches (component view, configuration or flow path view, and procedure view) and diverse simulation and analysis approaches. Support is provided for integrated engineering in diverse design domains, including mechanical and electro-mechanical systems, distributed computer systems, and chemical processing and transport systems. CONFIG supports abstracted qualitative and symbolic modeling, for early conceptual design. System models are component structure models with operating modes, with embedded time-related behavior models. CONFIG supports failure modeling and modeling of state or configuration changes that result in dynamic changes in dependencies among components. Operations and procedure models are activity structure models that interact with system models. CONFIG is designed to support evaluation of system operability, diagnosability and fault tolerance, and analysis of the development of system effects of problems over time, including faults, failures, and procedural or environmental difficulties.

Evaluation of potential sources and transport mechanisms of fecal indicator bacteria to beach water, Murphy Park Beach, Door County, Wisconsin

Science.gov (United States)

Juckem, Paul F.; Corsi, Steven R.; McDermott, Colleen; Kleinheinz, Gregory; Fogarty, Lisa R.; Haack, Sheridan K.; Johnson, Heather E.

2013-01-01

Fecal Indicator Bacteria (FIB) concentrations in beach water have been used for many years as a criterion for closing beaches due to potential health concerns. Yet, current understanding of sources and transport mechanisms that drive FIB occurrence remains insufficient for accurate prediction of closures at many beaches. Murphy Park Beach, a relatively pristine beach on Green Bay in Door County, Wis., was selected for a study to evaluate FIB sources and transport mechanisms. Although the relatively pristine nature of the beach yielded no detection of pathogenic bacterial genes and relatively low FIB concentrations during the study period compared with other Great Lakes Beaches, its selection limited the number of confounding FIB sources and associated transport mechanisms. The primary sources of FIB appear to be internal to the beach rather than external sources such as rivers, storm sewer outfalls, and industrial discharges. Three potential FIB sources were identified: sand, swash-zone groundwater, and Cladophora mats. Modest correlations between FIB concentrations in these potential source reservoirs and FIB concentrations at the beach from the same day illustrate the importance of understanding transport mechanisms between FIB sources and the water column. One likely mechanism for transport and dispersion of FIB from sand and Cladophora sources appears to be agitation of Cladophora mats and erosion of beach sand due to storm activity, as inferred from storm indicators including turbidity, wave height, current speed, wind speed, sky visibility, 24-hour precipitation, and suspended particulate concentration. FIB concentrations in beach water had a statistically significant relation (p-value ‹0.05) with the magnitude of these storm indicators. In addition, transport of FIB in swash-zone groundwater into beach water appears to be driven by groundwater recharge associated with multiday precipitation and corresponding increased swash-zone groundwater discharge at

New mechanism for the control of sodium transport in wheat

International Nuclear Information System (INIS)

James, R.A.; Munns, R.; Huang, C.X.

2002-01-01

Full text: Durum and other tetraploid wheats are typically very salt-sensitive compared to hexaploid bread wheats. This is primarily due to high rates of Na + accumulation in the leaves in tetraploid wheat. Recently, we have discovered a durum landrace with low Na + accumulation and enhanced K + /Na + discrimination, much lower than current durum cultivars and similar to bread wheat. We have identified 3 different mechanisms for the control of Na + transport to the leaves in this landrace, 1) control of Na + uptake at the epidermis of the root, 2) control of Na + loading into the xylem and 3) partitioning of Na + into the leaf sheath. The low Na + durum landrace had 3-4 fold lower Na + uptake rates than durum cultivars. Using X ray microanalysis on snap-frozen root sections, we found Na + to be high in the epidermis, a decreasing gradient through the cortex, low in the endodermis and again high in the stele (pencycle and xylem parenchyma), indicative of control points at the epidermis and in the stele. Partitioning of Na + between shoot and root was at least 5 times lower in the durum landrace, suggestive of greater control of Na + transport at the site of xylem loading. A third and novel control mechanism was found in the leaf sheath. Short and long term salinity treatments showed that Na + was partitioned preferentially into the sheaths of the low Na + durum landrace, keeping leaf blade Na + levels very low and similar to that of bread wheat Na + partitioned in the leaf sheath was stored primarily in the parenchyma cells and Cl - in the epidermal cells. Collectively, these data show that we have identified germplasm that has the potential to increase the salt tolerance of durum wheat. Additionally, as bread wheat does not contain the mechanism for partitioning Na + into the sheath, this trait may be useful for further increasing the salt tolerance of this species

Modification and Performance Evaluation of a Low Cost Electro-Mechanically Operated Creep Testing Machine

Directory of Open Access Journals (Sweden)

John J. MOMOH

2010-12-01

Full Text Available Existing mechanically operated tensile and creep testing machine was modified to a low cost, electro-mechanically operated creep testing machine capable of determining the creep properties of aluminum, lead and thermoplastic materials as a function of applied stress, time and temperature. The modification of the testing machine was necessitated by having an electro-mechanically operated creep testing machine as a demonstration model ideal for use and laboratory demonstrations, which will provide an economical means of performing standard creep experiments. The experimental result is a more comprehensive understanding of the laboratory experience, as the technology behind the creep testing machine, the test methodology and the response of materials loaded during experiment are explored. The machine provides a low cost solution for Mechanics of Materials laboratories interested in creep testing experiment and demonstration but not capable of funding the acquisition of commercially available creep testing machines. Creep curves of strain versus time on a thermoplastic material were plotted at a stress level of 1.95MPa, 3.25MPa and 4.55MPa and temperature of 20oC, 40oC and 60oC respectively. The machine is satisfactory since it is always ready for operation at any given time.

Experimental evidence for the suitability of ELMing H-mode operation in ITER with regard to core transport of helium

International Nuclear Information System (INIS)

Wade, M.R.; Hillis, D.L.; Burrell, K.H.

1996-09-01

Studies have been conducted in DIII-D to assess the viability of the ITER design with regard to helium ash removal, including both global helium exhaust studies and detailed helium transport studies. With respect to helium ash accumulation, the results are encouraging for successful operation of ITER in ELMing H-mode plasmas with conventional high-recycling divertor operation. Helium can be removed from the plasma core with a characteristic time constant of ∼ 8 energy confinement times, even with a central source of helium. Furthermore, the exhaust rate is limited by the pumping efficiency of the system and not by transport of helium within the plasma core. Helium transport studies have shown that D He /X eff ∼ 1 in all confinement regimes studied to date and there is little dependence of D He /X eff on normalized gyroradius in dimensionless scaling studies, suggesting that D He /X eff will be ∼ 1 in ITER. These observations suggest that helium transport within the plasma core should be sufficient to prevent unacceptable fuel dilution in ITER. However, helium exhaust is also strongly dependent on many factors (e.g., divertor plasma conditions, plasma and baffling geometry, flux amplification, pumping speed, etc.) that are difficult to extrapolate. Studies have revealed the helium diffusivity decreases as the plasma density increases, which is unfavorable to ITER's extremely high density operation

Exploratory study of mechanical kinematic innovation design based on gene recombination operation

Energy Technology Data Exchange (ETDEWEB)

Feng, Yixiong; Gao, Yicong; Tan, Jianrong [Zhejiang University, Hangzhou (China); Hagiwara, Ichiro [Tokyo Institute of Technology, Tokyo (Korea, Republic of)

2013-03-15

This paper analyzes the influencing factor of motion output of the inspired mechanism under the premise that the motion input is invariant. These factors are respectively expressed as kinematic pair chromosome number, kinematic pair feature gene and distance relationship vector gene by virtue of several concepts and principles in genetics, and then they are encoded. Mechanism chromosome model is established, which is constituted by mechanism chromosome relationship graph and mechanism chromosome matrix. Three kinematic pair chromosome gene recombination operations on mechanism chromosome model (dominance, translocation and metastasis), are proposed by using meiosis and chromosome variance in genetics for reference. Finally the paper takes shaper as the original mechanism and acquires its inspired mechanism, which proves the convenience and practicality of the methods.

Exploratory study of mechanical kinematic innovation design based on gene recombination operation

International Nuclear Information System (INIS)

Feng, Yixiong; Gao, Yicong; Tan, Jianrong; Hagiwara, Ichiro

2013-01-01

This paper analyzes the influencing factor of motion output of the inspired mechanism under the premise that the motion input is invariant. These factors are respectively expressed as kinematic pair chromosome number, kinematic pair feature gene and distance relationship vector gene by virtue of several concepts and principles in genetics, and then they are encoded. Mechanism chromosome model is established, which is constituted by mechanism chromosome relationship graph and mechanism chromosome matrix. Three kinematic pair chromosome gene recombination operations on mechanism chromosome model (dominance, translocation and metastasis), are proposed by using meiosis and chromosome variance in genetics for reference. Finally the paper takes shaper as the original mechanism and acquires its inspired mechanism, which proves the convenience and practicality of the methods.

Safety Standard for Oxygen and Oxygen Systems: Guidelines for Oxygen System Design, Materials Selection, Operations, Storage, and Transportation

Science.gov (United States)

1996-01-01

NASA's standard for oxygen system design, materials selection, operation, and transportation is presented. Minimum guidelines applicable to NASA Headquarters and all NASA Field Installations are contained.

Development of transport mechanical engineering as the condition of maintenance of social and economic security of region

Directory of Open Access Journals (Sweden)

Vsevolod Petrovich Babushkin

2012-12-01

Full Text Available In the article, the transport role in the decision of problems of innovative and scientifically-technological development of territory is defined. Dependence of quality, completeness and timeliness of granting of transport services on replenishment and updating of park of locomotives, cars, i.e. from a level of development of domestic transport mechanical engineering is shown. The basic problems of development given branches –low competitiveness of made production are revealed. The basic accent in the course of such analysis is made on research of competitive possibilities of the enterprises of railway mechanical engineering of Sverdlovsk area. Such enterprises play the increasing role, become points of development of region’s economy and maintenance of its social and economic safety. The cooperation communications, which have developed in an industrial complex of Sverdlovsk area on the basis of development of modern manufacture on building of electric locomotives, have allowed to generate in region cluster railway mechanical engineering. The structure cluster is shown, development prospects, the estimation of its influence on the economy of Sverdlovsk area and maintenance of its social and economic security is given

Improving transportation systems management and operations (TSM&O), capability maturity model workshop white paper : systems and technology.

Science.gov (United States)

2015-04-01

Research done through the Second Strategic Highway Research Program (SHRP 2) determined : that agencies with the most effective transportation systems management and operations : (TSM&O) activities were differentiated not by budgets or technical skil...

Investigation of particle reduction and its transport mechanism in UHF-ECR dielectric etching system

International Nuclear Information System (INIS)

Kobayashi, Hiroyuki; Yokogawa, Ken'etsu; Maeda, Kenji; Izawa, Masaru

2008-01-01

Control of particle transport was investigated by using a UHF-ECR etching apparatus with a laser particle monitor. The particles, which float at a plasma-sheath boundary, fall on a wafer when the plasma is turned off. These floating particles can be removed from the region above the wafer by changing the plasma distribution. We measured the distribution of the rotational temperature of nitrogen molecules across the wafer to investigate the effect of the thermophoretic force. We found that mechanisms of particle transport in directions parallel to the wafer surface can be explained by the balance between thermophoretic and gas viscous forces

Mechanisms of vitamin K transport and metabolism in Swiss 3T3 mouse fibroblasts

International Nuclear Information System (INIS)

Canfield, L.M.; Townsend, A.F.; Hibbs, D.B.

1986-01-01

Transport of vitamin K into isolated fibroblasts was followed using 3 H vitamin K 1 . The initial rate is saturable by 5 min. at 25μM vitamin K with a Km(app) of 10μM and V/sub max/ of 50 pmols/min/10 6 cells. Kinetics of uptake are biphasic with a second slower rate ensuing after 10 minutes. Insensitivity of the initial rate of uptake to FCCP or ouabain indicates an ATP-independent transport mechanism. Specificity of transport is shown by competition of uptake of 3 H vitamin K by unlabelled vitamin and strong (>90%) inhibition of the initial rate by equimolar concentrations of the vitamin K analog, Chloro-K. In addition, following uptake, both vitamins K 1 and K 2 are metabolized to their respective epoxides. Vitamin K 1 epoxide is also transported into fibroblasts and metabolized to the parent quinone in a Warfarin-sensitive reaction. Following alkaline hydrolysis of isolated intracellular protein, the vitamin K-dependent amino acid, gamma carboxyglutamic acid (gla) was detected. It is concluded that vitamin K is specifically transported into fibroblasts and metabolized via the classical pathway described in liver with the concomitant production of vitamin K-dependent proteins

Mechanisms of molecular transport through the urea channel of Helicobacter pylori

Science.gov (United States)

McNulty, Reginald; Ulmschneider, Jakob P.; Luecke, Hartmut; Ulmschneider, Martin B.

2013-12-01

Helicobacter pylori survival in acidic environments relies on cytoplasmic hydrolysis of gastric urea into ammonia and carbon dioxide, which buffer the pathogen’s periplasm. Urea uptake is greatly enhanced and regulated by HpUreI, a proton-gated inner membrane channel protein essential for gastric survival of H. pylori. The crystal structure of HpUreI describes a static snapshot of the channel with two constriction sites near the center of the bilayer that are too narrow to allow passage of urea or even water. Here we describe the urea transport mechanism at atomic resolution, revealed by unrestrained microsecond equilibrium molecular dynamics simulations of the hexameric channel assembly. Two consecutive constrictions open to allow conduction of urea, which is guided through the channel by interplay between conserved residues that determine proton rejection and solute selectivity. Remarkably, HpUreI conducts water at rates equivalent to aquaporins, which might be essential for efficient transport of urea at small concentration gradients.

Nuclear transport

International Nuclear Information System (INIS)

Anon.

2003-01-01

During january and february 2003, a unique event concerning nuclear transport was reported and rated 1 on the INES scale. This event concerns the absence of a maintenance operation on a shipping cask. This shipping cask was used for several years for nuclear transport inside La-hague site before being re-assigned to transport on public thoroughfare. The re-assignment of the cask should have been preceded and conditioned by a maintenance operation whose purpose is to check the efficiency of its radiation shield. During this period 2 on-site inspections concerning the transport of nuclear materials were performed. (A.C.)

Basic transport phenomena in materials engineering

CERN Document Server

Iguchi, Manabu

2014-01-01

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

Developing a Mechanism for Assessment of the Mobile Operator Staff

Directory of Open Access Journals (Sweden)

Zhukovska Liudmyla E.

2017-04-01

Full Text Available The article is aimed at determining and substantiating practical recommendations on improving the assessment of staff of mobile operators based on an analysis of the existing theoretical and methodological foundations of formation and implementation of an effective mechanism for staff assessment and the suitability of their application in the competitive conditions. General tendencies in the development of mobile operators have been determined, existing approaches to assessing their staff have been explored. The article substantiates the need for cooperation and exchange of experts among mobile operators on staff assessment issues, using the assessment center technology and the use of an integrated staff assessment based on the points system, which will provide an objective assessment of each employee and will also contribute to the development of staff assessment technology for all telecommunications companies. The organizational and economic foundations for the implementation of these activities and the determination of level of their performance for mobile operators will be purpose of further researches.

Cask fleet operations study

International Nuclear Information System (INIS)

1988-01-01

The Nuclear Waste Policy Act of 1982 assigned to the Department of Energy's (DOE) Office of Civilian Waste Management the responsibility for disposing of high-level waste and spent fuel. A significant part of that responsibility involves transporting nuclear waste materials within the federal waste management system; that is, from the waste generator to the repository. The lead responsibility for transportation operations has been assigned to Oak Ridge Operations, with Oak Ridge National Laboratory (ORNL) providing technical support through the Transportation Operations Support Task Group. One of the ORNL support activities involves assessing what facilities, equipment and services are required to assure that an acceptable, cost-effective and safe transportation operations system can be designed, operated and maintained. This study reviews, surveys and assesses the experience of Nuclear Assurance Corporation (NAC) in operating a fleet of spent-fuel shipping casks to aid in developing the spent-fuel transportation system

Structural basis for polyspecificity in the POT family of proton-coupled oligopeptide transporters

DEFF Research Database (Denmark)

Lyons, Joseph A.; Parker, Joanne L.; Solcan, Nicolae

2014-01-01

An enigma in the field of peptide transport is the structural basis for ligand promiscuity, as exemplified by PepT1, the mammalian plasma membrane peptide transporter. Here, we present crystal structures of di‐ and tripeptide‐bound complexes of a bacterial homologue of PepT1, which reveal at least...... two mechanisms for peptide recognition that operate within a single, centrally located binding site. The dipeptide was orientated laterally in the binding site, whereas the tripeptide revealed an alternative vertical binding mode. The co‐crystal structures combined with functional studies reveal...... that biochemically distinct peptide‐binding sites likely operate within the POT/PTR family of proton‐coupled symporters and suggest that transport promiscuity has arisen in part through the ability of the binding site to accommodate peptides in multiple orientations for transport...

Density operators in quantum mechanics

International Nuclear Information System (INIS)

Burzynski, A.

1979-01-01

A brief discussion and resume of density operator formalism in the way it occurs in modern physics (in quantum optics, quantum statistical physics, quantum theory of radiation) is presented. Particularly we emphasize the projection operator method, application of spectral theorems and superoperators formalism in operator Hilbert spaces (Hilbert-Schmidt type). The paper includes an appendix on direct sums and direct products of spaces and operators, and problems of reducibility for operator class by using the projection operators. (author)

77 FR 34457 - Pipeline Safety: Mechanical Fitting Failure Reports

Science.gov (United States)

2012-06-11

... DEPARTMENT OF TRANSPORTATION Pipeline and Hazardous Materials Safety Administration [Docket No... notice provides clarification to owners and operators of gas distribution pipeline facilities when... of a gas distribution pipeline facility to file a written report for any mechanical fitting failure...

Operating a pneumatic-mechanical flotation machine for coal-slurry flotation

Energy Technology Data Exchange (ETDEWEB)

Shmaenok, N M; Bedran, N G; Konstantinov, V K; Kochetkov, Yu I; Sysoev, V S

1976-01-01

The FPM-GMO-1.6 pneumatic-mechanical flotation machine is easy to operate and regulate and maintains a high throughput at a low energy consumption. The flotation process is stable, the quality of the concentrate and tailings satisfactory, and the selectivity of separation high. The machine cannot handle coal slurries at higher throughputs because the rate of froth removal is too low across the entire flotation front. Experience on the pneumatic-mechanical flotation machine at the ''Kolosnikovskaya'' Central Washery indicates that a similar machine should be developed for a throughput of 1000 m/sup 3//hr.

Air Transport and Operations. Proceedings of the Third International Air Transport and Operations Symposium 2012

NARCIS (Netherlands)

Curran, R.; Fischer, L.; Pérez, D.; Klein, K.; Hoekstra, J.; Roling, P.; Verhagen, W.J.C.

2012-01-01

Air transport must evolve if it is to optimize its value in the 21st century. The mood in the aerospace industry is positive with regard to economic recovery, but the focus in this transitional time must be on sustaining value, without losing sight of environmental and safety priorities

Essential spectra and exponential estimates of eigenfunctions of lattice operators of quantum mechanics

International Nuclear Information System (INIS)

Rabinovich, Vladimir S; Roch, Steffen

2009-01-01

This paper is devoted to estimates of the exponential decay of eigenfunctions of difference operators on the lattice Z n which are discrete analogs of the Schroedinger, Dirac and square-root Klein-Gordon operators. Our investigation of the essential spectra and the exponential decay of eigenfunctions of the discrete spectra is based on the calculus of pseudodifference operators (i.e., pseudodifferential operators on the group Z n with analytic symbols), and the limit operators method. We obtain a description of the location of the essential spectra and estimates of the eigenfunctions of the discrete spectra of the main lattice operators of quantum mechanics, namely: matrix Schroedinger operators on Z n , Dirac operators on Z 3 and square root Klein-Gordon operators on Z n .

Building a Mechanism for the Function of an Innovation-Oriented Machine-Building Enterprise in Operating the Development

Directory of Open Access Journals (Sweden)

Boiarynova Кateryna О.

2017-07-01

Full Text Available The article is aimed at developing and substantiating a mechanism for the function of an innovation-oriented machine-building enterprise in operating the development in order to increase effectuality in the space of ecosystem of operation and to satisfy the economic interests of development. The article proposes a mechanism for the function of an innovation-oriented machine-building enterprise in operating the development, its structure and building based on a business model; operating the development through responsibility centers; functional transformation of economic interest of actors in the ecosystem of function into the economic interest of enterprise; use of economic-institutional regulators and management technologies. Implementation of the mechanism would ensure the value of enterprise, the ability to manage development with the prolonged satisfaction of the joint economic interest, the ability to operate the economic interest of actors in the ecosystem, and maintenance the development mode in the operating process. Prospect for further research will be development of technologies for implementation of the proposed mechanism in the machine-building enterprises.

Probabilistic transport models for plasma transport in the presence of critical thresholds: Beyond the diffusive paradigma)

Science.gov (United States)

Sánchez, R.; van Milligen, B. Ph.; Carreras, B. A.

2005-05-01

It is argued that the modeling of plasma transport in tokamaks may benefit greatly from extending the usual local paradigm to accommodate scale-free transport mechanisms. This can be done by combining Lévy distributions and a nonlinear threshold condition within the continuous time random walk concept. The advantages of this nonlocal, nonlinear extension are illustrated by constructing a simple particle density transport model that, as a result of these ideas, spontaneously exhibits much of nondiffusive phenomenology routinely observed in tokamaks. The fluid limit of the system shows that the kind of equations that are appropriate to capture these dynamics are based on fractional differential operators. In them, effective diffusivities and pinch velocities are found that are dynamically set by the system in response to the specific characteristics of the fueling source and external perturbations. This fact suggests some dramatic consequences for the extrapolation of these transport properties to larger size systems.

Financial Mechanism for the Implementation of Strategic and Operational Financial Decisions of Modern Enterprises

Science.gov (United States)

Nikeriasova, Veronika V.; Ordov, Konstantin V.; Khvostenko, Oleg A.

2016-01-01

In modern conditions of world depression, it is urgent for increasing the efficiency of the financial mechanism. Company's future depends on the correct choice of the financial mechanism strategy. The article deals with the issues of improving the financial mechanism of enterprises in the implementation of strategic and operational financial…

Performance Analysis of a Burst Transmission Mechanism Using Microsleep Operation for Green IEEE 802.11 WLANs

Directory of Open Access Journals (Sweden)

Raul Palacios-Trujillo

2017-07-01

Full Text Available This paper evaluates the performance of a burst transmission mechanism using microsleep operation to support high energy efficiency in IEEE 802.11 Wireless Local Area Networks (WLANs. This mechanism is an implementation of the IEEE 802.11ac Transmission Opportunity Power Save Mode (TXOP PSM. A device using the TXOP PSM-based mechanism can switch to a low-power sleep state for the time that another device transmits a burst of data frames to a third one. This operation is called microsleep and its feasibility strongly depends on the time and energy consumption that a device incurs in the transitions from and to the sleep state. This paper accounts for the impact of these transitions in the derivation of an analytical model to calculate the energy efficiency of the TXOP PSM-based mechanism under network saturation. Results obtained show that the impact of the transition requirements on the feasibility of microsleep operation can be significant depending on the selected system parameters, although it can be reduced by using burst transmissions. When microsleep operation is feasible, the TXOP PSM-based mechanism can improve the energy efficiency of other legacy mechanisms by up to 424% under high traffic loads.

Mechanisms Regulating Acid-Base Transporter Expression in Breast- and Pancreatic Cancer

DEFF Research Database (Denmark)

Gorbatenko, Andrej

, characteristics of which are a shift towards glycolytic metabolism and increased acid production. HER2 receptor overexpression in breast cancer leads to further increased glycolysis, invasion and metastasis, drug resistance and poor prognosis. Increased tumor glycolysis requires acquisition of mechanisms...... for dealing with excess acid production. In this light, evidence accumulates on the importance of pH regulatory proteins to cancer cell survival and motility. Our group previously demonstrated upregulation of the Na+/HCO3 - co-transporter NBCn1 (SLC4A7) by a constitutively active form of HER2 receptor (p95HER...

Constraints on Transport and Emplacement Mechanisms of Labile Fractions in Lunar Cold Traps

Science.gov (United States)

Rickman, D.; Gertsch, L.

2014-01-01

Sustaining the scientific exploration of the Solar System will require a significant proportion of the necessary fuels and propellants, as well as other bulk commodities, to be produced from local raw materials [1]. The viability of mineral production depends on the ability to locate and characterize mineable deposits of the necessary feedstocks. This requires, among other things, a workable understanding of the mechanisms by which such deposits form, which is the subject of Economic Geology. Multiple deposition scenarios are possible for labile materials on the Moon. This paper suggests labile fractions moved diffusely through space; deposits may grow richer with depth until low porosity rock; lateral transport is likely to have occurred with the regolith, at least for short distances; crystalline ice may not exist; the constituent phases could be extremely complex. At present we can constrain the sources only mildly; once on the Moon, the transport mechanisms inherently mix and therefore obscure the origins. However, the importance of expanding our understanding of ore-forming processes on the Moon behooves us to make the attempt. Thus begins a time of new inquiry for Economic Geology.

Operating experience with the Harwell thermo-mechanical generators

International Nuclear Information System (INIS)

Cooke-Yarborough, E.H.

1980-06-01

The Stirling-cycle thermo-mechanical generator (TMG) provides small amounts of electrical power continuously over long periods, while requiring much less fuel than other power sources running from hydrocarbon fuel or radio-isotopes. Two of these 25-watt generators, fuelled by propane, have been used to power the UK National Buoy on two successive missions. A total of more than three years experience at sea has now been accumulated. In addition, a 60-watt version has provided the power for a major lighthouse for more than a year. An early development version of the Thermo-mechanical Generator, adapted to run from the heat of a radio-isotope source, was loaded with strontium 90 titanate in October 1974 and has run continuously in the laboratory ever since. The improvements and changes found necessary in the course of 90,000 generator-hours of running time are described, and the improvements in operational performance and reliability which have resulted are outlined. (author)

Computerized simulation of the mechanical behavior of wood-filled shock absorbers of radioactive materials transport casks

International Nuclear Information System (INIS)

Neumann, Martin; Wille, Frank

2011-01-01

In Germany the mechanical component inspection of transport containers for radioactive materials is performed by BAM (Bundesanstalt fuer Materialforschung und -pruefung) under consideration of national and international standards and guidelines. Experimental and calculative (analytical and numerical) techniques combined with material and/or component testing are the basis of assessment concepts according the state of the art. The authors describe the experiences of BAM concerning assessment and description of the mechanical behavior of shock absorbing components, including modeling strategies, material models, drop tests and experiment-calculation comparison. Energy absorbing components are used to reduce the impact forces at the container in case of a transport accident. In Germany wood filled thin-walled constructions are used. The deformation behavior of the wood is a main part of the calculative simulation procedures in comparison with experimental tests.

THE SHAPING OF SOME LIFTING AND TRANSPORTATION SYSTEMS, USING AUTODESK INVENTOR

Directory of Open Access Journals (Sweden)

URSE Cătălin

2011-11-01

Full Text Available The paper presents, through the use of Autodesk Inventor software package, several mechanisms from the structure of lifting and transportation machines, in this case lifting system with winch operated by screw,lifting system type with muffle with hook, respectively bridge crane type.

Piezo-Operated Shutter Mechanism Moves 1.5 cm

Science.gov (United States)

Glaser, Robert; Bamford, Robert

2005-01-01

The figure shows parts of a shutter mechanism designed to satisfy a number of requirements specific to its original intended application as a component of an atomic clock to be flown in outer space. The mechanism may also be suitable for use in laboratory and industrial vacuum systems on Earth for which there are similar requirements. The requirements include the following: a) To alternately close, then open, a 1.5-cm-diameter optical aperture twice per second, with a stroke time of no more than 15 ms, during a total operational lifetime of at least a year; b) To attenuate light by a factor of at least 1012 when in the closed position; c) To generate little or no magnetic field; d) To be capable of withstanding bakeout at a temperature of 200 C to minimize outgassing during subsequent operation in an ultrahigh vacuum; and e) To fit within a diameter of 12 in. (=305 mm) a size limit dictated by the size of an associated magnetic shield. The light-attenuation requirement is satisfied by use of overlapping shutter blades. The closure of the aperture involves, among other things, insertion of a single shutter blade between a pair of shutter blades. The requirement to minimize the magnetic field is satisfied by use of piezoelectric actuators. Because piezoelectric actuators cannot withstand bakeout, they must be mounted outside the vacuum chamber, and, hence, motion must be transmitted from the actuators to the shutter levers via a vacuum-chamber-wall diaphragm.

Combination study of operation characteristics and heat transfer mechanism for pulsating heat pipe

International Nuclear Information System (INIS)

Cui, Xiaoyu; Zhu, Yue; Li, Zhihua; Shun, Shende

2014-01-01

Pulsating heat pipe (PHP) is becoming a promising heat transfer device for the application like electronics cooling. However, due to its complicated operation mechanism, the heat transfer properties of the PHP still have not been fully understood. This study experimentally investigated on a closed-loop PHP charged with four types of working fluids, deionized water, methanol, ethanol and acetone. Combined with the visualization experimental results from the open literature, the operation characteristics and the corresponding heat transfer mechanisms for different heat inputs (5 W up to 100 W) and different filling ratios (20% up to 95%) have been presented and elaborated. The results show that heat-transfer mechanism changed with the transition of operation patterns; before valid oscillation started, the thermal resistance was not like that described in the open literature where it decreased almost linearly, but would rather slowdown descending or even change into rise first before further decreasing (i.e. an inflection point existed); when the heat input further increased to certain level, e.g. 65 W or above, there presented a limit of heat-transfer performance which was independent of the types of working fluids and the filling ratios, but may be related to the structure, the material, the size and the inclination of the PHP. - Highlights: •The thermal mechanisms altered accordingly with the operation features in the PHP. •Unlike conventional heat pipes, continuous temperature soaring would not happen in the PHP. •Before the oscillation start-up, there existed a heat-transfer limit for the relatively stagnated flow in the PHP. •A limit of thermal performance existed in the PHP at relatively high heat inputs

Transport in the Nordic countries

International Nuclear Information System (INIS)

Gustafsson, B.; Pettersson, S.; Vilkamo, S.

1989-01-01

Transport of radioactive material from different fields of operation is well advanced in the Nordic countries: waste from the medical sector, industry, research, and now in increasing amounts from reactor operation, including spent fuel. In the future, waste from decommissioning will also be transported. This report gives the amount of radioactive waste material to be transported in the Nordic countries. Transport routes, transport containers, and transport systems are described. Legislations and transport regulatins are discussed. (author)

Mechanism transition of cell-impedance-controlled lithium transport through Li1-δMn2O4 composite electrode caused by surface-modification and temperature variation

International Nuclear Information System (INIS)

Jung, Kyu-Nam; Pyun, Su-Il

2007-01-01

The mechanism transition of lithium transport through a Li 1-δ Mn 2 O 4 composite electrode caused by the surface-modification and temperature variation was investigated using the galvanostatic intermittent titration technique (GITT), electrochemical impedance spectroscopy (EIS) and the potentiostatic current transient technique. From the analyses of the ac-impedance spectra, experimentally measured from unmodified Li 1-δ Mn 2 O 4 and surface-modified Li 1-δ Mn 2 O 4 with MgO composite electrodes, the internal cell resistance of the MgO-modified Li 1-δ Mn 2 O 4 electrode was determined to be much smaller in value than that of the unmodified electrode over the whole potential range. Moreover, from the analysis of the anodic current transients measured on the MgO-modified Li 1-δ Mn 2 O 4 electrode, it was found that the cell-impedance-controlled constraint at the electrode surface is changed to a diffusion-controlled constraint, which is characterised by a large potential step and simultaneously by a small amount of lithium transferred during lithium transport. This strongly suggests that the internal cell resistance plays a significant role in determining the cell-impedance-controlled lithium transport through the MgO-modified Li 1-δ Mn 2 O 4 electrode. Furthermore, from the temperature dependence of the internal cell resistance and diffusion resistance in the unmodified Li 1-δ Mn 2 O 4 composite electrode measured by GITT and EIS, it was concluded that which mechanism of lithium transport will be operative strongly depends on the diffusion resistance as well as on the internal cell resistance

Point-to-Point! Validation of the Small Aircraft Transportation System Higher Volume Operations Concept

Science.gov (United States)

Williams, Daniel M.

2006-01-01

Described is the research process that NASA researchers used to validate the Small Aircraft Transportation System (SATS) Higher Volume Operations (HVO) concept. The four phase building-block validation and verification process included multiple elements ranging from formal analysis of HVO procedures to flight test, to full-system architecture prototype that was successfully shown to the public at the June 2005 SATS Technical Demonstration in Danville, VA. Presented are significant results of each of the four research phases that extend early results presented at ICAS 2004. HVO study results have been incorporated into the development of the Next Generation Air Transportation System (NGATS) vision and offer a validated concept to provide a significant portion of the 3X capacity improvement sought after in the United States National Airspace System (NAS).

Anomalous transport in toroidal plasmas

International Nuclear Information System (INIS)

Punjabi, A.

1989-12-01

When the magnetic moment of particle is conserved, there are three mechanisms which cause anomalous transport. These are: variation of magnetic field strength in flux surface, variation of electrostatic potential in flux surface, and destruction of flux surface. The anomalous transport of different groups of particles resulting from each of these mechanisms is different. This fact can be exploited to determine the cause of transport operative in an experimental situation. This approach can give far more information on the transport than the standard confinement time measurements. To implement this approach, we have developed Monte Carlo codes for toroidal geometries. The equations of motion are developed in a set of non-canonical, practical Boozer co-ordinates by means of Jacobian transformations of the particle drift Hamiltonian equations of motion. Effects of collisions are included by appropriate stochastic changes in the constants of motion. Effects of the loop voltage on particle motions are also included. We plan to apply our method to study two problems: the problem of the hot electron tail observed in edge region of ZT-40, and the energy confinement time in TOKAPOLE II. For the ZT-40 problem three situations will be considered: a single mode in the core, a stochastic region that covers half the minor radius, a stochastic region that covers the entire plasma. A turbulent spectrum of perturbations based on the experimental data of TOKAPOLE II will be developed. This will be used to simulate electron transport resulting from ideal instabilities and resistive instabilities in TOKAPOLE II

Quantum Hamilton mechanics: Hamilton equations of quantum motion, origin of quantum operators, and proof of quantization axiom

International Nuclear Information System (INIS)

Yang, C.-D.

2006-01-01

This paper gives a thorough investigation on formulating and solving quantum problems by extended analytical mechanics that extends canonical variables to complex domain. With this complex extension, we show that quantum mechanics becomes a part of analytical mechanics and hence can be treated integrally with classical mechanics. Complex canonical variables are governed by Hamilton equations of motion, which can be derived naturally from Schroedinger equation. Using complex canonical variables, a formal proof of the quantization axiom p → p = -ih∇, which is the kernel in constructing quantum-mechanical systems, becomes a one-line corollary of Hamilton mechanics. The derivation of quantum operators from Hamilton mechanics is coordinate independent and thus allows us to derive quantum operators directly under any coordinate system without transforming back to Cartesian coordinates. Besides deriving quantum operators, we also show that the various prominent quantum effects, such as quantization, tunneling, atomic shell structure, Aharonov-Bohm effect, and spin, all have the root in Hamilton mechanics and can be described entirely by Hamilton equations of motion

Modelling the role of intrinsic electric fields in microtubules as an additional control mechanism of bi-directional intracellular transport.

Science.gov (United States)

Sataric, M V; Budinski-Petkovic, L; Loncarevic, I; Tuszynski, J A

2008-01-01

Active transport is essential for cellular function, while impaired transport has been linked to diseases such as neuronal degeneration. Much long distance transport in cells uses opposite polarity molecular motors of the kinesin and dynein families to move cargos along microtubules. It is clear that many types of cargo are moved by both sets of motors, and frequently in a reverse direction. The general question of how the direction of transport is regulated is still open. The mechanism of the cell's differential control of diverse cargos within the same cytoplasmic background is still unclear as is the answer to the question how endosomes and mitochondria move to different locations within the same cell. To answer these questions we postulate the existence of a local signaling mechanism used by the cell to specifically control different cargos. In particular, we propose an additional physical mechanism that works through the use of constant and alternating intrinsic (endogenous) electric fields as a means of controlling the speed and direction of microtubule-based transport. A specific model is proposed and analyzed in this paper. The model involves the rotational degrees of freedom of the C-termini of tubulin, their interactions and the coupling between elastic and dielectric degrees of freedom. Viscosity of the solution is also included and the resultant equation of motion is found as a nonlinear elliptic equation with dissipation. A particular analytical solution of this equation is obtained in the form of a kink whose properties are analyzed. It is concluded that this solution can be modulated by the presence of electric fields and hence may correspond to the observed behavior of motor protein transport along microtubules.

Mining Pribram in science and technology. Proceedings of Session R - Mechanization of mine operations

International Nuclear Information System (INIS)

Kolar, J.; Bernatik, O.

1987-01-01

The proceedings contain 30 papers of which two deal with uranium mine problems, viz.: ''Current and prospective orientation of mechanized driving of mines and underground infrastructures'' and ''The operation of rail-less mine mechanization in the Hamr area''. (J.B.)

Charge transport in organic semiconductors.

Science.gov (United States)

Bässler, Heinz; Köhler, Anna

2012-01-01

Modern optoelectronic devices, such as light-emitting diodes, field-effect transistors and organic solar cells require well controlled motion of charges for their efficient operation. The understanding of the processes that determine charge transport is therefore of paramount importance for designing materials with improved structure-property relationships. Before discussing different regimes of charge transport in organic semiconductors, we present a brief introduction into the conceptual framework in which we interpret the relevant photophysical processes. That is, we compare a molecular picture of electronic excitations against the Su-Schrieffer-Heeger semiconductor band model. After a brief description of experimental techniques needed to measure charge mobilities, we then elaborate on the parameters controlling charge transport in technologically relevant materials. Thus, we consider the influences of electronic coupling between molecular units, disorder, polaronic effects and space charge. A particular focus is given to the recent progress made in understanding charge transport on short time scales and short length scales. The mechanism for charge injection is briefly addressed towards the end of this chapter.

Reliability and risk evaluation of a port oil pipeline transportation system in variable operation conditions

Energy Technology Data Exchange (ETDEWEB)

Soszynska, Joanna, E-mail: joannas@am.gdynia.p [Department of Mathematics, Gdynia Maritime University, ul. Morska 83, 81-225 Gdynia (Poland)

2010-02-15

The semi-Markov model of the system operation processes is proposed and its selected characteristics are determined. A system composed on multi-state components is considered and its reliability and risk characteristics are found. Next, the joint model of the system operation process and the system multi-state reliability is applied to the reliability and risk evaluation of the port oil pipeline transportation system. The pipeline system is described and its operation process unknown parameters are identified on the basis of real statistical data. The mean values of the pipeline system operation process unconditional sojourn times in particular operation states are found and applied to determining this process transient probabilities in these states. The piping different reliability structures in various its operation states are fixed and their conditional reliability functions on the basis of data coming from experts are approximately determined. Finally, after applying earlier estimated transient probabilities and system conditional reliability functions in particular operation states the unconditional reliability function, the mean values and standard deviations of the pipeline lifetimes in particular reliability states, risk function and the moment when the risk exceeds a critical value are found.

Reliability and risk evaluation of a port oil pipeline transportation system in variable operation conditions

International Nuclear Information System (INIS)

Soszynska, Joanna

2010-01-01

The semi-Markov model of the system operation processes is proposed and its selected characteristics are determined. A system composed on multi-state components is considered and its reliability and risk characteristics are found. Next, the joint model of the system operation process and the system multi-state reliability is applied to the reliability and risk evaluation of the port oil pipeline transportation system. The pipeline system is described and its operation process unknown parameters are identified on the basis of real statistical data. The mean values of the pipeline system operation process unconditional sojourn times in particular operation states are found and applied to determining this process transient probabilities in these states. The piping different reliability structures in various its operation states are fixed and their conditional reliability functions on the basis of data coming from experts are approximately determined. Finally, after applying earlier estimated transient probabilities and system conditional reliability functions in particular operation states the unconditional reliability function, the mean values and standard deviations of the pipeline lifetimes in particular reliability states, risk function and the moment when the risk exceeds a critical value are found.

Mechanisms of the 40-70 Day Variability in the Yucatan Channel Volume Transport

Science.gov (United States)

van Westen, René M.; Dijkstra, Henk A.; Klees, Roland; Riva, Riccardo E. M.; Slobbe, D. Cornelis; van der Boog, Carine G.; Katsman, Caroline A.; Candy, Adam S.; Pietrzak, Julie D.; Zijlema, Marcel; James, Rebecca K.; Bouma, Tjeerd J.

2018-02-01

The Yucatan Channel connects the Caribbean Sea with the Gulf of Mexico and is the main outflow region of the Caribbean Sea. Moorings in the Yucatan Channel show high-frequent variability in kinetic energy (50-100 days) and transport (20-40 days), but the physical mechanisms controlling this variability are poorly understood. In this study, we show that the short-term variability in the Yucatan Channel transport has an upstream origin and arises from processes in the North Brazil Current. To establish this connection, we use data from altimetry and model output from several high resolution global models. A significant 40-70 day variability is found in the sea surface height in the North Brazil Current retroflection region with a propagation toward the Lesser Antilles. The frequency of variability is generated by intrinsic processes associated with the shedding of eddies, rather than by atmospheric forcing. This sea surface height variability is able to pass the Lesser Antilles, it propagates westward with the background ocean flow in the Caribbean Sea and finally affects the variability in the Yucatan Channel volume transport.

Transport coefficients and mechanical response in hard-disk colloidal suspensions

Science.gov (United States)

Zhang, Bo-Kai; Li, Jian; Chen, Kang; Tian, Wen-De; Ma, Yu-Qiang

2016-11-01

We investigate the transport properties and mechanical response of glassy hard disks using nonlinear Langevin equation theory. We derive expressions for the elastic shear modulus and viscosity in two dimensions on the basis of thermal-activated barrier-hopping dynamics and mechanically accelerated motion. Dense hard disks exhibit phenomena such as softening elasticity, shear-thinning of viscosity, and yielding upon deformation, which are qualitatively similar to dense hard-sphere colloidal suspensions in three dimensions. These phenomena can be ascribed to stress-induced “landscape tilting”. Quantitative comparisons of these phenomena between hard disks and hard spheres are presented. Interestingly, we find that the density dependence of yield stress in hard disks is much more significant than in hard spheres. Our work provides a foundation for further generalizing the nonlinear Langevin equation theory to address slow dynamics and rheological behavior in binary or polydisperse mixtures of hard or soft disks. Project supported by the National Basic Research Program of China (Grant No. 2012CB821500) and the National Natural Science Foundation of China (Grant Nos. 21374073 and, 21574096).

Mechanical coupling of microtubule-dependent motor teams during peroxisome transport in Drosophila S2 cells.

Science.gov (United States)

De Rossi, María Cecilia; Wetzler, Diana E; Benseñor, Lorena; De Rossi, María Emilia; Sued, Mariela; Rodríguez, Daniela; Gelfand, Vladimir; Bruno, Luciana; Levi, Valeria

2017-12-01

Intracellular transport requires molecular motors that step along cytoskeletal filaments actively dragging cargoes through the crowded cytoplasm. Here, we explore the interplay of the opposed polarity motors kinesin-1 and cytoplasmic dynein during peroxisome transport along microtubules in Drosophila S2 cells. We used single particle tracking with nanometer accuracy and millisecond time resolution to extract quantitative information on the bidirectional motion of organelles. The transport performance was studied in cells expressing a slow chimeric plus-end directed motor or the kinesin heavy chain. We also analyzed the influence of peroxisomes membrane fluidity in methyl-β-ciclodextrin treated cells. The experimental data was also confronted with numerical simulations of two well-established tug of war scenarios. The velocity distributions of retrograde and anterograde peroxisomes showed a multimodal pattern suggesting that multiple motor teams drive transport in either direction. The chimeric motors interfered with the performance of anterograde transport and also reduced the speed of the slowest retrograde team. In addition, increasing the fluidity of peroxisomes membrane decreased the speed of the slowest anterograde and retrograde teams. Our results support the existence of a crosstalk between opposed-polarity motor teams. Moreover, the slowest teams seem to mechanically communicate with each other through the membrane to trigger transport. Copyright © 2017 Elsevier B.V. All rights reserved.

Radioactive materials transport: worldwide excellence in safety, past, present and future

International Nuclear Information System (INIS)

Heywood, J.D.; Blenkin, J.J.; Wilkinson, H.L.; Murray, M.

1997-01-01

The safety record of the transport of radioactive material (RAM) is excellent. This level of safety has been achieved on a global scale principally through the adoption into national legislation of the International Atomic Energy Agency (IAEA) Transport Regulations by all countries which participate in the movement of RAM. The engineered and operational controls address containment of the RAM, radiation emitted from the package, dissipation of heat and prevention of criticality. The nuclear industry and its regulators have constantly sought to improve the safety of RAM transport operations, and also to measure the degree of safety compared with other industries and with generic safety criteria. Because of the extremely low incident rate and the consequent absence of direct historical data, probabilistic methods have been applied to provide a conservative assessment of the risks associated with specific transport operations. This paper illustrates the effectiveness of the IAEA Regulations in ensuring safety by reference to UK and worldwide experience, the results of quantified risk assessments and the mechanisms in place for continued review and improvement of the Regulations. The following topics are explored: (1) The controls controls embodied in the IAEA Regulations and how they minimise the consequences of accidents. (2) A review of quantified risk assessments carried out in this country and abroad. (3) A summary of the RAM transport incident record and a brief review of the results of surveys of RAM transport operations in the UK and worldwide. (4) Discussion of the risks associated with RAM transport compared with other industries. The paper concludes that the IAEA Regulations provide a robust and effective framework for the safe transport of RAM, ensuring that risks are kept at very low levels compared to relevant accepted criteria and other dangerous goods transport operations. The provisions for review and revision of the IAEA Regulations ensure that they

Charge transport mechanism in p-type copper ion containing triazine thiolate metallopolymer thin film devices

Science.gov (United States)

K, Deepak; Roy, Amit; Anjaneyulu, P.; Kandaiah, Sakthivel; Pinjare, Sampatrao L.

2017-10-01

The charge transport mechanism in copper ions containing 1,3,5-Triazine-2,4,6-trithiolate (CuTCA) based polymer device in sandwich (Ag/CuTCA/Cu) geometry is studied. The current-voltage (I-V) characteristics of the metallopolymer CuTCA device have shown a transition in the charge transport mechanism from Ohmic to Space-charge limited conduction when temperature and voltage are varied. The carriers in CuTCA devices exhibit hopping transport, in which carriers hop from one site to the other. The hole mobility in this polymer device is found to be dependent on electric field E ( μpα√{E } ) and temperature, which suggests that the polymer has inherent disorder. The electric-field coefficient γ and zero-field mobility μ0 are temperature dependent. The values of mobility and activation energies are estimated from temperature (90-140 K) dependent charge transport studies and found to be in the range of 1 × 10-11-8 × 10-12 m2/(V s) and 16.5 meV, respectively. Temperature dependent electric-field coefficient γ is in the order of 17.8 × 10-4 (m/V)1/2, and the value of zero-field mobility μ0 is in the order of 1.2 × 10-11 m2/(V s) at 140 K. A constant phase element (Q) is used to model the device parameters, which are extracted using the Impedance spectroscopy technique. The bandgap of the polymer is estimated to be 2.6 eV from UV-Vis reflectance spectra.

Mechanical stress analysis for a fuel rod under normal operating conditions

International Nuclear Information System (INIS)

Pino, Eddy S.; Giovedi, Claudia; Serra, Andre da Silva; Abe, Alfredo Y.

2013-01-01

Nuclear reactor fuel elements consist mainly in a system of a nuclear fuel encapsulated by a cladding material subject to high fluxes of energetic neutrons, high operating temperatures, pressure systems, thermal gradients, heat fluxes and with chemical compatibility with the reactor coolant. The design of a nuclear reactor requires, among a set of activities, the evaluation of the structural integrity of the fuel rod submitted to different loads acting on the fuel rod and the specific properties (dimensions and mechanical and thermal properties) of the cladding material and coolant, including thermal and pressure gradients produced inside the rod due to the fuel burnup. In this work were evaluated the structural mechanical stresses of a fuel rod using stainless steel as cladding material and UO 2 with a low degree of enrichment as fuel pellet on a PWR (pressurized water reactor) under normal operating conditions. In this sense, tangential, radial and axial stress on internal and external cladding surfaces considering the orientations of 0 deg, 90 deg and 180 deg were considered. The obtained values were compared with the limit values for stress to the studied material. From the obtained results, it was possible to conclude that, under the expected normal reactor operation conditions, the integrity of the fuel rod can be maintained. (author)

The application of fracture mechanics to the safety assessment of transport casks for radioactive materials

International Nuclear Information System (INIS)

Zencker, U.; Mueller, K.; Droste, B.; Roedel, R.; Voelzke, H.

2004-01-01

BAM is the German responsible authority for the mechanical and thermal design safety assessment of packages for the transport of radioactive materials. The assessment has to cover the brittle fracture safety proof of package components made of potentially brittle materials. This paper gives a survey of the regulatory and technical requirements for such an assessment according to BAM's new ''Guidelines for the Application of Ductile Cast Iron for Transport and Storage Casks for Radioactive Materials''. Based on these guidelines higher stresses than before can become permissible, but it is necessary to put more effort into the safety assessment procedure. The fundamentals of such a proof with the help of the methods of fracture mechanics are presented. The recommended procedure takes into account the guidelines of the IAEA Advisory Material which are based on the prevention of crack initiation. Examples of BAM's research and safety assessment practices are given. Recommendations for further developments towards package designs with higher acceptable stress levels will be concluded

The application of fracture mechanics to the safety assessment of transport casks for radioactive material

International Nuclear Information System (INIS)

Zencker, U.; Mueller, K.; Droste, B.; Roedel, R.; Voelzke, H.

2004-01-01

BAM is the responsible authority in Germany for the assessment of the mechanical and thermal design safety of packages for the transport of radioactive materials. The assessment has to cover the brittle fracture safety 'proof of package' for components made of potentially brittle materials. This paper gives a survey of the regulatory and technical requirements for such an assessment according to BAM's new 'Guidelines for the application of ductile cast iron for transport and storage casks for radioactive materials'. Based on these guidelines, higher stresses than before will be permissible, but it is necessary to put more effort into the safety assessment procedure. The fundamentals of such a proof using the methods of fracture mechanics are presented. The recommended procedure takes into account the guidelines of the IAEA's advisory material which are based on the prevention of crack initiation. Examples of BAM's research and safety assessment practices are given. Recommendations for further developments towards package designs with higher acceptable stress levels will conclude the paper. (author)

Smart Collision Avoidance and Hazard Routing Mechanism for Intelligent Transport Network

Science.gov (United States)

Singh, Gurpreet; Gupta, Pooja; Wahab, Mohd Helmy Abd

2017-08-01

The smart vehicular ad-hoc network is the network that consists of vehicles for smooth movement and better management of the vehicular connectivity across the given network. This research paper aims to propose a set of solution for the VANETs consisting of the automatic driven vehicles, also called as the autonomous car. Such vehicular networks are always prone to collision due to the natural or un-natural reasons which must be solved before the large-scale deployment of the autonomous transport systems. The newly designed intelligent transport movement control mechanism is based upon the intelligent data propagation along with the vehicle collision and traffic jam prevention schema [8], which may help the future designs of smart cities to become more robust and less error-prone. In the proposed model, the focus is on designing a new dynamic and robust hazard routing protocol for intelligent vehicular networks for improvement of the overall performance in various aspects. It is expected to improve the overall transmission delay as well as the number of collisions or adversaries across the vehicular network zone.

Comparison of particle trajectories and collision operators for collisional transport in nonaxisymmetric plasmas

Energy Technology Data Exchange (ETDEWEB)

Landreman, M., E-mail: mattland@umd.edu [Institute for Research in Electronics and Applied Physics, University of Maryland, College Park, Maryland 20742 (United States); Smith, H. M.; Helander, P. [Max-Planck-Institut für Plasmaphysik, 17491 Greifswald (Germany); Mollén, A. [Department of Applied Physics, Chalmers University of Technology, Göteborg (Sweden)

2014-04-15

In this work, we examine the validity of several common simplifying assumptions used in numerical neoclassical calculations for nonaxisymmetric plasmas, both by using a new continuum drift-kinetic code and by considering analytic properties of the kinetic equation. First, neoclassical phenomena are computed for the LHD and W7-X stellarators using several versions of the drift-kinetic equation, including the commonly used incompressible-E × B-drift approximation and two other variants, corresponding to different effective particle trajectories. It is found that for electric fields below roughly one third of the resonant value, the different formulations give nearly identical results, demonstrating the incompressible E × B-drift approximation is quite accurate in this regime. However, near the electric field resonance, the models yield substantially different results. We also compare results for various collision operators, including the full linearized Fokker-Planck operator. At low collisionality, the radial transport driven by radial gradients is nearly identical for the different operators; while in other cases, it is found to be important that collisions conserve momentum.

Impact of mechanized logging operations on wet and dry soils of ...

African Journals Online (AJOL)

Mechanization of timber harvesting operations in Tanzania involves use of machinery such as feller bunchers, skidders and tractors which are generally heavy in weight ranging from 12 to 16 tones in unloaded state. The movements of these machines induce soil compaction owing to the exerted normal pressure, vibrations ...

Turbulent transport regimes and the scrape-off layer heat flux width

Science.gov (United States)

Myra, J. R.; D'Ippolito, D. A.; Russell, D. A.

2015-04-01

Understanding the responsible mechanisms and resulting scaling of the scrape-off layer (SOL) heat flux width is important for predicting viable operating regimes in future tokamaks and for seeking possible mitigation schemes. In this paper, we present a qualitative and conceptual framework for understanding various regimes of edge/SOL turbulence and the role of turbulent transport as the mechanism for establishing the SOL heat flux width. Relevant considerations include the type and spectral characteristics of underlying instabilities, the location of the gradient drive relative to the SOL, the nonlinear saturation mechanism, and the parallel heat transport regime. We find a heat flux width scaling with major radius R that is generally positive, consistent with the previous findings [Connor et al., Nucl. Fusion 39, 169 (1999)]. The possible relationship of turbulence mechanisms to the neoclassical orbit width or heuristic drift mechanism in core energy confinement regimes known as low (L) mode and high (H) mode is considered, together with implications for the future experiments.

Turbulent transport regimes and the scrape-off layer heat flux width

International Nuclear Information System (INIS)

Myra, J. R.; D'Ippolito, D. A.; Russell, D. A.

2015-01-01

Understanding the responsible mechanisms and resulting scaling of the scrape-off layer (SOL) heat flux width is important for predicting viable operating regimes in future tokamaks and for seeking possible mitigation schemes. In this paper, we present a qualitative and conceptual framework for understanding various regimes of edge/SOL turbulence and the role of turbulent transport as the mechanism for establishing the SOL heat flux width. Relevant considerations include the type and spectral characteristics of underlying instabilities, the location of the gradient drive relative to the SOL, the nonlinear saturation mechanism, and the parallel heat transport regime. We find a heat flux width scaling with major radius R that is generally positive, consistent with the previous findings [Connor et al., Nucl. Fusion 39, 169 (1999)]. The possible relationship of turbulence mechanisms to the neoclassical orbit width or heuristic drift mechanism in core energy confinement regimes known as low (L) mode and high (H) mode is considered, together with implications for the future experiments

Supporting inland waterway transport on German waterways by operational forecasting services - water-levels, discharges, river ice

Science.gov (United States)

Meißner, Dennis; Klein, Bastian; Ionita, Monica; Hemri, Stephan; Rademacher, Silke

2017-04-01

Inland waterway transport (IWT) is an important commercial sector significantly vulnerable to hydrological impacts. River ice and floods limit the availability of the waterway network and may cause considerable damages to waterway infrastructure. Low flows significantly affect IWT's operation efficiency usually several months a year due to the close correlation of (low) water levels / water depths and (high) transport costs. Therefore "navigation-related" hydrological forecasts focussing on the specific requirements of water-bound transport (relevant forecast locations, target parameters, skill characteristics etc.) play a major role in order to mitigate IWT's vulnerability to hydro-meteorological impacts. In light of continuing transport growth within the European Union, hydrological forecasts for the waterways are essential to stimulate the use of the free capacity IWT still offers more consequently. An overview of the current operational and pre-operational forecasting systems for the German waterways predicting water levels, discharges and river ice thickness on various time-scales will be presented. While short-term (deterministic) forecasts have a long tradition in navigation-related forecasting, (probabilistic) forecasting services offering extended lead-times are not yet well-established and are still subject to current research and development activities (e.g. within the EU-projects EUPORIAS and IMPREX). The focus is on improving technical aspects as well as on exploring adequate ways of disseminating and communicating probabilistic forecast information. For the German stretch of the River Rhine, one of the most frequented inland waterways worldwide, the existing deterministic forecast scheme has been extended by ensemble forecasts combined with statistical post-processing modules applying EMOS (Ensemble Model Output Statistics) and ECC (Ensemble Copula Coupling) in order to generate water level predictions up to 10 days and to estimate its predictive