Development of a Malian food exchange system based on local ...

African Journals Online (AJOL)

No significant differences were found for the intakes of legumes, milk, vegetables and sugar-added foods. Conclusions: This study allowed the development of Malian food exchange lists and demonstrated their usefulness for the description of the dietary pattern and energy and macronutrient intakes of male and female ...

Modeling Of Proton Exchange Membrane Fuel Cell Systems

DEFF Research Database (Denmark)

Nielsen, Mads Pagh

The objective of this doctoral thesis was to develop reliable steady-state and transient component models suitable to asses-, develop- and optimize proton exchange membrane (PEM) fuel cell systems. Several components in PEM fuel cell systems were characterized and modeled. The developed component...... cell systems. Consequences of indirectly fueling PEM stacks with hydrocarbons using reforming technology were investigated using a PEM stack model including CO poisoning kinetics and a transient Simulink steam reforming system model. Aspects regarding the optimization of PEM fuel cell systems...

Modem: data exchange among decision support systems

International Nuclear Information System (INIS)

Baig, S.; Zaehringer, M.

2003-01-01

The aim of the European Research and Development project MODEM (Monitoring Data and Information Exchange Among Decision Support Systems) is to achieve practical improvements for data exchange among decision support systems (DSS). Hence, the results of model calculations become comparable. This is a precondition for harmonised decision making. Based on the analysis of existing procedures, it was decided to use the PUSH-PULL concept. Notifications are actively and automatically sent by the DSS (PUSH). The data can then be downloaded form an in-formation server (PULL). The format of the data is defined in XML (extended markup language). Participants of the project are the DSS: RODOS, ARGOS and RECASS. First, the data is comprised of the source term and meteorological information. Results of the prognoses and measurement data are also to be exchanged. Exercises testing and improving the pro-cedures form an integral part of the project. (orig.)

Development of Preparation Methods for Alkaline Anion Exchange Membranes by Radiation

International Nuclear Information System (INIS)

Shin, Jun Hwa; Nho, Young Chang; Sohn, Joon Yong

2010-01-01

The objective of this project is to contribute to the environmentally friendly fuel cell system by developing a radiation grafting method for the preparation of anion exchange membranes for alkaline fuel cell and finally to the radiation technology industry. In this project, the preparation methods for the VBC-grafted fluoropolymer films using radiation have been developed and anion exchange membranes have been prepared via the reaction between the VBC-grafted fluoropolymer films and amines. The prepared anion exchange membranes were characterized and the performance of the membranes were evaluated

Effects and Implications for Adoption of Brokerage System in Korea's Foreign Exchange Market

Directory of Open Access Journals (Sweden)

Yunjong Wang

1999-03-01

Full Text Available Since January 1st 1999, the South Korean government has begun to establish the understructure of the foreign exchange market in order to achieve the liberalization of foreign exchange. As one of the plans, the trade of foreign exchange which was under the monopolized mediation of the capital medium of financial settlement center will be in the charge of several commercial brokers. In the developed countries, the foreign exchange & stock system and the liberalization of foreign exchange are both widely used in a flexible way. So it is predicted that the introduction of commercial foreign exchange & stock system will bring positive effect to the enhancement of the market efficiency and the function of price both in South Korean market and overseas market, the foster of competitive power of the domestic broker and the improvement of the understructure of domestic foreign exchange market. But more importantly is that the foreign exchange market must expand the scale of its participator, bring in various relevant foreign exchange products and develop the bond market which has a close relationship with the foreign exchange market for further development.

Developing maintenance technologies for FBR's heat exchanger units by advanced laser processing

International Nuclear Information System (INIS)

Nishimura, Akihiko; Shimada, Yukihiro

2011-01-01

Laser processing technologies were developed for the purpose of maintenance of FBR's heat exchanger units. Ultrashort laser processing fabricated fiber Bragg grating sensor for seismic monitoring. Fiber laser welding with a newly developed robot system repair cracks on inner wall of heat exchanger tubes. Safety operation of the heat exchanger units will be improved by the advanced laser processing technologies. These technologies are expected to be applied to the maintenance for the next generation FBRs. (author)

The Development of a Patient-Identification-Oriented Nursing Shift Exchange Support System Using Wireless RFID PDA Techniques

OpenAIRE

Huang, Pin-Jen; She, Chien-Cheng; Chang, Polun

2005-01-01

The objectives of this study were to technically testing the feasibility of combining RFID and PDA technologies in nursing care and to develop a support system for the nursing shift exchange, which featured with “Positive Patient Identification” and “Point of Care” for patient’s safety and security. The most challenging part for the future work would be to embed the system into the real workflow. Future study would be to examine the practical effectiveness of the system....

The Picture Exchange Communication System: Effects on Manding and Speech Development for School-Aged Children with Autism

Science.gov (United States)

Tincani, Matt; Crozier, Shannon; Alazett, Shannon

2006-01-01

We examined the effects of the Picture Exchange Communication System (PECS; Frost & Bondy, 2002) on the manding (requesting) and speech development of school-aged children with autism. In study 1, two participants, Damian and Bob, were taught PECS within a delayed multiple baseline design. Both participants demonstrated increased levels of manding…

Study of kinetics, equilibrium and isotope exchange in ion exchange systems Pt. 6

International Nuclear Information System (INIS)

Plicka, J.; Stamberg, K.; Cabicar, J.; Gosman, A.

1986-01-01

The description of kinetics of ion exchange in ternary system was based upon three Nernst-Planck equations, each of them describing the particle diffusion flux of a given counterion as an independent process. For experimental verification, the strongly acidic cation exchanger OSTION KS 08 the shallow-bed technique, and 0.2 mol x dm -3 aqueous nitrate solutions were chosen. The kinetics of ion exchange in the system of cations Na + - Mg 2+ - UO 2 2+ was studied. The values of diffusion coefficients obtained by evaluating of kinetics of isotope exchange and binary ion exchange were used for calculation. The comparison of calculated exchange rate curves with the experimental ones was made. It was found that the exchanging counterions were affected by each other. (author)

Development of volume-reduction system for ion exchange resin using inductively coupled plasma

International Nuclear Information System (INIS)

Fujisawa, Morio; Katagiri, Genichi

2002-01-01

The spent ion exchange resin generated as radioactive waste in water purifying system at nuclear power stations or related facilities of nuclear power has been stored in the site, and its volume has been increasing year by year. We had developed a full-scale system of IC plasma volume-reduction system for the spent resin, and have performed basic performance test using some samples imitating the spent resin. As the results, the imitation of the resin can be reduced in volume by more than 90% so that the processing performance in actual scale was proved to be effective. In addition, it was clarified that the residuum after volume-reduction process is easy to mix with cement, and solidity containing 30wt% residuum provides high strength of 68 MPa. Therefore, we evaluate the application of this process to stabilization of the disposal to be very effective. (author)

Active heat exchange system development for latent heat thermal energy storage

Science.gov (United States)

Alario, J.; Kosson, R.; Haslett, R.

1980-01-01

Various active heat exchange concepts were identified from among three generic categories: scrapers, agitators/vibrators and slurries. The more practical ones were given a more detailed technical evaluation and an economic comparison with a passive tube-shell design for a reference application (300 MW sub t storage for 6 hours). Two concepts were selected for hardware development: (1) a direct contact heat exchanger in which molten salt droplets are injected into a cooler counterflowing stream of liquid metal carrier fluid, and (2) a rotating drum scraper in which molten salt is sprayed onto the circumference of a rotating drum, which contains the fluid salt is sprayed onto the circumference of a rotating drum, which contains the fluid heat sink in an internal annulus near the surface. A fixed scraper blade removes the solidified salt from the surface which was nickel plated to decrease adhesion forces. In addition to improving performance by providing a nearly constant transfer rate during discharge, these active heat exchanger concepts were estimated to cost at least 25% less than the passive tube-shell design.

Compact interior heat exchangers for CO{sub 2} mobile heat pumping systems

Energy Technology Data Exchange (ETDEWEB)

Hafner, Armin

2003-07-01

The natural refrigerant carbon dioxide (CO{sub 2}) offers new possibilities for design of flexible, efficient and environmentally safe mobile heat pumping systems. As high-efficient car engines with less waste heat are developed, extra heating of the passenger compartment is needed in the cold season. A reversible transcritical CO{sub 2} system with gliding temperature heat rejection can give high air delivery temperature which results in rapid heating of the passenger compartment and rapid defogging or defrosting of windows. When operated in cooling mode, the efficiency of transcritical CO{sub 2} systems is higher compared to common (HFC) air conditioning systems, at most dominant operating conditions. Several issues were identified for the design of compact interior heat exchangers for automotive reversible CO{sub 2} heat pumping systems. Among theses issues are: (1) Refrigerant flow distribution, (2) Heat exchanger fluid flow circuiting, (3) Air temperature uniformity downstream of the heat exchanger, (4) Minimization of temperature approach, (5) Windshield flash fogging due to retained water inside the heat exchanger, (6) Internal beat conduction in heating mode operation, and (7) Refrigerant side pressure drop In order to provide a basis for understanding these issues, the author developed a calculation model and set up a test facility and investigated different prototype heat exchangers experimentally.

New counter flow heat exchanger designed for ventilation systems in cold climates

DEFF Research Database (Denmark)

Kragh, Jesper; Rose, Jørgen; Nielsen, Toke Rammer

2007-01-01

In cold climates, mechanical ventilation systems with highly efficient heat recovery will experience problems with condensing water from the extracted humid indoor air. If the condensed water changes to ice in the heat exchanger, the airflow rate will quickly fall due to the increasing pressure...... problem is therefore desirable. In this paper, the construction and test measurements of a new counter flow heat exchanger designed for cold climates are presented. The developed heat exchanger is capable of continuously defrosting itself without using supplementary heating. Other advantages...... of the developed beat exchanger are low pressure loss, cheap materials and a simple construction. The disadvantage is that the exchanger is big compared with other heat exchangers. In this paper, the new heat exchanger's efficiency is calculated theoretically and measured experimentally. The experiment shows...

The on-line European Community urgent radiological information exchange (ECURIE) information system

International Nuclear Information System (INIS)

De Cort, M.; Breitenbach, L.; De Vries, G.

1998-01-01

Immediately after the accident at the Chernobyl NPP, both the International Atomic Energy Agency (IAEA) and the Commission of the European Communities (CEC) set up a system to meet the requirements for early warning and exchange of information. The Environment Institute of the CEC JRC-Ispra provides technical assistance for the European community Urgent Radiological Information Exchange system (ECURIE). By this system, Member State contact points can exchange information in a coded format. In order to facilitate the use and to assure the data quality, a Coding-Decoding Software (CDS) was developed in collaboration with the I.A.E.A. A new version, called CoDecS, is under development. An ECURIE data bank is under construction, which will automatically recognize and store incoming ECURIE messages. Further on, query and reporting software will be developed. The background objectives and the conceptual basis for the structure of the on-line information system is described. (author)

Modeling and simulation of control system response to temperature disturbances in a coupled heat exchangers-AHTR system

International Nuclear Information System (INIS)

Skavdahl, I.; Utgikar, V.P.; Christensen, R.; Sabharwall, P.; Chen, M.; Sun, X.

2016-01-01

Highlights: • Control architecture defined for nuclear reactor-coupled heat exchangers system. • MATLAB code developed for simulation of system response for various temperature disturbances in the system. • Control system effective in maintaining controlled variables at desired set points. • New equilibrium steady state established using controllers. • Adaptive control system capable of switching manipulated variables based on system constraints. - Abstract: An effective control strategy is essential for maintaining optimum operational efficiency of the Advanced High Temperature Reactor (AHTR)-intermediate heat exchanger (IHX)-secondary heat exchanger (SHX) system for power conversion or process heat applications. A control system design is presented in this paper for the control of the coupled intermediate and secondary heat exchangers. The cold side outlet temperature of the SHX (T_c_o) and the hot side outlet temperature of the IHX (T_h_o_2) were identified as the controlled variables that were maintained at their set points by manipulating the flow rates of heat exchange media. Transfer functions describing the relationships between the controlled variables and the manipulated and load variables were developed and the system response to various temperature disturbances was simulated using a custom-developed MATLAB program. It was found that a step disturbance of ±10 °C in the process loop changed the thermal duty by ±650 kW, equal to 6.5% of the initial duty. Similar disturbances in the primary loop had a higher impact on the system. The control system design included a provision for the switching of manipulated variables to limit the adjustment in the magnitudes of the primary manipulated variables. Simulation results indicate that the controlled variables are maintained successfully at their desired points by the control system.

Modeling and simulation of control system response to temperature disturbances in a coupled heat exchangers-AHTR system

Energy Technology Data Exchange (ETDEWEB)

Skavdahl, I. [Department of Chemical and Materials Engineering, University of Idaho, Moscow, ID 83844 (United States); Utgikar, V.P., E-mail: vutgikar@uidaho.edu [Department of Chemical and Materials Engineering, University of Idaho, Moscow, ID 83844 (United States); Christensen, R. [Nuclear Engineering Program, University of Idaho, Idaho Falls, ID 83402 (United States); Sabharwall, P. [Idaho National Laboratory, Idaho Falls, ID 83415 (United States); Chen, M.; Sun, X. [Nuclear Engineering Program, Department of Mechanical and Aerospace Engineering, The Ohio State University, Columbus, OH 43210 (United States)

2016-04-15

Highlights: • Control architecture defined for nuclear reactor-coupled heat exchangers system. • MATLAB code developed for simulation of system response for various temperature disturbances in the system. • Control system effective in maintaining controlled variables at desired set points. • New equilibrium steady state established using controllers. • Adaptive control system capable of switching manipulated variables based on system constraints. - Abstract: An effective control strategy is essential for maintaining optimum operational efficiency of the Advanced High Temperature Reactor (AHTR)-intermediate heat exchanger (IHX)-secondary heat exchanger (SHX) system for power conversion or process heat applications. A control system design is presented in this paper for the control of the coupled intermediate and secondary heat exchangers. The cold side outlet temperature of the SHX (T{sub co}) and the hot side outlet temperature of the IHX (T{sub ho2}) were identified as the controlled variables that were maintained at their set points by manipulating the flow rates of heat exchange media. Transfer functions describing the relationships between the controlled variables and the manipulated and load variables were developed and the system response to various temperature disturbances was simulated using a custom-developed MATLAB program. It was found that a step disturbance of ±10 °C in the process loop changed the thermal duty by ±650 kW, equal to 6.5% of the initial duty. Similar disturbances in the primary loop had a higher impact on the system. The control system design included a provision for the switching of manipulated variables to limit the adjustment in the magnitudes of the primary manipulated variables. Simulation results indicate that the controlled variables are maintained successfully at their desired points by the control system.

The Exchange Value Embedded in a Transport System

International Nuclear Information System (INIS)

Xia Qinglan; Xu Shaofeng

2010-01-01

This paper shows that a well designed transport system has an embedded exchange value by serving as a market for potential exchange between consumers. Under suitable conditions, one can improve the welfare of consumers in the system simply by allowing some exchange of goods between consumers during transportation without incurring additional transportation cost. We propose an explicit valuation formula to measure this exchange value for a given compatible transport system. This value is always nonnegative and bounded from above. Criteria based on transport structures, preferences and prices are provided to determine the existence of a positive exchange value. Finally, we study a new optimal transport problem with an objective taking into account of both transportation cost and exchange value.

Magnetic stability in exchange-spring and exchange bias systems after multiple switching cycles.

Energy Technology Data Exchange (ETDEWEB)

Jiang, J. S.; Inomata, A.; You, C.-Y.; Pearson, J. E.; Bader, S. D.

2001-06-01

We have studied the magnetic stability in exchange bias and exchange spring systems prepared via epitaxial sputter deposition. The two interfacial exchange coupled systems, Fe/Cr(211) double superlattices consisting of a ferromagnetic and an antiferromagnetic Fe/Cr superlattice that are exchange coupled through a Cr spacer, and Sin-Co/Fe exchange-spring bilayer structures with ferromagnetically coupled hard Sin-Co layer and soft Fe layer, were epitaxially grown on suitably prepared Cr buffer layers to give rise to different microstructure and magnetic anisotropy. The magnetic stability was investigated using the magneto-optic Kerr effect during repeated reversal of the soft layer magnetization by field cycling up to 10{sup 7} times. For uniaxial Fe/Cr exchange biased double superlattices and exchange spring bilayers with uniaxial Sin-Co, small but rapid initial decay in the exchange bias field HE and in the remanent magnetization is observed. However, the exchange spring bilayers with biaxial and random in-plane anisotropy in the Sin-Co layer shows gradual decay in H{sub E} and without large reduction of the magnetization. The different decay behaviors are attributed to the different microstructure and spin configuration of the pinning layers.

Membrane heat exchanger in HVAC energy recovery systems, systems energy analysis

Energy Technology Data Exchange (ETDEWEB)

Nasif, M. [School of Mechanical and Manufacturing Engineering, The University of New South Wales, Sydney, NSW 2052 (Australia); Opus International Consultants (New Zealand); AL-Waked, R. [Mechanical Engineering Department, Prince Mohammad Bin Fahd University (PMU), P.O. Box 1614, AlKhobar 31952 (Saudi Arabia); Morrison, G. [School of Mechanical and Manufacturing Engineering, The University of New South Wales, Sydney, NSW 2052 (Australia); Behnia, M. [School of Aerospace, Mechanical and Mechatronic Engineering, University of Sydney, NSW 2006 (Australia)

2010-10-15

The thermal performance of an enthalpy/membrane heat exchanger is experimentally investigated. The heat exchanger utilizes a 60gsm Kraft paper as the heat and moisture transfer surface for HVAC energy recovery. The heat exchanger sensible, latent and total effectiveness have been determined through temperature and moisture content measurements. The annual energy consumption of an air conditioner coupled with an enthalpy/membrane heat exchanger is also studied and compared with a conventional air conditioning cycle using in-house modified HPRate software. The heat exchanger effectiveness are used as thermal performance indicators and incorporated in the modified software. Energy analysis showed that an air conditioning system coupled with a membrane heat exchanger consumes less energy than a conventional air conditioning system in hot and humid climates where the latent load is high. It has been shown that in humid climate a saving of up to 8% in annual energy consumption can be achieved when membrane heat exchanger is used instead of a conventional HVAC system. (author)

STOCK AND STOCK EXCHANGE AS A PART OF FINANCIAL INSTITUTIONS IN DEVELOPED COUNTRIES

Directory of Open Access Journals (Sweden)

Vesna Petrović

2018-01-01

Full Text Available The authors have tried to present the term, meaning and importance of stocks and stock exchange as a part of the financial system of developed countries. By observing the financial system growth, especially in financial institutions, it can be noticed that there are changes in relative positions of various types of financial agents in developed market industries. What determines financial markets, and by that the stocks and stock exchange is the permanent movement of financial instruments and neglecting the national market boundaries.

Invariant exchange perturbation theory for multicenter systems: Time-dependent perturbations

International Nuclear Information System (INIS)

Orlenko, E. V.; Evstafev, A. V.; Orlenko, F. E.

2015-01-01

A formalism of exchange perturbation theory (EPT) is developed for the case of interactions that explicitly depend on time. Corrections to the wave function obtained in any order of perturbation theory and represented in an invariant form include exchange contributions due to intercenter electron permutations in complex multicenter systems. For collisions of atomic systems with an arbitrary type of interaction, general expressions are obtained for the transfer (T) and scattering (S) matrices in which intercenter electron permutations between overlapping nonorthogonal states belonging to different centers (atoms) are consistently taken into account. The problem of collision of alpha particles with lithium atoms accompanied by the redistribution of electrons between centers is considered. The differential and total charge-exchange cross sections of lithium are calculated

Exchange bias in nearly perpendicularly coupled ferromagnetic/ferromagnetic system

International Nuclear Information System (INIS)

Bu, K.M.; Kwon, H.Y.; Oh, S.W.; Won, C.

2012-01-01

Exchange bias phenomena appear not only in ferromagnetic/antiferromagnetic systems but also in ferromagnetic/ferromagnetic systems in which two layers are nearly perpendicularly coupled. We investigated the origin of the symmetry-breaking mechanism and the relationship between the exchange bias and the system's energy parameters. We compared the results of computational Monte Carlo simulations with those of theoretical model calculation. We found that the exchange bias exhibited nonlinear behaviors, including sign reversal and singularities. These complicated behaviors were caused by two distinct magnetization processes depending on the interlayer coupling strength. The exchange bias reached a maximum at the transition between the two magnetization processes. - Highlights: ► Exchange bias phenomena are found in perpendicularly coupled F/F systems. ► Exchange bias exhibits nonlinear behaviors, including sign reversal and singularities. ► These complicated behaviors were caused by two distinct magnetization processes. ► Exchange bias reached a maximum at the transition between the two magnetization processes. ► We established an equation to maximize the exchange bias in perpendicularly coupled F/F system.

Advanced Heat/Mass Exchanger Technology for Geothermal and Solar Renewable Energy Systems

Energy Technology Data Exchange (ETDEWEB)

Greiner, Miles [Univ. of Nevada, Reno, NV (United States); Childress, Amy [Univ. of Nevada, Reno, NV (United States); Hiibel, Sage [Univ. of Nevada, Reno, NV (United States); Kim, Kwang [Univ. of Nevada, Reno, NV (United States); Park, Chanwoo [Univ. of Nevada, Reno, NV (United States); Wirtz, Richard [Univ. of Nevada, Reno, NV (United States)

2014-12-16

Northern Nevada has abundant geothermal and solar energy resources, and these renewable energy sources provide an ample opportunity to produce economically viable power. Heat/mass exchangers are essential components to any energy conversion system. Improvements in the heat/mass exchange process will lead to smaller, less costly (more efficient) systems. There is an emerging heat transfer technology, based on micro/nano/molecular-scale surface science that can be applied to heat/mass exchanger design. The objective is to develop and characterize unique coating materials, surface configurations and membranes capable of accommodating a 10-fold increase in heat/mass exchanger performance via phase change processes (boiling, condensation, etc.) and single phase convective heat/mass transfer.

Development and implementation of an automated system to exchange attenuators of the OB85/1 gamma irradiator

International Nuclear Information System (INIS)

Silva Junior, Iremar A.; Ramos, Marcio A.G.; Carvalho, Valdir S.; Diniz, Raphael E.; Cescon, Claudinei T.; Vivolo, Vitor; Potiens, Maria da Penha A.

2011-01-01

In order to improve the calibration process of portable detectors of the Instrument Calibration Laboratory of IPEN, an automated system to exchange the attenuators of the OB85/1 irradiator system was developed. This automation was developed following this sequence: (i) development of the device with the cooperation of the IPEN Sector of Projects, using the Solid Edge software to design the mechanical part of the exchanging device of the attenuators, in 3D; (ii) simulation with the Festo's FluidSim software to define the pneumatic components and their respective actuators; (iii) machining and assembly of mechanical parts; (iv) assembly of pneumatic components and their actuators, like magnetic pneumatic cylinders, which allow the use of magnetic sensors, used to confirm the attenuators opened or closed positions: actuators 5/2 each, with double solenoid; (v) assembly of the control panel for operating the device remotely from the operating room. With this automation, the technicians in charge of the detectors calibration and research testing will have no hand contact with lead attenuators, improving the calibration process due to the decrease in time spent with manual shift from the attenuators and avoiding accidents, like the fall of the lead attenuators. It has been a concern of the LCI-IPEN group the decrease in the time spent by the technicians in the calibration room controlled areas should follow the recommendations of the radiological protection rules, which recommend the shortest time possible of workers in these areas. Automated systems have, usually, a better rate of reproducibility, due to the small participation by the system operator, so the LCI-IPEN is following the trend of several laboratories and automating its processes. (author)

Model Adoption Exchange Payment System: Executive Summary.

Science.gov (United States)

Ambrosino, Robert J.

This executive summary provides a brief description of the Model Adoption Exchange Payment System (MAEPS), a unique payment system aimed at improving the delivery of adoption exchange services throughout the United States. Following a brief introductory overview, MAEPS is described in terms of (1) its six components (registration, listing,…

Choice of optimal exchange rate system For the Republic of Croatia

Directory of Open Access Journals (Sweden)

Dražen Koški

2008-12-01

Full Text Available The aim of research whose results are presented in this article was to choose the optimal system of exchange rate for the Republic of Croatia, of course before its accession to EU. The analyzed exchange rate systems here range from free-floating exchange rate to system without domestic currency in circulation. Naturally, the classification of International Monetary Fond is included in it. After that, the comparison of basic economic advantages and disadvantages of the fixed exchange rate in relation to floating exchange rate were carried out. Although the question is about the extreme systems, disregarding the system without domestic currency in circulation, their comparison makes possible completely satisfactory basis for the right conclusions on the choice of optimal exchange rate system for the Republic of Croatia. Considering its economic particularities, the system of managed-floating exchange rate without proclaimed exchange direction in advance is certainly optimal for the Republic of Croatia. Namely, within the framework of this system the limited floating exchange rates decrease the foreign exchange risk allowing to monetary authorities, at least partly, the independent monetary policy

Annual simulations of heat pump systems with vertical ground heat exchangers

Energy Technology Data Exchange (ETDEWEB)

Bernier, M.A.; Randriamiarinjatovo, D. [Ecole Polytechnique, Montreal, PQ (Canada). Dept. de Genie Mecanique

2001-06-01

The recent increased popularity in ground-coupled heat pump (GCHP) systems is due to their energy saving potential. However, in order for a GCHP to operate efficiently, they must be sized correctly. This paper presents a method to perform annual simulations of GCHP systems to optimize the length of the ground heat exchanger and provide annual energy consumption data. A computer program has been developed to simulate the building load, heat pump and the ground heat exchanger, the three most distinct parts of the system. The coupled governing equations of these three models are solved simultaneously until a converged solution is obtained at each time step. The simulations are performed using the Engineering Equation Solver (EES). This program has proven to be useful in balancing ground heat exchanger length against heat pump energy consumption.15 refs., 9 figs.

Design and Development of a Sub-Zero Fluid System for Demonstration of Orion's Phase Change Material Heat Exchangers on ISS

Science.gov (United States)

Sheth, Rubik B.; Ahlstrom, Thomas D.; Le, Hung V.

2016-01-01

NASA's Orion Multipurpose Crew Vehicle's Exploration Mission 2 is expected to loiter in Lunar orbit for a relatively long period of time. In low Lunar orbit (LLO) the thermal environment is cyclic - extremely cold in the eclipse and relatively hot near the subsolar point. Phase change material heat exchangers (PCM HXs) are the best option for long term missions in these environments. A PCM HX allows a vehicle to store excess waste energy by thawing a phase change material such as n-pentadecane wax. During portions of the orbit that are extremely cold, the excess energy is rejected, resolidifying the wax. Due to the inherent risk of compromising the heat exchanger during multiple freeze and thaw cycles, a unique payload was designed for the International Space Station to test and demonstration the functions of a PCM HX. The payload incorporates the use of a pumped fluid system and a thermoelectric heat exchanger to promote the freezing and thawing of the PCM HX. This paper shall review the design and development undertaken to build such a system.

Evolutionary Perspectives on the Development of Social Exchanges.

Science.gov (United States)

Sheese, Brad E.; Graziano, William G.

2002-01-01

Argues that apparent incompatibilities between social exchange and developmental perspectives can be resolved by using evolutionary theories to extend the logic of social exchange. Discusses the implications of an expanded evolutionary perspective on social exchange and development, proposing that developmental context and genetic relatedness may…

Concept development of exchange liquid regeneration

International Nuclear Information System (INIS)

Mader, D.L.

1985-08-01

Concepts are described for regeneration of the intermediate liquid used for isotope exchange in indirect laser isotope separation processes where the laser operates on a process gas distinct from the feed stream. The specific case of regeneration of an exchange liquid consisting of water, sodium hydroxide, and dimethyl sulfoxide for a process to separate deuterium from hydrogen using laser irradiation of trifluoromethane gas is developed. A water feed stream is converted to steam which rises in a chemical process column where it redeuterates a descending flow of exchange liquid without causing significant changes in its chemical composition

40 CFR 63.1409 - Heat exchange system provisions.

Science.gov (United States)

2010-07-01

... detect leaks. (2)(i) For recirculating heat exchange systems (cooling tower systems), the monitoring of...-through heat exchange systems, the monitoring of speciated HAP or total HAP refers to the HAP listed in... operator shall maintain, at all times, the monitoring plan that is currently in use. The current plan shall...

Active heat exchange system development for latent heat thermal energy storage

Science.gov (United States)

Lefrois, R. T.; Mathur, A. K.

1980-01-01

Five tasks to select, design, fabricate, test and evaluate candidate active heat exchanger modules for future applications to solar and conventional utility power plants were discussed. Alternative mechanizations of active heat exchange concepts were analyzed for use with heat of fusion phase change materials (PCMs) in the temperature range of 250 to 350 C. Twenty-six heat exchange concepts were reviewed, and eight were selected for detailed assessment. Two candidates were selected for small-scale experimentation: a coated tube and shell heat exchanger and a direct contact reflux boiler. A dilute eutectic mixture of sodium nitrate and sodium hydroxide was selected as the PCM from over 50 candidate inorganic salt mixtures. Based on a salt screening process, eight major component salts were selected initially for further evaluation. The most attractive major components in the temperature range of 250 to 350 C appeared to be NaNO3, NaNO2, and NaOH. Sketches of the two active heat exchange concepts selected for test are given.

Development of heat exchangers for nuclear service

International Nuclear Information System (INIS)

Hodge, R.I.; Dalrymple, D.G.

1976-01-01

Unusual design constraints, due to tube vibration, are called for when tube-in-shell heat exchangers are incorporated into CANDU type reactor power plants. CRNL has programs studying tube excitation and response, flow conditions, and the fretting process in such exchangers, tube plugging techniques, and eddy current scanning systems for inside bores of full-length tubes. (E.C.B.)

Improvements to a Markerless Allelic Exchange System for Bacillus anthracis.

Directory of Open Access Journals (Sweden)

Roger D Plaut

Full Text Available A system was previously developed for conducting I-SceI-mediated allelic exchange in Bacillus anthracis. In this system, recombinational loss of a chromosomally-integrated allelic exchange vector is stimulated by creation of a double-stranded break within the vector by the homing endonuclease I-SceI. Although this system is reasonably efficient and represents an improvement in the tools available for allelic exchange in B. anthracis, researchers are nonetheless required to "pick and patch" colonies in order to identify candidate "exchangeants." In the present study, a number of improvements have been made to this system: 1 an improved I-SceI-producing plasmid includes oriT so that both plasmids can now be introduced by conjugation, thus avoiding the need for preparing electro-competent cells of each integration intermediate; 2 antibiotic markers have been changed to allow the use of the system in select agent strains; and 3 both plasmids have been marked with fluorescent proteins, allowing the visualization of plasmid segregation on a plate and obviating the need for "picking and patching." These modifications have made the process easier, faster, and more efficient, allowing for parallel construction of larger numbers of mutant strains. Using this improved system, the genes encoding the tripartite anthrax toxin were deleted singly and in combination from plasmid pXO1 of Sterne strain 34F2. In the course of this study, we determined that DNA transfer to B. anthracis could be accomplished by conjugation directly from a methylation-competent E. coli strain.

Building knowledge development and exchange capacity in Canada: lessons from Youth Excel.

Science.gov (United States)

Riley, B; Wong, K; Manske, S

2014-07-01

Youth Excel was a 3-year pan-Canadian initiative to advance youth health through improving knowledge development and exchange (KDE) capacity. KDE capacity refers to an improvement cycle linking evidence and action. Capacities include local surveillance of youth behaviours; knowledge exchange; skills, resources and a supportive environment to use knowledge; and evaluation. Interviews were conducted with Youth Excel members, including 7 provincial teams and 2 national organizations. Interviews explored participant experiences with building KDE capacity. Local surveillance systems were considered the backbone to KDE capacity, strengthened by co-ordinating surveys within and across jurisdictions and using common indicators and measures. The most effective knowledge exchange included tailored products and opportunities for dialogue and action planning. Evaluation is the least developed KDE component. Building KDE capacity requires frequent dialogue, mutually beneficial partnerships and trust. It also requires attention to language, vision, strategic leadership and funding. Youth Excel reinforces the need for a KDE system to improve youth health that will require new perspectives and sustained commitment from individual champions and relevant organizations.

Investigation of Condensation Heat Transfer Correlation of Heat Exchanger Design in Secondary Passive Cooling System

Energy Technology Data Exchange (ETDEWEB)

Ju, Yun Jae; Lee, Hee Joon [Kookmin Univ., Seoul (Korea, Republic of); Kang, Hanok; Lee, Taeho; Park, Cheontae [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2013-12-15

Recently, condensation heat exchangers have been studied for applications to the passive cooling systems of nuclear plants. To design vertical-type condensation heat exchangers in secondary passive cooling systems, TSCON (Thermal Sizing of CONdenser), a thermal sizing program for a condensation heat exchanger, was developed at KAERI (Korea Atomic Energy Research Institute). In this study, the existing condensation heat transfer correlation of TSCON was evaluated using 1,157 collected experimental data points from the heat exchanger of a secondary passive cooling system for the case of pure steam condensation. The investigation showed that the Shah correlation, published in 2009, provided the most satisfactory results for the heat transfer coefficient with a mean absolute error of 34.8%. It is suggested that the Shah correlation is appropriate for designing a condensation heat exchanger in TSCON.

Exchange bias of patterned systems: Model and numerical simulation

International Nuclear Information System (INIS)

Garcia, Griselda; Kiwi, Miguel; Mejia-Lopez, Jose; Ramirez, Ricardo

2010-01-01

The magnitude of the exchange bias field of patterned systems exhibits a notable increase in relation to the usual bilayer systems, where a continuous ferromagnetic film is deposited on an antiferromagnet insulator. Here we develop a model, and implement a Monte Carlo calculation, to interpret the experimental observations which is consistent with experimental results, on the basis of assuming a small fraction of spins pinned ferromagnetically in the antiferromagnetic interface layer.

Respiratory system. Part 2: Gaseous exchange.

Science.gov (United States)

McLafferty, Ella; Johnstone, Carolyn; Hendry, Charles; Farley, Alistair

This article, which isthe last in the life sciences series and the second of two articles on the respiratory system, describes gaseous exchange in the lungs, transport of oxygen and carbon dioxide, and internal and external respiration. The article concludes with a brief consideration of two conditions that affect gas exchange and transport: carbon monoxide poisoning and chronic obstructive pulmonary disease.

Study of kinetics, equilibrium and isotope exchange in ion exchange systems Pt. 4

International Nuclear Information System (INIS)

Stamberg, K.; Plicka, J.; Calibar, J.; Gosman, A.

1985-01-01

The kinetics of ion exchange in the Nasup(+)-Mgsup(2+)-strongly acidic cation exchanger system in a batch stirred reactor was studied. The samples of exchangers OSTION KS (containing DVB in the range of 1.5 - 12%) and AMBERLITE IR 120 for experimental work were used; the concentration of the aqueous nitrate solution was always 0.2M. The Nernst-Planck equation for description of diffusion of ions in a particle was used. The values of diffusion coefficients of magnesium ions in the exchangers and their dependence on the content of DVB were obtained by evaluating the experimental data and using the self-diffusion coefficients of sodium. (author)

Development of a system using the library of the Genie spectroscopy software and exchange of samples

International Nuclear Information System (INIS)

Lapolli, Andre L.; Munita, Casimiro S.

2011-01-01

One the great difficulties in using the NAA method is in regards to the time that the operator spends exchanging the samples after each measurement. It becomes a big problem in routine analyses when various chemical elements are determined and then each sample must be measured at different decay times. The application of the automatic sample exchanger reduces the time analysis by several hours and reduces the tedious manual operation. Then, the effective use of NAA depends on the availability of a suitable automatic sample changer. There are some systems that are sold commercially, however many laboratories can not acquire them because they are costly. This paper presents altered programs the G2KNAA.REX, which created a screen making possible automatic or manual acquisitions by calling the old program NAAACQ.rex for the procurement manual and the new program NAAACQ2.rex for automatic requisitions. In conclusion, as can be seen in the program lines, the synchronization to automation, which unites the three systems (the computer, the Canberra Set, the sample exchanger) is done in a timely manner. The system was tested and is functioning in a satisfactory manner. (author)

Development of the system based code. v. 5. Method of margin exchange. pt. 2. Determination of quality assurance index based on a 'Vector Method'

International Nuclear Information System (INIS)

Asayama, Tai

2003-03-01

For the commercialization of fast breeder reactors, 'System Based Code', a completely new scheme of a code on structural integrity, is being developed. One of the distinguished features of the System Based Code is that it is able to determine a reasonable total margin on a structural of system, by allowing the exchanges of margins between various technical items. Detailed estimation of failure probability of a given combination of technical items and its comparison with a target value is one way to achieve this. However, simpler and easier methods that allow margin exchange without detailed calculation of failure probability are desirable in design. The authors have developed a simplified method such as a 'design factor method' from this viewpoint. This report describes a 'Vector Method', which was been newly developed. Following points are reported: 1) The Vector Method allows margin exchange evaluation on an 'equi-quality assurance plane' using vector calculation. Evaluation is easy and sufficient accuracy is achieved. The equi-quality assurance plane is obtained by a projection of an 'equi-failure probability surface in a n-dimensional space, which is calculated beforehand for typical combinations of design variables. 2) The Vector Method is considered to give the 'Quality Assurance Index Method' a probabilistic interpretation. 3) An algebraic method was proposed for the calculation of failure probabilities, which is necessary to obtain a equi-failure probability surface. This method calculates failure probabilities without using numerical methods such as Monte Carlo simulation or numerical integration. Under limited conditions, this method is quite effective compared to numerical methods. 4) An illustration of the procedure of margin exchange evaluation is given. It may be possible to use this method to optimize ISI plans; even it is not fully implemented in the System Based Code. (author)

Development of heat transfer calculation program for finned-tune heat exchanger of multi-burner boiler

International Nuclear Information System (INIS)

Jang, Sae Byul; Kim, Jong Jin; Ahn, Joon

2009-01-01

We develop a heat exchanger modules for a multi-burner boiler. The heat exchanger module is kind of a Heat Recovery Steam Generator (HRSG). This heat recovery system has 8 heat exchanger modules. The 1st module consists of 27 bare tubes due to high temperature exhaust gas and the others consist of 27 finned tubes. The maximum steam pressure of each module is 1 MPa and tested steam pressure is 0.7 MPa. In order to test these heat exchanger modules, we make a 0.5 t/h flue tube boiler (LNG, 40 Nm 3 /h). We tested the heat exchanger module with changing the position of each heat exchanger module. We measured the inlet and outlet temperature of each heat exchanger module and calculated the heat exchange rate. Based on test results, we develop a heat transfer calculation program to predict flue gas. Calculation results show that temperature and temperature difference between measured and calculated flue gas exit temperature is less than 20 .deg. C when flue gas inlet temperature is 620 .deg. C.

ASN.1 notation for exchange of data in computer-based railway control systems

Directory of Open Access Journals (Sweden)

Zbigniew ŁUKASIK

2009-01-01

Full Text Available Development of railway control systems aims at computerization. In most cases these systems are Distributed Real Time Systems. However, a huge problem in their putting into practice is the lack of interface standardization in the range of data structures and information exchange methods. It results in a variety of solutions, and thus in problems concerning cooperation of systems that come from different software vendors. Specification of protocols for data exchanging applications should therefore be created with the use of generally accepted standards. One of them is ASN.1 (Abstract Syntax Notation One language, which shall be presented in this article.

CLAIM (CLinical Accounting InforMation)--an XML-based data exchange standard for connecting electronic medical record systems to patient accounting systems.

Science.gov (United States)

Guo, Jinqiu; Takada, Akira; Tanaka, Koji; Sato, Junzo; Suzuki, Muneou; Takahashi, Kiwamu; Daimon, Hiroyuki; Suzuki, Toshiaki; Nakashima, Yusei; Araki, Kenji; Yoshihara, Hiroyuki

2005-08-01

With the evolving and diverse electronic medical record (EMR) systems, there appears to be an ever greater need to link EMR systems and patient accounting systems with a standardized data exchange format. To this end, the CLinical Accounting InforMation (CLAIM) data exchange standard was developed. CLAIM is subordinate to the Medical Markup Language (MML) standard, which allows the exchange of medical data among different medical institutions. CLAIM uses eXtensible Markup Language (XML) as a meta-language. The current version, 2.1, inherited the basic structure of MML 2.x and contains two modules including information related to registration, appointment, procedure and charging. CLAIM 2.1 was implemented successfully in Japan in 2001. Consequently, it was confirmed that CLAIM could be used as an effective data exchange format between EMR systems and patient accounting systems.

Choice of the exchange policies in the developments countries: Study of the competitiveness of Tunisia

Directory of Open Access Journals (Sweden)

Benahji Sfaxi Hend

2008-01-01

Full Text Available After the collapse of the Breton Woods system, the increased fluctuations of the exchange rates pushed the developing countries to adopt exchange rate policies to avoid rocking of the balance of payments. Since 1973, Tunisia adopted fixed or intermediary exchange rate policies to support or ameliorate her competitiveness and later to balance her current account. By calculating the real effective exchange rate misalignment, we showed that this country did not achieve her goals and that amelioration of competitiveness occurred only as from the moment when she softened her exchange policies. A policy of floating exchange rate is recommended for Tunisia specially why this country is more and more open. .

Thermal Analysis for Ion-Exchange Column System

Energy Technology Data Exchange (ETDEWEB)

Lee, Si Y.; King, William D.

2012-12-20

Models have been developed to simulate the thermal characteristics of crystalline silicotitanate ion exchange media fully loaded with radioactive cesium either in a column configuration or distributed within a waste storage tank. This work was conducted to support the design and operation of a waste treatment process focused on treating dissolved, high-sodium salt waste solutions for the removal of specific radionuclides. The ion exchange column will be installed inside a high level waste storage tank at the Savannah River Site. After cesium loading, the ion exchange media may be transferred to the waste tank floor for interim storage. Models were used to predict temperature profiles in these areas of the system where the cesium-loaded media is expected to lead to localized regions of elevated temperature due to radiolytic decay. Normal operating conditions and accident scenarios (including loss of solution flow, inadvertent drainage, and loss of active cooling) were evaluated for the ion exchange column using bounding conditions to establish the design safety basis. The modeling results demonstrate that the baseline design using one central and four outer cooling tubes provides a highly efficient cooling mechanism for reducing the maximum column temperature. In-tank modeling results revealed that an idealized hemispherical mound shape leads to the highest tank floor temperatures. In contrast, even large volumes of CST distributed in a flat layer with a cylindrical shape do not result in significant floor heating.

Document Management and Exchange System – Supporting Education Process

Directory of Open Access Journals (Sweden)

Emil Egredzija

2010-03-01

Full Text Available Development and implementation of new technologies are very important in education. One of the most challenging tasks in the education process is to build efficient and cost-friendly system for content management and exchange. The system has to be reliable, easy manageable and open. Centralized storage, secured access, and ubiquitous client technologies have emerged as best-practice solutions in engineering that kind of services. Users can easily publish or exchange documents and not need to worry about their distribution, storage or technical skills required for efficient document management. The system that will be presented is built on open source technologies and is deployable on all today's popular web software platforms. The web server, the programming language and operating system that are used to build and deploy such a system are all non-proprietary and completely open because our mission was to build system that can be easily extended and not limited by its corporate license. The system uses security mechanisms such as user group access policy, operating system level security (file system and secured data storage in database. Because of the growing need for document management in education process we believe that this project will find its place in practice.

Troublesome telephony: how users and non-users shaped the development of early British exchange telephony

Directory of Open Access Journals (Sweden)

Dr Michael Kay

2015-05-01

Full Text Available When exchange telephony was first marketed to the British public by the early telephone companies in the late nineteenth century it was as an intuitive technology requiring no specialist knowledge or training. This has gone unquestioned in subsequent telephone historiography but, as this article demonstrates, telephone instruments and systems were not always unproblematic or easy to use. Whilst other scholars have discussed important factors in the development and uptake of telephony, such as business economics and intellectual property, this article focuses on usage, and argues that difficulties in using telephone instruments and systems also influenced key changes in the operations of early British exchange systems. To understand these responses and developments it is necessary to look at the opinions and complaints of both users and non-users of telephone exchange systems. In investigating non-users as well as users, this article is influenced by the work of Sally Wyatt in Oudshoorn and Pinch's (2003 edited volume regarding users and non-users of technologies. Recovering the reactions of such people is possible through extensive use of letters received by the telephone companies or published in the periodical press, and opinions voiced at select committee meetings investigating the state of the country's telephone system. In recovering the difficulties early users and non-users faced when confronted with exchange telephone systems this article emphasises the importance of problematising the historical uptake of new technologies, and highlights how, in the case of early British telephony in particular, these problems can reveal specific facts both about historical telephone use-experience and about how exchange telephony spread around the country.

Modelling fireside corrosion of heat exchangers in co-fired pulverised fuel power systems

Energy Technology Data Exchange (ETDEWEB)

Simms, N.J. [Cranfield Univ. (United Kingdom). Energy Technology Centre; Fry, A.T. [National Physical Laboratory, Teddington, Middlesex (United Kingdom)

2010-07-01

As a result of concerns about the effects of CO{sub 2} emissions on the global environment, there is increasing pressure to reduce such emissions from power generation systems. The use of biomass co-firing with coal in conventional pulverised fuel power stations has provided the most immediate route to introduce a class of fuel that is regarded as both sustainable and carbon neutral. In the future it is anticipated that increased levels of biomass will need to be used in such systems to achieve the desired CO{sub 2} emission targets. However there are concerns over the risk of fireside corrosion damage to the various heat exchangers and boiler walls used in such systems. Future pulverised fuel power systems will need to be designed to cope with the effects of using a wide range of coal-biomass mixes. However, such systems will also need to use much higher heat exchanger operating temperatures to increase their conversion efficiencies and counter the effects of the CO{sub 2} capture technologies that will need to be used in them. Higher operating temperatures will also increase the risk of fireside corrosion damage to the critical heat exchangers. This paper reports work that has been carried out to develop quantitative corrosion models for heat exchangers in pulverised fuel power systems. These developments have been particularly targeted at producing models that enable the evaluation of the effects of using different coal-biomass mixtures and of increasing heat exchanger operating conditions. Models have been produced that have been targeted at operating conditions and materials used in (a) superheaters/reheaters and (b) waterwalls. Data used in the development of these models has been produced from full scale and pilot scale plants in the UK using a wide range of coal and biomass mixtures, as well as from carefully targeted series of laboratory corrosion tests. Mechanistic and neural network based models have been investigated during this development process to

Business Information Exchange System with Security, Privacy, and Anonymity

Directory of Open Access Journals (Sweden)

Sead Muftic

2016-01-01

Full Text Available Business Information Exchange is an Internet Secure Portal for secure management, distribution, sharing, and use of business e-mails, documents, and messages. It has three applications supporting three major types of information exchange systems: secure e-mail, secure instant messaging, and secure sharing of business documents. In addition to standard security services for e-mail letters, which are also applied to instant messages and documents, the system provides innovative features of privacy and full anonymity of users and their locations, actions, transactions, and exchanged resources. In this paper we describe design, implementation, and use of the system.

The development of heat exchangers with advanced thermomechanical materials

International Nuclear Information System (INIS)

Capra, Marcello

1997-07-01

Current metallurgical limitations necessarily impose a number of restrictions on the efficiency of power plant and combustion systems. These limitations include both temperature and corrosion resistance. If significant improvements can be made in these areas, then not only will it be possible to obtain higher system efficiencies, but it will also be possible to further exploit new technologies. Consequently, there is appreciable interest in the development of ceramic tubes for heat exchangers. Such tubes would offer the potential of operation at much higher temperatures combined with a much improved resistance to chemical attack. They are unlikely to be suitable for high pressure operation, at least in the foreseeable future, and hence their use would be limited generally to gas to gas exchangers. In spite of the limitations on details and specific technological solutions imposed by industrial property conditions, this report provides an overview on the development of these components, which is in charge of all the major international industrial companies of the field, in consideration of the relevant benefits coming from their large industrialization. After an analysis of the industrial situation of the product, in terms both of possible applications and economical impacts on the market, an overview of major on-going R and D programmes is carried out. At present, these programmes are mostly within the general frame of the study of advanced thermomechanical components and the related manufacturing technologies development

Materials, Turbomachinery and Heat Exchangers for Supercritical CO2 Systems

Energy Technology Data Exchange (ETDEWEB)

Anderson, Mark; Nellis, Greg; Corradini, Michael

2012-10-19

The objective of this project is to produce the necessary data to evaluate the performance of the supercritical carbon dioxide cycle. The activities include a study of materials compatibility of various alloys at high temperatures, the heat transfer and pressure drop in compact heat exchanger units, and turbomachinery issues, primarily leakage rates through dynamic seals. This experimental work will serve as a test bed for model development and design calculations, and will help define further tests necessary to develop high-efficiency power conversion cycles for use on a variety of reactor designs, including the sodium fast reactor (SFR) and very high-temperature gas reactor (VHTR). The research will be broken into three separate tasks. The first task deals with the analysis of materials related to the high-temperature S-CO{sub 2} Brayton cycle. The most taxing materials issues with regard to the cycle are associated with the high temperatures in the reactor side heat exchanger and in the high-temperature turbine. The system could experience pressures as high as 20MPa and temperatures as high as 650°C. The second task deals with optimization of the heat exchangers required by the S-CO{sub 2} cycle; the S-CO{sub 2} flow passages in these heat exchangers are required whether the cycle is coupled with a VHTR or an SFR. At least three heat exchangers will be required: the pre-cooler before compression, the recuperator, and the heat exchanger that interfaces with the reactor coolant. Each of these heat exchangers is unique and must be optimized separately. The most challenging heat exchanger is likely the pre-cooler, as there is only about a 40°C temperature change but it operates close to the CO{sub 2} critical point, therefore inducing substantial changes in properties. The proposed research will focus on this most challenging component. The third task examines seal leakage through various dynamic seal designs under the conditions expected in the S-CO{sub 2} cycle

Apparent exchange rate imaging in anisotropic systems

DEFF Research Database (Denmark)

Sønderby, Casper Kaae; Lundell, Henrik M; Søgaard, Lise V

2014-01-01

Double-wave diffusion experiments offer the possibility of probing correlation between molecular diffusion at multiple time points. It has recently been shown that this technique is capable of measuring the exchange of water across cellular membranes. The aim of this study was to investigate...... the effect of macroscopic tissue anisotropy on the measurement of the apparent exchange rate (AXR) in multicompartment systems....

Are expert systems needed on the power exchange?

International Nuclear Information System (INIS)

Nilsson, David.

1991-09-01

The goal of this masters thesis is to investigate whether it is possible to improve the activities at the power production unit (PDP) at Sydkraft with the help of expert systems. Another goal is that the produced result should work as an education material for the production operators. Therefore the work contains a detailed description of the power exchange and the factors that influence it, in addition to a description of the work tasks of the operators. The conclusions are, first, that an embedded critiquing system would enable a quicker training of new operators, while also giving the more experienced operators feedback on their decisions. Secondly, the water storage operation should be documented, to create a basis for the development of an expert system, and to create more material for education. The thesis also suggests a new model for the development of expert systems in areas where it is not known whether such a solution is possible. (au)

Triangularly arranged heat exchanger bundles to restrain wind effects on natural draft dry cooling system

International Nuclear Information System (INIS)

Liao, H.T.; Yang, L.J.; Du, X.Z.; Yang, Y.P.

2016-01-01

Highlights: • Triangularly arranged heat exchanger around the dry-cooling tower is proposed. • By coupling condenser with dry cooling system, TACHE performance is obtained. • At low wind speeds, cooling performance with TACHE is inferior to that with CACHE. • Better performance can be achieved for cooling system with TACHE at high wind speeds. • TACHE can be applied to the region with the strong prevailing wind all year around. - Abstract: It has been commonly recognized that the crosswind may deteriorate the cooling performance of the natural draft dry cooling system with vertically arranged heat exchanger bundles around the circumference of dry-cooling tower. With the purpose for restraining the adverse effects of ambient winds, a novel triangular configuration of heat exchanger bundles is proposed in this work. The air-side flow and heat transfer models coupled with the circulating water heat transfer process are developed for two kinds of natural draft dry cooling systems with the conventional circularly arranged and novel triangularly arranged heat exchanger bundles, by which the flow and temperature fields, mass flow rate of cooling air, outlet water temperature of heat exchanger and turbine back pressure are obtained. Three wind directions of 0°, 90°, and 180° are investigated at various wind speeds for the natural draft dry cooling system with triangularly arranged heat exchanger bundles, which are compared with the conventional system with circularly arranged heat exchanger bundles. The results show that the thermo-flow performances of the natural draft dry cooling system with triangularly arranged heat exchanger get improved significantly at high wind speeds and in the wind direction of 180°, thus a low turbine back pressure can be achieved, which is of benefit to the energy efficiency of the power generating unit. The natural draft dry cooling system with triangularly arranged heat exchanger is recommended to apply to the regions with

A platform independent prototype for data and information exchange between decision support systems

International Nuclear Information System (INIS)

Carle, B.; Baig, S.

2003-01-01

Full text: A survey amongst participants in the Decision Support System network (DSSNET) community showed that the organization dealing with the Information exchange between participants and stakeholders in nuclear emergency is too disparate to be defined in one well defined procedure or analysis. Looking at the organization of the national emergency response organizations, and especially when modelling the information flow, diversity is the most striking finding: originators of the information are different, decision making organisation can be different, the approval and publishing of information to press and wider public is dealt with in different ways and the responsibilities for the information flow to other authorities differ as well. Moreover, the place of decision support systems (DSS) in the emergency response organization varies for the different countries. This variation can be found in the way one of the 'big three' (RODOS, ARGOS and RECASS) systems is implemented, and even more in the way other, often country-specific systems, are in use and function more integrated with the particular emergency response organization of the country. Hence we can conclude that there is a need to structure the information exchange system, but this has to be flexible enough to work with the above described variety of existing organizations and procedures. Though it may not be feasible to agree on all specifications of information to be exchanged, we can define at least a minimal set. A prototype for data and information exchange is being developed under the EC project MODEM (Monitoring data and Information exchange among decision support systems). It establishes links between the decision support systems RODOS, ARGOS and RECASS. For setting up this data exchange, the use of xml-based data specifications allows a flexible integration with existing applications. The power to include metadata in a structured way allows the use of automated transformation tools and limits the

Application of expert systems to heat exchanger control at the 100-megawatt high-flux isotope reactor

International Nuclear Information System (INIS)

Clapp, N.E. Jr.; Clark, F.H.; Mullens, J.A.; Otaduy, P.J.; Wehe, D.K.

1985-01-01

The High-Flux Isotope Reactor (HFIR) is a 100-MW pressurized water reactor at the Oak Ridge National Laboratory. It is used to produce isotopes and as a source of high neutron flux for research. Three heat exchangers are used to remove heat from the reactor to the cooling towers. A fourth heat exchanger is available as a spare in case one of the operating heat exchangers malfunctions. It is desirable to maintain the reactor at full power while replacing the failed heat exchanger with the spare. The existing procedures used by the operators form the initial knowledge base for design of an expert system to perform the switchover. To verify performance of the expert system, a dynamic simulation of the system was developed in the MACLISP programming language. 2 refs., 3 figs

Current status and development of heat exchangers for boiling water reactor nuclear power plant

International Nuclear Information System (INIS)

Uchiyama, Yoshio; Nishioka, Shuji; Ito, Shizuo

1975-01-01

More efficient and reliable operation is required for BWR heat exchangers because of nuclear plant safety and other reasons. Heat exchangers are classified into two categories of systems, the system for normal operation and the system for emergency operation. The present state and future improvement of heat exchangers are described in view of heat transfer performance, material selection, structural design, vibration, and so on. When noncondensing gas exists in vapour, heat transfer performance deteriorates, so that the heat transfer characteristics should be corrected by the adaption of venting the non condensing gas from the system. Heat transfer tubes should have high corrosion resistance to working fluid as well as high thermal conductivity, strength and economy. From that point of view, 30% cupro-nickel tubes will be replaced with 10% cupro-nickel tubes or titanium tubes though some technical development is necessary. These heat exchangers are now designed according to the MITI criteria for the technology concerning nuclear and thermal power generation, ASME Boiler and Pressure Vessel Code Sec. III and some other criteria. Most of heat transfer tube failures are caused from the tube vibration induced by working fluid flow, so that the vibration test and analysis were performed on U-tube elements. Some correction was obtained for design and fabrication techniques. (Iwase, T.)

Technology Development Roadmap for the Advanced High Temperature Reactor Secondary Heat Exchanger

Energy Technology Data Exchange (ETDEWEB)

P. Sabharwall; M. McCllar; A. Siahpush; D. Clark; M. Patterson; J. Collins

2012-09-01

This Technology Development Roadmap (TDRM) presents the path forward for deploying large-scale molten salt secondary heat exchangers (MS-SHX) and recognizing the benefits of using molten salt as the heat transport medium for advanced high temperature reactors (AHTR). This TDRM will aid in the development and selection of the required heat exchanger for: power production (the first anticipated process heat application), hydrogen production, steam methane reforming, methanol to gasoline production, or ammonia production. This TDRM (a) establishes the current state of molten salt SHX technology readiness, (b) defines a path forward that systematically and effectively tests this technology to overcome areas of uncertainty, (c) demonstrates the achievement of an appropriate level of maturity prior to construction and plant operation, and (d) identifies issues and prioritizes future work for maturing the state of SHX technology. This study discusses the results of a preliminary design analysis of the SHX and explains the evaluation and selection methodology. An important engineering challenge will be to prevent the molten salt from freezing during normal and off-normal operations because of its high melting temperature (390°C for KF ZrF4). The efficient transfer of energy for industrial applications depends on the ability to incorporate cost-effective heat exchangers between the nuclear heat transport system and industrial process heat transport system. The need for efficiency, compactness, and safety challenge the capabilities of existing heat exchanger technology. The description of potential heat exchanger configurations or designs (such as printed circuit, spiral or helical coiled, ceramic, plate and fin, and plate type) were covered in an earlier report (Sabharwall et al. 2011). Significant future work, much of which is suggested in this report, is needed before the benefits and full potential of the AHTR can be realized. The execution of this TDRM will focuses

Joint research and development and exchange of technology on toxic material emergency response between LLNL and ENEA. 1985 progress report

International Nuclear Information System (INIS)

Dickerson, M.H.; Caracciolo, R.

1986-01-01

For the past six years, the US Department of Energy, LLNL, and the ENEA, Rome, Italy, have participated in cooperative studies for improving a systems approach to an emergency response following nuclear accidents. Technology exchange between LLNL and the ENEA was initially confined to the development, application, and evaluation of atmospheric transport and diffusion models. With the emergence of compatible hardware configurations between LLNL and ENEA, exchanges of technology and ideas for improving the development and implementation of systems are beginning to emerge. This report describes cooperative work that has occurred during the past three years, the present state of each system, and recommendations for future exchanges of technology

Integrated system of nuclear reactor and heat exchanger

International Nuclear Information System (INIS)

McDonald, B.N.; Schluderberg, D.C.

1977-01-01

The invention concerns PWRs in which the heat exchanger is associated with a pressure vessel containing the core and from which it can be selectively detached. This structural configuration applies to electric power generating uses based on land or on board ships. An existing reactor of this kind is fitted with a heat exchanger in which the tubes are 'U' shaped. This particular design of heat exchangers requires that the ends of the curved tubes be solidly maintained in a tube plate of great thickness, hence difficult to handle and to fabricate and requiring unconventional fine control systems for the control rods and awkward coolant pump arrangements. These complications limit the thermal power of the system to level below 100 megawatts. On the contrary, the object of this invention is to provide a one-piece PWR reactor capable of reaching power levels of 1500 thermal megawatts at least. For this, a pressure vessel is provided in the cylindrical assembly with not only a transversal separation on a plane located between the reactor and the heat exchanger but also a cover selectively detachable which supports the fine control gear of the control rods. Removing the cover exposes a part of the heat exchanger for easy inspection and maintenance. Further, the heat exchanger can be removed totally from the pressure vessel containing the core by detaching the cylindrical part, which composes the heat exchanger section, from the part that holds the reactor core on a level with the transversal separation [fr

The Picture Exchange Communication System (PECS): What Do the Data Say?

Science.gov (United States)

Sulzer-Azaroff, Beth; Hoffman, Anne O.; Horton, Catherine B.; Bondy, Andrew; Frost, Lori

2009-01-01

Originally designed to enable young children with autism lacking functional communication to initiate requests and to describe what they observed, the Picture Exchange Communication System (PECS) has been the subject of an ever-expanding body of research and development. Thirty-four peer-reviewed published reports on PECS are analyzed in this…

Gas exchange measurements in natural systems

International Nuclear Information System (INIS)

Broecker, W.S.; Peng, T.H.

1983-01-01

Direct knowledge of the rates of gas exchange in lakes and the ocean is based almost entirely on measurements of the isotopes 14 C, 222 Rn and 3 He. The distribution of natural radiocarbon has yielded the average rate of CO 2 exchange for the ocean and for several closed basin lakes. That of bomb produced radiocarbon has been used in the same systems. The 222 Rn to 226 Ra ratio in open ocean surface water has been used to give local short term gas exchange rates. The radon method generally cannot be used in lakes, rivers, estuaries or shelf areas because of the input of radon from sediments. A few attempts have been made to use the excess 3 He produced by decay of bomb produced tritium in lakes to give gas transfer rates. The uncertainty in the molecular diffusivity of helium and in the diffusivity dependence of the rate of gas transfer holds back the application of this method. A few attempts have been made to enrich the surface waters of small lakes with 226 Ra and 3 H in order to allow the use of the 222 Rn and 3 He methods. While these studies give broadly concordant results, many questions remain unanswered. The wind velocity dependence of gas exchange rate has yet to be established in field studies. The dependence of gas exchange rate on molecular diffusivity also remains in limbo. Finally, the degree of enhancement of CO 2 exchange through chemical reactions has been only partially explored. 49 references, 2 figures, 2 tables

A Controlled Environment System For Measuring Plant-Atmosphere Gas Exchange

Science.gov (United States)

James M. Brown

1975-01-01

Describes an inexpensive, efficient system for measuring plant-atmosphere gas exchange. Designed to measure transpiration from potted tree seedlings, it is readily adaptable for measuring other gas exchanges or gas exchange by plant parts. Light level, air and root temperature can be precisely controlled at minimum cost.

Dual temperature isotope exchange system

International Nuclear Information System (INIS)

Spevack, J.S.

1976-01-01

Improvements in the method for isotope concentration by dual temperature exchange between feed and auxiliary fluids in a multistage system are described. In a preferred embodiment the first is a vaporizable liquid and the auxiliary fluid a gas, comprising steps for improving the heating and/or cooling and/or humidifying and/or dehumidifying operations

H- charge exchange injection systems

International Nuclear Information System (INIS)

Ankenbrandt, C.; Curtis, C.; Hojvat, C.; Johnson, R.P.; Owen, C.; Schmidt, C.; Teng, L.; Webber, R.C.

1980-01-01

The techniques and components required for injection of protons into cyclic accelerators by means of H - charge exchange processes are reviewed, with emphasis on the experience at Fermilab. The advantages of the technique are described. The design and performance of the system of injection of H - ions into the Fermilab Booster are detailed. (Auth.)

Optimizing the Heat Exchanger Network of a Steam Reforming System

DEFF Research Database (Denmark)

Nielsen, Mads Pagh; Korsgaard, Anders Risum; Kær, Søren Knudsen

2004-01-01

Proton Exchange Membrane (PEM) based combined heat and power production systems are highly integrated energy systems. They may include a hydrogen production system and fuel cell stacks along with post combustion units optionally coupled with gas turbines. The considered system is based on a natural...... stationary numerical system model was used and process integration techniques for optimizing the heat exchanger network for the reforming unit are proposed. Objective is to minimize the system cost. Keywords: Fuel cells; Steam Reforming; Heat Exchanger Network (HEN) Synthesis; MINLP....... gas steam reformer along with gas purification reactors to generate clean hydrogen suited for a PEM stack. The temperatures in the various reactors in the fuel processing system vary from around 1000°C to the stack temperature at 80°C. Furthermore, external heating must be supplied to the endothermic...

Choice of optimal exchange rate system For the Republic of Croatia

OpenAIRE

Dražen Koški

2008-01-01

The aim of research whose results are presented in this article was to choose the optimal system of exchange rate for the Republic of Croatia, of course before its accession to EU. The analyzed exchange rate systems here range from free-floating exchange rate to system without domestic currency in circulation. Naturally, the classification of International Monetary Fond is included in it. After that, the comparison of basic economic advantages and disadvantages of the fixed exchan...

Development of ANN-based models to predict the static response and dynamic response of a heat exchanger in a real MVAC system

International Nuclear Information System (INIS)

Hu Qinhua; So, Albert T P; Tse, W L; Ren, Qingchang

2005-01-01

This paper presents a systematic approach to develop artificial neural network (ANN) models to predict the performance of a heat exchanger operating in real mechanical ventilation and air-conditioning (MVAC) system. Two approaches were attempted and presented. Every detailed components of the MVAC system have been considered and we attempt to model each of them by one ANN. This study used the neural network technique to obtain a static and a dynamic model for a heat exchanger mounted in an air handler unit (AHU), which is the key component of the MVAC system. It has been verified that almost all of the predicted values of the ANN model were within 95% - 105% of the measured values, with a consistent mean relative error (MRE) smaller than 2.5%. The paper details our experiences in using ANNs, especially those with back-propagation (BP) structures. Also, the weights and biases of our trained-up ANN models are listed out, which serve as good reference for readers to deal with their own situations

Simulation and economic analysis of a liquid-based solar system with a direct-contact liquid-liquid heat exchanger, in comparison to a system with a conventional heat exchanger

Science.gov (United States)

Brothers, P.; Karaki, S.

Using a solar computer simulation package called TRNSYS, simulations of the direct contact liquid-liquid heat exchanger (DCLLHE) solar system and a system with conventional shell-and-tube heat exchanger were developed, based in part on performance measurements of the actual systems. The two systems were simulated over a full year on an hour-by-hour basis at five locations; Boston, Massachusetts, Charleston, South Carolina, Dodge City, Kansas, Madison, Wisconsin, and Phoenix, Arizona. Typically the direct-contact system supplies slightly more heat for domestic hot water and space heating in all locations and about 5 percentage points more cooling as compared to the conventional system. Using a common set of economic parameters and the appropriate federal and state income tax credits, as well as property tax legislation for solar systems in the corresponding states, the results of the study indicate for heating-only systems, the DCLLHE system has a slight life-cycle cost disadvantage compared to the conventional system. For combined solar heating and cooling systems, the DCLLHE has a slight life-cycle cost advantage which varies with location and amounts to one to three percent difference from the conventional system.

The exchange of radiotherapy data as part of an electronic patient-referral system

International Nuclear Information System (INIS)

Lomax, Antony; Grossmann, Martin; Cozzi, Luca; Tercier, Pierre-Alain; Boehringer, Terence; Schneider, Uwe; Logean, Marianne; Volken, Werner; Ratib, Osman; Miralbell, Raymond

2000-01-01

Purpose: To describe the implementation and use of an electronic patient-referral system as an aid to the efficient referral of patients to a remote and specialized treatment center. Methods and Materials: A system for the exchange of radiotherapy data between different commercial planning systems and a specially developed planning system for proton therapy has been developed through the use of the PAPYRUS diagnostic image standard as an intermediate format. To ensure the cooperation of the different TPS manufacturers, the number of data sets defined for transfer has been restricted to the three core data sets of CT, VOIs, and three-dimensional dose distributions. As a complement to the exchange of data, network-wide application-sharing (video-conferencing) technologies have been adopted to provide methods for the interactive discussion and assessment of treatments plans with one or more partner clinics. Results: Through the use of evaluation plans based on the exchanged data, referring clinics can accurately assess the advantages offered by proton therapy on a patient-by-patient basis, while the practicality or otherwise of the proposed treatments can simultaneously be assessed by the proton therapy center. Such a system, along with the interactive capabilities provided by video-conferencing methods, has been found to be an efficient solution to the problem of patient assessment and selection at a specialized treatment center, and is a necessary first step toward the full electronic integration of such centers with their remotely situated referral centers

Study of heat exchange in cooling systems of heat-stressed structures

Science.gov (United States)

Vikulin, A. V.; Yaroslavtsev, N. L.; Zemlyanaya, V. A.

2017-01-01

Increasing working parameters of the cycle of gas-turbine engines, complicating design of gas-turbine plants, as well as growing aerodynamic, thermal, static, and dynamic loads, necessitate the development of promising cooling systems for heat-stressed structures. This work is devoted to an experimental study of heat exchange in ducts equipped with systems of inclined and cross walls (fins). It has been found that an increase in the Reynolds number Re from 3000 to 20000 leads to a decrease in the heat exchange, which is characterized by the relative Nusselt number overline{Nu}, by 19-30% at the angle of inclination of the walls φ = 0, 40°, 50°, and 90° if the length of the walls x w is comparable to the spacing b s and by 12-15% at φ = 30° and 90° if x w ≫ b s. If cross walls are used in cooling ducts, the length of the walls x w plays the governing role; an increase in this characteristic from 1.22 × 10-3 to 3.14 × 10-3 m leads to an increase in the intensity of heat exchange by 30-40% and to a decrease in the capacity of the entire system of the walls. It has been shown that, on surfaces with wavy fins, the intensity of heat exchange is closest to that determined in the models under study. For example, values of the Colborne criterion StPr2/3 for ducts equipped with wavy fins and for the models under study differ only slightly (by 2-20% depending on the value of the angle φ). However, the difference for surfaces with short plate fins and ducts equipped with inclined walls is high (30-40%). This is due to the design features of these surfaces and to the severe effect of the inlet portion on heat exchange, since the surfaces are characterized by a higher ratio of the duct length to the hydraulic diameter L/d h at small fin thicknesses ((0.1-0.15) × 10-3 m). The experimental results can be used in developing designs of nozzle and rotor blades of high-temperature gas turbines in gas-turbine engines and plants.

Estimation of Global 1km-grid Terrestrial Carbon Exchange Part I: Developing Inputs and Modelling

Science.gov (United States)

Sasai, T.; Murakami, K.; Kato, S.; Matsunaga, T.; Saigusa, N.; Hiraki, K.

2015-12-01

Global terrestrial carbon cycle largely depends on a spatial pattern in land cover type, which is heterogeneously-distributed over regional and global scales. However, most studies, which aimed at the estimation of carbon exchanges between ecosystem and atmosphere, remained within several tens of kilometers grid spatial resolution, and the results have not been enough to understand the detailed pattern of carbon exchanges based on ecological community. Improving the sophistication of spatial resolution is obviously necessary to enhance the accuracy of carbon exchanges. Moreover, the improvement may contribute to global warming awareness, policy makers and other social activities. In this study, we show global terrestrial carbon exchanges (net ecosystem production, net primary production, and gross primary production) with 1km-grid resolution. As methodology for computing the exchanges, we 1) developed a global 1km-grid climate and satellite dataset based on the approach in Setoyama and Sasai (2013); 2) used the satellite-driven biosphere model (Biosphere model integrating Eco-physiological And Mechanistic approaches using Satellite data: BEAMS) (Sasai et al., 2005, 2007, 2011); 3) simulated the carbon exchanges by using the new dataset and BEAMS by the use of a supercomputer that includes 1280 CPU and 320 GPGPU cores (GOSAT RCF of NIES). As a result, we could develop a global uniform system for realistically estimating terrestrial carbon exchange, and evaluate net ecosystem production in each community level; leading to obtain highly detailed understanding of terrestrial carbon exchanges.

Effects on Communicative Requesting and Speech Development of the Picture Exchange Communication System in Children with Characteristics of Autism

Science.gov (United States)

Ganz, Jennifer B.; Simpson, Richard L.

2004-01-01

Few studies on augmentative and alternative communication (AAC) systems have addressed the potential for such systems to impact word utterances in children with autism spectrum disorders (ASD). The Picture Exchange Communication System (PECS) is an AAC system designed specifically to minimize difficulties with communication skills experienced by…

The Software Bus, an Object-Oriented Data Exchange System

International Nuclear Information System (INIS)

Akerbaek, T.; Louka, M.

1996-01-01

This document describes the Software Bus System, developed for object-oriented task to task communication in a TCP/IP based network. The Software Bus is a set of library functions, developed to be used for the Picasso-3 UIMS, and as a general purpose tool for dynamically interfacing programs at run-time. The Software Bus offers a high level object-oriented data exchange mechanism that relieves the application programmer of the low level TCP/IP-programming and communication protocol handling. The Software Bus is currently available under several UNIX platforms and a version for Windows NT is planned for late 1996. (author)

The role of the spiracles in gas exchange during development of Samia cynthia (Lepidoptera, Saturniidae).

Science.gov (United States)

Hetz, Stefan K

2007-12-01

Spiracles and the tracheal system of insects allow effective delivery of respiratory gases. During development, holometabolous insects encounter large changes in the functional morphology of gas exchange structures. To investigate changes in respiratory patterns during development, CO2-release was measured in larvae, pre-pupae and pupae of Samia cynthia (Lepidoptera, Saturniidae). Gas exchange patterns showed great variability. Caterpillars had high metabolic rates and released carbon dioxide continuously. Pre-pupae and pupae showed typical discontinuous gas exchange cycles (DGC) at reduced metabolic rates. Changes in gas exchange patterns can partly be explained with low metabolic rates during pupation. Sequential blocking of spiracles in pre-pupae and pupae reduced spiracle conductance with tracheal conductance remaining unaffected. Analysis of gas exchange patterns indicates that caterpillars and pre-pupae use more than 14 spiracles simultaneously while pupae only use 8 to 10 spiracles. Total conductance is not a simple multiple of single spiracles, but may be gradually adaptable to gas exchange demands. Surprisingly, moth pupae showed a DGC if all except one spiracle were blocked. The huge conductance of single spiracles is discussed as a pre-adaptation to high metabolic demands at the beginning and the end of the pupal as well as in the adult stage.

Nuclear code case development of printed-circuit heat exchangers with thermal and mechanical performance testing

Energy Technology Data Exchange (ETDEWEB)

Aakre, Shaun R. [Univ. of Wisconsin, Madison, WI (United States). Dept. of Mechanical Engineering; Jentz, Ian W. [Univ. of Wisconsin, Madison, WI (United States). Dept. of Mechanical Engineering; Anderson, Mark H. [Univ. of Wisconsin, Madison, WI (United States). Dept. of Mechanical Engineering

2018-03-27

The U.S. Department of Energy has agreed to fund a three-year integrated research project to close technical gaps involved with compact heat exchangers to be used in nuclear applications. This paper introduces the goals of the project, the research institutions, and industrial partners working in collaboration to develop a draft Boiler and Pressure Vessel Code Case for this technology. Heat exchanger testing, as well as non-destructive and destructive evaluation, will be performed by researchers across the country to understand the performance of compact heat exchangers. Testing will be performed using coolants and conditions proposed for Gen IV Reactor designs. Preliminary observations of the mechanical failure mechanisms of the heat exchangers using destructive and non-destructive methods is presented. Unit-cell finite element models assembled to help predict the mechanical behavior of these high-temperature components are discussed as well. Performance testing methodology is laid out in this paper along with preliminary modeling results, an introduction to x-ray and neutron inspection techniques, and results from a recent pressurization test of a printed-circuit heat exchanger. The operational and quality assurance knowledge gained from these models and validation tests will be useful to developers of supercritical CO₂ systems, which commonly employ printed-circuit heat exchangers.

Assessment, Cleanup and Redevelopment Exchange System (ACRES)

Data.gov (United States)

U.S. Environmental Protection Agency — The Assessment, Cleanup and Redevelopment Exchange System (ACRES) is an online database for Brownfields Grantees to electronically submit data directly to EPA.

Shell-and-tube heat exchanger selection aid

International Nuclear Information System (INIS)

Lupton, L.R.; Basso, R.A.J.

1989-11-01

A prototype has been developed to investigate the feasibility of using expert systems to aid junior process system designers with the selection of components for shell-and-tube heat exchangers. The selection criteria for heat exchanger design were based on process, environmental and administrative constraints. The system was developed using EXSYS and consists of approximately 140 rules. This paper describes the development process and the lessons learned

[Phylogeny of gas exchange systems].

Science.gov (United States)

Jürgens, K D; Gros, G

2002-04-01

Several systems of gas transport have developed during evolution, all of which are able to sufficiently supply oxygen to the tissues and eliminate the CO2 produced by the metabolism, in spite of great distances between the environment and the individual cells of the tissues. Almost all these systems utilize a combination of convection and diffusion steps. Convection achieves an efficient transport of gas over large distances, but requires energy and cannot occur across tissue barriers. Diffusion, on the other hand, achieves gas transport across barriers, but requires optimization of diffusion paths and diffusion areas. When two convectional gas flows are linked via a diffusional barrier (gas/fluid in the case of the avian lung, fluid/fluid in the case of gills), the directions in which the respective convectional movements pass each other are important determinants of gas exchange efficiency (concurrent, countercurrent and cross-current systems). The tracheal respiration found in insects has the advantage of circumventing the convective gas transport step in the blood, thereby avoiding the high energy expenditure of circulatory systems. This is made possible by a system of tracheae, ending in tracheoles, that reaches from the body surface to every cell within the body. The last step of gas transfer in these animals occurs by diffusion from the tracheoles ("air capillaries") to the mitochondria of cells. The disadvantage is that the tracheal system occupies a substantial fraction of body volume and that, due to limited mechanical stability of tracheal walls, this system would not be able to operate under conditions of high hydrostatic pressures, i. e. in large animals. Respiration in an "open" system, i. e. direct exposure of the diffusional barrier to the environmental air, eliminates the problem of bringing the oxygen to the barrier by convection, as is necessary in the avian and mammalian lung, in the insects' tracheal system and in the gills. An open system is

Evaluating the Uncertainty in Exchange Parameters Determined from Off-Resonance R1ρ Relaxation Dispersion for Systems in Fast Exchange

Science.gov (United States)

Bothe, Jameson R.; Stein, Zachary W.; Al-Hashimi, Hashim M.

2014-01-01

Spin relaxation in the rotating frame (R1ρ) is a powerful NMR technique for characterizing fast microsecond timescale exchange processes directed toward short-lived excited states in biomolecules. At the limit of fast exchange, only kex = k1 + k−1 and Φıx = pGpE(Δω)2 can be determined from R1ρ data limiting the ability to characterize the structure and energetics of the excited state conformation. Here, we use simulations to examine the uncertainty with which exchange parameters can be determined for two state systems in intermediate-to-fast exchange using off-resonance R1ρ relaxation dispersion. R1ρ data computed by solving the Bloch-McConnell equations reveals small but significant asymmetry with respect to offset (R1ρ(ΔΩ) ≠ R1ρ(−ΔΩ)), which is a hallmark of slow-to-intermediate exchange, even under conditions of fast exchange for free precession chemical exchange line broadening (kex/Δω > 10). A grid search analysis combined with bootstrap and Monte-Carlo based statistical approaches for estimating uncertainty in exchange parameters reveals that both the sign and magnitude of Δω can be determined at a useful level of uncertainty for systems in fast exchange (kex/Δω exchange parameters. Results from simulations are complemented by analysis of experimental R1ρ data measured in three nucleic acid systems with exchange processes occurring on the slow (kex/Δω = 0.2; pE = ~ 0.7%), fast (kex/Δω = ~10–16; pE = ~13%) and very fast (kex = 39,000 s−1) chemical shift timescales. PMID:24819426

Verification on reliability of heat exchanger for primary cooling system

International Nuclear Information System (INIS)

Koike, Sumio; Gorai, Shigeru; Onoue, Ryuji; Ohtsuka, Kaoru

2010-07-01

Prior to the JMTR refurbishment, verification on reliability of the heat exchangers for primary cooling system was carried out to investigate an integrity of continuously use component. From a result of the significant corrosion, decrease of tube thickness, crack were not observed on the heat exchangers, and integrity of heat exchangers were confirmed. In the long terms usage of the heat exchangers, the maintenance based on periodical inspection and a long-term maintenance plan is scheduled. (author)

Grating exchange system of independent mirror supported by floating rotary stage

Science.gov (United States)

Zhang, Jianhuan; Tao, Jin; Liu, Yan; Nan, Yan

2015-10-01

The performance of The Grating Exchange System can satisfy the Thirty Meter Telescope - TMT for astronomical observation WFOS index requirements and satisfy the requirement of accuracy in the grating exchange. It is used to install in the MOBIE and a key device of MOBIE. The Wide Field Optical Spectrograph (WFOS) is one of the three first-light observing capabilities selected by the TMT Science Advisory Committee. The Multi-Object Broadband Imaging Echellette (MOBIE) instrument design concept has been developed to address the WFOS requirements as described in the TMT Science-Based Requirements Document (SRD). The Grating Exchange System uses a new type of separate movement way of three grating devices and a mirror device. Three grating devices with a mirror are able to achieve independence movement. This kind of grating exchange system can effectively solve the problem that the volume of the grating change system is too large and that the installed space of MOBIE instruments is too limit. This system adopts the good stability, high precision of rotary stage - a kind of using air bearing (Air bearing is famous for its ultra-high precision, and can meet the optical accuracy requirement) and rotation positioning feedback gauge turntable to support grating device. And with a kind of device which can carry greater weight bracket fixed on the MOBIE instrument, with two sets of servo motor control rotary stage and the mirror device respectively. And we use the control program to realize the need of exercising of the grating device and the mirror device. Using the stress strain analysis software--SolidWorks for stress and strain analysis of this structure. And then checking the structure of the rationality and feasibility. And prove that this system can realize the positioning precision under different working conditions can meet the requirements of imaging optical grating diffraction efficiency and error by the calculation and optical performance analysis.

System for exchanging tools and end effectors on a robot

International Nuclear Information System (INIS)

Burry, D.B.; Williams, P.M.

1991-01-01

A system and method for exchanging tools and end effectors on a robot permits exchange during a programmed task. The exchange mechanism is located off the robot, thus reducing the mass of the robot arm and permitting smaller robots to perform designated tasks. A simple spring/collet mechanism mounted on the robot is used which permits the engagement and disengagement of the tool or end effector without the need for a rotational orientation of the tool to the end effector/collet interface. As the tool changing system is not located on the robot arm no umbilical cords are located on robot. 12 figures

Development of Passive Fuel Cell Thermal Management Heat Exchanger

Science.gov (United States)

Burke, Kenneth A.; Jakupca, Ian J.; Colozza, Anthony J.

2010-01-01

The NASA Glenn Research Center is developing advanced passive thermal management technology to reduce the mass and improve the reliability of space fuel cell systems for the NASA Exploration program. The passive thermal management system relies on heat conduction within highly thermally conductive cooling plates to move the heat from the central portion of the cell stack out to the edges of the fuel cell stack. Using the passive approach eliminates the need for a coolant pump and other cooling loop components within the fuel cell system which reduces mass and improves overall system reliability. Previous development demonstrated the performance of suitable highly thermally conductive cooling plates that could conduct the heat, provide a sufficiently uniform temperature heat sink for each cell of the fuel cell stack, and be substantially lighter than the conventional thermal management approach. Tests were run with different materials to evaluate the design approach to a heat exchanger that could interface with the edges of the passive cooling plates. Measurements were made during fuel cell operation to determine the temperature of individual cooling plates and also to determine the temperature uniformity from one cooling plate to another.

Exchange Rate Policy in Philippine Development

OpenAIRE

Bautista, Romeo M.

2003-01-01

This paper examines the conduct of exchange rate policy in the Philippines since the early 1980s, paying particular attention to the influence of exchange rate adjustments on relative production incentives. While primary interest is in the exchange rate regime and its incentive effects, the role of trade policy has to be simultaneously analyzed in view of its influence on the conduct of exchange rate policy as well as its direct effect on the real exchange rate. Moreover, there are analytical...

Data Exchange Inventory System for Telecommunications and Systems Operations (DEXI-OTSO)

Data.gov (United States)

Social Security Administration — This Data Exchange Inventory (DEXI) for the Office of Telecommunications and System Operations, (OTSO) Network Troubleshooting is a browser-based inventory database...

A new cascade method for studying isotope effect in chemical exchange system without valance change

International Nuclear Information System (INIS)

Wen Xiaoning; Luo Wenzong

1987-01-01

A new cascade method for studying isotope effect in chemical exchange system without valance change is developed and described. This method is simple to use and consumes less extractant as compared with the commonly used Woodward method. It is also convenient for unstable systems

Subscale Water Based Phase Change Material Heat Exchanger Development

Science.gov (United States)

Sheth, Rubik; Hansen, Scott

2016-01-01

Supplemental heat rejection devices are required in many spacecraft as the radiators are not sized to meet the full heat rejection demand. One means of obtaining additional heat rejection is through the use of phase change material heat exchangers (PCM HX's). PCM HX's utilize phase change to store energy in unfavorable thermal environments (melting) and reject the energy in favorable environments (freezing). Traditionally, wax has been used as a PCM on spacecraft. However, water is an attractive alternative because it is capable of storing about 40% more energy per unit mass due to its higher latent heat of fusion. The significant problem in using water as a PCM is its expansion while freezing, leading to structural integrity concerns when housed in an enclosed heat exchanger volume. Significant investigation and development has taken place over the past five years to understand and overcome the problems associated with water PCM HX's. This paper reports on the final efforts by Johnson Space Center's Thermal Systems Branch to develop a water based PCM HX. The test article developed and reported on is a subscale version of the full-scale water-based PCM HX's constructed by Mezzo Technologies. The subscale unit was designed by applying prior research on freeze front propagation and previous full-scale water PCM HX development. Design modifications to the subscale unit included use of urethane bladder, decreased aspect ratio, perforated protection sheet, and use of additional mid-plates. Testing of the subscale unit was successful and 150 cycles were completed without fail.

Review on the Recent Developments of Photovoltaic Thermal (PV/T and Proton Exchange Membrane Fuel Cell (PEMFC Based Hybrid System

Directory of Open Access Journals (Sweden)

Zulkepli Afzam

2016-01-01

Full Text Available Photovoltaic Thermal (PV/T system emerged as one of the convenient type of renewable energy system acquire the ability to generate power and thermal energy in the absence of moving parts. However, the power output of PV/T is intermittent due to dependency on solar irradiation condition. Furthermore, its efficiency decreases because of cells instability at high temperature. On the other hand, fuel cell co-generation system (CGS is another technology that can generate power and heat simultaneously. Integration of PV/T and fuel cell CGS could enhance the reliability and sustainability of both systems as well as increasing the overall system performance. Hence, this paper intended to present the parameters that affect performance of PV/T and Proton Exchange Membrane Fuel Cell (PEMFC CGS. Moreover, recent developments on PV/T-fuel cell hybrid system are also presented. Based on literates, mass flow rate of moving fluid in PV/T was found to affect the system efficiency. For the PEMFC, when the heat is utilized, the system performance can be increased where the heat efficiency is similar to electrical efficiency which is about 50%. Recent developments of hybrid PV/T and fuel cell show that most of the studies only focus on the power generation of the system. There are less study on the both power and heat utilization which is indeed necessary in future development in term of operation strategy, optimization of size, and operation algorithm.

MANAGED FLOAT EXCHANGE RATE SYSTEM: THE SINGAPORE EXPERIENCE

OpenAIRE

HOE EE KHOR; JASON LEE; EDWARD ROBINSON; SAKTIANDI SUPAAT

2007-01-01

This paper examines the key characteristics of Singapore's exchange rate-centered monetary policy; in particular, its managed float regime which incorporates key features of the basket, band and crawl system popularized by Williamson (1998, 1999). We assess how the flexibility accorded by this framework has been advantageous in facilitating adjustment to various shocks to the economy. A characterization of the countercyclical nature of Singapore's exchange rate policy is also offered, with re...

Development of a NO/x/-free combustion system

Science.gov (United States)

Sadakata, M.; Furusawa, T.; Kunii, D.; Imagawa, M.; Nawada, M.

1980-04-01

The development of a NO(x)-free combustion-heating system realizing both pollution control and energy savings is described. An experiment was carried out by using a small model plant. The system consists of a combustion furnace and a new-type multifunctional heat exchanger. The heat exchanger is a rotary continuous type designed for soot collection and for catalytic combustion of CO and H2 as well as for preheating combustion air.

Research on Heat Exchange Process in Aircraft Air Conditioning System

Science.gov (United States)

Chichindaev, A. V.

2017-11-01

Using of heat-exchanger-condenser in the air conditioning system of the airplane Tu-204 (Boeing, Airbus, Superjet 100, MS-21, etc.) for cooling the compressed air by the cold air with negative temperature exiting the turbine results in a number of operational problems. Mainly it’s frosting of the heat exchange surface, which is the cause of live-section channels frosting, resistance increasing and airflow in the system decreasing. The purpose of this work is to analyse the known freeze-up-fighting methods for heat-exchanger-condenser, description of the features of anti-icing protection and offering solutions to this problem. For the problem of optimizing the design of heat exchangers in this work used generalized criterion that describes the ratio of thermal resistances of cold and hot sections, which include: the ratio of the initial values of heat transfer agents flow state; heat exchange surface finning coefficients; factors which describes the ratio of operating parameters and finning area. By controlling the ratio of the thermal resistances can be obtained the desired temperature of the heat exchange surface, which would prevent freezing. The work presents the results of a numerical study of the effect of different combinations of regime and geometrical factors changes on reduction of the heat-exchanger-condenser freezing surface area, including using of variable ratio of thermal resistances.

Terms of trade and exchange rate regimes in developing countries

OpenAIRE

Christian Broda

2002-01-01

Since Friedman (1953), an advantage often attributed to flexible exchange rate regimes over fixed regimes is their ability to insulate more effectively the economy against real shocks. I use a post-Bretton Woods sample (1973-96) of seventy-five developing countries to assess whether the responses of real GDP, real exchange rates, and prices to terms-of-trade shocks differ systematically across exchange rate regimes. I find that responses are significantly different across regimes in a way tha...

Analysis of Ion-Exchange Resin Capability of the RSG-GAS Demineralized Water System (GCA01)

International Nuclear Information System (INIS)

Diyah Erlina Lestari; Setyo Budi Utomo; Harsono

2012-01-01

The Demineralized water system (GCA01) is a system which is function to process raw water to be demineralized water using ion exchange resin unit consisting of a column of cation exchange resins, anion exchange resin column and the column resin mix bed. After certain time the ion exchange resins to be saturated so that is needed regeneration. The RSG-GAS demineralized water system (GCA01) not operated continuously and indication of when does an ion exchange resin regeneration on The RSG-GAS demineralized water system (GCA01) is the water conductivity from anion exchange resin column output indicates ≥ 5μS/cm. Analysis of capability of the ion exchange resin demineralized water system (GCA01) line I has been performed. The analysis was done by comparing the time required in the system operating cycle of regeneration to the next regeneration during the period 2011 and 2012. From the results of the analysis showed the cycle regeneration time is varies. This shows that ion exchange resin capability of the RSG-GAS demineralized water system (GCA01) is varies depending on the raw water quality and success of the regeneration ion exchange resin. (author)

Developing bulk exchange spring magnets

Science.gov (United States)

Mccall, Scott K.; Kuntz, Joshua D.

2017-06-27

A method of making a bulk exchange spring magnet by providing a magnetically soft material, providing a hard magnetic material, and producing a composite of said magnetically soft material and said hard magnetic material to make the bulk exchange spring magnet. The step of producing a composite of magnetically soft material and hard magnetic material is accomplished by electrophoretic deposition of the magnetically soft material and the hard magnetic material to make the bulk exchange spring magnet.

Electronic bulletin board system for image and information exchange

International Nuclear Information System (INIS)

Halama, J.R.; Henkin, R.E.; Wagner, R.H.

1990-01-01

This paper provides nuclear medicine professionals access to an electronic bulletin board (EBB) for image and information exchange. EBB users access the system remotely via modem and personal computer. A public message board is maintained containing messages posted by users. New messages or replies to existing messages may be posted. A public library board contains documents and images for users to access by transmitting them locally for off-line review. Comments and replies may be posted in the library board. New files may be posted in the library at any time. The EBB programs were developed on a multi-user computer system, allowing simultaneous access of users and on-line conferencing among active users

Development of inorganic ion exchangers for nuclear waste remediation. 1997 annual progress report

International Nuclear Information System (INIS)

Clearfield, A.; Collins, J.L.; Egan, B.Z.

1997-01-01

'In this research program, Oak Ridge National Laboratory (ORNL) is collaborating with Texas A and M University in the development of highly selective inorganic ion exchangers for the removal of cesium and strontium from nuclear tank-waste and from groundwater. Inorganic ion exchangers are developed and characterized at Texas A and M University; ORNL is involved in preparing the powders in engineered forms and testing the performance of the sorbents in actual nuclear waste solutions. The Texas A and M studies are divided into two main categories: (1) exchangers for tank wastes and (2) exchangers for groundwater remediation. These are subdivided into exchangers for use in acid and alkaline solutions for tank wastes and those that can be recycled for use in groundwater remediation. The exchangers will also be considered for in situ immobilization of radionuclides. The approach will involve a combination of exchanger synthesis, structural characterization, and ion exchange behavior. ORNL has developed a technique for preparing inorganic ion exchangers in the form of spherules by a gel-sphere internal gelation process. This technology, which was developed and used for making nuclear fuels, has the potential of greatly enhancing the usability of many other special inorganic materials because of the improved flow dynamics of the spherules. Also, pure inorganic spherules can be made without the use of binders. ORNL also has access to actual nuclear waste in the form of waste tank supernatant solutions for testing the capabilities of the sorbents for removing the cesium and strontium radionuclides from actual waste solutions. The ORNL collaboration will involve the preparation of the powdered ion exchangers, developed and synthesized at Texas A and M, in the form of spherules, and evaluating the performance of the exchangers in real nuclear waste solutions. Selected sorbents will be provided by Texas A and M for potential incorporation into microspheres, and the performance

Heat pipe heat exchangers in heat recovery systems

Energy Technology Data Exchange (ETDEWEB)

Stulc, P; Vasiliev, L L; Kiseljev, V G; Matvejev, Ju N

1985-01-01

The results of combined research and development activities of the National Research Institute for Machine Design, Prague, C.S.S.R. and the Institute for Heat and Mass Transfer, Minsk, U.S.S.R. concerning intensification heat pipes used in heat pipe heat exchangers are presented. This sort of research has been occasioned by increased interest in heat power economy trying to utilise waste heat produced by various technological processes. The developed heat pipes are deployed in construction of air-air, gas-air or gas-gas heat recovery exchangers in the field of air-engineering and air-conditioning. (author).

Segmented heat exchanger

Science.gov (United States)

Baldwin, Darryl Dean; Willi, Martin Leo; Fiveland, Scott Byron; Timmons, Kristine Ann

2010-12-14

A segmented heat exchanger system for transferring heat energy from an exhaust fluid to a working fluid. The heat exchanger system may include a first heat exchanger for receiving incoming working fluid and the exhaust fluid. The working fluid and exhaust fluid may travel through at least a portion of the first heat exchanger in a parallel flow configuration. In addition, the heat exchanger system may include a second heat exchanger for receiving working fluid from the first heat exchanger and exhaust fluid from a third heat exchanger. The working fluid and exhaust fluid may travel through at least a portion of the second heat exchanger in a counter flow configuration. Furthermore, the heat exchanger system may include a third heat exchanger for receiving working fluid from the second heat exchanger and exhaust fluid from the first heat exchanger. The working fluid and exhaust fluid may travel through at least a portion of the third heat exchanger in a parallel flow configuration.

Development, design, construction and testing of pumps, intermediate heat exchangers and manipulator systems for in-service inspection of SNR 300

International Nuclear Information System (INIS)

Vroom, J.P.; Heslenfeld, M.W.; Westerweele, W.J.; Willigen, A. van

1978-01-01

The first part of this paper reviews the development, design, construction and testing of sodium pumps and intermediate heat exchangers as carried out by NERATOOM in the Netherlands. Testing of full-size components under operational conditions yielded important information for the design of the components for SNR 300. Information is also given in brief on the manufacture of the components. The second part reviews the work done on manipulator systems for in-service inspection as carried out by INTERATOM in Germany. In this field again experience gained from tests had important consequences for the design of the apparatus for SNR 300. (author)

Capital Controls and Foreign Investor Subsidies Implicit in South Africa's Dual Exchange Rate System

NARCIS (Netherlands)

Huizinga, H.P.; Schaling, E.; van der Windt, P.C.

2007-01-01

Both in theory and practice, capital controls and dual exchange rate systems can be part of a country's optimal tax policy. We first show how a dual exchange rate system can be interpreted as a tax (or subsidy) on international capital income. We show that a dual exchange rate system, with separate

Community Exchange Systems. What They Are. How They Work. How to Set One Up.

Science.gov (United States)

Page, Leslie

This booklet explains the concept of a community exchange system (CES), or barter system, for the exchange of goods and services and describes how to set one up. The booklet is concerned only with nonprofit, voluntary organizations. The booklet is organized in four sections. The first section introduces the community exchange systems idea and…

Development of a High-Throughput Ion-Exchange Resin Characterization Workflow.

Science.gov (United States)

Liu, Chun; Dermody, Daniel; Harris, Keith; Boomgaard, Thomas; Sweeney, Jeff; Gisch, Daryl; Goltz, Bob

2017-06-12

A novel high-throughout (HTR) ion-exchange (IEX) resin workflow has been developed for characterizing ion exchange equilibrium of commercial and experimental IEX resins against a range of different applications where water environment differs from site to site. Because of its much higher throughput, design of experiment (DOE) methodology can be easily applied for studying the effects of multiple factors on resin performance. Two case studies will be presented to illustrate the efficacy of the combined HTR workflow and DOE method. In case study one, a series of anion exchange resins have been screened for selective removal of NO 3 - and NO 2 - in water environments consisting of multiple other anions, varied pH, and ionic strength. The response surface model (RSM) is developed to statistically correlate the resin performance with the water composition and predict the best resin candidate. In case study two, the same HTR workflow and DOE method have been applied for screening different cation exchange resins in terms of the selective removal of Mg 2+ , Ca 2+ , and Ba 2+ from high total dissolved salt (TDS) water. A master DOE model including all of the cation exchange resins is created to predict divalent cation removal by different IEX resins under specific conditions, from which the best resin candidates can be identified. The successful adoption of HTR workflow and DOE method for studying the ion exchange of IEX resins can significantly reduce the resources and time to address industry and application needs.

Feasibility study on development of plate-type heat exchanger for BWR plants

International Nuclear Information System (INIS)

Ohyama, Nobuhiro; Suda, Kenichi; Ogata, Hiroshi; Matsuda, Shinichi; Nagasaka, Kazuhiro; Fujii, Toshi; Nozawa, Toshiya; Ishihama, Kiyoshi; Higuchi, Tomokazu

2004-01-01

In order to apply plate-type heat exchanger to RCW, TCW and FPC system in BWR plants, heat test and seismic test of RCW system heat exchanger sample were carried out. The results of these tests showed new design plate-type heat exchanger satisfied the fixed pressure resistance and seismic resistance and keep the function. The evaluation method of seismic design was constructed and confirmed by the results of tests. As anti-adhesion measure of marine organism, an ozone-water circulation method, chemical-feed method and combination of circulation of hot water and air bubbling are useful in place of the chlorine feeding method. Application of the plate-type heat exchanger to BWR plant is confirmed by these investigations. The basic principles, structure, characteristics, application limit and reliability are stated. (S.Y.)

Uncertainty quantification of surface-water/groundwater exchange estimates in large wetland systems using Python

Science.gov (United States)

Hughes, J. D.; Metz, P. A.

2014-12-01

Most watershed studies include observation-based water budget analyses to develop first-order estimates of significant flow terms. Surface-water/groundwater (SWGW) exchange is typically assumed to be equal to the residual of the sum of inflows and outflows in a watershed. These estimates of SWGW exchange, however, are highly uncertain as a result of the propagation of uncertainty inherent in the calculation or processing of the other terms of the water budget, such as stage-area-volume relations, and uncertainties associated with land-cover based evapotranspiration (ET) rate estimates. Furthermore, the uncertainty of estimated SWGW exchanges can be magnified in large wetland systems that transition from dry to wet during wet periods. Although it is well understood that observation-based estimates of SWGW exchange are uncertain it is uncommon for the uncertainty of these estimates to be directly quantified. High-level programming languages like Python can greatly reduce the effort required to (1) quantify the uncertainty of estimated SWGW exchange in large wetland systems and (2) evaluate how different approaches for partitioning land-cover data in a watershed may affect the water-budget uncertainty. We have used Python with the Numpy, Scipy.stats, and pyDOE packages to implement an unconstrained Monte Carlo approach with Latin Hypercube sampling to quantify the uncertainty of monthly estimates of SWGW exchange in the Floral City watershed of the Tsala Apopka wetland system in west-central Florida, USA. Possible sources of uncertainty in the water budget analysis include rainfall, ET, canal discharge, and land/bathymetric surface elevations. Each of these input variables was assigned a probability distribution based on observation error or spanning the range of probable values. The Monte Carlo integration process exposes the uncertainties in land-cover based ET rate estimates as the dominant contributor to the uncertainty in SWGW exchange estimates. We will discuss

Anion-exchange membranes in electrochemical energy systems

NARCIS (Netherlands)

Varcoe, J.R.; Atanassov, P.; Dekel, D.R.; Herring, A.M.; Hickner, M.A.; Kohl, P.A.; Kucernak, A. R.; Mustain, W.E.; Nijmeijer, K.; Scott, Keith; Xu, Tongwen; Zhuang, Lin

2014-01-01

This article provides an up-to-date perspective on the use of anion-exchange membranes in fuel cells, electrolysers, redox flow batteries, reverse electrodialysis cells, and bioelectrochemical systems (e.g. microbial fuel cells). The aim is to highlight key concepts, misconceptions, the current

OLYMPUS system and development of its pre-processor

International Nuclear Information System (INIS)

Okamoto, Masao; Takeda, Tatsuoki; Tanaka, Masatoshi; Asai, Kiyoshi; Nakano, Koh.

1977-08-01

The OLYMPUS SYSTEM developed by K. V. Roverts et al. was converted and introduced in computer system FACOM 230/75 of the JAERI Computing Center. A pre-processor was also developed for the OLYMPUS SYSTEM. The OLYMPUS SYSTEM is very useful for development, standardization and exchange of programs in thermonuclear fusion research and plasma physics. The pre-processor developed by the present authors is not only essential for the JAERI OLYMPUS SYSTEM, but also useful in manipulation, creation and correction of program files. (auth.)

Developing Sociolinguistic Competence through Intercultural Online Exchange

Science.gov (United States)

Ritchie, Mathy

2011-01-01

The main goal of this study was to investigate whether computer-mediated communication (CMC) intercultural exchange offers the conditions necessary for the development of the sociolinguistic competence of second language learners. Non-native speakers (NNS) of French in British Columbia interacted through CMC with native speakers (NS) of French in…

Development of sample exchange robot PAM-HC for beamline BL-1A at the photon factory

Energy Technology Data Exchange (ETDEWEB)

Hiraki, Masahiko, E-mail: masahiko.hiraki@kek.jp [Mechanical Engineering Center, Applied Research Laboratory, KEK (High Energy Accelerator Research Organization), 1-1 Oho, Tsukuba, Ibaraki 305-0801 Japan (Japan); Department of Accelerator Science, SOKENDAI (the Graduate University for Advanced Studies), 1-1 Oho, Tsukuba, Ibaraki 305-0801 Japan (Japan); Matsugaki, Naohiro; Yamada, Yusuke; Senda, Toshiya [Structural Biology research Center, Institute of Materials Structure Science, KEK (Japan); Department of Materials Structure Science, SOKENDAI (Japan)

2016-07-27

A macromolecular crystallography beamline, BL-1A, has been built at the Photon Factory (PF) for low energy experiments and has been operational since 2010. We have installed a sample exchange robot, PAM (PF Automated Mounting system), similar to other macromolecular crystallography beamlines. However, following the installation of a helium chamber to reduce the absorption of the diffraction signal by air, we developed a new sample exchange robot to replace PAM. The new robot, named PAM-HC (Helium Chamber), is designed with the goal of minimizing leakage of helium gas from the chamber. Here, the PAM-HC hardware and the flow of its movement are described. Furthermore, measurements of temperature changes during sample exchange are presented in this paper.

Development of sample exchange robot PAM-HC for beamline BL-1A at the photon factory

International Nuclear Information System (INIS)

Hiraki, Masahiko; Matsugaki, Naohiro; Yamada, Yusuke; Senda, Toshiya

2016-01-01

A macromolecular crystallography beamline, BL-1A, has been built at the Photon Factory (PF) for low energy experiments and has been operational since 2010. We have installed a sample exchange robot, PAM (PF Automated Mounting system), similar to other macromolecular crystallography beamlines. However, following the installation of a helium chamber to reduce the absorption of the diffraction signal by air, we developed a new sample exchange robot to replace PAM. The new robot, named PAM-HC (Helium Chamber), is designed with the goal of minimizing leakage of helium gas from the chamber. Here, the PAM-HC hardware and the flow of its movement are described. Furthermore, measurements of temperature changes during sample exchange are presented in this paper.

e-Government for Development Information Exchange (DIE): Zambia

Science.gov (United States)

Joseph, Bwalya Kelvin

In most parts of the world, political systems which utilize authoritative rule and mostly employ top-down decision-making processes are slowly transcending towards democratic norms. Information Technology Systems have been identified and adopted as one of the most efficient vehicles for appropriate, transparent and inclusive / participatory decision making. Zambia has shown a higher propensity to indigenous knowledge systems which are full of inefficiencies, a lot of red tape in public service delivery, and prone to corrupt practices. Despite that being the case, it is slowly trying to implement e-government. The adoption of e-government promises a sharp paradigm shift where public institutions will be more responsive and transparent, promote efficient PPP (Public Private Partnerships), and empower citizens by making knowledge and other resources more directly accessible. This paper examines three cases from Zambia where ICT in support of e-government has been implemented for Development Information Exchange (DIE) - knowledge-based decision making. The paper also assesses the challenges, opportunities, and issues together with e-government adoption criteria regarding successful encapsulation of e-government into the Zambian contextual environment. I propose a conceptual model which offers balanced e-government adoption criteria involving a combination of electronic and participatory services. This conceptual e-government adoption model can later be replicated to be used at the Southern African Development Community (SADC) level given the similarity in the contextual environment.

Feedwater heater performance evaluation using the heat exchanger workstation

International Nuclear Information System (INIS)

Ranganathan, K.M.; Singh, G.P.; Tsou, J.L.

1995-01-01

A Heat Exchanger Workstation (HEW) has been developed to monitor the condition of heat exchanging equipment power plants. HEW enables engineers to analyze thermal performance and failure events for power plant feedwater heaters. The software provides tools for heat balance calculation and performance analysis. It also contains an expert system that enables performance enhancement. The Operation and Maintenance (O ampersand M) reference module on CD-ROM for HEW will be available by the end of 1995. Future developments of HEW would result in Condenser Expert System (CONES) and Balance of Plant Expert System (BOPES). HEW consists of five tightly integrated applications: A Database system for heat exchanger data storage, a Diagrammer system for creating plant heat exchanger schematics and data display, a Performance Analyst system for analyzing and predicting heat exchanger performance, a Performance Advisor expert system for expertise on improving heat exchanger performance and a Water Calculator system for computing properties of steam and water. In this paper an analysis of a feedwater heater which has been off-line is used to demonstrate how HEW can analyze the performance of the feedwater heater train and provide an economic justification for either replacing or repairing the feedwater heater

Real time alert system: a disease management system leveraging health information exchange.

Science.gov (United States)

Anand, Vibha; Sheley, Meena E; Xu, Shawn; Downs, Stephen M

2012-01-01

Rates of preventive and disease management services can be improved by providing automated alerts and reminders to primary care providers (PCPs) using of health information technology (HIT) tools. Using Adaptive Turnaround Documents (ATAD), an existing Health Information Exchange (HIE) infrastructure and office fax machines, we developed a Real Time Alert (RTA) system. RTA is a computerized decision support system (CDSS) that is able to deliver alerts to PCPs statewide for recommended services around the time of the patient visit. RTA is also able to capture structured clinical data from providers using existing fax technology. In this study, we evaluate RTA's performance for alerting PCPs when their patients with asthma have an emergency room visit anywhere in the state. Our results show that RTA was successfully able to deliver "just in time" patient-relevant alerts to PCPs across the state. Furthermore, of those ATADs faxed back and automatically interpreted by the RTA system, 35% reported finding the provided information helpful. The PCPs who reported finding information helpful also reported making a phone call, sending a letter or seeing the patient for follow up care. We have successfully demonstrated the feasibility of electronically exchanging important patient related information with the PCPs statewide. This is despite a lack of a link with their electronic health records. We have shown that using our ATAD technology, a PCP can be notified quickly of an important event such as a patient's asthma related emergency room admission so further follow up can happen in near real time.

Gain measurements of the Ca-Xe charge exchange system. [for UV lasers

Science.gov (United States)

Michels, C. J.; Chubb, D. L.

1978-01-01

Charge-exchange-pumped Ca(+) was studied for possible positive laser gain at 370.6 and 315.9 nm using an Xe MPD arc as the Xe(+) source. The present paper describes the MPD arc, the calcium injection system, the diagnostics for gain, and spontaneous emission measurements and results. No positive gain measurements were observed. A small Xe-Ca charge exchange cross section compared to He-metal laser systems charge exchange cross sections is the most probable reason why the result was negative.

Heat Exchanger/Humidifier Trade Study and Conceptual Design for the Constellation Space Suit Portable Life Support System Ventilation Subsystem

Science.gov (United States)

Paul, Heather L.; Sompayrac, Robert; Conger, Bruce; Chamberlain, Mateo

2009-01-01

As development of the Constellation Space Suit Element progresses, designing the most effective and efficient life support systems is critical. The baseline schematic analysis for the Portable Life Support System (PLSS) indicates that the ventilation loop will need some method of heat exchange and humidification prior to entering the helmet. A trade study was initiated to identify the challenges associated with conditioning the spacesuit breathing gas stream for temperature and water vapor control, to survey technological literature and resources on heat exchanger and humidifiers to provide solutions to the problems of conditioning the spacesuit breathing gas stream, and to propose potential candidate technologies to perform the heat exchanger and humidifier functions. This paper summarizes the results of this trade study and also describes the conceptual designs that NASA developed to address these issues.

NMR magnetization exchange dynamics for three spin-1/2 systems

International Nuclear Information System (INIS)

Demco, D.E.; Filip, X.; Filip, C.

1997-01-01

The magnetization exchange dynamics in one-dimensional NMR exchange experiments performed with static samples is analyzed for the relevant case of three spin systems. The magnetization decays recorded in the experiments performed with different chemical shift filters for the short mixing times are derived analytically. In this regime the decay rates depend on the dipolar coupling between the spins belonging to different functional groups. The predictions of the theoretical model are compared with the magnetization exchange data obtained for cross-linked poly(styrene-co-butadiene) samples. The residual dipolar coupling between the functional CH- and CH2-groups of butadiene are measured from the magnetization exchange experiments in the short mixing time regime. (authors)

Ion exchange equilibrium for some uni-univalent and uni-divalent reaction systems using strongly basic anion exchange resin Duolite A-102 D

Directory of Open Access Journals (Sweden)

R.S. Lokhande

2008-04-01

Full Text Available The study on thermodynamics of ion exchange equilibrium for uni-univalent Cl-/I-, Cl-/Br-, and uni-divalent Cl-/SO42-, Cl-/C2O42- reaction systems was carried out using ion exchange resin Duolite A-102 D. The equilibrium constant K was calculated by taking into account the activity coefficient of ions both in solution as well as in the resin phase. The K values calculated for uni-univalent and uni-divalent anion exchange reaction systems was observed to increase with rise in temperature, indicating the endothermic exchange reactions having enthalpy values of 13.7, 38.0, 23.9, 22.9 kJ/mol, respectively.

Design study of plastic film heat exchanger

Science.gov (United States)

Guyer, E. C.; Brownell, D. L.

1986-02-01

This report presents the results of an effort to develop and design a unique thermoplastic film heat exchanger for use in an industrial heat pump evaporator system and other energy recovery applications. The concept for the exchanger is that of individual heat exchange elements formed by two adjoining and freely hanging plastic films. Liquid flows downward in a regulated fashion between the films due to the balance of hydrostatic and frictional forces. The fluid stream on the outside of film may be a free-falling liquid film, a condensing gas, or a noncondensing gas. The flow and structural principles are similar to those embodied in an earlier heat exchange system developed for use in waste water treatment systems (Sanderson). The design allows for high heat transfer rates while working within the thermal and structural limitations of thermoplastic materials. The potential of this new heat exchanger design lies in the relatively low cost of plastic film and the high inherent corrosion and fouling resistance. This report addresses the selection of materials, the potential heat transf er performance, the mechanical design and operation of a unit applied in a low pressure steam recovery system, and the expected selling price in comparison to conventional metallic shell and tube heat exchangers.

Are there differences in health information exchange by health system type?

Science.gov (United States)

Opoku-Agyeman, William; Menachemi, Nir

2016-01-01

Despite the potential of health information exchange (HIE) to improve safety and reduce cost, hospitals have been slow to adopt HIE with only 30% of U.S. hospitals doing so in 2012. The aim of this study was to explore the relationship between different health system types and how they engage in HIE. Data on health system types and engagement in HIE activity were combined with secondary hospital characteristics. Ordinal logistic regression analyses were used to examine the relationship between a scale measuring the level of HIE engagement and health system type controlling for hospital and market characteristics. Data from 1552 hospitals were available for analyses. Overall, hospital in a health system of any kind exchanged more patient data elements (e.g., patient demographics, clinical summaries, laboratory results, medication history, and radiology report) compared with stand-alone hospitals (3.82 vs. 1.80, p centralized health systems, 75 (4.8%) were in centralized physician/insurance health system, 284 (18.3%) were in moderately centralized health system, 391 (25.2%) were in decentralized health system, and 91 (5.9%) were in independent health system. In regression analyses, hospitals belonging to a health system were more likely to exchange patient health data with other hospitals in the same system (OR = 3.94, p < .001) but not with hospitals outside their system (OR = 1.89, p = .445). Across health system types, there was no significant difference in the exchange of patient health data. Hospital engagement in HIE is associated with health system membership. These findings will assist hospital leaders and managers to better understand how the structure and nature of their system may influence what their individual hospital can and cannot do in their decision to engage in HIE and other decisions that support the overall system objectives.

Electrically switched cesium ion exchange

International Nuclear Information System (INIS)

Lilga, M.A.; Orth, R.J.; Sukamto, J.P.H.; Schwartz, D.T.; Haight, S.M.; Genders, J.D.

1997-04-01

Electrically Switched Ion Exchange (ESIX) is a separation technology being developed as an alternative to conventional ion exchange for removing radionuclides from high-level waste. The ESIX technology, which combines ion exchange and electrochemistry, is geared toward producing electroactive films that are highly selective, regenerable, and long lasting. During the process, ion uptake and elution are controlled directly by modulating the potential of an ion exchange film that has been electrochemically deposited onto a high surface area electrode. This method adds little sodium to the waste stream and minimizes the secondary wastes associated with traditional ion exchange techniques. Development of the ESIX process is well underway for cesium removal using ferrocyanides as the electroactive films. Films having selectivity for perrhenate (a pertechnetate surrogate) over nitrate also have been deposited and tested. A case study for the KE Basin on the Hanford Site was conducted based on the results of the development testing. Engineering design baseline parameters for film deposition, film regeneration, cesium loading, and cesium elution were used for developing a conceptual system. Order of magnitude cost estimates were developed to compare with conventional ion exchange. This case study demonstrated that KE Basin wastewater could be processed continuously with minimal secondary waste and reduced associated disposal costs, as well as lower capital and labor expenditures

Ion-exchange equilibrium of Fe3+-Cl- and UO22+-Cl- systems in a porous anion exchanger

International Nuclear Information System (INIS)

Takeda, Kunihiko; Kawakami, Fumiaki; Sasaki, Mitsunaga

1985-01-01

The ion-exchange equilibrium behavior of complex ions was investigatided in the systems of UO 2 2+ - Cl - and Fe 3+ - Cl - using an anion exchanger. It was performed by examining the dependency of adsorption distribution and selectivity of complexes on the micro structure of ion-exchangers, and temperature-dependency of selectivity. Changes in micropore structure of the ion-exchanger were found to have a significant effect on selectivity; the coefficient of selectivity and the average valence of the adsorbed species increased as the discrete pore ratio used as the index for pore structure decreased. In this study, equilibrium reactions were regarded as a sort of addition reaction for a easier analysis. This analysis based on the concept of addition chemical potential suggested that decreases in the discrete pore ratio were advantageous for the adsorption of complex ion species with higher valence, and average valence of the adsorbed species within the exchanger was shifted to the higher side. For this reason, it is assumed that the coefficient of selectivity became larger with a decrease in the discrete pore ratio. There is also a marked change in the coefficient of selectivity with temperature, and this becomes greater the higher the temperature. The ΔH of the present system accompanying the complex forming reaction is estimated to be 7 to 8 kcal/mol, and this value suggests that the temperature effect of the complex forming reaction contributes greatly to the change in selectivity with temperature. (author)

Exact exchange-correlation potentials of singlet two-electron systems

Science.gov (United States)

Ryabinkin, Ilya G.; Ospadov, Egor; Staroverov, Viktor N.

2017-10-01

We suggest a non-iterative analytic method for constructing the exchange-correlation potential, v XC ( r ) , of any singlet ground-state two-electron system. The method is based on a convenient formula for v XC ( r ) in terms of quantities determined only by the system's electronic wave function, exact or approximate, and is essentially different from the Kohn-Sham inversion technique. When applied to Gaussian-basis-set wave functions, the method yields finite-basis-set approximations to the corresponding basis-set-limit v XC ( r ) , whereas the Kohn-Sham inversion produces physically inappropriate (oscillatory and divergent) potentials. The effectiveness of the procedure is demonstrated by computing accurate exchange-correlation potentials of several two-electron systems (helium isoelectronic series, H2, H3 + ) using common ab initio methods and Gaussian basis sets.

Data Exchange Inventory System (DEXI)

Data.gov (United States)

Social Security Administration — Enterprise tool used to identify data exchanges occurring between SSA and our trading partners. DEXI contains information on both incoming and outgoing exchanges and...

EPR of exchange coupled systems

CERN Document Server

Bencini, Alessandro

2012-01-01

From chemistry to solid state physics to biology, the applications of Electron Paramagnetic Resonance (EPR) are relevant to many areas. This unified treatment is based on the spin Hamiltonian approach and makes extensive use of irreducible tensor techniques to analyze systems in which two or more spins are magnetically coupled. This edition contains a new Introduction by coauthor Dante Gatteschi, a pioneer and scholar of molecular magnetism.The first two chapters review the foundations of exchange interactions, followed by examinations of the spectra of pairs and clusters, relaxation in oligon

Kinetics of isotope exchange reactions involving intra- and intermolecular reactions: 1. Rate law for a system with two chemical compounds and three exchangeable atoms

International Nuclear Information System (INIS)

Xuelei Chu; Ohmoto, Hiroshi

1991-01-01

For an isotopic exchange reaction between two compounds (X and AB) in a homogeneous system, such as a gaseous or aqueous system, where one (AB) of them possesses two exchangeable atoms in non-equivalent positions and where one intramolecular isotope exchange (A ↔ B) and two intermolecular isotope exchange reactions (X ↔ A and X ↔ B) may occur, its rate law no longer obeys a pseudo-first order rate equation described for simple two-component systems by many previous investigators. The change with time of the δ value of each of the three components (X, A, and B) in a closed and homogeneous system is a complicated function of the initial δ values of the three components, the chemical concentrations of the two compounds, and the overall rate constants of the forward and reverse reactions involving the two intermolecular and one intramolecular reactions of isotope exchanges. Also, for some one of the three components, the change of its δ value with time may not be monotonic, and the relationship of 1n (1 - F) with time may be non-linear in a plot of 1n (1 - F) vs. t. In addition, the rate law of the isotope exchange reaction in this system also provides a quantitative method to estimate the overall rate constants for the one-intra-and two intermolecular isotope exchanges and the equilibrium isotopic fractionation factors among the three components

Determination of Minimum Data Set (MSD) in Echocardiography Reporting System to Exchange with Iran's Electronic Health Record (EHR) System.

Science.gov (United States)

Mahmoudvand, Zahra; Kamkar, Mehran; Shahmoradi, Leila; Nejad, Ahmadreza Farzaneh

2016-04-01

Determination of minimum data set (MDS) in echocardiography reports is necessary for documentation and putting information in a standard way, and leads to the enhancement of electrocardiographic studies through having access to precise and perfect reports and also to the development of a standard database for electrocardiographic reports. to determine the minimum data set of echocardiography reporting system to exchange with Iran's electronic health record (EHR) system. First, a list of minimum data set was prepared after reviewing texts and studying cardiac patients' records. Then, to determine the content validity of the prepared MDS, the expert views of 10 cardiologists and 10 health information management (HIM) specialists were obtained; to estimate the reliability of the set, test-retest method was employed. Finally, the data were analyzed using SPSS software. The highest degree of consensus was found for the following MDSs: patient's name and family name (5), accepting doctor's name and family name, familial death records due to cardiac disorders, the image identification code, mitral valve, aortic valve, tricuspid valve, pulmonary valve, left ventricle, hole, atrium valve, Doppler examination of ventricular and atrial movement models and diagnoses with an average of. To prepare a model of echocardiography reporting system to exchange with EHR system, creation a standard data set is the vital point. Therefore, based on the research findings, the minimum reporting system data to exchange with Iran's electronic health record system include information on entity, management, medical record, carried-out acts, and the main content of the echocardiography report, which the planners of reporting system should consider.

Giant spin torque in systems with anisotropic exchange interaction

OpenAIRE

Korenev, Vladimir L.

2012-01-01

Control of magnetic domain wall movement by the spin-polarized current looks promising for creation of a new generation of magnetic memory devices. A necessary condition for this is the domain wall shift by a low-density current. Here I show that a strongly anisotropic exchange interaction between mobile heavy holes and localized magnetic moments enormously increases the current-induced torque on the domain wall as compared to systems with isotropic exchange. This enables one to control the d...

Interfacial spin cluster effects in exchange bias systems

Energy Technology Data Exchange (ETDEWEB)

Carpenter, R., E-mail: rc548@york.ac.uk; Vallejo-Fernandez, G.; O' Grady, K. [Department of Physics, The University of York, York YO10 5DD (United Kingdom)

2014-05-07

In this work, the effect of exchange bias on the hysteresis loop of CoFe is observed. The evolution of the coercivities and the shift of the hysteresis loop during the annealing process has been measured for films deposited on NiCr and Cu seed layers. Through comparison of the as deposited and field annealed loops, it is clear that for an exchange biased material, the two coercivities are due to different reversal processes. This behaviour is attributed to spin clusters at the ferromagnet/antiferromagnet interface, which behave in a similar manner to a fine particle system.

Data Exchange Inventory (DEXI) System

Data.gov (United States)

Social Security Administration — DEXI is an intranet application used by SSA users to track all incoming and outgoing data exchanges between SSA and our data exchange partners. Information such as...

A novel electrochemical ion exchange system and its application in water treatment.

Science.gov (United States)

Li, Yansheng; Li, Yongbin; Liu, Zhigang; Wu, Tao; Tian, Ying

2011-06-01

A novel electrochemical ion exchange system with porous cylinder electrodes is proposed for treatment of wastewater. This system can be used for desalination without the costly ion-exchange membrane and extra chemical reagents. Since the electrodes are completely uniform and no ion-exchange membrane was used in this system, it can be operated by switching anodes and cathodes flexibly for eliminating the scaling on the surface of electrodes. The strong base ion-exchange resin grains placed among the anode and cathode have played as supporting electrolyte, which is capable for the treatment of wastewater with low conductivity. The concentrated and neutralized anolyte containing chlorine is effective for disinfection and contaminants removal. Under the experimental conditions, the removal percentage of total dissolved salts was 83% and the removal percentage of chemical oxygen demand was 92% without consumption of extra chemical reagents. Copyright © 2011 The Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.

Heat exchanger modeling and identification for control of waste heat recovery systems in diesel engines

NARCIS (Netherlands)

Feru, E.; Willems, F.P.T.; Rojer, C.; Jager, B. de; Steinbuch, M.

2013-01-01

To meet future CO2 emission targets, Waste Heat Recovery systems have recently attracted much attention for automotive applications, especially for long haul trucks. This paper focuses on the development of a dynamic counter-flow heat exchanger model for control purposes. The model captures the

The impact of technological improvements on developing financial markets: The case of the Johannesburg Stock Exchange

Directory of Open Access Journals (Sweden)

Mehmet F. Dicle

2013-07-01

Full Text Available Can a significant technological improvement make an economically justifiable contribution to a financial market's development? The Johannesburg Stock Exchange (JSE incorporated the SETS system from the London Stock Exchange in 2002. It is certain that SETS is a technologically efficient trading system, and it would undoubtedly improve trading in the JSE. We test whether SETS represents a structural break by examining whether there was an increase in the JSE's liquidity, market efficiency and international integration after the introduction of SETS. While SETS is certainly a technological improvement with increased liquidity, it is not a sufficient factor to render it efficient. After the incorporation of SETS, the JSE has become more independent and it now offers better diversification opportunities for international investors.

Plasma exchange in progressive systemic sclerosis

Directory of Open Access Journals (Sweden)

Mohammad Bagher Owlia

2015-10-01

Full Text Available Systemic sclerosis (SSc is an autoimmune systemic disease of unknown etiology. Present treatment modalities have limited impact on clinical/ laboratory outcomes. For the first time in our center, we used plasma exchange (PEx in a rather young woman with recent onset but progressive SSc. She is a 39-year-old woman with a recent history of skin stiffness, Raynaud’s phenomenon, nail fold capillary changes and newly diagnosis of SSc presented to us due to worsening her clinical symptoms even after initiation of routine remedies such as low dose oral prednisolone, Ca-channel blockers, azathioprine and pentoxyfylline. After obtaining written consent, interdisciplinary discussion with experts in this field and agreement we started a series of plasma exchange with FFP replacement for her. A dramatic clinical response was observed in respect to Raynaud’s phenomenon, skin stiffness, tendon rub after three sessions of PEx. Her modified Rodnan skin score (MRSS dropped from 36 (before commencement of therapy to 28 in day 4 and 18 in day 20 after 15 sessions of PEx. In conclusion PEx could significantly modify the course of SSc as observed in our case study. Elimination of culprit immune mediators/cytokines/autoantibodies could be the possible mechanism of action of PEx. 

Exchange Rate Regimes – A periodical overview and a critical analysis of exchange rate regimes in Kosovo

Directory of Open Access Journals (Sweden)

Flamur Bunjaku

2015-03-01

Full Text Available Exchange rate regimes and the monetary policy are the key instruments governments use to achieve their economic and financial objectives. Moreover, due to global financial crisis the latter instruments get more importance. Empirical evidences show that exchange rate regimes in Kosovo and its monetary policy throughout their development were mainly influenced by different political and historical developments. In regard of Euroisation of monetary system in Kosovo it was found that this action generated macro - financial stability in terms of inflation and price fluctuation. However, in terms of microeconomic aspects, the unilateral adaptation of Euro as the official currency of Kosovo failed to provide microeconomic advantages such as to export stimulation, and so forth. The main exchange rate regime systems were discussed focusing in their advantages and disadvantages, and it was concluded that there is no commonly accepted theory regarding the optimality of exchange rate regimes. In addition, the global financial crisis impact in the financial system of Kosovo is also discussed and it was found that negative impacts of global financial crisis were moderate and indirect.

Development of a new generation of ion exchange resin for nuclear and fossil power plant

International Nuclear Information System (INIS)

Tsuzuki, Shintaro; Tagawa, Hidemi; Yamashita, Futoshi; Okamoto, Ryutaro

2008-01-01

It is required to maintain water quality supplied to steam generator to the water designed based on its water chemistry in order to keep the sound operation of nuclear power plants or fossil power plants. Condensate Polishing Plant (CPP) is installed for removing ions in the water which uses a mixed bed of cation exchange resin and anion exchange resin. We have developed new generation of CPP resin. The product is a unique combination of super high exchange capacity cation exchange resin and high fouling resistant anion exchange resin. The CPP resin has been used in many power plants. Amberjet 1006 was developed as a cation exchange resin with high oxidative stability, high operational capacity and New IRA900CP was developed as an anion exchange resin with high fouling resistant to leachables released out of cation exchange resin by oxidative degradation over the service period. The novel CPP resin was first used in 2000 and has now been used in many power plants in Japan. The CPP resin has been giving excellent quality of water. (author)

Instrumentation and Control Systems for Sodium thermal hydraulic Experiment Loop for Finned-tube sodium-to-Air heat exchanger (SELFA)

Energy Technology Data Exchange (ETDEWEB)

Kim, Byeong Yeon; Kim, Hyung Mo; Cho, Youn Gil; Kim, Jong Man; Ko, Yung Joo; Kang, Byeong Su; Jung, Min Hwan; Jeong, Ji Young [KAERI, Daejeon (Korea, Republic of)

2016-05-15

A forced-draft sodium-to-air heat exchanger (FHX) is a part of decay heat removal system (DHRS) in Prototype Gen-IV Sodium-cooled fast reactor (PGSFR), which is being developed at Korea Atomic Energy Research Institute (KAERI). Sodium thermal hydraulic Experiment Loop for Finned-tube sodium-to-Air heat exchanger (SELFA) is a test facility for verification and validation of the design code for a forced-draft sodium-to-air heat exchanger (FHX). In this paper, we have provided design and fabrication features for the instrumentation and control systems of SELFA. In general, the instrumentation systems and control systems are coupled for measurement and control of process variables. Instrumentation systems have been designed for investigating thermal-hydraulic characteristics of FHX and control systems have been designed to control the main components (e.g. electromagnetic pumps, heaters, valves etc.) required for test in SELFA. In this paper, we have provided configurations of instrumentation and control systems for Sodium thermal hydraulic Experiment Loop for Finned-tube sodium-to-Air heat exchanger (SELFA). The instrumentation and control systems of SELFA have been implemented based on the expected operation ranges and lesson learned from operational experience of 'Sodium integral effect test loop for safety simulation and assessment-1' (STELLA-1)

Indigenous development of system integration for proton exchange membrane fuel cell operation

International Nuclear Information System (INIS)

Hussain, S.; Arshad, M.; Anjum, A.R.

2011-01-01

System integration was developed for fuel cell to control various parameters including voltage, current, power, temperature, pressure of gas (H/sub 2/), humidification, etc. The compact software has also been developed for monitoring different parameters of fuel cell system. System integrated was installed on fuel cell stack to manipulate these parameters. The compact software has been linked with the integrated system for visual monitoring of different parameters of fuel cell system during operation on PC. The installation of software and integrated system on fuel cell stack is the key achievement for the safe operation of fuel cell stack and for the provision of requisite power to any electric device for optimum performance. The compact software was developed for micro controller in KIEL. Control card and driver card are controlled by software-driven micro controller. A communication protocol was designed and developed. PC software has been developed to control and watch the values of all parameters of fuel cell such as voltage, current, power, temperature, pressure of hydrogen, pressure of oxygen, operational times and performance of the system on computer screen. (author)

International exchange of radiological information in emergency conditions

International Nuclear Information System (INIS)

De Cort, M.; De Vries, G.; Breitenbach, L.; Fraser, G.; Vade, S.

1998-01-01

Description of the current system, experience gained, and expected future developments is given for the ECURIE system and, in particular, the EURDEP European-wide radiological information exchange system. It is concluded that the existing situation continues to be inhomogeneous. Although EURDEP foresees a common format for data exchange, which has been successfully implemented in 9 European countries, and regular exercises for data have been performed for a few years, important efforts will still have to be made to come to a more homogeneous and consistent European system for radiological information exchange. (P.A.)

Development of ion exchanging membranes synthesized by means of radiation grafting coplolymerization

International Nuclear Information System (INIS)

Xiong Jie; Xu Yunshu; Huang Wei

2006-01-01

Separation material is an important type of functional materials. In this paper, the development of cation- exchange membranes was reviewed, the synthesis of fluoropolymer based sulfonic acid type membranes and other polymers based cation-exchange membranes were selectively introduced. (authors)

National Information Exchange Model (NIEM): DoD Adoption and Implications for C2 (Briefing Charts)

Science.gov (United States)

2014-06-18

Application Data Consumers Information Exchange Package ( IEP ) the data exchanged at runtime Data Producers IES defines Information Exchange...Specification (IES) build-time description of the data to be exchanged Developers System / Application System / Application IEP | 9 | Data...Exchange Package ( IEP ) the data exchanged at runtime Data Producers System / Application System / Application IEP Consumer’s Understanding

A Novel RFID Sensing System Using Enhanced Surface Wave Technology for Battery Exchange Stations

Directory of Open Access Journals (Sweden)

Yeong-Lin Lai

2014-01-01

Full Text Available This paper presents a novel radio-frequency identification (RFID sensing system using enhanced surface wave technology for battery exchange stations (BESs of electric motorcycles. Ultrahigh-frequency (UHF RFID technology is utilized to automatically track and manage battery and user information without manual operation. The system includes readers, enhanced surface wave leaky cable antennas (ESWLCAs, coupling cable lines (CCLs, and small radiation patches (SRPs. The RFID sensing system overcomes the electromagnetic interference in the metallic environment of a BES cabinet. The developed RFID sensing system can effectively increase the efficiency of BES operation and promote the development of electric vehicles which solve the problem of air pollution as well as protect the environment of the Earth.

Investigations on installation of the heat exchange system in geothermal wells; Chinetsu koseinai netsukokan system donyu ni kansuru chosa

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-03-01

The heat exchange system in geothermal wells is a system that replaces the air source heat pump and uses underground beds or groundwater as a heat source to heat rooms by collecting underground heat in winter, and cool rooms in summer by operating a heat media circuit in reverse direction through the action of a reverse flow valve to discharge heat underground. This paper describes feasibility investigations on the system including its technical trend for introducing the system technology. Technological and economic discussions were given by classifying the intra-well heat exchange device in its installation direction (horizontal loop type and vertical installation type), underground heat exchange media (antifreeze solution/water cyclic system and direct expansion system), and underground heat transfer (heat conduction system and heat convection system). As a result of discussing each system, it was concluded that the following two systems are promising: A = vertical installation, antifreeze solution/water cyclic and heat conduction system, and B = vertical installation, antifreeze solution/water cyclic and heat convection system. Since the system B was found to have better efficiency and economy among both systems, it is necessary to verify an intra-well heat exchange system and operation methods that suit the system B effectively. 21 refs., 8 tabs.

Technical complications during veno-venous extracorporeal membrane oxygenation and their relevance predicting a system-exchange--retrospective analysis of 265 cases.

Directory of Open Access Journals (Sweden)

Matthias Lubnow

Full Text Available OBJECTIVES: Technical complications are a known hazard in veno-venous extracorporeal membrane oxygenation (vvECMO. Identifying these complications and predictive factors indicating a developing system-exchange was the goal of the study. METHODS: Retrospective study on prospectively collected data of technical complications including 265 adult patients (Regensburg ECMO Registry, 2009-2013 with acute respiratory failure treated with vvECMO. Alterations in blood flow resistance, gas transfer capability, hemolysis, coagulation and hemostasis parameters were evaluated in conjunction with a system-exchange in all patients with at least one exchange (n = 83. RESULTS: Values presented as median (interquartile range. Patient age was 50(36-60 years, the SOFA score 11(8-14.3 and the Murray lung injury Score 3.33(3.3-3.7. Cumulative ECMO support time 3411 days, 9(6-15 days per patient. Mechanical failure of the blood pump (n = 5, MO (n = 2 or cannula (n = 1 accounted for 10% of the exchanges. Acute clot formation within the pump head (visible clots, increase in plasma free hemoglobin (frHb, serum lactate dehydrogenase (LDH, n = 13 and MO (increase in pressure drop across the MO, n = 16 required an urgent system-exchange, of which nearly 50% could be foreseen by measuring the parameters mentioned below. Reasons for an elective system-exchange were worsening of gas transfer capability (n = 10 and device-related coagulation disorders (n = 32, either local fibrinolysis in the MO due to clot formation (increased D-dimers [DD], decreased platelet count; n = 24, or device-induced hyperfibrinolysis (increased DD, decreased fibrinogen [FG], decreased platelet count, diffuse bleeding tendency; n = 8, which could be reversed after system-exchange. Four MOs were exchanged due to suspicion of infection. CONCLUSIONS: The majority of ECMO system-exchanges could be predicted by regular inspection of the complete ECMO circuit, evaluation of gas exchange, pressure drop

[To exercise caution in developing intraocular lens exchange].

Science.gov (United States)

Song, X D; Wang, X Z; Qian, J

2018-05-11

Nowadays cataract extraction combined intraocular lens (IOL) implantation has become the conventional treatment for cataract. Numbers of IOL exchange after cataract extraction combined IOL implantation have been increasing in recent years. As a non-routine surgery, IOL exchange is normally combined with other surgeries and accompanied by some complications to various extents. Is IOL exchange necessary for all abnomal IOLs? Can IOL exchange be avoided? How to avoid IOL exchange? The purpose of this article is to stress the importance of indication of IOL exchange and how to avoid IOL exchange. (Chin J Ophthalmol, 2018, 54: 324-327) .

Sutudy on exchange flow under the unstably stratified field

OpenAIRE

文沢, 元雄

2005-01-01

This paper deals with the exchange flow under the unstably stratified field. The author developed the effective measurement system as well as the numerical analysis program. The system and the program are applied to the helium-air exchange flow in a rectangular channel with inclination. Following main features of the exchange flow were discussed based on the calculated results.(1) Time required for establishing a quasi-steady state exchange flow.(2) The relationship between the inclination an...

Characterizing volumetric discontinuities present in NPP heat exchangers with EASY: an eddy current data analysis system

Energy Technology Data Exchange (ETDEWEB)

Alencar, Donizete A.; Silva Junior, Silverio F., E-mail: daa@cdtn.b, E-mail: silvasf@cdtn.b [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

2011-07-01

Eddy current is a very important NDT inspection method widely used to perform integrity evaluation of tubes installed in heat exchangers. For nuclear power plants, a classical example is the remote inspection of steam generators and condensers, as well as other ordinary auxiliary equipment. Data evaluation can be performed by means of precise phase and amplitude measurements of complex impedance signals, represented as Lissajous figures plotted on the screen of the inspection systems. This paper presents the software EASY, a computer assisted analysis system developed at CDTN to help the characterization of volumetric discontinuities present in heat exchangers tubes. Data to be analyzed are obtained from commercial eddy current equipment data file, such as ECT MAD8D. Main advantage of that system is its portability and easy use, since it can be executed in ordinary PC, under Microsoft Windows operating system. (author)

Characterizing volumetric discontinuities present in NPP heat exchangers with EASY: an eddy current data analysis system

International Nuclear Information System (INIS)

Alencar, Donizete A.; Silva Junior, Silverio F.

2011-01-01

Eddy current is a very important NDT inspection method widely used to perform integrity evaluation of tubes installed in heat exchangers. For nuclear power plants, a classical example is the remote inspection of steam generators and condensers, as well as other ordinary auxiliary equipment. Data evaluation can be performed by means of precise phase and amplitude measurements of complex impedance signals, represented as Lissajous figures plotted on the screen of the inspection systems. This paper presents the software EASY, a computer assisted analysis system developed at CDTN to help the characterization of volumetric discontinuities present in heat exchangers tubes. Data to be analyzed are obtained from commercial eddy current equipment data file, such as ECT MAD8D. Main advantage of that system is its portability and easy use, since it can be executed in ordinary PC, under Microsoft Windows operating system. (author)

Determination of γ-hydroxybutyrate in human urine samples by ion exclusion and ion exchange two-dimensional chromatography system.

Science.gov (United States)

Liu, Junwei; Deng, Zhifen; Zhu, Zuoyi; Wang, Yong; Wang, Guoqing; Sun, Yu-An; Zhu, Yan

2017-12-15

A two-dimensional ion chromatography system was developed for the determination of γ-hydroxybutyrate (GHB) in human urine samples. Ion exclusion chromatography was used in the first dimensional separation for elimination of urine matrices and detection of GHB above 10mgL -1 , ion exchange chromatography was used in the second dimensional separation via column-switching technique for detection of GHB above 0.08mgL -1 . Under the optimized chromatographic conditions, the ion exclusion and ion exchange chromatography separation system exhibited satisfactory repeatability (RSDchromatography system was convenient and practical for the determination of GHB in human urine samples. Copyright © 2017 Elsevier B.V. All rights reserved.

Application of metal foam heat exchangers for a high-performance liquefied natural gas regasification system

International Nuclear Information System (INIS)

Kim, Dae Yeon; Sung, Tae Hong; Kim, Kyung Chun

2016-01-01

The intermediate fluid vaporizer has wide applications in the regasification of LNG (liquefied natural gas). The heat exchanger performance is one of the main contributors to the thermodynamic and cost effectiveness of the entire LNG regasification system. Within the paper, the authors discuss a new concept for a compact heat exchanger with a micro-cellular structure medium to minimize volume and mass and to increase thermal efficiency. Numerical calculations have been conducted to design a metal-foam filled plate heat exchanger and a shell-and-tube heat exchanger using published experimental correlations. The geometry of both heat exchangers was optimized using the conditions of thermolators in LNG regasification systems. The heat transfer and pressure drop performance was predicted to compare the heat exchangers. The results show that the metal-foam plate heat exchanger has the best performance at different channel heights and mass flow rates of fluid. In the optimized configurations, the metal-foam plate heat exchanger has a higher heat transfer rate and lower pressure drop than the shell-and-tube heat exchanger as the mass flow rate of natural gas is increased. - Highlights: • A metal foam heat exchanger is proposed for LNG regasification system. • Comparison was made with a shell and tube heat exchanger. • Heat transfer and pressure drop characteristics were estimated. • The geometry of both heat exchangers is optimized for thermolators. • It can be used as a compact and high performance thermolators.

Modeling and operation optimization of a proton exchange membrane fuel cell system for maximum efficiency

International Nuclear Information System (INIS)

Han, In-Su; Park, Sang-Kyun; Chung, Chang-Bock

2016-01-01

Highlights: • A proton exchange membrane fuel cell system is operationally optimized. • A constrained optimization problem is formulated to maximize fuel cell efficiency. • Empirical and semi-empirical models for most system components are developed. • Sensitivity analysis is performed to elucidate the effects of major operating variables. • The optimization results are verified by comparison with actual operation data. - Abstract: This paper presents an operation optimization method and demonstrates its application to a proton exchange membrane fuel cell system. A constrained optimization problem was formulated to maximize the efficiency of a fuel cell system by incorporating practical models derived from actual operations of the system. Empirical and semi-empirical models for most of the system components were developed based on artificial neural networks and semi-empirical equations. Prior to system optimizations, the developed models were validated by comparing simulation results with the measured ones. Moreover, sensitivity analyses were performed to elucidate the effects of major operating variables on the system efficiency under practical operating constraints. Then, the optimal operating conditions were sought at various system power loads. The optimization results revealed that the efficiency gaps between the worst and best operation conditions of the system could reach 1.2–5.5% depending on the power output range. To verify the optimization results, the optimal operating conditions were applied to the fuel cell system, and the measured results were compared with the expected optimal values. The discrepancies between the measured and expected values were found to be trivial, indicating that the proposed operation optimization method was quite successful for a substantial increase in the efficiency of the fuel cell system.

Two-phase plate-fin heat exchanger modeling for waste heat recovery systems in diesel engines

NARCIS (Netherlands)

Feru, E.; Jager, de A.G.; Willems, F.P.T.; Steinbuch, M.

2014-01-01

This paper presents the modeling and model validation for a modular two-phase heat exchanger that recovers energy in heavy-duty diesel engines. The model is developed for temperature and vapor quality prediction and for control design of the waste heat recovery system. In the studied waste heat

Brief Report: Randomized Test of the Efficacy of Picture Exchange Communication System on Highly Generalized Picture Exchanges in Children with ASD

OpenAIRE

Yoder, Paul J.; Lieberman, Rebecca G.

2010-01-01

A randomized control trial comparing two social-communication interventions in young children with autism examined far-transfer of the use of picture exchange to communicate. Thirty-six children were randomly assigned to one of two treatment conditions, one of which was the Picture Exchange Communication System (PECS). All children had access to picture symbols during assessments. Post-treatment measurement of the number of picture exchanges in a far-transfer, assessment context favored the P...

The use of Hewlett Packard minicomputers for data acquisition and data analysis in heat exchanger research and development

International Nuclear Information System (INIS)

Lepp, R.M.; Mastorakos, J.; Shaw, J.D.; Tromp, J.H.

1984-07-01

Failures in heat exchange equipment are usually caused by vibration-induced fatigue or fretting wear, or by corrosion. The need for high reliability and performance of this equipment, particularly in nuclear power plants, has resulted in research and development programs on heat exchangers at the Chalk River Nuclear Laboratories. Much of this work has been experimental, requiring the use of computer-based data acquisition/analysis systems. The way in which we have satisfied these needs using equipment supplied by Hewlett-Packard is described

Characterization of a mini-channel heat exchanger for a heat pump system

International Nuclear Information System (INIS)

Arteconi, A; Giuliani, G; Tartuferi, M; Polonara, F

2014-01-01

In this paper a mini-channel aluminum heat exchanger used in a reversible heat pump is presented. Mini-channel finned heat exchangers are getting more and more interest for refrigeration systems, especially when compactness and low refrigerant charge are desired. Purpose of this paper was to characterize the mini-channel heat exchanger used as evaporator in terms of heat transfer performance and to study the refrigerant distribution in the manifold. The heat exchanger characterization was performed experimentally by means of a test rig built up for this purpose. It is composed of an air-to-air heat pump, air channels for the external and internal air circulation arranged in a closed loop, measurement sensors and an acquisition system. The overall heat transfer capacity was assessed. Moreover, in order to characterize the flow field of the refrigerant in the manifold of the heat exchanger, a numerical investigation of the fluid flow by means of CFD was performed. It was meant to evaluate the goodness of the present design and to identify possible solutions for the future improvement of the manifold design.

The Picture Exchange Communication System: Digital Photographs versus Picture Symbols

Science.gov (United States)

Jonaitis, Carmen

2011-01-01

The Picture Exchange Communication System (PECS) is an augmentative and alternative system (AAC) used to improve and increase communication for children with Autism Spectrum Disorder (ASD) and other developmental disorders. Research addressing the efficacy of this system is increasing; however, there is limited information published that evaluates…

Exchange rate system and policy in the present world

Directory of Open Access Journals (Sweden)

Grubišić Zoran

2005-01-01

Full Text Available The choice of exchange rate regime is important, not only in terms of its effect on trade flows, but also with respect to inflation expectations. Countries facing disinflation may find that pegs regimes are more appropriate solution. But where the trade balance account is significantly deteriorated and growth has been sluggish, a more flexible regime might be called for. The natural classification in eighties and early nineties suggests that intermediate regimes may provide important advantages – to capture some of the benefits of both extremes while avoiding many of the costs. However today many experts predicted that exchange rate regimes would move in a "bipolar" manner to the extremes of "hard" pegs or free floats. An increasing number of countries did announce their intent to allow greater exchange rate flexibility. But, in practice, countries had a "fear of floating ". Distinction is made among advanced, emerging and other developing countries. Emerging markets have stronger links to international capital markets than do other developing economies. Thus, while non-emerging market developing economies may gain credibility through pegging their exchange rates, emerging markets find it harder to do so and could benefit from investing in "learning to float". More advanced economies with their access to international capital market are best positioned to enjoy the benefits of flexibility. It is found that the proportion of countries adopting intermediate regimes has indeed been shrinking in favor of greater flexibility or greater fixity, especially for countries more integrated with international markets. But, there is no final conclusion on the idea that intermediate regimes will dissapear.

A PC-based system for simulation of processes in the isotopic exchange column of a cryogenic pilot plant

International Nuclear Information System (INIS)

Retevoi, Carmen Maria; Stefan, Liviu; Baltateanu, Ovidiu; Stefan, Iuliana

2001-01-01

The technology developed at the Institute of Cryogenics and Isotope Separations is based on catalytic isotope exchange between water and hydrogen gas both carrying various isotopes of hydrogen: normal hydrogen, deuterium, and tritium. This isotope exchange is followed by cryogenic distillation to separate the various isotopes of hydrogen gas. The detritiation process was simulated using water as working fluid, with a small content of deuterium and a gaseous mixture of hydrogen and deuterium. Isotopic separation of hydrogen is very important for nuclear plants utilizing the CANDU reactor concept. Tritiated water is extracted from the moderator of the reactor and the tritium is removed in order to reduce the radiation levels from the reactor. One of the most important steps in this process is the catalytic isotope exchange between tritiated water and hydrogen gas. In the 'Catalytic isotope exchange' system, tritium transfer occurs from the liquid phase (tritiated heavy water) into the gaseous phase (hydrogen) in an isotope exchange column. The column is packed with alternating layers of two types of catalysts: an ordered B7 type of phosphorous bronze to catalyze the equilibration between liquid and gaseous water and a PT/C/PTFE catalyst to catalyze the reaction between water vapor and hydrogen gas. The corresponding reactions are (DTO) L + (D 2 O) V ↔ (D 2 O) L + (DTO) V and (DTO) V + (D 2 ) G ↔ (D 2 O) V + (DT)G. The design of the process requires a constant catalytic exchange temperature that must be maintained at a value of 90 deg.C. To achieve this, the plant is equipped with electrical heat exchangers for heating the gas (hydrogen) and the heavy water. The control is achieved using an array of sensors and controllers. The sensors used for monitoring the process are type J thermocouples. The temperature control is achieved by controlling the electrical power fed to the heaters. Besides sensing the fluid temperatures at various points, we also monitor the

Real Exchange Rate Variability: An Empirical Analysis of the Developing Countries Case

OpenAIRE

Sebastian Edwards

1986-01-01

The purpose of this paper is to investigate the potential role of monetary and real factors in explaining real exchange rate variability in developing countries. For this purpose two indexes of real effective exchange rate variability that measure short-term and long-term variability were constructed for 30 countries. The results obtained, using a generalized least squares procedures on cross section data, indicate that real exchange rate variability has been affected both by real and monetar...

Tuning antiferromagnetic exchange interaction for spontaneous exchange bias in MnNiSnSi system

Science.gov (United States)

Jia, Liyun; Shen, Jianlei; Li, Mengmeng; Wang, Xi; Ma, Li; Zhen, Congmian; Hou, Denglu; Liu, Enke; Wang, Wenhong; Wu, Guangheng

2017-12-01

Based on almost all the data from the literature on spontaneous exchange bias (SEB), it is expected that the system will show SEB if it meets two conditions simultaneously: (i) there are the coexistence and competition of antiferromagnetic (AFM) and ferromagnetic (FM) interactions and (ii) AFM interaction should dominate but not be too strong in this competition. In order to verify this view, a systematic study on SEB has been performed in this work. Mn50Ni40Sn10 with strong FM interaction and without SEB is chosen as the mother composition, and the negative chemical pressure is introduced by the substitution of Sn by Si to enhance AFM interaction. It is found that a long-range FM ordering window is closed, and a long-range AFM ordering window is opened. As a result, SEB is triggered and a continuous tuning of the spontaneous exchange bias field (HSEB) from 0 Oe to 1300 Oe has been realized in a Mn50Ni40Sn10-xSix system by the enhanced AFM interaction.

Spin-exchange and spin-destruction rates for the 3He-Na system

International Nuclear Information System (INIS)

Borel, P.I.; Soegaard, L.V.; Svendsen, W.E.; Andersen, N.

2003-01-01

Optically pumped Na is used as a spin-exchange partner to polarize 3 He. Polarizations around 20% have routinely been achieved in sealed spherical glass cells containing 3 He, N 2 , and a few droplets of Na. An optical technique has been developed to determine the Na- 3 He spin-exchange rate coefficient. By monitoring the Na spin relaxation ''in the dark,'' the average Na-Na spin-destruction cross section at 330 degree sign C is estimated to be around 5x10 -19 cm 2 . This value is 2-5 (15-30) times smaller than the previously reported values for the K-K (Rb-Rb) spin-relaxation cross section. In the temperature range 310-355 degree sign C the spin-exchange rate coefficient is found to be (6.1±0.6)x10 -20 cm 3 /s with no detectable temperature dependence. This value is in good agreement with a previous theoretical estimate reported by Walker and it is only slightly lower than the corresponding Rb- 3 He spin-exchange rate coefficient. The total Na- 3 He spin-destruction rate coefficient is, within errors, found to be the same as the Na- 3 He spin-exchange rate coefficient, thereby indicating that the maximum possible photon efficiency may approach unity for the Na- 3 He system. A technique, in which a charge-coupled device camera is used to take images of faint unquenched fluorescence light, has been utilized to allow for an instantaneous determination of the sodium number densities during the rate coefficient measurements

Is It Possible To Use Intelligent Systems To Design A Profitable Foreign Exchange Trading Agent?

OpenAIRE

Julian, Pomfret-Pudelsky

2009-01-01

In this paper, a trading agent is developed using a basket of intelligent systems with the goal of trading the GBPUSD currency pair profitably in the Foreign Exchange market. The basket of intelligent system consists of two regression models: a radial basis neural network and a TSK-fuzzy inference system; and three classification models: k-nearest neighbour, support vector machine and a decision tree. The trading strategy combines the predictions of each model using a Kalman-type filter to...

Horizontal Heat Exchanger Design and Analysis for Passive Heat Removal Systems

Energy Technology Data Exchange (ETDEWEB)

Vierow, Karen

2005-08-29

This report describes a three-year project to investigate the major factors of horizontal heat exchanger performance in passive containment heat removal from a light water reactor following a design basis accident LOCA (Loss of Coolant Accident). The heat exchanger studied in this work may be used in advanced and innovative reactors, in which passive heat removal systems are adopted to improve safety and reliability The application of horizontal tube-bundle condensers to passive containment heat removal is new. In order to show the feasibility of horizontal heat exchangers for passive containment cooling, the following aspects were investigated: 1. the condensation heat transfer characteristics when the incoming fluid contains noncondensable gases 2. the effectiveness of condensate draining in the horizontal orientation 3. the conditions that may lead to unstable condenser operation or highly degraded performance 4. multi-tube behavior with the associated secondary-side effects This project consisted of two experimental investigations and analytical model development for incorporation into industry safety codes such as TRAC and RELAP. A physical understanding of the flow and heat transfer phenomena was obtained and reflected in the analysis models. Two gradute students (one funded by the program) and seven undergraduate students obtained research experience as a part of this program.

Inverse Problem and Variation Method to Optimize Cascade Heat Exchange Network in Central Heating System

Institute of Scientific and Technical Information of China (English)

ZHANG Yin; WEI Zhiyuan; ZHANG Yinping; WANG Xin

2017-01-01

Urban heating in northern China accounts for 40％ of total building energy usage.In central heating systems,heat is often transfened from heat source to users by the heat network where several heat exchangers arc installed at heat source,substations and terminals respectively.For given overall heating capacity and heat source temperarure,increasing the terminal fluid temperature is an effective way to improve the thermal performance of such cascade heat exchange network for energy saving.In this paper,the mathematical optimization model of the cascade heat exchange network with three-stage heat exchangers in series is established.Aim at maximizing the cold fluid temperature for given hot fluid temperature and overall heating capacity,the optimal heat exchange area distribution and the medium fluids' flow rates are determined through inverse problem and variation method.The preliminary results show that the heat exchange areas should be distributed equally for each heat exchanger.It also indicates that in order to improve the thernmal performance of the whole system,more heat exchange areas should be allocated to the heat exchanger where flow rate difference between two fluids is relatively small.This work is important for guiding the optimization design of practical cascade heating systems.

Development of wet-proofed catalyst and catalytic exchange process for tritium extraction

Energy Technology Data Exchange (ETDEWEB)

Song, Myung Jae; Son, Soon Hwan; Chung, Yang Gun; Lee, Gab Bock [Korea Electric Power Corp. (KEPCO), Taejon (Korea, Republic of). Research Center

1996-12-31

To apply a liquid phase catalytic exchange(LPCE) process for the tritium extraction from tritiated heavy water, the wet proofed catalyst to allow the hydrogen isotopic exchange reaction between liquid water and hydrogen gas was developed. A styrene divinyl benzene copolymer was selected as am effective catalyst support and prepared by suspension copolymerization. After post-treatment, final catalyst supports were dipped in chloroplatinic acid solution. The catalyst support had a good physical properties at a particular preparation condition. The catalytic performance was successfully verified through hydrogen isotopic exchange reaction in the exchange column. A mathematical model for the tritium removal process consisted of LPCE front-ended process and cryogenic distillation process was established using the NTU-HTU method for LPCE column and the FUG method for cryogenic distillation column, respectively. A computer program was developed using the model and then used to investigate optimum design variables which affect the size of columns and tritium inventory (author). 84 refs., 113 figs.

Recent developments on ion-exchange membranes and electro-membrane processes.

Science.gov (United States)

Nagarale, R K; Gohil, G S; Shahi, Vinod K

2006-02-28

Rapid growth of chemical and biotechnology in diversified areas fuels the demand for the need of reliable green technologies for the down stream processes, which include separation, purification and isolation of the molecules. Ion-exchange membrane technologies are non-hazardous in nature and being widely used not only for separation and purification but their application also extended towards energy conversion devices, storage batteries and sensors etc. Now there is a quite demand for the ion-exchange membrane with better selectivities, less electrical resistance, high chemical, mechanical and thermal stability as well as good durability. A lot of work has been done for the development of these types of ion-exchange membranes during the past twenty-five years. Herein we have reviewed the preparation of various types of ion-exchange membranes, their characterization and applications for different electro-membrane processes. Primary attention has been given to the chemical route used for the membrane preparation. Several general reactions used for the preparation of ion-exchange membranes were described. Methodologies used for the characterization of these membranes and their applications were also reviewed for the benefit of readers, so that they can get all information about the ion-exchange membranes at one platform. Although there are large number of reports available regarding preparations and applications of ion-exchange membranes more emphasis were predicted for the usefulness of these membranes or processes for solving certain type of industrial or social problems. More efforts are needed to bring many products or processes to pilot scale and extent their applications.

Developing mixed convection in a coiled heat exchanger

NARCIS (Netherlands)

Sillekens, J.J.M.; Rindt, C.C.M.; Steenhoven, van A.A.

1998-01-01

In this paper the development of mixed convection in a helically coiled heat exchanger for Re = 500, Pr = 5 and d = 1/14 is studied. The influence of buoyancy forces (Gr = ¢O (105)) on heat transfer and secondary flow is analyzed. In the method used the parabolized equations are solved using a

Internal dust recirculation system for a fluidized bed heat exchanger

Science.gov (United States)

Gamble, Robert L.; Garcia-Mallol, Juan A.

1981-01-01

A fluidized bed heat exchanger in which air is passed through a bed of particulate material containing fuel disposed in a housing. A steam/water natural circulation system is provided in a heat exchange relation to the bed and includes a steam drum disposed adjacent the bed and a tube bank extending between the steam drum and a water drum. The tube bank is located in the path of the effluent gases exiting from the bed and a baffle system is provided to separate the solid particulate matter from the effluent gases. The particulate matter is collected and injected back into the fluidized bed.

Development of micro-structured heat exchangers; Developpement d'echangeurs de chaleur microstructures

Energy Technology Data Exchange (ETDEWEB)

Bouzon, C

2004-10-01

This study has been carried out to defend the Technological Diploma of Research, in the aim to develop micro-structured heat exchangers. Realized within the Research Group on the Heat exchangers and Energy (GREThE) of the Atomic Energy Commission (CEA) of Grenoble. The rise of micro-technologies and the optimization of heat exchangers have led to emergence from few years of new structures of fluid paths with scales lower than the millimeter, thus making it possible to produce heat exchangers ultra-compacts. The micro-structured exchangers are heat exchangers whose hydraulic diameters are lower than the millimeter but with external dimensions of several centimeters. The study is based on two patents filed by the CEA and the characterization of these two geometries. A first concept of cross flow type finds applications with Gas/Liquid heat exchanger. A second type, a countercurrent, is more adapted to Liquid/Liquid applications. An approach with simplified analytical models and by numerical simulation was employed for each concept. An experimental study on the Gas/Liquid concept was also carried out. (author)

Theoretical evaluation on the impact of heat exchanger in Advanced Adiabatic Compressed Air Energy Storage system

International Nuclear Information System (INIS)

Yang, Ke; Zhang, Yuan; Li, Xuemei; Xu, Jianzhong

2014-01-01

Highlights: • A multi-stage AA-CAES system model is established based on thermodynamic theory. • Four Cases about pressure loss and effectiveness of heat exchanger are investigated. • The impact of pressure loss on conversion of heat energy in TES is more sensitive. • The impact of heat exchanger effectiveness in charge process on system is stronger. • Pressure loss in heat exchanger affects the change trends of system efficiency. - Abstract: Advanced Adiabatic Compressed Air Energy Storage (AA-CAES) is a large-scale energy storage system based on gas turbine technology and thermal energy storage (TES). Electrical energy can be converted into internal energy of air and heat energy in TES during the charge process, while reverse energy conversion proceeds during discharge process. The performance of AA-CAES system requires further improvement in order to increase efficiency. In this paper, a multi-stage AA-CAES system model is established, and the influence of effectiveness and pressure loss in heat exchanger on energy conversion and utilization efficiency of AA-CAES system is analyzed theoretically based on the theory of thermodynamics. Four Cases about effectiveness and pressure loss of heat exchanger are investigated and compared with each other. It is found that effectiveness and pressure loss of heat exchanger are directly related to energy conversion and utilization in AA-CAES system. System efficiency changes with the variation of heat exchanger effectiveness and the impact of pressure loss on conversion of heat energy in TES is more sensitive than that of internal energy of air. Pressure loss can cause the complexity of system efficiency change. With appropriate selection of the values of heat exchanger effectiveness for both charge and discharge processes, an AA-CAES system with a higher efficiency could be expected

Investigation of heat exchangers for energy conversion systems of megawatt-class space power plants

Science.gov (United States)

Ilmov, D. N.; Mamontov, Yu. N.; Skorohodov, A. S.; Smolyarov, V. A.; Filatov, N. I.

2016-01-01

The specifics of operation (high temperatures in excess of 1000 K and large pressure drops of several megapascals between "hot" and "cold" coolant paths) of heat exchangers in the closed circuit of a gasturbine power converter operating in accordance with the Brayton cycle with internal heat recovery are analyzed in the context of construction of space propulsion systems. The design of a heat-exchange matrix made from doubly convex stamped plates with a specific surface relief is proposed. This design offers the opportunity to construct heat exchangers with the required parameters (strength, rigidity, weight, and dimensions) for the given operating conditions. The diagram of the working area of a test bench is presented, and the experimental techniques are outlined. The results of experimental studies of heat exchange and flow regimes in the models of heat exchangers with matrices containing 50 and 300 plates for two pairs of coolants (gas-gas and gas-liquid) are detailed. A criterion equation for the Nusselt number in the range of Reynolds numbers from 200 to 20 000 is proposed. The coefficients of hydraulic resistance for each coolant path are determined as functions of the Reynolds number. It is noted that the pressure in the water path in the "gas-liquid" series of experiments remained almost constant. This suggests that no well-developed processes of vaporization occurred within this heat-exchange matrix design even when the temperature drop between gas and water was as large as tens or hundreds of degrees. The obtained results allow one to design flight heat exchangers for various space power plants.

Developing mixed convection in a coiled heat exchanger

NARCIS (Netherlands)

Sillekens, J.J.M.; Rindt, C.C.M.; Steenhoven, van A.A.

1998-01-01

In this paper the development of mixed convection in a helically coiled heat exchanger for Re = 500, Pr = 5 and
δ =114
is studied. The influence of buoyancy forces ¢
(Gr = ¢O (105))
on heat transfer and secondary flow is analyzed. In the method used the parabolized equations are

Leak detection in a high-pressure heat exchanger system in a refinery using radiotracer technique

International Nuclear Information System (INIS)

Samantray, J.S.; Sunil Goswami; Sharma, V.K.; Jayashree Biswal; Pant, H.J.

2014-01-01

A radiotracer investigation was carried out in a diesel hydrotreater (DHDT) unit in a refinery for leak detection in a breech-lock heat exchanger system. The main objectives of the study were to identify the leaking heat exchanger in a system with six heat exchangers and estimate the leak rate. Bromine-82 as dibromobiphenyl was selected and used as radiotracer for the investigation. The radiotracer was instantaneously injected into the suction end of the feed pump line to the heat exchanger of the DHDT unit. The movement of the tracer was measured at strategically selected locations using NaI(Tl) scintillation detectors. Based upon the results of the radiotracer investigation, it was found that out of six heat exchangers, exchanger E-1F was leaking. (author)

Optimization of Heat Exchangers

International Nuclear Information System (INIS)

Catton, Ivan

2010-01-01

The objective of this research is to develop tools to design and optimize heat exchangers (HE) and compact heat exchangers (CHE) for intermediate loop heat transport systems found in the very high temperature reator (VHTR) and other Generation IV designs by addressing heat transfer surface augmentation and conjugate modeling. To optimize heat exchanger, a fast running model must be created that will allow for multiple designs to be compared quickly. To model a heat exchanger, volume averaging theory, VAT, is used. VAT allows for the conservation of mass, momentum and energy to be solved for point by point in a 3 dimensional computer model of a heat exchanger. The end product of this project is a computer code that can predict an optimal configuration for a heat exchanger given only a few constraints (input fluids, size, cost, etc.). As VAT computer code can be used to model characteristics (pumping power, temperatures, and cost) of heat exchangers more quickly than traditional CFD or experiment, optimization of every geometric parameter simultaneously can be made. Using design of experiment, DOE and genetric algorithms, GE, to optimize the results of the computer code will improve heat exchanger design.

New system applying image processor to automatically separate cation exchange resin and anion exchange resin for condensate demineralizer

International Nuclear Information System (INIS)

Adachi, Tsuneyasu; Nagao, Nobuaki; Yoshimori, Yasuhide; Inoue, Takashi; Yoda, Shuji

2014-01-01

In PWR plant, condensate demineralizer is equipped to remove corrosive ion in condensate water. Mixed bed packing cation exchange resin (CER) and anion exchange resin (AER) is generally applied, and these are regenerated after separation to each layer periodically. Since the AER particle is slightly lighter than the CER particle, the AER layer is brought up onto the CER layer by feeding water upward from the bottom of column (backwashing). The separation performance is affected by flow rate and temperature of water for backwashing, so normally operators set the proper condition parameters regarding separation manually every time for regeneration. The authors have developed the new separation system applying CCD camera and image processor. The system is comprised of CCD camera, LED lamp, image processor, controller, flow control valves and background color panel. Blue color of the panel, which is corresponding to the complementary color against both ivory color of AER and brown color of CER, is key to secure the system precision. At first the color image of the CER via the CCD camera is digitized and memorized by the image processor. The color of CER in the field of vision of the camera is scanned by the image processor, and the position where the maximum difference of digitized color index is indicated is judged as the interface. The detected interface is able to make the accordance with the set point by adjusting the flow rate of backwashing. By adopting the blue background panel, it is also possible to draw the AER out of the column since detecting the interface of the CER clearly. The system has provided the reduction of instability factor concerning separation of resin during regeneration process. The system has been adopted in two PWR plants in Japan, it has been demonstrating its stable and precise performance. (author)

Numerical analysis of the efficiency of earth to air heat exchange systems in cold and hot-arid climates

International Nuclear Information System (INIS)

Fazlikhani, Faezeh; Goudarzi, Hossein; Solgi, Ebrahim

2017-01-01

Highlights: • A numerical model is developed to evaluate performance of earth to air heat exchanger. • The cooling/heating potential of earth to air heat exchanger is investigated in hot-dry and cold climates. • The more performance of earth to air heat exchanger in hot-dry climates compared to cold climates. • The high efficiency of earth to air heat exchanger for pre-heating in both hot-dry and cold climates. - Abstract: In order to examine and compare the efficiency of earth to air heat exchanger (EAHE) systems in hot-arid (Yazd) and cold (Hamadan) climates in Iran a steady state model was developed to evaluate the impact of various parameters including inlet air temperatures, pipe lengths and ground temperatures on the cooling and heating potential of EAHEs in both climates. The results demonstrated the ability of the system to not only improve the average temperature and decrease the temperature fluctuation of the outlet air temperature of EAHE, but also to trigger considerable energy saving. It was found that in both climates, the system is highly utilized for pre-heating, and its usage is unfeasible in certain periods throughout the year. In winter, EAHEs have the potential of increasing the air temperature in the range of 0.2–11.2 °C and 0.1–17.2 °C for Yazd and Hamadan, respectively. However, in summer, the system decreases the air temperature for the aforementioned cities in the range of 1.3–11.4 °C and 5.7–11.1 °C, respectively. The system ascertains to be more efficient in the hot-arid climate of Yazd, where it can be used on 294 days of the year, leading to 50.1–63.6% energy saving, when compared to the cold climate of Hamadan, where it can be used on 225 days of the year resulting in a reduction of energy consumption by 24.5–47.9%.

Characterization and control of the microbial community affiliated with copper or aluminum heat exchangers of HVAC systems.

Science.gov (United States)

Schmidt, Michael G; Attaway, Hubert H; Terzieva, Silva; Marshall, Anna; Steed, Lisa L; Salzberg, Deborah; Hamoodi, Hameed A; Khan, Jamil A; Feigley, Charles E; Michels, Harold T

2012-08-01

Microbial growth in heating ventilation and air-conditioning (HVAC) systems with the subsequent contamination of indoor air is of increasing concern. Microbes and the subsequent biofilms grow easily within heat exchangers. A comparative study where heat exchangers fabricated from antimicrobial copper were evaluated for their ability to limit microbial growth was conducted using a full-scale HVAC system under conditions of normal flow rates using single-pass outside air. Resident bacterial and fungal populations were quantitatively assessed by removing triplicate sets of coupons from each exchanger commencing the fourth week after their installation for the next 30 weeks. The intrinsic biofilm associated with each coupon was extracted and characterized using selective and differential media. The predominant organisms isolated from aluminum exchangers were species of Methylobacterium of which at least three colony morphologies and 11 distinct PFGE patterns we found; of the few bacteria isolated from the copper exchangers, the majority were species of Bacillus. The concentrations and type of bacteria recovered from the control, aluminum, exchangers were found to be dependent on the type of plating media used and were 11,411-47,257 CFU cm(-2) per coupon surface. The concentration of fungi was found to average 378 CFU cm(-2). Significantly lower concentrations of bacteria, 3 CFU cm(-2), and fungi, 1 CFU cm(-2), were recovered from copper exchangers regardless of the plating media used. Commonly used aluminum heat exchangers developed stable, mixed, bacterial/fungal biofilms in excess of 47,000 organisms per cm(2) within 4 weeks of operation, whereas the antimicrobial properties of metallic copper were able to limit the microbial load affiliated with the copper heat exchangers to levels 99.97 % lower during the same time period.

Advanced heat exchanger development for molten salts

Energy Technology Data Exchange (ETDEWEB)

Sabharwall, Piyush, E-mail: Piyush.Sabharwall@inl.gov [Idaho National Laboratory, Idaho Falls, ID 83415 (United States); Clark, Denis; Glazoff, Michael [Idaho National Laboratory, Idaho Falls, ID 83415 (United States); Zheng, Guiqiu; Sridharan, Kumar; Anderson, Mark [University of Wisconsin, Madison (United States)

2014-12-15

Highlights: • Hastelloy N and 242, shows corrosion resistance to molten salt at nominal operating temperatures. • Both diffusion welds and sheet material in Hastelloy N were corrosion tested in at 650, 700, and 850 °C for 200, 500, and 1000 h. • Thermal gradients and galvanic couples in the molten salts enhance corrosion rates. • Corrosion rates found were typically <10 mils per year. - Abstract: This study addresses present work concerned with advanced heat exchanger development for molten salt in nuclear and non-nuclear thermal systems. The molten salt systems discussed herein use alloys, such as Hastelloy N and 242, that show good corrosion resistance in molten salt at nominal operating temperatures up to 700 °C. These alloys were diffusion welded, and the corresponding information is presented. Test specimens were prepared for exposing diffusion welds to molten salt environments. Hastelloy N and 242 were found to be weldable by diffusion welding, with ultimate tensile strengths about 90% of base metal values. Both diffusion welds and sheet material in Hastelloy N were corrosion tested in 58 mol% KF and 42 mol% ZrF{sub 4} at 650, 700, and 850 °C for 200, 500, and 1000 h. Corrosion rates were similar between welded and nonwelded materials, typically <100 μm per year after 1000 h of corrosion tests. No catastrophic corrosion was observed in the diffusion welded regions. For materials of construction, nickel-based alloys and alloys with dense nickel coatings are effectively inert to corrosion in fluorides, but not so in chlorides. Hence, additional testing of selected alloys for resistance to intergranular corrosion is needed, as is a determination of corrosion rate as a function of the type of salt impurity and alloy composition, with respect to chromium and carbon, to better define the best conditions for corrosion resistance. Also presented is the division of the nuclear reactor and high-temperature components per American Society of Mechanical

Modelling and simulation of a heat exchanger

Science.gov (United States)

Xia, Lei; Deabreu-Garcia, J. Alex; Hartley, Tom T.

1991-01-01

Two models for two different control systems are developed for a parallel heat exchanger. First by spatially lumping a heat exchanger model, a good approximate model which has a high system order is produced. Model reduction techniques are applied to these to obtain low order models that are suitable for dynamic analysis and control design. The simulation method is discussed to ensure a valid simulation result.

Flexible Exchange of Farming Device Data

DEFF Research Database (Denmark)

Iftikhar, Nadeem; Pedersen, Torben Bach

2011-01-01

A new trend in the farming business is to replace conventional farming devices with computerized farming devices. Accordingly, numerous computer-based farming devices for logging, processing and exchanging data have recently been installed on moving farm machinery such as tractors. The exchange o......-directional data exchange as well as efficient requirements change management through a graphical user interface. The paper also demonstrates the use of the proposed solution based on a farming case study and open source technologies....... and systems to exchange data based on a predefined set of rules. In consequence, many hand-coded data exchange solutions have been developed in the farming business. Although efforts regarding incorporating data exchange standards have been made, their actual usage so far has been limited, due to the fact...

Effect of Tube Diameter on The Design of Heat Exchanger in Solar Drying system

Science.gov (United States)

Husham Abdulmalek, Shaymaa; Khalaji Assadi, Morteza; Al-Kayiem, Hussain H.; Gitan, Ali Ahmed

2018-03-01

The drying of agriculture product consumes a huge fossil fuel rates that demand to find an alternative source of sustainable environmental friendly energy such as solar energy. This work presents the difference between using solar heat source and electrical heater in terms of design aspect. A circular-finned tube bank heat exchanger is considered against an electrical heater used as a heat generator to regenerate silica gel in solar assisted desiccant drying system. The impact of tube diameter on the heat transfer area was investigated for both the heat exchanger and the electrical heater. The fin performance was investigated by determining fin effectiveness and fin efficiency. A mathematical model was developed using MATLAB to describe the forced convection heat transfer between hot water supplied by evacuated solar collector with 70 °C and ambient air flow over heat exchanger finned tubes. The results revealed that the increasing of tube diameter augments the heat transfer area of both heat exchanger and electrical heater. The highest of fin efficiency was around 0.745 and the lowest was around 0.687 while the fin effectiveness was found to be around 0.998.

Development of design window evaluation and display system. 1. System development and performance confirmation

International Nuclear Information System (INIS)

Muramatsu, Toshiharu; Yamaguchi, Akira

2003-07-01

Purpose: The work was performed to develop a design window evaluation and display system for the purpose of obtaining the effects of various design parameters on the typical thermal hydraulic issues resulting from a use of various kind of working fluid etc. easily. Method: The function of the system were 'confirmation of design margin' of the present design, 'confirmation of the affected design zone' when a designer changed some design parameter, and search for an design improvement' for design optimization. The system was developed using existing soft wares on PC and the database relating analytical results of typical thermal hydraulic issues provided by separate work. Results: (1) System design: In order to develop a design window evaluation and display system, 'numerical analysis unit', 'statistical analysis unit', 'MMI unit', 'optimization unit' were designed based on the result of selected optimization procedure and display visualization. Further, total system design was performed combining these units. Typical thermal hydraulic issues to be considered are upper plenum thermal hydraulics, thermal stratification, free surface sloshing, flow-induced vibration of a heat exchanger and thermal striping in the T-junction piping systems. (2) Development of prototype system and a functional check: A prototype system of a design window evaluation and display system was developed and the functions were confirmed as was planned. (author)

The structure of social exchange in self-help support groups: development of a measure.

Science.gov (United States)

Brown, Louis D; Tang, Xiaohui; Hollman, Ruth L

2014-03-01

Self-help support groups are indigenous community resources designed to help people manage a variety of personal challenges, from alcohol abuse to xeroderma pigmentosum. The social exchanges that occur during group meetings are central to understanding how people benefit from participation. This paper examines the different types of social exchange behaviors that occur during meetings, using two studies to develop empirically distinct scales that reliably measure theoretically important types of exchange. Resource theory informed the initial measurement development efforts. Exploratory factor analyses from the first study led to revisions in the factor structure of the social exchange scales. The revised measure captured the exchange of emotional support, experiential information, humor, unwanted behaviors, and exchanges outside meetings. Confirmatory factor analyses from a follow-up study with a different sample of self-help support groups provided good model fit, suggesting the revised structure accurately represented the data. Further, the scales demonstrated good convergent and discriminant validity with related constructs. Future research can use the scales to identify aspects of social exchange that are most important in improving health outcomes among self-help support group participants. Groups can use the scales in practice to celebrate strengths and address weaknesses in their social exchange dynamics.

Performance study of desiccant coated heat exchanger air conditioning system in winter

International Nuclear Information System (INIS)

Ge, T.S.; Dai, Y.J.; Wang, R.Z.

2016-01-01

Highlights: • Performance of desiccant coated heat exchanger AC system is predicted. • Effects of main operation parameters and climatic conditions are discussed. • Regeneration temperature of 30 °C is recommended under simulation condition. • Higher ambient humidity ratio results in increased humidity ratio of supply air. • Temperature of ambient air has neglectable effect on supply air. - Abstract: Conventional air source heat pump system faces several challenges when adopted in winter season. Solid desiccant air conditioning system can provide humidification and heating power simultaneously and can be driven by low grade thermal energy; it provides a good alternative for air source heat pump systems. However, conventional solid desiccant air conditioning system adopts desiccant wheel with high cost as core component, which hinders the development of such system. Recently, desiccant coated heat exchanger (DCHE) with low initial cost and high efficiency was developed and this paper aims to investigate performance of DCHE air conditioning system adopted in Shanghai winter season. Performance of the system is predicted by a developed mathematical model where supply air states, mass of humidification and coefficient of performance (COP) are adopted as performance indices to evaluate the feasibility and energy utilization ratio of the system. Effects of regeneration water temperature on system performance are analyzed. It is found that under the simulation condition, relatively low regeneration temperature (such as 20 °C) cannot meet the designed standard and relatively high regeneration temperature (such as 40 °C) provides too much extra heating power, thus moderate regeneration temperature around 30 °C is recommended. Meanwhile, switch time is a crucial operation parameter for the system to obtain satisfied supply air, switch time from 40 s to 80 s and from 70 s to 240 s are recommended for transient and average supply air states, respectively. Both

Determination of Minimum Data Set (MSD) in Echocardiography Reporting System to Exchange with Iran’s Electronic Health Record (EHR) System

Science.gov (United States)

Mahmoudvand, Zahra; Kamkar, Mehran; Shahmoradi, Leila; Nejad, Ahmadreza Farzaneh

2016-01-01

Background: Determination of minimum data set (MDS) in echocardiography reports is necessary for documentation and putting information in a standard way, and leads to the enhancement of electrocardiographic studies through having access to precise and perfect reports and also to the development of a standard database for electrocardiographic reports. Aim: to determine the minimum data set of echocardiography reporting system to exchange with Iran’s electronic health record (EHR) system. Methods: First, a list of minimum data set was prepared after reviewing texts and studying cardiac patients’ records. Then, to determine the content validity of the prepared MDS, the expert views of 10 cardiologists and 10 health information management (HIM) specialists were obtained; to estimate the reliability of the set, test-retest method was employed. Finally, the data were analyzed using SPSS software. Results: The highest degree of consensus was found for the following MDSs: patient’s name and family name (5), accepting doctor’s name and family name, familial death records due to cardiac disorders, the image identification code, mitral valve, aortic valve, tricuspid valve, pulmonary valve, left ventricle, hole, atrium valve, Doppler examination of ventricular and atrial movement models and diagnoses with an average of. Conclusions: To prepare a model of echocardiography reporting system to exchange with EHR system, creation a standard data set is the vital point. Therefore, based on the research findings, the minimum reporting system data to exchange with Iran’s electronic health record system include information on entity, management, medical record, carried-out acts, and the main content of the echocardiography report, which the planners of reporting system should consider. PMID:27147803

Factors influencing intentions to use social recommender systems: a social exchange perspective.

Science.gov (United States)

Chang, Tsung-Sheng; Hsiao, Wei-Hung

2013-05-01

This study employs the perspective of social exchange theory and seeks to understand users' intentions to use social recommender systems (SRS) through three psychological factors: trust, shared values, and reputation. We use structural equation modeling to analyze 221 valid questionnaires. The results show that trust has a direct positive influence on the intention to use SRS, followed by shared values, whereas reputation has an indirect influence on SRS use. We further discuss specific recommendations concerning these factors for developing SRS.

FY 1999 project report on the invitation program for developing countries. International researcher exchange project - Researcher exchange/technical guidance project; 1999 nendo kenkyu koryu gijutsu shido jigyo / kokusai kenkyu koryu jigyo kaigai kenkyusha shohei jigyo hokokusho

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-03-01

For the promotion of research exchanges on global environmental preservation with developing countries, Ms. Malee Santikunaporn, lecturer of Faculty of Engineering, Thammasat University, Bankok, Thailand was invited. Desulfurization/denitrification facilities, which are being widely spread in developed countries, have marked effects, but high prices are an obstacle to the spread in developing countries. To make them spread in developing countries, it is needed to develop the technology which is low in price and meets the actual state in developing countries. As a technology with high viability, a system to simultaneously remove SOx and NOx was cited in which Cu is used as catalyst and adsorbent and into which the catalyst regeneration process is integrated. Considering it, technical exchanges on Cu-SiO{sub 2} catalyst as the basic theme were made during September 26 - December 23, 1999. Through visits on and exchanges with Tokyo Institute of Technology, ICEET, University of Kyoto, etc., understanding was deepened about how each country is tackling environmental problems. The theme 'Oxidative sorption of SO2 by Cu-SiO{sub 2} catalyst: characteristics of catalyst' could deepen knowledge/information of the developmental research as a system for simultaneous removal of SOx/NOx. The data obtained indicated great practicality of Cu-SiO{sub 2}. (NEDO)

Development of a helium/helium intermediate heat exchanger with helical coil tube bundle

International Nuclear Information System (INIS)

Czimczik, A.; Hirschle, G.

1984-01-01

Besides the research and development work leading to the design basis for the reference heat exchanger, the stages of development up to the realisation of a nuclear He/He intermediate heat exchanger (IHX) include selected experiments in manufacturing techniques and with individual test components, as well as the design, fabrication and testing of representative prototype component. The process of manufacturing and experiences gained so far are described

Thermal and water management of low temperature Proton Exchange Membrane Fuel Cell in fork-lift truck power system

International Nuclear Information System (INIS)

Hosseinzadeh, Elham; Rokni, Masoud; Rabbani, Abid; Mortensen, Henrik Hilleke

2013-01-01

Highlights: ► Developing a general zero dimensional Proton Exchange Membrane Fuel Cell (PEMFC) model for a forklift. ► System performance with different cooling fluids. ► Water and thermal management of fuel cell system. ► Effect of inlet temperature, outlet temperature and temperature gradient on system performance. - Abstract: A general zero-dimensional Proton Exchange Membrane Fuel Cell (PEMFC) model has been developed for forklift truck application. The balance of plant (BOP) comprises of a compressor, an air humidifier, a set of heat exchangers and a recirculation pump. Water and thermal management of the fuel cell stack and BOP has been investigated in this study. The results show that humidification of the inlet air is of great importance. By decreasing the relative humidity of inlet air from 95% to 25%, the voltage can drop by 29%. In addition, elevated stack temperature can lead to a higher average cell voltage when membrane is fully hydrated otherwise it causes a drastic voltage drop in the stack. Furthermore, by substituting liquid water with water–ethylene glycol mixture of 50%, the mass flow of coolant increases by about 32–33% in the inner loop and 60–65% in the outer loop for all ranges of current. The system can then be started up at about −25 °C with negligible change in the efficiency

Developing a Climate Change Boundary Organization: the Montana Adaptation Exchange

Science.gov (United States)

Whitlock, C. L.; Brooks, S.; Armstrong, T.; Bryan, B.

2016-12-01

Small-population large-area states like Montana are often challenged by a need to offer timely and relevant climate-change information that addresses diverse and widely dispersed stakeholder groups. In Montana, filling the gap between science and various types of decision-makers has motivated development of the first Montana Climate Assessment (MCA1), to be released in 2017 with a focus on climate-change impacts for agricultural, water and forestry sectors. To sustain and build on the MCA1 effort, we are also in the process of creating a Boundary Organization (defined by the National Academy of Sciences) called the Montana Adaptation Exchange (the Exchange); this entity will facilitate the flow of information across the boundaries between science, knowledge and implementation. In Montana, the Exchange brings scientists and practitioners together to seek solutions related to climate-change adaptation and other pressing environmental and social-economic challenges. The Montana Adaptation Exchange (1) is a collaborative partnership of members from the science and practitioner communities under a shared governance and participatory model; (2) presents research that has been vetted by the scientific community at large and represents the current state of knowledge; (3) allows for revision and expansion of assessments like the MCA; (4) communicates relevant, often technical, research and findings to a wide variety of resource managers and other stakeholders; (5) develops and maintains an extensive online database that organizes, regularly updates, and makes research data products readily available; and (6) offers an online portal and expert network of affiliated researchers and climate adaptation specialists to provide effective customer support. Boundary organizations, such as the Montana Adaptation Exchange, offer a scalable path to effectively move from "science to knowledge to action" while also allowing stakeholder needs to help inform research agendas.

Brief Report: Randomized Test of the Efficacy of Picture Exchange Communication System on Highly Generalized Picture Exchanges in Children with ASD

Science.gov (United States)

Yoder, Paul J.; Lieberman, Rebecca G.

2010-01-01

A randomized control trial comparing two social-communication interventions in young children with autism examined far-transfer of the use of picture exchange to communicate. Thirty-six children were randomly assigned to one of two treatment conditions, one of which was the Picture Exchange Communication System (PECS). All children had access to…

Past and future challenges in developing remote systems technology

International Nuclear Information System (INIS)

Ferguson, K.R.

1978-01-01

During the early development of remote systems for processing and examining fuel and materials from nuclear reactors, the facility designer and operator worked closely together to meet the challenges of this new field. Numerous challenges still face the nuclear remote systems engineer, e.g., the development of systems that reduce the exposure of workers, the need for advances in basic technology, and the development of cost-effective facilities. The solution to these and other challenges can be accelerated by an expanded program of information exchange, an aggressive development program, and improved project management procedures

Searching for an Appropriate Exchange Rate Regime

Directory of Open Access Journals (Sweden)

Yunjong Wang

2001-06-01

Full Text Available This paper attempts to survey current debates on the choice of exchange rate regime in emerging market economies. The issue of choosing an appropriate exchange rate regime is being actively discussed since the recent Asian crisis. As a lesson from the recent crises, one widely shared conclusion is that soft peg exchange rate regimes are extremely vulnerable in a world of volatile capital movements. Consequently, new orthodoxy based on the impossible trinity hypothesis favours two corner solutions ― greater flexibility or credible institutional assurance, like a currency board system or dollarization. Nevertheless, questions whether such corner solutions are adequate for developing countries are rising of late. "Fear of floating" is still conspicuous in many developing countries having adopted nominally a free-floating exchange rate regime. Developing countries are sensitive to exchange rate fluctuations because the cost of exchange rate volatility is greater than the benefit when compared to developed countries. Monitoring bands is a compromise solution, but it still needs further enhancement of estimation techniques for fundamental equilibrium exchange rates in order to make those estimation results more workable in practice. Other alternatives include the creation of soft peg of the G-3 currencies. Despite counterarguments, the stability of G-3 currencies could prove to be beneficial to emerging market economies.

KRW/USD Exchange Rate Volatility and Efficient Risk Management

Directory of Open Access Journals (Sweden)

Sang-Yong Joo

1999-03-01

Full Text Available This thesis analyzes the relationship between the exchange rate of Korean Won and US dollar and the amount of foreign exchange, and studies the direction of the amendment of the risk control of foreign exchange. The GARCH (Generalized Auto Regressive Conditional Heteroscedasticity model which visually embodies the auto-regress of the wave of exchange rate shows that the amount of trade will enhance the fluidity of the exchange rate, that is, the various expects of the participators of the market affect the amount of trade and the fluidity, so in the process of trading, the trader who is in the dry tree of information bears more trading expenditure. It is predicted that the liberalization of foreign exchange rate and fluctuated exchange rate system will jointly bring the enhancement of the fluidity of the exchange rate and the amount of exchange trade. The change of this system will bring the rise of participators in foreign exchange market; meanwhile, it will also initiate superfluous fluidity of foreign exchange market. In order to overcome this problem, the government needs to implement the development strategy of the understructure of the foreign exchange market and the enterprises need to carry through systemic exchange rate risk control.

Activation energies for iodine-exchange systems containing organic iodine compounds

Energy Technology Data Exchange (ETDEWEB)

Ikeda, N. (Takyo Univ. of Education (Japan). Faculty of Science) Takahashi, Yasuko

1976-01-01

In studies on the nonequilibrium isotopic exchange method for determining iodine in organic iodine compounds, activation energies have been measured to find systems having appropriate rate of exchange reactions. Activation energies are discussed by considering the effect of the structure of organic iodine compounds, the concentrations of reactants and solvent, etc. In homogeneous systems, activation energy is found to become larger in the order of CH/sub 3/Isystems, e.g. org. I(aq.)--I/sub 2/(CCL/sub 4/ or C/sub 2/H/sub 4/Cl/sub 2/), activation energy increases in the order of 3,5-diiodotyrosine<3-iodotyrosine<5-iodouracil. The catalytic effect of I/sub 2/ is large, and the iodine ratio between I/sub 2/ and organic iodine is a predominant factor in determining the rate of the exchange reaction.

Fluidized-Bed Heat Transfer Modeling for the Development of Particle/Supercritical-CO2 Heat Exchanger

Energy Technology Data Exchange (ETDEWEB)

Ma, Zhiwen [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Martinek, Janna G [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

2017-06-03

Concentrating solar power (CSP) technology is moving toward high-temperature and high-performance design. One technology approach is to explore high-temperature heat-transfer fluids and storage, integrated with a high-efficiency power cycle such as the supercritical carbon dioxide (s-CO2) Brayton power cycle. The s-CO2 Brayton power system has great potential to enable the future CSP system to achieve high solar-to-electricity conversion efficiency and to reduce the cost of power generation. Solid particles have been proposed as a possible high-temperature heat-transfer medium that is inexpensive and stable at high temperatures above 1,000 degrees C. The particle/heat exchanger provides a connection between the particles and s-CO2 fluid in the emerging s-CO2 power cycles in order to meet CSP power-cycle performance targets of 50% thermal-to-electric efficiency, and dry cooling at an ambient temperature of 40 degrees C. The development goals for a particle/s-CO2 heat exchanger are to heat s-CO2 to =720 degrees C and to use direct thermal storage with low-cost, stable solid particles. This paper presents heat-transfer modeling to inform the particle/s-CO2 heat-exchanger design and assess design tradeoffs. The heat-transfer process was modeled based on a particle/s-CO2 counterflow configuration. Empirical heat-transfer correlations for the fluidized bed and s-CO2 were used in calculating the heat-transfer area and optimizing the tube layout. A 2-D computational fluid-dynamics simulation was applied for particle distribution and fluidization characterization. The operating conditions were studied from the heat-transfer analysis, and cost was estimated from the sizing of the heat exchanger. The paper shows the path in achieving the cost and performance objectives for a heat-exchanger design.

Vacuum system design and tritium inventory for the TFTR charge exchange diagnostic

International Nuclear Information System (INIS)

Medley, S.S.

1979-05-01

The charge exchange diagnostic for the TFTR is comprised of two analyzer systems which contain a total of twenty independent mass/energy analyzers and one diagnostic neutral beam tentatively rated at 80 keV, 15 A. The associated vacuum systems were analyzed using the Vacuum System Transient Simulator (VSTS) computer program which models the transient transport of multi-gas species through complex networks of ducts, valves, traps, vacuum pumps, and other related vacuum system components. In addition to providing improved design performance at reduced cost, the analysis yields estimates for the exchange of tritium from the torus to the diagnostic components and of the diagnostic working gases to the torus

Development of commodity exchange in Croatia

OpenAIRE

Sicel, Mladen

2009-01-01

Purpose of this thesis work is to show relevance and necessarity for existing of commodity exchange and it’s influence to the economy of Croatia. Because eastern part of Croatia, region called Slavonia is mostly agricultural oriented, it is of essential relevance to establish and make operate of first commodity exchange in Croatia.

Characterization of primary coolant purification system samples for assay of spent ion exchanger radionuclide inventor

International Nuclear Information System (INIS)

Sajin Prasad, S.; Pant, Amar; Sharma, Ranjit; Pal, Sanjit

2018-01-01

The primary coolant system water of a research reactor contains various fission and activation products and the water is circulated continuously through ion exchange resin cartridges, to reduce the radioactive ionic impurity present in it. The coolant purification system comprises of an ion exchange cooler, two micro filters, and a battery of six ion exchanger beds, associated valves, piping and instrumentation (Heavy water System Operating manual, 2014). The spent cartridge is finally disposed off as active solid waste which contains predominantly long lived fission and activation products. The heavy water coolant is also used to cool the structural assemblies after passing through primary heat exchanger and a metallic strainer, which accumulates the fission and activation products. When there is a reduction of coolant flow through these strainers, they are removed for cleaning and decontamination. This paper describes the characterization of ion exchange resin samples and liquid effluent generated during ultra sonic decontamination of strainer. The results obtained can be used as a methodology for the assay of the spent ion exchanger cartridges radionuclide inventory, during its disposal

Isotope anomalies in oxygen isotope exchange equilibrium systems

International Nuclear Information System (INIS)

Kotaka, M.

1997-01-01

The purpose of the present work is to elucidate the isotope anomalies in oxygen isotope exchange equilibrium systems, according to the calculations of the equilibrium constants for oxygen isotopic exchange reactions, and the calculations of the oxygen isotope separation factors between two phases. The equilibrium constants (K65, K67, K68 and K69) of 16 O- 15 O, 16 O 17 O, 16 O- 18 O, and 16 O- 19 O exchange reactions between diatomic oxides were calculated in a wide temperature range on the basis of quantum statistical mechanics. Many equilibrium constants showed the anomalous mass effects, and then had the crossover temperatures and the mass independent fractionation (MIF) temperatures which held K67 = K65, K67 = K68, or K67 = K69, etc. For example, the equilibrium constants for the reactions between OH and the other diatomic oxides (MO) showed the anomalous mass effects, when M was Li, Na, Mg, K, Fe, Al, Ge, Zr, Pt, etc. The 16 O 15 O, 16 O 17 O, 16 O- 18 O, and 16 O- 19 O oxygen isotope separation factors (S65, S67, S68 and S69) between two phases were calculated, when OH and CO were in the first phase, and SiO was in the second phase. Although the oxygen isotopic exchange equilibria in the two phases had no MIF and crossover temperatures, the separation factors showed the anomalous mass effects and had the temperatures. According to what is called the normal mass effects for the equilibrium constant of isotopic exchange reaction, the value of InK68/InK67 is 1.885. Therefore, the value of InS68/InS67 should be 1.885 too. The value calculated, however, widely changed. It can be concluded from the results obtained in the present work that some oxygen isotopic exchange equilibria cause the anomalous mass effects, the anomalous oxygen isotope separation factors, and then isotope anomalies

Nanofiltration: ion exchange system for effective surfactant removal from water solutions

Directory of Open Access Journals (Sweden)

I. Kowalska

2014-12-01

Full Text Available A system combining nanofiltration and ion exchange for highly effective separation of anionic surfactant from water solutions was proposed. The subjects of the study were nanofiltration polyethersulfone membranes and ion-exchange resins differing in type and structure. The quality of the treated solution was affected by numerous parameters, such as quality of the feed solution, membrane cut-off, resin type, dose and the solution contact time with the resin. A properly designed purification system made it possible to reduce the concentration of anionic surfactant below 1 mg L-1 from feed solutions containing surfactant in concentrations above the CMC value.

Household of care in electronic health information exchange systems

CSIR Research Space (South Africa)

Sibiya, Mhlupheki G

2017-09-01

Full Text Available by the organisation have presented the protocols and message profiles that can be used for communication among the systems within Electronic Health Information Exchange (HIE)[17, 6]. HIE “allows doctors, nurses, pharmacists, other healthcare providers and patients...

Development and Validation of a Simple Analytical Model of the Proton Exchange Membrane Fuel Cell (Pemfc) in a Fork-Lift Truck Power System

DEFF Research Database (Denmark)

Hosseinzadeh, Elham; Rokni, Masoud

2013-01-01

In this study, a general proton exchange membrane fuel cell (PEMFC) model has been developed in order to investigate the balance of plant of a fork-lift truck thermodynamically. The model takes into account the effects of pressure losses, water crossovers, humidity aspects, and voltage overpotent......In this study, a general proton exchange membrane fuel cell (PEMFC) model has been developed in order to investigate the balance of plant of a fork-lift truck thermodynamically. The model takes into account the effects of pressure losses, water crossovers, humidity aspects, and voltage...

Replica exchange with solute tempering: A method for sampling biological systems in explicit water

Science.gov (United States)

Liu, Pu; Kim, Byungchan; Friesner, Richard A.; Berne, B. J.

2005-09-01

An innovative replica exchange (parallel tempering) method called replica exchange with solute tempering (REST) for the efficient sampling of aqueous protein solutions is presented here. The method bypasses the poor scaling with system size of standard replica exchange and thus reduces the number of replicas (parallel processes) that must be used. This reduction is accomplished by deforming the Hamiltonian function for each replica in such a way that the acceptance probability for the exchange of replica configurations does not depend on the number of explicit water molecules in the system. For proof of concept, REST is compared with standard replica exchange for an alanine dipeptide molecule in water. The comparisons confirm that REST greatly reduces the number of CPUs required by regular replica exchange and increases the sampling efficiency. This method reduces the CPU time required for calculating thermodynamic averages and for the ab initio folding of proteins in explicit water. Author contributions: B.J.B. designed research; P.L. and B.K. performed research; P.L. and B.K. analyzed data; and P.L., B.K., R.A.F., and B.J.B. wrote the paper.Abbreviations: REST, replica exchange with solute tempering; REM, replica exchange method; MD, molecular dynamics.*P.L. and B.K. contributed equally to this work.

Development of an integral computer code for simulation of heat exchangers

International Nuclear Information System (INIS)

Horvat, A.; Catton, I.

2001-01-01

Heat exchangers are one of the basic installations in power and process industries. The present guidelines provide an ad-hoc solution to certain design problems. A unified approach based on simultaneous modeling of thermal-hydraulics and structural behavior does not exist. The present paper describes the development of integral numerical code for simulation of heat exchangers. The code is based on Volume Averaging Technique (VAT) for porous media flow modeling. The calculated values of the whole-section drag and heat transfer coefficients show an excellent agreement with already published values. The matching results prove the correctness of the selected approach and verify the developed numerical code used for this calculation.(author)

Heat exchanges in coarsening systems

Energy Technology Data Exchange (ETDEWEB)

Corberi, Federico [Dipartimento di Fisica ' E R Caianiello' , Università di Salerno, via Ponte don Melillo, 84084 Fisciano (Italy); Gonnella, Giuseppe; Piscitelli, Antonio [Dipartimento di Fisica, Università di Bari and Istituto Nazionale di Fisica Nucleare, Sezione di Bari, via Amendola 173, 70126 Bari (Italy)

2011-10-15

This paper is a contribution to the understanding of the thermal properties of ageing systems where statistically independent degrees of freedom with greatly separated time scales are expected to coexist. Focusing on the prototypical case of quenched ferromagnets, where fast and slow modes can be respectively associated with fluctuations in the bulk of the coarsening domains and in their interfaces, we perform a set of numerical experiments specifically designed to compute the heat exchanges between different degrees of freedom. Our studies promote a scenario with fast modes acting as an equilibrium reservoir to which interfaces may release heat through a mechanism that allows fast and slow degrees to maintain their statistical properties independently.

The Life Science Exchange: a case study of a sectoral and sub-sectoral knowledge exchange programme.

Science.gov (United States)

Perkins, Brian Lee; Garlick, Rob; Wren, Jodie; Smart, Jon; Kennedy, Julie; Stephens, Phil; Tudor, Gwyn; Bisson, Jonathan; Ford, David V

2016-04-27

Local and national governments have implemented sector-specific policies to support economic development through innovation, entrepreneurship and knowledge exchange. Supported by the Welsh Government through the European Regional Development Fund, The Life Science Exchange® project was created with the aim to increase interaction between stakeholders, to develop more effective knowledge exchange mechanisms, and to stimulate the formation and maintenance of long-term collaborative relationships within the Welsh life sciences ecosystem. The Life Science Exchange allowed participants to interact with other stakeholder communities (clinical, academic, business, governmental), exchange perspectives and discover new opportunities. Six sub-sector focus groups comprising over 200 senior stakeholders from academia, industry, the Welsh Government and National Health Service were established. Over 18 months, each focus group provided input to inform healthcare innovation policy and knowledge mapping exercises of their respective sub-sectors. Collaborative projects identified during the focus groups and stakeholder engagement were further developed through sandpit events and bespoke support. Each sub-sector focus group produced a report outlining the significant strengths and opportunities in their respective areas of focus, made recommendations to overcome any 'system failures', and identified the stakeholder groups which needed to take action. A second outcome was a stakeholder-driven knowledge mapping exercise for each area of focus. Finally, the sandpit events and bespoke support resulted in participants generating more than £1.66 million in grant funding and inward investment. This article outlines four separate outcomes from the Life Science Exchange programme. The Life Science Exchange process has resulted in a multitude of collaborations, projects, inward investment opportunities and special interest group formations, in addition to securing over ten times its own

Ocean thermal energy conversion (OTEC) power system development. Preliminary design report, Appendices, Part 1 (Final)

Energy Technology Data Exchange (ETDEWEB)

1978-12-04

The objective of this project is the development of a preliminary design for a full-sized, closed cycle, ammonia power system module for the 100 MWe OTEC demonstration plant. In turn, this demonstration plant is to demonstrate, by 1984, the operation and performance of an Ocean Thermal Power Plant having sufficiently advanced heat exchanger design to project economic viability for commercial utilization in the late 1980's and beyond. Included in this power system development are the preliminary designs for a proof-of-concept pilot plant and test article heat exchangers which are scaled in such a manner as to support a logically sequential, relatively low-cost development of the full-scale power system module. The conceptual designs are presented for the demonstration plant power module, the proof-of-concept pilot plant, and for a pair of test article heat exchangers. Costs associated with the design, development, fabrication, checkout, delivery, installation, and operation are included. The accompanying design and producibilty studies on the full-scale power system module project the performance/economics for the commercial plant. This section of the report contains appendices on the developed computer models, water system dynamic studies, miscellaneous performance analysis, materials and processes, detailed equipment lists, turbine design studies, tube cleaner design, ammonia leak detection, and heat exchanger design supporting data. (WHK)

Developing a testing tool for a port terminal operating system

OpenAIRE

Perič, Miran

2011-01-01

This thesis describes the approach for development of a testing tool which simulates the terminal operating system. Main result of the thesis is presentation of the approach for the development and operation of the application, which was developed in C# programming language. The application communicates with the port information system by messages exchange. Data is stored on a database. With the support of the application we can test the port information system before of future implem...

First results of a coated heat exchanger for the use in dehumidification and cooling processes

International Nuclear Information System (INIS)

Munz, Gunther M.; Bongs, C.; Morgenstern, A.; Lehmann, S.; Kummer, H.; Henning, H.-M.; Henninger, Stefan K.

2013-01-01

In this work a novel solar driven dehumidification and cooling system is presented. The core components of this combined system are a sorptive dehumidification device based on high performance sorptive coatings and a novel evacuated tube solar air collector providing the driving heat. The essential part of the system is the coated heat exchanger. The chosen adsorbent is attached to the heat exchanger surface by a newly developed coating technique. Besides a brief description of the novel components and the experimental setup, the development of the aluminum heat exchanger, the coating procedure and scale up for geometries comparable to the heat exchanger in the dehumidification setup, as well as a first characterization of a small-sized coated heat exchanger regarding water uptake and dehumidification performance are presented. For estimating an overall system performance, a 2-dimensional thermodynamic model was applied, using the parameters in focus for the development of heat exchanger, coating and demonstration system. Highlights: • A novel developed technology is applied for sorptive coating of heat exchangers. • Upscaling to dimensions of 100 × 100 × 400 mm 3 was successful. • A small scale heat exchanger was coated and characterized showing good results. • Evaluation of adsorbents and simulation of system performance were carried out. • SAPO-34 gives best performance for driving temperatures of 100 °C and above

The Influence of Organizational Systems on Information Exchange in Long-Term Care Facilities: An Institutional Ethnography.

Science.gov (United States)

Caspar, Sienna; Ratner, Pamela A; Phinney, Alison; MacKinnon, Karen

2016-06-01

Person-centered care is heavily dependent on effective information exchange among health care team members. We explored the organizational systems that influence resident care attendants' (RCAs) access to care information in long-term care (LTC) settings. We conducted an institutional ethnography in three LTC facilities. Investigative methods included naturalistic observations, in-depth interviews, and textual analysis. Practical access to texts containing individualized care-related information (e.g., care plans) was dependent on job classification. Regulated health care professionals accessed these texts daily. RCAs lacked practical access to these texts and primarily received and shared information orally. Microsystems of care, based on information exchange formats, emerged. Organizational systems mandated written exchange of information and did not formally support an oral exchange. Thus, oral information exchanges were largely dependent on the quality of workplace relationships. Formal systems are needed to support structured oral information exchange within and between the microsystems of care found in LTC. © The Author(s) 2016.

Verifier-based three-party authentication schemes using extended chaotic maps for data exchange in telecare medicine information systems.

Science.gov (United States)

Lee, Tian-Fu

2014-12-01

Telecare medicine information systems provide a communicating platform for accessing remote medical resources through public networks, and help health care workers and medical personnel to rapidly making correct clinical decisions and treatments. An authentication scheme for data exchange in telecare medicine information systems enables legal users in hospitals and medical institutes to establish a secure channel and exchange electronic medical records or electronic health records securely and efficiently. This investigation develops an efficient and secure verified-based three-party authentication scheme by using extended chaotic maps for data exchange in telecare medicine information systems. The proposed scheme does not require server's public keys and avoids time-consuming modular exponential computations and scalar multiplications on elliptic curve used in previous related approaches. Additionally, the proposed scheme is proven secure in the random oracle model, and realizes the lower bounds of messages and rounds in communications. Compared to related verified-based approaches, the proposed scheme not only possesses higher security, but also has lower computational cost and fewer transmissions. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Optimization of parameters of heat exchangers vehicles

Directory of Open Access Journals (Sweden)

Andrei MELEKHIN

2014-09-01

Full Text Available The relevance of the topic due to the decision of problems of the economy of resources in heating systems of vehicles. To solve this problem we have developed an integrated method of research, which allows to solve tasks on optimization of parameters of heat exchangers vehicles. This method decides multicriteria optimization problem with the program nonlinear optimization on the basis of software with the introduction of an array of temperatures obtained using thermography. The authors have developed a mathematical model of process of heat exchange in heat exchange surfaces of apparatuses with the solution of multicriteria optimization problem and check its adequacy to the experimental stand in the visualization of thermal fields, an optimal range of managed parameters influencing the process of heat exchange with minimal metal consumption and the maximum heat output fin heat exchanger, the regularities of heat exchange process with getting generalizing dependencies distribution of temperature on the heat-release surface of the heat exchanger vehicles, defined convergence of the results of research in the calculation on the basis of theoretical dependencies and solving mathematical model.

Development of micro-structured heat exchangers; Developpement d'echangeurs de chaleur microstructures

Energy Technology Data Exchange (ETDEWEB)

Bouzon, C.

2004-10-01

This study has been carried out to defend the Technological Diploma of Research, in the aim to develop micro-structured heat exchangers. Realized within the Research Group on the Heat exchangers and Energy (GREThE) of the Atomic Energy Commission (CEA) of Grenoble. The rise of micro-technologies and the optimization of heat exchangers have led to emergence from few years of new structures of fluid paths with scales lower than the millimeter, thus making it possible to produce heat exchangers ultra-compacts. The micro-structured exchangers are heat exchangers whose hydraulic diameters are lower than the millimeter but with external dimensions of several centimeters. The study is based on two patents filed by the CEA and the characterization of these two geometries. A first concept of cross flow type finds applications with Gas/Liquid heat exchanger. A second type, a countercurrent, is more adapted to Liquid/Liquid applications. An approach with simplified analytical models and by numerical simulation was employed for each concept. An experimental study on the Gas/Liquid concept was also carried out. (author)

Building a national electronic medical record exchange system - experiences in Taiwan.

Science.gov (United States)

Li, Yu-Chuan Jack; Yen, Ju-Chuan; Chiu, Wen-Ta; Jian, Wen-Shan; Syed-Abdul, Shabbir; Hsu, Min-Huei

2015-08-01

There are currently 501 hospitals and about 20,000 clinics in Taiwan. The National Health Insurance (NHI) system, which is operated by the NHI Administration, uses a single-payer system and covers 99.9% of the nation's total population of 23,000,000. Taiwan's NHI provides people with a high degree of freedom in choosing their medical care options. However, there is the potential concern that the available medical resources will be overused. The number of doctor consultations per person per year is about 15. Duplication of laboratory tests and prescriptions are not rare either. Building an electronic medical record exchange system is a good method of solving these problems and of improving continuity in health care. In November 2009, Taiwan's Executive Yuan passed the 'Plan for accelerating the implementation of electronic medical record systems in medical institutions' (2010-2012; a 3-year plan). According to this plan, a patient can, at any hospital in Taiwan, by using his/her health insurance IC card and physician's medical professional IC card, upon signing a written agreement, retrieve all important medical records for the past 6 months from other participating hospitals. The focus of this plan is to establish the National Electronic Medical Record Exchange Centre (EEC). A hospital's information system will be connected to the EEC through an electronic medical record (EMR) gateway. The hospital will convert the medical records for the past 6 months in its EMR system into standardized files and save them on the EMR gateway. The most important functions of the EEC are to generate an index of all the XML files on the EMR gateways of all hospitals, and to provide search and retrieval services for hospitals and clinics. The EEC provides four standard inter-institution EMR retrieval services covering medical imaging reports, laboratory test reports, discharge summaries, and outpatient records. In this system, we adopted the Health Level 7 (HL7) Clinical Document

A continuous exchange factor method for radiative exchange in enclosures with participating media

International Nuclear Information System (INIS)

Naraghi, M.H.N.; Chung, B.T.F.; Litkouhi, B.

1987-01-01

A continuous exchange factor method for analysis of radiative exchange in enclosures is developed. In this method two types of exchange functions are defined, direct exchange function and total exchange function. Certain integral equations relating total exchange functions to direct exchange functions are developed. These integral equations are solved using Gaussian quadrature integration method. The results obtained based on the present approach are found to be more accurate than those of the zonal method

Communication: Near-locality of exchange and correlation density functionals for 1- and 2-electron systems

Science.gov (United States)

Sun, Jianwei; Perdew, John P.; Yang, Zenghui; Peng, Haowei

2016-05-01

The uniform electron gas and the hydrogen atom play fundamental roles in condensed matter physics and quantum chemistry. The former has an infinite number of electrons uniformly distributed over the neutralizing positively charged background, and the latter only one electron bound to the proton. The uniform electron gas was used to derive the local spin density approximation to the exchange-correlation functional that undergirds the development of the Kohn-Sham density functional theory. We show here that the ground-state exchange-correlation energies of the hydrogen atom and many other 1- and 2-electron systems are modeled surprisingly well by a different local spin density approximation (LSDA0). LSDA0 is constructed to satisfy exact constraints but agrees surprisingly well with the exact results for a uniform two-electron density in a finite, curved three-dimensional space. We also apply LSDA0 to excited or noded 1-electron densities, where it works less well. Furthermore, we show that the localization of the exact exchange hole for a 1- or 2-electron ground state can be measured by the ratio of the exact exchange energy to its optimal lower bound.

Communication: Near-locality of exchange and correlation density functionals for 1- and 2-electron systems

Energy Technology Data Exchange (ETDEWEB)

Sun, Jianwei; Yang, Zenghui; Peng, Haowei [Department of Physics, Temple University, Philadelphia, Pennsylvania 19122 (United States); Perdew, John P. [Department of Physics, Temple University, Philadelphia, Pennsylvania 19122 (United States); Department of Chemistry, Temple University, Philadelphia, Pennsylvania 19122 (United States)

2016-05-21

The uniform electron gas and the hydrogen atom play fundamental roles in condensed matter physics and quantum chemistry. The former has an infinite number of electrons uniformly distributed over the neutralizing positively charged background, and the latter only one electron bound to the proton. The uniform electron gas was used to derive the local spin density approximation to the exchange-correlation functional that undergirds the development of the Kohn-Sham density functional theory. We show here that the ground-state exchange-correlation energies of the hydrogen atom and many other 1- and 2-electron systems are modeled surprisingly well by a different local spin density approximation (LSDA0). LSDA0 is constructed to satisfy exact constraints but agrees surprisingly well with the exact results for a uniform two-electron density in a finite, curved three-dimensional space. We also apply LSDA0 to excited or noded 1-electron densities, where it works less well. Furthermore, we show that the localization of the exact exchange hole for a 1- or 2-electron ground state can be measured by the ratio of the exact exchange energy to its optimal lower bound.

Communication: Near-locality of exchange and correlation density functionals for 1- and 2-electron systems

International Nuclear Information System (INIS)

Sun, Jianwei; Yang, Zenghui; Peng, Haowei; Perdew, John P.

2016-01-01

The uniform electron gas and the hydrogen atom play fundamental roles in condensed matter physics and quantum chemistry. The former has an infinite number of electrons uniformly distributed over the neutralizing positively charged background, and the latter only one electron bound to the proton. The uniform electron gas was used to derive the local spin density approximation to the exchange-correlation functional that undergirds the development of the Kohn-Sham density functional theory. We show here that the ground-state exchange-correlation energies of the hydrogen atom and many other 1- and 2-electron systems are modeled surprisingly well by a different local spin density approximation (LSDA0). LSDA0 is constructed to satisfy exact constraints but agrees surprisingly well with the exact results for a uniform two-electron density in a finite, curved three-dimensional space. We also apply LSDA0 to excited or noded 1-electron densities, where it works less well. Furthermore, we show that the localization of the exact exchange hole for a 1- or 2-electron ground state can be measured by the ratio of the exact exchange energy to its optimal lower bound.

Measurement of backbone hydrogen-deuterium exchange in the type III secretion system needle protein PrgI by solid-state NMR

Science.gov (United States)

Chevelkov, Veniamin; Giller, Karin; Becker, Stefan; Lange, Adam

2017-10-01

In this report we present site-specific measurements of amide hydrogen-deuterium exchange rates in a protein in the solid state phase by MAS NMR. Employing perdeuteration, proton detection and a high external magnetic field we could adopt the highly efficient Relax-EXSY protocol previously developed for liquid state NMR. According to this method, we measured the contribution of hydrogen exchange on apparent 15N longitudinal relaxation rates in samples with differing D2O buffer content. Differences in the apparent T1 times allowed us to derive exchange rates for multiple residues in the type III secretion system needle protein.

The evolutionary synchronization of the exchange rate system in ASEAN+6

Science.gov (United States)

Feng, Xiaobing; Hu, Haibo; Wang, Xiaofan

2010-12-01

Although there are extensive researches on the behavior of the world currency network, the complexity of the Asian regional currency system is not well understood regardless of its importance. Using daily exchange rates this paper examines exchange rate co-movements in the region before and after the China exchange rate reform. It was found that the correlation between Asian currencies and the US Dollar, the previous regional key currency has become weaker and intra-Asia interactions have increased. Cross sample entropy and cross entropy approaches are also applied to examine the synchrony behavior among the Asian currencies. The study also shows that the Asian exchange rate markets featured are neither stochastic nor efficient. These findings may shed some light on the in-depth understanding of collective behaviors in a regional currency network; they will also lay a theoretical foundation for further policy formulation in Asian currency integration.

Data exchange system in cooler-storage-ring virtual accelerator

International Nuclear Information System (INIS)

Liu Wufeng; Qiao Weimin; Jing Lan; Guo Yuhui

2009-01-01

The data exchange system of the cooler-storage-ring (CSR) control system for heavy ion radiotherapy has been introduced for the heavy ion CSR at Lanzhou (HIRFL-CSR). Using techniques of Java, component object model (COM), Oracle, DSP and FPGA, this system can achieve real-time control of magnet power supplies sanctimoniously, and control beams and their switching in 256 energy levels. It has been used in the commissioning of slow extraction for the main CSR (CSRm), showing stable and reliable performance. (authors)

Development of Design Criteria for Fluid Induced Structural Vibrations in Steam Generators and Heat Exchangers

International Nuclear Information System (INIS)

Uvan Catton; Dhir, Vijay K.; Deepanjan Mitra; Omar Alquaddoomi; Pierangelo Adinolfi

2004-01-01

Flow-induced vibration in heat exchangers has been a major cause of concern in the nuclear industry for several decades. Many incidents of failure of heat exchangers due to apparent flow-induced vibration have been reported through the USNRC incident reporting system. Almost all heat exchangers have to deal with this problem during their operation. The phenomenon has been studied since the 1970s and the database of experimental studies on flow-induced vibration is constantly updated with new findings and improved design criteria for heat exchangers

Development of Design Criteria for Fluid Induced Structural Vibrations in Steam Generators and Heat Exchangers

International Nuclear Information System (INIS)

Catton, Ivan; Dhir, Vijay K.; Alquaddoomi, O.S.; Mitra, Deepanjan; Adinolfi, Pierangelo

2004-01-01

OAK-B135 Flow-induced vibration in heat exchangers has been a major cause of concern in the nuclear industry for several decades. Many incidents of failure of heat exchangers due to apparent flow-induced vibration have been reported through the USNRC incident reporting system. Almost all heat exchangers have to deal with this problem during their operation. The phenomenon has been studied since the 1970s and the database of experimental studies on flow-induced vibration is constantly updated with new findings and improved design criteria for heat exchangers. In the nuclear industry, steam generators are often affected by this problem. However, flow-induced vibration is not limited to nuclear power plants, but to any type of heat exchanger used in many industrial applications such as chemical processing, refrigeration and air conditioning. Specifically, shell and tube type heat exchangers experience flow-induced vibration due to the high velocity flow over the tube banks. Flow-induced vibration in these heat exchangers leads to equipment breakdown and hence expensive repair and process shutdown. The goal of this research is to provide accurate measurements that can help modelers to validate their models using the measured experimental parameters and thereby develop better design criteria for avoiding fluid-elastic instability in heat exchangers. The research is divided between two primary experimental efforts, the first conducted using water alone (single phase) and the second using a mixture of air or steam and water as the working fluid (two phase). The outline of this report is as follows: After the introduction to fluid-elastic instability, the experimental apparatus constructed to conduct the experiments is described in Chapter 2 along with the measurement procedures. Chapter 3 presents results obtained on the tube array and the flow loop, as well as techniques used in data processing. The project performance is described and evaluated in Chapter 4 followed by

Helium-air exchange flows through partitioned opening and two-opening

International Nuclear Information System (INIS)

Kang, T. I.

1997-01-01

This paper describes experimental investigations of helium-air exchange flows through partitioned opening and two-opening. Such exchange flows may occur following rupture accident of stand pipe in high temperature engineering test reactor. A test vessel with the two types of small opening on top of test cylinder is used for experiments. An estimation method of mass increment is developed to measure the exchange flow rate. Upward flow of the helium and downward flow of the air in partitioned opening system interact out of entrance and exit of the opening. Therefore, an experiment with two-opening system is made to investigate effect of the fluids interaction of partitioned opening system. As a result of comparison of the exchange flow rates between two types of the opening system, it is demonstrated that the exchange flow rate of the two-opening system is larger than that of the partitioned opening system because of absence of the effect of fluids interaction. (author)

Quantifying the Pathway and Predicting Spontaneous Emulsification during Material Exchange in a Two Phase Liquid System.

Science.gov (United States)

Spooner, Stephen; Rahnama, Alireza; Warnett, Jason M; Williams, Mark A; Li, Zushu; Sridhar, Seetharaman

2017-10-30

Kinetic restriction of a thermodynamically favourable equilibrium is a common theme in materials processing. The interfacial instability in systems where rate of material exchange is far greater than the mass transfer through respective bulk phases is of specific interest when tracking the transient interfacial area, a parameter integral to short processing times for productivity streamlining in all manufacturing where interfacial reaction occurs. This is even more pertinent in high-temperature systems for energy and cost savings. Here the quantified physical pathway of interfacial area change due to material exchange in liquid metal-molten oxide systems is presented. In addition the predicted growth regime and emulsification behaviour in relation to interfacial tension as modelled using phase-field methodology is shown. The observed in-situ emulsification behaviour links quantitatively the geometry of perturbations as a validation method for the development of simulating the phenomena. Thus a method is presented to both predict and engineer the formation of micro emulsions to a desired specification.

A run-around heat exchanger system to improve the energy efficiency of a home appliance using hot water

International Nuclear Information System (INIS)

Park, Jae Sung; Jacobi, Anthony M.

2009-01-01

A significant portion of the energy consumed by many home appliances using hot water is used to heat cold supply water. Such home appliances generally are supplied water at a temperature lower than the ambient temperature, and the supply water is normally heated to its maximum operating temperature, often using natural gas or an electrical heater. In some cases, it is possible to pre-heat the supply water and save energy that would normally be consumed by the natural gas or electrical heater. In order to save the energy consumed by an appliance using water heater, a run-around heat exchanger system is used to transfer heat from the ambient to the water before an electrical heater is energized. A simple model to predict the performance of this system is developed and validated, and the model is used to explore design and operating issues relevant to the run-around heat exchanger system. Despite the additional power consumption by the fan and pump of the run-around heat exchanger system, the experimental data and analysis show that for some systems the overall energy efficiency of the appliance can be improved, saving about 6% of the energy used by the baseline machine.

Development of an automatic prompt gamma-ray activation analysis system

International Nuclear Information System (INIS)

Osawa, Takahito

2013-01-01

An automatic prompt gamma-ray activation analysis system was developed and installed at the Japan Research Reactor No. 3 Modified (JRR-3M). The main control software, referred to as AutoPGA, was developed using LabVIEW 2011 and the hand-made program can control all functions of the analytical system. The core of the new system is an automatic sample exchanger and measurement system with several additional automatic control functions integrated into the system. Up to fourteen samples can be automatically measured by the system. (author)

Pressure Pump Power Control in the Primary Circuit of the Heat Exchange System

Directory of Open Access Journals (Sweden)

Shilin Aleksandr

2017-01-01

Full Text Available In this paper we consider the problem of speed in hot water systems where highly efficient plate heat exchanger is used. Especially marked the problem which is connected with long transition drive of constant speed exceeding the time of the heat exchanger accumulative tank emptying more than twice. As a regulating element in the heat exchange system there was proposed to use asynchronous electric drive of pressure pump in the primary circuit of the heat exchanger. For correct use of such electric drive we solved the problem of control object mathematical model synthesis, which has non-linear properties, in particular, the transfer coefficient of the circuit can vary in more than 6 times. At the same time there was revealed the dependence of the transfer coefficient on the motor speed, which must be considered in the controller synthesis. In conclusion we suggested the solutions of regulators synthesis tasks with customizable settings for speed and switchable structure between relay λ and PI regulators.

Development of a micro-heat exchanger with stacked plates using LTCC technology

Directory of Open Access Journals (Sweden)

E. Vásquez-Alvarez

2010-09-01

Full Text Available A green ceramic tape micro-heat exchanger was developed using Low Temperature Co-fired Ceramics technology (LTCC. The device was designed by using Computational Aided Design software and simulations were made using a Computational Fluid Dynamics package (COMSOL Multiphysics to evaluate the homogeneity of fluid distribution in the microchannels. Four geometries were proposed and simulated in two and three dimensions to show that geometric details directly affect the distribution of velocity in the micro-heat exchanger channels. The simulation results were quite useful for the design of the microfluidic device. The micro-heat exchanger was then constructed using the LTCC technology and is composed of five thermal exchange plates in cross-flow arrangement and two connecting plates, with all plates stacked to form a device with external dimensions of 26 x 26 x 6 mm³.

Exchange interactions in two-state systems: rare earth pyrochlores

Science.gov (United States)

Curnoe, S. H.

2018-06-01

The general form of the nearest neighbour exchange interaction for rare earth pyrochlores is derived based on symmetry. Generally, the rare earth angular momentum degeneracy is lifted by the crystal electric field (CEF) into singlets and doublets. When the CEF ground state is a doublet that is well-separated from the first excited state the CEF ground state doublet can be treated as a pseudo-spin of some kind. The general form of the nearest neighbour exchange interaction for pseudo-spins on the pyrochlore lattice is derived for three different types of pseudo-spins. The methodology presented in this paper can be applied to other two-state spin systems with a high space group symmetry.

Evolution of the Tropical Cyclone Integrated Data Exchange And Analysis System (TC-IDEAS)

Science.gov (United States)

Turk, J.; Chao, Y.; Haddad, Z.; Hristova-Veleva, S.; Knosp, B.; Lambrigtsen, B.; Li, P.; Licata, S.; Poulsen, W.; Su, H.;

Development of a heat exchanger root-cause analysis methodology

International Nuclear Information System (INIS)

Jarrel, D.B.

1989-01-01

The objective of this work is to determine a generic methodology for approaching the accurate identification of the root cause of component failure. Root-cause determinations are an everyday challenge to plant personnel, but they are handled with widely differing degrees of success due to the approaches, levels of diagnostic expertise, and documentation. The criterion for success is simple: If the root cause of the failure has truly been determined and corrected, the same causal failure relationship will not be demonstrated again in the future. The approach to root-cause analysis (RCA) element definition was to first selectively choose and constrain a functionally significant component (in this case a component cooling water to service water heat exchanger) that has demonstrated prevalent failures. Then a root cause of failure analysis was performed by a systems engineer on a large number of actual failure scenarios. The analytical process used by the engineer was documented and evaluated to abstract the logic model used to arrive at the root cause. For the case of the heat exchanger, the actual root-cause diagnostic approach is described. A generic methodology for the solution of the root cause of component failure is demonstrable for this general heat exchanger sample

Exchange-Rate Unification with Black Market Leakages; Russia 1992

OpenAIRE

Linda S. Goldberg

1993-01-01

In 1992 Russia unified the multiple exchange rates that had applied to international transactions. This paper describes the multiple exchange rate system that existed in Russia prior to mid-1992 and undertakes a theoretical exploration of the effects of the exchange rate unification that took place in July 1992. The model developed here allows for leakages between official and black markets and permits flexibility of the exchange rates in both official and parallel currency markets. Within th...

Exact exchange and Wilson-Levy correlation: a pragmatic device for studying complex weakly-bonded systems.

Science.gov (United States)

Walsh, T R

2005-02-07

The Wilson-Levy (WL) correlation functional is used together with Hartree-Fock (HF) theory to evaluate interaction energies at intermediate separations (i.e. around equilibrium separation) for several weakly-bonded systems. The HF+WL approach reproduces binding trends for all complexes studied: selected rare-gas dimers, isomers of the methane dimer, benzene dimer and naphthalene dimer, and base-pair stacking structures for pyrimidine, cytosine, uracil and guanine dimers. These HF+WL data are contrasted against results obtained from some popular functionals (including B3LYP and PBE), as well as two newly-developed functionals, X3LYP and xPBE. The utility of HF+WL, with reference to exact-exchange (EXX) density-functional theory, is discussed in terms of a suggested EXXWL exchange-correlation functional.

Hydrogen deuterium exchange mass spectrometry in biopharmaceutical discovery and development – A review

International Nuclear Information System (INIS)

Deng, Bin; Lento, Cristina; Wilson, Derek J.

2016-01-01

Protein therapeutics have emerged as a major class of biopharmaceuticals over the past several decades, a trend that has motivated the advancement of bioanalytical technologies for protein therapeutic characterization. Hydrogen deuterium exchange mass spectrometry (HDX-MS) is a powerful and sensitive technique that can probe the higher order structure of proteins and has been used in the assessment and development of monoclonal antibodies (mAbs), antibody-drug conjugates (ADCs) and biosimilar antibodies. It has also been used to quantify protein-ligand, protein-receptor and other protein-protein interactions involved in signaling pathways. In manufacturing and development, HDX-MS can validate storage formulations and manufacturing processes for various biotherapeutics. Currently, HDX-MS is being refined to provide additional coverage, sensitivity and structural specificity and implemented on the millisecond timescale to reveal residual structure and dynamics in disordered domains and intrinsically disordered proteins. - Highlights: • The pharmaceuticals industry is increasingly shifting to protein therapeutics. • Hydrogen deuterium exchange mass spectrometry is uniquely well suited to support biopharmaceutical development. • Applications for hydrogen deuterium exchange span drug discovery, development and manufacturing. • Future developments will allow improved sensitivity, structural resolution and a broader range of dynamics to be monitored.

Hydrogen deuterium exchange mass spectrometry in biopharmaceutical discovery and development – A review

Energy Technology Data Exchange (ETDEWEB)

Deng, Bin, E-mail: dengbin@yorku.ca [Chemistry Department, York University, 4700 Keele Street, Toronto, ON, M3J 1P3 (Canada); The Centre for Research in Mass Spectrometry, York University, Toronto, ON, M3J1P3 (Canada); Lento, Cristina, E-mail: clento@yorku.ca [Chemistry Department, York University, 4700 Keele Street, Toronto, ON, M3J 1P3 (Canada); The Centre for Research in Mass Spectrometry, York University, Toronto, ON, M3J1P3 (Canada); Wilson, Derek J., E-mail: dkwilson@yorku.ca [Chemistry Department, York University, 4700 Keele Street, Toronto, ON, M3J 1P3 (Canada); The Centre for Research in Mass Spectrometry, York University, Toronto, ON, M3J1P3 (Canada)

2016-10-12

Protein therapeutics have emerged as a major class of biopharmaceuticals over the past several decades, a trend that has motivated the advancement of bioanalytical technologies for protein therapeutic characterization. Hydrogen deuterium exchange mass spectrometry (HDX-MS) is a powerful and sensitive technique that can probe the higher order structure of proteins and has been used in the assessment and development of monoclonal antibodies (mAbs), antibody-drug conjugates (ADCs) and biosimilar antibodies. It has also been used to quantify protein-ligand, protein-receptor and other protein-protein interactions involved in signaling pathways. In manufacturing and development, HDX-MS can validate storage formulations and manufacturing processes for various biotherapeutics. Currently, HDX-MS is being refined to provide additional coverage, sensitivity and structural specificity and implemented on the millisecond timescale to reveal residual structure and dynamics in disordered domains and intrinsically disordered proteins. - Highlights: • The pharmaceuticals industry is increasingly shifting to protein therapeutics. • Hydrogen deuterium exchange mass spectrometry is uniquely well suited to support biopharmaceutical development. • Applications for hydrogen deuterium exchange span drug discovery, development and manufacturing. • Future developments will allow improved sensitivity, structural resolution and a broader range of dynamics to be monitored.

Scientific Verification Test of Orbitec Deployable Vegetable Production System for Salad Crop Growth on ISS- Gas Exchange System design and function

Science.gov (United States)

Eldemire, Ashleigh

2007-01-01

The ability to produce and maintain salad crops during long term missions would be a great benefit to NASA; the renewable food supply would save cargo space, weight and money. The ambient conditions of previous ground controlled crop plant experiments do not reflect the microgravity and high CO2 concentrations present during orbit. It has been established that microgravity does not considerably alter plant growth. (Monje, Stutte, Chapman, 2005). To support plants in a space-craft environment efficient and effective lighting and containment units are necessary. Three lighting systems were previously evaluated for radish growth in ambient air; fluorescent lamps in an Orbitec Biomass Production System Educational (BPSE), a combination of red, blue, and green LED's in a Deployable Vegetable Production System (Veggie), and a combination of red and blue LED's in a Veggie. When mass measurements compared the entire possible growing area vs. power consumed by the respective units, the Veggies clearly exceeded the BPSE indicating that the LED units were a more resource efficient means of growing radishes under ambient conditions in comparison with fluorescent lighting. To evaluate the most productive light treatment system for a long term space mission a more closely simulated ISS environment is necessary. To induce a CO2 dense atmosphere inside the Veggie's and BPSE a gas exchange system has been developed to maintain a range of 1000-1200 ppm CO2 during a 21-day light treatment experiment. This report details the design and function of the gas exchange system. The rehabilitation, trouble shooting, maintenance and testing of the gas exchange system have been my major assignments. I have also contributed to the planting, daily measurements and harvesting of the radish crops 21-day light treatment verification test.

Activity systems modeling as a theoretical lens for social exchange studies

Directory of Open Access Journals (Sweden)

Ernest Jones

2016-01-01

Full Text Available The social exchange perspective seeks to acknowledge, understand and predict the dynamics of social interactions. Empirical research involving social exchange constructs have grown to be highly technical including confirmatory factor analysis to assess construct distinctiveness and structural equation modeling to assess construct causality. Each study seemingly strives to assess how underlying social exchange theoretic constructs interrelate. Yet despite this methodological depth and resultant explanatory and predictive power, a significant number of studies report findings that, once synthesized, suggest an underlying persistent threat of conceptual or construct validity brought about by a search for epistemological parsimony. Further, it is argued that a methodological approach that embraces inherent complexity such as activity systems modeling facilitates the search for simplified models while not ignoring contextual factors.

Resonating-group study and importance of exchange effects in the α + 6Li system

International Nuclear Information System (INIS)

Suenkel, W.; Tang, Y.C.

1979-01-01

The resonating-group method in the one-channel approximation is used to investigate the α + 6 Li system. The result shows that, especially at relatively high energies, reasonable agreement with experiment can be obtained. In particular, the cross section rise in the backward angular region is well reproduced. The effects of internuclear antisymmetrization, represented by various nucleon-exchange terms in the kernel function, are also carefully examined. Some of the interesting findings are that the blocking effect is quite significant in this system and the two-exchange terms (sometimes even the three-exchange terms) seem to have only minor influence on the scattering cross section. 7 figures, 1 table

FREE FLOATING EXCHANGE RATE SYSTEM DAN PENERAPANNYA PADA KEBIJAKSANAAN EKONOMI DI NEGARA YANG BERPEREKONOMIAN KECIL DAN TERBUKA

Directory of Open Access Journals (Sweden)

Adwin Surya Atmadja

2001-01-01

Full Text Available Since the Bretton Wood sistem collapsed in early 1970s, the free floating exchange rate system has been being applied in many countries around the world. The exchange rate system choice is based on some economic advantages that will be obtained from it, considering some economic disadvantages that might be occurred. The valuation toward the advantages and disadvantages of the exchange rate system implementation exactly depends on the national economy it self, because such economy will give some responses in different ways. In a small-opened economy, the effect that occurred in its national economy by the implementation of the floating exchange rate system will be different with the one which is received by a developed country. The exposition about the phenomenon that is happened in the small-opened economy country will become more clearly explainable by Mundell - Fleming - model which is specially developed for those purposes-, and also by some basic theories related with the topic. By using the perfectly capital mobility asumption, Mundell - Fleming model is able to explain the effect of the economic policies implementation, specially fiscal policy and monetary policy, in a small economy country that has already applied the free floating exchange rate system will be different with other countries. Fiscal policy that has been implemented in the country will not significantly alter its national income, but it will cause an alteration in its exchange rate. However, monetary policy implemented in the same countries, will cause changes in its national income as a result of its exchange rate alteration. Abstract in Bahasa Indonesia : Sejak runtuhnya sistem Bretton Wood pada awal tahun 1970-an, sistem nilai tukar mengambang bebas telah diterapkan di banyak negara di dunia. Pemilihan terhadap sistem nilai tukar ini didasarkan kepada keuntungan ekonomis yang akan diperoleh dari padanya, tanpa mengabaikan kerugian yang ditimbulkan. Penilaian terhadap

[Problems encountered by hospital pharmacists with information systems: Analysis of exchanges within social networks].

Science.gov (United States)

Charpiat, B; Mille, F; Fombeur, P; Machon, J; Zawadzki, E; Bobay-Madic, A

2018-05-21

The development of information systems in French hospitals is mandatory. The aim of this work was to analyze the content of exchanges carried out within social networks, dealing with problems encountered with hospital pharmacies information systems. Messages exchanged via the mailing list of the Association pour le Digital et l'Information en Pharmacie and abstracts of communications presented at hospital pharmacists trade union congresses were analyzed. Those referring to information systems used in hospital pharmacies were selected. From March 2015 to June 2016, 122 e-mails sent by 80 pharmacists concerned information systems. From 2002 to 2016, 45 abstracts dealt with this topic. Problems most often addressed in these 167 documents were "parameterization and/or functionalities" (n=116), interfaces and complexity of the hospital information systems (n=52), relationship with health information technologies vendors and poor reactivity (n=32), additional workload (n=32), ergonomics (n=30), insufficient user training (n=22). These problems are interdependent, lead to errors and in order to mitigate their consequences, they compel pharmacy professionals to divert a significant amount of working hours to the detriment of pharmaceutical care and dispensing and preparing drugs. Hospital pharmacists are faced with many problems of insecurity and inefficiency generated by information systems. Researches are warranted to determine their cost, specify their deleterious effects on care and identify the safest information systems. Copyright © 2018 Académie Nationale de Pharmacie. Published by Elsevier Masson SAS. All rights reserved.

Characterization of Na+-linked and Na+-independent Cl-/HCO3- exchange systems in Chinese hamster lung fibroblasts

International Nuclear Information System (INIS)

Cassel, D.; Scharf, O.; Rotman, M.; Cragoe, E.J. Jr.; Katz, M.

1988-01-01

The PS120 variant of Chinese hamster lung fibroblasts which lacks Na + /H + exchange activity was used to investigate bicarbonate transport systems and their role in intracellular pH (pH/sub i/) regulation. When pH/sub i/ was decreased by acid load, bicarbonate caused pH/sub i/ increase and stimulated 36 Cl - efflux from the cells, both in a Na + -dependent manner. These results together with previous findings that bicarbonate stimulates 22 Na + uptake in PS120 cells demonstrate the presence of a Na + -linked Cl - /HCO 3 - exchange system. In cells with normal initial pH/sub i/, bicarbonate caused Na + -independent pH/sub i/ increase in Cl - -free solutions and stimulated Na + -independent 36 Cl - efflux, indicating that a Na + -independent Cl - /HCO 3 - exchanger is also present in the cell. Na + -linked and Na + -independent Cl - /HCO 3- exchange is apparently mediated by two distinct systems, since a [(tetrahydrofluorene-7-yl)oxy]acetic acid derivative selectively inhibits the Na + -independent exchanger. An additional distinctive features is a 10-fold lower affinity for chloride of the Na + -linked exchanger. The Na + -linked and Na + -independent Cl - /HCO 3 - exchange systems are likely to protect the cell from acid and alkaline load, respectively

The development of air cooled condensation systems

International Nuclear Information System (INIS)

Bodas, J.

1990-01-01

EGI - Contracting/Engineering has had experience with the development of air cooled condensing systems since the 1950's. There are two accepted types of dry cooling systems,the direct and the indirect ones. Due to the fact that the indirect system has several advantages over the direct one, EGI's purpose was to develop an economic, reliable and efficient type of indirect cooling system, both for industrial and power station applications. Apart from system development, the main components of dry cooling plant have been developed as well. These are: the water-to-air heat exchangers; the direct contact (DC, or jet) condenser; the cooling water circulating pumps and recovery turbines; and the peak cooling/preheating units. As a result of this broad development work which was connected with intensive market activity, EGI has supplied about 50% of the dry cooling plants employed for large power stations all over the world. This means that today the cumulated capacity of power units using Heller type dry cooling systems supplied and contracted by EGI is over 6000 MW

Free Floating Exchange Rate System Dan Penerapannya Pada Kebijaksanaan Ekonomi Di Negara Yang Berperekonomian Kecil Dan Terbuka

OpenAIRE

Atmadja, Adwin Surya

2001-01-01

Since the Bretton Wood sistem collapsed in early 1970s, the free floating exchange rate system has been being applied in many countries around the world. The exchange rate system choice is based on some economic advantages that will be obtained from it, considering some economic disadvantages that might be occurred. The valuation toward the advantages and disadvantages of the exchange rate system implementation exactly depends on the national economy it self, because such economy will give so...

FREE FLOATING EXCHANGE RATE SYSTEM DAN PENERAPANNYA PADA KEBIJAKSANAAN EKONOMI DI NEGARA YANG BERPEREKONOMIAN KECIL DAN TERBUKA

OpenAIRE

Adwin Surya Atmadja

2001-01-01

Since the Bretton Wood sistem collapsed in early 1970s, the free floating exchange rate system has been being applied in many countries around the world. The exchange rate system choice is based on some economic advantages that will be obtained from it, considering some economic disadvantages that might be occurred. The valuation toward the advantages and disadvantages of the exchange rate system implementation exactly depends on the national economy it self, because such economy will give so...

The generalisation effects of picture exchange communication system (pecs) training for children with autism and language delay

OpenAIRE

Yoon, Jung ae

2017-01-01

The Picture Exchange Communication System (PECS) has been widely used in intervention programs to develop functional communication for children who have no or little vocal communication. Studies have shown that PECS training is effective in developing communication and social interaction (Carr & Felce, 2006; Ganz, Simpson, & Corbin-Newsome, 2007) for children with autism. However, most research on the effectiveness of PECS has been limited in several ways. Firstly, few studies have evaluated ...

The Usage of Informational Gateways for Data Exchange between Personal Data Systems of Different Classes

Directory of Open Access Journals (Sweden)

E. I. Goncharov

2010-03-01

Full Text Available When personal data exchange between informational systems takes place, one must guarantee the systems are not integrating but just interacting. This task can not be accomplished by using traditional tools such as firewalls, cryptography and so on. To solve the problem we suggest deploying of informational gateway in personal data exchange process.

Comparative Efficacy of the Picture Exchange Communication System (PECS) versus a Speech-Generating Device: Effects on Requesting Skills

Science.gov (United States)

Boesch, Miriam C.; Wendt, Oliver; Subramanian, Anu; Hsu, Ning

2013-01-01

An experimental, single-subject research study investigated the comparative efficacy of the Picture Exchange Communication System (PECS) versus a speech-generating device (SGD) in developing requesting skills for three elementary-age children with severe autism and little to no functional speech. Results demonstrated increases in requesting…

Mastering Microsoft Exchange Server 2010

CERN Document Server

McBee, Jim

2010-01-01

A top-selling guide to Exchange Server-now fully updated for Exchange Server 2010. Keep your Microsoft messaging system up to date and protected with the very newest version, Exchange Server 2010, and this comprehensive guide. Whether you're upgrading from Exchange Server 2007 SP1 or earlier, installing for the first time, or migrating from another system, this step-by-step guide provides the hands-on instruction, practical application, and real-world advice you need.: Explains Microsoft Exchange Server 2010, the latest release of Microsoft's messaging system that protects against spam and vir

The Effectiveness of the "Picture Exchange Communication System" with Nonspeaking Adults

Science.gov (United States)

Stoner, Julia B.; Beck, Ann R.; Bock, Stacey Jones; Hickey, Katherine; Kosuwan, Kullaya; Thompson, James R.

2006-01-01

"Picture Exchange Communication System" (PECS) training was implemented with 5 nonspeaking adults with mental retardation who were not currently using any type of functional communication system. A modified ABAB, single-subject design was used to assess the effectiveness of PECS in enhancing the functional communication skills of these…

Automated ion-exchange system for the radiochemical separation of the noble metals

International Nuclear Information System (INIS)

Parry, S.J.

1980-01-01

Ion-exchange separation is particularly suitable for mechanisation and automated ion exchange has been applied to the activation analysis of biological and environmental samples. In this work a system has been designed for experimental studies, which can be adapted for different modes of operation. The equipment is based on a large-volume sampler for the automatic presentation of 500 ml of liquid to a sampling probe. The sample is delivered to the ion-exchange column by means of a peristaltic pump. The purpose of this work was to automate a procedure for separating the noble metals from irradiated geological samples, for neutron-activation analysis. The process of digesting the rock sample is carried out manually in 30 min and is not suited to unattended operation. The volume of the resulting liquid sample may be 100 ml and so the manual separation step may take as long as 1.25 h per sample. The reason for automating this part of the procedure is to reduce the separation time for a group of five samples and consequently to improve the sensitivity of the analysis for radionuclides with short half-lives. This paper describes the automatic ion-exchange system and the ways in which it can be used. The mode of operation for the separation of the noble metals is given in detail. The reproducibility of the system has been assessed by repeated measurements on a standard reference matte. (author)

Development of plate-fin heat exchanger for intermediate heat exchanger of high-temperature gas cooled reactor. Fabrication process, high-temperature strength and creep-fatigue life prediction of plate-fin structure made of Hastelloy X

International Nuclear Information System (INIS)

Mizokami, Yorikata; Igari, Toshihide; Nakashima, Keiichi; Kawashima, Fumiko; Sakakibara, Noriyuki; Kishikawa, Ryouji; Tanihira, Masanori

2010-01-01

The helium/helium heat exchanger (i.e., intermediate heat exchanger: IHX) of a high-temperature gas-cooled reactor (HTGR) system with nuclear heat applications is installed between a primary system and a secondary system. IHX is operated at the highest temperature of 950degC and has a high capacity of up to 600 MWt. A plate-fin-type heat exchanger is the most suitable for IHX to improve construction cost. The purpose of this study is to develop an ultrafine plate-fin-type heat exchanger with a finer pitch fin than a conventional technology. In the first step, fabrication conditions of the ultrafine plate fin were optimized by press tests. In the second step, a brazing material was selected from several candidates through brazing tests of rods, and brazing conditions were optimized for plate-fin structures. In the third step, tensile strength, creep rupture, fatigue, and creep-fatigue tests were performed as typical strength tests for plate-fin structures. The obtained data were compared with those of the base metal and plate-fin element fabricated from SUS316. Finally, the accuracy of the creep-fatigue life prediction using both the linear cumulative damage rule and the equivalent homogeneous solid method was confirmed through the evaluation of creep-fatigue test results of plate-fin structures. (author)

Nonlocal exchange and kinetic-energy density functionals for electronic systems

International Nuclear Information System (INIS)

Glossman, M.D.; Rubio, A.; Balbas, L.C.; Alonso, J.A.

1992-01-01

The nonlocal weighted density approximation (WDA) to the exchange and kinetic-energy functionals of many electron systems proposed several years ago by Alonso and Girifalco is used to compute, within the framework of density functional theory, the ground-state electronic density and total energy of noble gas atoms and of neutral jellium-like sodium clusters containing up to 500 atoms. These results are compared with analogous calculations using the well known Thomas-Fermi-Weizsacker-Dirac (TFWD) approximations for the kinetic (TFW) and exchange (D) energy density functionals. An outstanding improvement of the total and exchange energies, of the density at the nucleus and of the expectation values is obtained for atoms within the WDA scheme. For sodium clusters the authors notice a sizeable contribution of the nonlocal effects to the total energy and to the density profiles. In the limit of very large clusters these effects should affect the surface energy of the bulk metal

Systematic generation of buffer systems for pH gradient ion exchange chromatography and their application.

Science.gov (United States)

Kröner, Frieder; Hubbuch, Jürgen

2013-04-12

pH gradient protein separations are widely used techniques in the field of protein analytics, of which isoelectric focusing is the most well known application. The chromatographic variant, based on the formation of pH gradients in ion exchange columns is only rarely applied due to the difficulties to form controllable, linear pH gradients over a broad pH range. This work describes a method for the systematic generation of buffer compositions with linear titration curves, resulting in well controllable pH gradients. To generate buffer compositions with linear titration curves an in silico method was successfully developed. With this tool, buffer compositions for pH gradient ion exchange chromatography with pH ranges spanning up to 7.5 pH units were established and successfully validated. Subsequently, the buffer systems were used to characterize the elution behavior of 22 different model proteins in cation and anion exchange pH gradient chromatography. The results of both chromatographic modes as well as isoelectric focusing were compared to describe differences in between the methods. Copyright © 2013 Elsevier B.V. All rights reserved.

Effect of wind and currents on gas exchange in an estuarine system. Final technical report, 1 August 1986-31 July 1987

International Nuclear Information System (INIS)

Broecker, W.S.; Ledwell, J.R.; Bopp, R.

1987-11-01

The objectives were to develop a non-volatile tracer to use in gas exchange experiments in laterally unconfined systems and to study applications of deliberate tracers in limnology and oceanography. Progress was made on both fronts but work on the development of the non-volatile tracer proved to be more difficult and labor intensive that anticipated so no field experiments using non-volatile tracers was performed as yet. In the search for a suitable non-volatile tracer for an ocean scale gas exchange experiment a tracer was discovered which does not have the required sensitivity for a large scale experiment, but is very easy to analyze and will be well suited for smaller experiments such as gas exchange determinations on rivers and streams. Sulfur hexafluoride, SF 6 , was used successfully as a volatile tracer along with tritium as a non-volatile tracer to study gas exchange rates from a primary stream. This is the first gas exchange experiment in which gas exchange rates were determined on a head water stream where significant groundwater input occurs along the reach. In conjunction with SF 6 , Radon-222 measurements were performed on the groundwater and in the stream. The feasibility of using a combination of SF 6 and radon is being studied to determine groundwater inputs and gas exchange of rates in streams with significant groundwater input without using a non-volatile tracer

Exchange market pressure

NARCIS (Netherlands)

Jager, H.; Klaassen, F.; Durlauf, S.N.; Blume, L.E.

2010-01-01

Currencies can be under severe pressure in the foreign exchange market, but in a fixed (or managed) exchange rate regime that is not fully visible via the change in the exchange rate. Exchange market pressure (EMP) is a concept developed to nevertheless measure the pressure in such cases. This

Domain wall engineering through exchange bias

International Nuclear Information System (INIS)

Albisetti, E.; Petti, D.

2016-01-01

The control of the structure and position of magnetic domain walls is at the basis of the development of different magnetic devices and architectures. Several nanofabrication techniques have been proposed to geometrically confine and shape domain wall structures; however, a fine tuning of the position and micromagnetic configuration is hardly achieved, especially in continuous films. This work shows that, by controlling the unidirectional anisotropy of a continuous ferromagnetic film through exchange bias, domain walls whose spin arrangement is generally not favored by dipolar and exchange interactions can be created. Micromagnetic simulations reveal that the domain wall width, position and profile can be tuned by establishing an abrupt change in the direction and magnitude of the exchange bias field set in the system. - Highlights: • Micromagnetic simulations study domain walls in exchange biased thin films. • Novel domain wall configurations can be stabilized via exchange bias. • Domain walls nucleate at the boundary of regions with different exchange bias. • Domain wall width and spin profile are controlled by tuning the exchange bias.

Standardizing exchange formats

International Nuclear Information System (INIS)

Lemmel, H.D.; Schmidt, J.J.

1992-01-01

An international network of co-operating data centres is described who maintain identical data bases which are simultaneously updated by an agreed data exchange procedure. The agreement covers ''data exchange formats'' which are compatible to the centres' internal data storage and retrieval systems which remain different, optimized at each centre to the available computer facilities and to the needs of the data users. Essential condition for the data exchange is an agreement on common procedures for the data exchange is an agreement on common procedures for the data compilation, including critical data analysis and validation. The systems described (''EXFOR'', ''ENDF'', ''CINDA'') are used for ''nuclear reaction data'', but the principles used for data compilation and exchange should be valid also for other data types. (author). 24 refs, 4 figs

Mathematical modeling and control of plate fin and tube heat exchangers

International Nuclear Information System (INIS)

Taler, Dawid

2015-01-01

Highlights: • A method for numerical modeling of plate fin and tube heat exchangers was proposed. • A numerical model of an automobile radiator was developed. • Numerical models of the radiator were compared with an exact analytical model. • A model-based control system of water outlet temperature was built and tested. • A digital proportional–integral–derivative controller of heat exchanger was tested. - Abstract: The aim of the study is to develop a new method for numerical modeling of tubular cross-flow heat exchangers. Using the method proposed in the paper, a numerical model of a car radiator was developed and implemented in a digital control system of the radiator. To evaluate the accuracy of the numerical method proposed in the paper, the numerical model of the car radiator was compared with an analytic model. The proposed method based on a finite volume method and integral averaging of gas temperature across a tube row is appropriate for modeling of plate fin and tube heat exchangers, especially for exchangers in which substantial gas temperature differences in one tube row occur. The target of control is to regulate the number of fan revolutions per minute so that the water temperature at the heat exchanger outlet is equal to a set value. Two control techniques were developed. The first is based on the numerical model of the heat exchanger developed in the paper while the second is a digital proportional–integral–derivative control. The first control method is very stable. The digital proportional–integral–derivative controller becomes unstable when the water volume flow rate varies considerably. The developed techniques were implemented in digital control system of the water exit temperature in a plate fin and tube heat exchanger. The measured exit temperature of the water was very close to the set value of the temperature if the first method was used. The experiments show that the proportional–integral–derivative controller

Development of suitability maps for ground-coupled heat pump systems using groundwater and heat transport models

Energy Technology Data Exchange (ETDEWEB)

Fujii, Hikari; Itoi, Ryuichi [Department of Earth Resources Engineering, Faculty of Engineering, Kyushu University, Motooka 744, Nishi-ku, Fukuoka 819-0395 (Japan); Inatomi, Tadasuke [YBM Co. Ltd., Kishiyama 589-10 Kitahata, Karatsu 847-1211 (Japan); Uchida, Youhei [Geological Survey of Japan, AIST Tsukuba Central 7, Tsukuba 305-8567 (Japan)

2007-10-15

The thermophysical properties of subsurface materials (soils, sediments and rocks) and groundwater flow strongly affect the heat exchange rates of ground heat exchangers (GHEs). These rates can be maximized and the installation costs of the ground-coupled heat pump (GCHP) systems reduced by developing suitability maps based on local geological and hydrological information. Such maps were generated for the Chikushi Plain (western Japan) using field-survey data and a numerical modeling study. First, a field-wide groundwater model was developed for the area and the results matched against measured groundwater levels and vertical temperature profiles. Single GHE models were then constructed to simulate the heat exchange performance at different locations in the plain. Finally, suitability maps for GCHP systems were prepared using the results from the single GHE models. Variations in the heat exchange rates of over 40% revealed by the map were ascribed to differences in the GHE locations, confirming how important it is to use appropriate thermophysical data when designing GCHP systems. (author)

Development of techniques to dispose of the Windscale AGR heat exchangers

International Nuclear Information System (INIS)

Crossley, H.; Wakefield, J.R.

1991-01-01

In a gas-cooled nuclear power plant the gas side of the heat exchanger tubes becomes contaminated with radioactive deposits carried from the reactor in the coolant stream. In order to dispose of the heat exchangers in the safest and most cost-effective way during plant decommissioning, the deposits have to be removed. In situ chemical decontamination is considered to be the only viable method. This paper describes the research and development of chemical decontamination methods for the Windscale AGR heat exchangers, and the testing of a selected method on an in situ superheater. The research involved characterization of tube corrosion and radioactivity deposits, laboratory testing of chemical reagents on actual tube samples, and the provision and operation of a plant to apply the selected reagent. Disposal of radioactive effluent is an important consideration in chemical decontamination and in the present case was the major factor in determining the process

Heat exchanger selection and design analyses for metal hydride heat pump systems

DEFF Research Database (Denmark)

Mazzucco, Andrea; Voskuilen, Tyler G.; Waters, Essene L.

2016-01-01

This study presents a design analysis for the development of highly efficient heat exchangers within stationary metal hydride heat pumps. The design constraints and selected performance criteria are applied to three representative heat exchangers. The proposed thermal model can be applied to select...... the most efficient heat exchanger design and provides outcomes generally valid in a pre-design stage. Heat transfer effectiveness is the principal performance parameter guiding the selection analysis, the results of which appear to be mildly (up to 13%) affected by the specific Nusselt correlation used....... The thermo-physical properties of the heat transfer medium and geometrical parameters are varied in the sensitivity analysis, suggesting that the length of independent tubes is the physical parameter that influences the performance of the heat exchangers the most. The practical operative regions for each...

Professional ideologies and the development of syringe exchange: Wales as a case study.

Science.gov (United States)

Keene, J M; Stimson, G V

1997-12-01

This paper is derived from an evaluative study of HIV prevention programs for drug injectors across Wales. It considers how different professional territories and ideologies, concepts of drug misuse and models of HIV prevention may influence policy development. The research involved monitoring the introduction and development of agency and community based syringe exchange schemes and initiatives taken by community pharmacists. Interviews with staff, managers and administrators, and descriptions of service history, development and delivery inform the discussion. HIV prevention varied in different areas of Wales depending on the particular professional group involved, local ideologies regarding drug use treatment, and the extent to which HIV prevention was seen either as a specialist area of expertise and specific remit of drug workers or a generic health care task. Drug agencies with an abstinence policy rejected syringe exchange; instead, prevention in those areas developed in ad hoc ways as health care workers and pharmacists attempted to develop a community based service. Drug agencies with a pre-existing harm minimisation model easily integrated syringe exchange into their work and played the major part in establishing the service, but there was difficulty in extending it beyond their professional caseloads. As there were disincentives to use treatment agencies, and their catchment areas were limited, these factors influenced effective service provision.

Eddy current testing of heat exchangers tubes

International Nuclear Information System (INIS)

Gouez, J.F.; Rieusset, A.; Groix, F.

An automatic system for Eddy Current testing of heat exchangers tubes of warships was developed. The advantages are an exposure of the controller limited at the time required to put in place the system and a reduced time of control [fr

Heat exchanger

International Nuclear Information System (INIS)

Leigh, D.G.

1976-01-01

The arrangement described relates particularly to heat exchangers for use in fast reactor power plants, in which heat is extracted from the reactor core by primary liquid metal coolant and is then transferred to secondary liquid metal coolant by means of intermediate heat exchangers. One of the main requirements of such a system, if used in a pool type fast reactor, is that the pressure drop on the primary coolant side must be kept to a minimum consistent with the maintenance of a limited dynamic head in the pool vessel. The intermediate heat exchanger must also be compact enough to be accommodated in the reactor vessel, and the heat exchanger tubes must be available for inspection and the detection and plugging of leaks. If, however, the heat exchanger is located outside the reactor vessel, as in the case of a loop system reactor, a higher pressure drop on the primary coolant side is acceptable, and space restriction is less severe. An object of the arrangement described is to provide a method of heat exchange and a heat exchanger to meet these problems. A further object is to provide a method that ensures that excessive temperature variations are not imposed on welded tube joints by sudden changes in the primary coolant flow path. Full constructional details are given. (U.K.)

18 CFR 301.4 - Exchange Period Average System Cost determination.

Science.gov (United States)

2010-04-01

... REGULATORY COMMISSION, DEPARTMENT OF ENERGY REGULATIONS FOR FEDERAL POWER MARKETING ADMINISTRATIONS AVERAGE... Period and extend through four (4) years after the Exchange Period. The load forecast for Contract System... Utility's ASC until the change in service territory takes place. (g) ASC determination for Consumer-owned...

Ion-Exchange Processes and Mechanisms in Glasses

International Nuclear Information System (INIS)

McGrail, B.P.; Icenhower, J.P.; Darab, J.G.; Shuh, D.K.; Baer, D.R.; Shutthanandan, V.; Thevuthasan, S.; Engelhard, M.H.; Steele, J.L.; Rodriguez, E.A.; Liu, P.; Ivanov, K.E.; Booth, C.H.; Nachimuthu, P.

2001-01-01

[14,15]. Renewed interest in alkali ion exchange reactions has come about because of interest in development of durable Na-rich silicate glasses for immobilization of low-activity waste (LAW) at Hanford, Washington [16] and high-level wastes in China [17]. In reactive transport simulations of a LAW glass disposed in a shallow subsurface facility, Chen, McGrail, and Engel [18] showed that ion-exchange reactions increased the radionuclide release rate by over two orders of magnitude when compared with simulations where ion exchange was excluded. Sheng, Luo, and Tang [17] conducted static tests in a simulated groundwater and showed that alkali ion exchange was the dominant release mechanism over a large temperature range. Although the significance of alkali ion exchange reactions in long-term disposal system performance has now been recognized, the fundamental processes and mechanisms controlling the exchange reactions are still remarkably poorly understood, especially with regard to how glass structure affects alkali ion exchange kinetics. Experimental studies of Na release from various simple silicate glasses are numerous [19-23]. However, in all previous studies of which we are aware, no attempt was made to distinguish between M + release through alkali exchange versus matrix dissolution. The release rate of alkali in all of the early work was convoluted by contributions from matrix dissolution, which dominates in dilute solutions. Also, none of the previous studies attempted to define the relationship, if any, between glass structure (composition) and the kinetics of the ion exchange reaction. The motivation behind this Environmental Management Science Project (EMSP) is to develop a better understanding of how glass structure impacts sodium ion exchange so that improved glasses can be developed. Development of low ion-exchange rate glasses may also permit engineers to use higher loadings in nuclear waste glasses, which would result in substantial savings in

Interoperability and models for exchange of data between information systems in public administration

Science.gov (United States)

Glavev, Victor

2016-12-01

The types of software applications used by public administrations can be divided in three main groups: document management systems, record management systems and business process systems. Each one of them generates outputs that can be used as input data to the others. This is the main reason that requires exchange of data between these three groups and well defined models that should be followed. There are also many other reasons that will be discussed in the paper. Interoperability is a key aspect when those models are implemented, especially when there are different manufactures of systems in the area of software applications used by public authorities. The report includes examples of implementation of models for exchange of data between software systems deployed in one of the biggest administration in Bulgaria.

Poster 29. Modelling of ion exchange processes in ultrapure water

International Nuclear Information System (INIS)

Berg, A.; Torstenfelt, B.; Fejes, P.; Foutch, G.L.

1992-01-01

The ion exchange process of the Reactor Water Clean-up (RWCU) system has been studied to better use the maximum possible exchange capacity of the ion exchange resin. Laboratory data have been correlated with computer simulations of the ion exchange process. Data were correlated using a mixed-bed ion exchange model for ultralow ionic concentrations developed at Oklahoma State University. Experimental results of the ion exchange column operation in the concentration range of 10 -3 M boric acid is compared with the simulated performance predicted by the computer model. The model is found to agree reasonably well with the data. (author)

Augmentative and Alternative Communication in Autism: A Comparison of the Picture Exchange Communication System and Speech-Output Technology

Science.gov (United States)

Boesch, Miriam Chacon

2011-01-01

The purpose of this comparative efficacy study was to investigate the Picture Exchange Communication System (PECS) and a speech-generating device (SGD) in developing requesting skills, social-communicative behavior, and speech for three elementary-age children with severe autism and little to no functional speech. Requesting was selected as the…

A Multidimensional System for Phosphopeptide Analysis Using TiO{sub 2} Enrichment and Ion-exchange Chromatography with Mass Spectrometry

Energy Technology Data Exchange (ETDEWEB)

Cho, Kun; Yoo, Jisun; Kim, Eunmin; Kim, Jin Young; Kim, Young Hwan; Yoo, Jong Shin [Korea Basic Science Institute, Ochang (Korea, Republic of); Oh, Han Bin [Sogang Univ., Seoul (Korea, Republic of)

2012-10-15

Although offline enrichment of phosphorylated peptides is widely used, enrichment for phosphopeptides using TiO{sub 2} is often performed manually, which is labor-intensive and can lead to irreproducible results. To address the problems associated with offline enrichment and to improve the effectiveness of phosphopeptide detection, we developed an automated online enrichment system for phosphopeptide analysis. A standard protein mixture comprising BSA, fetuin, crystalline, α-casein and β-casein, and ovalbumin was assessed using our new system. Our multidimensional system has four main parts: a sample pump, a 20-mm TiO{sub 2}-based column, a weak anion-exchange, and a strong cation-exchange (2:1 WAX:SCX) separation column with LC/MS. Phosphorylated peptides were successfully detected using the TiO{sub 2}-based online system with little interference from nonphosphorylated peptides. Our results confirmed that our online enrichment system is a simple and efficient method for detecting phosphorylated peptides.

HESTIA Commodities Exchange Pallet and Sounding Rocket Test Stand

Science.gov (United States)

Chaparro, Javier

2013-01-01

During my Spring 2016 internship, my two major contributions were the design of the Commodities Exchange Pallet and the design of a test stand for a 100 pounds-thrust sounding rocket. The Commodities Exchange Pallet is a prototype developed for the Human Exploration Spacecraft Testbed for Integration and Advancement (HESTIA) program. Under the HESTIA initiative the Commodities Exchange Pallet was developed as a method for demonstrating multi-system integration thru the transportation of In-Situ Resource Utilization produced oxygen and water to a human habitat. Ultimately, this prototype's performance will allow for future evaluation of integration, which may lead to the development of a flight capable pallet for future deep-space exploration missions. For HESTIA, my main task was to design the Commodities Exchange Pallet system to be used for completing an integration demonstration. Under the guidance of my mentor, I designed, both, the structural frame and fluid delivery system for the commodities pallet. The fluid delivery system includes a liquid-oxygen to gaseous-oxygen system, a water delivery system, and a carbon-dioxide compressors system. The structural frame is designed to meet safety and transportation requirements, as well as the ability to interface with the ER division's Portable Utility Pallet. The commodities pallet structure also includes independent instrumentation oxygen/water panels for operation and system monitoring. My major accomplishments for the commodities exchange pallet were the completion of the fluid delivery systems and the structural frame designs. In addition, parts selection was completed in order to expedite construction of the prototype, scheduled to begin in May of 2016. Once the commodities pallet is assembled and tested it is expected to complete a fully integrated transfer demonstration with the ISRU unit and the Environmental Control and Life Support System test chamber in September of 2016. In addition to the development of

Simulation of embedded heat exchangers of solar aided ground source heat pump system

Institute of Scientific and Technical Information of China (English)

王芳; 郑茂余; 邵俊鹏; 李忠建

2008-01-01

Aimed at unbalance of soil temperature field of ground source heat pump system, solar aided energy storage system was established. In solar assisted ground-source heat pump (SAGSHP) system with soil storage, solar energy collected in three seasons was stored in the soil by vertical U type soil exchangers. The heat abstracted by the ground-source heat pump and collected by the solar collector was employed to heating. Some of the soil heat exchangers were used to store solar energy in the soil so as to be used in next winter after this heating period; and the others were used to extract cooling energy directly in the soil by circulation pump for air conditioning in summer. After that solar energy began to be stored in the soil and ended before heating period. Three dimensional dynamic numerical simulations were built for soil and soil heat exchanger through finite element method. Simulation was done in different strata month by month. Variation and restoration of soil temperature were studied. Economy and reliability of long term SAGSHP system were revealed. It can be seen that soil temperature is about 3 ℃ higher than the original one after one year’s running. It is beneficial for the system to operate for long period.

The Impact of the Picture Exchange Communication System on Requesting and Speech Development in Preschoolers with Autism Spectrum Disorders and Similar Characteristics

Science.gov (United States)

Ganz, Jennifer B.; Simpson, Richard L.; Corbin-Newsome, Jawanda

2008-01-01

By definition children with autism spectrum disorders (ASD) experience difficulty understanding and using language. Accordingly, visual and picture-based strategies such as the Picture Exchange Communication System (PECS) show promise in ameliorating speech and language deficits. This study reports the results of a multiple baseline across…

Lab-scale experiment of a closed thermochemical heat storage system including honeycomb heat exchanger

International Nuclear Information System (INIS)

Fopah-Lele, Armand; Rohde, Christian; Neumann, Karsten; Tietjen, Theo; Rönnebeck, Thomas; N'Tsoukpoe, Kokouvi Edem; Osterland, Thomas; Opel, Oliver

2016-01-01

A lab-scale thermochemical heat storage reactor was developed in the European project “thermal battery” to obtain information on the characteristics of a closed heat storage system, based on thermochemical reactions. The present type of storage is capable of re-using waste heat from cogeneration system to produce useful heat for space heating. The storage material used was SrBr 2 ·6H 2 O. Due to agglomeration or gel-like problems, a structural element was introduced to enhance vapour and heat transfer. Honeycomb heat exchanger was designed and tested. 13 dehydration-hydration cycles were studied under low-temperature conditions (material temperatures < 100 °C) for storage. Discharging was realized at water vapour pressure of about 42 mbar. Temperature evolution inside the reactor at different times and positions, chemical conversion, thermal power and overall efficiency were analysed for the selected cycles. Experimental system thermal capacity and efficiency of 65 kWh and 0.77 are respectively obtained with about 1 kg of SrBr 2 ·6H 2 O. Heat transfer fluid recovers heat at a short span of about 43 °C with an average of 22 °C during about 4 h, acceptable temperature for the human comfort (20 °C on day and 16 °C at night). System performances were obtained for a salt bed energy density of 213 kWh·m 3 . The overall heat transfer coefficient of the honeycomb heat exchanger has an average value of 147 W m −2  K −1 . Though promising results have been obtained, ameliorations need to be made, in order to make the closed thermochemical heat storage system competitive for space heating. - Highlights: • Lab-scale thermochemical heat storage is designed, constructed and tested. • The use of honeycomb heat exchanger as a heat and vapour process enhancement. • Closed system (1 kg SrBr 2 ·6H 2 O) able to give back 3/4 of initial thermal waste energy. • System storage capacity and thermal efficiency are respectively 65 kWh and 0.77. �

Selection of engineering materials for heat exchangers (An expert system approach)

International Nuclear Information System (INIS)

Ahmed, K.; Abou-Ali, M.; Bassuni, M.

1997-01-01

The materials selection as a part of the design process of the heat exchangers is one of the most important steps in the whole industry. The clear recognition of the service requirements of the different types of the heat exchangers is very important to select the adequate and economic materials to meet such requirements. of course the manufacturer should ensure that failure does not occur in service specially it is one of the main and fetal component of the nuclear reactor, pressurized water type (PWR). It is necessary to know the possible mechanisms of failure. Also the achievement of the materials selection using the expert system approach in the process sequence of heat exchanger manufacturing is introduced. Different parameters and requirements controlling each process and the linkage between these parameters and the final product will be shown. 2 figs., 3 tabs

Development of integrated CAD system PV-1

International Nuclear Information System (INIS)

Miyamoto, Hitoshi; Ogawa, Kazuya; Shibata, Masayoshi.

1997-01-01

An integrated CAD system for pressure vessels, such as heat exchangers, drums, towers, jacketed vessels, and tanks, has been developed. The system is operated by MS-DOS personal computers combined in a LAN. Pressure vessel designers can work watching using the computer display because the system automatically manages design work, on a common data base. The project team members in other sections, such as production, cost control, and design, have the same data concurrently. Personal computers unite the 3D CAD system, and the generated design with detail dimensions and shapes is stored in the 3D CAD system automatically. The system has promoted higher design quality and greatly reduced design cost. (author)

Efficient data exchange: Integrating a vector GIS with an object-oriented, 3-D visualization system

International Nuclear Information System (INIS)

Kuiper, J.; Ayers, A.; Johnson, R.; Tolbert-Smith, M.

1996-01-01

A common problem encountered in Geographic Information System (GIS) modeling is the exchange of data between different software packages to best utilize the unique features of each package. This paper describes a project to integrate two systems through efficient data exchange. The first is a widely used GIS based on a relational data model. This system has a broad set of data input, processing, and output capabilities, but lacks three-dimensional (3-D) visualization and certain modeling functions. The second system is a specialized object-oriented package designed for 3-D visualization and modeling. Although this second system is useful for subsurface modeling and hazardous waste site characterization, it does not provide many of the, capabilities of a complete GIS. The system-integration project resulted in an easy-to-use program to transfer information between the systems, making many of the more complex conversion issues transparent to the user. The strengths of both systems are accessible, allowing the scientist more time to focus on analysis. This paper details the capabilities of the two systems, explains the technical issues associated with data exchange and how they were solved, and outlines an example analysis project that used the integrated systems

Performance Improvement Based Authentication Protocol for Intervessel Traffic Service Data Exchange Format Protocol Based on U-Navigation System in WoT Environment

Directory of Open Access Journals (Sweden)

Byunggil Lee

2014-01-01

Full Text Available International Association of Lighthouse Authorities (IALA is developing the standard intersystem VTS exchange format (IVEF protocol for exchange of navigation and vessel information between VTS systems and between VTS and vessels. VTS (vessel traffic system is an important marine traffic monitoring system which is designed to improve the safety and efficiency of navigation and the protection of the marine environment. And the demand of Inter-VTS networking has been increased for realization of e-Navigation as shore side collaboration for maritime safety. And IVEF (inter-VTS data exchange format for inter-VTS network has become a hot research topic of VTS system. Currently, the IVEF developed by the International Association of Lighthouse Authorities (IALA does not include any highly trusted certification technology for the connectors. The output of standardization is distributed as the IALA recommendation V-145, and the protocol is implemented with an open source. The IVEF open source, however, is the code used to check the functions of standard protocols. It is too slow to be used in the field and requires a large memory. And the vessel traffic information requires high security since it is highly protected by the countries. Therefore, this paper suggests the authentication protocol to increase the security of the VTS systems using the main certification server and IVEF.

Working parameters affecting earth-air heat exchanger (EAHE) system performance for passive cooling: A review

Science.gov (United States)

Darius, D.; Misaran, M. S.; Rahman, Md. M.; Ismail, M. A.; Amaludin, A.

2017-07-01

The study on the effect of the working parameters such as pipe material, pipe length, pipe diameter, depth of burial of the pipe, air flow rate and different types of soils on the thermal performance of earth-air heat exchanger (EAHE) systems is very crucial to ensure that thermal comfort can be achieved. In the past decade, researchers have performed studies to develop numerical models for analysis of EAHE systems. Until recently, two-dimensional models replaced the numerical models in the 1990s and in recent times, more advanced analysis using three-dimensional models, specifically the Computational Fluid Dynamics (CFD) simulation in the analysis of EAHE system. This paper reviews previous models used to analyse the EAHE system and working parameters that affects the earth-air heat exchanger (EAHE) thermal performance as of February 2017. Recent findings on the parameters affecting EAHE performance are also presented and discussed. As a conclusion, with the advent of CFD methods, investigational work have geared up to modelling and simulation work as it saves time and cost. Comprehension of the EAHE working parameters and its effect on system performance is largely established. However, the study on type of soil and its characteristics on the performance of EAHEs systems are surprisingly barren. Therefore, future studies should focus on the effect of soil characteristics such as moisture content, density of soil, and type of soil on the thermal performance of EAHEs system.

Small Column Ion Exchange

International Nuclear Information System (INIS)

Huff, Thomas

2010-01-01

Small Column Ion Exchange (SCIX) leverages a suite of technologies developed by DOE across the complex to achieve lifecycle savings. Technologies are applicable to multiple sites. Early testing supported multiple sites. Balance of SRS SCIX testing supports SRS deployment. A forma Systems Engineering Evaluation (SEE) was performed and selected Small Column Ion Exchange columns containing Crystalline Silicotitanate (CST) in a 2-column lead/lag configuration. SEE considered use of Spherical Resorcinol-Formaldehyde (sRF). Advantages of approach at SRS include: (1) no new buildings, (2) low volume of Cs waste in solid form compared to aqueous strip effluent; and availability of downstream processing facilities for immediate processing of spent resin.

Development of gas-solid direct contact heat exchanger by use of axial flow cyclone

Energy Technology Data Exchange (ETDEWEB)

Shimizu, Akihiko; Yokomine, Takehiko [Kyushu University (Japan). Interdisciplinary Graduate School of Engineering Sciences; Nagafuchi, Tatsuro [Miura Co. Ltd., Matsuyamashi (Japan)

2004-10-01

A heat exchanger between particulate or granular materials and gas is developed. It makes use of a swirling gas flow similar to the usual cyclone separators but the difference from them is that the swirl making gas is issued into the cyclone chamber with downward axial velocity component. After it turns the flow direction near the bottom of the chamber, the low temperature gas receives heat from high temperature particles supplied from above at the chamber's center. Through this configuration, a direct contact and quasi counter-flow heat exchange pattern is realized so that the effective recovery of heat carried by particles is achieved. A model heat exchanger was manufactured via several numerical experiments and its performances of heat exchange as well as particle recovery were examined. Attaching a small particle diffuser below the particle-feeding nozzle brought about a drastic improvement of the heat exchange performance without deteriorating the particle recovery efficiency. The outlet gas temperature much higher than the particle outlet temperature was finally obtained, which is never realized in the parallel flow heat exchanger. (author)

Training Paraprofessionals to Implement the Picture Exchange Communication System (PECS)

Science.gov (United States)

Sloman, Glenn Matthew

2010-01-01

Based on Skinner's "Verbal Behavior" (1957), the picture exchange communication system (PECS) was designed to teach children with autism functional verbal behavior. Much research has demonstrated the effectiveness and efficiency of PECS in building verbal behavior. However, because PECS training is typically presented in a group format and later…

Two-dimensional exchange and nutation exchange nuclear quadrupole resonance spectroscopy

International Nuclear Information System (INIS)

Mackowiak, M.; Sinyavsky, N.; Velikite, N.; Nikolaev, D.

2002-01-01

A theoretical treatment of the 2D exchange NQR pulse sequence is presented and applied to a quantitative study of exchange processes in molecular crystals. It takes into account the off-resonance irradiation, which critically influences the spin dynamics. The response to the three-pulse sequence of a system of spins I=3/2 in zero applied field, experiencing electric quadrupole couplings, is analysed. The mixing dynamics by exchange and the expected cross-peak intensities as a function of the frequency offset have been derived. The theory is illustrated by a study of the optimization procedure, which is of crucial importance for the detection of the cross- and diagonal-peaks in a 2D-exchange spectrum. The systems investigated are hexachloroethane and tetrachloroethylene. They show threefold and twofold reorientational jumps about the carbon-carbon axis, respectively. A new method of direct determination of rotational angles based on two-dimensional nutation exchange NQR spectroscopy is proposed. The method involves the detection of exchange processes through NQR nutation spectra recorded after the mixing interval. The response of a system of spins I=3/2 to the three-pulse sequence with increasing pulse widths is analyzed. It is shown that the 2D-nutation exchange NQR spectrum exhibits characteristic ridges, which manifest the motional mechanism in a model-independent fashion. The angles through which the molecule rotates can be read directly from elliptical ridges in the 2D spectrum, which are also sensitive to the asymmetry parameter of the electric field gradient tensor. (orig.)

Borehole heat exchangers: Longterm operational characteristics of a decentral geothermal heating system

International Nuclear Information System (INIS)

Rybach, L.; Eugster, W.J.; Hopkirk, R.J.; Kaelin, B.

1992-01-01

The heat pump-coupled borehole heat exchanger (BHE) is an efficient and small geothermal energy system for supplying heat typically to a single dwelling house. The long-term performance characteristics have been investigated by computer simulations. The numerical models were validated by measurements at instrumented BHE facilities. The results show the development of a new thermal equilibrium state after the first few years of BHE operation. The thermal influence is limited to the first few meters of the ground surrounding the BHE. The BHE could be scaled up in order to be installed in deep 'failed' holes (e.g. dry geothermal or hydrocarbon exploration holes)

Thermal energy storage systems using fluidized bed heat exchangers

Science.gov (United States)

Weast, T.; Shannon, L.

1980-06-01

A rotary cement kiln and an electric arc furnace were chosen for evaluation to determine the applicability of a fluid bed heat exchanger (FBHX) for thermal energy storage (TES). Multistage shallow bed FBHX's operating with high temperature differences were identified as the most suitable for TES applications. Analysis of the two selected conceptual systems included establishing a plant process flow configuration, an operational scenario, a preliminary FBHX/TES design, and parametric analysis. A computer model was developed to determine the effects of the number of stages, gas temperatures, gas flows, bed materials, charge and discharge time, and parasitic power required for operation. The maximum national energy conservation potential of the cement plant application with TES is 15.4 million barrels of oil or 3.9 million tons of coal per year. For the electric arc furnance application the maximum national conservation potential with TES is 4.5 million barrels of oil or 1.1 million tons of coal per year. Present time of day utility rates are near the breakeven point required for the TES system. Escalation of on-peak energy due to critical fuel shortages could make the FBHX/TES applications economically attractive in the future.

Development of energy economic ventilation system with heat recovery in dwellings; Udvikling af energioekonomisk ventilationsloesning med varmegenvinding til boliger

Energy Technology Data Exchange (ETDEWEB)

Drivsholm, C.; Olsen, Hans; Groenborg Larsen, C.; Jensen, John Steen; Rammer Nielsen, T.; Kragh, J.; Svendsen, Svend

2005-07-01

This report describes and documents the development of a counter flow heat exchanger with efficiency of approximately 90% and a highly efficient axial fan both developed for small mechanical ventilation systems for use in single family houses. The report also treats problems concerning condensation and ice formation in efficient counter flow heat exchangers. The influence of condensate and ice is investigated by measurements on an efficient heat exchanger and different strategies for de-icing are tested. A computer program is developed to calculate how condensation and frost influence the heat exchange under stationary conditions. In the project a counter flow heat exchanger of aluminium is developed with a calculated efficiency of approximately 90%. The heat exchanger is hereby legal for ventilation of more than one fire section. CAD drawings of the exchanger are coded to a CNC milling machine and two cylinders (a positive and a negative mould) are produced. The joints of the heat exchanger are glued and placed in a protecting aluminium frame. (BA)

DEVELOPMENT OF HOLE RECOGNITION SYSTEM FROM STEP FILE

Directory of Open Access Journals (Sweden)

C. F. Tan

2017-11-01

Full Text Available This paper describes the development of Hole Recognition System (HRS for Computer-Aided Process Planning (CAPP using a neutral data format produced by CAD system. The geometrical data of holes is retrieved from STandard for the Exchange of Product model data (STEP. Rule-based algorithm is used during recognising process. Current implementation of feature recognition is limited to simple hole feat ures. Test results are presented to demonstrate the capabilities of the feature recognition algorithm.

Temporal Dynamics of Social Exchange and the Development of Solidarity: "Testing the Waters" versus "Taking a Leap of Faith"

Science.gov (United States)

Kuwabara, Ko; Sheldon, Oliver

2012-01-01

In their concerted efforts to unpack the microprocesses that transform repeated exchanges into an exchange relation, exchange theorists have paid little attention to how actors perceive changes and dynamics in exchanges over time. We help fill this gap by studying how temporal patterns of exchange affect the development of cohesion. Some exchange…

New waste heat district heating system with combined heat and power based on absorption heat exchange cycle in China

International Nuclear Information System (INIS)

Sun Fangtian; Fu Lin; Zhang Shigang; Sun Jian

2012-01-01

A new waste heat district heating system with combined heat and power based on absorption heat exchange cycle (DHAC) was developed to increase the heating capacity of combined heat and power (CHP) through waste heat recovery, and enhance heat transmission capacity of the existing primary side district heating network through decreasing return water temperature by new type absorption heat exchanger (AHE). The DHAC system and a conventional district heating system based on CHP (CDH) were analyzed in terms of both thermodynamics and economics. Compared to CDH, the DHAC increased heating capacity by 31% and increased heat transmission capacity of the existing primary side district heating network by 75%. The results showed that the exergetic efficiency of DHAC was 10.41% higher and the product exergy monetary cost was 36.6¥/GJ less than a CHD. DHAC is an effective way to increase thermal utilization factor of CHP, and to reduce district heating cost. - Highlights: ► Absorption heat pumps are used to recover waste heat in CHP. ► Absorption heat exchanger can reduce exergy loss in the heat transfer process. ► New waste heat heating system (DHAC) can increase heating capacity of CHP by 31%. ► DHAC can enhance heat transmission capacity of the primary pipe network by 75%. ► DHAC system has the higher exergetic efficiency and the better economic benefit.

A computational model of insect discontinuous gas exchange: A two-sensor, control systems approach.

Science.gov (United States)

Grieshaber, Beverley J; Terblanche, John S

2015-06-07

The insect gas exchange system is characterised by branching air-filled tubes (tracheae/tracheoles) and valve-like structures in their outer integument (spiracles) which allow for a periodic gas exchange pattern known as the discontinuous gas exchange cycle (DGC). The DGC facilitates the temporal decoupling of whole animal gas exchange from cellular respiration rates and may confer several physiological benefits, which are nevertheless highly controversial (primarily reduction of cellular oxidative damage and/or respiratory water saving). The intrinsic and extrinsic factors influencing DGCs are the focus of extensive ongoing research and little consensus has been reached on the evolutionary genesis or mechanistic costs and benefits of the pattern. Despite several hypotheses and much experimental and evolutionary biology research, a mechanistic physical model, which captures various key elements of the DGC pattern, is currently lacking. Here, we present a biologically realistic computational, two-sensor DGC model (pH/carbon dioxide and oxygen setpoints) for an Orthopteran gas exchange system, and show computationally for the first time that a control system of two interacting feedback loops is capable of generating a full DGC pattern with outputs which are physiologically realistic, quantitatively matching experimental results found in this taxonomic model elsewhere. A finite-element mathematical approach is employed and various trigger sets are considered. Parameter sensitivity analyses suggest that various aspects of insect DGC are adequately captured in this model. In particular, with physiologically relevant input parameters, the full DGC pattern is induced; and the phase durations, endotracheal carbon dioxide partial pressure ranges, and pH fluctuations which arise are physically realistic. The model results support the emergent property hypothesis for the existence of DGC, and indicate that asymmetric loading and off-loading (hysteresis) in one of the sensor

Radiant exchange in partially specular architectural environments

Science.gov (United States)

Beamer, C. Walter; Muehleisen, Ralph T.

2003-10-01

The radiant exchange method, also known as radiosity, was originally developed for thermal radiative heat transfer applications. Later it was used to model architectural lighting systems, and more recently it has been extended to model acoustic systems. While there are subtle differences in these applications, the basic method is based on solving a system of energy balance equations, and it is best applied to spaces with mainly diffuse reflecting surfaces. The obvious drawback to this method is that it is based around the assumption that all surfaces in the system are diffuse reflectors. Because almost all architectural systems have at least some partially specular reflecting surfaces in the system it is important to extend the radiant exchange method to deal with this type of surface reflection. [Work supported by NSF.

Control and prevention of ice formation and accretion on heat exchangers for ventilation systems

DEFF Research Database (Denmark)

Rahimi, Maral; Afshari, Alireza

2015-01-01

In cold climates, the application of mechanical ventilation systems with heat recovery like are airto-air exchangers is used for reducing energy consumption for heating buildings by transferring heat exhausted air to supply air. However, increase efficiency of heat exchanger results in lower...... exhaust air temperatures and Ice formation on heat exchanger fins, which can cause problem and is not favourable. Therefore, prevention and control of ice formation on heat exchangers is necessary. The existing methods are divided into two different methods: active and passive ice control methods....... The active methods are e.g. bypass, recirculation, preheating. The passive methods relate to the surface characteristics of the heat exchanger fins as they have effect on ice formation in initial phase. All these methods have varying levels of success, cost, and effectiveness, which are depending on the heat...

Marriage exchanges, seed exchanges, and the dynamics of manioc diversity.

Science.gov (United States)

Delêtre, Marc; McKey, Doyle B; Hodkinson, Trevor R

2011-11-08

The conservation of crop genetic resources requires understanding the different variables-cultural, social, and economic-that impinge on crop diversity. In small-scale farming systems, seed exchanges represent a key mechanism in the dynamics of crop genetic diversity, and analyzing the rules that structure social networks of seed exchange between farmer communities can help decipher patterns of crop genetic diversity. Using a combination of ethnobotanical and molecular genetic approaches, we investigated the relationships between regional patterns of manioc genetic diversity in Gabon and local networks of seed exchange. Spatially explicit Bayesian clustering methods showed that geographical discontinuities of manioc genetic diversity mirror major ethnolinguistic boundaries, with a southern matrilineal domain characterized by high levels of varietal diversity and a northern patrilineal domain characterized by low varietal diversity. Borrowing concepts from anthropology--kinship, bridewealth, and filiation--we analyzed the relationships between marriage exchanges and seed exchange networks in patrilineal and matrilineal societies. We demonstrate that, by defining marriage prohibitions, kinship systems structure social networks of exchange between farmer communities and influence the movement of seeds in metapopulations, shaping crop diversity at local and regional levels.

Municipal and Treasury Bond Market Segments Development at Bucharest Stock Exchange

Directory of Open Access Journals (Sweden)

Cornelia POP

2012-02-01

Full Text Available The current paper reviews the developments that took place, starting with November 2001, inside the Romanian Municipal and Treasury bond market segments at the Bucharest Stock Exchange. The development of a debt market has as a main objective to encourage the central, regional and local governments to consider bond finance as an important way for regional and local project investments; it could enhance the quality and the efficiency of financed projects and encourage long term financial planning. The relatively modest profile of the Romanian public bond sector at Bucharest Stock Exchange can be explained by the late introduction of the T-bonds (7 years after the bond sector was launched. Lacking the benchmark the T-bonds could offer, it was only natural for investors to avoid the (Municipal bond sector. The development of the domestic public bond sector is expected to continue in the years to come, mainly if through bond financing the central/regional and local authorities will support investment projects that will trigger and/or generate economic development.

Exchange reactions in the systems of alkali metal, silver and thallium, sulfates, niobates and tantalates

International Nuclear Information System (INIS)

Belyaev, I.N.; Lupejko, T.G.; Nalbandyan, V.B.; Abanina, E.V.

1978-01-01

Investigated are exchange interactions in diagonal cross sections of twenty triple mutual systems with A and A' cations and SO 4 and MO 3 anions where A and A'-Li, Na, K, Ag, Tl, M-Nb, Ta using the methods of X-ray phase, chemical and differential thermal analyses. Exchange reaction between crystal complex oxide and melted salt are effective synthesis method. These reactions in particular permitted to obtain pure AgNbO 3 , AgTaO 3 and their solid solutions at temperatures hundreds degrees lower than in displacement reactions. Equilibrium samples of AMO 3 -A'MO 3 systems, continuous or discontinuous solid solutions, compounds (except NaMO 3 -KMO 3 , and also LiTaO 3 -KTaO 3 ) are formed in exchange reactions when there is sulfate shortage. Thus, exchange reactions can be applied for solid solution synthesis, and also for phase diagram study

The development of continuous fluidized-bed ion exchange in South Africa, and its use in the recovery of uranium

International Nuclear Information System (INIS)

Haines, A.K.

1978-01-01

The status of the South African research and development programme on continouos ion exchange, which was aimed at the technical and economic assesment of that process for the recovery of uranium, is reviewed. The first phase of this programme, which has now been completed, involved devolopment investigations on various pilot plants and culminated in the successfull operation of a large-scale demonstration plant and the incorporation of the system in a number of new South African uranium plants. This account highlights the engineering aspects and the design for the system, its adaptation to process flowsheets, and plans for future development [af

Ion exchange and hydrolysis reactions in zeolites

International Nuclear Information System (INIS)

Harjula, Risto.

1993-09-01

Among other uses, zeolites are efficient cation exchangers for aquatic pollution control. At present they they are mainly used in nuclear waste effluent treatment and in detergency. In the thesis, several ion exchange equilibria, important in these main fields of zeolite applications, were studied, with special emphasis on the formulation and calculation of the equilibria. The main interest was the development of thermodynamic formulations for the calculation of zeolite ion exchange equilibria in solutions of low or very low (trace) ion concentration, which are relevant for the removal of trace pollutants, such as radionuclides, from waste waters. Two groups of zeolite-cation systems were studied. First, binary Ca 2+ /Na + exchange in zeolites X and Y, which are of interest for detergency applications. Second, binary Cs + /Na + and Cs + /K + exchanges, and ternary Cs + /Na + /K + exchange in mordenite, which are important in nuclear waste effluent treatment. The thesis is based on five previous publications by author. (100 refs., 7 figs.)

Development of maintenance procedure for plate type heat exchanger taking into account preventing radioactive contamination

International Nuclear Information System (INIS)

Terai, Kensuke; Someki, Hiroyuki; Ueda, Yuya

2017-01-01

In Japanese pressurized water reactors (PWR), heat loads of spent fuel pools (SFP) is increasing due to rising spent fuels and use of mixed oxide (MOX) fuels. Therefore, SFP cooling capacities are necessary to be enhanced, and replacement of SFP coolers or installation of additional coolers is needed. On the other hand, installation spaces of SFP coolers are limited in existing buildings. Therefore, plate type heat exchangers which can be designed to be compact because of the high heat efficiency have often been adopted for SFP coolers instead of shell and tube type heat exchangers in general use. Plate type heat exchangers have to be overhauled periodically for inspection and gasket replacement. However, in plate type SFP coolers, radioactive SFP water and non-radioactive component cooling water (CCW) alternately run through between each plate. Thus there is a concern that the CCW system may be contaminated by radioactive materials from the SFP water during overhaul of the SFP cooler. In order to solve this problem, we have developed the maintenance procedure of the plate type SFP coolers to prevent CCW side contamination by coating the contaminated surfaces with strippable paint prior to disassembly. Before applying this developed maintenance procedure to actual equipment, we have performed the following verification tests. (1) Confirmation of fundamental characteristics for strippable paint. Firstly, we selected both water-based and solvent-based strippable paints. Secondly, we tested and confirmed the detachability and the drying time of the selected strippable paints respectively. Moreover we also confirmed that the selected strippable paints are appropriate materials from the viewpoint of chemical composition restriction of consumable materials used in nuclear power plant. (2) Confirmation of workability for paint filling, drying and peeling off. The strippable paints need to be peeled off after filling into plate type heat exchanger and draining

Advanced ion exchange resins for PWR condensate polishing

International Nuclear Information System (INIS)

Hoffman, B.; Tsuzuki, S.

2002-01-01

The severe chemical and mechanical requirements of a pressurized water reactor (PWR) condensate polishing plant (CPP) present a major challenge to the design of ion exchange resins. This paper describes the development and initial operating experience of improved cation and anion exchange resins that were specifically designed to meet PWR CPP needs. Although this paper focuses specifically on the ion exchange resins and their role in plant performance, it is also recognized and acknowledged that excellent mechanical design and operation of the CPP system are equally essential to obtaining good results. (authors)

Automated Sample Exchange Robots for the Structural Biology Beam Lines at the Photon Factory

International Nuclear Information System (INIS)

Hiraki, Masahiko; Watanabe, Shokei; Yamada, Yusuke; Matsugaki, Naohiro; Igarashi, Noriyuki; Gaponov, Yurii; Wakatsuki, Soichi

2007-01-01

We are now developing automated sample exchange robots for high-throughput protein crystallographic experiments for onsite use at synchrotron beam lines. It is part of the fully automated robotics systems being developed at the Photon Factory, for the purposes of protein crystallization, monitoring crystal growth, harvesting and freezing crystals, mounting the crystals inside a hutch and for data collection. We have already installed the sample exchange robots based on the SSRL automated mounting system at our insertion device beam lines BL-5A and AR-NW12A at the Photon Factory. In order to reduce the time required for sample exchange further, a prototype of a double-tonged system was developed. As a result of preliminary experiments with double-tonged robots, the sample exchange time was successfully reduced from 70 seconds to 10 seconds with the exception of the time required for pre-cooling and warming up the tongs

Plate heat exchanger - inertia flywheel performance in loss of flow transient

International Nuclear Information System (INIS)

Abou-El-Maaty, Talal; Abd-El-Hady, Amr

2009-01-01

One of the most versatile types of heat exchangers used is the plate heat exchanger. It has principal advantages over other heat exchangers in that plates can be added and/or removed easily in order to change the area available for heat transfer and therefore its overall performance. The cooling systems of Egypt's second research reactor (ETRR 2) use this type of heat exchanger for cooling purposes in its primary core cooling and pool cooling systems. In addition to the change in the number of heat exchanger cooling channels, the effect of changing the amount of mass flow rate on the heat exchanger performance is an important issues in this study. The inertia flywheel mounted on the primary core cooling system pump with the plate heat exchanger plays an important role in the case of loss of flow transients. The PARET code is used to simulate the effect of loss of flow transients on the reactor core. Hence, the core outlet temperature with the pump-flywheel flow coast down is fed into the plate heat exchanger model developed to estimate the total energy transferred to the cooling tower, the primary side heat exchanger temperature variation, the transmitted heat exchanger power, and the heat exchanger effectiveness. In addition, the pressure drop in both, the primary side and secondary side of the plate heat exchanger is calculated in all simulated transients because their values have limits beyond which the heat exchanger is useless. (orig.)

Application of transient analysis methodology to heat exchanger performance monitoring

International Nuclear Information System (INIS)

Rampall, I.; Soler, A.I.; Singh, K.P.; Scott, B.H.

1994-01-01

A transient testing technique is developed to evaluate the thermal performance of industrial scale heat exchangers. A Galerkin-based numerical method with a choice of spectral basis elements to account for spatial temperature variations in heat exchangers is developed to solve the transient heat exchanger model equations. Testing a heat exchanger in the transient state may be the only viable alternative where conventional steady state testing procedures are impossible or infeasible. For example, this methodology is particularly suited to the determination of fouling levels in component cooling water system heat exchangers in nuclear power plants. The heat load on these so-called component coolers under steady state conditions is too small to permit meaningful testing. An adequate heat load develops immediately after a reactor shutdown when the exchanger inlet temperatures are highly time-dependent. The application of the analysis methodology is illustrated herein with reference to an in-situ transient testing carried out at a nuclear power plant. The method, however, is applicable to any transient testing application

Co-optimized design of microchannel heat exchangers and thermoelectric generators

DEFF Research Database (Denmark)

Kolaei, Alireza Rezania; Yazawa, K.; Rosendahl, Lasse

2013-01-01

Designs of heat exchangers have mostly been disconnected to the performance of thermoelectric generator (TEG) systems. The development work, mostly focused on thermoelectric materials, required a significant amount of engineering parametric analysis. In this work, a micro plate-fin heat exchanger...... applied to a TEG is investigated and optimized to maximize the output power and the cost performance of generic TEG systems. The cost per performance is counted by a measure of price per power output ($/W). The channel width, channel height, fin thickness of heat exchanger, and fill factor of TEG...... are theoretically optimized for a wide range of pumping power. In conjunction with effective numeric tests, the model discusses the optimum size of the system components’ dimensions at two area sizes of the substrate plate of heat exchanger. Results show that at every pumping power, there are particular values...

Proton exchange in systems: Glucose-water and uric acid-water

International Nuclear Information System (INIS)

Maarof, S.

2007-01-01

It is clear that formation of glucose-water and uric acid-water solutions is related in principle to interaction accepter - donor between hydrogen atom in water and oxygen atom in glucose or uric acid. The proton exchange in hydrogen bond system is an integral process and it goes by tunnel mechanism (transfer of proton within the hydrogen bridge in these structures). Proton exchange process goes very quickly at low concentrations for glucose and uric acid solutions, because these compounds are able to form more than one hydrogen bond, which helps the proton transfer within obtained structure. However, at its high concentrations, the process becomes very slow due to higher viscosity of its solutions, which result in break down of the structures, and more hydrogen bonds. (author)

Choice Of Exchange Rate Regimes For Developing Countries: Better Be Fixed Or Floating?

OpenAIRE

Elif O. Kan

2011-01-01

The following paper is a summary article about the choice of exchange rate regime for a developing country considering the importance of currency mismatches, debt intolerance, and fear of floating, financial globalization, institutions and sudden stops. In this paper, I first summarize recent researches and papers on this specific issue. In a recent work of theirs, Calvo and Mishkin(2003) argue that much of the debate on choosing an exchange rate regime misses the boat and concludes that choi...

Research and development on super heat pump energy accumulation system. Final report

Energy Technology Data Exchange (ETDEWEB)

NONE

1993-06-01

This is the final report on research and development of super heat pump energy accumulation system, which has been carried out from FY 1985 to 1992. It describes outline of the research and development program, R and D results, final evaluation methodology, evaluation of the R and D, proposals for the commercialization, and so on. The super high performance compression heat pumps are technically evaluated for highly efficient type (for heating, and cooling and heating), high temperature type (utilizing high temperature heat source, and low temperature heat source), working fluids (alcohol-based and nonalcohol-based), stainless steel plate fin type heat exchanger, EHD heat exchanger, and so on. The other techniques evaluated include those for chemical heat storage, combined systems, plant simulation, and systemization. The evaluation works are also directed to the economic and environmental aspects. Finally, the R and D themes are proposed to leap over various hurdles, e.g., reliability and economic viability, for the eventual commercialization of the energy accumulation system. (NEDO)

Exchangeability of RI image data and its effect

Energy Technology Data Exchange (ETDEWEB)

Kojima, K; Hiraki, T [Kanazawa Univ. (Japan). School of Paramedicine; Nakajima, K; Hisada, K; Yamada, M

1981-10-01

Of RI image data processing machines, the exchangeability of data between the VIP-450 system (Ohio-Nuclear Inc.) and the DAP-5000N system (Toshiba Co.) was examined. The exchangeability requires uniformity of arrangement of bits and the data sequence between the machines. Otherwise, the form of memory of either machine should be changed. The exchangeability of data between the machines would have the following advantages: characteristic programs of each machine can be used for the same data, producing more valuable information. Data collection can be performed by any machine, increasing the efficiency of examination. It is not necessary to provide all machines with special attachments. It permits data input into large machines or minicomputers in the development of programs.

Exchangeability of RI image data and its effect

International Nuclear Information System (INIS)

Kojima, Kazuhiko; Hiraki, Tatsunosuke; Nakajima, Kenichi; Hisada, Kinichi; Yamada, Masato.

1981-01-01

Of RI image data processing machines, the exchangeability of data between the VIP-450 system (Ohio-Nuclear Inc.) and the DAP-5000N system (Toshiba Co.) was examined. The exchangeability requires uniformity of arrangement of bits and the data sequence between the machines. Otherwise, the form of memory of either machine should be changed. The exchangeability of data between the machines would have the following advantages: characteristic programs of each machine can be used for the same data, producing more valuable information. Data collection can be performed by any machine, increasing the efficiency of examination. It is not necessary to provide all machines with special attachments. It permits data input into large machines or minicomputers in the development of programs. (Chiba, N.)

RRB's SVES Input File - Post Entitlement State Verification and Exchange System (PSSVES)

Data.gov (United States)

Social Security Administration — Several PSSVES request files are transmitted to SSA each year for processing in the State Verification and Exchange System (SVES). This is a first step in obtaining...

Liquid Salt Heat Exchanger Technology for VHTR Based Applications

Energy Technology Data Exchange (ETDEWEB)

Anderson, Mark; Sridhara, Kumar; Allen, Todd; Peterson, Per

2012-10-11

The objective of this research is to evaluate performance of liquid salt fluids for use as a heat carrier for transferring high-temperature process heat from the very high-temperature reactor (VHTR) to chemical process plants. Currently, helium is being considered as the heat transfer fluid; however, the tube size requirements and the power associated with pumping helium may not be economical. Recent work on liquid salts has shown tremendous potential to transport high-temperature heat efficiently at low pressures over long distances. This project has two broad objectives: To investigate the compatibility of Incoloy 617 and coated and uncoated SiC ceramic composite with MgCl2-KCl molten salt to determine component lifetimes and aid in the design of heat exchangers and piping; and, To conduct the necessary research on the development of metallic and ceramic heat exchangers, which are needed for both the helium-to-salt side and salt-to-process side, with the goal of making these heat exchangers technologically viable. The research will consist of three separate tasks. The first task deals with material compatibility issues with liquid salt and the development of techniques for on-line measurement of corrosion products, which can be used to measure material loss in heat exchangers. Researchers will examine static corrosion of candidate materials in specific high-temperature heat transfer salt systems and develop an in situ electrochemical probe to measure metallic species concentrations dissolved in the liquid salt. The second task deals with the design of both the intermediate and process side heat exchanger systems. Researchers will optimize heat exchanger design and study issues related to corrosion, fabrication, and thermal stresses using commercial and in-house codes. The third task focuses integral testing of flowing liquid salts in a heat transfer/materials loop to determine potential issues of using the salts and to capture realistic behavior of the salts in a

Radionuclide separations in the nuclear fuel cycle development and application of micro and meso porous inorganic ion-exchangers

International Nuclear Information System (INIS)

Griffith, C.S.; Luca, V.

2006-01-01

Full text: Full text: From the mining of uranium-containing ores to the reprocessing of spent nuclear fuel, separations technologies play a crucial role in determining the efficiency and viability of the nuclear fuel cycle. With respect to proposed Advanced Nuclear Fuel Cycles (ANFC), the integral role of separations is no different with solvent extraction and pyroelectrometalurgical processing dominating efforts to develop a sustainable and publicly acceptable roadmap for nuclear power in the next 100 years. An often forgotten or overlooked separation technology is ion-exchange, more specifically, inorganic ion-exchangers. This is despite the fact that these materials offer the potential advantages of process simplicity; exceptional selectivity against high background concentrations of competing ions; and the possibility of a simple immobilization route for the separated radionculides. ANSTO's principal interest in inorganic ion-exchange materials in recent years has been the development of an inorganic ion-exchanger for the pretreatment of acidic legacy 9 Mo production waste to simultaneously remove radiogenic cesium and strontium. Radiogenic cesium and strontium comprise the majority of activity in such waste and may offer increased ease in the downstream processing to immobilise this waste in a Synroc wasteform. With the reliance on separations technologies in all current ANFC concepts, and the recent admission of ANSTO to the European Commissions EUROPART project, the development of new inorganic ion-exchangers has also expanded within our group. This presentation will provide a background of the fundamentals of inorganic and composite inorganic-organic ion-exchange materials followed by specific discussion of some selected inorganic and composite ion-exchange materials being developed and studied at ANSTO. The detailed structural and ion-exchange chemistry of these materials will be discussed and note made of how such materials could benefit any of the

EFFICIENCY OF FOREIGN EXCHANGE MARKETS: A DEVELOPING COUNTRY PERSPECTIVE

Directory of Open Access Journals (Sweden)

Guneratne B Wickremasinghe

2005-01-01

Full Text Available This study tests weak and semi-strong form efficiency of the foreign exchange market in Sri Lanka during the recent float using six bilateral exchange rates. Weak-form efficiency is examined using unit root tests while semi-strong form efficiency is tested using co-integration, Granger causality tests and variance decomposition analysis. Results indicate that the Sri Lankan foreign exchange market is consistent with the weak-form of the efficient market hypothesis (EMH. However, the results provide evidence against the semi-strong version of the EMH. These results have important implications for government policy makers and participants in the foreign exchange market of Sri Lanka.

Development of Electrically Switched Ion Exchange Process for Selective Ion Separations

International Nuclear Information System (INIS)

Rassat, Scot D.; Sukamto, Johanes H.; Orth, Rick J.; Lilga, Michael A.; Hallen, Richard T.

1999-01-01

The electrically switched ion exchange (ESIX) process, being developed at Pacific Northwest National Laboratory, provides an alternative separation method to selectively remove ions from process and waste streams. In the ESIX process, in which an electroactive ion exchange film is deposited onto a high surface area electrode, uptake and elution are controlled directly by modulating the electrochemical potential of the film. This paper addresses engineering issues necessary to fully develop ESIX for specific industrial alkali cation separation challenges. The cycling and chemical stability and alkali cation selectivity of nickel hexacyanoferrate (NiHCF) electroactive films were investigated. The selectivity of NiHCF was determined using cyclic voltammetry and a quartz crystal microbalance to quantify ion uptake in the film. Separation factors indicated a high selectivity for cesium and a moderate selectivity for potassium in high sodium content solutions. A NiHCF film with improved redox cycling and chemical stability in a simulated pulp mill process stream, a targeted application for ESIX, was also prepared and tested

Offering Prescriptions of Leader-Member Exchanges towards Developing Academic Talent in Higher Education

Science.gov (United States)

Horne, Andre Leonard

2017-01-01

This paper examines leader-member exchange behaviour for the development of academic talent in higher education. Drawing from a sample of academic leaders at a large South African university, interviews conducted with the chairs of departments (CoDs) provide new insight on development practices and actions for follower development within a…

Synthetic inorganic ion-exchange materials

International Nuclear Information System (INIS)

Abe, M.

1979-01-01

Exchange isotherms for hydrogen ion/alkali metal ions have been measured at 20 and 40 0 C, with a solution ionic strength of 0.1, in crystalline antimonic(V) acid as a cation-exchanger. The isotherms showed S-shaped curves for the systems of H + /Na + , H + /K + , H + /Rb + and H + /Cs + , but not for H + /Li + exchange. The selectivity coefficients (logarithm scale) vs equivalent fraction of alkali metal ions in the exchanger give linear functions for all systems studied. The selectivity sequences are shown. Overall and hypothetical (zero loading) thermodynamic equilibrium constants were evaluated for these ion-exchange reactions. (author)

Exchange effects in Relativistic Schroedinger Theory

International Nuclear Information System (INIS)

Sigg, T.; Sorg, M.

1998-01-01

The Relativistic Schroedinger Theory predicts the occurrence of exchange and overlap effects in many-particle systems. For a 2-particle system, the interaction energy of the two particles consists of two contributions: Coulomb energy and exchange energy, where the first one is revealed to be the same as in standard quantum theory. However the exchange energy is mediated by an exchange potential, contrary to the kinematical origin of the exchange term in the standard theory

Development and properties of crystalline silicotitanate (CST) ion exchangers for radioactive waste applications

Energy Technology Data Exchange (ETDEWEB)

Miller, J.E.; Brown, N.E.

1997-04-01

Crystalline silicotitanates (CSTs) are a new class of ion exchangers that were jointly invented by researchers at Sandia National Laboratories and Texas A&M University. One particular CST, known as TAM-5, is remarkable for its ability to separate parts-per-million concentrations of cesium from highly alkaline solutions (pH> 14) containing high sodium concentrations (>5M). It is also highly effective for removing cesium from neutral and acidic solutions, and for removing strontium from basic and neutral solutions. Cesium isotopes are fission products that account for a large portion of the radioactivity in waste streams generated during weapons material production. Tests performed at numerous locations with early lab-scale TAM-5 samples established the material as a leading candidate for treating radioactive waste volumes such as those found at the Hanford site in Washington. Thus Sandia developed a Cooperative Research and Development Agreement (CRADA) partnership with UOP, a world leader in developing, commercializing, and supplying adsorbents and associated process technology to commercialize and further develop the material. CSTs are now commercially available from UOP in a powder (UOP IONSIV{reg_sign} IE-910 ion exchanger) and granular form suitable for column ion exchange operations (UOP IONSIV{reg_sign} IE-911 ion exchanger). These materials exhibit a high capacity for cesium in a wide variety of solutions of interest to the Department of Energy, and they are chemically, thermally, and radiation stable. They have performed well in tests at numerous sites with actual radioactive waste solutions, and are being demonstrated in the 100,000 liter Cesium Removal Demonstration taking place at Oak Ridge National Laboratory with Melton Valley Storage Tank waste. It has been estimated that applying CSTs to the Hanford cleanup alone will result in a savings of more than $300 million over baseline technologies.

Development and properties of crystalline silicotitanate (CST) ion exchangers for radioactive waste applications

International Nuclear Information System (INIS)

Miller, J.E.; Brown, N.E.

1997-04-01

Crystalline silicotitanates (CSTs) are a new class of ion exchangers that were jointly invented by researchers at Sandia National Laboratories and Texas A ampersand M University. One particular CST, known as TAM-5, is remarkable for its ability to separate parts-per-million concentrations of cesium from highly alkaline solutions (pH> 14) containing high sodium concentrations (>5M). It is also highly effective for removing cesium from neutral and acidic solutions, and for removing strontium from basic and neutral solutions. Cesium isotopes are fission products that account for a large portion of the radioactivity in waste streams generated during weapons material production. Tests performed at numerous locations with early lab-scale TAM-5 samples established the material as a leading candidate for treating radioactive waste volumes such as those found at the Hanford site in Washington. Thus Sandia developed a Cooperative Research and Development Agreement (CRADA) partnership with UOP, a world leader in developing, commercializing, and supplying adsorbents and associated process technology to commercialize and further develop the material. CSTs are now commercially available from UOP in a powder (UOP IONSIV reg-sign IE-910 ion exchanger) and granular form suitable for column ion exchange operations (UOP IONSIV reg-sign IE-911 ion exchanger). These materials exhibit a high capacity for cesium in a wide variety of solutions of interest to the Department of Energy, and they are chemically, thermally, and radiation stable. They have performed well in tests at numerous sites with actual radioactive waste solutions, and are being demonstrated in the 100,000 liter Cesium Removal Demonstration taking place at Oak Ridge National Laboratory with Melton Valley Storage Tank waste. It has been estimated that applying CSTs to the Hanford cleanup alone will result in a savings of more than $300 million over baseline technologies

Emergency exercises and information exchange. Does practice make perfect? Final report

Energy Technology Data Exchange (ETDEWEB)

Naadland Holo, E

1999-09-01

This project has covered a series of exercises and exercise like activities, in addition to a survey of scenario development tools and development of a suggestion for a Nordic system for data and information exchange. The results from the activities are presented in this report in a methodical perspective. The results reveal three similar components in almost all exercise activities: tools and methods to be used in an emergency situation need further development, systems for communication and information exchange should be developed and implemented, and the format and content of the information to be exchanged in an emergency situation should be agreed upon. Recommendations for future tasks regarding Nordic exercises are given according to this methodical approach. A major aspect here is to develop strategies for the over-all emergency planning. Such strategies should include the use of systematically chosen exercise types to improve the emergency response in a systematic way. (au)

Theory and design of heat exchanger : air cooled plate, spiral heat exchanger

International Nuclear Information System (INIS)

Min, Ui Dong

1960-02-01

This book deals with air cooled heat exchanger, which introduces heat rejection system, wet surface cooler in new from, explanation of structure and design, materials, basic design like plenums chambers and fan ring, finned tube fouling factor, airflow in forced draft and fan design. It also tells of plate heat exchanger and spiral heat exchanger giving descriptions of summary, selection, basic design, device and safety function, maintenance, structure of plate heat exchanger, frames and connector plate and, basic things of spiral tube heat exchanger.

NutriSonic web expert system for meal management and nutrition counseling with nutrient time-series analysis, e-food exchange and easy data transition.

Science.gov (United States)

Hong, Soon-Myung; Cho, Jee-Ye; Lee, Jin-Hee; Kim, Gon; Kim, Min-Chan

2008-01-01

This study was conducted to develop the NutriSonic Web Expert System for Meal Management and Nutrition Counseling with Analysis of User's Nutritive Changes of selected days and food exchange information with easy data transition. This program manipulates a food, menu and meal and search database that has been developed. Also, the system provides a function to check the user's nutritive change of selected days. Users can select a recommended general and therapeutic menu using this system. NutriSonic can analyze nutrients and e-food exchange ("e" means the food exchange data base calculated by a computer program) in menus and meals. The expert can insert and store a meal database and generate the synthetic information of age, sex and therapeutic purpose of disease. With investigation and analysis of the user's needs, the meal planning program on the internet has been continuously developed. Users are able to follow up their nutritive changes with nutrient information and ratio of 3 major energy nutrients. Also, users can download another data format like Excel files (.xls) for analysis and verify their nutrient time-series analysis. The results of analysis are presented quickly and accurately. Therefore it can be used by not only usual people, but also by dietitians and nutritionists who take charge of making a menu and experts in the field of food and nutrition. It is expected that the NutriSonic Web Expert System can be useful for nutrition education, nutrition counseling and expert meal management.

Evaluating humidity recovery efficiency of currently available heat and moisture exchangers: a respiratory system model study

Directory of Open Access Journals (Sweden)

Jeanette Janaina Jaber Lucato

2009-06-01

Full Text Available OBJECTIVES: To evaluate and compare the efficiency of humidification in available heat and moisture exchanger models under conditions of varying tidal volume, respiratory rate, and flow rate. INTRODUCTION: Inspired gases are routinely preconditioned by heat and moisture exchangers to provide a heat and water content similar to that provided normally by the nose and upper airways. The absolute humidity of air retrieved from and returned to the ventilated patient is an important measurable outcome of the heat and moisture exchangers' humidifying performance. METHODS: Eight different heat and moisture exchangers were studied using a respiratory system analog. The system included a heated chamber (acrylic glass, maintained at 37°C, a preserved swine lung, a hygrometer, circuitry and a ventilator. Humidity and temperature levels were measured using eight distinct interposed heat and moisture exchangers given different tidal volumes, respiratory frequencies and flow-rate conditions. Recovery of absolute humidity (%RAH was calculated for each setting. RESULTS: Increasing tidal volumes led to a reduction in %RAH for all heat and moisture exchangers while no significant effect was demonstrated in the context of varying respiratory rate or inspiratory flow. CONCLUSIONS: Our data indicate that heat and moisture exchangers are more efficient when used with low tidal volume ventilation. The roles of flow and respiratory rate were of lesser importance, suggesting that their adjustment has a less significant effect on the performance of heat and moisture exchangers.

Multi-column step-gradient chromatography system for automated ion exchange separations

International Nuclear Information System (INIS)

Rucker, T.L.

1985-01-01

A multi-column step-gradient chromatography system has been designed to perform automated sequential separations of radionuclides by ion exchange chromatography. The system consists of a digital programmer with automatic stream selection valve, two peristaltic pumps, ten columns, and a fraction collector. The automation allows complicated separations of radionuclides to be made with minimal analyst attention and allows for increased productivity and reduced cost of analyses. Results are reported for test separations on mixtures of radionuclides by the system

Role of Department Heads in Academic Development: A Leader-Member Exchange and Organizational Resource Perspective

Science.gov (United States)

Horne, Andre Leonard; du Plessis, Yvonne; Nkomo, Stella

2016-01-01

This article examines the role of leadership in the development of academic talent in higher education from a social exchange and organizational support perspective. Drawing from a sample of academic staff at a large South African university, the study investigates the extent to which a quality leader-member exchange relationship versus a formal…

New Trends in Magnetic Exchange Bias

Science.gov (United States)

Mougin, Alexandra; Mangin, Stéphane; Bobo, Jean-Francois; Loidl, Alois

2005-05-01

The study of layered magnetic structures is one of the hottest topics in magnetism due to the growing attraction of applications in magnetic sensors and magnetic storage media, such as random access memory. For almost half a century, new discoveries have driven researchers to re-investigate magnetism in thin film structures. Phenomena such as giant magnetoresistance, tunneling magnetoresistance, exchange bias and interlayer exchange coupling led to new ideas to construct devices, based not only on semiconductors but on a variety of magnetic materials Upon cooling fine cobalt particles in a magnetic field through the Néel temperature of their outer antiferromagnetic oxide layer, Meiklejohn and Bean discovered exchange bias in 1956. The exchange bias effect through which an antiferromagnetic AF layer can cause an adjacent ferromagnetic F layer to develop a preferred direction of magnetization, is widely used in magnetoelectronics technology to pin the magnetization of a device reference layer in a desired direction. However, the origin and effects due to exchange interaction across the interface between antiferromagneic and ferromagnetic layers are still debated after about fifty years of research, due to the extreme difficulty associated with the determination of the magnetic interfacial structure in F/AF bilayers. Indeed, in an AF/F bilayer system, the AF layer acts as “the invisible man” during conventional magnetic measurements and the presence of the exchange coupling is evidenced indirectly through the unusual behavior of the adjacent F layer. Basically, the coercive field of the F layer increases in contact with the AF and, in some cases, its hysteresis loop is shifted by an amount called exchange bias field. Thus, AF/F exchange coupling generates a new source of anisotropy in the F layer. This induced anisotropy strongly depends on basic features such as the magnetocrystalline anisotropy, crystallographic and spin structures, defects, domain patterns etc

Analysis of a radiative heat exchanger for systems for thermal control of space vehicles

International Nuclear Information System (INIS)

Vasil'ev, L.L.; Kanonchik, L.E.; Babenko, V.A.

1995-01-01

Starting from the solution of a two-dimensional heat conduction problem, a mathematical model of a heat pipe-based radiative heat exchanger is developed. Good agreement between the predicted and experimental results is obtained. The effect of operational and structural parameters on the characteristics of the radiative heat exchanger is analyzed

Uranium isotope separation using styrene cation exchangers

International Nuclear Information System (INIS)

Kahovec, J.

1980-01-01

The separation of 235 U and 238 U isotopes is carried out either by simple isotope exchange in the system uranium-cation exchanger (sulphonated styrene divinylbenzene resin), or by combination of isotope exchange in a uranium-cation exchanger (Dowex 50, Amberlite IR-120) system and a chemical reaction. A review is presented of elution agents used, the degree of cation exchanger cross-linking, columns length, and 235 U enrichment. The results are described of the isotope effect study in a U(IV)-U(VI)-cation exchanger system conducted by Japanese and Romanian authors (isotope exchange kinetics, frontal analysis, reverse (indirect) frontal analysis). (H.S.)

Study of a Coil Heat Exchanger with an Ice Storage System

Directory of Open Access Journals (Sweden)

Yan Li

2017-12-01

Full Text Available In this study, a coil heat exchanger with an ice storage system is analyzed by theoretical analysis, numerical analysis, and experimental analysis. The dynamic characteristics of ice thickness variation is studied by means of unstable heat conduction theory in cylindrical coordinates, and the change rule of the ice layer thickness is obtained. The computational fluid dynamics method is employed to simulate the flow field and ice melting process of the coil heat exchanger. The effect of the agitator height on the flow characteristics and heat transfer characteristics is investigated. The numerical results show that the turbulence intensity of the fluid near the wall of the heat exchanger is the largest with an agitator height of 80 mm. Furthermore, the process of ice melting is analyzed. The ice on the outer side of the evaporator tube close to the container wall melts faster than the inner side and this agrees well with the experimental result. The experimental study on the process of the operational period and deicing of the coil heat exchanger is conducted and the temperature variation curves are obtained by the arrangement of thermocouples. It is found that the temperature of the evaporating tube increases with increasing height in the process of ice storage.

Ocean thermal energy conversion power system development-I. Phase I. Preliminary design report. Volume 1. Final report

Energy Technology Data Exchange (ETDEWEB)

1978-12-18

The results of a conceptual and preliminary design study of Ocean Thermal Energy Conversion (OTEC) closed loop ammonia power system modules performed by Lockheed Missiles and Space Company, Inc. (LMSC) are presented. This design study is the second of 3 tasks in Phase I of the Power System Development-I Project. The Task 2 objectives were to develop: 1) conceptual designs for a 40 to 50-MW(e) closed cycle ammonia commercial plant size power module whose heat exchangers are immersed in seawater and whose ancillary equipments are in a shirt sleeve environment; preliminary designs for a modular application power system sized at 10-MW(e) whose design, construction and material selection is analogous to the 50 MW(e) module, except that titanium tubes are to be used in the heat exchangers; and 3) preliminary designs for heat exchanger test articles (evaporator and condenser) representative of the 50-MW(e) heat exchangers using aluminum alloy, suitable for seawater service, for testing on OTEC-1. The reference ocean platform was specified by DOE as a surface vessel with the heat exchanger immersed in seawater to a design depth of 0 to 20 ft measured from the top of the heat exchanger. For the 50-MW(e) module, the OTEC 400-MW(e) Plant Ship, defined in the Platform Configuration and Integration study, was used as the reference platform. System design, performance, and cost are presented. (WHK)

Improving performance in the ED through laboratory information exchange systems.

Science.gov (United States)

Raymond, Louis; Paré, Guy; Maillet, Éric; Ortiz de Guinea, Ana; Trudel, Marie-Claude; Marsan, Josianne

2018-03-12

The accessibility of laboratory test results is crucial to the performance of emergency departments and to the safety of patients. This study aims to develop a better understanding of which laboratory information exchange (LIE) systems emergency care physicians (ECPs) are using to consult their patients' laboratory test results and which benefits they derive from such use. A survey of 163 (36%) ECPs in Quebec was conducted in collaboration with the Quebec's Department of Health and Social Services. Descriptive statistics, chi-square tests, cluster analyses, and ANOVAs were conducted. The great majority of respondents indicated that they use several LIE systems including interoperable electronic health record (iEHR) systems, laboratory results viewers (LRVs), and emergency department information systems (EDIS) to consult their patients' laboratory results. Three distinct profiles of LIE users were observed. The extent of LIE usage was found to be primarily determined by the functional design differences between LIE systems available in the EDs. Our findings also indicate that the more widespread LIE usage, the higher the perceived benefits. More specifically, physicians who make extensive use of iEHR systems and LRVs obtain the widest range of benefits in terms of efficiency, quality, and safety of emergency care. Extensive use of LIE systems allows ECPs to better determine and monitor the health status of their patients, verify their diagnostic assumptions, and apply evidence-based practices in laboratory medicine. But for such benefits to be possible, ECPs must be provided with LIE systems that produce accurate, up-to-date, complete, and easy-to-interpret information.

Development of gradient-corrected exchange-correlation functionals in the density functional theory; Developpement de fonctionnelles corrigees du gradient en theorie de la fonctionnelle de la densite

Energy Technology Data Exchange (ETDEWEB)

Lembarki, A.

1994-12-01

In this work, we have developed some gradient-corrected exchange-correlation functionals. This study is in keeping with the density functional theory (DFT) formalism. In the first part of this memory, a description of Hartree-Fock (HF), post-HF and density functional theories is given. The second part is devoted the study the different approximations of DFT exchange-correlation functionals which have been proposed in the last years. In particular, we have underlined the approximations used for the construction of these functionals. The third part of this memory consists in the development of new gradient-corrected functionals. In this study, we have established a new relation between exchange energy, correlation energy and kinetic energy. We have deduced two new possible forms of exchange or correlation functionals, respectively. In the fourth part, we have studied the exchange potential, for which the actual formulation does not satisfy some theoretical conditions, such as the asymptotic behavior -1/r. Our contribution lies in the development of an exchange potential with a correct asymptotic -1/r behavior for large values of r. In this chapter, we have proposed a model which permits the obtention of the exchange energy from the exchange potential, using the virial theorem. The fifth part of this memory is devoted the application of these different functionals to simple systems (H{sub 2}O, CO, N{sub 2}O, H{sub 3}{sup +} and H{sub 5}{sup +}) in order to characterize the performance of DFT calculations in regards to those obtained with post-HF methods. (author). 215 refs., 8 figs., 28 tabs.

Systems Analysis Developed for All-Electric Aircraft Propulsion

Science.gov (United States)

Kohout, Lisa L.

2004-01-01

There is a growing interest in the use of fuel cells as a power source for all-electric aircraft propulsion as a means to substantially reduce or eliminate environmentally harmful emissions. Among the technologies under consideration for these concepts are advanced proton exchange membrane (PEM) and solid oxide fuel cells (SOFCs), alternative fuels and fuel processing, and fuel storage. A multidisciplinary effort is underway at the NASA Glenn Research Center to develop and evaluate concepts for revolutionary, nontraditional fuel cell power and propulsion systems for aircraft applications. As part of this effort, system studies are being conducted to identify concepts with high payoff potential and associated technology areas for further development. To support this effort, a suite of component models was developed to estimate the mass, volume, and performance for a given system architecture. These models include a hydrogen-air PEM fuel cell; an SOFC; balance-of-plant components (compressor, humidifier, separator, and heat exchangers); compressed gas, cryogenic, and liquid fuel storage tanks; and gas turbine/generator models for hybrid system applications. First-order feasibility studies were completed for an all-electric personal air vehicle utilizing a fuel-cell-powered propulsion system. A representative aircraft with an internal combustion engine was chosen as a baseline to provide key parameters to the study, including engine power and subsystem mass, fuel storage volume and mass, and aircraft range. The engine, fuel tank, and associated ancillaries were then replaced with a fuel cell subsystem. Various configurations were considered including a PEM fuel cell with liquid hydrogen storage, a direct methanol PEM fuel cell, and a direct internal reforming SOFC/turbine hybrid system using liquid methane fuel. Each configuration was compared with the baseline case on a mass and range basis.

Exchange of pressurizer safeguarding system at Biblis nuclear power station

International Nuclear Information System (INIS)

Weber, D.; Hofbeck, W.

1991-01-01

Valves and piping of the pressurizer safeguarding system are exchanged and reset in such a way that they are suitable not only for discharging steam, but also for discharging a water-steam mixture and hot pressurized water; for the emergency measure of primary depressurization by hand (bleed) in the event of failure of the entire feedwater supply and station black-out, and in the event of operational transients with supposed failure of the reactor scram (ATWS). To achieve this, in addition to the requirements of the pressurizer discharging station, changes have to be made to the valve drive to dominate the water loads. During the 1990 inspection this exchange of the pressurizer discharging station was performed at the Biblis A unit as the first German plant. (orig.) [de

Fault diagnosis for the heat exchanger of the aircraft environmental control system based on the strong tracking filter.

Science.gov (United States)

Ma, Jian; Lu, Chen; Liu, Hongmei

2015-01-01

The aircraft environmental control system (ECS) is a critical aircraft system, which provides the appropriate environmental conditions to ensure the safe transport of air passengers and equipment. The functionality and reliability of ECS have received increasing attention in recent years. The heat exchanger is a particularly significant component of the ECS, because its failure decreases the system's efficiency, which can lead to catastrophic consequences. Fault diagnosis of the heat exchanger is necessary to prevent risks. However, two problems hinder the implementation of the heat exchanger fault diagnosis in practice. First, the actual measured parameter of the heat exchanger cannot effectively reflect the fault occurrence, whereas the heat exchanger faults are usually depicted by utilizing the corresponding fault-related state parameters that cannot be measured directly. Second, both the traditional Extended Kalman Filter (EKF) and the EKF-based Double Model Filter have certain disadvantages, such as sensitivity to modeling errors and difficulties in selection of initialization values. To solve the aforementioned problems, this paper presents a fault-related parameter adaptive estimation method based on strong tracking filter (STF) and Modified Bayes classification algorithm for fault detection and failure mode classification of the heat exchanger, respectively. Heat exchanger fault simulation is conducted to generate fault data, through which the proposed methods are validated. The results demonstrate that the proposed methods are capable of providing accurate, stable, and rapid fault diagnosis of the heat exchanger.

Fault diagnosis for the heat exchanger of the aircraft environmental control system based on the strong tracking filter.

Directory of Open Access Journals (Sweden)

Jian Ma

Full Text Available The aircraft environmental control system (ECS is a critical aircraft system, which provides the appropriate environmental conditions to ensure the safe transport of air passengers and equipment. The functionality and reliability of ECS have received increasing attention in recent years. The heat exchanger is a particularly significant component of the ECS, because its failure decreases the system's efficiency, which can lead to catastrophic consequences. Fault diagnosis of the heat exchanger is necessary to prevent risks. However, two problems hinder the implementation of the heat exchanger fault diagnosis in practice. First, the actual measured parameter of the heat exchanger cannot effectively reflect the fault occurrence, whereas the heat exchanger faults are usually depicted by utilizing the corresponding fault-related state parameters that cannot be measured directly. Second, both the traditional Extended Kalman Filter (EKF and the EKF-based Double Model Filter have certain disadvantages, such as sensitivity to modeling errors and difficulties in selection of initialization values. To solve the aforementioned problems, this paper presents a fault-related parameter adaptive estimation method based on strong tracking filter (STF and Modified Bayes classification algorithm for fault detection and failure mode classification of the heat exchanger, respectively. Heat exchanger fault simulation is conducted to generate fault data, through which the proposed methods are validated. The results demonstrate that the proposed methods are capable of providing accurate, stable, and rapid fault diagnosis of the heat exchanger.

Advanced integrated solvent extraction and ion exchange systems

International Nuclear Information System (INIS)

Horwitz, P.

1996-01-01

Advanced integrated solvent extraction (SX) and ion exchange (IX) systems are a series of novel SX and IX processes that extract and recover uranium and transuranics (TRUs) (neptunium, plutonium, americium) and fission products 90 Sr, 99 Tc, and 137 Cs from acidic high-level liquid waste and that sorb and recover 90 Sr, 99 Tc, and 137 Cs from alkaline supernatant high-level waste. Each system is based on the use of new selective liquid extractants or chromatographic materials. The purpose of the integrated SX and IX processes is to minimize the quantity of waste that must be vitrified and buried in a deep geologic repository by producing raffinates (from SX) and effluent streams (from IX) that will meet the specifications of Class A low-level waste

Energetic and Exergetic Analysis of a Heat Exchanger Integrated in a Solid Biomass-Fuelled Micro-CHP System with an Ericsson Engine

Directory of Open Access Journals (Sweden)

Marie Creyx

2016-04-01

Full Text Available A specific heat exchanger has been developed to transfer heat from flue gas to the working fluid (hot air of the Ericsson engine of a solid biomass-fuelled micro combined heat and power (CHP. In this paper, the theoretical and experimental energetic analyses of this heat exchanger are compared. The experimental performances are described considering energetic and exergetic parameters, in particular the effectiveness on both hot and cold sides. A new exergetic parameter called the exergetic effectiveness is introduced, which allows a comparison between the real and the ideal heat exchanger considering the Second Law of Thermodynamics. A global analysis of exergetic fluxes in the whole micro-CHP system is presented, showing the repartition of the exergy destruction among the components.

Mastering Microsoft Exchange Server 2013

CERN Document Server

Elfassy, David

2013-01-01

The bestselling guide to Exchange Server, fully updated for the newest version Microsoft Exchange Server 2013 is touted as a solution for lowering the total cost of ownership, whether deployed on-premises or in the cloud. Like the earlier editions, this comprehensive guide covers every aspect of installing, configuring, and managing this multifaceted collaboration system. It offers Windows systems administrators and consultants a complete tutorial and reference, ideal for anyone installing Exchange Server for the first time or those migrating from an earlier Exchange Server version.Microsoft

System for enrichment by dual temperature exchange

International Nuclear Information System (INIS)

Spevack, J.S.

1975-01-01

In dual temperature isotope exchange systems utilizing different fluid substances in liquid and gas phases separable from and soluble in each other (for example H 2 O and H 2 S), the phases are passed countercurrent to each other in towers maintained at relatively hot and cold temperatures. Combinations of method and means are provided by which the gas is raised to hot tower temperature and humidity conditions principally by heat derived from the cooling and dehumidification of the gas leaving the hot tower as it is being reduced in temperature and humidity to cold tower conditions. Special provisions are made in the combinations for transferring this heat and for completing the conditioning of the gas to the respective tower conditions with high efficiency, for economically controlling the temperature of the condensate to adapt it for transfer to different parts of the system, and for economically stripping dissolved gas and heat from the effluent liquid and returning it to the system in manners that aid the thermal conditioning of the main gas stream

EFFICIENCY OF FOREIGN EXCHANGE MARKETS: A DEVELOPING COUNTRY PERSPECTIVE

OpenAIRE

Guneratne Banda Wickremasinghe

2004-01-01

This study tests weak and semi-strong form efficiency of the foreign exchange market in Sri Lanka using six bilateral foreign exchange rates during the recent float. Weak-form efficiency is examined using unit root tests while semi-strong form efficiency is tested using co- integration and Granger causality tests and variance decomposition analysis. Results indicate that the Sri Lankan foreign exchange market is consistent with the weak -form of the Efficient Market Hypothesis. However, the r...

Implications of WWW technologies for exchanging medical records

Directory of Open Access Journals (Sweden)

Maurice Dixon

1999-09-01

Full Text Available This article addresses some of the implications for medical record exchange of very recent developments in technology and tools that support the World Wide Web. It argues that XML (Extensible Mark-up Language is a very good enabling technology for medical record exchange. XML provides a much cheaper way of executing the exchange of medical information that circumvents the need for proprietary software. Use of XML can also simplify solutions to the problems associated with coping with the evolution of medical systems in time. However XML on its own does not resolve all the semantic heterogeneities.

Preliminary Study of Printed Circuit Heat Exchanger (PCHE) for various power conversion systems for SMART

Energy Technology Data Exchange (ETDEWEB)

Kwon, Jinsu; Baik, Seungjoon; Lee, Jeong Ik [KAIST, Daejeon (Korea, Republic of)

2016-10-15

The steam-Rankine cycle was the most widely used power conversion system for a nuclear power plant. The size of the heat exchanger is important for the modulation. Such a challenge was conducted by Kang et al. They change the steam generator type for the SMART from helical type heat exchanger to Printed Circuit Heat Exchanger (PCHE). Recently, there has been a growing interest in the supercritical carbon dioxide (S-CO{sub 2}) Brayton cycle as the most promising power conversion system. The reason is high efficiency with simple layout and compact power plant due to small turbomachinery and compact heat exchanger technology. That is why the SCO{sub 2} Brayton cycle can enhance the existing advantages of Small Modular Reactor (SMR) like SMART, such as reduction in size, capital cost, and construction period. Thermal hydraulic and geometric parameters of a PCHE for the S-CO{sub 2} power cycle coupled to SMART. The results show that the water - CO{sub 2} printed circuit heat exchanger size is smaller than printed circuit steam generator for the superheated steam Rankine cycle. This results show the potential benefit of using the S-CO-2 Brayton power cycle to a water-cooled small modular reactor.

Development of the gas puff charge exchange recombination spectroscopy (GP-CXRS) technique for ion measurements in the plasma edge

International Nuclear Information System (INIS)

Churchill, R. M.; Theiler, C.; Lipschultz, B.; Dux, R.; Pütterich, T.; Viezzer, E.

2013-01-01

A novel charge-exchange recombination spectroscopy (CXRS) diagnostic method is presented, which uses a simple thermal gas puff for its donor neutral source, instead of the typical high-energy neutral beam. This diagnostic, named gas puff CXRS (GP-CXRS), is used to measure ion density, velocity, and temperature in the tokamak edge/pedestal region with excellent signal-background ratios, and has a number of advantages to conventional beam-based CXRS systems. Here we develop the physics basis for GP-CXRS, including the neutral transport, the charge-exchange process at low energies, and effects of energy-dependent rate coefficients on the measurements. The GP-CXRS hardware setup is described on two separate tokamaks, Alcator C-Mod and ASDEX Upgrade. Measured spectra and profiles are also presented. Profile comparisons of GP-CXRS and a beam based CXRS system show good agreement. Emphasis is given throughout to describing guiding principles for users interested in applying the GP-CXRS diagnostic technique

Development of the gas puff charge exchange recombination spectroscopy (GP-CXRS) technique for ion measurements in the plasma edge

Energy Technology Data Exchange (ETDEWEB)

Churchill, R. M.; Theiler, C.; Lipschultz, B. [MIT Plasma Science and Fusion Center, Cambridge, Massachusetts 02139 (United States); Dux, R.; Pütterich, T.; Viezzer, E. [Max-Planck-Institut für Plasmaphysik, EURATOM Association, Boltzmannstrasse 2, D-85748 Garching (Germany); Collaboration: Alcator C-Mod Team; ASDEX Upgrade Team

2013-09-15

A novel charge-exchange recombination spectroscopy (CXRS) diagnostic method is presented, which uses a simple thermal gas puff for its donor neutral source, instead of the typical high-energy neutral beam. This diagnostic, named gas puff CXRS (GP-CXRS), is used to measure ion density, velocity, and temperature in the tokamak edge/pedestal region with excellent signal-background ratios, and has a number of advantages to conventional beam-based CXRS systems. Here we develop the physics basis for GP-CXRS, including the neutral transport, the charge-exchange process at low energies, and effects of energy-dependent rate coefficients on the measurements. The GP-CXRS hardware setup is described on two separate tokamaks, Alcator C-Mod and ASDEX Upgrade. Measured spectra and profiles are also presented. Profile comparisons of GP-CXRS and a beam based CXRS system show good agreement. Emphasis is given throughout to describing guiding principles for users interested in applying the GP-CXRS diagnostic technique.

Analysis of a membrane-based condesate recovery heat exchanger (CRX)

Science.gov (United States)

Newbold, D.D.

1993-01-01

The development of a temperature and humidity control system that can remove heat and recover water vapor is key to the development of an Environmental Control and Life Support System (ECLSS). Large quantities of water vapor must be removed from air, and this operation has proven difficult in the absense of gravity. This paper presents the modeling results from a program to develop a novel membrane-based heat exchanger known as the condensate recovery heat exchanger (CRX). This device cools and dehumidifies humid air and simultaneously recovers water-vapor condensate. In this paper, the CRX is described and the results of an analysis of the heat- and mass-transfer characteristics of the device are given.

Interface adjustment and exchange coupling in the IrMn/NiFe system

Energy Technology Data Exchange (ETDEWEB)

Spizzo, F.; Tamisari, M.; Chinni, F.; Bonfiglioli, E.; Del Bianco, L., E-mail: lucia.delbianco@unife.it

2017-01-01

The exchange bias effect was investigated, in the 5–300 K temperature range, in samples of IrMn [100 Å]/NiFe [50 Å] (set A) and in samples with inverted layer-stacking sequence (set B), produced at room temperature by DC magnetron sputtering in a static magnetic field of 400 Oe. The samples of each set differ for the nominal thickness (t{sub Cu}) of a Cu spacer, grown at the interface between the antiferromagnetic and ferromagnetic layers, which was varied between 0 and 2 Å. It has been found out that the Cu insertion reduces the values of the exchange field and of the coercivity and can also affect their thermal evolution, depending on the stack configuration. Indeed, the latter also determines a peculiar variation of the exchange bias properties with time, shown and discussed with reference to the samples without Cu of the two sets. The results have been explained considering that, in this system, the exchange coupling mechanism is ruled by the glassy magnetic behavior of the IrMn spins located at the interface with the NiFe layer. Varying the stack configuration and t{sub Cu} results in a modulation of the structural and magnetic features of the interface, which ultimately affects the spins dynamics of the glassy IrMn interfacial component. - Highlights: • Exchange bias effect in IrMn/NiFe samples with interfacial Cu spacer. • A variation of exchange bias with time is observed in as-deposited samples. • Magnetic modification of the interface by varying the stack sequence and Cu thickness. • Interface adjustment affects the dynamics of interfacial IrMn spins. • The exchange bias properties can be tuned by interface adjustment.

Effect of Moisture Exchange on Interface Formation in the Repair System Studied by X-ray Absorption

Directory of Open Access Journals (Sweden)

Mladena Lukovic

2015-12-01

Full Text Available In concrete repair systems, material properties of the repair material and the interface are greatly influenced by the moisture exchange between the repair material and the substrate. If the substrate is dry, it can absorb water from the repair material and reduce its effective water-to-cement ratio (w/c. This further affects the hydration rate of cement based material. In addition to the change in hydration rate, void content at the interface between the two materials is also affected. In this research, the influence of moisture exchange on the void content in the repair system as a function of initial saturation level of the substrate is investigated. Repair systems with varying level of substrate saturation are made. Moisture exchange in these repair systems as a function of time is monitored by the X-ray absorption technique. After a specified curing age (3 d, the internal microstructure of the repair systems was captured by micro-computed X-ray tomography (CT-scanning. From reconstructed images, different phases in the repair system (repair material, substrate, voids can be distinguished. In order to quantify the void content, voids were thresholded and their percentage was calculated. It was found that significantly more voids form when the substrate is dry prior to application of the repair material. Air, initially filling voids and pores of the dry substrate, is being released due to the moisture exchange. As a result, air voids remain entrapped in the repair material close to the interface. These voids are found to form as a continuation of pre-existing surface voids in the substrate. Knowledge about moisture exchange and its effects provides engineers with the basis for recommendations about substrate preconditioning in practice.

Effect of Moisture Exchange on Interface Formation in the Repair System Studied by X-ray Absorption.

Science.gov (United States)

Lukovic, Mladena; Ye, Guang

2015-12-22

In concrete repair systems, material properties of the repair material and the interface are greatly influenced by the moisture exchange between the repair material and the substrate. If the substrate is dry, it can absorb water from the repair material and reduce its effective water-to-cement ratio (w/c). This further affects the hydration rate of cement based material. In addition to the change in hydration rate, void content at the interface between the two materials is also affected. In this research, the influence of moisture exchange on the void content in the repair system as a function of initial saturation level of the substrate is investigated. Repair systems with varying level of substrate saturation are made. Moisture exchange in these repair systems as a function of time is monitored by the X-ray absorption technique. After a specified curing age (3 d), the internal microstructure of the repair systems was captured by micro-computed X-ray tomography (CT-scanning). From reconstructed images, different phases in the repair system (repair material, substrate, voids) can be distinguished. In order to quantify the void content, voids were thresholded and their percentage was calculated. It was found that significantly more voids form when the substrate is dry prior to application of the repair material. Air, initially filling voids and pores of the dry substrate, is being released due to the moisture exchange. As a result, air voids remain entrapped in the repair material close to the interface. These voids are found to form as a continuation of pre-existing surface voids in the substrate. Knowledge about moisture exchange and its effects provides engineers with the basis for recommendations about substrate preconditioning in practice.

Implications of Leader-Member Exchange Theory and Research for Human Resource Development Research.

Science.gov (United States)

Burns, Janet Z.; Otte, Fred L.

1999-01-01

Leader/member exchange theory is proposed as an alternate approach to the study of organizational leadership. Recent research supports the theory but additional development work is needed. The theory seeks to explain how leader/member relationships develop and the behavioral components of leadership relations. Contains 74 references. (Author/JOW)

Optimization of porous microchannel heat exchanger

Science.gov (United States)

Kozhukhov, N. N.; Konovalov, D. A.

2017-11-01

The technical progress in information and communication sphere leads to a sharp increase in the use of radio electronic devices. Functioning of radio electronics is accompanied by release of thermal energy, which must be diverted from the heat-stressed element. Moreover, using of electronics at negative temperatures, on the contrary, requires supply of a certain amount of heat to start the system. There arises the task of creating a system that allows both to supply and to divert the necessary amount of thermal energy. The development of complex thermostabilization systems for radio electronic equipment is due to increasing the efficiency of each of its elements separately. For more efficient operation of a heat exchanger, which directly affects the temperature of the heat-stressed element, it is necessary to calculate the mode characteristics and to take into account the effect of its design parameters. The results of optimizing the microchannel heat exchanger are presented in the article. The target optimization functions are the mass, pressure drop and temperature. The parameters of optimization are the layout of porous fins, their geometric dimensions and coolant flow. For the given conditions, the optimum variant of porous microchannel heat exchanger is selected.

Expert system for aiding fuel exchange planning

International Nuclear Information System (INIS)

Shiratori, Yoshitake.

1992-01-01

A fuel exchange plan is prepared based on intelligence bases such as a method of zoning a reactor core, a fuel arrangement rule and a procedure for fuel exchange, as well as initial data. Then, the fuel exchange plans are patterned to several groups based on the intelligence bases such as patterning of fuel arrangement. A typical pattern is analyzed by a reactor core analyzing code and allowance or rejection for the analyzed patterns is judged based on intelligence bases regarding life time of the reactor core, thermal limit value of fuels, burning of fuel for irradiation test. The result of the judgement is fed-back as an estimation information and the initial data and the intelligence data are added to prepare a plan again. A similar analysis is also conducted for the plan of the rejected group. The allowance or rejection is judged for all of the plans in the same manner. The intelligence bases are used and the result of the judgement is fed-back as a condition for estimation, thereby enabling to remarkably save labors and time and prepare non-typical exchange plans. (N.H.)

The strategic use of standardized information exchange technology in a university health system.

Science.gov (United States)

Cheng, Po-Hsun; Chen, Heng-Shuen; Lai, Feipei; Lai, Jin-Shin

2010-04-01

This article illustrates a Web-based health information system that is comprised of specific information exchange standards related to health information for healthcare services in National Taiwan University Health System. Through multidisciplinary teamwork, medical and informatics experts collaborated and studied on system scope definition, standard selection challenges, system implementation barriers, system management outcomes, and further expandability of other systems. After user requirement analysis and prototyping, from 2005 to 2008, an online clinical decision support system with multiple functions of reminding and information push was implemented. It was to replace its original legacy systems and serve among the main hospital and three branches of 180-200 clinics and 7,500-8,000 patient visits per day. To evaluate the effectiveness of this system, user surveys were performed, which revealed that the average score of user satisfaction increased from 2.80 to 3.18 on a 4-point scale. Among the items, especially e-learning for training service, courtesy communications for system requests, and courtesy communications for system operations showed statistically significant improvement. From this study, the authors concluded that standardized information exchange technologies can be used to create a brand new enterprise value and steadily obtain more competitive advantages for a prestige healthcare system.

Recent research and development of intermediate heat exchanger for VHTR plant

Energy Technology Data Exchange (ETDEWEB)

Shimizu, Akira; Matsumura, Noboru; Nishikawa, Hidetsugu; Yamada, Seiya [Nagasaki Shipyard and Engine Works, Mitsubishi Heavy Industries, Ltd., Nagasaki (Japan)

1984-07-01

This paper describes recent tests which show progress in design of Intermediate Heat Exchanger (IHX) for high-temperature gas cooled reactor plants developed for process heat application utilizing nuclear thermal energy. As the IHX must have a large heat exchanging capacity, the most important consideration is to design a compact heat exchanger having high efficiency. For the improvement of heat transfer characteristics, tests were performed at Mitsubishi Heavy Industries such as, trial manufacturing, heat transfer characteristic tests and nondestructive inspection tests of finned tubes. Results are as follows; (1) Finned tubes produced by rolling were able to be wound helically by bending machine. (2) Laboratory tests showed this tube had good heat transfer characteristics. (3) There was not much difference between finned tubes and bare tubes for detection of defects by the eddy current tests. (4) A trial assembly using the same scale model showed that the present design is easy to assemble. (5) Automatic orbital welding can be adopted for the welding between tube and tube sheet. As the result of the experiences gained from these successful tests, the design of the IHX has been greatly improved. (author)

Development of the interactive model between Component Cooling Water System and Containment Cooling System using GOTHIC

International Nuclear Information System (INIS)

Byun, Choong Sup; Song, Dong Soo; Jun, Hwang Yong

2006-01-01

In a design point of view, component cooling water (CCW) system is not full-interactively designed with its heat loads. Heat loads are calculated from the CCW design flow and temperature condition which is determined with conservatism. Then the CCW heat exchanger is sized by using total maximized heat loads from above calculation. This approach does not give the optimized performance results and the exact trends of CCW system and the loads during transient. Therefore a combined model for performance analysis of containment and the component cooling water(CCW) system is developed by using GOTHIC software code. The model is verified by using the design parameters of component cooling water heat exchanger and the heat loads during the recirculation mode of loss of coolant accident scenario. This model may be used for calculating the realistic containment response and CCW performance, and increasing the ultimate heat sink temperature limits

Real-time data exchange system in CSRe and RIBBLL II

International Nuclear Information System (INIS)

Liu Wufeng; Xu Yang; Li Guohua; Guo Yuhui; Chinese Academy of Sciences, Beijing; Qiao Weimin; Jing Lan; Wang Yongping; Gou Shizhe

2008-01-01

The design of real-time data exchange system in HIRFL-CSR's CSRe and RIBLL II has been introduced, including it's design of software and hardware. This system realizes controlling power devices at the same time. In system, data is from web browser to center Oracle database. And then, it arrives at sqlite database in ARM module by way of front-server's Oracle database by COM module. Finally, ARM module transmits data to DSP module's memory to control power devices when event is same. At the same time, ADC can acquire device's current value or voltage value which is saved in center Oracle data-base. Practice shows that this system has the character of high reliability and stability. (authors)

Air Circulation and Heat Exchange under Reduced Pressures

Science.gov (United States)

Rygalov, Vadim; Wheeler, Raymond; Dixon, Mike; Hillhouse, Len; Fowler, Philip

Low pressure atmospheres were suggested for Space Greenhouses (SG) design to minimize sys-tem construction and re-supply materials, as well as system manufacturing and deployment costs. But rarified atmospheres modify heat exchange mechanisms what finally leads to alter-ations in thermal control for low pressure closed environments. Under low atmospheric pressures (e.g., lower than 25 kPa compare to 101.3 kPa for normal Earth atmosphere), convection is becoming replaced by diffusion and rate of heat exchange reduces significantly. During a period from 2001 to 2009, a series of hypobaric experiments were conducted at Space Life Sciences Lab (SLSLab) NASA's Kennedy Space Center and the Department of Space Studies, University of North Dakota. Findings from these experiments showed: -air circulation rate decreases non-linearly with lowering of total atmospheric pressure; -heat exchange slows down with pressure decrease creating risk of thermal stress (elevated leaf tem-peratures) for plants in closed environments; -low pressure-induced thermal stress could be reduced by either lowering system temperature set point or increasing forced convection rates (circulation fan power) within certain limits; Air circulation is an important constituent of controlled environments and plays crucial role in material and heat exchange. Theoretical schematics and mathematical models are developed from a series of observations. These models can be used to establish optimal control algorithms for low pressure environments, such as a space greenhouse, as well as assist in fundamental design concept developments for these or similar habitable structures.

Density functionals for surface science: Exchange-correlation model development with Bayesian error estimation

DEFF Research Database (Denmark)

Wellendorff, Jess; Lundgård, Keld Troen; Møgelhøj, Andreas

2012-01-01

A methodology for semiempirical density functional optimization, using regularization and cross-validation methods from machine learning, is developed. We demonstrate that such methods enable well-behaved exchange-correlation approximations in very flexible model spaces, thus avoiding the overfit......A methodology for semiempirical density functional optimization, using regularization and cross-validation methods from machine learning, is developed. We demonstrate that such methods enable well-behaved exchange-correlation approximations in very flexible model spaces, thus avoiding...... the energetics of intramolecular and intermolecular, bulk solid, and surface chemical bonding, and the developed optimization method explicitly handles making the compromise based on the directions in model space favored by different materials properties. The approach is applied to designing the Bayesian error...... sets validates the applicability of BEEF-vdW to studies in chemistry and condensed matter physics. Applications of the approximation and its Bayesian ensemble error estimate to two intricate surface science problems support this....

Pu Anion Exchange Process Intensification

International Nuclear Information System (INIS)

Taylor-Pashow, Kathryn M. L.

2017-01-01

This research is focused on improving the efficiency of the anion exchange process for purifying plutonium. While initially focused on plutonium, the technology could also be applied to other ion-exchange processes. Work in FY17 focused on the improvement and optimization of porous foam columns that were initially developed in FY16. These foam columns were surface functionalized with poly(4-vinylpyridine) (PVP) to provide the Pu specific anion-exchange sites. Two different polymerization methods were explored for maximizing the surface functionalization with the PVP. The open-celled polymeric foams have large open pores and large surface areas available for sorption. The fluid passes through the large open pores of this material, allowing convection to be the dominant mechanism by which mass transport takes place. These materials generally have very low densities, open-celled structures with high cell interconnectivity, small cell sizes, uniform cell size distributions, and high structural integrity. These porous foam columns provide advantages over the typical porous resin beads by eliminating the slow diffusion through resin beads, making the anion-exchange sites easily accessible on the foam surfaces. The best performing samples exceeded the Pu capacity of the commercially available resin, and also offered the advantage of sharper elution profiles, resulting in a more concentrated product, with less loss of material to the dilute heads and tails cuts. An alternate approach to improving the efficiency of this process was also explored through the development of a microchannel array system for performing the anion exchange.

Pu Anion Exchange Process Intensification

Energy Technology Data Exchange (ETDEWEB)

Taylor-Pashow, Kathryn M. L. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

2017-10-06

This research is focused on improving the efficiency of the anion exchange process for purifying plutonium. While initially focused on plutonium, the technology could also be applied to other ion-exchange processes. Work in FY17 focused on the improvement and optimization of porous foam columns that were initially developed in FY16. These foam columns were surface functionalized with poly(4-vinylpyridine) (PVP) to provide the Pu specific anion-exchange sites. Two different polymerization methods were explored for maximizing the surface functionalization with the PVP. The open-celled polymeric foams have large open pores and large surface areas available for sorption. The fluid passes through the large open pores of this material, allowing convection to be the dominant mechanism by which mass transport takes place. These materials generally have very low densities, open-celled structures with high cell interconnectivity, small cell sizes, uniform cell size distributions, and high structural integrity. These porous foam columns provide advantages over the typical porous resin beads by eliminating the slow diffusion through resin beads, making the anion-exchange sites easily accessible on the foam surfaces. The best performing samples exceeded the Pu capacity of the commercially available resin, and also offered the advantage of sharper elution profiles, resulting in a more concentrated product, with less loss of material to the dilute heads and tails cuts. An alternate approach to improving the efficiency of this process was also explored through the development of a microchannel array system for performing the anion exchange.

Down-Hole Heat Exchangers: Modelling of a Low-Enthalpy Geothermal System for District Heating

Directory of Open Access Journals (Sweden)

M. Carlini

2012-01-01

Full Text Available In order to face the growing energy demands, renewable energy sources can provide an alternative to fossil fuels. Thus, low-enthalpy geothermal plants may play a fundamental role in those areas—such as the Province of Viterbo—where shallow groundwater basins occur and conventional geothermal plants cannot be developed. This may lead to being fuelled by locally available sources. The aim of the present paper is to exploit the heat coming from a low-enthalpy geothermal system. The experimental plant consists in a down-hole heat exchanger for civil purposes and can supply thermal needs by district heating. An implementation in MATLAB environment is provided in order to develop a mathematical model. As a consequence, the amount of withdrawable heat can be successfully calculated.

Prediction of Heat Removal Capacity of Horizontal Condensation Heat Exchanger submerged in Pool

Energy Technology Data Exchange (ETDEWEB)

Jeon, Seong-Su; Hong, Soon-Joon [FNC Tech., Yongin (Korea, Republic of); Cho, Hyoung-Kyu [Seoul National University, Seoul (Korea, Republic of); Park, Goon-Cherl [KEPCO International Nuclear Graduate School, Ulsan (Korea, Republic of)

2014-10-15

As representative passive safety systems, there are the passive containment cooling system (PCCS) of ESBWR, the emergency condenser system (ECS) of the SWR-1000, the passive auxiliary feed-water system (PAFS) of the APR+ and etc. During the nuclear power plant accidents, these passive safety systems can cool the nuclear system effectively via the heat transfer through the steam condensation, and then mitigate the accidents. For the optimum design and the safety analysis of the passive safety system, it is essential to predict the heat removal capacity of the heat exchanger well. The heat removal capacity of the horizontal condensation heat exchanger submerged in a pool is determined by a combination of a horizontal in-tube condensation heat transfer and a boiling heat transfer on the horizontal tube. Since most correlations proposed in the previous nuclear engineering field were developed for the vertical tube, there is a certain limit to apply these correlations to the horizontal tube. Therefore, this study developed the heat transfer model for the horizontal Ushaped condensation heat exchanger submerged in a pool to predict well the horizontal in-tube condensation heat transfer, the boiling heat transfer on the horizontal tube and the overall heat removal capacity of the heat exchanger using the best-estimate system analysis code, MARS.

Conceptual Design of a Condensing Heat Exchanger for Space Systems Using Porous Media

Science.gov (United States)

Hasan, Mohammad M.; Khan, Lutful I.; Nayagam, Vedha; Balasubramaniam, Ramaswamy

2006-01-01

Condensing heat exchangers are used in many space applications in the thermal and humidity control systems. In the International Space Station (ISS), humidity control is achieved by using a water cooled fin surface over which the moist air condenses, followed by "slurper bars" that take in both the condensate and air into a rotary separator and separates the water from air. The use of a cooled porous substrate as the condensing surface provides and attractive alternative that combines both heat removal as well as liquid/gas separation into a single unit. By selecting the pore sizes of the porous substrate a gravity independent operation may also be possible with this concept. Condensation of vapor into and on the porous surface from the flowing air and the removal of condensate from the porous substrate are the critical processes involved in the proposed concept. This paper describes some preliminary results of the proposed condensate withdrawal process and discusses the on-going design and development work of a porous media based condensing heat exchanger at the NASA Glenn Research Center in collaboration with NASA Johnson Space Center.

The Effect of Picture Exchange Communication System and Speech Therapy on Communication Development of 4-8 Years Old Autistic Children

Directory of Open Access Journals (Sweden)

Zahra Pour-Ismaili

2011-01-01

Full Text Available Objective: This study compares the effect of speech therapy and picture exchange communication system (PECS on communication development of 4-8 year old autistic children. Materials & Methods: This is an experimental and comparison study. In this study 10 subjects including PECS and speech therapy groups were selected using the available sampling method on the base of including and excluding criteria. Both groups were matched according to age and developmental indices of Niusha scale. Dependent variables were listening, receptive language, expressive language, cognition, speech and social communication. Intervention was applied for both groups similarly divided in 40 minute sessions 3 times a weak for 3 months. Our parameters were evaluated by Niusha development scale before and after interventions. The results were analyzed clinically and statistically by sum-ranks willkokson and rank- signed willkokson. Results: Post test comparison between the two groups revealed that the members of PECS group had a more progress in listening, receptive language, cognition and social communication skills rather than speech therapy group. But these differences were not significant statistically and T(sum ranks was between critical values. Conclusion: considering the results, it could be concluded that PECS is a effective strategy to train non-verbal autistic children. Moreover it could be used as a supplement teaching method beside other therapeutic method such as speech therapy.

Social dilemmas as exchange dilemmas

NARCIS (Netherlands)

Dijkstra, Jacob; van Assen, Marcel A.L.M.

2016-01-01

We develop a new paradigm to study social dilemmas, called exchange dilemmas. Exchange dilemmas arise from externalities of exchanges with third parties, and many real-life social dilemmas are more accurately modeled as exchange dilemmas rather than prisoner's dilemmas. Building on focusing and

Social dilemmas as exchange dilemmas

NARCIS (Netherlands)

Dijkstra, J.; van Assen, M.A.L.M.

2016-01-01

We develop a new paradigm to study social dilemmas, called exchange dilemmas. Exchange dilemmas arise from externalities of exchanges with third parties, and many real-life social dilemmas are more accurately modeled as exchange dilemmas rather than prisoner's dilemmas. Bulding on focusing and

The development of pedagogical content knowledge in science teachers: New opportunities through technology-mediated reflection and peer-exchange

Science.gov (United States)

Madeira, M. Cheryl-Ann

how PCK develops as a result of teachers' engagement in the complex set of activities that constitute the practices of lesson planning and enactment. The primary implication of this study is that engaging teachers in scaffolded reflections and peer exchange can be a valuable in-service professional development activity. A methodological strength is derived from an approach to coding teachers' lesson planning and enactment according to an activity systems perspective, drawing on a spectrum of data sources (e.g., wiki-based reflections, planning artefacts, videotaped classroom enactments). Teacher learning---particularly the development of PCK---is recognized as critical in promoting student understanding of science concepts. This dissertation lays out a possible foundation for professional development models that promote effective teacher learning.

"Price-quakes" shaking the world's stock exchanges.

Directory of Open Access Journals (Sweden)

Jørgen Vitting Andersen

Full Text Available BACKGROUND: Systemic risk has received much more awareness after the excessive risk taking by major financial instituations pushed the world's financial system into what many considered a state of near systemic failure in 2008. The IMF for example in its yearly 2009 Global Financial Stability Report acknowledged the lack of proper tools and research on the topic. Understanding how disruptions can propagate across financial markets is therefore of utmost importance. METHODOLOGY/PRINCIPAL FINDINGS: Here, we use empirical data to show that the world's markets have a non-linear threshold response to events, consistent with the hypothesis that traders exhibit change blindness. Change blindness is the tendency of humans to ignore small changes and to react disproportionately to large events. As we show, this may be responsible for generating cascading events--pricequakes--in the world's markets. We propose a network model of the world's stock exchanges that predicts how an individual stock exchange should be priced in terms of the performance of the global market of exchanges, but with change blindness included in the pricing. The model has a direct correspondence to models of earth tectonic plate movements developed in physics to describe the slip-stick movement of blocks linked via spring forces. CONCLUSIONS/SIGNIFICANCE: We have shown how the price dynamics of the world's stock exchanges follows a dynamics of build-up and release of stress, similar to earthquakes. The nonlinear response allows us to classify price movements of a given stock index as either being generated internally, due to specific economic news for the country in question, or externally, by the ensemble of the world's stock exchanges reacting together like a complex system. The model may provide new insight into the origins and thereby also prevent systemic risks in the global financial network.