WorldWideScience

Sample records for circulation cooldown tests

  1. Cooldown of circulation-type supepconducting magnetic systems

    International Nuclear Information System (INIS)

    Cool-down of two channels of superconducting systems with cryoagent once-through flow is considered analytically. Heat exchange between channels through ''heat bridges'' (electric insulation spacers, etc) in case of stepwise changes of the inlet gas temperature is considered. The model proposed and analytical dependences obtained can be used for calculating the cool-down time for superconducting magne-- tic systems. Determining the cool-down time is shown to be feasible for complex multichannel objects with different boundary conditions by reducing the object to one channel in a definite thermal resistance range

  2. Feasibility test of the concept of long-term passive cooling system of emergency cooldown tank

    International Nuclear Information System (INIS)

    Highlights: • The concept of long-term passive cooling system of emergency cooldown tank (ECT). • Existing natural circulation of steam from ECT and measurement of its condensing flow. • Evaluation of cooling capacity and heat transfer of air-cooled condensing heat exchanger. - Abstract: When a passive cooling system is activated in the accident of a nuclear reactor, the water in the emergency cooldown tank of that system will eventually be fully depleted by evaporation. If, however, the evaporating water could be returned to the tank through an air-cooled condensing heat exchanger mounted on top of the tank, the passive cooling system could provide cooling for an extended period. This feasibility of new concept of long-term passive cooling with an emergency cooldown tank was tested by performing an energy balance test with a scaled-down experimental setup. As a result, it was determined that a naturally circulating steam flow can be used to refill the tank. For an air-cooled heat exchanger, the cooling capacity and air-side natural convective heat transfer coefficient were obtained to be 37% of the heat load and between 9 and 10.2 W/m2/K depending on the heat load, respectively. Moreover, it was clearly verified that the water level in the emergency cooldown tank could be maintained over the long-term operation of the passive cooling system

  3. Qualification of TRACE V5.0 Code against Fast Cooldown Transient in the PKL-III Integral Test Facility

    OpenAIRE

    Eugenio Coscarelli; Alessandro Del Nevo; Francesco D'Auria

    2013-01-01

    The present paper deals with the analytical study of the PKL experiment G3.1 performed using the TRACE code (version 5.0 patch1). The test G3.1 simulates a fast cooldown transient, namely, a main steam line break. This leads to a strong asymmetry caused by an increase of the heat transfer from the primary to the secondary side that induces a fast cooldown transient on the primary side-affected loop. The asymmetric overcooling effect requires an assessment of the reactor pressure vessel integr...

  4. Qualification of TRACE V5.0 Code against Fast Cooldown Transient in the PKL-III Integral Test Facility

    Directory of Open Access Journals (Sweden)

    Eugenio Coscarelli

    2013-01-01

    Full Text Available The present paper deals with the analytical study of the PKL experiment G3.1 performed using the TRACE code (version 5.0 patch1. The test G3.1 simulates a fast cooldown transient, namely, a main steam line break. This leads to a strong asymmetry caused by an increase of the heat transfer from the primary to the secondary side that induces a fast cooldown transient on the primary side-affected loop. The asymmetric overcooling effect requires an assessment of the reactor pressure vessel integrity considering PTS (pressurized thermal shock and an assessment of potential recriticality following entrainment of colder water into the core area. The aim of this work is the qualification of the heat transfer capabilities of the TRACE code from primary to secondary side in the intact and affected steam generators (SGs during the rapid depressurization and the boiloff in the affected SG against experimental data.

  5. Pre-test calculations for PMK-2 test 3.1 with ATHLET code. 30% cold leg break during cooldown. Rev. 0

    International Nuclear Information System (INIS)

    Test 3.1 is a 30% cold leg break during cooldown, with the pressurizer filled with nitrogen. As for the ECCS, only LPIS is available. The calculation was performed with help of the system thermal-hydraulic code ATHLET. (author)

  6. Qualification of TRACE v5 code against fast cooldown transient in the PKL-III integral test facility

    International Nuclear Information System (INIS)

    The present paper deals with the analytical study of the PKL experiment G3.1 performed using the TRACE code (version 5.0 patch 1). The G-series consists of eight tests carried out at the PKL-III facility located in Germany. In particular, the test G3.1 simulates a fast cooldown transient, namely, a main steam line break. The break in the steam line, causes a rapid depressurization of the affected steam generator. This leads to a strong asymmetry caused by an increase of the heat transfer from the primary to the secondary side that induces a fast cooldown transient on the primary side affected loop. The asymmetric overcooling effect requires an assessment of the reactor pressure vessel integrity considering PTS (pressurized thermal shock) and an assessment of potential recriticality following entrainment of colder water into the core area. The analytical investigation is performed by developing a complete TRACE input model of the PKL integral test facility, including 3-dimensional components to simulate the thermalhydraulic behavior of the fluid in the reactor vessel (RPV). The aim of this work is the qualification of the heat transfer capabilities of the TRACE code from primary to secondary side in the intact and affected steam generators (SGs) during the rapid depressurization and the boil-off in the affected SG against experimental data. The accuracy of the calculation is evaluated by qualitative and quantitative analysis. The quantification of the accuracy is performed using the Fast Fourier Transform Base Method (FFTBM) developed at University of Pisa. The tool provides an integral representation of the accuracy quantification in the frequency domain. (author)

  7. Cooldown of the Compact Ignition Tokamak

    International Nuclear Information System (INIS)

    Cooldown of the Compact Ignition Tokamak (CIT) with the baseline liquid nitrogen cooling system was analyzed. On the basis of this analysis and present knowledge of the two-phase heat transfer, the current baseline CIT can be cooled down in about 1.5 h. An extensive heat transfer test program is recommended to reduce uncertainty in the heat transfer performance and to explore methods for minimizing the cooldown time. An alternate CIT cooldown system is described which uses a pressurized gaseous helium coolant in a closed-loop system. It is shown analytically that this system will cool down the CIT well within 1 h. Confidence in this analysis is sufficiently high that a heat transfer test program would not be necessary. The added cost of this alternate system is estimated to be about $5.3 million. This helium cooling system represents a reasonable backup approach to liquid nitrogen cooling of the CIT. 3 refs., 12 figs., 3 tabs

  8. Plant cooldown test simulation after steam generator u-tube rupture under offsite power available without safety injection

    International Nuclear Information System (INIS)

    The objective of the PKL III A 4.4 experiment is to examine that the plant could be controlled by manually operative actions after Steam Generator Tube Rupture under Offsite Power Available without Safety Injection. In order to verify the limitation and ability of the system code NLOOP in the experiment simulation, the behaviors of the PKL III facility obtained in the experiment are compared with the results of NLOOP code. NLOOP code, which is originally developed to simulate the transients of the Westinghouse type PWRs by KAERI/SIEMENS, modified properly to simulate the PKL III facility. Particular attention is given to the RCS mass flow rate of the natural circulation in loops and the termination behavior of the natural circulation in the isolated loop. The comparisons between the experimental and calculational results show the simulation ability and problems of the code. 10 figs., 2 tabs., 6 refs. (Author)

  9. LHC Cooldown, sector 7-8 closed

    CERN Multimedia

    2007-01-01

    The first cooldown of the LHC machine starts in sector 7-8. Access is forbidden between UJ83 and UJ76 from Monday January 15th at 8 a.m. until Monday February 5th at 8:30 a.m. During these tests, access to the underground at point 7 is forbidden. At point 8, the LHCb cavern (except cryo zone), the LHC tunnel towards point 1 and UA83 remain accessible. For detailed information please refer to EDMS document 805687. The LHC Safety Coordination

  10. LHC Cooldown, sector 7-8 closed

    CERN Multimedia

    2007-01-01

    The first cooldown of the LHC machine has started in sector 7-8. Access is forbidden between UJ83 and UJ76 from 8 a.m. on Monday 15 January to 8:30 a.m. on Monday 5 February. During these tests, access to the underground at point 7 is forbidden. At Point 8, the LHCb cavern (except cryo zone), the LHC tunnel towards Point 1 and UA83 will remain accessible. For detailed information please refer to EDMS document 805687. The LHC Safety Coordination Team

  11. Gas cooled fast breeder reactor design for a circulator test facility (modified HTGR circulator test facility)

    Energy Technology Data Exchange (ETDEWEB)

    1979-10-01

    A GCFR helium circulator test facility sized for full design conditions is proposed for meeting the above requirements. The circulator will be mounted in a large vessel containing high pressure helium which will permit testing at the same power, speed, pressure, temperature and flow conditions intended in the demonstration plant. The electric drive motor for the circulator will obtain its power from an electric supply and distribution system in which electric power will be taken from a local utility. The conceptual design decribed in this report is the result of close interaction between the General Atomic Company (GA), designer of the GCFR, and The Ralph M. Parson Company, architect/engineer for the test facility. A realistic estimate of total project cost is presented, together with a schedule for design, procurement, construction, and inspection.

  12. Gas cooled fast breeder reactor design for a circulator test facility (modified HTGR circulator test facility)

    International Nuclear Information System (INIS)

    A GCFR helium circulator test facility sized for full design conditions is proposed for meeting the above requirements. The circulator will be mounted in a large vessel containing high pressure helium which will permit testing at the same power, speed, pressure, temperature and flow conditions intended in the demonstration plant. The electric drive motor for the circulator will obtain its power from an electric supply and distribution system in which electric power will be taken from a local utility. The conceptual design decribed in this report is the result of close interaction between the General Atomic Company (GA), designer of the GCFR, and The Ralph M. Parson Company, architect/engineer for the test facility. A realistic estimate of total project cost is presented, together with a schedule for design, procurement, construction, and inspection

  13. Experimental study of the nuclotron magnet cool-down and warm-up processes

    International Nuclear Information System (INIS)

    A circuit of the experimental setup is escribed. The results of the study of cool-down process for a single magnet, string of two and four magnets as well as warm-up process for a single magnet are presented. The test data which are necessary for calculation and the following choice of the nuclotron magnet system cool-down and warm-up modes have been obtained. 6 refs.; 5 figs

  14. Investigation of azimuthal stresses due to welding and cooldown

    International Nuclear Information System (INIS)

    For some time, it has been known that a prestress in the cold mass skin surrounding the yoke was desirable for the prevention of unwanted ''loose'' coil effects on the performance of magnets. From practical experience, it was determined that the hoop stresses developed by seam welding were adequate to provide the desired preload on the coils. The tests reported here were intended to: (1) Determine the stresses developed by welding, (2) Attempt to determine the friction coefficient between the yoke laminations and the stainless steel shell, (3) Determine the effects of repeated cooldown cycles on the stresses in the shell

  15. Shuttle Centaur engine cooldown evaluation and effects of expanded inlets on start transient

    Science.gov (United States)

    1987-01-01

    As part of the integration of the RL10 engine into the Shuttle Centaur vehicle, a satisfactory method of conditioning the engine to operating temperatures had to be established. This procedure, known as cooldown, is different from the existing Atlas Centaur due to vehicle configuration and mission profile differenced. The program is described, and the results of a Shuttle Centaur cooldown program are reported. Mission peculiarities cause substantial variation in propellant inlet conditions between the substantiated Atlas Centaur and Shuttle Centaur with the Shuttle Centaur having much larger variation in conditions. A test program was conducted to demonstrate operation of the RL10 engine over the expanded inlet conditions. As a result of this program, the Shuttle Centaur requirements were proven satisfactory. Minor configuration changes incorporated as a result of this program provide substantial reduction in cooldown propellant consumption.

  16. Validation of SSC using the FFTF natural-circulation tests

    International Nuclear Information System (INIS)

    As part of the Super System Code (SSC) validation program, the 100% power FFTF natural circulation test has been simulated using SSC. A detailed 19 channel, 2 loop model was used in SSC. Comparisons showed SSC calculations to be in good agreement with the Fast Flux Test Facility (FFTF), test data. Simulation of the test was obtained in real time

  17. Design realization towards the qualification test of ITER cold circulator

    Science.gov (United States)

    Bhattacharya, R.; Sarkar, B.; Vaghela, H.; Patel, P.; Das, J.; Srinivasa, M.; Shukla, V.

    2015-12-01

    Cold circulators, part of ITER Cryo-distribution system, have now reached to a stage of final qualification to demonstrate the design to cater the maximum mass flow and operational demands of the toroidal field (TF) superconducting magnet of ITER with a very high isentropic efficiency. The design for the two numbers of TF cold circulators are now complete gratifying additionally the operational requirements of poloidal field & central solenoid superconducting magnet as well as the cryopumps towards the fulfilment of standardization aspects. Management of physical and functional interfaces has been identified as one the most critical aspect towards the performance of cold circulator. All the interfaces of cold circulators have been analysed with the help of optimized interfacing parameters of Test Auxiliary Cold Box (TACB) and cryogenic test facility at JAEA, Japan during the course of design finalization. Testing at the warm conditions after completion of precise manufacturing of cold circulators has been performed before integrating into the TACB to fulfil the Japanese as well as European regulatory requirements simultaneously. The paper elaborates the methodology of interface management and control, analysis performed towards the interface management and preliminary test results towards the qualification test of the ITER cold circulator.

  18. Natural circulation in an integral CANDU test facility

    International Nuclear Information System (INIS)

    Over 70 single- and two-phase natural circulation experiments have been completed in the RD-14M facility, an integral CANDU thermalhydraulic test loop. This paper describes the RD-14M facility and provides an overview of the impact of key parameters on the results of natural circulation experiments. Particular emphasis will be on phenomena which led to heat up at high system inventories in a small subset of experiments. Clarification of misunderstandings in a recently published comparison of the effectiveness of natural circulation flows in RD-14M to integral facilities simulating other reactor geometries will also be provided. (author)

  19. Cool-down induced hydride reorientation of hydrogen-charged Zirconium alloy cladding tubes

    International Nuclear Information System (INIS)

    250 and 500ppm hydrogen-charged Zirconium alloy tubes were employed to investigate hydride reorientation behaviors when they were cool down from 400 to 300, 200degC and room temperature with various cooling rates of 0.3, 2.0, 4.0, 7.0 and 15.0degC/min under a tensile hoop stress of 150MPa. These cool-down tests indicate that the slower cooling rate and the lower terminal cool-down temperature produced the more hydrides precipitated along with the larger fraction and the longer length of radial hydrides. These phenomena may be explained by terminal solid solubility of hydrogen for dissolution and precipitation and cooling rate-dependent hydride nucleation and growth rates. On the other hand, a dramatic decrease of ultimate tensile strength and plastic strain of the cool-down tested specimens may be explained by the amount of the radial hydrides precipitated during the cool-down process. (author)

  20. External verification of the ATHLET code by analytical and phenomenological evaluation of one PKL and TRAM test each. Pt. 1. Post-test calculation of the PKL III test A 4.3. Cooldown of a PWR facility with two running main coolant pumps after a steam generator U-tube rupture. Final report

    International Nuclear Information System (INIS)

    A post test calculation of the PKL III test A 4.3 using the GRS system code ATHLET MOD 1.0 Cycle E is presented. This integral test was performed to investigate the overall system hehaviour and the thermohydraulic phenomena during the cooldown of a PWR-facility with two running main coolant pumps after a steam generator u-tube rupture. Using a 3-loop input model with nearly the same nodalization as chosen for the analyses of transients in PWR facilities the most important phenomena could be simulated qualitatively: Development of pressure and water level in the defective, isolated steam generator, development of system pressure and of water level in the pressurizer, leak mass flow, formation and disappearance of a steam bubble in the upper head of the reactor vessel. The nodalization of the secondary side was rather coarse and the u-tubes were only represented by one pipe. Therefore the sudden pressure decrease in the defective steam generator caused by condensation after the clearence of the top of the u-tubes could only be well predicted by a strong reduction of the condensation rate. (orig.)

  1. Circulation and Purification in the LUX-ZEPLIN System Test

    Science.gov (United States)

    Alsum, Shaun; Lz Collaboration

    2016-03-01

    LZ is a dark-matter direct detection experiment whose detector is a two-phase TPC using approximately seven tons of active xenon as its scintillator. The xenon must have few electronegative impurities to ensure sufficient electron transport through the drift region. The LZ purification system is being prototyped in the LZ system test, a test platform located at SLAC using about 100kg of Xenon, which consists of gas circulation through a SAES getter. We utilize a dual-phase and a gas-phase heat exchanger to reduce needed cooling power. To achieve this circulation we employ an all metal seal triple diaphragm pump, also prototyped in the System Test. This talk will present early results from the system test as well as some baseline LZ designs. The LUX-ZEPLIN dark matter direct detection experiment.

  2. Cool-down and frozen start-up behavior of a grooved water heat pipe

    Science.gov (United States)

    Jang, Jong Hoon

    1990-01-01

    A grooved water heat pipe was tested to study its characteristics during the cool-down and start-up periods. The water heat pipe was cooled down from the ambient temperature to below the freezing temperature of water. During the cool-down, isothermal conditions were maintained at the evaporator and adiabatic sections until the working fluid was frozen. When water was frozen along the entire heat pipe, the heat pipe was rendered inactive. The start-up of the heat pipe from this state was studied under several different operating conditions. The results show the existence of large temperature gradients between the evaporator and the condenser, and the moving of the melting front of the working fluid along the heat pipe. Successful start-up was achieved for some test cases using partial gravity assist. The start-up behavior depended largely on the operating conditions.

  3. Production circulator fabrication and testing for core flow test loop. Final report, Phase III

    International Nuclear Information System (INIS)

    The performance testing of two production helium circulators utilizing gas film lubrication is described. These two centrifugal-type circulators plus an identical circulator prototype will be arranged in series to provide the helium flow requirements for the Core Flow Test Loop which is part of the Gas-Cooled Fast Breeder Reactor Program (GCFR) at the Oak Ridge National Laboratory. This report presents the results of the Phase III performance and supplemental tests, which were carried out by MTI during the period of December 18, 1980 through March 19, 1981. Specific test procedures are outlined and described, as are individual tests for measuring the performance of the circulators. Test data and run descriptions are presented

  4. A Cool-down and Fault Study of a Long Length HTS Power Transmission Cable

    Science.gov (United States)

    Yuan, J.; Maguire, J.; Allais, A.; Schmidt, F.

    2006-04-01

    High temperature superconductor (HTS) power transmission cables offer significant advantages in power density over conventional copper-based cables. Currently the US Department of Energy is funding the design, development, and demonstration of the first long length, transmission level voltage, cold dielectric, underground high temperature superconductor power cable. The cable is 620 meters long and is designed for permanent installation in the Long Island Power Authority (LIPA) grid. The cable is specified to carry 574 MVA at a voltage of 138 kV and is designed to withstand a 69 kA fault current for a duration of 200ms. The superconducting state of the cable conductors is maintained by circulating sub-cooled liquid nitrogen, which flows through one phase conductor of the cable and returns through the other two. As HTS cables develop and lengths increase to what may be considered commercial, it is critical to study the cable thermal behavior during cool-down process and fault condition to avoid any possible damage to the cable core due to the thermal stress, over heating or bubble formation. This paper reviews the efforts that have been made to study the cool-down process and fault condition. Descriptions of the transient thermal and fluid model are provided. A discussion of the simulation results is also included.

  5. Experimental study of the UNK superconducting dipole cooldown and warmup

    International Nuclear Information System (INIS)

    The results of the experimental investigations for cooldown to 4.5 K and warmup precesses in the single 6 m SC dipole magnet of the UNK with a cold iron are presented. The temperature distributions were measured with 232 temperature sensors arranged in 14 cross sections of the dipole. Both usual cryogenic technological processes and regimes connected with the SC magnet transition into a normal state were investigated. 3 refs.; 9 figs

  6. Heat transfer in a cooling water pool with tube bundles under natural circulation

    International Nuclear Information System (INIS)

    Highlights: • SMART adopts a passive system to enhance its safety. • Heat transfer tests for the straight tube bundle in the cooling water pool are performed. • Heat transfer is affected by cooling water temperature, and radial location of the tube. • Heat transfer for the tube bundle is slightly high due to turbulence effect. - Abstract: SMART was developed for electricity generation and seawater desalination and adopted a passive system to enhance its safety. This system could passively remove decay heat from the reactor core to the emergency cooldown tank (ECT) through the heat exchanger. A natural circulation flow was established as water covered the tube bundle inside the emergency cooldown tank. Heat transfer tests for the upward straight tube bundle in the emergency cooldown tank were performed to find the characteristics of the passive system design under natural circulation conditions. The heat transfer coefficient at the tube bundle was affected by the cooling water temperature, and the radial location of the tube. However, it has nearly a similar value at the bottom region regardless of the tube location. The average heat transfer coefficient for the tube bundle was slightly higher than that for the single tube owing to the turbulence effect among the tube bundles

  7. Cooldown and warmup computer simulations of the SSC ring

    International Nuclear Information System (INIS)

    The Superconducting Super Collider (SSC) consists of two stacked rings of superconducting magnets; each ring is about 86 km in circumference. The total mass to be cooled to liquid helium temperature amounts to about 1 x 108 kg, and the total helium inventory under nominal operating conditions (4.15 K and 4 atm) is about 2.8 x 105 kg. The cooldown and warmup process of a long string of magnets has to be well understood in order to design a cryogenic system that can satisfy the requirements of helium inventory handling, magnet temperature gradients, and process time for the different cooldown and warmup scenarios being planned for the SSC. A system that can be convincingly simulated can be understood, controlled, operated and improved in a systematic way. In this paper, we introduce two numerical models, a lumped model and a distributed model, for cooldown and warmup of the SSC ring, and present simulation results for an SSC string (4320 m long, or 1/20th of the full ring circumference). The models cover the temperature range between room and liquid helium temperature; the distributed model includes radial temperature distribution in the cold mass. Low temperature range simulations are particularly important to study inventory handling strategies because of the relationship between rapid changes in density and the system mass flow rate. 9 refs., 9 figs

  8. High-power Circulator Test Results at 350 MHz and 700 MHz

    OpenAIRE

    Roybal, W. T.; Bradley III, J.; Rees, D.; Torrez, P. A.; Warner, D. K.; DeBaca, J.

    2000-01-01

    The high-power RF systems for the Accelerator Production of Tritium (APT) program require high-power circulators at 350 MHz and 700 MHz to protect 1 MW Continuous Wave (CW) klystrons from reflected power. The 350 MHz circulator is based on the CERN, ESRF, and APS designs and has performed very well. The 700 MHz circulator is a new design. Prototype 700 MHz circulators have been high-power tested at Los Alamos National Laboratory (LANL). The first of these circulators has satisfied performance...

  9. Cooldown Measurements in a Standing Wave Thermoacoustic Refrigerator

    CERN Document Server

    Dhuley, R C

    2016-01-01

    Thermoacoustic Refrigerators (TARs) use acoustic power to generate cold temperatures. Apart from the operating frequency and the mean temperature of the working medium, the charging pressure and the dynamic pressure in the TAR govern its attainable cold temperature. The effect of charging pressure on the dynamic pressure in a loudspeaker driven gas filled standing wave column has been well understood. The present work aims to investigate the effect of charging pressure on the cold end temperature of a standing wave TAR. The cold end temperature lift and the cooldown for several changing pressures are reported. The effect of vacuum around the cold end on the TAR performance is also presented.

  10. Evaluation of the natural circulation capability test results for Ulchin nuclear power plant unit 3

    Energy Technology Data Exchange (ETDEWEB)

    Sung, Kang Sik; Jeong, Weon Sang; Lee, Ju Han; Seo, Jong Tae; Lee, Sang Keun [Korea Power Engineering Company, Inc., Taejon (Korea, Republic of); Mo, Yong Won; Ryuk, Keun Su; Shin, Bong Chul; Kim, Byung Ho; Oh, Chul Sung [KEPCO, Ulchin (Korea, Republic of)

    1998-10-01

    During the Power Ascension Test (PAT) period, the transient tests related to the natural circulation capability were successfully completed for Ulchin Nuclear Power Plant Unit 3 (UCN 3). The tests were successfully completed by meeting all acceptance criteria. The post-trip PCS shows good performance as designed and the measured natural circulation capacity was demonstrated to be adequate for the core decay heat removal for UCN 3.

  11. Evaluation of the natural circulation capability test results for Ulchin nuclear power plant unit 3

    International Nuclear Information System (INIS)

    During the Power Ascension Test (PAT) period, the transient tests related to the natural circulation capability were successfully completed for Ulchin Nuclear Power Plant Unit 3 (UCN 3). The tests were successfully completed by meeting all acceptance criteria. The post-trip PCS shows good performance as designed and the measured natural circulation capacity was demonstrated to be adequate for the core decay heat removal for UCN 3

  12. Engineering, Manufacture and Preliminary Testing of the ITER Toroidal Field (TF) Magnet Helium Cold Circulator

    Science.gov (United States)

    Rista, P. E. C.; Shull, J.; Sargent, S.

    2015-12-01

    The ITER cryodistribution system provides the supercritical Helium (SHe) forced flow cooling to the magnet system using cold circulators. The cold circulators are located in each of five separate auxiliary cold boxes planned for use in the facility. Barber-Nichols Inc. has been awarded a contract from ITER-India for engineering, manufacture and testing of the Toroidal Field (TF) Magnet Helium Cold Circulator. The cold circulator will be extensively tested at Barber-Nichols’ facility prior to delivery for qualification testing at the Japan Atomic Energy Agency's (JAEA) test facility at Naka, Japan. The TF Cold Circulator integrates features and technical requirements which Barber-Nichols has utilized when supplying helium cold circulators worldwide over a period of 35 years. Features include a vacuum-jacketed hermetically sealed design with a very low helium leak rate, a heat shield for use with both nitrogen & helium cold sources, a broad operating range with a guaranteed isentropic efficiency over 70%, and impeller design features for high efficiency. The cold circulator will be designed to meet MTBM of 17,500 hours and MTBF of 36,000 hours. Vibration and speed monitoring are integrated into a compact package on the rotating assembly with operation and health monitoring in a multi-drop PROFIBUS communication environment using an electrical cabinet with critical features and full local and network PLC interface and control. For the testing in Japan and eventual installation in Europe, the cold circulator must be certified to the Japanese High Pressure Gas Safety Act (JHPGSA) and CE marked in compliance with the European Pressure Equipment Directive (PED) including Essential Safety Requirements (ESR). The test methodology utilized at Barber-Nichols’ facility and the resulting test data, validating the high efficiency of the TF Cold Circulator across a broad operating range, are important features of this paper.

  13. Feasibility analysis of aggressive cooldown in OPR-1000 nuclear power plants

    International Nuclear Information System (INIS)

    Highlights: • We examine the feasibility of aggressive cooldown, particularly in OPR-1000 plants. • We review experimental and simulation results, EOPs, and time estimates. • Aggressive cooldown is, in general, expected to be performed successfully. • There is potential for failure to initiate aggressive cooldown in a timely manner. • Investigation on allowing higher cooldown rate in OPR-1000 plants is recommended. - Abstract: Aggressive cooldown is the action taken by main control room (MCR) operators to rapidly cool down and depressurize the reactor coolant system at the maximum allowed cooldown rate during a small break loss of coolant accident (SBLOCA) or a steam generator tube rupture accident with failure of high-pressure safety injection (HPSI) in a pressurized water reactor. We examined the feasibility of aggressive cooldown in OPR-1000 nuclear power plants by establishing success criteria based on experimental results and thermal–hydraulic code simulations, reviewing emergency operating procedures, and estimating the necessary time for MCR operators to initiate aggressive cooldown based on experimental results with licensed nuclear power plant operators. For an SBLOCA with a break size of 0.02 ft2 combined with total failure of HPSI, we found that aggressive cooldown can generally be performed successfully, but there is potential for failure to initiate aggressive cooldown in a timely manner. We discuss the potential effects of introducing the Ultimate Procedure on reducing the core damage potential. Detailed analysis and further discussion are necessary to reduce uncertainties associated with aggressive cooldown and its positive effect on the safety of nuclear power plants

  14. An experimental substantiation of the emergency cooldown system project for the KLT-40S reactor installation of a floating nuclear cogeneration station

    Science.gov (United States)

    Balunov, B. F.; Shcheglov, A. A.; Il'in, V. A.; Saikova, E. N.; Bol'Shukhin, M. A.; Bykh, O. A.; Khizbullin, A. M.; Sokolov, A. N.

    2011-05-01

    Results from thermal-hydraulic tests of a full-scale module of the emergency cooldown system for a KLT-40S reactor installation are presented. The validity of the solutions adopted in its design is shown. Recommendations for calculating the heat transfer coefficients during steam flow condensation and condensate cooling are given.

  15. Analysis of the NPP-V1 primary circuit fast cooldown

    International Nuclear Information System (INIS)

    Results of thermal-hydraulic calculations of the NPP-V1 primary circuit fast cooldown during small leakage through openings of diameter 20, 32 and 50 mm as well as analyses of cooldown following the steam pipeline break at nominal and null reactor power are given in this paper. 4 refs, 24 figs, 1 tab

  16. Design of Automated Function for Safe Cooldown Using F and B Operation

    International Nuclear Information System (INIS)

    Human error has been handled as one of the main reasons of nuclear power plant (NPP) accidents, and people have made a lot of effort to reduce the human error in NPPs. Automation has led to increased comfort, safety, quality control, efficiency, magnification and scale of work within the NPP industry. The automation not only reduces the operator's workload, but also increases the accuracy of operation. To reduce the operator's workload and perform the operation accurate after the accident, automated function for safe cooldown based on the F and B operation is suggested. The F and B operation is the process of primary cooling system and it is important because it is last resort if all other attempts failed. AFSC should be not only reflected the procedure of the F and B operation for the automation, but also considered the reactor condition including accident scenarios and possible components to expect the success of heat removal. To expect the success of AFSC, success boundary should be identified according to the critical conditions. Critical conditions are largely affected whether LOCA or non-LOCA occurs. Moreover, the break size of LOCA is important to maintain the heat transfer from primary system to secondary system. Cases studies are performed for available range of natural circulation according to break size with/without the F and B operation. Based on these results, the effects of availability of relevant components for success boundary of AFSC could be obtained

  17. Quantitative measurement of blood circulation in tests of rats using nuclear medical methods

    International Nuclear Information System (INIS)

    The experiments show that is it is possible to quantitatively assess the blood circulation and, within limits, the germinative function of tests by measuring the impulses of an incorporated radionuclide (99-Tc-pertechnetate) using an uptake measuring instrument. This is a rapid and unbloody method to be adopted in human medicine. 'Acute tests' or pre-damaged tests can thus be exactly diagnosed. In the former case the circulation modification and in the latter the evaluation of the germinative function ability is of main interest. The most important measuring criterion is the 15-minute-uptake U; it represents the blood circulation in the tests measured. The germinative function ability is evaluated on the basis of the accumulation activity Nsub(max). (orig./MG)

  18. Cool-down of a vertical line with liquid nitrogen

    Science.gov (United States)

    Hedayatpour, A.; Antar, B. N.; Kawaji, M.

    1993-09-01

    Analytical and numerical modeling is presented for predicting the thermofluid parameters of the cool-down process of an open-to-air vertical tube carrying liquid nitrogen. A two-fluid mathematical model is employed to describe the flowfield. In this model four distinct flow regions were analyzed: (1) fully liquid, (2) inverted annular film boiling, (3) dispersed flow, and (4) fully vapor. These flow regimes were observed in an experimental investigation constructed for validating the mathematical model, and also in previous experiments by other investigators. For the single-phase regions, the one-dimensional form of mass, momentum, and energy equations were used. For the two-phase regions, the volume-averaged, phasic one-dimensional form of conservation equations were applied. The one-dimensional energy equation was formulated to determine the tube wall temperature history. The numerical procedure is based on the semi-implicit, finite-difference technique. The calculations for the inverted annular film boiling were performed implicitly. The computations for the tube wall, fully liquid, and dispersed flow regions were performed explicitly. In each region, the appropriate models for heat transfer and shear stress rates are used. Results and comparisons of the predicted numerical models with the experimental data for several constant inlet flow rates of liquid nitrogen into a vertical, insulated tube are presented.

  19. Steady state performance of subcritical and supercritical pressure natural circulation in the same test facility

    International Nuclear Information System (INIS)

    For supercritical pressure natural circulation loops, explicit correlation for steady state flow are not available. While using the subcritical natural circulation flow correlation for supercritical pressure data, it has been observed that subcritical flow correlation is not able to predict the steady state flow accurately near supercritical pressure condition. A generalized correlation has been proposed to estimate the steady state flow in supercritical pressure natural circulation loop based on a relationship between dimensionless density and dimensionless enthalpy reported in literature. This generalized correlation has been tested with the steady state supercritical pressure CO2 data and found to be in good agreement. Subsequently supercritical pressure data for different working fluids reported in literature has also been compared with the proposed correlation. It is observed that the same generalized correlation is applicable for other fluids also. The present paper deals with the details of the test facility, the derivation of the generalized correlation and comparison with experimental data. (author)

  20. Integral test facilities for validation of the performance of passive safety systems and natural circulation

    International Nuclear Information System (INIS)

    Passive safety systems are becoming an important component in advanced reactor designs. This has led to an international interest in examining natural circulation phenomena as this may play an important role in the operation of these passive safety systems. Understanding reactor system behaviour is a challenging process due to the complex interactions between components and associated phenomena. Properly scaled integral test facilities can be used to explore these complex interactions. In addition, system analysis computer codes can be used as predictive tools in understanding the complex reactor system behaviour. However, before the application of system analysis computer codes for reactor design, it is capability in making predictions needs to be validated against the experimental data from a properly scaled integral test facility. The IAEA has organized a coordinated research project (CRP) on natural circulation phenomena, modeling and reliability of passive systems that utilize natural circulation. This paper is a part of research results from this CRP and describes representative international integral test facilities that can be used for data collection for reactor types in which natural circulation may play an important role. Example experiments were described along with the analyses of these example cases in order to examine the ability of system codes to model the phenomena that are occurring in the test facilities. (Author)

  1. Fort St. Vrain helium circulator auxiliary systems: dynamic performance evaluation and acceptance tests

    International Nuclear Information System (INIS)

    The purpose of the tests described is to show that the dynamic performance of the Fort St. Vrain helium circulator auxiliary systems satisfies all the guidelines and criteria established and agreed to by Public Service Company of Colorado (PSC), Proto-Power, and General Atomic Company (GA). Specifically, it is shown that transfers to and from backup bearing water and helium purification system transients do not cause any circulator trips. Furthermore, at PSC's request, in an effort to resolve any NFSC questions concerning these systems, the satisfactory repeatability of their dynamic performance is shown beyond any doubt.

  2. Design, Development and Testing of a Drillable Straddle Packer for Lost Circulation Control in Geothermal Drilling

    Energy Technology Data Exchange (ETDEWEB)

    Gabaldon, J.; Glowka, D.A.; Gronewald, P.; Knudsen, S.D.; Raymond, D.W.; Staller, G.E.; Westmoreland, J.J.; Whitlow, G.L.; Wise, J.L.; Wright, E.K.

    1999-04-01

    Lost Circulation is a widespread problem encountered when drilling geothermal wells, and often represents a substantial portion of the cost of drilling a well. The U.S. Department of Energy sponsors research and development work at Sandia National Laboratories in an effort to reduce these lost circulation expenditures. Sandia has developed a down hole tool that improves the effectiveness and reduces th cost of lost circulation cement treatment while drilling geothermal wells. This tool, the Drillable Straddle Packer, is a low-cost disposable device that is used to isolate the loss zone and emplace the cement treatment directly into the region of concern. This report documents the design and development of the Drillabe Straddle Packer, the laboratory and field test results, and the design package that is available to transfer this technology to industry users.

  3. Two-phase flow patterns recognition and parameters estimation through natural circulation test loop image analysis

    International Nuclear Information System (INIS)

    Visualization of natural circulation test loop cycles is used to study two-phase flow patterns associated with phase transients and static instabilities of flow. Experimental studies on natural circulation flow were originally related to accidents and transient simulations relative to nuclear reactor systems with light water refrigeration. In this regime, fluid circulation is mainly caused by a driving force ('thermal head') which arises from density differences due to temperature gradient. Natural circulation phenomenon has been important to provide residual heat removal in cases of 'loss of pump power' or plant shutdown in nuclear power plant accidents. The new generation of compact nuclear reactors includes natural circulation of their refrigerant fluid as a security mechanism in their projects. Two-phase flow patterns have been studied for many decades, and the related instabilities have been object of special attention recently. Experimental facility is an all glass-made cylindrical tubes loop which contains about twelve demineralized water liters, a heat source by an electrical resistor immersion heater controlled by a Variac, and a helicoidal heat exchanger working as cold source. Data is obtained through thermo-pairs distributed over the loop and CCD cameras. Artificial intelligence based algorithms are used to improve (bubble) border detection and patterns recognition, in order to estimate and characterize, phase transitions patterns and correlate them with the periodic static instability (chugging) cycle observed in this circuit. Most of initial results show good agreement with previous numerical studies in this same facility. (author)

  4. Test Results of Reactor Coolant System Natural Circulation using the SMART-ITL Facility

    International Nuclear Information System (INIS)

    In this paper, the Sequence Of Event (SOE) and test conditions of RCS natural circulation test using SMART-ITL are presented, and the major measuring parameters and the test results will be introduced. In this test, the steady state operation satisfied the initial condition of the prescribed test procedure and the boundary conditions were properly simulated. After the RCPs stop, the RCS natural circulation flow was generated by heating in the core region and cooling in the SG heat exchanger region, and the major thermalhydraulic parameters reached at a stable condition. Through this experiment, it has been validated that the SMART-ITL facility can adequately simulate the RCS natural circulation behavior. In addition, it is expected that the experimental data can be used for the code assessment of the TASS/SMR-S code and experiences from this test can be utilized to the subsequent SBLOCA simulation test. SMART (System-integrated Modular Advanced Reactor) is an integral type reactor which major primary components such as the steam generator, the pressurizer, and the reactor coolant pump are installed inside one single reactor vessel and connecting primary pipes are removed. The TASS/SMR-S code is used to perform the performance and safety analysis of the SMART. To evaluate the capability of TASS/SMR-S code on the natural circulation and accident scenarios such as Small-Break Loss of Coolant Accident (SBLOCA) for predicting the thermal-hydraulic phenomena in steady state and transient operation, it is essential to perform a series of validation tests

  5. Improvement of Emergency Cooldown Tank in terms of long-term cooling

    International Nuclear Information System (INIS)

    SMART received its Standard Design Approval(SDA) from Korea Government in 2012. After Fukushima accident, passively cooling system of nuclear reactor gets great attention and a consentience reached that at least 72 hours of grace time after an accident should be secured, during which a nuclear reactor remains in safe condition without any operator's intervention. To meet this requirement, SMART adapted passive cooling system such as passive residual heat removal system(PRHRS). It is composed of an emergency cooldown tank(ETC), a heat exchanger and a makeup tank. The ETC should be refilled periodically by auxiliary water supply system in order to use it beyond 72 hours. Otherwise the immersed heat exchanger would be exposed to the air, which would damage the function of PRHRS. To overcome this shortcoming, installation of an air-cooling heat exchanger at the top of the ETC is proposed as shown in Fig. 2. Here the top of the ETC is now closed. Evaporated steam is collected through the vertical duct and condensed through air-cooling heat exchanger. By natural circulation, water level of ETC can be maintained at steady state for a very long-term period. The purpose of the present study is to investigate the thermal sizing of air-cooling heat exchanger which extends the cooling period of ETC. Thermal sizing of air-cooling heat exchanger had been investigated by using several heat transfer correlations for natural convection of vertical tubes. Quantitative comparisons were made to find out how many tubes are required to remove the residual heat. This work would contribute to improve the current design of ETC and to extend the cooling period much longer than 72 hours, which will promote the passive safety function of SMART

  6. Acceptance tests of the BEPC II RF transmitter and the circulator

    International Nuclear Information System (INIS)

    The high power RF transmitter and the circulator with 500 MHz/250 kW which will be operated in Beijing Electron-Positron Collider Upgrade (BEPC II) project have been installed on site, and adjustments and acceptance test have been finished, which is the first transmitter system of 500 MHz/250 kW in China. In this paper, the test principle and all measurements as well as commissioning result in the acceptance test are introduced in details, and the actual machine technical parameters and performance are presented. An acceptance test conclusion by comparing with the design requirements is given. (authors)

  7. High-Reynolds Number Circulation Control Testing in the National Transonic Facility

    Science.gov (United States)

    Milholen, William E., II; Jones, Gregory S.; Chan, David T.; Goodliff, Scott L.

    2012-01-01

    A new capability to test active flow control concepts and propulsion simulations at high Reynolds numbers in the National Transonic Facility at the NASA Langley Research Center is being developed. The first active flow control experiment was completed using the new FAST-MAC semi-span model to study Reynolds number scaling effects for several circulation control concepts. Testing was conducted over a wide range of Mach numbers, up to chord Reynolds numbers of 30 million. The model was equipped with four onboard flow control valves allowing independent control of the circulation control plenums, which were directed over a 15% chord simple-hinged flap. Preliminary analysis of the uncorrected lift data showed that the circulation control increased the low-speed maximum lift coefficient by 33%. At transonic speeds, the circulation control was capable of positively altering the shockwave pattern on the upper wing surface and reducing flow separation. Furthermore, application of the technique to only the outboard portion of the wing demonstrated the feasibility of a pneumatic based roll control capability.

  8. Cool-down, static heat load and warm-up performance of the central solenoid model coil and the central solenoid insert model coil

    International Nuclear Information System (INIS)

    In International Thermonuclear Experimental Reactor (ITER) Engineering Design Activities, the Central Solenoid model Coil (CSMC) and the CS Insert Coil (CSIC) have been fabricated, and installed into the ITER CSMS test facility at Naka Fusion Establishment, Japan Atomic Energy Research Institute (JAERI). The CSMS and CSIC conductors are applied to the cable-in-conduit conductors cooled by forced-flow supercritical helium (SHe) at 4.5 K. There are 48 parallel cooling channels for the CSMC, the CSIC and the structures. In the CSMC experiment, the cool-down and the warm-up were finished successfully. The cool-down time was within 480 hours. The steady head load without coil current was measured and evaluated. (author)

  9. Water test of natural circulation for decay heat removal in JSFR

    International Nuclear Information System (INIS)

    Japan Atomic Energy Agency (JAEA) is conducting a design study of Japan Sodium-cooled Fast Reactor (JSFR), in which a decay heat removal system (DHRS) utilizing natural circulation (NC) is applied as an innovative technology. The Central Research Institute of Electric Power Industry (CRIEPI) has carried out a water test to verify the applicability of NC to decay heat removal. The test used a 1/10-scale model of JSFR. Key issues on thermal-hydraulics were identified through simulation tests on representative events. Measures were also proposed to resolve these issues. The present study has demonstrated that a sufficient and stable NC is established in each event. (author)

  10. A Test Facility for MEIC ERL Circulator Ring Based Electron Cooler Design

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yuhong [JLAB; Derbenev, Yaroslav S. [JLAB; Douglas, David R. [JLAB; Hutton, Andrew M. [JLAB; Krafft, Geoffrey A. [JLAB; Nissen, Edward W. [JLAB

    2013-05-01

    An electron cooling facility which is capable to deliver a beam with energy up to 55 MeV and average current up to 1.5 A at a high bunch repetition rate up to 750 MHz is required for MEIC. The present cooler design concept is based on a magnetized photo-cathode SRF gun, an SRF ERL and a compact circulator ring. In this paper, we present a proposal of a test facility utilizing the JLab FEL ERL for a technology demonstration of this cooler design concept. Beam studies will be performed and supporting technologies will also be developed in this test facility.

  11. Cool-down by compact refrigerators system for srf cavities in JAERI FEL

    International Nuclear Information System (INIS)

    We have developed a built-in cryogenic system using compact refrigerators for the JAERI FEL superconducting accelerator modules. The cryogenic system consists of a refrigerator operated at 4.2 K to keep liquid helium level and a Gifford-McMahon cycle refrigerator to cool duplex heat shields. By applying the compact refrigerators, the cryogenic system can be operated successfully without an operator of the cryogenic system. A Cool-down of the JAERI superconducting accelerating cavities by the compact refrigerators system was carried out without liquid N2 or cold helium gas. The cool-down will be reported and discussed in detail. (author)

  12. Two-phase natural-circulation experiments in a test facility modeled after Three Mile Island Unit-2. Final report

    International Nuclear Information System (INIS)

    A series of natural circulation experiments was conducted in a test facility that was configured after the primary and the secondary cooling systems of TMI-2. Results support the feasibility of core residual heat removal by two-phase natural circulation. Tests with noncondensable gas in the primary system indicate that two-phase natural circulation is quite tolerant of the presence of noncondensable gas. The different modes of natural circulation were discovered. Mode 1, during which only saturated steam flows in the hot leg, accomplishes the heat removal via phase changes in the vessel and in the steam generator tubes. Mode 2, during which a percolating flow exists in the hot leg, removes the heat by means of a much faster circulation in the primary loop

  13. Non-Stationary Star and the Trajectory of a Circulating Test Body

    CERN Document Server

    Petry, Walter

    2010-01-01

    A simple model of a spherically symmetric, pulsating star is calculated. The application to the Sun gives a 166-min radial pulsation. The theory of gravitation in flat space-time implies for a spherically symmetric, nonstationary star small time-dependent exterior gravitational effects. The perturbed equations of motion of a test body moving around the non-stationary star are given. The test body moves away from the center during the epoch of collapsing star and moves towards the center during the epoch of expanding star but the converse is also possible under some conditions. The application to the Sun-Earth system is too small to be measured. This effect may be measurable for very compact, non-stationary objects circulated of a nearby test body.

  14. Performance evaluation of 352.21 MHz, 1 MW klystrons and circulators at high power pulsed test stand at RRCAT

    International Nuclear Information System (INIS)

    A 1 MW pulsed test stand operating at 352.21 MHz was set up at RRCAT for tests and qualification of components and devices for the pulsed proton linac program. The test facility comprises of an indigenously built 100kV solid state bouncer modulator, WR 2300 waveguide system, high power circulator and high power RF load. The test facility has stand alone control system for taking the measurement data. We have used the test stand to qualify the 1 MW CW klystrons and circulators obtained from CERN under DAE CERN Collaboration for use in LEHIPA project of BARC and H- pulsed proton Linac at RRCAT. The present paper describes the test results of the qualifications done on the 1MW klystron and 1MW three port circulators for the LEHIPA project as well as for pulsed proton linac at RRCAT. (author)

  15. Experiments on the Heat Transfer and Natural Circulation Characteristics of the Passive Residual Heat Removal System for the Advanced Integral Type Reactor

    International Nuclear Information System (INIS)

    Experiments on the heat transfer characteristics and natural circulation performance of the passive residual heat removal system (PRHRS) for the SMART-P have been performed using the high temperature/high pressure thermal-hydraulic test facility (VISTA). The VISTA facility consists of the primary loop, the secondary loop, the PRHRS loop, and auxiliary systems to simulate the SMART-P, a pilot plant of the SMART. The primary loop is composed of the steam generator (SG) primary side, a simulated core, a main coolant pump, and loop piping, and the PRHRS loop consists of the SG secondary side, a PRHRS heat exchanger, and loop piping. The natural circulation performance of the PRHRS, the heat transfer characteristics of the PRHRS heat exchangers and the emergency cooldown tank (ECT), and the thermal-hydraulic behavior of the primary loop are intensively investigated. The experimental results show that the coolant flows steadily in the PRHRS loop and the heat transfers through the PRHRS heat exchanger and the emergency cooldown tank are sufficient enough to enable the natural circulation of the coolant. The results also show that the core decay heat can be sufficiently removed from the primary loop with the operation of the PRHRS. (authors)

  16. An Experimental Study of Natural Circulation in a Loop with Parallel Flow Test Sections

    International Nuclear Information System (INIS)

    The dynamic behaviour of a natural circulation loop parallel round duct channels has been studied. The test sections were both electrically heated and the power distribution was uniform along the 4300 mm heated length of the 20 mm dia. channels. The inter channel interference and the threshold of flow instability were obtained by using a dynamically calibrated flowmeter in each channel. The pressure was 50 bars and the sub-cooling 6 deg C. The main parameters varied, were the flow restrictions in the one-phase and two-phase sections. The instability data were correlated to the resistance coefficients due to these restrictions. Theoretical calculations for parallel channels in natural circulation have been compared with the experimental results. For the conditions determined by the above mentioned magnitudes, the steady-state computations are in excellent agreement with experiment. The transients are also nearly similar, except for the resonance frequency which for the theoretical case is higher by an amount between 0.3 and 0.5 c.p.s

  17. Pre-test of the KYLIN-II thermal-hydraulics mixed circulation LBE loop using RELAP5

    International Nuclear Information System (INIS)

    To investigate the behavior of lead bismuth eutectic (LBE) as coolant in China LEAd-based Research Reactor, Institute of Nuclear Energy Safety Institute (INEST), Chinese Academy of Sciences has built a multi-functional LBE experiment facility KYLIN-II. Mixed circulation loop, which is one of the KYLIN-II thermal-hydraulics loops, has the capability to drive the flowing LBE in different ways such as pump, gas lift and temperature difference (natural circulation). In this contribution, preliminary numerical simulations in support of the operation and experiment of KYLIN-II thermal-hydraulics mixed circulation LBE loop have been carried out and the obtained results have been studied. The RELAP5 Mod4.0 with LBE model has been utilized. Pre-test analysis showed the LBE circulation capability can reach the object under several driven patterns. The maximum velocity in fuel pin bundles can be larger than 0.15 m/s for natural circulation, 0.5 m/s for gas enhanced circulation, and 2 m/s for pump driven circulation. (author)

  18. Performance test results of helium gas circulator of mock-up test facility with full-scale reaction tube for HTTR hydrogen production system. Contract research

    Energy Technology Data Exchange (ETDEWEB)

    Shimizu, Akira; Kato, Michio; Hayashi, Koji [Japan Atomic Energy Research Inst., Oarai, Ibaraki (Japan). Oarai Research Establishment] [and others

    2003-03-01

    Hydrogen production system by steam reforming of methane will be connected to the High Temperature Engineering Test Reactor (HTTR) of the Japan Atomic Energy Research Institute (JAERI) against development of nuclear heat utilization system. To obtain design and safety database of the HTTR hydrogen production system, mock-up test facility with full-scale reaction was constructed in FY 2001 and hydrogen of 120m{sup 3}N{sub /}h was successfully produced in overall performance test. This report describes performance test results of a helium gas circulator in this facility. The circulator performance curves regarding to pressure-rise, input power and adiabatic thermal efficiency at standard revolution number were made based on the measured flow-rate, temperature and pressure data in overall performance test. The circulator performance prediction code was made based on these performance curves. The code can calculate revolution number, electric power and temperature-rise of the circulator using flow-rate, inlet temperature, inlet pressure and pressure-rise data. The verification of the code was carried out with the test data in FY 2002. Total pressure loss of the helium gas circulation loop was also evaluated. The circulator should be operated in conditions such as pressure from 2.7MPa to 4.0MPa and flow-rate from 250g/s to 400g/s and at maximum pressure-rise of 250 kPa in test operation. It was confirmed in above verification and evaluations that the circulator had performance to satisfy above conditions within operation limitation of the circulator such as maximum input-power of 150 kW and maximum revolution number of 12,000 rpm. (author)

  19. Feasibility of cell-free circulating tumor DNA testing for lung cancer.

    Science.gov (United States)

    Santarpia, Mariacarmela; Karachaliou, Niki; González-Cao, Maria; Altavilla, Giuseppe; Giovannetti, Elisa; Rosell, Rafael

    2016-04-01

    Tumor tissue genotyping is used routinely for lung cancer to identify specific targetable oncogenic alterations, including EGFR mutations and ALK rearrangements. However, tumor tissue from a single biopsy is often insufficient for molecular testing, may offer a limited evaluation because of tumor heterogeneity and can be difficult to obtain. Cell-free circulating tumor DNA has been widely investigated as a potential surrogate for tissue biopsy for noninvasive assessment of tumor-related genomic alterations. New techniques have improved EGFR mutations detection in ctDNA, thus supporting the use of this liquid biopsy for predicting response to EGFR tyrosine kinase inhibitors (TKIs) and monitoring the emergence of resistance. The serial evaluation of ctDNA during treatment is feasible and can be used to track tumor changes in real time and for a wide range of clinically useful applications. PMID:26974841

  20. Evaluation of nephelometry and complement-based tests for the detection of circulating immune complexes

    Energy Technology Data Exchange (ETDEWEB)

    Izzard, L.; Van Wyk, H.A.; Anderson, R. (Pretoria Univ. (South Africa). Dept. of Medical Microbiology); Potgieter, N.; Brighton, S. (Pretoria Univ. (South Africa). Dept. of Internal Medicine)

    1983-02-12

    Sera from 20 normal adult control subjects and 28 patients suffering from various diseases which may be associated with an immune complex disorder were investigated, using three different techniques for detection of circulating immune complexes (ClCs). The sera from the patients were assigned expected positive or negative ratings by the clinicians according to clinical and laboratory criteria. This information as well as the diagnoses was withheld until the results of immune complex determinations were available. The three tests used to detect ClCs were laser nephelometry (LN), /sup 125/l-C1q binding and measurement of the C3 breakdown product C3c. Serum levels of the complement components C3 and C4 were assessed on the serum specimens from the patients. Results obtained from normal control sera showed that 18 of the 20 and all 20 were negative with the C1q binding technique and LN respectively. Of 16 sera for which a positive result was expected, 5(31,3%) and 14(87%) were positive when examined by the C1q binding technique and LN respectively; C3c determination produced no positive results. No false-negative results were obtained with the C1q binding and C3c tests, but 2 out of 16(13%) results obtained with the LN test were false negative. LN is a rapid, sensitive test for the detection of ClCs.

  1. Cooldown strategies for a steam generator tube rupture event with failure of main steam safety valve

    International Nuclear Information System (INIS)

    This paper provides an evaluation of the thermal-hydraulic response of a pressurized water reactor (PWR) during a steam generator tube rupture (SGTR) event with the failure of a main steam safety valve (MSSV). Operator actions to successfully mitigate the consequences of this SGTR event are proposed. The desired actions are those which provide for control of the affected steam generator water level and minimize radiological doses to the environment. Specifically, the purpose of this paper is to demonstrate the results of differences in operator actions to cooldown the power plant in terms of: (1) dose releases to the environment, (2) control of the affected steam generator level, (3) and optimal reactor coolant system cooldown and depressurization

  2. Simulation Study of Cool-Down of the CLIC Wiggler Magnets

    CERN Document Server

    Liu, L; van Weelderen, R; Xiong, L

    2013-01-01

    The cryogenic system for the CLIC wiggler magnets is under design. The cooldown process is one of the main dimensioning factors for the system. In this paper, the heat transfer model used to simulate the cool-down process is presented. Different configurations are then investigated and a detailed analysis of the corresponding temperature evolutions along the magnet strings is calculated. The temperature profiles are evaluated for the flowing helium as well as for the magnets allowing a detailed analysis of the temperature gradients. The impact of some key parameters, like the mass-flow rate, the diameter of the cooling channels and of the thermal coupling between the helium and the magnets is also investigated.

  3. Experimental Modeling of VHTR Plenum Flows during Normal Operation and Pressurized Conduction Cooldown

    Energy Technology Data Exchange (ETDEWEB)

    Glenn E McCreery; Keith G Condie

    2006-09-01

    The Very High Temperature Reactor (VHTR) is the leading candidate for the Next Generation Nuclear Power (NGNP) Project in the U.S. which has the goal of demonstrating the production of emissions free electricity and hydrogen by 2015. The present document addresses experimental modeling of flow and thermal mixing phenomena of importance during normal or reduced power operation and during a loss of forced reactor cooling (pressurized conduction cooldown) scenario. The objectives of the experiments are, 1), provide benchmark data for assessment and improvement of codes proposed for NGNP designs and safety studies, and, 2), obtain a better understanding of related phenomena, behavior and needs. Physical models of VHTR vessel upper and lower plenums which use various working fluids to scale phenomena of interest are described. The models may be used to both simulate natural convection conditions during pressurized conduction cooldown and turbulent lower plenum flow during normal or reduced power operation.

  4. Natural Circulation High Pressure Loop Dynamics Around Operating Point, Tests and Modelling With Retran 02

    International Nuclear Information System (INIS)

    The Natural Circulation High Pressure Loop (CAPCN) reproduces in scale all the one-dimensional thermal-hydraulic phenomena occurring in the primary loop of CAREM-25 reactor.It plays an important role in the qualification process of calculating computer codes.This facility demanded to develop several technological solutions in order to achieve the measuring and control quality required by that process.This engineering and experimental development allowed completing the first stage of dynamic tests during 1998.The trends of recorded data were systematically evaluated in terms of the deviations of main variables in response to different perturbations.By this analysis a group of eight transients was selected, providing a Minimum Representative Set (MRS) of dynamic tests, allowing the evaluation of all dynamic phenomena.Each of these transients was simulated with RETRAN-02, using a spreadsheet to facilitate the consistent elaboration and modification of input files.Comparing measured data and computer simulations, it may be concluded that it is possible to reproduce the dynamic response of all the transients with a level of approximation quite homogeneous and generally acceptable.It is possible to identify the detailed physical models that fit better the dynamic phenomena, and which of the limitations of RETRAN code are more relevant

  5. Experiment data report for Semiscale MOD-2A Natural-Circulation Test Series (tests S-NC-8B and S-NC-9)

    International Nuclear Information System (INIS)

    This report presents test data recorded for Tests S-NC-8B and S-NC-9 of the Semiscale Mod-2A Natural Circulation Test Series. These tests are part of a series of Semiscale tests that investigate the thermal-hydraulic phenomena resulting from operational transients involving loss of mechanical primary coolant circulation in a pressurized water reactor. Both tests also simulated a loss-of-coolant accident resulting from a 0.4% communicative cold-leg break. These tests provide experimental data to develop and assess the analytical capability of computer models used to predict the results of small-break loss-of-coolant accidents or operational transients involving the loss of primary pumping ability. The primary objective of Tests S-NC-8B and S-NC-9 was to experimentally characterize the thermal-hydraulic behavior of a system during single-phase, two-phase, and reflux natural circulation conditions experienced in the course of an integral small break with and without the presence of emergency core cooling water. Of special interest were the effects on single-phase natural circulation flow caused by changes in core power, primary pressure, and external heater power. This report presents the uninterpreted data from Tests S-NC-8B and S-NC-9 for future analysis. The data, presented as graphs in engineering units, have been analyzed only to the extent necessary to ensure that they are reasonable and consistent

  6. Thrust Removal Scheme for the FAST-MAC Circulation Control Model Tested in the National Transonic Facility

    Science.gov (United States)

    Chan, David T.; Milholen, William E., II; Jones, Gregory S.; Goodliff, Scott L.

    2014-01-01

    A second wind tunnel test of the FAST-MAC circulation control semi-span model was recently completed in the National Transonic Facility at the NASA Langley Research Center. The model allowed independent control of four circulation control plenums producing a high momentum jet from a blowing slot near the wing trailing edge that was directed over a 15% chord simple-hinged flap. The model was configured for transonic testing of the cruise configuration with 0deg flap deflection to determine the potential for drag reduction with the circulation control blowing. Encouraging results from analysis of wing surface pressures suggested that the circulation control blowing was effective in reducing the transonic drag on the configuration, however this could not be quantified until the thrust generated by the blowing slot was correctly removed from the force and moment balance data. This paper will present the thrust removal methodology used for the FAST-MAC circulation control model and describe the experimental measurements and techniques used to develop the methodology. A discussion on the impact to the force and moment data as a result of removing the thrust from the blowing slot will also be presented for the cruise configuration, where at some Mach and Reynolds number conditions, the thrust-removed corrected data showed that a drag reduction was realized as a consequence of the blowing.

  7. Numerical analysis of JOYO MK-II natural circulation test with fast reactor plant dynamics code super-COPD

    International Nuclear Information System (INIS)

    An analysis of JOYO MK-II natural circulation test has been performed to evaluate the applicability of the fast reactor plant dynamics code super-COPD to natural circulation decay heat removal phenomena. The analysis domain is set from the reactor core to the intermediate heat exchanger (IHX) so as to focus on the simulation accuracy of natural circulation behavior in the primary system and we compared the numerical results with experimental measurement. The inlet coolant temperature and the flow rate at the secondary side of IHX were the boundary conditions and the measured data were provided. As a result, it was found that natural circulation behavior is much influenced by the coolant mixing regime in the upper plenum of the reactor vessel. The predicted transient changes of the core outlet coolant temperature and the primary flow rate showed good agreement with the test results by using a variable mesh partitioning method and by setting appropriate mixing volume in the upper plenum region which can include the effect of thermal stratification phenomena on the natural circulation behavior. (author)

  8. PIV Measurement of Isothermal Flow in the Moderator Circulation Test (MCT) Facility

    Energy Technology Data Exchange (ETDEWEB)

    Im, Sunghyuk; Sung, Hyung Jin [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of); Seo, Han; Bang, In Cheol [Ulsan National Institute of Science and Technology, Ulsan (Korea, Republic of); Kim, Hyoung Tae [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-05-15

    One of the important design features of a CANDU reactor (a pressurize heavy water reactor) is the use of moderator as a heat sink during some postulated accidents such as a large break Loss Of Coolant Accident (LOCA). If the moderator available subcooling at the onset of a large LOCA is greater than the subcooling requirements, a sustained calandria tube dryout is avoided. The subcooling requirements are determined from a set of experiments known as the fuel channel contact boiling experiments. The difference between available subcooling and required subcooling is called subcooling margins. The local temperature of the moderator is a key parameter in determining the available subcooling. To predict the local temperature in the calandria, Korea Atomic Energy Research Institute (KAERI) started the experimental research on moderator circulation as one of a national R and D research programs from 2012. In the present work the test vessel is equipment with 380 acrylic pipes instead of the heater rods and a preliminary measurement of velocity field using PIV is performed under the iso-thermal test conditions. The 2D velocity is measured on the cross-sectional plane normal to the axial direction of the tank. The PIV measurement results could capture the same flow pattern as that expected in the CANDU6 calandria tank under momentum dominant flow condition, where the inlet jets penetrate to the top of the tank and produce a downward flow through the center of the tube columns towards the outlet nozzle and the flow fields are in symmetric distributions. The measurements of downward velocities are performed at different locations. The velocity is shown to be axially uniform. The velocity is rapidly decreased as the measurement location is far from the center of tank, since the downward flow is dominant along the center of the tube columns. More experimental works for the iso-thermal conditions as well as the heating conditions will be performed using PIV measurement in the

  9. JV Task 108 - Circulating Fluidized-Bed Combustion and Combustion Testing of Turkish Tufanbeyli Coal

    Energy Technology Data Exchange (ETDEWEB)

    Douglas Hajicek; Jay Gunderson; Ann Henderson; Stephen Sollom; Joshua Stanislowski

    2007-08-15

    Two combustion tests were performed at the Energy & Environmental Research Center (EERC) using Tufanbeyli coal from Turkey. The tests were performed in a circulating fluidized-bed combustor (CFBC) and a pulverized coal-fired furnace, referred to as the combustion test facility (CTF). One of the goals of the project was to determine the type of furnace best suited to this coal. The coal is high in moisture, ash, and sulfur and has a low heating value. Both the moisture and the sulfur proved problematic for the CTF tests. The fuel had to be dried to less than 37% moisture before it could be pulverized and further dried to about 25% moisture to allow more uniform feeding into the combustor. During some tests, water was injected into the furnace to simulate the level of flue gas moisture had the fuel been fed without drying. A spray dryer was used downstream of the baghouse to remove sufficient sulfur to meet the EERC emission standards permitted by the North Dakota Department of Health. In addition to a test matrix varying excess air, burner swirl, and load, two longer-term tests were performed to evaluate the fouling potential of the coal at two different temperatures. At the lower temperature (1051 C), very little ash was deposited on the probes, but deposition did occur on the walls upstream of the probe bank, forcing an early end to the test after 2 hours and 40 minutes of testing. At the higher temperature (1116 C), ash deposition on the probes was significant, resulting in termination of the test after only 40 minutes. The same coal was burned in the CFBC, but because the CFBC uses a larger size of material, it was able to feed this coal at a higher moisture content (average of 40.1%) compared to the CTF (ranging from 24.2% to 26.9%). Sulfur control was achieved with the addition of limestone to the bed, although the high calcium-to-sulfur rate required to reduce SO{sub 2} emissions resulted in heat loss (through limestone calcination) and additional ash

  10. Reduction of helium loss from a superconducting accelerating cavity during initial cool-down and cryostat exchange by pre-cooling the re-condensing cryostat

    International Nuclear Information System (INIS)

    A Zero-Boil-Off (ZBO) cryostat is designed to realize a compact, stand-alone cryogenic system for the AIST superconducting accelerator (SCA). Under normal operation there is no evaporative helium loss from the cryomodule and therefore operating costs associated with the supply of liquid helium can be eliminated. The only significant loss of helium from the module occurs during the initial cavity cool-down procedure or when the re-condensing cryostat is replaced. It takes about 3 h to cool down the cryostat head from room temperature (300 K) to 4 K. During this time around 100 L of liquid helium is lost due to evaporation. By pre-cooling the cryostat inside a low heat load vacuum tube before transfer to the cryomodule, this evaporative loss could be essentially eliminated, significantly reducing the volume of liquid helium required for the initial cryomodule cool-down. The pre-cooling system also provides an efficient method to test the cryostat prior to use

  11. The ultracold neutron source at the Paul Scherrer Institut: cool-down soon

    International Nuclear Information System (INIS)

    Full text: The Paul Scherrer Institut is constructing a source for ultracold neutrons with the goal of surpassing by a factor of ∼ 100 the current ultracold neutron densities available for fundamental research such as the search for a neutron electric dipole moment. The source is based on neutron production via spallation of protons on lead followed by neutron thermalization in heavy water and cooling in a solid deuterium crystal. Commissioning of the source is scheduled for fall 2009. The working principle, present status and path towards first cool-down will be presented. (author)

  12. Development and Analysis of the FlowManager? Cooldown and Restart Simulator

    OpenAIRE

    Solvang, Bård

    2008-01-01

    During the work presented in this thesis, the Shut-down flow model of the FlowManager? Cooldown and Restart Simulator has been developed into a transient multiphase flow model that is able to handle shut-down flow and restart flow for horizontal pipelines with uniform discretization.It has been shown that the momentum equation solver originally used in the Shut-down flow model fails to transfer momentum across velocity sign changes. As a result of this, the original momentum equation solver m...

  13. ANSYS modeling of thermal contraction of SPL HOM couplers during cool-down

    CERN Document Server

    Papke, K

    2016-01-01

    During the cool-down the HOM coupler as well as the cavity inside the cryo module experience a thermal contraction. For most materials between room temperature and liquid helium temperatures, the changes in dimension are in the order of a few tenths of a percent change in volume. This paper presents the effect of thermal contraction on the RF transmission behavior of HOM couplers, and in particular the influence on its notch filter. Furthermore the simulation process with APDL is explained in detail. Conclusions about the necessary tuning range of the notch filter are made which is especially a concern for couplers with only notch filter.

  14. Computational simulation of the natural circulation occurring in an experimental test section of a pool type research reactor

    International Nuclear Information System (INIS)

    The present work presents a computational simulation of the natural circulation phenomenon developing in an experimental test section of a pool type research reactor. The test section has been designed using a reduced scale in height 1:4.7 in relation to a pool type 30 MW research reactor prototype. It comprises a cylindrical vessel, which is opened to atmosphere, and representing the reactor pool; a natural circulation pipe, a lower plenum, and a heater containing electrical resistors in rectangular plate format, which represents the fuel elements, with a chimney positioned on the top of the resistor assembly. In the computational simulation, it was used a commercial CFD software, without any turbulence model. Besides, in the presence of the natural circulation, a laminar flow has been assumed and the equations of the mass conservation, momentum and energy were solved by the finite element method. In addition, the results of the simulation are presented in terms of velocities and temperatures differences, respectively: at inlet and outlet of the heater and of the natural circulation pipe. (author)

  15. Computational simulation of the natural circulation occurring in an experimental test section of a pool type research reactor

    Energy Technology Data Exchange (ETDEWEB)

    Nascimento, Francisco R.T. do; Lima Junior, Carlos A.S.; Oliveira, Andre F.S. de; Affonso, Renato R.W.; Faccini, Jose L.H.; Moreira, Maria L., E-mail: rogerio.tdn@gmail.com, E-mail: souzalima_ca@ien.gov.br, E-mail: oliveira.afelipe@gmail.com, E-mail: raoniwa@yahoo.com.br, E-mail: faccini@ien.gov.br, E-mail: malu@ien.gov.br [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2015-07-01

    The present work presents a computational simulation of the natural circulation phenomenon developing in an experimental test section of a pool type research reactor. The test section has been designed using a reduced scale in height 1:4.7 in relation to a pool type 30 MW research reactor prototype. It comprises a cylindrical vessel, which is opened to atmosphere, and representing the reactor pool; a natural circulation pipe, a lower plenum, and a heater containing electrical resistors in rectangular plate format, which represents the fuel elements, with a chimney positioned on the top of the resistor assembly. In the computational simulation, it was used a commercial CFD software, without any turbulence model. Besides, in the presence of the natural circulation, a laminar flow has been assumed and the equations of the mass conservation, momentum and energy were solved by the finite element method. In addition, the results of the simulation are presented in terms of velocities and temperatures differences, respectively: at inlet and outlet of the heater and of the natural circulation pipe. (author)

  16. Radon-222 as a test of convective transport in a general circulation model

    International Nuclear Information System (INIS)

    The distribution of 222Rn over North America is simulated with a 3-d chemical tracer model (CTM) based on the meteorology of the GISS general circulation model (GCM). The GISS GCM has been used extensively for studies of climate change and global transport of chemical tracers. Simulation of 222Rn (e-folding lifetime 5.5 days) tests the ability of the model to describe the transport of pollutants in the boundary layer and the exchange of mass between the boundary layer and the free troposphere. Model results are compared to surface observations from 5 sites in the United States. It is found that the 222Rn concentrations are regulated primarily by dry convection. At night, the model underpredicts observations because it does not resolve the sharp 222Rn concentration gradient which forms near the surface. In daytime, the predicted and observed concentrations are usually in good agreement, indicating that vertical mixing of surface air is reasonably simulated. Inspection of seasonal trends reveals, however, several significant discrepancies which are traced to anomalies in the GCM meteorology. In particular, the simulated 222Rn concentrations over the northeastern United States are too high in the spring, because of excessive rainfall which suppresses dry convection, and too low in the fall, because of a severe drought which allows intense dry convection. Ventilation of 222Rn to the free troposphere is most efficient in the western half of the North American continent, due to intense dry convection, and is followed by rapid eastward advection of 222Rn in the upper westerlies. This transport mechanism produces a layer of high 222Rn concentrations in the upper troposphere over the eastern United States and over the western Atlantic Ocean in summer. (orig.)

  17. Cool-down acceleration of G-M cryocoolers with thermal oscillations passively damped by helium

    Science.gov (United States)

    Webber, R. J.; Delmas, J.

    2015-12-01

    4 K Gifford-McMahon cryocoolers suffer from inherent temperature oscillations which can be a problem for certain attached electronic instrumentation. Sumitomo Heavy Industries has exploited the high volumetric specific heat of super-critical He to quell these oscillations (approx. 10 dB) by strongly thermally linking a separate vessel of He to the second stage; no significant thermal resistance is added between the payload and the working gas of the cryocooler. A noticeable effect of the helium damper is to increase the cool-down time of the second stage below 10 K. For the operation of niobium-based superconducting electronics (NbSCE), a common practice is to warm the circuits above the critical temperature (∼9 K) and then cool to the operating point in order to redistribute trapped magnetic fluxons, so for NbSCE users, the time to cool from 10 K is important. The gas in the helium damper is shared between a room-temperature buffer tank and the 2nd stage vessel, which are connected by a capillary tube. We show that the total cool-down time below 10 K can be substantially reduced by introducing a combination of thermal linkages between the cryocooler and the capillary tube and in-line relief valves, which control the He mass distribution between the warm canister and cold vessel. The time to reach operating temperature from the superconducting transition has been reduced to <25% of the time needed without these low-cost modifications.

  18. Efficacy of Cool-Down Exercises In the Practice Regimen of Elite Singers

    Science.gov (United States)

    Gottliebson, Renee O.

    Cool-down exercises are routinely prescribed for singers, yet few data exist about the efficacy of active recovery or cooling down of the vocal mechanism. The purpose of the present study was to compare three aspects of vocal function after using different recovery methods following rigorous voice use. Vocal function was assessed using (1) phonation threshold pressure (PTP); (2) acoustic measures (accuracy of tone production, duration of notes and duration of intervals between notes); and (3) measures of subjective perception: perceived phonatory effort (PPE) and Singing Voice Handicap Index (SVHI). Data were collected after 10-minutes of cool-down exercises, complete voice rest, and conversation immediately following a 50-minute voice lesson. Data were collected again 12-24 hours later. Participants included actively performing elite singers (7 women, 2 men) enrolled in the graduate program (M.M., D.M.A.) at the University of Cincinnati's College-Conservatory of Music. While it was expected that PTP estimates after cool downs would be significantly lower than baselines and the other conditions, it turns out that PTP estimates after cool downs were significantly higher at the 80% level of the pitch range. Statistically significant correlations between PTP estimates and PPE scores were found when comparing levels of the participants' pitch ranges (10%, 20%, 80%). Mean PPE scores were highest at the 80% level of the pitch range. The acoustic measures yielded variable results. Cool-down exercises did not result in significantly more accurate tone production and shorter staccato note duration and duration of intervals between staccato notes as compared to baselines and recovery conditions. Instead, participants demonstrated greater accuracy of tone production during baselines and lesser accuracy after voice rest. Staccato notes were significantly shorter in duration after the conversation condition as compared to voice rest. Duration between staccato notes was

  19. WCOBRA/TRAC-TF2 simulation of ROSA-IV/LSTF natural circulation test ST-NC-02

    International Nuclear Information System (INIS)

    The paper presents WCOBRA/TRAC-TF2 simulation results of the high-pressure (∼7 MPa) steady-state natural circulation test ST-NC-02 conducted at the ROSA-IV Large Scale Test Facility (LSTF). The simulations used a fairly detailed noding of the LSTF particularly in the vessel and the primary and secondary side of the steam generators. A single flow channel is used to model the primary side of the steam generator U-tubes. In general, the results are in good agreement with those observed in the ST-NC-02 test. (author)

  20. Comparison between warm-up and cool-down stretching programs on hamstring extensibility gains in primary schoolchildren

    OpenAIRE

    Daniel Mayorga-Vega; Rafael Merino-Marban; Francisco Javier Garrido; Jesús Viciana

    2014-01-01

    The purpose of this study was to compare the effects of a physical education-based stretching program performed during warm-up and cool-down periods on hamstring extensibility in schoolchildren aged 9-10 years. A sample of 73 schoolchildren, 36 boys and 37 girls, aged 9-10 years old from three classes were clustered randomly assigned to a no-training group (n = 24), warm-up group (n = 25), or cooldown group (n = 24). During physical education classes, the students of the warm-up and cool-d...

  1. [Lung cancer molecular testing, what role for Next Generation Sequencing and circulating tumor DNA].

    Science.gov (United States)

    Pécuchet, Nicolas; Legras, Antoine; Laurent-Puig, Pierre; Blons, Hélène

    2016-01-01

    Molecular screening has become a standard of care for patients with advanced cancers and impacts on how to treat a patient. Advances in genomic technologies with the development of high throughput sequencing methods will certainly improve the possibilities to access a more accurate molecular diagnosis and to go beyond the identification of validated targets as a large number of genes can be screened for actionable changes. Moreover, accurate high throughput testing may help tumor classification in terms of prognosis and drug sensitivity. Finally, it will be possible to assess tumor heterogeneity and changes in molecular profiles during follow-up using ultra-deep sequencing technologies and circulating tumor DNA characterization. The accumulation of somatic ADN alterations is considered as the main contributing factor in carcinogenesis. The alterations can occur at different levels: mutation, copy number variations or gene translocations resulting in altered expression of the corresponding genes or impaired protein functions. Genes involved are mainly tumor suppressors, oncogenes or ADN repair genes whose modifications in tumors will impinge cell fate and proliferation from tumor initiation to metastasis. The entire genome of various tumor types, have now been sequenced. In lung cancer, the average number of mutations is very high with more than 8.9 mutations/Mb (Network TCGAR, 2014) that is to say more than 10,000 mutations/genome. These alterations need to be classified, indeed, some are true drivers that directly impact proliferation and some are passenger mutations linked to genetic instability. The development of targeted therapies relies on the identification of oncogenic drivers. The identification of genotype-phenotype associations as in the case of EGFR-TKI (Epidermal growth factor receptor-tyrosine kinase inhibitor) and EGFR mutations in lung cancer led to the restriction of drugs to patients for which tumor genotype predicts efficacy. Tumor

  2. Titan's Detached Haze as a Test of Circulation and Microphysical Models

    Science.gov (United States)

    West, R. A.

    2011-12-01

    In 1981 Voyager ISS images showed a thin, high haze layer above Titan's main haze. Rages and Pollack (Icarus 55, 50-62, 1983) measured the altitude of this so-called detached haze to be at 357 km at the equator and about 27 km lower in the high southern latitudes. In the Voyager images and later in the Cassini ISS images starting in 2004 the detached haze was observed to be present and continuous over all latitudes south of the northern polar vortex boundary, but in the Cassini images beginning in 2004 the altitude of the haze was significantly higher (just over 500 km ) and more circular. West et al. (Geophys. Res. Lett., 38, L06204, doi:10.1029/2011GL046843, 2011) tracked the altitude of the haze from 2004 to August of 2010, and found that the altitude dropped dramatically and most rapidly near equinox in 2009. More recent images taken in 2011 show the altitude to be the same, within a few km, as the altitude measured by Rages and Pollack almost 30 earth years and one Titan year earlier. Two very different models to explain the existence and properties of the detached were put forward prior to the observation of the altitude shift. One by Rannou et al. (Nature 418, 853-856, 2002) produces the detached haze via a global meridional cell and includes seasonal variations. Another by Lavvas et al. (Icarus, 201, 626-633, doi:10.1016/j.icarus.2009.01.004, 2009), produces the haze by a purely steady-state microphysical mechanism and must be coupled with a dynamical process to produce the evolution. The collapse of Titan's detached haze is most likely a feature of the breakdown of a global meridional cell in the high stratosphere at equinox as solar heating becomes symmetric, although the haze does not disappear with the change in altitude as predicted by the model of Rannou et al.. The detached haze, a scientific curiosity for almost 30 years, has become an incisive test for Titan circulation and haze microphysical models. Part of this work was performed by the Jet

  3. TRAC-PF1 post-test predictions for the Semiscale Natural-Circulation Tests S-NC-2 and S-NC-6

    International Nuclear Information System (INIS)

    The TRAC prediction are compared to the data for the Semiscale natural-circular Tests S-NC-2B and S-NC-6. S-NC-2B is a baseline test covering single- and two-phase natural circulation as well as reflux; here TRAC compares quite well with the experiment results for mass flow. For Test S-NC-6, which is a reflux test with various amounts of nitrogen injected into the system, the TRAC prediction of the reflux rate is close to the experiment value with no nitrogen in the system. Ultimately, the maximum reflux rate predicted by TRAC is about 20% higher than the data

  4. Studies on natural circulation in reactor loops under progressively depleted inventory conditions - post test analysis of ISP-33

    International Nuclear Information System (INIS)

    Nuclear reactors are designed for safety not only during normal operation, but also under abnormal/accident conditions. A number of accident scenarios are postulated and analysed using the computer codes developed for this purpose. The phenomena involved being complex, the codes need to be validated. The International Standard Problem exercise 33 (ISP-33) was conducted on the PACTEL test facility to validate and compare methodology for natural circulation phenomena under depleted inventory conditions. This paper presents the results of post-test calculation using ATHLET code in terms of flows, fluid temperatures, pressures in various nodes of the facility and describes the various modifications made for post-test analysis to improve the predictions. Pre-test/post-test predictions and experimental results are also compared. (author). 4 refs., 10 figs., 1 tab

  5. Reliable cool-down of GridPix detectors for cryogenic applications

    International Nuclear Information System (INIS)

    In this paper we present thermal cycling experiments of GridPix radiation imaging detectors, in view of a potential application in a cryogenic experiment. The robustness of the GridPix detector is studied for various grid designs, as well as various mechanical and thermal surroundings. The grid design variations had insignificant effect on the grid strength. A low cool-down rate as well as good thermal contact are crucial for the durability of the grid. Further, additional strengthening at the grid edges proved necessary to maintain the integrity of the structure during thermal cycling, which was done using globtop adhesive. The combination of these measures led to 100% survival rate after thermal cycling down to −130 °C

  6. Reliable cool-down of GridPix detectors for cryogenic applications

    Energy Technology Data Exchange (ETDEWEB)

    Schön, R., E-mail: rolfs@nikhef.nl [National Institute for Subatomic Physics Nikhef, Science Park 105, 1098XG Amsterdam (Netherlands); Schmitz, J.; Smits, S. [MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500AE Enschede (Netherlands); Bilevych, Y. [Physics Institute, University of Bonn, Nußallee 12, 53115 Bonn (Germany); Bakel, N. van [National Institute for Subatomic Physics Nikhef, Science Park 105, 1098XG Amsterdam (Netherlands)

    2015-04-21

    In this paper we present thermal cycling experiments of GridPix radiation imaging detectors, in view of a potential application in a cryogenic experiment. The robustness of the GridPix detector is studied for various grid designs, as well as various mechanical and thermal surroundings. The grid design variations had insignificant effect on the grid strength. A low cool-down rate as well as good thermal contact are crucial for the durability of the grid. Further, additional strengthening at the grid edges proved necessary to maintain the integrity of the structure during thermal cycling, which was done using globtop adhesive. The combination of these measures led to 100% survival rate after thermal cycling down to −130 °C.

  7. Multi-dimensional pool analysis of Phenix end-of-life natural circulation test with MARS-LMR code

    International Nuclear Information System (INIS)

    Highlights: • The natural circulation test performed in Phenix reactor has been analyzed with MARS-LMR code. • A multi-dimensional approach for the hot pool and the cold pool has been adopted in the analysis. • A detailed comparison between the test data and the simulation results has been performed. - Abstract: The MARS-LMR code is a key system analysis tool for the development of a sodium-cooled fast reactor in Korea. The code has been successfully applied for the transient analysis of conceptual designs of SFR since 2007 mainly based on a one-dimensional approach. In recent studies, it was identified that one-dimensional modeling of a pool-type SFR has limitations on describing complicated thermal–hydraulic phenomena in pool regions at natural circulation conditions. In the present study, the natural circulation test performed in Phenix reactor by CEA has been analyzed with a multi-dimensional approach of MARS-LMR. Only the hot pool and the cold pool regions are modeled multi-dimensionally and other parts of the plant are described one-dimensionally in the analysis. Even though a very careful treatment of initial flow condition is required, this multi-dimensional modeling of pool regions results in quite accurate prediction of the temperature distributions measured at several points during the test when it is compared to the results with one-dimensional pool nodalization. It is suggested that a detailed modeling of pool regions is essential for the future analysis of pool-type SFRs. The multi-dimensional modeling capability can be enhanced through the improvement of the existing system code or by the combination of system code and CFD code

  8. The evaluation of collateral cerebral circulation using 99mTc-HM-PAO SPECT during the balloon Matas test

    International Nuclear Information System (INIS)

    A balloon Matas test using single-photon emission computed tomography (SPECT) and 99mTC-hexamethyl propyleneamine oxime (99mTc-HM-PAO) was performed to evaluate collateral cerebral circulation during temporary carotid occlusion in 14 patients (6 with internal carotid artery aneurysms, 2 with basilar skull tumors, 5 with neck tumors, and one with traumatic common carotid artery aneurysm). The occlusion sites were internal carotid artery in 12 patients and common carotid artery in 2 patients. The observation of the neurological state, the carotid stump pressure, cerebral angiography for assessing collateral circulation and electroencephalographic (EEG) monitoring were also undertaken in all patients. In four patients, regional cerebral blood flow (rCBF) was measured by xenon-inhalation method and compared with the CBF image by 99mTc-HM-PAO SPECT. The 99mTC-HM-PAO (20 mCi) was injected intravenously 3 minutes before balloon deflation. In all patients, the neurological state and EEG showed no abnormality during the balloon Matas test. Eight patients were considered treatable by the permanent occlusion of the carotid artery. Permanent carotid ligation was carried out in five of these 8 patients, and no neurological deficit occurred. Permanent occlusion of the carotid artery was impossible in 5 patients because of marked reduction of CBF. 99mTc-HM-PAO SPECT should three-dimensional cerebral perfusion pattern. In conclusion, a balloon Matas test using 99mTC-HM-PAO SPECT is a reliable, simple and safe method of evaluating the collateral cerebral circulation. (J.P.N.)

  9. TRAC-PF1 analysis of loss-of-fluid test L6-7/L9-2

    International Nuclear Information System (INIS)

    The Los Alamos National Laboratory is developing the Transient Reactor Analysis Code (TRAC-PF1) to provide the capability for advanced best-estimate predictions of postulated accidents in pressurized-water reactors (PWRs) and for many thermal-hydraulic experimental facilities. As part of an independent assessment of TRAC-PF1, Loss-of-Fluid Test (LOFT) L6-7/L9-2 is analyzed and compared to the calculated results. Test L6-7 simulated a cooldown transient similar to the Arkansas Nuclear One Unit-2 turbine-trip transient. During the L9-2 phase of the test, the primary-coolant pumps were tripped and natural circulation cooled the core while the plant cooldown continued. The TRAC results matched the test data well during the L6-7 portion of the transient (0.0-324 s). However, during the L9-2 portion the calculated natural-circulation flow rate in the intact loop was much higher than the measured rate

  10. Analysis of natural circulation stability in a low pressure thermohydraulic test loop

    International Nuclear Information System (INIS)

    This paper discusses an instability study of a natural circulation (NC) loop performed with the aid of Relap5 thermal-hydraulic system code. This loop has been designed and constructed for the analysis of relevant thermohydraulic parameters of a nuclear reactor. In this study, the main parameters for the stability of NC are identified and characterized through the execution of proper code runs. The obtained stability boundary (SB) in the dimensionless Zuber- Sub-cooling plane is compared with the SB reported in referenced literature. The agreement of predicted NC stability boundaries with the results of independent studies demonstrates both the capability of the mentioned code in assessing NC loop stability and the quality of the performed calculations.(author)

  11. Conceptual Design of a Natural Circulation Test Loop Assisted by System Code

    International Nuclear Information System (INIS)

    This paper reports the results of the simulation of natural circulation (NC) loop performance with the aid of Relap5 thermalhydraulic system code. This loop has been constructed for the analysis of relevant thermalhydraulic parameters of a nuclear reactor. Changes in the electric power and in the elevation of the heat sink relatively to the heat source are allowed. In this study two different scenarios for the elevation of the heat sink relatively to the heat source are considered assuming the same power level. The analysis shows that NC is established and fluid temperatures and mass flow rates achieve reasonable values. Comparison of the simulation results with reference experimental data base, not documented in this paper, shows the quality of the achieved design. Increase of mass flow rate, lower fluid temperature at the heated region inlet and lower average void fraction in the loop occur owing to higher elevations. These characteristics lead to an increased power removal capability in the NC loop. (author)

  12. Development of an Immunochromatographic Test for Diagnosis of Visceral Leishmaniasis Based on Detection of a Circulating Antigen.

    Directory of Open Access Journals (Sweden)

    Chun-hua Gao

    Full Text Available Visceral leishmaniasis (VL is a life-threatening disease caused by protozoan parasites of the Leishmania donovani complex. Early case detection followed by adequate treatment is essential to the control of VL. However, the available diagnostic tests are either invasive and require considerable expertise (parasitological demonstration of the parasite in tissue smears or unable to distinguish between past and active infection (serological methods. Therefore, we aimed to develop a lateral flow assay in the form of an immunochromatographic test (ICT device based on the detection of a circulating Leishmania antigen using monoclonal antibodies (mAbs.mAbs were produced by fusion of murine myeloma cells with splenocytes isolated from a mouse immunized with L. donovani soluble crude antigen. Out of 12 cloned hybridoma cell lines, two secreted mAbs recognizing the same leishmanial protein. These mAbs were used to produce an ICT as a sandwich assay for the detection of circulating antigen in serum and blood samples. The ICT was evaluated with 213 serum samples from VL patients living in VL endemic areas in China, and with 156 serum samples from patients with other diseases as well as 78 serum samples from healthy donors. Sensitivity, specificity and diagnostic efficiency of the new ICT was 95.8%, 98.7% and 97.3%, respectively. Compared with a commercially available antibody detecting ICT, our antigen-based ICT performed slightly better.The newly developed ICT is an easy to use and more accurate diagnostic tool which fulfils the performance and operational characteristics required for VL case detection under field and laboratory conditions. As our ICT detects a circulating antigen, it will also be useful in monitoring treatment success and diagnosing VL in immunocompromised patients.

  13. Examining Effects of Volleyball Trainings on Some Respiration and Circulation Parameters of 11 - 14 Years Old Female Test Subjects

    Directory of Open Access Journals (Sweden)

    Yeliz ÖZVEREN

    2014-08-01

    Full Text Available The aim of this study is to determine the effects of the training done by the students on their respiration and blood circulation systems who plays volleyball, aged 11 - 14, at Izmir. 42 students doing sports average age 12.93 ± 0.74 and 36 students not doing an y sports, with the age average 12.46 ± 0.91, voluntary involved in this study, which aims to determine the effects of the training done by test subjects on respiration and blood circulation systems. Parameters of age, height, weight, resting pulse measures , systolic - diastolic blood pressure, and vital capacity (VC, force vital capacity (FVC, force expiration volume (FEV, and maximum voluntary ventilation (MVV values of respiration system were recorded. Findings obtained by SPSS 11.0 statistics program. The differences between the averages of groups were examined with independent t test at 0.01 and 0.05 levels. The differences between groups in terms of age, height, weight and diastolic blood pressure valves are not significant. There were significant dif ference on resting pulse and systolic blood pressure, vital capacity, force vital capacity and force expiration volume, maximum voluntary ventilation values of experimental group. In conclusion, resting pulse and blood pressure values of the students, who do training, were found to be lower; the respiration values VC, FVC, FEV1 and MVV were higher than those of the students not doing sports.

  14. Flow characteristic of Hijiori HDR reservoir from circulation test in 1991; Koon tantai Hijiori jikkenjo ni okeru senbu choryuso shiken (1991 nendo) kekka to ryudo kaiseki

    Energy Technology Data Exchange (ETDEWEB)

    Shiga, T.; Hyodo, M.; Shinohara, N.; Takasugi, S. [Geothermal Energy Research and Development Co. Ltd., Tokyo (Japan)

    1996-05-01

    This paper reports one example of flow analyses on a circulation test carried out in fiscal 1991 at the Hijiori hot dry rock experimental field (Yamagata Prefecture). A fluid circulation model was proposed to simulate an HDR circulation system for a shallow reservoir (at a depth of about 1800 m) demonstrated in the circulation test by using an electric circuit network (which expresses continuity impedance in resistance and fluid storage in capacitance). Storage capacity of the reservoir was estimated by deriving time constant of the system from data of time-based change in reservoir pressure associated with transition phenomena during the circulation test. The storage capacity was estimated separately by dividing change of storage in the reservoir by change in the reservoir pressure. To derive the storage in the reservoir, a method to calculate non-recovered flows in the circulation test was utilized. The results of evaluating the reservoir capacity in the shallow reservoir using the above two independent methods were found substantially consistent. 3 refs., 6 figs., 1 tab.

  15. A Targeted Q-PCR-Based Method for Point Mutation Testing by Analyzing Circulating DNA for Cancer Management Care.

    Science.gov (United States)

    Thierry, Alain R

    2016-01-01

    Circulating cell-free DNA (cfDNA) is a valuable source of tumor material available with a simple blood sampling enabling a noninvasive quantitative and qualitative analysis of the tumor genome. cfDNA is released by tumor cells and exhibits the genetic and epigenetic alterations of the tumor of origin. Circulating cell-free DNA (cfDNA) analysis constitutes a hopeful approach to provide a noninvasive tumor molecular test for cancer patients. Based upon basic research on the origin and structure of cfDNA, new information on circulating cell-free DNA (cfDNA) structure, and specific determination of cfDNA fragmentation and size, we revisited Q-PCR-based method and recently developed a the allele-specific-Q-PCR-based method with blocker (termed as Intplex) which is the first multiplexed test for cfDNA. This technique, named Intplex(®) and based on a refined Q-PCR method, derived from critical observations made on the specific structure and size of cfDNA. It enables the simultaneous determination of five parameters: the cfDNA total concentration, the presence of a previously known point mutation, the mutant (tumor) cfDNA concentration (ctDNA), the proportion of mutant cfDNA, and the cfDNA fragmentation index. Intplex(®) has enabled the first clinical validation of ctDNA analysis in oncology by detecting KRAS and BRAF point mutations in mCRC patients and has demonstrated that a blood test could replace tumor section analysis for the detection of KRAS and BRAF mutations. The Intplex(®) test can be adapted to all mutations, genes, or cancers and enables rapid, highly sensitive, cost-effective, and repetitive analysis. As regards to the determination of mutations on cfDNA Intplex(®) is limited to the mutational status of known hotspot mutation; it is a "targeted approach." However, it offers the opportunity in detecting quantitatively and dynamically mutation and could constitute a noninvasive attractive tool potentially allowing diagnosis, prognosis, theranostics

  16. Cool-down performance of the new apparatus for fuel layering demonstrations of FIREX targets

    Science.gov (United States)

    Iwamoto, A.; Norimatsu, T.; Nakai, M.; Sakagami, H.; Shiraga, H.; Azechi, H.

    2016-03-01

    FIREX targets have been developed under two layering strategies: foam shell and cone guide laser heating methods. Basic studies have been conducted by the collaboration research between ILE and NIFS. Then the next stage requires the characterization of a layered solid fuel. The present system is at the disadvantage of optical observations. Therefore, a new apparatus is designed to solve it. Glass windows with a wide aperture are installed for an interferometer and a microscope. To isolate the vibration from a cryocooler, active vibration control units are equipped, and flexible thermal conductive links are utilized. Furthermore, a quick target exchange mechanism is applied to deal with different types of FIREX targets. A target holder is detachable from a main vacuum chamber. A metal gasket with not fixing bolts but a load of ∼ thousand newtons on ensures GHe leak tightness for target cooling. Eventually, the design temperature of 10.00 K at a target container has been achieved. The cool-down performance indecates that the new apparatus provides a cryogenic environment for fuel layering demonstrations.

  17. Tests of Shaft Seal Systems of Circulation Pumps during Station Blackout

    International Nuclear Information System (INIS)

    AREVA GmbH operates a unique Thermal-hydraulic plat form in Germany, France and USA. It is recognised as a test body according to ISO 17025. The Deutsche Akkreditierungsstelle GmbH (DAkkS - German Society for Accreditation) has also certified the Thermal-hydraulic platform as an independent inspection body Type C according to ISO 17020. A part of this platform is the Component Laboratory located in Karlstein, Germany which is in operation since more than 50 years. The testing activities cover a wide range as: Critical Heat Flux Tests, Valve Testing and Environmental Qualification for safety related components. Since 2011 the Component Qualification Karlstein extended their testing scope for different types of Shaft Seal Systems. (Author)

  18. Food, stress, and circulating testosterone: Cue integration by the testes, not the brain, in male zebra finches (Taeniopygia guttata).

    Science.gov (United States)

    Lynn, Sharon E; Perfito, Nicole; Guardado, Daisy; Bentley, George E

    2015-05-01

    Food abundance is closely associated with reproductive readiness in vertebrates. Food scarcity can activate the hypothalamo-pituitary-adrenal axis, decrease sex steroid secretion, and dampen reproductive behavior. However, the mechanisms underlying these transient effects are unclear. Gonadotropin inhibitory hormone (GnIH), a neuropeptide present in the brain and gonads, is also influenced by glucocorticoids and fasting in some species. We investigated whether fasting stress activated the GnIH system in zebra finches (Taeniopygia guttata), with the potential for downstream effects on reproductive physiology and behavior. We fasted or fed males ad libitum for 10h. Fasting increased corticosterone and decreased testosterone in circulation. To assess whether the decrease in testosterone was mediated by changes in the hypothalamus and/or the gonads, we (1) quantified GnRH- and GnIH-positive neurons in the hypothalamus, (2) assessed hypothalamic gene expression for GnRH and GnIH, and (3) examined gene expression for proteins involved in testosterone synthesis in fasted and control birds. No measure of hypothalamic neuropeptides was related to treatment or circulating steroids. However, birds with higher corticosterone had higher testicular GnIH expression and lower testosterone. StAR and LHR expression were lower in the testes of fasted birds than controls. Thus, the decrease in testosterone was not likely mediated by hypothalamic GnIH, but rather by direct actions of fasting and/or corticosterone on the testes, indicating that the testes can integrate and respond to cues of stress directly. Such local inhibition of testosterone synthesis may allow for rapid and reversible changes in physiology and behavior when conditions are inappropriate for breeding. PMID:25849310

  19. Non-Stationary Star and the Trajectory of a Circulating Test Body

    OpenAIRE

    Petry, Walter

    2010-01-01

    A simple model of a spherically symmetric, pulsating star is calculated. The application to the Sun gives a 166-min radial pulsation. The theory of gravitation in flat space-time implies for a spherically symmetric, nonstationary star small time-dependent exterior gravitational effects. The perturbed equations of motion of a test body moving around the non-stationary star are given. The test body moves away from the center during the epoch of collapsing star and moves towards the center durin...

  20. Reduced-scale water test of natural circulation for decay heat removal in loop-type sodium-cooled fast reactor

    International Nuclear Information System (INIS)

    Highlights: • The natural circulation characteristics of a loop-type SFR are examined by a water test. • The performance of decay heat removal system is evaluated using a similarity law. • The effects of flow deviation in the parallel piping of a primary loop are clarified. • The reproducibility of the natural circulation test is confirmed. - Abstract: Water tests of a loop-type sodium-cooled fast reactor have been conducted to physically evaluate the natural circulation characteristics. The water test apparatus was manufactured as a 1/10-scale mock-up of the Japan Sodium-Cooled Fast Reactor, which adopts a decay heat removal system (DHRS) utilizing natural circulation. Tests simulating a variety of events and operation conditions clarified the thermal hydraulic characteristics and core-cooling performance of the natural circulation in the primary loop. Operation conditions such as the duration of the pump flow coast-down and the activation time of the DHRS affect the natural circulation characteristics. A long pump flow coast-down cools the upper plenum of the reactor vessel (RV). This causes the loss of the buoyant force in the RV. The test result indicates that a long pump flow coast-down tends to result in a rapid increase in the core temperature because of the loss of the buoyant force. The delayed activation of the DHRS causes a decrease in the natural circulation flow rate and a temperature rise in the RV. Flow rate deviation and a reverse flow appear in the parallel cold-leg piping in some events, which cause thermal stratification in the cold-leg piping. The DHRS prevents the core temperature from fatally rise even for the most severe design-basis event, in which sodium leakage in a secondary loop of the DHRS and the opening failure of a single damper of the air cooler occur simultaneously. In the water test for the case of siphon break in the primary loop, which is one of the design extension conditions, a circulation flow consisting of ascendant

  1. Thermal response of a modular high temperature reactor during passive cooldown under pressurized and depressurized conditions

    International Nuclear Information System (INIS)

    The concept of inherent safety features of the modular HTR design with respect to passive decay heat removal through conduction, radiation and natural convection was first introduced in the German HTR-module (pebble fuel) design and subsequently extended to other modular HTR design in recent years, e.g. PBMR (pebble fuel), GT-MHR (prismatic fuel) and the new generation reactor V/HTR (prismatic fuel). This paper presents the numerical simulations of the V/HTR using the thermal-hydraulic code THERMIX which was initially developed for the analysis of HTRs with pebble fuels, verified by experiments, subsequently adopted for applications in the HTRs with prismatic fuels and checked against the results of CRP-3 benchmark problem analyzed by various countries with diverse codes. In this paper, the thermal response of the V/HTR (operating inlet/outlet temperatures 490/1000 deg. C) during post shutdown passive cooling under pressurized and depressurized primary system conditions has been investigated. Additional investigations have also been carried out to determine the influence of other inlet/outlet operating temperatures (e.g. 490/850, 350/850 or 350/1000 deg. C) on the maximum fuel and pressure vessel temperature during depressurized cooldown condition. In addition, some sensitivity analyses have also been performed to evaluate the effect of varying the parameters, i.e. decay heat, graphite conductivity, surface emissivity, etc., on the maximum fuel and pressure vessel temperature. The results show that the nominal peak fuel temperatures remain below 1600 deg. C for all these cases, which is the limiting temperature relating to radioactivity release from the fuel. The analyses presented in this paper demonstrate that the code THERMIX can be successfully applied for the thermal calculation of HTRs with prismatic fuel. The results also provide some fundamental information for the design optimization of V/HTR with respect to its maximum thermal power, operating

  2. Aptamer-polymer functionalized silicon nanosubstrates for enhanced recovered circulating tumor cell viability and in vitro chemosensitivity testing

    Directory of Open Access Journals (Sweden)

    Shen QL

    2016-05-01

    Full Text Available Qinglin Shen1,2,*, Caixia Peng2,3,*, Yan Zhan1, Liang Fan1, Mengyi Wang1, Qing Zhou4, Jue Liu2,4, Xiaojuan Lv1, Qiu Tang1, Jun Li1,2, Xiaodong Huang2, Jiahong Xia2 1Department of Oncology, 2Key Laboratory for Molecular Diagnosis of Hubei Province, 3Central Laboratory, 4Department of Pharmacy, The Central Hospital of Wuhan, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, People’s Republic of China *These authors contributed equally to this work Abstract: Selection of the optimal chemotherapy regimen for an individual cancer patient is challenging. The existing chemosensitivity tests are costly, time-consuming, and not amenable to wide utilization within a clinic. This limitation might be addressed by the recently proposed use of circulating tumor cells (CTCs, which provide an opportunity to noninvasively monitor response to therapy. Over the past few decades, various techniques were developed to capture and recover CTCs, but these techniques were often limited by a capture and recovery performance tradeoff between high viability and high efficiency. In this work, we used anti-epithelial cell adhesion molecule coated aptamer–poly (N-isopropylacrylamide functionalized silicon nanowire substrates to capture and release epithelial cell adhesion molecule-positive CTCs at 32°C and 4°C, respectively. Then, we applied the nuclease to digest the aptamer to release the captured CTCs (near or at the end of the polymer brush, which cannot be released by heating/cooling process. High viability and purity CTCs could be achieved by decreasing the heating/cooling cycles and enzymatic treatment rounds. Furthermore, the time-saving process is helpful to maintain the morphology and enhance vitality of the recovered CTCs and is beneficial to the subsequent cell culture in vitro. We validated the feasibility of chemosensitivity testing based on the recovered HCC827 cells using an adenosine triphosphate–tumor chemosensitivity

  3. A study of longwave radiation codes for climate studies: Validation with ARM observations and tests in general circulation models

    International Nuclear Information System (INIS)

    This report summarizes the activities of our group to meet our stated objectives. The report is divided into sections entitled: Radiation Model Testing Activities, General Circulation Model Testing Activities, Science Team Activities, and Publications, Presentations and Meetings. The section on Science Team Activities summarizes our participation with the science team to further advance the observation and modeling programs. Appendix A lists graduate students supported, and post-doctoral appointments during the project. Reports on the activities during each of the first two years are included as Appendix B. Significant progress has been made in: determining the ability of line-by-line radiation models to calculate the downward longwave flux at the surface; determining the uncertainties in calculated the downwelling radiance and flux at the surface associated with the use of different proposed profiling techniques; intercomparing clear-sky radiance and flux observations with calculations from radiation codes from different climate models; determining the uncertainties associated with estimating N* from surface longwave flux observations; and determining the sensitivity of model calculations to different formulations of the effects of finite sized clouds

  4. Fetal Circulation

    Science.gov (United States)

    ... Pressure High Blood Pressure Tools & Resources Stroke More Fetal Circulation Updated:Jul 8,2016 click to enlarge The ... fetal heart. These two bypass pathways in the fetal circulation make it possible for most fetuses to survive ...

  5. Post-test analysis with RELAP5/MOD2 of ROSA-IV/LSTF natural circulation test ST-NC-02

    International Nuclear Information System (INIS)

    Results of post-test analysis for the ROSA-IV/LSTF natural circulation experiment ST-NC-02 are presented. The experiment consisted of many steady-state stages registered for different primary inventories. The calculation was done with RELAP5/MOD2 CYCLE 36.00. Discrepancies between the calculation and the experiment are observed: the core flow rate is overestimated at inventories between 80 % and 95 %; the inventory at which dryout occurs in the core is also much overestimated. The causes of these discrepancies are studies through sensitivity calculations and the following key parameters are pointed out: the interfacial friction and the form loss coefficients in the vessel riser, the SG U-tube multidimensional behaviour, the interfacial friction in the SG inlet plenum and in the pipe located underneath. (author)

  6. Aptamer–polymer functionalized silicon nanosubstrates for enhanced recovered circulating tumor cell viability and in vitro chemosensitivity testing

    Science.gov (United States)

    Shen, Qinglin; Peng, Caixia; Zhan, Yan; Fan, Liang; Wang, Mengyi; Zhou, Qing; Liu, Jue; Lv, Xiaojuan; Tang, Qiu; Li, Jun; Huang, Xiaodong; Xia, Jiahong

    2016-01-01

    Selection of the optimal chemotherapy regimen for an individual cancer patient is challenging. The existing chemosensitivity tests are costly, time-consuming, and not amenable to wide utilization within a clinic. This limitation might be addressed by the recently proposed use of circulating tumor cells (CTCs), which provide an opportunity to noninvasively monitor response to therapy. Over the past few decades, various techniques were developed to capture and recover CTCs, but these techniques were often limited by a capture and recovery performance tradeoff between high viability and high efficiency. In this work, we used anti-epithelial cell adhesion molecule coated aptamer–poly (N-isopropylacrylamide) functionalized silicon nanowire substrates to capture and release epithelial cell adhesion molecule-positive CTCs at 32°C and 4°C, respectively. Then, we applied the nuclease to digest the aptamer to release the captured CTCs (near or at the end of the polymer brush), which cannot be released by heating/cooling process. High viability and purity CTCs could be achieved by decreasing the heating/cooling cycles and enzymatic treatment rounds. Furthermore, the time-saving process is helpful to maintain the morphology and enhance vitality of the recovered CTCs and is beneficial to the subsequent cell culture in vitro. We validated the feasibility of chemosensitivity testing based on the recovered HCC827 cells using an adenosine triphosphate–tumor chemosensitivity assay, and the results suggested that our method can determine which agent and what concentration have the best chemosensitivity for the culturing recovered CTCs. So, the novel method capable of a highly effective capture and recovery of high viability CTCs will pave the way for chemosensitivity testing. PMID:27274239

  7. Aptamer-polymer functionalized silicon nanosubstrates for enhanced recovered circulating tumor cell viability and in vitro chemosensitivity testing.

    Science.gov (United States)

    Shen, Qinglin; Peng, Caixia; Zhan, Yan; Fan, Liang; Wang, Mengyi; Zhou, Qing; Liu, Jue; Lv, Xiaojuan; Tang, Qiu; Li, Jun; Huang, Xiaodong; Xia, Jiahong

    2016-01-01

    Selection of the optimal chemotherapy regimen for an individual cancer patient is challenging. The existing chemosensitivity tests are costly, time-consuming, and not amenable to wide utilization within a clinic. This limitation might be addressed by the recently proposed use of circulating tumor cells (CTCs), which provide an opportunity to noninvasively monitor response to therapy. Over the past few decades, various techniques were developed to capture and recover CTCs, but these techniques were often limited by a capture and recovery performance tradeoff between high viability and high efficiency. In this work, we used anti-epithelial cell adhesion molecule coated aptamer-poly (N-isopropylacrylamide) functionalized silicon nanowire substrates to capture and release epithelial cell adhesion molecule-positive CTCs at 32°C and 4°C, respectively. Then, we applied the nuclease to digest the aptamer to release the captured CTCs (near or at the end of the polymer brush), which cannot be released by heating/cooling process. High viability and purity CTCs could be achieved by decreasing the heating/cooling cycles and enzymatic treatment rounds. Furthermore, the time-saving process is helpful to maintain the morphology and enhance vitality of the recovered CTCs and is beneficial to the subsequent cell culture in vitro. We validated the feasibility of chemosensitivity testing based on the recovered HCC827 cells using an adenosine triphosphate-tumor chemosensitivity assay, and the results suggested that our method can determine which agent and what concentration have the best chemosensitivity for the culturing recovered CTCs. So, the novel method capable of a highly effective capture and recovery of high viability CTCs will pave the way for chemosensitivity testing. PMID:27274239

  8. Clinical test on circulating tumor cells in peripheral blood of lung cancer patients, based on novel immunomagnetic beads.

    Science.gov (United States)

    Wang, Bo; Wang, Bin; Zhang, Daoyun; Guo, Hongyin; Zhang, Lianbin; Zhou, Wenpeng

    2016-05-01

    This paper aims to establish a novel and highly sensitive method to detect circulating tumor cells (CTCs) in the peripheral blood of patients with lung cancer. This therefore enables the discovery of invisible micrometastasis in the early stage of lung cancer, leading to better prognostic assessments of lung cancer and detection of the post-operative tumor recurrence and metastasis, treatment options, and evaluation of curative effects. In this research study, various lung cancer cells were mixed with adult blood samples to simulate blood samples of tumor patients. With novel test methods, CTCs in peripheral blood of lung cancer patients were calculated, after the reaction between the cells obtained from the mix and EpCAM (epithelial cell adhesion molecule) antibodies which were marked by immunomagnetic beads. The results showed that 18 out of 42 (42.9%) lung cancer patients had a positive CTCs, which increased with tumor enlargement or metastasis. CTCs were not detected in a total of 20 blood samples from healthy volunteers. This indicated that the technology of novel immunomagnetic bead-enrichment could effectively separate and identify CTCs in peripheral blood of lung cancer patients, which is of great clinical value for prognostic assessments and treatment guidance of lung cancer. PMID:25682839

  9. Analysis of natural circulation in the in-core structure test section (T2) in the case of a blower trip

    International Nuclear Information System (INIS)

    When a blower trip occurs in an abnormal condition of the in-core structure test section (T2), natural circulation will develop in the two flow channels which are formed by the gap between the fixed reflector and the side shield and the gap between the side shield and the core barrel. The natural circulation heats up the structures of T2, such as a core restraint mechanism and a core barrel and others. Moreover, the radiation emitted from the heated core barrel enhances markably heating-up of the pressure vessel. This report deals with an analysis of the natural circulation accurred after a blower trip, and with the effect on the temperature rise of the structures of T2. Possible countermeasures are also discussed. (author)

  10. Evaluations on shutdown cooling performance test for Korean standard nuclear power plants

    International Nuclear Information System (INIS)

    The new acceptance criteria for shutdown cooling performance test for Korean Standard Nuclear Power Plant (KSNP) were developed using KDSCNT1 code and to adequately evaluate the actual pre-core cooldown test conditions. The UCN 5 cooldown tests from hot shutdown to refueling modes under the pre-core hot functional test (HFT) conditions were performed using Shutdown Cooling System (SCS) Train A and B, respectively. The test results were evaluated as compared with the new acceptance criteria. These evaluations show that the new acceptance criteria appear to be reasonable to verify the SCS performance during the pre-core HFT cooldown stage, although there is a little deviation at the later stage of cooldown between the test result and the prediction. This deviation seems to be caused by the energy addition of the Reactor Coolant Pump (RCP) operations and the heat removal of steam generators, which is not assumed in the prediction assumptions

  11. Monitoring of tritium purity during long-term circulation in the KATRIN test experiment LOOPINO using laser Raman spectroscopy

    OpenAIRE

    Fischer, Sebastian; Sturm, Michael; Schlösser, Magnus; Bornschein, Beate; Drexlin, Guido; Priester, Florian; Lewis, Richard J.; Telle, Helmut H.

    2012-01-01

    The gas circulation loop LOOPINO has been set up and commissioned at Tritium Laboratory Karlsruhe (TLK) to perform Raman measurements of circulating tritium mixtures under conditions similar to the inner loop system of the neutrino-mass experiment KATRIN, which is currently under construction. A custom-made interface is used to connect the tritium containing measurement cell, located inside a glove box, with the Raman setup standing on the outside. A tritium sample (purity > 95%, 20 kPa total...

  12. Flow characteristics of Hijiori HDR reservoir form circulation test in 1995; Koon tantai Hijiori jikkenjo ni okeru shinbu choryuso yobi junkan shiken (1995 nendo) kekka to ryudo kaiseki

    Energy Technology Data Exchange (ETDEWEB)

    Fukushima, N.; Hyodo, M.; Shinohara, N.; Takasugi, S. [Geothermal Energy Research and Development Co. Ltd., Tokyo (Japan)

    1996-05-01

    This paper reports the result of a preliminary circulation test conducted in fiscal 1995 on a deep reservoir (at a depth of about 2200 m) in the Hijiori hot dry rock experimental field. One water injection well and two production wells were drilled to constitute a circulation loop, to which the circulation test was performed to investigate the flow characteristics thereof. The result revealed the following matters: total amount of injected water of 51500 m{sup 3} resulted in a total fluid recovery rate of about 40%; as a result of well stimulation given twice during the initial stage of the water injection, the continuity impedance in the vicinity of the injection well decreased largely (however, the continuity improvement upon the second attempt was considerably inferior to that from the first attempt); and increase in the water injection amount does not necessarily lead to increase in the production amount. The paper describes additionally that it is extremely difficult to interpret non-linearity between the injection and production amounts by using a model prepared previously with a main objective to analyze the Hijiori HDR circulation system. 1 ref., 9 figs., 1 tab.

  13. AMELIA CESTOL Test: Acoustic Characteristics of Circulation Control Wing with Leading- and Trailing-Edge Slot Blowing

    Science.gov (United States)

    Horne, William C.; Burnside, Nathan J.

    2013-01-01

    The AMELIA Cruise-Efficient Short Take-off and Landing (CESTOL) configuration concept was developed to meet future requirements of reduced field length, noise, and fuel burn by researchers at Cal Poly, San Luis Obispo and Georgia Tech Research Institute under sponsorship by the NASA Fundamental Aeronautics Program (FAP), Subsonic Fixed Wing Project. The novel configuration includes leading- and trailing-edge circulation control wing (CCW), over-wing podded turbine propulsion simulation (TPS). Extensive aerodynamic measurements of forces, surfaces pressures, and wing surface skin friction measurements were recently measured over a wide range of test conditions in the Arnold Engineering Development Center(AEDC) National Full-Scale Aerodynamics Complex (NFAC) 40- by 80-Ft Wind Tunnel. Acoustic measurements of the model were also acquired for each configuration with 7 fixed microphones on a line under the left wing, and with a 48-element, 40-inch diameter phased microphone array under the right wing. This presentation will discuss acoustic characteristics of the CCW system for a variety of tunnel speeds (0 to 120 kts), model configurations (leading edge(LE) and/or trailing-edge(TE) slot blowing, and orientations (incidence and yaw) based on acoustic measurements acquired concurrently with the aerodynamic measurements. The flow coefficient, Cmu= mVSLOT/qSW varied from 0 to 0.88 at 40 kts, and from 0 to 0.15 at 120 kts. Here m is the slot mass flow rate, VSLOT is the slot exit velocity, q is dynamic pressure, and SW is wing surface area. Directivities at selected 1/3 octave bands will be compared with comparable measurements of a 2-D wing at GTRI, as will as microphone array near-field measurements of the right wing at maximum flow rate. The presentation will include discussion of acoustic sensor calibrations as well as characterization of the wind tunnel background noise environment.

  14. The Effect of Warm-Up and Cool-Down Exercise on Delayed Onset Muscle Soreness in the Quadriceps Muscle: a Randomized Controlled Trial

    OpenAIRE

    Olsen, Olav; Sjøhaug, Mona; van Beekvelt, Mireille; Mork, Paul Jarle

    2012-01-01

    The aim of the present study was to investigate the effect of warm-up and cool-down exercise on delayed onset of muscle soreness at the distal and central parts of rectus femoris following leg resistance exercise. Thirty-six volunteers (21 women, 15 men) were randomly assigned to the warm-up (20 min ergometer cycling prior to the resistance exercise), cool-down (20 min cycling after the resistance exercise), or control group performing resistance exercise only. The resistance exercise consist...

  15. Lung Circulation.

    Science.gov (United States)

    Suresh, Karthik; Shimoda, Larissa A

    2016-01-01

    The circulation of the lung is unique both in volume and function. For example, it is the only organ with two circulations: the pulmonary circulation, the main function of which is gas exchange, and the bronchial circulation, a systemic vascular supply that provides oxygenated blood to the walls of the conducting airways, pulmonary arteries and veins. The pulmonary circulation accommodates the entire cardiac output, maintaining high blood flow at low intravascular arterial pressure. As compared with the systemic circulation, pulmonary arteries have thinner walls with much less vascular smooth muscle and a relative lack of basal tone. Factors controlling pulmonary blood flow include vascular structure, gravity, mechanical effects of breathing, and the influence of neural and humoral factors. Pulmonary vascular tone is also altered by hypoxia, which causes pulmonary vasoconstriction. If the hypoxic stimulus persists for a prolonged period, contraction is accompanied by remodeling of the vasculature, resulting in pulmonary hypertension. In addition, genetic and environmental factors can also confer susceptibility to development of pulmonary hypertension. Under normal conditions, the endothelium forms a tight barrier, actively regulating interstitial fluid homeostasis. Infection and inflammation compromise normal barrier homeostasis, resulting in increased permeability and edema formation. This article focuses on reviewing the basics of the lung circulation (pulmonary and bronchial), normal development and transition at birth and vasoregulation. Mechanisms contributing to pathological conditions in the pulmonary circulation, in particular when barrier function is disrupted and during development of pulmonary hypertension, will also be discussed. © 2016 American Physiological Society. Compr Physiol 6:897-943, 2016. PMID:27065170

  16. A study on shaft vibration of gas circulators with gas-bearings for HENDEL helium test facility

    International Nuclear Information System (INIS)

    The gas circulator is a one of the most important component in Gas-Cooled Reactor system. Being low density of the coolant helium gas of HTGR, multi-stage compression or high-speed driving are required for the coolant circulator to accomplish the required head. The gas circulators for the large scale HTGRs with mechanical and buffer-gas sealing in the shaft penetration had encountered troubles at the part more or less. On the other hand, smaller scale electric driven gas circulators with gas bearings as used for HENDEL and former DRAGON reactor enable fully encased construction and provide easier maintainability, however, those types of the circulator need highly precise machining, adjustment and superior operational techniques. Moreover, practical rotor weight seems to be limited up to around 150kg for the gas-bearing machinery. The fine dynamic mass-balancing of the rotor becomes extremely difficult in the large gas-bearing machine. The whirling phenomena of the journal tend to originate and to grow approaching the rotating frequency to the first bending natural frequency or the third critical speed of the rotor. Inspite of many efforts and works on instability of the gas-bearing system, concrete or practical condition and countermeasure to the instability have not clarified. Present report describes the experimental result on shaft vibration and bearing characteristics of typical gas circulators among the five machines which have gas-bearings and are largest class in those types. It is clarified through the experiments that the fine dynamic balancing of the rotor, dynamic response of the bearing pads and gas-film thickness in the bearing clearance are extremely important to suppress the instability. However, it is also found that too much difficulties make them impractical in these machines. So one might conclude that the countermeasure with fine sensing technique of the half-speed whirling must be practical and usefull. (author)

  17. Accident management following loss-of-coolant accidents during cooldown in a Westinghouse two-loop PWR

    International Nuclear Information System (INIS)

    Operation of pressurised water reactors involves shutdown periods for refuelling and maintenance. In preparation for this, the reactor system is cooled down, depressurised and partially drained. Although reactor coolant pressure is lower than during full-power operation, there remains the possibility of a loss-of-coolant accident (LOCA), with a certain but low probability. While the decay heat to be removed is lower than that from a LOCA at full power, the reduced availability of safety systems implies a risk of failing to maintain core cooling, and hence of core damage. This is recognised though probabilistic safety analyses (PSA), which identify low but non-negligible contributions to core damage frequency from accidents during cooldown and shutdown. Analyses are made for a typical two-loop Westinghouse PWR of the consequences of a range of LOCAs during hot and intermediate shutdown, 4 and 5 h after reactor shutdown respectively. The accumulators are isolated, while power to some of the pumped safety injection systems (SIs) is racked out. The study assesses the effectiveness of the nominally assumed SIs in restoring coolant inventory and preventing core damage, and the margin against core damage where their actuation is delayed. The calculations use the engineering-level MELCOR1.8.5 code, supplemented by the SCDAPSIM and SCDAP/RELAP5 codes, which provide a more detailed treatment of coolant system thermal hydraulics and core behaviour. Both treatments show that the core is readily quenched, without damage, by the nominal SI which assumes operation of only one pump. Margins against additional scenario and model uncertainties are assessed by assuming a delay of 900 s (the time needed to actuate the remaining pumps) and a variety of assumptions regarding models and the number of pumps available in conjunction with both MELCOR and versions of SCDAP. Overall, the study provides confidence in the inherent robustness of the plant design with respect to LOCA during

  18. Accident management following loss-of-coolant accidents during cooldown in a Westinghouse two-loop PWR

    Energy Technology Data Exchange (ETDEWEB)

    Haste, T.J., E-mail: tim.haste@irsn.f [Paul Scherrer Institut (PSI), CH-5232 Villigen (Switzerland); Birchley, J. [Paul Scherrer Institut (PSI), CH-5232 Villigen (Switzerland); Richner, M. [Nordostschweizerische Kraftwerke (NOK) - NPP Beznau, CH-5312 Doettingen (Switzerland)

    2010-06-15

    Operation of pressurised water reactors involves shutdown periods for refuelling and maintenance. In preparation for this, the reactor system is cooled down, depressurised and partially drained. Although reactor coolant pressure is lower than during full-power operation, there remains the possibility of a loss-of-coolant accident (LOCA), with a certain but low probability. While the decay heat to be removed is lower than that from a LOCA at full power, the reduced availability of safety systems implies a risk of failing to maintain core cooling, and hence of core damage. This is recognised though probabilistic safety analyses (PSA), which identify low but non-negligible contributions to core damage frequency from accidents during cooldown and shutdown. Analyses are made for a typical two-loop Westinghouse PWR of the consequences of a range of LOCAs during hot and intermediate shutdown, 4 and 5 h after reactor shutdown respectively. The accumulators are isolated, while power to some of the pumped safety injection systems (SIs) is racked out. The study assesses the effectiveness of the nominally assumed SIs in restoring coolant inventory and preventing core damage, and the margin against core damage where their actuation is delayed. The calculations use the engineering-level MELCOR1.8.5 code, supplemented by the SCDAPSIM and SCDAP/RELAP5 codes, which provide a more detailed treatment of coolant system thermal hydraulics and core behaviour. Both treatments show that the core is readily quenched, without damage, by the nominal SI which assumes operation of only one pump. Margins against additional scenario and model uncertainties are assessed by assuming a delay of 900 s (the time needed to actuate the remaining pumps) and a variety of assumptions regarding models and the number of pumps available in conjunction with both MELCOR and versions of SCDAP. Overall, the study provides confidence in the inherent robustness of the plant design with respect to LOCA during

  19. Testing the 231Pa/230Th paleo-circulation proxy: A data versus 2D model comparison

    International Nuclear Information System (INIS)

    Variations of the Atlantic Meridional Overturning Circulation (AMOC) are believed to have crucially influenced Earth's climate due to its key role in the inter-hemispheric redistribution of heat and carbon. To assess its past strength, the sedimentary 231Pa/230Th proxy has been developed and improved but also contested due to its sensitivity to other factors beyond ocean circulation. In order to provide a better basis for the understanding of the Atlantic 231Pa/230Th system, and therefore to shed light on the controversy, we compare new measurements of Holocene sediments from the north Brazilian margin to water column data and the output of a two-dimensional scavenging-circulation model, based on modern circulation patterns and reversible scavenging parameters. We show that sedimentary 231Pa/230Th data from one specific area of the Atlantic are in very good agreement with model results suggesting that sedimentary 231Pa/230Th is predominantly driven by the AMOC. Therefore, 231Pa/230Th represents an appropriate method to reconstruct past AMOC at least qualitatively along the western margin. (authors)

  20. Modeling of Coil Pre-stress Loss During Cool-down in the Main Dipoles of the Large Hadron Collider

    CERN Document Server

    Ferracin, P; Todesco, Ezio; Tommasini, D

    2002-01-01

    We describe a finite element mechanical model of the main LHC dipole, based on the geometry and on the properties of its components; coil characteristics are derived from measurements on stacks of conductors. We show how to define equivalent properties of cable blocks that take into account the collaring procedure when it is not explicitly modelled. Numerical results are then compared to experimental measurements of loads and deformations in dipole prototypes. At cryogenic temperature, equivalent properties are used to implement in the model a pressure- dependent thermal contraction factor observed in stack measurements. This allows to forecast the large pre-stress loss during the cool-down observed in the LHC dipole prototypes.

  1. Reliability and functional testing scheme for cold circulating pumps required to cool large size fusion grade superconducting magnets and cryo-pumps

    International Nuclear Information System (INIS)

    Forced flow cooling using supercritical helium is the most preferable method due to the distinct advantages over the other cooling procedures for the superconducting magnets and cryo-pumps in fusion research devices. The flow requirements are high to fulfill the stability requirement of the magnet system during all operational modes. The flow requirements are met with cold circulation pump at 4 K level. These pumps require state of the art design due to constraints from temperature and associated process requirements with a demand of high efficiency. The future requirement of the future fusion research reactor (ITER) is foreseen as ∼ 2.7 kg/s mass flow rate with adiabatic efficiency > 70%. Against the future requirement, the maximum capacity ever built till now has a capacity of 1.2 kg/s mass flow with adiabatic efficiency ∼ 60%. Therefore, the up scaling of existing cold circulating pumps with improvement of efficiency is necessary to meet the future requirement. This paper discusses the major risks associated with cold circulating pumps and a test proposal with basic testing scheme to validate the performance. (author)

  2. TESTING THE INTERACTION OF HEART LEFT VENTRICLE AND CONTINUOUS-FLOW PUMP ON A MOCK CIRCULATION MODEL UNDER NORMAL AND PATHOLOGICAL CONDITIONS

    Directory of Open Access Journals (Sweden)

    G. P. Itkin

    2015-10-01

    Full Text Available Introduction. The preliminary study of new developed pumps for circulatory support on the hydrodynamic circulation model is an important step in the process of their designing. Hydrodynamic circulation models that can closely imitate cardio – vascular system are important to defi ne the range of effective functioning of the pumps under normal and heart disease conditions which is of great importance for defi ning the mode of these pumps in real clinical conditions.The aim of study is to create a new hydrodynamic circulation model of the systemic circulation to study the processes of interaction of heart left ventricle and continuous – fl ow pumps.Materials and methods. The main components of the mock circulation model (arterial and venous blocks are designed as closed reservoirs with an air bag providing the necessary elasticity value of these reservoirs. The heart left ventricle was simulated with an artifi cial heart ventricle with a pneumatic drive Sinus-IS which allows to change its options in a wide range. As a test pump we used the fi rst native implantable axial pump VISH – 1. In the course of research we made the registration and recording of the basic hemodynamic parameters (pressure, fl ow with a multichannel module Pumpax for the measurement of pressure parameters.Results. The designed circulation model allows to adequately reproduce the main hemodynamic parameters of the circulatory system in normal (arterial pressure – 110/77 mmHg, left atrium pressure – 7 mmHg and cardiac output – 4.2 l/min and heart failure conditions (arterial pressure – 79/53 mmHg, left atrium pressure – 15 mmHg and cardiac output – 3.1 l/min. On the circulation model the interaction of heart left ventricle and continuous-fl ow pump in heart failure simulation was studied. The dynamics of the main circulation fi gures is shown under conditions of changing of the pump rotor speed. Meanwhile, the conditions of the closing of

  3. Hypertension of Both the Pulmonary and Systemic Circulations and the Vasodilator Properties of L-Arginine (Acute Drug Testing)

    OpenAIRE

    Kupnovytska, I. H.; Dron, L. A.

    2015-01-01

    The article highlights the problems of the correction of endothelial dysfunction and peripheral hemodynamics of both the pulmonary and systemic circulations in patients with arterial hypertension (AH) stage II and co-existent chronic obstructive pulmonary disease (COPD) by acute intravenous L-arginine infusion. Materials and methods. 20 patients with AH stage II and co-existent COPD in remission phase without respiratory failure with the average age of 48±3.9 years (males to females = 1:1) su...

  4. Monitoring of tritium purity during long-term circulation in the KATRIN test experiment LOOPINO using laser Raman spectroscopy

    CERN Document Server

    Fischer, Sebastian; Schlösser, Magnus; Bornschein, Beate; Drexlin, Guido; Priester, Florian; Lewis, Richard J; Telle, Helmut H

    2012-01-01

    The gas circulation loop LOOPINO has been set up and commissioned at Tritium Laboratory Karlsruhe (TLK) to perform Raman measurements of circulating tritium mixtures under conditions similar to the inner loop system of the neutrino-mass experiment KATRIN, which is currently under construction. A custom-made interface is used to connect the tritium containing measurement cell, located inside a glove box, with the Raman setup standing on the outside. A tritium sample (purity > 95%, 20 kPa total pressure) was circulated in LOOPINO for more than three weeks with a total throughput of 770 g of tritium. Compositional changes in the sample and the formation of tritiated and deuterated methanes CT_(4-n)X_n (X=H,D; n=0,1) were observed. Both effects are caused by hydrogen isotope exchange reactions and gas-wall interactions, due to tritium {\\beta} decay. A precision of 0.1% was achieved for the monitoring of the T_2 Q_1-branch, which fulfills the requirements for the KATRIN experiment and demonstrates the feasibility ...

  5. Blink Reflex as a Complementary Test to MRI in Early Detection of Brainstem Infarctions: Comparison of Blink Reflex Abnormalities in Anterior Versus Posterior Circulation Strokes

    Directory of Open Access Journals (Sweden)

    K Basiri

    2004-08-01

    Full Text Available Background: Early detection of vertebro-basilar insufficiency is of paramount importance. Brain MRI was the only method of diagnosis for many years, but in addition to high cost and delay in report, it may not detect all brain stem lesions. In this study Blink reflex (BR was evaluated as a complementary test to MRI. Methods: Fifty-four patients were studied [27 anterior circulation stroke patients (ACSP and 27 posterior circulation stroke patients (PCSP]. MRI was performed within the first week after the onset of stroke. Nineteen age and sex matched healthy people enrolled as controls. BR was performed within the first 24 hours of the onset. Frequency of abnormal blink reflex in ACSP and PCSP was compared with MRI findings. Then abnormal responses in two groups were compared by chi-square test. Results: In both ACSP and PCSP, two patients had normal BR responses, and in 25 patients R1 or R2 components of blink responses were absent or prolonged (92.5%. R1was absent or delayed in 16 PCSP, but it was abnormal in only two ACSP (P < 0.001. Abnormal R2 responses were detected in 22 PCSP and 24 ACSP. Conclusion: BR abnormalities had high correlation with MRI findings in PCSP (92.5% BR can be performed within the first 24 hours of onset of stroke, and its results is available immediately. This test is easy to perform and comfortable for the patient, has low cost, and is available every where. Therefore we introduced BR as a complementary (but not replacing test to MRI in early detection of brainstem infarctions. Comparison of BR responses in ACSP and PCSP showed that abnormalities of R1 responses had high accuracy in differentiation between anterior and posterior circulation strokes. We concluded that BR responses not only can detect brainstem infarctions rapidly and readily in its early stages, but also can differentiate ACSP from PCSP with high accuracy. Keywords: Blink Reflex, Anterior Circulation Stroke, Posterior Circulation Stroke Patients

  6. Lead-bismuth cooled reactor with a high level of natural circulation (RBEC-M)

    International Nuclear Information System (INIS)

    The RBEC-M is a lead-bismuth cooled fast reactor with a high level of primary coolant natural circulation and a gas lift system in the primary circuit to ensure a supply of inert gas (argon) in the coolant under the core. The name reflects the basic technology of the concept: a fast neutron spectrum, heavy metal lead-bismuth coolant, a high level of natural circulation with a nominal operation of inert gas blowers and safe cooldown of the core after the trip of gas supply blowers. The RBEC-M reactor is a conceptual development based on the preliminary design of the RBEC reactor, hereafter referred to as a 'basic project'. The direct predecessor of the RBEC-M is the design named RBEC, one of the Russian-developed designs of fast reactors with heavy metal coolants. The preliminary design of the RBEC reactor of 900 MW(th) and 340 MW(e) was completed in the 1990s by Russian design and scientific institutions: OKB 'Gidropress', Russian Research Centre (RRC) 'Kurchatov Institute' and IPPE, with the participation of VNIINM and RIAR. The main objective of the development of the RBEC lead-bismuth cooled fast reactor was to provide a reliable solution for nuclear fuel breeding, while using an approach alternative to sodium cooled fast reactors. It was assumed that design development of a nuclear power plant (NPP) with such reactor could be completed in a rather short period, with modest expenditures for additional testing and qualification of separate equipment units

  7. Benchmark Analyses on the Natural Circulation Test Performed During the PHENIX End-of-Life Experiments. Final Report of a Co-ordinated Research Project 2008-2011

    International Nuclear Information System (INIS)

    The International Atomic Energy Agency (IAEA) supports Member State activities in the area of advanced fast reactor technology development by providing a forum for information exchange and collaborative research programmes. The Agency's activities in this field are mainly carried out within the framework of the Technical Working Group on Fast Reactors (TWG-FR), which assists in the implementation of corresponding IAEA activities and ensures that all technical activities are in line with the expressed needs of Member States. Among its broad range of activities, the IAEA proposes and establishes coordinated research projects (CRPs) aimed at the improvement of Member State capabilities in the area of fast reactor design and analysis. An important opportunity to undertake collaborative research was provided by the experimental campaign of the French Alternative Energies and Atomic Energy Commission (CEA) in the prototype sodium fast reactor PHENIX before it was shut down in 2009. The overall purpose of the end of life tests was to gather additional experience on the operation of sodium cooled reactors. As the CEA opened the experiments to international cooperation, in 2007 the IAEA launched a CRP on ''Control Rod Withdrawal and Sodium Natural Circulation Tests Performed during the PHENIX End-of-Life Experiments''. The CRP, with the participation of institutes from eight countries, contributed to improving capabilities in sodium cooled reactor simulation through code verification and validation, with particular emphasis on temperature and power distribution calculations and the analysis of sodium natural circulation phenomena. The objective of this report is to document the results and main achievements of the benchmark analyses on the natural circulation test performed in the framework of the PHENIX end of life experimental campaign

  8. Transient two-phase flow of cryogenic fluid in a vertical transfer line during the cooldown process

    International Nuclear Information System (INIS)

    The analytical and numerical modeling for prediction of the thermo-fluid parameters of the cooldown process of a vertical tube carrying cryogenic liquid are presented. Formulation of the problem is based on flow patterns observed in the experimental studies. In this model, the flow field consists of four distinct regions of fully liquid, inverted annular film boiling, dispersed flow film boiling, and fully vapor. For the fully liquid and fully vapor regions, the one-dimensional form of the mass, momentum, and energy conservation equations are used. For the two-phase regions, the volume-averaged, one-dimensional two-fluid model conservation equations are applied. In addition, a one-dimensional energy equation is formulated to determine the tube-wall history. The numerical approximations are based on the finite-difference technique. Calculations for inverted annular flow are based on a semi-implicit model while computations for the wall, fully liquid, and dispersed flow regions are performed explicitly. Comparison of calculated results with experimental data for water and liquid nitrogen are presented

  9. Overall results of and lessons learned from the IAEA CRP on sodium natural circulation test performed during the Phenix end-of-life experiments

    International Nuclear Information System (INIS)

    In 2007, the International Atomic Energy Agency (IAEA) launched the Coordinated Research Project (CRP) 'Control Rod Withdrawal and Sodium Natural Circulation Tests Performed during the Phenix End-of-Life Experiments'. The overall purpose of the CRP, performed within the framework of the IAEA programme in support of innovative fast reactor technology development and deployment, is to improve the Member States' analytical capabilities in the various fields of research and design of sodium-cooled fast reactors through data and codes verification and validation. In particular the CRP, taking advantage of the End-of-Life set of experiments performed before the final shut-down of the French prototype fast breeder power reactor Phenix, aims at improving fast reactor simulation methods and design capabilities in the field of temperature and power distribution evaluation, as well as of the analysis of sodium natural circulation phenomena. The paper presents the overall results of the CRP, including blind calculations and post-test and sensitivity analyses carried out by the CRP participants, as well as lessons learned and recommendations for further future implementations to resolve open issues. (authors)

  10. Horizontal coring using air as the circulating fluid: Some prototype studies conducted in G Tunnel at the Nevada Test Site for the Yucca Mountain Project

    Energy Technology Data Exchange (ETDEWEB)

    Chornack, M.P. [Geological Survey, Las Vegas, NV (USA); French, C.A. [Reynolds Electrical and Engineering Co., Inc., Las Vegas, NV (USA)

    1989-12-31

    Horizontal coring using air as the circulating fluid has been conducted in the G Tunnel Underground Facility (GTUF) at the Nevada Test Site. This work is part of the prototype investigations of hydrogeology for the Yucca Mountain Project. The work is being conducted to develop methods and procedures that will be used at the Department of Energy`s Yucca Mountain Site, a candidate site for the nation`s first high-level nuclear waste repository, during the site characterization phase of the investigations. The United States Geological Survey (USGS) is conducting this prototype testing under the guidance of the Los Alamos National Laboratory (LANL) and in conjunction with Reynolds Electrical & Engineering Company (REECo), the drilling contractor. 7 refs., 8 figs., 5 tabs.

  11. Some test results of Maritsa East lignite mine- first large-scale circulating fluidized bed combustion - as the basis of the restructuring process

    International Nuclear Information System (INIS)

    One of the consequences of energy sector restructuring in the transition countries is an increasing number of shareholders interested in profitable power plants. The traditional energy sector structural and operating paradigms evolved together, in symbiosis. power generation from coal is still negatively associated with severe pollutant emissions like NOx, SO2. In Bulgaria particularly power generation relies on the Maritsa-East coal mine as the single national energy source. The coal has an extremely poor quality (high sulphur, ash and water content) yielding high emissions of pollutants during combustion. The first large-scale test of circulating fluidized bed combustion (CFB) of Maritsa-East coal mine took place in 1998. For this purpose, test facilities in Austria Energy and Environment (AEE) and RWE's power plant Niederraussen were used. This analysis is very important for the management of National Energy Company as regards restructuring and privatisation. (author)

  12. Novel circulating microRNA signature as a potential non-invasive multi-marker test in ER-positive early-stage breast cancer

    DEFF Research Database (Denmark)

    Kodahl, Annette R; Lyng, Maria Bibi; Binder, Harald;

    2014-01-01

    specific algorithm based on the 9 miRNA signature, the risk for future individuals can be predicted. Since microRNAs are highly stable in blood components, this signature might be useful in the development of a blood-based multi-marker test to improve early detection of breast cancer. Such a test could......INTRODUCTION: There are currently no highly sensitive and specific minimally invasive biomarkers for detection of early-stage breast cancer. MicroRNAs (miRNAs) are present in the circulation and may be unique biomarkers for early diagnosis of human cancers. The aim of this study was to investigate...... the differential expression of miRNAs in the serum of breast cancer patients and healthy controls. METHODS: Global miRNA analysis was performed on serum from 48 patients with ER-positive early-stage breast cancer obtained at diagnosis (24 lymph node-positive and 24 lymph node-negative) and 24 age...

  13. Testing an astronomically-based decadal-scale empirical harmonic climate model versus the IPCC (2007) general circulation climate models

    CERN Document Server

    Scafetta, Nicola

    2012-01-01

    We compare the performance of a recently proposed empirical climate model based on astronomical harmonics against all available general circulation climate models (GCM) used by the IPCC (2007) to interpret the 20th century global surface temperature. The proposed model assumes that the climate is resonating with, or synchronized to a set of natural harmonics that have been associated to the solar system planetary motion, mostly determined by Jupiter and Saturn. We show that the GCMs fail to reproduce the major decadal and multidecadal oscillations found in the global surface temperature record from 1850 to 2011. On the contrary, the proposed harmonic model is found to well reconstruct the observed climate oscillations from 1850 to 2011, and it is able to forecast the climate oscillations from 1950 to 2011 using the data covering the period 1850-1950, and vice versa. The 9.1-year cycle is shown to be likely related to a decadal Soli/Lunar tidal oscillation, while the 10-10.5, 20-21 and 60-62 year cycles are sy...

  14. Measurement of Circulating Filarial Antigen Levels in Human Blood with a Point-of-Care Test Strip and a Portable Spectrodensitometer.

    Science.gov (United States)

    Chesnais, Cédric B; Vlaminck, Johnny; Kunyu-Shako, Billy; Pion, Sébastien D; Awaca-Uvon, Naomi-Pitchouna; Weil, Gary J; Mumba, Dieudonné; Boussinesq, Michel

    2016-06-01

    The Alere Filariasis Test Strip (FTS) is a qualitative, point-of-care diagnostic tool that detects Wuchereria bancrofti circulating filarial antigen (CFA) in human blood, serum, or plasma. The Global Program to Eliminate Lymphatic Filariasis employs the FTS for mapping filariasis-endemic areas and assessing the success of elimination efforts. The objective of this study was to explore the relationship between the intensity of positive test lines obtained by FTS with CFA levels as determined by enzyme-linked immunosorbent assay (ELISA) with blood and plasma samples from 188 individuals who live in a filariasis-endemic area. The intensity of the FTS test line was assessed visually to provide a semiquantitative score (visual Filariasis Test Strip [vFTS]), and line intensity was measured with a portable spectrodensitometer (quantitative Filariasis Test Strip [qFTS]). These results were compared with antigen levels measured by ELISA in plasma from the same subjects. qFTS measurements were highly correlated with vFTS scores (ρ = 0.94; P bancrofti CFA levels in human blood, which are correlated with adult worm burdens. This tool may be useful for assessing the impact of treatment on adult filarial worms in individuals and communities. PMID:27114288

  15. Comparison of tests for the detection of circulating filarial antigen (Og4C3-ELISA and AD12-ICT and ultrasound in diagnosis of lymphatic filariasis in individuals with microfilariae

    Directory of Open Access Journals (Sweden)

    Abraham Rocha

    2009-07-01

    Full Text Available Significant advances were made in the diagnosis of filariasis in the 1990s with the emergence of three new alternative tools: ultrasound and tests to detect circulating antigen using two monoclonal antibodies, Og4C3 and AD12-ICT-card. This study aimed to identify which of these methods is the most sensitive for diagnosis of infection. A total of 256 individuals, all male and carrying microfilariae (1-15,679 MF/mL, diagnosed by nocturnal venous blood samples, were tested by all three techniques. The tests for circulating filarial antigen concurred 100% and correctly identified 246/256 (96.69% of the positive individuals, while ultrasound detected only 186/256 (73.44%. Of the circulating antigen tests, ICT-card was the most convenient method for identification of Wuchereria bancrofti carriers. It was easy to perform, practical and quick.

  16. Cryogenic Optical Assembly (COA) cooldown analysis for the Cosmic Background Explorer (COBE)

    Science.gov (United States)

    Coladonato, Robert J.; Irish, Sandra M.; Mosier, Carol L.

    1990-01-01

    The Cosmic Background Explorer (COBE) spacecraft, developed by Goddard Space Flight Center (GSFC), was successfully launched on November 18, 1989 aboard a Delta expendable launch vehicle. Two of the three instruments for this mission were mounted inside a liquid helium (LHe) dewar which operates at a temperature of 2 K. These two instruments are the Diffuse Infrared Background Experiment (DIRBE) and the Far Infrared Absolute Spectrophotometer (FIRAS). They are mounted to a common Instrument Interface Structure (IIS) and the entire assembly is called the Cryogenic Optical Assembly (COA). As part of the structural verification requirement, it was necessary to show that the entire COA exhibited adequate strength and would be capable of withstanding the launch environment. This requirement presented an unique challenge for COBE because the COA is built and assembled at room temperature (300 K), cooled to 2 K, and then subjected to launch loads. However, strength testing of the entire COA at 2 K could not be done because of facility limitations. Therefore, it was decided to perform the strength verification of the COA by analysis.

  17. Circulation economics

    DEFF Research Database (Denmark)

    Ingebrigtsen, Stig; Jakobsen, Ove

    2006-01-01

    Purpose - This paper is an attempt to advance the critical discussion regarding environmental and societal responsibility in economics and business. Design/methodology/approach - The paper presents and discusses as a holistic, organic perspective enabling innovative solutions to challenges...... concerning the responsible and efficient use of natural resources and the constructive interplay with culture. To reach the goal of sustainable development, the paper argues that it is necessary to make changes in several dimensions in mainstream economics. This change of perspective is called a turn towards...... presupposes a perspective integrating economic, natural and cultural values. Third, to organize the interplay between all stakeholders we introduce an arena for communicative cooperation. Originality/value - The paper concludes that circulation economics presupposes a change in paradigm, from a mechanistic...

  18. Examples of natural circulation in PHWR

    International Nuclear Information System (INIS)

    The main objective of this lecture is to provide deep insight into the complex natural circulation phenomena in the core of a Pressurised Heavy Water Reactor. A detailed account of natural circulation tests conducted in an Indian PHWR is given in this lecture. This will enable the participants to appreciate the importance of natural circulation in a nuclear reactor to a greater extent. (author)

  19. A serendipitous, long-term infiltration experiment: water and tritium circulation beneath the CAMBRIC trench at the Nevada Test Site.

    Science.gov (United States)

    Maxwell, Reed M; Tompson, Andrew F B; Kollet, Stefan

    2009-08-11

    Underground nuclear weapons testing at the Nevada Test Site introduced numerous radionuclides that may be used subsequently to characterize subsurface hydrologic transport processes in arid climates. In 1965, a unique, 16-year pumping experiment designed to examine radionuclide migration away from the CAMBRIC nuclear test, conducted in the saturated zone beneath Frenchman Flat, Nevada, USA, gave rise to an unintended second experiment involving radionuclide infiltration through the vadose zone, as induced by seepage of pumping effluents beneath an unlined discharge trench. The combined experiments have been reanalyzed using a detailed, three-dimensional numerical model of transient, variably saturated flow and mass transport in a heterogeneous subsurface, tailored specifically for large-scale and efficient calculations. Simulations have been used to estimate tritium travel and residence times in various parts of the system for comparison with observations in wells. Model predictions of mass transport were able to clearly demonstrate radionuclide recycling behavior between the trench and pumping well previously suggested by isotopic age dating information; match travel time estimates for radionuclides moving between the trench, the water table, and monitoring and pumping wells; and provide more realistic ways in which to interpret the pumping well elution curves. Collectively, the results illustrate the utility of integrating detailed numerical modeling with diverse observational data in developing more accurate interpretations of contaminant migration processes. PMID:19501933

  20. A study on a MATRA-LMR-FB prediction capability with an EBR-II natural circulation test

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Won-Pyo; Yoo, Jin; Choi, Chi-Woong; Ha, Kwi-Seok [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-10-15

    A subassembly containing more than 37 pins with a wire-wrap spacer was desirable to demonstrate predictability of the code. In this regard, a 61-pin test subassembly (XX09) placed in EBR-II (Experimental Breeder Reactor II) core was analyzed to demonstrate its extensive applicability in the present study. Power operation of the EBR-II was begun by Argonne National Lab. (ANL) in 1964. Rated thermal power was 62.5 MW with rated primary sodium at 485 kg/s. The initial purpose of the operation was only demonstration of the feasibility of a closed fuel cycle that required the addition of only Uranium-238 to fuel the breeding process and allow for sustained operation until it was shut down in 1994. The shutdown Heat Removal Test (SHRT) program was carried out in EBRII between 1984 and 1986 in order to provide not only test data for validation of computer codes but also demonstration of passive reactor shutdown and decay heat removal in response of protected and unprotected transients. Figure 1 illustrates the primary tank in EBR-II. All major primary system components were submerged in the primary tank, which contained approximately 340 m{sub 3} of liquid sodium at 371 .deg. C. Hot sodium heated up though subassemblies exited into a common upper plenum where it mixed before passing through the outlet pipe into the intermediate heat exchanger (IHX). The pipe feeding sodium to the IHX is referred to as the 'Z-pipe'. Sodium then exited the IHX back into the primary sodium tank before entering the primary sodium pumps again. The core in the reactor vessel accommodated 637 hexagonal subassemblies. Two positions in the central core in Row 5 contained the instrumented subassemblies, XX09 and XX10. Figure 2 schematically illustrates the pin arrangement and the instrument loading for the XX09 subassembly. The EBR-II SHRT-17 test data were used to demonstrate the prediction capability of MATRA-LMRFB for the steady state temperature distributions.

  1. A study on a MATRA-LMR-FB prediction capability with an EBR-II natural circulation test

    International Nuclear Information System (INIS)

    A subassembly containing more than 37 pins with a wire-wrap spacer was desirable to demonstrate predictability of the code. In this regard, a 61-pin test subassembly (XX09) placed in EBR-II (Experimental Breeder Reactor II) core was analyzed to demonstrate its extensive applicability in the present study. Power operation of the EBR-II was begun by Argonne National Lab. (ANL) in 1964. Rated thermal power was 62.5 MW with rated primary sodium at 485 kg/s. The initial purpose of the operation was only demonstration of the feasibility of a closed fuel cycle that required the addition of only Uranium-238 to fuel the breeding process and allow for sustained operation until it was shut down in 1994. The shutdown Heat Removal Test (SHRT) program was carried out in EBRII between 1984 and 1986 in order to provide not only test data for validation of computer codes but also demonstration of passive reactor shutdown and decay heat removal in response of protected and unprotected transients. Figure 1 illustrates the primary tank in EBR-II. All major primary system components were submerged in the primary tank, which contained approximately 340 m3 of liquid sodium at 371 .deg. C. Hot sodium heated up though subassemblies exited into a common upper plenum where it mixed before passing through the outlet pipe into the intermediate heat exchanger (IHX). The pipe feeding sodium to the IHX is referred to as the 'Z-pipe'. Sodium then exited the IHX back into the primary sodium tank before entering the primary sodium pumps again. The core in the reactor vessel accommodated 637 hexagonal subassemblies. Two positions in the central core in Row 5 contained the instrumented subassemblies, XX09 and XX10. Figure 2 schematically illustrates the pin arrangement and the instrument loading for the XX09 subassembly. The EBR-II SHRT-17 test data were used to demonstrate the prediction capability of MATRA-LMRFB for the steady state temperature distributions

  2. The unified model, a fully-compressible, non-hydrostatic, deep atmosphere global circulation model, applied to hot Jupiters. ENDGame for a HD 209458b test case

    Science.gov (United States)

    Mayne, Nathan J.; Baraffe, Isabelle; Acreman, David M.; Smith, Chris; Browning, Matthew K.; Skålid Amundsen, David; Wood, Nigel; Thuburn, John; Jackson, David R.

    2014-01-01

    We are adapting the global circulation model (GCM) of the UK Met Office, the so-called unified model (UM), for the study of hot Jupiters. In this work we demonstrate the successful adaptation of the most sophisticated dynamical core, the component of the GCM which solves the equations of motion for the atmosphere, available within the UM, ENDGame (Even Newer Dynamics for General atmospheric modelling of the environment). Within the same numerical scheme ENDGame supports solution to the dynamical equations under varying degrees of simplification. We present results from a simple, shallow (in atmospheric domain) hot Jupiter model (SHJ), and a more realistic (with a deeper atmosphere) HD 209458b test case. For both test cases we find that the large-scale, time-averaged (over the 1200 days prescribed test period), dynamical state of the atmosphere is relatively insensitive to the level of simplification of the dynamical equations. However, problems exist when attempting to reproduce the results for these test cases derived from other models. For the SHJ case the lower (and upper) boundary intersects the dominant dynamical features of the atmosphere meaning the results are heavily dependent on the boundary conditions. For the HD 209458b test case, when using the more complete dynamical models, the atmosphere is still clearly evolving after 1200 days, and in a transient state. Solving the complete (deep atmosphere and non-hydrostatic) dynamical equations allows exchange between the vertical and horizontal momentum of the atmosphere, via Coriolis and metric terms. Subsequently, interaction between the upper atmosphere and the deeper more slowly evolving (radiatively inactive) atmosphere significantly alters the results, and acts over timescales longer than 1200 days. Figures 1, 4-8, 10 and 11 are available in electronic form at http://www.aanda.org

  3. Overview of the system alone and system/CFD coupled calculations of the PHENIX Natural Circulation Test within the THINS project

    Energy Technology Data Exchange (ETDEWEB)

    Pialla, David, E-mail: david.pialla@cea.fr [Commissariat à l’Energie Atomique et aux Energies Alternatives (CEA), DEN/DM2S/STMF, 17 rue des martyrs, 38054 Grenoble Cedex 9 (France); Tenchine, Denis [Commissariat à l’Energie Atomique et aux Energies Alternatives (CEA), DEN/DM2S/STMF, 17 rue des martyrs, 38054 Grenoble Cedex 9 (France); Li, Simon [Commissariat à l’Energie Atomique et aux Energies Alternatives (CEA), DEN/DM2S/STMF, 91191 Gif-sur-Yvette Cedex (France); Gauthe, Paul; Vasile, Alfredo [Commissariat à l’Energie Atomique et aux Energies Alternatives (CEA), DEN/DER/SESI, 13108 Saint Paul Lez Durance Cedex (France); Baviere, Roland; Tauveron, Nicolas; Perdu, Fabien [Commissariat à l’Energie Atomique et aux Energies Alternatives (CEA), DEN/DM2S/STMF, 17 rue des martyrs, 38054 Grenoble Cedex 9 (France); Maas, Ludovic; Cocheme, François [Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PSN/SEMIA/BAST, B.P. 17, 92262 Fontenay-aux-Roses Cedex (France); Huber, Klaus; Cheng, Xu [Karlsruhe Institute of Technology (KIT), Institute of Fusion and Reactor Technology (IFRT), Kaiserstraße 12, Building 07.08, 76131 Karlsruhe (Germany)

    2015-08-15

    Highlights: • The PHENIX natural convection test performed during the end of life tests program. • The calculation with system codes and theirs limits. • The calculation with coupling CFD and system code, which allows better prediction. • The tasks of code validation have been done in the frame of the THINS project. - Abstract: The PHENIX sodium cooled fast reactor started operation in 1973 and was shut down in 2009. Before decommissioning, an ultimate test program was designed and performed to provide valuable data for the development of future sodium cooled fast reactors, as the so-called Astrid prototype in France. Among these ultimate tests, a thermal-hydraulic Natural Convection Test (NCT) was set-up in June 2009. Starting from a reduced power state of 120 MWt, the NCT consists of a loss of the heat sink combined with a reactor scram and a primary pumps trip leading to stabilized natural circulation in the primary sodium system. The thermal-hydraulics innovative system project (THINS project), sponsored by the European Community in the frame of the 7th FP has selected this transient for validation of both stand-alone system code simulations and coupled simulations using system and CFD codes. Participants from three organizations (CEA, IRSN and KIT) have addressed this transient using different system codes (CATHARE, DYN2B and ATHLET) and CFD codes (TRIO-U and OPEN FOAM). The present paper depicts the different modeling approaches, methodologies and compares the numerical results with the available experimental data. Finally, the main lessons learned from the work performed within the THINS project on the PHENIX NCT with respect to code development and validation are summarized.

  4. Overview of the system alone and system/CFD coupled calculations of the PHENIX Natural Circulation Test within the THINS project

    International Nuclear Information System (INIS)

    Highlights: • The PHENIX natural convection test performed during the end of life tests program. • The calculation with system codes and theirs limits. • The calculation with coupling CFD and system code, which allows better prediction. • The tasks of code validation have been done in the frame of the THINS project. - Abstract: The PHENIX sodium cooled fast reactor started operation in 1973 and was shut down in 2009. Before decommissioning, an ultimate test program was designed and performed to provide valuable data for the development of future sodium cooled fast reactors, as the so-called Astrid prototype in France. Among these ultimate tests, a thermal-hydraulic Natural Convection Test (NCT) was set-up in June 2009. Starting from a reduced power state of 120 MWt, the NCT consists of a loss of the heat sink combined with a reactor scram and a primary pumps trip leading to stabilized natural circulation in the primary sodium system. The thermal-hydraulics innovative system project (THINS project), sponsored by the European Community in the frame of the 7th FP has selected this transient for validation of both stand-alone system code simulations and coupled simulations using system and CFD codes. Participants from three organizations (CEA, IRSN and KIT) have addressed this transient using different system codes (CATHARE, DYN2B and ATHLET) and CFD codes (TRIO-U and OPEN FOAM). The present paper depicts the different modeling approaches, methodologies and compares the numerical results with the available experimental data. Finally, the main lessons learned from the work performed within the THINS project on the PHENIX NCT with respect to code development and validation are summarized

  5. Radiation Heat Transfer Effect on Thermal Sizing of Air-Cooling Heat Exchanger of Emergency Cooldown Tank

    International Nuclear Information System (INIS)

    An attempt has begun to extend the life time of emergency cooldown tank (ECT) by Korea Atomic Energy Research Institute (KAERI) researchers. Moon et al. recently reported a basic concept upon how to keep the ECT in operation beyond 72 hours after an accident occurs without any active corrective actions for the postulated design basis accidents. When the SMART (System-integrated Modular Advanced Reac-Tor) received its Standard Design Approval (SDA) for the first time in the world, hybrid safety systems are applied. However, the passive safety systems of SMART are being enforced in response to the public concern for much safer reactors since the Fukushima accident occurred. The ECT is a major component of a passive residual heat removal system (PRHRS), which is one of the most important systems to enhance the safety of SMART. It is being developed in a SMART safety enhancement project to contain enough cooling water to remove a sensible heat and a decay heat from reactor core for 72 hours since an accident occurs. Moon et al. offered to install another heat exchanger above the ECT and to recirculate an evaporated steam into water, which enables the ECT to be in operation, theoretically, indefinitely. An investigation was made to determine how long and how many tubes were required to meet the purpose of the study. In their calculation, however, a radiation heat transfer effect was neglected. The present study is to consider the radiation heat transfer for the design of air-cooling heat exchanger. Radiation heat transfer is normally ignored in many situations, but this is not the case for the present study. Kim et al. conducted thermal sizing of scaled-down ECT heat exchanger, which will be used to validate experimentally the basic concept of the present study. Their calculation is also examined to see if a radiation heat transfer effect was taken into consideration. The thermal sizing of an air-cooling heat exchanger was conducted including radiation heat transfer

  6. Probabilistic fracture mechanics applied for DHC assessment in the cool-down transients for CANDU pressure tubes

    Energy Technology Data Exchange (ETDEWEB)

    Radu, Vasile, E-mail: vasile.radu@nuclear.ro [Institute for Nuclear Research Pitesti, 1st Campului Street, 115400 Mioveni, Arges, P.O. Box 78, Mioveni (Romania); Roth, Maria [Institute for Nuclear Research Pitesti, 1st Campului Street, 115400 Mioveni, Arges, P.O. Box 78, Mioveni (Romania)

    2012-12-15

    irradiation in reactor. The paper describes a prospective way for the probabilistic approach of CANDU pressure tube failure by DHC mechanisms during cool-down cycles by using probabilistic fracture mechanics principles. The limit state functions are defined for fracture instability and plastic collapse according to the Canadian Standard N285.8-05 criteria. British Procedure R6 is used to define another limit state function based on reserve factors. Discussion of lifetime probability values obtained from both procedures is made.

  7. The Effect of the Wall Contact and Post-Growth, Cool-Down on Defects in CdTe Crystals Grown By 'Contactless' PVT

    Science.gov (United States)

    Palosz, W.; Grasza, K.; Dudley, M.; Raghothamachar, B.; Cai, L.; Dunrose, K.; Halliday, D.; Boyall, N. M.; Rose, M. Franklin (Technical Monitor)

    2001-01-01

    To take a maximum advantage of materials processing in microgravity for understanding the effects of gravity, gravity-independent effects should be minimized. In crystal growth, the quality of the grown crystals may depend, among other factors, on their interaction with the walls of the processing container during and after growth, and on the rate of the crystal cool-down at the end of the process. To investigate the above phenomena, a series of CdTe crystal growth processes was carried out. The crystals were grown by physical vapor transport without contact with the side walls of the silica glass ampoules. To eliminate the effect of the seed quality, and to reduce the number of nuclei and related crystal grains, the Low Supersaturation Nucleation technique was applied. The source temperature was 930 C, the undercooling was a few degrees. The crystals, having the diameter of 25 mm, grew at the rate of a few mm per day. The post-growth cool-down to the room temperature was conducted at different rates, and lasted from a few minutes to four days. The crystals were characterized using chemical etching, low temperature luminescence, and Synchrotron White Beam X-ray Topography techniques. The dislocation (etch pit) density was measured and its distribution was analyzed by comparison with Poisson curves and with the Normalized Radial Distribution Correlation Function. In the regions where the crystal is in contact with silica, the materials show a considerable strain field which extends for a few mm or more from the silica-crystal interface. In the reference crystal grown with contact with the ampoule walls, and when the crystals are cooled at the highest rates, the etch pit/dislocation density is in the high 10(exp 5) per square centimeter region. Typical EPD values for lower cool-down rates are in the lower 10(exp 4) per square centimeter region. In some areas the actual dislocation density was about 10(exp 3) per square centimeter or even less. No apparent effect of

  8. Thermal hydraulic analysis of aggressive secondary cooldown in a small break loss of coolant accident with a total loss of high pressure safety injection

    International Nuclear Information System (INIS)

    To support the development of a Probabilistic Safety Assessment (PSA) model usable in Riskinformed Applications (RIA) for Korea Standard Nuclear power Plants (KSNP), we have performed a thermal hydraulic analysis of Aggressive Secondary Cooldown (ASC) in a 2-inch Small Break Loss Of Coolant Accident (SBLOCA) with a total loss of High Pressure Safety Injection (HPSI). The present study focuses on the estimation of the success criteria of ASC, and the enhanced understanding of the detailed thermal hydraulic behavior and phenomena. The results have shown that the Reactor Coolant System (RCS) pressure can be reduced to the Low Pressure Safety Injection (LPSI) operation conditions without core damage. It was also shown that more relaxed success criteria compared to those in the previous PSA models of KSNP could be used in the new PSA model. However, it was found that the results could be affected by various parameters related with ASC operation, i.e., reference temperature for the calculation of the cooldown rate and its control method

  9. Computing 3-D wavefields in mantle circulations models to test hypotheses on the origin of lower mantle heterogeneity under Africa directly against seismic observations

    Science.gov (United States)

    Schuberth, Bernhard; Zaroli, Christophe; Nolet, Guust

    2015-04-01

    Of particular interest for the tectonic evolution of the Atlantic region is the influence of lower mantle structure under Africa on flow in the upper mantle beneath the ocean basin. Along with its Pacific counterpart, the large African anomaly in the lowermost mantle with strongly reduced seismic velocities has received considerable attention in seismological and geodynamic studies. Several seismological observations are typically taken as an indication that these two anomalies are being caused by large-scale compositional variations and that they are piles of material with higher density than normal mantle rock. This would imply negative buoyancy in the lowermost mantle under Africa, which has important implications for the flow at shallower depth and inferences on the processes that led to the formation of the Atlantic Ocean basin. However, a large number of recent studies argue for a strong thermal gradient across the core-mantle boundary that might provide an alternative explanation for the lower mantle anomaly through the resulting large lateral temperature variations. Recently, we developed a new joint forward modeling approach to test such geodynamic hypotheses directly against the seismic observations: Seismic heterogeneity is predicted by converting the temperature field of a high-resolution 3-D mantle circulation model into seismic velocities using thermodynamic models of mantle mineralogy. 3-D global wave propagation in the synthetic elastic structures is then simulated using a spectral element method. Being based on forward modelling only, this approach allows us to generate synthetic wavefields and seismograms independently of seismic observations. The statistics of observed long-period body wave traveltime variations show a markedly different behaviour for P- and S-waves: the standard deviation of P-wave delay times stays almost constant with ray turning depth, while that of the S-wave delay times increases strongly throughout the mantle. In an

  10. Start-up transient test simulation with and without void-reactivity feedback for a two-phase natural circulation reactor

    International Nuclear Information System (INIS)

    Highlights: • A scaled experimental facility is designed based on the sound scaling approach. • Starts up transients are performed to identify the instability phenomena. • Four heater rods are used to simulate the chaotic flashing phenomena. • Experiments are performed with and without void-reactivity feedback. • Modify power scaling is used for transient tests. - Abstract: The new small-scaled light water reactor design, known as integral modular water reactor (IMR), has an advantage compared to conventional light water reactor in terms of costs by adopting innovative technologies. However, this reactor may be susceptible to flow instabilities due to two-phase natural circulation inside the reactor pressure vessel (RPV). Flow instabilities may be amplified due to strong interaction between the flow and core power through the void-reactivity feedback mechanism. During the start-up of the IMR, system pressure is low. At low pressure, the density ratio can be quite high, which leads to large variation in void fraction due to change in flow quality. In the IMR design, the long riser and large volume of water can lead to thermal non-equilibrium between the phases due to the significant variation of the saturation temperature along flow direction. This can result in flow oscillations at certain operating conditions. In order to understand and identify the instability phenomena during the start-up of the reactor, a scaled experimental facility is designed based on the sound scaling approach. The scaling laws are used to obtain design parameters to maintain the similarities between prototype and experimental facility. Modified power scaling is used for transient tests. Four heater rods are used to simulate the chaotic flashing phenomena. In order to investigate the instability during the start-up procedure, start-up transient tests are performed with and without void-reactivity feedback for different core heat-up rate. These experimental results show that IMR is

  11. Hanford spent nuclear fuel hot conditioning system test procedure

    International Nuclear Information System (INIS)

    This document provides the test procedures for cold testing of the prototype Hot Conditioning System (HCS) at the 306E Facility. The primary objective of this testing is to confirm design choices and provide data for the detailed design package prior to procurement of the process equipment. The current scope of testing in this document includes a fabricability study of the HCS, equipment performance testing of the HCS components, heat-up and cool-down cycle simulation, and robotic arm testing

  12. Sensitivity and specificity of multiple Kato-Katz thick smears and a circulating cathodic antigen test for Schistosoma mansoni diagnosis pre- and post-repeated-praziquantel treatment.

    Directory of Open Access Journals (Sweden)

    Poppy H L Lamberton

    2014-09-01

    Full Text Available Two Kato-Katz thick smears (Kato-Katzs from a single stool are currently recommended for diagnosing Schistosoma mansoni infections to map areas for intervention. This 'gold standard' has low sensitivity at low infection intensities. The urine point-of-care circulating cathodic antigen test (POC-CCA is potentially more sensitive but how accurately they detect S. mansoni after repeated praziquantel treatments, their suitability for measuring drug efficacy and their correlation with egg counts remain to be fully understood. We compared the accuracies of one to six Kato-Katzs and one POC-CCA for the diagnosis of S. mansoni in primary-school children who have received zero to ten praziquantel treatments. We determined the impact each diagnostic approach may have on monitoring and evaluation (M&E and drug-efficacy findings.In a high S. mansoni endemic area of Uganda, three days of consecutive stool samples were collected from primary school-aged children (six - 12 years at five time-points in year one: baseline, one-week-post-, four-weeks-post-, six-months-post-, and six-months-one-week-post-praziquantel and three time-points in years two and three: pre-, one-week-post- and four-weeks-post-praziquantel-treatment/retreatment (n = 1065. Two Kato-Katzs were performed on each stool. In parallel, one urine sample was collected and a single POC-CCA evaluated per child at each time-point in year one (n = 367. At baseline, diagnosis by two Kato-Katzs (sensitivity = 98.6% or one POC-CCA (sensitivity = 91.7%, specificity = 75.0% accurately predicted S. mansoni infections. However, one year later, a minimum of three Kato-Katzs, and two years later, five Kato-Katzs were required for accurate diagnosis (sensitivity >90% and drug-efficacy evaluation. The POC-CCA was as sensitive as six Kato-Katzs four-weeks-post and six-months-post-treatment, if trace readings were classified as positive.Six Kato-Katzs (two/stool from three stools and/or one POC-CCA are required

  13. Proper Sizing of Circulation Pumps

    DEFF Research Database (Denmark)

    Tommerup, Henrik M.; Nørgaard, Jørgen

    2007-01-01

    The paper describes the preliminary results from field tests of replacing various types of old pumps used for circulating water in heating systems in single- and double-family houses with new types of pumps. The tests were carried out in Denmark for the Danish Electricity Savings Trust, but the...... results can be applied to Europe in general. Despite the small sample of houses involved in the test, 15 houses, some rather safe conclusions can be drawn from the results, which showed that newly developed pumps with power consumption around 5-8 W, can perform the task of circulating the water...... sufficiently to keep the houses satisfactorily warm during the heating season of the test. The old replaced pumps used 5-10 times more power. In Europe alone, a gradual replacement of the present vastly oversized pumps with such small but sufficient pumps can save the construction of 17 large power plants as...

  14. A first system/CFD coupled simulation of a complete nuclear reactor transient using CATHARE2 and TRIO{sub U}. Preliminary validation on the Phénix Reactor Natural Circulation Test

    Energy Technology Data Exchange (ETDEWEB)

    Bavière, R., E-mail: roland.baviere@cea.fr; Tauveron, N., E-mail: nicolas.tauveron@cea.fr; Perdu, F., E-mail: fabien.perdu@cea.fr; Garré, E., E-mail: emile.garre@cea.fr; Li, S., E-mail: simon.li@cea.fr

    2014-10-01

    Highlights: • A system/CFD coupling methodology for thermal-hydraulics analysis. • Application of the model to the Phénix Reactor Natural Circulation Test. • Validation of the methodology against experimental data. - Abstract: The natural circulation test (NCT) was conducted in the Phénix prototype French 580 MWth sodium fast reactor (SFR) in 2009. The main goal of the Phénix NCT is to validate system- and CFD-codes with respect to the establishment of natural circulation in the primary system of a pool type SFR. The present paper describes the calculation of the NCT by coupling the 3D computational fluid dynamics (CFD) code TRIO{sub U} with the best estimate thermal hydraulic system code CATHARE. The coupling methodology and the modeling at the system and at the CFD scales are first presented. A validation of the coupling methodology based on a coupled CATHARE/CATHARE calculation compared to the standard CATHARE predictions is then proposed. In a second step, the results of the TRIO{sub U}/CATHARE calculation are compared both to the available experimental data and to the results of a CATHARE alone computation. These comparisons highlight the effectiveness of coupling CFD- and system-codes for the analysis of plant transients where three-dimensional phenomena play an important role.

  15. A first system/CFD coupled simulation of a complete nuclear reactor transient using CATHARE2 and TRIOU. Preliminary validation on the Phénix Reactor Natural Circulation Test

    International Nuclear Information System (INIS)

    Highlights: • A system/CFD coupling methodology for thermal-hydraulics analysis. • Application of the model to the Phénix Reactor Natural Circulation Test. • Validation of the methodology against experimental data. - Abstract: The natural circulation test (NCT) was conducted in the Phénix prototype French 580 MWth sodium fast reactor (SFR) in 2009. The main goal of the Phénix NCT is to validate system- and CFD-codes with respect to the establishment of natural circulation in the primary system of a pool type SFR. The present paper describes the calculation of the NCT by coupling the 3D computational fluid dynamics (CFD) code TRIOU with the best estimate thermal hydraulic system code CATHARE. The coupling methodology and the modeling at the system and at the CFD scales are first presented. A validation of the coupling methodology based on a coupled CATHARE/CATHARE calculation compared to the standard CATHARE predictions is then proposed. In a second step, the results of the TRIOU/CATHARE calculation are compared both to the available experimental data and to the results of a CATHARE alone computation. These comparisons highlight the effectiveness of coupling CFD- and system-codes for the analysis of plant transients where three-dimensional phenomena play an important role

  16. Shutdown cooling helium circulator design considerations for MHTGR [Modular High Temperature Gas-Cooled Reactor] power plant

    International Nuclear Information System (INIS)

    The Modular High Temperature Gas-Cooled Reactor (MHTGR) plant embodies a shutdown cooling system to expedite plant cooldown for refueling, maintenance, and repair in the event that the main cooling loop is unavailable. This is a non safety related system. A key component in this system, is a helium circulator. Oriented vertically, the rotating assembly in this machine is supported on active magnetic bearings, and the radial flow compressor is driven by a submerged induction electric motor rated at 160 kW(e). This paper gives details of the circulator design considerations and includes topics related to the machine operation and maintenance, and the technology base. 12 refs., 11 figs., 3 tabs

  17. Thermal hydraulic analysis of aggressive secondary cooldown in a small break loss of coolant accident with a total loss of high pressure safety injection

    International Nuclear Information System (INIS)

    Recently, Probabilistic Safety Assessment (PSA) has being applied to various fields as a basic technique of Risk-Informed Applications (RIA). The present study focuses on detailed thermal hydraulic analyses for major accident sequences and success criteria to support a development of PSA model using RIA for Korea Standard Nuclear Power plant (KSNP). The primary purpose of the present study in this year is to evaluate the success cri-teria of Aggressive Secondary Cooldown (ASC) in a Small Size Loss Of Coolant Accident (SBLOCA) without HPSI and to enhance the understanding of related thermal hydraulic behavior and phenomena. An effort was made to evaluate the system success criteria and a mission time for the recovery action by an operator to prevent the core damage for that accident scenario. The accident scenario for KSNP was a 2 inch coldleg break LOCA with a total loss of High Pressure Safety Injection (HPSI) and 1/2 Low Pressure Safety Injection (LPSI) available and perform-ing ASC limited by 55.6 .deg. C/hr (100 .deg. F/hr) cooldown rate at 15 minute after reactor trip. It successively reached the LPSI condition for about 1.5hr after starting the ASC operation with the Peak Cladding Temperature (PCT) of the hottest rod below the core damage criteria of 1204.4 .deg. C (2200 .deg. F). Sensitivity studies were performed for (1) cool-ant average temperature parameters, (2) ASC operation control method, (3) operation start time, (4) 1 inch break size. The present analysis identified thermal hydraulic phenomena and parameters affecting on the behavior, which consist of coolant break flow and inventory, parameters governing secondary heat removal, ASC operation control method, and its reference temperature parameters. In the present study, more relaxed success criteria than the previous PSA for KSNP could be generated under an assumption that an operator should maintain the ade-quate ASC operation. However, it is necessary to evaluate the uncertainties arisen from the

  18. A study of flow mixing in a PWR vessel in asymmetric cooldown faults using the FLOW3D code

    International Nuclear Information System (INIS)

    The Harwell computational fluid dynamics code, FLOW3D has been used to simulate a flow mixing test in the Oconee-1 reactor. The object was to test the ability of FLOW3D to describe thermal mixing in a PWR pressure vessel for the conditions of an over-cooling fault. The code produced reasonable estimates of the thermal diffusion observed in the Oconee test, with a tendency to underpredict mixing. However, the test exhibited gross swirl and asymmetric mixing which was not predicted by FLOW3D. Sensitivity studies to investigate the effects of downcomer ovality, inlet flow vorticity and flow imbalance between loops, have not revealed the source of the observed asymmetries

  19. Microwave circulator design

    CERN Document Server

    Linkhart, Douglas K

    2014-01-01

    Circulator design has advanced significantly since the first edition of this book was published 25 years ago. The objective of this second edition is to present theory, information, and design procedures that will enable microwave engineers and technicians to design and build circulators successfully. This resource contains a discussion of the various units used in the circulator design computations, as well as covers the theory of operation. This book presents numerous applications, giving microwave engineers new ideas about how to solve problems using circulators. Design examples are provided, which demonstrate how to apply the information to real-world design tasks.

  20. RCGVS design improvement and depressurization capability tests for Ulchin nuclear power plant units 3 and 4

    Energy Technology Data Exchange (ETDEWEB)

    Sung, Kang Sik; Seong, Ho Je; Jeong, Won Sang; Seo, Jong Tae; Lee, Sang Keun [Korea Power Engineering Company, Inc., Seoul (Korea, Republic of); Lim, Keun Hyo; Choi, Kwon Sik; Oh, Chul Sung [Korea Electric Power Cooperation, Taejon (Korea, Republic of)

    1998-12-31

    The Reactor Coolant Gas Vent System(RCGVS) design for Ulchin Nuclear Power Plant Units 3 and 4 (UCN 3 and 4) has been improved from the Yonggwang Nuclear Power Plant Units 3 and 4 (YGN 3 and 4) based on the evaluation results for depressurization capability tests performed at YGN 3 and 4. There has been a series of plant safety analyses for Natural Circulation Cooldown(NCC) event and thermo-dynamic analyses with RELAP5 code for the steam blowdown phenomena in order to optimize the orifice size of UCN 3 and 4 RCGVS. Based on these analyses results, the RCGVS orifics size for UCN 3 and 4 has been reduced to 9/32 inch from the 11/32 inch for YGN 3 and 4. The depressurization capability tests, which were performed at UCN 3 in order to verify the FSAR NCC analysis results, show that the RCGVS depressurization rates are being within the acceptable ranges. Therefore, it is concluded that the orificed flow path of UCN 3 and 4 RCGVS is adequately designed, and can provide the safety-grade depressurization capability required for a safe plant operation. 6 refs., 5 figs., 1 tab. (Author)

  1. Performance test results on a miniature Stirling cryocooler for use in integrated dewar detector assemblies

    International Nuclear Information System (INIS)

    An Integral Stirling Minicooler has been introduced to operate with 'integrated' cooler/dewar structures. Performance of prototype units is being measured with platinum silicide, indium antimonide, lead selenide, and mercury cadmium telluride detector arrays. Results of tests on cooler capacity, power consumption, cooldown time, acoustic noise, and self-induced vibration are presented. 3 refs

  2. Circulation model for water circulation and purification in a water Cerenkov detector

    Institute of Scientific and Technical Information of China (English)

    LU Hao-Qi; YANG Chang-Gen; WANG Ling-Yu; XU Ji-Lei; WANG aui-Guang; WANG Zhi-Min; WANG Yi-Fang

    2009-01-01

    Owing to its low cost and good transparency, highly purified water is widely used as a medium in large water Cerenkov detector experiments. The water circulation and purification system is usually needed to keep the water in good quality. In this work, a practical circulation model is built to describe the variation of the water resistivity in the circulation process and compared with the data obtained from a prototype experiment. The successful test of the model makes it useful in the future design and optimization of the circulation/purification system.

  3. Pre-test prediction report LOBI-MOD2 Test BT-12 large steam line break

    International Nuclear Information System (INIS)

    The RETRAN-02 code has been selected by the CEGB for independent assessment of the thermal hydraulic component of the intact circuit fault safety case for Sizewell B. An important source of validation data for RETRAN is the European Community sponsored LOB1-MOD2 Integral Test Facility. One component of the agreed LOB1 test matrix is the large (100%) steam line break test BT-12 for which the UK has been designated as partner country. This report details the pre-test predictions undertaken in support of Test BT-12 using the RETRAN-02/Mod 3 code. Three separate analyses are presented. In addition to the best estimate prediction, two scoping predictions are presented which respectively minimise and maximise the primary cooldown. The best estimate calculation was undertaken using dynamic slip with multi-node steam generator representations. The maximum cooldown was obtained using a single bubble rise volume broken loop steam generator model to minimise the liquid carryover to the break. The minimum cooldown used full noding for the broken loop steam generator but without slip (ie equal phase velocities) to maximise the carryover. A number of modelling difficulties had to be overcome including steady state initialisation at the zero feed and steam flow hot standby condition. (author)

  4. Startup Test Report of ATLAS

    International Nuclear Information System (INIS)

    This report describes the startup test result of the ATLAS, which is the thermal-hydraulic integral effect test facility of KAERI. The performance results of the ATLAS, which is designed to simulate various accident and transient conditions of APR1400 and OPR1000 at prototypic pressure and temperature conditions, were described in this report. Flushing, hydro/leakage test, and operating test for unit equipment showed that the facility can be operated properly with minor modifications to fix some errors found in those tests. Performance test for pre-insulated pressurizer, operation test for core heater, heatup operation for pre-insulated primary/secondary system, performance test for pressurizer completely equipped with insulation, preliminary SBLOCA tests with heatup and cooldown operation were performed and showed that the ATLAS can be operated properly in the view point of system level and integral aspects. The final integral test showed that the ATLAS can be operated properly during the heatup/cooldown operation and the 5 mm-SBLOCA test

  5. Natural Circulation with Boiling

    International Nuclear Information System (INIS)

    A number of parameters with dominant influence on the power level at hydrodynamic instability in natural circulation, two-phase flow, have been studied experimentally. The geometrical dependent quantities were: the system driving head, the boiling channel and riser dimensions, the single-phase as well as the two phase flow restrictions. The parameters influencing the liquid properties were the system pressure and the test section inlet subcooling. The threshold of instability was determined by plotting the noise characteristics in the mass flow records against power. The flow responses to artificially obtained power disturbances at instability conditions were also measured in order to study the nature of hydrodynamic instability. The results presented give a review over relatively wide ranges of the main parameters, mainly concerning the coolant performance in both single and parallel boiling channel flow. With regard to the power limits the experimental results verified that the single boiling channel performance was intimately related to that of the parallel channels. In the latter case the additional inter-channel factors with attenuating effects were studied. Some optimum values of the parameters were observed

  6. Natural circulation loop using liquid nitrogen for cryo-detection system

    International Nuclear Information System (INIS)

    The natural circulation loop is designed for the cryogenic insert in a Fourier transform ion cyclotron resonance (FTICR) mass spectrometer. Sensitivity is the key parameter of a FTICR mass spectrometer and the cryo-cooling of the pre-amplifier can reduce the thermal noise level and thereby improve the signal-to-noise ratio. The pre-amplifier consisted of non-magnetic materials is thermally connected to the cooling loop which is passing through the flange maintaining ultra-high vacuum in the ion cell. The liquid nitrogen passes through inside of the loop to cool the pre-amplifier indirectly. At the end, a cryocooler is located to re-condense nitrogen vapor generated due to the heat from the pre-amplifier. The circulating fluid removes heat from the pre-amplifier and transports it to the cryocooler or heat sink. In this paper the natural circulation loop for cryogenic pre-amplifier is introduced for improving the sensitivity of cryo-detector. In addition, the initial cool-down of the system by a cryocooler is presented and the temperature of the radiation shield is discussed with respect to the thickness of shield and the thermal radiation load

  7. Input Calibration and Validation of RELAP5 Against CIRCUS-IV Single Channel Tests on Natural Circulation Two-Phase Flow Instability

    Directory of Open Access Journals (Sweden)

    Viet-Anh Phung

    2015-01-01

    Full Text Available RELAP5 is a system thermal-hydraulic code that is used to perform safety analysis on nuclear reactors. Since the code is based on steady state, two-phase flow regime maps, there is a concern that RELAP5 may provide significant errors for rapid transient conditions. In this work, the capability of RELAP5 code to predict the oscillatory behavior of a natural circulation driven, two-phase flow at low pressure is investigated. The simulations are compared with a series of experiments that were performed in the CIRCUS-IV facility at the Delft University of Technology. For this purpose, we developed a procedure for calibration of the input and code validation. The procedure employs (i multiple parameters measured in different regimes, (ii independent consideration of the subsections of the loop, and (iii assessment of importance of the uncertain input parameters. We found that predicted system parameters are less sensitive to variations of the uncertain input and boundary conditions in high frequency oscillations regime. It is shown that calculation results overlap experimental values, except for the high frequency oscillations regime where the maximum inlet flow rate was overestimated. This finding agrees with the idea that steady state, two-phase flow regime maps might be one of the possible reasons for the discrepancy in case of rapid transients in two-phase systems.

  8. Concepts in Assisted Circulation

    OpenAIRE

    Lefemine, Armand A.; Dunbar, Jacob; DeLucia, Anthony

    1986-01-01

    Assisted circulation by extracorporeal and extracardiac bypass techniques must be based on the requirements of the heart and of the total body, though these may differ. The cardiac problem in cardiogenic shock is more likely to be a biventricular problem demanding decompression of both sides. Extra pulmonary oxygenation should be avoided because of complexity in long-term use. Principles of assisted circulation may be applied in an extra-thoracic temporary manner or as an intracorporeal long-...

  9. Gaussian Fibonacci Circulant Type Matrices

    Directory of Open Access Journals (Sweden)

    Zhaolin Jiang

    2014-01-01

    Full Text Available Circulant matrices have become important tools in solving integrable system, Hamiltonian structure, and integral equations. In this paper, we prove that Gaussian Fibonacci circulant type matrices are invertible matrices for n>2 and give the explicit determinants and the inverse matrices. Furthermore, the upper bounds for the spread on Gaussian Fibonacci circulant and left circulant matrices are presented, respectively.

  10. PULMONARY CIRCULATION AT EXERCISE

    OpenAIRE

    R. Naeije; CHESLER, N

    2012-01-01

    The pulmonary circulation is a high flow and low pressure circuit, with an average resistance of 1 mmHg.min.L−1 in young adults, increasing to 2.5 mmHg.min.L−1 over 4–6 decades of life. Pulmonary vascular mechanics at exercise are best described by distensible models. Exercise does not appear to affect the time constant of the pulmonary circulation or the longitudinal distribution of resistances. Very high flows are associated with high capillary pressures, up to a 20–25 mmHg threshold associ...

  11. Investigations of the enterohepatic bile salt circulation using the 14C-glycol cholate/14CO2 exhalation test in persons with Billroth-II stomach resection

    International Nuclear Information System (INIS)

    A 14C-glycol cholate/14CO2 exhalation test was carried out in 34 normal persons, 32 persons with a Billroth-II resection stomach, and 9 patients with a Billroth-II resection stomach and gastroenterological disorders. Persons with a normal stomach function after B-II resection and an objective lack of symptoms of a gastroenterological disease had normal test results in all cases. In 7 of the 9 B-II resected patients with various disorders or diseases of the intestinal tract of the liver gallbladder on pancreas, 14CO2 exhalation was pathologically increased. In agreement with the hypothesis that deconjugation of bile salts can only be caused by bacterial enzymes, a pathological finding can be explained by a pathological bacteria population in the upper intestinal tract or by a loss of bile salts. However, the clinical importance of pathological test results remains doubtful as 3 out of the 7 patients with pathological results presented with no clinical symptoms. (orig.)

  12. Circulator performance during THTR trial and post-commissioning operation

    International Nuclear Information System (INIS)

    Since the first trial runs the circulators have scored more than two years of trouble-free operation during the trial operation and commissioning phases. At no time the circulators gave reason for plant shutdown. The circulators which had been ordered in 1972 were delivered already ten years ago. Only two out of the six circulators were tested on a test stand in the workshop. In 1987 another identical standby circulator was supplied in support of an initiative to increase the basic conditions of plant availability. In view of the excellent result of the test period it can be assumed that the standby circulator will never be required. The 6 circulators equipped with oil bearings are each provided with a separate oil system whose pressure corresponds to that of the primary system. Safety aspects resulting from licensing requirements led to extensive efforts regarding the oil systems. These efforts involve also that part of the buffer helium flow which is released from the circulators with the oil draining from the bearings. During the commissioning phase it has been verified that the internal barrier helium system of the circulators is capable to retain the lubrication oil inventory within the circulator range, even if the external make-up barrier helium supply from the helium purification system is shut off. Thus it is ensured that leakage of oil into the primary helium system is ruled out by the shaft seal system. Further development work on the circulators is currently being continued for the only reason that active magnetic bearings permit vertical arrangement of the circulators with the impeller at the lower end without requiring the operation of an extremely complicated and expensive oil system. Apart from that, the experience gained with the THTR operation did not result in any changes in the design characteristics which had already been used in the AVR circulators. 7 refs, 13 figs

  13. Design of an additional heat sink based on natural circulation in pressurized water reactors

    International Nuclear Information System (INIS)

    Residual heat removal through the steam generators in Nuclear Power Plant with pressurized water reactors (PWR) or pressurized heavy water reactors (PHWR in pressured vessel or pressured tube types) requires the maintenance of the steam generator inventory and the availability of and appropriate heat sink, which are based on the operability of the steam generators feedwater system. This paper describes the conceptual design of an assured heat removal system which includes only passive elements and is based on natural circulation. The system can supplement the original systems of the plant. The new system includes a condenser/boiler heat exchanger to condense the steam produced in the steam generator, transferring the heat to the water of an open pool at atmospheric pressure. The condensed steam flows back to the steam generators by natural circulation effects. The performance of an Atucha type PHWR nuclear power station with and without the proposed system is calculated in an emergency power case for the first 5000 seconds after the incident. The analysis shows that the proposed system offers the possibility to cool-down the plant to a low energy state during several hours and avoids the repeated actuation of the primary and secondary system safety valves. (Author)

  14. A Circulation Model for Busy Public Libraries.

    Science.gov (United States)

    Bagust, A.

    1983-01-01

    Develops stochastic model of library borrowing using Negative Binomial distribution applied to circulation data obtained from Huddersfield Public Library. Evidence concerning process of popularity decay is presented and method is given by which relegation tests can be constructed to maintain optimum turnover. Eight references and statistical…

  15. Test completion plan for Spent Fuel Test - Climax, Nevada Test Site

    International Nuclear Information System (INIS)

    The Spent Fuel Test - Climax is being conducted 420 m below surface in the quartz monzonite unit of the Climax granitic stock at the US Department of Energy's Nevada Test Site. This test, which is under the technical direction of the Lawrence Livermore National Laboratory, was initiated in June 1978. Eleven spent-fuel assemblies from an operating commercial nuclear reactor were emplaced in test storage at the facility in April and May 1980. Technical data acquired during the first 2 years of the test indicated that all original test objectives will be met with a 3-year storage phase followed by post-retrieval cool-down, sampling, and analysis. This report describes the facility, the current status of test objectives, and the proposed post-retrieval monitoring and sampling of the test area. Current plans concerning decommissioning and future utilization of the facility are also presented

  16. INTERNAL CIRCULATION ENVELOPES

    CERN Multimedia

    Mail Office

    2001-01-01

    Internal mail envelopes often finish up in large piles in certain offices, thus creating a shortage for other users of the mail service, who would be grateful if everyone with an unused stock could deposit them in their mail box, after attaching them together with an elastic band or a piece of string. The messengers will then collect them so that the Mail Office can put them back in circulation. Thank you for your understanding and collaboration.

  17. Use of natural circulation flow map

    International Nuclear Information System (INIS)

    Natural circulation in complex systems, considering the experimental simulators of PWR and the experience gained in analyzing natural circulation experiments performed in those systems are referred to. In particular, the NC scenarios occurring at different values of the primary system mass inventory are studied. Data have been gathered and analyzed coming from the experimental facilities (PWR simulators, or Integral Test Facilities, ITF) named Semiscale, Spes, Lobi, Bethsy, Pkl and Lstf. The case of PWR design, the NC should be seen as the fundamental mechanism for removing core following accidents or events that cause unavailability of primary circulation pumps. The NC phenomenon constitutes the basis for the layout of the primary system with core located in the bottom of vessel and steam generators a few meters above the top of the active fuel

  18. Fort St. Vrain circulator operating experience

    International Nuclear Information System (INIS)

    Fort St. Vrain, on the system of Public Service Company of Colorado, is the only high-temperature gas-cooled power reactor in the United States. Four helium circulators are utilized in this plant to transfer heat from the reactor to the steam generators. These unique machines have a single stage axial flow helium compressor driven by a single stage steam turbine. A single stage water driven (pelton wheel) turbine is the back-up drive utilizing either feed water, condensate, or fire water as the driving fluid. Developmental testing of the circulators was accomplished prior to installation into Fort St. Vrain. A combined machine operating history of approximately 250,000 hours has shown these machines to be of conservative design and proven mechanical integrity. However, many problems have been encountered in operating the complex auxiliaries which are necessary for successful circulator and plant operation. It has been 15 years since initial installation of the circulators occurred at Fort St. Vrain. During this time, a number of significant issues had to be resolved dealing specifically with machine performance. These events include cavitation damage of the pelton wheels during the initial plant hot functional testing, cracks in the water turbine buckets and cervic coupling, static shutdown seal bellows failure, and, most recently, degradation of components within the steam drive assembly. Unreliable operation particularly with the circulator auxiliaries has been a focus of attention by Public Service Company of Colorado. Actions to replace or significantly modify the existing circulators and their auxiliaries are currently awaiting decisions concerning the long-term future of the Fort St. Vrain plant. (author). 10 refs, 7 figs, 2 tabs

  19. The aerodynamics of circulation control

    Science.gov (United States)

    Wood, N. J.

    1981-01-01

    Two dimensional subsonic wind tunnel tests were conducted on a 20% thickness: chord ratio circulation controlled elliptic aerofoil section equipped with forward and reverse blowing slots. Overall performance measurements were made over a range of trailing edge blowing momentum coefficients from 0 to 0.04; some included the effect of leading edge blowing. A detailed investigation of the trailing edge wall jet, using split film probes, hot wire probes and total head tubes, provided measurements of mean velocity components, Reynolds normal and shear stresses, and radial static pressure. The closure of the two dimensional angular momentum and continuity equations was examined using the measured data, with and without correction, and the difficulty of obtaining a satisfactory solution illustrated. Suggestions regarding the nature of the flow field which should aid the understanding of Coanda effect and the theoretical solution of highly curved wall jet flows are presented.

  20. GREENHOUSE GAS EMISSIONS CONTROL BY OXYGEN FIRING IN CIRCULATING FLUIDIZED BED BOILERS: PHASE II--PILOT SCALE TESTING AND UPDATED PERFORMANCE AND ECONOMICS FOR OXYGEN FIRED CFB WITH CO2 CAPTURE

    Energy Technology Data Exchange (ETDEWEB)

    Nsakala ya Nsakala; Gregory N. Liljedahl; David G. Turek

    2004-10-27

    Because fossil fuel fired power plants are among the largest and most concentrated producers of CO{sub 2} emissions, recovery and sequestration of CO{sub 2} from the flue gas of such plants has been identified as one of the primary means for reducing anthropogenic CO{sub 2} emissions. In this Phase II study, ALSTOM Power Inc. (ALSTOM) has investigated one promising near-term coal fired power plant configuration designed to capture CO{sub 2} from effluent gas streams for sequestration. Burning fossil fuels in mixtures of oxygen and recirculated flue gas (made principally of CO{sub 2}) essentially eliminates the presence of atmospheric nitrogen in the flue gas. The resulting flue gas is comprised primarily of CO{sub 2}, along with some moisture, nitrogen, oxygen, and trace gases like SO{sub 2} and NO{sub x}. Oxygen firing in utility scale Pulverized Coal (PC) fired boilers has been shown to be a more economical method for CO{sub 2} capture than amine scrubbing (Bozzuto, et al., 2001). Additionally, oxygen firing in Circulating Fluid Bed Boilers (CFB's) can be more economical than in PC or Stoker firing, because recirculated gas flow can be reduced significantly. Oxygen-fired PC and Stoker units require large quantities of recirculated flue gas to maintain acceptable furnace temperatures. Oxygen-fired CFB units, on the other hand, can accomplish this by additional cooling of recirculated solids. The reduced recirculated gas flow with CFB plants results in significant Boiler Island cost savings resulting from reduced component The overall objective of the Phase II workscope, which is the subject of this report, is to generate a refined technical and economic evaluation of the Oxygen fired CFB case (Case-2 from Phase I) utilizing the information learned from pilot-scale testing of this concept. The objective of the pilot-scale testing was to generate detailed technical data needed to establish advanced CFB design requirements and performance when firing coals and

  1. Resolvability in Circulant Graphs

    Institute of Scientific and Technical Information of China (English)

    Muhammad SALMAN; Imran JAVAID; Muhammad Anwar CHAUDHRY

    2012-01-01

    A set W of the vertices of a connected graph G is called a resolving set for G if for every two distinct vertices u,v ∈ V(G) there is a vertex w ∈ W such that d(u,w) ≠ d(v,w).A resolving set of minimum cardinality is called a metric basis for G and the number of vertices in a metric basis is called the metric dimension of G,denoted by dim(G).For a vertex u of G and a subset S of V(G),the distance between u and S is the number mins∈s d(u,s).A k-partition H ={S1,S2,...,Sk} of V(G) is called a resolving partition if for every two distinct vertices u,v ∈ V(G) there is a set Si in Π such that d(u,Si) ≠ d(v,Si).The minimum k for which there is a resolving k-partition of V(G) is called the partition dimension of G,denoted by pd(G).The circulant graph is a graph with vertex set Zn,an additive group ofintegers modulo n,and two vertices labeled i and j adjacent if and only if i - j (mod n) ∈ C,where C C Zn has the property that C =-C and 0(∈) C.The circulant graph is denoted by Xn,△ where A =|C|.In this paper,we study the metric dimension of a family of circulant graphs Xn,3 with connection set C ={1,-n/2,n - 1} and prove that dim(Xn,3) is independent of choice of n by showing that 3 for all n =0 (mod 4),dim(X,n,3) ={ 4 for all n =2 (mod 4).We also study the partition dimension of a family of circulant graphs Xn,4 with connection set C ={±1,±2} and prove that pd(Xn,4) is independent of choice of n and show that pd(X5,4) =5 and 3 forall odd n≥9,pd(Xn,4) ={ 4 for all even n ≥ 6 and n =7.

  2. The Explicit Identities for Spectral Norms of Circulant-Type Matrices Involving Binomial Coefficients and Harmonic Numbers

    Directory of Open Access Journals (Sweden)

    Jianwei Zhou

    2014-01-01

    Full Text Available The explicit formulae of spectral norms for circulant-type matrices are investigated; the matrices are circulant matrix, skew-circulant matrix, and g-circulant matrix, respectively. The entries are products of binomial coefficients with harmonic numbers. Explicit identities for these spectral norms are obtained. Employing these approaches, some numerical tests are listed to verify the results.

  3. Nucla circulating atmospheric fluidized bed demonstration project

    Energy Technology Data Exchange (ETDEWEB)

    1991-01-31

    During the fourth quarter of 1990, steady-state performance testing at the Nucla Circulating Fluidized Bed (CFB) resumed under sponsorship of the US Department of Energy. Co-sponsorship of the Demonstration Test Program by the Electric Power Research Institute (EPRI) was completed on June 15, 1990. From October through December, 1990, Colorado-Ute Electric Association (CUEA) completed a total of 23 steady-state performance tests, 4 dynamic tests, and set operating records during November and December as the result of improved unit operating reliability. Highlight events and achievements during this period of operation are presented.

  4. Circulation of Stars

    Science.gov (United States)

    Boitani, P.

    2016-01-01

    Since the dawn of man, contemplation of the stars has been a primary impulse in human beings, who proliferated their knowledge of the stars all over the world. Aristotle sees this as the product of primeval and perennial “wonder” which gives rise to what we call science, philosophy, and poetry. Astronomy, astrology, and star art (painting, architecture, literature, and music) go hand in hand through millennia in all cultures of the planet (and all use catasterisms to explain certain phenomena). Some of these developments are independent of each other, i.e., they take place in one culture independently of others. Some, on the other hand, are the product of the “circulation of stars.” There are two ways of looking at this. One seeks out forms, the other concentrates on the passing of specific lore from one area to another through time. The former relies on archetypes (for instance, with catasterism), the latter constitutes a historical process. In this paper I present some of the surprising ways in which the circulation of stars has occurred—from East to West, from East to the Far East, and from West to East, at times simultaneously.

  5. The results of the KSTAR superconducting coil test

    International Nuclear Information System (INIS)

    The KSTAR (Korea Superconducting Tokamak Advanced Research) device is under construction using superconducting (SC) coils for long pulse operation. The KSTAR superconducting magnet system consists of 16 D-shaped toroidal field (TF) coils, 3 pairs of poloidal field (PF) coils, and 4 pairs of central solenoid (CS) coils. Two kinds of SC coils have been fabricated and tested in the coil test facility in the Korea Basic Science Institute (KBSI). One of the coils was a prototype TF coil, TF00 coil, which has been fabricated in the same size as the real coils using Nb3Sn SC cable-in-conduit conductor (CICC). The other was a pair of CS model coils, which were fabricated as a part of a background field system to test the superconductor in a pulsed field environment. The major objectives of the SC coil tests were (i) to verify the coil design and fabrication process in the KSTAR coil development, (ii) to measure the coil performances during cool-down, current excitation, and discharge scenarios, and (iii) to achieve the operational experience of the SC coil test facility and the SC magnet system in the KSTAR device. The prototype TF coil was cooled down to the operating temperature of 4.5 K in 10 days. The coil was charged in steps and this was followed by slow or fast discharges. The transient hydraulic parameters were measured according to the different scenarios. The results of the coil test showed that no noticeable defects of the coil were found, such as helium leaks at cryogenic temperature, and helium circulation through the coil was sufficient to keep the coil at the operating temperature. The CS model coil was also cooled down in 9 days and basic current excitation and discharge tests of the coil have been done. To assess the ac performance of the coil, current charging experiments of the coil will be continued until the end of 2004. In this paper, the experimental results of the prototype TF coil and the CS model coil are described as well as the general coil test

  6. A comparitive study on concepts of circulation of blood.

    Science.gov (United States)

    Pandey, V N; Pandey, A

    1990-04-01

    This study traces the progressively evolving concepts of blood circulation. Evidences from medical and non-medical Sanskrit literature have been presented to high the fact that the Ayurvedic concepts of physiology are time tested. PMID:22557695

  7. A COMPARITIVE STUDY ON CONCEPTS OF CIRCULATION OF BLOOD

    OpenAIRE

    Pandey, V. N.; Pandey, Ayodhya

    1990-01-01

    This study traces the progressively evolving concepts of blood circulation. Evidences from medical and non-medical Sanskrit literature have been presented to high the fact that the Ayurvedic concepts of physiology are time tested.

  8. Experimental study of natural circulation circuit

    Energy Technology Data Exchange (ETDEWEB)

    Lemos, Wanderley F.; Su, Jian, E-mail: wlemos@lasme.coppe.ufrj.br, E-mail: sujian@lasme.coppe.ufrj.br [Coordenacao dos Programas de Pos-Graduacao de Engenharia (LASME/COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Lab. de Simulacao e Metodos Numericos; Faccini, Jose L.H., E-mail: faccini@ien.gov.br [Instituto de Engenharia Nuclear (LTE/IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil). Lab. de Termo-Hidraulica Experimental

    2011-07-01

    This work presents an experimental study about fluid flows behavior in natural circulation, under conditions of single-phase flow. The experiment was performed through experimental thermal-hydraulic circuit built at IEN. This test equipment has performance similar to passive system of residual heat removal present in Advanced Pressurized Water Reactors (APWR). This experimental study aims to observing and analyzing the natural circulation phenomenon, using this experimental circuit that was dimensioned and built based on concepts of similarity and scale. This philosophy allows the analysis of natural circulation behavior in single-phase flow conditions proportionally to the functioning real conditions of a nuclear reactor. The experiment was performed through procedures to initialization of hydraulic feeding of primary and secondary circuits and electrical energizing of resistors installed inside heater. Power controller has availability to adjust values of electrical power to feeding resistors, in order to portray several conditions of energy decay of nuclear reactor in a steady state. Data acquisition system allows the measurement and monitoring of the evolution of the temperature in various points through thermocouples installed in strategic points along hydraulic circuit. The behavior of the natural circulation phenomenon was monitored by graphical interface on computer screen, showing the temperature evolutions of measuring points and results stored in digital spreadsheets. The results stored in digital spreadsheets allowed the getting of data to graphic construction and discussion about natural circulation phenomenon. Finally, the calculus of Reynolds number allowed the establishment for a correlation of friction in function of geometric scales of length, heights and cross section of tubing, considering a natural circulation flow throughout in the region of hot leg. (author)

  9. Pesquisa do antígeno circulante de Cryptococcus neoformans em líquido cefalorraqueano pelo teste de coaglutinação Coaglutination test (COA for Cryptococcus neoformans circulating antigen detection in cerebral spinal fluid (CSF

    Directory of Open Access Journals (Sweden)

    Maria Isabel Nogueira Cano

    1990-12-01

    Full Text Available Foram utilizadas 82 LCR de transplantados renais (24 pacientes, 43 LCR de pacientes com críptococose comprovada (controles positivos, 35 LCR de pacientes com outras doenças (histoplasmose, paracoccidioidomicose e infecções bacterianas como controles negativos. Os primeiros foram cultivados em ágar Sabouraud com sementes de girassol e juntamente com os demais examinado pelo teste de látex para pesquisa de antígeno circulante de C. neoformans, qualitativamente. O teste de Coaglutinação foi realizado qualitativamente e quantitativamente, encontrando-se títulos até a diluição 1:2048. Não foram detectadas reações falso-positivas ou falso-negativas entre os controles. Como prova de valor diagnóstico demonstrou: sensibilidade - 92,1%; especificidade - 92,6% e eficiência - 92,3%. Provou também ser um teste rápido, exato e econômico, embora sua escolha dependa do pré-tratamento de LCR (80ºC por 3 a 5 minutos e soros (diluição ou álcali-precipitação para evitar autoaglutinação e aumentar a sensibilidade da reação.We tested 82 CSF of 24 renal transplanted patients (RT with cerebral cryptococcosis, 8 CSF of asymptomatic RT patients, 43 CSF of proven cryptococcosis cases (positive control and 35 CSF of patients with other diseases (histoplasmosis, paracoccidioidomycosis and bacterial infections as negative control. The RT CSF were cultured in Sabouraud agar slant added with sunflower seeds and both control and RT CSF were qualitatively examined by cryptococcosis latex test (Crypto-LA test. The COA test was developed both qualitatively and quantitatively. The highest titre encountered was 1:2048. No false reactions appeared among the controls. The diagnostic value demonstrated by Galen and Gambino's method was: sensitivity - 92.1%; specificity - 92.6% and efficiency - 92.3%. Besides that, the COA proved to be quick, exact and cheap, but it depends on CSF and sera pre-treatment, in order to avoid autoagglutination and increase

  10. Effect of Coolant Inventories and Parallel Loop Interconnections on the Natural Circulation in Various Heat Transport Systems of a Nuclear Power Plant during Station Blackout

    Directory of Open Access Journals (Sweden)

    Avinash J. Gaikwad

    2008-01-01

    Full Text Available Provision of passive means to reactor core decay heat removal enhances the nuclear power plant (NPP safety and availability. In the earlier Indian pressurised heavy water reactors (IPHWRs, like the 220 MWe and the 540 MWe, crash cooldown from the steam generators (SGs is resorted to mitigate consequences of station blackout (SBO. In the 700 MWe PHWR currently being designed an additional passive decay heat removal (PDHR system is also incorporated to condense the steam generated in the boilers during a SBO. The sustainability of natural circulation in the various heat transport systems (i.e., primary heat transport (PHT, SGs, and PDHRs under station blackout depends on the corresponding system's coolant inventories and the coolant circuit configurations (i.e., parallel paths and interconnections. On the primary side, the interconnection between the two primary loops plays an important role to sustain the natural circulation heat removal. On the secondary side, the steam lines interconnections and the initial inventory in the SGs prior to cooldown, that is, hooking up of the PDHRs are very important. This paper attempts to open up discussions on the concept and the core issues associated with passive systems which can provide continued heat sink during such accident scenarios. The discussions would include the criteria for design, and performance of such concepts already implemented and proposes schemes to be implemented in the proposed 700 MWe IPHWR. The designer feedbacks generated, and critical examination of performance analysis results for the added passive system to the existing generation II & III reactors will help ascertaining that these safety systems/inventories in fact perform in sustaining decay heat removal and augmenting safety.

  11. Model test on intake channel of seawater circulating pump house and its optimization design%海水循环水泵房流道模型试验及优化设计研究

    Institute of Scientific and Technical Information of China (English)

    陈守河; 程璐; 赵建钧

    2012-01-01

    Taking the seawater circulating pump house of a LNG project as the research object, a physical model test on the intake channel of the said pump house was carried out, and the methods for its optimization design was discussed. In view of the surface vortex, surface reflux, circumfluence outside the pipe, and some other bad flow patterns which may happen in the suction chamber if the original design scheme were used, some modification measures for improving the flow pattern such as: prolong the partition wall, build submerged breast wall and so on were adopted. The mentioned measures made the flow velocity distribution in the suction chamber to be symmetrical, and eliminated bad flow pattern. The recommended optimization scheme could ensure the safe and stable operation of the seawater pump, besides, the research results provided references for those similar projects with large or medium-sized seawater pump.%结合某LNG项目,对其循环水泵房流道进行物理模型试验,探讨了泵房流道优化设计方法,针对原设计方案下吸水室内存在的表面吸气涡、表面回流、管外环流等不利流态,采用了延长隔墙、增加淹没胸墙等整流措施,有效地改善了泵房吸水室内流速分布的均匀性,消除了不利流态.优化后的推荐方案能够满足海水泵安全稳定运行的要求,研究成果也为其它类似的大中型海水泵工程提供了参考.

  12. Ocean General Circulation Models

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Jin-Ho; Ma, Po-Lun

    2012-09-30

    1. Definition of Subject The purpose of this text is to provide an introduction to aspects of oceanic general circulation models (OGCMs), an important component of Climate System or Earth System Model (ESM). The role of the ocean in ESMs is described in Chapter XX (EDITOR: PLEASE FIND THE COUPLED CLIMATE or EARTH SYSTEM MODELING CHAPTERS). The emerging need for understanding the Earth’s climate system and especially projecting its future evolution has encouraged scientists to explore the dynamical, physical, and biogeochemical processes in the ocean. Understanding the role of these processes in the climate system is an interesting and challenging scientific subject. For example, a research question how much extra heat or CO2 generated by anthropogenic activities can be stored in the deep ocean is not only scientifically interesting but also important in projecting future climate of the earth. Thus, OGCMs have been developed and applied to investigate the various oceanic processes and their role in the climate system.

  13. Trypanosoma cruzi: circulating antigens

    Directory of Open Access Journals (Sweden)

    V. Bongertz

    1981-03-01

    Full Text Available Circulating antigens were detected in sera of mice experimentally infected with a high close of Trypanosoma cruzi by reaction with sera from chronically infected mice. The immunodiffusion reaction between homologous acute and chronic sera produced four precipitation lines. By reaction with chronic mouse serum, circulating antingens were detected in sera from heavily infected hamsters, dogs, rabbits and in sera from chagasic patients. A reaction was also found in urine from acutely infected mice and dogs. Trypanosoma cruzi exoantigen was detected in trypanosome culture medium and in the supernatant of infected cell cultures. Attempts to isolate the antigens are described.Antígenos circulantes foram detectados em soros de camundongos infectados experimentalmente com elevadas doses de Trypanosoma cruzi pela reação com soros obtidos de camundongos em fase crônica de infecção. A reação de imunodifusão entre soros homólogos agudo e crônico produziu quatro linhas de precipitação. Por reação com soro crônico de camundongo antígenos circulantes foram detectados em soros de crícetos, cães e coelhos infectados com doses elevadas de Trypanosoma cruzi e em soros de pacientes chagásicos. Uma reação foi também observada com urina de camundongos e cães infectados de forma aguda. Exoantígeno de Trypanosoma cruzi foi detectado em meio de cultura de tripanosomas e em sobrenadantes de culturas de células infectadas. Tentativas de isolamento dos antigenos são descritas.

  14. Comparison of Modified Chandler, Roller Pump, and Ball Valve Circulation Models for In Vitro Testing in High Blood Flow Conditions: Application in Thrombogenicity Testing of Different Materials for Vascular Applications

    OpenAIRE

    Wim van Oeveren; Tielliu, Ignace F.; Jurgen de Hart

    2012-01-01

    Three different models, a modified Chandler loop, roller pump, and a new ball valve model (Hemobile), were compared with regard to intrinsic damage of blood components and activation of platelets. The Hemobile was used for testing of polymer tubes. High flow was not possible with the Chandler loop. The roller pump and the Hemobile could be adjusted to high flow, but he pump induced hemolysis. Platelet numbers were reduced in the roller pump and Chandler loop (P < 0.05), but remained high in t...

  15. Water circulation forecasting in Spanish harbours

    OpenAIRE

    Grifoll, Manel; Jordá, Gabriel; Sotillo, Marcos G.; Ferrer, Luis; Espino, Manuel; Sánchez-Arcilla, Agustín; Álvarez-Fanjul, Enrique

    2012-01-01

    This paper describes the first harbour circulation forecasting system implemented in Spain. The configuration design was based on previous analyses of the morphologic and hydrodynamic behaviour of three harbours: Barcelona, Tarragona and Bilbao. A nested system of oceanic models was implemented, with a scope ranging from the regional scale (with a mean horizontal resolution of 5 km) to the harbour scale (with a mean horizontal resolution of 40 m). A set of sensitivity tests was carried out in...

  16. TROPICAL METEOROLOGY & Climate: Hadley Circulation

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Jian; Vecchi, Gabriel A.

    2015-01-30

    The Hadley circulation, a prominent circulation feature characterized by rising air near the Equator and sinking air in the subtropics, defines the position of dry subtropical areas and is a fundamental regulator of the earth’s energy and momentum budgets. The character of the Hadley circulation, and its related precipitation regimes, exhibits variation and change in response to both climate variability and radiative forcing changes. The strength and position of the Hadley circulation change from year to year paced by El Niño and La Niña events. Over the last few decades of the twentieth century, the Hadley cell has expanded poleward in both hemispheres, with changes in atmospheric composition (including stratospheric ozone depletion and greenhouse gas increases) thought to have contributed to its expansion. This article introduces the basic phenomenology and driving mechanism of the Hadley circulation and discusses its variations under both natural and anthropogenic climate forcings.

  17. Sino-Danish Brain Circulation

    DEFF Research Database (Denmark)

    Bertelsen, Rasmus Gjedssø; Du, Xiangyun; Søndergaard, Morten Karnøe

    2014-01-01

    China is faced with urgent needs to develop an economically and environmentally sustainable economy based on innovation and knowledge. Brain circulation and research and business investments from the outside are central for this development. Sino-American brain circulation and research...... and investment by overseas researchers and entrepreneurs are well described. In that case, the US is the center of global R&D and S&T. However, the brain circulation and research and investments between a small open Scandinavian economy, such as Denmark, and the huge developing economy of China are not well...... understood. In this case, Denmark is very highly developed, but a satellite in the global R&D and S&T system. With time and the growth of China as a R&D and S&T power house, both Denmark and China will benefit from brain circulation between them. Such brain circulation is likely to play a key role in flows...

  18. Stability of the Horizontal Curvature of the LHC Cryodipoles During Cold Tests

    CERN Document Server

    Cano, E D Fernandez; García-Pérez, J; Jeanneret, Jean Bernard; Poncet, A; Seyvet, F; Tovar-Gonzalez, A; Wildner, E; IEEE Trans. Nucl. Sci.

    2006-01-01

    The LHC will be composed of 1232 horizontally curved, 15 meter long, superconducting dipole magnets cooled at 1.9 K. They are supported within their vacuum vessel by three Glass Fiber Reinforced Epoxy (GFRE) support posts. Each cryodipole is individually cold tested at CERN before its installation and interconnection in the LHC 27 km circumference tunnel. As the magnet geometry under cryogenic operation is extremely important for the LHC machine aperture, a new method has been developed at CERN in order to monitor the magnet curvature change between warm and cold states. It enabled us to conclude that there is no permanent horizontal curvature change of the LHC dipole magnet between warm and cold states, although a systematic horizontal transient deformation during cool-down was detected. This deformation generates loads in the dipole supporting system; further investigation permitted us to infer this behavior to the asymmetric thermal contraction of the rigid magnet thermal shield during cool-down. Controlli...

  19. Cryogenic testing of the TPC superconducting solenoid

    Science.gov (United States)

    Green, M. A.; Smits, R. G.; Taylor, J. D.; Vanslyke, V.; Barrera, F.; Petersen, H.; Rago, C. E.; Rinta, R. I.; Talaska, D.; Watt, R. D.

    1983-06-01

    This report describes the results of a series of tests on the TPC superconducting magnet cryogenic system which occurred during the winter and spring of 1983. The tests occurred at interaction region 2 of the PEP colliding beam facility at the Stanford Linear Accelerator Center (SLAC). The TPC Magnet Cryogenic System which was tested includes the following major components: a remote helium compressor with a full flow liquid nitrogen purification station, 400 meters of high pressure supply and low pressure return lines; and locally a CTi Model 2800 refrigerator with two Sulzer gas bearing turbines, the TPC magnet control dewar, 70 meters of transfer lines, and the TPC thin superconducting solenoid magnet. In addition, there is a conditioner (liquid nitrogen heat exchangers and gas heaters) system for cooldown and warmup of the magnet. This report describes the local cryogenic system and describes the various steps in the cooldown and operation of the TPC magnet. The tests were successful in that they showed that the TPC magnet could be cooled down in 24 hours and the magnet could be operated on the refrigerator or a helium pump with adequate cooling margin.

  20. Natural circulation in pressurized water reactors

    International Nuclear Information System (INIS)

    Several analytical modelling have been done for steady-state and slow transients conditions, besides more sophisticated studies considering two and three dimensional effects in a very simple geometry. Under severe accident conditions for PWR a code to analyse natural circulation has been developed by Westinghouse. This paper discusses the problem of natural circulation in a complex geometry similar to that of nuclear power plants. A first experiment has been done at the integral test facility of 'Co-ordination of Special Projects-Ministry of Naval Affairs' (Coordenadoria para Projetos Especiais -Ministerio da Marinha, COPESP) for several flux conditions. The results obtained were compared with numerical simulations for the steady-state regime. 09 refs, 05 figs, 01 tab. (B.C.A.)

  1. RELAP5/MOD3 assessment using the Semiscale 50% Feed Line Break test S-FS-11

    Energy Technology Data Exchange (ETDEWEB)

    Lee, E.J.; Chung, B.D.; Kim, H.J. [Korea Inst. of Nuclear Safety, Taejon (Korea, Republic of)

    1993-06-01

    The RELAP5/MOD3 5m5 code was assessed using the 1/1705 volume scaled Semiscale 50% Feed Line Break (FLB) test S-FS-11. Test S-FS-11 was designed in three phases: (a) blowdown phase, (b) stabilization phase, and (c) refill phase. The first objective was to assess the code applicability to 50% FLB situation, the second was to evaluate the FSAR conservatisms regarding SG heat transfer degradation, steam line check valve failure, break flow state, and peak primary system pressure, and the third was to validate the EOP effectiveness. The code was able to simulate the major T/H parameters except for the two-phase break flow and the secondary convective heat transfer rate. The two-phase break flow had still deficiencies. The current boiling heat transfer rate was developed from the data for flow inside of a heated tube, not for flow around heated tubes in a tube bundle. Results indicated that the assumption of 100% heat transfer until the liquid inventory depletion was not conservative, the failed affected steam generator main steam line check valve assumption was not either conservative, the measured break flow experienced all types of flow conditions, the relative proximity to the 110% design pressure limit was conservative. The automatic actions during the blowdown phase were effective in mitigating the consequences. The stabilization operation performed by operator actions were effective to permit natural circulation cooldown and depressurization. The voided secondary refill operations also verified the effectiveness of the operations while recovering the inventory in a voided steam generator.

  2. RELAP5/MOD3 assessment using the Semiscale 50% Feed Line Break test S-FS-11

    International Nuclear Information System (INIS)

    The RELAP5/MOD3 5m5 code was assessed using the 1/1705 volume scaled Semiscale 50% Feed Line Break (FLB) test S-FS-11. Test S-FS-11 was designed in three phases: (a) blowdown phase, (b) stabilization phase, and (c) refill phase. The first objective was to assess the code applicability to 50% FLB situation, the second was to evaluate the FSAR conservatisms regarding SG heat transfer degradation, steam line check valve failure, break flow state, and peak primary system pressure, and the third was to validate the EOP effectiveness. The code was able to simulate the major T/H parameters except for the two-phase break flow and the secondary convective heat transfer rate. The two-phase break flow had still deficiencies. The current boiling heat transfer rate was developed from the data for flow inside of a heated tube, not for flow around heated tubes in a tube bundle. Results indicated that the assumption of 100% heat transfer until the liquid inventory depletion was not conservative, the failed affected steam generator main steam line check valve assumption was not either conservative, the measured break flow experienced all types of flow conditions, the relative proximity to the 110% design pressure limit was conservative. The automatic actions during the blowdown phase were effective in mitigating the consequences. The stabilization operation performed by operator actions were effective to permit natural circulation cooldown and depressurization. The voided secondary refill operations also verified the effectiveness of the operations while recovering the inventory in a voided steam generator

  3. Development of CO2 circulators

    International Nuclear Information System (INIS)

    The development of the basic machine types we have supplied has not been without problems. The Windscale AGR (the prototype AGR) was a small 1.2 MW vertically up circulator with an inlet temperature of 237 deg. C (459 deg. F). Oil leakage problems occurred and were cured in the works test facility and the machine went into service with no other problems. The Horizontal 5 MW machines for Hinkley/Hunterston were not so fortunate with vibration problems, interface corrosion problems (effecting the whole reactor) and material dimensional stability problems. Oil ingress problems did not show up in test work but were later reported from site. These reports were initially exagerated due to the measuring techniques which took the operators some time to resolve. In the vertical 5 MW machines for Hartlepool and Heysham 1 there are two interesting factors, firstly a spar failure and secondly shaft axial stability. Many of the problems were due to modifications at site or our inability to model all aspects of site installation from which lessons for the future can be learned. The latest stations Torness and Heysham II incorporate these lessons. The machines have been designed with so much margin that during the resolution of the reactor control rod gag problems the machines were run continuously at 20% overload (6.3 MW). From an initial accident case of 350 deg. C inlet temperature, this increased to 458 deg. C and now stands at 585 deg. C. No modifications to the impeller were required. The site experience to date is good with no operational problems reported. (author). 4 figs

  4. The circulation physiology of agroecosystems

    Institute of Scientific and Technical Information of China (English)

    Cao Zhiping; Richard Dawson

    2007-01-01

    This paper represents an effort to enlarge the understanding of the biophysical foundation of agroecosystems by using an analogy with the circulation of the blood in the human body. The circulation function in the human body can be represented as arterial pressure. The factors affecting arterial pressure in the human body have direct counterparts in the cultivation-husbandry system. The relationship between circulation pressure and the factors affecting that pressure in the cultivation-husbandry system are similar to the relationship between the arterial pressure and factors affecting arterial pressure in the human body. Furthermore, circulation resistance in the cultivation-husbandry system can be shown to be analogous to the calculation of peripheral resistance in the human body by Poiseuille's formula.

  5. A model with simplified circulation dynamics for a baroclinic ocean with topograpgy, Part I: Waves and wind-driven circulations

    OpenAIRE

    D. Olbers; Eden, Carsten

    2003-01-01

    A new type of ocean general circulation model with simplified physics is described and tested for various simple wind-driven circulation problems. The model consists of the vorticity balance of the depth-averaged flow and a hierarchy of equations for “vertical moments” of density and baroclinic velocity. The first vertical density moment is the (vertically integrated) potential energy, which is used to describe the predominant link between the barotropic and the baroclinic oceanic flow in the...

  6. A simplified general circulation model for a baroclinic ocean with topography. Part I: Theory, waves and wind-driven circulations

    OpenAIRE

    Olbers, Dirk; Eden, C.

    2003-01-01

    A new type of ocean circulation model is described and tested for various simplewind-driven circulation problems. The model resides on the vorticity balance ofthe depth averaged velocity and a hierarchy of balance equations for thevertical moments of baroclinic velocity and density, the lowest density momentbeing the baroclinic potential energy. The latter is the most importantdynamical link between the barotropic and the baroclinic motion in the presenceof a sloping topography. We derive a c...

  7. Atmospheric Circulation of Terrestrial Exoplanets

    OpenAIRE

    Showman, Adam P.; Wordsworth, Robin D.; Merlis, Timothy M.; Kaspi, Yohai

    2013-01-01

    The investigation of planets around other stars began with the study of gas giants, but is now extending to the discovery and characterization of super-Earths and terrestrial planets. Motivated by this observational tide, we survey the basic dynamical principles governing the atmospheric circulation of terrestrial exoplanets, and discuss the interaction of their circulation with the hydrological cycle and global-scale climate feedbacks. Terrestrial exoplanets occupy a wide range of physical a...

  8. Hanford spent nuclear fuel cold vacuum drying proof of performance test procedure

    International Nuclear Information System (INIS)

    This document provides the test procedure for cold testing of the first article skids for the Cold Vacuum Drying (CVD) process at the Facility. The primary objective of this testing is to confirm design choices and provide data for the initial start-up parameters for the process. The current scope of testing in this document includes design verification, drying cycle determination equipment performance testing of the CVD process and MCC components, heat up and cool-down cycle determination, and thermal model validation

  9. Test

    DEFF Research Database (Denmark)

    Bendixen, Carsten

    2014-01-01

    Bidrag med en kortfattet, introducerende, perspektiverende og begrebsafklarende fremstilling af begrebet test i det pædagogiske univers.......Bidrag med en kortfattet, introducerende, perspektiverende og begrebsafklarende fremstilling af begrebet test i det pædagogiske univers....

  10. Seasonal overturning circulation in the Red Sea: 2. Winter circulation

    KAUST Repository

    Yao, Fengchao

    2014-04-01

    The shallow winter overturning circulation in the Red Sea is studied using a 50 year high-resolution MITgcm (MIT general circulation model) simulation with realistic atmospheric forcing. The overturning circulation for a typical year, represented by 1980, and the climatological mean are analyzed using model output to delineate the three-dimensional structure and to investigate the underlying dynamical mechanisms. The horizontal model circulation in the winter of 1980 is dominated by energetic eddies. The climatological model mean results suggest that the surface inflow intensifies in a western boundary current in the southern Red Sea that switches to an eastern boundary current north of 24N. The overturning is accomplished through a cyclonic recirculation and a cross-basin overturning circulation in the northern Red Sea, with major sinking occurring along a narrow band of width about 20 km along the eastern boundary and weaker upwelling along the western boundary. The northward pressure gradient force, strong vertical mixing, and horizontal mixing near the boundary are the essential dynamical components in the model\\'s winter overturning circulation. The simulated water exchange is not hydraulically controlled in the Strait of Bab el Mandeb; instead, the exchange is limited by bottom and lateral boundary friction and, to a lesser extent, by interfacial friction due to the vertical viscosity at the interface between the inflow and the outflow. Key Points Sinking occurs in a narrow boundary layer along the eastern boundary Surface western boundary current switches into an eastern boundary current Water exchange in the Strait of Bab el Mandeb is not hydraulically controlled © 2014. American Geophysical Union. All Rights Reserved.

  11. The Invertibility, Explicit Determinants, and Inverses of Circulant and Left Circulant and g-Circulant Matrices Involving Any Continuous Fibonacci and Lucas Numbers

    Directory of Open Access Journals (Sweden)

    Zhaolin Jiang

    2014-01-01

    Full Text Available Circulant matrices play an important role in solving delay differential equations. In this paper, circulant type matrices including the circulant and left circulant and g-circulant matrices with any continuous Fibonacci and Lucas numbers are considered. Firstly, the invertibility of the circulant matrix is discussed and the explicit determinant and the inverse matrices by constructing the transformation matrices are presented. Furthermore, the invertibility of the left circulant and g-circulant matrices is also studied. We obtain the explicit determinants and the inverse matrices of the left circulant and g-circulant matrices by utilizing the relationship between left circulant, g-circulant matrices and circulant matrix, respectively.

  12. Circulating Fibronectin Controls Tumor Growth

    Directory of Open Access Journals (Sweden)

    Anja von Au

    2013-08-01

    Full Text Available Fibronectin is ubiquitously expressed in the extracellular matrix, and experimental evidence has shown that it modulates blood vessel formation. The relative contribution of local and circulating fibronectin to blood vessel formation in vivo remains unknown despite evidence for unexpected roles of circulating fibronectin in various diseases. Using transgenic mouse models, we established that circulating fibronectin facilitates the growth of bone metastases by enhancing blood vessel formation and maturation. This effect is more relevant than that of fibronectin produced by endothelial cells and pericytes, which only exert a small additive effect on vessel maturation. Circulating fibronectin enhances its local production in tumors through a positive feedback loop and increases the amount of vascular endothelial growth factor (VEGF retained in the matrix. Both fibronectin and VEGF then cooperate to stimulate blood vessel formation. Fibronectin content in the tumor correlates with the number of blood vessels and tumor growth in the mouse models. Consistent with these results, examination of three separate arrays from patients with breast and prostate cancers revealed that a high staining intensity for fibronectin in tumors is associated with increased mortality. These results establish that circulating fibronectin modulates blood vessel formation and tumor growth by modifying the amount of and the response to VEGF. Furthermore, determination of the fibronectin content can serve as a prognostic biomarker for breast and prostate cancers and possibly other cancers.

  13. Atmospheric Circulation of Terrestrial Exoplanets

    CERN Document Server

    Showman, Adam P; Merlis, Timothy M; Kaspi, Yohai

    2013-01-01

    The investigation of planets around other stars began with the study of gas giants, but is now extending to the discovery and characterization of super-Earths and terrestrial planets. Motivated by this observational tide, we survey the basic dynamical principles governing the atmospheric circulation of terrestrial exoplanets, and discuss the interaction of their circulation with the hydrological cycle and global-scale climate feedbacks. Terrestrial exoplanets occupy a wide range of physical and dynamical conditions, only a small fraction of which have yet been explored in detail. Our approach is to lay out the fundamental dynamical principles governing the atmospheric circulation on terrestrial planets--broadly defined--and show how they can provide a foundation for understanding the atmospheric behavior of these worlds. We first survey basic atmospheric dynamics, including the role of geostrophy, baroclinic instabilities, and jets in the strongly rotating regime (the "extratropics") and the role of the Hadle...

  14. Non-standard natural circulation in primary circuit of VVR-440, behavior of horizontal steam generator in this regime

    International Nuclear Information System (INIS)

    Analyzing various SBLOCA with high pressure safety injection (HPSI) at VVER-440/213, we met a surprising phenomenon - a 'natural' circulation post SG heat transfer reversal. This is not usual, because normal natural circulation (NC) in primary circuit is connected with positive heat transfer at SG. If there is reverse heat transfer at SG (as soon as the break enthalpy outflow is sufficient for removal of reactor decay heat), it should obstruct any natural circulation. The question was, what is the driving force of this 'non-standard natural circulation'. After all we revealed that force - it is the density difference between the colder water in reactor downcomer (cold water from HPSI) and warmer water in inner reactor (lower plenum, core, upper plenum). This phenomenon could be confusing for operating personal, because there would be an opposite temperature difference at the loop than by normal natural circulation (under non-standard NC conditions water is heated in SG so there is warmer water in cold leg than in hot leg). If operating personal recognises natural circulation according AT loops, this could lead to misunderstanding and potentially to incorrect actions. The phenomenon of non-standard NC occurred also in results of most of participants of IAEA PTS benchmark (PRZ SV stuck-open from zero reactor power). Despite of early reversal of SG heat transfer (about 100 s), there was usually long 'cost- down' of natural circulation in loops (about 1500 s). In this case with very low core decay heat (0.15 % Nnom) the non-standard natural circulation lasted as long as there was a primary circuit cooldown. As the temperatures in primary circuit got closer to temperature of HPSI water, the circulation became weaker and finally the flow stagnation occurred in all loops. The predicted circulation is influenced by 1-D or 2-D modelling of reactor downcomer (DC). Usual 1-D representation of the DC is connected with perfect mixing in DC inlet section and impossibility of

  15. VanderLaan Circulant Type Matrices

    Directory of Open Access Journals (Sweden)

    Hongyan Pan

    2015-01-01

    Full Text Available Circulant matrices have become a satisfactory tools in control methods for modern complex systems. In the paper, VanderLaan circulant type matrices are presented, which include VanderLaan circulant, left circulant, and g-circulant matrices. The nonsingularity of these special matrices is discussed by the surprising properties of VanderLaan numbers. The exact determinants of VanderLaan circulant type matrices are given by structuring transformation matrices, determinants of well-known tridiagonal matrices, and tridiagonal-like matrices. The explicit inverse matrices of these special matrices are obtained by structuring transformation matrices, inverses of known tridiagonal matrices, and quasi-tridiagonal matrices. Three kinds of norms and lower bound for the spread of VanderLaan circulant and left circulant matrix are given separately. And we gain the spectral norm of VanderLaan g-circulant matrix.

  16. Conservation of Circulation in Magnetohydrodynamics

    CERN Document Server

    Bekenstein, J D; Bekenstein, Jacob D.; Oron, Asaf

    2000-01-01

    We demonstrate, both at the Newtonian and (general) relativistic levels, theexistence of a generalization of Kelvin's circulation theorem (for pure fluids)which is applicable to perfect magnetohydrodynamics. The argument is based onthe least action principle for magnetohydrodynamic flow. Examples of the newconservation law are furnished. The new theorem should be helpful inidentifying new kinds of vortex phenomena distinct from magnetic ropes or fluidvortices.

  17. Neural Control of the Circulation

    Science.gov (United States)

    Thomas, Gail D.

    2011-01-01

    The purpose of this brief review is to highlight key concepts about the neural control of the circulation that graduate and medical students should be expected to incorporate into their general knowledge of human physiology. The focus is largely on the sympathetic nerves, which have a dominant role in cardiovascular control due to their effects to…

  18. ENDEMIC ORTHOPOXVIRUS CIRCULATING IN PROCYONIDS IN MEXICO.

    Science.gov (United States)

    Gallardo-Romero, Nadia F; Aréchiga-Ceballos, Nidia; Emerson, Ginny L; Martínez-Martínez, Flor O; Doty, Jeffrey B; Nakazawa, Yoshinori J; Rendón-Franco, Emilio; Muñoz-García, Claudia I; Villanueva-García, Claudia; Ramírez-Cid, Citlali; Gama-Campillo, Lilia M; Gual-Sill, Fernando; Aguilar-Setién, Álvaro; Carroll, Darin S

    2016-07-01

    Limited serosurveillance studies suggested that orthopoxviruses (OPXV) are widespread in the US (e.g., Raccoonpox virus, Skunkpox virus, Volepox virus) and Brazil (Vaccinia virus); however, their animal reservoir(s) remain unconfirmed. Mexican mammal diversity includes several species related to those in which evidence for OPXV infections has been found (Oryzomys, Peromyscus, Microtus, and Procyonidae). The presence of these groups of mammals in Mexico and the evidence of their possible involvement in the maintenance of OPXV in nature suggest the same or similar OPXV are circulating in Mexico. We tested 201 sera from 129 procyonids via modified enzyme-linked immunosorbent assay (ELISA) and Western blot (WB) to estimate OPXV antibody prevalence in these animals. We detected a prevalence of 16.67% in Nasua narica (white-nosed coati), 35% in Procyon lotor (raccoon), and 30.4% in Bassariscus astutus (ring-tailed cat) when tested by either ELISA or WB. Western blot results presented protein bands consistent with the size of some OPXV immunodominant bands (14, 18, 32, 36, and 62 kDa). These results support the hypothesis that OPXV circulate in at least three genera of Procyonidae in Central and Southeast Mexico. PMID:27224209

  19. CIRCULATING MOVING BED COMBUSTION PROOF OF CONCEPT

    Energy Technology Data Exchange (ETDEWEB)

    Jukkola, Glen

    2010-06-30

    Circulating Moving Bed (CMB) combustion technology has its roots in traditional circulating fluidized bed technology and involves a novel method of solid fuel combustion and heat transfer. CMB technology represents a step change in improved performance and cost relative to conventional PC and FBC boilers. The CMB heat exchanger preheats the energy cycle working fluid, steam or air, to the high temperature levels required in systems for advanced power generation. Unique features of the CMB are the reduction of the heat transfer surfaces by about 60% as a result of the enhanced heat transfer rates, flexibility of operation, and about 30% lower cost over existing technology. The CMB Phase I project ran from July 2001 through March 2003. Its objective was to continue development of the CMB technology with a series of proof of concept tests. The tests were conducted at a scale that provided design data for scale up to a demonstration plant. These objectives were met by conducting a series of experiments in ALSTOM Power’s Multi-use Test Facility (MTF). The MTF was modified to operate under CMB conditions of commercial interest. The objective of the tests were to evaluate gas-to-solids heat transfer in the upper furnace, assess agglomeration in the high temperature CMB bubbling bed, and evaluate solids-to-tube heat transfer in the moving bed heat exchanger. The Phase I program results showed that there are still some significant technical uncertainties that needed to be resolved before the technology can be confidently scaled up for a successful demonstration plant design. Work remained in three primary areas: • scale up of gas to solid heat transfer • high temperature finned surface design • the overall requirements of mechanical and process design. The CMB Phase II workscope built upon the results of Phase I and specifically addressed the remaining technical uncertainties. It included a scaled MTF heat transfer test to provide the necessary data to scale up gas

  20. Changes in large-scale air circulation and connection with climate variables in Romania

    Science.gov (United States)

    Stefan, Sabina; Barbu, Nicu

    2016-04-01

    The aim of this paper is the analysis of the relationship between climate variables (seasonal mean air temperature - T2m, and seasonal amount of precipitation - PP) and large-scale air circulation. In order to achieve this, the air circulation types were derived from GrossWetterTypen (GWT) and WetterLagenKlassifikation (WLK) Catalogues developed within COST733 framework. Daily air circulation types are divided into 18 groups according to the GWT Catalogue and in 40 groups according to the WLK Catalogue and for each type winter (DJF) and summer (JJA) occurrence frequency were calculated. To this end the Pearson correlation coefficient between climate variables and circulation type's frequency were computed. The results reveals that in wintertime the GWT circulation types captures better than WLK circulation types the T2m variability in time that for summer the WLK circulation types captures better than GWT circulation types. This is due to the seasonal variability of the horizontal extension of air masses. We found that the T2m is positive correlated to anticyclonic circulation types and negative correlated with cyclonic types and the PP is correlated to the cyclonic circulation and negative correlated to anticyclonic ones. Additionally, the trend significance of the climate variables as well as air circulation types have been analysed with the non-parametric Mann-Kendall test. The changes of the trends were detected by employing the non-parametric Pettit test. From the trend analysis we can state that some of the anticyclonic circulation types presents upward tendency and some of the cyclonic circulation presents downward tendency. This is an important results because explain the upward trend of the T2m and the downward trend of the PP.

  1. Liquid Fluoride Salt Experimentation Using a Small Natural Circulation Cell

    Energy Technology Data Exchange (ETDEWEB)

    Yoder Jr, Graydon L [ORNL; Heatherly, Dennis Wayne [ORNL; Williams, David F [ORNL; Elkassabgi, Yousri M. [Texas A& M University, Kingsville; Caja, Joseph [Electrochemical Systems, Inc.; Caja, Mario [ORNL; Jordan, John [Texas A& M University, Kingsville; Salinas, Roberto [Texas A& M University, Kingsville

    2014-04-01

    A small molten fluoride salt experiment has been constructed and tested to develop experimental techniques for application in liquid fluoride salt systems. There were five major objectives in developing this test apparatus: Allow visual observation of the salt during testing (how can lighting be introduced, how can pictures be taken, what can be seen) Determine if IR photography can be used to examine components submerged in the salt Determine if the experimental configuration provides salt velocity sufficient for collection of corrosion data for future experimentation Determine if a laser Doppler velocimeter can be used to quantify salt velocities. Acquire natural circulation heat transfer data in fluoride salt at temperatures up to 700oC All of these objectives were successfully achieved during testing with the exception of the fourth: acquiring velocity data using the laser Doppler velocimeter. This paper describes the experiment and experimental techniques used, and presents data taken during natural circulation testing.

  2. Data Collection and Cost Modeling for Library Circulation Systems.

    Science.gov (United States)

    Bourne, Charles P.

    The objectives of the study leading to this report were to review, analyze and summarize published library cost data; and to develop a cost model and a methodology for reporting data in a more consistent and useful way. The cost model and reporting procedure were developed and tested on the circulation system of three libraries: a large university…

  3. Using Time-Series Regression to Predict Academic Library Circulations.

    Science.gov (United States)

    Brooks, Terrence A.

    1984-01-01

    Four methods were used to forecast monthly circulation totals in 15 midwestern academic libraries: dummy time-series regression, lagged time-series regression, simple average (straight-line forecasting), monthly average (naive forecasting). In tests of forecasting accuracy, dummy regression method and monthly mean method exhibited smallest average…

  4. Journalism as Cultures of Circulation

    DEFF Research Database (Denmark)

    Bødker, Henrik

    2013-01-01

    The universe of journalism has always consisted of interspersed texts, meanings and practices. Yet, much journalism research has often isolated either texts and/or contexts and as such assumed relations between professional practices, informed (rational) readers and (conceived) core texts...... of journalism. It is, however, more important than ever to shift attention away from texts to the processes through which they are circulated. This is partly because the many cultural forms of journalism (textual, institutional, technological, material, behavioural and imagined) are undergoing significant......, likes, comments, searches, journalist roles, writing and reading positions and identities etc. Such forms will be traced within the mediation of a specific event with the overall aim of beginning a theorization of the landscape of journalism as highly interrelated cultures of circulation....

  5. Radioisotopic evaluation of portal circulation

    International Nuclear Information System (INIS)

    The use of a radio-tracer of portal circulation through the intestine, should prevent cruel punctures in the portal-vein or spleen as it is usually the case with traditional methods in the study of portal-system. The absorption of I-131 and Tc-99m, previously cheked in rabbits presented similar results in dogs. The time of circulation between terminal large-intestine and the liver (t-RF) was determined by external counting at hepatic level by recording radioactivity variation-time. In healthy animals the t-RF was from 20to 60 seconds, with average time of 42 seconds. In 2 animals with partial binding of portal-vein the t-RF went up to 110 and 120 seconds. (Author)

  6. Ocean circulation generated magnetic signals

    DEFF Research Database (Denmark)

    Manoj, C.; Kuvshinov, A.; Maus, S.;

    2006-01-01

    Conducting ocean water, as it flows through the Earth's magnetic field, generates secondary electric and magnetic fields. An assessment of the ocean-generated magnetic fields and their detectability may be of importance for geomagnetism and oceanography. Motivated by the clear identification of...... ocean tidal signatures in the CHAMP magnetic field data we estimate the ocean magnetic signals of steady flow using a global 3-D EM numerical solution. The required velocity data are from the ECCO ocean circulation experiment and alternatively from the OCCAM model for higher resolution. We assume an...... magnetic field, as compared to the ECCO simulation. Besides the expected signatures of the global circulation patterns, we find significant seasonal variability of ocean magnetic signals in the Indian and Western Pacific Oceans. Compared to seasonal variation, interannual variations produce weaker signals....

  7. The Sun's Shallow Meridional Circulation

    CERN Document Server

    Hathaway, David H

    2011-01-01

    The Sun's global meridional circulation is evident as a slow poleward flow at its surface. This flow is observed to carry magnetic elements poleward - producing the Sun's polar magnetic fields as a key part of the 11-year sunspot cycle. Current theories for the sunspot cycle assume that this surface flow is part of a circulation which sinks inward at the poles and turns equatorward at depths below 100 Mm. Here we use the advection of the Sun's convection cells by the meridional flow to map the flow velocity in latitude and depth. Our measurements show the largest cells clearly moving equatorward at depths below 35 Mm - the base of the Sun's surface shear layer. This surprisingly shallow return flow indicates the need for substantial revisions to solar/stellar dynamo theory.

  8. Natural circulation systems: advantages and challenges

    International Nuclear Information System (INIS)

    This lecture briefly explains the principle of working of a natural circulation system, its various advantages and applications in nuclear and other industries. The major challenges to be overcome before the wide acceptance of natural circulation as the normal mode of coolant circulation in nuclear power reactors are briefly described. Classification of NCSs and the terminologies commonly encountered in natural circulation literature are also briefly explained. (author)

  9. The general circulation of the atmosphere

    OpenAIRE

    Schneider, Tapio

    2006-01-01

    Theories of how Earth's surface climate may change in the future, of how it may have been in the past, and of how it is related to climates of other planets must build upon a theory of the general circulation of the atmosphere. The view of the atmospheric general circulation presented here focuses not on Earth's general circulation as such but on a continuum of idealized circulations with axisymmetric flow statistics. Analyses of observational data for Earth's atmosphere, simulations with ide...

  10. Conservation of circulation in magnetohydrodynamics

    Science.gov (United States)

    Bekenstein; Oron

    2000-10-01

    We demonstrate at both the Newtonian and (general) relativistic levels the existence of a generalization of Kelvin's circulation theorem (for pure fluids) that is applicable to perfect magnetohydrodynamics. The argument is based on the least action principle for magnetohydrodynamic flow. Examples of the new conservation law are furnished. The new theorem should be helpful in identifying new kinds of vortex phenomena distinct from magnetic ropes or fluid vortices. PMID:11089118

  11. Electronic circulation of accounting documents

    OpenAIRE

    Kremláčková, Kateřina

    2014-01-01

    This thesis describes a circulation of accounting documents in an accounting entity, deals with legal requirements of the entire process and discusses it as a part of an internal control system of the entity. In connection with the theme of the work there are also defined legislative conditions for using information and communication technologies and introduced possibilities of involving these technologies in the process of processing of the accounting documents. Above all the electronic data...

  12. Purchase, circulation and fuel taxation

    OpenAIRE

    Potter, Stephen

    2008-01-01

    During the last decade, the UK and many other developed nations have reformed existing forms of road transport taxation to address a number of transport policy goals. This has involved modifying the design of purchase, circulation and fuel taxation to promote: • More fuel efficient vehicles • Alternative fuel vehicles • Cleaner fuels (lower emissions and/or low carbon) • Modal shift and traffic volume • Congestion reduction This chapter particularly explores the use of...

  13. Measurement of cerebral circulation time in man

    International Nuclear Information System (INIS)

    A simple, inexpensive method for measuring the cerebral circulation time (CCT) was developed. The CCT was considered to be equal to the time that an intravenously injected bolus of sodium pertechnetate Tc 99m took to go from the subclavian artery to the posterior venous confluence. The dilution curves were externally recorded at these two vessels. Particular attenion was given to the curve treatment. The computer programmes were specially conceived in order to detect and, if possible, correct the experimental curve defects. Several reliability criteria were also defined in order to test the validity of each measurement. From a physiological point of view, the CCT is equal to the ratio of the global cerebral blood volume to the global cerebral blood flow. Thus, it can be widely applied in clinical research. For example, in a study of the relationship between CCT and age, sex and light cerebrovascular impairment, the technique was sensitive enough to discriminate between healthy subjects and patients suffering from-transient ischemic attack, or regressive stroke, and to show the action of a drug on the cerebral circulation in such patients. (orig.)

  14. Nanocrystalline gadolinium iron garnet for circulator applications

    International Nuclear Information System (INIS)

    Due to high resistivity and low microwave losses, gadolinium iron garnets (GdIG) are useful materials for non-reciprocal devices such as circulators or isolators. Keeping the miniaturization and cost reduction in mind, the trend is to modify the conventional methods of preparation of samples. In this connection we have synthesized nanocystalline GdIG by using the Microwave Hydrothermal method at 160 °C/45 min. As synthesized powders were characterized by using X-ray diffraction (XRD), transmission electron microscopy and Fourier Transform Infrared Spectroscopy. XRD patterns show the formation of a garnet phase with crystallite size varying between 19 nm and 40 nm. Differential Thermal Analysis studies were also carried out on the nanopowders. The powders were densified at a lower sintering temperature of 1100 °C/45 min using a microwave sintering method. The sintered samples were characterized by XRD and atomic force microscopy. The frequency dependence of complex permittivity and ferromagnetic resonance were measured in the Ka band frequency (27–40 GHz). Magnetic properties were also measured at room temperature. - Highlights: ► GdIG ferrites were synthesized using the microwave hydrothermal method. ► Densification of the GdIG samples was done at a low temperature of 1100 °C/45 min. ► Our samples possess low dielectric constant and loss at a Ka band frequency. ► Nanocrystalline GdIG samples for circulator application have been tested.

  15. TESTING OF JET PUMPS INSTALLED ON THE RECIRCULATING LINE OF CIRCULATION AXIAL FLOW PUMPS OF NOVOCHERKASSK HYDROELECTRIC POWER STATION Испытания струйных насосов, установленных на линии рециркуляции циркуляционных осевых насосов Новочеркасской ГРЭС

    Directory of Open Access Journals (Sweden)

    Ananyev S. S.

    2012-05-01

    Full Text Available The testing of jet pumps, installed on the recirculation line of circulation axial pumps are dealt with in this article. A number of experiments with nozzles of different diameter and installation sites have been conducted to increase the suction head of circulation pumps. The main conclusions have been done after testing

  16. 21 CFR 866.6020 - Immunomagnetic circulating cancer cell selection and enumeration system.

    Science.gov (United States)

    2010-04-01

    ... cancer cells in a prepared sample of whole blood. This device is intended for adjunctive use in... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Immunomagnetic circulating cancer cell selection... Associated Antigen immunological Test Systems § 866.6020 Immunomagnetic circulating cancer cell selection...

  17. The Clinical Utilization of Circulating Cell Free DNA (CCFDNA in Blood of Cancer Patients

    Directory of Open Access Journals (Sweden)

    Yanyuan Wu

    2013-09-01

    Full Text Available Qualitative and quantitative testing of circulating cell free DNA (CCFDNA can be applied for the management of malignant and benign neoplasms. Detecting circulating DNA in cancer patients may help develop a DNA profile for early stage diagnosis in malignancies. The technical issues of obtaining, using, and analyzing CCFDNA from blood will be discussed.

  18. Ischemic Posterior Circulation Stroke: A Review of Anatomy, Clinical Presentations, Diagnosis and Current Management

    Directory of Open Access Journals (Sweden)

    Amre eNouh

    2014-04-01

    Full Text Available Posterior circulation (PC strokes represent approximately 20% of all ischemic strokes. In contrast to the anterior circulation (AC several differences in presenting symptoms, clinical evaluation, diagnostic testing and management strategy exist which may present a challenge to the treating physician. This review will discuss the anatomical, etiological and clinical classification of PC strokes, identify diagnostic pitfalls and overview current therapeutic regimens.

  19. Cryomodule tests of tesla-like superconducting cavities in S1-Global

    International Nuclear Information System (INIS)

    S1-Global project for ILC is an international collaboration for cryomodule tests including eight 9-cell superconducting cavities delivered from DESY, FNAL and KEK. One of two 6-m cryomodules, Cryomodule-A, contains four Tesla-like cavities equipped with a slide-jack tuner system and an STF-II input coupler. Construction of the S1-Global cryomodule was started in January, 2010, and the cryomodule was installed in the STF tunnel in May. Low power rf tests of the Tesla-like cavities in the first cool-down of the cryomodule were successfully carried out in June-July, 2010. (author)

  20. Model for large scale circulation of nuclides in nature, 1

    Energy Technology Data Exchange (ETDEWEB)

    Ohnishi, Teruaki

    1988-12-01

    A model for large scale circulation of nuclides was developed, and a computer code named COCAIN was made which simulates this circulation system-dynamically. The natural environment considered in the present paper consists of 2 atmospheres, 8 geospheres and 2 lithospheres. The biosphere is composed of 4 types of edible plants, 5 cattles and their products, 4 water biota and 16 human organs. The biosphere is assumed to be given nuclides from the natural environment mentioned above. With the use of COCAIN, two numerical case studies were carried out; the one is the study on nuclear pollution in nature by the radioactive nuclides originating from the past nuclear bomb tests, and the other is the study on the response of environment and biota to the pulse injection of nuclides into one compartment. From the former case study it was verified that this model can well explain the observation and properly simulate the large scale circulation of nuclides in nature.

  1. In vivo acoustic and photoacoustic focusing of circulating cells

    Science.gov (United States)

    Galanzha, Ekaterina I.; Viegas, Mark G.; Malinsky, Taras I.; Melerzanov, Alexander V.; Juratli, Mazen A.; Sarimollaoglu, Mustafa; Nedosekin, Dmitry A.; Zharov, Vladimir P.

    2016-03-01

    In vivo flow cytometry using vessels as natural tubes with native cell flows has revolutionized the study of rare circulating tumor cells in a complex blood background. However, the presence of many blood cells in the detection volume makes it difficult to count each cell in this volume. We introduce method for manipulation of circulating cells in vivo with the use of gradient acoustic forces induced by ultrasound and photoacoustic waves. In a murine model, we demonstrated cell trapping, redirecting and focusing in blood and lymph flow into a tight stream, noninvasive wall-free transportation of blood, and the potential for photoacoustic detection of sickle cells without labeling and of leukocytes targeted by functionalized nanoparticles. Integration of cell focusing with intravital imaging methods may provide a versatile biological tool for single-cell analysis in circulation, with a focus on in vivo needleless blood tests, and preclinical studies of human diseases in animal models.

  2. Model for large scale circulation of nuclides in nature, 1

    International Nuclear Information System (INIS)

    A model for large scale circulation of nuclides was developed, and a computer code named COCAIN was made which simulates this circulation system-dynamically. The natural environment considered in the present paper consists of 2 atmospheres, 8 geospheres and 2 lithospheres. The biosphere is composed of 4 types of edible plants, 5 cattles and their products, 4 water biota and 16 human organs. The biosphere is assumed to be given nuclides from the natural environment mentioned above. With the use of COCAIN, two numerical case studies were carried out; the one is the study on nuclear pollution in nature by the radioactive nuclides originating from the past nuclear bomb tests, and the other is the study on the response of environment and biota to the pulse injection of nuclides into one compartment. From the former case study it was verified that this model can well explain the observation and properly simulate the large scale circulation of nuclides in nature. (author)

  3. In vivo acoustic and photoacoustic focusing of circulating cells

    Science.gov (United States)

    Galanzha, Ekaterina I.; Viegas, Mark G.; Malinsky, Taras I.; Melerzanov, Alexander V.; Juratli, Mazen A.; Sarimollaoglu, Mustafa; Nedosekin, Dmitry A.; Zharov, Vladimir P.

    2016-01-01

    In vivo flow cytometry using vessels as natural tubes with native cell flows has revolutionized the study of rare circulating tumor cells in a complex blood background. However, the presence of many blood cells in the detection volume makes it difficult to count each cell in this volume. We introduce method for manipulation of circulating cells in vivo with the use of gradient acoustic forces induced by ultrasound and photoacoustic waves. In a murine model, we demonstrated cell trapping, redirecting and focusing in blood and lymph flow into a tight stream, noninvasive wall-free transportation of blood, and the potential for photoacoustic detection of sickle cells without labeling and of leukocytes targeted by functionalized nanoparticles. Integration of cell focusing with intravital imaging methods may provide a versatile biological tool for single-cell analysis in circulation, with a focus on in vivo needleless blood tests, and preclinical studies of human diseases in animal models. PMID:26979811

  4. Ensemble meteorological reconstruction using circulation analogues of 1781–1785

    Directory of Open Access Journals (Sweden)

    P. Yiou

    2013-09-01

    Full Text Available This paper uses a method of atmospheric flow analogues to reconstruct an ensemble of atmospheric variables (namely sea-level pressure, surface temperature and wind speed between 1781 and 1785. The properties of this ensemble are investigated and tested against observations of temperature. The goal of the paper is to assess whether the atmospheric circulation during the Laki volcanic eruption (in 1783 and the subsequent winter were similar to the conditions that prevailed in the winter 2009/2010 and during spring 2010. We find that the three months following the Laki eruption in June 1783 barely have analogues in 2010. The cold winter of 1783/1784 yields circulation analogues in 2009/2010. Our analysis suggests that it is unlikely that the Laki eruption was responsible for the cold winter of 1783/1784, of the relatively short memory of the atmospheric circulation.

  5. Self-biased circulators for high power applications

    Science.gov (United States)

    Sokolov, Alexander S.

    Self-biased circulators exploit the properties of high anisotropy magnetic field in hexagonal ferrites, thus allowing operation without biasing magnets and a significant size and weight reduction. Although first self-biased circulators were demonstrated more than 20 years ago, all the prototypes constructed so far are unsuitable for practical applications. An attempt to design a self-biased circulator from scratch was made. Novel exceptionally low dielectric loss and high heat conductivity ceramic materials were developed and innovative substrate synthesis techniques were employed. Low temperature cofiring of green body ferrite compacts and dielectric ceramic slurries were mastered, resulting in solid composite substrates. Original device design was developed. Key features (including wide coupling angles, wide microstriplines, thick substrate, and absence of impedance transformers) enable low insertion loss, broadband operation, high power handling, and compact size. Fabrication and testing of Ka band Y-junction self-biased circulator are reported herein. Furthermore, design approach and fabrication techniques developed here can be readily applied for the construction of X-band self-biased circulators, provided that suitable ferrite materials are available. Low temperature cofiring of ferrite and dielectric materials is especially beneficial for various RF and high-frequency applications. Multiple devices can be readily fabricated on a single wafer using conventional lithographic techniques, resulting in true microwave monolithic integrated circuit.

  6. Experimental study of two-phase natural circulation circuit

    International Nuclear Information System (INIS)

    This paper reports an experimental study on the behavior of fluid flow in natural circulation under single-and two-phase flow conditions. The natural circulation circuit was designed based on concepts of similarity and scale in proportion to the actual operating conditions of a nuclear reactor. This test equipment has similar performance to the passive system for removal of residual heat presents in Advanced Pressurized Water Reactors (A PWR). The experiment was carried out by supplying water to primary and secondary circuits, as well as electrical power resistors installed inside the heater. Power controller has available to adjust the values for supply of electrical power resistors, in order to simulate conditions of decay of power from the nuclear reactor in steady state. Data acquisition system allows the measurement and control of the temperature at different points by means of thermocouples installed at several points along the circuit. The behavior of the phenomenon of natural circulation was monitored by a software with graphical interface, showing the evolution of temperature measurement points and the results stored in digital format spreadsheets. Besides, the natural circulation flow rate was measured by a flowmeter installed on the hot leg. A flow visualization technique was used the for identifying vertical flow regimes of two-phase natural circulation. Finally, the Reynolds Number was calculated for the establishment of a friction factor correlation dependent on the scale geometrical length, height and diameter of the pipe. (author)

  7. Multiple model identification of a cold flow circulating fluidized bed

    Energy Technology Data Exchange (ETDEWEB)

    Panday, Rupen; Famouri, P.; Woerner, B.D.; Turton, R.; •Ludlow, J.C.; Shadle, L.J.; Boyle, E.J.

    2008-05-13

    Solids circulation rate is an important parameter that is essential to the control and improved performance of a circulating fluidized bed system. The present work focuses on the identification of a cold flow circulating fluidized bed using a multiple model identification technique that considers the given set-up as a nonlinear dynamic system and predicts the solids circulation rate as a function of riser aeration, move air flow rate, and total riser pressure drop. The predictor model obtained from this technique is trained on glass beads data sets in which riser aeration and move air flow are varied randomly one at a time. The global linear state space model obtained from the N4SID algorithm is trained on the same data set and the prediction results of solids circulation rate from both these algorithms are tested against data obtained at operating conditions different from the training data. The comparison between the two methods shows that the prediction results obtained from the multiple model technique are better than those obtained from the global linear model. The number of local models is increased from two to five and two third order state space models are sufficient for the present sets of data.

  8. Circulating follistatin in relation to energy metabolism.

    Science.gov (United States)

    Hansen, Jakob Schiøler; Plomgaard, Peter

    2016-09-15

    Recently, substantial evidence has emerged that the liver contributes significantly to the circulating levels of follistatin and that circulating follistatin is tightly regulated by the glucagon-to-insulin ratio. Both observations are based on investigations of healthy subjects. These novel findings challenge the present view of circulating follistatin in human physiology, being that circulating follistatin is a result of spill-over from para/autocrine actions in various tissues and cells. Follistatin as a liver-derived protein under the regulation of glucagon-to-insulin ratio suggests a relation to energy metabolism. In this narrative review, we attempt to reconcile the existing findings on circulating follistatin with the novel concept that circulating follistatin is a liver-derived molecule regulated by the glucagon-to-insulin ratio. The picture emerging is that conditions associated with elevated levels of circulating follistatin have a metabolic denominator with decreased insulin sensitivity and/or hyperglucagoneimia. PMID:27264073

  9. A small centrifugal pump for circulating cryogenic helium

    International Nuclear Information System (INIS)

    A small centrifugal pump is described which has been developed to circulate supercritical helium through a test loop for superconducting magnets. The pump has a fully enclosed warm and which contains the adjustable speed brushless DC drive motor and self-acting bearings operating in helium gas. The drive and bearing system is designed to minimize contaimination to the circulating supercritical helium in the test loop. The performance data which have been obtained show that the pump operates very close to its design specifications. Additional tests are planned to provide a more complete range of performance data for the pump. Subsequent record discussion concerned the pump shaft and the efficiency of the heat leak to the heat station. Efficiency of at least 65% is attainable with this pump, including all heat leak

  10. Intestinal circulation during inhalation anesthesia

    International Nuclear Information System (INIS)

    This study was designed to evaluate the influence of inhalational agents on the intestinal circulation in an isolated loop preparation. Sixty dogs were studied, using three intestinal segments from each dog. Selected intestinal segments were pumped with aortic blood at a constant pressure of 100 mmHg. A mixture of 86Rb and 9-microns spheres labeled with 141Ce was injected into the arterial cannula supplying the intestinal loop, while mesenteric venous blood was collected for activity counting. A very strong and significant correlation was found between rubidium clearance and microsphere entrapment (r = 0.97, P less than 0.0001). Nitrous oxide anesthesia was accompanied by a higher vascular resistance (VR), lower flow (F), rubidium clearance (Cl-Rb), and microspheres entrapment (Cl-Sph) than pentobarbital anesthesia, indicating that the vascular bed in the intestinal segment was constricted and flow (total and nutritive) decreased. Halothane, enflurane, and isoflurane anesthesia were accompanied by a much lower arteriovenous oxygen content difference (AVDO2) and oxygen uptake than pentobarbital or nitrous oxide. Compared with pentobarbital, enflurane anesthesia was not accompanied by marked differences in VR, F, Cl-Rb, and Cl-Sph; halothane at 2 MAC decreased VR and increased F and Cl-Rb while isoflurane increased VR and decreased F. alpha-Adrenoceptor blockade with phentolamine (1 mg . kg-1) abolished isoflurane-induced vasoconstriction, suggesting that the increase in VR was mediated via circulating catecholamines

  11. Visual and optical evaluation of bank notes in circulation

    Science.gov (United States)

    Church, Sara; Lacelle, Martine; Garanzotis, Theodoros

    2006-02-01

    A method for comparing quality of bank notes in circulation based on both a subjective visual sorting technique and on quantitative wear evaluations is described and applied to circulated Canadian bank notes. The sample notes, which were part of a $5 circulation trial, issued over a 4 to 6 week period, had been in circulation for roughly 6 months. Notes were first sorted visually into four defined substrate categories (No Edge Wear, Corner Folds, Minimal Edge Wear and Edge Wear) and four surface wear categories (None, Low, Medium and High). Samples of each category were tested at Crane and Co. using a range of physical and optical techniques: air resistance, air permeability, stiffness deflection, double folds, gray scale, brightness, perimeter length, and top/bottom mean and maximum deviations. The visual sort showed that neither soiling nor ink loss are the major wear problems for bank notes in Canada. However, the substrate does become tattered and worn. The mechanical and optical wear tests show that most of the parameters change logically as the soil level increases. The changes for other parameters are less clear as a function of wear categories, but are relatively consistent in distinguishing between the No Edge Wear and Edge Wear. Impact of wear on the effectiveness of security features will also be described.

  12. The value of peripheral blood circulating tumor cells in KRAS mutation testing of colorectal cancer patients%外周血循环肿瘤细胞在评估结直肠癌患者KRAS基因突变中的价值

    Institute of Scientific and Technical Information of China (English)

    刘彦魁; 王晓莉; 金琳芳; 齐晓薇

    2015-01-01

    Objective To explore the value of peripheral blood samples in KRAS mutation testing of colorectal cancer patients and the correlation between the number of circulating tumor cells and KRAS mutation testing.Methods We detected KRAS mutation using amplification refractory mutation system PCR method in paraffin embedded tissues and matched peripheral blood samples obtained from 112 colorectal cancer patients and 10 proctitic peripheral blood samples in Affiliated Hospital of Jiangnan University between 2013 and 2014.Meanwhile,immunofluorescence in situ hybridization method was used to count the circulating tumor cells in peripheral blood samples and proctitic control samples.Results Among the 112 colorectal cancer samples tested,25 cases of peripheral blood samples found KRAS mutation (41.1%) and which was 46 in formalin fixed paraffin embedded tissues testing (22.3 %),with a significant difference (x2 =40.12,P < 0.001).One case with KRAS wild type in formalin fixed paraffin embedded tissues was mutation type in peripheral samples.In another case,mutation site was different in different kinds of samples.The sensibility of KRAS mutation testing was 73.3%,41.9% and 16.7% when the number of circulating tumor cells was more than 15,5 to 15,and 1 to 5,respectively,with significant differences (x2 =23.70,P < 0.001).No KRAS mutation and no circulating tumor cells were found in 10 proctitic control samples.Conclusion We find high specificity in KRAS mutation testing of peripheral blood samples.but the accurate rate is not satisfying.KRAS mutation testing in peripheral blood samples may be an optional choice to test KRAS mutations for colorectal cancer patients who were not subjected to surgery.The sensibility of KRAS mutation testing in peripheral blood samples has a corretion with the number of circulating tumor cells.%目的 探索外周血标本在结直肠癌患者KRAS基因突变检测中的价值以及循环肿瘤细胞个数与KRAS基因

  13. A blood circulation model for reference man

    Energy Technology Data Exchange (ETDEWEB)

    Leggett, R.W.; Eckerman, K.F. [Oak Ridge National Lab., TN (United States). Health Sciences Research Div.; Williams, L.R. [Indiana Univ., South Bend, IN (United States). Div. of Liberal Arts and Sciences

    1999-01-01

    This paper describes a dynamic blood circulation model that predicts the movement and gradual dispersal of a bolus of material in the circulation after its intravascular injection into an adult human. The main purpose of the model is to improve the dosimetry of internally deposited radionuclides that decay in the circulation to a significant extent. The total blood volume is partitioned into the blood contents of 24 separate organs or tissues, right heart chambers, left heart chambers, pulmonary circulation, arterial outflow to the systemic tissues (aorta and large arteries), and venous return from the systemic tissues (large veins). As a compromise between physical reality and computational simplicity, the circulation of blood is viewed as a system of first-order transfers between blood pools, with the delay time depending on the mean transit time across the pool. The model allows consideration of incomplete, tissue-dependent extraction of material during passage through the circulation and return of material from tissues to plasma.

  14. Circulation of Venus upper mesosphere.

    Science.gov (United States)

    Zasova, Ludmila; Gorinov, Dmitry; Shakun, Alexey; Altieri, Francesca; Migliorini, Alessandra; Piccioni, Giuseppe; Drossart, Pierre

    2014-05-01

    Observation of the O2 1.27 μm airglow intensity distribution on the night side of Venus is one of the methods of study of the circulation in upper mesosphere 90-100 km. VIRTIS-M on board Venus Express made these observations in nadir and limb modes in Southern and Northern hemispheres respectively. Global map of the O2 night glow is published (Piccioni et al. 2009). In this work we use for analysis only data, obtained with exposure > 3 s to avoid high noisy data. It was found that intensity of emission decreases to poles and to terminators (similar to Piccioni et al.2009) in both hemispheres, which gives evidence for existence of SS-AS circulation with transport of the air masses through poles and terminators with ascending/descending flows at SS/AS areas. However, asymmetry of distribution of intensity of airglow is observed in both hemispheres. Global map for southern hemisphere (from nadir data) has good statistics at φ > 10-20° S and pretty poor at low latitude. Maximum emission is shifted from midnight by 1 - 2 hours to the evening (22-23h) and deep minimum of emission is found at LT=2-4 h at φ > 20° S. This asymmetry is extended up to equatorial region, however statistic is poor there. No evident indication for existence of the Retrograde Zonal Superrotation (RZS) is found: maximum emission in this case, which is resulting from downwards flow, should be shifted to the morning. The thermal tides, gravity waves are evidently influence on the night airglow distribution. VIRTIS limb observations cover the low northern latitudes and they are more sparse at higher latitudes. Intensity of airglow at φ = 0 - 20° N shows wide maximum, which is shifted by 1- 2 h from midnight to morning terminator. This obviously indicates that observed O2 night glow distribution in low North latitudes is explained by a superposition of SS-AS flow and RZS circulation at 95-100 km. This behavior is similar to the NO intensity distribution, obtained by SPICAV.

  15. A reliable method to concentrate circulating DNA.

    Science.gov (United States)

    Bryzgunova, Olga; Bondar, Anna; Morozkin, Evgeniy; Mileyko, Vladislav; Vlassov, Valentin; Laktionov, Pavel

    2011-01-15

    Concentration of circulating DNA probes is required to increase the amount of DNA involved in subsequent study (by polymerase chain reaction, sequencing, and microarray). This work was dedicated to the comparison of five different methods used for concentration of DNA circulating in blood. Precipitation of circulating DNA with acetone in the presence of triethylamine provides minimal DNA loss, high reproducibility, and at least three times higher DNA yield in comparison with the standard ethanol protocol. PMID:20828533

  16. Space-Time Radar Waveforms: Circulating Codes

    OpenAIRE

    Babur, G.; Aubry, P.; Le Chevalier, F.

    2013-01-01

    This paper describes a concept of the circulating codes covering the whole class of the space-time codes. The circulating codes do not narrow the radiated pattern of the antenna array, thus providing a wide angular coverage, possibly tunable. In turn, the beam-forming on transmit is achievable by means of the signal processing in one (or each) receiver channel. The modelling results demonstrate the efficiency of the circulating codes based on their multidimensional ambiguity functions.

  17. Linear thermal circulator based on Coriolis forces.

    Science.gov (United States)

    Li, Huanan; Kottos, Tsampikos

    2015-02-01

    We show that the presence of a Coriolis force in a rotating linear lattice imposes a nonreciprocal propagation of the phononic heat carriers. Using this effect we propose the concept of Coriolis linear thermal circulator which can control the circulation of a heat current. A simple model of three coupled harmonic masses on a rotating platform permits us to demonstrate giant circulating rectification effects for moderate values of the angular velocities of the platform. PMID:25768443

  18. The Ten Relationships in Rural Land Circulation

    OpenAIRE

    Cai, Zhirong; Ren, Shuo; Zhang, Zhigang

    2009-01-01

    The ten relationships during land circulation are discussed. Among them, the relationship between peasant household and government indicates that government should only carry out its service and regulatory functions and farmers should be the main body of land circulation, because peasants usually have no discourse power during land circulation. In the relationship between land ownership and contracting management right, we mainly discuss the transfer of land contracting management right and p...

  19. Main circulator design features for HTR 100, HTR 500 and space heating plants

    International Nuclear Information System (INIS)

    design is underway. This circulator will be tested in a test stand designed for test runs of all different circulator sizes. (author). 8 figs

  20. Role of Circulating Fibrocytes in Cardiac Fibrosis

    Science.gov (United States)

    Lin, Rong-Jie; Su, Zi-Zhuo; Liang, Shu-Min; Chen, Yu-Yang; Shu, Xiao-Rong; Nie, Ru-Qiong; Wang, Jing-Feng; Xie, Shuang-Lun

    2016-01-01

    Objective: It is revealed that circulating fibrocytes are elevated in patients/animals with cardiac fibrosis, and this review aims to provide an introduction to circulating fibrocytes and their role in cardiac fibrosis. Data Sources: This review is based on the data from 1994 to present obtained from PubMed. The search terms were “circulating fibrocytes” and “cardiac fibrosis”. Study Selection: Articles and critical reviews, which are related to circulating fibrocytes and cardiac fibrosis, were selected. Results: Circulating fibrocytes, which are derived from hematopoietic stem cells, represent a subset of peripheral blood mononuclear cells exhibiting mixed morphological and molecular characteristics of hematopoietic and mesenchymal cells (CD34+/CD45+/collagen I+). They can produce extracellular matrix and many cytokines. It is shown that circulating fibrocytes participate in many fibrotic diseases, including cardiac fibrosis. Evidence accumulated in recent years shows that aging individuals and patients with hypertension, heart failure, coronary heart disease, and atrial fibrillation have more circulating fibrocytes in peripheral blood and/or heart tissue, and this elevation of circulating fibrocytes is correlated with the degree of fibrosis in the hearts. Conclusions: Circulating fibrocytes are effector cells in cardiac fibrosis. PMID:26831236

  1. Improvement of Classification of Enterprise Circulating Funds

    Directory of Open Access Journals (Sweden)

    Rohanova Hanna O.

    2014-02-01

    Full Text Available The goal of the article lies in revelation of possibilities of increase of efficiency of managing enterprise circulating funds by means of improvement of their classification features. Having analysed approaches of many economists to classification of enterprise circulating funds, systemised and supplementing them, the article offers grouping classification features of enterprise circulating funds. In the result of the study the article offers an expanded classification of circulating funds, which clearly shows the role of circulating funds in managing enterprise finance and economy in general. The article supplements and groups classification features of enterprise circulating funds by: the organisation level, functioning character, sources of formation and their cost, and level of management efficiency. The article shows that the provided grouping of classification features of circulating funds allows exerting all-sided and purposeful influence upon indicators of efficiency of circulating funds functioning and facilitates their rational management in general. The prospect of further studies in this direction is identification of the level of attraction of loan resources by production enterprises for financing circulating funds.

  2. A blood circulation model for reference man

    International Nuclear Information System (INIS)

    A dynamic blood circulation model that predicts the movement and gradual dispersion of a bolus of material in the circulation after its intravenous injection into an adult human. The main purpose of the model is improve the dosimetry of internally deposited radionuclides that decay in the circulation to a significant extent. The model partitions the blood volume into 24 separate organs or tissues, right heart chamber, left heart chamber, pulmonary circulation, arterial outflow to the aorta and large arteries, and venous return via the large veins. Model results were compared to data obtained from injection of carbon 11 labeled carbon monoxide or rubidium 86

  3. Modeling biomass gasification in circulating fluidized beds

    Science.gov (United States)

    Miao, Qi

    In this thesis, the modeling of biomass gasification in circulating fluidized beds was studied. The hydrodynamics of a circulating fluidized bed operating on biomass particles were first investigated, both experimentally and numerically. Then a comprehensive mathematical model was presented to predict the overall performance of a 1.2 MWe biomass gasification and power generation plant. A sensitivity analysis was conducted to test its response to several gasifier operating conditions. The model was validated using the experimental results obtained from the plant and two other circulating fluidized bed biomass gasifiers (CFBBGs). Finally, an ASPEN PLUS simulation model of biomass gasification was presented based on minimization of the Gibbs free energy of the reaction system at chemical equilibrium. Hydrodynamics plays a crucial role in defining the performance of gas-solid circulating fluidized beds (CFBs). A 2-dimensional mathematical model was developed considering the hydrodynamic behavior of CFB gasifiers. In the modeling, the CFB riser was divided into two regions: a dense region at the bottom and a dilute region at the top of the riser. Kunii and Levenspiel (1991)'s model was adopted to express the vertical solids distribution with some other assumptions. Radial distributions of bed voidage were taken into account in the upper zone by using Zhang et al. (1991)'s correlation. For model validation purposes, a cold model CFB was employed, in which sawdust was transported with air as the fluidizing agent. A comprehensive mathematical model was developed to predict the overall performance of a 1.2 MWe biomass gasification and power generation demonstration plant in China. Hydrodynamics as well as chemical reaction kinetics were considered. The fluidized bed riser was divided into two distinct sections: (a) a dense region at the bottom of the bed where biomass undergoes mainly heterogeneous reactions and (b) a dilute region at the top where most of homogeneous

  4. Irregular Labellings of Circulant Graphs

    OpenAIRE

    Anholcer, Marcin

    2011-01-01

    We investigate the \\textit{irregularity strength} ($s(G)$) and \\textit{total vertex irregularity strength} ($tvs(G)$) of circulant graphs $Ci_n(1,2,...,k)$ and prove that $tvs(Ci_n(1,2,...,k))=\\lceil\\frac{n+2k}{2k+1}\\rceil$, while $s(Ci_n(1,2,...,k))=\\lceil\\frac{n+2k-1}{2k}\\rceil$ except the case when $(n \\bmod 4k = 2k+1 \\wedge k\\bmod 2=1) \\vee n=2k+1$ and $s(Ci_n(1,2,...,k))=\\lceil\\frac{n+2k-1}{2k}\\rceil+1$.

  5. Inflammatory response and extracorporeal circulation.

    Science.gov (United States)

    Kraft, Florian; Schmidt, Christoph; Van Aken, Hugo; Zarbock, Alexander

    2015-06-01

    Patients undergoing cardiac surgery with extracorporeal circulation (EC) frequently develop a systemic inflammatory response syndrome. Surgical trauma, ischaemia-reperfusion injury, endotoxaemia and blood contact to nonendothelial circuit compounds promote the activation of coagulation pathways, complement factors and a cellular immune response. This review discusses the multiple pathways leading to endothelial cell activation, neutrophil recruitment and production of reactive oxygen species and nitric oxide. All these factors may induce cellular damage and subsequent organ injury. Multiple organ dysfunction after cardiac surgery with EC is associated with an increased morbidity and mortality. In addition to the pathogenesis of organ dysfunction after EC, this review deals with different therapeutic interventions aiming to alleviate the inflammatory response and consequently multiple organ dysfunction after cardiac surgery. PMID:26060024

  6. Computer simulation of natural circulation in FFTF secondary loops

    International Nuclear Information System (INIS)

    A thermal/hydraulic model of the FFTF secondary heat transport loop has been calibrated against transient natural circulation test data collected March to May 1979. The tests verified that the transition to natural convective flow could be effected from near isothermal conditions without excessive cooling at the air dump heat exchangers. Key empirical parameters of pressure drop and heat loss were found to be at 88% and 81% of pretest estimates, respectively. Pretest piping thermal transport and flow calculational models required no further revision to produce good agreement with test data

  7. Semiquantitative determination of circulating islet cell surface antibodies in diabetes

    International Nuclear Information System (INIS)

    Circulating pancreatic islet cell antibodies have been demonstrated in patients with insulin-dependent diabetes (IDD). The islet cell surface antibodies (ICSA) were determined by an indirect immunofluorescence test using a suspension of viable islet cells, and similar cytoplasmic antibodies which require the use of group O human pancreas were also found in the serum of some patients. A strong association exists between the presence of islet cell antibodies and the onset of insulin-dependent diabetes. The quantitative determination of circulating ICSA using 125I-protein A, which binds to IgG attached to the islet cell surface, was essentially as described by Lernmark et al. In the present study, we determined the circulating ICSA in diabetes, especially in IDD. The ICSA were estimated in various sera from both indirect immunofluorescence and 125I-protein A. Controls bound 125I-protein A. Sera from 4 IDD patients with circulating ICSA demonstrated by immunofluorescence showed >3,000 cpm 125I-protein A binding activity, and that from 5 patients without ICSA bound <2,000 cpm. Sera from newly-diagnosed diabetics who had severe hyperglycemia showed <2,000 cpm, with or without ICSA. (author)

  8. Meridional circulation and the lithium abundance gap in F stars

    International Nuclear Information System (INIS)

    The effect of meridional circulation on the time evolution of superficial abundances of helium, lithium, and beryllium in F stars is calculated in detail. It is shown that, as long as the presence of convection zones is assumed not to modify global meridional circulation patterns, the maximum equatorial rotational velocity allowing the settling of Li and He decreases rapidly with T(eff), going from 50 km/s at 7250 K to only 5 km/s at 6400 K. It is also shown that, for stars of the age of the Hyades with T(eff) less than 7000 K and rotational velocities larger than about 25 km/s, meridional circulation is rapid enough to bring to the surface matter that originally was deep enough to have been depleted of its Li through nuclear burning. Observational tests are suggested to distinguish between this scenario and the gravitational settling model or turbulent diffusion model. It is shown how the Li/Be ratio varies in the presence of transport by meridional circulation. 48 references

  9. Circulating Nonphosphorylated Carboxylated Matrix Gla Protein Predicts Survival in ESRD

    OpenAIRE

    Schlieper, Georg; Westenfeld, Ralf; Krüger, Thilo; Cranenburg, Ellen C.; Magdeleyns, Elke J.; Brandenburg, Vincent M.; Djuric, Zivka; Damjanovic, Tatjana; Ketteler, Markus; Vermeer, Cees; Dimkovic, Nada; Floege, Jürgen; Schurgers, Leon J.

    2011-01-01

    The mechanisms for vascular calcification and its associated cardiovascular mortality in patients with ESRD are not completely understood. Dialysis patients exhibit profound vitamin K deficiency, which may impair carboxylation of the calcification inhibitor matrix gla protein (MGP). Here, we tested whether distinct circulating inactive vitamin K–dependent proteins associate with all-cause or cardiovascular mortality. We observed higher levels of both desphospho-uncarboxylated MGP (dp-ucMGP) a...

  10. Unit group of algebra of circulant matrices

    Directory of Open Access Journals (Sweden)

    Rajendra Sharma

    2013-12-01

    Full Text Available Let Crn(Fp denote the algebra of nXn circulant matrices over Fp, finite field of order p of prime characteristic p. The order of the unit groups U(Cr3(Fp, U(Cr4(Fp and U(Cr5(Fp of algebras of circulant matrices over Fp are characterized.

  11. Introduction to instabilities in natural circulation systems

    International Nuclear Information System (INIS)

    This lecture reviews the various natural circulation instabilities and their classification instabilities observed during various stages of natural circulation such as single-phase, boiling inception and fully developed two-phase flow are described. The mechanisms causing the instabilities are also briefly described. (author)

  12. Kelvin's Canonical Circulation Theorem in Hall Magnetohydrodynamics

    CERN Document Server

    Shivamoggi, B K

    2016-01-01

    The purpose of this paper is to show that, thanks to the restoration of the legitimate connection between the current density and the plasma flow velocity in Hall magnetohydrodynamics (MHD), Kelvin's Circulation Theorem becomes valid in Hall MHD. The ion-flow velocity in the usual circulation integral is now replaced by the canonical ion-flow velocity.

  13. PIE on Safety-Tested AGR-1 Compact 5-1-1

    Energy Technology Data Exchange (ETDEWEB)

    Hunn, John D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Morris, Robert Noel [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Baldwin, Charles A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Montgomery, Fred C. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Gerczak, Tyler J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-08-01

    Post-irradiation examination (PIE) is being performed in support of tristructural isotropic (TRISO) coated particle fuel development and qualification for High-Temperature Gas-cooled Reactors (HTGRs). AGR-1 was the first in a series of TRISO fuel irradiation experiments initiated in 2006 under the Advanced Gas Reactor (AGR) Fuel Development and Qualification Program; this work continues to be funded by the Department of Energy's Office of Nuclear Energy as part of the Advanced Reactor Technologies (ART) initiative. AGR-1 fuel compacts were fabricated at Oak Ridge National Laboratory (ORNL) in 2006 and irradiated for three years in the Idaho National Laboratory (INL) Advanced Test Reactor (ATR) to demonstrate and evaluate fuel performance under HTGR irradiation conditions. PIE is being performed at INL and ORNL to study how the fuel behaved during irradiation, and to examine fuel performance during exposure to elevated temperatures at or above temperatures that could occur during a depressurized conduction cooldown event. This report summarizes safety testing of irradiated AGR-1 Compact 5-1-1 in the ORNL Core Conduction Cooldown Test Facility (CCCTF) and post-safety testing PIE.

  14. A mock circulation model for cardiovascular device evaluation

    International Nuclear Information System (INIS)

    The aim of this study was to develop an integrated mock circulation system that functions in a physiological manner for testing cardiovascular devices under well-controlled circumstances. In contrast to previously reported mock loops, the model includes a systemic, pulmonary, and coronary circulation, an elaborate heart contraction model, and a realistic heart rate control model. The behavior of the presented system was tested in response to changes in left ventricular contractile states, loading conditions, and heart rate. For validation purposes, generated hemodynamic parameters and responses were compared to literature. The model was implemented in a servo-motor driven mock loop, together with a relatively simple lead-lag controller. The pressure and flow signals measured closely mimicked human pressure under both physiological and pathological conditions. In addition, the system's response to changes in preload, afterload, and heart rate indicate a proper implementation of the incorporated feedback mechanisms (frequency and cardiac function control). Therefore, the presented mock circulation allows for generic in vitro testing of cardiovascular devices under well-controlled circumstances. (paper)

  15. Acceptance tests of cryogenic components for SST-1

    International Nuclear Information System (INIS)

    The cryogenics system is one of the critical sub-systems in SST-1. The role of cryogenics systems is to facilitate the smooth cool-down, warm up and steady state operation as well as to take care about any abnormal events in safe mode during the operation. As a part of SST-1 machine shell, the cryogenics division is responsible for cold helium (at 4.5 K) and liquid nitrogen (at 77 K) hydraulics. This hydraulic network consists of headers, 80 K embossed shields, interconnecting loops, ceramic feed through at the vacuum barrier, flexible hoses and electrical breaks for cold helium as well as liquid nitrogen circuits. Before installation of individual components in SST-1, the performance validation tests were mandatory as part of mandatory stringent protocols fulfillment. The performance validation tests were conducted from individual components to integrated assembly level. In this paper, we report the essence of procedures followed and the performance test results. (author)

  16. Thermomechanical modeling of the Spent Fuel Test-Climax

    International Nuclear Information System (INIS)

    The Spent Fuel Test-Climax (SFT-C) was conducted to evaluate the feasibility of retrievable deep geologic storage of commercially generated spent nuclear-reactor fuel assemblies. One of the primary aspects of the test was to measure the thermomechanical response of the rock mass to the extensive heating of a large volume of rock. Instrumentation was emplaced to measure stress changes, relative motion of the rock mass, and tunnel closures during three years of heating from thermally decaying heat sources, followed by a six-month cooldown period. The calculations reported here were performed using the best available input parameters, thermal and mechanical properties, and power levels which were directly measured or inferred from measurements made during the test. This report documents the results of these calculations and compares the results with selected measurements made during heating and cooling of the SFT-C

  17. Numerical Modeling of Ocean Circulation

    Science.gov (United States)

    Miller, Robert N.

    2007-01-01

    The modelling of ocean circulation is important not only for its own sake, but also in terms of the prediction of weather patterns and the effects of climate change. This book introduces the basic computational techniques necessary for all models of the ocean and atmosphere, and the conditions they must satisfy. It describes the workings of ocean models, the problems that must be solved in their construction, and how to evaluate computational results. Major emphasis is placed on examining ocean models critically, and determining what they do well and what they do poorly. Numerical analysis is introduced as needed, and exercises are included to illustrate major points. Developed from notes for a course taught in physical oceanography at the College of Oceanic and Atmospheric Sciences at Oregon State University, this book is ideal for graduate students of oceanography, geophysics, climatology and atmospheric science, and researchers in oceanography and atmospheric science. Features examples and critical examination of ocean modelling and results Demonstrates the strengths and weaknesses of different approaches Includes exercises to illustrate major points and supplement mathematical and physical details

  18. Construction of a Sequencing Library from Circulating Cell-Free DNA.

    Science.gov (United States)

    Fang, Nan; Löffert, Dirk; Akinci-Tolun, Rumeysa; Heitz, Katja; Wolf, Alexander

    2016-01-01

    Circulating DNA is cell-free DNA (cfDNA) in serum or plasma that can be used for non-invasive prenatal testing, as well as cancer diagnosis, prognosis, and stratification. High-throughput sequence analysis of the cfDNA with next-generation sequencing technologies has proven to be a highly sensitive and specific method in detecting and characterizing mutations in cancer and other diseases, as well as aneuploidy during pregnancy. This unit describes detailed procedures to extract circulating cfDNA from human serum and plasma and generate sequencing libraries from a wide concentration range of circulating DNA. © 2016 by John Wiley & Sons, Inc. PMID:27038390

  19. Interannual variability of the Adriatic Sea circulation

    Science.gov (United States)

    Beg Paklar, Gordana; Sepic, Jadranka; Grbec, Branka; Dzoic, Tomislav; Kovac, Zarko; Ivatek-Sahdan, Stjepan

    2016-04-01

    The Regional Ocean Modeling System (ROMS) was implemented in order to reproduce interannual variability of the Adriatic Sea circulation. Simulations and model result analysis were performed for a three-year period from 1st January 2011 to 31st December 2013. ROMS model run was forced with realistic atmospheric fields obtained from meteorological model Aladin, climatological river discharges, tides and Mediterranean circulation imposed at the southern open boundary. Atmospheric forcing included momentum, heat and water fluxes calculated interactively from the Aladin surface fields during ROMS model simulations. Model results were compared with available CTD and ADCP measurements and discussed in the light of the climatological circulation and thermohaline properties of the Adriatic Sea and its coastal areas. Interannual variability in the Adriatic circulation is related to the prevailing atmospheric conditions, changes in the hydrological conditions and water mass exchange at the Otranto Strait. Basic features of the Adriatic circulation - basin-wide cyclonic circulation with several embedded smaller cyclonic gyres around main pits - are well reproduced by ROMS model. Modelled temperatures and salinities are within corresponding seasonal intervals, although measured profiles generally indicate stronger stratification than modelled ones. Summer circulation in 2011 with current reversal obtained along the eastern Adriatic coast was related to the sampling results of the early fish stages as well as to ARGO drifter movements. Simulated fields from the Adriatic scale model were used to prescribe the initial and open boundary conditions for the interannual simulation in the middle Adriatic coastal domain.

  20. Studies Related to the Oregon State University High Temperature Test Facility: Scaling, the Validation Matrix, and Similarities to the Modular High Temperature Gas-Cooled Reactor

    International Nuclear Information System (INIS)

    The Oregon State University (OSU) High Temperature Test Facility (HTTF) is an integral experimental facility that will be constructed on the OSU campus in Corvallis, Oregon. The HTTF project was initiated, by the U.S. Nuclear Regulatory Commission (NRC), on September 5, 2008 as Task 4 of the 5 year High Temperature Gas Reactor Cooperative Agreement via NRC Contract 04-08-138. Until August, 2010, when a DOE contract was initiated to fund additional capabilities for the HTTF project, all of the funding support for the HTTF was provided by the NRC via their cooperative agreement. The U.S. Department of Energy (DOE) began their involvement with the HTTF project in late 2009 via the Next Generation Nuclear Plant project. Because the NRC interests in HTTF experiments were only centered on the depressurized conduction cooldown (DCC) scenario, NGNP involvement focused on expanding the experimental envelope of the HTTF to include steady-state operations and also the pressurized conduction cooldown (PCC). Since DOE has incorporated the HTTF as an ingredient in the NGNP thermal-fluids validation program, several important outcomes should be noted: (1) The reference prismatic reactor design, that serves as the basis for scaling the HTTF, became the modular high temperature gas-cooled reactor (MHTGR). The MHTGR has also been chosen as the reference design for all of the other NGNP thermal-fluid experiments. (2) The NGNP validation matrix is being planned using the same scaling strategy that has been implemented to design the HTTF, i.e., the hierarchical two-tiered scaling methodology developed by Zuber in 1991. Using this approach a preliminary validation matrix has been designed that integrates the HTTF experiments with the other experiments planned for the NGNP thermal-fluids verification and validation project. (3) Initial analyses showed that the inherent power capability of the OSU infrastructure, which only allowed a total operational facility power capability of 0.6 MW

  1. Studies Related to the Oregon State University High Temperature Test Facility: Scaling, the Validation Matrix, and Similarities to the Modular High Temperature Gas-Cooled Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Richard R. Schultz; Paul D. Bayless; Richard W. Johnson; William T. Taitano; James R. Wolf; Glenn E. McCreery

    2010-09-01

    The Oregon State University (OSU) High Temperature Test Facility (HTTF) is an integral experimental facility that will be constructed on the OSU campus in Corvallis, Oregon. The HTTF project was initiated, by the U.S. Nuclear Regulatory Commission (NRC), on September 5, 2008 as Task 4 of the 5 year High Temperature Gas Reactor Cooperative Agreement via NRC Contract 04-08-138. Until August, 2010, when a DOE contract was initiated to fund additional capabilities for the HTTF project, all of the funding support for the HTTF was provided by the NRC via their cooperative agreement. The U.S. Department of Energy (DOE) began their involvement with the HTTF project in late 2009 via the Next Generation Nuclear Plant project. Because the NRC interests in HTTF experiments were only centered on the depressurized conduction cooldown (DCC) scenario, NGNP involvement focused on expanding the experimental envelope of the HTTF to include steady-state operations and also the pressurized conduction cooldown (PCC). Since DOE has incorporated the HTTF as an ingredient in the NGNP thermal-fluids validation program, several important outcomes should be noted: 1. The reference prismatic reactor design, that serves as the basis for scaling the HTTF, became the modular high temperature gas-cooled reactor (MHTGR). The MHTGR has also been chosen as the reference design for all of the other NGNP thermal-fluid experiments. 2. The NGNP validation matrix is being planned using the same scaling strategy that has been implemented to design the HTTF, i.e., the hierarchical two-tiered scaling methodology developed by Zuber in 1991. Using this approach a preliminary validation matrix has been designed that integrates the HTTF experiments with the other experiments planned for the NGNP thermal-fluids verification and validation project. 3. Initial analyses showed that the inherent power capability of the OSU infrastructure, which only allowed a total operational facility power capability of 0.6 MW, is

  2. Endogenous circulating sympatholytic factor in orthostatic intolerance

    Science.gov (United States)

    Shapiro, R. E.; Winters, B.; Hales, M.; Barnett, T.; Schwinn, D. A.; Flavahan, N.; Berkowitz, D. E.

    2000-01-01

    Sympathotonic orthostatic hypotension (SOH) is an idiopathic syndrome characterized by tachycardia, hypotension, elevated plasma norepinephrine, and symptoms of orthostatic intolerance provoked by assumption of an upright posture. We studied a woman with severe progressive SOH with blood pressure unresponsive to the pressor effects of alpha(1)-adrenergic receptor (AR) agonists. We tested the hypothesis that a circulating factor in this patient interferes with vascular adrenergic neurotransmission. Preincubation of porcine pulmonary artery vessel rings with patient plasma produced a dose-dependent inhibition of vasoconstriction to phenylephrine in vitro, abolished vasoconstriction to direct electrical stimulation, and had no effect on nonadrenergic vasoconstrictive stimuli (endothelin-1), PGF-2alpha (or KCl). Preincubation of vessels with control plasma was devoid of these effects. SOH plasma inhibited the binding of an alpha(1)-selective antagonist radioligand ([(125)I]HEAT) to membrane fractions derived from porcine pulmonary artery vessel rings, rat liver, and cell lines selectively overexpressing human ARs of the alpha(1B) subtype but not other AR subtypes (alpha(1A) and alpha(1D)). We conclude that a factor in SOH plasma can selectively and irreversibly inhibit adrenergic ligand binding to alpha(1B) ARs. We propose that this factor contributes to a novel pathogenesis for SOH in this patient. This patient's syndrome represents a new disease entity, and her plasma may provide a unique tool for probing the selective functions of alpha(1)-ARs.

  3. Tumor heterogeneity and circulating tumor cells.

    Science.gov (United States)

    Zhang, Chufeng; Guan, Yan; Sun, Yulan; Ai, Dan; Guo, Qisen

    2016-05-01

    In patients with cancer, individualized treatment strategies are generally guided by an analysis of molecular biomarkers. However, genetic instability allows tumor cells to lose monoclonality and acquire genetic heterogeneity, an important characteristic of tumors, during disease progression. Researchers have found that there is tumor heterogeneity between the primary tumor and metastatic lesions, between different metastatic lesions, and even within a single tumor (either primary or metastatic). Tumor heterogeneity is associated with heterogeneous protein functions, which lowers diagnostic precision and consequently becomes an obstacle to determining the appropriate therapeutic strategies for individual cancer patients. With the development of novel testing technologies, an increasing number of studies have attempted to explore tumor heterogeneity by examining circulating tumor cells (CTCs), with the expectation that CTCs may comprehensively represent the full spectrum of mutations and/or protein expression alterations present in the cancer. In addition, this strategy represents a minimally invasive approach compared to traditional tissue biopsies that can be used to dynamically monitor tumor evolution. The present article reviews the potential efficacy of using CTCs to identify both spatial and temporal tumor heterogeneity. This review also highlights current issues in this field and provides an outlook toward future applications of CTCs. PMID:26902424

  4. Scaling laws for single-phase natural circulation loops

    International Nuclear Information System (INIS)

    The power-to-volume scaling laws used for the construction of scaled test facilities simulating the primary system of nuclear power plants result in loops of the same elevation (and length) with reduced diameters. The adequacy of these scaling laws for simulating single-phase natural circulation was tested in three rectangular loops, each having the same elevation but different loop diameters of 6mm, 11mm and 23.2mm respectively. The experiments showed that the power-to-volume scaling principles adequately describe the steady state behaviour. The stability behaviour observed in the loop 23.2mm in diameter, however, could not be reproduced in the smaller diameter loops. Subsequent theoretical investigation of the single-phase natural circulation phenomenon showed that the transient and stability behaviour can be simulated only if the diameter ratio Dp/Dm is also simulated. The theoretical investigation suggested the following scaling laws for single-phase natural circulation: (Grm)p=(Grm)m LpLm=DpDm=HpHm=(Lh)p(Lh)m (Stm)p=(Stm)m For simulating the steady state behaviour alone, it is sufficient to simulate the product Grm(D/L). ((orig.))

  5. Natural Circulation Performance in Nuclear Power Plants

    International Nuclear Information System (INIS)

    The present paper deals with a study of natural circulation in PWR systems, The study consists of two parts: in the first one, natural circulation in experimental facilities simulating PWR plants was analyzed. This made it possible to gather a broad data base which was assumed as a reference for the subsequent part of the research. Seven Nuclear Power Plants nodalizations and additional experimental data from ''non-PWR'' facilities have been considered in the second part of the paper. Conclusions are drawn about natural circulation capabilities derived for the seven Nuclear Power Plants nodalizations and from data base pertinent to three ''non-PWR'' facilities. (author)

  6. Natural circulation performance in nuclear power plants

    International Nuclear Information System (INIS)

    The present paper deals with a study of natural circulation in PWR systems. The study consists of two parts: in the first one, natural circulation in experimental facilities simulating PWR plants was analysed. This made it possible to gather a broad data base which was assumed as a reference for the subsequent part of the research. Seven Nuclear Power Plants nodalization and additional experimental data from 'non-PWR' facilities have been considered in the second part of the paper. Conclusions are drawn about natural circulation capabilities derived for the seven Nuclear Power Plants nodalization and from data base pertinent to three 'non-PWR' facilities. (author)

  7. General Circulation Modeling of the Jovian stratosphere

    Science.gov (United States)

    Sethunadh, J.; Medvedev, A. S.; Hartogh, P.

    2014-04-01

    The middle atmosphere of Jupiter (1 bar to 1 μ bar) is primarily driven by the heat generated in the interior and by radiative heating and cooling. The stratosphere of Jupiter is less studied, and the mechanisms behind many observed phenomena (e.g.,QQO) in the middle atmosphere as well as the stratospheric circulation patterns remain unknown. We have developed a new General Circulation Model (GCM) to simulate the middle atmospheres of gas giants, which can give important insights to the stratospheric circulation and to the physical and dynamical processes underlying the observed middle atmospheric phenomena.

  8. Circulating miRNA and cancer diagnosis

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    miRNAs are a class of small RNA molecules with regulatory function, and play an important role in tumor development and progression. It has been demonstrated that tumor-derived miRNAs exist in the circulating nucleic acids of cancer patients. This phenomenon implies that detection of the circulating miRNA may be an effective method for non-invasive diagnosis of cancer. In this review, we summarize the applications of the circulating miRNA as biomarkers in cancer diagnosis, as well as the latest research progress in this area.

  9. A GM cryocooler with cold helium circulation for remote cooling

    Science.gov (United States)

    Wang, Chao; Brown, Ethan

    2014-01-01

    A GM cryocooler with new cold helium circulation system has been developed at Cryomech. A set of check valves connects to the cold heat exchanger to convert a small portion of AC oscillating flow in the cold head to a DC gas flow for circulating cold helium in the remote loop. A cold finger, which is used for remote cooling, is connected to the check valves through a pair of 5 m long vacuum insulated flexible lines. The GM cryocooler, Cryomech model AL125 having 120 W at 80 K, is employed in the testing. The cold finger can provide 50 W at 81 K for the power input of 4.1 kW and 70.5 W at 81.8 K for the power input of 6 kW. This simple and low cost design is very attractive for some applications in the near future.

  10. Polymer grouts for plugging lost circulation in geothermal wells.

    Energy Technology Data Exchange (ETDEWEB)

    Galbreath, D. (Green Mountain International, Waynesvile, NC); Mansure, Arthur James; Bauer, Stephen J.

    2004-12-01

    We have concluded a laboratory study to evaluate the survival potential of polymeric materials used for lost circulation plugs in geothermal wells. We learned early in the study that these materials were susceptible to hydrolysis. Through a systematic program in which many potential chemical combinations were evaluated, polymers were developed which tolerated hydrolysis for eight weeks at 500 F. The polymers also met material, handling, cost, and emplacement criteria. This screening process identified the most promising materials. A benefit of this work is that the components of the polymers developed can be mixed at the surface and pumped downhole through a single hose. Further strength testing is required to determine precisely the maximum temperature at which extrusion through fractures or voids causes failure of the lost circulation plug.

  11. Active Circulation Control for Horizontal Axis Wind Turbine

    Science.gov (United States)

    Dumitrache, Alexandru; Dumitrescu, Horia; Preotu, Octavian

    2011-09-01

    A based method for modeling the aerodynamics of horizontal axis wind turbine has been developed. Circulation control is implemented by tangentially blowing a small high-velocity jet over a highly curved surface, such as a rounded trailing edge. This causes the boundary layer and the jet sheet to remain attached along the curved surface due to the Coanda effect and causing the jet to turn without separation. This analysis has been validated for the experimental data of a rotor tested at NASA Ames Research Center. Comparisons have been done against measurements for surface pressure distribution, force coefficients normal and tangential to the chord line, torque and root bending moments. This approach for enhancing the circulation around the airfoil sections (and hence L/D and power production) has been examined and found to produce useful increases in power at low wind speeds.

  12. Analysis on Non-Uniform Flow in Steam Generator During Steady State Natural Circulation Cooling

    OpenAIRE

    Susyadi; T. Yonomoto

    2007-01-01

    Investigation on non uniform flow behavior among U-tube in steam generator during natural circulation cooling has been conducted using RELAP5. The investigation is performed by modeling the steam generator into multi channel models, i.e. 9-tubes model. Two situations are implemented, high pressure and low pressure cases. Using partial model, the calculation simulates situation similar to the natural circulation test performed in LSTF. The imposed boundary conditions are flow rate, quality, pr...

  13. Reformation of the surface oceanic circulation during Paleogene: Calcareous nannoplanktonic, foraminiferal and oxygen isotopic evidences

    OpenAIRE

    Ushakova, Maola; Blyum, Natalia

    1995-01-01

    [EN] Paleogene calcareous nannoplankton evolution with regard to morphotype changes was analysed. The^°0/1"0 ratio in planktonic foraminifera tests was studied. Conclusions about surface water temperature and salinity changes and about main features of surface circulation based on these data were arrived. Can be seen that the reformation from the mainly halinotypic circulation of the early Paleogene into halotherme one took place in the middle Eocene. In the same time the notable climatic zon...

  14. Effects of Elevated Circulating Cortisol Concentrations on Maternal Behavior in Common Marmoset Monkeys (Callithrix jacchus)

    OpenAIRE

    Saltzman, Wendy; Abbott, David H.

    2009-01-01

    Both acute and chronic stress can impair maternal behavior and increase rates of infant abuse in several species. The mechanisms inducing these effects are unknown, but experimental manipulation of circulating corticosterone levels alters maternal behavior in rats, and circulating or excreted cortisol concentrations have been found to correlate either positively or negatively with maternal behavior in humans and nonhuman primates. In this study, therefore, we experimentally tested the hypothe...

  15. Oil Circulation Effects on Evaporation Heat Transfer in Brazed Plate Heat Exchanger using R134A

    OpenAIRE

    Jang, Jaekyoo; Chang, Youngsoo; Kang, Byungha

    2012-01-01

    Experimental study was performed for oil circulation effects on evaporation heat transfer in the brazed type plate heat exchangers using R134A. In this study, distribution device was installed to ensure uniform flow distribution in the refrigerant flow passage, which enhances heat transfer performance of plate type heat exchanger. Tests were conducted for three evaporation temperature; 33℃, 37℃, and 41℃ and several oil circulation conditions. The nominal conditions of refrigerant are as follo...

  16. An Open Source Low-Cost Wireless Control System for a Forced Circulation Solar Plant

    OpenAIRE

    Francesco Salamone; Lorenzo Belussi; Ludovico Danza; Matteo Ghellere; Italo Meroni

    2015-01-01

    The article describes the design phase, development and practical application of a low-cost control system for a forced circulation solar plant in an outdoor test cell located near Milan. Such a system provides for the use of an electric pump for the circulation of heat transfer fluid connecting the solar thermal panel to the storage tank. The running plant temperatures are the fundamental parameter to evaluate the system performance such as proper operation, and the control and management sy...

  17. Development of a Multi Megawatt Circulator for X Band

    International Nuclear Information System (INIS)

    (which minimizes arcing problems) and reduced propensity for mode conversion compared to non-asymmetric circular waveguide modes. Unfortunately, no current designs exist for circulators using the circular TE01 mode. The basic building block for all low-loss circulators and isolators is a nonreciprocal element with a phase shift dependent on the propagation direction in the guide. Such an element can be constructed by placement of a hollow ferrite rod in a cylindrical waveguide. An inner conductor placed inside the ferrite rod conducts a current pulse that induces an azimuthal magnetic field inside the ferrite. This configuration is depicted in Figure 1a. An alternate configuration using permanent magnets is shown in Figure 1b. Either of these configurations will create a different phase shift for waves propagating in opposite directions along the waveguide axis. This feature can be used to develop a high power circulator. We are currently testing a TE01 nonreciprocal phase shifter in a 50 MW test stand. This device is in the configuration shown in Figure 1a. The induced differential phase shift and loss will be measured and compared to calculations

  18. Energy saver A-sector power test results

    International Nuclear Information System (INIS)

    The superconducting magnets and associated cryogenic components in A-sector represent the initial phase of installation of the Fermilab superconducting accelerator, designed to accelerate proton beams to energies of 1 TeV. Installation of the magnets, comprising one-eighth of the ring, was completed in December, 1981. Cooldown and power tests took place in the first half of 1982, concurrent with main ring use for 400 GeV high energy physics. The tests described in this paper involved 151 cryogenic components in the tunnel: 94 dipoles, 24 quadrupoles, 25 spool pieces, 3 feed cans, 4 turn-around boxes and 1 bypass. Refrigeration was supplied by three satellite refrigerators, the Central Helium Liquefier, and two compressor buildings. The magnets were powered by a single power supply

  19. Cryogenic tests of the first two LHC quadrupole prototypes

    International Nuclear Information System (INIS)

    Two LHC (Large Hadron Collider) twin aperture quadrupole prototypes were constructed at CEA Saclay (a CERN-CEA collaboration agreement). Their main characteristics are: 3.05 m length, 56 mm coil aperture, 180 mm between the two apertures, 252 T/m nominal gradient at 15060 A. They have been tested and measured in the 1.8 K Saclay test facility in an horizontal cryostat. The magnets are instrumented in order to investigate their behaviour during cool-down, stand-by, powering and current ramping, quenching and warming-up. A summary of the cryogenic, mechanical, pressure and electrical measurements is presented. The quench protection heaters are efficient down to 3000 A. Losses during ramping up and down are reported. (from authors) 5 fig., 11 ref

  20. EOP MIT General Circulation Model (MITgcm)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data contains a regional implementation of the Massachusetts Institute of Technology general circulation model (MITgcm) at a 1-km spatial resolution for the...

  1. Global warming and changes in ocean circulation

    Energy Technology Data Exchange (ETDEWEB)

    Duffy, P.B.; Caldeira, K.C.

    1998-02-01

    This final report provides an overview of the goals and accomplishments of this project. Modeling and observational work has raised the possibility that global warming may cause changes in the circulation of the ocean. If such changes would occur they could have important climatic consequences. The first technical goal of this project was to investigate some of these possible changes in ocean circulation in a quantitative way, using a state-of -the-art numerical model of the ocean. Another goal was to develop our ocean model, a detailed three-dimensional numerical model of the ocean circulation and ocean carbon cycles. A major non-technical goal was to establish LLNL as a center of excellence in modelling the ocean circulation and carbon cycle.

  2. Sedimentary response to ocean gateway circulation changes

    Science.gov (United States)

    Heinze, Christoph; Crowley, Thomas J.

    1997-12-01

    Previous modeling studies suggested that changes in ocean gateways may have exerted a dramatic influence on the ocean circulation. In this pilot study we extend those results to examining the potential ramifications of circulation changes on the sedimentary record. A version of the Hamburg carbon cycle/sediment model is used in these sensitivity experiments. Results indicate that internal reorganization of the ocean circulation can potentially cause very large regional changes in lysocline depth (1500-3000 m) and opal deposition. These shifts are sometimes comparable in magnitude to those imposed by changes in external forcing (e.g., climate, sea level, and weathering). Comparisons of the model response with the geologic record indicate some significant levels of first-order agreement. This exercise suggests that opportunities now exist for physically based modeling of past sediment responses to circulation and climate changes.

  3. GCFR main helium circulator and electric drive

    International Nuclear Information System (INIS)

    One of the major objectives of the helium circulators for the gas-cooled fast breeder reactor (GCFR) is to achieve the highest possible operational reliability. This is no simple task considering the plant system integration requirements, auxiliary support systems, all possible transient requirements, and resulting complexity in supplying the driving power, primary coolant flow control, and lubrication and sealing. Therefore, the design of the circulator itself is highly dependent on the type of prime mover selected to drive the circulator, e.g., series turbine, parallel turbine, or electric motor. The circulator main drive has evolved from the series steam turbine drive into the variable-speed, synchronous electric motor drive mounted externally to the reactor and controlled by thyristor variable frequency controller. This design is a result of 18 months of joint effort by General Atomic Company and Westinghouse Electric Corporation

  4. A cryogenic test stand for full length SSC magnets with superfluid capability

    International Nuclear Information System (INIS)

    The Fermilab Magnet Test Facility performs testing of the full scale SSC magnets on test stands capable of simulating the cryogenic environment of the SSC main ring. One of these test stands, Stand 5, also has the ability to operate the magnet under test at temperatures from 1.8K to 4.5K with either supercritical helium or subcooled liquid, providing at least 25 Watts of refrigeration. At least 50 g/s flow is available from 2.3K to 4.5K, whereas superfluid operation occurs with zero flow. Cooldown time from 4.5K to 1.8K is 1.5 hours. A maximum current capability of 10,000 amps is provided, as is instrumentation to monitor and control the cryogenic conditions. This paper describes the cryogenic design of this test stand. 8 refs., 6 figs

  5. STRUCTURES OF CIRCULANT INVERSE M-MATRICES

    Institute of Scientific and Technical Information of China (English)

    Yurui Lin; Linzhang Lu

    2007-01-01

    In this paper,we present a useful result on the structures of circulant inverse Mis not a positive matrix and not equal to c0I,then A is an inverse M-matrix if and only if there exists a positive integer k,which is a proper factor of n,such that cjk>0 for The result is then extended to the so-called generalized circulant inverse M-matrices.

  6. Dynamic Transition Theory for Thermohaline Circulation

    OpenAIRE

    Ma, Tian; Wang, Shouhong

    2009-01-01

    The main objective of this and its accompanying articles is to derive a mathematical theory associated with the thermohaline circulations (THC). This article provides a general transition and stability theory for the Boussinesq system, governing the motion and states of the large-scale ocean circulation. First, it is shown that the first transition is either to multiple steady states or to oscillations (periodic solutions), determined by the sign of a nondimensional parameter $K$, depending o...

  7. Efficient Circulation of Railway Rolling Stock

    OpenAIRE

    Alfieri, Arianna; Groot, Rutger; Kroon, Leo; Schrijver, Lex

    2002-01-01

    textabstractRailway rolling stock (locomotives, carriages, and train units) is one of the most significant cost sources for operatorsof passenger trains, both public and private. Rolling stock costsare due to material acquisition, power supply, and material maintenance. The efficient circulation of rolling stock material is therefore one of the objectives pursued. In this paper we focus on the circulation of train units on a single line. In order to utilize the train units on this line in an ...

  8. The Nordic Seas circulation and exchanges.

    OpenAIRE

    Hawker, E.J.

    2005-01-01

    The Nordic Seas provide the main oceanic connection between the Arctic and the deep global oceans via dense overflows between Greenland and Scotland, into the North Atlantic. An understanding of the circulation and exchanges of this region is vital for any consideration of the implications of high latitude climate change to variability in the Atlantic thermohaline circulation and consequences for regional (European) climate. This thesis makes use of a unique data set of near synoptic hyd...

  9. Local phenomena associated with natural circulation

    International Nuclear Information System (INIS)

    The objective of this lecture is to impart to the participants an adequate knowledge of various phenomena encountered in the natural circulation systems of a nuclear reactor. All the components of the primary system of a nuclear reactor are described and phenomena occurring in each of them are explained. A comprehensive coverage of related thermohydraulic relationships is provided which will enable the participants to carryout the process design of a natural circulation system. (author)

  10. Southern Meridional Atmospheric Circulation Associated with IOD

    Institute of Scientific and Technical Information of China (English)

    LIU Na; CHEN Hongxia

    2006-01-01

    Using the monthly wind and sea surface temperature (SST) data, southern meridional atmospheric circulation cells associated with the Indian Ocean Dipole Mode (IOD) events in the Indian Ocean are for the first time described and examined. The divergent wind and pressure vertical velocity are employed for the identification of atmospheric circulation cells. During the four different phases of the positive IOD events, the anomalous meridional Hadley circulation over the western Indian Ocean shows that the air rises in the tropics, flows poleward in the upper troposphere, sinks in the subtropics, and returns back to the tropics in the lower troposphere. The anomalous Hadley circulation over the eastern Indian Ocean is opposite to that over the western Indian Ocean. During positive IOD events, the meridional Hadley circulation over the eastern Indian Ocean is weakened while it is strengthened over the western Indian Ocean. Correlation analysis between the IOD index and the indices of the Hadley cells also proves that, the atmospheric circulation patterns are evident in every IOD event over the period of record.

  11. An experimental approach to improve the basin type solar still using an integrated natural circulation loop

    International Nuclear Information System (INIS)

    Highlights: • A new experimental approach to improve the conventional solar still performances is proposed. • A passive natural circulation loop is integrated to the conventional solar still. • Natural circulation of humid-air in a closed loop is studied by the present study. • Natural circulation capability in driving air convection in the still was demonstrated. • Air convection created inside the still increase the evaporation heat and mass transfer. - Abstract: In this paper, a new experimental approach is proposed to enhance the performances of the conventional solar still using the natural circulation effect inside the still. The idea consists in generating air flow by a rectangular natural circulation loop appended to the rear side of the still. The proposed still was tested during summer period and the experimental data presented in this paper concerns four typical days. The convective heat transfer coefficient is evaluated and compared with Dunkle’s model. The comparison shows that convective heat transfer is considerably improved by the air convection created inside the still. The natural circulation phenomenon in the still is studied and a good agreement between the experimental data and Vijajan’s laminar correlation is found. Therefore, natural circulation phenomenon is found to have a good effect on the still performances where the still daily productivity is of 3.72 kg/m2 and the maximum efficiency is of 45.15%

  12. Standardization of an enzyme linked immunosorbent assay (ELISA for detecting circulating toxic venom antigens in patients stung by the scorpion Tityus serrulatus Padronização de um teste imunoenzimático (ELISA para detectar antígenos tóxicos circulantes do veneno em pacientes picados pelo escorpião Tityus serrulatus

    Directory of Open Access Journals (Sweden)

    Nilton Alves de Rezende

    1995-02-01

    Full Text Available The sensitivity and specificity of an enzyme-linked immunosorbent assay (ELISA for the detection of circulating antigens from toxic components of Tityus serrulatus scorpion venom was determined in patients stung by T. serrulatus before antivenom administration. Thirty-seven patients were classified as mild cases and 19 as moderate or severe cases. The control absorbance in the venom assay was provided by serum samples from 100 individuals of same socioeconomic group and geographical area who had never been stung by scorpions or treated with horse antisera. The negative cutoff value (mean + 2 SD corresponded to a venom concentration of 4.8 ng/ml. Three out of the 100 normal sera were positive, resulting in a specificity of 97%. The sensitivity of the ELISA when all cases of scorpion sting were included was 39.3%. When mild cases were excluded, the sensitivity increased to 94.7%. This study showed that this ELISA can be used for the detection of circulating venom toxic antigens in patients with systemic manifestations following. T. serrulatus sting but cannot be used for clinical studies in mild cases of envenoming since the test does not discriminate mild cases from control patients.Neste trabalho foram determinadas a sensibilidade e a especificidade da técnica imunoenzimática (ELISA desenvolvida por CHAVÉZ-OLORTEGUI et al. para detectar antígenos circulantes de veneno em pacientes picados po Tityus serrulatus. A média mais dois desvios padrão da observância do soro de 100 pacientes controles foi utilizada como limite entre teste positivo e teste negativo ("cutoff". A especificidade do ELISA foi igual a 97,0%. A sensibilidade do método, quando incluidos pacientes classificados como casos leves, moderados e graves de escorpionismo, foi de 39,3% e aumentou para 94,7% quando considerados apenas os casos moderados e graves. Estes resultados mostram que o ELISA pode ser utilizado para detecção de antígenos tóxicos circulantes em pacientes

  13. Global climate and ocean circulation on an aquaplanet ocean-atmosphere general circulation model

    OpenAIRE

    Smith, R.; Dubois, C.; Marotzke, J.

    2006-01-01

    A low-resolution coupled ocean–atmosphere general circulation model (OAGCM) is used to study the characteristics of the large-scale ocean circulation and its climatic impacts in a series of global coupled aquaplanet experiments. Three configurations, designed to produce fundamentally different ocean circulation regimes, are considered. The first has no obstruction to zonal flow, the second contains a low barrier that blocks zonal flow in the ocean at all latitudes, creating a single enclosed ...

  14. Platelet Function During Hypothermia in Experimental Mock Circulation.

    Science.gov (United States)

    Van Poucke, Sven; Stevens, Kris; Kicken, Cécile; Simons, Antoine; Marcus, Abraham; Lancé, Marcus

    2016-03-01

    Alterations in platelet function are a common finding in surgical procedures involving cardiopulmonary bypass and hypothermia. Although the combined impact of hypothermia and artificial circulation on platelets has been studied before, the ultimate strategy to safely minimize the risk for bleeding and thrombosis is yet unknown. The aim of this study was to evaluate the use of a mock circulation loop to study the impact of hypothermia for platelet-related hemostatic changes. Venous blood was collected from healthy adult humans (n = 3). Closed mock circulation loops were assembled, each consisting of a centrifugal pump, an oxygenator with integrated heat exchanger, and a hardshell venous reservoir. The experiment started with the mock circulation temperature set at 37°C (T0 [0 h]). Cooling was then initiated at T1 (+2 h), where temperature was adjusted from 37°C to 32°C. Hypothermia was maintained from T2 (+4 h) to T3 (+28 h). From that point in time, rewarming from 32°C to 37°C was initiated with similar speed as cooling. From time point T4 (+30 h), normothermia (37°C) was maintained until the experiment ended at T5 (+32 h). Blood samples were analyzed in standard hematological tests: light transmission aggregometry (LTA) (arachidonic acid [AA], adenosine diphosphate [ADP], collagen [COL], thrombin-receptor-activating-peptide-14 [TRAP]), multiple electrode aggregometry (MEA) (AA, ADP, COL, TRAP), and rotational thromboelastometry (ROTEM) (EXTEM, FIBTEM, PLTEM). Hemoglobin, hematocrit, and platelet count decrease more substantially during temperature drop (37-32°C) than during hypothermia maintenance. Hb and Hct continue to follow this trend during active rewarming (32-37°C). PC increase from the moment active rewarming was initiated. None of the values return to the initial values. LTA values demonstrate a similar decrease in aggregation after stimulation with the platelet agonists between the start of the mock circulation and the start of

  15. Experimental and numerical investigation of natural circulation phenomena in a rectangular natural circulation loop

    International Nuclear Information System (INIS)

    Natural circulation is the key phenomena in the passive cooling systems. Thus, it is important to study the flow characteristics and heat transfer behavior in natural circulation. The natural circulation phenomena in steady state and transient form is investigated using 3D CFD simulations, carried out using OpenFoam 2.2.0. The first part consists of a steady-state study, in which the results are validated by data available from a set of experiments conducted over a range of heater power (130W-360W). The second part consists of a transient study of flow development and establishment of natural circulation within this loop. (author)

  16. Preliminary study of testing circulating tumor cells in patients with renal cell carcinoma by Cell-search System%肾细胞癌外周血循环肿瘤细胞检测方法的初步探讨

    Institute of Scientific and Technical Information of China (English)

    张玉石; 李汉忠; 周春

    2013-01-01

    目的 探讨应用细胞搜索系统(cell-search system,CSS)检测肾细胞癌患者外周血循环肿瘤细胞(circulating tumor cell,CTC)的方法及可行性. 方法 2012年1-6月收治的中晚期肾细胞癌患者8例,男5例,女3例.年龄57~70岁,平均64岁.依据2009年UICC的TNM分期标准:T3N0M0期2例,T4N0M1期6例.3例行肾癌根治手术,5例进行靶向药物治疗.所有患者治疗前采取外周血7.5 ml,15℃~30℃专用试管内保存,96 h内送检.用CSS对患者外周血进行CTC定量检测,标志物选用抗细胞角蛋白CK8/18/19荧光抗体. 结果 8例外周血CTC定量检测结果均为阴性,1例T4N0M1患者外周血中发现25个CK8/18/19和CD45的双阳性细胞. 结论 利用上皮细胞肿瘤标志物CK8/18/19抗体标记肾癌CTC,采用CSS方法未能检测出中晚期肾癌患者血中的CTC,抗CK8/18/19抗体不能作为所有上皮来源肿瘤的细胞标志物来检测CTC.%Objective To explore the feasibility and to improve the efficiency of testing circulating tumor cells(CTC)in patients with renal cell carcinoma by Cell-search System(CSS).Methods Eight patients with renal cell carcinoma hospitalized in the PUMC urology department for further clinical evaluation in Jan.to Jun.2012 were enrolled in this study.There were 5 males and 3 females with mean age of 64 (57-70)years.There were 2 cases in clinical stage T3N0M0 and 6 cases in T4N0M1;3 cases were treated with radical nephrectomy,5 cases were treated with targeted therapy drugs.7.5 ml peripheral blood samples from these patients were collected and saved in test tube at the temperature of 15 ℃-30 ℃.The tests had to be done within 96 hrs after the blood sample drawn.We selected fluorescent anti-CKS/18/19 antibodies as CTC makers for renal cell carcinoma.Then the number of CTC was quantitative detected by CSS.The feasibility and detection rate of testing CTC in patients with RCC by CSS was evaluated,and the improvement of method was discussed.Results Quantitative

  17. Startup transient simulation for natural circulation boiling water reactors in PUMA facility

    International Nuclear Information System (INIS)

    In view of the importance of instabilities that may occur at low-pressure and -flow conditions during the startup of natural circulation boiling water reactors, startup simulation experiments were performed in the Purdue University Multi-Dimensional Integral Test Assembly (PUMA) facility. The simulations used pressure scaling and followed the startup procedure of a typical natural circulation boiling water reactor. Two simulation experiments were performed for the reactor dome pressures ranging from 55 kPa to 1 MPa, where the instabilities may occur. The experimental results show the signature of condensation-induced oscillations during the single-phase-to-two-phase natural circulation transition. The results also suggest that a rational startup procedure is needed to overcome the startup instabilities in natural circulation boiling water reactor designs

  18. Natural Circulation Characteristics at Low-Pressure Conditions through PANDA Experiments and ATHLET Simulations

    Directory of Open Access Journals (Sweden)

    Domenico Paladino

    2008-01-01

    Full Text Available Natural circulation characteristics at low pressure/low power have been studied by performing experimental investigations and numerical simulations. The PANDA large-scale facility was used to provide valuable, high quality data on natural circulation characteristics as a function of several parameters and for a wide range of operating conditions. The new experimental data allow for testing and improving the capabilities of the thermal-hydraulic computer codes to be used for treating natural circulation loops in a range with increased attention. This paper presents a synthesis of a part of the results obtained within the EU-Project NACUSP “natural circulation and stability performance of boiling water reactors.” It does so by using the experimental results produced in PANDA and by showing some examples of numerical simulations performed with the thermal-hydraulic code ATHLET.

  19. A novel interface for hybrid mock circulations to evaluate ventricular assist devices.

    Science.gov (United States)

    Ochsner, Gregor; Amacher, Raffael; Amstutz, Alois; Plass, André; Schmid Daners, Marianne; Tevaearai, Hendrik; Vandenberghe, Stijn; Wilhelm, Markus J; Guzzella, Lino

    2013-02-01

    This paper presents a novel mock circulation for the evaluation of ventricular assist devices (VADs), which is based on a hardware-in-the-loop concept. A numerical model of the human blood circulation runs in real time and computes instantaneous pressure, volume, and flow rate values. The VAD to be tested is connected to a numerical-hydraulic interface, which allows the interaction between the VAD and the numerical model of the circulation. The numerical-hydraulic interface consists of two pressure-controlled reservoirs, which apply the computed pressure values from the model to the VAD, and a flow probe to feed the resulting VAD flow rate back to the model. Experimental results are provided to show the proper interaction between a numerical model of the circulation and a mixed-flow blood pump. PMID:23204266

  20. Changes in zonal surface temperature gradients and Walker circulations in a wide range of climates

    CERN Document Server

    Merlis, Timothy M

    2010-01-01

    Variations in zonal surface temperature gradients and zonally asymmetric tropical overturning circulations (Walker circulations) are examined over a wide range of climates simulated with an idealized atmospheric general circulation model (GCM). The asymmetry in the tropical climate is generated by an imposed ocean energy flux, which does not vary with climate. The range of climates is simulated by modifying the optical thickness of an idealized longwave absorber (representing greenhouse gases). The zonal surface temperature gradient in low latitudes generally decreases as the climate warms in the idealized GCM simulations. A scaling relationship based on a two-term balance in the surface energy budget accounts for the changes in the zonally asymmetric component of the GCM-simulated surface temperature gradients. As in comprehensive simulations of climate change, the Walker circulation weakens as the climate warms in the idealized simulations. The wide range of climates allows a systematic test of energetic ar...

  1. Identifying cancer origin using circulating tumor cells.

    Science.gov (United States)

    Lu, Si-Hong; Tsai, Wen-Sy; Chang, Ying-Hsu; Chou, Teh-Ying; Pang, See-Tong; Lin, Po-Hung; Tsai, Chun-Ming; Chang, Ying-Chih

    2016-04-01

    Circulating tumor cells (CTCs) have become an established clinical evaluation biomarker. CTC count provides a good correlation with the prognosis of cancer patients, but has only been used with known cancer patients, and has been unable to predict the origin of the CTCs. This study demonstrates the analysis of CTCs for the identification of their primary cancer source. Twelve mL blood samples were equally dispensed on 6 CMx chips, microfluidic chips coated with an anti-EpCAM-conjugated supported lipid bilayer, for CTC capture and isolation. Captured CTCs were eluted to an immunofluorescence (IF) staining panel consisting of 6 groups of antibodies: anti-panCK, anti-CK18, anti-CK7, anti-TTF-1, anti-CK20/anti-CDX2, and anti-PSA/anti-PSMA. Cancer cell lines of lung (H1975), colorectal (DLD-1, HCT-116), and prostate (PC3, DU145, LNCaP) were selected to establish the sensitivity and specificity for distinguishing CTCs from lung, colorectal, and prostate cancer. Spiking experiments performed in 2mL of culture medium or whole blood proved the CMx platform can enumerate cancer cells of lung, colorectal, and prostate. The IF panel was tested on blood samples from lung cancer patients (n = 3), colorectal cancer patients (n = 5), prostate cancer patients (n = 5), and healthy individuals (n = 12). Peripheral blood samples found panCK(+) and CK18(+) CTCs in lung, colorectal, and prostate cancers. CTCs expressing CK7(+) or TTF-1(+), (CK20/ CDX2)(+), or (PSA/ PSMA)(+) corresponded to lung, colorectal, or prostate cancer, respectively. In conclusion, we have designed an immunofluorescence staining panel to identify CTCs in peripheral blood to correctly identify cancer cell origin. PMID:26828696

  2. Gasification of sawdust in pressurised internally circulating fluidized bed

    Energy Technology Data Exchange (ETDEWEB)

    Maartensson, R.; Lindblom, M. [Lund Univ. (Sweden). Dept. of Chemical Engineering

    1996-12-31

    A test plant for pressurised gasification of biofuels in a internally circulating fluidized bed has been built at the department of Chemical Engineering II at the University of Lund. The design performance is set to maximum 20 bar and 1 050 deg C at a thermal input of 100 kW or a maximum fuel input of 18 kg/in. The primary task is to study pressurised gasification of biofuels in relation to process requirements of the IGCC concept (integrated gasification combined cycle processes), which includes studies in different areas of hot gas clean-up in reducing atmosphere for gas turbine applications. (orig.)

  3. Natural circulation in water cooled nuclear power plants: Phenomena, models, and methodology for system reliability assessments

    International Nuclear Information System (INIS)

    order to focus the CRP activities on advancing the state of knowledge. With the benefit of the results of the CRP, this publication will be updated in the future to produce a report on the state of the art of natural circulation in water cooled nuclear power plants. This publication also contains material from an intensive IAEA training course on Natural Circulation in Water Cooled Reactors for research scientists and engineers involved in the design, testing or analysis of natural circulation systems

  4. Scaling Studies for High Temperature Test Facility and Modular High Temperature Gas-Cooled Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Richard R. Schult; Paul D. Bayless; Richard W. Johnson; James R. Wolf; Brian Woods

    2012-02-01

    The Oregon State University (OSU) High Temperature Test Facility (HTTF) is an integral experimental facility that will be constructed on the OSU campus in Corvallis, Oregon. The HTTF project was initiated, by the U.S. Nuclear Regulatory Commission (NRC), on September 5, 2008 as Task 4 of the 5-year High Temperature Gas Reactor Cooperative Agreement via NRC Contract 04-08-138. Until August, 2010, when a DOE contract was initiated to fund additional capabilities for the HTTF project, all of the funding support for the HTTF was provided by the NRC via their cooperative agreement. The U.S. Department of Energy (DOE) began their involvement with the HTTF project in late 2009 via the Next Generation Nuclear Plant (NGNP) project. Because the NRC's interests in HTTF experiments were only centered on the depressurized conduction cooldown (DCC) scenario, NGNP involvement focused on expanding the experimental envelope of the HTTF to include steady-state operations and also the pressurized conduction cooldown (PCC).

  5. The BaBar superconducting coil: design, construction and test

    International Nuclear Information System (INIS)

    The BABAR Detector, located in the PEP-II B-Factory at the Stanford Linear Accelerator Center, includes a large 1.5 Tesla superconducting solenoid, 2.8 m bore and length 3.7 m. The two layer solenoid is wound with an aluminum stabilized conductor which is graded axially to produce a +/- 3% field uniformity in the tracking region. This paper summarizes the 3 year design, fabrication and testing program of the superconducting solenoid. The work was carried out by an international collaboration between INFN, LLNL and SLAC. The coil was constructed by Ansaldo Energia. Critical current measurements of the superconducting strand, cable and conductor, cool-down, operation with the thermo-siphon cooling, fast and slow discharges, and magnetic forces are discussed in detail

  6. Experimental study of the natural circulation phenomena

    International Nuclear Information System (INIS)

    The objective of this paper is to study the natural circulation in experimental loops and extend the results to nuclear facilities. New generation of compact nuclear power plants use the natural circulation as cooling and residual heat removal systems in case of accidents or shutdown. Lately the interest in this phenomenon, by scientific community, has increased. The experimental loop, described in this paper, was assembled at Escola Politecnica - USP at the Chemical Engineering Department. It is the goal to generate information to help with the understanding of the one and two phase natural circulation phenomena. Some experiments were performed with different levels of heat power and different flow of the cooling water at the secondary circuit. The data generated from these experiments are going to be used to validate some computational thermal hydraulic codes. Experimental results for one and two phase regimes are presented as well as the proposed model to simulate the flow regimes with the RELAP5 code. (author)

  7. MAGNETICALLY CONTROLLED CIRCULATION ON HOT EXTRASOLAR PLANETS

    International Nuclear Information System (INIS)

    Through the process of thermal ionization, intense stellar irradiation renders hot Jupiter atmospheres electrically conductive. Simultaneously, lateral variability in the irradiation drives the global circulation with peak wind speeds of the order of ∼km s–1. In turn, the interactions between the atmospheric flows and the background magnetic field give rise to Lorentz forces that can act to perturb the flow away from its purely hydrodynamical counterpart. Using analytical theory and numerical simulations, we show here that significant deviations away from axisymmetric circulation are unstable in presence of a non-negligible axisymmetric magnetic field. Specifically, our results suggest that dayside-to-nightside flows, often obtained within the context of three-dimensional circulation models, only exist on objects with anomalously low magnetic fields, while the majority of highly irradiated exoplanetary atmospheres are entirely dominated by zonal jets

  8. Tropical convective transport and the Walker circulation

    Directory of Open Access Journals (Sweden)

    J. S. Hosking

    2012-05-01

    Full Text Available We introduce a methodology to visualise rapid vertical and zonal tropical transport pathways. Using prescribed sea-surface temperatures in four monthly model integrations for 2005, preferred transport routes from the troposphere to the stratosphere are found in the model over the Maritime Continent (MC in November and February, i.e., boreal winter. In these months, the ascending branch of the Walker Circulation over the MC is formed in conjunction with strong deep convection, allowing fast transport into the stratosphere. At the same time, the downwelling branch of the Walker Circulation is enhanced over the East Pacific, compared to other months in 2005, reducing locally the upward transport from emissions below. We conclude that the Walker circulation plays an important role in the seasonality of fast tropical transport from the troposphere to the stratosphere and so impacts at the same time the potential supply of surface emissions.

  9. Cryogenic hydrogen circulation system of neutron source

    International Nuclear Information System (INIS)

    Cold neutron sources of reactors and spallation neutron sources are classic high flux neutron sources in operation all over the world. Cryogenic fluids such as supercritical or supercooled hydrogen are commonly selected as a moderator to absorb the nuclear heating from proton beams. By comparing supercritical hydrogen circulation systems and supercooled hydrogen circulation systems, the merits and drawbacks in both systems are summarized. When supercritical hydrogen circulates as the moderator, severe pressure fluctuations caused by temperature changes will occur. The pressure control system used to balance the system pressure, which consists of a heater as an active controller for thermal compensation and an accumulator as a passive volume controller, is preliminarily studied. The results may provide guidelines for design and operation of other cryogenic hydrogen system for neutron sources under construction

  10. Quantification of bronchial circulation perfusion in rats

    Science.gov (United States)

    Wietholt, Christian; Molthen, Robert C.; Haworth, Steven T.; Roerig, David L.; Dawson, Christopher A.; Clough, Anne V.

    2004-04-01

    The bronchial circulation is thought to be the primary blood supply for pulmonary carcinomas. Thus, we have developed a method for imaging and quantifying changes in perfusion in the rat lung due to development of the bronchial circulation. A dual-modality micro-CT/SPECT system was used to detect change in perfusion in two groups of rats: controls and those with a surgically occluded left pulmonary artery. Both groups were imaged following injections on separate days i) 2mCi of Tc99m labeled macroaggregated albumin (MAA) into the left carotid artery (IA) and ii) a similar injection into the femoral vein (IV). The IA injection resulted in Tc99m accumulation in capillaries of the systemic circulation including the bronchial circulation, whereas the IV resulted in Tc99m accumulation in the pulmonary capillaries. Ordered subset expectation maximization (OSEM) was used to reconstruct the SPECT image volumes and a Feldkamp algorithm was used to reconstruct the micro-CT image volumes. The micro-CT and SPECT volumes were registered, the SPECT image volume was segmented using the right and left lung boundaries defined from the micro-CT volume, and the ratio of IA radioactivity accumulation in the left lung to IV radioactivity accumulation in both lungs was used as a measure of left lung flow via the bronchial circulation. This ratio was ~0.02 for the untreated rats compared to the treated animals that had an increased flow ratio of ~0.21 40 days after left pulmonary artery occlusion. This increase in flow to the occluded left lung via the bronchial circulation suggests this will be a useful model for further investigating antiangiogenic treatments.

  11. The stripline circulator theory and practice

    CERN Document Server

    Helszajn, J

    2008-01-01

    Stripline circulator theory and applications from the world's foremost authority. The stripline junction circulator is a unique three-port non-reciprocal microwave junction used to connect a single antenna to both a transmitter and a receiver. Its operation relies on the interaction between an electron spin in a suitably magnetized insulator with an alternating radio frequency magnetic field. In its simplest form, it consists of a microwave planar gyromagnetic resonator symmetrically coupled by three transmission lines. This book explores the magnetic interaction involved in the stripline circ.

  12. Quenching phenomena in natural circulation loop

    Energy Technology Data Exchange (ETDEWEB)

    Umekawa, Hisashi; Ozawa, Mamoru [Kansai Univ., Osaka (Japan); Ishida, Naoki [Daihatsu Motor Company, Osaka (Japan)

    1995-09-01

    Quenching phenomena has been investigated experimentally using circulation loop of liquid nitrogen. During the quenching under natural circulation, the heat transfer mode changes from film boiling to nucleate boiling, and at the same time flux changes with time depending on the vapor generation rate and related two-phase flow characteristics. Moreover, density wave oscillations occur under a certain operating condition, which is closely related to the dynamic behavior of the cooling curve. The experimental results indicates that the occurrence of the density wave oscillation induces the deterioration of effective cooling of the heat surface in the film and the transition boiling regions, which results in the decrease in the quenching velocity.

  13. The circulation of the Mozambique channel

    Science.gov (United States)

    Sætre, Roald; Da Silva, António Jorge

    1984-05-01

    Based on hydrographic data from 1977 to 1980 off the coast of Mozambique and historical data from the Mozambique Channel, the general circulation pattern of the area is described. The circulation pattern is characterized by the influence of three anticyclonic gyres covering the northern, the central, and the southern parts of the channel. Additionally, smaller cyclonic eddies are observed, of which some probably are topographically induced. The results strongly indicate that in the upper 1000 m the role of the Mozambique Current as one of the tributaries to the Agulhas Current is of minor significance and draw into question the concept of the Mozambique Current as a continuous one.

  14. Blowing Circulation Control on a Seaplane Airfoil

    Science.gov (United States)

    Guo, B. D.; Liu, P. Q.; Qu, Q. L.

    2011-09-01

    RANS simulations are presented for blowing circulation control on a seaplane airfoil. Realizable k-epsilon turbulent model and pressure-based coupled algorithm with second-order discretization were adopted to simulate the compressible flow. Both clear and simple flap configuration were simulated with blowing momentum coefficient Cμ = 0, 0.15 and 0.30. The results show that blowing near the airfoil trailing edge could enhance the Coanda effect, delay the flow separation, and increase the lift coefficient dramatically. The blowing circulation control is promising to apply to taking off and landing of an amphibious aircraft or seaplane.

  15. Scaling Analysis of Natural Circulation Flow Loop

    International Nuclear Information System (INIS)

    To improve the thermal margin for the severe accident measures in high-power reactors, engineered corium cooling systems involving boiling-induced two-phase natural circulation have been proposed for decay heat removal. The boiling-induced natural circulation flow is generated in a coolant path between a hot vessel wall and cold coolant reservoir. In general, an increase in the natural circulation mass flow rate of the coolant leads to an increase in the critical heat flux (CHF) on the hot wall, thus enhancing the thermal margin. An ex-vessel core catcher under consideration, which is one of the engineered corium cooling system, is a passive system consisting of an inclined engineered cooling channel made of a single channel between the body of the core catcher and the inside wall of the reactor cavity. Under severe accident conditions, water is supplied from the IRWST to the engineered cooling channel. The water in the inclined channel absorbs the decay heat transferred from the corium through the carbon steel structure of the core catcher body and boils off as steam. The latter is subsequently released into the free volume of the containment above the corium spreading compartment. Water continues to flow from the IRWST to the cooling channel as a result of buoyancy-driven natural circulation. The engineered cooling channel is designed to provide effective long-term cooling and stabilization of the corium mixture in the core catcher body while facilitating steam venting. In this study, the scaling analysis was performed by solving the natural circulation flow loop equation for the cooling channel in the ex-vessel core catcher. The scaling analysis was performed by solving the natural circulation flow loop equation for the cooling channel in the ex-vessel core catcher. The boiling-induced natural circulation flow in the cooling channel of the core catcher has been modeled by considering the conservation of mass, momentum and energy in the two-phase mixture, along

  16. Applications of Circulation Control, Yesterday and Today

    OpenAIRE

    Jonathan Kweder; Chad C. Panthe; James E. Smit

    2010-01-01

    Circulation control, an aerodynamic method of changing the properties of an airfoil, such as lift, camber and angle of attack, has been used in several unique ways since its inception, as an enhancement to fixed wing aircraft, in the 1960’s. Early in the research venture, this technology was used on the main wing of an aircraft in conjunction with a Coandă surface, such as a rounded trailing edge or a deployable flap. Research during this time proved to be the foundation of the circulation co...

  17. Applications of Circulation Control, Yesterday and Today

    Directory of Open Access Journals (Sweden)

    Jonathan Kweder

    2010-12-01

    Full Text Available Circulation control, an aerodynamic method of changing the properties of an airfoil, such as lift, camber and angle of attack, has been used in several unique ways since its inception, as an enhancement to fixed wing aircraft, in the 1960’s. Early in the research venture, this technology was used on the main wing of an aircraft in conjunction with a Coandă surface, such as a rounded trailing edge or a deployable flap. Research during this time proved to be the foundation of the circulation control technology and showed that small amounts of exit jet velocity could have a large impact on the aerodynamics of an airfoil. In the 1970’s the inspirations that drove circulation control research changed from design work to optimization of the parameters which were found to have the most effect on circulation control. These studies included slot placement, favorable momentum coefficient, and pressurization benefits and determents. This research period also allowed for expansion of the uses of circulation control to submarine/hydrodynamic and rotary wing applications. Newest research has brought on several propeller driven applications and the recent push for efficient renewable research has allowed circulation control research technologies to evolve into use in wind turbine and water turbine applications. The idea being that with circulation control the turbine can adapt easier to the changing wind velocity and direction and ultimately capture more power than an un-augmented turbine. As with most new and novel technologies there is a process and time delay associated with their development and ultimate application. For some technologies the market, or the supporting hardware, are lacking and sometimes the technology has strong advocacies for yet to be fulfilled expectations. In most of these cases a strong idea will re-surface repeatedly until the art has matured, or the better solution is found. This paper will focus on the previously developed

  18. An experimental study on the flow instabilities and critical heat flux under natural circulation

    International Nuclear Information System (INIS)

    This study has been carried out to investigate the hydrodynamic stabilities of natural circulation and to analyze Critical Heat Flux (CHF) characteristics for the natural and forced circulation. A low pressure experimental loop was constructed, and experiments under various conditions have been performed. In the experiments of the natural circulation, flow oscillations and the average mass flux have been observed. Several parameters such as heat flux, the inlet temperature of test section, friction valve opening and riser length have been varied in order to investigate their effects on the flow stability of the natural circulation system. The results show that the flow instability has strongly dependent on geometric conditions and operating parameters, the inlet temperature and the heat flux of test section. It was found that unstable region for the heat flux and the inlet temperature exists between the single-phase stable region of low heat and low inlet temperature and the two-phase stable region of very high heat flux and high inlet temperature. The CHF data from the natural and forced circulation experiments have been compared each other to identify the effects of the flow instabilities on the CHF for the natural circulation mode. The test conditions were low flow less than 70 kg/m2s of water in vertical round tube with diameter of 0.008m at near atmospheric pressure. In this study, no difference in CHF values is observed between natural and fored circulation. Since low flow usually has the oscillation characteristic of relatively low amplitude and high frequency, the effect of the flow instabilities on the CHF seems to be negligible

  19. A Study on Planetary Atmospheric Circulations using THOR

    Science.gov (United States)

    Mendonça, João; Grosheintz, Luc; Lukas Grimm, Simon; Heng, Kevin

    2015-12-01

    The large variety of planetary parameters observed leads us to think that exoplanets may show a large range of possible climates. It is therefore of the uttermost importance to investigate the influence of astronomical and planetary bulk parameters in driving the atmospheric circulations. In the solar system the results from planetary spacecraft missions have demonstrated how different the planetary climate and atmospheric circulations can be. The study of exoplanets will require probing a far wider range of physical and orbital parameters than the ones of our neighbor planets. For this reason, such a study will involve exploring an even larger diversity of circulation and climate regimes. Our new atmospheric model, THOR, is intended to be extremely flexible and to explore the large diversity of planetary atmospheres.THOR is part of the Exoclimes Simulation Platform, and is a project of the Exoplanet and Exoclimes Group (see www.exoclime.org). THOR solves the complex atmospheric fluid equations in a rotating sphere (fully compressible - nonhydrostatic system) using an icosahedral grid. The main advantages of using our new platform against other recent exoplanet models is that 1) The atmospheric fluid equations are completely represented and no approximations are used that could compromise the physics of the problem; 2) The model uses for the first time in exoplanet studies, a specific icosahedral grid that solves the pole problem; 3) The interface is user friendly and can be easily adapted to a multitude of atmospheric conditions; 4) By using GPU computation, our code greatly improves the typical code running time.We will present and discuss the first detailed results of our simulations, more specifically of two benchmark tests that are a representative sample of the large range of exoplanetary parameters: Earth-like conditions (the Held-Suarez test) and a tidally locked hot-Jupiter. THOR has successfully passed these tests and is able to determine the main

  20. Indigenous development of ferrite circulator for RF system of accelerator at RRCAT

    International Nuclear Information System (INIS)

    We have undertaken indigenous development of temperature stable high power ferrite circulators for RF System of Indus Accelerators and Proton linac at RRCAT Indore. The high power ferrite circulators at 476 MHz, 505 MHz and 650 MHz are being indigenously developed for RF system of IRFEL, Indus- 2 and Proton Linac. Ferrite circulator technology is advanced, complex, sophisticated and not available in. A lot of innovative R and D on ferrite and circulator have done in terms of both materials and devices at Ferrite Laboratory of Accelerator Magnet Technology Division. A 200 mm diameter disks in Calcium Vanadium garnet, Gadolinium Dy garnet and NiAl spinel ferrite compositions have been successfully indigenously developed and tested at 505.8 MHz and 650 MHz. An excellent magnetic stability w.r.t temp (up to 250 °C), narrow resonance line width (∼ 50 Oe) and large spin wave width (∼ 10 Oe) have been achieved. A ferrite/garnet disk (∼200 mm) resonator with composite magnetic circuit has been fabricated and characterized. A detailed indigenous large ferrite and garnet disk technology, power threshold of ferrite, technical challenges in circulator design and development, permanent magnetic circuits, current status and indigenous development strategies for high power ferrite circulators for future accelerators will be discussed in this paper

  1. Transient characteristic analysis of integral pressurized water reactor from forced circulation to natural circulation

    International Nuclear Information System (INIS)

    Natural circulation of nuclear reactor has heat dumpling capacity, which can improve the inherent safety of reactor. In this paper, the conceptional design of integrated pressurized water reactor was studied and RELAP5/MOD3.4 was used to analyze transient characteristic in the process from forced circulation to natural circulation. What's more, the influence of reactor power, resistance, moment of inertia of main pump, and various operation strategies on transient characteristic in this conversion process were also studied. (authors)

  2. On Pareto theory of circulation of elites

    OpenAIRE

    Ricardo P\\'erez-Marco

    2014-01-01

    We prove that Pareto theory of circulation of elites results from our wealth evolution model, Kelly criterion for optimal betting and Keynes' observation of "animal spirits" that drive the economy and cause that human financial decisions are prone to excess risk-taking.

  3. General circulation modeling of the Jupiter stratosphere

    Science.gov (United States)

    Sethunadh, J.; Medvedev, A. S.; Hartogh, P.

    2012-09-01

    The stratosphere of Jupiter extends for more than 350 km above the cloud top. It is driven almost equally by the radiative heating and cooling within the atmosphere, and by heat from below. We present first results of simulations with the newly developed general circulation model (GCM).

  4. General circulation of the Jovian stratosphere

    Science.gov (United States)

    Medvedev, Alexander S.; Sethunadh, Jisesh; Hartogh, Paul

    The stratosphere of Jupiter is a convectively stable and coldest layer that extends for about 350 km above the tropopause. The dynamics of stratospheres of fast rotating gas giants differ from that of terrestrial-like planets, their modeling is more challenging, and is still little known despite a growing number of observations. We present results of simulations with a newly developed Jovian general circulation model, which covers the altitudes between one bar and one microbar. The results demonstrate a high sensitivity of the circulation to variations of eddy diffusion, which, in turn, depends on the model resolution and assumed background viscosity. In the lower stratosphere, the multiple circulation cells associated with the tropospheric alternating jets dominate. Higher, a weak two-cell equator-to-pole transport forms due to the influence of smaller-scale eddies. The strength and extent of this circulation are defined by the momentum supplied by shallow and vertically propagating waves, and are consistent with observations of the Shoemaker-Levi 9 comet traces. We will also discuss the dynamical implications of our recent finding that radiative forcing exponentially increases with height, rather than approximately constant throughout the Jovian stratosphere, as was thought before (see presentation of T. Kuroda at B0.3 session).

  5. Detecting Holocene changes in thermohaline circulation

    OpenAIRE

    L. D. Keigwin; Boyle, E. A.

    2000-01-01

    Throughout the last glacial cycle, reorganizations of deep ocean water masses were coincident with rapid millennial-scale changes in climate. Climate changes have been less severe during the present interglacial, but evidence for concurrent deep ocean circulation change is ambiguous.

  6. Circulating amounts of osteoprotegerin and RANK ligand

    DEFF Research Database (Denmark)

    Abrahamsen, Bo; Hjelmborg, Jacob Vb; Kostenuik, Paul;

    2005-01-01

    UNLABELLED: Osteoprotegerin (OPG) is a circulating receptor that inhibits osteoclastogenesis by binding to RANK ligand (RANKL). OPG knock-out animals develop severe osteoporosis. Treatment with OPG lowers bone resorption and increases BMD. OPG production is influenced by a wide range of hormones ...

  7. [Regional liver circulation and the scintigraphic representation of the portal circulation with 133Xe].

    Science.gov (United States)

    Kroiss, A

    1984-01-01

    Regional hepatic blood flow has been determined by 4 methods with the aid of the 133Xe washout technique: scintisplenoportography (direct application of 133Xe into the spleen by means of a thin needle); arterial method (133Xe is injected into the A. hepatica by means of a catheter); retrograde-venous method (133Xe administered by an occluding hepatic vein catheter); percutaneous intrahepatic method (133Xe administered directly into the parenchyma by means of a Chiba needle). Ad 1.: Scintisplenoportography (SSP) was executed with 97 patients: 8 patients with a healthy liver presented a hepatic blood flow of 103.37 +/- 11.5 ml/100 g/min. 4 patients with a chronic hepatitis showed a hepatic blood flow of 105.67 +/- 10.2 ml/100 g/min. In 38 patients with compensated cirrhosis, hepatic blood flow was determined with 58.15 +/- 11.5 ml/100 g/min and 19 patients with decompensated cirrhosis showed a blood flow of 34.54 +/- 7.2 ml/100 g/min. Of the 19 patients, who did not present any liver image, 2 patients suffered from a prehepatic block, 1 patient (female) from a posthepatic block, the rest were decompensated cirrhoses. In 5 patients suffering from steatosis only collateral circulation was determined and in 4 patients the spleen could not be punctured. In the patients with compensated and decompensated cirrhosis of the liver, hepatic blood flow differentiated significantly (p less than 0.001) from patients with healthy livers and chronic hepatitis. In the patients with bioptically assured steatosis only the washout constant was determined. Reproducibility of this method was tested in 4 patients and no statistical difference of hepatic blood flow values could be found and the correlation coefficient amounted to 0.9856. The advantage of SSP lies in the possibility of recording the portal vein circulation: cranial collaterals were found in 33 patients, 2 patients had caudal collaterals exclusively and 29 patients cranial and caudal collaterals. 33 cirrhosis patients

  8. Study in rabbits of portal circulation by a radioisotopic method

    International Nuclear Information System (INIS)

    The development of a precocius - and noninvasive method for the detection of portal circulation alterations by means of time interval measurements between the rectal administration of radiotracers and their detection in liver and head is aimed at. The pertecnetate (99sup(m)Tc)- and iodate (131I) absorption by the terminal large intestine was tested in 22 rabbits. The time iinterval between rectal administration of the radiotracer and its appearance in liver and head was determined in 12 rabbits, by external detection with a scintillation camera. The same parameters were studied in 9 animals submitted to the ligature of the portal vein. Iodate and pertecnetate are absorbed by the terminal large intestine, the pertecnetate absorption being significantly smaller than that of iodate. The pertecnetate distribution volume is smaller than that of iodate; the rectum - liver - and rectum - head time intervals is increased in animals with the ligature of portal vein. Application of the method to larger animals will permit the necessary improvements for its utilization as a precocius - noninvasive - and inocuous test in the evaluation of alteration of the human portal circulation. (Author)

  9. Two-phase natural circulation experiments in a pressurized water loop with CANDU geometry

    International Nuclear Information System (INIS)

    To provide information on two-phase natural circulation in a CANDU-type coolant circuit a series of tests has been performed in the RD-12 loop at the Whiteshell Nuclear Research Establishment. RD-12 is a 10-MPa pressurized-water loop containing two active boilers, two pumps, and two, or four, heated horizontal channels arranged in a symmetrical figure-of-eight configuration characteristic of the CANDU reactor primary heat-transport system. In the tests, single-phase natural circulation was established in the loop and void was introduced by controlled draining, with the surge tank (pressurizer) valved out of the system. The paper reviews the experimental results obtained and describes the evolution of natural circulation flow in particular cases as voidage is progressively increased. The stability behaviour is discussed briefly with reference to a simple stability model

  10. CIRCUS and DESIRE: Experimental facilities for research on natural-circulation-cooled boiling water reactors

    International Nuclear Information System (INIS)

    At the Delft University of Technology two thermohydraulic test facilities are being used to study the characteristics of Boiling Water Reactors (BWRs) with natural circulation core cooling. The focus of the research is on the stability characteristics of the system. DESIRE is a test facility with freon-12 as scaling fluid in which one fuel bundle of a natural-circulation BWR is simulated. The neutronic feedback can be simulated artificially. DESIRE is used to study the stability of the system at nominal and beyond nominal conditions. CIRCUS is a full-height facility with water, consisting of four parallel fuel channels and four parallel bypass channels with a common riser or with parallel riser sections. It is used to study the start-up characteristics of a natural-circulation BWR at low pressures and low power. In this paper a description of both facilities is given and the research items are presented. (author)

  11. Development of liquefaction circulation system for liquid-Ar TPC detector

    International Nuclear Information System (INIS)

    We are developing the high efficiently circulation system for refining liquid argon to high purity for the hundred kton liquid argon TPC. In this measurement, the liquefaction efficiency was measured with the length and the material of the heat exchanger coil. The performance of re-condenser was measured with the test bench and the prototype cryostat with size of 250 L. The efficiency of liquefaction was about 86% with the test bench. With the system of connecting of the re-condenser to the 250LAr container, the flow rate of circulating gas is the maximum 25L/min on -188.5degC of cold head temperature and the maximum 48L/min on -185.7degC. When operating by 48L/min of flow rate of supplied gas, the liquid argon of 300L was able to circulate in about 82 hours. (author)

  12. Observations of the summer Red Sea circulation

    Science.gov (United States)

    Sofianos, Sarantis S.; Johns, William E.

    2007-06-01

    Aiming at exploring and understanding the summer circulation in the Red Sea, a cruise was conducted in the basin during the summer of 2001 involving hydrographic, meteorological, and direct current observations. The most prominent feature, characteristic of the summer circulation and exchange with the Indian Ocean, is a temperature, salinity, and oxygen minimum located around a depth of 75 m at the southern end of the basin, associated with Gulf of Aden Intermediate Water inflowing from the Gulf of Aden during the summer season as an intruding subsurface layer. Stirring and mixing with ambient waters lead to marked increases in temperature (from 16.5 to almost 33°C) and salinity (from 35.7 to more than 38 psu) in this layer by the time it reaches midbasin. The observed circulation presents a very vigorous pattern with strong variability and intense features that extend the width of the basin. A permanent cyclone, detected in the northern Red Sea, verifies previous observations and modeling studies, while in the central sector of the basin a series of very strong anticyclones were observed with maximum velocities exceeding 1 m/s. The three-layer flow pattern, representative of the summer exchange between the Red Sea and the Gulf of Aden, is observed in the strait of Bab el Mandeb. In the southern part of the basin the layer flow is characterized by strong banking of the inflows and outflows against the coasts. Both surface and intermediate water masses involved in the summer Red Sea circulation present prominent spatial variability in their characteristics, indicating that the eddy field and mixing processes play an important role in the summer Red Sea circulation.

  13. Decontamination of CAGR gas circulator components

    International Nuclear Information System (INIS)

    This paper describes the development and full-scale trial of two methods for removal of radioactive contamination on the surfaces of CAGR gas circulator components. The two methods described are a particle impact cleaning (PIC) decontamination technique and an electrochemical technique, 'electro-swabbing', which is based on the principle of decontamination by electro-polishing. In developing these techniques it was necessary to take account of the physical and chemical nature of the surface deposits on the gas circulator components; these were shown to consist of magnetite-type oxide and carbonaceous material. In order to follow the progress of the decontamination it was also necessary to develop a surface sampling technique which was effective and precise under these conditions; an electrochemical technique, employing similar principles to the electro-swabbing process, was developed for this purpose. The full-scale trial of the PIC decontamination technique was carried out on an inlet guide vane (IGV) assembly, this having been identified as the component from the gas circulator which contributes most to the radiation dose accumulated during routine circulator maintenance. The technique was shown to be practically viable and some 99% of the radioactive contamination was readily removed from the treated surfaces with only negligible surface damage being caused. The full-scale trial of the electro-swabbing decontamination technique was carried out on a gas circulator impeller. High decontamination factors were again achieved with ≥ 99% of the radioactive contamination being removed from the treated surfaces. The technique has practical limitations in terms of handling and treatment of waste-arisings. However, the use of specially-designed swabbing electrodes may allow the treatment of constricted geometries inaccessible to techniques such as PIC. The technique is also highly suitable for the treatment of soft-finish materials and of components fabricated from a

  14. Effects of Microtopography on Overmarsh Circulation

    Science.gov (United States)

    Sullivan, J. C.; Torres, R.; Garrett, A.

    2013-12-01

    Authors: J.C. Sullivan, R. Torres, A.J. Garrett In this study we systematically degrade a high-resolution, high precision salt marsh DEM and characterize the effects of DEM smoothing on overmarsh circulation. The question driving this effort is: How much topographic detail is needed to accurately simulate salt marsh circulation? The hydrodynamic model Delft3D was applied to data from a previous dye-tracer study in a 2 km2 semi-enclosed salt marsh basin at Skidaway Institute of Oceanography near Savannah, Georgia, USA. Overmarsh circulation was simulated for each smoothed DEM over a 5 day period corresponding to spring tide conditions. Results show that flood and ebb pathways differ significantly, but this effect is less apparent as the DEM is smoothed. Also, the flushing time (Tf) decreases with smoothing leading to greater dilution of a dye tracer with each tidal cycle. Observations at the macro, meso and micro scale show that flood and ebb flows become stronger through a consistent set of flow paths, including intertidal creeks, and differences in overmarsh circulation are more apparent in low marsh and channel head areas. This work shows that accurate representation of overmarsh circulation requires that the DEM resolve creek and low lying marsh structures at a spatial scale of 2-4m, but not necessarily the smallest tidal creeks (< 1m in width and depth). The next phase of this work will be to incorporate spatial variations in vegetation cover using RULLI (Remote Ultra Low-Light Imaging) remote sensing technology developed by the Department of Energy.

  15. Circulation factors affecting precipitation over Bulgaria

    Science.gov (United States)

    Nojarov, Peter

    2015-09-01

    The objective of this paper is to determine the influence of circulation factors on precipitation in Bulgaria. The study succeeds investigation on the influence of circulation factors on air temperatures in Bulgaria, as the focus here is directed toward precipitation amounts. Circulation factors are represented through two circulation indices, showing west-east or south-north transport of air masses over Bulgaria and four teleconnection indices (patterns)—North Atlantic Oscillation, East Atlantic, East Atlantic/Western Russia, and Scandinavian. Omega values at 700-hPa level show vertical motions in the atmosphere. Annual precipitation trends are mixed and not statistically significant. A significant decrease of precipitation in Bulgaria is observed in November due to the strengthening of the eastward transport of air masses (strengthening of EA teleconnection pattern) and anticyclonal weather (increase of descending motions in the atmosphere). There is also a precipitation decrease in May and June due to the growing influence of the Azores High. An increase of precipitation happens in September. All this leads to a redistribution of annual precipitation course, but annual precipitation amounts remain the same. However, this redistribution has a negative impact on agriculture and winter ski tourism. Zonal circulation has a larger influence on precipitation in Bulgaria compared to meridional. Eastward transport throughout the year leads to lower than the normal precipitation, and vice versa. With regard to the four teleconnection patterns, winter precipitation in Bulgaria is determined mainly by EA/WR teleconnection pattern, spring and autumn by EA teleconnection pattern, and summer by SCAND teleconnection pattern.

  16. Experimental investigations in high-pressure natural circulation loop: progress report for the period January-June, 1999

    International Nuclear Information System (INIS)

    The Advanced Heavy Water Reactor employs natural circulation as the normal mode of coolant circulation. This is expected to enhance safety and reliability as it eliminates all safety issues associated with the pump failure. Two-phase natural circulation, however, is susceptible to several types of instabilities. In addition, the flow rate in a natural circulation loop is a dependent quantity and is not known a priori. Reliable calculations of the flow rate and stability behaviour are essential to ensure the success of AHWR design. Hence computer codes developed to predict the steady state flow rate and stability behaviour require validation against test data under natural circulation. For this purpose a high-pressure natural circulation loop has been designed, constructed and commissioned. Steady state experiments have been carried out in this loop to study the effect of pressure on natural circulation flow rate. The experimental results for this case are presented in this report. More experiments are planned in future to study the various aspects of two-phase natural circulation. (author)

  17. Development Strategies for Rural Key Circulation Service Network

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    The rural key circulation service network is an important channel for ensuring agricultural products’entry to market and urban industrial products’entry to rural areas.Through in-depth survey and research,we took a look at development changes and current situations of three circulation service networks,namely,circulation of nondurable consumer goods,circulation of agricultural means of production,and circulation of agricultural products.Based on several key problems in rural circulation service network,such as logistics problem,delivery problem,backward transaction mode,and the last kilometer information,we put forward corresponding development countermeasures.

  18. An experimental study on the flow instabilities and critical heat flux under natural circulation

    International Nuclear Information System (INIS)

    This study has been carried out to investigate the hydrodynamic stabilities and Critical Heat Flux (CHF) characteristics for the natural and forced circulation. A low pressure experimental loop was constructed, and experiments under various conditions have been performed. In the experiments of the natural circulation, flow oscillations has been observed and the average mass flux under flow oscillation have been measured. Several parameters such as heat flux, the inlet temperature of test section, friction valve opening and riser length have been varied in order to investigate their effects on the flow stability of the natural circulation system. And the CHF data from low flow experiments, namely the natural and forced circulation, have been compared with each other to identify the effects of the flow instabilities on the CHF for the natural circulation mode. The test conditions for the CHF experiments were a low flow of less than 70 kg/m2s of water in a vertical round tube with diameter of 0.008 m at near atmospheric pressure. (author)

  19. Intercomparison of General Circulation Models for Hot Extrasolar Planets

    CERN Document Server

    Polichtchouk, Inna; Watkins, Chris; Thrastarson, Heidar Thor; Umurhan, Orkan M; Juarez, Manuel de la Torre

    2013-01-01

    We compare five general circulation models (GCMs) which have been recently used to study hot extrasolar planet atmospheres (BOB, CAM, IGCM, MITgcm, and PEQMOD), under three test cases useful for assessing model convergence and accuracy. Such a broad, detailed intercomparison has not been performed thus far for extrasolar planets study. The models considered all solve the traditional primitive equations, but employ different numerical algorithms or grids (e.g., pseudospectral and finite volume, with the latter separately in longitude-latitude and `cubed-sphere' grids). The test cases are chosen to cleanly address specific aspects of the behaviors typically reported in hot extrasolar planet simulations: 1) steady-state, 2) nonlinearly evolving baroclinic wave, and 3) response to fast timescale thermal relaxation. When initialized with a steady jet, all models maintain the steadiness, as they should -- except MITgcm in cubed-sphere grid. A very good agreement is obtained for a baroclinic wave evolving from an in...

  20. The spacing of Langmuir circulation under modest wind

    Institute of Scientific and Technical Information of China (English)

    LI Shuang; SONG Jinbao

    2012-01-01

    Spacing characteristics of Langmuir circulation (LC) are computed by large eddy simulation (LES) model under modest wind.LC is an organized vertical motion,evidenced as buoyant materials forming lines nearly parallel to the wind direction.The horizontal distribution of velocity computed by LES shows clear lines formed by LC.These lines grow and parallel to each other for a while,which we call the stable state,before they finally form Y-junctions.We computed spacing between every two parallel lines by averaging them under the stable state.Statistically,spacing results of 154 tests (seven wind speed cases of 22 test runs each) show high correlations berween spacing and wind speed,as well as mixed layer depth.The relationship of spacing and wind is important for future LC parameterization of upper-ocean mixing.

  1. Forced circulation type steam generator simulation code: HT4

    International Nuclear Information System (INIS)

    The purpose of this code is a understanding of dynamic characteristics of the steam generator, which is a component of High-temperature Heat Transfer Components Test Unit. This unit is a number 4th test section of Helium Engineering Demonstration Loop (HENDEL). Features of this report are as follows, modeling of the steam generator, a basic relationship for the continuity equation, numerical analysis techniques of a non-linear simultaneous equation and computer graphics output techniques. Forced circulation type steam generator with strait tubes and horizontal cut baffles, applied in this code, have be designed at the Over All System Design of the VHTRex. The code is for use with JAERI's digital computer FACOM M200. About 1.5 sec required for each time step reiteration, then about 40 sec cpu time required for a standard problem. (author)

  2. Analysis, testing, and operation of the MAGI thermal control system

    International Nuclear Information System (INIS)

    The Aerospace Corporation has completed the development of the Mineral and Gas Identifier (MAGI) sensor - an airborne multi-spectral infrared instrument that is designed to discriminate surface composition and to detect gas emissions from the environment. Sensor performance was demonstrated in a series of flights aboard a Twin Otter aircraft in December 2011 as a stepping stone to a future satellite sensor design. To meet sensor performance requirements the thermal control system was designed to operate the HgCdTe focal plane array (FPA) at 50 K with a 1.79 W heat rejection load to a 44.7 K sink and the optical assembly at 100 K with a 7.5 W heat load to a 82.3 K sink. Two commercial off-theshelf (COTS) Sunpower Stirling cryocoolers were used to meet the instrument’s cooling requirements. A thermal model constructed in Thermal Desktop was used to run parametric studies that guided the mechanical design and sized the two cryocoolers. This paper discusses the development, validation, and operation of the MAGI thermal control system. Detailed energy balances and temperature predictions are presented for various test cases to demonstrate the utility and accuracy of the thermal model. Model inputs included measured values of heat lift as a function of input power and cold tip temperature for the two cryocoolers. These measurements were also used to make predictions of the cool-down behavior from ambient conditions. Advanced heater software was developed to meet unique requirements for both sensor cool-down rate and stability at the set point temperatures

  3. Twenty-five years of Brown Boveri experience in development, design and fabrication of circulators for HTGR

    International Nuclear Information System (INIS)

    The two circulators for the AVR experimental reactor in Juelich, Federal Republic of Germany, were supplied. The circulators, which are equipped with oil bearings, have been operating troublefree since the start of commissioning in 1966. As a consequence of a water ingress into the reactor resulting from a steam generator damage one bearing was replaced in 1977 after 72,000 operating hours. Up to the present date, each of the circulators has scored 115,000 hours of operation, one of them without any disassembly. In the THTR 300 in Schmehausen, Federal Republic of Germany, 6 BBC circulators are in operation. The insertable circulator units equipped with oil bearings have successfully proven their operating capability without any problems during the commissioning phase and the 100% power operation which was started recently. Currently active magnetic bearings are being developed for advanced gas-cooled reactors such as the HTR 100, the HTR 500 and the heating reactor after excellent results have been furnished by a small prototype in a test loop. This ADI circulator has since scored more than 15,000 operating hours without any trouble. A retainer bearing test stand also equipped with active magnetic bearings has been in operation for nearly 2 years. This test stand serves for developing the conditions for safe rundown of the rotors of even the largest circulators after the magnetic bearings have been deenergized unintentionally. Development work is conducted on the prototype of a safety-relevant circulator held in magnetic bearings, to be used for decay heat removal in the HTR 500. The original aim to have circulators without auxiliary medium for bearing lubrication will thus be reached. The advantages to be obtained in process and systems design are a supplementary support to the inherent safety characteristics of high-temperature reactors. Another advantage of these bearings is cost reduction. 5 refs, 7 figs

  4. Apoptosis of circulating lymphocytes during pediatric cardiac surgery

    Science.gov (United States)

    Bocsi, J.; Pipek, M.; Hambsch, J.; Schneider, P.; Tárnok, A.

    2006-02-01

    There is a constant need for clinical diagnostic systems that enable to predict disease course for preventative medicine. Apoptosis, programmed cell death, is the end point of the cell's response to different induction and leads to changes in the cell morphology that can be rapidly detected by optical systems. We tested whether apoptosis of T-cells in the peripheral blood is useful as predictor and compared different preparation and analytical techniques. Surgical trauma is associated with elevated apoptosis of circulating leukocytes. Increased apoptosis leads to partial removal of immune competent cells and could therefore in part be responsible for reduced immune defence. Cardiovascular surgery with but not without cardiopulmonary bypass (CPB) induces transient immunosuppression. Its effect on T-cell apoptosis has not been shown yet. Flow-cytometric data of blood samples from 107 children (age 3-16 yr.) who underwent cardiac surgery with (78) or without (29) CPB were analysed. Apoptotic T-lymphocytes were detected based on light scatter and surface antigen (CD45/CD3) expression (ClinExpImmunol2000;120:454). Results were compared to staining with CD3 antibodies alone and in the absence of antibodies. T-cell apoptosis rate was comparable when detected with CD45/CD3 or CD3 alone, however not in the absence of CD3. Patients with but not without CPB surgery had elevated lymphocyte apoptosis. T-cell apoptosis increased from 0.47% (baseline) to 0.97% (1 day postoperatively). In CPB patients with complication 1.10% significantly higher (ANOVA p=0.01) comparing to CPB patients without complications. Quantitation of circulating apoptotic cells based on light scatter seems an interesting new parameter for diagnosis. Increased apoptosis of circulating lymphocytes and neutrophils further contributes to the immune suppressive response to surgery with CPB. (Support: MP, Deutsche Herzstiftung, Frankfurt, Germany)

  5. Circulation patterns in active lava lakes

    Science.gov (United States)

    Redmond, T. C.; Lev, E.

    2014-12-01

    Active lava lakes provide a unique window into magmatic conduit processes. We investigated circulation patterns of 4 active lava lakes: Kilauea's Halemaumau crater, Mount Erebus, Erta Ale and Nyiragongo, and in an artificial "lava lake" constructed at the Syracuse University Lava Lab. We employed visual and thermal video recordings collected at these volcanoes and use computer vision techniques to extract time-dependent, two-dimensional surface velocity maps. The large amount of data available from Halemaumau enabled us to identify several characteristic circulation patterns. One such pattern is a rapid acceleration followed by rapid deceleration, often to a level lower than the pre-acceleration level, and then a slow recovery. Another pattern is periodic asymmetric peaks of gradual acceleration and rapid deceleration, or vice versa, previously explained by gas pistoning. Using spectral analysis, we find that the dominant period of circulation cycles at approximately 30 minutes, 3 times longer than the dominant period identified previously for Mount Erebus. Measuring a complete surface velocity field allowed us to map and follow locations of divergence and convergence, therefore upwelling and downwelling, thus connecting the surface flow with that at depth. At Nyiragongo, the location of main upwelling shifts gradually, yet is usually at the interior of the lake, for Erebus it is usually along the perimeter yet often there is catastrophic downwelling at the interior; For Halemaumau upwelling/downwelling position is almost always on the perimeter. In addition to velocity fields, we developed an automated tool for counting crustal plates at the surface of the lava lakes, and found a correlation, and a lag time, between changes if circulation vigor and the average size of crustal plates. Circulation in the artificial basaltic lava "lake" was limited by its size and degree of foaming, yet we measured surface velocities and identify patterns. Maximum surface velocity

  6. Improvement of ATHLET modelling capability for asymmetric natural circulation phenomenon using uncertainty and sensitivity measures

    International Nuclear Information System (INIS)

    Highlights: • Overprediction of mass flow during asymmetric natural circulation of PKL facility is observed by ATHLET code. • Uncertainty and sensitivity measures are used to evaluate the influence of various input and model parameters. • Bypass heating location, values, and heat loss coefficient of isolated steam generator are identified. • The mass flow reduction phenomenon in the isolated loop can be captured by the improved modelling. - Abstract: Natural circulation is one of the most important phenomena relating to nuclear reactor safety. In the last years of 20th century, lots of test facilities were set up to conduct natural circulation experiments. At the same time, some system codes, such as RELAP5 and CATHARE, have been validated by the experimental data carried out by these facilities. The calculation results show that these codes can capture most of the characters during the natural circulation transient, except some special processes. One of the examples is PKL IIIB3.1 test, an asymmetric natural circulation transient in the primary loop with an isolated steam generator. The cooled down process using the intact steam generators by reducing the secondary side pressure is the driving force of the natural circulation in primary loop. In this paper, a post-test calculation is performed by best-estimate thermal-hydraulic code ATHLET to simulate PKL IIIB3.1 test. Due to the effect of isolated steam generator on the whole primary cooling system, the results show that the mass flow in the isolated loop is overpredicted significantly comparing to the experimental data. Many measures have been tried to improve the simulation results, but an effective method is still missing. Based on the post-test calculation results, an uncertainty and sensitivity analysis is carried out to find out the main reason causing this higher circulation mass flow. Lots of factors are considered in this study, e.g. the boundary conditions, thermal-hydraulic correlations, and

  7. EVALUATION OF AERATION/CIRCULATION AS A LAKE RESTORATION TECHNIQUE

    Science.gov (United States)

    Artificial circulation and hypolimnetic aeration are management techniques for oxygenating eutrophic lakes subject to water quality problems, algal blooms, and fishkills. Artificial circulation is achieved by injecting diffused air into lower waters, by mechanial pumping of water...

  8. Silent Circulation of Ross River Virus in French Polynesia

    Directory of Open Access Journals (Sweden)

    Maite Aubry

    2015-08-01

    Discussion: Our results support the existence of autochthonous RRV transmission and suggest that this pathogen has silently circulated in French Polynesia. These findings raise the question of possible undetected circulation of RRV in other Pacific Island Countries and Territories.

  9. Valuation of main circulation pumps vibration for the WWER nuclear power plants

    International Nuclear Information System (INIS)

    The problems of valuation of main circulation pumps vibration on delivery trials, in start-up tests and in operation have been considered. The frequency range, number and arrangement of detectors as well as their operation conditions under which the vibrocontrol is being performed, have been determined

  10. Ultra-filtration rhenium extraction out of circulating waters of copper production

    International Nuclear Information System (INIS)

    Possibility of effective rhenium extraction via complex formation - ultra-filtration out of circulating waters, forming in copper ores concentration is shown. The most selectivity to rhenium is found for polyelectrolyte VA-212, among different tested water-soluble polymers containing groups of quaternary ammonium base. The method for regeneration of polyelectrolyte is proposed, possibility of its multiple usage for rhenium extraction is shown

  11. Efficient global solution of residual heat removal system with natural circulation

    International Nuclear Information System (INIS)

    The mathematical model of the residual heat removal system with multiple coupled natural circulation loops has distinct nonlinear characteristics. The global solution method with high efficiency was developed, implemented and tested. Compared with the original method which uses the nested point iteration procedure, one magnitude of calculation speed improvement is achieved. (authors)

  12. Anti-cyclonic circulation driven by the estuarine circulation in a gulf type ROFI

    Science.gov (United States)

    Fujiwara, T.; Sanford, L. P.; Nakatsuji, K.; Sugiyama, Y.

    1997-08-01

    Baroclinic residual circulation processes are examined in gulf type Regions Of Freshwater Influence (ROFIs), which have large rivers discharging into a rounded head wider than the Rossby internal deformation radius. Theoretical and observational investigations concentrate on Ise Bay, Japan, with supporting data from Osaka Bay and Tokyo Bay. Simplified analytical solutions are derived to describe the primary features of the circulation. Three dimensional residual current data collected using moored current meters and shipboard acoustic doppler current profilers (ADCPs), satellite imagery and density structure data observed using STDs, are presented for comparison to the theoretical predictions. There are three key points to understanding the resulting circulation in gulf type ROFIs. First, there are likely to be three distinct water masses: the river plume, a brackish upper layer, and a higher salinity lower layer. Second, baroclinic processes in gulf type ROFIs are influenced by the Earth's rotation at first order. Residual currents are quasi-geostrophic and potential vorticity is approximately conserved. Third, the combined effects of a classical longitudinal estuarine circulation and the Earth's rotation are both necessary to produce the resulting circulation. Anti-cyclonic vorticity is generated in the upper layer by the horizontal divergence associated with upward entrainment, which is part of the estuarine circulation. The interaction between anti-cyclonic vorticity and horizontal divergence results in two regions of qualitatively different circulation, with gyre-like circulation near the bay head and uniformly seaward anti-cyclonicly sheared flow further towards the mouth. The stagnation point separating the two regions is closer to (further away from) the bay head for stronger (weaker) horizontal divergence, respectively. The vorticity and spin-up time of this circulation are-(ƒ-ω 1)/2 and h/2w 0, respectively, where ƒ is the Coriolis parameter, ω 1 is

  13. Cognitive problems related to vertebrobasilar circulation.

    Science.gov (United States)

    Koçer, Abdulkadir

    2015-01-01

    Neurodegenerative disorders are characterized by decreased regional cerebral blood flow. Supporting this concept, both cognitive training exercises and physical activity promote blood flow increase and correlate with healthy cognitive aging. The terminal branches of the posterior circulation supply blood to areas of the brain, such as the thalamus, hippocampus, occipital lobe, and cerebellum, involved with important intellectual functions, particularly recent memory, visual-spatial functioning, and visuomotor adaptations. Amnesia and visual agnosia may be a complication of not only posterior circulation infarctions but also vertebrobasilar insufficiency (VBI) without accompanying structural infarcts. The cognitive impairment maybe a manifestation of transient attacks and may persist beyond resolution of symptoms related to ischemia. Early recognition of cognitive deficits in the VBI patient is important because several recent reports show stent placements or medical treatment may improve cognition. PMID:26738337

  14. The circulation of care in transnational families

    Directory of Open Access Journals (Sweden)

    Laura Merla

    2014-09-01

    Full Text Available This article presents an approach to transnational family solidarity in terms of the “circulation of care”. This approach is based on a multidimensional vision of care-giving that goes beyond the personal care given to a dependent person. It takes the whole family network as its unit of analysis, and uses it to show the multiplicity of actors and the roles they play in the maintenance of transnational family solidarity in the long term. The article provides an analysis model of the institutional contexts that partially constitute the resources necessary for the circulation of care, recognising that other factors, such as the history of intra-family relationships, influence the dynamics at play.

  15. Meridional circulation in turbulent protoplanetary disks

    CERN Document Server

    Fromang, Sebastien; Masset, Frederic

    2011-01-01

    Based on viscous disk theory, a number of recent studies have suggested the existence of a large scale meridional circulation in protoplanetary disks. Such a flow could account for the presence of crystalline silicates, among which Calcium and Aluminium-rich Inclusions (CAIs), at large distances from the sun. This paper aims at examining whether such large scale flows exist in turbulent protoplanetary disks. High resolution global hydrodynamical and magnetohydrodynamical numerical simulations of turbulent protoplanetary disks are used to infer the properties of the flow in such disks. By performing hydrodynamic simulations using explicit viscosity, we demonstrate that our numerical setup does not suffer from any numerical artifact. The aforementioned meridional circulation is readily recovered in viscous and laminar disks. In MHD simulations, the magneto-rotational instability drives turbulence in the disks. Averaging out the turbulent fluctuations over long timescale, the results fail to show any large scale...

  16. The design of large natural circulation BWR's

    International Nuclear Information System (INIS)

    Boiling water reactors (BWR) with natural circulation are applied for capacities up to 60 MWe. Based on scale studies, however, it appears that larger production units are more efficient. It is recommended to investigate the bottlenecks in realizing larger reactors (>1000 MWe). The aim of the study on the title subject is to study to what extent the production capacity of BWRs with natural circulation can be increased. Based on data from the literature a simple analytic method has been chosen and existing BWR designs were compared. Capacities of 1300 MWe appear to be possible. These reactors will have a smaller pin diameter and a lower water supply temperature. Also steam separators with a minor pressure reduction must be available. The reliability of the stability measurement must be increased. Based on the results of this investigation the priorities for research on the design of future BWRs have been determined

  17. Formation and plasma circulation of solar prominences

    CERN Document Server

    Xia, Chun

    2016-01-01

    Solar prominences are long-lived cool and dense plasma curtains in the hot and rarefied outer solar atmosphere or corona. The physical mechanism responsible for their formation and especially for their internal plasma circulation has been uncertain for decades. The observed ubiquitous down flows in quiescent prominences are difficult to interpret as plasma with high conductivity seems to move across horizontal magnetic field lines. Here we present three-dimensional numerical simulations of prominence formation and evolution in an elongated magnetic flux rope as a result of in-situ plasma condensations fueled by continuous plasma evaporation from the solar chromosphere. The prominence is born and maintained in a fragmented, highly dynamic state with continuous reappearance of multiple blobs and thread structures that move mainly downward dragging along mass-loaded field lines. The prominence plasma circulation is characterized by the dynamic balance between the drainage of prominence plasma back to the chromos...

  18. The global ocean circulation on a retrograde rotating earth

    OpenAIRE

    Kamphuis, V.; Huisman, S.E.; Dijkstra, H. A.

    2011-01-01

    To understand the three-dimensional ocean circulation patterns that have occurred in past continental geometries, it is crucial to study the role of the present-day continental geometry and surface (wind stress and buoyancy) forcing on the present-day global ocean circulation. This circulation, often referred to as the Conveyor state, is characterised by an Atlantic Meridional Overturning Circulation (MOC) with a deep water formation at northern latitudes and the absence of ...

  19. Meridional circulation in turbulent protoplanetary disks

    OpenAIRE

    Fromang, Sebastien; Lyra, Wladimir; Masset, Frederic

    2011-01-01

    Based on the viscous disk theory, a number of recent studies have suggested there is large scale meridional circulation in protoplanetary disks. Such a flow could account for the presence of crystalline silicates, including calcium- and aluminum-rich inclusions (CAIs), at large distances from the sun. This paper aims at examining whether such large-scale flows exist in turbulent protoplanetary disks. High-resolution global hydrodynamical and magnetohydrodynamical (MHD) numerical simulations o...

  20. Isolation of Circulating Tumor Cells by Dielectrophoresis

    OpenAIRE

    Gascoyne, Peter R.C.; Sangjo Shim

    2014-01-01

    Dielectrophoresis (DEP) is an electrokinetic method that allows intrinsic dielectric properties of suspended cells to be exploited for discrimination and separation. It has emerged as a promising method for isolating circulation tumor cells (CTCs) from blood. DEP-isolation of CTCs is independent of cell surface markers. Furthermore, isolated CTCs are viable and can be maintained in culture, suggesting that DEP methods should be more generally applicable than antibody-based approaches. The aim...

  1. Parallel Computing of Ocean General Circulation Model

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    This paper discusses the parallel computing of the thirdgeneration Ocea n General Circulation Model (OGCM) from the State Key Laboratory of Numerical Mo deling for Atmospheric Science and Geophysical Fluid Dynamics(LASG),Institute of Atmosphere Physics(IAP). Meanwhile, several optimization strategies for paralle l computing of OGCM (POGCM) on Scalable Shared Memory Multiprocessor (S2MP) are presented. Using Message Passing Interface (MPI), we obtain super linear speedup on SGI Origin 2000 for parallel OGCM(POGCM) after optimization.

  2. Transients in a circulating fluidized bed boiler

    OpenAIRE

    Baskakov, A. P.; Munts, V. A.; Pavlyuk, E. Yu.

    2013-01-01

    Transients in a circulating fluidized bed boiler firing biomass are considered. An attempt is made to describe transients with the use of concepts applied in the automatic control theory. The parameters calculated from an analysis of unsteady heat balance equations are compared with the experimental data obtained in the 12-MW boiler of the Chalmers University of Technology. It is demonstrated that these equations describe the transient modes of operation with good accuracy. Dependences for ca...

  3. Circulating fluidized bed boilers design and operations

    CERN Document Server

    Basu, Prabir

    1991-01-01

    This book provides practicing engineers and students with insight into the design and operation of circulating fluidized bed (CFB) boilers. Through a combination of theoretical concepts and practical experience, this book gives the reader a basic understanding of the many aspects of this subject.Important environmental considerations, including solid waste disposal and predicted emissions, are addressed individually in separate chapters. This book places an emphasis on combustion, hydrodynamics, heat transfer, and material issues, and illustrates these concepts with numerous examples of pres

  4. Fluctuation Theorem in an Atmospheric Circulation Model

    CERN Document Server

    Schalge, Bernd; Wouters, Jeroen; Fraedrich, Klaus; Lunkeit, Frank

    2012-01-01

    Evidence for the validity of the Fluctuation Theorem (FT) in an atmospheric Global Circulation Model is found. The model is hydrostatic with variable numbers of vertical levels and different horizontal resolutions. For finite time intervals the largest local Lyapunov exponent (LLLE) is found to be negative consistent with predictions of the FT. The effect is present for resolutions up to wave numbers l=42 (~ 250km) and 10 levels.

  5. The creation and circulation of public geographies

    OpenAIRE

    Kitchin, Rob; Linehan, Denis; O'Callaghan, Cian; Lawton, Philip

    2013-01-01

    In response to the commentaries, we discuss further how social media disrupts and remakes the creation and circulation of geographical knowledges and potentially reconfigures the moral economy of the social sciences. In particular, we examine questions of what is meant by public geography, the publics which such geographies serve, alternative and complementary approaches to social media, the politics of authorship within collective blogs, the politics and mechanisms of knowledge c...

  6. Circulating somatostatin. Physiological regulator of pancreatic function?

    OpenAIRE

    Gyr, K; Beglinger, C; Köhler, E; Trautzl, U; Keller, U.; Bloom, S R

    1987-01-01

    The present study was designed to determine whether somatostatin is released into the circulation in sufficient amounts to regulate exocrine and endocrine pancreatic function and to evaluate the possible role of somatostatin as a hormonal regulator of the pancreas. Mean plasma somatostatin levels (SLI) increased from 11 +/- 2 pmol liter-1 to peak concentrations of 18 +/- 2 in six healthy male volunteers after a steak meal (P less than 0.05). Infusion of somatostatin inhibited hormone-induced ...

  7. When Prostate Cancer Circulates in the Bloodstream

    Directory of Open Access Journals (Sweden)

    Virginie Vlaeminck-Guillem

    2015-10-01

    Full Text Available Management of patients with prostate cancer is currently based on imperfect clinical, biological, radiological and pathological evaluation. Prostate cancer aggressiveness, including metastatic potential, remains difficult to accurately estimate. In an attempt to better adapt therapeutics to an individual (personalized medicine, reliable evaluation of the intrinsic molecular biology of the tumor is warranted, and particularly for all tumor sites (primary tumors and secondary sites at any time of the disease progression. As a consequence of their natural tendency to grow (passive invasion or as a consequence of an active blood vessel invasion by metastase-initiating cells, tumors shed various materials into the bloodstream. Major efforts have been recently made to develop powerful and accurate methods able to detect, quantify and/or analyze all these circulating tumor materials: circulating tumors cells, disseminating tumor cells, extracellular vesicles (including exosomes, nucleic acids, etc. The aim of this review is to summarize current knowledge about these circulating tumor materials and their applications in translational research.

  8. Acoustic streaming and Sun's meridional circulation

    Science.gov (United States)

    Valverde, Jose Manuel

    2016-09-01

    A vast number of physical processes involving oscillations of a bounded viscous fluid are relevantly influenced by acoustic streaming. When this happens a steady circulation of fluid develops in a thin boundary adjacent to the interface. Some examples are refracted sound waves, a fluid inside a spherical cavity undergoing torsional oscillations or a pulsating liquid droplet. Steady streaming around circular interfaces consists of a hemispherically symmetric recirculation of fluid from the equatorial plane to the polar axes closely resembling the meridional circulation pattern observed in the Sun's convection zone that determines the solar cycle. In this paper, it is argued that the acoustic pulsations exhibited by the Sun would lead to acoustic streaming in the boundary of the convection zone. A simple estimation using a typical dominant frequency of 3 mHz and the observed surface oscillation amplitude yields a steady streaming velocity us ∼ 10 m s‑1, which is on the order of the meridional circulation velocity observed in the Sun's convection zone.

  9. Tropical convective transport and the Walker circulation

    Directory of Open Access Journals (Sweden)

    J. S. Hosking

    2012-10-01

    Full Text Available We introduce a methodology to visualise rapid vertical and zonal tropical transport pathways. Using prescribed sea-surface temperatures in four monthly model integrations for 2005, we characterise preferred transport routes from the troposphere to the stratosphere in a high resolution climate model. Most efficient transport is modelled over the Maritime Continent (MC in November and February, i.e., boreal winter. In these months, the ascending branch of the Walker Circulation over the MC is formed in conjunction with strong deep convection, allowing fast transport into the stratosphere. In the model the upper tropospheric zonal winds associated with the Walker Circulation are also greatest in these months in agreement with ERA-Interim reanalysis data. We conclude that the Walker circulation plays an important role in the seasonality of fast tropical transport from the lower and middle troposphere to the upper troposphere and so impacts at the same time the potential supply of surface emissions to the tropical tropopause layer (TTL and subsequently to the stratosphere.

  10. Computer-aided design of stripline ferrite junction circulators

    Science.gov (United States)

    Uzdy, Z.

    1980-01-01

    A general design procedure is presented for stripline Y-junction circulators employing solid dielectric between ground planes. The resonator design and impedance matching are derived in a form suitable for computer evaluation. The procedure is applicable to cases where either the circulator bandwidth or the ground plane spacing is specified. An experimental S-band switching circulator design illustrates the technique.

  11. 19 CFR 207.63 - Circulation of draft questionnaires.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 3 2010-04-01 2010-04-01 false Circulation of draft questionnaires. 207.63... SUBSIDIZED EXPORTS TO THE UNITED STATES Five-Year Reviews § 207.63 Circulation of draft questionnaires. (a) The Director shall circulate draft questionnaires to the parties for comment in each full review....

  12. Algorithms for Finding the Inverses of Factor Block Circulant Matrices

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    In this paper, algorithms for finding the inverse of a factor block circulant matrix,a factor block retrocirculant matrix and partitioned matrix with factor block circulant blocks over the complex field are presented respectively. In addition, two algorithms for the inverse of a factor block circulant matrix over the quaternion division algebra are proposed.

  13. 21 CFR 868.5250 - Breathing circuit circulator.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Breathing circuit circulator. 868.5250 Section 868...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5250 Breathing circuit circulator. (a) Identification. A breathing circuit circulator is a turbine device that is attached to a closed breathing...

  14. Anisotropic Mesoscale Eddy Transport in Ocean General Circulation Models

    Science.gov (United States)

    Reckinger, S. J.; Fox-Kemper, B.; Bachman, S.; Bryan, F.; Dennis, J.; Danabasoglu, G.

    2014-12-01

    Modern climate models are limited to coarse-resolution representations of large-scale ocean circulation that rely on parameterizations for mesoscale eddies. The effects of eddies are typically introduced by relating subgrid eddy fluxes to the resolved gradients of buoyancy or other tracers, where the proportionality is, in general, governed by an eddy transport tensor. The symmetric part of the tensor, which represents the diffusive effects of mesoscale eddies, is universally treated isotropically in general circulation models. Thus, only a single parameter, namely the eddy diffusivity, is used at each spatial and temporal location to impart the influence of mesoscale eddies on the resolved flow. However, the diffusive processes that the parameterization approximates, such as shear dispersion, potential vorticity barriers, oceanic turbulence, and instabilities, typically have strongly anisotropic characteristics. Generalizing the eddy diffusivity tensor for anisotropy extends the number of parameters to three: a major diffusivity, a minor diffusivity, and the principal axis of alignment. The Community Earth System Model (CESM) with the anisotropic eddy parameterization is used to test various choices for the newly introduced parameters, which are motivated by observations and the eddy transport tensor diagnosed from high resolution simulations. Simply setting the ratio of major to minor diffusivities to a value of five globally, while aligning the major axis along the flow direction, improves biogeochemical tracer ventilation and reduces global temperature and salinity biases. These effects can be improved even further by parameterizing the anisotropic transport mechanisms in the ocean.

  15. Formation of germline chimera Gaok chicken used circulation primordial germ cells (circulation PGCs fresh and thawed

    Directory of Open Access Journals (Sweden)

    Kostaman T

    2014-03-01

    Full Text Available Formation of germline chimeras by transfer of chicken primordial germ cells (PGCs is one of the effective techniques for preservation and regeneration of genetic resources in chickens. This study attempted to form germline chimeras of Gaok chicken buy purifying circulated PGCs of donor embryo before it is transferred to the recipient (White Leghorn chickens=WL and studied the ability of recipient embryo on survival in incubators, and hatchability. This study used 200 fertile eggs of Gaok and 90 fertile WL breed all of the eggs was incubated at 380C and 60% humidity in a portable incubator. PGCs-circulation of the blood collected Gaok embryos at stage 14-16 were taken from the dorsal aorta, and then purified by centrifugation method using nycodenz. PGCs-circulation results further purification frozen in liquid nitrogen before being transferred to the recipient embryo. The results showed that for the development of embryos transferred to the fresh circulation of PGCs-circulation as many as 25 cells can survive up to day 14, while one of the transferred of 50 and 100 cells into recipient embryos was hatched (10%. On the contrari recipient embryos that are transferred to the frozen PGCs-circulation the embryos development was shorter, and only survived until day 10th (treatment 25 cells, day 14th (treatment of 50 cells and day 17th (treatment of 100 cells. It is concluded that the amount of PGCs-circulation embryos transferred to the recipient is one factor that influence the success of the development germline chimeras.

  16. Thermo-mechanical tests on W7-X current lead flanges

    Energy Technology Data Exchange (ETDEWEB)

    Dhard, Chandra Prakash, E-mail: dhard@ipp.mpg.de; Rummel, Thomas; Zacharias, Daniel; Bykov, Victor; Moennich, Thomas; Buscher, Klaus-Peter

    2013-10-15

    Highlights: • There are significant mechanical loads on the cryostat and radial flanges for W7-X current leads. • These are due to evacuation of W7-X cryostat, cool-down of cold mass, electro-magnetic forces and self weight of leads. • The actual mechanical loads were reduced to simplify the experimental set-up. • The tests were carried out on mock-up flanges test assembly at ambient temperature and at 77 K. • The thermo-mechanical tests on W7-X current lead flanges validate the design and joints of these flanges to the leads. -- Abstract: Fourteen pieces of high temperature superconducting current leads (CL) arranged in seven pairs, will be installed on the outer vessel of Wendelstein 7-X (W7-X) stellarator. In order to support the CL, it is provided with two glass fiber reinforce plastic (GFRP) flanges, namely, the lower cryostat flange (CF) remaining at room temperature and upper radial flange (RF) at about 5 K. Both the flanges i.e. CF and RF experience high mechanical loads with respect to the CL, due to the evacuation of W7-X cryostat, cool-down of cold mass including the CL, electro-magnetic forces due to current and plasma operations and self weight of CL. In order to check the integrity of these flanges for such mechanical loads, thermo-mechanical tests were carried out on these flanges at room temperatures and at liquid nitrogen (LN2) temperatures. The details of test set-up, results and modeling are described in the paper.

  17. Thermo-mechanical tests on W7-X current lead flanges

    International Nuclear Information System (INIS)

    Highlights: • There are significant mechanical loads on the cryostat and radial flanges for W7-X current leads. • These are due to evacuation of W7-X cryostat, cool-down of cold mass, electro-magnetic forces and self weight of leads. • The actual mechanical loads were reduced to simplify the experimental set-up. • The tests were carried out on mock-up flanges test assembly at ambient temperature and at 77 K. • The thermo-mechanical tests on W7-X current lead flanges validate the design and joints of these flanges to the leads. -- Abstract: Fourteen pieces of high temperature superconducting current leads (CL) arranged in seven pairs, will be installed on the outer vessel of Wendelstein 7-X (W7-X) stellarator. In order to support the CL, it is provided with two glass fiber reinforce plastic (GFRP) flanges, namely, the lower cryostat flange (CF) remaining at room temperature and upper radial flange (RF) at about 5 K. Both the flanges i.e. CF and RF experience high mechanical loads with respect to the CL, due to the evacuation of W7-X cryostat, cool-down of cold mass including the CL, electro-magnetic forces due to current and plasma operations and self weight of CL. In order to check the integrity of these flanges for such mechanical loads, thermo-mechanical tests were carried out on these flanges at room temperatures and at liquid nitrogen (LN2) temperatures. The details of test set-up, results and modeling are described in the paper

  18. Quantifying circulating hypoxia-induced RNA transcripts in maternal blood to determine in utero fetal hypoxic status

    OpenAIRE

    Whitehead, Clare; Teh, Wan Tinn; Walker, Susan P.; Leung, Cheryl; Mendis, Sonali; Larmour, Luke; Tong, Stephen

    2013-01-01

    Background Hypoxia in utero can lead to stillbirth and severe perinatal injury. While current prenatal tests can identify fetuses that are hypoxic, none can determine the severity of hypoxia/acidemia. We hypothesized a hypoxic/acidemic fetus would up-regulate and release hypoxia-induced mRNA from the fetoplacental unit into the maternal circulation, where they can be sampled and quantified. Furthermore, we hypothesized the abundance of hypoxia induced mRNA in the maternal circulation would co...

  19. North Atlantic Deep Water and Antarctic Bottom Water: Their Interaction and Influence on Modes of the Global Ocean Circulation

    OpenAIRE

    Brix, Holger

    2001-01-01

    Interhemispheric signal transmission in the Atlantic Ocean connects the deep water production regions of both hemispheres. The nature of these interactions and large scale responses to perturbations on time scales of years to millenia have been investigated using a global general circulation model based on the primitive equations coupled to a dynamic-thermodynamic sea ice model with a viscous-plastic rheology. The coupled model reproduces many aspects of today´s oceanic circulation. Testing t...

  20. Combined intermittent hypobaric hypoxia and muscle electro-stimulation: a method to increase circulating progenitor cell concentration?

    OpenAIRE

    Corral, Luisa; Javierre, Casimiro; Blasi, Juan; Viscor, Ginés; Ricart, Antoni; Ventura, Josep Lluis

    2014-01-01

    Background Our goal was to test whether short-term intermittent hypobaric hypoxia (IHH) at a level well tolerated by healthy humans could, in combination with muscle electro-stimulation (ME), mobilize circulating progenitor cells (CPC) and increase their concentration in peripheral circulation. Methods Nine healthy male subjects were subjected, as the active group (HME), to a protocol involving IHH plus ME. IHH exposure consisted of four, three-hour sessions at a barometric pressure of 540 hP...

  1. Land cover, landscape structure, and West Nile virus circulation in southern France.

    Science.gov (United States)

    Pradier, S; Leblond, A; Durand, B

    2008-04-01

    The transmission of West Nile virus (WNV) is strongly influenced by environmental factors. In France, two endemic areas for WNV have been identified: Camargue and Var. The objective of our study was to test whether landscape characteristics could be associated with the risk of endemic circulation of WNV in these two ecologically different areas. Equine serological data collected during outbreaks in Var (2003) and Camargue (2004) were used. Both areas were marked out in cells of 5 km(2), and data were aggregated for each cell. Sixteen cells, classified as "high" level viral circulation, and 28 cells, classified as "low" level viral circulation were used for the analysis. The Corine Land Cover database (European Environment Agency) was used to evaluate, for each geographic cell, the area covered by 12 land cover classes, as well as the value of 5 landscape metrics (patch richness and density, edge density, the Shannon's diversity index, and interspersion and juxtaposition index (IJI). Multivariate linear generalized regression showed that IJI as well as the surface covered by heterogeneous agricultural areas were significantly higher in high level WNV circulation cells than in low level ones (p = 0.01 and 0.05 respectively). Both variables are indicators of a complex spatial biotope configuration that may favor the co-existence of competent vectors and reservoir hosts: the structure of the landscape thus appeared as a key element in WNV circulation. An internal validation was performed and the model was used to compute a risk map for the French Mediterranean coast. Cells with a probability > 0.8 of having a high level of viral circulation were found near Aix-en-Provence, Beziers, and Perpignan, areas where no serological study has yet been conducted. Equine cases reported in 2006 were all located in the neighborhood of cells having a > 0.8 probability for high WNV circulation status. PMID:18429693

  2. Effects of the Intermittent Pneumatic Circulator on Blood Pressure during Hemodialysis

    Directory of Open Access Journals (Sweden)

    Miao-Ju Hsu

    2010-11-01

    Full Text Available Hypotension is frequently reported during hemodialysis. This study aimed to examine the effect of the intermittent pneumatic circulator on blood pressure during hemodialysis. Sixteen subjects with chronic hemodialysis were recruited. Each subject randomly received two test conditions on separate days, hemodialysis with and without the circulator. The circulator was applied to the subject on lower extremities during 0.5–1 hr, 1.5–2 hr, 2.5–3 hr, and 3.5–4 hr of hemodialysis. Systolic and diastolic blood pressures (SBP and DBP and heart rate (HR were analyzed at pre-dialysis, 1 hr, 2 hr, and 3 hr of hemodialysis. Stroke volume (SV and cardiac output (CO were evaluated between 2.5 and 3.0 hr of hemodialysis. Blood chemicals (sodium, calcium, potassium, and phosphorous and Kt/V before and after each hemodialysis session were analyzed. The number of episodes of hypotension was also recorded. The circulator intervention significantly improved SBP and DBP across all time points (P = 0.002 for SBP; P = 0.002 for DBP. The frequency of hypotension was significantly decreased (P = 0.028. SV and CO were significantly improved with the circulator intervention (P = 0.017 for SV; P = 0.026 for CO and no statistical significances were found on blood chemicals or Kt/V analyses. The results suggested that the circulator intervention helps stabilize blood pressure and appears to be a practical treatment. Future studies are suggested to develop new circulator innovations with sensor feedback systems to enhance safety and maximize treatment efficiency.

  3. Hot helium flow test facility summary report

    International Nuclear Information System (INIS)

    This report summarizes the results of a study conducted to assess the feasibility and cost of modifying an existing circulator test facility (CTF) at General Atomic Company (GA). The CTF originally was built to test the Delmarva Power and Light Co. steam-driven circulator. This circulator, as modified, could provide a source of hot, pressurized helium for high-temperature gas-cooled reactor (HTGR) and gas-cooled fast breeder reactor (GCFR) component testing. To achieve this purpose, a high-temperature impeller would be installed on the existing machine. The projected range of tests which could be conducted for the project is also presented, along with corresponding cost considerations

  4. Lightweight Magnetic Cooler With a Reversible Circulator

    Science.gov (United States)

    Chen, Weibo; McCormick, John

    2011-01-01

    A design of a highly efficient and lightweight space magnetic cooler has been developed that can continuously provide remote/distributed cooling at temperatures in the range of 2 K with a heat sink at about 15 K. The innovative design uses a cryogenic circulator that enables the cooler to operate at a high cycle frequency to achieve a large cooling capacity. The ability to provide remote/distributed cooling not only allows flexible integration with a payload and spacecraft, but also reduces the mass of the magnetic shields needed. The active magnetic regenerative refrigerator (AMRR) system is shown in the figure. This design mainly consists of two identical magnetic regenerators surrounded by their superconducting magnets and a reversible circulator. Each regenerator also has a heat exchanger at its warm end to reject the magnetization heat to the heat sink, and the two regenerators share a cold-end heat exchanger to absorb heat from a cooling target. The circulator controls the flow direction, which cycles in concert with the magnetic fields, to facilitate heat transfer. Helium enters the hot end of the demagnetized column, is cooled by the refrigerant, and passes into the cold-end heat exchanger to absorb heat. The helium then enters the cold end of the magnetized column, absorbing heat from the refrigerant, and enters the hot-end heat exchanger to reject the magnetization heat. The efficient heat transfer in the AMRR allows the system to operate at a relatively short cycle period to achieve a large cooling power. The key mechanical components in the magnetic cooler are the reversible circulator and the magnetic regenerators. The circulator uses non-contacting, self-acting gas bearings and clearance seals to achieve long life and vibration- free operation. There are no valves or mechanical wear in this circulator, so the reliability is predicted to be very high. The magnetic regenerator employs a structured bed configuration. The core consists of a stack of thin

  5. Temperature Structure and Atmospheric Circulation of Dry, Tidally Locked Rocky Exoplanets

    CERN Document Server

    Koll, Daniel D B

    2016-01-01

    Next-generation space telescopes will observe the atmospheres of rocky planets orbiting nearby M-dwarfs. Understanding these observations will require well-developed theory in addition to numerical simulations. Here we present theoretical models for the temperature structure and atmospheric circulation of dry, tidally locked rocky exoplanets with grey radiative transfer and test them using a general circulation model (GCM). First, we develop a radiative-convective model that captures surface temperatures of slowly rotating and cool atmospheres. Second, we show that the atmospheric circulation acts as a global heat engine, which places strong constraints on large-scale wind speeds. Third, we develop a radiative-convective-subsiding model which extends our radiative-convective model to hot and thin atmospheres. We find that rocky planets develop large day-night temperature gradients at a ratio of wave-to-radiative timescales up to two orders of magnitude smaller than the value suggested by work on hot Jupiters....

  6. Performance evaluation and effect of biogas circulation rate of a bubble column for biological desulfurization.

    Science.gov (United States)

    Kobayashi, Takuro; Xu, Kai-Qin; Li, Yu-You; Inamori, Yuhei

    2012-01-01

    Biological desulfurization using a bubble column reactor was investigated in a continuous biogas treatment. Rapid biogas circulation between the digester and the bubble column for biological desulfurization was used to stimulate the gas-liquid mass transfer of H(2)S. A positive correlation between the biogas circulation rate and H(2)S removal rate was observed. Moreover, the increase in the circulation rate stimulated the O(2) mass transfer, eventually translating into an increase in sulfate production from the oxidation of H(2)S. Throughout the continuous experiment, the reactor retained sufficient levels of sulfide-oxidizing bacteria. A comparison of the results of the continuous biogas treatment and batch tests suggests that the gas-liquid mass transfer rate of H(2)S was the rate-limiting step in the biological desulfurization in the reactor, indicating that the mass transfer efficiency of H(2)S needs to be improved to enhance the desulfurization performance. PMID:22925864

  7. Seasonal overturning circulation in the Red Sea: 1. Model validation and summer circulation

    KAUST Repository

    Yao, Fengchao

    2014-04-01

    The overturning circulation in the Red Sea exhibits a distinct seasonally reversing pattern and is studied using high-resolution MIT general circulation model simulations. In the first part of this study, the vertical and horizontal structure of the summer overturning circulation and its dynamical mechanisms are presented from the model results. The seasonal water exchange in the Strait of Bab el Mandeb is successfully simulated, and the structures of the intruding subsurface Gulf of Aden intermediate water are in good agreement with summer observations in 2011. The model results suggest that the summer overturning circulation is driven by the combined effect of the shoaling of the thermocline in the Gulf of Aden resulting from remote winds in the Arabian Sea and an upward surface slope from the Red Sea to the Gulf of Aden set up by local surface winds in the Red Sea. In addition, during late summer two processes associated, respectively, with latitudinally differential heating and increased salinity in the southern Red Sea act together to cause the reversal of the contrast of the vertical density structure and the cessation of the summer overturning circulation. Dynamically, the subsurface northward pressure gradient force is mainly balanced by vertical viscosity resulting from the vertical shear and boundary friction in the Strait of Bab el Mandeb. Unlike some previous studies, the three-layer summer exchange flows in the Strait of Bab el Mandeb do not appear to be hydraulically controlled.

  8. The stability of the thermohaline circulation in a coupled ocean-atmosphere general circulation model

    Energy Technology Data Exchange (ETDEWEB)

    Schiller, A. [Max-Planck-Institut fuer Meteorologie, Hamburg (Germany); Mikolajewicz, U. [Max-Planck-Institut fuer Meteorologie, Hamburg (Germany); Voss, R. [Deutsches Klimarechenzentrum (DKRZ), Hamburg (Germany)

    1996-02-01

    The stability of the Atlantic thermohaline circulation against meltwater input is investigated in a coupled ocean-atmosphere general circulation model. The meltwater input to the Labrador Sea is increased linearly for 250 years to a maximum input of 0.625 Sv and then reduced again to 0 (both instantaneously and slowly decreasing over 250 years). The resulting freshening forces a shutdown of the formation of North Atlantic deepwater and a subsequent reversal of the thermohaline circulation of the Atlantic, filling the deep Atlantic with Antarctic bottom water. The change in the overturning pattern causes a drastic reduction of the Atlantic northward heat transport, resulting in a strong cooling with maximum amplitude over the northern North Atlantic and a southward shift of the sea-ice margin in the Atlantic. Due to the increased meridional temperature gradient, the Atlantic intertropical convergence zone is displaced southward and the westerlies in the northern hemisphere gain strength. We identify four main feedbacks affecting the stability of the thermohaline circulation: the change in the overturning circulation of the Atlantic leads to longer residence times of the surface waters in high northern latitudes, which allows them to accumulate more precipitation and runoff from the continents, which results in an increased stability in the North Atlantic.

  9. Study of startup transients and power ramping of natural circulation boiling systems

    Energy Technology Data Exchange (ETDEWEB)

    Lakshmanan, S.P. [Department of Mechanical Engineering, Indian Institute of Technology Guwahati, Guwahati 781039 (India); Pandey, Manmohan [Department of Mechanical Engineering, Indian Institute of Technology Guwahati, Guwahati 781039 (India)], E-mail: manmohan@iitg.ac.in; Pradeep Kumar, P.; Iyer, Kannan N. [Department of Mechanical Engineering, Indian Institute of Technology Bombay, Mumbai 400076 (India)

    2009-06-15

    Numerical models of a natural circulation test facility and its prototype have been developed with RELAP5/MOD3.4 code and verified for their grid independence by nodal sensitivity studies. The model of the test facility has been validated for its steady state as well as transient predictions with the help of experimental observations. The transient predictions and parametric trends obtained by the numerical model of the prototype have been compared with those of the numerical model of the test facility. Thus, the ability of RELAP5 code to predict the transients during startup of a natural circulation boiling water reactor is verified. A powering procedure for the test facility has been conceptualized with the help of its RELAP5 model and demonstrated experimentally. Based on this, a similar powering procedure for the prototype has been proposed and simulated numerically with its RELAP5 model.

  10. Explicit Determinants of the RFPrLrR Circulant and RLPrFrL Circulant Matrices Involving Some Famous Numbers

    Directory of Open Access Journals (Sweden)

    Tingting Xu

    2014-01-01

    Full Text Available Circulant matrices may play a crucial role in solving various differential equations. In this paper, the techniques used herein are based on the inverse factorization of polynomial. We give the explicit determinants of the RFPrLrR circulant matrices and RLPrFrL circulant matrices involving Fibonacci, Lucas, Pell, and Pell-Lucas number, respectively.

  11. Standardization of an enzyme linked immunosorbent assay (ELISA) for detecting circulating toxic venom antigens in patients stung by the scorpion Tityus serrulatus Padronização de um teste imunoenzimático (ELISA) para detectar antígenos tóxicos circulantes do veneno em pacientes picados pelo escorpião Tityus serrulatus

    OpenAIRE

    Nilton Alves de Rezende; Mariana Borges Dias; Délio Campolina; Carlos Chavéz-Olortegui; Carlos Faria Santos Amaral

    1995-01-01

    The sensitivity and specificity of an enzyme-linked immunosorbent assay (ELISA) for the detection of circulating antigens from toxic components of Tityus serrulatus scorpion venom was determined in patients stung by T. serrulatus before antivenom administration. Thirty-seven patients were classified as mild cases and 19 as moderate or severe cases. The control absorbance in the venom assay was provided by serum samples from 100 individuals of same socioeconomic group and geographical area who...

  12. Stability of flashing-driven natural circulation in a passive moderator cooling system for Canadian SCWR

    International Nuclear Information System (INIS)

    Highlights: • The stability in a passive moderator cooling system of a unique system in the Canadian SCWR. • Identify and analyze unstable oscillations using flashing-driven natural circulation test results. • The flashing-driven oscillations categorized as a flashing-driven Type-I density wave instability including a geysering-like feature. • A stability map on the dimensionless plane with the Subcooling number and Phase Change number. - Abstract: This paper presents an examination of the instability mechanisms in a Passive Moderator Cooling System for the Canadian SCWR (Supercritical Water-cooled Reactor). The passive system is being developed at AECL using a flashing-driven natural circulation loop. Unstable intermittent and sinusoidal oscillations were identified from experimental data of the flashing-driven natural circulation passive moderator cooling system. The oscillation periods were correlated with the boiling delay time. A stability map for a flashing-driven two-phase natural circulation loop was established on the dimensionless plane with Subcooling number and Phase Change number. It was observed that there is thermal non-equilibrium in the single-phase and two-phase oscillation stages of the flashing-driven natural circulation

  13. Experimental study on circulation characteristics of secondary passive heat removal system for Chinese pressurized water reactor

    International Nuclear Information System (INIS)

    Nuclear safety has attracted increasingly global attention. The secondary side natural circulation heat removal system is one of several passive safety systems designed to ensure the safety of the reactor core. The passive heat removal systems are also adopted in the safety system design of Chinese third-generation pressurized water reactor. To complete its design and verify its feasibility, an experimental facility, which is named SPHRS, was built to investigate the heat removal capacity and the stability characteristics of the steam generator secondary side passive heat removal system. The experimental facility consists of a steam generator simulator, an instrumented condenser test section with a secondary pool boiling section, a pump, a water storage tank, and associated piping and instrumentation. The heat removal capacity under varying pressures and characteristics of natural circulation at steady-state as well as system power input drop condition were obtained. The results show that the SPHRS has sufficient capacity to remove the decay heat. It is found that the natural circulation can be maintained under different pressures, the heat load sudden change condition as well, which indicates that the SPHRS natural circulation has good stability. - Highlights: • The stability of secondary side passive heat removal system of a PWR was studied. • The heat removal capacity of the condenser tube was investigated. • The natural circulation characteristics of SPHRS were investigated

  14. Considerations on the design of a helium circulator for a high temperature modular reactor system

    International Nuclear Information System (INIS)

    A modular helium cooled, high temperature reactor system with a thermal output of 200 MW per reactor has been developed by the KWU group for cogeneration of electricity and process steam. The flow of the reactor coolant - Helium at 60 bars and 250/700 deg. C is maintained by one circulator per reactor. The circulator is driven by a variable speed Siemens asynchronous motor and is submerged in the helium primary system. For operational reasons high reliability and availability of the circulator is required. The operational requirements for the circulator design are presented in this paper. The actual design has been carried out in close cooperation with the designer and manufacturer of all submerged circulators operating in AGR plants in Great Britain, James Howden Co. Renfrew, Scotland. Design solutions received so far and mainly based on sufficiently proven components - such as oil bath lubricated bearing systems - will be described. Special attention will be paid on the necessary test work; especially for the prototype to confirm the lay out. (author). 9 figs

  15. Effect of vegetation on the Late Miocene ocean circulation

    Directory of Open Access Journals (Sweden)

    G. Lohmann

    2006-08-01

    Full Text Available A weak and shallow thermohaline circulation in the North Atlantic Ocean is related to an open Central American gateway and exchange with fresh Pacific waters. We estimate the effect of vegetation on the ocean general circulation using the atmospheric circulation model simulations for the Late Miocene climate. Caused by an increase in net evaporation in the Miocene North Atlantic, the North Atlantic water becomes more saline which enhances the overturning circulation and thus the northward heat transport. This effect reveals a potentially important feedback between the ocean circulation, the hydrological cycle and the land surface cover for Cenozoic climate evolution.

  16. [Regional liver circulation and scintigraphic imaging of portal circulation with 133Xe].

    Science.gov (United States)

    Kroiss, A

    1984-01-01

    Regional hepatic blood flow has been determined by 4 methods with the aid of the 133Xe washout technique: scintisplenoportography (direct application of 133Xe into the spleen by means of a thin needle); arterial method (133Xe is injected into the A. hepatica by means of a catheter); retrograde-venous method (133Xe administered by an occluding hepatic vein catheter); percutaneous intrahepatic method (133Xe administered directly into the parenchyma by means of a Chiba needle). Ad 1.: Scintisplenoportography (SSP) was executed with 97 patients: 8 patients with a healthy liver presented a hepatic blood flow of 103.37 +/- 11.5 ml/100 g/min. 4 patients with a chronic hepatitis showed a hepatic blood flow of 105.67 +/- 10.2 ml/100 g/min. In 38 patients with compensated cirrhosis, hepatic blood flow was determined with 58.15 +/- 11.5 ml/100 g/min and 19 patients with decompensated cirrhosis showed a blood flow of 34.54 +/- 7.2 ml/100 g/min. Of the 19 patients, who did not present any liver image, 2 patients suffered from a prehepatic block, 1 patient (female) from a posthepatic block, the rest were decompensated cirrhoses. In 5 patients suffering from steatosis only collateral circulation was determined and in 4 patients the spleen could not be punctured. In the patients with compensated and decompensated cirrhosis of the liver, hepatic blood flow differentiated significantly (p less than 0.001) from patients with healthy livers and chronic hepatitis. In the patients with bioptically assured steatosis only the washout constant was determined. Reproducibility of this method was tested in 4 patients and no statistical difference of hepatic blood flow values could be found and the correlation coefficient amounted to 0.9856. The advantage of SSP lies in the possibility of recording the portal vein circulation: cranial collaterals were found in 33 patients, 2 patients had caudal collaterals exclusively and 29 patients cranial and caudal collaterals. 33 cirrhosis patients

  17. Transient Behaviour of a Heat Pipe with Extracapillary Circulation

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Heat pipe devices, for their typical working mode, are particularly suitable for zero gravity applications, and have also been considered for applications in space satellites with nuclear generators because of the absence of active systems for the coolant circulation. The present work reports the results of experimental tests carried out on a heat pipe facility designed to investigate the thermal-hydraulic performance of a water heat pipe. The device layout, configuration and geometry, simulate a heat pipe working mode utilizable in space applications under zero gravity conditions. The evaporating section, completely lined (covered) with wicks (sintered stainless steel), and nearly plane shaped, is housed in a cylindrical container. The obtained results show that the system can approach steady-state conditions, at a pressure of 4 bar and with a heat flux transferred of about 150 W/cm2, supporting an electric power step of about 1.8 Kw.

  18. Avoidance-related EEG asymmetry predicts circulating interleukin-6.

    Science.gov (United States)

    Shields, Grant S; Moons, Wesley G

    2016-03-01

    Recent research has linked avoidance-oriented motivational states to elevated pro-inflammatory cytokine levels. According to one of many theories regarding the association between avoidance and cytokine levels, because the evolutionarily basic avoidance system may be activated when an organism is threatened or overwhelmed, an associated inflammatory response may be adaptive for dealing with potential injury in such threatening situations. To examine this hypothesis, we tested whether the neural correlate of avoidance motivation associates with baseline levels of the circulating pro-inflammatory cytokine interleukin-6 (IL-6). Controlling for covariates, greater resting neural activity in the right frontal cortex relative to the left frontal cortex-the neural correlate of avoidance motivation-was associated with baseline IL-6. These results thus support the hypothesis that the avoidance motivational system may be closely linked to systemic inflammatory activity. PMID:26461246

  19. Parametric Study of NOx Emissions in Circulating Fluidized Bed Combustor

    International Nuclear Information System (INIS)

    Fluidized bed combustion behavior of coal and biomass is of practical interest due to its significant involvement in heating systems and power plant operations. This combustion behavior has been studied by many experimental techniques. . Use of biomass in coal-fired power plants results in high efficiencies and fuel diversity. Co-combustion experiments were carried out in a pilot scale test facility of circulating fluidized bed combustor (70KW). Effect of operating parameters on the NOx emissions is studied while burning coal with wheat straw. Relation between NOx emissions and operating parameters like bed temperature, excess air ratio, air staging, Ca/S molar ratio and fluidizing air velocity have been studied and discussed. (author)

  20. Investigations into natural circulation driven heat removal systems

    International Nuclear Information System (INIS)

    Passive safety systems can make an important contribution to decay heat removal in existing and next Generation NPP. Two-phase natural circulation systems have under certain circumstances instabilities which have to be analysed in detail. For this reason the test facility GENEVA has been constructed and commissioned at the TU Dresden. The experiments described in the experimental matrix will be started this year. First experimental data showed flow instabilities e.g. flashing as expected. Generic studies are necessary to examine two-phase flow and especially two-phase flow instabilities in further detail. The influence of subcooling and the diameters of downcomer and riser are of particular interest. These will help to evaluate the system behaviour of passive heat removal systems as well as their safety and reliability for nuclear reactors. (orig.)

  1. Experiment research and calculation method of natural circulation flow for AC600/1000

    International Nuclear Information System (INIS)

    Passive safety concept is extensively used in the design for next generation advanced PWR nuclear power plant. The decay heat of reactor core can be removed through natural circulation flow of coolant following an accident. This not only increases reliability of engineered safety systems and reduces core melt frequency, but also simplifies systems and increases plant economy. Nuclear Power Institute of China (NPIC) has performed preliminary experiment research and relative theoretical analysis for passive characteristics of advanced PWR nuclear power plant AC600/1000. Three tests about natural circulation flow have finished as the following: residual heat removal through SG secondary side, core makeup tank behavior and wind flow of containment. The above mentioned three mechanism tests have verified natural circulation flow concept of AC600/1000. By the end of this year NPIC will finish other two single tests in order to research the following key technology of the passive safety systems: The natural circulation characteristics of tandem system of SG secondary side loop and air flow loop for emergency residual heat removal system (ERHRS) after station blackout accident; The water flow behavior in primary coolant system contained by core makeup tank, pressurizer, accumulator and reactor pressure vessel after small break accident; Computer code development and verification. Meanwhile, NPIC will cooperate with Karlsruhe Technology Center of Germany to research natural circulation characteristics of air in the annular channel between the steel shell and the concrete shell of containment. NPIC plans to build two large integral test facilities. One of which is used to research natural circulation flow and residual heat removal through primary loop, secondary loop and air flow loop from reactor core to ultimate sink - atmosphere after station blackout accident. It is also used to research the passive safety injection features for emergency core cooling system. The second

  2. Review of the ATLAS B0 model coil test program

    CERN Document Server

    Dolgetta, N; Acerbi, E; Berriaud, C; Boxman, H; Broggi, F; Cataneo, F; Daël, A; Delruelle, N; Dudarev, A; Foussat, A; Haug, F; ten Kate, H H J; Mayri, C; Paccalini, A; Pengo, R; Rivoltella, G; Sbrissa, E

    2004-01-01

    The ATLAS B0 model coil has been extensively tested, reproducing the operational conditions of the final ATLAS Barrel Toroid coils. Two test campaigns have taken place on B0, at the CERN facility where the individual BT coils are about to be tested. The first campaign aimed to test the cool-down, warm-up phases and to commission the coil up to its nominal current of 20.5 kA, reproducing Lorentz forces similar to the ones on the BT coil. The second campaign aimed to evaluate the margins above the nominal conditions. The B0 was tested up to 24 kA and specific tests were performed to assess: the coil temperature margin with respect to the design value, the performance of the double pancake internal joints, static and dynamic heat loads, behavior of the coil under quench conditions. The paper reviews the overall test program with emphasis on second campaign results not covered before. 10 Refs.

  3. Heavy liquid metal natural circulation in a one-dimensional loop

    Energy Technology Data Exchange (ETDEWEB)

    Coccoluto, G.; Gaggini, P.; Labanti, V. [ENEA Brasimone, 40032 Camugnano (Italy); Tarantino, M., E-mail: mariano.tarantino@enea.i [ENEA Brasimone, 40032 Camugnano (Italy); Ambrosini, W.; Forgione, N.; Napoli, A.; Oriolo, F. [Universita degli Studi di Pisa, Dipartimento di Ingegneria Meccanica, Nucleare e della Produzione Via Diotisalvi, 2 - 56126 Pisa (Italy)

    2011-05-15

    The ENEA Brasimone Research Centre since 1999 is strongly involved in the national and European research programmes performed in the field of heavy liquid metal technology aiming at the development of critical (LFR) and subcritical (ADS) nuclear systems. In particular, in the frame of the IP-EUROTRANS, (6th Framework Program EU), ENEA assumed the commitment to perform an integral experiment with the aim to reproduce the primary flow path of a HLM pool-type nuclear reactor, cooled by lead bismuth eutectics (LBE). This new experimental activity, named ICE 'Integral Circulation Experiment', will be performed by an appropriate test section designed to be installed in the CIRCE facility. In order to support the ICE activity, as well as characterize the natural and gas enhanced circulation flow regimes in a HLM loop, qualify test procedures and components which are nuclear relevant, a new facility was designed and built-up by Brasimone Research Centre, named NACIE 'NAtural CIrculation Experiment'. The paper reports a detailed description of the loop and the main experimental results carried out from the natural circulation tests already performed on the NACIE loop. Numerical simulations have been performed in collaboration with the University of Pisa, adopting the RELAP5/Mod3.3 system code modified to allow for LBE as a cooling fluid. The aim of the performed post-test calculations is to compare the code response with the experimental results under the natural circulation flow regime, allowing to qualify the adopted nodalization as well as the performance of the code when employed on HLM loop.

  4. Operating experience of gas bearing helium circulators in HTGR development facility

    International Nuclear Information System (INIS)

    The large scale helium gas test facility (HENDEL) has been constructed and operated since March 1982 at the Japan Atomic Energy Research Institute to develop HTGR components. The five electric driven gas circulators with dynamic gas bearings are used to circulate the helium gas of 4MPa and 400 deg. C in loops for their compactness, gas tightness, easy maintenance and free from gas contamination. All of these circulators are variable speed types of 3,000 to 12,000 rpm and have the same gas bearings and electric motors. The four machines among them are equipped with centrifugal impeller and one other machine has regenerative type, and the weight of both type rotors are nearly the same. After the troubles and repairing, both type of circulators were tested and the vibration characteristics were measured as preventing maintenance. From the test and measurements of the circulators, it was presumed that the first trouble on regenerative type was caused from excess unbalance force by falling off of a small pin from the rotating part and the second severe trouble on it was caused by the whipping in gas bearing. The static load on tilting pads indicated close relations to occurrence of the whirling through the measurements. It is recognized that fine balancing of the rotors and delicate clearance adjustment of the bearings are very important for the rotor stability and that the mechanism should be designed and machined so precise as to be adjustable. As the gas bearing would be damaged in an instantaneously short time, the monitoring technique for it should be so fast and predictive as to prevent serious damage. Through the tests, the vibration spectrum monitoring method seems to be predictive and useful for early detection of the shaft instability. It will be concluded that the gas bearing machine is an excellent system in its design philosophy, however, it also needs highly precise machining and delicate maintenance technique. 4 refs, 10 figs, 1 tab

  5. Atmospheric General Circulation Changes under Global Warming

    Science.gov (United States)

    Palipane, Erool

    The work in this thesis is mainly two-fold. First we study the internal variability of the general circulation and focus our study on the annular modes and how important it is to simulate the subsynoptic scales in the circulation. In the next major section we will try to understand the mechanisms of the forced response and the mechanisms leading towards the jet shift from transient evolution in Atmospheric general circulation models. In the first part, in an attempt to assess the benefit of resolving the sub-synoptic to mesoscale processes, the spatial and temporal characteristics of the Annular Modes (AMs), in particular those related to the troposphere-stratosphere interaction, are evaluated for moderate- and high-horizontal resolution simulations with a global atmospheric general circulation model (AGCM), in comparison with the ERA40 re- analysis. Relative to the CMIP-type climate models, the IFS AGCM demonstrates notable improvement in capturing the key characteristics of the AMs. Notably, the performance with the high horizontal resolution version of the model is systematically superior to the moderate resolution on all metrics examined, including the variance of the AMs at different seasons of the year, the intrinsic e-folding time scales of the AMs, and the downward influence from the stratosphere to troposphere in the AMs. Moreover, the high-resolution simulation with a greater persistence in the intrinsic variability of the SAM projects an appreciably larger shift of the surface westerly wind during the Southern Hemisphere summer under climate change. In the second part, the response of the atmospheric circulation to greenhouse gas-induced SST warming is investigated using large ensemble experiments with two AGCMs, with a focus on the robust feature of the poleward shift of the eddy driven jet. In these experiments, large ensembles of simulations are conducted by abruptly switching the SST forcing on from January 1st to focus on the wintertime circulation

  6. Containment air circulation for optimal hydrogen recombination

    International Nuclear Information System (INIS)

    An accepted first-line defense for hydrogen mitigation is to design for the hydrogen to be rapidly mixed with the containment atmosphere and diluted to below flammability concentrations. Then, as hydrogen continues to be produced in the longer term, recombiners can be used to remove hydrogen: recombiners can be located in forced-air ducts or passive recombiners can be distributed within containment and the heat of recombination used to promote local air circulation. However, this principle does not eliminate the possibility of high hydrogen concentrations at locations removed from the recombiners. An improvement on this strategy is to arrange for a specific, buoyancy-driven, overall circulation of the containment atmosphere such that the recombiners can be located within the recirculation flow, immediately downstream of the hydrogen source. This would make the mixing process more predictable and solve the mass-transfer problem associated with distributed recombiners. Ideally, the recombiners would be located just above the hydrogen source so that the heat of recombination would assist the overall circulation. In this way, the hydrogen would be removed as close as possible to the source, thereby minimizing the amount of hydrogen immediately downstream of the source and reducing the hydrogen concentration to acceptable levels at other locations. Such a strategy requires the containment volume to be divided into an upflow path, past the hydrogen source and the recombiner, and a downflow path to complete the circuit. The flow could be generated actively using fans or passively using buoyancy forces arising from the difference in density of gases in the upfiow and downflow paths; the gases in the downflow path being cooled at an elevated heat sink. (author)

  7. Early concepts and charts of ocean circulation

    Science.gov (United States)

    Peterson, R. G.; Stramma, L.; Kortum, G.

    Charts of ocean currents from the late nineteenth century show that already by then the patterns of surface circulation in regions away from polar latitudes were well understood. This fundamental knowledge accumulated gradually through centuries of sea travel and had reached a state of near correctness by the time dedicated research cruises, full-depth measurements and the practical application of the dynamical method were being instituted. Perhaps because of the foregoing, many of the pioneering works, critical to establishing what the upper-level circulation is like, the majority of the charts accompanying them, and several of the groundbreaking theoretical treatments on the physics of currents, are only poorly known to present-day oceanographers. In this paper we trace Western developments in knowledge and understanding of ocean circulation from the earliest times to the late-1800s transition into the modern era. We also discuss certain peripheral advances that proved critical to the subject. The earliest known ideas, dating from the Bronze Age and described by Homer, necessarily reflect severe limitations to geographical knowledge, as well as basic human predilections toward conjecture and exaggeration in the face of inadequate information. People considered the earth to be flat and circular, with the ocean flowing like a river around it. They also believed in horrific whirlpools, a concept that persisted into the Renaissance and which would later provide subject material for modern literature. From the Greek Classical Age, we find hydrologic theories of Earth's interior being laced with subterranean channels (Socrates) and all motion deriving from a divine force forever propelling the heavens toward the west, the primum mobile (Aristotle). These ideas, particularly the latter, dominated opinions about ocean circulation into the late Renaissance. By late Antiquity mariners had very likely acquired intimate knowledge of coastal currents in the Mediterranean, but

  8. Estuarine circulation in the Taranto Seas.

    Science.gov (United States)

    Pascalis, Francesca De; Petrizzo, Antonio; Ghezzo, Michol; Lorenzetti, Giuliano; Manfè, Giorgia; Alabiso, Giorgio; Zaggia, Luca

    2016-07-01

    The Taranto basin is a shallow water marine system in the South of Italy characterized by the presence of a lagoon environment together with a semi-enclosed bay connected to the Ionian Sea. This marine system experienced over the last few decades strong biochemical pollution and environmental degradation, and it is considered a hotspot study site for economic, ecological and scientific reasons. The aim of this study was to examine, on an annual temporal scale and with high spatial resolution, the main hydrodynamical processes and transport scales of the system by means of a 3D finite element numerical model application, adopting the most realistic forcing available. The model allowed us to assess the role played by baroclinic terms in the basin circulation, describing its estuarine nature. In particular, the main features of water circulation, salinity and temperature distribution, water renewal time and bottom stress were investigated. Our results allowed us to equate this system dynamic to that of a weakly stratified estuary, identifying the main driving sources of this mechanism. The vertical stratification over the whole year was proved to be stable, leading to a dual circulation flowing out on the surface, mainly through Porta Napoli channel, and inflowing on the bottom mainly through Navigabile channel. This process was responsible also for the renewal time faster on the bottom of the Mar Piccolo basin than the surface. Due to the great importance of the Taranto basin for what concerns sediment pollution, also the effect of currents in terms of bottom stress was investigated, leading to the conclusion that only in the inlets area the values of bottom stress can be high enough to cause erosion. PMID:26408109

  9. Seawater bicarbonate removal during hydrothermal circulation

    Science.gov (United States)

    Proskurowski, G. K.; Seewald, J.; Sylva, S. P.; Reeves, E.; Lilley, M. D.

    2013-12-01

    High temperature fluids sampled at hydrothermal vents represent a complex alteration product of water-rock reactions on a multi-component mixture of source fluids. Sources to high-temperature hydrothermal samples include the 'original' seawater present in the recharge limb of circulation, magmatically influenced fluids added at depth as well as any seawater entrained during sampling. High-temperature hydrothermal fluids are typically enriched in magmatic volatiles, with CO2 the dominant species, characterized by concentrations of 10's-100's of mmol/kg (1, 2). Typically, the high concentration of CO2 relative to background seawater bicarbonate concentrations (~2.3 mmol/kg) obscures a full analysis of the fate of seawater bicarbonate during high-temperature hydrothermal circulation. Here we present data from a suite of samples collected over the past 15 years from high-temperature hydrothermal vents at 9N, Endeavour, Lau Basin, and the MAR that have endmember CO2 concentrations less than 10 mmol/kg. Using stable and radiocarbon isotope measurements these samples provide a unique opportunity to examine the balance between 'original' seawater bicarbonate and CO2 added from magmatic sources. Multiple lines of evidence from multiple hydrothermal settings consistently points to the removal of ~80% of the 'original' 2.3 mmol/kg seawater bicarbonate. Assuming that this removal occurs in the low-temperature, 'recharge' limb of hydrothermal circulation, this removal process is widely occurring and has important contributions to the global carbon cycle over geologic time. 1. Lilley MD, Butterfield DA, Lupton JE, & Olson EJ (2003) Magmatic events can produce rapid changes in hydrothermal vent chemistry. Nature 422(6934):878-881. 2. Seewald J, Cruse A, & Saccocia P (2003) Aqueous volatiles in hydrothermal fluids from the Main Endeavour Field, northern Juan de Fuca Ridge: temporal variability following earthquake activity. Earth and Planetary Science Letters 216(4):575-590.

  10. Effects of Buoyancy on Langmuir Circulation

    Institute of Scientific and Technical Information of China (English)

    SONG Jun; SONG Jin-Bao

    2008-01-01

    Based on the Navier-Stokes equation,an equation describing the Langmuir circulation is derived by a perturbation method when the influences of Coriolis force and buoyancy force are both considered.The approach used in the analysis is similar to the works carried out by Craik and Leibovich[J.Fluid Mech.73 (1976)401],Leibovich [J.Fluid Mech.79 (1977) 715]and Huang[J.Fluid Mech.91 (1979) 191].Potential applications of the equation proposed are discussed in the area of Antarctic circumpolar current.

  11. Tropical Atmospheric Circulations with Humidity Effects

    CERN Document Server

    Hsia, Chun-Hsiung; Ma, Tian; Wang, Shouhong

    2011-01-01

    The main objective of this article is to study the effect of the moisture on the planetary scale atmospheric circulation over the tropics. The modeling we adopt is the Boussinesq equations coupled with a diffusive equation of humidity and the humidity dependent heat source is modeled by a linear approximation of the humidity. The rigorous mathematical analysis is carried out using the dynamic transition theory. In particular, we obtain the same types of transitions and hence the scenario of the El Ni\\~no mechanism as described in \\cite{MW2,MW3}. The effect of the moisture only lowers slightly the magnitude of the critical thermal Rayleigh number.

  12. Transients in a circulating fluidized bed boiler

    Science.gov (United States)

    Baskakov, A. P.; Munts, V. A.; Pavlyuk, E. Yu.

    2013-11-01

    Transients in a circulating fluidized bed boiler firing biomass are considered. An attempt is made to describe transients with the use of concepts applied in the automatic control theory. The parameters calculated from an analysis of unsteady heat balance equations are compared with the experimental data obtained in the 12-MW boiler of the Chalmers University of Technology. It is demonstrated that these equations describe the transient modes of operation with good accuracy. Dependences for calculating the time constants of unsteady processes are obtained.

  13. Caffeine induced changes in cerebral circulation

    International Nuclear Information System (INIS)

    While the caffeine induced cerebral vasoconstriction is well documented, the effects of oral ingestion of the drug in a dose range comparable to the quantities in which it is usually consumed and the intensity and duration of the associated reduction in cerebral circulation are unknown. Cerebral blood flow was measured via the 133Xenon inhalation technique before and thirty and ninety minutes after the oral administration of 250 mg of caffeine or a placebo, under double-blind conditions. Caffeine ingestion was found to be associated with significant reductions in cerebral perfusion thirty and ninety minutes later. The placebo group showed no differences between the three sets of cerebral blood flow values

  14. Long term survival following the detection of circulating tumour cells in head and neck squamous cell carcinoma

    International Nuclear Information System (INIS)

    Techniques for detecting circulating tumor cells in the peripheral blood of patients with head and neck cancers may identify individuals likely to benefit from early systemic treatment. Reconstruction experiments were used to optimise immunomagnetic enrichment and RT-PCR detection of circulating tumor cells using four markers (ELF3, CK19, EGFR and EphB4). This method was then tested in a pilot study using samples from 16 patients with advanced head and neck carcinomas. Seven patients were positive for circulating tumour cells both prior to and after surgery, 4 patients were positive prior to but not after surgery, 3 patients were positive after but not prior to surgery and 2 patients were negative. Two patients tested positive for circulating cells but there was no other evidence of tumor spread. Given this patient cohort had mostly advanced disease, as expected the detection of circulating tumour cells was not associated with significant differences in overall or disease free survival. For the first time, we show that almost all patients with advanced head and neck cancers have circulating cells at the time of surgery. The clinical application of techniques for detection of spreading disease, such as the immunomagnetic enrichment RT-PCR analysis used in this study, should be explored further

  15. Haemodynamic evaluation of the cerebral circulation by periorbital Doppler examination and cerebral blood flow (CBF) measurement in carotid artery disease

    DEFF Research Database (Denmark)

    Sillesen, H; Schroeder, T; Buchardt Hansen, H J

    1988-01-01

    To assess the haemodynamic significance of an internal carotid artery (ICA) stenosis, angiography or direct ultrasound examination should be supplemented by indirect physiologic testing of the collateral circulation. Among the tests proposed, we used the periorbital flow direction, assessed by Do...

  16. Enhancement of natural circulation type domestic solar hot water system performance by using a wind turbine

    Science.gov (United States)

    Ramasamy, K. K.; Srinivasan, P. S. S.

    2011-08-01

    Performance improvement of existing 200 litres capacity natural convection type domestic solar hot water system is attempted. A two-stage centrifugal pump driven by a vertical axis windmill having Savonius type rotor is added to the fluid loop. The windmill driven pump circulates the water through the collector. The system with necessary instrumentation is tested over a day. Tests on Natural Circulation System (NCS) mode and Wind Assisted System (WAS) mode are carried out during January, April, July and October, 2009. Test results of a clear day are reported. Daily average efficiency of 25-28 % during NCS mode and 33-37 % during WAS mode are obtained. With higher wind velocities, higher collector flow rates and hence higher efficiencies are obtained. In general, WAS mode provides improvements in efficiency when compared to NCS mode.

  17. Nucla circulating atmospheric fluidized bed demonstration project. Quarterly technical progress report, October--December 1990

    Energy Technology Data Exchange (ETDEWEB)

    1991-01-31

    During the fourth quarter of 1990, steady-state performance testing at the Nucla Circulating Fluidized Bed (CFB) resumed under sponsorship of the US Department of Energy. Co-sponsorship of the Demonstration Test Program by the Electric Power Research Institute (EPRI) was completed on June 15, 1990. From October through December, 1990, Colorado-Ute Electric Association (CUEA) completed a total of 23 steady-state performance tests, 4 dynamic tests, and set operating records during November and December as the result of improved unit operating reliability. Highlight events and achievements during this period of operation are presented.

  18. Causal mechanisms in airfoil-circulation formation

    Science.gov (United States)

    Zhu, J. Y.; Liu, T. S.; Liu, L. Q.; Zou, S. F.; Wu, J. Z.

    2015-12-01

    In this paper, we trace the dynamic origin, rather than any kinematic interpretations, of lift in two-dimensional flow to the physical root of airfoil circulation. We show that the key causal process is the vorticity creation by tangent pressure gradient at the airfoil surface via no-slip condition, of which the theoretical basis has been given by Lighthill ["Introduction: Boundary layer theory," in Laminar Boundary Layers, edited by L. Rosenhead (Clarendon Press, 1963), pp. 46-113], which we further elaborate. This mechanism can be clearly revealed in terms of vorticity formulation but is hidden in conventional momentum formulation, and hence has long been missing in the history of one's efforts to understand lift. By a careful numerical simulation of the flow around a NACA-0012 airfoil, and using both Eulerian and Lagrangian descriptions, we illustrate the detailed transient process by which the airfoil gains its circulation and demonstrate the dominating role of relevant dynamical causal mechanisms at the boundary. In so doing, we find that the various statements for the establishment of Kutta condition in steady inviscid flow actually correspond to a sequence of events in unsteady viscous flow.

  19. Sustaining observations of the unsteady ocean circulation.

    Science.gov (United States)

    Frajka-Williams, E

    2014-09-28

    Sustained observations of ocean properties reveal a global warming trend and rising sea levels. These changes have been documented by traditional ship-based measurements of ocean properties, whereas more recent Argo profiling floats and satellite records permit estimates of ocean changes on a near real-time basis. Through these and newer methods of observing the oceans, scientists are moving from quantifying the 'state of the ocean' to monitoring its variability, and distinguishing the physical processes bringing signals of change. In this paper, I give a brief overview of the UK contributions to the physical oceanographic observations, and the role they have played in the wider global observing systems. While temperature and salinity are the primary measurements of physical oceanography, new transbasin mooring arrays also resolve changes in ocean circulation on daily timescales. Emerging technologies permit routine observations at higher-than-ever spatial resolutions. Following this, I then give a personal perspective on the future of sustained observations. New measurement techniques promise exciting discoveries concerning the role of smaller scales and boundary processes in setting the large-scale ocean circulation and the ocean's role in climate. The challenges now facing the scientific community include sustaining critical observations in the case of funding system changes or shifts in government priorities. These long records will enable a determination of the role and response of the ocean to climate change. PMID:25157191

  20. The biology of circulating tumor cells.

    Science.gov (United States)

    Pantel, K; Speicher, M R

    2016-03-10

    Metastasis is a biologically complex process consisting of numerous stochastic events which may tremendously differ across various cancer types. Circulating tumor cells (CTCs) are cells that are shed from primary tumors and metastatic deposits into the blood stream. CTCs bear a tremendous potential to improve our understanding of steps involved in the metastatic cascade, starting from intravasation of tumor cells into the circulation until the formation of clinically detectable metastasis. These efforts were propelled by novel high-resolution approaches to dissect the genomes and transcriptomes of CTCs. Furthermore, capturing of viable CTCs has paved the way for innovative culturing technologies to study fundamental characteristics of CTCs such as invasiveness, their kinetics and responses to selection barriers, such as given therapies. Hence the study of CTCs is not only instrumental as a basic research tool, but also allows the serial monitoring of tumor genotypes and may therefore provide predictive and prognostic biomarkers for clinicians. Here, we review how CTCs have contributed to significant insights into the metastatic process and how they may be utilized in clinical practice. PMID:26050619

  1. Reversing circulation patterns in a tropical estuary

    Science.gov (United States)

    Valle-Levinson, Arnoldo; Bosley, Kathryn T.

    2003-10-01

    A combination of current velocity and water density measurements was used to characterize the basic patterns of water exchange in the Gulf of Fonseca, a tropical estuary on the Pacific Ocean side of Central America. The measurements were obtained during spring and neap tides in March (dry season) and June (wet season) of 2001 and consisted of profiles of current velocity and density along four transects. From mid-March to mid-April a time series of hourly surface current velocity maps was also obtained with a high-frequency radar system of two antennas. The sampling transects and the radar coverage concentrated in the portion of the estuary that has open communication with the ocean. During the dry season, water exchange at the entrance to the gulf suggested an inverse estuarine circulation that was more robust, and its dynamics were closer to geostrophy during neap than during spring tides. It is likely that salinity increased toward the tributaries of the system and then decreased within those tributaries because of the persistent influence of fresh water. In contrast, during the wet season, salinity decreased into the estuary, and the circulation resembled that of a typical estuary. In this season the fortnightly modulation of exchange flows was masked by wind effects, which also played a relevant role in the dynamics. The net volume inflows measured in both seasons suggested that the residence time of the Gulf of Fonseca varies from 2 weeks to 1 month.

  2. Formation and Plasma Circulation of Solar Prominences

    Science.gov (United States)

    Xia, C.; Keppens, R.

    2016-05-01

    Solar prominences are long-lived cool and dense plasma curtains in the hot and rarefied outer solar atmosphere or corona. The physical mechanism responsible for their formation and especially for their internal plasma circulation has been uncertain for decades. The observed ubiquitous downflows in quiescent prominences are difficult to interpret because plasma with high conductivity seems to move across horizontal magnetic field lines. Here we present three-dimensional numerical simulations of prominence formation and evolution in an elongated magnetic flux rope as a result of in situ plasma condensations fueled by continuous plasma evaporation from the solar chromosphere. The prominence is born and maintained in a fragmented, highly dynamic state with continuous reappearance of multiple blobs and thread structures that move mainly downward, dragging along mass-loaded field lines. The circulation of prominence plasma is characterized by the dynamic balance between the drainage of prominence plasma back to the chromosphere and the formation of prominence plasma via continuous condensation. Plasma evaporates from the chromosphere, condenses into the prominence in the corona, and drains back to the chromosphere, establishing a stable chromosphere–corona plasma cycle. Synthetic images of the modeled prominence with the Solar Dynamics Observatory Atmospheric Imaging Assembly closely resemble actual observations, with many dynamical threads underlying an elliptical coronal cavity.

  3. A generalized flow correlation for two-phase natural circulation loops

    International Nuclear Information System (INIS)

    In the present generation of nuclear reactors the two-phase natural circulation core power removal capabilities is extensively exploited for accident situations, basically to demonstrate the inherent safety features of the plants. Scaling is particularly important in research application where full scale testing or experiments are prohibitively expensive or have significant safety implications such as in Light Water Reactor (LWR) or Heavy Water Reactor (HWR) safety research. The general objective of a scaling analysis is to obtain the physical dimension and operating condition of a reduced scale facility capable of simulating the important flow and heat transfer behavior of the system under investigation. Scaling laws also make possible the comparison of the performance of different natural circulation systems and to extrapolate the data from small scale to prototype systems. The scaling criterion for a natural circulation loop under two-phase condition has been derived. The scaling law proposed has been tested with experimental data from five different two-phase natural circulation loops. The experimental results are found to be in reasonable agreement with the proposed correlation. (author)

  4. Reliability Analysis of a Boiling Two-phase Natural Circulation System using the APSRA methodology

    International Nuclear Information System (INIS)

    In this paper, we present a methodology known as APSRA (Assessment of Passive System ReliAbility) for evaluation of reliability of passive systems. The methodology has been applied to the boiling natural circulation system in the Main Heat Transport System of the Indian AHWR (Advanced Heavy Water Reactor) concept. In the APSRA methodology, the passive system reliability is evaluated from the evaluation of the failure probability of the system to carry out the desired function. The methodology first determines the operational characteristics of the system and the failure conditions by assigning a predetermined failure criterion. The failure surface is predicted using a best estimate code considering deviations of the operating parameters from their nominal states, which affect the natural circulation performance. Since applicability of the best estimate codes to passive systems are neither proven nor understood enough, APSRA relies more on experimental data for various aspects of natural circulation such as steady state natural circulation, flow instabilities, CHF (critical heat flux) under oscillatory condition, etc. APSRA proposes to compare the code predictions with the test data to generate the uncertainties on the failure parameter prediction, which is later considered in the code for accurate prediction of failure surface of the system. Once the failure surface of the system is predicted, the cause of failure is examined through root diagnosis, which occurs mainly due to failure of mechanical components. The failure probabilities of these components are evaluated through a classical PSA (Probabilistic Safety Assessment) treatment using the generic data. Reliability of the natural circulation system is evaluated from the probability of availability of the components for the success of natural circulation in the system. (author)

  5. Decreased circulating endothelial progenitor cell levels and function in patients with nonalcoholic fatty liver disease.

    Directory of Open Access Journals (Sweden)

    Chia-Hung Chiang

    Full Text Available OBJECTIVES: Nonalcoholic fatty liver disease (NAFLD is associated with advanced atherosclerosis and a higher risk of cardiovascular disease. Increasing evidence suggests that injured endothelial monolayer is regenerated by circulating bone marrow derived-endothelial progenitor cells (EPCs, and levels of circulating EPCs reflect vascular repair capacity. However, the relation between NAFLD and EPC remains unclear. Here, we tested the hypothesis that patients with nonalcoholic fatty liver disease (NAFLD might have decreased endothelial progenitor cell (EPC levels and attenuated EPC function. METHODS AND RESULTS: A total of 312 consecutive patients undergoing elective coronary angiography because of suspected coronary artery disease were screened and received examinations of abdominal ultrasonography between July 2009 and November 2010. Finally, 34 patients with an ultrasonographic diagnosis of NAFLD, and 68 age- and sex-matched controls without NAFLD were enrolled. Flow cytometry with quantification of EPC markers (defined as CD34(+, CD34(+KDR(+, and CD34(+KDR(+CD133(+ in peripheral blood samples was used to assess circulating EPC numbers. The adhesive function, and migration, and tube formation capacities of EPCs were also determined in NAFLD patients and controls. Patients with NAFLD had a significantly higher incidence of metabolic syndrome, previous myocardial infarction, hyperuricemia, and higher waist circumference, body mass index, fasting glucose and triglyceride levels. In addition, patients with NAFLD had significantly decreased circulating EPC levels (all P<0.05, attenuated EPC functions, and enhanced systemic inflammation compared to controls. Multivariate logistic regression analysis showed that circulating EPC level (CD34(+KDR(+ [cells/10(5 events] was an independent reverse predictor of NAFLD (Odds ratio: 0.78; 95% confidence interval: 0.69-0.89, P<0.001. CONCLUSIONS: NAFLD patients have decreased circulating EPC numbers and

  6. Analysis of the multi-application small light-water reactor (MASLWR) design natural circulation phenomena

    International Nuclear Information System (INIS)

    Today the use of advanced nuclear power plants, have an important role in the environment and economic sustainability of country energy strategy considering the capacity of a nuclear reactor of producing energy in safe and stable way contributing in cutting the CO2 emissions. In the last 20 years, in fact, the international community, taking into account the excellent operational experience of the nuclear reactors, starts the development of new advanced reactor designs, by including also the use of the natural circulation for the cooling of the core in normal and transient conditions. In this international framework, Oregon State University has constructed, under a U.S. Department of Energy grant, a system level test facility to examine natural circulation phenomena of importance to Multi-Application Small Light-Water Reactor (MASLWR) design. The MASLWR is a small modular integral pressurized water reactor relying on natural circulation during both steady state and transient operation, including an integrated helical coil steam generator. Starting from an experimental campaign in support of the MASLWR concept design verification, the planned work, related to the OSU-MASLWR test facility, will be not only to specifically investigate the MASLWR concept design further but also advance the broad understanding of integral natural circulation reactor plants and accompanying passive safety features as well. Four tests have been performed at this facility in order to assess the thermal hydraulic behavior of the MASLWR design in normal and transient operation and to assess the passive safety system under transient condition. This paper illustrates a preliminary analyses, performed by TRACE code, aiming at the evaluation of the code capability in predicting natural circulation, heat exchange from primary to secondary side by helical steam generator in superheated condition and primary/containment coupling phenomena typical of the MASLWR design. The tests take into account

  7. Testing of a 3 tesla superconducting magnet for the AMY detector at TRISTAN

    International Nuclear Information System (INIS)

    A 3 tesla magnet was constructed and installed in an experimental hall at TRISTAN. Cooldown and excitation tests of the magnet were carried out with a dedicated cryogenic system. The coil has a 2.39 m inner diameter and is 1.54 m long with a radial thickness of 0.1 m. The rated current is 5 kA and the stored energy is 40 MJ. The refrigerator and 17-ton magnet cold mass were cooled to 4.4 K in seven days. Then the magnet was energized to the design current of 5 kA and the mechanical stress of the coil supports was measured. The stress on the supports was well below the allowed maximum. Measurements of the discharge characteristics of the magnet confirmed that the magnet was stable and reliable

  8. Tests results of Nb$_{3}$Sn quadrupole magnets using a shell-based support structure

    CERN Document Server

    Caspi, S

    2009-01-01

    In support of the development of a 90 mm aperture Nb3Sn superconducting quadrupole for the US LHC Accelerator Research Program (LARP), test results of five quadrupole magnets are compared. All five assemblies used key and bladder technology to compress and support the coils within an iron yoke and an aluminium shell. The first three models (TQS01a, b, c) used Nb3Sn MJR conductor and segmented bronze poles. The last two models (TQS02a, b) used Nb3Sn RRP conductor, and segmented titanium alloy (TiAl6V4) poles, with no axial gaps during reaction. This presentation summarizes the magnets performance during assembly, cool-down and excitation and compares measurements with design expectations.

  9. Effect of Vegetation on the Late Miocene Ocean Circulation

    Directory of Open Access Journals (Sweden)

    Gerrit Lohmann

    2015-11-01

    Full Text Available We examine the role of the vegetation cover and the associated hydrological cycle on the deep ocean circulation during the Late Miocene (~10 million years ago. In our simulations, an open Central American gateway and exchange with fresh Pacific waters leads to a weak and shallow thermohaline circulation in the North Atlantic Ocean which is consistent with most other modeling studies for this time period. Here, we estimate the effect of a changed vegetation cover on the ocean general circulation using atmospheric circulation model simulations for the late Miocene climate with 353 ppmv CO2 level. The Late Miocene land surface cover reduces the albedo, the net evaporation in the North Atlantic catchment is affected and the North Atlantic water becomes more saline leading to a more vigorous North Atlantic Deep Water circulation. These effects reveal potentially important feedbacks between the ocean circulation, the hydrological cycle and the land surface cover for Cenozoic climate evolution.

  10. Experimental study for convective heat transfer of staged tube bundles

    International Nuclear Information System (INIS)

    The lack of potable water is one of the most serious problems the world is facing at present. SMART which is a 330 MWt advanced integral PWR, was developed by the KAERI for electricity generation and seawater desalination. SMART adopted a passive system to enhance its safety. The passive system can passively remove a decay heat from a reactor core to an emergency cooldown tank through the heat exchanger. Tube bundles of the heat exchanger, which is submerged in an emergency cooldown tank, transfer heat to an emergency cooldown tank by natural circulation. Heat transfer tests for the upward straight tube bundle were performed to confirm the capability of the SMART design under natural circulation conditions. The heat transfer at the tube bundle was affected by the fluid temperature in the emergency cooldown tank and the radial location of tube bundle. However, it had nearly the same value at the inlet region regardless of the tube location. The average heat transfer at the tube bundle was slightly higher than that at the single tube. (author)

  11. Human cerebral circulation. Positron emission tomography studies

    International Nuclear Information System (INIS)

    We reviewed the literature on human cerebral circulation and oxygen metabolism, as measured by positron emission tomography (PET), with respect to normal values and of regulation of cerebral circulation. A multicenter study in Japan showed that between-center variations in cerebral blood flow (CBF), cerebral blood volume (CBV), cerebral oxygen extraction fraction (OEF) and cerebral metabolic rate of oxygen (CMRO2) values were not considerably larger than the corresponding within-center variations. Overall mean±SD values in cerebral cortical regions of normal human subjects were as follows: CBF=44.4±6.5 ml/100 ml/min; CBV=3.8±0.7 ml/100 ml; OEF=0.44±0.06; CMRO2=3.3±0.5 ml/100 ml/min (11 PET centers, 70 subjects). Intrinsic regulation of cerebral circulation involves several factors. Autoregulation maintains CBF in response to changes in cerebral perfusion pressure; chemical factors such as PaCO2 affect cerebral vascular tone and alter CBF; changes in neural activity cause changes in cerebral energy metabolism and CBF; neurogenic control of CBF occurs by sympathetic innervation. Regional differences in vascular response to changes in PaCO2 have been reported, indicating regional differences in cerebral vascular tone. Relations between CBF and CBV during changes in PaCO2 and during changes in neural activity were in good agreement with Poiseuille's law. The mechanisms of vascular response to neural activation and deactivation were independent on those of responses to PaCO2 changes. CBV in a brain region is the sum of three components: arterial, capillary and venous blood volumes. It has been reported that the arterial blood volume fraction is approximately 30% in humans and that changes in human CBV during changes in PaCO2 are caused by changes in arterial blood volume without changes in venous blood volume. These findings should be considered in future studies of the pathophysiology of cerebrovascular diseases. (author) 136 refs

  12. Microsurgical anatomy of the posterior circulation

    Directory of Open Access Journals (Sweden)

    Pai Balaji

    2007-01-01

    Full Text Available Context: The microsurgical anatomy of the posterior circulation is very complex and variable. Surgical approaches to this area are considered risky due to the presence of the various important blood vessels and neural structures. Aims: To document the microsurgical anatomy of the posterior circulation along with variations in the Indian population. Materials and Methods: The authors studied 25 cadaveric brain specimens. Microsurgical dissection was carried out from the vertebral arteries to the basilar artery and its branches, the basilar artery bifurcation, posterior cerebral artery and its various branches. Measurements of the outer diameters of the vertebral artery, basilar artery and posterior cerebral artery and their lengths were taken. Results: The mean diameter of the vertebral artery was 3.4 mm on the left and 2.9 mm on the right. The diameter of the basilar artery varied from 3-7 mm (mean of 4.3 mm. The length varied from 24-35 mm (mean of 24.9 mm. The basilar artery gave off paramedian and circumferential perforating arteries. The origin of the anterior inferior cerebellar artery (AICA varied from 0-21 mm (mean 10.0 mm from the vertebrobasilar junction. The diameter of the AICA varied from being hypoplastic i.e., < 0.5 mm to 2 mm (mean 1.0 mm. The superior cerebellar artery (SCA arises very close to the basilar bifurcation, in our series (1-3 mm from the basilar artery bifurcation. The diameter of the SCA varied from 0.5-2.5 mm on both sides. The posterior cerebral artery (PCA is divided into four segments. The PCA gave rise to perforators (thalamoperforators, thalamogeniculate arteries, circumflex arteries and peduncular arteries, medial posterior choroidal artery, lateral posterior choroidal artery and cortical branches. In 39 specimens the P1 segment was found to be larger than the posterior communicating artery, in six specimens it was found to be equal to the diameter of the posterior communicating artery and in five specimens it

  13. Large coil test facility conceptual design report

    International Nuclear Information System (INIS)

    In the development of a superconducting toroidal field (TF) magnet for The Next Step (TNS) tokamak reactor, several different TF coils, about half TNS size, will be built and tested to permit selection of a design and fabrication procedure for full-scale TNS coils. A conceptual design has been completed for a facility to test D-shaped TF coils, 2.5 x 3.5-m bore, operating at 4-6 K, cooled either by boiling helium or by forced-flow supercritical helium. Up to six coils can be accommodated in a toroidal array housed in a single vacuum tank. The principal components and systems in the facility are an 11-m vacuum tank, a test stand providing structural support and service connections for the coils, a liquid nitrogen system, a system providing helium both as saturated liquid and at supercritical pressure, coils to produce a pulsed vertical field at any selected test coil position, coil power supplies, process instrumentation and control, coil diagnostics, and a data acquisition and handling system. The test stand structure is composed of a central bucking post, a base structure, and two horizontal torque rings. The coils are bolted to the bucking post, which transmits all gravity loads to the base structure. The torque ring structure, consisting of beams between adjacent coils, acts with the bucking structure to react all the magnetic loads that occur when the coils are energized. Liquid helium is used to cool the test stand structure to 5 K to minimize heat conduction to the coils. Liquid nitrogen is used to precool gaseous helium during system cooldown and to provide thermal radiation shielding

  14. Thermal modeling of the NASA-Ames Research Center Cryogenic Optical Test Facility and a single-arch, fused-natural-quartz mirror

    Science.gov (United States)

    Ng, Y. S.; Augason, Gordon C.; Young, Jeffrey A.; Howard, Steven D.; Melugin, Ramsey K.

    1990-01-01

    A thermal model of the dewar and optical system of the Cryogenic Optical Test Facility at NASA-Ames Research Center was developed using the computer codes SINDA and MONTE CARLO. The model was based on the geometry, boundary conditions, and physical properties of the test facility and was developed to investigate heat transfer mechanisms and temperatures in the facility and in test mirrors during cryogenic optical tests. A single-arch, fused-natural-quartz mirror was the first mirror whose thermal loads and temperature distributions were modeled. From the temperature distribution, the thermal gradients in the mirror were obtained. The model predicted that a small gradient should exist for the single arch mirror. This was later verified by the measurement of mirror temperatures. The temperatures, predicted by the model at various locations within the dewar, were in relatively good agreement with the measured temperatures. The model is applicable to both steady-state and transient cooldown operations.

  15. Hadley Circulation Response to Orbital Precession. Part I: Aquaplanets

    OpenAIRE

    Merlis, Timothy M.; Schneider, Tapio; Bordoni, Simona; Eisenman, Ian

    2013-01-01

    The response of the monsoonal and annual-mean Hadley circulation to orbital precession is examined in an idealized atmospheric general circulation model with an aquaplanet slab-ocean lower boundary. Contrary to expectations, the simulated monsoonal Hadley circulation is weaker when perihelion occurs at the summer solstice than when aphelion occurs at the summer solstice. The angular momentum balance and energy balance are examined to understand the mechanisms that produce this result. That th...

  16. The ElGamal cryptosystem over circulant matrices

    OpenAIRE

    Mahalanobis, Ayan

    2011-01-01

    In this paper we study extensively the discrete logarithm problem in the group of non-singular circulant matrices. The emphasis of this study was to find the exact parameters for the group of circulant matrices for a secure implementation. We tabulate these parameters. We also compare the discrete logarithm problem in the group of circulant matrices with the discrete logarithm problem in finite fields and with the discrete logarithm problem in the group of rational points of an elliptic curve.

  17. Mid-Latitude Circulation and Extremes in a Changing Climate

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Gang [Cornell Univ., Ithaca, NY (United States)

    2016-08-04

    Mid-latitude extreme weather events are responsible for a large part of climate-related damage. Yet large uncertainties remain in climate model projections of heat waves, droughts, and heavy rain/snow events on regional scales, limiting our ability to effectively use these projections for climate adaptation and mitigation. These uncertainties can be attributed to both the lack of spatial resolution in the models, and to the lack of a dynamical understanding of these extremes. The approach of this project is to relate the fine-scale features to the large scales in current climate simulations, seasonal re-forecasts, and climate change projections in a very wide range of models, including the atmospheric and coupled models of ECMWF over a range of horizontal resolutions (125 to 10 km), aqua-planet configuration of the Model for Prediction Across Scales and High Order Method Modeling Environments (resolutions ranging from 240 km – 7.5 km) with various physics suites, and selected CMIP5 model simulations. The large scale circulation will be quantified both on the basis of the well tested preferred circulation regime approach, and very recently developed measures, the finite amplitude Wave Activity (FAWA) and its spectrum. The fine scale structures related to extremes will be diagnosed following the latest approaches in the literature. The goal is to use the large scale measures as indicators of the probability of occurrence of the finer scale structures, and hence extreme events. These indicators will then be applied to the CMIP5 models and time-slice projections of a future climate.

  18. Thermal hydraulic modeling of a natural circulation loop

    International Nuclear Information System (INIS)

    The experiment was carried out on the test loop HRTL-5, which simulates the geometry and system design of a 5 MW nuclear heating reactor. The analysis was based on a one-dimensional two-phase flow drift model with conservation equations for mass, steam, energy and momentum. Clausius-Clapeyron equation was used for the calculation of flashing front in the riser. A set of ordinary equations, which describes the behavior of two-phase flow in the natural circulation system, was derived through integration of the above conservation equations for the subcooled boiling region, bulk boiling region in the heated section and for the riser. The method of time-domain was used for the calculation. Both static and dynamic results are presented. System pressure, inlet subcooling and heat flux are varied as input parameters. The results show that subcooled boiling in the heated section and void flashing in the riser have significant influence on the distribution of the void fraction, mass flow rate and flow instability of the system, especially at low pressure. The response of mass flow rate, after a small disturbance in the heat flux is shown, and based on it the instability map of the system is given through experiment and calculation. There exists three regions in the instability map of the investigated natural circulation system, namely, the stable two-phase flow region, the unstable bulk and subcooled boiling flow region and the stable subcooled boiling and single phase flow region. The mechanism of two-phase flow oscillation is interpreted. (orig.)

  19. Thermal hydraulic modeling of a natural circulation loop

    Science.gov (United States)

    Jiang, S. Y.; Wu, X. X.; Zhang, Y. J.; Jia, H. J.

    The experiment was carried out on the test loop HRTL-5, which simulates the geometry and system design of a 5MW nuclear heating reactor. The analysis was based on a one-dimensional two-phase flow drift model with conservation equations for mass, steam, energy and momentum. Clausius-Clapeyron equation was used for the calculation of flashing front in the riser. A set of ordinary equations, which describes the behavior of two-phase flow in the natural circulation system, was derived through integration of the above conservation equations for the subcooled boiling region, bulk boiling region in the heated section and for the riser. The method of time-domain was used for the calculation. Both static and dynamic results are presented. System pressure, inlet subcooling and heat flux are varied as input parameters. The results show that subcooled boiling in the heated section and void flashing in the riser have significant influence on the distribution of the void fraction, mass flow rate and flow instability of the system, especially at low pressure. The response of mass flow rate, after a small disturbance in the heat flux is shown, and based on it the instability map of the system is given through experiment and calculation. There exists three regions in the instability map of the investigated natural circulation system, namely, the stable two-phase flow region, the unstable bulk and subcooled boiling flow region and the stable subcooled boiling and single phase flow region. The mechanism of two-phase flow oscillation is interpreted.

  20. Doppler ultrasound scan during normal gestation: umbilical circulation

    International Nuclear Information System (INIS)

    To determine normal umbilical circulation patterns by means of Doppler ultrasound scan in a healthy gestating population without risk factors and with normal perinatal results, and to evaluate any occurring modifications relative to gestational age by obtaining records kept during pregnancy. One hundred and sixteen pregnant women carrying a single fetus have been studied. These women had no risk factors, with both clinical and analytical controls, as well as ultrasound scans, all being normal. There were performed a total of 193 Doppler ultrasound scans between weeks 15 and 41 of gestation, with blood-flow analysis in the arteries and vein of the umbilical cord. The obtained information was correlated with parameters that evaluate fetal well-being (fetal monitoring and/or oxytocin test) and perinatal result (delivery type, birth weight, Apgar score). Statistical analysis was performed with the programs SPSS 6.0.1 for Windows and EPIINFO 6.0.4. With pulsed Doppler, the umbilical artery in all cases demonstrated a biphasic morphology with systolic and diastolic components and without retrograde blood flow. As the gestation period increased, there was observed a progressive decrease in resistance along with an increase in blood-flow velocity during the diastolic phase. The Doppler ultrasound scan is a non-invasive method that permits the hemodynamic study of umbilical blood circulation. A knowledge of normal blood-flow signal morphology, as well as of the normal values for Doppler indices in relation to gestational age would permit us to utilize this method in high-risk pregnancies. (Author) 30 refs

  1. Three-dimensional numerical modeling of nearshore circulation

    Institute of Scientific and Technical Information of China (English)

    SUN Detong

    2008-01-01

    A three-dimensional nearshore circulation model was developed by coupling CH3D, a three-dimensional hydrodynamic model and REF/DIF, a nearsbore wave transformation model. The model solves the three-dimensional wave-averaged equations of motion. Wave-induced effects on circulation were introduced in the form of radiation stresses, wave-induced mass transport, wave-induced enhancement of bottom friction and wave-induced turbulent mixing. Effects of breaking waves were considered following Svendsen (1984a and 1984b) and Stive and Wind (1986). The model was successfully tested against the analytical solution of longshore currents by Longuet and Higgins (1970). The model successfully simulated the undertow as observed in a laboratory experiment by Stive and Wind (1982). In addition, the model was applied to a physical model by Mory and Hamm (1997) and successfully reproduced the eddy behind a detached breakwater as well as the longshore current on the open beach and the contiguous eddy in the open area of the wave tank. While the qualitative agreement between model results and experimental observations was very good, the quantitative agreement needs to be further improved. Albeit difficult to explain every discrepancy between the model re- suits and observations, in general, sources of errors are attributed to the lack of understanding and comprehensive description of following processes: (1) the horizontal and vertical distribution of radiation stress, especially for breaking waves; (2) the detailed structure of turbulence;(3)Wave-current interaction (not included at this moment) ; and (4)the wave- current boundary layer and the resulting bottom shear stress.

  2. Methodical Approaches to Diagnostics of Circulating Assets of an Enterprise

    Directory of Open Access Journals (Sweden)

    Oleksandrenko Iryna V.

    2014-02-01

    Full Text Available The article is devoted to the study of theoretical and practical grounds of diagnostics of circulation assets. It identifies essence of circulating assets and their types. It shows main stages of diagnostics of circulating assets and systemises main tasks, which should be solved in the process of diagnostics. It specifies methods used in the process of diagnostics of the enterprise circulating assets. It identifies and shows the order of calculation of indicators of efficiency of use of circulating assets. Based on the proposed indicators of efficiency of use of circulating assets the article identifies methodical grounds of carrying out their factor analysis. The provided methods of conduct of a factor analysis of the circulating assets turnover ration allows finding out how growth (reduction of components of circulating assets influenced the change of the effective indicator. Based on the results of diagnostics of circulating assets the article shows main managerial decisions that could be taken into account. The reflected theoretical and practical aspects of diagnostics are a foundation of conduct of diagnostics of property and the financial state of the enterprise in general.

  3. r-BlockPermutation Factor Circulant Matrix and Inverse Matrix

    OpenAIRE

    SUN Ji zhong; QIN Keyun; Hu, Yan

    2012-01-01

    The concept of r-block permutation factor circulant matrix is presented. The characteristics of r-block permutation factor circulant matrix are discussed by Kronecker. The interchange ability of r-block permutation factor circulant matrix has been demonstrated, that is AB=BA. The calculation method of matrix determinant and the sufficient condition of nonsingular matrix based on the diagonalization of circulant matrices are given. Finally, the method of inverse matrix is given in r-blo...

  4. Optimization of reverse circulation bit based on field experiment

    Institute of Scientific and Technical Information of China (English)

    Hong REN; Kun YIN; Kun BO

    2008-01-01

    By field experiment in Sandaozhuang W-Mo mining area in Luanchuan of Henan Province, the authors analyzed the Experimental result of reverse circulation bit on the basis of different structures and obtained the following conclusion: the design parameter of reverse circulation bit, the number, diameter and angle of the spurt hole can influence on the reverse circulation effect. The bit with inner spurt hole is better obviously than that one without inner spurt hole in reverse circulation, one or two right and the best choice of inner spurt hole is that the diameter is Φ8, the angle is 30° dip up and the suitable number is two to three.

  5. BIM-enabled Conceptual Modelling and Representation of Building Circulation

    Directory of Open Access Journals (Sweden)

    Jin Kook Lee

    2014-08-01

    Full Text Available This paper describes how a building information modelling (BIM-based approach for building circulation enables us to change the process of building design in terms of its computational representation and processes, focusing on the conceptual modelling and representation of circulation within buildings. BIM has been designed for use by several BIM authoring tools, in particular with the widely known interoperable industry foundation classes (IFCs, which follow an object-oriented data modelling methodology. Advances in BIM authoring tools, using space objects and their relations defined in an IFC’s schema, have made it possible to model, visualize and analyse circulation within buildings prior to their construction. Agent-based circulation has long been an interdisciplinary topic of research across several areas, including design computing, computer science, architectural morphology, human behaviour and environmental psychology. Such conventional approaches to building circulation are centred on navigational knowledge about built environments, and represent specific circulation paths and regulations. This paper, however, places emphasis on the use of ‘space objects’ in BIM-enabled design processes rather than on circulation agents, the latter of which are not defined in the IFCs’ schemas. By introducing and reviewing some associated research and projects, this paper also surveys how such a circulation representation is applicable to the analysis of building circulation-related rules.

  6. Circulating Tumor Cells, Enumeration and Beyond

    Directory of Open Access Journals (Sweden)

    Jian-Mei Hou

    2010-06-01

    Full Text Available The detection and enumeration of circulating tumor cells (CTCs has shown significant clinical utility with respect to prognosis in breast, colorectal and prostate cancers. Emerging studies show that CTCs can provide pharmacodynamic information to aid therapy decision making. CTCs as a ‘virtual and real-time biopsy’ have clear potential to facilitate exploration of tumor biology, and in particular, the process of metastasis. The challenge of profiling CTC molecular characteristics and generating CTC signatures using current technologies is that they enrich rather than purify CTCs from whole blood; we face the problem of looking for the proverbial ‘needle in the haystack’. This review summarizes the current methods for CTC detection and enumeration, focuses on molecular characterization of CTCs, unveils some aspects of CTC heterogeneity, describes attempts to purify CTCs and scans the horizon for approaches leading to comprehensive dissection of CTC biology.

  7. The Circulation Pattern in Simulated Contact Binaries

    Science.gov (United States)

    Motl, Patrick M.; Frank, J.; Tohline, J. E.

    2006-06-01

    We present a three-dimensional hydrodynamical simulation of an initially symmetric (equal mass) binary where both components are marginally in contact. The simulation evolves the binary through approximately 150 orbital periods and within the first 20 orbits, a global velocity field is established that carries material between both components. In the equatorial plane, the flow is along a figure eight pattern with streams of material sliding past one another in the neighborhood of the inner Lagrange point. For our chosen equation of state, mass transfer is ultimately unstable in this binary though the growth time is long compared to the orbital period. We are therefore able to observe that the circulation pattern, once established, is quite close to steady state. We explore the role that similar steady state flows may play in real contact systems.

  8. NUCLA Circulating Atmospheric Fluidized Bed Demonstration Project

    Energy Technology Data Exchange (ETDEWEB)

    Keith, Raymond E.; Heller, Thomas J.; Bush, Stuart A.

    1991-01-01

    This Annual Report on Colorado-Ute Electric Association's NUCLA Circulating Fluidized Bed (CFB) Demonstration Program covers the period from February 1987 through December 1988. The outline for presentation in this report includes a summary of unit operations along with individual sections covering progress in study plan areas that commenced during this reporting period. These include cold-mode shakedown and calibration, plant commercial performance statistics, unit start-up (cold), coal and limestone preparation and handling, ash handling system performance and operating experience, tubular air heater, baghouse operation and performance, materials monitoring, and reliability monitoring. During this reporting period, the coal-mode shakedown and calibration plan was completed. (VC)

  9. Circulating tumor cells: utopia or reality?

    Science.gov (United States)

    Conteduca, Vincenza; Zamarchi, Rita; Rossi, Elisabetta; Condelli, Valentina; Troiani, Laura; Aieta, Michele

    2013-09-01

    Circulating tumor cells (CTCs) could be considered a sign of tumor aggressiveness, but highly sensitive and specific methods of CTC detection are necessary owing to the rarity and heterogeneity of CTCs in peripheral blood. This review summarizes recent studies on tumor biology, with particular attention to the metastatic cascade, and the molecular characterization and clinical significance of CTCs. Recent technological approaches to enrich and detect these cells and challenges of CTCs for individualized cancer treatment are also discussed. This review also provides an insight into the positive and negative features of the future potential applications of CTC detection, which sometimes remains still a 'utopia', but its actual utility remains among the fastest growing research fields in oncology. PMID:23980681

  10. Particle pollution changes the atmospheric circulation

    International Nuclear Information System (INIS)

    Industrial emissions and combustion of fossil fuels create large amounts of sulfate- and carbon containing soot particles. These mix with natural particles to change the natural aerosols. Such anthropogenic changes in the aerosols may have a great impact on the climate of the earth. Altered properties of the aerosols may change the atmosphere's absorption and reflection of solar radiation and contribute to heating or cooling. This is the direct effect. Changes in the properties of aerosols may also affect the number and size of recently formed cloud droplets. This may change the ability of the clouds to reflect solar radiation and to produce precipitation. This is the indirect effect. Recent research at the University of Oslo shows that anthropogenic particles significantly change the atmospheric circulation, in particular in the tropics, but also at European latitudes

  11. Circulating Tumor Cells, Enumeration and Beyond

    International Nuclear Information System (INIS)

    The detection and enumeration of circulating tumor cells (CTCs) has shown significant clinical utility with respect to prognosis in breast, colorectal and prostate cancers. Emerging studies show that CTCs can provide pharmacodynamic information to aid therapy decision making. CTCs as a ‘virtual and real-time biopsy’ have clear potential to facilitate exploration of tumor biology, and in particular, the process of metastasis. The challenge of profiling CTC molecular characteristics and generating CTC signatures using current technologies is that they enrich rather than purify CTCs from whole blood; we face the problem of looking for the proverbial ‘needle in the haystack’. This review summarizes the current methods for CTC detection and enumeration, focuses on molecular characterization of CTCs, unveils some aspects of CTC heterogeneity, describes attempts to purify CTCs and scans the horizon for approaches leading to comprehensive dissection of CTC biology

  12. Circulation and Dissipation on Hot Jupiters

    CERN Document Server

    Li, Jason

    2010-01-01

    Many global circulation models predict supersonic zonal winds and large vertical shears in the atmospheres of short-period jovian exoplanets. Using linear analysis and nonlinear local simulations, we investigate hydrodynamic dissipation mechanisms to balance the thermal acceleration of these winds. The adiabatic Richardson criterion remains a good guide to linear stability, although thermal diffusion allows some modes to violate it at very long wavelengths and very low growth rates. Nonlinearly, wind speeds saturate at Mach numbers $\\approx 2$ and Richardson numbers $\\lesssim 1/4$ for a broad range of plausible diffusivities and forcing strengths. Turbulence and vertical mixing, though accompanied by weak shocks, dominate the dissipation, which appears to be the outcome of a recurrent Kelvin-Helmholtz instability. An explicit shear viscosity, as well as thermal diffusivity, is added to ZEUS to capture dissipation outside of shocks. The wind speed is not monotonic nor single valued for shear viscosities larger...

  13. CIRCULATION AND DISSIPATION ON HOT JUPITERS

    International Nuclear Information System (INIS)

    Many global circulation models predict supersonic zonal winds and large vertical shears in the atmospheres of short-period Jovian exoplanets. Using linear analysis and nonlinear local simulations, we investigate hydrodynamic dissipation mechanisms to balance the thermal acceleration of these winds. The adiabatic Richardson criterion remains a good guide to linear stability, although thermal diffusion allows some modes to violate it at very long wavelengths and very low growth rates. Nonlinearly, wind speeds saturate at Mach numbers ∼2 and Richardson numbers ∼-3 of the sound speed times the pressure scale height. Coarsening the numerical resolution can also increase the speed. Hence global simulations that are incapable of representing vertical turbulence and shocks, either because of reduced physics or because of limited resolution, may overestimate wind speeds. We recommend that such simulations include artificial dissipation terms to control the Mach and Richardson numbers and to capture mechanical dissipation as heat.

  14. Circulating Tumor Cells, Enumeration and Beyond

    Energy Technology Data Exchange (ETDEWEB)

    Hou, Jian-Mei [Clinical and Experimental Pharmacology Group, Paterson Institute for Cancer Research, Manchester M20 4BX (United Kingdom); Krebs, Matthew [Clinical and Experimental Pharmacology Group, Paterson Institute for Cancer Research, Manchester M20 4BX (United Kingdom); Christie Hospital Foundation NHS Trust, Manchester M20 4BX (United Kingdom); Ward, Tim; Morris, Karen; Sloane, Robert [Clinical and Experimental Pharmacology Group, Paterson Institute for Cancer Research, Manchester M20 4BX (United Kingdom); Blackhall, Fiona [Clinical and Experimental Pharmacology Group, Paterson Institute for Cancer Research, Manchester M20 4BX (United Kingdom); School of Cancer and Enabling Sciences, University of Manchester, Manchester Cancer Research Centre, Manchester Academic Health Sciences Centre, Manchester M20 4BX (United Kingdom); Christie Hospital Foundation NHS Trust, Manchester M20 4BX (United Kingdom); Dive, Caroline, E-mail: cdive@picr.man.ac.uk [Clinical and Experimental Pharmacology Group, Paterson Institute for Cancer Research, Manchester M20 4BX (United Kingdom); School of Cancer and Enabling Sciences, University of Manchester, Manchester Cancer Research Centre, Manchester Academic Health Sciences Centre, Manchester M20 4BX (United Kingdom)

    2010-06-09

    The detection and enumeration of circulating tumor cells (CTCs) has shown significant clinical utility with respect to prognosis in breast, colorectal and prostate cancers. Emerging studies show that CTCs can provide pharmacodynamic information to aid therapy decision making. CTCs as a ‘virtual and real-time biopsy’ have clear potential to facilitate exploration of tumor biology, and in particular, the process of metastasis. The challenge of profiling CTC molecular characteristics and generating CTC signatures using current technologies is that they enrich rather than purify CTCs from whole blood; we face the problem of looking for the proverbial ‘needle in the haystack’. This review summarizes the current methods for CTC detection and enumeration, focuses on molecular characterization of CTCs, unveils some aspects of CTC heterogeneity, describes attempts to purify CTCs and scans the horizon for approaches leading to comprehensive dissection of CTC biology.

  15. Meridional circulation in the Sun and stars

    CERN Document Server

    Kitchatinov, L L

    2016-01-01

    Mean-field hydrodynamics advanced to clear explanations for the origin and properties of the global meridional flow in stellar convection zones. Qualitative arguments and analysis of basic equations both show that the meridional circulation is driven by non-conservative centrifugal and buoyancy forces and results from a slight disbalance between these two drivers. The deviations from the thermal wind balance are relatively large near the boundaries of convection zones. Accordingly, the meridional flow attains its largest velocities in the boundary layers and decreases inside the convection zone. This picture, however, is neither supported nor dismissed by the conflicting results of recent helioseismic soundings or 3D numerical experiments. The relevant physics of the differential temperature and its possible relation to the solar oblateness are briefly discussed.

  16. Boiling Heat Transfer in Circulating Fluidized Beds

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A model is proposed to predict boiling heat transfer coefficient in a three-phase circulating fluidized bed (CFB), which is a new type of evaporation boiling means for enhancing heat transfer and preventing fouling. To verify the model, experiments are conducted in a stainless steel column with 39mm ID and 2.0m height, in which the heat transfer coefficient is measured for different superficial velocities, steam pressures, particle concentrations and materials of particle. As the steam pressure and particle concentrations increase, the heat transfer coefficient in the bed increases. The heat transfer coefficient increases with the liquid velocity but it exhibits a local minimum. The heat transfer coefficient is correlated with cluster renewed model and two-mechanism method. The prediction of the model is in good agreement with experimental data.

  17. Boiling Heat Transfer in Circulating Fluidized Beds

    Institute of Scientific and Technical Information of China (English)

    张利斌; 李修伦

    2001-01-01

    A model is proposed to predict boiling heat transfer coefficient in a three-phase circulating fluidized bed (CFB), which is a new type of evaporation boiling means for enhancing heat transfer and preventing fouling. To verify the model, experiments are conducted in a stainless steel column with 39 mm ID and 2.0 m height, in which the heat transfer coefficient is measured for different superficial velocities, steam pressures, particle concentrations and materials of particle. As the steam pressure and particle concentrations increase, the heat transfer coefficient in the bed increases. The heat transfer coefficient increases with the liquid velocity but it exhibits a local minimum.The heat transfer coefficient is correlated with cluster renewed model and two-mechanism method. The prediction of the model is in good agreement with experimental data.

  18. Nucla circulating atmospheric fluidized bed demonstration project

    Energy Technology Data Exchange (ETDEWEB)

    Keith, Raymond E.

    1991-10-01

    Colorado-Ute Electric Association began a study to evaluate options for upgrading and extending the life of its Nucla power station in 1982. Located in southwestern Colorado near the town of Nucla, this station was commissioned in 1959 with a local bituminous coal as its design fuel for three identical stoker-fired units, each rated at 12.6 MW(e). Poor station efficiency, high fuel costs, and spiraling boiler maintenance costs forced the Nucla Station into low priority in the CUEA dispatch order as early as 1981. Among the options CUEA considered was to serve as a host utility to demonstrate Atmospheric Fluidized Bed Combustion (AFBC) technology. The anticipated environmental benefits and apparent attractive economics of a circulating AFBC led to Colorado-Ute's decision to proceed with the design and construction of a demonstration project in 1984 at the Nucla facility.

  19. Re-circulating linac vacuum system

    International Nuclear Information System (INIS)

    The vacuum system for a proposed 2.5 GeV, 10ΜA recirculating linac synchrotron light source [1] is readily achievable with conventional vacuum hardware and established fabrication processes. Some of the difficult technical challenges associated with synchrotron light source storage rings are sidestepped by the relatively low beam current and short beam lifetime requirements of a re-circulating linac. This minimal lifetime requirement leads directly to relatively high limits on the background gas pressure through much of the facility. The 10ΜA average beam current produces very little synchrotron radiation induced gas desorption and thus the need for an ante-chamber in the vacuum chamber is eliminated. In the arc bend magnets, and the insertion devices, the vacuum chamber dimensions can be selected to balance the coherent synchrotron radiation and resistive wall wakefield effects, while maintaining the modest limits on the gas pressure and minimal outgassing

  20. Spontaneous circulation of confined active suspensions.

    Science.gov (United States)

    Woodhouse, Francis G; Goldstein, Raymond E

    2012-10-19

    Many active fluid systems encountered in biology are set in total geometric confinement. Cytoplasmic streaming in plant cells is a prominent and ubiquitous example, in which cargo-carrying molecular motors move along polymer filaments and generate coherent cell-scale flow. When filaments are not fixed to the cell periphery, a situation found both in vivo and in vitro, we observe that the basic dynamics of streaming are closely related to those of a nonmotile stresslet suspension. Under this model, it is demonstrated that confinement makes possible a stable circulating state; a linear stability analysis reveals an activity threshold for spontaneous autocirculation. Numerical analysis of the longtime behavior reveals a phenomenon akin to defect separation in nematic liquid crystals and a high-activity bifurcation to an oscillatory regime. PMID:23215137

  1. Circulating Tumor Cells in Prostate Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Brian [Institute of Urology, University of Southern California, 1441 Eastlake Avenue, Suite 7416, Los Angeles, CA 90033 (United States); Rochefort, Holly [Department of Surgery, University of Southern California, 1520 San Pablo Street, HCT 4300, Los Angeles, CA 90033 (United States); Goldkorn, Amir, E-mail: agoldkor@usc.edu [Department of Internal Medicine and Norris Comprehensive Cancer Center, University of Southern California Keck School of Medicine, 1441 Eastlake Avenue, Suite 3440, Los Angeles, CA 90033 (United States)

    2013-12-04

    Circulating tumor cells (CTCs) can provide a non-invasive, repeatable snapshot of an individual patient’s tumor. In prostate cancer, CTC enumeration has been extensively studied and validated as a prognostic tool and has received FDA clearance for use in monitoring advanced disease. More recently, CTC analysis has been shifting from enumeration to more sophisticated molecular characterization of captured cells, which serve as a “liquid biopsy” of the tumor, reflecting molecular changes in an individual’s malignancy over time. Here we will review the main CTC studies in advanced and localized prostate cancer, highlighting the important gains as well as the challenges posed by various approaches, and their implications for advancing prostate cancer management.

  2. Circulating Tumor Cells in Prostate Cancer

    International Nuclear Information System (INIS)

    Circulating tumor cells (CTCs) can provide a non-invasive, repeatable snapshot of an individual patient’s tumor. In prostate cancer, CTC enumeration has been extensively studied and validated as a prognostic tool and has received FDA clearance for use in monitoring advanced disease. More recently, CTC analysis has been shifting from enumeration to more sophisticated molecular characterization of captured cells, which serve as a “liquid biopsy” of the tumor, reflecting molecular changes in an individual’s malignancy over time. Here we will review the main CTC studies in advanced and localized prostate cancer, highlighting the important gains as well as the challenges posed by various approaches, and their implications for advancing prostate cancer management

  3. Circulating Tumor Cells in Prostate Cancer

    Directory of Open Access Journals (Sweden)

    Brian Hu

    2013-12-01

    Full Text Available Circulating tumor cells (CTCs can provide a non-invasive, repeatable snapshot of an individual patient’s tumor. In prostate cancer, CTC enumeration has been extensively studied and validated as a prognostic tool and has received FDA clearance for use in monitoring advanced disease. More recently, CTC analysis has been shifting from enumeration to more sophisticated molecular characterization of captured cells, which serve as a “liquid biopsy” of the tumor, reflecting molecular changes in an individual’s malignancy over time. Here we will review the main CTC studies in advanced and localized prostate cancer, highlighting the important gains as well as the challenges posed by various approaches, and their implications for advancing prostate cancer management.

  4. Hydrodynamics of circulating and bubbling fluidized beds

    International Nuclear Information System (INIS)

    This paper reports that a review of modeling of the hydrodynamics of fluidization of bubbling beds showed that inviscid two-fluid models were able to predict a great deal of the behavior of bubbling beds because the dominant mechanism of energy dissipation is the drag between the particles and the fluid. The formation, the growth and the bursting of bubbles were predicted. Predicted wall-to-bed heat transfer coefficients and velocity profiles of jets agreed with measurements. Time average porosity distributions agreed with measurements done using gamma-ray densitometers without the use of any adjustable parameters. However, inviscid models could not correctly predict rates of erosion around tubes immersed into fluidized beds. To correctly model such behavior, granular stresses involving solids viscosity were added into the computer model. This viscosity arises due to random collision of particles. Several models fro this viscosity were investigated and the results compared to measurements of solids distributions in two-dimensional beds and to particle velocities reported in the literature. While in the case of bubbling beds the solids viscosity plays the role of a correction, modeling of a circulating fluidized bed (CFB) without a viscosity is not possible. Recent experimental data obtained at IIT and at IGT show that in CFB the solids viscous dissipation is responsible for as much as half of the pressure drop. From such measurement, solids viscosities were computed. These were used in the two fluid hydrodynamic model, to predict radial solids distributions and solids velocities which matched the experimental distributions. Most important, the model predicted cluster formation and transient internal circulation which is responsible for the favorable characteristics of CFBs, such as good wall-to-bed heat transfer. Video tape movies of computations compared favorably with high speed movies of the experiments

  5. Fate of circulating renin in conscious rats

    International Nuclear Information System (INIS)

    Highly purified 125I-labeled rat renal renin (125I-renin) was given intravenously to conscious rats to study the fate of circulating renin. Specific antirat renin antiserum was used to identify the labeled renin molecules. In sham-operated rats, the disappearance of 125I-renin from the plasma showed two exponential components with a half-life of 6.7 +/- 0.4 min for the rapid component and 65.1 +/- 5.7 min for the slow component. The metabolic clearance rate was 11.4 +/- 1.0 ml X min-1 X kg-1. In bilaterally nephrectomized rats, the metabolic clearance rate of 125I-renin was reduced by 55%, but the half-life of the slow component remained unchanged. Seventy percent hepatectomy caused a 54% decrement in the metabolic clearance and prolonged the half-life of the slow component. Five minutes after injection of 125I-renin, approximately 59 and 11% of the administered 125I-renin had accumulated in the liver and the kidneys, respectively, and at later time points the 125I-renin was highly concentrated in these organs. High-performance liquid chromatographic analysis of the liver and kidney extracts demonstrated that 125I-renin was catabolized by these organs. Biliary excretion of 125I-renin was negligible. Urinary excretion of 125I-renin up to 120 min was approximately 2% of the injected dose. We conclude that both the liver and the kidney are responsible for the clearance of circulating renin, with participation of the liver being predominant

  6. Conveying Global Circulation Patterns in HDTV

    Science.gov (United States)

    Gardiner, N.; Janowiak, J.; Kinzler, R.; Trakinski, V.

    2006-12-01

    The American Museum of Natural History has partnered with the National Centers for Environmental Prediction (NCEP) to educate general audiences about weather and climate using high definition video broadcasts built from half-hourly global mosaics of infrared (IR) data from five geostationary satellites. The dataset being featured was developed by NCEP to improve precipitation estimates from microwave data that have finer spatial resolution but poorer temporal coverage. The IR data span +/-60 degrees latitude and show circulation patterns at sufficient resolution to teach informal science center visitors about both weather and climate events and concepts. Design and editorial principles for this media program have been guided by lessons learned from production and annual updates of visualizations that cover eight themes in both biological and Earth system sciences. Two formative evaluations on two dates, including interviews and written surveys of 480 museum visitors ranging in age from 13 to over 60, helped refine the design and implementation of the weather and climate program and demonstrated that viewers understood the program's initial literacy objectives, including: (1) conveying the passage of time and currency of visualized data; (2) geographic relationships inherent to atmospheric circulation patterns; and (3) the authenticity of visualized data, i.e., their origin from earth-orbiting satellites. Surveys also indicated an interest and willingness to learn more about weather and climate principles and events. Expanded literacy goals guide ongoing, biweekly production and distribution of global cloud visualization pieces that reach combined audiences of approximately 10 million. Two more rounds of evaluation are planned over the next two years to assess the effectiveness of the media program in addressing these expanded literacy goals.

  7. Station blackout analysis of natural circulation reactor

    International Nuclear Information System (INIS)

    Full text of publication follows: The natural circulation reactor is a vertical pressure tube type boiling light water cooled and heavy water moderated reactor. One of the important passive design features of this reactor is that the heat removal is achieved through natural circulation of primary coolant at all power level with no primary coolant pumps. There is no auxiliary feed pump available as Isolation Condenser (IC) is meant to remove decay heat. Station Blackout lead to feed water pump trip and loss of condenser vacuum which in turn results in to loss of feed water as well as the turbine trip on low condenser vacuum signal. This leads to bottle up of the system, leading to pressure rise in PHT. The bypass flow is not available due to loss of condenser vacuum. Reactor is tripping on high pressure signal. As the pressure continue to raise, IC valve starts opening at a pressure of 76.0 bar to limit the pressure rise. Relief valve may open in case of IC's capacity is not adequate. This analysis highlights the thermal hydraulic conditions following station blackout with IC's to limit the pressure rise. The paper discusses the thermal hydraulic transient analysis for evaluating the safety of the reactor; following station blackout with IC's using RELAP5/MOD3.2. Predictions are made for different parameters like pressure, temperature, steam quality and flow in different parts of the Primary Heat Transport (PHT) system. In this paper summary of analysis for event is presented. In this paper, various modeling complexities are brought out; evaluation of acceptance criteria is made and design implications of event are discussed. (authors)

  8. Clinical relevance of circulating cell-free microRNAs in ovarian cancer.

    Science.gov (United States)

    Nakamura, Koji; Sawada, Kenjiro; Yoshimura, Akihiko; Kinose, Yasuto; Nakatsuka, Erika; Kimura, Tadashi

    2016-01-01

    Ovarian cancer is the leading cause of death among gynecologic malignancies. Since ovarian cancer develops asymptomatically, it is often diagnosed at an advanced and incurable stage. Despite many years of research, there is still a lack of reliable diagnostic markers and methods for early detection and screening. Recently, it was discovered that cell-free microRNAs (miRNAs) circulate in the body fluids of healthy and diseased patients, suggesting that they may serve as a novel diagnostic marker. This review summarizes the current knowledge regarding the potential clinical relevance of circulating cell-free miRNA for ovarian cancer diagnosis, prognosis, and therapeutics. Despite the high levels of ribonucleases in many types of body fluids, most of the circulating miRNAs are packaged in microvesicles, exosomes, or apoptotic bodies, are binding to RNA-binding protein such as argonaute 2 or lipoprotein complexes, and are thus highly stable. Cell-free miRNA signatures are known to be parallel to those from the originating tumor cells, indicating that circulating miRNA profiles accurately reflect the tumor profiles. Since it is well established that the dysregulation of miRNAs is involved in the tumorigenesis of ovarian cancer, cell-free miRNAs circulating in body fluids such as serum, plasma, whole blood, and urine may reflect not only the existence of ovarian cancer but also tumor histology, stage, and prognoses of the patients. Several groups have successfully demonstrated that serum or plasma miRNAs are able to discriminate patients with ovarian cancer patients from healthy controls, suggesting that the addition of these miRNAs to current testing regimens may improve diagnosis accuracies for ovarian cancer. Furthermore, recent studies have revealed that changes in levels of cell-free circulating miRNAs are associated with the condition of cancer patients. Discrepancies between the results across studies due to the lack of an established endogenous miRNA control to

  9. Analysis of integral circulation and decay heat removal experiments in the lead-bismuth CIRCE facility with RELAP5 code

    International Nuclear Information System (INIS)

    In this paper, the results of the post-test analysis of some integral circulation experiments conducted on the lead-bismuth CIRCE facility are presented in comparison with the experimental data. These experiments include the simulation of unprotected loss of flow and unprotected loss of heat sink transients in a pool-type heavy liquid metal reactor. Furthermore, the results of the pre-test analysis of a protected loss of heat sink and flow transient with decay heat removal by a heat exchanger immersed in the pool and operating in natural circulation is presented. All transient analyses have been performed with the RELAP5 thermal-hydraulic code. (author)

  10. Study on the steady state and transient behaviour of natural circulation loop with various heat transfer media

    International Nuclear Information System (INIS)

    The advanced reactor concepts use, various heat transfer media e.g., sodium, lead alloy, supercritical water, helium and molten salt mixtures etc. The capability of core heat removal by natural circulation is extensively exploited for normal as well as accidental situations. Thus it is necessary to study the steady state and transient behaviour of a natural circulation loop using different heat transfer media. Towards this objective, a general purpose computer code LeBENC (Lead Bismuth Eutectic Natural Circulation) based on finite difference method is developed. The code is first used to obtain the steady state and transient behaviour of a uniform diameter rectangular water-loop. The results obtained for steady state conditions are compared with the experimental data. After validating the code as mentioned above, steady state and transient behaviour of Heavy-metal Alloy Natural Circulation Study (HANS) loop set up in BARC, with LBE as heat transfer media, is predicted. Transient studies for start-up of natural circulation and loss of heat sink circulation in the HANS loop have been carried out. The transient results are subsequently compared with experimental data and are found in good agreement with the latter. A Molten Salt Loop (MSL) is also being constructed at BARC to carry out heat transfer and pressure drop studies. Pre-test analysis for the same is also carried out for steady state and various postulated transients using code LeBENC. (author)

  11. THOR: A New and Flexible Global Circulation Model to Explore Planetary Atmospheres

    CERN Document Server

    Mendonça, João M; Grosheintz, Luc; Heng, Kevin

    2016-01-01

    We have designed and developed, from scratch, a global circulation model named THOR that solves the three-dimensional non-hydrostatic Euler equations. Our general approach lifts the commonly used assumptions of a shallow atmosphere and hydrostatic equilibrium. We solve the "pole problem" (where converging meridians on a sphere lead to increasingly smaller time steps near the poles) by implementing an icosahedral grid. Irregularities in the grid, which lead to grid imprinting, are smoothed using the "spring dynamics" technique. We validate our implementation of spring dynamics by examining calculations of the divergence and gradient of test functions. To prevent the computational time step from being bottlenecked by having to resolve sound waves, we implement a split-explicit method together with a horizontally explicit and vertically implicit integration. We validate our global circulation model by reproducing the Earth and also the hot Jupiter-like benchmark tests. THOR was designed to run on Graphics Proces...

  12. First experience with the prototype Atlas MDT gas circulation system at GIF

    CERN Document Server

    Cernoch, C

    2002-01-01

    In addition to being the largest detector subsystem in size, the MDT part of the Atlas Muon Spectrometer also comprises a significant active gas volume of roughly 800 cubic meters. Although the chosen MDT operating gas, Argon:CO2 in relation 93:7, is made up of fairly inexpensive and inert standard gases, financial and technical constraints still necessitate that the detector gas is circulated through the Atlas MDT system with only a small percentage being replaced each cycle. A first test system, using the final Atlas MDT gas circulator, has been built and is at present under study at the CERN Gamma Irradiation Facility GIF together with a BIS type MDT chamber. This note describes the test setup, the goals of the measurement program and summarises first experiences with the system.

  13. Circulational characteristics of a natural circulation circuit of a weakly boiling reactor large-scale model

    International Nuclear Information System (INIS)

    A large-scale model for determining circulational characteristics of a natural circulation circuit of weakly boiling (core outlet steam content below 4%) tank tpype water cooled reactors is described. The model consists of 61 elecrtroheated fuel elements 14 mm in-diameter and 3 m height. Outlet pressure can vary within 1.7-5.0 MPa inlet water subcooling is 20-90 deg C, weight outlet balance steam content from-9 to 3.2 %. Results of the experiments performed for checking the algorithms developed for thermohydraulic calculation of steady-state characteristics of the investigated circuit are given. It is concluded that for one-phase coolant estimated and experimental values for pressure head and hydraulic resistance agree well with

  14. Attempts on cardoon gasification in two different circulating fluidized beds

    Directory of Open Access Journals (Sweden)

    Chr. Christodoulou

    2014-11-01

    Full Text Available Few tests have been carried out in order to evaluate the use of cardoon in gasification and combustion applications most of the researchers dealt with agglomeration problems. The aim of this work is to deal with the agglomeration problem and to present a solution for the utilization of this biofuel at a near industrial application scale. For this reason, two experiments were conducted, one in TU Delft and one in Centre for Research and Technology Hellas (CERTH, using fuel cardoon and 50% w/w cardoon blended with 50% w/w giant reed respectively. Both experimental campaigns were carried out in similar atmospheric circulating fluidized bed gasifiers. Apart from the feedstock, the other differences were the gasification medium and the bed material used in each trial. The oxidizing agent at TUD׳s run was O2/steam, whereas CERTH׳s tests used air. When experiments with the cardoon 50% w/w–giant reed 50% w/w blend were performed no agglomeration problems were presented. Consequently, gasification could be achieved in higher temperature than that of pure cardoon which led to the reduction of tar concentration.

  15. Nanostructured Substrates for Capturing Circulating Tumor Cells in Whole Blood

    Science.gov (United States)

    Tseng, Hsian-Rong

    2009-03-01

    Over the past decade, circulating tumor cells (CTCs) has become an emerging ``biomarker'' for detecting early-stage cancer metastasis, predicting patient prognosis, as well as monitoring disease progression and therapeutic outcomes. However, isolation of CTCs has been technically challenging due to the extremely low abundance (a few to hundreds per ml) of CTCs among a high number of hematologic cells (109 per mL) in the blood. Our joint research team at UCLA has developed a new cell capture technology for quantification of CTCs in whole blood samples. Similar to most of the existing approaches, epithelial cell adhesion molecule antibody (anti-EpCAM) was grafted onto the surfaces to distinguish CTCs from the surrounding hematologic cells. The uniqueness of our technology is the use of nanostructured surfaces, which facilitates local topographical interactions between CTCs and substrates at the very first cell/substrate contacting time point. We demonstrated the ability of these nanostructured substrates to capture CTCs in whole blood samples with significantly improved efficiency and selectivity. The successful demonstration of this cell capture technology using brain, breast and prostate cancer cell lines encouraged us to test this approach in clinical setting. We have been able to bond our first validation study with a commercialized technology based on the use of immunomagnetic nanoparticles. A group of clinically well-characterized prostate cancer patients at UCLA hospital have been recruited and tested in parallel by these two technologies.

  16. Circulation system for flowing uranium hexafluoride cavity reactor experiments

    Science.gov (United States)

    Jaminet, J. F.; Kendall, J. S.

    1976-01-01

    Research related to determining the feasibility of producing continuous power from fissile fuel in the gaseous state is presented. The development of three laboratory-scale flow systems for handling gaseous UF6 at temperatures up to 500 K, pressure up to approximately 40 atm, and continuous flow rates up to approximately 50g/s is presented. A UF6 handling system fabricated for static critical tests currently being conducted is described. The system was designed to supply UF6 to a double-walled aluminum core canister assembly at temperatures between 300 K and 400 K and pressure up to 4 atm. A second UF6 handling system designed to provide a circulating flow of up to 50g/s of gaseous UF6 in a closed-loop through a double-walled aluminum core canister with controlled temperature and pressure is described. Data from flow tests using UF6 and UF6/He mixtures with this system at flow rates up to approximately 12g/s and pressure up to 4 atm are presented. A third UF6 handling system fabricated to provide a continuous flow of UF6 at flow rates up to 5g/s and at pressures up to 40 atm for use in rf-heated, uranium plasma confinement experiments is described.

  17. Climatology of the HOPE-G global ocean general circulation model - Sea ice general circulation model

    Energy Technology Data Exchange (ETDEWEB)

    Legutke, S. [Deutsches Klimarechenzentrum (DKRZ), Hamburg (Germany); Maier-Reimer, E. [Max-Planck-Institut fuer Meteorologie, Hamburg (Germany)

    1999-12-01

    The HOPE-G global ocean general circulation model (OGCM) climatology, obtained in a long-term forced integration is described. HOPE-G is a primitive-equation z-level ocean model which contains a dynamic-thermodynamic sea-ice model. It is formulated on a 2.8 grid with increased resolution in low latitudes in order to better resolve equatorial dynamics. The vertical resolution is 20 layers. The purpose of the integration was both to investigate the models ability to reproduce the observed general circulation of the world ocean and to obtain an initial state for coupled atmosphere - ocean - sea-ice climate simulations. The model was driven with daily mean data of a 15-year integration of the atmosphere general circulation model ECHAM4, the atmospheric component in later coupled runs. Thereby, a maximum of the flux variability that is expected to appear in coupled simulations is included already in the ocean spin-up experiment described here. The model was run for more than 2000 years until a quasi-steady state was achieved. It reproduces the major current systems and the main features of the so-called conveyor belt circulation. The observed distribution of water masses is reproduced reasonably well, although with a saline bias in the intermediate water masses and a warm bias in the deep and bottom water of the Atlantic and Indian Oceans. The model underestimates the meridional transport of heat in the Atlantic Ocean. The simulated heat transport in the other basins, though, is in good agreement with observations. (orig.)

  18. Heat transfer to water from a vertical tube bundle under natural-circulation conditions

    International Nuclear Information System (INIS)

    The natural circulation heat transfer data for longitudinal flow of water outside a vertical rod bundle are needed for developing correlations which can be used in best estimate computer codes to model thermal-hydraulic behavior of nuclear reactor cores under accident or shutdown conditions. The heat transfer coefficient between the fuel rod surface and the coolant is the key parameter required to predict the fuel temperature. Because of the absence of the required heat transfer coefficient data base under natural circulation conditions, experiments have been performed in a natural circulation loop. A seven-tube bundle having a pitch-to-diameter ratio of 1.25 was used as a test heat exchanger. A circulating flow was established in the loop, because of buoyancy differences between its two vertical legs. Steady-state and transient heat transfer measurements have been made over as wide a range of thermal conditions as possible with the system. Steady state heat transfer data were correlated in terms of relevant dimensionless parameters. Empirical correlations for the average Nusselt number, in terms of Reynolds number, Rayleigh number and the ratio of Grashof to Reynolds number are given

  19. Identification of circulating tumor cells as a promising method of genitourinary cancer diagnosis 

    Directory of Open Access Journals (Sweden)

    Natalia Gurtowska

    2012-12-01

    Full Text Available Circulating tumor cells (CTCs are cells circulating in the blood, which in terms of antigenic or genetic profile correspond to a particular type of cancer. It is suspected that CTCs possess properties of cancer stem cells. Detection, quantification and characterization of CTCs in the peripheral blood can be of great importance for modern oncology. In the case of early-stage disease, CTCs may help in cancer detection, estimation of metastasis risk and treatment prognosis. In advanced cancer patients, CTCs may also have prognostic significance and may facilitate monitoring response to treatment. Identification of CTCs in the circulation and their differentiation from hematopoietic cells and normal epithelial cells could be based on physical and biological properties such as size, density and expression of specific proteins. Immunomagnetic techniques are the most commonly used methods of CTCs isolation. CellSearch System (CSS is the only test for detecting CTCs in the peripheral blood approved by the Food and Drug Administration (FDA for clinical use. The paper presents the characteristics of circulating tumor cell isolation methods and the results of studies concerning CTCs isolation in patients with prostate, bladder and kidney cancer. 

  20. Analysis of flow excursion in a natural circulation system with low pressure and low steam quality

    International Nuclear Information System (INIS)

    A series of experiments were performed on the test loop (HRTL-5), which simulates the geometry and system design of the 5 MW nuclear heating reactor. The flow excursion accompanied with flow oscillation was observed under certain conditions. Some experimental results have been summarized in the natural circulation with low pressure and low steam quality. The mechanism of subcooled boiling and flashing is analyzed, and an entire process of flow excursion is described too. The analysis shows: 1) Sub-cooled boiling and flashing play an important role on the flow instabilities in a natural circulation system. 2) The static flow excursion in the natural circulation is a rather long thermo-hydraulic process, which can be accompanied by the dynamic flow oscillation. 3) In the course of the flow excursion's beginning, developing and gradually converting to the flow oscillation, the flow instability is first dominate by sub-cooled boiling, then is dominated by void flashing, last is mainly the density wave oscillation. The investigation on flow excursion in the natural circulation is important for the design and accident analysis and upgrading development of the 5 MW nuclear heating reactor