Science.gov

Sample records for initial coolant temperature

  1. Modeling wave processes at the outflowing of a water coolant with supercritical initial parameters

    NASA Astrophysics Data System (ADS)

    Vozhakov, I. S.; Alekseev, M. V.; Lezhnin, S. I.; Pribaturin, N. A.

    2016-10-01

    Numerical simulation of the outflow of a coolant with supercritical initial parameters at a butt-break of high-pressure pipeline is carried out. The results of calculation of the outflow dynamics on a PV-diagram, as well as the pressure evolution are presented. It is shown that the flow rate weakly depends on temperature at its low values (up to 0, 9 Tc ). In the second region (from 0, 9 Tc to Tc ), the coolant boiling occurs inside the channel, which leads to a sharp drop in the flow rate with increasing temperature. And the third area (above Tc ) is typical for the gas coolant outflow, in which the density strongly depends on pressure and temperature.

  2. Stagnation region gas film cooling: Effects of dimensionless coolant temperature

    NASA Technical Reports Server (NTRS)

    Bonnice, M. A.; Lecuyer, M. R.

    1983-01-01

    An experimental investigation was conducted to mode the film cooling performance for a turbine vane leading edge using the stagnation region of a cylinder in cross flow. Experiments were conducted with a single row of spanwise angled (25 deg) coolant holes for a range of the coolant blowing ratio and dimensionless coolant temperature with free stream-to-wall temperature ratio approximately 1.7 and Re sub D = 90000. the cylindrical test surface was instrumented with miniature heat flux gages and wall thermocouples to determine the percentage reduction in the Stanton number as a function of the distance downstream from injection (x/d sub 0) and the location between adjacent holes (z/S). Data from local heat flux measurements are presented for injection from a single row located at 5 deg, 22.9 deg, 40.8 deg, from stagnation using a hole spacing ratio of S/d = 5. The film coolant was injected with T sub c T sub w with a dimensionless coolant temperature in the range 1.18 or equal to theta sub c or equal to 1.56. The data for local Stanton Number Reduction (SNR) showed a significant increase in SNR as theta sub c was increased above 1.0.

  3. Effect of Coolant Temperature and Mass Flow on Film Cooling of Turbine Blades

    NASA Technical Reports Server (NTRS)

    Garg, Vijay K.; Gaugler, Raymond E.

    1997-01-01

    A three-dimensional Navier Stokes code has been used to study the effect of coolant temperature, and coolant to mainstream mass flow ratio on the adiabatic effectiveness of a film-cooled turbine blade. The blade chosen is the VKI rotor with six rows of cooling holes including three rows on the shower head. The mainstream is akin to that under real engine conditions with stagnation temperature = 1900 K and stagnation pressure = 3 MPa. Generally, the adiabatic effectiveness is lower for a higher coolant temperature due to nonlinear effects via the compressibility of air. However, over the suction side of shower-head holes, the effectiveness is higher for a higher coolant temperature than that for a lower coolant temperature when the coolant to mainstream mass flow ratio is 5% or more. For a fixed coolant temperature, the effectiveness passes through a minima on the suction side of shower-head holes as the coolant to mainstream mass flow, ratio increases, while on the pressure side of shower-head holes, the effectiveness decreases with increase in coolant mass flow due to coolant jet lift-off. In all cases, the adiabatic effectiveness is highly three-dimensional.

  4. Method of and apparatus for removing silicon from a high temperature sodium coolant

    DOEpatents

    Yunker, Wayne H.; Christiansen, David W.

    1987-05-05

    A method of and system for removing silicon from a high temperature liquid sodium coolant system for a nuclear reactor. The sodium is cooled to a temperature below the silicon saturation temperature and retained at such reduced temperature while inducing high turbulence into the sodium flow for promoting precipitation of silicon compounds and ultimate separation of silicon compound particles from the liquid sodium.

  5. Method of and apparatus for removing silicon from a high temperature sodium coolant

    DOEpatents

    Yunker, Wayne H.; Christiansen, David W.

    1987-01-01

    A method of and system for removing silicon from a high temperature liquid sodium coolant system for a nuclear reactor. The sodium is cooled to a temperature below the silicon saturation temperature and retained at such reduced temperature while inducing high turbulence into the sodium flow for promoting precipitation of silicon compounds and ultimate separation of silicon compound particles from the liquid sodium.

  6. Coolant and ambient temperature control for chillerless liquid cooled data centers

    DOEpatents

    Chainer, Timothy J.; David, Milnes P.; Iyengar, Madhusudan K.; Parida, Pritish R.; Simons, Robert E.

    2016-02-02

    Cooling control methods include measuring a temperature of air provided to a plurality of nodes by an air-to-liquid heat exchanger, measuring a temperature of at least one component of the plurality of nodes and finding a maximum component temperature across all such nodes, comparing the maximum component temperature to a first and second component threshold and comparing the air temperature to a first and second air threshold, and controlling a proportion of coolant flow and a coolant flow rate to the air-to-liquid heat exchanger and the plurality of nodes based on the comparisons.

  7. Coolant and ambient temperature control for chillerless liquid cooled data centers

    DOEpatents

    Chainer, Timothy J.; David, Milnes P.; Iyengar, Madhusudan K.; Parida, Pritish R.; Simons, Robert E.

    2017-08-29

    Cooling control methods and systems include measuring a temperature of air provided to one or more nodes by an air-to-liquid heat exchanger; measuring a temperature of at least one component of the one or more nodes and finding a maximum component temperature across all such nodes; comparing the maximum component temperature to a first and second component threshold and comparing the air temperature to a first and second air threshold; and controlling a proportion of coolant flow and a coolant flow rate to the air-to-liquid heat exchanger and the one or more nodes based on the comparisons.

  8. Effect of coolant flow ejection on aerodynamic performance of low-aspect-ratio vanes. 2: Performance with coolant flow ejection at temperature ratios up to 2

    NASA Technical Reports Server (NTRS)

    Hass, J. E.; Kofskey, M. G.

    1977-01-01

    The aerodynamic performance of a 0.5 aspect ratio turbine vane configuration with coolant flow ejection was experimentally determined in a full annular cascade. The vanes were tested at a nominal mean section ideal critical velocity ratio of 0.890 over a range of primary to coolant total temperature ratio from 1.0 to 2.08 and a range of coolant to primary total pressure ratio from 1.0 to 1.4 which corresponded to coolant flows from 3.0 to 10.7 percent of the primary flow. The variations in primary and thermodynamic efficiency and exit flow conditions with circumferential and radial position were obtained.

  9. Effects of coolant parameters on steady state temperature distribution in phospheric-acid fuel cell electrode

    NASA Technical Reports Server (NTRS)

    Alkasab, K. A.; Abdul-Aziz, A.

    1991-01-01

    The influence of thermophysical properties and flow rate on the steady-state temperature distribution in a phosphoric-acid fuel cell electrode plate was experimentally investigated. An experimental setup that simulates the operating conditions prevailing in a phosphoric-acid fuel cell stack was used. The fuel cell cooling system utilized three types of coolants to remove excess heat generated in the cell electrode and to maintain a reasonably uniform temperature distribution in the electrode plate. The coolants used were water, engine oil, and air. These coolants were circulated at Reynolds number ranging from 1165 to 6165 for water; 3070 to 6864 for air; and 15 to 79 for oil. Experimental results are presented.

  10. Method of and apparatus for removing silicon from a high temperature sodium coolant

    DOEpatents

    Yunker, W.H.; Christiansen, D.W.

    1983-11-25

    This patent discloses a method of and system for removing silicon from a high temperature liquid sodium coolant system for a nuclear reactor. The sodium is cooled to a temperature below the silicon saturation temperature and retained at such reduced temperature while inducing high turbulence into the sodium flow for promoting precipitation of silicon compounds and ultimate separation of silicon compound particles from the liquid sodium.

  11. Barriers to the Application of High-Temperature Coolants in Hybrid Electric Vehicles

    SciTech Connect

    Hsu, J.S.; Staunton, M.R.; Starke, M.R.

    2006-09-30

    This study was performed by the Oak Ridge National Laboratory (ORNL) to identify practical approaches, technical barriers, and cost impacts to achieving high-temperature coolant operation for certain traction drive subassemblies and components of hybrid electric vehicles (HEV). HEVs are unique in their need for the cooling of certain dedicated-traction drive subassemblies/components that include the electric motor(s), generators(s), inverter, dc converter (where applicable), and dc-link capacitors. The new coolant system under study would abandon the dedicated 65 C coolant loop, such as used in the Prius, and instead rely on the 105 C engine cooling loop. This assessment is important because automotive manufacturers are interested in utilizing the existing water/glycol engine cooling loop to cool the HEV subassemblies in order to eliminate an additional coolant loop with its associated reliability, space, and cost requirements. In addition, the cooling of power electronic devices, traction motors, and generators is critical in meeting the U.S. Department of Energy (DOE) FreedomCAR and Vehicle Technology (FCVT) goals for power rating, volume, weight, efficiency, reliability, and cost. All of these have been addressed in this study. Because there is high interest by the original equipment manufacturers (OEMs) in reducing manufacturing cost to enhance their competitive standing, the approach taken in this analysis was designed to be a positive 'can-do' approach that would be most successful in demonstrating the potential or opportunity of relying entirely on a high-temperature coolant system. Nevertheless, it proved to be clearly evident that a few formidable technical and cost barriers exist and no effective approach for mitigating the barriers was evident in the near term. Based on comprehensive thermal tests of the Prius reported by ORNL in 2005 [1], the continuous ratings at base speed (1200 rpm) with different coolant temperatures were projected from test data at

  12. Barriers to the Application of High-Temperature Coolants in Hybrid Electric Vehicles

    SciTech Connect

    Staunton, Robert H; Hsu, John S; Starke, Michael R

    2006-09-01

    This study was performed by the Oak Ridge National Laboratory (ORNL) to identify practical approaches, technical barriers, and cost impacts to achieving high-temperature coolant operation for certain traction drive subassemblies and components of hybrid electric vehicles (HEV). HEVs are unique in their need for the cooling of certain dedicated-traction drive subassemblies/components that include the electric motor(s), generators(s), inverter, dc converter (where applicable), and dc-link capacitors. The new coolant system under study would abandon the dedicated 65 C coolant loop, such as used in the Prius, and instead rely on the 105 C engine cooling loop. This assessment is important because automotive manufacturers are interested in utilizing the existing water/glycol engine cooling loop to cool the HEV subassemblies in order to eliminate an additional coolant loop with its associated reliability, space, and cost requirements. In addition, the cooling of power electronic devices, traction motors, and generators is critical in meeting the U.S. Department of Energy (DOE) FreedomCAR and Vehicle Technology (FCVT) goals for power rating, volume, weight, efficiency, reliability, and cost. All of these have been addressed in this study. Because there is high interest by the original equipment manufacturers (OEMs) in reducing manufacturing cost to enhance their competitive standing, the approach taken in this analysis was designed to be a positive 'can-do' approach that would be most successful in demonstrating the potential or opportunity of relying entirely on a high-temperature coolant system. Nevertheless, it proved to be clearly evident that a few formidable technical and cost barriers exist and no effective approach for mitigating the barriers was evident in the near term. Based on comprehensive thermal tests of the Prius reported by ORNL in 2005 [1], the continuous ratings at base speed (1200 rpm) with different coolant temperatures were projected from test data at

  13. Cooling Characteristics of the V-1650-7 Engine. II - Effect of Coolant Conditions on Cylinder Temperatures and Heat Rejection at Several Engine Powers

    NASA Technical Reports Server (NTRS)

    Povolny, John H.; Bogdan, Louis J.; Chelko, Louis J.

    1947-01-01

    An investigation has been conducted on a V-1650-7 engine to determine the cylinder temperatures and the coolant and oil heat rejections over a range of coolant flows (50 to 200 gal/min) and oil inlet temperatures (160 to 2150 F) for two values of coolant outlet temperature (250 deg and 275 F) at each of four power conditions ranging from approximately 1100 to 2000 brake horsepower. Data were obtained for several values of block-outlet pressure at each of the two coolant outlet temperatures. A mixture of 30 percent by volume of ethylene glycol and 70-percent water was used as the coolant. The effect of varying coolant flow, coolant outlet temperature, and coolant outlet pressure over the ranges investigated on cylinder-head temperatures was small (0 deg to 25 F) whereas the effect of increasing the engine power condition from ll00 to 2000 brake horsepower was large (maximum head-temperature increase, 110 F).

  14. Cooled-turbine aerodynamic performance prediction from reduced primary to coolant total-temperature-ratio results

    NASA Technical Reports Server (NTRS)

    Goldman, L. J.

    1976-01-01

    The prediction of the cooled aerodynamic performance, for both stators and turbines, at actual primary to coolant inlet total temperature ratios from the results obtained at a reduced total temperature ratio is described. Theoretical and available experimental results were compared for convection film and transpiration cooled stator vanes and for a film cooled, single stage core turbine. For these tests the total temperature ratio varied from near 1.0 to about 2.7. The agreement between the theoretical and the experimental results was, in general, reasonable.

  15. The high-temperature sodium coolant technology in nuclear power installations for hydrogen power engineering

    NASA Astrophysics Data System (ADS)

    Kozlov, F. A.; Sorokin, A. P.; Alekseev, V. V.; Konovalov, M. A.

    2014-05-01

    In the case of using high-temperature sodium-cooled nuclear power installations for obtaining hydrogen and for other innovative applications (gasification and fluidization of coal, deep petroleum refining, conversion of biomass into liquid fuel, in the chemical industry, metallurgy, food industry, etc.), the sources of hydrogen that enters from the reactor plant tertiary coolant circuit into its secondary coolant circuit have intensity two or three orders of magnitude higher than that of hydrogen sources at a nuclear power plant (NPP) equipped with a BN-600 reactor. Fundamentally new process solutions are proposed for such conditions. The main prerequisite for implementing them is that the hydrogen concentration in sodium coolant is a factor of 100-1000 higher than it is in modern NPPs taken in combination with removal of hydrogen from sodium by subjecting it to vacuum through membranes made of vanadium or niobium. Numerical investigations carried out using a diffusion model showed that, by varying such parameters as fuel rod cladding material, its thickness, and time of operation in developing the fuel rods for high-temperature nuclear power installations (HT NPIs) it is possible to exclude ingress of cesium into sodium through the sealed fuel rod cladding. However, if the fuel rod cladding loses its tightness, operation of the HT NPI with cesium in the sodium will be unavoidable. Under such conditions, measures must be taken for deeply purifying sodium from cesium in order to minimize the diffusion of cesium into the structural materials.

  16. Corrosion of Ferritic Steels in High Temperature Molten Salt Coolants for Nuclear Applications

    SciTech Connect

    Farmer, J; El-Dasher, B; de Caro, M S; Ferreira, J

    2008-11-25

    Corrosion of ferritic steels in high temperature molten fluoride salts may limit the life of advanced reactors, including some hybrid systems that are now under consideration. In some cases, the steel may be protected through galvanic coupling with other less noble materials with special neutronic properties such a beryllium. This paper reports the development of a model for predicting corrosion rates for various ferritic steels, with and without oxide dispersion strengthening, in FLiBe (Li{sub 2}BeF{sub 4}) and FLiNaK (Li-Na-K-F) coolants at temperatures up to 800 C. Mixed potential theory is used to account for the protection of steel by beryllium, Tafel kinetics are used to predict rates of dissolution as a function of temperature and potential, and the thinning of the mass-transfer boundary layer with increasing Reynolds number is accounted for with dimensionless correlations. The model also accounts for the deceleration of corrosion as the coolants become saturated with dissolved chromium and iron. This paper also reports electrochemical impedance spectroscopy of steels at their corrosion potentials in high-temperature molten salt environments, with the complex impedance spectra interpreted in terms of the interfacial charge transfer resistance and capacitance, as well as the electrolyte conductivity. Such in situ measurement techniques provide valuable insight into the degradation of materials under realistic conditions.

  17. Assessment of Candidate Molten Salt Coolants for the Advanced High Temperature Reactor (AHTR)

    SciTech Connect

    Williams, D.F.

    2006-03-24

    The Advanced High-Temperature Reactor (AHTR) is a novel reactor design that utilizes the graphite-matrix high-temperature fuel of helium-cooled reactors, but provides cooling with a high-temperature fluoride salt. For applications at temperatures greater than 900 C the AHTR is also referred to as a Liquid-Salt-Cooled Very High-Temperature Reactor (LS-VHTR). This report provides an assessment of candidate salts proposed as the primary coolant for the AHTR based upon a review of physical properties, nuclear properties, and chemical factors. The physical properties most relevant for coolant service were reviewed. Key chemical factors that influence material compatibility were also analyzed for the purpose of screening salt candidates. Some simple screening factors related to the nuclear properties of salts were also developed. The moderating ratio and neutron-absorption cross-section were compiled for each salt. The short-lived activation products, long-lived transmutation activity, and reactivity coefficients associated with various salt candidates were estimated using a computational model. Table A presents a summary of the properties of the candidate coolant salts. Certain factors in this table, such as melting point, vapor pressure, and nuclear properties, can be viewed as stand-alone parameters for screening candidates. Heat-transfer properties are considered as a group in Sect. 3 in order to evaluate the combined effects of various factors. In the course of this review, it became apparent that the state of the properties database was strong in some areas and weak in others. A qualitative map of the state of the database and predictive capabilities is given in Table B. It is apparent that the property of thermal conductivity has the greatest uncertainty and is the most difficult to measure. The database, with respect to heat capacity, can be improved with modern instruments and modest effort. In general, ''lighter'' (low-Z) salts tend to exhibit better heat

  18. Self-actuated nuclear reactor shutdown system using induction pump to facilitate sensing of core coolant temperature

    DOEpatents

    Sievers, Robert K.; Cooper, Martin H.; Tupper, Robert B.

    1987-01-01

    A self-actuated shutdown system incorporated into a reactivity control assembly in a nuclear reactor includes pumping means for creating an auxiliary downward flow of a portion of the heated coolant exiting from the fuel assemblies disposed adjacent to the control assembly. The shutdown system includes a hollow tubular member which extends through the outlet of the control assembly top nozzle so as to define an outer annular flow channel through the top nozzle outlet separate from an inner flow channel for primary coolant flow through the control assembly. Also, a latching mechanism is disposed in an inner duct of the control assembly and is operable for holding absorber bundles in a raised position in the control assembly and for releasing them to drop them into the core of the reactor for shutdown purposes. The latching mechanism has an inner flow passage extending between and in flow communication with the absorber bundles and the inner flow channel of the top nozzle for accommodating primary coolant flow upwardly through the control assembly. Also, an outer flow passage separate from the inner flow passage extends through the latching mechanism between and in flow communication with the inner duct and the outer flow channel of the top nozzle for accommodating inflow of a portion of the heated coolant from the adjacent fuel assemblies. The latching mechanism contains a magnetic material sensitive to temperature and operable to cause mating or latching together of the components of the latching mechanism when the temperature sensed is below a known temperature and unmating or unlatching thereof when the temperature sensed is above a given temperature. The temperature sensitive magnetic material is positioned in communication with the heated coolant flow through the outer flow passage for directly sensing the temperature thereof. Finally, the pumping means includes a jet induction pump nozzle and diffuser disposed adjacent the bottom nozzle of the control assembly

  19. UO2 and PuO2 utilization in high temperature engineering test reactor with helium coolant

    NASA Astrophysics Data System (ADS)

    Waris, Abdul; Aji, Indarta K.; Novitrian, Pramuditya, Syeilendra; Su'ud, Zaki

    2016-03-01

    High temperature engineering test reactor (HTTR) is one of high temperature gas cooled reactor (HTGR) types which has been developed by Japanese Atomic Energy Research Institute (JAERI). The HTTR is a graphite moderator, helium gas coolant, 30 MW thermal output and 950 °C outlet coolant temperature for high temperature test operation. Original HTTR uses UO2 fuel. In this study, we have evaluated the use of UO2 and PuO2 in form of mixed oxide (MOX) fuel in HTTR. The reactor cell calculation was performed by using SRAC 2002 code, with nuclear data library was derived from JENDL3.2. The result shows that HTTR can obtain its criticality condition if the enrichment of 235U in loaded fuel is 18.0% or above.

  20. UO{sub 2} and PuO{sub 2} utilization in high temperature engineering test reactor with helium coolant

    SciTech Connect

    Waris, Abdul Novitrian,; Pramuditya, Syeilendra; Su’ud, Zaki; Aji, Indarta K.

    2016-03-11

    High temperature engineering test reactor (HTTR) is one of high temperature gas cooled reactor (HTGR) types which has been developed by Japanese Atomic Energy Research Institute (JAERI). The HTTR is a graphite moderator, helium gas coolant, 30 MW thermal output and 950 °C outlet coolant temperature for high temperature test operation. Original HTTR uses UO{sub 2} fuel. In this study, we have evaluated the use of UO{sub 2} and PuO{sub 2} in form of mixed oxide (MOX) fuel in HTTR. The reactor cell calculation was performed by using SRAC 2002 code, with nuclear data library was derived from JENDL3.2. The result shows that HTTR can obtain its criticality condition if the enrichment of {sup 235}U in loaded fuel is 18.0% or above.

  1. Correlation of cylinder-head temperatures and coolant heat rejections of a multicylinder, liquid-cooled engine of 1710-cubic-inch displacement

    NASA Technical Reports Server (NTRS)

    Lundin, Bruce T; Povolny, John H; Chelko, Louis J

    1949-01-01

    Data obtained from an extensive investigation of the cooling characteristics of four multicylinder, liquid-cooled engines have been analyzed and a correlation of both the cylinder-head temperatures and the coolant heat rejections with the primary engine and coolant variables was obtained. The method of correlation was previously developed by the NACA from an analysis of the cooling processes involved in a liquid-cooled-engine cylinder and is based on the theory of nonboiling, forced-convection heat transfer. The data correlated included engine power outputs from 275 to 1860 brake horsepower; coolant flows from 50 to 320 gallons per minute; coolants varying in composition from 100 percent water to 97 percent ethylene glycol and 3 percent water; and ranges of engine speed, manifold pressure, carburetor-air temperature, fuel-air ratio, exhaust-gas pressure, ignition timing, and coolant temperature. The effect on engine cooling of scale formation on the coolant passages of the engine and of boiling of the coolant under various operating conditions is also discussed.

  2. JAEA Studies on High Burnup Fuel Behaviors during Reactivity-Initiated Accident and Loss-of-Coolant Accident

    SciTech Connect

    Fuketa, Toyoshi; Sugiyama, Tomoyuki; Nagase, Fumihisa; Suzuki, Motoe

    2007-07-01

    The objectives of fuel safety research program at Japan Atomic Energy Agency (JAEA) are; to evaluate adequacy of present safety criteria and safety margins; to provide a database for future regulation on higher burnup UO{sub 2} and MOX fuels, new cladding and pellets; and to provide reasonably mechanistic computer codes for regulatory application. The JAEA program is comprised of reactivity-initiated accident (RIA) studies including pulse-irradiation experiments in the NSRR and cladding mechanical tests, loss-of-coolant accident (LOCA) tests including integral thermal shock test and oxidation rate measurement, development and verification of computer codes FEMAXI-6 and RANNS, and so on. In addition to an overview of the fuel safety research at JAEA, most recent progresses in the RIA and LOCA tests programs and the codes development are described and discussed in the paper. (authors)

  3. Comparison of Calculated and Experimental Temperatures and Coolant Pressure Losses for a Cascade of Small Air-Cooled Turbine Rotor Blades

    NASA Technical Reports Server (NTRS)

    Stepka, Francis S

    1958-01-01

    Average spanwise blade temperatures and cooling-air pressure losses through a small (1.4-in, span, 0.7-in, chord) air-cooled turbine blade were calculated and are compared with experimental nonrotating cascade data. Two methods of calculating the blade spanwise metal temperature distributions are presented. The method which considered the effect of the length-to-diameter ratio of the coolant passage on the blade-to-coolant heat-transfer coefficient and assumed constant coolant properties based on the coolant bulk temperature gave the best agreement with experimental data. The agreement obtained was within 3 percent at the midspan and tip regions of the blade. At the root region of the blade, the agreement was within 3 percent for coolant flows within the turbulent flow regime and within 10 percent for coolant flows in the laminar regime. The calculated and measured cooling-air pressure losses through the blade agreed within 5 percent. Calculated spanwise blade temperatures for assumed turboprop engine operating conditions of 2000 F turbine-inlet gas temperature and flight conditions of 300 knots at a 30,000-foot altitude agreed well with those obtained by the extrapolation of correlated experimental data of a static cascade investigation of these blades.

  4. Analysis of temperature rise and the use of coolants in the dissipation of ultrasonic heat buildup during post removal.

    PubMed

    Davis, Stephen; Gluskin, Alan H; Livingood, Philip M; Chambers, David W

    2010-11-01

    This study was designed to calculate probabilities for tissue injury and to measure effectiveness of various coolant strategies in countering heat buildup produced by dry ultrasonic vibration during post removal. A simulated biological model was used to evaluate the cooling efficacy of a common refrigerant spray, water spray, and air spray in the recovery of post temperatures deep within the root canal space. The data set consisted of cervical and apical measures of temperature increase at 1-second intervals from baseline during continuous ultrasonic instrumentation until a 10 °C increase in temperature at the cervical site was registered, wherein instrumentation ceased, and the teeth were allowed to cool under ambient conditions or with the assistance of 4 coolant methods. Data were analyzed with analysis of variance by using the independent variables of time of ultrasonic application (10, 15, 20 seconds) and cooling method. In addition to the customary means, standard deviations, and analysis of variance tests, analyses were conducted to determine probabilities that procedures would reach or exceed the 10 °C threshold. Both instrumentation time and cooling agent effects were significant at P <.0001. Under the conditions of this study, it was shown that injurious heat transfer occurs in less than 1 minute during dry ultrasonic instrumentation of metallic posts. Cycles of short instrumentation times with active coolants were effective in reducing the probability of tissue damage when teeth were instrumented dry. With as little as 20 seconds of continuous dry ultrasonic instrumentation, the consequences of thermal buildup to an individual tooth might contribute to an injurious clinical outcome. Copyright © 2010 American Association of Endodontists. All rights reserved.

  5. Steam as turbine blade coolant: Experimental data generation

    SciTech Connect

    Wilmsen, B.; Engeda, A.; Lloyd, J.R.

    1995-10-01

    Steam as a coolant is a possible option to cool blades in high temperature gas turbines. However, to quantify steam as a coolant, there exists practically no experimental data. This work deals with an attempt to generate such data and with the design of an experimental setup used for the purpose. Initially, in order to guide the direction of experiments, a preliminary theoretical and empirical prediction of the expected experimental data is performed and is presented here. This initial analysis also compares the coolant properties of steam and air.

  6. FORTRAN program for calculating coolant flow and metal temperatures of a full-coverage-film-cooled vane or blade

    NASA Technical Reports Server (NTRS)

    Meitner, P. L.

    1978-01-01

    A computer program that calculates the coolant flow and the metal temperatures of a full-coverage-film-cooled vane or blade was developed. The analysis was based on compressible, one-dimensional fluid flow and on one-dimensional heat transfer and treats the vane or blade shell as a porous wall. The calculated temperatures are average values for the shell outer-surface area associated with each film-cooling hole row. A thermal-barrier coating may be specified on the shell outer surface, and centrifugal effects can be included for blade calculations. The program is written in FORTRAN 4 and is operational on a UNIVAC 1100/42 computer. The method of analysis, the program input, the program output, and two sample problems are provided.

  7. Cooling Characteristics of the V-1650-7 Engine. 1; Coolant-Flow Distribution, Cylinder Temperatures, and Heat Rejections at Typical Operating Conditions

    NASA Technical Reports Server (NTRS)

    Povolny, John H.; Bogdan, Louis J.

    1947-01-01

    An investigation was conducted to determine the coolant-flow distribu tion, the cylinder temperatures, and the heat rejections of the V-165 0-7 engine . The tests were run a t several power levels varying from minimum fuel consumption to war emergency power and at each power l evel the coolant flows corresponded to the extremes of those likely t o be encountered in typical airplane installations, A mixture of 30-p ercent ethylene glycol and 70-percent water was used as the coolant. The temperature of each cylinder was measured between the exhaust val ves, between the intake valves, in the center of the head, on the exh aust-valve guide, at the top of the barrel on the exhaust side, and o n each exhaust spark-plug gasket. For an increase in engine power fro m 628 to approximately 1700 brake horsepower the average temperature for the cylinder heads between the exhaust valves increased from 437 deg to 517 deg F, the engine coolant heat rejection increased from 12 ,600 to 22,700 Btu. per minute, the oil heat rejection increased from 1030 to 4600 Btu per minute, and the aftercooler-coolant heat reject ion increased from 450 to 3500 Btu -per minute.

  8. Assessment of a large break loss of coolant accident scenario requiring operator action to initiate safety injection

    SciTech Connect

    Grendys, R.C.; Nissley, M.E.; Baker, D.C.

    1996-11-01

    As part of the licensing basis for a nuclear power plant, the acceptability of the Emergency Core Cooling Systems (ECCS) following a postulated Loss-of-Coolant Accident (LOCA) as described in the Code of Federal Regulations (CFR), Title 10, Chapter 1, Part 50.46, must be verified. The LOCA analysis is performed with an acceptable ECCS Evaluation Model and results must show compliance with the 10 CFR 50.46 acceptance criteria. Westinghouse Electric Corporation performs Large and Small Break LOCA and LOCA-related analyses to support the licensing basis of various nuclear power plants and also performs evaluations against the licensing basis analyses as required. Occasionally, the need arises for the holder of an operating license of a nuclear power plant to submit a Licensee Event Report (LER) to the US Nuclear Regulatory Commission (USNRC) for any event of the type described in the Code of Federal Regulations, Title 10, Chapter 1, Part 50.73. To support the LER, a Justification for Past Operation (JPO) may be performed to assess the safety consequences and implications of the event based on previous operating conditions. This paper describes the work performed for the Large Break LOCA to assess the impact of an event discovered by Florida Power and Light and reported in LER-94-005-02. For this event, it was determined that under certain circumstances, operator action would have been required to initiate safety injection (SI), thus challenging the acceptability of the ECCS. This event was specifically addressed for the Large Break LOCA by using an advanced thermal hydraulic analysis methodology with realistic input assumptions.

  9. Metal temperatures and coolant flow in a wire cloth transpiration cooled turbine vane

    NASA Technical Reports Server (NTRS)

    Gladden, H. J.

    1975-01-01

    An experimental heat transfer investigation was conducted on an air-cooled turbine vane made from wire-wound cloth material and supported by a central strut. Vane temperature data obtained are compared with temperature data from two full-coverage film-cooled vanes made of different laminated construction. Measured porous-airfoil temperatures are compared with predicted temperatures.

  10. Bypass valve and coolant flow controls for optimum temperatures in waste heat recovery systems

    DOEpatents

    Meisner, Gregory P

    2013-10-08

    Implementing an optimized waste heat recovery system includes calculating a temperature and a rate of change in temperature of a heat exchanger of a waste heat recovery system, and predicting a temperature and a rate of change in temperature of a material flowing through a channel of the waste heat recovery system. Upon determining the rate of change in the temperature of the material is predicted to be higher than the rate of change in the temperature of the heat exchanger, the optimized waste heat recovery system calculates a valve position and timing for the channel that is configurable for achieving a rate of material flow that is determined to produce and maintain a defined threshold temperature of the heat exchanger, and actuates the valve according to the calculated valve position and calculated timing.

  11. Determination of transient radial-azimuthal temperature distributions in fuel bundles under loss-of-coolant-accident conditions

    SciTech Connect

    Saltos, N.T.; Christensen, R.N.; Aldemir, T.

    1988-10-01

    A methodology is presented to determine the transient temperature distributions in fuel bundles under loss-of-coolant accident (LOCA) conditions using a recently developed variational technique for the solution of radial-azimuthal heat conduction in the fuel rods and the modified view factor concept proposed by Uchida and Nakamure to model the radiative heat transfer between the rods. The variational technique is based on the Lebron-Labermont restricted variational principle and represents the temperature distribution in the rods at a given time during the LOCA via parabolic and circular trial functions in the radial and azimuthal directions, respectively. The methodology is implemented to a 4 x 4 boiling water reactor fuel bundle under typical LOCA conditions to investigate the effects of changes in rod heat transfer characteristics and simplifying modeling assumptions on predicted rod temperature distributions. The results show that these effects depend on the rod location in the assembly and LOCA phase under consideration and indicate that same degree of modelling detail may not be necessary for all the rods in the bundle at all times during the LOCA.

  12. Coolant line hydrometer

    SciTech Connect

    Barber, M.D.; Kipp, W.G.

    1987-03-17

    This patent describes a hydrometer unit for connection in an automobile coolant flow line comprising: a tubular fitting adapted to be connected to the coolant flow line; a coolant receiving chamber means connected to the tubular fitting for receiving coolant from the tubular fitting; and indicating float elements contained within the coolant receiving chamber means and adapted to rise therein individually as a function of the specific gravity of the coolant. The coolant receiving chamber means includes a closure cap which when connected to the tubular fitting forms a coolant receiving chamber, retaining means for retaining the indicating float elements within the coolant receiving chamber, a viewing window member of a substantially clear material through which the float elements can be visually observed within the coolant receiving chamber means, and air venturi means located within the coolant receiving chamber means for automatically removing air which may collect within the coolant chamber means.

  13. Oxygen sensors for Heavy Liquid Metal coolants: Calibration and assessment of the minimum reading temperature

    NASA Astrophysics Data System (ADS)

    Bassini, S.; Antonelli, A.; Di Piazza, I.; Tarantino, M.

    2017-04-01

    Oxygen sensors for Heavy Liquid Metals (HLMs) such as lead and LBE (lead-bismuth eutectic) will be essential devices in future Lead Fast Reactor (LFR) and Accelerator Driven System (ADS). Potentiometric sensors based on solid electrolytes were developed in recent years to this purpose. Internal reference electrodes such as Pt-air and Bi/Bi2O3 liquid metal/metal-oxide are among the most used but they both have a weak point: Pt-air sensor has a high minimum reading temperature around 400 °C whereas Bi/Bi2O3 suffers from internal stresses induced by Bi volume variations with temperature, which may lead to the sensor failure in the long-term. The present work describes the performance of standard Pt-air and Bi/Bi2O3 sensors and compares them with recent Cu/Cu2O sensor. Sensors with Yttria Partially Stabilized Zirconia (YPSZ) electrolyte were calibrated in oxygen-saturated HLM between 160 and 550 °C and the electric potential compared to the theoretical one to define the accuracy and the minimum reading temperature. Standard Pt-air sensor were also tested using Yttria Totally Stabilized Zirconia (YTSZ) to assess the effect of a different electrolyte on the minimum reading temperature. The performance of Pt-air and Cu/Cu2O sensors with YPSZ electrolyte were then tested together in low-oxygen HLM between 200 and 450 °C. The results showed that Pt-air, Bi/Bi2O3 and Cu/Cu2O sensors with YPSZ measured oxygen in HLMs down to 400 °C, 290 °C and 200 °C respectively. When the YTSZ electrolyte was used in place of the YPSZ, the Pt-air sensor measured correctly down to at least 350 °C thanks to the superior ionic conductivity of the YTSZ. When Cu/Cu2O and Pt-air sensors were tested together in the same low-oxygen HLM between 200 and 450 °C, Cu/Cu2O sensor worked predictably in the whole temperature range whereas Pt-air sensor exhibited a correct output only above 400 °C.

  14. The international surface temperature initiative

    NASA Astrophysics Data System (ADS)

    Thorne, P. W.; Lawrimore, J. H.; Willett, K. M.; Allan, R.; Chandler, R. E.; Mhanda, A.; de Podesta, M.; Possolo, A.; Revadekar, J.; Rusticucci, M.; Stott, P. A.; Strouse, G. F.; Trewin, B.; Wang, X. L.; Yatagai, A.; Merchant, C.; Merlone, A.; Peterson, T. C.; Scott, E. M.

    2013-09-01

    The aim of International Surface Temperature Initiative is to create an end-to-end process for analysis of air temperature data taken over the land surface of the Earth. The foundation of any analysis is the source data. Land surface air temperature records have traditionally been stored in local, organizational, national and international holdings, some of which have been available digitally but many of which are available solely on paper or as imaged files. Further, economic and geopolitical realities have often precluded open sharing of these data. The necessary first step therefore is to collate readily available holdings and augment these over time either through gaining access to previously unavailable digital data or through data rescue and digitization activities. Next, it must be recognized that these historical measurements were made primarily in support of real-time weather applications where timeliness and coverage are key. At almost every long-term station it is virtually certain that changes in instrumentation, siting or observing practices have occurred. Because none of the historical measures were made in a metrologically traceable manner there is no unambiguous way to retrieve the true climate evolution from the heterogeneous raw data holdings. Therefore it is desirable for multiple independent groups to produce adjusted data sets (so-called homogenized data) to adequately understand the data characteristics and estimate uncertainties. Then it is necessary to benchmark the performance of the contributed algorithms (equivalent to metrological software validation) through development of realistic benchmark datasets. In support of this, a series of successive benchmarking and assessment cycles are envisaged, allowing continual improvement while avoiding over-tuning of algorithms. Finally, a portal is proposed giving access to related data-products, utilizing the assessment results to provide guidance to end-users on which product is the most suited to

  15. Analysis of in-core coolant temperatures of FFTF instrumented fuels tests at full power

    SciTech Connect

    Hoth, C.W

    1981-01-01

    Two full size highly instrumented fuel assemblies were inserted into the core of the Fast Flux Test Facility in December of 1979. The major objectives of these instrumented tests are to provide verification of the FFTF core conditions and to characterize temperature patterns within FFTF driver fuel assemblies. A review is presented of the results obtained during the power ascents and during irradiation at a constant reactor power of 400 MWt. The results obtained from these instrumented tests verify the conservative nature of the design methods used to establish core conditions in FFTF. The success of these tests also demonstrates the ability to design, fabricate, install and irradiate complex, instrumented fuel tests in FFTF using commercially procured components.

  16. Temperature initiated passive cooling system

    DOEpatents

    Forsberg, C.W.

    1994-11-01

    A passive cooling system for cooling an enclosure only when the enclosure temperature exceeds a maximum standby temperature comprises a passive heat transfer loop containing heat transfer fluid having a particular thermodynamic critical point temperature just above the maximum standby temperature. An upper portion of the heat transfer loop is insulated to prevent two phase operation below the maximum standby temperature. 1 fig.

  17. Temperature initiated passive cooling system

    DOEpatents

    Forsberg, Charles W.

    1994-01-01

    A passive cooling system for cooling an enclosure only when the enclosure temperature exceeds a maximum standby temperature comprises a passive heat transfer loop containing heat transfer fluid having a particular thermodynamic critical point temperature just above the maximum standby temperature. An upper portion of the heat transfer loop is insulated to prevent two phase operation below the maximum standby temperature.

  18. A fracture mechanics approach for estimating fatigue crack initiation in carbon and low-alloy steels in LWR coolant environments

    SciTech Connect

    Park, H. B.; Chopra, O. K.

    2000-04-10

    A fracture mechanics approach for elastic-plastic materials has been used to evaluate the effects of light water reactor (LWR) coolant environments on the fatigue lives of carbon and low-alloy steels. The fatigue life of such steel, defined as the number of cycles required to form an engineering-size crack, i.e., 3-mm deep, is considered to be composed of the growth of (a) microstructurally small cracks and (b) mechanically small cracks. The growth of the latter was characterized in terms of {Delta}J and crack growth rate (da/dN) data in air and LWR environments; in water, the growth rates from long crack tests had to be decreased to match the rates from fatigue S-N data. The growth of microstructurally small cracks was expressed by a modified Hobson relationship in air and by a slip dissolution/oxidation model in water. The crack length for transition from a microstructurally small crack to a mechanically small crack was based on studies on small crack growth. The estimated fatigue S-N curves show good agreement with the experimental data for these steels in air and water environments. At low strain amplitudes, the predicted lives in water can be significantly lower than the experimental values.

  19. Effects of turbulence model on convective heat transfer of coolant flow in a prismatic very high temperature reactor core

    SciTech Connect

    Lee, S. N.; Tak, N. I.; Kim, M. H.; Noh, J. M.

    2012-07-01

    The existing study of Spall et al. shows that only {nu}{sup 2}-f turbulence model well matches with the experimental data of Shehata and McEligot which were obtained under strongly heated gas flows. Significant over-predictions in those literatures were observed in the convective heat transfer with the other famous turbulence models such as the k-{epsilon} and k-{omega} models. In spite of such good evidence about the performance of the{nu}{sup 2}-f model, the application of the {nu}{sup 2}-f model to the thermo-fluid analysis of a prismatic core is very rare. In this paper, therefore, the convective heat transfer of the coolant flow in a prismatic core has been investigated using the {nu}{sup 2}-f model. Computational fluid dynamics (CFD) calculations have been carried out for the typical unit cell geometry of a prismatic fuel column with typical operating conditions of prismatic designs. The tested Reynolds numbers of the coolant flow are 10,000, 20,000, 30,000 and 50,000. The predicted Nusselt numbers with the {nu}{sup 2}-f model are compared with the results by the other turbulence models (k-{epsilon} and SST) as well as the empirical correlations. (authors)

  20. Measuring flow and pressure of lithium coolant under developmental testing of a high-temperature cooling system of a space nuclear power plant

    NASA Astrophysics Data System (ADS)

    Sobolev, V. Ya.; Sinyavsky, V. V.

    2014-12-01

    Sub-megawatt space NPP use lithium as a coolant and niobium alloy as a structural material. In order to refine the lithium-niobium technology of the material and design engineering, lithium-niobium loops were worked out in RSC Energia, and they were tested at a working temperature of lithium equal to 1070-1300 K. In order to measure the lithium flow and pressure, special gauges were developed, which made possible the calibration and checkout of the loops without their dismantling. The paper describes the architecture of the electromagnetic flowmeter and the electromagnetic vibrating-wire pressure transducer (gauge) for lithium coolant in the nuclear power plant cooling systems. The operating principles of these meters are presented. Flowmeters have been developed for channel diameters ranging from 10 to 100 mm, which are capable of measuring lithium flows in the range of 0.1 to 30 L/s with the error of 3% for design calibration and 1% for volume graduation. The temperature error of the pressure transducers does not exceed 0.4% per 100 K; the nonlinearity and hysteresis of the calibration curve do not exceed 0.3 and 0.4%, respectively. The transducer applications are illustrated by the examples of results obtained from tests on the NPP module mockup and heat pipes of a radiation cooler.

  1. F. E. L. coolant

    SciTech Connect

    Schumann, D.; Lepper, J.

    1987-11-20

    The compatibility of a number of organic and inorganic materials with Freon-113 in ETA-II is studied. The stability of Freon-113 in the simulated electrical environment is also discussed. It would be desirable to use Freon-113 as the dielectric coolant because it is a factor of twenty less expensive than the currently used Flourinert-75. No substantial problems were observed with any of the materials of interest. Polycarbonate will craze under certain conditions of exposure to Freon-113, mechanical stress, temperature and time. Extruded polymethylmethacrylate crazes on exposure to Freon-113. This is assumed to result from residual stress or processing aids because the cast polymer shows no effects. The polysiloxane swelled severely in the Freon-113 which is no surprise since solubility parameters are close. The Freon-113 did not break down under electrical arcing which simulated service conditions to produce HF or HCl within the detection limits of a Karl Fisher titration even with substantial added water.

  2. Minimizing thermal damage of aerospace components using coolant nozzle and coolant system optimization

    SciTech Connect

    Mindek, R.B. Jr.; Webster, J.A.

    1994-12-31

    Research to optimize the application of coolant in the creep feed grinding of aerospace components was conducted at the Center for Grinding Research and Development during the past year. During this research, work was performed in the areas of coolant jet nozzle and coolant system design to identify optimum jet nozzle designs, nozzle positioning and coolant system configurations. The knowledge gained from initial screening tests and grinding trials of flat surfaces was applied to final grinding trials on actual blade and vane (profiled) production components. Final grinding test results of four specific production operations showed that at least a 27% improvement in wheel life could be realized, relative to the levels previously established in production, by optimizing grinding fluid application. In addition, a set of guidelines for optimized coolant nozzle and coolant system design and manufacture have been developed from the results of this research, and are applicable to other types of grinding or machining as well.

  3. Purification of liquid metal systems with sodium coolant from oxygen using getters

    NASA Astrophysics Data System (ADS)

    Kozlov, F. A.; Konovalov, M. A.; Sorokin, A. P.

    2016-05-01

    For increasing the safety and economic parameters of nuclear power stations (NPSs) with sodium coolant, it was decided to install all systems contacting radioactive sodium, including purification systems of circuit I, in the reactor vessel. The performance and capacity of cold traps (CTs) (conventional element of coolant purification systems) in these conditions are limited by their volume. It was proposed to use hot traps (HTs) in circuit I for coolant purification from oxygen. It was demonstrated that, at rated parameters of the installation when the temperature of the coolant streamlining the getter (gas absorber) is equal to 550°C, the hot trap can provide the required coolant purity. In shutdown modes at 250-300°C, the performance of the hot trap is reduced by four orders of magnitude. Possible HT operation regimes for shutdown modes and while reaching rated parameters were proposed and analyzed. Basic attention was paid to purification modes at power rise after commissioning and accidental contamination of the coolant when the initial oxygen concentration in it reached 25 mln-1. It was demonstrated that the efficiency of purification systems can be increased using HTs with the getter in the form of a foil or granules. The possibility of implementing the "fast purification" mode in which the coolant is purified simultaneously with passing over from the shutdown mode to the rated parameters was substantiated.

  4. Assessment of Candidate Molten Salt Coolants for the NGNP/NHI Heat-Transfer Loop

    SciTech Connect

    Williams, D. F.

    2006-06-30

    This report provides an assessment of candidate salts proposed as the coolant for the loop that shuttles heat from the Next Generation Nuclear Plant (NGNP) to the Nuclear Hydrogen Initiative (NHI) hydrogen-production plant. The physical properties most relevant for coolant service were reviewed, and key chemical factors that influence material compatibility were also analyzed for the purpose of screening candidate salts. A preliminary assessment of the cost of the raw materials required to produce the coolant is also presented. Salts that are suitable for use as the primary coolant in a high-temperature nuclear reactor were previously analyzed. Some of the fluoride salts identified in the previous study are also appropriate for consideration as the secondary coolant in a heat-transfer loop; therefore, results from the previous report are used in this document. However, alternative coolant salts (i.e., chlorides and fluoroborates) that were not considered in the previous report should be considered for service in the heat-transfer loop. These alternative coolants are considered in this report.

  5. Machine coolant waste reduction by optimizing coolant life. Project summary

    SciTech Connect

    Pallansch, J.

    1995-08-01

    The project was designed to study the following: A specific water-soluble coolant (Blasocut 2000 Universal) in use with a variety of machines, tools, and materials; Coolant maintenance practices associated with three types of machines; Health effects of use and handling of recycled coolant; Handling practices for chips and waste coolant; Chip/coolant separation; and Oil/water separation.

  6. Experimental investigations of heat transfer and temperature fields in models simulating fuel assemblies used in the core of a nuclear reactor with a liquid heavy-metal coolant

    NASA Astrophysics Data System (ADS)

    Belyaev, I. A.; Genin, L. G.; Krylov, S. G.; Novikov, A. O.; Razuvanov, N. G.; Sviridov, V. G.

    2015-09-01

    The aim of this experimental investigation is to obtain information on the temperature fields and heat transfer coefficients during flow of liquid-metal coolant in models simulating an elementary cell in the core of a liquid heavy metal cooled fast-neutron reactor. Two design versions for spacing fuel rods in the reactor core were considered. In the first version, the fuel rods were spaced apart from one another using helical wire wound on the fuel rod external surface, and in the second version spacer grids were used for the same purpose. The experiments were carried out on the mercury loop available at the Moscow Power Engineering Institute National Research University's Chair of Engineering Thermal Physics. Two experimental sections simulating an elementary cell for each of the fuel rod spacing versions were fabricated. The temperature fields were investigated using a dedicated hinged probe that allows temperature to be measured at any point of the studied channel cross section. The heat-transfer coefficients were determined using the wall temperature values obtained at the moment when the probe thermocouple tail end touched the channel wall. Such method of determining the wall temperature makes it possible to alleviate errors that are unavoidable in case of measuring the wall temperature using thermocouples placed in slots milled in the wall. In carrying out the experiments, an automated system of scientific research was applied, which allows a large body of data to be obtained within a short period of time. The experimental investigations in the first test section were carried out at Re = 8700, and in the second one, at five values of Reynolds number. Information about temperature fields was obtained by statistically processing the array of sampled probe thermocouple indications at 300 points in the experimental channel cross section. Reach material has been obtained for verifying the codes used for calculating velocity and temperature fields in channels with

  7. Exploratory Investigation of Transpiration Cooling of a 40 deg Double Wedge using Nitrogen and Helium as Coolants at Stagnation Temperatures from 1,295 deg F to 2,910 deg F

    NASA Technical Reports Server (NTRS)

    Rashis, Bernard

    1961-01-01

    An investigation of transpiration cooling has been conducted in the preflight jet of the Langley Pilotless Aircraft Research Station at Wallops Island, Va. The model consisted of a double wedge of 40 deg included angle having a porous stainless-steel specimen inserted flush with the top surface of the wedge. The tests were conducted at a free-stream Mach number of 2.0 for stagnation temperatures ranging from 1,295 F to 2,910 F. Nitrogen and helium were used as coolants and tests were conducted for values ranging from approximately 0.03 to 0.30 percent of the local weight flow rate. The data for both the nitrogen and helium coolants indicated greater cooling effectiveness than that predicted by theory and were in good agreement with the results for an 8 deg cone tested at a stagnation temperature of 600 F. The results indicate that the helium coolant, for the same amount of heat-transfer reduction, requires only about one-fourth to one-fifth the coolant flow weight as the nitrogen coolant.

  8. NUCLEAR REACTOR COOLANT

    DOEpatents

    Colichman, E.L.

    1959-10-20

    The formation of new reactor coolants which suppress polymerization resulting from pyrolytic and radiation decomposition is described. The coolants consist of polyphenyls and condensed ring compounds having from two to about four carbon rings and from 0.1 to about 5% of beryllium or magnesium dispersed in the hydrocarbon.

  9. NUCLEAR REACTOR COOLANT

    DOEpatents

    Colichman, E.L.

    1959-10-20

    The formation of new reactor coolants which suppress polymerization resulting from pyrolitic and radiation decomposition is described. The coolants consist of polyphenyls and condensed ring compounds having from two to about four carbon rings and from 0.1 to about 10% of an alkall metal dispersed in the hydrocarbon.

  10. Shock Initiation of Energetic Materials at Different Initial Temperatures

    SciTech Connect

    Urtiew, P A; Tarver, C M

    2005-01-14

    Shock initiation is one of the most important properties of energetic materials, which must transition to detonation exactly as intended when intentionally shocked and not detonate when accidentally shocked. The development of manganin pressure gauges that are placed inside the explosive charge and record the buildup of pressure upon shock impact has greatly increased the knowledge of these reactive flows. This experimental data, together with similar data from electromagnetic particle velocity gauges, has allowed us to formulate the Ignition and Growth model of shock initiation and detonation in hydrodynamic computer codes for predictions of shock initiation scenarios that cannot be tested experimentally. An important problem in shock initiation of solid explosives is the change in sensitivity that occurs upon heating (or cooling). Experimental manganin pressure gauge records and the corresponding Ignition and Growth model calculations are presented for two solid explosives, LX-17 (92.5 % triaminotrinitrobenzene (TATB) with 7.5 % Kel-F binder) and LX-04 (85 % octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazine (HMX) with 15 % Viton binder) at several initial temperatures.

  11. Flow boiling test of GDP replacement coolants

    SciTech Connect

    Park, S.H.

    1995-08-01

    The tests were part of the CFC replacement program to identify and test alternate coolants to replace CFC-114 being used in the uranium enrichment plants at Paducah and Portsmouth. The coolants tested, C{sub 4}F{sub 10} and C{sub 4}F{sub 8}, were selected based on their compatibility with the uranium hexafluoride process gas and how well the boiling temperature and vapor pressure matched that of CFC-114. However, the heat of vaporization of both coolants is lower than that of CFC-114 requiring larger coolant mass flow than CFC-114 to remove the same amount of heat. The vapor pressure of these coolants is higher than CFC-114 within the cascade operational range, and each coolant can be used as a replacement coolant with some limitation at 3,300 hp operation. The results of the CFC-114/C{sub 4}F{sub 10} mixture tests show boiling heat transfer coefficient degraded to a minimum value with about 25% C{sub 4}F{sub 10} weight mixture in CFC-114 and the degree of degradation is about 20% from that of CFC-114 boiling heat transfer coefficient. This report consists of the final reports from Cudo Technologies, Ltd.

  12. MACHINE COOLANT WASTE REDUCTION BY OPTIMIZING COOLANT LIFE

    EPA Science Inventory

    Machine shops use coolants to improve the life and function of machine tools. hese coolants become contaminated with oils with use, and this contamination can lead to growth of anaerobic bacteria and shortened coolant life. his project investigated methods to extend coolant life ...

  13. MACHINE COOLANT WASTE REDUCTION BY OPTIMIZING COOLANT LIFE

    EPA Science Inventory

    Machine shops use coolants to improve the life and function of machine tools. hese coolants become contaminated with oils with use, and this contamination can lead to growth of anaerobic bacteria and shortened coolant life. his project investigated methods to extend coolant life ...

  14. The effect of fuel thermal conductivity on the behavior of LWR cores during loss-of-coolant accidents

    SciTech Connect

    Terrani, Kurt A.; Wang, Dean; Ott, Larry J.; Montgomery, Robert O.

    2014-05-01

    The effect of variation in thermal conductivity of light water reactor fuel elements on core response during loss-of-coolant accident scenarios is examined. Initially, a simplified numerical analysis is utilized to determine the time scales associated with dissipation of stored energy from the fuel into the coolant once the fission reaction is stopped. The analysis is then followed by full reactor system thermal-hydraulics analysis of a typical boiling and pressurized water reactor subjected to a large break loss-of-coolant accident scenario using the TRACE code. Accordingly, sensitivity analyses to examine the effect of an increase in fuel thermal conductivity, up to 500%, on fuel temperature evolution during these transients are performed. Given the major differences in thermal-hydraulics design aspects of boiling and pressurized water reactors, different fuel and temperature responses during the simulated loss-of-coolant transients are observed.

  15. Identification and Ranking of Phenomena Leading to Peak Cladding Temperatures in Boiling Water Reactors During Large Break Loss of Coolant Accident Transients

    SciTech Connect

    Ratnayake, Ruwan K.; Ergun, S.; Hochreiter, L.E.; Baratta, A.J.

    2002-07-01

    In the licensing and validation process of best estimate codes for the analysis of nuclear reactors and postulated accident scenarios, the identification and quantification of the calculational uncertainty is required. One of the most important aspects in this process is the identification and recognition of the crucial contributing phenomena to the overall code uncertainty. The establishment of Phenomena Identification and Ranking Tables (PIRT) provides a vehicle to assist in assessing the capabilities of the computer code, and to guide the uncertainty analysis of the calculated results. The process used in this work to identify the phenomena was reviewing both licensing and best estimate calculations, as well as experiments, which had been performed for BWR LOCA analyses. The initial PIRT was developed by a group of analysts and was compared to existing BWR LOCA PIRTs as well as BWR LOCA analyses. The initial PIRT was then independently reviewed by a second panel of experts for the selected ranking of phenomena, identification of phenomena which were ignored, as well as the basis and rationale for the ranking of the phenomena. The differences between the two groups were then resolved. PIRTs have been developed for BWR types 4 and 5/6 for the Large Break Loss of Coolant Accidents (LB-LOCA). The ranking and the corresponding rationale for each phenomenon is included in tables together with the assessed uncertainty of the code capability to predict the phenomena. (authors)

  16. Assessment of the Use of Nitrogen Trifluoride for Purifying Coolant and Heat Transfer Salts in the Fluoride Salt-Cooled High-Temperature Reactor

    SciTech Connect

    Scheele, Randall D.; Casella, Andrew M.

    2010-09-28

    This report provides an assessment of the use of nitrogen trifluoride for removing oxide and water-caused contaminants in the fluoride salts that will be used as coolants in a molten salt cooled reactor.

  17. Adsorption removal of carbon dioxide from the helium coolant of high-temperature gas-cooled reactors

    SciTech Connect

    Varezhin, A.V.; Fedoseenkov, A.N.; Khrulev, A.A.; Metlik, I.V.; Zel venskii, Y.D.

    1986-10-01

    This paper conducts experiments on the removal of CO/sub 2/ from helium by means of a Soviet-made adsorbent under the conditions characteristic of high-temperature gas-cooled reactor cleaning systems. The adsorption of CO/sub 2/ from helium was studied under dynamic conditions with a fixed layer of adsorbent in a flow-through apparatus with an adsorber 16 mm in diameter. The analysis of the helium was carried out by means of a TVT chromatograph. In order to compare the adsorption of CO/sub 2/ on CaA zeolite under dynamic conditions from the helium stream under pressure with the equilibrium adsorption on the basis of pure CO/sub 2/, the authors determined the adsorption isotherm at 293 K by the volumetric method over a range of CO/sub 2/ equilibrium pressures from 260 to 11,970 Pa. Reducing the adsorption temperature to 273 K leads to a considerable reduction in the energy costs for regeneration, owing to the increase in adsorption and the decrease in the number of regeneration cycles; the amount of the heating gas used is reduced to less than half.

  18. Environmentally Friendly Coolant System

    SciTech Connect

    David Jackson Principal Investigator

    2011-11-08

    Energy reduction through the use of the EFCS is most improved by increasing machining productivity. Throughout testing, nearly all machining operations demonstrated less land wear on the tooling when using the EFCS which results in increased tool life. These increases in tool life advance into increased productivity. Increasing productivity reduces cycle times and therefore reduces energy consumption. The average energy savings by using the EFCS in these machining operations with these materials is 9%. The advantage for end milling stays with flood coolant by about 6.6% due to its use of a low pressure pump. Face milling and drilling are both about 17.5% less energy consumption with the EFCS than flood coolant. One additional result of using the EFCS is improved surface finish. Certain machining operations using the EFCS result in a smoother surface finish. Applications where finishing operations are required will be able to take advantage of the improved finish by reducing the time or possibly eliminating completely one or more finishing steps and thereby reduce their energy consumption. Some machining operations on specific materials do not show advantages for the EFCS when compared to flood coolants. More information about these processes will be presented later in the report. A key point to remember though, is that even with equivalent results, the EFCS is replacing petroleum based coolants whose production produces GHG emissions and create unsafe work environments.

  19. Radiant energy receiver having improved coolant flow control means

    DOEpatents

    Hinterberger, H.

    1980-10-29

    An improved coolant flow control for use in radiant energy receivers of the type having parallel flow paths is disclosed. A coolant performs as a temperature dependent valve means, increasing flow in the warmer flow paths of the receiver, and impeding flow in the cooler paths of the receiver. The coolant has a negative temperature coefficient of viscosity which is high enough such that only an insignificant flow through the receiver is experienced at the minimum operating temperature of the receiver, and such that a maximum flow is experienced at the maximum operating temperature of the receiver. The valving is accomplished by changes in viscosity of the coolant in response to the coolant being heated and cooled. No remotely operated valves, comparators or the like are needed.

  20. A Heated Tube Facility for Rocket Coolant Channel Research

    NASA Technical Reports Server (NTRS)

    Green, James M.; Pease, Gary M.; Meyer, Michael L.

    1995-01-01

    The capabilities of a heated tube facility used for testing rocket engine coolant channels at the NASA Lewis Research Center are presented. The facility uses high current, low voltage power supplies to resistively heat a test section to outer wall temperatures as high as 730 C (1350 F). Liquid or gaseous nitrogen, gaseous helium, or combustible liquids can be used as the test section coolant. The test section is enclosed in a vacuum chamber to minimize heat loss to the surrounding system. Test section geometry, size, and material; coolant properties; and heating levels can be varied to generate heat transfer and coolant performance data bases.

  1. Automatic coolant flow control device for a nuclear reactor assembly

    SciTech Connect

    Hutter, Ernest

    1986-01-01

    A device which controls coolant flow through a nuclear reactor assembly comprises a baffle means at the exit end of said assembly having a plurality of orifices, and a bimetallic member in operative relation to the baffle means such that at increased temperatures said bimetallic member deforms to unblock some of said orifices and allow increased coolant flow therethrough.

  2. Automatic coolant flow control device for a nuclear reactor assembly

    DOEpatents

    Hutter, E.

    1984-01-27

    A device which controls coolant flow through a nuclear reactor assembly comprises a baffle means at the exit end of said assembly having a plurality of orifices, and a bimetallic member in operative relation to the baffle means such that at increased temperatures said bimetallic member deforms to unblock some of said orifices and allow increased coolant flow therethrough.

  3. Development of Figure of Merits (FOMs) for Intermediate Coolant Characterization and Selection

    SciTech Connect

    Eung Soo Kim; Piyush Sabharwall; Nolan Anderson

    2011-06-01

    This paper focuses on characterization of several coolant performances in the IHTL. There are lots of choices available for the IHTL coolants; gases, liquid metals, molten salts, and etc. Traditionally, the selection of coolants is highly dependent on engineer's experience and decisions. In this decision, the following parameters are generally considered: melting point, vapor pressure, density, thermal conductivity, heat capacity, viscosity, and coolant chemistry. The followings are general thermal-hydraulic requirements for the coolant in the IHTL: (1) High heat transfer performance - The IHTL coolant should exhibit high heat transfer performance to achieve high efficiency and economics; (2) Low pumping power - The IHTL coolant requires low pumping power to improve economics through less stringent pump requirements; (3) Low amount of coolant volume - The IHTL coolant requires less coolant volume for better economics; (4) Low amount of structural materials - The IHTL coolant requires less structural material volume for better economics; (5) Low heat loss - The IHTL requires less heat loss for high efficiency; and (6) Low temperature drop - The IHTL should allow less temperature drop for high efficiency. Typically, heat transfer coolants are selected based on various fluid properties such as melting point, vapor pressure, density, thermal conductivity, heat capacity, viscosity, and coolant chemistry. However, the selection process & results are highly dependent on the engineer's personal experience and skills. In the coolant selection, if a certain coolant shows superior properties with respect to the others, the decision will be very straightforward. However, generally, each coolant material exhibits good characteristics for some properties but poor for the others. Therefore, it will be very useful to have some figures of merits (FOMs), which can represent and quantify various coolant thermal performances in the system of interest. The study summarized in this

  4. Reactor coolant pump flywheel

    DOEpatents

    Finegan, John Raymond; Kreke, Francis Joseph; Casamassa, John Joseph

    2013-11-26

    A flywheel for a pump, and in particular a flywheel having a number of high density segments for use in a nuclear reactor coolant pump. The flywheel includes an inner member and an outer member. A number of high density segments are provided between the inner and outer members. The high density segments may be formed from a tungsten based alloy. A preselected gap is provided between each of the number of high density segments. The gap accommodates thermal expansion of each of the number of segments and resists the hoop stress effect/keystoning of the segments.

  5. Method for removing cesium from a nuclear reactor coolant

    DOEpatents

    Colburn, Richard P.

    1986-01-01

    A method of and system for removing cesium from a liquid metal reactor coolant including a carbon packing trap in the primary coolant system for absorbing a major portion of the radioactive cesium from the coolant flowing therethrough at a reduced temperature. A regeneration subloop system having a secondary carbon packing trap is selectively connected to the primary system for isolating the main trap therefrom and connecting it to the regeneration system. Increasing the temperature of the sodium flowing through the primary trap diffuses a portion of the cesium

  6. Experimental evaluation of machining parameters in machining of 7075 aluminium alloy with cryogenic liquid nitrogen coolant

    NASA Astrophysics Data System (ADS)

    Muthuraman, V.; Arunkumar, S.

    2017-03-01

    The experimental results on investigation on the turning of 7075 aluminium alloy, using Cryogenic Liquid Nitrogen (LN2) as a coolant was analyzed in this paper. The influence of the cryogenic LN2 coolant compared with that of the conventional coolant on the cuting performance parameters, such as the cutting force, cutting temperature, andbsurface finish was analysed and investigated. The use of the cryogenic liquid nitrogen coolant influenced the cutting temperature and the cutting force by about 17 to 29% and 11 to 20% reduction respectively. The surface finish value of the machined workpiece is about 15 to 23% better than that of the conventional coolant.

  7. RAPID INDUCTION OF HETEROGENEOUS ICE NUCLEATION IN A BIOLOGICALLY COMPATIBLE COOLANT

    PubMed Central

    Lampe, Joshua; Bull, Diana; Becker, Lance

    2012-01-01

    Hypothermia is gaining recognition as an important medical treatment. To treat local cases of injury such as stroke, or certain surgical procedures, there is a need to induce local hypothermia. To treat shock or cardiac arrest survivors, there is a need to rapidly induce global hypothermia. Rapid induction of hypothermia has been achieved in animal research, but it has yet to be achieved clinically using a simple, widely practicable method. The clinical need for therapeutic hypothermia represents an engineering opportunity to develop an easy to use coolant that is sterile, biologically compatible, and maximizes coolant heat capacity. Here we present an initial characterization of a prototype platform technology designed to create a sterile, biologically compatible, high heat capacity coolant that has the potential to be used in all of these clinical applications. The coolant is a specially processed micro-particulate ice saline slurry, that can be easily pumped into a patient through surgical tubing, syringes, or minimally invasive surgical instruments. The device induces heterogeneous ice nucleation in a saline stream that has been super-cooled from room temperature to a temperature below the saline freezing point. Currently, the device begins continuous production of ice slurry that contains ~30 % ice by mass within 10 minutes. The nominal ice particle diameter is smaller than 100 μm. This work represents a significant first step toward addressing clinical needs for rapid human cooling. PMID:25954121

  8. RAPID INDUCTION OF HETEROGENEOUS ICE NUCLEATION IN A BIOLOGICALLY COMPATIBLE COOLANT.

    PubMed

    Lampe, Joshua; Bull, Diana; Becker, Lance

    Hypothermia is gaining recognition as an important medical treatment. To treat local cases of injury such as stroke, or certain surgical procedures, there is a need to induce local hypothermia. To treat shock or cardiac arrest survivors, there is a need to rapidly induce global hypothermia. Rapid induction of hypothermia has been achieved in animal research, but it has yet to be achieved clinically using a simple, widely practicable method. The clinical need for therapeutic hypothermia represents an engineering opportunity to develop an easy to use coolant that is sterile, biologically compatible, and maximizes coolant heat capacity. Here we present an initial characterization of a prototype platform technology designed to create a sterile, biologically compatible, high heat capacity coolant that has the potential to be used in all of these clinical applications. The coolant is a specially processed micro-particulate ice saline slurry, that can be easily pumped into a patient through surgical tubing, syringes, or minimally invasive surgical instruments. The device induces heterogeneous ice nucleation in a saline stream that has been super-cooled from room temperature to a temperature below the saline freezing point. Currently, the device begins continuous production of ice slurry that contains ~30 % ice by mass within 10 minutes. The nominal ice particle diameter is smaller than 100 μm. This work represents a significant first step toward addressing clinical needs for rapid human cooling.

  9. Initial fuel temperature effects on burning rate of pool fire.

    PubMed

    Chen, Bing; Lu, Shou-Xiang; Li, Chang-Hai; Kang, Quan-Sheng; Lecoustre, Vivien

    2011-04-15

    The influence of the initial fuel temperature on the burning behavior of n-heptane pool fire was experimentally studied at the State Key Laboratory of Fire Science (SKLFS) large test hall. Circular pool fires with diameters of 100mm, 141 mm, and 200 mm were considered with initial fuel temperatures ranging from 290 K to 363 K. Burning rate and temperature distributions in fuel and vessel wall were recorded during the combustion. The burning rate exhibited five typical stages: initial development, steady burning, transition, bulk boiling burning, and decay. The burning rate during the steady burning stage was observed to be relatively independent of the initial fuel temperature. In contrast, the burning rate of the bulk boiling burning stage increases with increased initial fuel temperature. It was also observed that increased initial fuel temperature decreases the duration of steady burning stage. When the initial temperature approaches the boiling point, the steady burning stage nearly disappears and the burning rate moves directly from the initial development stage to the transition stage. The fuel surface temperature increases to its boiling point at the steady burning stage, shortly after ignition, and the bulk liquid reaches boiling temperature at the bulk boiling burning stage. No distinguished cold zone is formed in the fuel bed. However, boiling zone is observed and the thickness increases to its maximum value when the bulk boiling phenomena occurs.

  10. Load following capability of CANDLE reactor by adjusting coolant operation condition

    NASA Astrophysics Data System (ADS)

    Sekimoto, Hiroshi; Nakayama, Sinsuke

    2012-06-01

    The load following capability of CANDLE reactor is investigated in the condition that the control rods are unavailable. Both sodium cooled metallic fuel fast reactor (SFR) and 208Pb cooled metallic fuel fast reactor (LFR) are investigated for their performance in power rate changing by changing its coolant operation condition; either coolant flow rate or coolant inlet temperature. The change by coolant flow rate is difficult especially for SFR because the maximum temperature criteria on cladding material may be violated. The power rate can be changed for its full range easily by changing the coolant temperature at the core inlet. LFR can reduce the same amount of power rate by smaller change of temperature than SFR. However, the coolant output temperature is generally decreased for this method and the thermal efficiency becomes worse.

  11. Load following capability of CANDLE reactor by adjusting coolant operation condition

    SciTech Connect

    Sekimoto, Hiroshi; Nakayama, Sinsuke

    2012-06-06

    The load following capability of CANDLE reactor is investigated in the condition that the control rods are unavailable. Both sodium cooled metallic fuel fast reactor (SFR) and {sup 208}Pb cooled metallic fuel fast reactor (LFR) are investigated for their performance in power rate changing by changing its coolant operation condition; either coolant flow rate or coolant inlet temperature. The change by coolant flow rate is difficult especially for SFR because the maximum temperature criteria on cladding material may be violated. The power rate can be changed for its full range easily by changing the coolant temperature at the core inlet. LFR can reduce the same amount of power rate by smaller change of temperature than SFR. However, the coolant output temperature is generally decreased for this method and the thermal efficiency becomes worse.

  12. Coolant passage heat transfer with rotation

    NASA Technical Reports Server (NTRS)

    Hajek, T. J.; Wagner, J.; Johnson, B. V.

    1986-01-01

    In current and advanced gas turbine engines, increased speeds, pressures and temperatures are used to reduce specific fuel consumption and increase thrust/weight ratios. Hence, the turbine airfoils are subjected to increased heat loads escalating the cooling requirements to satisfy life goals. The efficient use of cooling air requires that the details of local geometry and flow conditions be adequately modeled to predict local heat loads and the corresponding heat transfer coefficients. The objective of this program is to develop a heat transfer and pressure drop data base, computational fluid dynamic techniques and correlations for multi-pass rotating coolant passages with and without flow turbulators. The experimental effort is focused on the simulation of configurations and conditions expected in the blades of advanced aircraft high pressure turbines. With the use of this data base, the effects of Coriolis and buoyancy forces on the coolant side flow can be included in the design of turbine blades.

  13. Small-break loss-of-coolant accidents in the updated PIUS 600 advanced reactor design

    SciTech Connect

    Boyack, B.E.; Steiner, J.L.; Harmony, S.C.

    1995-09-01

    The PIUS advanced reactor is a 640-MWe pressurized water reactor developed by Asea Brown Boveri (ABB). A unique feature of the PIUS concept is the absence of mechanical control and shutdown rods. Reactivity is normally controlled by coolant boron concentration and the temperature of the moderator coolant. ABB submitted the PIUS design to the US Nuclear Regulatory Commission (NRC) for preapplication review, and Los Alamos supported the NRC`s review effort. Baseline analyses of small-break initiators at two locations were performed with the system neutronic and thermal-hydraulic analysis code TRAC-PF1/MOD2. In addition, sensitivity studies were performed to explore the robustness of the PIUS concept to severe off-normal conditions having a very low probability of occurrence.

  14. Treatment of mixed waste coolant

    SciTech Connect

    Kidd, S.; Bowers, J.S.

    1995-02-01

    The primary processes used at Lawrence Livermore National Laboratory (LLNL) for treatment of radioactively contaminated machine coolants are industrial waste treatment and in situ carbon adsorption. These two processes simplify approaches to meeting the sanitary sewer discharge limits and subsequent Land Disposal Restriction criteria for hazardous and mixed wastes (40 CFR 268). Several relatively simple technologies are used in industrial water treatment. These technologies are considered Best Demonstrated Available Technologies, or BDAT, by the Environmental Protection Agency. The machine coolants are primarily aqueous and contain water soluble oil consisting of ethanol amine emulsifiers derived from fatty acids, both synthetic and natural. This emulsion carries away metal turnings from a part being machined on a lathe or other machining tool. When the coolant becomes spent, it contains chlorosolvents carried over from other cutting operations as well as a fair amount of tramp oil from machine bearings. This results in a multiphasic aqueous waste that requires treatment of metal and organic contaminants. During treatment, any dissolved metals are oxidized with hydrogen peroxide. Once oxidized, these metals are flocculated with ferric sulfate and precipitated with sodium hydroxide, and then the precipitate is filtered through diatomaceous earth. The emulsion is broken up by acidifying the coolant. Solvents and oils are adsorbed using powdered carbon. This carbon is easily separated from the remaining coolant by vacuum filtration.

  15. Treatment of mixed waste coolant

    SciTech Connect

    Kidd, S.; Bowers, J.S.

    1995-09-01

    The primary processes used at Lawrence Livermore National Laboratory (LLNL) for treatment of radioactively contaminated machine coolants are industrial waste treatment and in situ carbon adsorption. These two processes simplify approaches to meetings the sanitary sewer discharge limits and subsequent Land Disposal REstriction criteria for hazardous and mixed wastes (40 CFR 268). Several relatively simple technologies are used in industrial water treatment. These technologies are considered {open_quotes}Best Demonstrated Available Technologies,{close_quotes} or BDAT, by the Environmental Protection Agency. The machine coolants are primarily aqueous and contain water soluble oil consisting of ethanol amine emulsifiers derived from fatty acids, both synthetic and natural. This emulsion carries away metal turnings from a part being machined on a lathe or other machining tool. When the coolant becomes spent, it contains chlorosolvents carried over from other cutting operations as well as a fair amount of tramp oil from machine bearings. This results in a mutiphasic aqueous waste that requires treatment of metal and organic contaminants. During treatment, any dissolved metals are oxidized with hydrogen peroxide. Once oxidized, these metals are flocculated with ferric sulfate and precipitated with sodium hydroxide, and then the precipitate is filtered through diatomaceous earth. The emulsion is broken up by acidifying the coolant. Solvents and oils are adsorbed using powdered carbon. This carbon is easily separated from the remaining coolant by vacuum filtration.

  16. 1996 Coolant Flow Management Workshop

    NASA Technical Reports Server (NTRS)

    Hippensteele, Steven A. (Editor)

    1997-01-01

    The following compilation of documents includes a list of the 66 attendees, a copy of the viewgraphs presented, and a summary of the discussions held after each session at the 1996 Coolant Flow Management Workshop held at the Ohio Aerospace Institute, adjacent to the NASA Lewis Research Center, Cleveland, Ohio on December 12-13, 1996. The workshop was organized by H. Joseph Gladden and Steven A. Hippensteele of NASA Lewis Research Center. Participants in this workshop included Coolant Flow Management team members from NASA Lewis, their support service contractors, the turbine engine companies, and the universities. The participants were involved with research projects, contracts and grants relating to: (1) details of turbine internal passages, (2) computational film cooling capabilities, and (3) the effects of heat transfer on both sides. The purpose of the workshop was to assemble the team members, along with others who work in gas turbine cooling research, to discuss needed research and recommend approaches that can be incorporated into the Center's Coolant Flow Management program. The workshop was divided into three sessions: (1) Internal Coolant Passage Presentations, (2) Film Cooling Presentations, and (3) Coolant Flow Integration and Optimization. Following each session there was a group discussion period.

  17. Method for removing cesium from a nuclear reactor coolant

    DOEpatents

    Colburn, R.P.

    1983-08-10

    A method of and system for removing cesium from a liquid metal reactor coolant including a carbon packing trap in the primary coolant system for absorbing a major portion of the radioactive cesium from the coolant flowing therethrough at a reduced temperature. A regeneration subloop system having a secondary carbon packing trap is selectively connected to the primary system for isolating the main trap therefrom and connecting it to the regeneration system. Increasing the temperature of the sodium flowing through the primary trap diffuses a portion of the cesium inventory thereof further into the carbon matrix while simultaneously redispersing a portion into the regeneration system for absorption at a reduced temperature by the secondary trap.

  18. Experimental Investigation of Coolant Boiling in a Half-Heated Circular Tube - Final CRADA Report

    SciTech Connect

    Yu, Wenhua; Singh, Dileep; France, David M.

    2016-11-01

    Coolant subcooled boiling in the cylinder head regions of heavy-duty vehicle engines is unavoidable at high thermal loads due to high metal temperatures. However, theoretical, numerical, and experimental studies of coolant subcooled flow boiling under these specific application conditions are generally lacking in the engineering literature. The objective of this project was to provide such much-needed information, including the coolant subcooled flow boiling characteristics and the corresponding heat transfer coefficients, through experimental investigations.

  19. Shock initiation of explosives: High temperature hot spots explained

    NASA Astrophysics Data System (ADS)

    Bassett, Will P.; Johnson, Belinda P.; Neelakantan, Nitin K.; Suslick, Kenneth S.; Dlott, Dana D.

    2017-08-01

    We investigated the shock initiation of energetic materials with a tabletop apparatus that uses km s-1 laser-driven flyer plates to initiate tiny explosive charges and obtains complete temperature histories with a high dynamic range. By comparing various microstructured formulations, including a pentaerythritol tetranitrate (PETN) based plastic explosive (PBX) denoted XTX-8003, we determined that micron-scale pores were needed to create high hot spot temperatures. In charges where micropores (i.e., micron-sized pores) were present, a hot spot temperature of 6000 K was observed; when the micropores were pre-compressed to nm scale, however, the hot spot temperature dropped to ˜4000 K. By comparing XTX-8003 with an analog that replaced PETN by nonvolatile silica, we showed that the high temperatures require gas in the pores, that the high temperatures were created by adiabatic gas compression, and that the temperatures observed can be controlled by the choice of ambient gases. The hot spots persist in shock-compressed PBXs even in vacuum because the initially empty pores became filled with gas created in-situ by shock-induced chemical decomposition.

  20. Long life coolant pump technology

    NASA Technical Reports Server (NTRS)

    1976-01-01

    Design concepts were investigated to improve space system coolant pump technology to be suitable for mission durations of two years and greater. These design concepts included an improved bearing system for the pump rotating elements, consisting of pressurized conical bearings. This design was satisfactorily endurance tested as was a new prototype pump built using various other improved design concepts. Based upon an overall assessment of the results of the program it is concluded that reliable coolant pumps can be designed for three year space missions.

  1. Knock-limited performance of several internal coolants

    NASA Technical Reports Server (NTRS)

    Bellman, Donald R; Evvard, John C

    1945-01-01

    The effect of internal cooling on the knock-limited performance of an-f-28 fuel was investigated in a CFR engine, and the following internal coolants were used: (1) water, (2), methyl alcohol-water mixture, (3) ammonia-methyl alcohol-water mixture, (4) monomethylamine-water mixture, (5) dimethylamine-water mixture, and (6) trimethylamine-water mixture. Tests were run at inlet-air temperatures of 150 degrees and 250 degrees F. to indicate the temperature sensitivity of the internal-coolant solutions.

  2. Evaluation of engine coolants under flow boiling conditions

    SciTech Connect

    McAssey, E.V. Jr.; Stinson, C.; Gollin, M.

    1995-12-31

    An experimental program has been conducted to evaluate the heat transfer performance of two engine coolant mixtures, propylene-glycol/water and ethylene-glycol/water. In each mixture, the concentration was 50-50 by volume. Performance in this situation is defined as the ability to maintain a lower surface temperature for a given flux. The heat transfer regimes considered covered the range from single phase forced convection through saturated flow boiling. Results show that both coolants perform satisfactorily. However, in single phase convection, ethylene-glycol/water is slightly more effective. Conversely, for sub-cooled nucleate boiling and saturated boiling, propylene-glycol/water results in slightly lower metal temperatures.

  3. COOLANT STABILIZED WITH KETONE

    DOEpatents

    Burr, J.G.; Strong, J.D.

    1961-11-21

    sion). U. S. Patent 3,009.88l. Nov. 2l, l06l. A method is given for inhibiting radiolytic damage to a polyphenyl composition undergoing nuclear irradiation, the polyphenyl composition initially consisting essentially of polyphenyls having 2 to 4 phenyl rings. The method comprises adding approximately 5 mole% anthraquinone to the polyphenyl composition. (AEC)

  4. Initial-temperature profiles on the PDX inner toroidal limiter

    SciTech Connect

    Ulrickson, M.; Kugel, H.W.

    1983-09-01

    The temperature profiles resulting from plasma operation on the PDX vertical, large area, inner toroidal limiter have been measured during both ohmic and neutral-beam-heated discharges using a scanning infrared camera. An asymmetric double-peaked temperature profile is seen after neutral-beam-heated discharges. Disruptions in ohmically heated discharges are found to be preceded by a single-peaked deposition and succeeded by an initially symmetric double-peaked deposition. The results were compared with the Schmidt model for scrape-off at a toroidal limiter and it was found that the measured double-peaked temperature profiles yielded scrape-off lengths consistent with previous measurements.

  5. Vertical reactor coolant pump instabilities

    NASA Technical Reports Server (NTRS)

    Jones, R. M.

    1985-01-01

    The investigation conducted at the Tennessee Valley Authority's Sequoyah Nuclear Power Plant to determine and correct increasing vibrations in the vertical reactor coolant pumps is described. Diagnostic procedures to determine the vibration causes and evaluate the corrective measures taken are also described.

  6. Effects of mine strata thermal behavior and mine initial temperatures on mobile refuge alternative temperature

    PubMed Central

    Yantek, D.S.; Yan, L.; Bissert, P.T.; Klein, M.D.

    2017-01-01

    Federal regulations require the installation of refuge alternatives (RAs) in underground coal mines. Mobile RAs have a limited ability to dissipate heat, and heat buildup can lead to a life-threatening condition as the RA internal air temperature and relative humidity increase. The U.S. National Institute for Occupational Safety and Health (NIOSH) performed heat testing on a 10-person tent-type training RA and contracted ThermoAnalytics Inc. to develop a validated thermal simulation model of the tested RA. The model was used to examine the effects of the constant mine strata temperature assumption, initial mine air temperature, initial mine strata surface temperature (MSST), initial mine strata temperature at depth (MSTD) and mine strata thermal behavior on RA internal air temperature using 117 W (400 Btu/h) of sensible heat input per simulated miner. For the studied RA, when the mine strata temperature was treated as a constant, the final predicted RA internal air temperature was 7.1°C (12.8°F) lower than it was when the mine strata thermal behavior was included in the model. A 5.6°C (10.0°F) increase in the initial MSST resulted in a 3.9°C (7.1°F) increase in the final RA internal air temperature, whereas a 5.6°C (10°F) increase in the initial MSTD yielded a 1.4°C (2.5°F) increase in the final RA internal air temperature. The results indicate that mine strata temperature increases and mine strata initial temperatures must be accounted for in the physical testing or thermal simulations of RAs. PMID:28867830

  7. A method for measuring cooling air flow in base coolant passages of rotating turbine blades

    NASA Technical Reports Server (NTRS)

    Liebert, C. H.; Pollack, F. G.

    1975-01-01

    Method accurately determines actual coolant mass flow rate in cooling passages of rotating turbine blades. Total and static pressures are measured in blade base coolant passages. Mass flow rates are calculated from these measurements of pressure, measured temperature and known area.

  8. Full reactor coolant system chemical decontamination qualification programs

    SciTech Connect

    Miller, P.E.

    1995-03-01

    Corrosion and wear products are found throughout the reactor coolant system (RCS), or primary loop, of a PWR power plant. These products circulate with the primary coolant through the reactor where they may become activated. An oxide layer including these activated products forms on the surfaces of the RCS (including the fuel elements). The amount of radioactivity deposited on the different surface varies and depends primarily on the corrosion rate of the materials concerned, the amount of cobalt in the coolant and the chemistry of the coolant. The oxide layer, commonly called crud, on the surfaces of nuclear plant systems leads to personnel radiation exposure. The level of the radiation fields from the crud increases with time from initial plant startup and typically levels off after 4 to 6 cycles of plant operation. Thereafter, significant personnel radiation exposure may be incurred whenever major maintenance is performed. Personnel exposure is highest during refueling outages when routine maintenance on major plant components, such as steam generators and reactor coolant pumps, is performed. Administrative controls are established at nuclear plants to minimize the exposure incurred by an individual and the plant workers as a whole.

  9. Data center coolant switch

    DOEpatents

    Iyengar, Madhusudan K.; Parida, Pritish R.; Schultz, Mark D.

    2015-10-06

    A data center cooling system is operated in a first mode; it has an indoor portion wherein heat is absorbed from components in the data center, and an outdoor heat exchanger portion wherein outside air is used to cool a first heat transfer fluid (e.g., water) present in at least the outdoor heat exchanger portion of the cooling system during the first mode. The first heat transfer fluid is a relatively high performance heat transfer fluid (as compared to the second fluid), and has a first heat transfer fluid freezing point. A determination is made that an appropriate time has been reached to switch from the first mode to a second mode. Based on this determination, the outdoor heat exchanger portion of the data cooling system is switched to a second heat transfer fluid, which is a relatively low performance heat transfer fluid, as compared to the first heat transfer fluid. It has a second heat transfer fluid freezing point lower than the first heat transfer fluid freezing point, and the second heat transfer fluid freezing point is sufficiently low to operate without freezing when the outdoor air temperature drops below a first predetermined relationship with the first heat transfer fluid freezing point.

  10. Fracture mechanics evaluation for at typical PWR primary coolant pipe

    SciTech Connect

    Tanaka, T.; Shimizu, S.; Ogata, Y.

    1997-04-01

    For the primary coolant piping of PWRs in Japan, cast duplex stainless steel which is excellent in terms of strength, corrosion resistance, and weldability has conventionally been used. The cast duplex stainless steel contains the ferrite phase in the austenite matrix and thermal aging after long term service is known to change its material characteristics. It is considered appropriate to apply the methodology of elastic plastic fracture mechanics for an evaluation of the integrity of the primary coolant piping after thermal aging. Therefore we evaluated the integrity of the primary coolant piping for an initial PWR plant in Japan by means of elastic plastic fracture mechanics. The evaluation results show that the crack will not grow into an unstable fracture and the integrity of the piping will be secured, even when such through wall crack length is assumed to equal the fatigue crack growth length for a service period of up to 60 years.

  11. Analysis of automobile radiator performance with ethylene glycol/water and propylene glycol/water coolants

    SciTech Connect

    Gollin, M.; Bjork, D.

    1996-12-31

    The heat transfer and hydraulic performance of the following coolants was examined in five automobile radiators in a wind tunnel: 100% water; 100% propylene glycol; 70/30 propylene glycol/water (volume); 50/50 propylene glycol/water (volume); 70/30 ethylene glycol/water (volume); 50/50 ethylene glycol water (volume). The results of these studies are presented to demonstrate the relative performance of these coolant mixtures in terms of heat transfer, coolant pressure drop and radiator effectiveness for a range of coolant and air flowrates. It is concluded that the most effective of the coolants in transferring heat in the test radiators was water, followed by 50/50 ethylene glycol/water, 50/50 propylene glycol/water, 70/30 ethylene glycol/water, 70/30 propylene glycol and, finally, 100% propylene glycol. There will be a negligible differences between the performance of a radiator using a 50/50 propylene glycol/water coolant and a 50/50 ethylene glycol/water coolant. It is estimated that, with 50/50 propylene glycol coolant replacing 50/50 ethylene glycol/water, the temperature of the coolant throughout the cooling loop will increase by approximately 5%. The effect that the flow regime (fully turbulent/transition/laminar) has upon the performance of a given radiator/coolant combination was found to be significant. The design of the coolant passages in radiators can affect the onset of fully turbulent flow in the coolant passages in a radiator.

  12. Effects of the reactor-coolant pumps during a small-break loss-of-coolant accident

    SciTech Connect

    Elliott, J.L.

    1983-01-01

    TRAC-PD2 calculations indicate that more coolant mass remains in the system when the reactor coolant pumps are left in operation following a small cold-leg break. The analyses were performed for a Westinghouse plant (Zion-1) to help determine whether to trip the pumps at high-pressure injection initiation (the present operator directive), to trip the pumps at some later time in the transient, or to leave the pumps running indefinitely. The loop seals' behavior and the system refill characteristics primarily determined the results. 9 figures.

  13. Experimental Investigation of Heat Transfer Characteristics of Automobile Radiator using TiO2-Nanofluid Coolant

    NASA Astrophysics Data System (ADS)

    Salamon, V.; Senthil kumar, D.; Thirumalini, S.

    2017-08-01

    The use of nanoparticle dispersed coolants in automobile radiators improves the heat transfer rate and facilitates overall reduction in size of the radiators. In this study, the heat transfer characteristics of water/propylene glycol based TiO2 nanofluid was analyzed experimentally and compared with pure water and water/propylene glycol mixture. Two different concentrations of nanofluids were prepared by adding 0.1 vol. % and 0.3 vol. % of TiO2 nanoparticles into water/propylene glycol mixture (70:30). The experiments were conducted by varying the coolant flow rate between 3 to 6 lit/min for various coolant temperatures (50°C, 60°C, 70°C, and 80°C) to understand the effect of coolant flow rate on heat transfer. The results showed that the Nusselt number of the nanofluid coolant increases with increase in flow rate. At low inlet coolant temperature the water/propylene glycol mixture showed higher heat transfer rate when compared with nanofluid coolant. However at higher operating temperature and higher coolant flow rate, 0.3 vol. % of TiO2 nanofluid enhances the heat transfer rate by 8.5% when compared to base fluids.

  14. Coolant passage heat transfer with rotation

    NASA Technical Reports Server (NTRS)

    Rohde, J. E.

    1982-01-01

    Although the effects of the coriolis and buoyancy forces due to rotation on coolant-side heat transfer are generally not included in the design methods for blades, the influence of these forces could be large. Comparisons of nonrotating heat transfer data and extrapolations of available correlation for the average heat transfer coefficients with radial outflow of cooling air showed that neglecting rotation at gas turbine engine conditions result in variations in the heat transfer coefficient by as much as 45 percent. This, in effect, results in blade metal temperatures running as much as 100 F different from predicted values. This also may explain why rotating blade metal temperatures in engine tests are often higher than expected from results obtained in nonrotating cascade tests.

  15. Transpiration cooling using air as a coolant

    SciTech Connect

    Kikkawa, Shinzo; Senda, Mamoru; Sakagushi, Katsuji; Shibutani, Hideki )

    1993-02-01

    Transpiration cooling is one of the most effective techniques for protecting a surface exposed to a high-temperature gas stream. In the present paper, the transpiration cooling effectiveness was measured under steady state. Air as a coolant was transpired from the surface of a porous plate exposed to hot gas stream, and the transpiration rate was varied in the range of 0.001 [approximately] 0.006. The transpiration cooling effectiveness was evaluated by measuring the temperature of the upper surface of the plate. Also, a theoretical study was performed and it was clarified that the effectiveness increases with increasing transpiration rate and heat-transfer coefficient of the upper surface. Further, the effectiveness was expressed as a function of the blowing parameter only. The agreement between the experimental results and theoretical ones was satisfactory.

  16. Vapor pressures of mixtures of CFC-114 with the potential replacement coolants C{sub 4}F{sub 10} and c-C{sub 4}F{sub 8}

    SciTech Connect

    Trowbridge, L.D.; Otey, M.G.

    1994-09-01

    The U.S. Enrichment Corporation`s production of isotopically enriched uranium depends solely on two plants which utilize the gaseous diffusion process. This process uses large quantities of CFC-114 as an evaporative coolant. CFC-114, however, will be phased out of production at the end of 1995 due to its potential to deplete stratospheric ozone. A search has been underway for substitutes for a number of years. The initial search (1988-89) for an ozone-friendly, commercially available, chemically compatible substitute yielded two candidates, FC-c318 (c-C{sub 4}F{sub 8}) and FC-3110 (C{sub 4}F{sub 10}). The intended mode of replacing coolant was to stage the new coolant into independent subsystems of the plants, so that some systems would continue to operate on CFC-114, and an increasing number would operate on the new coolant. During that changeover process, the possibility of coolant mixing arises in variety of scenarios. This work was intended to generate sufficient experimental information to be able to predict the vapor pressure of coolant mixtures over the range of operating conditions likely to be found in the diffusion plants. Specifically, vapor pressures were measured over the temperature range 322 to 355 K (120{degrees}F to 180{degrees}F) and over the full range of mole fractions for binary mixtures of CFC-114 with FC-3110, and of CFC-114 with FC-c318.

  17. The international surface temperature initiative's global land surface databank

    NASA Astrophysics Data System (ADS)

    Lawrimore, J. H.; Rennie, J.; Gambi de Almeida, W.; Christy, J.; Flannery, M.; Gleason, B.; Klein-Tank, A.; Mhanda, A.; Ishihara, K.; Lister, D.; Menne, M. J.; Razuvaev, V.; Renom, M.; Rusticucci, M.; Tandy, J.; Thorne, P. W.; Worley, S.

    2013-09-01

    The International Surface Temperature Initiative (ISTI) consists of an end-to-end process for land surface air temperature analyses. The foundation is the establishment of a global land surface Databank. This builds upon the groundbreaking efforts of scientists in the 1980s and 1990s. While using many of their principles, a primary aim is to improve aspects including data provenance, version control, openness and transparency, temporal and spatial coverage, and improved methods for merging disparate sources. The initial focus is on daily and monthly timescales. A Databank Working Group is focused on establishing Stage-0 (original observation forms) through Stage-3 data (merged dataset without quality control). More than 35 sources of data have already been added and efforts have now turned to development of the initial version of the merged dataset. Methods have been established for ensuring to the extent possible the provenance of all data from the point of observation through all intermediate steps to final archive and access. Databank submission procedures were designed to make the process of contributing data as easy as possible. All data are provided openly and without charge. We encourage the use of these data and feedback from interested users.

  18. Temperature induced smoothing of initially fractal grain boundaries

    SciTech Connect

    Streitenberger, P.; Foerster, D.; Kolbe, G.; Veit, P.

    1996-01-01

    Recently the effect of serrated or rugged grain boundaries on the mechanical properties of alloys and the numerical characterization of such a geometrically irregular microstructure by means of the concept of fractal geometry has attracted great attention. It has been reported that the generation of serrated or rugged grain boundaries, e.g. by cold work or heat treatment, is one of the most effective methods to improve the high-temperature strength of alloys, especially the creep rupture properties. In the present paper, for the first time, measurements of the change in the roughness of initially fractal grain boundaries after annealing are presented. The experimental results are discussed on the basis of a coarsening model for self-similar interfaces, which predicts a dependency of the smoothing kinetics of the grain boundaries on their initially fractal dimension.

  19. YNPS main coolant system decontamination

    SciTech Connect

    Metcalf, E.T.

    1996-12-31

    The Yankee Nuclear Power Station (YNPS) located in Rowe, Massachusetts, is a four-loop pressurized water reactor that permanently ceased power operation on February 26, 1992. Decommissioning activities, including steam generator removal, reactor internals removal, and system dismantlement, have been in progress since the shutdown. One of the most significant challenges for YNPS in 1996 was the performance of the main coolant system chemical decontamination. This paper describes the objectives, challenges, and achievements involved in the planning and implementation of the chemical decontamination.

  20. INHIBITING THE POLYMERIZATION OF NUCLEAR COOLANTS

    DOEpatents

    Colichman, E.L.

    1959-10-20

    >The formation of new reactor coolants which contain an additive tbat suppresses polymerization of the primary dissoclation free radical products of the pyrolytic and radiation decomposition of the organic coolants is described. The coolants consist of polyphenyls and condensed ring compounds having from two to about four carbon rings and from 0.1 to 5% of a powdered metal hydride chosen from the group consisting of the group IIA and IVA dispersed in the hydrocarbon.

  1. Analysis of Coolant Options for Advanced Metal Cooled Nuclear Reactors

    DTIC Science & Technology

    2006-12-01

    Nuclear Data File/B-Version V FENDL Fusion Evaluated Nuclear Data Library HLMC Heavy Liquid Metal Coolant LBE Lead-Bismuth Eutectic LMFBR ...According to a Generation IV Nuclear Energy Systems report29 released February 21, 2006, the core outlet temperature and peak cladding temperature...24 sodium for Liquid Metal Fast Breeder Reactor ( LMFBR ) systems worldwide.32 The pumping power requirements for lead, LBE and tin are much

  2. Engine coolant compatibility with the nonmetals found in automotive cooling systems

    SciTech Connect

    Greaney, J.P.; Smith, R.A.

    1999-08-01

    High temperature, short term immersion testing was used to determine the impact of propylene and ethylene glycol base coolants on the physical properties of a variety of elastomeric and thermoplastic materials found in automotive cooling systems. The materials tested are typically used in cooling system hoses, radiator end tanks, and water pump seals. Traditional phosphate or borate-buffered silicated coolants as well as extended-life organic acid formulations were included. A modified ASTM protocol was used to carry out the testing both in the laboratory and at an independent testing facility. Post-test fluid chemistry including an analysis of any solids which may have formed is also reported. Coolant impact on elastomer integrity as well as elastomer-induced changes in fluid chemistry were found to be independent of the coolant`s glycol base.

  3. Cleaning of aluminum after machining with coolants

    SciTech Connect

    Roop, B.

    1995-07-01

    An x-ray photoemission spectroscopic study was undertaken to compare the cleaning of the Advanced Photon Source (APS) aluminum extrusion storage ring vacuum chambers after machining with and without water soluble coolants. While there was significant contamination left by the coolants, the cleaning process was capable of removing the residue. The variation of the surface and near surface composition of samples machined either dry or with coolants was negligible after cleaning. The use of such coolants in the machining process is therefore recommended.

  4. Design and fabrication of magnetic coolant filter

    NASA Astrophysics Data System (ADS)

    Prashanth, B. N.

    2017-07-01

    Now a day's use of coolants in industry has become dominant because of high production demands. Coolants not only help in speeding up the production but also provide many advantages in the metal working operation. As the consumption of coolants is very high a system is badly in need, so as to recirculate the used coolant. Also the amount of hazardous waste generated by industrial plants has become an increasingly costly problem for the manufactures and an additional stress on the environment. Since the purchase and disposal of the spent cutting fluids is becoming increasingly expensive, fluid recycling is a viable option for minimizing the cost. Separation of metallic chips from the coolants by using magnetic coolant separation has proven a good management and maintenance of the cutting fluid. By removing the metallic chips, the coolant life is greatly extended, increases the machining quality and reduces downtime. Above being the case, a magnetic coolant filter is developed which utilizes high energy permanent magnets to develop a dense magnetic field along a narrow flow path into which the contaminated coolant is directed. The ferromagnetic particles captured and aligned by the dense magnetic field, from the efficient filter medium. This enables the unit to remove ferromagnetic particles from the coolant. Magnetic coolant filters use the principle of magnetic separation to purify the used coolant. The developed magnetic coolant separation has the capability of purifying 40 litres per minute of coolant with the size of the contaminants ranging from 1 µm to 30 µm. The filter will be helpful in saving the production cost as the cost associated with the proposed design is well justified by the cost savings in production. The magnetic field produced by permanent magnets will be throughout the area underneath the reservoir. This produces magnetic field 30mm above the coolant reservoir. Very fine particles are arrested without slip. The magnetic material used will not

  5. Corrosion of structural materials by lead-based reactor coolants.

    SciTech Connect

    Abraham, D. P.; Leibowitz, L.; Maroni, V. A.; McDeavitt, S. M.; Raraz, A. G.

    2000-11-16

    Advanced nuclear reactor design has, in recent years, focused increasingly on the use of heavy-liquid-metal coolants, such as lead and lead-bismuth eutectic. Similarly, programs on accelerator-based transmutation systems have also considered the use of such coolants. Russian experience with heavy-metal coolants for nuclear reactors has lent credence to the validity of this approach. Of significant concern is the compatibility of structural materials with these coolants. We have used a thermal convection-based test method to allow exposure of candidate materials to molten lead and lead-bismuth flowing under a temperature gradient. The gradient was deemed essential in evaluating the behavior of the test materials in that should preferential dissolution of components of the test material occur we would expect dissolution in the hotter regions and deposition in the colder regions, thus promoting material transport. Results from the interactions of a Si-rich mild steel alloy, AISI S5, and a ferritic-martensitic stainless steel, HT-9, with the molten lead-bismuth are presented.

  6. The initial, thermal oxidation of zirconium at room temperature

    NASA Astrophysics Data System (ADS)

    Lyapin, A.; Jeurgens, L. P. H.; Graat, P. C. J.; Mittemeijer, E. J.

    2004-12-01

    Angle-resolved x-ray photoelectron spectroscopy (ARXPS) and in situ spectroscopic ellipsometry have been used to investigate the initial oxidation of polycrystalline zirconium at room temperature in the partial oxygen pressure range of 1.3×10-7-1.3×10-4Pa. Detailed quantitative analysis of the measured Zr3d ARXPS spectra of the oxidized metal allowed separation of the intrinsic and extrinsic metallic and oxidic contributions to the spectra. It was shown that, in addition to the metallic contribution from the substrate and the oxidic contribution from stoichiometric ZrO2, two additional suboxidic components are contained in the measured Zr3d spectra of the oxidized Zr metal. As evidenced by angle-resolved XPS and in situ ellipsometry, both of these components can be attributed to a gradient of Zr enrichment in the region of the oxide film adjacent to the metal/oxide interface (with the highest Zr enrichment at the metal/oxide interface). Investigation of the oxide-film growth kinetics at various pO2, as determined independently using both techniques, showed the occurrence of an initial regime of very fast, electric-field-controlled growth, followed by a much slower oxidation stage. As a result, an, on average, nonstoichiometric oxide film develops. The observed effect of the pO2 on the low-temperature oxidation of Zr has been discussed in terms of the relationship between the fraction of coverage of the surface with physi- and chemisorbed oxygen and the applied pO2.

  7. 40 CFR 1065.745 - Coolants.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 34 2013-07-01 2013-07-01 false Coolants. 1065.745 Section 1065.745 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS ENGINE-TESTING PROCEDURES Engine Fluids, Test Fuels, Analytical Gases and Other Calibration Standards § 1065.745 Coolants...

  8. Cleaning of uranium vs machine coolant formulations

    SciTech Connect

    Cristy, S.S.; Byrd, V.R.; Simandl, R.F.

    1984-10-01

    This study compares methods for cleaning uranium chips and the residues left on chips from alternate machine coolants based on propylene glycol-water mixtures with either borax, ammonium tetraborate, or triethanolamine tetraborate added as a nuclear poison. Residues left on uranium surfaces machined with perchloroethylene-mineral oil coolant and on surfaces machined with the borax-containing alternate coolant were also compared. In comparing machined surfaces, greater chlorine contamination was found on the surface of the perchloroethylene-mineral oil machined surfaces, but slightly greater oxidation was found on the surfaces machined with the alternate borax-containing coolant. Overall, the differences were small and a change to the alternate coolant does not appear to constitute a significant threat to the integrity of machined uranium parts.

  9. Numerical simulation of PWR response to a small break LOCA (loss-of-coolant accident) with reactor coolant pumps operating

    SciTech Connect

    Adams, J.P.; Dobbe, C.A.; Bayless, P.D.

    1986-01-01

    Calculations have been made of the response of pressurized water reactors (PWRs) during a small-break, loss-of-coolant accident with the reactor coolant pumps (RCPs) operating. This study was conducted, as part of a comprehensive project, to assess the relationship between measurable RCP parameters, such as motor power or current, and fluid density, both local (at the RCP inlet) and global (average reactor coolant system). Additionally, the efficacy of using these RCP parameters, together with fluid temperature, to identify an off-nominal transient as either a LOCA, a heatup transient, or a cooldown transient and to follow recovery from the transient was assessed. The RELAP4 and RELAP5 computer codes were used with three independent sets of RCP, two-phase degradation multipliers. These multipliers were based on data obtained in two-phase flow conditions for the Semiscale, LOFT, and Creare/Combustion Engineering (CE)/Electric Power Research Institute (EPRI) pumps, respectively. Two reference PWRs were used in this study: Zion, a four-loop, 1100-MWe, Westinghouse plant operated by Commonwealth Edison Co. in Zion, Illinois and Bellefonte, a two-by-four loop, 1213 MWe, Babcock and Wilcox designed plant being built by the Tennessee Valley Authority in Scottsboro, Alabama. The results from this study showed that RCP operation resulted in an approximately homogeneous reactor coolant system and that this result was independent of reference plant, computer code, or two-phase RCP head degradation multiplier used in the calculation.

  10. Solar receiver protection means and method for loss of coolant flow

    DOEpatents

    Glasgow, L.E.

    1980-11-24

    An apparatus and method are disclosed for preventing a solar receiver utilizing a flowing coolant liquid for removing heat energy therefrom from overheating after a loss of coolant flow. Solar energy is directed to the solar receiver by a plurality of reflectors which rotate so that they direct solar energy to the receiver as the earth rotates. The apparatus disclosed includes a first storage tank for containing a first predetermined volume of the coolant and a first predetermined volume of gas at a first predetermined pressure. The first storage tank includes an inlet and outlet through which the coolant can enter and exit. The apparatus also includes a second storage tank for containing a second predetermined volume of the coolant and a second predetermined volume of the gas at a second predetermined pressure, the second storage tank having an inlet through which the coolant can enter. The first and second storage tanks are in fluid communication with each other through the solar receiver. The first and second predetermined coolant volumes, the first and second gas volumes, and the first and second predetermined pressures are chosen so that a predetermined volume of the coolant liquid at a predetermined rate profile will flow from the first storage tank through the solar receiver and into the second storage tank. Thus, in the event of a power failure so that coolant flow ceases and the solar reflectors stop rotating, a flow rate maintained by the pressure differential between the first and second storage tanks will be sufficient to maintain the coolant in the receiver below a predetermined upper temperature until the solar reflectors become defocused with respect to the solar receiver due to the earth's rotation.

  11. Solar receiver protection means and method for loss of coolant flow

    DOEpatents

    Glasgow, Lyle E.

    1983-01-01

    An apparatus and method for preventing a solar receiver (12) utilizing a flowing coolant liquid for removing heat energy therefrom from overheating after a loss of coolant flow. Solar energy is directed to the solar receiver (12) by a plurality of reflectors (16) which rotate so that they direct solar energy to the receiver (12) as the earth rotates. The apparatus disclosed includes a first storage tank (30) for containing a first predetermined volume of the coolant and a first predetermined volume of gas at a first predetermined pressure. The first storage tank (30) includes an inlet and outlet through which the coolant can enter and exit. The apparatus also includes a second storage tank (34) for containing a second predetermined volume of the coolant and a second predetermined volume of the gas at a second predetermined pressure, the second storage tank (34) having an inlet through which the coolant can enter. The first and second storage tanks (30) and (34) are in fluid communication with each other through the solar receiver (12). The first and second predetermined coolant volumes, the first and second gas volumes, and the first and second predetermined pressures are chosen so that a predetermined volume of the coolant liquid at a predetermined rate profile will flow from the first storage tank (30) through the solar receiver (12) and into the second storage tank (34). Thus, in the event of a power failure so that coolant flow ceases and the solar reflectors (16) stop rotating, a flow rate maintained by the pressure differential between the first and second storage tanks (30) and (34) will be sufficient to maintain the coolant in the receiver (12) below a predetermined upper temperature until the solar reflectors (16) become defocused with respect to the solar receiver (12) due to the earth's rotation.

  12. Coolant Design System for Liquid Propellant Aerospike Engines

    NASA Astrophysics Data System (ADS)

    McConnell, Miranda; Branam, Richard

    2015-11-01

    Liquid propellant rocket engines burn at incredibly high temperatures making it difficult to design an effective coolant system. These particular engines prove to be extremely useful by powering the rocket with a variable thrust that is ideal for space travel. When combined with aerospike engine nozzles, which provide maximum thrust efficiency, this class of rockets offers a promising future for rocketry. In order to troubleshoot the problems that high combustion chamber temperatures pose, this research took a computational approach to heat analysis. Chambers milled into the combustion chamber walls, lined by a copper cover, were tested for their efficiency in cooling the hot copper wall. Various aspect ratios and coolants were explored for the maximum wall temperature by developing our own MATLAB code. The code uses a nodal temperature analysis with conduction and convection equations and assumes no internal heat generation. This heat transfer research will show oxygen is a better coolant than water, and higher aspect ratios are less efficient at cooling. This project funded by NSF REU Grant 1358991.

  13. Analysis of coolant entrance boundary shape of porous region to control cooling along exit boundary

    NASA Technical Reports Server (NTRS)

    Siegel, R.; Snyder, A.

    1983-01-01

    A cooled porous region has a plane surface exposed to a specified spatially varying heat flux. The coolant leaves the region through this surface, and it is desired to control the flow distribution to maintain a specified uniform surface temperature. This is accomplished by having the coolant entrance surface shaped to provide in the region the necessary variation of path length and, hence, flow resistance. The surface shape at the coolant entrance is found by solving a Cauchy boundary value problem. An exact solution is obtained that will deal with a wide variety of heating distributions for both two- and three-dimensional shapes.

  14. Thermal stratification potential in rocket engine coolant channels

    NASA Technical Reports Server (NTRS)

    Kacynski, Kenneth J.

    1992-01-01

    The potential for rocket engine coolant channel flow stratification was computationally studied. A conjugate, 3-D, conduction/advection analysis code (SINDA/FLUINT) was used. Core fluid temperatures were predicted to vary by over 360 K across the coolant channel, at the throat section, indicating that the conventional assumption of a fully mixed fluid may be extremely inaccurate. Because of the thermal stratification of the fluid, the walls exposed to the rocket engine exhaust gases will be hotter than an assumption of full mixing would imply. In this analysis, wall temperatures were 160 K hotter in the turbulent mixing case than in the full mixing case. The discrepancy between the full mixing and turbulent mixing analyses increased with increasing heat transfer. Both analysis methods predicted identical channel resistances at the coolant inlet, but in the stratified analysis the thermal resistance was negligible. The implications are significant. Neglect of thermal stratification could lead to underpredictions in nozzle wall temperatures. Even worse, testing at subscale conditions may be inadequate for modeling conditions that would exist in a full scale engine.

  15. Emergence of a Detonation due to an Initial Temperature Gradient

    NASA Astrophysics Data System (ADS)

    Hawa, Takumi; Schwendeman, Donald; Kapila, Ashwani

    2000-11-01

    Emergence of a detonation in a homogeneous, exothermically reacting medium can be deemed to occur in two phases. The first phase processes the medium so as to create conditions ripe for the onset of detonation. The actual events leading up to preconditioning may vary from one experiment to the next, but typically, at the end of this stage the medium is hot and in a state of nonuniformity. The second phase consists of the actual formation of the detonation wave via chemico-gasdynamic interactions. This phase is analyzed in detail, for an idealized medium with simple, state-sensitive kinetics and a prescribed initial temperature gradient. Depending upon the size of the gradient, there are two distinct pathways to a ZND detonation. For shallow gradients the event begins with a nearly constant-volume localized explosion, followed by the emergence of a supersonic, shockless reaction wave that decelerates to the CJ speed and then rapidly transforms into the ZND structure. For sharp gradients the localized explosion occurs at nearly constant pressure, and the detonation is then formed as a result of an accelerating reaction wave catching up to a shock. Within the second scenario there are further variations. The manner in which the above processes are affected by flow divergence (cylindrical and spherical symmetric cases) is examined as well. The analysis is based on a combination of asymptotics and finely resolved numerics.

  16. The origin of pressure inhomogeneities at early stages of fuel-coolant interaction and melt fragmentation criteria

    SciTech Connect

    Glaskov, V.V.; Sinkevich, O.A.; Nigmatulin, B.I.

    1997-12-01

    It is proposed the mechanism of melt fragmentation by fuel-coolant interaction (vapor explosion). The criteria of melt surface fragmentation are formulated for cases subcritical and supercritical temperatures of melt-coolant contact surface. These criteria are in agreement with know experimental data about small scale spontaneous and triggered vapor explosions. 8 refs.

  17. Bi-coolant flat plate solar collector

    NASA Astrophysics Data System (ADS)

    Chon, W. Y.; Green, L. L.

    The feasibility study of a flat plate solar collector which heats air and water concurrently or separately was carried out. Air flows above the collector absorber plate, while water flows in tubes soldered or brazed beneath the plate. The collector efficiencies computed for the flow of both air and water are compared with those for the flow of a single coolant. The results show that the bi-coolant collector efficiency computed for the entire year in Buffalo, New York is higher than the single-coolant collector efficiency, although the efficiency of the water collector is higher during the warmer months.

  18. Coolant mass flow equalizer for nuclear fuel

    DOEpatents

    Betten, Paul R.

    1978-01-01

    The coolant mass flow distribution in a liquid metal cooled reactor is enhanced by restricting flow in sub-channels defined in part by the peripheral fuel elements of a fuel assembly. This flow restriction, which results in more coolant flow in interior sub-channels, is achieved through the use of a corrugated liner positioned between the bundle of fuel elements and the inner wall of the fuel assembly coolant duct. The corrugated liner is expandable to accommodate irradiation induced growth of fuel assembly components.

  19. Peculiarities of evolution of shock waves generated by boiling coolant

    NASA Astrophysics Data System (ADS)

    Alekseev, M. V.; Vozhakov, I. S.; Lezhnin, S. I.; Pribaturin, N. A.

    2016-11-01

    Simulation of compression wave generation and evolution at the disk target was performed for the case of explosive-type boiling of coolant; the boiling is initiated by endwall rupture of a high-pressure pipeline. The calculations were performed for shock wave amplitude at different times and modes of pipe rupture. The simulated pressure of a target-reflected shock wave is different from the theoretical value for ideal gas; this discrepancy between simulation and theory becomes lower at higher distances of flow from the nozzle exit. Comparative simulation study was performed for flow of two-phase coolant with account for slip flow effect and for different sizes of droplets. Simulation gave the limiting droplet size when the single-velocity homogeneous flow model is valid, i.e., the slip flow effect is insignificant.

  20. 40 CFR 1065.745 - Coolants.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... without rust inhibitors. (c) For coolants allowed in paragraphs (a) and (b) of this section, you may use rust inhibitors and additives required for lubricity, up to the levels that the additive...

  1. Coolant passage heat transfer with rotation

    NASA Technical Reports Server (NTRS)

    Hajek, T. J.; Higgins, A. W.

    1985-01-01

    The objective is to develop a heat transfer and pressure drop data base, computational fluid dynamic techniques, and correlations for multi-pass rotating coolant passages with and without flow turbulators. The experimental effort is focused on the simulation of configurations and conditions expected in the blades of advanced aircraft high pressure turbines. With the use of this data base, the effects of Coriolis and buoyancy forces on the coolant side flow can be included in the design of turbine blades.

  2. Application of CFX-10 to the Investigation of RPV Coolant Mixing in VVER Reactors

    SciTech Connect

    Moretti, Fabio; Melideo, Daniele; Terzuoli, Fulvio; D'Auria, Francesco

    2006-07-01

    Coolant mixing phenomena occurring in the pressure vessel of a nuclear reactor constitute one of the main objectives of investigation by researchers concerned with nuclear reactor safety. For instance, mixing plays a relevant role in reactivity-induced accidents initiated by de-boration or boron dilution events, followed by transport of a de-borated slug into the vessel of a pressurized water reactor. Another example is constituted by temperature mixing, which may sensitively affect the consequences of a pressurized thermal shock scenario. Predictive analysis of mixing phenomena is strongly improved by the availability of computational tools able to cope with the inherent three-dimensionality of such problem, like system codes with three-dimensional capabilities, and Computational Fluid Dynamics (CFD) codes. The present paper deals with numerical analyses of coolant mixing in the reactor pressure vessel of a VVER-1000 reactor, performed by the ANSYS CFX-10 CFD code. In particular, the 'swirl' effect that has been observed to take place in the downcomer of such kind of reactor has been addressed, with the aim of assessing the capability of the codes to predict that effect, and to understand the reasons for its occurrence. Results have been compared against experimental data from V1000CT-2 Benchmark. Moreover, a boron mixing problem has been investigated, in the hypothesis that a de-borated slug, transported by natural circulation, enters the vessel. Sensitivity analyses have been conducted on some geometrical features, model parameters and boundary conditions. (authors)

  3. Computer code for predicting coolant flow and heat transfer in turbomachinery

    NASA Technical Reports Server (NTRS)

    Meitner, Peter L.

    1990-01-01

    A computer code was developed to analyze any turbomachinery coolant flow path geometry that consist of a single flow passage with a unique inlet and exit. Flow can be bled off for tip-cap impingement cooling, and a flow bypass can be specified in which coolant flow is taken off at one point in the flow channel and reintroduced at a point farther downstream in the same channel. The user may either choose the coolant flow rate or let the program determine the flow rate from specified inlet and exit conditions. The computer code integrates the 1-D momentum and energy equations along a defined flow path and calculates the coolant's flow rate, temperature, pressure, and velocity and the heat transfer coefficients along the passage. The equations account for area change, mass addition or subtraction, pumping, friction, and heat transfer.

  4. Radiative Transfer Modeling of AVHRR Brightness Temperatures for Improved Sea Surface Temperature Retrievals: Initial Results

    NASA Astrophysics Data System (ADS)

    Ignatov, A.; Dash, P.

    2007-05-01

    Operational Sea Surface Temperature (SST) products at NOAA/NESDIS have been derived from the Advanced Very High Resolution Radiometers (AVHRR) onboard NOAA satellites since the early 1980s. The two major SST algorithms, the multi-channel and non-linear SST (MC/NLSST), were initially introduced for the AVHRR in the mid- 1980s and mid-1990s, respectively. Both algorithms are based on solid physical principles but also include some empirical elements (such as for instance treatment of the view angle dependence in the SST equations and tuning their coefficients against in-situ SST), to account for approximations and assumptions in their derivation. The simple MC/NLSST formulations proved to be accurate and robust, and are still in use with the newer sensors, such as the Moderate Resolution Imaging Spectro-Radiometer (MODIS). They are also considered for the future sensors such as the Visible Infrared Imager and Radiometer Suite (VIIRS) onboard NPOESS, and the Advanced Baseline Imager (ABI) onboard GOES-R. Despite the apparent success and good accuracies, improved SST formulations should be explored based on improved and accurate Radiative Transfer Models (RTM). In order to be useful for inverse problem simulation (i.e., SST retrieval), the RTM should be able to adequately reproduce the top-of-the-atmosphere brightness temperatures. In this study, we use MODTRAN 4.2 model, coupled with two surface reflection models (black body and Fresnel), to simulate TOA brightness temperatures in the three thermal infrared AVHRR bands. Atmospheric profiles and SST come from the National Centers for Environmental Prediction (NCEP) Global Data Analysis System (GDAS) data as input, assuming aerosol- and cloud-free conditions. The simulation results are then convoluted with the respective relative spectral response functions of the individual sensors, and compared with collocated TOA brightness temperatures measured from NOAA-16, -17, and -18 satellites during nighttime. Initial results

  5. Effects of coolant volatility on simulated HCDA bubble expansions. Technical report No. 10

    SciTech Connect

    Tobin, R.J.

    1980-09-01

    The effects of coolant volatility on the expansion dynamics and cover loading of hypothetical core disruptive accidents (HCDA) were studied by performing experiments with a transparent 1/30-scale model of a typical demonstration size loop-type liquid metal fast breeder reactor (LMFBR). Freon 113 and Freon 11 were used as coolant simulants of increasing volatility. High-pressure nitrogen gas (1450 psia) or flashing water (1160 psia) were used to simulate the qualitative features of sodium vapor or molten fuel expansions. To validate the use of constant mass and constant geometry experiments as a means of evaluating the effects of coolant volatility, a set of baseline experiments was performed in these configurations with the room temperature nitrogen bubble source. In all the experiments, the expanding HCDA bubbles, the motion of the coolant simulant, and the vessel loads were monitored by pressure transducers, a thermocouple in the bubble, and high-speed photography. Results of the constant mass experiments with the flashing water source show that higher volatility results in higher pressure driving the coolant slug and therefore higher impact loads. The Freon experiments had about 50% higher pressure in the upper core and bubble, a 30% larger slug impact impulse, and 25% greater expansion work done on the coolant slug. The higher pressure in the Freon experiments is believed due to vaporization of some of the Freon that mixes with the hot flashing water in the upper core very early in the expansion. Entrainment of coolant within the bubble and the bubble shape were comparable in the Freon and water experiments. Entrainment at slug impact varied between 20 and 40% of the bubble volume. The presence of internal vessel structures attenuated the slug impact impulse by about 50%, whether the coolant was Freon 113 or water. 79 figures, 23 tables.

  6. Temperature changes in an initially frozen wood chip pile.

    Treesearch

    George R. Sampson; Jenifer H. McBeath

    1987-01-01

    White spruce trees and tops were chipped and placed in a pile near Fairbanks, Alaska, in February 1983. The pile was 6 meters in diameter and 6 meters high in a cylindrical shape. Thermocouples were placed at 25 locations within the pile so that temperatures could be tracked over time. Gypsum blocks were placed at 10 locations to determine changes in moisture content....

  7. TACT1- TRANSIENT THERMAL ANALYSIS OF A COOLED TURBINE BLADE OR VANE EQUIPPED WITH A COOLANT INSERT

    NASA Technical Reports Server (NTRS)

    Gaugler, R. E.

    1994-01-01

    As turbine-engine core operating conditions become more severe, designers must develop more effective means of cooling blades and vanes. In order to design reliable, cooled turbine blades, advanced transient thermal calculation techniques are required. The TACT1 computer program was developed to perform transient and steady-state heat-transfer and coolant-flow analyses for cooled blades, given the outside hot-gas boundary condition, the coolant inlet conditions, the geometry of the blade shell, and the cooling configuration. TACT1 can analyze turbine blades, or vanes, equipped with a central coolant-plenum insert from which coolant-air impinges on the inner surface of the blade shell. Coolant-side heat-transfer coefficients are calculated with the heat transfer mode at each station being user specified as either impingement with crossflow, forced convection channel flow, or forced convection over pin fins. A limited capability to handle film cooling is also available in the program. The TACT1 program solves for the blade temperature distribution using a transient energy equation for each node. The nodal energy balances are linearized, one-dimensional, heat-conduction equations which are applied at the wall-outer-surface node, at the junction of the cladding and the metal node, and at the wall-inner-surface node. At the mid-metal node a linear, three-dimensional, heat-conduction equation is used. Similarly, the coolant pressure distribution is determined by solving the set of transfer momentum equations for the one-dimensional flow between adjacent fluid nodes. In the coolant channel, energy and momentum equations for one-dimensional compressible flow, including friction and heat transfer, are used for the elemental channel length between two coolant nodes. The TACT1 program first obtains a steady-state solution using iterative calculations to obtain convergence of stable temperatures, pressures, coolant-flow split, and overall coolant mass balance. Transient

  8. TACT1- TRANSIENT THERMAL ANALYSIS OF A COOLED TURBINE BLADE OR VANE EQUIPPED WITH A COOLANT INSERT

    NASA Technical Reports Server (NTRS)

    Gaugler, R. E.

    1994-01-01

    As turbine-engine core operating conditions become more severe, designers must develop more effective means of cooling blades and vanes. In order to design reliable, cooled turbine blades, advanced transient thermal calculation techniques are required. The TACT1 computer program was developed to perform transient and steady-state heat-transfer and coolant-flow analyses for cooled blades, given the outside hot-gas boundary condition, the coolant inlet conditions, the geometry of the blade shell, and the cooling configuration. TACT1 can analyze turbine blades, or vanes, equipped with a central coolant-plenum insert from which coolant-air impinges on the inner surface of the blade shell. Coolant-side heat-transfer coefficients are calculated with the heat transfer mode at each station being user specified as either impingement with crossflow, forced convection channel flow, or forced convection over pin fins. A limited capability to handle film cooling is also available in the program. The TACT1 program solves for the blade temperature distribution using a transient energy equation for each node. The nodal energy balances are linearized, one-dimensional, heat-conduction equations which are applied at the wall-outer-surface node, at the junction of the cladding and the metal node, and at the wall-inner-surface node. At the mid-metal node a linear, three-dimensional, heat-conduction equation is used. Similarly, the coolant pressure distribution is determined by solving the set of transfer momentum equations for the one-dimensional flow between adjacent fluid nodes. In the coolant channel, energy and momentum equations for one-dimensional compressible flow, including friction and heat transfer, are used for the elemental channel length between two coolant nodes. The TACT1 program first obtains a steady-state solution using iterative calculations to obtain convergence of stable temperatures, pressures, coolant-flow split, and overall coolant mass balance. Transient

  9. A Case Study Of Applying Infrared Thermography To Identify A Coolant Leak In A Municipal Ice Skating Rink

    NASA Astrophysics Data System (ADS)

    Wallace, Jay R.

    1989-03-01

    This paper deals with the application of infrared imaging radiometry as a diagnostic inspection tool for locating a concealed leak in the refrigeration system supplying glycol coolant to the arena floor of an ice skating rink in a municipal coliseum facility. Scanning approximately 10 miles of black iron tubing embedded in the arena floor resulted in locating a leak within the supply/return side of the system. A secondary disclosure was a restriction to normal coolant flow in some delivery loops caused by sludge build-up. Specific inspection procedures were established to enhance temperature differentials suitable for good thermal imaging. One procedure utilized the temperature and pressure of the city water supply; a second the availability of 130F hot water from the facility's boiler system; and a third the building's own internal ambient temperature. Destructive testing and other data collection equipment confirmed the thermographic findings revealing a section of corrosion damaged pipe. Repair and flushing of the system was quickly completed with a minimum of construction costs and inconvenience. No financial losses were incurred due to the interruption of scheduled revenue events. Probable cause for the shutdown condition was attributed to a flawed installation decision made 15 years earlier during the initial construction stage.

  10. Shock initiation of explosives: Temperature spikes and growth spurts

    NASA Astrophysics Data System (ADS)

    Bassett, Will P.; Dlott, Dana D.

    2016-08-01

    When energetic materials are subjected to high-velocity impacts, the first steps in the shock-to-detonation transition are the creation, ignition, and growth of hot spots. We used 1-3.2 km s-1 laser-launched flyer plates to impact powdered octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine, a powerful explosive, and monitored hundreds of emission bursts with an apparatus that determined temperature and emissivity at all times. The time-dependent volume fraction of hot spots was determined by measuring the time-dependent emissivity. After the shock, most hot spots extinguished, but the survivors smoldered for hundreds of nanoseconds until their temperatures spiked, causing a hot spot growth spurt. Depending on the impact duration, the growth spurts could be as fast as 300 ns and as slow as 13 μs.

  11. Viscosity of alumina nanoparticles dispersed in car engine coolant

    SciTech Connect

    Kole, Madhusree; Dey, T.K.

    2010-09-15

    The present paper, describes our experimental results on the viscosity of the nanofluid prepared by dispersing alumina nanoparticles (<50 nm) in commercial car coolant. The nanofluid prepared with calculated amount of oleic acid (surfactant) was tested to be stable for more than 80 days. The viscosity of the nanofluids is measured both as a function of alumina volume fraction and temperature between 10 and 50 C. While the pure base fluid display Newtonian behavior over the measured temperature, it transforms to a non-Newtonian fluid with addition of a small amount of alumina nanoparticles. Our results show that viscosity of the nanofluid increases with increasing nanoparticle concentration and decreases with increase in temperature. Most of the frequently used classical models severely under predict the measured viscosity. Volume fraction dependence of the nanofluid viscosity, however, is predicted fairly well on the basis of a recently reported theoretical model for nanofluids that takes into account the effect of Brownian motion of nanoparticles in the nanofluid. The temperature dependence of the viscosity of engine coolant based alumina nanofluids obeys the empirical correlation of the type: log ({mu}{sub nf}) = A exp(BT), proposed earlier by Namburu et al. (author)

  12. On-Line Coolant Chemistry Analysis

    SciTech Connect

    LM Bachman

    2006-07-19

    Impurities in the gas coolant of the space nuclear power plant (SNPP) can provide valuable indications of problems in the reactor and an overall view of system health. By monitoring the types and amounts of these impurities, much can be implied regarding the status of the reactor plant. However, a preliminary understanding of the expected impurities is important before evaluating prospective detection and monitoring systems. Currently, a spectroscopy system is judged to hold the greatest promise for monitoring the impurities of interest in the coolant because it minimizes the number of entry and exit points to the plant and provides the ability to detect impurities down to the 1 ppm level.

  13. Coolant monitoring apparatus for nuclear reactors

    DOEpatents

    Tokarz, Richard D.

    1983-01-01

    A system for monitoring coolant conditions within a pressurized vessel. A length of tubing extends outward from the vessel from an open end containing a first line restriction at the location to be monitored. The flowing fluid is cooled and condensed before passing through a second line restriction. Measurement of pressure drop at the second line restriction gives an indication of fluid condition at the first line restriction. Multiple lengths of tubing with open ends at incremental elevations can measure coolant level within the vessel.

  14. Vegetable oils: Liquid coolants for solar heating and cooling applications

    NASA Astrophysics Data System (ADS)

    Ingley, H. A.

    1980-02-01

    Vegetable oils, renewable byproducts of agriculture processes, were investigated for possible use as liquid coolants. Several thermophysical properties of four vegetable oils were investigated. Vapor pressures, specific heat, viscosity, density, and thermal conductivity were determined over a range of temperatures for corn, soybeans, peanut, and cottonseed oil. ASTM standard methods were used for these determinations. In addition, chemical analyses were performed on samples of each oil. The samples were collected before and after each experiment so that any changes in composition could be noted. The tests included iodine number, fatty acid, and moisture content determination.

  15. Reactor coolant pump shaft seal stability during station blackout

    SciTech Connect

    Rhodes, D B; Hill, R C; Wensel, R G

    1987-05-01

    Results are presented from an investigation into the behavior of Reactor Coolant Pump shaft seals during a potential station blackout (loss of all ac power) at a nuclear power plant. The investigation assumes loss of cooling to the seals and focuses on the effect of high temperature on polymer seals located in the shaft seal assemblies, and the identification of parameters having the most influence on overall hydraulic seal performance. Predicted seal failure thresholds are presented for a range of station blackout conditions and shaft seal geometries.

  16. Vegetable oils: liquid coolants for solar heating and cooling applications

    SciTech Connect

    Ingley, H A

    1980-02-01

    It has been proposed that vegetable oils, renewable byproducts of agriculture processes, be investigated for possible use as liquid coolants. The major thrust of the project was to investigate several thermophysical properties of the four vegetable oils selected. Vapor pressures, specific heat, viscosity, density, and thermal conductivity were determined over a range of temperatures for corn, soybean, peanut, and cottonseed oil. ASTM standard methods were used for these determinations. In addition, chemical analyses were performed on samples of each oil. The samples were collected before and after each experiment so that any changes in composition could be noted. The tests included iodine number, fatty acid, and moisture content determination. (MHR)

  17. Emergency cooling analysis for the loss of coolant malfunction

    NASA Technical Reports Server (NTRS)

    Peoples, J. A.

    1972-01-01

    This report examines the dynamic response of a conceptual space power fast-spectrum lithium cooled reactor to the loss of coolant malfunction and several emergency cooling concepts. The results show that, following the loss of primary coolant, the peak temperatures of the center most 73 fuel elements can range from 2556 K to the region of the fuel melting point of 3122 K within 3600 seconds after the start of the accident. Two types of emergency aftercooling concepts were examined: (1) full core open loop cooling and (2) partial core closed loop cooling. The full core open loop concept is a one pass method of supplying lithium to the 247 fuel pins. This method can maintain fuel temperature below the 1611 K transient damage limit but requires a sizable 22,680-kilogram auxiliary lithium supply. The second concept utilizes a redundant internal closed loop to supply lithium to only the central area of each hexagonal fuel array. By using this method and supplying lithium to only the triflute region, fuel temperatures can be held well below the transient damage limit.

  18. 40 CFR 1065.745 - Coolants.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... your engine in use. (b) For laboratory testing of liquid-cooled engines, you may use water with or... 40 Protection of Environment 33 2014-07-01 2014-07-01 false Coolants. 1065.745 Section 1065.745 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS ENGINE-TESTING...

  19. 40 CFR 1065.745 - Coolants.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... your engine in use. (b) For laboratory testing of liquid-cooled engines, you may use water with or... 40 Protection of Environment 34 2012-07-01 2012-07-01 false Coolants. 1065.745 Section 1065.745 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS ENGINE-TESTING...

  20. NGNP Reactor Coolant Chemistry Control Study

    SciTech Connect

    Brian Castle

    2010-11-01

    The main focus of this paper is to identify the most desirable ranges of impurity levels in the primary coolant to optimize component life in the primary circuit of the Next Generation Nuclear Plant (NGNP), which will either be a prismatic block or pebble bed reactor.

  1. Effect of initial temperature on water aggregation at a cold surface.

    PubMed

    Kier, Lemont B; Cheng, Chao-Kun

    2013-01-01

    Cellular automata models of water at two initial temperatures were created. Each model was exposed to a freezing surface. The formation of fully bonded water cells, f(4), was observed over time, beginning with a model of initially warm water and with initially cool water. The warm water formed more f(4) cells earlier than the initially cool water. A high percentage of f(4) cells is interpreted as the formation of ice. This is a model of the Mpemba effect. A description of the initial states for these two temperatures is offered in explanation of this effect. Copyright © 2013 Verlag Helvetica Chimica Acta AG, Zürich.

  2. The initial freezing temperature of foods at high pressure.

    PubMed

    Guignon, B; Torrecilla, J S; Otero, L; Ramos, A M; Molina-García, A D; Sanz, P D

    2008-04-01

    The Pure water (P,T)-phase diagram is known in the form of empirical equations or tables from nearly a century as a result of Bridgman's work. However, few data are available on other aqueous systems probably due to the difficulty of high-pressure measurements. As an alternative, six approaches are presented here to obtain the food phase diagrams in the range of pressure 0.1-210 MPa. Both empirical and theoretical methods are described including the use of an artificial neural network (ANN). Experimental freezing points obtained at the laboratory of the authors and from literature are statistically compared to the calculated ones. About 400 independent freezing data points of aqueous solutions, gels, and foods are analysed. A polynomial equation is the most accurate and simple method to describe the entire melting curve. The ANN is the most versatile model, as only one model allows the calculation of the initial freezing point of all the aqueous systems considered. Robinson and Stokes' equation is successfully extended to the high pressures domain with an average prediction error of 0.4 degrees C. The choice of one approach over the others depends mainly on the availability of experimental data, the accuracy required and the intended use for the calculated data.

  3. Initial Tile Temperature and Heat Flux Measurements in NSTX

    NASA Astrophysics Data System (ADS)

    Maingi, Rajesh; Kugel, Henry; Roquemore, Lane; Lasnier, Charles; Johnson, Dave

    1999-11-01

    Due to their compact nature, spherical tori are projected to experience higher peak heat flux than conventional aspect ratio tokamaks of comparable heating power. For NSTX, it has been predicted[1,2] that the peak heat flux in double-null divertor configuration could reach between 10-15 MW/m2, and single-null operation would result in even higher peak heat flux. To test these predictions and support physics operations, two infrared television cameras (Inframetrics 525) have been installed on NSTX to monitor real-time tile heating and surface heat flux. The data are analyzed in real-time with a frame grabber (IMAXX) and software, and these data are also archived on videotape for future analysis. The first set of measurements will focus on thermal emission from the RF antenna, the center stack, and divertor regions. Initial data and comparison with the earlier predictions will be presented. 1 R.Maingi, et. al., "Estimates of Scrape-Off Layer and Divertor Parameters in NSTX", Proc. 1996 Int’l Workshop on the Spherical Torus, Abingdon, U.K., Dec. 4-6, 1996. 2 R. Maingi, et. al., "2-D Edge Plasma Transport Calculations for NSTX", Proc. 1997 Int’l Workshop on the Spherical Torus, St. Petersburg, Russia, Sept. 3-5, 1997.

  4. Initial development of high-temperature titanium silicide alloys

    SciTech Connect

    Liu, C.T.; Lee, E.H.; Henson, T.J.

    1988-01-01

    Mechanical and metallurgical properties of Ti/sub 5/Si/sub 3/ and its alloys were studied for the purpose of developing high-temperature silicides for structural use. Titanium silicides are extremely hard and brittle. Microcracks that formed transgranularly were observed in the silicide and its alloys, indicating a poor cleavage strength for Ti/sub 5/Si/sub 3/. Microalloying with boron and carbon gave no apparent beneficial effect. The tendency for cracking can be reduced by lowering the silicon content or by alloying with 2 to 4% Cr and 4% Zr. In particular, almost no cracks were observed in the alloy Ti-33Si-4Zr-4Cr (at. %). Titanium silicide has a hardness of 980 dph. The hardness shows a slight increase with zirconium additions and a decrease with chromium additions. Tensile tests indicate that the silicide and its alloys are brittle even at 1000/degree/C. All alloys fractured with a strength less than 100 MPa. Among the silicides tested, the alloys containing 4 to 8% Cr have better fracture strength. The fracture mode of the silicide alloys is mainly transgranular with a cleavage appearance. The silicides showed basically a parabolic oxidation rate at 800/degree/C, with an oxidation rate higher by an order of magnitude than that of nickel aluminides. 10 figs., 5 tabs.

  5. Design criteria for Waste Coolant Processing Facility and preliminary proposal 722 for Waste Coolant Processing Facility

    SciTech Connect

    Not Available

    1991-09-27

    This document contains the design criteria to be used by the architect-engineer (A-E) in the performance of Titles 1 and 2 design for the construction of a facility to treat the biodegradable, water soluble, waste machine coolant generated at the Y-12 plant. The purpose of this facility is to reduce the organic loading of coolants prior to final treatment at the proposed West Tank Farm Treatment Facility.

  6. Review of cladding-coolant interactions during LWR accident transients

    SciTech Connect

    Hobson, D.O.

    1980-01-01

    Some of the coolant-cladding interactions that can take place during the design basis loss-of-coolant accident and the Three Mile Island loss-of-coolant accident are analyzed. The physical manifestations of the interactions are quite similar, but the time sequences involved can cause very different end results. These results are described and a listing is given of the main research programs that are involved in coolant-cladding interaction research.

  7. NMR initiatives on understanding high-temperature superconductivity

    NASA Astrophysics Data System (ADS)

    Kitaoka, Y.; Mukuda, H.; Shimizu, S.; Abe, M.; Iyo, A.; Tanaka, Y.; Kito, H.; Tokiwa, K.; Watanabe, T.

    2007-03-01

    We review a recent progress of NMR studies [H. Mukuda, et al., Phys. Rev. Lett 96 (2006) 087001; S. Shimizu, et al., submitted for publication.] on multi-layered cuprates. This work has shed new light to a generic phase diagram of high-temperature superconductivity (HTSC) which suggests a competition between antiferromagnetism (AFM) and superconductivity (SC). The multi-layered cuprates include two types of CuO2 planes, an outer CuO2 plane (OP) in a pyramidal coordination and an inner CuO2 plane (IP) in a square one with no apical oxygen. Remarkable feature of the multi-layered systems is the presence of ideally flat CuO2 planes that are homogeneously doped. Systematic Cu-NMR studies on the optimally-doped five-layered HgBa2Ca4Cu5O(Hg-1245(OPT)) and slightly overdoped Tl-1245(OVD) have revealed the coexistent phase of SC and AFM in a unit cell [H. Kotegawa, et al., Phys. Rev. B 64 (2001) 064515; H. Kotegawa, et al., Phys. Rev. B 69 (2004) 014501.]. The optimally doped two OPs are predominantly superconducting with Tc=108 and 100 K, whereas the under-doped three IPs show the AFM order below TN=60 and 45 K for Hg-1245(OPT) and Tl-1245(OVD), respectively. Recently exciting is the finding of the uniform mixing of AFM and HTSC in a single CuO2 layer in the under-doped Hg-1245(UD) and the heavily underdoped four-layered Ba2Ca3Cu4O8F2 (0234F(2.0)) that has fluorine ions (F) as apical ions [H. Mukuda, et al., Phys. Rev. Lett 96 (2006) 087001; S. Shimizu, et al., submitted for publication.]. In Hg-1245(UD) with Tc=72 K and TN=290 K, the OPs exhibit the uniform mixing of AFM and HTSC with AFM moment of MAFM(OP)=0.1 μB, whereas the IPs are possibly AFM insulators with a small doping [H. Mukuda, et al., Phys. Rev. Lett 96 (2006) 087001.]. In 0234F(2.0) with Tc=55 K and TN=100 K, the uniform mixing of AFM and HTSC is demonstrated to take place in electron (n)- doped IPs [S. Shimizu, et al., submitted for publication.], thanks to insight from recent ARPES results [Y. Chen, et

  8. Study of coolant activation and dose rates with flow rate and power perturbations in pool-type research reactors

    SciTech Connect

    Mirza, N.M.; Mirza, S.M.; Ahmad, N. )

    1991-12-01

    This paper reports on a computer code using the multigroup diffusion theory based LEOPARD and ODMUG programs that has been developed to calculate the activity in the coolant leaving the core of a pool-type research reactor. Using this code, the dose rates at various locations along the coolant path with varying coolant flow rate and reactor power perturbations are determined. A flow rate decrease from 1000 to 145 m{sup 3}/h is considered. The results indicate that a flow rate decrease leads to an increase in the coolant outlet temperature, which affects the neutron group constants and hence the group fluxes. The activity in the coolant leaving the core increases with flow rate decrease. However, at the inlet of the holdup tank, the total dose rate first increases, then passes through a maximum at {approximately} 500 m{sup 3}/h, and finally decreases with flow rate decrease. The activity at the outlet of the holdup tank is mainly due to {sup 24}Na and {sup 56}Mn, and it increases by {approximately} 2% when the flow rate decreases from 1000 to 145 m{sup 3}/h. In an accidental power rise at constant flow rate, the activity in the coolant increases, and the dose rates at all the points along the coolant path show a slight nonlinear rise as the reactor power density increases.

  9. Use of MODIS Land and Sea Surface Temperatures to Initialize Mesoscale Models

    NASA Technical Reports Server (NTRS)

    Arnold, James E. (Technical Monitor); Lapenta, William M.; Haines, Stephanie; Jedlovec, Gary; Mackaro, Scott

    2003-01-01

    As computer power continues to increase, mesoscale models are initialized at all hours of the day and continue to be run at higher and higher spatial resolutions. As a result, initializing land surface temperature can be problematic. The majority of research-based models are initialized at 00 and 12 UTC when upper air observations and reanalysis fields are available. The landsea surface temperatures are then set equal to the two-meter air temperature produced by the preprocessor analysis system. This particular procedure might be valid in the early morning hours just prior to sunrise, but it becomes less valid during the remainder of the diurnal cycle. Operational models, such as the Rapid Update Cycle run at the National Centers for Environmental Prediction (NCEP), are initialized every hour on a daily basis. This presents a unique challenge to the initial specification of the land temperature, especially during the first several hours of the solar heating cycle when land and overlying air temperatures are far from being the same. Another issue that needs to be addressed is the spatial variability of land surface temperature. By early next year, the NCEP operational Eta model will be employed at 8 km resolution. Methods to accurately specify the initial land surface temperature at such high resolution need to be explored. This paper presents the results of using data from the NASA Moderate Imaging Sensor aboard the TERRA Satellite to initialize land and sea surface temperatures within the Pennsylvania State University/National Center for Atmospheric Research (PSU/NCAR) 5'th generation Mesoscale Model (MM5). We have simulated a northern Gulf Coast sea breeze case to demonstrate the utility of using the MODIS data to initialize both the land and sea surface temperature fields. Model grid configurations of 12-, 4-, and l-km are employed.

  10. Estimation of Surface Heat Flux and Surface Temperature during Inverse Heat Conduction under Varying Spray Parameters and Sample Initial Temperature

    PubMed Central

    Aamir, Muhammad; Liao, Qiang; Zhu, Xun; Aqeel-ur-Rehman; Wang, Hong

    2014-01-01

    An experimental study was carried out to investigate the effects of inlet pressure, sample thickness, initial sample temperature, and temperature sensor location on the surface heat flux, surface temperature, and surface ultrafast cooling rate using stainless steel samples of diameter 27 mm and thickness (mm) 8.5, 13, 17.5, and 22, respectively. Inlet pressure was varied from 0.2 MPa to 1.8 MPa, while sample initial temperature varied from 600°C to 900°C. Beck's sequential function specification method was utilized to estimate surface heat flux and surface temperature. Inlet pressure has a positive effect on surface heat flux (SHF) within a critical value of pressure. Thickness of the sample affects the maximum achieved SHF negatively. Surface heat flux as high as 0.4024 MW/m2 was estimated for a thickness of 8.5 mm. Insulation effects of vapor film become apparent in the sample initial temperature range of 900°C causing reduction in surface heat flux and cooling rate of the sample. A sensor location near to quenched surface is found to be a better choice to visualize the effects of spray parameters on surface heat flux and surface temperature. Cooling rate showed a profound increase for an inlet pressure of 0.8 MPa. PMID:24977219

  11. Estimation of surface heat flux and surface temperature during inverse heat conduction under varying spray parameters and sample initial temperature.

    PubMed

    Aamir, Muhammad; Liao, Qiang; Zhu, Xun; Aqeel-ur-Rehman; Wang, Hong; Zubair, Muhammad

    2014-01-01

    An experimental study was carried out to investigate the effects of inlet pressure, sample thickness, initial sample temperature, and temperature sensor location on the surface heat flux, surface temperature, and surface ultrafast cooling rate using stainless steel samples of diameter 27 mm and thickness (mm) 8.5, 13, 17.5, and 22, respectively. Inlet pressure was varied from 0.2 MPa to 1.8 MPa, while sample initial temperature varied from 600°C to 900°C. Beck's sequential function specification method was utilized to estimate surface heat flux and surface temperature. Inlet pressure has a positive effect on surface heat flux (SHF) within a critical value of pressure. Thickness of the sample affects the maximum achieved SHF negatively. Surface heat flux as high as 0.4024 MW/m(2) was estimated for a thickness of 8.5 mm. Insulation effects of vapor film become apparent in the sample initial temperature range of 900°C causing reduction in surface heat flux and cooling rate of the sample. A sensor location near to quenched surface is found to be a better choice to visualize the effects of spray parameters on surface heat flux and surface temperature. Cooling rate showed a profound increase for an inlet pressure of 0.8 MPa.

  12. Surface Treatment to Improve Corrosion Resistance in Lead-Alloy Coolants

    SciTech Connect

    Todd R. Allen; Kumar Sridharan; McLean T. Machut; Lizhen Tan

    2007-08-29

    One of the six proposed advanced reactor designs of the Generation IV Initiative, the Leadcooled Fast Reactor (LFR) possesses many characteristics that make it a desirable candidate for future nuclear energy production and responsible actinide management. These characteristics include favorable heat transfer, fluid dynamics, and neutronic performance compared to other candidate coolants. However, the use of a heavy liquid metal coolant presents a challenge for reactor designers in regards to reliable structural and fuel cladding materials in both a highly corrosive high temperature liquid metal and an intense radiation fieldi. Flow corrosion studies at the University of Wisconsin have examined the corrosion performance of candidate materials for application in the LFR concept as well as the viability of various surface treatments to improve the materials’ compatibility. To date this research has included several focus areas, which include the formulation of an understanding of corrosion mechanisms and the examination of the effects of chemical and mechanical surface modifications on the materials’ performance in liquid lead-bismuth by experimental testing in Los Alamos National Laboratory’s DELTA Loop, as well as comparison of experimental findings to numerical and physical models for long term corrosion prediction. This report will first review the literature and introduce the experiments and data that will be used to benchmark theoretical calculations. The experimental results will be followed by a brief review of the underlying theory and methodology for the physical and theoretical models. Finally, the results of theoretical calculations as well as experimentally obtained benchmarks and comparisons to the literature are presented.

  13. Evaluation of engine coolant recycling processes: Part 2

    SciTech Connect

    Bradley, W.H.

    1999-08-01

    Engine coolant recycling continues to provide solutions to both economic and environmental challenges often faced with the disposal of used engine coolant. General Motors` Service Technology Group (STG), in a continuing effort to validate the general practice of recycling engine coolants, has conducted an in-depth study on the capabilities of recycled coolants. Various recycling processes ranging from complex forms of fractional distillation to simple filtration were evaluated in this study to best represent the current state of coolant recycling technology. This study incorporates both lab and (limited) fleet testing to determine the performance capabilities of the recycled coolants tested. While the results suggest the need for additional studies in this area, they reveal the true capabilities of all types of engine coolant recycling technologies.

  14. Effect of initial product temperature and initial pH on foaming time during vacuum evaporation of liquid whole eggs.

    PubMed

    Girton, A R; Macneil, J H; Anantheswaran, R C

    1999-10-01

    During earlier studies on vacuum concentration of liquid egg white, the phenomena of foaming during the initial stages of the process were reported. In these studies, it was also shown that no concentration took place during the foaming period that varied from test to test. To minimize the total process time, this present study was undertaken to investigate what variables contributed to foaming, how they could be controlled, and what effect they had on product quality and functional properties. This study investigated the relationships among initial product temperature, initial pH, and foaming of liquid whole eggs. Two temperatures (9 and 20 C) and three pH levels (6.5, 7.3, and 8.5) were studied using a vacuum evaporation system with a maximum vacuum of 5 kPa. Tests showed that higher initial pH levels had decreased foaming times. At the end of foaming experiments, the liquid whole egg was evaluated to determine the extent of functional property change during foaming. A decrease in foaming time resulted in a decrease in whip time. The cakes made from the processed liquid whole egg had larger volumes than those from the unprocessed control. Furthermore, the liquid whole egg, which foamed the longest, had higher (P < 0.05) cake volumes. Our current experiments also verified our earlier findings that no product concentration takes place during the foaming process.

  15. Evaluation of secondary coolant control design alternatives and their effects on heat removal performance

    SciTech Connect

    Khayat, M.I.; Anderson, J.; Battle, R.; March-Leuba, J.

    1994-03-01

    This report documents a series of calculations that evaluate the performance of the core-inlet temperature controller under different transient conditions and design options. The present analyses show that the core-inlet temperature can be controlled at {approx}45{degrees}C under all transient conditions analyzed using the controller design described in the conceptual design report, which includes variable-speed secondary coolant pumps and variable-speed cooling tower fans. This study also shows that a constant-speed secondary pump would be sufficient to maintain core-inlet temperature <45{degrees}C if this temperature is allowed to drop below the set point during some demanding transients, such as normal startup. The use of secondary loop hot coolant to warm the reactor building was also evaluated; however, optimization of the secondary hot-leg temperature can only be achieved by trading off control of the primary side core-inlet temperature.

  16. Impact of temperature on the initial emittable concentration of formaldehyde in building materials: experimental observation.

    PubMed

    Xiong, J; Zhang, Y

    2010-12-01

    The initial emittable concentration of volatile organic compounds (VOC) is a key parameter not only in evaluating the 'green' degree of building materials but also in modeling their emission characteristics. Although the impact of temperature on initial emittable concentration is important, it has not been reported in the literature. Using the multi-emission/flush regression method we developed, the impact of temperature on the initial emittable concentration of formaldehyde in medium density board has been experimentally studied. It is observed that the initial emittable concentration increases significantly with increasing temperature. When the temperature rises by 25.4°C, it increases by about 507%. However, the initial emittable concentration at room temperature is far less than the value measured by the perforator method recommended by the Chinese National Standard GB/T 17657-1999, which measures the total concentration of formaldehyde in medium density board. This means most of formaldehyde in the building material cannot emit out at room temperature. The results will be very helpful in estimating the emission characteristics of building materials at different temperatures as well as for developing green building materials. Knowledge of initial emittable concentration is important for VOC emission prediction. According to our experimental study, the initial emittable concentration is heavily dependent on temperature, and this factor should be considered in dealing with heating or cooling process of building materials. The significant difference between the initial emittable concentration and total concentration suggests that the total concentration seems not appropriate for judging the pollution level of building materials. © 2010 John Wiley & Sons A/S.

  17. Fitness for service assessment of coolant channels of Indian PHWRs

    NASA Astrophysics Data System (ADS)

    Sinha, R. K.; Sinha, S. K.; Madhusoodanan, K.

    2008-12-01

    A typical coolant channel assembly of pressurised heavy water reactors mainly consists of pressure tube, calandria tube, garter spring spacers, all made of zirconium alloys and end fittings made of SS 403. The pressure tube is rolled at both its ends to the end fittings and is located concentrically inside the calandria tube with the help of garter spring spacers. Pressure tube houses the fuel bundles, which are cooled by means of pressurised heavy water. It, thus, operates under the environment of high pressure and temperature (typically 10 MPa and 573 K), and fast neutron flux (typically 3 × 10 17 n/m 2 s, E > 1 MeV neutrons). Under this operating environment, the material of the pressure tube undergoes degradation over a period of time, and eventually needs to be assessed for fitness for continued operation, without jeopardising the safety of the reactor. The other components of the coolant channel assembly, which are inaccessible for any in-service inspection, are assessed for their fitness, whenever a pressure tube is removed for either surveillance purpose or any other reasons. This paper, while describing the latest developments taking place to address the issue of fitness for service of the Zr-2.5 wt% Nb pressure tubes, also dwells briefly upon the developments taken place, to address the issues of life management and extension of zircaloy-2 pressure tubes in the earlier generation of Indian pressurised heavy water reactors.

  18. Preliminary analysis of loss-of-coolant accident in Fukushima nuclear accident

    SciTech Connect

    Su'ud, Zaki; Anshari, Rio

    2012-06-06

    Loss-of-Coolant Accident (LOCA) in Boiling Water Reactor (BWR) especially on Fukushima Nuclear Accident will be discussed in this paper. The Tohoku earthquake triggered the shutdown of nuclear power reactors at Fukushima Nuclear Power station. Though shutdown process has been completely performed, cooling process, at much smaller level than in normal operation, is needed to remove decay heat from the reactor core until the reactor reach cold-shutdown condition. If LOCA happen at this condition, it will cause the increase of reactor fuel and other core temperatures and can lead to reactor core meltdown and exposure of radioactive material to the environment such as in the Fukushima Dai Ichi nuclear accident case. In this study numerical simulation has been performed to calculate pressure composition, water level and temperature distribution on reactor during this accident. There are two coolant regulating system that operational on reactor unit 1 at this accident, Isolation Condensers (IC) system and Safety Relief Valves (SRV) system. Average mass flow of steam to the IC system in this event is 10 kg/s and could keep reactor core from uncovered about 3,2 hours and fully uncovered in 4,7 hours later. There are two coolant regulating system at operational on reactor unit 2, Reactor Core Isolation Condenser (RCIC) System and Safety Relief Valves (SRV). Average mass flow of coolant that correspond this event is 20 kg/s and could keep reactor core from uncovered about 73 hours and fully uncovered in 75 hours later. There are three coolant regulating system at operational on reactor unit 3, Reactor Core Isolation Condenser (RCIC) system, High Pressure Coolant Injection (HPCI) system and Safety Relief Valves (SRV). Average mass flow of water that correspond this event is 15 kg/s and could keep reactor core from uncovered about 37 hours and fully uncovered in 40 hours later.

  19. Preliminary analysis of loss-of-coolant accident in Fukushima nuclear accident

    NASA Astrophysics Data System (ADS)

    Su'ud, Zaki; Anshari, Rio

    2012-06-01

    Loss-of-Coolant Accident (LOCA) in Boiling Water Reactor (BWR) especially on Fukushima Nuclear Accident will be discussed in this paper. The Tohoku earthquake triggered the shutdown of nuclear power reactors at Fukushima Nuclear Power station. Though shutdown process has been completely performed, cooling process, at much smaller level than in normal operation, is needed to remove decay heat from the reactor core until the reactor reach cold-shutdown condition. If LOCA happen at this condition, it will cause the increase of reactor fuel and other core temperatures and can lead to reactor core meltdown and exposure of radioactive material to the environment such as in the Fukushima Dai Ichi nuclear accident case. In this study numerical simulation has been performed to calculate pressure composition, water level and temperature distribution on reactor during this accident. There are two coolant regulating system that operational on reactor unit 1 at this accident, Isolation Condensers (IC) system and Safety Relief Valves (SRV) system. Average mass flow of steam to the IC system in this event is 10 kg/s and could keep reactor core from uncovered about 3,2 hours and fully uncovered in 4,7 hours later. There are two coolant regulating system at operational on reactor unit 2, Reactor Core Isolation Condenser (RCIC) System and Safety Relief Valves (SRV). Average mass flow of coolant that correspond this event is 20 kg/s and could keep reactor core from uncovered about 73 hours and fully uncovered in 75 hours later. There are three coolant regulating system at operational on reactor unit 3, Reactor Core Isolation Condenser (RCIC) system, High Pressure Coolant Injection (HPCI) system and Safety Relief Valves (SRV). Average mass flow of water that correspond this event is 15 kg/s and could keep reactor core from uncovered about 37 hours and fully uncovered in 40 hours later.

  20. TACT 1: A computer program for the transient thermal analysis of a cooled turbine blade or vane equipped with a coolant insert. 2. Programmers manual

    NASA Technical Reports Server (NTRS)

    Gaugler, R. E.

    1979-01-01

    A computer program to calculate transient and steady state temperatures, pressures, and coolant flows in a cooled axial flow turbine blade or vane with an impingement insert is described. Coolant-side heat transfer coefficients are calculated internally in the program, with the user specifying either impingement or convection heat transfer at each internal flow station. Spent impingement air flows in a chordwise direction and is discharged through the trailing edge and through film cooling holes. The ability of the program to handle film cooling is limited by the internal flow model. Input to the program includes a description of the blade geometry, coolant-supply conditions, outside thermal boundary conditions, and wheel speed. The blade wall can have two layers of different materials, such as a ceramic thermal barrier coating over a metallic substrate. Program output includes the temperature at each node, the coolant pressures and flow rates, and the coolant-side heat transfer coefficients.

  1. Influence of temperature on spring flight initiation for southwestern ponderosa pine bark beetles (Coleoptera: Curculionidae, Scolytinae)

    Treesearch

    M. L. Gaylord; K. K. Williams; R. W. Hofstetter; J. D. McMillin; T. E. Degomez; M. R. Wagner

    2008-01-01

    Determination of temperature requirements for many economically important insects is a cornerstone of pest management. For bark beetles (Coleoptera: Curculionidae, Scolytinae), this information can facilitate timing of management strategies. Our goals were to determine temperature predictors for flight initiation of three species of Ips bark beetles...

  2. Investigating Liquid CO2 as a Coolant for a MTSA Heat Exchanger Design

    NASA Technical Reports Server (NTRS)

    Paul, Heather L.; Padilla, Sebastian; Powers, Aaron; Iacomini, Christie

    2009-01-01

    Metabolic heat regenerated Temperature Swing Adsorption (MTSA) technology is being developed for thermal and carbon dioxide (CO 2) control for a future Portable Life Support System (PLSS), as well as water recycling. CO 2 removal and rejection is accomplished by driving a sorbent through a temperature swing of approximately 210 K to 280 K . The sorbent is cooled to these sub-freezing temperatures by a Sublimating Heat Exchanger (SHX) with liquid coolant expanded to sublimation temperatures. Water is the baseline coolant available on the moon, and if used, provides a competitive solution to the current baseline PLSS schematic. Liquid CO2 (LCO2) is another non-cryogenic coolant readily available from Martian resources which can be produced and stored using relatively low power and minimal infrastructure. LCO 2 expands from high pressure liquid (5800 kPa) to Mars ambient (0.8 kPa) to produce a gas / solid mixture at temperatures as low as 156 K. Analysis and experimental work are presented to investigate factors that drive the design of a heat exchanger to effectively use this sink. Emphasis is given to enabling efficient use of the CO 2 cooling potential and mitigation of heat exchanger clogging due to solid formation. Minimizing mass and size as well as coolant delivery are also considered. The analysis and experimental work is specifically performed in an MTSA-like application to enable higher fidelity modeling for future optimization of a SHX design. In doing so, the work also demonstrates principles and concepts so that the design can be further optimized later in integrated applications (including Lunar application where water might be a choice of coolant).

  3. Investigating Liquid CO2 as a Coolant for a MTSA Heat Exchanger Design

    NASA Technical Reports Server (NTRS)

    Paul, Heather L.; Padilla, Sebastian; Powers, Aaron; Iacomini, Christie

    2009-01-01

    Metabolic heat regenerated Temperature Swing Adsorption (MTSA) technology is being developed for thermal and carbon dioxide (CO 2) control for a future Portable Life Support System (PLSS), as well as water recycling. CO 2 removal and rejection is accomplished by driving a sorbent through a temperature swing of approximately 210 K to 280 K . The sorbent is cooled to these sub-freezing temperatures by a Sublimating Heat Exchanger (SHX) with liquid coolant expanded to sublimation temperatures. Water is the baseline coolant available on the moon, and if used, provides a competitive solution to the current baseline PLSS schematic. Liquid CO2 (LCO2) is another non-cryogenic coolant readily available from Martian resources which can be produced and stored using relatively low power and minimal infrastructure. LCO 2 expands from high pressure liquid (5800 kPa) to Mars ambient (0.8 kPa) to produce a gas / solid mixture at temperatures as low as 156 K. Analysis and experimental work are presented to investigate factors that drive the design of a heat exchanger to effectively use this sink. Emphasis is given to enabling efficient use of the CO 2 cooling potential and mitigation of heat exchanger clogging due to solid formation. Minimizing mass and size as well as coolant delivery are also considered. The analysis and experimental work is specifically performed in an MTSA-like application to enable higher fidelity modeling for future optimization of a SHX design. In doing so, the work also demonstrates principles and concepts so that the design can be further optimized later in integrated applications (including Lunar application where water might be a choice of coolant).

  4. On detonation initiation by a temperature gradient for a detailed chemical reaction models

    NASA Astrophysics Data System (ADS)

    Liberman, M. A.; Kiverin, A. D.; Ivanov, M. F.

    2011-04-01

    The evolution from a temperature gradient to a detonation is investigated for combustion mixture whose chemistry is governed by a detailed chemical kinetics. We show that a detailed chemical reaction model has a profound effect on the spontaneous wave concept for detonation initiation by a gradient of reactivity. The evolution to detonation due to a temperature gradient is considered for hydrogen-oxygen and hydrogen-air mixtures at different initial pressures. It is shown that the minimal length of the temperature gradient for which a detonation can be ignited is much larger than that predicted from a one-step chemical model.

  5. Dynamic Fracture Initiation Toughness of a Gamma (Met-PX) Titanium Aluminide at Elevated Temperatures

    NASA Astrophysics Data System (ADS)

    Shazly, Mostafa; Prakash, Vikas; Draper, Susan

    2009-06-01

    Recently, a new generation of titanium aluminide alloy named Gamma-Met PX (GKSS, Geesthacht, Germany) has been developed with better rolling and postrolling characteristics. Previous work on this alloy has shown the material to have higher strengths at room and elevated temperatures when compared with other gamma titanium aluminides. In particular, this new alloy has shown increased ductility at elevated temperatures under both quasistatic and high-strain-rate uniaxial compressive loading. However, its high-strain-rate tensile ductility at room and elevated temperatures is limited to ~1 pct. In the present article, the results of a study investigating the effects of the loading rate and test temperature on the dynamic fracture initiation toughness in Gamma-Met PX are presented. A modified split Hopkinson pressure bar (MSHPB) was used along with high-speed photography, to determine the dynamic fracture initiation toughness. Three-point-bend fracture tests were conducted at impact speeds in the range 1 to 3.6 m/s and at test temperatures up to 1200 °C. Furthermore, the effect of long-time high-temperature air exposure on the fracture toughness was investigated. The results show that the dynamic fracture initiation toughness decreases at test temperatures beyond 600 °C. Moreover, the dynamic fracture initiation toughness was found to decrease with increasing exposure time. The reasons behind this drop are analyzed and discussed.

  6. Coupled reactor physics and coolant dynamics of heavy liquid metal coolant systems.

    SciTech Connect

    Cahalan, J. E.; Dunn, F. E.; Taiwo, T. A.

    1999-07-15

    Cooling of advanced nuclear designs with heavy liquid metals such as lead or lead-bismuth eutectic offers the potential for plant simplifications and higher operating efficiencies compared to previously considered liquid metal coolants such as sodium or NaK. Such applications would however also introduce additional safety concerns and design challenges, therefore necessitating a verifiable computational tool for transient design-basis analysis of heavy liquid metal coolant (HLMC) systems. This capability would enable analysts to compare operational and safety characteristics of design alternatives, and to evaluate relative performance advantages with a consistent, deterministic measure.

  7. Detonation Initiation by a Temperature Gradient for a Detailed Chemical Reaction Models

    NASA Astrophysics Data System (ADS)

    Liberman, Michael; Kiverin, Alexey; Chukalovsky, Alexander; Ivanov, Mikhail

    2011-04-01

    The evolution from a temperature gradient to a detonation is investigated using high resolution numerical simulations for combustion mixture whose chemistry is governed by a detailed chemical kinetics. We employ a model representing an initial linear temperature gradient in the fuel. Emphasis is on comparing the results with previous studies that used simple one-step kinetics. It is shown that the evolution to detonation from temperature nonuniformities is considerably different for one-step kinetics models than for chain-branching kinetic models and it is different in different fuels for the same initial conditions. A detailed chemical model has a profound effect on the validity of Zel'dovich's spontaneous wave concept for detonation initiation by a gradient of reactivity. The evolution to detonation from a temperature gradient is considered for hydrogen-air and methane-air mixtures at different initial pressures. The analysis shows that for a detailed chemical kinetics the temperature gradients, which was thought to appear in the form of hot spots and the like, are not satisfy the criteria to initiate detonation, and the gradient mechanism can not be origin of the deflagration-to-detonation transition.

  8. Detonation structure of C 2H 4-O 2-Ar mixtures at elevated initial temperature

    NASA Astrophysics Data System (ADS)

    Auffret, Y.; Desbordes, D.; Presles, H. N.

    The influence of initial pressure and temperature on the detonation structure of stoichiometric ethylene-oxygen-argon mixtures was studied. The detonation tube (53 mm i.d. and 7.2 m long) was electrically heated by Joule effect at a rate of about 100 K per minute. For initial pressures ranging from 0.1 to 1 bar, experimental results show that the detonation cell size increases with the initial temperature in the range of 300-600 K. The detonation cell size data were correlated with the chemical induction length calculated using the ZND model for the detonation wave and global chemical reaction kinetics. Due to the low value of the reduced global activation energy of the chemical kinetics (Ea/{R{ TZND}} ~= 5), the detonation cell size varies inversely with the initial density. Assuming that at elevated initial temperature the classical detonability criteria based on cell size are still valid, we find that the detonability of this mixture decreases when increasing initial temperature.

  9. Vibrations of rectangular plates with moderately large initial deflections at elevated temperatures using finite element method

    NASA Technical Reports Server (NTRS)

    Gray, C. C.

    1990-01-01

    A finite-element formulation is developed for the free vibration of rectangular plates which are under the influence of moderately large stress-free initial deflections and large thermal deflections. The von Karman nonlinear strain-displacement relations are used to account for the thermal deflections. The plates are thin, isotropic, and Hookean in nature. The temperature imposed on the plate is assumed to be constant through the thickness of the plate. Uniform and sinusoidal temperature distributions are studied. The material properties of the plates are temperature-dependent due to the relatively high temperatures imposed on the plates.

  10. Fleet test evaluation of fully formulated heavy-duty coolant technology maintained with a delayed-release filter compared with coolant inhibited with a nitrited organic acid technology: An interim report

    SciTech Connect

    Aroyan, S.S.; Eaton, E.R.

    1999-08-01

    This paper is a controlled extended service interval (ESI) study of the comparative behaviors of a nitrite/borate/low-silicate, low total dissolved solids (TDS) coolant maintained with delayed-release filters, and an organic acid inhibited coolant technology in heavy-duty engines. It reports both laboratory and fleet test data from 66 trucks, powered with different makes of heavy-duty diesel engines. The engines were cooled with three different types of inhibitors and two different glycol base (ethylene glycol and propylene glycol) coolants for an initial period exceeding two years and 500,000 km (300,000 miles). The data reported include chemical depletion rates, periodic coolant chemical analyses, and engine/cooling system reliability experience. The ongoing test will continue for approximately five years and a 1.6 million km (1 million miles) duration. Thirteen trucks were retained as controls, operating with ASTM D 4985 specification (GM-6038 type) coolant maintained with a standard ASTM D 57542 supplemental coolant additive (SCA). Engines produced by Caterpillar, Detroit Diesel Corp., Cummins Engine Co., and Mack Trucks are included in the test mix.

  11. Cryogenic-coolant He-4-superconductor interaction

    NASA Technical Reports Server (NTRS)

    Caspi, S.; Lee, J. Y.; Kim, Y. I.; Allen, R. J.; Frederking, T. H. K.

    1978-01-01

    The thermodynamic and thermal interaction between a type 2 composite alloy and cryo-coolant He4 was studied with emphasis on post quench phenomena of formvar coated conductors. The latter were investigated using a heater simulation technique. Overall heat transfer coefficients were evaluated for the quench onset point. Heat flux densities were determined for phenomena of thermal switching between a peak and a recovery value. The study covered near saturated liquid, pressurized He4, both above and below the lambda transition, and above and below the thermodynamic critical pressure. In addition, friction coefficients for relative motion between formvar insulated conductors were determined.

  12. FEM Analysis and Experimental Verification of the Integral Forging Process for AP1000 Primary Coolant Pipe

    NASA Astrophysics Data System (ADS)

    Wang, Shenglong; Yu, Xiaoyi; Yang, Bin; Zhang, Mingxian; Wu, Huanchun

    2016-10-01

    AP1000 primary coolant pipes must be manufactured by integral forging technology according to the designer—Westinghouse Electric Co. The characteristics of these large, special-shaped pipes create nonuniform temperatures, effective stress, and effective strain during shaping of the pipes. This paper presents a three-dimensional finite element simulation (3D FEM) of the integral forging process, and qualitatively evaluates the likelihood of forging defects. By analyzing the evolution histories of the three field variables, we concluded that the initial forging temperature should be strictly controlled within the interval 1123 K to 1423 K (850 °C to 1150 °C) to avoid second-phase precipitation. In the hard deformation zones, small strains do not contribute to recrystallization resulting in coarse grains. Conversely, in the free deformation zone, the large strains can contribute to the dynamic recrystallization, favoring grain refinement and closure of voids. Cracks are likely to appear, however, on the workpiece surface when forging leads to large deformations. Based on the simulation results, an eligible workpiece with good mechanical properties, few macroscopic defects, and favorable grain size has been successfully forged by experiments at an industrial scale, which validates the FEM simulation.

  13. Polyalphaolefins: A New Improved Cost Effective Aircraft Radar Coolant

    DTIC Science & Technology

    1991-06-01

    the silicate ester dielectric coolant used in many different aircraft electronic radar systems. Weather and environmental conditions, which can be...Naval Air Test Center in Patuxenti River, Maryland. 2. LABORATORY EVALUATION AND ASSESSMENT Several critical requirements of a dielectric coolant must...Study, Conclusions/Recommendations from Final Report, March, 1988. 3. PAO Summary Report - "Extended Testing of Poly Alpha Olefin as A Dielectric / Coolant Fluid

  14. Spring temperature, clutch initiation date and duck nest success: a test of the mismatch hypothesis.

    PubMed

    Drever, Mark C; Clark, Robert G

    2007-01-01

    1. Increases in average global temperature during the twentieth century have prompted calls for research on the effect of temperature variation on avian population dynamics. Particular attention has been paid to the hypothesis that increased temperatures may affect a species' ability to shift their breeding efforts to match the phenology of their prey, and thus result in reduced reproductive success (the 'mismatch hypothesis'). 2. We used data from a long-term study of breeding ducks to investigate how duck nest success varied with clutch initiation date, and to test whether spring temperature affected this relationship in a manner consistent with the mismatch hypothesis. We modelled five possible functional forms of how nest success might vary with clutch initiation date and spring temperature, and used an information-theoretic approach to determine which model best described the nesting outcomes of five dabbling duck species nesting in Saskatchewan, Canada. 3. Probability of nest success for the five species did not vary strongly with clutch initiation date, and we found evidence consistent with the mismatch hypothesis for one species, northern pintail Anas acuta, although weight of evidence was weak. 4. Overall nest success of all five species was positively associated with spring temperature. These results suggest that increasing spring temperature alone (within the range observed in this study) may not affect nest success in a manner that would result in lower populations of breeding ducks.

  15. Initial hydrogen detonation data from the High-Temperature Combustion Facility

    SciTech Connect

    Ginsberg, T.; Ciccarelli, G.; Boccio, J.

    1994-12-31

    The Brookhaven National Laboratory High-Temperature Combustion Facility (HTCF) is described and data from initial hydrogen detonation experiments are presented. Initial phase of the inherent detonability experimental program is described. Test gases thus far tested are hydrogen-air mixtures at one atmosphere initial pressure and temperatures 300K-650K. Detonation pressure, wave speed, and detonation cell size were measured. Data were consistent with earlier SSDA (small-scale development apparatus) test results. HTCF results confirm the conclusion from the SSDA program that the gas temperature decreases the cell size and, therefore, increases the sensitivity of mixtures to detonation. Data from the larger HTCF test vessel, however, also demonstrates that the effect of increased scale is to extend the range of detonable mixtures to lower concentration.

  16. Initial Operation of the High Temperature Electrolysis Integrated Laboratory Scale Experiment at INL

    SciTech Connect

    C. M. Stoots; J. E. O'Brien; K. G. Condie; J. S. Herring; J. J. Hartvigsen

    2008-06-01

    An integrated laboratory scale, 15 kW high-temperature electrolysis facility has been developed at the Idaho National Laboratory under the U.S. Department of Energy Nuclear Hydrogen Initiative. Initial operation of this facility resulted in over 400 hours of operation with an average hydrogen production rate of approximately 0.9 Nm3/hr. The integrated laboratory scale facility is designed to address larger-scale issues such as thermal management (feed-stock heating, high-temperature gas handling), multiple-stack hot-zone design, multiple-stack electrical configurations, and other “integral” issues. This paper documents the initial operation of the ILS, with experimental details about heat-up, initial stack performance, as well as long-term operation and stack degradation.

  17. Effect of initial temperature and concentration of catalyst in polyeugenol production

    SciTech Connect

    Widayat

    2015-12-29

    Objective of this research to study influencing of sulfuric acid concentration and initials temperature on polymerization of eugenol. Eugenol is the largest compound in the clove oil that used as raw material. Eugenol was polymerized laboratory scale. Polymerization processing conducted in reactor at 30 minutes. Polyeugenol was obtained in polymerization was conducted at temperature 40°C and ratio eugenol to sulfuric acid 1:15 mole. This research was pbtained the highest yield 81.49%. However, the weight would be increase in according with increasing of initial temperature. The polymerization in temperature 50°C with 1:1.5 mole ratio has the heaviest molecule weight; 47,530.76 gr/mole.

  18. Initiation Temperature for Runaway Tri-n-Butyl Phosphate/Nitric Acid Reaction

    SciTech Connect

    Rudisill, T.S.

    2001-09-14

    In a review of the safety basis for solvent extraction processes at the Department of Energy's Savannah River Site, a question was raised concerning the safety margin associated with a postulated accident involving a runaway tri-n-butyl phosphate (TBP)/nitric acid reaction due to the inadvertent heating of a tank. The safety margin was based on studies which showed the maximum temperature would not exceed 128 degrees Celsius compared to 130 degrees Celsius, the minimum initiation temperature for runaway reaction established in the 1950's following damaging incidents at the Savannah River and Hanford Sites. The reviewers were concerned the minimum temperature was not conservative since data for solutions containing 20 wt percent dissolved solids showed initiation temperatures at or below 130 degrees Celsius and process solutions normally contain some dissolved solids.

  19. Effect of initial temperature and concentration of catalyst in polyeugenol production

    NASA Astrophysics Data System (ADS)

    Widayat, Fatuchrohman, Alviano; Gustiasih, Ellen

    2015-12-01

    Objective of this research to study influencing of sulfuric acid concentration and initials temperature on polymerization of eugenol. Eugenol is the largest compound in the clove oil that used as raw material. Eugenol was polymerized laboratory scale. Polymerization processing conducted in reactor at 30 minutes. Polyeugenol was obtained in polymerization was conducted at temperature 40°C and ratio eugenol to sulfuric acid 1:15 mole. This research was pbtained the highest yield 81.49%. However, the weight would be increase in according with increasing of initial temperature. The polymerization in temperature 50°C with 1:1.5 mole ratio has the heaviest molecule weight; 47,530.76 gr/mole.

  20. CFD analyses of coolant channel flowfields

    NASA Technical Reports Server (NTRS)

    Yagley, Jennifer A.; Feng, Jinzhang; Merkle, Charles L.

    1993-01-01

    The flowfield characteristics in rocket engine coolant channels are analyzed by means of a numerical model. The channels are characterized by large length to diameter ratios, high Reynolds numbers, and asymmetrical heating. At representative flow conditions, the channel length is approximately twice the hydraulic entrance length so that fully developed conditions would be reached for a constant property fluid. For the supercritical hydrogen that is used as the coolant, the strong property variations create significant secondary flows in the cross-plane which have a major influence on the flow and the resulting heat transfer. Comparison of constant and variable property solutions show substantial differences. In addition, the property variations prevent fully developed flow. The density variation accelerates the fluid in the channels increasing the pressure drop without an accompanying increase in heat flux. Analyses of the inlet configuration suggest that side entry from a manifold can affect the development of the velocity profile because of vortices generated as the flow enters the channel. Current work is focused on studying the effects of channel bifurcation on the flow field and the heat transfer characteristics.

  1. Evaluation of zinc addition to PWR primary coolant

    SciTech Connect

    Pathania, R.; Yagnik, S.; Gold, R.E.; Dove, M.; Kolstad, E.

    1995-12-31

    Laboratory studies have shown that addition of zinc to a PWR environment reduces the general corrosion rates of materials in the primary system and delays the initiation of primary water stress corrosion cracking (PWSCC) in Alloy 600. Because of the potential benefits of zinc addition in reducing radiation fields and mitigating PWSCC of Alloy 600 a project was initiated to qualify zinc addition to a PWR. The objective of this work was to evaluate the effect of zinc addition on radiation fields, PWSCC of Alloy 600 and fuel cladding corrosion at the Farley-2 PWR. In order to provide an early warning of any potential adverse effects on the fuel cladding, corrosion studies were initiated at the Halden test reactor prior to zinc addition at Farley-2. This paper provides an overview of the scope of the zinc addition demonstration at Farley-2 and the fuel cladding corrosion tests at Halden. The zinc concentration in the Farley-2 coolant is approximately 40 ppb and that in Halden is 50 ppb. The paper presents initial results from these studies which are still in progress.

  2. Effect of glycol-based coolants on the suppression and recovery of platinum fuel cell electrocatalysts

    NASA Astrophysics Data System (ADS)

    Garsany, Yannick; Dutta, Sreya; Swider-Lyons, Karen E.

    2012-10-01

    We use cyclic and rotating disk electrode voltammetry to study glycol-based coolant formulations to show that individual constituents have either negligible or significant poisoning effects on the nanoscale Pt/carbon catalysts used in proton exchange membrane fuel cells. The base fluid in all these coolants is glycol (1, 3 propanediol), commercially available in a BioGlycol coolant formulation with an ethoxylated nonylphenol surfactant, and azole- and polyol-based non-ionic corrosion inhibitors. Exposure of a Pt/Vulcan carbon electrode to glycol-water or glycol-water-surfactant mixtures causes the loss of Pt electrochemical surface area (ECSA), but the Pt ECSA is fully recovered in clean electrolyte. Only mixtures with the azole corrosion inhibitor cause irreversible losses to the Pt ECSA and oxygen reduction reaction (ORR) activity. The Pt ECSA and ORR activity can only be recovered to within 70% of its initial values after aggressive voltammetric cycling to 1.50 V after azole poisoning. When poisoned with a glycol mixture containing the polyol corrosion inhibitor instead, the Pt ECSA and ORR activity is completely recovered by exposure to a clean electrolyte. The results suggest that prior to incorporation in a fuel cell, voltammetric evaluation of the constituents of coolant formulations is worthwhile.

  3. An Improved Design for Air Removal from Aerospace Fluid Loop Coolant Systems

    NASA Technical Reports Server (NTRS)

    Ritchie, Stephen M. C.; Holladay, Jon B.; Holt, J. Mike; Clark, Dallas W.

    2003-01-01

    Aerospace applications with requirements for large capacity heat removal (launch vehicles, platforms, payloads, etc.) typically utilize a liquid coolant fluid as a transport media to increase efficiency and flexibility in the vehicle design. An issue with these systems however, is susceptibility to the presence of noncondensable gas (NCG) or air. The presence of air in a coolant loop can have numerous negative consequences, including loss of centrifugal pump prime, interference with sensor readings, inhibition of heat transfer, and coolant blockage to remote systems. Hardware ground processing to remove this air is also cumbersome and time consuming which continuously drives recurring costs. Current systems for maintaining the system free of air are tailored and have demonstrated only moderate success. An obvious solution to these problems is the development and advancement of a passive gas removal device, or gas trap, that would be installed in the flight cooling system simplifying the initial coolant fill procedure and also maintaining the system during operations. The proposed device would utilize commercially available membranes thus increasing reliability and reducing cost while also addressing both current and anticipated applications. In addition, it maintains current pressure drop, water loss, and size restrictions while increasing tolerance for pressure increases due to gas build-up in the trap.

  4. The effect of temperature and initial pH on biomimetic apatite coating.

    PubMed

    Qu, Haibo; Wei, Mei

    2008-10-01

    Bone-like apatite coatings were prepared using a biomimetic method in a simulated body fluid (SBF). The effect of initial pH values and immersing temperatures on biomimetic apatite coating formation was studied. Three different temperatures were used in this study: 24 (room temperature), 40, and 60 degrees C. At each temperature, SBF solutions with three different initial pHs were chosen: low, medium, and high. The total inorganic carbon (TIC) content and pH-time profile of each coating system were recorded during the coating formation. The apatite coatings were characterized using X-ray diffraction (XRD), field emission scanning electron microscope (FESEM), and Fourier transform infra-red (FTIR). It has been found that SBF temperature has a great effect on the bicarbonate decomposition rate. The bicarbonate ions tend to decompose faster as the temperature increases. The decomposition of bicarbonate ions results in a pH increase in the SBF. With different initial SBF pHs, the decomposition of different amounts of bicarbonate ions is required to reach the critical pH range of apatite formation. With different amounts of bicarbonate ions in the SBF, the surface morphology of the biomimetic apatite coating formed is different. Therefore, the initial pH of the SBF solution plays a vital role in controlling the surface morphology of the biomimetic apatite coating. Also, it was found that as the SBF temperature increased, the critical pH range at which biomimetic apatite coating forms decreased. The critical pH range for the SBF prepared at 24, 40, and 60 degrees C was 6.65-6.71, 6.55-6.65, and 6.24-6.42, respectively. (c) 2008 Wiley Periodicals, Inc.

  5. High temperature reactors

    NASA Astrophysics Data System (ADS)

    Dulera, I. V.; Sinha, R. K.

    2008-12-01

    With the advent of high temperature reactors, nuclear energy, in addition to producing electricity, has shown enormous potential for the production of alternate transport energy carrier such as hydrogen. High efficiency hydrogen production processes need process heat at temperatures around 1173-1223 K. Bhabha Atomic Research Centre (BARC), is currently developing concepts of high temperature reactors capable of supplying process heat around 1273 K. These reactors would provide energy to facilitate combined production of hydrogen, electricity, and drinking water. Compact high temperature reactor is being developed as a technology demonstrator for associated technologies. Design has been also initiated for a 600 MWth innovative high temperature reactor. High temperature reactor development programme has opened new avenues for research in areas like advanced nuclear fuels, high temperature and corrosion resistant materials and protective coatings, heavy liquid metal coolant technologies, etc. The paper highlights design of these reactors and their material related requirements.

  6. A Knoevenagel Initiated Annulation Reaction Using Room Temperature or Microwave Conditions

    ERIC Educational Resources Information Center

    Cook, A. Gilbert

    2007-01-01

    An experiment is presented that has the student execute a Knoevenagel initiated annulation reaction. The reaction can be carried out either through use of a microwave reactor or by allowing the mixture to stand at room temperature for two days. The student is then challenged to identify the reaction product through a guided prelab exercise of the…

  7. Nickel sulfide formation at low temperature: initial precipitates, solubility and transformation products

    EPA Science Inventory

    The formation of nickel sulfides has been examined experimentally over the temperature range from 25 to 60°C. At all conditions studied, hexagonal (α-NiS) was the initial precipitate from solution containing Ni2+ and dissolved sulfide. The formation of millerite (β- NiS, rhombo...

  8. Nickel sulfide formation at low temperature: initial precipitates, solubility and transformation products

    EPA Science Inventory

    The formation of nickel sulfides has been examined experimentally over the temperature range from 25 to 60°C. At all conditions studied, hexagonal (α-NiS) was the initial precipitate from solution containing Ni2+ and dissolved sulfide. The formation of millerite (β- NiS, rhombo...

  9. Fast simulated annealing with a multivariate Cauchy distribution and the configuration's initial temperature

    NASA Astrophysics Data System (ADS)

    Lee, Chang-Yong

    2015-05-01

    We propose a multi-dimensional fast simulated annealing method based on a multivariate Cauchy probability distribution and an initial temperature estimated from the configuration's variation. While conventional multi-dimensional fast simulated annealing adopts the product of onedimensional random variables generated by a univariate Cauchy distribution, the proposed method generates a random vector from a multivariate Cauchy distribution. In this way, fast simulated annealing for a multi-dimensional problem maintains the same annealing schedule as that for the one-dimensional case. The proposed method also utilizes the initial temperature estimated from the configuration's variation to generate a candidate state in addition to the conventional initial temperature derived from the variation of the objective function for the acceptance probability. The proposed method is shown not only to guarantee a fast annealing schedule but also to enhance the search capability. The proposed method was tested against the optimization of real-valued functions. We empirically found that the configuration's initial temperature, together with multivariate Cauchy distribution, is more suitable than the conventional scheme for a fast annealing schedule. Moreover, the proposed method outperforms the conventional one in optimization problems having many variables.

  10. A Knoevenagel Initiated Annulation Reaction Using Room Temperature or Microwave Conditions

    ERIC Educational Resources Information Center

    Cook, A. Gilbert

    2007-01-01

    An experiment is presented that has the student execute a Knoevenagel initiated annulation reaction. The reaction can be carried out either through use of a microwave reactor or by allowing the mixture to stand at room temperature for two days. The student is then challenged to identify the reaction product through a guided prelab exercise of the…

  11. Initiation Temperature for Runaway Tri-n-Butyl Phosphate/Nitric Acid Reaction

    SciTech Connect

    Rudisill, T.S.

    2000-11-28

    During a review of the H-Canyon authorization basis, Defense Nuclear Facility Safety Board (DNFSB) staff members questioned the margin of safety associated with a postulated tri-n-butyl phosphate (TBP)/nitric acid runaway reaction due to the inadvertent heating of a canyon tank containing greater than 3000 lbs (1362 kg) of TBP. The margin of safety was partially based on experiments and calculations performed by the Actinide Technology Section (ATS) to support deletion of indication of tank agitation as a Safety Class System. In the technical basis for deletion of this system, ATS personnel conservatively calculated the equilibrium temperature distribution of a canyon tank containing TBP and nitric acid layers which were inadvertently heated by a steam jet left on following a transfer. The maximum calculated temperature (128 degrees C) was compared to the minimum initiation temperature for a runaway reaction (greater than 130 degrees C) documented by experimental work in the mid 195 0s. In this work, the initiation temperature as a function of nitric acid concentration was measured for 0 and 20 wt percent dissolved solids. The DNFSB staff members were concerned that data for 0 wt percent dissolved solids were not conservative given the facts that data for 20 wt percent dissolved solids show initiation temperatures at or below 130 degrees C and H-Canyon solutions normally contained a small amount of dissolved solids.

  12. Snow data assimilation-constrained land initialization improves seasonal temperature prediction

    NASA Astrophysics Data System (ADS)

    Lin, Peirong; Wei, Jiangfeng; Yang, Zong-Liang; Zhang, Yongfei; Zhang, Kai

    2016-11-01

    We present the first systematic study to quantify the impact of land initialization on seasonal temperature prediction in the Northern Hemisphere, emphasizing the role of land snow data assimilation (DA). Three suites of ensemble seasonal integrations are conducted for coupled land-atmosphere runs. The land component is initialized using datasets from (1) no DA, (2) assimilating Moderate Resolution Imaging Spectroradiometer (MODIS) snow cover fraction (SCF), and (3) assimilating both MODIS SCF and Gravity Recovery and Climate Experiment (GRACE) terrestrial water storage. Results show that snow DA improves temperature predictions especially in the Tibetan Plateau (by 5-20%) and high latitudes. Improvements at low latitudes are seen immediately and last up to 60 days, whereas improvements at high latitudes only appear later in transitional seasons. At high latitudes, assimilating GRACE data results in marked and prolonged improvements (by 25%) due to large initial snow mass changes. This study has great implications for future land DA and seasonal climate prediction studies.

  13. Temperature comparison of initial, middle and final point of polypropylene friction stir welded

    NASA Astrophysics Data System (ADS)

    Kusharjanta, Bambang; Raharjo, Wahyu P.; Triyono

    2016-03-01

    Friction Stir Welding is known as a new solid state joining process. This process is applied in thermoplastic polymers material recently. One of member thermoplastic polymer is polypropylene. Polypropylene sheet 6 mm thick was friction stir welded with a cone cut steel pin. Tool rotation, travelling speed, and plunge depth, as welding parameters were 620 rpm, 7.3 mm/minutes and 0.02 mm respectively. Temperature at the initial, middle, and final point of advance side working piece were measured and compared. Measurement were done by thermocouple and recorded by data acquisition. Based on this research, it is concluded that temperature at the initial, middle and final point of friction stir welding process are different. The highest temperature peak reach at the middle point on the advance side which affects face bending strength.

  14. Imaging of high-amylose starch tablets. 3. Initial diffusion and temperature effects.

    PubMed

    Thérien-Aubin, Héloïse; Baille, Wilms E; Zhu, Xiao Xia; Marchessault, Robert H

    2005-01-01

    The penetration of water into cross-linked high amylose starch tablets was studied at different temperatures by nuclear magnetic resonance (NMR) imaging, which follows the changes occurring at the surface and inside the starch tablets during swelling. It was found that the swelling was anisotropic, whereas water diffusion was almost isotropic. The water proton image profiles at the initial stage of water penetration were used to calculate the initial diffusion coefficient. The swelling and water concentration gradients in this controlled release system show significant temperature dependence. Diffusion behavior changed from Fickian to Case II diffusion with increasing temperature. The observed phenomena are attributed to the gelatinization of starch and the pseudo-cross-linking effect of double helix formation.

  15. The influence of initial temperature on flame acceleration and deflagration-to-detonation transition

    SciTech Connect

    Ciccarelli, G.; Boccio, J.L.; Ginsberg, T.

    1996-07-01

    The influence of initial mixture temperature on deflagration-to-detonation transition (DDT) has been investigated experimentally. The experiments were carried out in a 27-cm-inner diameter, 21.3-meter-long heated detonation tube, which was equipped with periodic orifice plates to promote flame acceleration. Hydrogen-air-steam mixtures were tested at a range of temperatures up to 650K and at an initial pressure of 0.1 MPa. In most cases, the limiting hydrogen mole fraction which resulted in transition to detonation corresponded to the mixture whose detonation cell size, {lambda}, was approximately equal to the inner diameter of the orifice plate, d (e.g., d/{lambda}{approximately}1). The only exception was in dry hydrogen-air mixtures at 650K where the DDT limit was observed to be 11 percent hydrogen, corresponding to a value of d/{lambda} equal to 5.5. For a 10.5 percent hydrogen mixture at 650K, the flame accelerated to a maximum velocity of about 120 m/s and then decelerated to below 2 m/s. This observation indicates that the d/{lambda} = 1 DDT limit criterion provides a necessary condition but not a sufficient one for the onset of DDT in obstacle-laden ducts. In this particular case, the mixture initial condition (i.e., temperature) resulted in the inability of the mixture to sustain flame acceleration to the point where DDT could occur. It was also observed that the distance required for the flame to accelerate to the onset of detonation was a function of both the hydrogen mole fraction and the mixture initial temperature. For example, decreasing the hydrogen mole fraction or increasing the initial mixture temperature resulted in longer transition distances.

  16. 73. View of line of stainless steel coolant storage tanks ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    73. View of line of stainless steel coolant storage tanks for bi-sodium sulfate/water coolant solution at first floor of transmitter building no. 102. - Clear Air Force Station, Ballistic Missile Early Warning System Site II, One mile west of mile marker 293.5 on Parks Highway, 5 miles southwest of Anderson, Anderson, Denali Borough, AK

  17. High pressure coolant effect on PVD coated inserts during end milling of Ti-6AL-4V

    NASA Astrophysics Data System (ADS)

    Sridharan, Arvind

    Titanium alloys are being employed extensively in engineering and aerospace applications for their high strength to weight ratio, mechanical strength and ability to withstand high temperatures. Out of the different alloys of titanium available, the most commonly used alloy is Ti-6Al-4V. It is also called `Grade-5 titanium alloy' or 'α+β titanium alloy'. High speed machining of titanium alloys generates high temperatures in the cutting zone, promoting accelerated tool wear and reducing the efficiency in metal cutting. Consequently, the ability of the coolant to remove heat from the cutting zone plays an increasingly important role in the economics of the process as well as on the life of tool inserts. With the introduction of thru-tool coolant delivery, the coolant can now be delivered directly at the point of machining without having to flood the area of machining. This research tries to address the effects that high pressure and thru-tool coolant has on insert wear while end milling Ti-6Al-4V. The parameters used in this study are speed, feed, axial depth of cut, radial depth of cut and coolant pressure. A structured design of experiments along with a central composite design approach is used to determine the main effects of coolant pressure and its interactions with the remaining parameters. The results show that, within the parameters of this experiment, coolant pressure was not a significant main effect. However, pressure seems to react positively with feed rate. Contributions from this research can be used to recommend settings of the cutting factors in order to obtain the minimal tool wear.

  18. Haematite natural crystals: non-linear initial susceptibility at low temperature

    NASA Astrophysics Data System (ADS)

    Guerrero-Suarez, S.; Martín-Hernández, F.

    2016-06-01

    Several works have reported that haematite has non-linear initial susceptibility at room temperature, like pyrrhotite or titanomagnetite, but there is no explanation for the observed behaviours yet. This study sets out to determine which physical property (grain size, foreign cations content and domain walls displacements) controls the initial susceptibility. The performed measurements include microprobe analysis to determine magnetic phases different to haematite; initial susceptibility (300 K); hysteresis loops, SIRM and backfield curves at 77 and 300 K to calculate magnetic parameters and minor loops at 77 K, to analyse initial susceptibility and magnetization behaviours below Morin transition. The magnetic moment study at low temperature is completed with measurements of zero field cooled-field cooled and AC susceptibility in a range from 5 to 300 K. The minor loops show that the non-linearity of initial susceptibility is closely related to Barkhausen jumps. Because of initial magnetic susceptibility is controlled by domain structure it is difficult to establish a mathematical model to separate magnetic subfabrics in haematite-bearing rocks.

  19. Testing of organic acids in engine coolants

    SciTech Connect

    Weir, T.W.

    1999-08-01

    The effectiveness of 30 organic acids as inhibitors in engine coolants is reported. Tests include glassware corrosion of coupled and uncoupled metals. FORD galvanostatic and cyclic polarization electrochemistry for aluminum pitting, and reserve alkalinity (RA) measurements. Details of each test are discussed as well as some general conclusions. For example, benzoic acid inhibits coupled metals well but is ineffective on cast iron when uncoupled. In benzoic acid inhibits coupled metals well but is ineffective on cast iron when uncoupled. In general, the organic acids provide little RA when titrated to a pH of 5.5, titration to a pH of 4.5 can result in precipitation of the acid. Trends with respect to acid chain length are reported also.

  20. Power module assemblies with staggered coolant channels

    DOEpatents

    Herron, Nicholas Hayden; Mann, Brooks S; Korich, Mark D

    2013-07-16

    A manifold is provided for supporting a power module assembly with a plurality of power modules. The manifold includes a first manifold section. The first face of the first manifold section is configured to receive the first power module, and the second face of the first manifold section defines a first cavity with a first baseplate thermally coupled to the first power module. The first face of the second manifold section is configured to receive the second power module, and the second face of the second manifold section defines a second cavity with a second baseplate thermally coupled to the second power module. The second face of the first manifold section and the second face of the second manifold section are coupled together such that the first cavity and the second cavity form a coolant channel. The first cavity is at least partially staggered with respect to second cavity.

  1. Protein synthesis during the initial phase of the temperature-induced bleaching response in Euglena gracilis

    SciTech Connect

    Ortiz, W. )

    1990-05-01

    Growing cultures of photoheterotrophic Euglena gracilis experience an increase in chlorophyll accumulation during the initial phase of the temperature-induced bleaching response suggesting an increase in the synthesis of plastid components at the bleaching temperature of 33{degree}C. A primary goal of this work was to establish whether an increase in the synthesis of plastid proteins accompanies the observed increase in chlorophyll accumulation. In vivo pulse-labeling experiments with ({sup 35}S)sodium sulfate were carried out with cells grown at room temperature or at 33{degree}C. The synthesis of a number of plastid polypeptides of nucleocytoplasmic origin, including some presumably novel polypeptides, increased in cultures treated for 15 hours at 33{degree}C. In contrast, while synthesis of thylakoid proteins by the plastid protein synthesis machinery decreased modestly, synthesis of the large subunit of the enzyme ribulosebisphosphate carboxylase was strongly affected at the elevated temperature. Synthesis of novel plastid-encoded polypeptides was not induced at the bleaching temperature. It is concluded that protein synthesis in plastids declines during the initial phase of the temperature response in Euglena despite an overall increase in cellular protein synthesis and an increase in chlorophyll accumulation per cell.

  2. Performance of the Extravehicular Mobility Unit (EMU) Airlock Coolant Loop Remediation (A/L CLR) Hardware - Final

    NASA Technical Reports Server (NTRS)

    Steele, John W.; Rector, Tony; Gazda, Daniel; Lewis, John

    2011-01-01

    An EMU water processing kit (Airlock Coolant Loop Recovery -- A/L CLR) was developed as a corrective action to Extravehicular Mobility Unit (EMU) coolant flow disruptions experienced on the International Space Station (ISS) in May of 2004 and thereafter. A conservative duty cycle and set of use parameters for A/L CLR use and component life were initially developed and implemented based on prior analysis results and analytical modeling. Several initiatives were undertaken to optimize the duty cycle and use parameters of the hardware. Examination of post-flight samples and EMU Coolant Loop hardware provided invaluable information on the performance of the A/L CLR and has allowed for an optimization of the process. The intent of this paper is to detail the evolution of the A/L CLR hardware, efforts to optimize the duty cycle and use parameters, and the final recommendations for implementation in the post-Shuttle retirement era.

  3. An iterative initialization procedure for transient ground temperature models with deep boundary conditions

    NASA Astrophysics Data System (ADS)

    Gruber, S.

    2009-04-01

    The initialization of deep soil thermal models is discussed here in view of two applications: (a) climate modeling, where land surface schemes comprise a soil thermal model; and (b) permafrost models. Stevens et al. (2007) and Alexeev et al. (2007) have recently demonstrated that the bottom boundary condition placement can significantly bias ground temperatures as well as the partitioning of surface energy budgets in long-term climate simulations. Addressing this problem with a deeper soil model requires dedicated initialization techniques because simple spin-up would require prohibitively long time windows, especially in the presence of frozen ground and snow cover. Physics-based models are increasingly used to estimate permafrost distribution as well as its temporal evolution, especially in mountain areas with high lateral variability of micro-climate and ground conditions. However, how can one know if the modeled presence/absence of permafrost in deeper layers is an artifact of the initialization or a valuable result? Strictly speaking, permafrost modeling with transient energy-balance and heat transfer models implicitly contains two steps: first, the finding of equilibrium conditions between the ground thermal profile and climate over one or several years and, then, possibly a transient simulation. Mean air temperature and mean ground temperature at the depth of several meters are usually related in a non-obvious way, especially in regions subject to ground freezing and snow cover. As a consequence, we cannot reliably estimate the deeper temperature profile without running the soil model - which in turn requires realistic temperatures at depth. In the method proposed to address this issue, equilibrium conditions are found by minimizing residuals between initial and final conditions of a model run over an initialization period and the near-surface part of the thermal profile. The success of this approach is judged by long-term model runs repeating only the

  4. Effects of rotation on coolant passage heat transfer. Volume 1: Coolant passages with smooth walls

    NASA Technical Reports Server (NTRS)

    Hajek, T. J.; Wagner, J. H.; Johnson, B. V.; Higgins, A. W.; Steuber, G. D.

    1991-01-01

    An experimental program was conducted to investigate heat transfer and pressure loss characteristics of rotating multipass passages, for configurations and dimensions typical of modern turbine blades. The immediate objective was the generation of a data base of heat transfer and pressure loss data required to develop heat transfer correlations and to assess computational fluid dynamic techniques for rotating coolant passages. Experiments were conducted in a smooth wall large scale heat transfer model.

  5. Aging and loss-of-coolant accident (LOCA) testing of electrical connections

    SciTech Connect

    Nelson, C.F.

    1998-01-01

    This report presents the results of an experimental program to determine the aging and loss-of-coolant accident (LOCA) behavior of electrical connections in order to obtain an initial scoping of their performance. Ten types of connections commonly used in nuclear power plants were tested. These included 3 types of conduit seals, 2 types of cable-to-device connectors, 3 types of cable-to-cable connectors, and 2 types of in-line splices. The connections were aged for 6 months under simultaneous thermal (99 C) and radiation (46 Gy/hr) conditions. A simulated LOCA consisting of sequential high dose-rate irradiation (3 kGy/hr) and high-temperature steam exposures followed the aging. Connection functionality was monitored using insulation resistance measurements during the aging and LOCA exposures. Because only 5 of the 10 connection types passed a post-LOCA, submerged dielectric withstand test, further detailed investigation of electrical connections and the effects of cable jacket integrity on the cable-connection system is warranted.

  6. Jet model for slot film cooling with effect of free-stream and coolant turbulence

    NASA Technical Reports Server (NTRS)

    Simon, Frederick F.

    1986-01-01

    An analysis was performed utilizing the model of a wall jet for obtaining equations that will predict slot film-cooling efficiency under conditions of variable turbulence intensity, flow, and temperature. The analysis, in addition to assessing the effects of the above variables, makes a distinction between an initial region and a fully developed region. Such a distinction is important in determining the role that the turbulence intensity of the coolant plays in effecting film-cooling effectiveness in the area of the slot exit. The results of the analysis were used in the correlation of the results of a well-designed film-cooling experiment. The result of the analysis and experiment was equations that predicted film-cooling efficiency within + or - 4% average deviation for lateral free-stream turbulence intensities up to 24% and blowing rates up to 1.9. These equations should be useful in determining the optimum quantity of cooling air requried for protecting the wall of a combustor.

  7. Parametric study on maximum transportable distance and cost for thermal energy transportation using various coolants

    SciTech Connect

    Su-Jong Yoon; Piyush Sabharwall

    2014-07-01

    The operation temperature of advanced nuclear reactors is generally higher than commercial light water reactors and thermal energy from advanced nuclear reactor can be used for various purposes such as district heating, desalination, hydrogen production and other process heat applications, etc. The process heat industry/facilities will be located outside the nuclear island due to safety measures. This thermal energy from the reactor has to be transported a fair distance. In this study, analytical analysis was conducted to identify the maximum distance that thermal energy could be transported using various coolants such as molten-salts, helium and water by varying the pipe diameter and mass flow rate. The cost required to transport each coolant was also analyzed. The coolants analyzed are molten salts (such as: KClMgCl2, LiF-NaF-KF (FLiNaK) and KF-ZrF4), helium and water. Fluoride salts are superior because of better heat transport characteristics but chloride salts are most economical for higher temperature transportation purposes. For lower temperature water is a possible alternative when compared with He, because low pressure He requires higher pumping power which makes the process very inefficient and economically not viable for both low and high temperature application.

  8. Inverse design of a proper number, shapes, sizes, and locations of coolant flow passages

    NASA Technical Reports Server (NTRS)

    Dulikravich, George S.

    1992-01-01

    During the past several years we have developed an inverse method that allows a thermal cooling system designer to determine proper sizes, shapes, and locations of coolant passages (holes) in, say, an internally cooled turbine blade, a scram jet strut, a rocket chamber wall, etc. Using this method the designer can enforce a desired heat flux distribution on the hot outer surface of the object, while simultaneously enforcing desired temperature distributions on the same hot outer surface as well as on the cooled interior surfaces of each of the coolant passages. This constitutes an over-specified problem which is solved by allowing the number, sizes, locations and shapes of the holes to adjust iteratively until the final internally cooled configuration satisfies the over-specified surface thermal conditions and the governing equation for the steady temperature field. The problem is solved by minimizing an error function expressing the difference between the specified and the computed hot surface heat fluxes. The temperature field analysis was performed using our highly accurate boundary integral element code with linearly varying temperature along straight surface panels. Examples of the inverse design applied to internally cooled turbine blades and scram jet struts (coated and non-coated) having circular and non-circular coolant flow passages will be shown.

  9. Inverse design of a proper number, shapes, sizes, and locations of coolant flow passages

    NASA Technical Reports Server (NTRS)

    Dulikravich, George S.

    1992-01-01

    During the past several years we have developed an inverse method that allows a thermal cooling system designer to determine proper sizes, shapes, and locations of coolant passages (holes) in, say, an internally cooled turbine blade, a scram jet strut, a rocket chamber wall, etc. Using this method the designer can enforce a desired heat flux distribution on the hot outer surface of the object, while simultaneously enforcing desired temperature distributions on the same hot outer surface as well as on the cooled interior surfaces of each of the coolant passages. This constitutes an over-specified problem which is solved by allowing the number, sizes, locations and shapes of the holes to adjust iteratively until the final internally cooled configuration satisfies the over-specified surface thermal conditions and the governing equation for the steady temperature field. The problem is solved by minimizing an error function expressing the difference between the specified and the computed hot surface heat fluxes. The temperature field analysis was performed using our highly accurate boundary integral element code with linearly varying temperature along straight surface panels. Examples of the inverse design applied to internally cooled turbine blades and scram jet struts (coated and non-coated) having circular and non-circular coolant flow passages will be shown.

  10. Assessment of Thermal and Hydrodynamic Fragmentation in Molten Fuel Coolant Interaction With Simulant System

    SciTech Connect

    Narayanan, K.S.; Das, S.K.; Jasmin Sudha, A.; Rao, E.H.V.M.; Lydia, G.; Murthy, S.S.; Kumareshan, M.; Harvey, J.; Kasinathan, N.; Rajan, M.

    2006-07-01

    In the Safety analysis of Fast Breeder Reactor, assessment of Molten Fuel Coolant Interaction (MFCI) assumes importance for two aspects, namely the characterization of the debris and severity of pressure pulses generation. An attempt has been made to investigate the debris generation characteristics with molten Woods Metal (Alloy of Bi 50% Pb 25% Sn 12.5% and Cd 12.5% and melting point of 346 K) - Water simulant system. Liquid Woods metal and liquid Uranium dioxide physical properties (Density, Surface tension and Kinematic viscosity) are similar. Experimental studies were conducted for various melt temperatures covering non - boiling, convective boiling and film boiling regimes of water, to assess the debris generation resulting from both hydrodynamic and thermal interaction. Woods metal was heated to the desired temperature and poured through a hot funnel having a nozzle of 8 mm release diameter into a water column of height up to 140 cm. Experiments were repeated for different coolant temperature and melt inventory up to 5 kg. The melt entry velocity was determined from video recordings. The debris is analyzed on the basis of interface temperature, Rayleigh-Taylor and Kelvin - Helmholtz instabilities. It is observed that Kelvin-Helmholtz instability is the dominant fragmentation phenomena. Contribution due to coolant boiling resulted in more debris generation in the size less than 4 mm. (authors)

  11. Analysis of Loss-of-Coolant Accidents in the NBSR

    SciTech Connect

    Baek J. S.; Cheng L.; Diamond, D.

    2014-05-23

    This report documents calculations of the fuel cladding temperature during loss-of-coolant accidents in the NBSR. The probability of a pipe failure is small and procedures exist to minimize the loss of water and assure emergency cooling water flows into the reactor core during such an event. Analysis in the past has shown that the emergency cooling water would provide adequate cooling if the water filled the flow channels within the fuel elements. The present analysis is to determine if there is adequate cooling if the water drains from the flow channels. Based on photographs of how the emergency water flows into the fuel elements from the distribution pan, it can be assumed that this water does not distribute uniformly across the flow channels but rather results in a liquid film flowing downward on the inside of one of the side plates in each fuel element and only wets the edges of the fuel plates. An analysis of guillotine breaks shows the cladding temperature remains below the blister temperature in fuel plates in the upper section of the fuel element. In the lower section, the fuel plates are also cooled by water outside the element that is present due to the hold-up pan and temperatures are lower than in the upper section. For small breaks, the simulation results show that the fuel elements are always cooled on the outside even in the upper section and the cladding temperature cannot be higher than the blister temperature. The above results are predicated on assumptions that are examined in the study to see their influence on fuel temperature.

  12. CREST Modelling of PBX 9502 Corner Turning Experiments at Different Initial Temperatures

    NASA Astrophysics Data System (ADS)

    Whitworth, Nicholas

    2013-06-01

    Corner turning is an important problem in regard to detonation wave propagation in TATB-based explosives. Experimentally, a sudden change in direction of the propagating wave, such as turning a sharp corner, can result in dead-zones being left behind in the corner turn region, with the observed behaviour being particularly sensitive to the initial temperature of the explosive. In this paper, the entropy-dependent CREST reactive burn model is used to simulate corner turning experiments on the TATB-based explosive PBX 9502. Calculated results of double cylinder tests at three different initial temperatures (-54°C, 25°C, and 75°C), and a ``hockey puck'' experiment at ambient temperature, are compared to the corresponding test measurements. The results show that the model is able to: (i) calculate persistent dead-zones in PBX 9502 without recourse to any shock desensitisation treatment, and (ii) predict changes in corner turning behaviour with initial temperature using one set of coefficients.

  13. CREST modelling of PBX 9502 corner turning experiments at different initial temperatures

    NASA Astrophysics Data System (ADS)

    Whitworth, N. J.

    2014-05-01

    Corner turning is an important problem in regard to detonation wave propagation in TATB-based explosives. Experimentally, a sudden change in the direction of the propagating wave, such as turning a sharp corner, can result in dead-zones being left behind in the corner turn region, with the observed behaviour being particularly sensitive to the initial temperature of the explosive. In this paper, the entropy-dependent CREST reactive burn model is used to simulate corner turning experiments on the TATB-based explosive PBX 9502. Calculated results of double cylinder tests at three different initial temperatures (-54°C, ~23°C, and 75°C), and a "hockey puck" experiment at ambient temperature, are compared to the corresponding test measurements. The results show that the model is able to: (i) calculate persistent dead-zones in PBX 9502 without recourse to any shock desensitisation treatment, and (ii) predict changes in corner turning behaviour with initial temperature using one set of coefficients.

  14. Characteristics of a Bacillus subtilis W23 mutant temperature sensitive for initiation of chromosome replication.

    PubMed

    Upcroft, P; Dyson, H J; Wake, R G

    1975-01-01

    A temperature-sensitive mutant of Bacillus subtilis W23, dna-20 (Ts), has been isolated and shown to be defective in initiation of rounds of chromosome replication at the nonpermissive temperature. Upon transfer of dna-20(Ts) from 30 to 45 C, deoxyribonucleic acid synthesis, as measured by [3H]thymine incorporation, gradually ceases. The distribution of genetic markers among unreplicated and replicated deoxyribonucleic acid, isolated from dna-20(Ts) after a period at 43 C in a medium containing 5-bromouracil, and fractionated in a CsCl gradient, shows that the cessation of initiation at the higher temperature is immediate. On the other hand, ribonucleic acid and protein synthesis continues at elevated or unaltered rates for some time after the shift to 45 C. Marker frequency analysis shows that all rounds of replication in progress at the time of the temperature shift terminate rapidly (within 40 min), even when chromosomes are replicating dichotomously in rich media. dna-20(Ts) remains 100% viable for at least 2 h at 45 C. Over a 5-h period at 45 C the nuclear bodies remain compact; a small number (less than 5%) of deoxyribonucleic acid-less cells are produced, but there is no morphological distortion of the cells. When the cells are returned to 30 C after 2 h at 45 C, chromosome replication is initiated rapidly at the normal origin and then proceeds in the normal established sequence. However, a second round of replication is initiated soon after the first. dna-20(Ts) has been shown to map as a B-group mutation, the major class of initiation mutants identified in B. subtillus 168.

  15. Characteristics of a Bacillus subtilis W23 mutant temperature sensitive for initiation of chromosome replication.

    PubMed Central

    Upcroft, P; Dyson, H J; Wake, R G

    1975-01-01

    A temperature-sensitive mutant of Bacillus subtilis W23, dna-20 (Ts), has been isolated and shown to be defective in initiation of rounds of chromosome replication at the nonpermissive temperature. Upon transfer of dna-20(Ts) from 30 to 45 C, deoxyribonucleic acid synthesis, as measured by [3H]thymine incorporation, gradually ceases. The distribution of genetic markers among unreplicated and replicated deoxyribonucleic acid, isolated from dna-20(Ts) after a period at 43 C in a medium containing 5-bromouracil, and fractionated in a CsCl gradient, shows that the cessation of initiation at the higher temperature is immediate. On the other hand, ribonucleic acid and protein synthesis continues at elevated or unaltered rates for some time after the shift to 45 C. Marker frequency analysis shows that all rounds of replication in progress at the time of the temperature shift terminate rapidly (within 40 min), even when chromosomes are replicating dichotomously in rich media. dna-20(Ts) remains 100% viable for at least 2 h at 45 C. Over a 5-h period at 45 C the nuclear bodies remain compact; a small number (less than 5%) of deoxyribonucleic acid-less cells are produced, but there is no morphological distortion of the cells. When the cells are returned to 30 C after 2 h at 45 C, chromosome replication is initiated rapidly at the normal origin and then proceeds in the normal established sequence. However, a second round of replication is initiated soon after the first. dna-20(Ts) has been shown to map as a B-group mutation, the major class of initiation mutants identified in B. subtillus 168. PMID:803947

  16. Some observations on simulated molten debris-coolant layer dynamics. [PWR; BWR

    SciTech Connect

    Greene, G.A.; Klein, J.; Klages, J.; Schwarz, E.; Sanborn, Y.

    1983-04-01

    Experiments are being performed to investigate high temperature liquid-liquid film boiling between a pool of liquid metal and an overlying coolant pool of R-11 or water. Film boiling has been observed to be stable for R-11; however, considerable liquid-liquid contact has been observed with water well beyond the minimum film boiling temperature. Unstable liquid-liquid film boiling of water has been observed to escalate into dispersive, non-energetic vapor explosions when the interface contact temperature exceeded the spontaneous nucleation temperature. Other parametric trends in the data are discussed.

  17. Gas-leaking fuel elements number and fission gas product coolant volumetric activities assessment in the VVER-440 nuclear power plant

    NASA Astrophysics Data System (ADS)

    Szuta, Marcin

    1992-07-01

    In a nuclear power plant it is required to monitor continuously the number of gas-leaking fuel elements and the contamination level of the primary coolant by fission gas products. It is proposed to use the radiation monitoring system equipped with the computer technics provided with the suitable program package for fulfilment this requirements. The input data to start up the program consists of the 88Kr volumetric activity measured by the radiation monitoring system and three actual technological parameters: coolant temperature at inlet, thermal power and coolant flow rate.

  18. Effect of initial core temperature on hyperthermic hyperventilation during prolonged submaximal exercise in the heat.

    PubMed

    Tsuji, Bun; Honda, Yasushi; Fujii, Naoto; Kondo, Narihiko; Nishiyasu, Takeshi

    2012-01-01

    We investigated whether a core temperature threshold for hyperthermic hyperventilation is seen during prolonged submaximal exercise in the heat when core temperature before the exercise is reduced and whether the evoked hyperventilatory response is affected by altering the initial core temperature. Ten male subjects performed three exercise trials at 50% of peak oxygen uptake in the heat (37°C and 50% relative humidity) after altering their initial esophageal temperature (T(es)). Initial T(es) was manipulated by immersion for 25 min in water at 18°C (Precooling), 35°C (Control), or 40°C (Preheating). T(es) after the water immersion was significantly higher in the Preheating trial (37.5 ± 0.3°C) and lower in the Precooling trial (36.1 ± 0.3°C) than in the Control trial (36.9 ± 0.3°C). In the Precooling trial, minute ventilation (Ve) showed little change until T(es) reached 37.1 ± 0.4°C. Above this core temperature threshold, Ve increased linearly in proportion to increasing T(es). In the Control trial, Ve increased as T(es) increased from 37.0°C to 38.6°C after the onset of exercise. In the Preheating trial, Ve increased from the initially elevated levels of T(es) (from 37.6 to 38.6°C) and Ve. The sensitivity of Ve to increasing T(es) above the threshold for hyperventilation (the slope of the T(es)-Ve relation) did not significantly vary across trials (Precooling trial = 10.6 ± 5.9, Control trial = 8.7 ± 5.1, and Preheating trial = 9.2 ± 6.9 L·min(-1)·°C(-1)). These results suggest that during prolonged submaximal exercise at a constant workload in humans, there is a clear core temperature threshold for hyperthermic hyperventilation and that the evoked hyperventilatory response is unaffected by altering initial core temperature.

  19. Experimental study of plate buckling induced by spatial temperature gradients

    NASA Technical Reports Server (NTRS)

    Thornton, Earl A.; Coyle, Marshall F.; Mcleod, Rory N.

    1992-01-01

    An experimental study of plate buckling induced by spatial temperature gradients is described. A rectangular Hastelloy-X panel is subjected to local line heating by a focused quartz heat lamp. Two parallel panel edges are maintained at constant temperature by coolant flow. Point supports provide well-defined thermal-structural boundary conditions. Test results from transient elastic and inelastic tests demonstrate that substantial panel bending occurs due to initial panel warpage and thermally induced membrane compressive stresses.

  20. Effect of temperature and initial dibutyl sulfide concentration in chloroform on its oxidation rate by ozone.

    PubMed

    Popiel, Stanisław; Nalepa, Tomasz; Dzierzak, Dorota; Stankiewicz, Romuald; Witkiewicz, Zygfryd

    2008-09-15

    A scheme of dibutyl sulfide (DBS) oxidation with ozone and generation of transitional products was determined in this study. The main identified intermediate product was dibutyl sulfoxide (DBSO), and the main end product of DBS oxidation was dibutyl sulfone (DBSO2). It was determined that for three temperatures: 0, 10 and 20 degrees C there was certain initial DBS concentration for which half-times observed in experimental conditions were equal and independent from temperature. Generation of phosgene and water as by-products was confirmed for the reaction of DBS with ozone in chloroform. Results of the described study allowed to present generalized mechanism of sulfide oxidation with ozone.

  1. Influence of initial temperature perturbations on precipitation using WRF modelling system over the Southern Peninsular India

    NASA Astrophysics Data System (ADS)

    Rajagopalan, R. A.; Sharan, M.; Haddad, Z. S.

    2016-12-01

    A methodology based on Principal Component Analysis (PCA) is applied to quantify the magnitude of perturbations in the vertical temperature profiles to incorporate the effect of atmospheric stability. In this study, the PCA technique is used to obtain dominant eigen values of a particular temperature data set and then used to perturb the vertical temperature profiles. For this purpose, the National Centre for Environmental Prediction (NCEP) final analysis (FNL) data with 1°´1° degree resolution (University Corporation for Atmospheric Research (UCAR) website: http://dss.ucar.edu/datasets/ds083.2/data) at 4 grid points over southern peninsular India (10°N76°E; 10°N77°E; 11°N76°E; 11°N77°E) at 0000 UTC in the month of April for 7 years (2003-2009) is utilized. The dominant eigen values in decreasing order of magnitude are deduced using the PCA from these vertical temperature profiles. Using the dominant eigen values, the temperature profiles in the FNL data are perturbed for initializing the WRF (Weather Research and Forecasting) modelling system version 3.6. To examine the influence of perturbed temperature in weather variables, the simulations are conducted for 24 hours on 02-Feb-2009, a day in winter, 23-May-2009, monsoon onset day, 12-Aug-2009, a day in the active monsoon season and 28-Oct-2009, a day in the north east monsoon season. Results computed from both with and without temperature perturbation are presented. The perturbation temperature plots show that the temperature perturbation using the PCA technique is a potential alternative for data assimilation. The simulated surface variables with the perturb initial temperature profiles are found to be relatively closer with observations. Also, perturbation in temperature increase the spatial rainfall and outgoing longwave radiation tendencies. These simulated results are comparable with those from TRMM (Tropical Rainfall Measuring Mission) and ERA-interim (European Centre for Medium Range Weather

  2. Reclamation and disposal of water-based machining coolants

    SciTech Connect

    Taylor, P.A.

    1982-01-01

    The Oak Ridge Y-12 Plant, which is operated by the Union Carbide Corporation, Nuclear Division for the Department of Energy under US government contract W-7405-eng-26, currently uses about 10{sup 6} L/yr (260,000 gal/yr) of water-based coolants in its machining operations. These coolants are disposed of in a 110,000-L (29,000-gal) activated sludge reactor. The reactor has oxidized an average of 38.6 kg of total organic carbon (TOC) per day with an overall efficiency of 90%. The predominant bacteria in the reactor have been identified once each year for the past three years. Six primary types of water-based coolants are currently used in the machine shops. In order to reduce the coolant usage rate, efforts are being made to introduce one universal coolant into the shops. By using a biocide to limit bacterial deterioration and using a filter and centrifuge system to remove dirt and tramp oils from the coolant, the coolant discard rate can be greatly reduced. 1 tab.

  3. ISS Internal Active Thermal Control System (IATCS) Coolant Remediation Project

    NASA Technical Reports Server (NTRS)

    Morrison, Russell H.; Holt, Mike

    2005-01-01

    The IATCS coolant has experienced a number of anomalies in the time since the US Lab was first activated on Flight 5A in February 2001. These have included: 1) a decrease in coolant pH, 2) increases in inorganic carbon, 3) a reduction in phosphate buffer concentration, 4) an increase in dissolved nickel and precipitation of nickel salts, and 5) increases in microbial concentration. These anomalies represent some risk to the system, have been implicated in some hardware failures and are suspect in others. The ISS program has conducted extensive investigations of the causes and effects of these anomalies and has developed a comprehensive program to remediate the coolant chemistry of the on-orbit system as well as provide a robust and compatible coolant solution for the hardware yet to be delivered. The remediation steps include changes in the coolant chemistry specification, development of a suite of new antimicrobial additives, and development of devices for the removal of nickel and phosphate ions from the coolant. This paper presents an overview of the anomalies, their known and suspected system effects, their causes, and the actions being taken to remediate the coolant.

  4. Advanced reactor vessel steels for reactors with supercritical coolant parameters

    NASA Astrophysics Data System (ADS)

    Markov, S. I.; Dub, V. S.; Lebedev, A. G.; Kuleshova, E. A.; Balikoev, A. G.; Makarycheva, E. V.; Tolstykh, D. S.; Frolov, A. S.; Krikun, E. V.

    2016-09-01

    A set of studies, tests, and technological works is performed to design promising high-strength vessel steels for reactors with supercritical coolant parameters. Compositions and technological parameters are proposed for the production of reference steel (within the limits of the grade composition of 15Kh2NMFA-A steel) and high-nickel steel. These steels are characterized by high properties, including metallurgical quality and service and technological parameters. Steel of the reference composition has high (higher by 15%) strength properties, improved viscoplastic properties, and ductile-brittle transition temperature t c of at most-125°C. The strength properties of the high-nickel steel are higher than those of the existing steels by 40-50% and higher than those of advanced foreign steels by 15-20% at ductile-brittle transition temperature t c of at most-165°C. Moreover, the designed steels are characterized by a low content of harmful impurity elements and nonmetallic inclusions, a fine-grained structure, and a low susceptibility to thermal embrittlement.

  5. High and low body temperature during the initiation of ventilation for near-term lambs.

    PubMed

    Ball, Molly K; Jobe, Alan H; Polglase, Graeme R; Kallapur, Suhas G; Cheah, Fook-Choe; Hillman, Noah H; Pillow, Jane J

    2009-01-01

    Recent literature suggests hypothermia may protect against lung injury. We evaluated body temperature as a variable in lung inflammation due to oxygenation and mechanical ventilation following delivery of near-term lambs. Twin fetuses were randomized prior to delivery at 140 d GA (term 150 d): unventilated controls, normothermic ventilated with room air, normothermic ventilated with 100% oxygen, low temperature ventilated (target 35 degrees C) with 100% oxygen, and high temperature (target 40 degrees C) with 100% oxygen. Lambs were intubated for gentle mechanical ventilation (tidal volume 7-8ml/kg). Temperature targeting was with radiant warmers and plastic wrap for normothermia, with heat lamps for hyperthermia, and with ice packs for hypothermia. Lambs were euthanized after 2h mechanical ventilation. Post-mortem, bronchoalveolar lavage fluid and lung tissue samples were evaluated for inflammatory responses by measuring inflammatory cell counts, protein, myeloperoxidase, protein carbonyl, and pro-inflammatory cytokine mRNA. Target temperatures were achieved by 30min of age and tightly maintained for the 2h study. There were no differences in physiologic variables among groups except those directly resulting from study protocol-PaO2 from air vs. 100% oxygen and body temperature. Indicators of inflammation increased similarly in all ventilated groups compared to unventilated controls. Moderate hyperthermia or hypothermia did not affect lung injury responses to the initiation of ventilation at birth in near-term lambs.

  6. Effects of coolant volatility on simulated HCDA bubble expansions. [LMFBR

    SciTech Connect

    Tobin, R.J.

    1980-09-01

    The effects of coolant volatility on the expansion dynamics and cover loading of hypothetical core disruptive accidents (HCDA) were studied by performing experiments with a transparent 1/30-scale model of a typical demonstration size loop-type liquid metal fast breeder reactor (LMFBR). In past experiments, water was used to simulate the sodium coolant in the prototype. In these experiments, Freon 113 and Freon 11 were used as coolant simulants of increasing volatility. High-pressure nitrogen gas (1450 psia) or flashing water (1160 psia) were used to simulate the qualitative features of sodium vapor or molten fuel expansions.

  7. Turbomachine injection nozzle including a coolant delivery system

    DOEpatents

    Zuo, Baifang [Simpsonville, SC

    2012-02-14

    An injection nozzle for a turbomachine includes a main body having a first end portion that extends to a second end portion defining an exterior wall having an outer surface. A plurality of fluid delivery tubes extend through the main body. Each of the plurality of fluid delivery tubes includes a first fluid inlet for receiving a first fluid, a second fluid inlet for receiving a second fluid and an outlet. The injection nozzle further includes a coolant delivery system arranged within the main body. The coolant delivery system guides a coolant along at least one of a portion of the exterior wall and around the plurality of fluid delivery tubes.

  8. Longer life for glyco-based stationary engine coolants

    SciTech Connect

    Hohlfeld, R.

    1996-07-01

    Large, stationary diesel engines used to compress natural gas that is to be transported down pipelines generate a great deal of heat. Unless this heat is dissipated efficiently, it will eventually cause an expensive breakdown. Whether the coolant uses ethylene glycol or propylene glycol, the two major causes of glycol degradation are heat and oxidation. The paper discusses inhibitors that enhance coolant service life and presents a comprehensive list of do`s and don`ts for users to gain a 20-year coolant life.

  9. Lead Coolant Test Facility Technical and Functional Requirements, Conceptual Design, Cost and Construction Schedule

    SciTech Connect

    Soli T. Khericha

    2006-09-01

    This report presents preliminary technical and functional requirements (T&FR), thermal hydraulic design and cost estimate for a lead coolant test facility. The purpose of this small scale facility is to simulate lead coolant fast reactor (LFR) coolant flow in an open lattice geometry core using seven electrical rods and liquid lead or lead-bismuth eutectic. Based on review of current world lead or lead-bismuth test facilities and research need listed in the Generation IV Roadmap, five broad areas of requirements of basis are identified: Develop and Demonstrate Prototype Lead/Lead-Bismuth Liquid Metal Flow Loop Develop and Demonstrate Feasibility of Submerged Heat Exchanger Develop and Demonstrate Open-lattice Flow in Electrically Heated Core Develop and Demonstrate Chemistry Control Demonstrate Safe Operation and Provision for Future Testing. These five broad areas are divided into twenty-one (21) specific requirements ranging from coolant temperature to design lifetime. An overview of project engineering requirements, design requirements, QA and environmental requirements are also presented. The purpose of this T&FRs is to focus the lead fast reactor community domestically on the requirements for the next unique state of the art test facility. The facility thermal hydraulic design is based on the maximum simulated core power using seven electrical heater rods of 420 kW; average linear heat generation rate of 300 W/cm. The core inlet temperature for liquid lead or Pb/Bi eutectic is 420oC. The design includes approximately seventy-five data measurements such as pressure, temperature, and flow rates. The preliminary estimated cost of construction of the facility is $3.7M. It is also estimated that the facility will require two years to be constructed and ready for operation.

  10. The BLOW-3A: A theoretical model to describe transient two phase flow conditions in Liquid Metal Fast Breeder Reactor (LMFBR) coolant channels

    NASA Astrophysics Data System (ADS)

    Bottoni, M.; Struwe, D.

    The theoretical background of the BLOW-3A program is reported, including the basic equations used to determine temperature fields in the fuel, clad, coolant and structure material as well as the coolant dynamics in single and two-phase flow conditions. The two-phase flow model assumes an annular flow regime. Special aspects to calculate two-phase pressure drops for these conditions are discussed. Examples of the experimental validation of the program are given.

  11. The effect of initial temperature on flame acceleration and deflagration-to-detonation transition phenomenon

    SciTech Connect

    Ciccarelli, G.; Boccio, J.L.; Ginsberg, T.; Finfrock, C.; Gerlach, L.; Tagawa, H.; Malliakos, A.

    1998-05-01

    The High-Temperature Combustion Facility at BNL was used to conduct deflagration-to-detonation transition (DDT) experiments. Periodic orifice plates were installed inside the entire length of the detonation tube in order to promote flame acceleration. The orifice plates are 27.3-cm-outer diameter, which is equivalent to the inner diameter of the tube, and 20.6-cm-inner diameter. The detonation tube length is 21.3-meters long, and the spacing of the orifice plates is one tube diameter. A standard automobile diesel engine glow plug was used to ignite the test mixture at one end of the tube. Hydrogen-air-steam mixtures were tested at a range of temperatures up to 650K and at an initial pressure of 0.1 MPa. In most cases, the limiting hydrogen mole fraction which resulted in DDT corresponded to the mixture whose detonation cell size, {lambda}, was equal to the inner diameter of the orifice plate, d (e.g., d/{lambda}=1). The only exception was in the dry hydrogen-air mixtures at 650K where the DDT limit was observed to be 11 percent hydrogen, corresponding to a value of d/{lambda} equal to 5.5. For a 10.5 percent hydrogen mixture at 650K, the flame accelerated to a maximum velocity of about 120 mIs and then decelerated to below 2 mIs. By maintaining the first 6.1 meters of the vessel at the ignition end at 400K, and the rest of the vessel at 650K, the DDT limit was reduced to 9.5 percent hydrogen (d/{lambda}=4.2). This observation indicates that the d/{lambda}=1 DDT limit criteria provides a necessary condition but not a sufficient one for the onset of DDT in obstacle laden ducts. In this particular case, the mixture initial condition (i.e., temperature) resulted in the inability of the mixture to sustain flame acceleration to the point where DDT could occur. It was also observed that the distance required for the flame to accelerate to the point of detonation initiation, referred to as the run-up distance, was found to be a function of both the hydrogen mole fraction

  12. The heat transfer characteristic of the reactor coolant pump canned motor

    NASA Astrophysics Data System (ADS)

    Gu, X. Y.; Xu, R.; Tao, G.; Yang, Y. L.; Wang, D. Z.

    2016-05-01

    This paper deals with the heat transfer characteristic of the reactor coolant pump canned motor. The cooling of the canned motor is an important issue for the design of the pump. In order to analyze the heat transfer characteristic of the canned motor, firstly the electromagnetic field of the canned motor is calculated with finite element method, and the magnetic resistance loss is gotten, then the heat distribution of the canned motor is obtained based on the electromagnetic field, finally the flow field and temperature field of the canned motor is calculated with CFD methods. The calculation indicates that the highest temperature and highest temperature rising are both occurred at the end winding.

  13. Quantitative trait loci controlling leaf appearance and curd initiation of cauliflower in relation to temperature.

    PubMed

    Hasan, Yaser; Briggs, William; Matschegewski, Claudia; Ordon, Frank; Stützel, Hartmut; Zetzsche, Holger; Groen, Simon; Uptmoor, Ralf

    2016-07-01

    QTL regions on chromosomes C06 and C09 are involved in temperature dependent time to curd induction in cauliflower. Temperature is the main environmental factor influencing curding time of cauliflower (Brassica oleracea var. botrytis). Temperatures above 20-22 °C inhibit development towards curding even in many summer cultivars. To identify quantitative trait loci (QTL) controlling curding time and its related traits in a wide range of different temperature regimes from 12 to 27 °C, a doubled haploid (DH) mapping population segregating for curding time was developed and days to curd initiation (DCI), leaf appearance rate (LAR), and final leaf number (FLN) were measured. The population was genotyped with 176 single nucleotide polymorphism (SNP) markers. Composite interval mapping (CIM) revealed repeatedly detected QTL for DCI on C06 and C09. The estimated additive effect increased at high temperatures. Significant QTL × environment interactions (Q × E) for FLN and DCI on C06 and C09 suggest that these hotspot regions have major influences on temperature mediated curd induction. 25 % of the DH lines did not induce curds at temperatures higher than 22 °C. Applying a binary model revealed a QTL with LOD >15 on C06. Nearly all lines carrying the allele of the reliable early maturing parental line (PL) on that locus induced curds at high temperatures while only half of the DH lines carrying the allele of the unreliable PL reached the generative phase during the experiment. Large variation in LAR was observed. QTL for LAR were detected repeatedly in several environments on C01, C04 and C06. Negative correlations between LAR and DCI and QTL co-localizations on C04 and C06 suggest that LAR has also effects on development towards curd induction.

  14. Reactor coolant pump monitoring and diagnostic system

    SciTech Connect

    Singer, R.M.; Gross, K.C.; Walsh, M. ); Humenik, K.E. )

    1990-01-01

    In order to reliably and safely operate a nuclear power plant, it is necessary to continuously monitor the performance of numerous subsystems to confirm that the plant state is within its prescribed limits. An important function of a properly designed monitoring system is the detection of incipient faults in all subsystems (with the avoidance of false alarms) coupled with an information system that provides the operators with fault diagnosis, prognosis of fault progression and recommended (either automatic or prescriptive) corrective action. In this paper, such a system is described that has been applied to reactor coolant pumps. This system includes a sensitive pattern-recognition technique based upon the sequential probability ratio test (SPRT) that detects incipient faults from validated signals, an expert system embodying knowledge bases on pump and sensor performance, extensive hypertext files containing operating and emergency procedures as well as pump and sensor information and a graphical interface providing the operator with easily perceived information on the location and character of the fault as well as recommended corrective action. This system is in the prototype stage and is currently being validated utilizing data from a liquid-metal cooled fast reactor (EBR-II). 3 refs., 4 figs.

  15. Corrosion problems with aqueous coolants, final report

    SciTech Connect

    Diegle, R B; Beavers, J A; Clifford, J E

    1980-04-11

    The results of a one year program to characterize corrosion of solar collector alloys in aqueous heat-transfer media are summarized. The program involved a literature review and a laboratory investigation of corrosion in uninhibited solutions. It consisted of three separate tasks, as follows: review of the state-of-the-art of solar collector corrosion processes; study of corrosion in multimetallic systems; and determination of interaction between different waters and chemical antifreeze additives. Task 1 involved a comprehensive review of published literature concerning corrosion under solar collector operating conditions. The reivew also incorporated data from related technologies, specifically, from research performed on automotive cooling systems, cooling towers, and heat exchangers. Task 2 consisted of determining the corrosion behavior of candidate alloys of construction for solar collectors in different types of aqueous coolants containing various concentrations of corrosive ionic species. Task 3 involved measuring the degradation rates of glycol-based heat-transfer media, and also evaluating the effects of degradation on the corrosion behavior of metallic collector materials.

  16. Effect of Initial Mixture Temperature on Flame Speed of Methane-Air, Propane-Air, and Ethylene-Air Mixtures

    NASA Technical Reports Server (NTRS)

    Dugger, Gordon L

    1952-01-01

    Flame speeds based on the outer edge of the shadow cast by the laminar Bunsen cone were determined as functions of composition for methane-air mixtures at initial mixture temperatures ranging from -132 degrees to 342 degrees c and for propane-air and ethylene-air mixtures at initial mixture temperatures ranging from -73 degrees to 344 degrees c. The data showed that maximum flame speed increased with temperature at an increasing rate. The percentage change in flame speed with change in initial temperature for the three fuels followed the decreasing order, methane, propane, and ethylene. Empirical equations were determined for maximum flame speed as a function of initial temperature over the temperature range covered for each fuel. The observed effect of temperature on flame speed for each of the fuels was reasonably well predicted by either the thermal theory as presented by Semenov or the square-root law of Tanford and Pease.

  17. Behaviour of a two rows of holes coolant film along the pressure side of a high pressure nozzle guide vane

    NASA Astrophysics Data System (ADS)

    Arts, T.; Bourguignon, A. E.

    1989-06-01

    The purpose of this paper is to quantify the influence on external convective heat transfer of a coolant film whose position varies along the pressure side of a high pressure turbine nozzle guide vane. The measurements were performed in the short duration Isentropic Light Piston Compression Tube facility of the von Karman Institute. The effects of external and internal flow are considered in terms of Mach number, Reynolds number, freestream turbulence intensity, blowing rate and coolant to freestream temperature ratio. The way to evaluate these results in terms of film cooling efficiency and heat transfer coefficient is finally discussed.

  18. Flow boiling with enhancement devices for cold plate coolant channel design

    NASA Astrophysics Data System (ADS)

    Boyd, Ronald D.; Turknett, Jerry C.; Smith, Alvin

    1989-08-01

    The effects of enhancement devices on flow boiling heat transfer in circular coolant channels, which are heated over a fraction of their perimeters, are studied. The variations were examined in both the mean and local (axial, and circumferential) heat transfer coefficients for a circular coolant channel with either smooth walls or with both a twisted tape and spiral finned walls. Improvements were initiated in the present data reduction analysis. These efforts should lead to the development of heat transfer correlations which include effects of single side heat flux and enhancement device configuration. It is hoped that a stage will be set for the study of heat transfer and pressure drop in single sided heated systems under zero gravity conditions.

  19. Flow boiling with enhancement devices for cold plate coolant channel design

    NASA Technical Reports Server (NTRS)

    Boyd, Ronald D.; Turknett, Jerry C.; Smith, Alvin

    1989-01-01

    The effects of enhancement devices on flow boiling heat transfer in circular coolant channels, which are heated over a fraction of their perimeters, are studied. The variations were examined in both the mean and local (axial, and circumferential) heat transfer coefficients for a circular coolant channel with either smooth walls or with both a twisted tape and spiral finned walls. Improvements were initiated in the present data reduction analysis. These efforts should lead to the development of heat transfer correlations which include effects of single side heat flux and enhancement device configuration. It is hoped that a stage will be set for the study of heat transfer and pressure drop in single sided heated systems under zero gravity conditions.

  20. Copper-based micro-channel cooler reliably operated using solutions of distilled-water and ethanol as a coolant

    NASA Astrophysics Data System (ADS)

    Chin, A. K.; Nelson, A.; Chin, R. H.; Bertaska, R.; Jacob, J. H.

    2015-03-01

    Copper-based micro-channel coolers (Cu-MCC) are the lowest thermal-resistance heat-sinks for high-power laserdiode (LD) bars. Presently, the resistivity, pH and oxygen content of the de-ionized water coolant, must be actively controlled to minimize cooler failure by corrosion and electro-corrosion. Additionally, the water must be constantly exposed to ultraviolet radiation to limit the growth of micro-organisms that may clog the micro-channels. In this study, we report the reliable, care-free operation of LD-bars attached to Cu-MCCs, using a solution of distilledwater and ethanol as the coolant. This coolant meets the storage requirements of Mil-Std 810G, e.g. exposure to a storage temperature as low as -51°C and no growth of micro-organisms during passive storage.

  1. Linear dependence of surface expansion speed on initial plasma temperature in warm dense matter

    SciTech Connect

    Bang, Woosuk; Albright, Brian James; Bradley, Paul Andrew; Vold, Erik Lehman; Boettger, Jonathan Carl; Fernández, Juan Carlos

    2016-07-12

    Recent progress in laser-driven quasi-monoenergetic ion beams enabled the production of uniformly heated warm dense matter. Matter heated rapidly with this technique is under extreme temperatures and pressures, and promptly expands outward. While the expansion speed of an ideal plasma is known to have a square-root dependence on temperature, computer simulations presented here show a linear dependence of expansion speed on initial plasma temperature in the warm dense matter regime. The expansion of uniformly heated 1–100 eV solid density gold foils was modeled with the RAGE radiation-hydrodynamics code, and the average surface expansion speed was found to increase linearly with temperature. The origin of this linear dependence is explained by comparing predictions from the SESAME equation-of-state tables with those from the ideal gas equation-of-state. In conclusion, these simulations offer useful insight into the expansion of warm dense matter and motivate the application of optical shadowgraphy for temperature measurement.

  2. Linear dependence of surface expansion speed on initial plasma temperature in warm dense matter

    DOE PAGES

    Bang, Woosuk; Albright, Brian James; Bradley, Paul Andrew; ...

    2016-07-12

    Recent progress in laser-driven quasi-monoenergetic ion beams enabled the production of uniformly heated warm dense matter. Matter heated rapidly with this technique is under extreme temperatures and pressures, and promptly expands outward. While the expansion speed of an ideal plasma is known to have a square-root dependence on temperature, computer simulations presented here show a linear dependence of expansion speed on initial plasma temperature in the warm dense matter regime. The expansion of uniformly heated 1–100 eV solid density gold foils was modeled with the RAGE radiation-hydrodynamics code, and the average surface expansion speed was found to increase linearly withmore » temperature. The origin of this linear dependence is explained by comparing predictions from the SESAME equation-of-state tables with those from the ideal gas equation-of-state. In conclusion, these simulations offer useful insight into the expansion of warm dense matter and motivate the application of optical shadowgraphy for temperature measurement.« less

  3. Linear dependence of surface expansion speed on initial plasma temperature in warm dense matter

    NASA Astrophysics Data System (ADS)

    Bang, W.; Albright, B. J.; Bradley, P. A.; Vold, E. L.; Boettger, J. C.; Fernández, J. C.

    2016-07-01

    Recent progress in laser-driven quasi-monoenergetic ion beams enabled the production of uniformly heated warm dense matter. Matter heated rapidly with this technique is under extreme temperatures and pressures, and promptly expands outward. While the expansion speed of an ideal plasma is known to have a square-root dependence on temperature, computer simulations presented here show a linear dependence of expansion speed on initial plasma temperature in the warm dense matter regime. The expansion of uniformly heated 1–100 eV solid density gold foils was modeled with the RAGE radiation-hydrodynamics code, and the average surface expansion speed was found to increase linearly with temperature. The origin of this linear dependence is explained by comparing predictions from the SESAME equation-of-state tables with those from the ideal gas equation-of-state. These simulations offer useful insight into the expansion of warm dense matter and motivate the application of optical shadowgraphy for temperature measurement.

  4. Linear dependence of surface expansion speed on initial plasma temperature in warm dense matter.

    PubMed

    Bang, W; Albright, B J; Bradley, P A; Vold, E L; Boettger, J C; Fernández, J C

    2016-07-12

    Recent progress in laser-driven quasi-monoenergetic ion beams enabled the production of uniformly heated warm dense matter. Matter heated rapidly with this technique is under extreme temperatures and pressures, and promptly expands outward. While the expansion speed of an ideal plasma is known to have a square-root dependence on temperature, computer simulations presented here show a linear dependence of expansion speed on initial plasma temperature in the warm dense matter regime. The expansion of uniformly heated 1-100 eV solid density gold foils was modeled with the RAGE radiation-hydrodynamics code, and the average surface expansion speed was found to increase linearly with temperature. The origin of this linear dependence is explained by comparing predictions from the SESAME equation-of-state tables with those from the ideal gas equation-of-state. These simulations offer useful insight into the expansion of warm dense matter and motivate the application of optical shadowgraphy for temperature measurement.

  5. Modulation of the neutron field in the multiplying condensed matter and coolant

    SciTech Connect

    Vodyanitskii, A. A.; Slyusarenko, Yu. V.

    2009-12-14

    The spatial damping of acoustic, neutron and thermal branches of oscillations are found in neutron multiplying medium with coolant. All three branches give additive contribution to the neutron density oscillations. However, their wave numbers and coefficients of spatial damping (at the same frequency) differ greatly from the sound with its high phase velocity and small attenuation to the neutron wave with the damping length, which is comparable with its wavelength. A spatial growth of neutron density oscillations is found in the case of large frequency of neutron capture and weak coupling of neutron density and temperature branches of oscillations. This fact is of importance for the noise diagnostics of the multiplying medium with coolant. The results can be applied to the development of the methods of noise diagnostics of the in core reactor equipment.

  6. Flow boiling with enhancement devices for cold plate coolant channel design

    NASA Technical Reports Server (NTRS)

    Boyd, Ronald D.

    1991-01-01

    Future space exploration and commercialization will require more efficient heat rejection systems. For the required heat transfer rates, such systems must use advanced heat transfer techniques. Forced two phase flow boiling heat transfer with enhancements falls in this category. However, moderate to high quality two phase systems tend to require higher pressure losses. This report is divided into two major parts: (1) Multidimensional wall temperature measurement and heat transfer enhancement for top heated horizontal channels with flow boiling; and (2) Improved analytical heat transfer data reduction for a single side heated coolant channel. Part 1 summarizes over forty experiments which involve both single phase convection and flow boiling in a horizontal channel heated externally from the top side. Part 2 contains parametric dimensionless curves with parameters such as the coolant channel radius ratio, the Biot number, and the circumferential coordinate.

  7. Design of the coolant system for the Large Coil Test Facility pulse coils

    SciTech Connect

    Bridgman, C.; Ryan, T.L.

    1983-01-01

    The pulse coils will be a part of the Large Coil Test Facility in Oak Ridge, Tennessee, which is designed to test six large tokamak-type superconducting coils. The pulse coil set consists of two resistive coaxial solenoid coils, mounted so that their magnetic axis is perpendicular to the toroidal field lines of the test coil. The pulse coils provide transient vertical fields at test coil locations to simulate the pulsed vertical fields present in tokamak devices. The pulse coils are designed to be pulsed for 30 s every 150 s, which results in a Joule heating of 116 kW per coil. In order to provide this capability, the pulse coil coolant system is required to deliver 6.3 L/s (100 gpm) of subcooled liquid nitrogen at 10-atm absolute pressure. The coolant system can also cool down each pulse coil from room temperature to liquid nitrogen temperature. This paper provides details of the pumping and heat exchange equipment designed for the coolant system and of the associated instrumentation and controls.

  8. MATLAB/Simulink Framework for Modeling Complex Coolant Flow Configurations of Advanced Automotive Thermal Management Systems

    SciTech Connect

    Titov, Gene; Lustbader, Jason; Leighton, Daniel; Kiss, Tibor

    2016-04-05

    The National Renewable Energy Laboratory's (NREL's) CoolSim MATLAB/Simulink modeling framework was extended by including a newly developed coolant loop solution method aimed at reducing the simulation effort for arbitrarily complex thermal management systems. The new approach does not require the user to identify specific coolant loops and their flow. The user only needs to connect the fluid network elements in a manner consistent with the desired schematic. Using the new solution method, a model of NREL's advanced combined coolant loop system for electric vehicles was created that reflected the test system architecture. This system was built using components provided by the MAHLE Group and included both air conditioning and heat pump modes. Validation with test bench data and verification with the previous solution method were performed for 10 operating points spanning a range of ambient temperatures between -2 degrees C and 43 degrees C. The largest root mean square difference between pressure, temperature, energy and mass flow rate data and simulation results was less than 7%.

  9. Role of initial state and final quench temperature on aging properties in phase-ordering kinetics

    NASA Astrophysics Data System (ADS)

    Corberi, Federico; Villavicencio-Sanchez, Rodrigo

    2016-05-01

    We study numerically the two-dimensional Ising model with nonconserved dynamics quenched from an initial equilibrium state at the temperature Ti≥Tc to a final temperature Tf below the critical one. By considering processes initiating both from a disordered state at infinite temperature Ti=∞ and from the critical configurations at Ti=Tc and spanning the range of final temperatures Tf∈[0 ,Tc[ we elucidate the role played by Ti and Tf on the aging properties and, in particular, on the behavior of the autocorrelation C and of the integrated response function χ . Our results show that for any choice of Tf, while the autocorrelation function exponent λC takes a markedly different value for Ti=∞ [λC(Ti=∞ ) ≃5 /4 ] or Ti=Tc [λC(Ti=Tc) ≃1 /8 ] the response function exponents are unchanged. Supported by the outcome of the analytical solution of the solvable spherical model we interpret this fact as due to the different contributions provided to autocorrelation and response by the large-scale properties of the system. As changing Tf is considered, although this is expected to play no role in the large-scale and long-time properties of the system, we show important effects on the quantitative behavior of χ . In particular, data for quenches to Tf=0 are consistent with a value of the response function exponent λχ=1/2 λC(Ti=∞ ) =5 /8 different from the one [λχ∈(0.5 -0.56 ) ] found in a wealth of previous numerical determinations in quenches to finite final temperatures. This is interpreted as due to important preasymptotic corrections associated to Tf>0 .

  10. Transient two-phase performance of LOFT reactor coolant pumps

    SciTech Connect

    Chen, T.H.; Modro, S.M.

    1983-01-01

    Performance characteristics of Loss-of-Fluid Test (LOFT) reactor coolant pumps under transient two-phase flow conditions were obtained based on the analysis of two large and small break loss-of-coolant experiments conducted at the LOFT facility. Emphasis is placed on the evaluation of the transient two-phase flow effects on the LOFT reactor coolant pump performance during the first quadrant operation. The measured pump characteristics are presented as functions of pump void fraction which was determined based on the measured density. The calculated pump characteristics such as pump head, torque (or hydraulic torque), and efficiency are also determined as functions of pump void fractions. The importance of accurate modeling of the reactor coolant pump performance under two-phase conditions is addressed. The analytical pump model, currently used in most reactor analysis codes to predict transient two-phase pump behavior, is assessed.

  11. INVESTIGATION OF CLEANER TECHNOLOGIES TO MINIMIZE AUTOMOTIVE COOLANT WASTES

    EPA Science Inventory

    The US Environmental Protection Agency in cooperation with the State of New Jersey evaluated chemical filtration and distillation technologies designed to recycle automotive and heavy-duty engine coolants. These evaluations addressed the product quality, waste reduction and econo...

  12. INVESTIGATION OF CLEANER TECHNOLOGIES TO MINIMIZE AUTOMOTIVE COOLANT WASTES

    EPA Science Inventory

    The US Environmental Protection Agency in cooperation with the State of New Jersey evaluated chemical filtration and distillation technologies designed to recycle automotive and heavy-duty engine coolants. These evaluations addressed the product quality, waste reduction and econo...

  13. Temperature and initial curvature effects in low-density panel flutter

    NASA Technical Reports Server (NTRS)

    Resende, Hugo B.

    1992-01-01

    The panel flutter phenomenon is studied assuming free-molecule flow. This kind of analysis is relevant in the case of hypersonic flight vehicles traveling at high altitudes, especially in the leeward portion of the vehicle. In these conditions the aerodynamic shear can be expected to be considerably larger than the pressure at a given point, so that the effects of such a loading are incorporated into the structural model. Both the pressure and shear loadings are functions of the panel temperature, which can lead to great variations on the location of the stability boundaries for parametric studies. Different locations can, however, be 'collapsed' onto one another by using as ordinate an appropriately normalized dynamic pressure parameter. This procedure works better for higher values of the panel temperature for a fixed undisturbed flow temperature. Finally, the behavior of the system is studied when the panel has some initial curvature. This leads to the conclusion that it may be unrealistic to try to distinguish between a parabolic or sinusoidal initial shape.

  14. Effect of ion bombardment on the initial growth in low temperature poly-Si formation

    NASA Astrophysics Data System (ADS)

    Murata, K.; Kamiya, K.; Nozawa, R.; Ito, M.; Hori, M.; Goto, T.

    1998-10-01

    Recently, poly-Si films have attracted much attention in the application for TFT of LCD. PECVD is a candidate for the low temperature poly-Si formation. However, the films with good crystallinity are hard to be obtained at lower temperatures (< 300 ^circ C). In this study, firstly, in ECR SiH_4/H2 plasma CVD, poly-Si films were deposited by removing the charged species by using permanent magnets to clarify the effect of ion bombardment. The crystalline fraction of films without charged species was about twice as high as that with charged species from Raman spectra. Moreover, poly-Si films were successfully formed on plastic substrates at a low temperature (150 ^circ C) by eliminating charged species. Furthermore, two step growth method was performed to evaluate the effect of the ion bombardment at the initial stage on the film quality. For the first step, the seed layer was formed without charged species, and the growth layer was formed on the seed layer with charged species. The surface roughness and the crystalline fraction were improved to be 2.5nm and 73% with almost the same deposition rate as that of the conventional ECR PECVD. These results indicate that the ion bombardment prevents the growth of nuclei at the initial stage and affect the roughness and crystallinity of the films.

  15. Effect of initial temperature changes on myocardial enzyme levels and cardiac function in acute myocardial infarction.

    PubMed

    Qian, Yuanyu; Liu, Jie; Ma, Jinling; Meng, Qingyi; Peng, Chaoying

    2014-07-01

    In the present study, the effect of initial body temperature changes on myocardial enzyme levels and cardiac function in acute myocardial infarction (AMI) patients was investigated. A total of 315 AMI patients were enrolled and the mean temperature was calculated based on their body temperature within 24 h of admission to hospital. The patients were divided into four groups according to their normal body temperature: Group A, <36.5°C; group B, ≥36.5°C and <37.0°C; group C, ≥37.0°C and <37.5°C and group D, ≥37.5°C. The levels of percutaneous coronary intervention, myocardial enzymes and troponin T (TNT), as well as cardiac ultrasound images, were analyzed. Statistically significant differences in the quantity of creatine kinase at 12 and 24 h following admission were identified between group A and groups C and D (P<0.01). A significant difference in TNT at 12 h following admission was observed between groups A and D (P<0.05), however, this difference was not observed with groups B and C. The difference in TNT between the groups at 24 h following admission was not statistically significant (P>0.05). Significant differences in lactate dehydrogenase at 12 and 24 h following admission were observed between groups A and D (P<0.05), however, differences were not observed with groups B and C (P>0.05). Significant differences in glutamic-oxaloacetic transaminase at 12 and 24 h following admission were observed between groups A and D (P<0.05), however, differences were not observed in groups B and C (P>0.05). However, no significant differences were identified in cardiac function index between all the groups. Therefore, the results of the present study indicated that AMI patients with low initial body temperatures exhibited decreased levels of myocardial enzymes and TNT. Thus, the observation of an initially low body temperature may be used as a protective factor for AMI and may improve the existing clinical program.

  16. A Comparison of Coolant Options for Brayton Power Conversion Heat Rejection Systems

    NASA Technical Reports Server (NTRS)

    Siamidis, John; Mason, Lee S.

    2006-01-01

    This paper describes potential heat rejection design concepts for Brayton power conversion systems. Brayton conversion systems are currently under study by NASA for Nuclear Electric Propulsion (NEP) and surface power applications. The Brayton Heat Rejection Subsystem (HRS) must dissipate waste heat generated by the power conversion system due to inefficiencies in the thermal-to-electric conversion process. Sodium potassium (NaK) and H2O are two coolant working fluids that have been investigated in the design of a pumped loop and heat pipe space HRS. In general NaK systems are high temperature (300 to 1000 K) low pressure systems, and H2O systems are low temperature (300 to 600 K) high pressure systems. NaK is an alkali metal with health and safety hazards that require special handling procedures. On the other hand, H2O is a common fluid, with no health hazards and no special handling procedures. This paper compares NaK and H2O for the HRS pumped loop coolant working fluid. A detailed Microsoft Excel (Microsoft Corporation, Redmond, WA) analytical model, HRS_Opt, was developed to evaluate the various HRS design parameters. It is capable of analyzing NaK or H2O coolant, parallel or series flow configurations, and numerous combinations of other key parameters (heat pipe spacing, diameter and radial flux, radiator facesheet thickness, fluid duct system pressure drop, system rejected power, etc.) of the HRS. This paper compares NaK against water for the HRS coolant working fluid with respect to the relative mass, performance, design and implementation issues between the two fluids.

  17. A Comparison of Coolant Options for Brayton Power Conversion Heat Rejection Systems

    NASA Technical Reports Server (NTRS)

    Mason, Lee S.; Siamidis, John

    2006-01-01

    This paper describes potential heat rejection design concepts for Brayton power conversion systems. Brayton conversion systems are currently under study by NASA for Nuclear Electric Propulsion (NEP) and surface power applications. The Brayton Heat Rejection Subsystem (HRS) must dissipate waste heat generated by the power conversion system due to inefficiencies in the thermal-to-electric conversion process. Sodium potassium (NaK) and H2O are two coolant working fluids that have been investigated in the design of a pumped loop and heat pipe space HRS. In general NaK systems are high temperature (300 to 1000 K) low pressure systems, and H2O systems are low temperature (300 to 600 K) high pressure systems. NaK is an alkali metal with health and safety hazards that require special handling procedures. On the other hand, H2O is a common fluid, with no health hazards and no special handling procedures. This paper compares NaK and H20 for the HRS pumped loop coolant working fluid. A detailed Microsoft Excel (Microsoft Corporation, Redmond, WA) analytical model, HRS_Opt, was developed to evaluate the various HRS design parameters. It is capable of analyzing NaK or H2O coolant, parallel or series flow configurations, and numerous combinations of other key parameters (heat pipe spacing, diameter and radial flux, radiator facesheet thickness, fluid duct system pressure drop, system rejected power, etc.) of the HRS. This paper compares NaK against water for the HRS coolant working fluid with respect to the relative mass, performance, design and implementation issues between the two fluids.

  18. A Comparison of Coolant Options for Brayton Power Conversion Heat Rejection Systems

    SciTech Connect

    Siamidis, John; Mason, Lee

    2006-01-20

    This paper describes potential heat rejection design concepts for Brayton power conversion systems. Brayton conversion systems are currently under study by NASA for Nuclear Electric Propulsion (NEP) and surface power applications. The Brayton Heat Rejection Subsystem (HRS) must dissipate waste heat generated by the power conversion system due to inefficiencies in the thermal-to-electric conversion process. Sodium potassium (NaK) and H2O are two coolant working fluids that have been investigated in the design of a pumped loop and heat pipe space HRS. In general NaK systems are high temperature (300 to 1000 K) low pressure systems, and H2O systems are low temperature (300 to 600 K) high pressure systems. NaK is an alkali metal with health and safety hazards that require special handling procedures. On the other hand, H2O is a common fluid, with no health hazards and no special handling procedures. This paper compares NaK and H2O for the HRS pumped loop coolant working fluid. A detailed excel analytical model, HRS{sub O}pt, was developed to evaluate the various HRS design parameters. It is capable of analyzing NaK or H2O coolant, parallel or series flow configurations, and numerous combinations of other key parameters (heat pipe spacing, diameter and radial flux, radiator facesheet thickness, fluid duct system pressure drop, system rejected power, etc.) of the HRS. This paper compares NaK against water for the HRS coolant working fluid with respect to the relative mass, performance, design and implementation issues between the two fluids.

  19. Chemical Characterization of Simulated Boiling Water Reactor Coolant

    DTIC Science & Technology

    1990-05-01

    industry to reduce personnel radiation exposure and down-time associated with the operation, mainte- nance and refueling of Light Water Reactor (LWR...AD-A226 654 t t-FILL UIY C CHEMICAL CHARACTERIZATION OF SIMULATED , .BOILING WATER REACTOR COOLANt by Li . . , . , - VERRDON HOLBROOK MASON f ; B.S...CHARACTERIZATION OF SIMULATED BOILING WATER REACTOR COOLANT by VERRDON HOLBROOK MASON Submitted to the Department of Nuclear Engineering on May 9, 1988 in

  20. Investigation of cleaner technologies to minimize automotive coolant wastes

    SciTech Connect

    Randall, P.M.

    1993-01-01

    The U.S. Environmental Protection Agency in cooperation with the State of New Jersey evaluated chemical filtration and distillation technologies designed to recycle automotive and heavy-duty engine coolants. These evaluations addressed the product quality, waste reduction, and economic issues. In addition, the authors examined the potential for substituting propylene glycol for ethylene glycol based engine coolant formulations. (Copyright (c) 1993 Butterworth-Heinemann Ltd.)

  1. Estimating Loss-of-Coolant Accident Frequencies for the Standardized Plant Analysis Risk Models

    SciTech Connect

    S. A. Eide; D. M. Rasmuson; C. L. Atwood

    2008-09-01

    The U.S. Nuclear Regulatory Commission maintains a set of risk models covering the U.S. commercial nuclear power plants. These standardized plant analysis risk (SPAR) models include several loss-of-coolant accident (LOCA) initiating events such as small (SLOCA), medium (MLOCA), and large (LLOCA). All of these events involve a loss of coolant inventory from the reactor coolant system. In order to maintain a level of consistency across these models, initiating event frequencies generally are based on plant-type average performance, where the plant types are boiling water reactors and pressurized water reactors. For certain risk analyses, these plant-type initiating event frequencies may be replaced by plant-specific estimates. Frequencies for SPAR LOCA initiating events previously were based on results presented in NUREG/CR-5750, but the newest models use results documented in NUREG/CR-6928. The estimates in NUREG/CR-6928 are based on historical data from the initiating events database for pressurized water reactor SLOCA or an interpretation of results presented in the draft version of NUREG-1829. The information in NUREG-1829 can be used several ways, resulting in different estimates for the various LOCA frequencies. Various ways NUREG-1829 information can be used to estimate LOCA frequencies were investigated and this paper presents two methods for the SPAR model standard inputs, which differ from the method used in NUREG/CR-6928. In addition, results obtained from NUREG-1829 are compared with actual operating experience as contained in the initiating events database.

  2. Coupled reactor physics and coolant dynamics of heavy-liquid-metal-coolant systems

    SciTech Connect

    Cahalan, J.E.; Dunn, F.E.; Taiwo, T.A.

    1999-07-01

    Cooling of advanced nuclear designs with heavy liquid metals such as lead or lead-bismuth eutectic offers improved safety characteristics and higher operating efficiencies compared with previously considered liquid-metal coolants such as sodium or NaK. Such applications would, however, also introduce additional safety concerns and design challenges, therefore necessitating a verifiable computational tool for transient design-basis analysis of heavy-liquid-metal-coolant (HLMC) systems. This capability would enable analysts to compare operational and safety characteristics of design alternatives and to evaluate relative performance advantages with a consistent, deterministic measure. No existing computer code provides all the computational capabilities needed for system analysis of HLMC designs. However, the SASSYS-1 computer code, long used for analysis of sodium-cooled designs, has been adapted to provide a scoping reactor kinetics/thermal-hydraulics analysis capability and a framework for future development. Revision of the SASSYS-1 reactor kinetics, thermophysical properties, convective heat transfer, and flow momentum transfer models has permitted preliminary design and safety assessments of HLMC systems. Preliminary results are given here.

  3. Analysis of High Temperature Reactor Control Rod Worth for the Initial and Full Core

    NASA Astrophysics Data System (ADS)

    Oktajianto, Hammam; Setiawati, Evi; Anam, Khoirul; Sugito, Heri

    2017-01-01

    Control rod is one important component in a nuclear reactor. In nuclear reactor operations the control rod functions to shut down the reactor. This research analyses ten control rods worth of HTR (High Temperature Reactor) at initial and full core. The HTR in this research adopts HTR-10 China and HTR- of pebble bed. Core calculations are performed by using MCNPX code after modelling the entire parts of core in condition of ten control rods fully withdrawn, all control rods in with 20 cm ranges of depth and the use of one control rod. Pebble bed and moderator balls are distributed in the core zone using a Body Centred Cubic (BCC) lattice by ratio of 57:43. The research results are obtained that the use of one control rod will decrease the reactor criticality of 2.04±0.12 %Δk/k at initial core and 1.57±0.10 %Δk/k at full core. The deeper control rods are in, the lesser criticality of reactor is with reactivity of ten control rods of 16.41±0.11 %Δk/k at initial core and 15.43±0.11 %Δk/k at full core. The results show that the use of ten control rods at full core will keep achieving subcritical condition even though the reactivity is smaller than reactivity at initial core.

  4. Radiation effects in the stainless steel primary coolant supply adapter

    SciTech Connect

    Farrell, K.

    1995-09-01

    The primary coolant supply adapter (PCSA) is a flanged, cylindrical collar of 316NG stainless steel that is part of the primary pressure boundary of the Advanced Neutron Source. The radiation fluxes on the PCSA are dominated by thermal neutrons. During its intended 40-year service life, the PCSA will receive a thermal neutron fluence of 1.8 {times} 10{sup 26} m{sup {minus}2} in its upper sections at a temperature of <1OO{degree}C. The PCSA will suffer radiation damage, caused primarily by the interaction of thermal neutrons with the 14% nickel in the steel, which will generate helium by the sequential reactions {sup 58}Ni (n,y){sup 59}Ni (n,{alpha}){sup 56}Fe and will concurrently produce significant atomic displacements per atom (dpa) from the {sup 59}Ni (n,{alpha}){sup 56}Fe recoils. It is estimated that the helium concentration and total atomic displacements in the upper parts of the PCSA will be about 430 atomic parts per million and 1 dpa, respectively. From newly compiled trend curves of tensile properties and fracture toughness data versus atomic displacements for 316 steel, it is deduced that the irradiated PCSA will retain at least 20% uniform tensile elongation and a fracture toughness of more than 200 Mpa{radical}m, which are judged adequate to resist brittle failure. Tberefore, employment of a neutron shield around the PCSA is unnecessary.

  5. Controlling the Velocity of Jumping Nanodroplets Via Their Initial Shape and Temperature

    SciTech Connect

    Kent, Paul R

    2011-01-01

    Controlling the movement of nanoscale objects is a significant goal of nanotechnology. Dewetting-induced ejection of nanodroplets could provide another means of achieving that goal. Molecular dynamics simulations were used to investigate the dewetting-induced ejection of nanoscale liquid copper nanostructures that were deposited on a graphitic substrate. Nanostructures in the shape of a circle, square, equilateral, and isosceles triangle dewet and form nanodroplets that are ejected from the substrate with a velocity that depends on the initial shape and temperature. The dependence of the ejected velocity on shape is ascribed to the temporal asymmetry of the mass coalescence during the droplet formation; the dependence on temperature is ascribed to changes in the density and viscosity. The results suggest that dewetting induced by nanosecond laser pulses could be used to control the velocity of ejected nanodroplets.

  6. PACER -- A fast running computer code for the calculation of short-term containment/confinement loads following coolant boundary failure. Volume 1: Code models and correlations

    SciTech Connect

    Sienicki, J.J.

    1997-06-01

    A fast running and simple computer code has been developed to calculate pressure loadings inside light water reactor containments/confinements under loss-of-coolant accident conditions. PACER was originally developed to calculate containment/confinement pressure and temperature time histories for loss-of-coolant accidents in Soviet-designed VVER reactors and is relevant to the activities of the US International Nuclear Safety Center. The code employs a multicompartment representation of the containment volume and is focused upon application to early time containment phenomena during and immediately following blowdown. Flashing from coolant release, condensation heat transfer, intercompartment transport, and engineered safety features are described using best estimate models and correlations often based upon experiment analyses. Two notable capabilities of PACER that differ from most other containment loads codes are the modeling of the rates of steam and water formation accompanying coolant release as well as the correlations for steam condensation upon structure.

  7. The development of Sn-Li coolant/breeding material for APEX/ALPS applications.

    SciTech Connect

    Sze, D.-K.

    1999-07-08

    A Sn-Li alloy has been identified to be a coolant/breeding material for D-T fusion applications. The key feature of this material is its very low vapor pressure, which will be very useful for free surface concepts employed in APEX, ALPS and inertial confinement fission. The vapor is dominated by lithium, which has very low Z. Initial assessment of the material indicates acceptable tritium breeding capability, high thermal conductivity, expected low tritium volubility, and expected low chemical reactivities with water and air. Some key concerns are the high activation and material compatibility issues. The initial assessment of this material, for fission applications, is presented in this paper.

  8. [Evaluation of the influence of humidity and temperature on the drug stability by initial average rate experiment].

    PubMed

    He, Ning; Sun, Hechun; Dai, Miaomiao

    2014-05-01

    To evaluate the influence of temperature and humidity on the drug stability by initial average rate experiment, and to obtained the kinetic parameters. The effect of concentration error, drug degradation extent, humidity and temperature numbers, humidity and temperature range, and average humidity and temperature on the accuracy and precision of kinetic parameters in the initial average rate experiment was explored. The stability of vitamin C, as a solid state model, was investigated by an initial average rate experiment. Under the same experimental conditions, the kinetic parameters obtained from this proposed method were comparable to those from classical isothermal experiment at constant humidity. The estimates were more accurate and precise by controlling the extent of drug degradation, changing humidity and temperature range, or by setting the average temperature closer to room temperature. Compared with isothermal experiments at constant humidity, our proposed method saves time, labor, and materials.

  9. A unique approach to demonstrating that apical bud temperature specifically determines leaf initiation rate in the dicot Cucumis sativus.

    PubMed

    Savvides, Andreas; Dieleman, Janneke A; van Ieperen, Wim; Marcelis, Leo F M

    2016-04-01

    Leaf initiation rate is largely determined by the apical bud temperature even when apical bud temperature largely deviates from the temperature of other plant organs. We have long known that the rate of leaf initiation (LIR) is highly sensitive to temperature, but previous studies in dicots have not rigorously demonstrated that apical bud temperature controls LIR independent of other plant organs temperature. Many models assume that apical bud and leaf temperature are the same. In some environments, the temperature of the apical bud, where leaf initiation occurs, may differ by several degrees Celsius from the temperature of other plant organs. In a 28-days study, we maintained temperature differences between the apical bud and the rest of the individual Cucumis sativus plants from -7 to +8 °C by enclosing the apical buds in transparent, temperature-controlled, flow-through, spheres. Our results demonstrate that LIR was completely determined by apical bud temperature independent of other plant organs temperature. These results emphasize the need to measure or model apical bud temperatures in dicots to improve the prediction of crop development rates in simulation models.

  10. Apparatus for controlling coolant level in a liquid-metal-cooled nuclear reactor

    DOEpatents

    Jones, Robert D.

    1978-01-01

    A liquid-metal-cooled fast-breeder reactor which has a thermal liner spaced inwardly of the pressure vessel and includes means for passing bypass coolant through the annulus between the thermal liner and the pressure vessel to insulate the pressure vessel from hot outlet coolant includes control ports in the thermal liner a short distance below the normal operating coolant level in the reactor and an overflow nozzle in the pressure vessel below the control ports connected to an overflow line including a portion at an elevation such that overflow coolant flow is established when the coolant level in the reactor is above the top of the coolant ports. When no makeup coolant is added, bypass flow is inwardly through the control ports and there is no overflow; when makeup coolant is being added, coolant flow through the overflow line will maintain the coolant level.

  11. Experimental research to investigate the performance of bio coolant when turning of mild carbon steel

    NASA Astrophysics Data System (ADS)

    Agus Susanto, Tri; Nur, Rusdi

    2017-04-01

    Some literatures have been reported that the using bio coolant show better lubricating and cooling performances and reduce the occupational health risks associated with petroleum-oil-based coolant since they have lower toxicity. This paper investigates the effect the cutting conditions on the surface roughness through turning of mild carbon steel using dry, coolant and bio coolant. Measurement of surface roughness was conducted and then compared with the change of the cutting conditions. The relationship between surface roughness and cutting conditions was created in a curve for different of the cutting speed and coolant. The results indicate that the surface roughness was reduced when the speed of cutting is set to the highest level for all of coolant conditions (dry, coolant, and bio coolant) and constant of DOC and feed. The surface roughness had better performance using bio coolant than coolant conventional (mineral fluid).

  12. Effects of rotation on coolant passage heat transfer. Volume 2: Coolant passages with trips normal and skewed to the flow

    NASA Technical Reports Server (NTRS)

    Johnson, B. V.; Wagner, J. H.; Steuber, G. D.

    1993-01-01

    An experimental program was conducted to investigate heat transfer and pressure loss characteristics of rotating multipass passages, for configurations and dimensions typical of modem turbine blades. This experimental program is one part of the NASA Hot Section Technology (HOST) Initiative, which has as its overall objective the development and verification of improved analysis methods that will form the basis for a design system that will produce turbine components with improved durability. The objective of this program was the generation of a data base of heat transfer and pressure loss data required to develop heat transfer correlations and to assess computational fluid dynamic techniques for rotating coolant passages. The experimental work was broken down into two phases. Phase 1 consists of experiments conducted in a smooth wall large scale heat transfer model. A detailed discussion of these results was presented in volume 1 of a NASA Report. In Phase 2 the large scale model was modified to investigate the effects of skewed and normal passage turbulators. The results of Phase 2 along with comparison to Phase 1 is the subject of this Volume 2 NASA Report.

  13. Transient tension changes initiated by laser temperature jumps in rabbit psoas muscle fibres.

    PubMed Central

    Goldman, Y E; McCray, J A; Ranatunga, K W

    1987-01-01

    1. A technique was developed to generate 2-8 degrees C step temperature perturbations (T-jumps) in single muscle fibres to study the thermodynamics of muscle contraction. A solid-state pulsed holmium laser emitting at 2.065 microns heated the fibre and surrounding solution in approximately 150 mus. The signal from a 100 microns thermocouple fed back to a heating wire maintained the elevated temperature after the laser pulse. 2. Tension of glycerol-extracted muscle fibres from rabbit psoas muscle did not change significantly following T-jumps when the fibre was relaxed. 3. In rigor, tension decreased abruptly on heating indicating normal (not rubber-like) thermoelasticity. The thermoelastic coefficient (negative ratio of relative length change to relative temperature change) of the fibre was estimated to be -0.021 at sarcomere lengths of 2.5-2.8 microns. Rigor tension was constant after the temperature step and returned to the original value on recooling. 4. In maximal Ca2+ activation, tension transients initiated by T-jumps had several phases. An immediate tension decrease suggests that thermoelasticity during contraction is similar to that in rigor. Active tension then recovered to the value before the T-jump with an apparent rate constant of approximately 400 s-1 (at 10-20 degrees C). This rate constant did not have an appreciable dependence on the final temperature. Finally, tension increased exponentially to a new higher level with a rate constant of approximately 20 s-1 at 20 degrees C. This rate constant increased with temperature with a Q10 of 1.4. 5. At submaximal Ca2+ activation the tension rise was followed by a decay to below the value before the T-jump. This decline was expected from the temperature dependence of steady pCa-tension curves. The final tension decline occurred on the 1-5 s time scale. 6. The value and amplitude dependence of the rate constant for the quick recovery following T-jumps were similar to those of the quick recovery following

  14. Buoyancy Driven Coolant Mixing Studies of Natural Circulation Flows at the ROCOM Test Facility Using ANSYS CFX

    SciTech Connect

    Hohne, Thomas; Kliem, Soren; Rohde, Ulrich; Weiss, Frank-Peter

    2006-07-01

    Coolant mixing in the cold leg, downcomer and the lower plenum of pressurized water reactors is an important phenomenon mitigating the reactivity insertion into the core. Therefore, mixing of the de-borated slugs with the ambient coolant in the reactor pressure vessel was investigated at the four loop 1:5 scaled ROCOM mixing test facility. Thermal hydraulics analyses showed, that weakly borated condensate can accumulate in particular in the pump loop seal of those loops, which do not receive safety injection. After refilling of the primary circuit, natural circulation in the stagnant loops can re-establish simultaneously and the de-borated slugs are shifted towards the reactor pressure vessel (RPV). In the ROCOM experiments, the length of the flow ramp and the initial density difference between the slugs and the ambient coolant was varied. From the test matrix experiments with 0 resp. 2% density difference between the de-borated slugs and the ambient coolant were used to validate the CFD software ANSYS CFX. To model the effects of turbulence on the mean flow a higher order Reynolds stress turbulence model was employed and a mesh consisting of 6.4 million hybrid elements was utilized. Only the experiments and CFD calculations with modeled density differences show a stratification in the downcomer. Depending on the degree of density differences the less dense slugs flow around the core barrel at the top of the downcomer. At the opposite side the lower borated coolant is entrained by the colder safety injection water and transported to the core. The validation proves that ANSYS CFX is able to simulate appropriately the flow field and mixing effects of coolant with different densities. (authors)

  15. Additional requirements for leak-before-break application to primary coolant piping in Belgium

    SciTech Connect

    Roussel, G.

    1997-04-01

    Leak-Before-Break (LBB) technology has not been applied in the first design of the seven Pressurized Water Reactors the Belgian utility is currently operating. The design basis of these plants required to consider the dynamic effects associated with the ruptures to be postulated in the high energy piping. The application of the LBB technology to the existing plants has been recently approved by the Belgian Safety Authorities but with a limitation to the primary coolant loop. LBB analysis has been initiated for the Doel 3 and Tihange 2 plants to allow the withdrawal of some of the reactor coolant pump snubbers at both plants and not reinstall some of the restraints after steam generator replacement at Doel 3. LBB analysis was also found beneficial to demonstrate the acceptability of the primary components and piping to the new conditions resulting from power uprating and stretch-out operation. LBB analysis has been subsequently performed on the primary coolant loop of the Tihange I plant and is currently being performed for the Doel 4 plant. Application of the LBB to the primary coolant loop is based in Belgium on the U.S. Nuclear Regulatory Commission requirements. However the Belgian Safety Authorities required some additional analyses and put some restrictions on the benefits of the LBB analysis to maintain the global safety of the plant at a sufficient level. This paper develops the main steps of the safety evaluation performed by the Belgian Safety Authorities for accepting the application of the LBB technology to existing plants and summarizes the requirements asked for in addition to the U.S. Nuclear Regulatory Commission rules.

  16. Assessment of fiber optic sensors for aging monitoring of industrial liquid coolants

    NASA Astrophysics Data System (ADS)

    Riziotis, Christos; El Sachat, Alexandros; Markos, Christos; Velanas, Pantelis; Meristoudi, Anastasia; Papadopoulos, Aggelos

    2015-03-01

    Lately the demand for in situ and real time monitoring of industrial assets and processes has been dramatically increased. Although numerous sensing techniques have been proposed, only a small fraction can operate efficiently under harsh industrial environments. In this work the operational properties of a proposed photonic based chemical sensing scheme, capable to monitor the ageing process and the quality characteristics of coolants and lubricants in industrial heavy machinery for metal finishing processes is presented. The full spectroscopic characterization of different coolant liquids revealed that the ageing process is connected closely to the acidity/ pH value of coolants, despite the fact that the ageing process is quite complicated, affected by a number of environmental parameters such as the temperature, humidity and development of hazardous biological content as for example fungi. Efficient and low cost optical fiber sensors based on pH sensitive thin overlayers, are proposed and employed for the ageing monitoring. Active sol-gel based materials produced with various pH indicators like cresol red, bromophenol blue and chorophenol red in tetraethylorthosilicate (TEOS), were used for the production of those thin film sensitive layers deposited on polymer's and silica's large core and highly multimoded optical fibers. The optical characteristics, sensing performance and environmental robustness of those optical sensors are presented, extracting useful conclusions towards their use in industrial applications.

  17. Nuclear-radiation-actuated valve. [Patent application; for increasing coolant flow to blanket

    DOEpatents

    Christiansen, D.W.; Schively, D.P.

    1982-01-19

    The present invention relates to a breeder reactor blanket fuel assembly coolant system valve which increases coolant flow to the blanket fuel assembly to minimize long-term temperature increases caused by fission of fissile fuel created from fertile fuel through operation of the breeder reactor. The valve has a valve first part (such as a valve rod with piston) and a valve second part (such as a valve tube surrounding the valve rod, with the valve tube having side slots surrounding the piston). Both valve parts have known nuclear radiation swelling characteristics. The valve's first part is positioned to receive nuclear radiation from the nuclear reactor's fuel region. The valve's second part is positioned so that its nuclear radiation induced swelling is different from that of the valve's first part. The valve's second part also is positioned so that the valve's first and second parts create a valve orifice which changes in size due to the different nuclear radiation caused swelling of the valve's first part compared to the valve's second part. The valve may be used in a nuclear reactor's core coolant system.

  18. Fuel, Structural Material and Coolant for an Advanced Fast Micro-Reactor

    NASA Astrophysics Data System (ADS)

    Do Nascimento, J. A.; Duimarães, L. N. F.; Ono, S.

    The use of nuclear reactors in space, seabed or other Earth hostile environment in the future is a vision that some Brazilian nuclear researchers share. Currently, the USA, a leader in space exploration, has as long-term objectives the establishment of a permanent Moon base and to launch a manned mission to Mars. A nuclear micro-reactor is the power source chosen to provide energy for life support, electricity for systems, in these missions. A strategy to develop an advanced micro-reactor technologies may consider the current fast reactor technologies as back-up and the development of advanced fuel, structural and coolant materials. The next generation reactors (GEN-IV) for terrestrial applications will operate with high output temperature to allow advanced conversion cycle, such as Brayton, and hydrogen production, among others. The development of an advanced fast micro-reactor may create a synergy between the GEN-IV and space reactor technologies. Considering a set of basic requirements and materials properties this paper discusses the choice of advanced fuel, structural and coolant materials for a fast micro-reactor. The chosen candidate materials are: nitride, oxide as back-up, for fuel, lead, tin and gallium for coolant, ferritic MA-ODS and Mo alloys for core structures. The next step will be the neutronic and burnup evaluation of core concepts with this set of materials.

  19. Flow boiling with enhancement devices for cold plate coolant channel design

    NASA Astrophysics Data System (ADS)

    Boyd, Ronald D., Sr.; Smith, Alvin

    1990-02-01

    The use of flow boiling for thermal energy transport is intended to provide an alternative for accommodating higher heat fluxes in commercial space systems. The objectives are to: (1) examine the variations in both the mean and local (axial and circumferential) heat transfer coefficients for a circular coolant channel with either smooth walls, spiral fins, or both spiral fins and a twisted tape; (2) examine the effects of channel diameter and subcooling; and (3) develop an improved reduction analysis and/or suggest possible heat transfer correlation of the present data. Freon-11 is the working fluid. Two-dimensional (circumferential and axial) wall temperature distributions were measured for coolant channels with the above noted internal geometries. The flow regimes which are being studied are: (1) single phase; (2) subcooled flow boiling; and (3) stratified flow boiling. The inside diameter of all test sections is near 1.0 cm. Cicumferentially averaged heat transfer coefficients at several axial locations were obtained for selected coolant channels for a mass velocity of 210 kg/sq m s, an exit pressure of 0.19 MPa (absolute), and an inlet subcooling of 20.8 C. Overall (averaged over the entire channel) heat transfer coefficients were compared for the above channel geometries. This comparison showed that the channel with large pitch spiral fins had higher heat transfer coefficients at all power levels.

  20. Effects of LWR coolant environments on fatigue design curves of carbon and low-alloy steels

    SciTech Connect

    Chopra, O.K.; Shack, W.J.

    1998-03-01

    The ASME Boiler and Pressure Vessel Code provides rules for the construction of nuclear power plant components. Figures I-9.1 through I-9.6 of Appendix I to Section III of the code specify fatigue design curves for structural materials. While effects of reactor coolant environments are not explicitly addressed by the design curves, test data indicate that the Code fatigue curves may not always be adequate in coolant environments. This report summarizes work performed by Argonne National Laboratory on fatigue of carbon and low-alloy steels in light water reactor (LWR) environments. The existing fatigue S-N data have been evaluated to establish the effects of various material and loading variables such as steel type, dissolved oxygen level, strain range, strain rate, temperature, orientation, and sulfur content on the fatigue life of these steels. Statistical models have been developed for estimating the fatigue S-N curves as a function of material, loading, and environmental variables. The results have been used to estimate the probability of fatigue cracking of reactor components. The different methods for incorporating the effects of LWR coolant environments on the ASME Code fatigue design curves are presented.

  1. Flow boiling with enhancement devices for cold plate coolant channel design

    NASA Technical Reports Server (NTRS)

    Boyd, Ronald D., Sr.; Smith, Alvin

    1990-01-01

    The use of flow boiling for thermal energy transport is intended to provide an alternative for accommodating higher heat fluxes in commercial space systems. The objectives are to: (1) examine the variations in both the mean and local (axial and circumferential) heat transfer coefficients for a circular coolant channel with either smooth walls, spiral fins, or both spiral fins and a twisted tape; (2) examine the effects of channel diameter and subcooling; and (3) develop an improved reduction analysis and/or suggest possible heat transfer correlation of the present data. Freon-11 is the working fluid. Two-dimensional (circumferential and axial) wall temperature distributions were measured for coolant channels with the above noted internal geometries. The flow regimes which are being studied are: (1) single phase; (2) subcooled flow boiling; and (3) stratified flow boiling. The inside diameter of all test sections is near 1.0 cm. Cicumferentially averaged heat transfer coefficients at several axial locations were obtained for selected coolant channels for a mass velocity of 210 kg/sq m s, an exit pressure of 0.19 MPa (absolute), and an inlet subcooling of 20.8 C. Overall (averaged over the entire channel) heat transfer coefficients were compared for the above channel geometries. This comparison showed that the channel with large pitch spiral fins had higher heat transfer coefficients at all power levels.

  2. Numerical Simulation of Film Cooling with a Coolant Supplied Through Holes in a Trench

    NASA Astrophysics Data System (ADS)

    Khalatov, A. A.; Panchenko, N. A.; Borisov, I. I.; Severina, V. V.

    2017-05-01

    The results of numerical simulation and experimental investigation of the efficiency of film cooling behind a row of holes in a trench in the range of blowing ratio variation 0.5 ≤ m ≤ 2.0 are presented. This scheme is of practical interest for use in the systems of cooling the blades of high-temperature gas turbines. Comparative analysis has shown that the efficiency of the trench scheme substantially exceeds the efficiency of the traditional scheme. The commercial package ANSYS CFX 14 was used in the Calculation Fluid Dynamics (CFD) modeling of film cooling. It is shown that the best agreement between predicted and experimental data is provided by the use of the SST model of turbulence. Analysis of the physical picture of flow has shown that the higher efficiency of film cooling with secondary air supply to the trench is mainly due to the preliminary spreading of a coolant in the trench, decrease in the intensity and scale of the vortex pair structure, absence of the coolant film departure from the plate surface, and to the more uniform transverse distribution of the coolant film.

  3. Influence of coolant pH on corrosion of 6061 aluminum under reactor heat transfer conditions

    SciTech Connect

    Pawel, S.J.; Felde, D.K.; Pawel, R.E.

    1995-10-01

    To support the design of the Advanced Neutron Source (ANS), an experimental program was conducted wherein aluminum alloy specimens were exposed at high heat fluxes to high-velocity aqueous coolants in a corrosion test loop. The aluminum alloys selected for exposure were candidate fuel cladding materials, and the loop system was constructed to emulate the primary coolant system for the proposed ANS reactor. One major result of this program has been the generation of an experimental database defining oxide film growth on 6061 aluminum alloy cladding. Additionally, a data correlation was developed from the database to permit the prediction of film growth for any reasonable thermal-hydraulic excursion. This capability was utilized effectively during the conceptual design stages of the reactor. During the course of this research, it became clear that the kinetics of film growth on the aluminum alloy specimens were sensitively dependent on the chemistry of the aqueous coolant and that relatively small deviations from the intended pH 5 operational level resulted in unexpectedly large changes in the corrosion behavior. Examination of the kinetic influences and the details of the film morphology suggested that a mechanism involving mass transport from other parts of the test loop was involved. Such a mechanism would also be expected to be active in the operating reactor. This report emphasizes the results of experiments that best illustrate the influence of the nonthermal-hydraulic parameters on film growth and presents data to show that comparatively small variations in pH near 5.0 invoke a sensitive response. Simply, for operation in the temperature and heat flux range appropriate for the ANS studies, coolant pH levels from 4.5 to 4.9 produced significantly less film growth than those from pH 5.1 to 6. A mechanism for this behavior based on the concept of treating the entire loop as an active corrosion system is presented.

  4. Heat-transfer dynamics during cryogen spray cooling of substrate at different initial temperatures

    NASA Astrophysics Data System (ADS)

    Jia, Wangcun; Aguilar, Guillermo; Wang, Guo-Xiang; Nelson, J. Stuart

    2004-12-01

    Cryogen spray cooling (CSC) is used to minimize the risk of epidermal damage during laser dermatologic therapy. However, the dominant mechanisms of heat transfer during the transient cooling process are incompletely understood. The objective of this study is to elucidate the physics of CSC by measuring the effect of initial substrate temperature (T0) on cooling dynamics. Cryogen was delivered by a straight-tube nozzle onto a skin phantom. A fast-response thermocouple was used to record the phantom temperature changes before, during and after the cryogen spray. Surface heat fluxes (q'') and heat-transfer coefficients (h) were computed using an inverse heat conduction algorithm. The maximum surface heat flux (q''max) was observed to increase with T0. The surface temperature corresponding to q''max also increased with T0 but the latter has no significant effect on h. It is concluded that heat transfer between the cryogen spray and skin phantom remains in the nucleate boiling region even if T0 is 80 °C.

  5. Effect of Initial Temperature Treatment on Phytochemicals and Antioxidant Activity of Azadirachta indica A. Juss.

    PubMed

    Vats, Sharad

    2016-02-01

    The present study was undertaken to evaluate the effect of initial temperature treatment on phytochemical and antioxidant potential of commercially important plant Azadirachta indica A. Juss. The leaves were differentially treated after harvest at temperatures 4, -20, and 110 °C and at room temperature, separately. It was found that a quick drying process at 110 °C followed by air-drying helped in maximum retention of bioactive compounds and antioxidant activity, which was significantly higher than other processing methods. Correlation analysis revealed that total phenolic content (TPC) and total flavonoid content (TFC) can be a measure to assess the antioxidant potential using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing/antioxidant power (FRAP) assays. Nitric oxide scavenging assay (NOSA) was insignificantly related to DPPH and FRAP. Also, FRAP and DPPH can be a predictive assay for each other, but not with NOSA. Thus, a quick drying process at 110 °C using an oven can be a cost-effective venture, especially in developing countries, for retaining the nutritive value and antioxidant activity of A. indica.

  6. Heat-transfer dynamics during cryogen spray cooling of substrate at different initial temperatures.

    PubMed

    Jia, Wangcun; Aguilar, Guillermo; Wang, Guo-Xiang; Nelson, J Stuart

    2004-12-07

    Cryogen spray cooling (CSC) is used to minimize the risk of epidermal damage during laser dermatologic therapy. However, the dominant mechanisms of heat transfer during the transient cooling process are incompletely understood. The objective of this study is to elucidate the physics of CSC by measuring the effect of initial substrate temperature (T0) on cooling dynamics. Cryogen was delivered by a straight-tube nozzle onto a skin phantom. A fast-response thermocouple was used to record the phantom temperature changes before, during and after the cryogen spray. Surface heat fluxes (q") and heat-transfer coefficients (h) were computed using an inverse heat conduction algorithm. The maximum surface heat flux (q"max) was observed to increase with T0. The surface temperature corresponding to q"max also increased with T0 but the latter has no significant effect on h. It is concluded that heat transfer between the cryogen spray and skin phantom remains in the nucleate boiling region even if T0 is 80 degrees C.

  7. How does low temperature coupled with different pressures affect initiation mechanisms and subsequent decompositions in nitramine explosive HMX?

    PubMed

    Wu, Qiong; Xiong, Guolin; Zhu, Weihua; Xiao, Heming

    2015-09-21

    We have performed ab initio molecular dynamics simulations to study coupling effects of temperature (534-873 K) and pressure (1-20 GPa) on the initiation mechanisms and subsequent chemical decompositions of nitramine explosive 1,3,5,7-tetranitro-1,3,5,7-tetrazocane (HMX). A new initiation decomposition mechanism of HMX was found to be the unimolecular C-H bond breaking, and this mechanism was independent of the coupling effects of different temperatures and pressures. The formed hydrogen radicals could promote subsequent decompositions of HMX. Subsequent decompositions were very sensitive to the pressure at low temperatures (534 and 608 K), while the temperature became the foremost factor that affected the decomposition at a high temperature (873 K) instead of the pressure. Our study may provide a new insight into understanding the coupling effects of the temperature and pressure on the initiation decomposition mechanisms of nitramine explosives.

  8. Modeling Cladding-Coolant Heat Transfer of High-Burnup Fuel During RIA

    SciTech Connect

    Wenfeng Liu; Kazimi, Mujid S.

    2006-07-01

    This paper describes a model for the cladding-coolant heat transfer of high burnup fuel during a Reactivity Initiated Accident (RIA) which is implemented in the fuel performance code FRAPTRAN 1.2. The minimum stable film boiling temperature, affected by the subcooling and the clad oxidation, is modeled by a modified Henry correlation. This accounts for the effects of thermal properties of the cladding surface on the transient temperature drop during liquid-solid contact. The transition boiling regime is described as the interpolation of the heat flux between two anchor points on the boiling curve: the Critical Heat Flux (CHF) and minimum stable film boiling. The CHF correlation is based on the Zuber hydrodynamic model multiplied by a subcooling factor. Frederking correlation is chosen to model the film boiling regime. The heat conduction through the oxide layer of the cladding surface of high burnup fuel is calculated by solving heat conduction equations with thermal properties of zirconia taken from MATPRO. This model is validated in the FRAPTRAN code for test cases of both high burnup and fresh test fuel rods including the burnup level (0--56 MW d/kg), peak fuel enthalpy deposit (70--190 cal/g), degree of subcooling (0--80 deg. C), and extent of oxidation (0--25 micron). The modified code demonstrates the capability of differentiating between the departure from nucleate boiling (DNB) and none-DNB cases. The predicted peak cladding temperature (PCT) and duration of DNB achieves generally good agreement with the experimental data. It is found that the cladding surface oxidation of high burnup fuel causes an early rewetting of cladding or suppresses DNB due to two factors: 1) Thick zirconia layer may delay the heat conducted to the surface while keeping the surface heat transfer in the most effective nucleate boiling regime. 2) The transient liquid-solid contact resulting from vapor breaking down would cause a lower interface temperature for an oxidized surface

  9. INITIAL RESULTS FROM INVESTIGATIONS TO ENHANCE THE PERFORMANCE OF HIGH TEMPERATURE IRRADIATION-RESISTANT THERMOCOUPLES

    SciTech Connect

    Crepeau, John; Rempe, Joy; Wilkins, S. Curtis; Knudson, Darrell L.; Condie, Keith G.; Daw, Joshua

    2007-04-01

    New fuel, cladding, and structural materials offer the potential for safer and more economic energy from existing reactor and advanced nuclear reactor designs. However, insufficient data are available to characterize these materials in high temperature, radiation conditions. To evaluate candidate material performance, robust instrumentation is needed that can survive these conditions. However, traditional thermocouples either drift due to degradation at high temperatures (above 1100 °C) or due to transmutation of thermocouple components. Thermocouples are needed which can withstand both high temperature and high radiation environments. To address this instrumentation need, the Idaho National Laboratory (INL) recently developed the design and evaluated the performance of a high temperature radiation-resistant thermocouple that contains commercially-available alloys of molybdenum and niobium (Rempe, 2006). Candidate thermocouple component materials were first identified based on their ability to withstand high temperature and radiation. Then, components were selected based on data obtained from materials interaction tests, ductility investigations, and resolution evaluations. Results from long duration (over 4000 hours) tests at high temperatures (up to 1400 °C) and thermal cycling tests demonstrate the stability and reliability of the INL-developed design. Tests in INL’s Advanced Test Reactor (ATR) are underway to demonstrate the in-pile performance of these thermocouples. However, several options have been identified that could further enhance the lifetime and reliability of the INL-developed thermocouples, allowing their use in higher temperature applications (up to at least 1700 °C). A joint University of Idaho (UI) and INL University Nuclear Energy Research Initiative (UNERI) is underway to investigate these options and ultimately, provide recommendations for an enhanced thermocouple design. This paper presents preliminary results from this UI/INL effort

  10. Targeted Temperature Management: Effects of Initial Protocol Implementation on Patient Outcomes.

    PubMed

    Wyse, Jessica; McNett, Molly

    2016-01-01

    Targeted temperature management (TTM) is a strategy used by critical care nurses to mitigate negative effects of out-of-hospital cardiac arrest (OHCA); however, integration and compliance of TTM protocols into routine clinical practice can be challenging. The aims of this study are to (1) investigate the effects of initial TTM protocol implementation on patient mortality, length of stay, and discharge disposition among patients who experience OHCA and (2) evaluate initial compliance and potential barriers to newly implemented TTM protocol. A retrospective cohort design was used. Data were gathered on adult patients experiencing OHCA before and after immediate implementation of a TTM protocol within a large academic public hospital. Demographic and clinical data were abstracted from medical records of both TTM and non-TTM groups. Additional compliance data were gathered on the TTM group. Outcome variables included hospital mortality, length of stay, and discharge disposition. Total accrual was 259. Mortality decreased after protocol implementation (89.4%, 75%, P < .05), which was supported in the regression analyses (P = .05; odds ratio, 2.8). A higher proportion of subjects were discharged home after the TTM protocol (21.5% discharged home after protocol implementation vs 5.1% discharged home before protocol implementation; P < .05). Full protocol compliance was 30%. Protocol documentation was inconsistent across units and personnel. Findings suggest that even initial implementation of TTM protocols can result in positive patient outcomes. Full compliance with protocols remains difficult. Critical care nurses are integral to initiation of and adherence to therapeutic hypothermia protocols and are in a key position to develop strategies for improved compliance across departments.

  11. Heat Exchanger Can Assembly for Provision of Helium Coolant Streams for Cryomodule Testing below 2K

    NASA Astrophysics Data System (ADS)

    Smith, E. N.; Eichhorn, R.; Quigley, P.; Sabol, D.; Shore, C.; Widger, D.

    2017-02-01

    A series of heat exchanger can (HXC) assemblies have been designed, constructed and built to utilize existing 4.2 K liquefaction and compressor capabilities to provide helium gas coolant streams of 80 K, 4.5 K, and liquid from 1.6 to 2.0 K for operating cryomodules containing from one to six superconducting RF cavities built for an energy recovery linear accelerator. Designs for the largest assemblies required up to 100 W of cooling at 1.8 K with precise temperature control, especially during cool-down, and up to 2000 W at 80 K (with a 40 K temperature rise). A novel feature of these assemblies was the use of relatively inexpensive brazed stainless steel plate heat exchangers intended for room-temperature operation with water or oil, but which in practice worked well at cryogenic temperatures. The choice of operating temperatures/pressures were to provide single-phase helium flow for better control of coolant distribution in the 80 K and 4.5 K streams, to take advantage of locally elevated heat capacity near the critical point for the 4.5 K stream, and in the region below 2 K to get the best possible Q from the niobium cavities under test.

  12. SCC Initiation in Alloy 600 Heat Affected Zones Exposed to High Temperature Water

    SciTech Connect

    E Richey; DS Morton; RA Etien; GA Young; RB Bucinell

    2006-11-03

    Studies have shown that grain boundary chromium carbides improve the stress corrosion cracking (SCC) resistance of nickel based alloys exposed to high temperature, high purity water. However, thermal cycles from welding can significantly alter the microstructure of the base material near the fusion line. In particular, the heat of welding can solutionize grain boundary carbides and produce locally high residual stresses and strains, reducing the SCC resistance of the Alloy 600 type material in the heat affected zone (HAZ). Testing has shown that the SCC growth rate in Alloy 600 heat affected zone samples can be {approx}30x faster than observed in the Alloy 600 base material under identical testing conditions due to fewer intergranular chromium rich carbides and increased plastic strain in the HAZ [1, 2]. Stress corrosion crack initiation tests were conducted on Alloy 600 HAZ samples at 360 C in hydrogenated, deaerated water to determine if these microstructural differences significantly affect the SCC initiation resistance of Alloy 600 heat affected zones compared to the Alloy 600 base material. Alloy 600 to EN82H to Alloy 600 heat-affected-zone (HAZ) specimens where fabricated from an Alloy 600 to Alloy 600 narrow groove weld with EN82H filler metal. The approximate middle third of the specimen gauge region was EN82H such that each specimen had two HAZ regions. Tests were conducted with in-situ monitored smooth tensile specimens under a constant load, and a direct current electric potential drop was used for in-situ detection of SCC. Test results suggest that the SCC initiation resistance of Alloy 600 and its weld metal follows the following order: EN82H > Alloy 600 HAZ > Alloy 600. The high SCC initiation resistance observed to date in Alloy 600 heat affected zones compared to wrought Alloy 600 is unexpected based on the microstructure of HAZ versus wrought material and based on prior SCC growth rate studies. The observed behavior for the HAZ specimens is likely

  13. Nuclear criticality safety assessment of the proposed CFC replacement coolants

    SciTech Connect

    Jordan, W.C.; Dyer, H.R.

    1993-12-01

    The neutron multiplication characteristics of refrigerant-114 (R-114) and proposed replacement coolants perfluorobutane (C{sub 4}F{sub 10}) and cycloperfluorobutane C{sub 4}F{sub 8}) have been compared by evaluating the infinite media multiplication factors of UF{sub 6}/H/coolant systems and by replacement calculations considering a 10-MW freezer/sublimer. The results of these comparisons demonstrate that R-114 is a neutron absorber, due to its chlorine content, and that the alternative fluorocarbon coolants are neutron moderators. Estimates of critical spherical geometries considering mixtures of UF{sub 6}/HF/C{sub 4}F{sub 10} indicate that the flourocarbon-moderated systems are large compared with water-moderated systems. The freezer/sublimer calculations indicate that the alternative coolants are more reactive than R-114, but that the reactivity remains significantly below the condition of water in the tubes, which was a limiting condition. Based on these results, the alternative coolants appear to be acceptable; however, several follow-up tasks have been recommended, and additional evaluation will be required on an individual equipment basis.

  14. Diesel engine coolant analysis, new application for established instrumentation

    SciTech Connect

    Anderson, D.P.; Lukas, M.; Lynch, B.K.

    1998-09-01

    Rotating disk electrode (RDE) arc emission spectrometers are used in many commercial, industrial and military laboratories throughout the world to analyze millions of oil and fuel samples each year. In fact, RDE spectrometers have been used exclusively for oil and fuel analysis for so long, that most practitioners have probably forgotten that when RDE spectrometers were first introduced more than 40 years ago, they were also routinely used for aqueous samples. This paper describes recent work to calibrate and modify RDE arc emission spectrometers for the analysis of engine coolant samples; a mixture of approximately 50% water and 50% glycol. The technique has been shown to be effective for the analysis of wear metals, contamination and supplemental coolant additives in ethylene and propylene glycol. A comparison of results for coolant samples measured by both inductively coupled plasma (ICP) and RDE spectrometers will be presented. The data correlates extremely well on new and relatively clean coolants. However, not surprisingly, RDE results are sometimes higher for samples containing particles larger than a few micrometers. This paper suggests that RDE spectrometers are appropriate, and sometimes preferred, for most types of coolants and certain types of aqueous samples. Actual field data is be presented to support the arguments.

  15. Numerical Simulation of Non-Rotating and Rotating Coolant Channel Flow Fields. Part 1

    NASA Technical Reports Server (NTRS)

    Rigby, David L.

    2000-01-01

    Future generations of ultra high bypass-ratio jet engines will require far higher pressure ratios and operating temperatures than those of current engines. For the foreseeable future, engine materials will not be able to withstand the high temperatures without some form of cooling. In particular the turbine blades, which are under high thermal as well as mechanical loads, must be cooled. Cooling of turbine blades is achieved by bleeding air from the compressor stage of the engine through complicated internal passages in the turbine blades (internal cooling, including jet-impingement cooling) and by bleeding small amounts of air into the boundary layer of the external flow through small discrete holes on the surface of the blade (film cooling and transpiration cooling). The cooling must be done using a minimum amount of air or any increases in efficiency gained through higher operating temperature will be lost due to added load on the compressor stage. Turbine cooling schemes have traditionally been based on extensive empirical data bases, quasi-one-dimensional computational fluid dynamics (CFD) analysis, and trial and error. With improved capabilities of CFD, these traditional methods can be augmented by full three-dimensional simulations of the coolant flow to predict in detail the heat transfer and metal temperatures. Several aspects of turbine coolant flows make such application of CFD difficult, thus a highly effective CFD methodology must be used. First, high resolution of the flow field is required to attain the needed accuracy for heat transfer predictions, making highly efficient flow solvers essential for such computations. Second, the geometries of the flow passages are complicated but must be modeled accurately in order to capture all important details of the flow. This makes grid generation and grid quality important issues. Finally, since coolant flows are turbulent and separated the effects of turbulence must be modeled with a low Reynolds number

  16. High-temperature nuclear closed Brayton cycle power conversion system for the space exploration initiative

    SciTech Connect

    Brandes, D.J. )

    1991-01-05

    The Space Exploration Initiative (SEI) has stated goals of colonizing the moon and conducting manned exploration of the planet Mars. Unlike previous ventures into space, both manned and unmanned, large quantities of electrical power will be required to provide the energy for lunar base sustenance and for highly efficient propulsion systems for the long trip to mars and return. Further, the requirement for electrical power of several megawatts will necessitate the use of nuclear reactor driven power conversion systems. This paper discusses a particle bed reactor closed Brayton cycle space power system that uses advanced materials technology to achieve a high-temperature, low-specific-weight modular system capable of providing the requisite electrical power for both a lunar base and a Mars flight vehicle propulsion system.

  17. High-temperature nuclear closed Brayton cycle power conversion system for the Space Exploration Initiative

    NASA Astrophysics Data System (ADS)

    Brandes, Donald J.

    The Space Exploration Initiative has stated goals of colonizing the moon and conducting manned exploration of the planet Mars. Unlike previous ventures into space, both manned and unmanned, large quantities of electrical power will be required to provide the energy for lunar base sustenance and for highly efficient propulsion systems for the long trip to Mars and return. Further, the requirement for electrical power of several megawatts will necessitate the use of nuclear reactor driven power conversion systems. This paper discusses a particle bed reactor closed Brayton cycle space power system that uses advanced materials technology to achieve a high-temperature, low-specific-weight modular system capable of providing the requisite electrical power for both a lunar base and a Mars flight vehicle propulsion system.

  18. High-temperature nuclear closed Brayton cycle power conversion system for the space exploration initiative

    NASA Astrophysics Data System (ADS)

    Brandes, Donald J.

    1991-01-01

    The Space Exploration Initiative (SEI) has stated goals of colonizing the moon and conducting manned exploration of the planet Mars. Unlike previous ventures into space, both manned and unmanned, large quantities of electrical power will be required to provide the energy for lunar base sustenance and for highly efficient propulsion systems for the long trip to mars and return. Further, the requirement for electrical power of several megawatts will necessitate the use of nuclear reactor driven power conversion systems. This paper discusses a particle bed reactor closed Brayton cycle space power system that uses advanced materials technology to achieve a high-temperature, low-specific-weight modular system capable of providing the requisite electrical power for both a lunar base and a Mars flight vehicle propulsion system.

  19. Actively controlling coolant-cooled cold plate configuration

    SciTech Connect

    Chainer, Timothy J.; Parida, Pritish R.

    2015-07-28

    A method is provided to facilitate active control of thermal and fluid dynamic performance of a coolant-cooled cold plate. The method includes: monitoring a variable associated with at least one of the coolant-cooled cold plate or one or more electronic components being cooled by the cold plate; and dynamically varying, based on the monitored variable, a physical configuration of the cold plate. By dynamically varying the physical configuration, the thermal and fluid dynamic performance of the cold plate are adjusted to, for example, optimally cool the one or more electronic components, and at the same time, reduce cooling power consumption used in cooling the electronic component(s). The physical configuration can be adjusted by providing one or more adjustable plates within the coolant-cooled cold plate, the positioning of which may be adjusted based on the monitored variable.

  20. Cladding embrittlement during postulated loss-of-coolant accidents.

    SciTech Connect

    Billone, M.; Yan, Y.; Burtseva, T.; Daum, R.; Nuclear Engineering Division

    2008-07-31

    The effect of fuel burnup on the embrittlement of various cladding alloys was examined with laboratory tests conducted under conditions relevant to loss-of-coolant accidents (LOCAs). The cladding materials tested were Zircaloy-4, Zircaloy-2, ZIRLO, M5, and E110. Tests were performed with specimens sectioned from as-fabricated cladding, from prehydrided (surrogate for high-burnup) cladding, and from high-burnup fuel rods which had been irradiated in commercial reactors. The tests were designed to determine for each cladding material the ductile-to-brittle transition as a function of steam oxidation temperature, weight gain due to oxidation, hydrogen content, pre-transient cladding thickness, and pre-transient corrosion-layer thickness. For short, defueled cladding specimens oxidized at 1000-1200 C, ring compression tests were performed to determine post-quench ductility at {le} 135 C. The effect of breakaway oxidation on embrittlement was also examined for short specimens oxidized at 800-1000 C. Among other findings, embrittlement was found to be sensitive to fabrication processes--especially surface finish--but insensitive to alloy constituents for these dilute zirconium alloys used as cladding materials. It was also demonstrated that burnup effects on embrittlement are largely due to hydrogen that is absorbed in the cladding during normal operation. Some tests were also performed with longer, fueled-and-pressurized cladding segments subjected to LOCA-relevant heating and cooling rates. Recommendations are given for types of tests that would identify LOCA conditions under which embrittlement would occur.

  1. Coolant monitoring apparatus for nuclear reactors. [PWR; BWR

    SciTech Connect

    Tokarz, R.D.

    1981-08-06

    A system for monitoring coolant conditions within a pressurized vessel is described. A length of tubing extends outward from the vessel from an open end containing a first line restriction at the location to be monitored. The flowing fluid is cooled and condensed before passing through a second line restriction. Measurement of pressure drop at the second line restriction gives an indication of fluid condition at the first line restriction. Multiple lengths of tubing with open ends at incremental elevations can measure coolant level within the vessel.

  2. Columbia's uninsulated water coolant lines in the payload bay

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Yesterday, NASA decided to postpone for 24-hours the launch of Columbia on mission STS-83 due to a requirement to add additional thermal insulation to water coolant lines in the orbiter's payload bay. The water coolant lines are seen here winding their way around the window on the left. Managers determined that the lines, which cool various electronics on the orbiter, were not properly insulated and could possibly freeze during Columbia's 16-days in space. Columbia's launch is now set for 2:00 p.m. EST on Friday, April 4, 1997.

  3. Flibe Use in Fusion Reactors - An Initial Safety Assessment

    SciTech Connect

    Cadwallader, Lee Charles; Longhurst, Glen Reed

    1999-04-01

    This report is an initial effort to identify and evaluate safety issues associated with the use of Flibe (LiF-BeF2) as a molten salt coolant for nuclear fusion power plant applications. Flibe experience in the Molten Salt Reactor Experiment is briefly reviewed. Safety issues identified include chemical toxicity, radiological issues resulting from neutron activation, and the operational concerns of handling a high temperature coolant. Beryllium compounds and fluorine pose be toxicological concerns. Some controls to protect workers are discussed. Since Flibe has been handled safely in other applications, its hazards appear to be manageable. Some safety issues that require further study are pointed out. Flibe salt interaction with strong magnetic fields should be investigated. Evolution of Flibe constituents and activation products at high temperature (i.e., will Fluorine release as a gas or remain in the molten salt) is an issue. Aerosol and tritium release from a Flibe spill requires study, as does neutronics analysis to characterize radiological doses. Tritium migration from Flibe into the cooling system is also a safety concern. Investigation of these issues will help determine the extent to which Flibe shows promise as a fusion power plant coolant or plasma-facing material.

  4. Flibe use in fusion reactors -- An initial safety assessment

    SciTech Connect

    Cadwallader, L.C.; Longhurst, G.R.

    1999-03-01

    This report is an initial effort to identify and evaluate safety issues associated with the use of Flibe (LiF-BeF{sub 2}) as a molten salt coolant for nuclear fusion power plant applications. Flibe experience in the Molten Salt Reactor Experiment is briefly reviewed. Safety issues identified include chemical toxicity, radiological issues resulting from neutron activation, and the operational concerns of handling a high temperature coolant. Beryllium compounds and fluorine pose be toxicological concerns. Some controls to protect workers are discussed. Since Flibe has been handled safely in other applications, its hazards appear to be manageable. Some safety issues that require further study are pointed out. Flibe salt interaction with strong magnetic fields should be investigated. Evolution of Flibe constituents and activation products at high temperature (i.e., will Fluorine release as a gas or remain in the molten salt) is an issue. Aerosol and tritium release from a Flibe spill requires study, as does neutronics analysis to characterize radiological doses. Tritium migration from Flibe into the cooling system is also a safety concern. Investigation of these issues will help determine the extent to which Flibe shows promise as a fusion power plant coolant or plasma-facing material.

  5. The effect of initial diameter on rainbow positions and temperature distributions of burning single-component n-Alkane droplets

    NASA Astrophysics Data System (ADS)

    Li, Haipeng; Rosebrock, Christopher D.; Wriedt, Thomas; Mädler, Lutz

    2017-07-01

    The effect of initial diameter on rainbow positions of burning single-component n-Alkane droplets has been investigated experimentally for the first time. The droplet diameters are determined with interferometric laser imaging for droplet sizing, and the temperature distributions inside burning droplets are assessed by rainbow refractometry together with a droplet combustion model developed in our previous work. Temperature gradients inside burning droplets influence rainbow positions, which first make the experimental scattering angles of the rainbow maxima increase and then decrease. The variations of initial diameter lead to variations of both experimental rainbow maxima and simulated temperature of n-Alkane burning droplets.

  6. Directly connected heat exchanger tube section and coolant-cooled structure

    DOEpatents

    Chainer, Timothy J; Coico, Patrick A; Graybill, David P; Iyengar, Madhusudan K; Kamath, Vinod; Kochuparambil, Bejoy J; Schmidt, Roger R; Steinke, Mark E

    2014-04-01

    A cooling apparatus for an electronics rack is provided which includes an air-to-liquid heat exchanger, one or more coolant-cooled structures and a tube. The heat exchanger, which is associated with the electronics rack and disposed to cool air passing through the rack, includes a plurality of distinct, coolant-carrying tube sections, each tube section having a coolant inlet and a coolant outlet, one of which is coupled in fluid communication with a coolant loop to facilitate flow of coolant through the tube section. The coolant-cooled structure(s) is in thermal contact with an electronic component(s) of the rack, and facilitates transfer of heat from the component(s) to the coolant. The tube connects in fluid communication one coolant-cooled structure and the other of the coolant inlet or outlet of the one tube section, and facilitates flow of coolant directly between that coolant-carrying tube section of the heat exchanger and the coolant-cooled structure.

  7. Analysis data on samples from the TMI-2 reactor-coolant system and reactor-coolant bleed tank

    SciTech Connect

    Nitschke, R.L.

    1982-05-01

    Two liquid samples from the Three Mile Island Unit 2 (TMI-2) Reactor Coolant System (RCS) and three liquid samples from the three Reactor Coolant Bleed Tanks (RCBT) were taken during the time period March 29, 1979 to August 14, 1980. The samples were analyzed for radionuclide concentrations by two independent laboratories, Exxon Nuclear Idaho Co., Inc. (ENICO) and EG and G Idaho, Inc. at the Idaho National Engineering Laboratory (INEL). The RCS sample taken on March 29, 1979 was also analyzed by Science Applications, Inc. (SAI). This report presents the methods used and the results of these analyes. 14 tables.

  8. Dynamic Fracture Initiation Toughness at Elevated Temperatures With Application to the New Generation of Titanium Aluminide Alloys. Chapter 8

    NASA Technical Reports Server (NTRS)

    Shazly, Mostafa; Prakash, Vikas; Draper, Susan; Shukla, Arun (Editor)

    2006-01-01

    Recently, a new generation of titanium aluminide alloy, named Gamma-Met PX, has been developed with better rolling and post-rolling characteristics. I'revious work on this alloy has shown the material to have higher strengths at room and elevated temperatures when compared with other gamma titanium aluminides. In particular, this new alloy has shown increased ductility at elevated temperatures under both quasi-static and high strain rate uniaxial compressive loading. However, its high strain rate tensile ductility at room and elevated temperatures is limited to approx. 1%. In the present chapter, results of a study to investigate the effects of loading rate and test temperature on the dynamic fracture initiation toughness in Gamma-Met PX are presented. Modified split Hopkinson pressure bar was used along with high-speed photography to determine the crack initiation time. Three-point bend dynamic fracture experiments were conducted at impact speeds of approx. 1 m/s and tests temperatures of up-to 1200 C. The results show that thc dynamic fracture initiation toughness decreases with increasing test temperatures beyond 600 C. Furthermore, thc effect of long time high temperature air exposure on the fracture toughness was investigated. The dynamic fracture initiation toughness was found to decrease with increasing exposure time. The reasons behind this drop are analyzed and discussed.

  9. Flame Speeds of Methane-Air, Propane-Air, and Ethylene-Air Mixtures at Low Initial Temperatures

    NASA Technical Reports Server (NTRS)

    Dugger, Gordon L; Heimel, Sheldon

    1952-01-01

    Flame speeds were determined for methane-air, propane-air, and ethylene-air mixtures at -73 C and for methane-air mixtures at -132 C. The data extend the curves of maximum flame speed against initial mixture temperature previously established for the range from room temperature to 344 C. Empirical equations for maximum flame speed u(cm/ sec) as a function of initial mixture temperature T(sub O) were determined to be as follows: for methane, for T(sub O) from 141 to 615 K, u = 8 + 0.000160 T(sub O)(exp 2.11); for propane, for T(sub O) from 200 to 616 K, u = 10 + 0.000342 T(sub O)(exp 2.00); for ethylene, for T(sub O) from 200 to 617 K, u = 10 + 0.00259 T(sub O)(exp 1.74). Relative flame speeds at low initial temperatures were predicted within approximately 20 percent by either the thermal theory as presented by Semenov or by the diffusion theory of Tanford and Pease. The same order was found previously for high initial temperatures. The low-temperature data were also found to extend the linear correlations between maximum flame speed and calculated equilibrium active-radical concentrations, which were established by the previously reported high-temperature data.

  10. Mixed convective/dynamic roll vortices and their effects on initial wind and temperature profiles

    NASA Technical Reports Server (NTRS)

    Haack, Tracy; Shirer, Hampton N.

    1991-01-01

    The onset and development of both dynamically and convectively forced boundary layer rolls are studied with linear and nonlinear analyses of a truncated spectral model of shallow Boussinesq flow. Emphasis is given here on the energetics of the dominant roll modes, on the magnitudes of the roll-induced modifications of the initial basic state wind and temperature profiles, and on the sensitivity of the linear stability results to the use of modified profiles as basic states. It is demonstrated that the roll circulations can produce substantial changes to the cross-roll component of the initial wind profile and that significant changes in orientation angle estimates can result from use of a roll-modified profile in the stability analysis. These results demonstrate that roll contributions must be removed from observed background wind profiles before using them to investigate the mechanisms underlying actual secondary flows in the boundary layer. The model is developed quite generally to accept arbitrary basic state wind profiles as dynamic forcing. An Ekman profile is chosen here merely to provide a means for easy comparison with other theoretical boundary layer studies; the ultimate application of the model is to study observed boundary layer profiles. Results of the analytic stability analysis are validated by comparing them with results from a larger linear model. For an appropriate Ekman depth, a complete set of transition curves is given in forcing parameter space for roll modes driven both thermally and dynamically. Preferred orientation angles, horizontal wavelengths and propagation frequencies, as well as energetics and wind profile modifications, are all shown to agree rather well with results from studies on Ekman layers as well as with studies on near-neutral and convective atmospheric boundary layers.

  11. A passively-safe fusion reactor blanket with helium coolant and steel structure

    SciTech Connect

    Crosswait, Kenneth Mitchell

    1994-04-01

    Helium is attractive for use as a fusion blanket coolant for a number of reasons. It is neutronically and chemically inert, nonmagnetic, and will not change phase during any off-normal or accident condition. A significant disadvantage of helium, however, is its low density and volumetric heat capacity. This disadvantage manifests itself most clearly during undercooling accident conditions such as a loss of coolant accident (LOCA) or a loss of flow accident (LOFA). This thesis describes a new helium-cooled tritium breeding blanket concept which performs significantly better during such accidents than current designs. The proposed blanket uses reduced-activation ferritic steel as a structural material and is designed for neutron wall loads exceeding 4 MW/m{sup 2}. The proposed geometry is based on the nested-shell concept developed by Wong, but some novel features are used to reduce the severity of the first wall temperature excursion. These features include the following: (1) A ``beryllium-joint`` concept is introduced, which allows solid beryllium slabs to be used as a thermal conduction path from the first wall to the cooler portions of the blanket. The joint concept allows for significant swelling of the beryllium (10 percent or more) without developing large stresses in the blanket structure. (2) Natural circulation of the coolant in the water-cooled shield is used to maintain shield temperatures below 100 degrees C, thus maintaining a heat sink close to the blanket during the accident. This ensures the long-term passive safety of the blanket.

  12. PIPING FOR COOLANT WATER IS INSTALLED INSIDE REACTOR STRUCTURE PRIOR ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    PIPING FOR COOLANT WATER IS INSTALLED INSIDE REACTOR STRUCTURE PRIOR TO EMBEDMENT IN CONCRETE. HIGHER PIPE IS INLET; THE OTHER, THE OUTLET LOOP. INLET PIPE WILL CONNECT TO TOP SECTION OF REACTOR VESSEL. INL NEGATIVE NO. 1287. Unknown Photographer, 1/18/1951 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  13. Coolant-Control Valves For Fluid-Sampling Probes

    NASA Technical Reports Server (NTRS)

    Schultz, Donald F.

    1989-01-01

    Small built-in leaks prevent overheating. Downstream flow-control globe valve replaced with modified gate valve. Modification consists of drilling small hole through valve gate, so valve never turned completely off. This "leaky" valve provides enough flow of coolant to prevent overheating causing probe to fail. Principle also applied to automatic control system by installing small bypass line around control valve.

  14. Coolants with selective optical filtering characteristics for ruby laser applications

    NASA Technical Reports Server (NTRS)

    Mc Devitt, F. R.; Rasquin, J. R.

    1968-01-01

    Coolant-filtering medium developed consists of a solution of copper sulfate in a 4-1 volumetric mixture of ethanol and methanol. This solution should be a useful addition to ruby laser systems, particularily in large pulse or Q switching applications.

  15. Fuels, Lubricants, and Coolants. FOS: Fundamentals of Service.

    ERIC Educational Resources Information Center

    John Deere Co., Moline, IL.

    This manual on fuels, lubricants, and coolants is one of a series of power mechanics tests and visual aids on automotive and off-the-road agricultural and construction equipment. Materials present basic information with illustrations for use by vocational students and teachers as well as shop servicemen and laymen. Focusing on fuels, the first of…

  16. AUTOMOTIVE AND HEAVY-DUTY ENGINE COOLANT RECYCLING BY DISTILLATION

    EPA Science Inventory

    This evaluation addresses the product quality, waste reduction, and economic issues involved in recycling automotive and heavy-duty engine coolants for a facility such as the New Jersey Department of Transportation garage in Ewing, New Jersey. he specific recycling evaluated is b...

  17. EVALUATION OF FILTRATION AND DISTILLATION METHODS FOR RECYCLING AUTOMOTIVE COOLANT.

    EPA Science Inventory

    This evaluation addresses the product quality, waste reduction, and economic issues involved in recycling automotive and heavy-duty engine coolants at a New Jersey Department of Transportation garage. The specific recycling units evaluated are based on the technologies of filtrat...

  18. EVALUATION OF FILTRATION AND DISTILLATION METHODS FOR RECYCLING AUTOMOTIVE COOLANT.

    EPA Science Inventory

    This evaluation addresses the product quality, waste reduction, and economic issues involved in recycling automotive and heavy-duty engine coolants at a New Jersey Department of Transportation garage. The specific recycling units evaluated are based on the technologies of filtrat...

  19. AUTOMOTIVE AND HEAVY-DUTY ENGINE COOLANT RECYCLING BY DISTILLATION

    EPA Science Inventory

    This evaluation addresses the product quality, waste reduction, and economic issues involved in recycling automotive and heavy-duty engine coolants for a facility such as the New Jersey Department of Transportation garage in Ewing, New Jersey. he specific recycling evaluated is b...

  20. Fuels, Lubricants, and Coolants. FOS: Fundamentals of Service.

    ERIC Educational Resources Information Center

    John Deere Co., Moline, IL.

    This manual on fuels, lubricants, and coolants is one of a series of power mechanics tests and visual aids on automotive and off-the-road agricultural and construction equipment. Materials present basic information with illustrations for use by vocational students and teachers as well as shop servicemen and laymen. Focusing on fuels, the first of…

  1. Substitution of Tolyltriazole for Mercaptobenzothiazole in Military Coolant Inhibitor Formulations

    DTIC Science & Technology

    coolant specifications (0.4% of the sodium salt ). 0.15% was found to be the optimum percentage of NaTT....antifreeze inhibitors with different percentages of sodium tolyltriazole (NaTT). The NaTT caused foaming in the tests, but a silicone type antifoam

  2. Integral coolant channels supply made by melt-out method

    NASA Technical Reports Server (NTRS)

    Escher, W. J. D.

    1964-01-01

    Melt-out method of constructing strong, pressure-tight fluid coolant channels for chambers is accomplished by cementing pins to the surface and by depositing a melt-out material on the surface followed by two layers of epoxy-resin impregnated glass fibers. The structure is heated to melt out the low-melting alloy.

  3. Antimony tartrate corrosion inhibitive composition for coolant systems

    SciTech Connect

    Payerle, N.E.

    1987-08-11

    An automobile coolant concentrate is described comprising (a) a liquid polyhydric alcohol chosen from the group consisting of ethylene glycol, propylene glycol, diethylene glycol and mixtures thereof, and (b) corrosion inhibitors in a corrosion inhibitory amount with respect to corrosion of lead-containing solders, the corrosion inhibitors comprising (i) an alkali metal antimony tartrate, and (ii) an azole compound.

  4. Customizing SNPSAM: Introducing a Secondary Coolant Loop.

    DTIC Science & Technology

    1988-03-01

    two irreversible phenomena connected with the gen- eration of thermoelectricity. The reversible are the Seebeck effect, the Thomson effect and the...The Thomson effect causes heat to be generated in a homogeneous material where there exists a temperature gradient when an electric current is

  5. Assessment of Sea Surface Temperature and Sea Ice Initial Conditions on Coupled Model Forecasts

    NASA Astrophysics Data System (ADS)

    Intrieri, J. M.; Solomon, A.; Persson, O. P. G.; Capotondi, A.; LaFontaine, F.; Jedlovec, G.

    2016-12-01

    We present weather-scale (0-10 day) sea ice forecast validation and skill results from an experimental coupled ice-ocean-atmosphere model during the fall freeze-up periods for 2015 and 2016. The model is a mesoscale, coupled atmosphere-ice-ocean mixed-layer model, termed RASM-ESRL, that was developed from the larger-scale Regional Arctic System Model (RASM) architecture. The atmospheric component of RASM-ESRL consists of the Weather Research and Forecasting (WRF) model, the sea-ice component is the Los Alamos CICE model, and the ocean model is POP. Experimental 5-day forecasts were run daily with RASM-ESRL from July through mid-November in 2015 and 2016. Our project focuses on how the modeled sea ice evolution compares to observed physical processes including atmospheric forcing of sea ice movement, melt, and freeze-up through energy fluxes. Model hindcast output is validated against buoy observations, satellite measurements, and concurrent in situ flux observations made from the R/V Sikuliaq in the fall of 2015. Model skill in predicting atmospheric state variables, wind and boundary layer structures, synoptic features, cloud microphysical and ocean properties will be discussed. We will show results of using different initializations of ocean sea surface temperature and sea ice extent and the impacts on sea ice edge prediction.

  6. Modular Porous Plate Sublimator /MPPS/ requires only water supply for coolant

    NASA Technical Reports Server (NTRS)

    Rathbun, R. J.

    1966-01-01

    Modular porous plate sublimators, provided for each location where heat must be dissipated, conserve the battery power of a space vehicle by eliminating the coolant pump. The sublimator requires only a water supply for coolant.

  7. Water as a coolant of the city

    NASA Astrophysics Data System (ADS)

    Solcerova, Anna; van de Ven, Frans; van de Giesen, Nick

    2014-05-01

    Rapid urbanization during the last century showed the necessity for understanding urban climate. Since already half of the world population lives in cities - and this number is predicted to increase in coming years and decades - making big urban areas comfortable places gains interest of the general public and policy makers, as well as scientists. It is well known fact that urban climate differs significantly from the climate of rural areas. This is caused by several factors such as lack of evaporation, anthropogenic heat, specific geometry of street canyons, etc. Magnitude of the effect of each of these factors is a widely discussed topic throughout the literature. One of the most important factors is a lack of evaporation and consequent change in the energy balance compared to rural areas. This research aims to reveal the effect of water in the city on the temperature and comfort of inhabitants. We hypothesize that water works as a cooling liquid of cities and the lack of it is the main reason for formation of so called urban heat island. We focus on two major ways water can be stored in cities; in a form of open water areas, and in plants and green areas in general. Open water buffers the temperature extremes in its surroundings, but also has a warming effect at night due to its higher heat capacity compared to buildings and pavements. Trees are then providing shading and transpirate significant amount of water. On the other hand, shading effect alone, as provided by for example mash, can increase the temperature in the area simply because it prevents ventilation. Human comfort is however not determined only by temperature; for example higher air humidity is known to lower comfort of inhabitants and therefore mitigate the cooling effect of evaporation. Understanding properly the different effects of urban climate, and the particular aspects that can influence it, is important for optimal urban design that provides pleasant living environment.

  8. The slope of the initial temperature drop predicts acute pulmonary vein isolation using the second-generation cryoballoon.

    PubMed

    Deubner, Nikolas; Greiss, Harald; Akkaya, Ersan; Zaltsberg, Sergey; Hain, Andreas; Berkowitsch, Alexander; Güttler, Norbert; Kuniss, Malte; Neumann, Thomas

    2017-09-01

    There is no objective, early indicator of occlusion quality, and efficacy of cryoballoon pulmonary vein isolation. As previous experience suggests that the initial cooling rate correlates with these parameters, we investigated the slope of the initial temperature drop as an objective measure. A systematic evaluation of 523 cryoapplications in 105 patients using a serial ROC-AUC analysis was performed. We found the slope of a linear regression of the temperature-time function to be a good predictor (PPV 0.9, specificity 0.72, sensitivity 0.71, and ROC-AUC 0.75) of acute isolation. It also correlated with nadir temperatures (P< 0.001, adjusted R2= 0.43), predicted very low nadir temperatures, and varied according to visual occlusion grades (ANOVA P< 0.001). About 25 s after freeze initiation, the temperature-time slope predicts important key characteristics of a cryoablation, such as nadir temperature. The slope is the only reported predictor to actually precede acute isolation and thus to support decisions about pull-down manoeuvres or aborting a cryoablation early on. It is also predictive of very low nadir temperatures and phrenic nerve palsy and thus may add to patient safety.

  9. Coolant pressure and airflow distribution in a strut-supported transpiration-cooled vane for a gas turbine engine

    NASA Technical Reports Server (NTRS)

    Kaufman, A.; Poferl, D. J.; Richards, H. T.

    1972-01-01

    An analysis to predict pressure and flow distribution in a strut-supported wire-cloth vane was developed. Results were compared with experimental data obtained from room-temperature airflow tests conducted over a range of vane inlet airflow rates from 10.7 to 40.4 g/sec (0.0235 to 0.0890 lb/sec). The analytical method yielded reasonably accurate predictions of vane coolant flow rate and pressure distribution.

  10. Directly connected heat exchanger tube section and coolant-cooled structure

    DOEpatents

    Chainer, Timothy J.; Coico, Patrick A.; Graybill, David P.; Iyengar, Madhusudan K.; Kamath, Vinod; Kochuparambil, Bejoy J.; Schmidt, Roger R.; Steinke, Mark E.

    2015-09-15

    A method is provided for fabricating a cooling apparatus for cooling an electronics rack, which includes an air-to-liquid heat exchanger, one or more coolant-cooled structures, and a tube. The heat exchanger is associated with the electronics rack and disposed to cool air passing through the rack, includes a plurality of coolant-carrying tube sections, each tube section having a coolant inlet and outlet, one of which is coupled in fluid communication with a coolant loop to facilitate flow of coolant through the tube section. The coolant-cooled structure(s) is in thermal contact with an electronic component(s) of the rack, and facilitates transfer of heat from the component(s) to the coolant. The tube connects in fluid communication one coolant-cooled structure and the other of the coolant inlet or outlet of the one tube section, and facilitates flow of coolant directly between that coolant-carrying tube section of the heat exchanger and the coolant-cooled structure.

  11. Beyond the D-DIA: new initiatives for deformation experiments at higher pressure and temperature

    NASA Astrophysics Data System (ADS)

    Wang, Y.; Jing, Z.; Yu, T.; Hilairet, N.; Nishiyama, N.

    2011-12-01

    Advances in experimental high-pressure, high-temperature deformation have relied to a large extent on technological developments. From the pioneer work of F.D. Adams [1] in generating differential stress at high pressure to deform rocks plastically to Griggs' famous deformation apparatus [2], each new invention has enabled numerous scientific publications and brought our understanding of rock deformation to a new level. For the past few years, two major workhorses in deformation experiments above 3 GPa are the rotational deformation apparatus (RDA) [3] and the deformation DIA (D-DIA) [4]. These developments brought us to almost 20 GPa under controlled differential stress and strain rates. Several new initiatives are being undertaken at GSECARS aiming at further enhancing experimental capabilities to higher pressures, temperatures and better in situ characterization of the deforming samples. We constructed a modified RDA with microtomography capability at high pressure which is used to image, in situ and in 3D, fabric evolution in multi-phase composites under large shear strains, to shed lights on the physics of complex earth materials during deformation. A large version of D-DIA (DDIA-30) has also been developed taking advantages of the rigidity of large guide blocks for much improved alignment. A 6-6 multianvil cell (MA6-6) [5] is used for deformation experiments with various truncated edge lengths, without having to change the large first-stage anvils. This configuration has the potential to reach pressure conditions corresponding to the lower mantle. We present recent results of these developments, and their potential applications for understanding dynamic processes from the upper mantle to the lower mantle. [1] Adams, F. D. and J. T. Nicolson (1900) Phil. Trans. Roy. Soc. London. A, 195: 363-401. [2] Griggs, D.T. (1967) Geophys. J. Roy. Astr. Soc., 14:19-31. [3] Yamazaki, D., and S. Karato (2001) Rev. Sci. Instrum., 72:4207-4211. [4] Wang, Y., I. Getting, W

  12. LOSS-OF-COOLANT ACIDENT SIMULATIONS IN THE NATIONAL RESEARCH UNIVERSAL REACTOR

    SciTech Connect

    Bennett, W D; Goodman, R L; Heaberlin, S W; Hesson, G M; Nealley, C; Kirg, L L; Marshall, R K; McNair, G W; Meitzler, W D; Neally, G W; Parchen, L J; Pilger, J P; Rausch, W N; Russcher, G E; Schreiber, R E; Wildung, N J; Wilson, C L

    1981-02-01

    Pressurized water reactor loss-of-coolant accident (LOCA) phenomena are being simulated with a series of experiments in the U-2 loop of the National Research Universal Reactor at Chalk River, Ontario, Canada. The first of these experiments includes up to 45 parametric thermal-hydraulic tests to establish the relationship among the reflood delay time of emergency coolant, the reflooding rate, and the resultant fuel rod cladding peak temperature. Subsequent experiments establish the fuel rod failure characteristics at selected peak cladding temperatures. Fuel rod cladding pressurization simulates high burnup fission gas pressure levels of modern PWRs. This document contains both an experiment overview of the LOCA simulation program and a review of the safety analyses performed by Pacific Northwest Laboratory (PNL) to define the expected operating conditions as well as to evaluate the worst case operating conditions. The primary intent of this document is to supply safety information required by the Chalk River Nuclear Laboratories (CRNL), to establish readiness to proceed from one test phase to the next and to establish the overall safety of the experiment. A hazards review summarizes safety issues, normal operation and three worst case accidents that have been addressed during the development of the experiment plan.

  13. Initial permeability peak in Gd/sub 3/Fe/sub 5/O/sub 12/ at low temperature

    SciTech Connect

    Pascard, H.; Globus, A.

    1986-09-01

    The existence of an initial permeability peak in polycrystalline toroidal samples of gadolinium iron garnet Gd/sub 3/Fe/sub 5/O/sub 12/ at low temperature, around 55 K, is shown. The origin of the phenomenon is explained, as in the case of the HOPKINSON peaks, by the relative variation of mangetization and anisotropy. It can be interesting to use this effect for fundamental investigations of cationic structure transformations and for applications at low temperature.

  14. Evidence for cumulative temperature as an initiating and terminating factor in downstream migratory behavior of Atlantic salmon (Salmo salar) smolts

    USGS Publications Warehouse

    Zydlewski, G.B.; Haro, A.; McCormick, S.D.

    2005-01-01

    Temperature control of Atlantic salmon (Salmo salar) smolt migration was tested using a novel technique allowing nearly continuous monitoring of behavior with complete control over environmental conditions. Parr and presmolts were implanted with passive integrated transponder tags, placed in simulated streams, and monitored for upstream and downstream movements. Beginning 18 April, temperature was increased 1??C every third day (advanced), fourth day (ambient), and tenth day (delayed). Smolt downstream movements were initially low, peaked in mid-May, and subsequently declined under all conditions. Parr downstream movements were significantly lower than those of smolts in all treatments (0.8 ?? 0.5 movement??day-1 versus 26.5 ?? 4.5 movements??day-1, mean ?? SE) and showed no increase. At delayed temperatures, smolts sustained downstream movements through July; those under ambient and advanced conditions ceased activity by mid-June. Initiation and termination of downstream movements occurred at significantly different temperatures but at the same number of degree-days in all treatments. Physiological changes associated with smolting (gill Na+,K +-ATPase activity and plasma thyroxine) were coincident with behavioral changes. This is the first evidence of a behavioral component to the smolt window. We found that temperature experience over time is more relevant to initiation and termination of downstream movement than a temperature threshold. ?? 2005 NRC Canada.

  15. Reduction of the Livestock Ammonia Emission under the Changing Temperature during the Initial Manure Nitrogen Biomineralization

    PubMed Central

    Bagdonienė, Indrė; Baležentienė, Ligita

    2013-01-01

    Experimental data were applied for the modelling optimal cowshed temperature environment in laboratory test bench by a mass-flow method. The principal factor affecting exponent growth of ammonia emission was increasing air and manure surface temperature. With the manure temperature increasing from 4°C to 30°C, growth in the ammonia emission grew fourfold, that is, from 102 to 430 mg m−2h−1. Especial risk emerges when temperature exceeds 20°C: an increase in temperature of 1°C contributes to the intensity of ammonia emission by 17 mg m−2h−1. The temperatures of air and manure surface as well as those of its layers are important when analysing emission processes from manure. Indeed, it affects the processes occurring on the manure surface, namely, dehydration and crust formation. To reduce ammonia emission from cowshed, it is important to optimize the inner temperature control and to manage air circulation, especially at higher temperatures, preventing the warm ambient air from blowing direct to manure. Decrease in mean annual temperature of 1°C would reduce the annual ammonia emission by some 5.0%. The air temperature range varied between −15°C and 30°C in barns. The highest mean annual temperature (14.6°C) and ammonia emission (218 mg m−2h−1) were observed in the semideep cowshed. PMID:24453912

  16. Reduction of the livestock ammonia emission under the changing temperature during the initial manure nitrogen biomineralization.

    PubMed

    Bleizgys, Rolandas; Bagdonienė, Indrė; Baležentienė, Ligita

    2013-01-01

    Experimental data were applied for the modelling optimal cowshed temperature environment in laboratory test bench by a mass-flow method. The principal factor affecting exponent growth of ammonia emission was increasing air and manure surface temperature. With the manure temperature increasing from 4°C to 30°C, growth in the ammonia emission grew fourfold, that is, from 102 to 430 mg m(-2)h(-1). Especial risk emerges when temperature exceeds 20°C: an increase in temperature of 1°C contributes to the intensity of ammonia emission by 17 mg m(-2)h(-1). The temperatures of air and manure surface as well as those of its layers are important when analysing emission processes from manure. Indeed, it affects the processes occurring on the manure surface, namely, dehydration and crust formation. To reduce ammonia emission from cowshed, it is important to optimize the inner temperature control and to manage air circulation, especially at higher temperatures, preventing the warm ambient air from blowing direct to manure. Decrease in mean annual temperature of 1°C would reduce the annual ammonia emission by some 5.0%. The air temperature range varied between -15°C and 30°C in barns. The highest mean annual temperature (14.6°C) and ammonia emission (218 mg m(-2)h(-1)) were observed in the semideep cowshed.

  17. The effects of temperature, relative humidity, light, and resource quality on flight initiation in the red flour beetle, Tribolium castaneum

    PubMed Central

    Drury, Douglas W.; Whitesell, Matthew E.; Wade, Michael J.

    2016-01-01

    We investigated the environmental conditions that induce a flight response in the red flour beetle, Tribolium castaneum Herbst (Coleoptera: Tenebrionidae), including resource quality, temperature, relative humidity, and light. Over 72-h trial periods, we observed the proportion of individuals emigrating by flight to range from 0.0 in extreme heat or cold to 0.82 with starvation. Resource quality, presence of a light source, and temperature all directly influenced the initiation of the flight response. We did not detect any effect of relative humidity or sudden change in temperature on the incidence of flight. We discuss our findings in the context of Tribolium ecology and evolution. PMID:27087697

  18. New Hydrophilic, Composite Membranes for Air Removal from Water Coolant Systems

    NASA Technical Reports Server (NTRS)

    Ritchie, Stephen M. C.; Luo, Qiang; Curtis, Salina S.; Holladay, Jon B.; Clark, Dallas W.

    2004-01-01

    Liquid coolants are commonly used as thermal transport media to increase efficiency and flexibility in aerospace vehicle design. The introduction of gas bubbles into the coolant can have negative consequences, including: loss of centrifugal pump prime, irregular sensor readings, and blockage of coolant flow to remote systems. One solution to mitigate these problems is the development of a passive gas removal device, or gas trap, installed in the flight cooling system. In this study, a new hydrophilic, composite membrane has been developed for passage of the coolant fluid and retention of gas bubbles. The trapped bubbles are subsequently vented from the system by a thin, hydrophobic, microporous membrane. The original design for this work employed a homogeneous membrane that was susceptible to fouling and pore plugging. Spare gas traps of this variety have degraded during storage, and recreation of the membranes has been complicated due to problems with polymer duplication and property variations in the final membranes. In this work, replacements have been developed based on deposition of a hydrophilic polymer on the bore-side of a porous polyethylene (PE) tube. The tube provides excellent chemical and mechanical stability, and the hydrophilic layer provides retention of gas bubbles. Preliminary results have shown that intimate contact is required between the deposited layer and the substrate to overcome material differences. This has been accomplished by presoaking the membrane tube in the solvent to raise its surface energy. Polymer solutions of various concentrations have been used to promote penetration of the polymer layer into the porous substrate and to control separation layer thickness. The resulting composite membranes have shown repeatable decrease in nitrogen permeability, which is indicative of a decrease in membrane pore size. Studies with water permeation have yielded similar results. We have observed some swelling of the added polymer layer, which

  19. Hybrid method for numerical modelling of LWR coolant chemistry

    NASA Astrophysics Data System (ADS)

    Swiatla-Wojcik, Dorota

    2016-10-01

    A comprehensive approach is proposed to model radiation chemistry of the cooling water under exposure to neutron and gamma radiation at 300 °C. It covers diffusion-kinetic processes in radiation tracks and secondary reactions in the bulk coolant. Steady-state concentrations of the radiolytic products have been assessed based on the simulated time dependent concentration profiles. The principal reactions contributing to the formation of H2, O2 and H2O2 were indicated. Simulation was carried out depending on the amount of extra hydrogen dissolved in the coolant to reduce concentration of corrosive agents. High sensitivity to the rate of reaction H+H2O=OH+H2 is shown and discussed.

  20. Health physics aspects of processing EBR-I coolant

    SciTech Connect

    Burke, L.L.; Thalgott, J.O.; Poston, J.W. Jr.

    1998-12-31

    The sodium-potassium reactor coolant removed from the Experimental Breeder Reactor Number One after a partial reactor core meltdown had been stored at the Idaho National Engineering and Environmental Laboratory for 40 years. The State of Idaho considered this waste the most hazardous waste stored in the state and required its processing. The reactor coolant was processed in three phases. The first phase converted the alkali metal into a liquid sodium-potassium hydroxide. The second phase converted this caustic to a liquid sodium-potassium carbonate. The third phase solidified the sodium-potassium carbonate into a form acceptable for land disposal. Health physics aspects and dose received during each phase of the processing are discussed.

  1. Optimization of fast breeder reactors employing innovative liquid metal coolants

    SciTech Connect

    Pilarski, Stevan

    2007-07-01

    In this paper we propose a comparative assessment of fast breeder reactor core concepts employing Pb, Pb- Mg and Pb-{sup 7}Li as primary coolants and oxide and nitride fuels. Starting from a common reference core to make the comparison relevant, each coolant candidate is associated to an optimized design that takes into account its specific physical properties. For each core, we perform a neutronic analysis and an assessment of its safety potential. In comparison with the case of Pb, the use of Pb-Mg and Pb-{sup 7}Li increases the void reactivity effect. On the other hand, the breeding gain also increases, and the Doppler effect is enhanced, leading to a favorable behaviour concerning safety. (author)

  2. Glycol coolants improve heat transfer and corrosion control

    SciTech Connect

    Holfield, R.

    1995-03-01

    Various liquids from plain water to exotic fluids have been used as coolants in large stationary diesel engines that drive compressors on natural gas pipeline distribution systems. Although water is an efficient heat transfer medium, its drawbacks of freezing at {minus}32 F and boiling at 212 F seriously limit its usefulness. Special glycol-based heat transfer fluids are available and refined specifically for long-term needs of gas compressor engines. Appropriate corrosion inhibitors have been formulated for metallurgy and operating conditions encountered with these engines. Propylene glycol was developed as an alternative for use in environmentally sensitive areas. Glycol-based fluids must be specifically inhibited for industrial applications because uninhibited or improperly inhibited coolants can seriously damage reciprocating engines.

  3. Initial substrate moisture content and storage temperature affect chemical properties of bagged substrates containing controlled release fertilizer

    USDA-ARS?s Scientific Manuscript database

    Bagged potting mixes can be stored for weeks or months before being used by consumers. Some bagged potting mixes are amended with controlled release fertilizers (CRF). The objective of this research was to observe how initial substrate moisture content and storage temperature affect the chemical p...

  4. Initial and apparent temperatures of finite nuclear systems - a quantum statistical thermodynamics study.

    NASA Astrophysics Data System (ADS)

    Majka; Staszel, P.; Natowitz, J. B.; Cibor, J.; Hagel, K.; Li, J.; Mdeiwayeh, N.; Wada, R.; Zhao, Y.

    1996-10-01

    Quantum statistical thermodynamics has been used to calculate the number of available states and their occupation for fermions and bosons at temperature, T_in, of finite nuclear sytems. An apparent temperature of these systems, T_app, has been calculated from double yield ratios of two isotope pairs. The importance of employing the quantum statistics when high densities and/or low temperatures are involved is shown. However, at high temperatures and low densities, the system behaves as a Maxwell-Boltzmann gas. Sequental decays of fragments from excited states influence the double yield ratio observable, causing problems with the temperature extraction. The model has been applied to study the high temperature branch of the "caloric curve".

  5. Expert system for online surveillance of nuclear reactor coolant pumps

    DOEpatents

    Gross, Kenny C.; Singer, Ralph M.; Humenik, Keith E.

    1993-01-01

    An expert system for online surveillance of nuclear reactor coolant pumps. This system provides a means for early detection of pump or sensor degradation. Degradation is determined through the use of a statistical analysis technique, sequential probability ratio test, applied to information from several sensors which are responsive to differing physical parameters. The results of sequential testing of the data provide the operator with an early warning of possible sensor or pump failure.

  6. 92. View of transmitter building no. 102 first floor coolant ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    92. View of transmitter building no. 102 first floor coolant process water tanks (sodium bisulfate solution), stainless steel, for electronic systems cooling in transmitter and MIP rooms. RCA Services Company 29 September, 1960, official photograph BMEWS Project by unknown photograph, Photographic Services, Riverton, NJ, BMEWS, clear as negative no. A-1226 - Clear Air Force Station, Ballistic Missile Early Warning System Site II, One mile west of mile marker 293.5 on Parks Highway, 5 miles southwest of Anderson, Anderson, Denali Borough, AK

  7. Evaluation of organic moderator/coolants for fusion breeder blankets

    SciTech Connect

    Romero, J.B.

    1980-03-01

    Organic coolants have several attractive features for fusion breeder blanket design. Their apparent compatibility with lithium and their ideal physical and nuclear properties allows straight-forward, high performance designs. Radiolytic damage can be reduced to about the same order as comparable fission systems by using multiplier/stripper blanket designs. Tritium recovery from the organic should be straightforward, but additional data is needed to make a better assessment of the economics of the process.

  8. Rotating solid radiative coolant system for space nuclear reactors

    SciTech Connect

    Apley, W.J.; Babb, A.L.

    1988-05-01

    The RING power system described in this paper is proposed as a primary or emergency heat rejection system for advanced space reactor power applications. The system employs a set of four (4) counter-rotating, 90 degree offset, coolant-carrying rings. The rings (segmented, corrugated, finned, thin-walled pipes, filled with liquid lithium) pass through a cavity heat exchanger and reradiate the absorbed heat to the space environment. 25 refs., 6 figs., 3 tabs.

  9. Alternative Approaches to Land Initialization for Seasonal Precipitation and Temperature Forecasts

    NASA Technical Reports Server (NTRS)

    Koster, Randal; Suarez, Max; Liu, Ping; Jambor, Urszula

    2004-01-01

    The seasonal prediction system of the NASA Global Modeling and Assimilation Office is used to generate ensembles of summer forecasts utilizing realistic soil moisture initialization. To derive the realistic land states, we drive offline the system's land model with realistic meteorological forcing over the period 1979-1993 (in cooperation with the Global Land Data Assimilation System project at GSFC) and then extract the state variables' values on the chosen forecast start dates. A parallel series of forecast ensembles is performed with a random (though climatologically consistent) set of land initial conditions; by comparing the two sets of ensembles, we can isolate the impact of land initialization on forecast skill from that of the imposed SSTs. The base initialization experiment is supplemented with several forecast ensembles that use alternative initialization techniques. One ensemble addresses the impact of minimizing climate drift in the system through the scaling of the initial conditions, and another is designed to isolate the importance of the precipitation signal from that of all other signals in the antecedent offline forcing. A third ensemble includes a more realistic initialization of the atmosphere along with the land initialization. The impact of each variation on forecast skill is quantified.

  10. An Analysis of an Automatic Coolant Bypass in the International Space Station Node 2 Internal Active Thermal Control System

    NASA Technical Reports Server (NTRS)

    Clanton, Stephen E.; Holt, James M.; Turner, Larry D. (Technical Monitor)

    2001-01-01

    A challenging part of International Space Station (ISS) thermal control design is the ability to incorporate design changes into an integrated system without negatively impacting performance. The challenge presents itself in that the typical ISS Internal Active Thermal Control System (IATCS) consists of an integrated hardware/software system that provides active coolant resources to a variety of users. Software algorithms control the IATCS to specific temperatures, flow rates, and pressure differentials in order to meet the user-defined requirements. What may seem to be small design changes imposed on the system may in fact result in system instability or the temporary inability to meet user requirements. The purpose of this paper is to provide a brief description of the solution process and analyses used to implement one such design change that required the incorporation of an automatic coolant bypass in the ISS Node 2 element.

  11. MATLAB/Simulink Framework for Modeling Complex Coolant Flow Configurations of Advanced Automotive Thermal Management Systems: Preprint

    SciTech Connect

    Titov, Eugene; Lustbader, Jason; Leighton, Daniel; Kiss, Tibor

    2016-03-22

    The National Renewable Energy Laboratory's (NREL's) CoolSim MATLAB/Simulink modeling framework was extended by including a newly developed coolant loop solution method aimed at reducing the simulation effort for arbitrarily complex thermal management systems. The new approach does not require the user to identify specific coolant loops and their flow. The user only needs to connect the fluid network elements in a manner consistent with the desired schematic. Using the new solution method, a model of NREL's advanced combined coolant loop system for electric vehicles was created that reflected the test system architecture. This system was built using components provided by the MAHLE Group and included both air conditioning and heat pump modes. Validation with test bench data and verification with the previous solution method were performed for 10 operating points spanning a range of ambient temperatures between -2 degrees C and 43 degrees C. The largest root mean square difference between pressure, temperature, energy and mass flow rate data and simulation results was less than 7%.

  12. Acceptance criteria for reactor coolant pumps and valves

    SciTech Connect

    Gupta, N.K.; Miller, R.F.; Sindelar, R.L.

    1993-05-01

    Each of the six primary coolant loop systems of the Savannah River Site (SRS) production reactors contains one reactor coolant pump, one PUMP suction side motor operated valve, and other smaller valves. The pumps me double suction, double volute, and radially split type pumps. The valves are different size shutoff and control valves rated from ANSI B16.5 construction class 150 to class 300. The reactor coolant system components, also known as the process water system (PWS), are classified as nuclear Safety Class I components. These components were constructed in the 1950`s in accordance with the then prevailing industry practices. No uniform construction codes were used for design and analysis of these components. However, no pressure boundary failures or bolting failures have ever been recorded throughout their operating history. Over the years, the in-service inspection (ISI) was limited to visual inspection of the pressure boundaries, and surface and volumetric examination of the pressure retaining bolts. Efforts are now underway to implement ISI requirements similar to the ASME Section XI requirements for pumps and valves. This report discusses the new ISI requirements which also call for volumetric examination of the pump casing and valve body welds.

  13. Crack stability analysis of low alloy steel primary coolant pipe

    SciTech Connect

    Tanaka, T.; Kameyama, M.; Urabe, Y.

    1997-04-01

    At present, cast duplex stainless steel has been used for the primary coolant piping of PWRs in Japan and joints of dissimilar material have been applied for welding to reactor vessels and steam generators. For the primary coolant piping of the next APWR plants, application of low alloy steel that results in designing main loops with the same material is being studied. It means that there is no need to weld low alloy steel with stainless steel and that makes it possible to reduce the welding length. Attenuation of Ultra Sonic Wave Intensity is lower for low alloy steel than for stainless steel and they have advantageous inspection characteristics. In addition to that, the thermal expansion rate is smaller for low alloy steel than for stainless steel. In consideration of the above features of low alloy steel, the overall reliability of primary coolant piping is expected to be improved. Therefore, for the evaluation of crack stability of low alloy steel piping to be applied for primary loops, elastic-plastic future mechanics analysis was performed by means of a three-dimensioned FEM. The evaluation results for the low alloy steel pipings show that cracks will not grow into unstable fractures under maximum design load conditions, even when such a circumferential crack is assumed to be 6 times the size of the wall thickness.

  14. Axi-symmetric generalized thermoelastic diffusion problem with two-temperature and initial stress under fractional order heat conduction

    NASA Astrophysics Data System (ADS)

    Deswal, Sunita; Kalkal, Kapil Kumar; Sheoran, Sandeep Singh

    2016-09-01

    A mathematical model of fractional order two-temperature generalized thermoelasticity with diffusion and initial stress is proposed to analyze the transient wave phenomenon in an infinite thermoelastic half-space. The governing equations are derived in cylindrical coordinates for a two dimensional axi-symmetric problem. The analytical solution is procured by employing the Laplace and Hankel transforms for time and space variables respectively. The solutions are investigated in detail for a time dependent heat source. By using numerical inversion method of integral transforms, we obtain the solutions for displacement, stress, temperature and diffusion fields in physical domain. Computations are carried out for copper material and displayed graphically. The effect of fractional order parameter, two-temperature parameter, diffusion, initial stress and time on the different thermoelastic and diffusion fields is analyzed on the basis of analytical and numerical results. Some special cases have also been deduced from the present investigation.

  15. Component evaluation for intersystem loss-of-coolant accidents in advanced light water reactors

    SciTech Connect

    Ware, A.G.

    1994-07-01

    Using the methodology outlined in NUREG/CR-5603 this report evaluates (on a probabilistic basis) design rules for components in ALWRs that could be subjected to intersystem loss-of-coolant accidents (ISLOCAs). The methodology is intended for piping elements, flange connections, on-line pumps and valves, and heat exchangers. The NRC has directed that the design rules be evaluated for BWR pressures of 7.04 MPa (1025 psig), PWR pressures of 15.4 MPa (2235 psig), and 177{degrees}C (350{degrees}F), and has established a goal of 90% probability that system rupture will not occur during an ISLOCA event. The results of the calculations in this report show that components designed for a pressure of 0.4 of the reactor coolant system operating pressure will satisfy the NRC survival goal in most cases. Specific recommendations for component strengths for BWR and PWR applications are made in the report. A peer review panel of nationally recognized experts was selected to review and critique the initial results of this program.

  16. Microstructural analysis of MTR fuel plates damaged by a coolant flow blockage

    NASA Astrophysics Data System (ADS)

    Leenaers, A.; Joppen, F.; Van den Berghe, S.

    2009-10-01

    In 1975, as a result of a blockage of the coolant inlet flow, two plates of a fuel element of the BR2 reactor of the Belgian Nuclear Research Centre (SCK•CEN) were partially melted. The fuel element consisted of Al-clad plates with 90% 235U enriched UAl x fuel dispersed in an Al matrix. The element had accumulated a burn up of 21% 235U before it was removed from the reactor. Recently, the damaged fuel plates were sent to the hot laboratory for detailed PIE. Microstructural changes and associated temperature markers were used to identify several stages in the progression to fuel melting. It was found that the temperature in the center of the fuel plate had increased above 900-950 °C before the reactor was scrammed. In view of the limited availability of such datasets, the results of this microstructural analysis provide valuable input in the analysis of accident scenarios for research reactors.

  17. Use of a temperature-initiated passive cooling system (TIPACS) for the modular high-temperature gas-cooled reactor cavity cooling system (RCCS)

    SciTech Connect

    Forsberg, C.W.; Conklin, J.; Reich, W.J.

    1994-04-01

    A new type of passive cooling system has been invented (Forsberg 1993): the Temperature-Initiated Passive Cooling System (TIPACS). The characteristics of the TIPACS potentially match requirements for an improved reactor-cavity-cooling system (RCCS) for the modular high-temperature gas-cooled reactor (MHTGR). This report is an initial evaluation of the TIPACS for the MHTGR with a Rankines (steam) power conversion cycle. Limited evaluations were made of applying the TIPACS to MHTGRs with reactor pressure vessel temperatures up to 450 C. These temperatures may occur in designs of Brayton cycle (gas turbine) and process heat MHTGRs. The report is structured as follows. Section 2 describes the containment cooling issues associated with the MHTGR and the requirements for such a cooling system. Section 3 describes TIPACS in nonmathematical terms. Section 4 describes TIPACS`s heat-removal capabilities. Section 5 analyzes the operation of the temperature-control mechanism that determines under what conditions the TIPACS rejects heat to the environment. Section 6 addresses other design and operational issues. Section 7 identifies uncertainties, and Section 8 provides conclusions. The appendixes provide the detailed data and models used in the analysis.

  18. Gas production and behavior in the coolant of the SP-100 space nuclear power system

    NASA Astrophysics Data System (ADS)

    McGhee, John Morton

    1989-08-01

    The radiologic generation and subsequent behavior of helium gas in the lithium coolant of SP-100 class space nuclear power reactors was investigated analytically in a two part study. Part One of the study consisted of a calculation of coolant radiologic helium gas production rates in a SP-100 class reactor using the discrete ordinates code TWODANT. Cross sections were developed from ENDF/B-V data via the MATXS6s master cross section library. Cross sections were self shielded assuming one homogeneous core region, and Doppler broadened to 1300 K using the cross section preparation code TRANSX. Calculations were performed using an S sub 4/P sub 1 approximation and 80 neutron energy groups. Part Two of the study consisted of a theoretical investigation into the behavior of helium gas in the primary loop of lithium cooled space reactors. The SP-100 space power system was used as a representative of such a system. Topics investigated included: (1) heterogeneous and homogeneous nucleation; (2) bubble growth/collapse by diffusion, mechanical temperature/pressure effects, and coalescence; and, (3) the effects on bubble distribution of microgravity, magnetic fields, and inertially induced buoyancy.

  19. Gas production and behavior in the coolant of the SP-100 Space Nuclear Power System

    SciTech Connect

    McGhee, J.M.

    1989-08-01

    The radiologic generation and subsequent behavior of helium gas in the lithium coolant of SP-100 class space nuclear power reactors was investigated analytically in a two part study. Part One of the study consisted of a calculation of coolant radiologic helium gas production rates in a SP-100 class reactor using the discrete ordinates code TWODANT. Cross sections were developed from ENDF/B-V data via the MATXS6s master cross section library. Cross sections were self shielded assuming one homogeneous core region, and doppler broadened to 1300 K using the cross section preparation code TRANSX. Calculations were performed using an S{sub 4}/P{sub 1} approximation and 80 neutron energy groups. Part Two of the study consisted of a theoretical investigation into the behavior of helium gas in the primary loop of lithium cooled space reactors. The SP-100 space power system was used as a representative of such a system. Topics investigated included: (1) heterogeneous and homogeneous nucleation; (2) bubble growth/collapse by diffusion, mechanical temperature/pressure effects, and coalescence; and, (3) the effects on bubble distribution of microgravity, magnetic fields, and inertially induced buoyancy. 104 refs., 78 figs., 28 tabs.

  20. System Assessment of Carbon Dioxide Used as Gas Oxidant and Coolant in Vanadium-Extraction Converter

    NASA Astrophysics Data System (ADS)

    Du, Wei Tong; Wang, Yu; Liang, Xiao Ping

    2017-10-01

    With the aim of reducing carbon dioxide (CO2) emissions and of using waste resources in steel plants, the use of CO2 as a gas oxidant and coolant in the converter to increase productivity and energy efficiency was investigated in this study. Experiments were performed in combination with thermodynamic theory on vanadium-extraction with CO2 and oxygen (O2) mixed injections. The results indicate that the temperature of the hot metal bath decreased as the amount of CO2 introduced into O2 increased. At an injection of 85 vol.% O2 and 15 vol.% CO2, approximately 12% of additional carbon was retained in the hot metal. Moreover, the content of vanadium trioxide in the slag was higher. In addition, the O2 consumption per ton of hot metal was reduced by 8.5% and additional chemical energy was recovered by the controlled injection of CO2 into the converter. Therefore, using CO2 as a gas coolant was conducive to vanadium extraction, and O2 consumption was reduced.

  1. System Assessment of Carbon Dioxide Used as Gas Oxidant and Coolant in Vanadium-Extraction Converter

    NASA Astrophysics Data System (ADS)

    Du, Wei Tong; Wang, Yu; Liang, Xiao Ping

    2017-07-01

    With the aim of reducing carbon dioxide (CO2) emissions and of using waste resources in steel plants, the use of CO2 as a gas oxidant and coolant in the converter to increase productivity and energy efficiency was investigated in this study. Experiments were performed in combination with thermodynamic theory on vanadium-extraction with CO2 and oxygen (O2) mixed injections. The results indicate that the temperature of the hot metal bath decreased as the amount of CO2 introduced into O2 increased. At an injection of 85 vol.% O2 and 15 vol.% CO2, approximately 12% of additional carbon was retained in the hot metal. Moreover, the content of vanadium trioxide in the slag was higher. In addition, the O2 consumption per ton of hot metal was reduced by 8.5% and additional chemical energy was recovered by the controlled injection of CO2 into the converter. Therefore, using CO2 as a gas coolant was conducive to vanadium extraction, and O2 consumption was reduced.

  2. Prediction of the crack initiation time of the alloys used in high temperature water

    SciTech Connect

    Tsubota, M.; Kanazawa, Y.

    1994-12-31

    Correlations between applied stress ({sigma}) and SCC initiation time (t) of sensitized 304 stainless steel, alloy 600 and alloy X-750 were studied. A general expression t = m {times} {sigma}{sup {minus}n} was obtained from both the analysis of the uni-axial constant load test data and the theoretical considerations of the crack initiation process. The n-value was determined from the process of crack initiation, and the m-value was a constant determined from material and environmental conditions.

  3. Temperature controller for a fluid cooled garment

    NASA Technical Reports Server (NTRS)

    Chambers, A. B.; Blackaby, J. R.; Billingham, J. (Inventor)

    1973-01-01

    An automatic controller for controlling the inlet temperature of the coolant to a fluid cooled garment without requiring skin sensors is described. Temperature is controlled by the wearer's evaporative water loss rate.

  4. The Feasibility of Applying AC Driven Low-Temperature Plasma for Multi-Cycle Detonation Initiation

    NASA Astrophysics Data System (ADS)

    Zheng, Dianfeng

    2016-11-01

    Ignition is a key system in pulse detonation engines (PDE). As advanced ignition methods, nanosecond pulse discharge low-temperature plasma ignition is used in some combustion systems, and continuous alternating current (AC) driven low-temperature plasma using dielectric barrier discharge (DBD) is used for the combustion assistant. However, continuous AC driven plasmas cannot be used for ignition in pulse detonation engines. In this paper, experimental and numerical studies of pneumatic valve PDE using an AC driven low-temperature plasma igniter were described. The pneumatic valve was jointly designed with the low-temperature plasma igniter, and the numerical simulation of the cold-state flow field in the pneumatic valve showed that a complex flow in the discharge area, along with low speed, was beneficial for successful ignition. In the experiments ethylene was used as the fuel and air as oxidizing agent, ignition by an AC driven low-temperature plasma achieved multi-cycle intermittent detonation combustion on a PDE, the working frequency of the PDE reached 15 Hz and the peak pressure of the detonation wave was approximately 2.0 MPa. The experimental verifications of the feasibility in PDE ignition expanded the application field of AC driven low-temperature plasma. supported by National Natural Science Foundation of China (No. 51176001)

  5. Heat transfer characteristics for some coolant additives used for water cooled engines

    SciTech Connect

    Abou-Ziyan, H.Z.; Helali, A.H.B.

    1996-12-31

    Engine coolants contain certain additives to prevent engine overheating or coolant freezing in cold environments. Coolants, also, contain corrosion and rust inhibitors, among other additives. As most engines are using engine cooling solutions, it is of interest to evaluate the effect of engine coolants on the boiling heat transfer coefficient. This has its direct impact on radiator size and environment. This paper describes the apparatus and the measurement techniques. Also, it presents the obtained boiling heat transfer results at different parameters. Three types of engine coolants and their mixtures in distilled water are evaluated, under sub-cooled and saturated boiling conditions. A profound effect of the presence of additives in the coolant, on heat transfer, was clear since changes of heat transfer for different coolants were likely to occur. The results showed that up to 180% improvement of boiling heat transfer coefficient is experienced with some types of coolants. However, at certain concentrations other coolants provide deterioration or not enhancement in the boiling heat transfer characteristics. This investigation proved that there are limitations, which are to be taken into consideration, for the composition of engine coolants in different environments. In warm climates, ethylene glycol should be kept at the minimum concentration required for dissolving other components, whereas borax is beneficial to the enhancement of the heat transfer characteristics.

  6. Effect of Hall current on an initially-stressed two-temperature thermoelastic material under G-N theory

    NASA Astrophysics Data System (ADS)

    Tantawi, Ramadan S.

    2016-11-01

    The influence of the initial stress and the Hall current on a two-temperature thermoelastic material is investigated in the framework of the modified Ohm's law and Green-Naghdi theory. Analytical expressions for the physical quantities are obtained by using the normal mode method and are presented graphically. Finally, the resulting physical quantities are discussed with and without the initial stress and the Hall current. The results of this study have applications in a wide range of physical problems, geophysical applications, and radiation physics.

  7. The initial freezing point temperature of beef rises with the rise in pH: a short communication.

    PubMed

    Farouk, M M; Kemp, R M; Cartwright, S; North, M

    2013-05-01

    This study tested the hypothesis that the initial freezing point temperature of meat is affected by pH. Sixty four bovine M. longissimus thoracis et lumborum were classified into two ultimate pH groups: low (<5.8) and high pH (>6.2) and their cooling and freezing point temperatures were determined. The initial freezing temperatures for beef ranged from -0.9 to -1.5°C (∆=0.6°C) with the higher and lower temperatures associated with high and low ultimate pH respectively. There was a significant correlation (r=+0.73, P<0.01) between beef pH and freezing point temperature in the present study. The outcome of this study has implications for the meat industry where evidence of freezing (ice formation) in a shipment as a result of high pH meat could result in a container load of valuable chilled product being downgraded to a lower value frozen product.

  8. Effect of temperature of HPT deformation and the initial orientation on the structural evolution in single-crystal niobium

    NASA Astrophysics Data System (ADS)

    Gapontseva, T. M.; Degtyarev, M. V.; Pilyugin, V. P.; Chashchukhina, T. I.; Voronova, L. M.; Patselov, A. M.

    2016-04-01

    The structural evolution and hardness of sing-crystal niobium with various initial orientations are investigated after its deformation in Bridgman anvils at room (290 K) and cryogenic (80 K) temperatures. It is shown that no twinning occurs upon cryogenic deformation; thin prolonged bands dividing the matrix into weakly misoriented regions are formed. The uniform-in-size structure of a nanoscale level ( d av = 40 nm) is formed during cryogenic deformation after the maximum achieved true strain. The average microcrystallite size observed after room-temperature deformation is 120 nm.

  9. Brief summary of the evolution of high-temperature creep-fatigue life prediction models for crack initiation

    NASA Astrophysics Data System (ADS)

    Halford, Gary R.

    1993-10-01

    The evolution of high-temperature, creep-fatigue, life-prediction methods used for cyclic crack initiation is traced from inception in the late 1940's. The methods reviewed are material models as opposed to structural life prediction models. Material life models are used by both structural durability analysts and by material scientists. The latter use micromechanistic models as guidance to improve a material's crack initiation resistance. Nearly one hundred approaches and their variations have been proposed to date. This proliferation poses a problem in deciding which method is most appropriate for a given application. Approaches were identified as being combinations of thirteen different classifications. This review is intended to aid both developers and users of high-temperature fatigue life prediction methods by providing a background from which choices can be made. The need for high-temperature, fatigue-life prediction methods followed immediately on the heels of the development of large, costly, high-technology industrial and aerospace equipment immediately following the second world war. Major advances were made in the design and manufacture of high-temperature, high-pressure boilers and steam turbines, nuclear reactors, high-temperature forming dies, high-performance poppet valves, aeronautical gas turbine engines, reusable rocket engines, etc. These advances could no longer be accomplished simply by trial and error using the 'build-em and bust-em' approach. Development lead times were too great and costs too prohibitive to retain such an approach. Analytic assessments of anticipated performance, cost, and durability were introduced to cut costs and shorten lead times. The analytic tools were quite primitive at first and out of necessity evolved in parallel with hardware development. After forty years more descriptive, more accurate, and more efficient analytic tools are being developed. These include thermal-structural finite element and boundary element

  10. Brief summary of the evolution of high-temperature creep-fatigue life prediction models for crack initiation

    NASA Technical Reports Server (NTRS)

    Halford, Gary R.

    1993-01-01

    The evolution of high-temperature, creep-fatigue, life-prediction methods used for cyclic crack initiation is traced from inception in the late 1940's. The methods reviewed are material models as opposed to structural life prediction models. Material life models are used by both structural durability analysts and by material scientists. The latter use micromechanistic models as guidance to improve a material's crack initiation resistance. Nearly one hundred approaches and their variations have been proposed to date. This proliferation poses a problem in deciding which method is most appropriate for a given application. Approaches were identified as being combinations of thirteen different classifications. This review is intended to aid both developers and users of high-temperature fatigue life prediction methods by providing a background from which choices can be made. The need for high-temperature, fatigue-life prediction methods followed immediately on the heels of the development of large, costly, high-technology industrial and aerospace equipment immediately following the second world war. Major advances were made in the design and manufacture of high-temperature, high-pressure boilers and steam turbines, nuclear reactors, high-temperature forming dies, high-performance poppet valves, aeronautical gas turbine engines, reusable rocket engines, etc. These advances could no longer be accomplished simply by trial and error using the 'build-em and bust-em' approach. Development lead times were too great and costs too prohibitive to retain such an approach. Analytic assessments of anticipated performance, cost, and durability were introduced to cut costs and shorten lead times. The analytic tools were quite primitive at first and out of necessity evolved in parallel with hardware development. After forty years more descriptive, more accurate, and more efficient analytic tools are being developed. These include thermal-structural finite element and boundary element

  11. Subcooled freon-11 flow boiling in top-heated finned coolant channels with and without a twisted tape

    NASA Technical Reports Server (NTRS)

    Smith, Alvin; Boyd, Ronald D., Sr.

    1989-01-01

    An experimental study was conducted in top-heated finned horizontal tubes to study the effect of enhancement devices on flow boiling heat transfer in coolant channels. The objectives are to examine the variations in both the mean and local (axial and circumferential) heat transfer coefficients for circular coolant channels with spiral finned walls and/or spiral fins with a twisted tape, and improve the data reduction technique of a previous investigator. The working fluid is freon-11 with an inlet temperature of 22.2 C (approximately 21 C subcooling). The coolant channel's exit pressure and mass velocity are 0.19 M Pa (absolute) and 0.21 Mg/sq. ms, respectively. Two tube configurations were examined; i.e., tubes had either 6.52 (small pitch) or 4.0 (large pitch) fins/cm of the circumferential length (26 and 16 fins, respectively). The large pitch fins were also examined with a twisted tape insert. The inside nominal diameter of the copper channels at the root of the fins was 1.0 cm. The results show that by adding enhancement devices, boiling occurs almost simultaneously at all axial locations. The case of spiral fins with large pitch resulted in larger mean (circumferentially averaged) heat transfer coefficients, h sub m, at all axial locations. Finally, when twisted tape is added to the tube with large-pitched fins, the power required for the onset of boiling is reduced at all axial and circumferential locations.

  12. Subcooled freon-11 flow boiling in top-heated finned coolant channels with and without a twisted tape

    NASA Astrophysics Data System (ADS)

    Smith, Alvin; Boyd, Ronald D., Sr.

    An experimental study was conducted in top-heated finned horizontal tubes to study the effect of enhancement devices on flow boiling heat transfer in coolant channels. The objectives are to examine the variations in both the mean and local (axial and circumferential) heat transfer coefficients for circular coolant channels with spiral finned walls and/or spiral fins with a twisted tape, and improve the data reduction technique of a previous investigator. The working fluid is freon-11 with an inlet temperature of 22.2 C (approximately 21 C subcooling). The coolant channel's exit pressure and mass velocity are 0.19 M Pa (absolute) and 0.21 Mg/sq. ms, respectively. Two tube configurations were examined; i.e., tubes had either 6.52 (small pitch) or 4.0 (large pitch) fins/cm of the circumferential length (26 and 16 fins, respectively). The large pitch fins were also examined with a twisted tape insert. The inside nominal diameter of the copper channels at the root of the fins was 1.0 cm. The results show that by adding enhancement devices, boiling occurs almost simultaneously at all axial locations. The case of spiral fins with large pitch resulted in larger mean (circumferentially averaged) heat transfer coefficients, h sub m, at all axial locations. Finally, when twisted tape is added to the tube with large-pitched fins, the power required for the onset of boiling is reduced at all axial and circumferential locations.

  13. Ion cooling in the plasmasphere during magnetic storm initial phase: modeling the proton temperature dynamics.

    NASA Astrophysics Data System (ADS)

    Kotova, Galina; Verigin, Mikhail; Bezrukikh, Vladilen

    The effect of ion temperature decreasing at L ¡ 3 during geomagnetic storm development was recently revealed by INTERBALL 2 and MAGION 5 thermal plasma data. A model of proton drift outward from the Earth caused by magnetic field decreasing in the inner plasmasphere is considered. Conservation of the first adiabatic invariant results in proton cooling during their outward motion. It is shown that model temperatures well agree with experimental data. The work is partially supported by the RAS programs P16 and OFN 15.

  14. Study of Compatibility of Stainless Steel Weld Joints with Liquid Sodium-Potassium Coolants for Fission Surface Power Reactors for Lunar and Space Applications

    SciTech Connect

    Grossbeck, Martin; Qualls, Louis

    2015-07-31

    To make a manned mission to the surface of the moon or to Mars with any significant residence time, the power requirements will make a nuclear reactor the most feasible source of energy. To prepare for such a mission, NASA has teamed with the DOE to develop Fission Surface Power technology with the goal of developing viable options. The Fission Surface Power System (FSPS) recommended as the initial baseline design includes a liquid metal reactor and primary coolant system that transfers heat to two intermediate liquid metal heat transfer loops. Each intermediate loop transfers heat to two Stirling heat exchangers that each power two Stirling converters. Both the primary and the intermediate loops will use sodium-potassium (NaK) as the liquid metal coolant, and the primary loop will operate at temperatures exceeding 600°C. The alloy selected for the heat exchangers and piping is AISI Type 316L stainless steel. The extensive experience with NaK in breeder reactor programs and with earlier space reactors for unmanned missions lends considerable confidence in using NaK as a coolant in contact with stainless steel alloys. However, the microstructure, chemical segregation, and stress state of a weld leads to the potential for corrosion and cracking. Such failures have been experienced in NaK systems that have operated for times less than the eight year goal for the FSPS. For this reason, it was necessary to evaluate candidate weld techniques and expose welds to high-temperature, flowing NaK in a closed, closely controlled system. The goal of this project was to determine the optimum weld configuration for a NaK system that will withstand service for eight years under FSPS conditions. Since the most difficult weld to make and to evaluate is the tube to tube sheet weld in the intermediate heat exchangers, it was the focus of this research. A pumped loop of flowing NaK was fabricated for exposure of candidate weld specimens at temperatures of 600°C, the expected

  15. Adhesive for polyester films cures at room temperature, has high initial tack

    NASA Technical Reports Server (NTRS)

    Christian, C. M.; Fust, G. W.; Welchel, C. J.

    1966-01-01

    Quick room-temperature-cure adhesive bonds polyester-insulated flat electrical cables to metal surfaces and various other substrates. The bond strength of the adhesive may be considerably increased by first applying a commercially available polyamide primer to the polyester film.

  16. Low temperature protects mammalian cells from apoptosis initiated by various stimuli in vitro

    SciTech Connect

    Sakurai, Toshiharu; Itoh, Katsuhiko; Liu Yu; Higashitsuji, Hiroaki; Sumitomo, Yasuhiko; Sakamaki, Kazuhiro; Fujita, Jun . E-mail: jfujita@virus.kyoto-u.ac.jp

    2005-10-01

    Mild hypothermia shows protective effects on patients with brain damage and cardiac arrest. To elucidate the molecular mechanisms underlying these effects, we examined the effects of low temperature (32 deg. C) on cells exposed to a variety of stress in vitro. We found that 32 deg. C suppressed induction of apoptosis by cytotoxic stimuli such as adriamycin, etoposide, thapsigargin, NaCl, H{sub 2}O{sub 2}, and anti-Fas antibody. In adriamycin-treated BALB/3T3 cells, the down-shift in temperature from 37 deg. C to 32 deg. C increased the Bcl-xL protein level and decreased the mRNA level of Puma and mitochondrial translocation of Bax, suppressing caspase-9-mediated apoptosis. Furthermore, the protein level and stability of p53 were decreased, and its nuclear export was increased concomitant with Mdm2 mRNA upregulation. The low temperature effect was not observed in p53 {sup -/-}/Mdm2 {sup -/-} mouse embryonic fibroblasts, suggesting that the effect is mediated by suppression of the p53 pathway. In contrast, while thapsigargin-induced apoptosis was suppressed by the low temperature, no effect on the p53 protein level was observed. Furthermore, the survival rate of p53 {sup -/-}/Mdm2 {sup -/-} cells exposed to thapsigargin was increased when cultured at 32 deg. C compared with 37 deg. C. In conclusion, mild hypothermia protects cells from a variety of stress by p53-dependent and p53-independent mechanisms.

  17. Cryostabilization of high-temperature superconducting magnets with subcooled flow in microchannels

    NASA Astrophysics Data System (ADS)

    Cha, Y. S.; Hull, J. R.; Choi, U. S.

    1992-07-01

    Subcooled flow of liquid nitrogen in microchannels is proposed as a means to enhance the stability of a superconducting magnet. Analysis shows high current density or a low stabilizer fraction is obtainable in a cryostable magnet. Increase in stability (using the Stekley criterion) is directly related to coolant velocity and coolant channel aspect ratio, however, there is a corresponding increase in pressure drop of the system. Another constraint is the coolant temperature rise, which is found to be a function of coolant residence time and the coolant to conductor ratio.

  18. Failure probability of PWR reactor coolant loop piping. [Double-ended guillotine break

    SciTech Connect

    Lo, T.; Woo, H.H.; Holman, G.S.; Chou, C.K.

    1984-02-01

    This paper describes the results of assessments performed on the PWR coolant loop piping of Westinghouse and Combustion Engineering plants. For direct double-ended guillotine break (DEGB), consideration was given to crack existence probability, initial crack size distribution, hydrostatic proof test, preservice inspection, leak detection probability, crack growth characteristics, and failure criteria based on the net section stress failure and tearing modulus stability concept. For indirect DEGB, fragilities of major component supports were estimated. The system level fragility was then calculated based on the Boolean expression involving these fragilities. Indirect DEGB due to seismic effects was calculated by convolving the system level fragility and the seismic hazard curve. The results indicate that the probability of occurrence of both direct and indirect DEGB is extremely small, thus, postulation of DEGB in design should be eliminated and replaced by more realistic criteria.

  19. Fifty hertz magnetic fields individually affect chromatin conformation in human lymphocytes: dependence on amplitude, temperature, and initial chromatin state.

    PubMed

    Sarimov, Ruslan; Alipov, Eugene D; Belyaev, Igor Y

    2011-10-01

    Effects of magnetic field (MF) at 50 Hz on chromatin conformation were studied by the method of anomalous viscosity time dependence (AVTD) in human lymphocytes from two healthy donors. MF within the peak amplitude range of 5-20 µT affected chromatin conformation. These MF effects differed significantly between studied donors, and depended on magnetic flux density and initial condensation of chromatin. While the initial state of chromatin was rather stable in one donor during one calendar year of measurements, the initial condensation varied significantly in cells from another donor. Both this variation and the MF effect depended on temperature during exposure. Despite these variations, the general rule was that MF condensed the relaxed chromatin and relaxed the condensed chromatin. Thus, in this study we show that individual effects of 50 Hz MF exposure at peak amplitudes within the range of 5-20 µT may be observed in human lymphocytes in dependence on the initial state of chromatin and temperature. Copyright © 2011 Wiley-Liss, Inc.

  20. Cryogenic-coolant He4-superconductor dynamic and static interactions

    NASA Technical Reports Server (NTRS)

    Caspi, S.; Chuang, C.; Kim, Y. I.; Allen, R. J.; Frederking, T. H. E.

    1980-01-01

    A composite superconducting material (NbTi-Cu) was evaluated with emphasis on post quench solid cooling interaction regimes. The quasi-steady runs confirm the existence of a thermodynamic limiting thickness for insulating coatings. Two distinctly different post quench regimes of coated composites are shown to relate to the limiting thickness. Only one regime,, from quench onset to the peak value, revealed favorable coolant states, in particular in He2. Transient recovery shows favorable recovery times from this post quench regime (not drastically different from bare conductors) for both single coated specimens and a coated conductor bundle.

  1. System Study: High-Pressure Coolant Injection 1998-2012

    SciTech Connect

    T. E. Wierman

    2013-10-01

    This report presents an unreliability evaluation of the high-pressure coolant injection system (HPCI) at 69 U.S. commercial nuclear power plants. Demand, run hours, and failure data from fiscal year 1998 through 2012 for selected components were obtained from the Equipment Performance and Information Exchange (EPIX). The unreliability results are trended for the most recent 10 year period while yearly estimates for system unreliability are provided for the entire active period. No statistically significant increasing or decreasing trends were identified in the HPCI results.

  2. System Study: High-Pressure Coolant Injection 1998-2014

    SciTech Connect

    Schroeder, John Alton

    2015-12-01

    This report presents an unreliability evaluation of the high-pressure coolant injection system (HPCI) at 25 U.S. commercial boiling water reactors. Demand, run hours, and failure data from fiscal year 1998 through 2014 for selected components were obtained from the Institute of Nuclear Power Operations (INPO) Consolidated Events Database (ICES). The unreliability results are trended for the most recent 10 year period, while yearly estimates for system unreliability are provided for the entire active period. No statistically significant increasing or decreasing trends were identified in the HPCI results.

  3. System Study: High-Pressure Coolant Injection 1998–2013

    SciTech Connect

    Schroeder, John Alton

    2015-01-31

    This report presents an unreliability evaluation of the high-pressure coolant injection system (HPCI) at 25 U.S. commercial boiling water reactors. Demand, run hours, and failure data from fiscal year 1998 through 2013 for selected components were obtained from the Institute of Nuclear Power Operations (INPO) Consolidated Events Database (ICES). The unreliability results are trended for the most recent 10-year period, while yearly estimates for system unreliability are provided for the entire active period. No statistically significant increasing or decreasing trends were identified in the HPCI results.

  4. Mechanism and estimation of fatigue crack initiation in austenitic stainless steels in LWR environments.

    SciTech Connect

    Chopra, O. K.; Energy Technology

    2002-08-01

    The ASME Boiler and Pressure Vessel Code provides rules for the construction of nuclear power plant components. Figures I-9.1 through I-9.6 of Appendix I to Section III of the Code specify fatigue design curves for structural materials. However, the effects of light water reactor (LWR) coolant environments are not explicitly addressed by the Code design curves. Existing fatigue strain-vs.-life ({var_epsilon}-N) data illustrate potentially significant effects of LWR coolant environments on the fatigue resistance of pressure vessel and piping steels. This report provides an overview of fatigue crack initiation in austenitic stainless steels in LWR coolant environments. The existing fatigue {var_epsilon}-N data have been evaluated to establish the effects of key material, loading, and environmental parameters (such as steel type, strain range, strain rate, temperature, dissolved-oxygen level in water, and flow rate) on the fatigue lives of these steels. Statistical models are presented for estimating the fatigue {var_epsilon}-N curves for austenitic stainless steels as a function of the material, loading, and environmental parameters. Two methods for incorporating environmental effects into the ASME Code fatigue evaluations are presented. The influence of reactor environments on the mechanism of fatigue crack initiation in these steels is also discussed.

  5. Annealing Temperature and Initial Iron Valence Ratio Effects on the Structural Characteristics of Nanoscale Nickel Zinc Ferrite

    SciTech Connect

    Calvin, S.; Shultz, M; Glowzenski, L; Carpenter, E

    2010-01-01

    Nickel zinc ferrite (NZFO) nanoparticles were synthesized via a reverse micelle method with a nonionic surfactant. Three different initial Fe{sup 3+}/Fe{sup 2+} ratios were employed along with three different firing temperatures (200, 500, 1000 C) to investigate the effects on the NZFO system. Extended x-ray absorption fine structure (EXAFS) results reveal zinc loss at high annealing temperatures; at 1000 C, the loss is nearly total for Fe{sup 3+}/Fe{sup 2+} ratios other than 10:90. Annealing at 500 C, however, appears necessary for fully incorporating the zinc and nickel into the spinel phase. The best nanoferrite was thus obtained using an initial Fe{sup 3+}/Fe{sup 2+} ratio of 10:90 and a moderate firing temperature of 500 C. This sample exhibits a room temperature saturation magnetization of 58 emu/g as measured via vibrating sample magnetometry, comparable with bulk values and greater than that of confirmed nano-NZFOs found in the literature. EXAFS also indicates that in all cases in which the elements adopted a spinel structure, the nickel occupies only octahedral sites and the zinc primarily tetrahedral sites.

  6. Temperature-Dependent Model of Multi-step Transcription Initiation in Escherichia coli Based on Live Single-Cell Measurements

    PubMed Central

    Lloyd-Price, Jason; Tran, Huy; Ribeiro, Andre S.

    2016-01-01

    Transcription kinetics is limited by its initiation steps, which differ between promoters and with intra- and extracellular conditions. Regulation of these steps allows tuning both the rate and stochasticity of RNA production. We used time-lapse, single-RNA microscopy measurements in live Escherichia coli to study how the rate-limiting steps in initiation of the Plac/ara-1 promoter change with temperature and induction scheme. For this, we compared detailed stochastic models fit to the empirical data in maximum likelihood sense using statistical methods. Using this analysis, we found that temperature affects the rate limiting steps unequally, as nonlinear changes in the closed complex formation suffice to explain the differences in transcription dynamics between conditions. Meanwhile, a similar analysis of the PtetA promoter revealed that it has a different rate limiting step configuration, with temperature regulating different steps. Finally, we used the derived models to explore a possible cause for why the identified steps are preferred as the main cause for behavior modifications with temperature: we find that transcription dynamics is either insensitive or responds reciprocally to changes in the other steps. Our results suggests that different promoters employ different rate limiting step patterns that control not only their rate and variability, but also their sensitivity to environmental changes. PMID:27792724

  7. TACT1, a computer program for the transient thermal analysis of a cooled turbine blade or vane equipped with a coolant insert. 1. Users manual

    NASA Technical Reports Server (NTRS)

    Gaugler, R. E.

    1978-01-01

    A computer program to calculate transient and steady state temperatures, pressures, and coolant flows in a cooled, axial flow turbine blade or vane with an impingement insert is described. Coolant side heat transfer coefficients are calculated internally in the program, with the user specifying either impingement or convection heat transfer at each internal flow station. Spent impingement air flows in a chordwise direction and is discharged through the trailing edge and through film cooling holes. The ability of the program to handle film cooling is limited by the internal flow model. Sample problems, with tables of input and output, are included in the report. Input to the program includes a description of the blade geometry, coolant supply conditions, outside thermal boundary conditions, and wheel speed. The blade wall can have two layers of different materials, such as a ceramic thermal barrier coating over a metallic substrate. Program output includes the temperature at each node, the coolant pressures and flow rates, and the inside heat-transfer coefficients.

  8. Computational evidence for self-initiation in spontaneous high-temperature polymerization of methyl methacrylate.

    PubMed

    Srinivasan, Sriraj; Lee, Myung Won; Grady, Michael C; Soroush, Masoud; Rappe, Andrew M

    2011-02-17

    This paper presents computational evidence for the occurrence of diradical mechanism of self-initiation in thermal polymerization of methyl methacrylate. Two self-initiation mechanisms of interest were explored with first-principles density functional theory calculations. Singlet and triplet potential energy surfaces were constructed. The formation of two Diels-Alder adducts, cis- and trans-dimethyl 1,2-dimethylcyclobutane-1,2-dicarboxylate and dimethyl 2-methyl-5-methylidene-hexanedioate, on the singlet surface was identified. Transition states were calculated using B3LYP/6-31G* and assessed using MP2/6-31G*. The calculated energy barriers and rate constants with different levels of theory were found to show good agreement to corresponding data obtained from laboratory experiments. The presence of a diradical intermediate on the triplet surface was identified. When MCSCF/6-31G* was used, the spin-orbit coupling constant for the singlet to triplet crossover was calculated to be 2.5 cm(-1). The mechanism of monoradical generation via a hydrogen abstraction by both triplet and singlet diradicals from a third monomer was identified to be the most likely mechanism of initiation in spontaneous polymerization of methyl methacrylate.

  9. Discrete element method study of fuel relocation and dispersal during loss-of-coolant accidents

    NASA Astrophysics Data System (ADS)

    Govers, K.; Verwerft, M.

    2016-09-01

    The fuel fragmentation, relocation and dispersal (FFRD) during LOCA transients today retain the attention of the nuclear safety community. The fine fragmentation observed at high burnup may, indeed, affect the Emergency Core Cooling System performance: accumulation of fuel debris in the cladding ballooned zone leads to a redistribution of the temperature profile, while dispersal of debris might lead to coolant blockage or to debris circulation through the primary circuit. This work presents a contribution, by discrete element method, towards a mechanistic description of the various stages of FFRD. The fuel fragments are described as a set of interacting particles, behaving as a granular medium. The model shows qualitative and quantitative agreement with experimental observations, such as the packing efficiency in the balloon, which is shown to stabilize at about 55%. The model is then applied to study fuel dispersal, for which experimental parametric studies are both difficult and expensive.

  10. Oxidation of SiC cladding under Loss of Coolant Accident (LOCA) conditions in LWRs

    SciTech Connect

    Lee, Y.; Yue, C.; Arnold, R. P.; McKrell, T. J.; Kazimi, M. S.

    2012-07-01

    An experimental assessment of Silicon Carbide (SiC) cladding oxidation rate in steam under conditions representative of Loss of Coolant Accidents (LOCA) in light water reactors (LWRs) was conducted. SiC oxidation tests were performed with monolithic alpha phase tubular samples in a vertical quartz tube at a steam temperature of 1140 deg. C and steam velocity range of 1 to 10 m/sec, at atmospheric pressure. Linear weight loss of SiC samples due to boundary layer controlled reaction of silica scale (SiO{sub 2} volatilization) was experimentally observed. The weight loss rate increased with increasing steam flow rate. Over the range of test conditions, SiC oxidation rates were shown to be about 3 orders of magnitude lower than the oxidation rates of zircaloy 4. A SiC volatilization correlation for developing laminar flow in a vertical channel is formulated. (authors)

  11. Liquid Cooling of Tractive Lithium Ion Batteries Pack with Nanofluids Coolant.

    PubMed

    Li, Yang; Xie, Huaqing; Yu, Wei; Li, Jing

    2015-04-01

    The heat generated from tractive lithium ion batteries during discharge-charge process has great impacts on the performances of tractive lithium ion batteries pack. How to solve the thermal abuse in tractive lithium ion batteries pack becomes more and more urgent and important for future development of electrical vehicles. In this work, TiO2, ZnO and diamond nanofluids are prepared and utilized as coolants in indirect liquid cooling of tractive lithium ion batteries pack. The results show that nanofluids present superior cooling performance to that of pure fluids and the diamond nanofluid presents relatively excellent cooling abilities than that of TiO2 and ZnO nanofluids. During discharge process, the temperature distribution of batteries in batteries pack is uniform and stable, due to steady heat dissipation by indirect liquid cooling. It is expected that nanofluids could be considered as a potential alternative for indirect liquid cooling in electrical vehicles.

  12. Chemistry control analysis of lead alloys systems to be used as nuclear coolant or spallation target

    NASA Astrophysics Data System (ADS)

    Courouau, J.-L.; Robin, J.-C.

    2004-11-01

    This study presents the lead alloy system chemistry analysis for use as nuclear coolant or spallation target in ADS related systems in order to set down the needs for purification processes and monitoring. The study is limited here to the two main impurities, oxygen and iron. The analysis of the various potential pollution sources that may occur during the various operating modes is given, as well as a first pollution rate assessment. In order to limit the consequences in term of contamination (clogging) and corrosion, it is necessary to define specifications for operation as regards oxygen and iron content in the fluid. As iron cannot be measured and controlled up to now, the best specification is to set the oxygen as high as possible, defined by the cold leg interface temperature to ensure tolerable contamination, in order to maximize the oxidation area to ensure corrosion protection by self-healing oxide layer for the entire system.

  13. The effect of bupivacaine with fentanyl temperature on initiation and maintenance of labor epidural analgesia: a randomized controlled study.

    PubMed

    Sviggum, H P; Yacoubian, S; Liu, X; Tsen, L C

    2015-02-01

    Labor epidural analgesia is highly effective, but can be limited by slow onset and incomplete blockade. The administration of warmed, compared to room temperature, bupivacaine has resulted in more rapid onset epidural anesthesia. We hypothesized that the administration of bupivacaine with fentanyl at 37°C versus 20°C would result in improved initial and ongoing labor epidural analgesia. In this prospective, randomized, doubled blinded study, 54 nulliparous, laboring women were randomized to receive epidural bupivacaine 0.125% with fentanyl 2 μg/mL (20 mL initial and 6 mL hourly boluses) at either 37°C or 20°C. Pain verbal rating scores (VRS), sensory level, oral temperature, and side effects were assessed after epidural loading (time 0), at 5, 10, 15, 20, 30, 60 min, and at hourly intervals. The primary outcome was the time to achieve initial satisfactory analgesia (VRS ⩽3). Secondary outcomes included ongoing quality of sensory blockade, body temperature and shivering. There were no differences between groups in patient demographics, initial pain scores, cervical dilatation, body temperature or mode of delivery. Epidural bupivacaine at 37°C resulted in shorter mean (±SD) analgesic onset time (9.2±4.7 vs. 16.0±10.5 min, P=0.005) and improved analgesia for the first 15 min after initial bolus (P=0.001-0.03). Although patient temperature increased during the study (P<0.01), there were no differences between the groups (P=0.09). Six (24%) and 10 (40%) patients experienced shivering in the 37°C and 20°C groups, respectively (P=0.23). The administration of epidural 0.125% bupivacaine with fentanyl 2μg/mL at 37°C versus 20°C resulted in more rapid onset and improved labor analgesia for the first 15 min. There was no evidence of improved ongoing labor analgesia or differences in side effects between groups. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. Initial analysis of ocean color data from the ocean color and temperature scanner. I. Imagery analysis.

    PubMed

    Gregg, W W

    1999-01-20

    The ocean color and temperature scanner (OCTS) collected global ocean color data from November 1996 to June 1997. Analyses of OCTS imagery indicate three features that impair scientific research uses: (1) band misalignments, (2) image striping, and (3) image noise. These are due to (1) band offsets in the sensor design, (2) detector radiometric response variability, and (3) primarily cloud contamination, respectively. Methods are analyzed to ameliorate the effects of each that facilitate use of OCTS ocean color data for quantitative scientific analyses.

  15. Analysis of the low temperature ceramics structure with consideration for polydispersity of initial refractory components

    NASA Astrophysics Data System (ADS)

    Leytsin, Vladimir N.; Dmitrieva, Mariya A.; Tovpinets, Alexandr O.; Ivonin, Ivan V.; Ponomarev, Sergey V.

    2016-11-01

    The results of computer simulation of the structure and physical properties of sintered low-temperature ceramics specimens with different volume fractions of different components of refractory components are presented. Properties of sintered ceramics, residual porosity, and shrinkage anisotropy are determined by features of packing of various fractions of refractory particles. The results indicate the determining factor of the presence of particles of the coarse fraction of refractory components capable of forming a internal skeleton of interacting particles.

  16. Germination and Initial Growth of Eastern Cottonwood as Influenced by Moisture Stress, Temperature, and Storage

    Treesearch

    R. E. Farmer

    1967-01-01

    Germination energy of cottonwood seed decreased gradually as moisture stress increased from 0.0 to 10.0 atm; 15.0 atm inhibited germination except at 32 and 38 C. Temperature extremes of 15 and 38 C drastically reduced germination energy, and the reductive effect of 38 C was particularly marked after storage. Only 15-atm moisture stress or 15 C greatly reduced total...

  17. Optimization of the water chemistry of the primary coolant at nuclear power plants with VVER

    SciTech Connect

    Barmin, L. F.; Kruglova, T. K.; Sinitsyn, V. P.

    2005-01-15

    Results of the use of automatic hydrogen-content meter for controlling the parameter of 'hydrogen' in the primary coolant circuit of the Kola nuclear power plant are presented. It is shown that the correlation between the 'hydrogen' parameter in the coolant and the 'hydrazine' parameter in the makeup water can be used for controlling the water chemistry of the primary coolant system, which should make it possible to optimize the water chemistry at different power levels.

  18. ACHIEVING THE REQUIRED COOLANT FLOW DISTRIBUTION FOR THE ACCELERATOR PRODUCTION OF TRITIUM (APT) TUNGSTEN NEUTRON SOURCE

    SciTech Connect

    D. SIEBE; K. PASAMEHMETOGLU

    2000-11-01

    The Accelerator Production of Tritium neutron source consists of clad tungsten targets, which are concentric cylinders with a center rod. These targets are arranged in a matrix of tubes, producing a large number of parallel coolant paths. The coolant flow required to meet thermal-hydraulic design criteria varies with location. This paper describes the work performed to ensure an adequate coolant flow for each target for normal operation and residual heat-removal conditions.

  19. Development and performance of a large-scale, transonic turbine blade cascade facility for aerodynamic studies of merging coolant-mainstream flows

    NASA Astrophysics Data System (ADS)

    Al-Sayeh, Amjad Isaaf

    1998-11-01

    , flow direction, total temperature and heavy gas concentration. Initial data are presented to demonstrate the range of the attainable operating parameters. The facility contains a number of adjustable components: the effects of these adjustments has been explored on pressure (Mach number) distributions in the approach duct, the exhaust duct and on the blades themselves. Boundary layer profiles have been determined in the approach duct for different inlet Mach numbers. The approach flow was affected by adjustments of the bleed system configuration. Shadowgraphs (still photos and video tapes) were taken that show clean, well-defined blade trailing edge shock patterns conforming to expectations. Good periodicity was demonstrated at subsonic speeds. At supersonic speeds the suction surface Mach number distributions, near the trailing edges, were found to be very sensitive to the angular setting and porosity of the nearby tailboard. The porous tailboards were effective in attenuating reflections of shocks incident on them. Solid tailboards (obtained by covering the perforated surface with tape) produced bifurcated Mach reflections. (Abstract shortened by UMI.)

  20. Carrier interactions and porosity initiated reversal of temperature dependence of thermal conduction in nanoscale tin films

    SciTech Connect

    Kaul, Pankaj B.; Prakash, Vikas

    2014-01-14

    Recently, tin has been identified as an attractive electrode material for energy storage/conversion technologies. Tin thin films have also been utilized as an important constituent of thermal interface materials in thermal management applications. In this regards, in the present paper, we investigate thermal conductivity of two nanoscale tin films, (i) with thickness 500 ± 50 nm and 0.45% porosity and (ii) with thickness 100 ± 20 nm and 12.21% porosity. Thermal transport in these films is characterized over the temperature range from 40 K–310 K, using a three-omega method for multilayer configurations. The experimental results are compared with analytical predictions obtained by considering both phonon and electron contributions to heat conduction as described by existing frequency-dependent phenomenological models and BvK dispersion for phonons. The thermal conductivity of the thicker tin film (500 nm) is measured to be 46.2 W/m-K at 300 K and is observed to increase with reduced temperatures; the mechanisms for thermal transport are understood to be governed by strong phonon-electron interactions in addition to the normal phonon-phonon interactions within the temperature range 160 K–300 K. In the case of the tin thin film with 100 nm thickness, porosity and electron-boundary scattering supersede carrier interactions, and a reversal in the thermal conductivity trend with reduced temperatures is observed; the thermal conductivity falls to 1.83 W/m-K at 40 K from its room temperature value of 36.1 W/m-K. In order to interpret the experimental results, we utilize the existing analytical models that account for contributions of electron-boundary scattering using the Mayadas-Shatzkes and Fuchs-Sondheimer models for the thin and thick films, respectively. Moreover, the effects of porosity on carrier transport are included using a previous treatment based on phonon radiative transport involving frequency-dependent mean free paths

  1. Diminished capability to recognize the optimal temperature for sleep initiation may contribute to poor sleep in elderly people.

    PubMed

    Raymann, Roy J E M; Van Someren, Eus J W

    2008-09-01

    Sleep propensity and skin temperature are functionally related. In young adults, changes of skin temperature within the comfortable thermoneutral zone affect sleep-onset latency and vigilance performance. Aging is associated with both decreased thermosensitivity and poorer sleep. Our goal was to test whether subtle manipulations of core body and skin temperature affect sleep onset in elderly people without sleep complaints and in elderly insomniacs and whether the subjective perception of these mild body temperature manipulations is preserved with aging and insomnia. In a 2-day semiconstant-routine protocol, 288 sleep-onset latencies were polysomnographically determined while manipulating core body and skin temperatures differentially in warm and cold directions within a comfortable thermoneutral range. Sleep laboratory of the Netherlands Institute for Neuroscience. Eight elderly subjects without sleep complaints (65.8 +/- 2.8 years, mean +/- SEM) and 8 elderly insomniacs (59.1 +/- 1.9 years). Warming the proximal skin by 0.4 degrees C facilitates sleep onset equally effective in healthy elderly (by 18% ie, by 1.84 minutes [95% confidence interval [CI], 0.76-2.92]) and elderly insomniacs (28%, 2.85 minutes [CI: 2.55-3.18]). These effects were comparable to the results in healthy young subjects, in spite of a marked decrease in the subjective perception of temperature changes in elderly subjects, especially in insomniacs. The findings show that mild changes in skin temperature have an effect on sleep propensity in elderly and indicate that elderly insomniacs may have a diminished capability to recognize that a slight increase in bed temperature facilitates the initiation or reinitiation of sleep.

  2. Development of mobile, on-site engine coolant recycling utilizing reverse-osmosis technology

    SciTech Connect

    Kughn, W.; Eaton, E.R.

    1999-08-01

    This paper presents the history of the development of self-contained, mobile, high-volume, engine coolant recycling by reverse osmosis (R/O). It explains the motivations, created by government regulatory agencies, to minimize the liability of waste generators who produce waste engine coolant by providing an engine coolant recycling service at the customer`s location. Recycling the used engine coolant at the point of origin minimizes the generators` exposure to documentation requirements, liability, and financial burdens by greatly reducing the volume of used coolant that must be hauled from the generator`s property. It describes the inherent difficulties of recycling such a highly contaminated, inconsistent input stream, such as used engine coolant, by reverse osmosis. The paper reports how the difficulties were addressed, and documents the state of the art in mobile R/O technology. Reverse osmosis provides a purified intermediate fluid that is reinhibited for use in automotive cooling systems. The paper offers a review of experiences in various automotive applications, including light-duty, medium-duty and heavy-duty vehicles operating on many types of fuel. The authors conclude that mobile embodiments of R/O coolant recycling technology provide finished coolants that perform equivalently to new coolants as demonstrated by their ability to protect vehicles from freezing, corrosion damage, and other cooling system related problems.

  3. Thorium Fuel Utilization Analysis on Small Long Life Reactor for Different Coolant Types

    NASA Astrophysics Data System (ADS)

    Permana, Sidik

    2017-07-01

    A small power reactor and long operation which can be deployed for less population and remote area has been proposed by the IAEA as a small and medium reactor (SMR) program. Beside uranium utilization, it can be used also thorium fuel resources for SMR as a part of optimalization of nuclear fuel as a “partner” fuel with uranium fuel. A small long-life reactor based on thorium fuel cycle for several reactor coolant types and several power output has been evaluated in the present study for 10 years period of reactor operation. Several key parameters are used to evaluate its effect to the reactor performances such as reactor criticality, excess reactivity, reactor burnup achievement and power density profile. Water-cooled types give higher criticality than liquid metal coolants. Liquid metal coolant for fast reactor system gives less criticality especially at beginning of cycle (BOC), which shows liquid metal coolant system obtains almost stable criticality condition. Liquid metal coolants are relatively less excess reactivity to maintain longer reactor operation than water coolants. In addition, liquid metal coolant gives higher achievable burnup than water coolant types as well as higher power density for liquid metal coolants.

  4. Hard metal lung disease: importance of cobalt in coolants.

    PubMed Central

    Sjögren, I; Hillerdal, G; Andersson, A; Zetterström, O

    1980-01-01

    Four patients were found to react to occupational exposure to grinding of hard metal (tungsten carbide). Three of the patients had symptoms and signs compatible with an allergic alveolitis, the symptoms disappearing and the chest radiograph clearing when they were absent from work for a few months. Re-exposure to the offending agent led to new signs and symptoms. The first patient was re-exposed twice and each time reacted a little more seriously. After the last episode her chest radiograph has not cleared completely, in contrast to the first two times. The fourth patient had more typical occupational asthma. All the cases occurred in the part of the factory where air concentrations of cobalt were the lowest. The cobalt there is dissolved in the coolant necessary for grinding the hard metal. It occurs mainly in the ionised form, which is known to react with proteins and therefore presumably acts as a hapten. Protective measures, including choosing a coolant with minimal ability to dissolve cobalt and an effective exhaust system, should minimise the risk of this occupational disease in the future. PMID:7444839

  5. The Use of Passive Initiation Aids in Self-Propagating High-Temperature Synthesis

    NASA Astrophysics Data System (ADS)

    Baker, A. H.; Kampe, S. L.

    2013-10-01

    A modification to initiation aid-assisted ignition in bomb calorimetry that involves systemically blending boron and potassium nitrate adjacent to, and within, a bulk structural energetic elemental power blend was developed. Linear regression was used to estimate the nominal heat of reaction for the primary reaction. The technique was applied to the synthesis of TiB2 as a validation study to see if proximity to the literature values could be achieved. X-ray diffraction was used to characterize the product phases of the reactions to determine the extent and the identity of the product phases and any by-products that may have formed as a result of adding the initiation aid. The experimental data indicate the technique approximates the heat of reaction value for the synthesis of TiB2 from Ti/B powder blends and the formation of TiB2 is supported by volume fraction analysis by X-ray diffraction. Some experimental uncertainty remains as X-ray diffraction revealed that the commercially labeled amorphous boron reactant exhibited some crystalline character and may be semicrystalline, as opposed to being completely amorphous.

  6. Initial enamel wear of glazed and polished leucite-based porcelains with different fusing temperatures.

    PubMed

    Adachi, Lena Katekawa; Saiki, Mitiko; de Campos, Tomie Nakakuki; Adachi, Eduardo Makoto; Shinkai, Rosemary Sadami

    2009-01-01

    This study used the radiotracer method to measure the initial enamel wear caused by low- and high-fusing porcelains after glazing or polishing. It also tested the correlation between enamel wear and porcelain surface roughness (Ra). Surface morphology was assessed by optical microscopy. Cylindrical specimens of three porcelains (two high-fusing, one low-fusing) were either autoglazed or polished. Flattened enamel specimens were irradiated with neutrons and submitted to the wear assay for 2,500 cycles in distilled water using a 285 g load; the released beta 32P particles were measured for 10 minutes. For all samples, Ra was recorded with a profilometer before and after testing. Enamel wear was not significantly different for porcelain or finishing method but there was a trend of interaction between the two variables (p = 0.08). A positive correlation was found between enamel wear and the initial Ra of porcelain (r = 0.71). The glazed surfaces of high-fusing porcelains were wavy and had a greater Ra, while the polished surfaces had grooves and pores prior to wear testing. The low-fusing porcelain demonstrated lower Ra and a more homogeneous surface. All abraded surfaces had similar morphology after the wear assay.

  7. Low-temperature combustion chemistry of biofuels: pathways in the initial low-temperature (550 K-750 K) oxidation chemistry of isopentanol.

    PubMed

    Welz, Oliver; Zádor, Judit; Savee, John D; Ng, Martin Y; Meloni, Giovanni; Fernandes, Ravi X; Sheps, Leonid; Simmons, Blake A; Lee, Taek Soon; Osborn, David L; Taatjes, Craig A

    2012-03-07

    The branched C(5) alcohol isopentanol (3-methylbutan-1-ol) has shown promise as a potential biofuel both because of new advanced biochemical routes for its production and because of its combustion characteristics, in particular as a fuel for homogeneous-charge compression ignition (HCCI) or related strategies. In the present work, the fundamental autoignition chemistry of isopentanol is investigated by using the technique of pulsed-photolytic Cl-initiated oxidation and by analyzing the reacting mixture by time-resolved tunable synchrotron photoionization mass spectrometry in low-pressure (8 Torr) experiments in the 550-750 K temperature range. The mass-spectrometric experiments reveal a rich chemistry for the initial steps of isopentanol oxidation and give new insight into the low-temperature oxidation mechanism of medium-chain alcohols. Formation of isopentanal (3-methylbutanal) and unsaturated alcohols (including enols) associated with HO(2) production was observed. Cyclic ether channels are not observed, although such channels dominate OH formation in alkane oxidation. Rather, products are observed that correspond to formation of OH viaβ-C-C bond fission pathways of QOOH species derived from β- and γ-hydroxyisopentylperoxy (RO(2)) radicals. In these pathways, internal hydrogen abstraction in the RO(2)⇄ QOOH isomerization reaction takes place from either the -OH group or the C-H bond in α-position to the -OH group. These pathways should be broadly characteristic for longer-chain alcohol oxidation. Isomer-resolved branching ratios are deduced, showing evolution of the main products from 550 to 750 K, which can be qualitatively explained by the dominance of RO(2) chemistry at lower temperature and hydroxyisopentyl decomposition at higher temperature.

  8. Characterization of an urban-rural CO 2 /temperature gradient and associated changes in initial plant productivity during secondary succession

    SciTech Connect

    Ziska, L. H.; Bunce, J. A.; Goins, E. W.

    2004-05-01

    To examine the impact of climate change on vegetative productivity, we exposed fallow agricultural soil to an in situ temperature and CO2 gradient between urban, suburban and rural areas in 2002. Along the gradient, average daytime CO2 concentration increased by 21% and maximum (daytime) and minimum (nighttime) daily temperatures increased by 1.6 and 3.3°C, respectively in an urban relative to a rural location. Consistent location differences in soil temperature were also ascertained. No other consistent differences in meteorological variables (e.g. wind speed, humidity, PAR, tropospheric ozone) as a function of urbanization were documented. The urban-induced environmental changes that were observed were consistent with most short-term (~50 year) global change scenarios regarding CO2 concentration and air temperature. Productivity, determined as final above-ground biomass, and maximum plant height were positively affected by daytime and soil temperatures as well as enhanced [CO2], increasing 60 and 115% for the suburban and urban sites, respectively, relative to the rural site. While long-term data are needed, these initial results suggest that urban environments may act as a reasonable surrogate for investigating future climatic change in vegetative communities.

  9. Analysis of loss-of-coolant accident for a fast-spectrum lithium-cooled nuclear reactor for space-power applications

    NASA Technical Reports Server (NTRS)

    Turney, G. E.; Petrik, E. J.; Kieffer, A. W.

    1972-01-01

    A two-dimensional, transient, heat-transfer analysis was made to determine the temperature response in the core of a conceptual space-power nuclear reactor following a total loss of reactor coolant. With loss of coolant from the reactor, the controlling mode of heat transfer is thermal radiation. In one of the schemes considered for removing decay heat from the core, it was assumed that the 4 pi shield which surrounds the core acts as a constant-temperature sink (temperature, 700 K) for absorption of thermal radiation from the core. Results based on this scheme of heat removal show that melting of fuel in the core is possible only when the emissivity of the heat-radiating surfaces in the core is less than about 0.40. In another scheme for removing the afterheat, the core centerline fuel pin was replaced by a redundant, constant temperature, coolant channel. Based on an emissivity of 0.20 for all material surfaces in the core, the calculated maximum fuel temperature for this scheme of heat removal was 2840 K, or about 90 K less than the melting temperature of the UN fuel.

  10. Quasi-dynamic pressure and temperature initiated β<-->δ solid phase transitions in HMX

    NASA Astrophysics Data System (ADS)

    Zaug, Joseph M.; Farber, Daniel L.; Craig, Ian M.; Blosch, Laura L.; Shuh, David K.; Hansen, Donald W.; Aracne-Ruddle, Chantel M.

    2000-04-01

    The phase transformation of β-HMX (>0.5% RDX) to δ phase has been studied for over twenty years and more recently with an high-contrast optical second harmonic generation technique. Shock studies of the plastic binder composites of HMX have indicated that the transition is perhaps irreversible, a result that concurs with the static pressure results published by F. Goetz et al. [1] in 1978. However, the stability field favors the β polymorph over δ as pressure is increased (up to 5.4 GPa) along any thermodynamically reasonable isotherm. In this experiment, strict control of pressure and temperature is maintained while x-ray and optical diagnostics are applied to monitor the conformational dynamics of HMX. Unlike the temperature induced β→δ transition, the pressure induced is heterogeneous in nature. The 1 bar 25 °C δ→β transition is not immediate, occuring over tens of hours. Transition points and kinetics are path dependent and consequently this paper describes our work in progress.

  11. Membrane-initiated Actions of Estradiol that Regulate Reproduction, Energy Balance and Body Temperature

    PubMed Central

    Kelly, Martin J.; Rønnekleiv, Oline K.

    2012-01-01

    It is well known that many of the actions of estrogens in the central nervous system are mediated via intracellular receptor/transcription factors that interact with steroid response elements on target genes. However, there now exists compelling evidence for membrane estrogen receptors in hypothalamic and other brain neurons. But, it is not well understood how estrogens signal via membrane receptors, and how these signals impact not only membrane excitability but also gene transcription in neurons. Indeed, it has been known for sometime that estrogens can rapidly alter neuronal activity within seconds, indicating that some cellular effects can occur via membrane delimited events. In addition, estrogens can affect second messenger systems including calcium mobilization and a plethora of kinases to alter cell signaling. Therefore, this review will consider our current knowledge of rapid membrane-initiated and intracellular signaling by estrogens in the hypothalamus, the nature of receptors involved and how they contribute to homeostatic functions. PMID:22871514

  12. Development of Safety Analysis Codes and Experimental Validation for a Very High Temperature Gas-Cooled Reactor

    SciTech Connect

    Chang, H. Oh, PhD; Cliff Davis; Richard Moore

    2004-11-01

    The very high temperature gas-cooled reactors (VHTGRs) are those concepts that have average coolant temperatures above 900 degrees C or operational fuel temperatures above 1250 degrees C. These concepts provide the potential for increased energy conversion efficiency and for high-temperature process heat application in addition to power generation and nuclear hydrogen generation. While all the High Temperature Gas Cooled Reactor (HTGR) concepts have sufficiently high temperatures to support process heat applications, such as desalination and cogeneration, the VHTGR's higher temperatures are suitable for particular applications such as thermochemical hydrogen production. However, the high temperature operation can be detrimental to safety following a loss-of-coolant accident (LOCA) initiated by pipe breaks caused by seismic or other events. Following the loss of coolant through the break and coolant depressurization, air from the containment will enter the core by molecular diffusion and ultimately by natural convection, leading to oxidation of the in-core graphite structures and fuel. The oxidation will release heat and accelerate the heatup of the reactor core. Thus, without any effective countermeasures, a pipe break may lead to significant fuel damage and fission product release. The Idaho National Engineering and Environmental Laboratory (INEEL) has investigated this event for the past three years for the HTGR. However, the computer codes used, and in fact none of the world's computer codes, have been sufficiently developed and validated to reliably predict this event. New code development, improvement of the existing codes, and experimental validation are imperative to narrow the uncertaninty in the predictions of this type of accident. The objectives of this Korean/United States collaboration are to develop advanced computational methods for VHTGR safety analysis codes and to validate these computer codes.

  13. Internal cooling of a lithium-ion battery using electrolyte as coolant through microchannels embedded inside the electrodes

    NASA Astrophysics Data System (ADS)

    Mohammadian, Shahabeddin K.; He, Ya-Ling; Zhang, Yuwen

    2015-10-01

    Two and three dimensional transient thermal analysis of a prismatic Li-ion cell has been carried out to compare internal and external cooling methods for thermal management of Lithium Ion (Li-ion) battery packs. Water and liquid electrolyte have been utilized as coolants for external and internal cooling, respectively. The effects of the methods on decreasing the temperature inside the battery and also temperature uniformity were investigated. The results showed that at the same pumping power, using internal cooling not only decreases the bulk temperature inside the battery more than external cooling, but also decreases the standard deviation of the temperature field inside the battery significantly. Finally, using internal cooling decreases the intersection angle between the velocity vector and the temperature gradient which according to field synergy principle (FSP) causes to increase the convection heat transfer.

  14. Zero waste machine coolant management strategy at Los Alamos National Laboratory

    SciTech Connect

    Carlson, B.; Algarra, F.; Wilburn, D.

    1998-12-01

    Machine coolants are used in machining equipment including lathes, grinders, saws and drills. The purpose of coolants is to wash away machinery debris in the form of metal fines, lubricate, and disperse heat between the part and the machine tool. An effective coolant prolongs tool life and protects against part rejection, commonly due to scoring or scorching. Traditionally, coolants have a very short effective life in the machine, often times being disposed of as frequently as once per week. The cause of coolant degradation is primarily due to the effects of bacteria, which thrive in the organic rich coolant environment. Bacteria in this environment reproduce at a logarithmic rate, destroying the coolant desirable aspects and causing potential worker health risks associated with the use of biocides to control the bacteria. The strategy described in this paper has effectively controlled bacterial activity without the use of biocides, avoided disposal of a hazardous waste, and has extend ed coolant life indefinitely. The Machine Coolant Management Strategy employed a combination of filtration, heavy lubricating oil removal, and aeration, which maintained the coolant peak performance without the use of biocides. In FY96, the Laboratory generated and disposed of 19,880 kg of coolants from 9 separate sites at a cost of $145K. The single largest generator was the main machine shop producing an average 14,000 kg annually. However, in FY97, the waste generation for the main machine shop dropped to 4,000 kg after the implementation of the zero waste strategy. It is expected that this value will be further reduced in FY98.

  15. Zero Waste Machine Coolant Management Strategy at Los Alamos National Laboratory

    SciTech Connect

    Carlson, B.; Algarra, F.; Wilburn, D.

    1998-06-01

    Machine coolants are used in machining equipment including lathes, grinders, saws and drills. The purpose of coolants is to wash away machinery debris in the form of metal fines, lubricate, and disperse heat between the part and the machine tool. An effective coolant prolongs tool life and protects against part rejection, commonly due to scoring or scorching. Traditionally, coolants have a very short effective life in the machine, often times being disposed of as frequently as once per week. The cause of coolant degradation is primarily due to the effects of bacteria, which thrive in the organic rich coolant environment. Bacteria in this environment reproduce at a logarithmic rate, destroying the coolant desirable aspects and causing potential worker health risks associated with the use of biocides to control the bacteria. The strategy described in this paper has effectively controlled bacterial activity without the use of biocides, avoided disposal of a hazardous waste, and has extend ed coolant life indefinitely. The Machine Coolant Management Strategy employed a combination of filtration, heavy lubricating oil removal, and aeration, which maintained the coolant peak performance without the use of biocides. In FY96, the Laboratory generated and disposed of 19,880 kg of coolants from 9 separate sites at a cost of $145K. The single largest generator was the main machine shop producing an average 14,000 kg annually. However, in FY97, the waste generation for the main machine shop dropped to 4,000 kg after the implementation of the zero waste strategy. It is expected that this value will be further reduced in FY98.

  16. Membrane-initiated actions of estradiol that regulate reproduction, energy balance and body temperature.

    PubMed

    Kelly, Martin J; Rønnekleiv, Oline K

    2012-10-01

    It is well known that many of the actions of estrogens in the central nervous system are mediated via intracellular receptor/transcription factors that interact with steroid response elements on target genes. However, there now exists compelling evidence for membrane estrogen receptors in hypothalamic and other brain neurons. But, it is not well understood how estrogens signal via membrane receptors, and how these signals impact not only membrane excitability but also gene transcription in neurons. Indeed, it has been known for sometime that estrogens can rapidly alter neuronal activity within seconds, indicating that some cellular effects can occur via membrane delimited events. In addition, estrogens can affect second messenger systems including calcium mobilization and a plethora of kinases to alter cell signaling. Therefore, this review will consider our current knowledge of rapid membrane-initiated and intracellular signaling by estrogens in the hypothalamus, the nature of receptors involved and how they contribute to homeostatic functions. Copyright © 2012 Elsevier Inc. All rights reserved.

  17. Crack initiation behavior of neutron irradiated model and commercial stainless steels in high temperature water

    NASA Astrophysics Data System (ADS)

    Stephenson, Kale J.; Was, Gary S.

    2014-01-01

    The objective of this study was to isolate key factors affecting the irradiation-assisted stress corrosion cracking (IASCC) susceptibility of eleven neutron-irradiated austenitic stainless steel alloys. Four commercial purity and seven high purity stainless steels were fabricated with specific changes in composition and microstructure, and irradiated in a fast reactor spectrum at 320 °C to doses between 4.4 and 47.5 dpa. Constant extension rate tensile (CERT) tests were performed in normal water chemistry (NWC), hydrogen water chemistry (HWC), or primary water (PW) environments to isolate the effects of environment, elemental solute addition, alloy purity, alloy heat, alloy type, cold work, and irradiation dose. The irradiated alloys showed a wide variation in IASCC susceptibility, as measured by the relative changes in mechanical properties and crack morphology. Cracking susceptibility measured by %IG was enhanced in oxidizing environments, although testing in the lowest potential environment caused an increase in surface crack density. Alloys containing solute addition of Ni or Ni + Cr exhibited no IASCC. Susceptibility was reduced in materials cold worked prior to irradiation, and increased with increasing irradiation dose. Irradiation-induced hardening was accounted for by the dislocation loop microstructure, however no relation between crack initiation and radiation hardening was found.

  18. Initial development of a new empirical model of the earth's inner magnetosphere for density, temperature, and composition

    NASA Technical Reports Server (NTRS)

    Gallagher, D. L.; Craven, P. D.

    1988-01-01

    The analytical representation of plasma characteristics in the near earth environment is a valuable tool for studying wave propagation, for new instrument and spacecraft design, and for developing a better theoretical understanding of plasmaspheric processes. There are no empirical models currently available that encompass the near-earth environment and include the core or low-energy plasma characteristic of that region. The initial steps to constructing a new empirical model of plasmaspheric density, temperature, and composition are discussed. A limited set of density measurements from the retarding ion mass spectrometer and the plasma wave instrument on the Dynamics Explorer 1 spacecraft is used to demonstrate features of the proposed analytical formalism.

  19. Initial stages of Ba adsorption on the Si(100)-(2×1) surface at room temperature

    NASA Astrophysics Data System (ADS)

    Yao, X.; Hu, Xiaoming; Sarid, D.; Yu, Z.; Wang, J.; Marshall, D. S.; Droopad, R.; Abrokwah, J. K.; Hallmark, J. A.; Ooms, W. J.

    1999-02-01

    Scanning tunneling microscopy has been used to study the initial stages of room-temperature adsorption of Ba atoms on a clean Si(100)-(2×1) surface. It is found that most Ba atoms are located at type C defects, which stabilizes the dimer buckling in their vicinity, while the rest are located at single dimer sites on top of the Si dimer rows. Analysis of the images reveals that the Ba-Si(100) interactions are mediated by a partial charge transfer from the adsorbate to the substrate.

  20. Initial adsorption of Ge on Si(1 1 1)-(7×7) surface at room temperature

    NASA Astrophysics Data System (ADS)

    Yan, Long; Yang, Haiqiang; Gao, Hongjun; Xie, Sishen; Pang, Shijin

    2002-02-01

    The initial stage of Ge adsorption on Si(1 1 1)-(7×7) surface has been investigated by ultrahigh-vacuum scanning tunneling microscopy at room temperature. We demonstrate that there is a critical nucleus for the adsorbed Ge clusters on Si(1 1 1)-(7×7) surface. Such clusters can behave like quantum dots, which display two states at +1.5 and -1.5 eV with respect to the Fermi level. The formation mechanism of the clusters is discussed.

  1. Initial Body Temperature in Ischemic Stroke: Non-Potentiation of TPA Benefit and Inverse Association with Severity

    PubMed Central

    Kim, Seo Hyun; Saver, Jeffrey L.

    2014-01-01

    Background and Purpose Body temperature (BT) is an important physiologic factor in acute ischemic stroke. However, the relation of initial BT to stroke severity and degree of benefit from thrombolytic therapy has been incompletely delineated. Methods We analyzed the public data set of the two National Institute of Neurological Disorders and Stroke tissue plaminogen activator (TPA) stroke trials, comparing patients with lower (<37.0°C) and higher (≥37.0°C) presenting BT. Results Among 595 patients (297 placebo- and 298 tPA-treated) with documented initial BT, 77.1% had initial BT <37.0°C and 22.9% ≥37.0°C. Patients with higher initial BT had lower baseline stroke severity in both tPA-treated patients (the National Institute of Health Stroke Scale median, 11 versus 15; p = 0.05) and placebo-treated patients (median, 13 versus 16; p <0.01). Patients with higher initial BT also had lower infarction volume on CT at 3 months in both tPA-treated patients (median, 9.6 versus 16.7 cm3; p = 0.08) and placebo-treated patients (median, 13.1 versus 28.1 cm3; p = 0.02), but no clinical outcome differences. Analysis of lytic treatment effect found no heterogeneity in the degree of tPA benefit in both higher and lower BT groups (≥37.0°C: odds ratio [OR] for the modified Rankin Scale 0-1 outcome 2.55, 95% confidence interval [CI] 1.05-6.21; <37.0°C: OR 2.30, 95% CI 1.38-3.84; heterogeneity p = 0.83). Conclusions In hyperacute stroke patients, higher presenting temperatures are associated with less severe neurological deficits and reduced final infarct volumes. Presenting temperature does not modify the benefit of tPA on 3-month favorable outcome. Clinical Trial Registration This trial was not registered because enrollment began prior to July 1, 2005. PMID:25424482

  2. Fast folding of RNA pseudoknots initiated by laser temperature-jump.

    PubMed

    Narayanan, Ranjani; Velmurugu, Yogambigai; Kuznetsov, Serguei V; Ansari, Anjum

    2011-11-23

    RNA pseudoknots are examples of minimal structural motifs in RNA with tertiary interactions that stabilize the structures of many ribozymes. They also play an essential role in a variety of biological functions that are modulated by their structure, stability, and dynamics. Therefore, understanding the global principles that determine the thermodynamics and folding pathways of RNA pseudoknots is an important problem in biology, both for elucidating the folding mechanisms of larger ribozymes as well as addressing issues of possible kinetic control of the biological functions of pseudoknots. We report on the folding/unfolding kinetics of a hairpin-type pseudoknot obtained with microsecond time-resolution in response to a laser temperature-jump perturbation. The kinetics are monitored using UV absorbance as well as fluorescence of extrinsically attached labels as spectroscopic probes of the transiently populated RNA conformations. We measure folding times of 1-6 ms at 37 °C, which are at least 100-fold faster than previous observations of very slow folding pseudoknots that were trapped in misfolded conformations. The measured relaxation times are remarkably similar to predictions of a computational study by Thirumalai and co-workers (Cho, S. S.; Pincus, D.L.; Thirumalai, D. Proc. Natl. Acad. Sci. U. S. A. 2009, 106, 17349-17354). Thus, these studies provide the first observation of a fast-folding pseudoknot and present a benchmark against which computational models can be refined.

  3. Interactive initialization of heat flux parameters for numerical models using satellite temperature measurements. [Kansas and Indiana

    NASA Technical Reports Server (NTRS)

    Carlson, T. N. (Principal Investigator)

    1982-01-01

    A method for obtaining patterns of moisture availability (and net evaporation) from satellite infrared measurements employs Carlson's boundary layer model and a variety of image processing routines executed by a minicomputer. To test the method with regard to regional scale moisture analyses, two case studies were chosen because of the availability of HCMM data and because of the presence of a large horizontal gradient in antecedent precipitation and crp moisture index. Results show some correlation in both cases between antecedent precipitation and derived moisture availability. Apparently, regional-scale moisture availability patterns can be determined with some degree of fidelity but the values themselves may be useful only in the relative sense and significant to within plus or minus one category of dryness over a range of 4 or 5 categories between absolutely dry and field saturation. Preliminary results suggest that the derived moisture values correlate best with longer-term precipitation totals, suggesting that the infrared temperatures respond more sensitively to a relatively deep substrate layer.

  4. Nanosecond laser-induced damage at different initial temperatures of Ta{sub 2}O{sub 5} films prepared by dual ion beam sputtering

    SciTech Connect

    Xu, Cheng Jia, Jiaojiao; Fan, Heliang; Qiang, Yinghuai; Liu, Jiongtian; Yang, Di; Hu, Guohang; Li, Dawei

    2014-08-07

    Ta{sub 2}O{sub 5} films were deposited by dual ion beam sputtering method. The nanosecond laser-induced damage threshold (LIDT) at different initial temperatures and time of the films was investigated by an in situ high temperature laser-induced damage testing platform. It was shown that, when the initial temperature increased from 298 K to 383 K, the LIDT at 1064 nm and 12 ns significantly decreased by nearly 14%. Then the LIDT at 1064 nm and 12 ns decreased slower with the same temperature increment. Different damage morphologies were found at different initial temperatures. At low initial temperatures, it was the defects-isolated damage while at high initial temperatures it was the defects-combined damage. The theoretical calculations based on the defect-induced damage model revealed that both the significant increase of the highest temperature and the duration contributed to the different damage morphologies. With the initial temperature being increased, the thermal-stress coupling damage mechanism transformed gradually to the thermal dominant damage mechanism.

  5. Sensitivity of high-temperature weather to initial soil moisture: a case study with the WRF model

    NASA Astrophysics Data System (ADS)

    Zeng, X.-M.; Wang, B.; Zhang, Y.; Song, S.; Huang, X.; Zheng, Y.; Chen, C.; Wang, G.

    2014-05-01

    Using the Weather Research and Forecasting model (WRF), we investigate the sensitivity of simulated short-range high-temperature weather to initial soil moisture for the East China extremely hot event in late July 2003 via a succession of 24 h simulations. The initial soil moisture (SMOIS) in the Noah land surface scheme is prescribed for five groups of designed simulations, i.e., relative to the control run (CTL), SMOIS is changed by -25, -50, +25 and +50% in the DRY25, DRY50, WET25 and WET50 groups, respectively, with ten 24 h-long integrations performed in each group. We focus on above-35 °C (standard of so-called "high-temperature" event in China) 2 m surface air temperature (SAT) at 06:00 UTC (roughly 12:00 LT in the study domain) to analyze the occurrence of the high-temperature event. Ten-day mean results show that the 06:00 UTC SAT (SAT06) is sensitive to the SMOIS change, i.e., SAT06 exhibits an apparent rising with the SMOIS decrease (e.g., compared with CTL, DRY25 results in a 1 °C SAT06 rising in general over land surface of East China), areas with above-35 °C SAT06 are most affected, and the simulations are found to be more sensitive to the SMOIS decrease than to the SMOIS increase, suggesting that hot weather can be amplified under low soil moisture conditions. With regard to the mechanism of influencing the extreme high SAT06, sensible heat flux shows to directly heat the lower atmosphere, latent heat flux is found to be more sensitive to the SMOIS change and results in the overall increase of surface net radiation due to the increased greenhouse effect (e.g., with the SMOIS increase of 25% from DRY25 to CTL, the ten-day mean net radiation is increased by 5 W m-2), and a negative (positive) feedback is found between regional atmospheric circulation and air temperature in the lower atmosphere (mid-troposphere) due to the unique dynamic nature of the western Pacific subtropical high. Using a method based on an analogous temperature relationship, a

  6. Nonflammable coolants for space vehicle environmental control systems Compatibility of component materials with selected dielectric fluids.

    NASA Technical Reports Server (NTRS)

    Howard, R. T.; Korpolinski, T. S.; Mace, E. W.

    1971-01-01

    This paper summarizes a 4-year effort to evaluate and implement a nonflammable substitute coolant for application in the Saturn instrument unit (IU) environmental control system (ECS). Discussed are candidate material evaluations, detailed investigations of the properties of the coolant selected, and a summary of the implementation into a flight vehicle.

  7. MTR, TRA603. FOUNDATION PLAN, SECTION C THROUGH COOLANT WATER EXIT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    MTR, TRA-603. FOUNDATION PLAN, SECTION C THROUGH COOLANT WATER EXIT TUNNEL ALONG NORTH SIDE AS IT RETURNS TO MAIN COOLANT TUNNEL LEAVING BUILDING TO THE NORTH. BLAW-KNOX 3150-803-35, 5/1950. INL INDEX NO. 531-0603-62-098-100591, REV. 2. - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  8. Using automatic particle counting to monitor aluminum cold mill coolant{copyright}

    SciTech Connect

    Adkins, D.L.

    1995-08-01

    A comprehensive program of testing and evaluation of aluminum cold rolling coolant conditions has been conducted using an automatic particle counting instrument. The project had three objectives. First, there was a need to know at what level of coolant particle contamination is surface cleanliness of an aluminum sheet affected during the rolling process. Secondly, is application of particle counting technology a reliable tool for troubleshooting coolant filtration systems and finally, what are the advantages of analyzing rolling coolants for contamination levels? A testing program was designed and performed over a two-year period. The test results revealed that mineral seal and synthetic-type coolants can begin to affect aluminum sheet surface cleanliness levels when particle sizes greater than five microns are in excess of 10,000 particles power 100 milliliters of rolling coolant. After performing over 3,000 separate tests, it was very clean that particle count levels are direct indicators of how well a filtration facility is performing. Through the application of particle counting, a number of conditions in coolant filtration facilities can be readily detected. Such items as defective filter valving, torn or fractured filter cloth, damaged filter parts, improper equipment operation and many other factors will directly impact the operation of aluminum cold rolling coolant filters. 11 figs.

  9. Nonflammable coolants for space vehicle environmental control systems Compatibility of component materials with selected dielectric fluids.

    NASA Technical Reports Server (NTRS)

    Howard, R. T.; Korpolinski, T. S.; Mace, E. W.

    1971-01-01

    This paper summarizes a 4-year effort to evaluate and implement a nonflammable substitute coolant for application in the Saturn instrument unit (IU) environmental control system (ECS). Discussed are candidate material evaluations, detailed investigations of the properties of the coolant selected, and a summary of the implementation into a flight vehicle.

  10. Some peculiarities of checking the Topaz-2 system coolant filling quality

    SciTech Connect

    Ogloblin, B.G.; Svishchev, A.M.; Shalaev, A.I.

    1996-03-01

    This paper contains the analysis of validity of methods used for checking the Topaz-2 system coolant filling quality by a metering tank according to the mathematical model developed. A number of criteria is proposed for detecting occluded gas in the coolant loop. {copyright} {ital 1996 American Institute of Physics.}

  11. 10 CFR 50.46a - Acceptance criteria for reactor coolant system venting systems.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... criteria for reactor coolant system venting systems. Each nuclear power reactor must be provided with high... 10 Energy 1 2012-01-01 2012-01-01 false Acceptance criteria for reactor coolant system venting systems. 50.46a Section 50.46a Energy NUCLEAR REGULATORY COMMISSION DOMESTIC LICENSING OF PRODUCTION AND...

  12. 10 CFR 50.46a - Acceptance criteria for reactor coolant system venting systems.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... criteria for reactor coolant system venting systems. Each nuclear power reactor must be provided with high... 10 Energy 1 2010-01-01 2010-01-01 false Acceptance criteria for reactor coolant system venting systems. 50.46a Section 50.46a Energy NUCLEAR REGULATORY COMMISSION DOMESTIC LICENSING OF PRODUCTION AND...

  13. 10 CFR 50.46a - Acceptance criteria for reactor coolant system venting systems.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... criteria for reactor coolant system venting systems. Each nuclear power reactor must be provided with high... 10 Energy 1 2014-01-01 2014-01-01 false Acceptance criteria for reactor coolant system venting systems. 50.46a Section 50.46a Energy NUCLEAR REGULATORY COMMISSION DOMESTIC LICENSING OF PRODUCTION AND...

  14. 10 CFR 50.46a - Acceptance criteria for reactor coolant system venting systems.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... criteria for reactor coolant system venting systems. Each nuclear power reactor must be provided with high... 10 Energy 1 2013-01-01 2013-01-01 false Acceptance criteria for reactor coolant system venting systems. 50.46a Section 50.46a Energy NUCLEAR REGULATORY COMMISSION DOMESTIC LICENSING OF PRODUCTION AND...

  15. 10 CFR 50.46a - Acceptance criteria for reactor coolant system venting systems.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... criteria for reactor coolant system venting systems. Each nuclear power reactor must be provided with high... 10 Energy 1 2011-01-01 2011-01-01 false Acceptance criteria for reactor coolant system venting systems. 50.46a Section 50.46a Energy NUCLEAR REGULATORY COMMISSION DOMESTIC LICENSING OF PRODUCTION AND...

  16. Fusion Blanket Coolant Section Criteria, Methodology, and Results

    SciTech Connect

    DeMuth, J. A.; Meier, W. R.; Jolodosky, A.; Frantoni, M.; Reyes, S.

    2015-10-02

    The focus of this LDRD was to explore potential Li alloys that would meet the tritium breeding and blanket cooling requirements but with reduced chemical reactivity, while maintaining the other attractive features of pure Li breeder/coolant. In other fusion approaches (magnetic fusion energy or MFE), 17Li- 83Pb alloy is used leveraging Pb’s ability to maintain high TBR while lowering the levels of lithium in the system. Unfortunately this alloy has a number of potential draw-backs. Due to the high Pb content, this alloy suffers from very high average density, low tritium solubility, low system energy, and produces undesirable activation products in particular polonium. The criteria considered in the selection of a tritium breeding alloy are described in the following section.

  17. Actively controlling coolant-cooled cold plate configuration

    DOEpatents

    Chainer, Timothy J.; Parida, Pritish R.

    2016-04-26

    Cooling apparatuses are provided to facilitate active control of thermal and fluid dynamic performance of a coolant-cooled cold plate. The cooling apparatus includes the cold plate and a controller. The cold plate couples to one or more electronic components to be cooled, and includes an adjustable physical configuration. The controller dynamically varies the adjustable physical configuration of the cold plate based on a monitored variable associated with the cold plate or the electronic component(s) being cooled by the cold plate. By dynamically varying the physical configuration, the thermal and fluid dynamic performance of the cold plate are adjusted to, for example, optimally cool the electronic component(s), and at the same time, reduce cooling power consumption used in cooling the electronic component(s). The physical configuration can be adjusted by providing one or more adjustable plates within the cold plate, the positioning of which may be adjusted based on the monitored variable.

  18. Robotic inspection of PWR coolant pump casing welds

    SciTech Connect

    Pratt, W.R.; Alford, J.W.; Davis, J.B.

    1997-12-01

    As of January 1, 1995, the Swedish Nuclear Inspectorate began requiring more thorough inspections of cast stainless-steel components in nuclear power plants, including pressurized water reactor (PWR) reactor coolant pump (RCP) casings. The examination requirements are established by fracture mechanics analyses of component weldments and demonstrated test system detection capabilities. This may include full volumetric inspection or some portion thereof. Ringhals station is a four-unit nuclear power plant, owned and operated by the Swedish State Power Board, Vattenfall. Unit 1 is a boiling water reactor. Units 2, 3, and 4 are Westinghouse-designed PWRs, ranging in size from 795 to 925 MW. The RCP casings at the PWR units are made of cast stainless steel and contain four circumferential welds that require inspection. Due to the thickness of the casings at the weld locations and configuration and surface conditions on the outside diameter of the casings, remote inspection from the inside diameter of the pump casing was mandated.

  19. Leak rate analysis of the Westinghouse Reactor Coolant Pump

    SciTech Connect

    Boardman, T.; Jeanmougin, N.; Lofaro, R.; Prevost, J.

    1985-07-01

    An independent analysis was performed by ETEC to determine what the seal leakage rates would be for the Westinghouse Reactor Coolant Pump (RCP) during a postulated station blackout resulting from loss of ac electric power. The object of the study was to determine leakage rates for the following conditions: Case 1: All three seals function. Case 2: No. 1 seal fails open while Nos. 2 and 3 seals function. Case 3: All three seals fail open. The ETEC analysis confirmed Westinghouse calculations on RCP seal performance for the conditions investigated. The leak rates predicted by ETEC were slightly lower than those predicted by Westinghouse for each of the three cases as summarized below. Case 1: ETEC predicted 19.6 gpm, Westinghouse predicted 21.1 gpm. Case 2: ETEC predicted 64.7 gpm, Westinghouse predicted 75.6 gpm. Case 3: ETEC predicted 422 gpm, Westinghouse predicted 480 gpm. 3 refs., 22 figs., 6 tabs.

  20. Loss of coolant analysis for the tower shielding reactor 2

    SciTech Connect

    Radcliff, T.D.; Williams, P.T.

    1990-06-01

    The operational limits of the Tower Shielding Reactor-2 (TSR-2) have been revised to account for placing the reactor in a beam shield, which reduces convection cooling during a loss-of-coolant accident (LOCA). A detailed heat transfer analysis was performed to set operating time limits which preclude fuel damage during a LOCA. Since a LOCA is survivable, the pressure boundary need not be safety related, minimizing seismic and inspection requirements. Measurements of reactor component emittance for this analysis revealed that aluminum oxidized in water may have emittance much higher than accepted values, allowing higher operating limits than were originally expected. These limits could be increased further with analytical or hardware improvements. 5 refs., 7 figs.

  1. Fabrication and Characterization of a Porous Silicon Drug Delivery System with an Initiated Chemical Vapor Deposition Temperature-Responsive Coating.

    PubMed

    McInnes, Steven J P; Szili, Endre J; Al-Bataineh, Sameer A; Vasani, Roshan B; Xu, Jingjing; Alf, Mahriah E; Gleason, Karen K; Short, Robert D; Voelcker, Nicolas H

    2016-01-12

    This paper reports on the fabrication of a pSi-based drug delivery system, functionalized with an initiated chemical vapor deposition (iCVD) polymer film, for the sustainable and temperature-dependent delivery of drugs. The devices were prepared by loading biodegradable porous silicon (pSi) with a fluorescent anticancer drug camptothecin (CPT) and coating the surface with temperature-responsive poly(N-isopropylacrylamide-co-diethylene glycol divinyl ether) (pNIPAM-co-DEGDVE) or non-stimulus-responsive poly(aminostyrene) (pAS) via iCVD. CPT released from the uncoated oxidized pSi control with a burst release fashion (∼21 nmol/(cm(2) h)), and this was almost identical at temperatures both above (37 °C) and below (25 °C) the lower critical solution temperature (LCST) of the switchable polymer used, pNIPAM-co-DEGDVE (28.5 °C). In comparison, the burst release rate from the pSi-pNIPAM-co-DEGDVE sample was substantially slower at 6.12 and 9.19 nmol/(cm(2) h) at 25 and 37 °C, respectively. The final amount of CPT released over 16 h was 10% higher at 37 °C compared to 25 °C for pSi coated with pNIPAM-co-DEGDVE (46.29% vs 35.67%), indicating that this material can be used to deliver drugs on-demand at elevated temperatures. pSi coated with pAS also displayed sustainable drug delivery profiles, but these were independent of the release temperature. These data show that sustainable and temperature-responsive delivery systems can be produced by functionalization of pSi with iCVD polymer films. Benefits of the iCVD approach include the application of the iCVD coating after drug loading without causing degradation of the drug commonly caused by exposure to factors such as solvents or high temperatures. Importantly, the iCVD process is applicable to a wide array of surfaces as the process is independent of the surface chemistry and pore size of the nanoporous matrix being coated.

  2. Initial stages of growth and the influence of temperature during chemical vapor deposition of sp{sup 2}-BN films

    SciTech Connect

    Chubarov, Mikhail; Pedersen, Henrik; Högberg, Hans; Henry, Anne; Czigány, Zsolt

    2015-11-15

    Knowledge of the structural evolution of thin films, starting by the initial stages of growth, is important to control the quality and properties of the film. The authors present a study on the initial stages of growth and the temperature influence on the structural evolution of sp{sup 2} hybridized boron nitride (BN) thin films during chemical vapor deposition (CVD) with triethyl boron and ammonia as precursors. Nucleation of hexagonal BN (h-BN) occurs at 1200 °C on α-Al{sub 2}O{sub 3} with an AlN buffer layer (AlN/α-Al{sub 2}O{sub 3}). At 1500 °C, h-BN grows with a layer-by-layer growth mode on AlN/α-Al{sub 2}O{sub 3} up to ∼4 nm after which the film structure changes to rhombohedral BN (r-BN). Then, r-BN growth proceeds with a mixed layer-by-layer and island growth mode. h-BN does not grow on 6H-SiC substrates; instead, r-BN nucleates and grows directly with a mixed layer-by-layer and island growth mode. These differences may be caused by differences in substrate surface temperature due to different thermal conductivities of the substrate materials. These results add to the understanding of the growth process of sp{sup 2}-BN employing CVD.

  3. Investigations of ice formation in the Space Shuttle Main Engine 0209 main injector coolant cavity

    NASA Technical Reports Server (NTRS)

    Richards, D. R.; Charklwick, D. M.

    1991-01-01

    Severe main combustion chamber wall and main injector baffle element deterioration occurred during tests of Space Shuttle Main Engine 0209. One of the possible causes considered is ice formation and blockage of coolant to these components, resulting from the mixing of leaking hot turbine exhaust gas (hydrogen rich steam) and hydrogen coolant in the injector coolant cavity. The plausibility of ice blockage is investigated through simple mixing calculations for hot gas and hydrogen, investigation of condensation and water droplet formation, calculation of the freezing times for droplets, and the prediction of ice layer thicknesses. It is concluded that condensation and droplet formation can occur, and small water droplets that form can freeze very quickly when in contact with the cold coolant cavity surfaces. Copnservative analysis predicts, however, that the maximum thickness of the ice layers formed is too small to result in significant blockage of the coolant flow.

  4. Investigations of ice formation in the Space Shuttle Main Engine 0209 main injector coolant cavity

    NASA Technical Reports Server (NTRS)

    Richards, D. R.; Charklwick, D. M.

    1991-01-01

    Severe main combustion chamber wall and main injector baffle element deterioration occurred during tests of Space Shuttle Main Engine 0209. One of the possible causes considered is ice formation and blockage of coolant to these components, resulting from the mixing of leaking hot turbine exhaust gas (hydrogen rich steam) and hydrogen coolant in the injector coolant cavity. The plausibility of ice blockage is investigated through simple mixing calculations for hot gas and hydrogen, investigation of condensation and water droplet formation, calculation of the freezing times for droplets, and the prediction of ice layer thicknesses. It is concluded that condensation and droplet formation can occur, and small water droplets that form can freeze very quickly when in contact with the cold coolant cavity surfaces. Copnservative analysis predicts, however, that the maximum thickness of the ice layers formed is too small to result in significant blockage of the coolant flow.

  5. Effect of external turbulence on the efficiency of film cooling with coolant injection into a transverse trench

    NASA Astrophysics Data System (ADS)

    Khalatov, A. A.; Panchenko, N. A.; Severin, S. D.

    2017-09-01

    Film cooling is among the basic methods used for thermal protection of blades in modern high-temperature gas turbines. Results of computer simulation of film cooling with coolant injection via a row of conventional inclined holes or a row of holes in a trench are presented in this paper. The ANSYS CFX 14 commercial software package was used for CFD-modeling. The effect is studied of the mainstream turbulence on the film cooling efficiency for the blowing ratio range between 0.6 and 2.3 and three different turbulence intensities of 1, 5, and 10%. The mainstream velocity was 150 and 400 m/s, while the temperatures of the mainstream and the injected coolant were 1100 and 500°C, respectively. It is demonstrated that, for the coolant injection via one row of trenched holes, an increase in the mainstream turbulence intensity reduces the film cooling efficiency in the entire investigated range of blowing ratios. It was revealed that freestream turbulence had varied effects on the film cooling efficiency depending on the blowing ratio and mainstream velocity in a blade channel. Thus, an increase in the mainstream turbulence intensity from 1 to 10% decreases the surface-averaged film cooling efficiency by 3-10% at a high mainstream velocity (400 m/s) in the blade channel and by 12-23% at a moderate velocity (of 150 m/s). Here, lower film cooling efficiencies correspond to higher blowing ratios. The effect of mainstream turbulence intensity on the film cooling efficiency decreases with increasing the mainstream velocity in the modeled channel for both investigated configurations.

  6. Sensitivity of high-temperature weather to initial soil moisture: a case study using the WRF model

    NASA Astrophysics Data System (ADS)

    Zeng, X.-M.; Wang, B.; Zhang, Y.; Song, S.; Huang, X.; Zheng, Y.; Chen, C.; Wang, G.

    2014-09-01

    Using a succession of 24 h Weather Research and Forecasting model (WRF) simulations, we investigate the sensitivity to initial soil moisture of a short-range high-temperature weather event that occurred in late July 2003 in East China. The initial soil moisture (SMOIS) in the Noah land surface scheme is adjusted (relative to the control run, CTL) for four groups of simulations: DRY25 (-25%), DRY50 (-50%), WET25 (+25%) and WET50 (+50%). Ten 24 h integrations are performed in each group. We focus on 2 m surface air temperature (SAT) greater than 35 °C (the threshold of "high-temperature" events in China) at 06:00 UTC (roughly 14:00 LT in the study domain) to analyse the occurrence of the high-temperature event. The 10-day mean results show that the 06:00 UTC SAT (SAT06) is sensitive to the SMOIS change; specifically, SAT06 exhibits an apparent increase with the SMOIS decrease (e.g. compared with CTL, DRY25 generally results in a 1 °C SAT06 increase over the land surface of East China), areas with 35 °C or higher SAT06 are the most affected, and the simulations are more sensitive to the SMOIS decrease than to the SMOIS increase, which suggests that hot weather can be amplified under low soil moisture conditions. Regarding the mechanism underlying the extremely high SAT06, sensible heat flux has been shown to directly heat the lower atmosphere, and latent heat flux has been found to be more sensitive to the SMOIS change, resulting in an overall increase in surface net radiation due to the increased greenhouse effect (e.g. with the SMOIS increase from DRY25 to CTL, the 10-day mean net radiation increases by 5 W m-2). Additionally, due to the unique and dynamic nature of the western Pacific subtropical high, negative feedback occurs between the regional atmospheric circulation and the air temperature in the lower atmosphere while positive feedback occurs in the mid-troposphere. Using a method based on an analogous temperature relationship, a detailed analysis of the

  7. Photoionization mass spectrometric measurements of initial reaction pathways in low-temperature oxidation of 2,5-dimethylhexane.

    PubMed

    Rotavera, Brandon; Zádor, Judit; Welz, Oliver; Sheps, Leonid; Scheer, Adam M; Savee, John D; Akbar Ali, Mohamad; Lee, Taek Soon; Simmons, Blake A; Osborn, David L; Violi, Angela; Taatjes, Craig A

    2014-11-06

    Product formation from R + O2 reactions relevant to low-temperature autoignition chemistry was studied for 2,5-dimethylhexane, a symmetrically branched octane isomer, at 550 and 650 K using Cl-atom initiated oxidation and multiplexed photoionization mass spectrometry (MPIMS). Interpretation of time- and photon-energy-resolved mass spectra led to three specific results important to characterizing the initial oxidation steps: (1) quantified isomer-resolved branching ratios for HO2 + alkene channels; (2) 2,2,5,5-tetramethyltetrahydrofuran is formed in substantial yield from addition of O2 to tertiary 2,5-dimethylhex-2-yl followed by isomerization of the resulting ROO adduct to tertiary hydroperoxyalkyl (QOOH) and exhibits a positive dependence on temperature over the range covered leading to a higher flux relative to aggregate cyclic ether yield. The higher relative flux is explained by a 1,5-hydrogen atom shift reaction that converts the initial primary alkyl radical (2,5-dimethylhex-1-yl) to the tertiary alkyl radical 2,5-dimethylhex-2-yl, providing an additional source of tertiary alkyl radicals. Quantum-chemical and master-equation calculations of the unimolecular decomposition of the primary alkyl radical reveal that isomerization to the tertiary alkyl radical is the most favorable pathway, and is favored over O2-addition at 650 K under the conditions herein. The isomerization pathway to tertiary alkyl radicals therefore contributes an additional mechanism to 2,2,5,5-tetramethyltetrahydrofuran formation; (3) carbonyl species (acetone, propanal, and methylpropanal) consistent with β-scission of QOOH radicals were formed in significant yield, indicating unimolecular QOOH decomposition into carbonyl + alkene + OH.

  8. Photoionization mass spectrometric measurements of initial reaction pathways in low-temperature oxidation of 2,5-dimethylhexane

    SciTech Connect

    Rotavera, Brandon; Zádor, Judit; Welz, Oliver; Sheps, Leonid; Scheer, Adam M.; Savee, John D.; Akbar Ali, Mohamad; Lee, Taek Soon; Simmons, Blake A.; Osborn, David L.; Violi, Angela; Taatjes, Craig A.

    2014-09-19

    The product formation from R + O2 reactions relevant to low-temperature autoignition chemistry was studied for 2,5-dimethylhexane, a symmetrically branched octane isomer, at 550 and 650 K using Cl-atom initiated oxidation and multiplexed photoionization mass spectrometry (MPIMS). The interpretation of time- and photon-energy-resolved mass spectra led to three specific results important to characterizing the initial oxidation steps: (1) quantified isomer-resolved branching ratios for HO2 + alkene channels; (2) 2,2,5,5-tetramethyltetrahydrofuran is formed in substantial yield from addition of O2 to tertiary 2,5-dimethylhex-2-yl followed by isomerization of the resulting ROO adduct to tertiary hydroperoxyalkyl (QOOH) and exhibits a positive dependence on temperature over the range covered leading to a higher flux relative to aggregate cyclic ether yield. The higher relative flux is explained by a 1,5-hydrogen atom shift reaction that converts the initial primary alkyl radical (2,5-dimethylhex-1-yl) to the tertiary alkyl radical 2,5-dimethylhex-2-yl, providing an additional source of tertiary alkyl radicals. Furthermore, quantum-chemical and master-equation calculations of the unimolecular decomposition of the primary alkyl radical reveal that isomerization to the tertiary alkyl radical is the most favorable pathway, and is favored over O2-addition at 650 K under the conditions herein. The isomerization pathway to tertiary alkyl radicals therefore contributes an additional mechanism to 2,2,5,5-tetramethyltetrahydrofuran formation; (3) carbonyl species (acetone, propanal, and methylpropanal) consistent with β-scission of QOOH radicals were formed in significant yield, indicating unimolecular QOOH decomposition into carbonyl + alkene + OH.

  9. Effect of dissolved oxygen, temperature, initial cell count, and sugar concentration on the viability of Saccharomyces cerevisiae in rapid fermentations.

    PubMed

    Nagodawithana, T W; Castellano, C; Steinkraus, K H

    1974-09-01

    By using 7 x 10(8) cells of Saccharomyces cerevisiae per ml with which 25 degrees Brix honey solutions were fermented to 9.5% (wt/vol; 12% vol/vol) ethanol in 2.5 to 3 h at 30 C, i.e., rapid fermentation, the death rate was found to be high, with only 2.1% of the yeast cells surviving at the end of 3 h under anaerobic conditions. As the dissolved oxygen in the medium was increased from 0 to 13 to 20 to 100% in rapid fermentations at 30 C, there was a progressive increase in the percentage of cells surviving. The ethanol production rate and total were not seriously affected by a dissolved oxygen concentration of 13%, but fermentation was retarded by 20% dissolved oxygen and still further decreased as the dissolved oxygen content reached 100%. When the fermentation temperature was decreased to 15 C (at 13% dissolved oxygen), the rate of fermentation decreased, and the fermentation time to 9.5% ethanol (wt/vol) increased to 6 h. It was found that the higher the temperature between 15 and 30 C, the greater the rate of death as initial cell counts were increased from 1.1 x 10(7) to 7.8 x 10(8) cells per ml. At the lowest level of inoculum, 1.1 x 10(7) cells per ml, there was actual multiplication, even at 30 C; however, the fermentation was no longer rapid. The addition of 15% sugar, initially followed after an hour by the remaining 10%, or addition of the sugar in increments of 2.5 or 5% yielded a better survival rate of yeast cells than when the fermentation was initiated with 25% sugar.

  10. Co-adsorption of perfluorooctane sulfonate and phosphate on boehmite: Influence of temperature, phosphate initial concentration and pH.

    PubMed

    Qian, Jin; Shen, Mengmeng; Wang, Peifang; Wang, Chao; Hu, Jing; Hou, Jun; Ao, Yanhui; Zheng, Hao; Li, Kun; Liu, Jingjing

    2017-03-01

    The co-presence of perfluorooctane sulfonate (PFOS) and phosphate in wastewater of various industries has been detected. Removing PFOS and phosphate simultaneously before discharging sewage into natural water can decrease effectively the environmental risk caused by the combined pollution of PFOS and phosphate. In this study, laboratory batch experiments were conducted for investigating the co-adsorption of PFOS and phosphate on boehmite and the influences of temperature, phosphate initial concentration and pH on the co-adsorption. The adsorption thermodynamics and kinetics of PFOS and phosphate on boehmite were also investigated completely and systematically. The results showed that lower temperature favored the co-adsorptions of PFOS and phosphate. The adsorption of PFOS and phosphate on boehmite agreed well with the Langmuir isotherm and the adsorption parameters of thermodynamics are ΔH=-16.9 and -20.0kJmol(-1) (PFOS and phosphate), ΔS=-5.69 and -7.63Jmol(-1) K(-1) (PFOS and phosphate) and ΔG <0 (PFOS and phosphate). It demonstrated that the co-adsorption of PFOS and phosphate on boehmite is a spontaneously exothermic process. Moreover, the co-adsorption process can be described well by a pseudo-second-order kinetic model. With increasing phosphate initial concentration, more phosphate could be adsorbed on boehmite, while the adsorption of PFOS decreased at phosphate initial concentration of less than 30mgL(-1) and increased at that of larger than 30mgL(-1). In the co-adsorption process, the adsorption amount of PFOS decreased with pH increasing, but that of phosphate changed little. Copyright © 2016. Published by Elsevier Inc.

  11. Improved prediction of severe thunderstorms over the Indian Monsoon region using high-resolution soil moisture and temperature initialization.

    PubMed

    Osuri, K K; Nadimpalli, R; Mohanty, U C; Chen, F; Rajeevan, M; Niyogi, D

    2017-01-27

    The hypothesis that realistic land conditions such as soil moisture/soil temperature (SM/ST) can significantly improve the modeling of mesoscale deep convection is tested over the Indian monsoon region (IMR). A high resolution (3 km foot print) SM/ST dataset prepared from a land data assimilation system, as part of a national monsoon mission project, showed close agreement with observations. Experiments are conducted with (LDAS) and without (CNTL) initialization of SM/ST dataset. Results highlight the significance of realistic land surface conditions on numerical prediction of initiation, movement and timing of severe thunderstorms as compared to that currently being initialized by climatological fields in CNTL run. Realistic land conditions improved mass flux, convective updrafts and diabatic heating in the boundary layer that contributed to low level positive potential vorticity. The LDAS run reproduced reflectivity echoes and associated rainfall bands more efficiently. Improper representation of surface conditions in CNTL run limit the evolution boundary layer processes and thereby failed to simulate convection at right time and place. These findings thus provide strong support to the role land conditions play in impacting the deep convection over the IMR. These findings also have direct implications for improving heavy rain forecasting over the IMR, by developing realistic land conditions.

  12. Improved prediction of severe thunderstorms over the Indian Monsoon region using high-resolution soil moisture and temperature initialization

    PubMed Central

    Osuri, K. K.; Nadimpalli, R.; Mohanty, U. C.; Chen, F.; Rajeevan, M.; Niyogi, D.

    2017-01-01

    The hypothesis that realistic land conditions such as soil moisture/soil temperature (SM/ST) can significantly improve the modeling of mesoscale deep convection is tested over the Indian monsoon region (IMR). A high resolution (3 km foot print) SM/ST dataset prepared from a land data assimilation system, as part of a national monsoon mission project, showed close agreement with observations. Experiments are conducted with (LDAS) and without (CNTL) initialization of SM/ST dataset. Results highlight the significance of realistic land surface conditions on numerical prediction of initiation, movement and timing of severe thunderstorms as compared to that currently being initialized by climatological fields in CNTL run. Realistic land conditions improved mass flux, convective updrafts and diabatic heating in the boundary layer that contributed to low level positive potential vorticity. The LDAS run reproduced reflectivity echoes and associated rainfall bands more efficiently. Improper representation of surface conditions in CNTL run limit the evolution boundary layer processes and thereby failed to simulate convection at right time and place. These findings thus provide strong support to the role land conditions play in impacting the deep convection over the IMR. These findings also have direct implications for improving heavy rain forecasting over the IMR, by developing realistic land conditions. PMID:28128293

  13. Improved prediction of severe thunderstorms over the Indian Monsoon region using high-resolution soil moisture and temperature initialization

    NASA Astrophysics Data System (ADS)

    Osuri, K. K.; Nadimpalli, R.; Mohanty, U. C.; Chen, F.; Rajeevan, M.; Niyogi, D.

    2017-01-01

    The hypothesis that realistic land conditions such as soil moisture/soil temperature (SM/ST) can significantly improve the modeling of mesoscale deep convection is tested over the Indian monsoon region (IMR). A high resolution (3 km foot print) SM/ST dataset prepared from a land data assimilation system, as part of a national monsoon mission project, showed close agreement with observations. Experiments are conducted with (LDAS) and without (CNTL) initialization of SM/ST dataset. Results highlight the significance of realistic land surface conditions on numerical prediction of initiation, movement and timing of severe thunderstorms as compared to that currently being initialized by climatological fields in CNTL run. Realistic land conditions improved mass flux, convective updrafts and diabatic heating in the boundary layer that contributed to low level positive potential vorticity. The LDAS run reproduced reflectivity echoes and associated rainfall bands more efficiently. Improper representation of surface conditions in CNTL run limit the evolution boundary layer processes and thereby failed to simulate convection at right time and place. These findings thus provide strong support to the role land conditions play in impacting the deep convection over the IMR. These findings also have direct implications for improving heavy rain forecasting over the IMR, by developing realistic land conditions.

  14. Characterization of uranium surfaces machined with aqueous propylene glycol-borax or perchloroethylene-mineral oil coolants

    SciTech Connect

    Cristy, S.S.; Bennett, R.K. Jr.; Dillon, J.J.; Richards, H.L.; Seals, R.D.; Byrd, V.R.

    1986-12-31

    The use of perchloroethylene (perc) as an ingredient in coolants for machining enriched uranium at the Oak Ridge Y-12 Plant has been discontinued because of environmental concerns. A new coolant was substituted in December 1985, which consists of an aqueous solution of propylene glycol with borax (sodium tetraborate) added as a nuclear poison and with a nitrite added as a corrosion inhibitor. Uranium surfaces machined using the two coolants were compared with respects to residual contamination, corrosion or corrosion potential, and with the aqueous propylene glycol-borax coolant was found to be better than that of enriched uranium machined with the perc-mineral oil coolant. The boron residues on the final-finished parts machined with the borax-containing coolant were not sufficient to cause problems in further processing. All evidence indicated that the enriched uranium surfaces machined with the borax-containing coolant will be as satisfactory as those machined with the perc coolant.

  15. Plasma-initiated rehydrogenation of amorphous silicon to increase the temperature processing window of silicon heterojunction solar cells

    DOE PAGES

    Shi, Jianwei; Boccard, Mathieu; Holman, Zachary

    2016-07-19

    The dehydrogenation of intrinsic hydrogenated amorphous silicon (a-Si:H) at temperatures above approximately 300°C degrades its ability to passivate silicon wafer surfaces. This limits the temperature of post-passivation processing steps during the fabrication of advanced silicon heterojunction or silicon-based tandem solar cells. We demonstrate that a hydrogen plasma can rehydrogenate intrinsic a-Si:H passivation layers that have been dehydrogenated by annealing. The hydrogen plasma treatment fully restores the effective carrier lifetime to several milliseconds in textured crystalline siliconwafers coated with 8-nm-thick intrinsic a-Si:H layers after annealing at temperatures of up to 450°C. Plasma-initiated rehydrogenation also translates to complete solar cells: A silicon heterojunction solar cell subjected to annealing at 450°C (following intrinsic a-Si:H deposition) had an open-circuit voltage of less than 600 mV, but an identical cell that received hydrogen plasma treatment reached a voltagemore » of over 710 mV and an efficiency of over 19%.« less

  16. Plasma-initiated rehydrogenation of amorphous silicon to increase the temperature processing window of silicon heterojunction solar cells

    SciTech Connect

    Shi, Jianwei; Boccard, Mathieu; Holman, Zachary

    2016-07-19

    The dehydrogenation of intrinsic hydrogenated amorphous silicon (a-Si:H) at temperatures above approximately 300°C degrades its ability to passivate silicon wafer surfaces. This limits the temperature of post-passivation processing steps during the fabrication of advanced silicon heterojunction or silicon-based tandem solar cells. We demonstrate that a hydrogen plasma can rehydrogenate intrinsic a-Si:H passivation layers that have been dehydrogenated by annealing. The hydrogen plasma treatment fully restores the effective carrier lifetime to several milliseconds in textured crystalline siliconwafers coated with 8-nm-thick intrinsic a-Si:H layers after annealing at temperatures of up to 450°C. Plasma-initiated rehydrogenation also translates to complete solar cells: A silicon heterojunction solar cell subjected to annealing at 450°C (following intrinsic a-Si:H deposition) had an open-circuit voltage of less than 600 mV, but an identical cell that received hydrogen plasma treatment reached a voltage of over 710 mV and an efficiency of over 19%.

  17. Blade-to-coolant heat-transfer results and operating data from a natural-convection water-cooled single-stage turbine

    NASA Technical Reports Server (NTRS)

    Diaguila, Anthony J; Freche, John C

    1951-01-01

    Blade-to-coolant heat-transfer data and operating data were obtained with a natural-convection water-cooled turbine over range of turbine speeds and inlet-gas temperatures. The convective coefficients were correlated by the general relation for natural-convection heat transfer. The turbine data were displaced from a theoretical equation for natural convection heat transfer in the turbulent region and from natural-convection data obtained with vertical cylinders and plates; possible disruption of natural convection circulation within the blade coolant passages was thus indicated. Comparison of non dimensional temperature-ratio parameters for the blade leading edge, midchord, and trailing edge indicated that the blade cooling effectiveness is greatest at the midchord and least at the trailing edge.

  18. Intraosseous temperature changes during the use of piezosurgical inserts in vitro.

    PubMed

    Schütz, S; Egger, J; Kühl, S; Filippi, A; Lambrecht, J Th

    2012-11-01

    This study concerns intraosseous temperature changes during the use of piezosurgical inserts. On six fresh pig jaws heated to body temperature (36°C), osteotomies and osteoplasties were performed in vitro with the Piezosurgery(®) 3 device (Mectron, Carasco, Italy) and various inserts. The intraosseous temperature increases were measured at a depth of 3mm and at a distance of 1mm from the working site using nickel-chromium/nickel temperature sensors. 20°C Ringer's solution was used for cooling in an initial test series and 10°C Ringer's in a second series. The processed bone was examined using digital volume tomography images to determine the ratio of cortical to cancellous bone thickness. Mean temperature increases of 4.4-10.9°C were found; maximum temperature peaks were over 47°C for an average of only 8.5 s. The type of piezosurgical insert had a marked influence on intraosseous temperature generation (p=0.026); the thickness of the cortical bone and the temperature of the coolant did not. Coolant temperature had an influence on the bone cooling time (p=0.013). The results show that correct use of the piezosurgery device does not give rise to prolonged temperature increases over 47°C and hence does not cause any irreversible thermal damage in the bone. Copyright © 2012 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

  19. Investigation of heat transfer in zirconium potassium perchlorate at low temperature: A study of the failure mechanism of the NASA standard initiator

    NASA Technical Reports Server (NTRS)

    Varghese, Philip L.

    1989-01-01

    The objective of this work was to study the reasons for the failure of pyrotechnic initiators at very low temperatures (10 to 100 K). A two-dimensional model of the NASA standard initiator was constructed to model heat transfer from the electrically heated stainless steel bridgewire to the zirconium potassium perchlorate explosive charge and the alumina charge cup. Temperature dependent properties were used in the model to simulate initiator performance over a wide range of initial temperatures (10 to 500 K). A search of the thermophysical property data base showed that pure alumina has a very high thermal conductivity at low temperatures. It had been assumed to act as a thermal insulator in all previous analyses. Rapid heat transfer from the bridgewire to the alumina at low initial temperatures was shown to cause failure of the initiators if the wire did not also make good contact with the zirconium potassium perchlorate charge. The mode is able to reproduce the results of the tests that had been conducted to investigate the cause for failure. It also provides an explanation for previously puzzling results and suggests simple design changes that will increase reliability at very low initial temperatures.

  20. Performance of the Extravehicular Mobility Unit (EMU): Airlock Coolant Loop Recovery (A/L CLR) Hardware - Phase II

    NASA Technical Reports Server (NTRS)

    Steele, John; Rector, tony; Gazda, Daniel; Lewis, John

    2009-01-01

    An EMU water processing kit (Airlock Coolant Loop Recovery A/L CLR) was developed as a corrective action to Extravehicular Mobility Unit (EMU) coolant flow disruptions experienced on the International Space Station (ISS) in May of 2004 and thereafter. Conservative schedules for A/L CLR use and component life were initially developed and implemented based on prior analysis results and analytical modeling. The examination of postflight samples and EMU hardware in November of 2006 indicated that the A/L CLR kits were functioning well and had excess capacity that would allow a relaxation of the initially conservative schedules of use and component life. A relaxed use schedule and list of component lives was implemented thereafter. Since the adoption of the relaxed A/L CLR schedules of use and component lives, several A/L CLR kit components, transport loop water samples and sensitive EMU transport loop components have been examined to gage the impact of the relaxed requirements. The intent of this paper is to summarize the findings of that evaluation, and to outline updated schedules for A/L CLR use and component life.

  1. Performance of the Extravehicular Mobility Unit (EMU): Airlock Coolant Loop Recovery (A/L CLR) Hardware - Phase II

    NASA Technical Reports Server (NTRS)

    Steele, John; Rector, tony; Gazda, Daniel; Lewis, John

    2009-01-01

    An EMU water processing kit (Airlock Coolant Loop Recovery A/L CLR) was developed as a corrective action to Extravehicular Mobility Unit (EMU) coolant flow disruptions experienced on the International Space Station (ISS) in May of 2004 and thereafter. Conservative schedules for A/L CLR use and component life were initially developed and implemented based on prior analysis results and analytical modeling. The examination of postflight samples and EMU hardware in November of 2006 indicated that the A/L CLR kits were functioning well and had excess capacity that would allow a relaxation of the initially conservative schedules of use and component life. A relaxed use schedule and list of component lives was implemented thereafter. Since the adoption of the relaxed A/L CLR schedules of use and component lives, several A/L CLR kit components, transport loop water samples and sensitive EMU transport loop components have been examined to gage the impact of the relaxed requirements. The intent of this paper is to summarize the findings of that evaluation, and to outline updated schedules for A/L CLR use and component life.

  2. Development of Safety Analysis Codes and Experimental Validation for a Very High Temperature Gas-Cooled Reactor - FY-05 Annual Report

    SciTech Connect

    Chang Oh

    2005-09-01

    The very high temperature gas-cooled reactors (VHTGRs) are those concepts that have average coolant temperatures above 9000C or operational fuel temperatures above 12500C. These concepts provide the potential for increased energy conversion efficiency and for high-temperature process heat application in addition to power generation and nuclear hydrogen generation. While all the High Temperature Gas Cooled Reactor (HTGR) concepts have sufficiently high temperatures to support process heat applications, such as desalination and cogeneration, the VHTGR’s higher temperatures are suitable for particular applications such as thermochemical hydrogen production. However, the high temperature operation can be detrimental to safety following a loss-of-coolant accident (LOCA) initiated by pipe breaks caused by seismic or other events. Following the loss of coolant through the break and coolant depressurization, air from the containment will enter the core by molecular diffusion and ultimately by natural convection, leading to oxidation of the in-core graphite structures and fuel. The oxidation will release heat and accelerate the heatup of the reactor core. Thus, without any effective countermeasures, a pipe break may lead to significant fuel damage and fission product release. The Idaho National Laboratory (INL) has investigated this event for the past three years for the HTGR. However, the computer codes used, and in fact none of the world’s computer codes, have been sufficiently developed and validated to reliably predict this event. New code development, improvement of the existing codes, and experimental validation are imperative to narrow the uncertainty in the predictions of this type of accident. The objectives of this Korean/United States collaboration are to develop advanced computational methods for VHTGR safety analysis codes and to validate these computer codes.

  3. Integrity of the reactor coolant boundary of the European pressurized water reactor (EPR)

    SciTech Connect

    Goetsch, D.; Bieniussa, K.; Schulz, H.; Jalouneix, J.

    1997-04-01

    This paper is an abstract of the work performed in the frame of the development of the IPSN/GRS approach in view of the EPR conceptual safety features. EPR is a pressurized water reactor which will be based on the experience gained by utilities and designers in France and in Germany. The reactor coolant boundary of a PWR includes the reactor pressure vessel (RPV), those parts of the steam generators (SGs) which contain primary coolant, the pressurizer (PSR), the reactor coolant pumps (RCPs), the main coolant lines (MCLs) with their branches as well as the other connecting pipes and all branching pipes including the second isolation valves. The present work covering the integrity of the reactor coolant boundary is mainly restricted to the integrity of the main coolant lines (MCLs) and reflects the design requirements for the main components of the reactor coolant boundary. In the following the conceptual aspects, i.e. design, manufacture, construction and operation, will be assessed. A main aspect is the definition of break postulates regarding overall safety implications.

  4. Flow in serpentine coolant passages with trip strips

    NASA Technical Reports Server (NTRS)

    Tse, D. G.-N.

    1995-01-01

    Under the subject contract, an effort is being conducted at Scientific Research Associates, Inc. (SRA) to obtain flow field measurements in the coolant passage of a rotating turbine blade with ribbed walls, both in the stationary and rotating frames. The data obtained will be used for validation of computational tools and assessment of turbine blade cooling strategies. The configuration of the turbine blade passage model is given, and the measuring plane locations are given. The model has a four-pass passage with three 180 turns. This geometry was chosen to allow analyses of the velocity measurements corresponding to the heat transfer results obtained by Wagner. Two passes of the passage have a rectangular cross-section of 1.0 in x 0.5 in. Another two passes have a square cross-section of 0.5 in x 0.5 in. Trips with a streamwise pitch to trip height (P/e) = 5 and trip height to coolant passage width (e/Z) = 0.1, were machined along the leading and trailing walls. These dimensions are typical of those used in turbine blade coolant passages. The trips on these walls are staggered by the half-pitch. The trips are skewed at +/- 45 deg, and this allows the effect of trip orientation to be examined. Experiments will be conducted with flow entering the model through the 1.0 in x 0.5 in rectangular passage (Configuration C) and the 0.5 in x 0. 5 in square passage (Configuration D) to examine the effect of passage aspect ratio. Velocity measurements were obtained with a Reynolds number (Re) of 25,000, based on the hydraulic diameter of and bulk mean velocity in the half inch square passage. The coordinate system used in presenting the results for configurations C and D, respectively, is shown. The first, second and third passes of the passage will be referred to as the first, second and third passages, respectively, in later discussion. Streamwise distance (x) from the entrance is normalized by the hydraulic diameter (D). Vertical (y) and tangential (z) distances are

  5. Radiogenic lead with dominant content of {sup 208}Pb: New coolant and neutron moderator for innovative nuclear reactors

    SciTech Connect

    Shmelev, A. N.; Kulikov, G. G.; Kryuchkov, E. F.; Apse, V. A.; Kulikov, E. G.

    2012-07-01

    The advantages of radiogenic lead with dominant content of {sup 208}Pb as a reactor coolant with respect to natural lead are caused by unique nuclear properties of {sup 208}Pb which is a double-magic nucleus with closed proton and neutron shells. This results in significantly lower micro cross section and resonance integral of radiative neutron capture by {sup 208}Pb than those for numerous light neutron moderators. The extremely weak ability of {sup 208}Pb to absorb neutrons results in the following effects. Firstly, neutron moderating factor (ratio of scattering to capture cross sections) is larger than that for graphite and light water. Secondly, age and diffusion length of thermal neutrons are larger than those for graphite, light and heavy water. Thirdly, neutron lifetime in {sup 208}Pb is comparable with that for graphite, beryllium and heavy water what could be important for safe reactor operation. The paper presents some results obtained in neutronics and thermal-hydraulics evaluations of the benefits from the use of radiogenic lead with dominant content of {sup 208}Pb instead of natural lead as a coolant of fast breeder reactors. The paper demonstrates that substitution of radiogenic lead for natural lead can offer the following benefits for operation of fast breeder reactors. Firstly, improvement of the reactor safety thanks to the better values of coolant temperature reactivity coefficient and, secondly, improvement of some thermal-hydraulic reactor parameters. Radiogenic lead can be extracted from thorium sludge without isotope separation as {sup 208}Pb is a final isotope in the decay chain of {sup 232}Th. (authors)

  6. Selection of an Alternate Biocide for the ISS Internal Thermal Control System Coolant, Phase 2

    NASA Technical Reports Server (NTRS)

    Wilson, Mark E.; Cole, Harold; Weir, Natalee; Oehler, Bill; Steele, John; Varsik, Jerry; Lukens, Clark

    2004-01-01

    The ISS (International Space Station) ITCS (Internal Thermal Control System) includes two internal coolant loops that utilize an aqueous based coolant for heat transfer. A silver salt biocide had previously been utilized as an additive in the coolant formulation to control the growth and proliferation of microorganisms within the coolant loops. Ground-based and in-flight testing demonstrated that the silver salt was rapidly depleted, and did not act as an effective long-term biocide. Efforts to select an optimal alternate biocide for the ITCS coolant application have been underway and are now in the final stages. An extensive evaluation of biocides was conducted to down-select to several candidates for test trials and was reported on previously. Criteria for that down-select included: the need for safe, non-intrusive implementation and operation in a functioning system; the ability to control existing planktonic and biofilm residing microorganisms; a negligible impact on system-wetted materials of construction; and a negligible reactivity with existing coolant additives. Candidate testing to provide data for the selection of an optimal alternate biocide is now in the final stages. That testing has included rapid biocide effectiveness screening using Biolog MT2 plates to determine minimum inhibitory concentration (amount that will inhibit visible growth of microorganisms), time kill studies to determine the exposure time required to completely eliminate organism growth, materials compatibility exposure evaluations, coolant compatibility studies, and bench-top simulated coolant testing. This paper reports the current status of the effort to select an alternate biocide for the ISS ITCS coolant. The results of various test results to select the optimal candidate are presented.

  7. Selection of an Alternate Biocide for the ISS Internal Thermal Control System Coolant, Phase 2

    NASA Technical Reports Server (NTRS)

    Wilson, Mark E.; Cole, Harold; Weir, Natalee; Oehler, Bill; Steele, John; Varsik, Jerry; Lukens, Clark

    2004-01-01

    The ISS (International Space Station) ITCS (Internal Thermal Control System) includes two internal coolant loops that utilize an aqueous based coolant for heat transfer. A silver salt biocide had previously been utilized as an additive in the coolant formulation to control the growth and proliferation of microorganisms within the coolant loops. Ground-based and in-flight testing demonstrated that the silver salt was rapidly depleted, and did not act as an effective long-term biocide. Efforts to select an optimal alternate biocide for the ITCS coolant application have been underway and are now in the final stages. An extensive evaluation of biocides was conducted to down-select to several candidates for test trials and was reported on previously. Criteria for that down-select included: the need for safe, non-intrusive implementation and operation in a functioning system; the ability to control existing planktonic and biofilm residing microorganisms; a negligible impact on system-wetted materials of construction; and a negligible reactivity with existing coolant additives. Candidate testing to provide data for the selection of an optimal alternate biocide is now in the final stages. That testing has included rapid biocide effectiveness screening using Biolog MT2 plates to determine minimum inhibitory concentration (amount that will inhibit visible growth of microorganisms), time kill studies to determine the exposure time required to completely eliminate organism growth, materials compatibility exposure evaluations, coolant compatibility studies, and bench-top simulated coolant testing. This paper reports the current status of the effort to select an alternate biocide for the ISS ITCS coolant. The results of various test results to select the optimal candidate are presented.

  8. Recycling used engine coolant using high-volume stationary, multiple technology equipment

    SciTech Connect

    Haddock, M.E.; Eaton, E.R.

    1999-08-01

    Recycling used engine coolant has become increasingly desirable due to two significant factors. First, engine coolant frequently merits designation as a hazardous waste under the Federal Clean Water Act. Federal and some state environmental protection agencies have instituted strict regulation of the disposal of used engine coolant. In some cases, the disposal of engine coolant requires imposition of waste disposal fees and surcharges. Secondly, ethylene glycol, the principal cost component of engine coolant, has experienced dramatic price fluctuations and occasional shortages in supply. Therefore, there are both environmental and economic pressures to recycle engine coolant and recover the ethylene glycol component in an efficient and cost-effective manner. This paper discusses a multistage apparatus and a process for recycling used engine coolant that employs a combination of filtration, centrifugation (hydrocyclone separation), dissolved air flotation, nanofiltration, reverse osmosis, continuous deionization, and ion exchange processes for separating ethylene glycol and water from used engine coolant. The engine coolant is prefiltered through a series of filters. The filters remove particulate contaminates. This filtered fluid is then subjected to dissolved air flotation and centrifugation to remove petroleum. Then it is heated and pressurized prior to being passed over a series of two different sets of semipermeable membranes. The membrane technologies separate the feed stream into a permeate solution of ethylene glycol and water and a concentrate waste solution. The concentrate solution is returned to a concentrate tank for continuous circulation through the apparatus. The permeate solution is subjected to final refining by continuous deionization followed by a cation and anion ion exchange polishing process. The continuous deionization reduces ionic contaminants, and the ion exchange system eliminates any ionic contaminants left by the previous purification

  9. A strong inorganic acid-initiated methacrylate polymerization strategy for room temperature preparation of monolithic columns for capillary electrochromatography.

    PubMed

    Wang, Man-Man; Wang, He-Fang; Jiang, Dong-Qing; Wang, Shan-Wei; Yan, Xiu-Ping

    2010-05-01

    A facile strong inorganic acid-initiated methacrylate polymerization strategy was developed for fabricating monolithic columns at room temperature. The prepared monoliths were characterized by FTIR spectrometry, mercury intrusion porosimeter and SEM, while their performance was evaluated by CEC for the separation of various types of compounds including alkyl benzenes, polycyclic aromatic hydrocarbons, nonsteroidal anti-inflammatory drugs, anilines, and nitrophenol isomers. The column-to-column and batch-to-batch reproducibility for the prepared monoliths in terms of the RSD of EOF flow velocity, retention factor, and the minimum plate height of naphthalene ranged from 3.4 to 12.4%. The fabricated monoliths gave excellent performance for the separation of the test neutral compounds with the theoretical plates of 170,000-232,000 plates per meter for thiourea, and 77,400-112,300 plates per meter for naphthalene. The proposed strong inorganic acid-initiated methacrylate polymerization strategy is a promising alternative for fabricating organic polymer-based monoliths.

  10. Photoionization mass spectrometric measurements of initial reaction pathways in low-temperature oxidation of 2,5-dimethylhexane

    DOE PAGES

    Rotavera, Brandon; Zádor, Judit; Welz, Oliver; ...

    2014-09-19

    The product formation from R + O2 reactions relevant to low-temperature autoignition chemistry was studied for 2,5-dimethylhexane, a symmetrically branched octane isomer, at 550 and 650 K using Cl-atom initiated oxidation and multiplexed photoionization mass spectrometry (MPIMS). The interpretation of time- and photon-energy-resolved mass spectra led to three specific results important to characterizing the initial oxidation steps: (1) quantified isomer-resolved branching ratios for HO2 + alkene channels; (2) 2,2,5,5-tetramethyltetrahydrofuran is formed in substantial yield from addition of O2 to tertiary 2,5-dimethylhex-2-yl followed by isomerization of the resulting ROO adduct to tertiary hydroperoxyalkyl (QOOH) and exhibits a positive dependence on temperaturemore » over the range covered leading to a higher flux relative to aggregate cyclic ether yield. The higher relative flux is explained by a 1,5-hydrogen atom shift reaction that converts the initial primary alkyl radical (2,5-dimethylhex-1-yl) to the tertiary alkyl radical 2,5-dimethylhex-2-yl, providing an additional source of tertiary alkyl radicals. Furthermore, quantum-chemical and master-equation calculations of the unimolecular decomposition of the primary alkyl radical reveal that isomerization to the tertiary alkyl radical is the most favorable pathway, and is favored over O2-addition at 650 K under the conditions herein. The isomerization pathway to tertiary alkyl radicals therefore contributes an additional mechanism to 2,2,5,5-tetramethyltetrahydrofuran formation; (3) carbonyl species (acetone, propanal, and methylpropanal) consistent with β-scission of QOOH radicals were formed in significant yield, indicating unimolecular QOOH decomposition into carbonyl + alkene + OH.« less

  11. Thermal X-Ray Spectral Tools. I. Parameterizing Impulsive X-Ray Heating with a Cumulative Initial Temperature (CIT) Distribution

    NASA Astrophysics Data System (ADS)

    Gayley, Kenneth G.

    2014-06-01

    In collisional ionization equilibrium, the X-ray spectrum from a plasma depends on the differential emission measure (DEM), distributed over temperature. Due to the well-known ill conditioning problem, no precisely resolved DEM can be inverted directly from the spectrum, so often only a gross parameterization of the DEM is used to approximate the data, in hopes that the parameterization can provide useful model-independent constraints on the heating process. However, ill conditioning also introduces ambiguity into the various different parameterizations that could approximate the data, which may spoil the perceived advantages of model independence. Thus, this paper instead suggests a single parameterization for both the heating mechanism and the X-ray sources, based on a model of impulsive heating followed by radiative cooling. This approach is similar to a "cooling flow" approach but allows injection at multiple initial temperatures and applies even when the steady state is a distribution of different shock strengths, as for a standing shock with a range of obliquities, or for embedded stochastic shocks that are only steady in a statistical sense. This produces an alternative parameterization for X-ray spectra that is especially streamlined for higher density plasmas with efficient radiative cooling and minimal thermal conduction and mixing. The method also provides some internal consistency checks on the validity of its assumptions. A heuristic general version is then applied over a wide range of astrophysical applications to schematically explore potential alternative models for these phenomena.

  12. Densification of tube-shaped transparent conducting oxide target at reduced temperature via initial heat treatment under pressure

    NASA Astrophysics Data System (ADS)

    Lee, Sung-Pyo; Lee, Jong-Rak; Chung, Tai-Joo; Paek, Yeong-Kyeun; Yang, Seung-Ho; Hong, Gil-Su; Oh, Kyung-Sik

    2015-11-01

    Transparent conducting oxide such as aluminum doped ZnO (Al-ZnO) needs to be prepared in a tube-shaped target for prolonged life time during sputtering. To prevent warping and coarsening during preparation, the densification of tube-shaped target need to be achieved at reduced temperature. In this study, tube-shaped 2 wt% Al-ZnO was prepared via two-step sintering route, consisted with initial heat treatment (IHT) at 700 °C or 800 °C under mild external pressure (1 MPa) and subsequent pressureless sintering at 1300 °C or 1350 °C. By applying pressure during the IHT, the density obtained by sintering at 1300 °C increased by 2.38% and reached the same level of density as material sintered at 1350 °C. The reduced sintering temperature rendered a fine grained tube, suitable for prevention of nodules during sputtering. The IHT under external pressure had limited effects for tall tubes, where loss of pressure was anticipated due to the difficulty in fine filling the pressing medium within the mold.

  13. [Effects of salting, cut type, and initial simmering temperature on protein and fat contents of meat broths: I. Beef].

    PubMed

    Gotera-Prado, Z; Quintero, J B; Huerta-Leidenz, N; Prado Gotera, Z

    1997-12-01

    A 2 x 2 x 4 factorial design was used to study variation of protein and fat contents in beef broths as affected by cut type (flank, shank), salt treatments (addition of salt to the medium, no salt), and initial temperatures of simmering (25, 70, 75, and 100 degrees C). Flank portions yielded slightly more protein (0.29 g/100 mL) and had three-fold less fat (0.39 g/mL) than those of shank (0.25 and 1.12 g/mL, respectively) (P < 0.05). No linear relationship of temperature and amount of extractable components was observed, but it was clear that the greatest protein extraction was accomplished when meat was immersed in cooking water at boiling point (P < 0.05). In general, salting of water reduced fat content of beef broths. However, a significant Salting x Cut type interaction showed this effect was only present in shanks (P < 0.05). Conversely, the reducing effect (P < 0.05) of salting on amount of protein extracted from flank was not observed in shanks. Based on these data, we conclude that larger amounts of protein and less fat could be transferred from meat pieces to the medium by immersing beef in salted water at the boiling point.

  14. Thermal X-ray spectral tools. I. Parameterizing impulsive X-ray heating with a cumulative initial temperature (CIT) distribution

    SciTech Connect

    Gayley, Kenneth G.

    2014-06-10

    In collisional ionization equilibrium, the X-ray spectrum from a plasma depends on the differential emission measure (DEM), distributed over temperature. Due to the well-known ill conditioning problem, no precisely resolved DEM can be inverted directly from the spectrum, so often only a gross parameterization of the DEM is used to approximate the data, in hopes that the parameterization can provide useful model-independent constraints on the heating process. However, ill conditioning also introduces ambiguity into the various different parameterizations that could approximate the data, which may spoil the perceived advantages of model independence. Thus, this paper instead suggests a single parameterization for both the heating mechanism and the X-ray sources, based on a model of impulsive heating followed by radiative cooling. This approach is similar to a 'cooling flow' approach but allows injection at multiple initial temperatures and applies even when the steady state is a distribution of different shock strengths, as for a standing shock with a range of obliquities, or for embedded stochastic shocks that are only steady in a statistical sense. This produces an alternative parameterization for X-ray spectra that is especially streamlined for higher density plasmas with efficient radiative cooling and minimal thermal conduction and mixing. The method also provides some internal consistency checks on the validity of its assumptions. A heuristic general version is then applied over a wide range of astrophysical applications to schematically explore potential alternative models for these phenomena.

  15. Computation of Space Shuttle high-pressure cryogenic turbopump ball bearing two-phase coolant flow

    NASA Technical Reports Server (NTRS)

    Chen, Yen-Sen

    1990-01-01

    A homogeneous two-phase fluid flow model, implemented in a three-dimensional Navier-Stokes solver using computational fluid dynamics methodology is described. The application of the model to the analysis of the pump-end bearing coolant flow of the high-pressure oxygen turbopump of the Space Shuttle main engine is studied. Results indicate large boiling zones and hot spots near the ball/race contact points. The extent of the phase change of the liquid oxygen coolant flow due to the frictional and viscous heat fluxes near the contact areas has been investigated for the given inlet conditions of the coolant.

  16. Computation of Space Shuttle high-pressure cryogenic turbopump ball bearing two-phase coolant flow

    NASA Technical Reports Server (NTRS)

    Chen, Yen-Sen

    1990-01-01

    A homogeneous two-phase fluid flow model, implemented in a three-dimensional Navier-Stokes solver using computational fluid dynamics methodology is described. The application of the model to the analysis of the pump-end bearing coolant flow of the high-pressure oxygen turbopump of the Space Shuttle main engine is studied. Results indicate large boiling zones and hot spots near the ball/race contact points. The extent of the phase change of the liquid oxygen coolant flow due to the frictional and viscous heat fluxes near the contact areas has been investigated for the given inlet conditions of the coolant.

  17. Evaluation of molten lead mixing in sodium coolant by diffusion for application to PAHR. [LMFBR

    SciTech Connect

    Chawla, T.C.; Pedersen, D.R.; Leaf, G.; Minkowycz, W.J.

    1983-01-01

    In post-accident heat removal (PAHR) applications the use of a lead slab is being considered for protecting a porous bed of steel shots in ex-vessel cavity from direct impingement of molten steel or fuel upon vessel failure following a hypothetical core dissembly accident in an LMFBR. The porous bed is provided to increase coolability of the fuel debris by the sodium coolant. The objectives of the present study are (1) to determine melting rates of lead slabs of various thicknesses in contact with sodium coolant and (2) to evaluate the extent of penetration and mixing rates of molten lead into sodium coolant by molecular diffusion alone.

  18. Computational study: Reduction of iron corrosion in lead coolant of fast nuclear reactor

    SciTech Connect

    Arkundato, Artoto; Su'ud, Zaki; Abdullah, Mikrajuddin; Widayani

    2012-06-20

    In this paper we report molecular dynamics simulation results of iron (cladding) corrosion in interaction with lead coolant of fast nuclear reactor. The goal of this work is to study effect of oxygen injection to the coolant to reduce iron corrosion. By evaluating diffusion coefficients, radial distribution functions, mean-square displacement curves and observation of crystal structure of iron before and after oxygen injection, we concluded that a significant reduction of corrosion can be achieved by issuing about 2% of oxygen atoms into lead coolant.

  19. Numerical study: Iron corrosion-resistance in lead-bismuth eutectic coolant by molecular dynamics method

    SciTech Connect

    Arkundato, Artoto; Su'ud, Zaki; Abdullah, Mikrajuddin; Widayani,; Celino, Massimo

    2012-06-06

    In this present work, we report numerical results of iron (cladding) corrosion study in interaction with lead-bismuth eutectic coolant of advanced nuclear reactors. The goal of this work is to study how the oxygen can be used to reduce the corrosion rate of cladding. The molecular dynamics method was applied to simulate corrosion process. By evaluating the diffusion coefficients, RDF functions, MSD curves of the iron and also observed the crystal structure of iron before and after oxygen injection to the coolant then we concluded that a significant and effective reduction can be achieved by issuing about 2% number of oxygen atoms to lead-bismuth eutectic coolant.

  20. Thermionic converter temperature controller

    DOEpatents

    Shaner, Benjamin J.; Wolf, Joseph H.; Johnson, Robert G. R.

    2001-04-24

    A method and apparatus for controlling the temperature of a thermionic reactor over a wide range of operating power, including a thermionic reactor having a plurality of integral cesium reservoirs, a honeycomb material disposed about the reactor which has a plurality of separated cavities, a solid sheath disposed about the honeycomb material and having an opening therein communicating with the honeycomb material and cavities thereof, and a shell disposed about the sheath for creating a coolant annulus therewith so that the coolant in the annulus may fill the cavities and permit nucleate boiling during the operation of the reactor.

  1. Thermionic Converter Temperature Controller

    SciTech Connect

    Shaner,B. J.; Wolf, Joseph H.; Johnson, Robert G. R.

    1999-08-23

    A method and apparatus for controlling the temperature of a thermionic reactor over a wide range of operating power, including a thermionic reactor having a plurality of integral cesium reservoirs, a honeycomb material disposed about the reactor which has a plurality of separated cavities, a solid sheath disposed about the honeycomb material and having an opening therein communicating with the honeycomb material and cavities thereof, and a shell disposed about the sheath for creating a coolant annulus therewith so that the coolant in the annulus may fill the cavities and permit nucleate boiling during the operation of the reactor.

  2. Cracked shaft detection on large vertical nuclear reactor coolant pump

    NASA Technical Reports Server (NTRS)

    Jenkins, L. S.

    1985-01-01

    Due to difficulty and radiation exposure associated with examination of the internals of large commercial nuclear reactor coolant pumps, it is necessary to be able to diagnose the cause of an excessive vibration problem quickly without resorting to extensive trial and error efforts. Consequently, it is necessary to make maximum use of all available data to develop a consistent theory which locates the problem area in the machine. This type of approach was taken at Three Mile Island, Unit #1, in February 1984 to identify and locate the cause of a continuously climbing vibration level of the pump shaft. The data gathered necessitated some in-depth knowledge of the pump internals to provide proper interpretation and avoid misleading conclusions. Therefore, the raw data included more than just the vibration characteristics. Pertinent details of the data gathered is shown and is necessary and sufficient to show that the cause of the observed vibration problem could logically only be a cracked pump shaft in the shaft overhang below the pump bearing.

  3. Reliable reactor coolant pump seal performance - the station's role

    SciTech Connect

    Pothier, N.E.; Metcalfe, R.

    1989-01-01

    During the early days of the Canada deuterium uranium (CANDU) power reactor program, operators and designers learned that close attention to reactor coolant pump (RCP) seals was imperative for achieving high-capacity factors. This lesson was driven home by unpredictable and frequent seal failures in the following early CANDU plants. Those seal failures caused forced outages, maintenance/dose burdens, and heavy-water losses. Because then-available industrial seal technology proved inadequate in providing satisfactory fixes, Atomic Energy of Canada Limited (AECL) began a major effort to understand seal performance, develop improved designs, and evolve the station technology needed to attain the RCP seal reliable lifetime requirement of 4 yr. The payback has been huge: Fixes have been successfully implemented and excellent performance is now being achieved with AECL improved RCP seals. In this paper, the CANDU RCP seal experience, the methodology (with emphasis on the station's role) for attaining reliable long RCP seal life, and the adaptability of this technology to US light water reactors (LWRs) are discussed.

  4. Cohnella lubricantis sp. nov., isolated from a coolant lubricant solution.

    PubMed

    Kämpfer, Peter; Glaeser, Stefanie P; Busse, Hans-Jürgen

    2017-02-01

    A Gram-stain-positive, aerobic, non-endospore-forming organism, isolated from a coolant lubricant solution was studied for its taxonomic position. On the basis of 16S rRNA gene sequence similarity comparisons, strain KSS-154-50T was grouped into the genus Cohnella, most closely related to Cohnella formosensisCC-ALFALFA-35T (97.3 % 16S rRNA gene sequence similarity), Cohnella rhizosphaerae CSE-5610T (97.1 %) and Cohnella nanjingensis D45T (97.0 %); the 16S rRNA gene sequence similarity to other species of the genus Cohnella was <97.0 %. The fatty acid profile from whole cell hydrolysates was very similar to those reported for other species of the genus Cohnella and supported the allocation to the genus Cohnella. In the fatty acid profiles, iso- and anteiso-branched fatty acids were found as major compounds. The quinone system consisted predominantly of menaquinone MK-7. The polar lipid profile contained the major lipids diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and an unidentified phospholipid. The major polyamine is spermidine. The results of physiological and biochemical characterization allowed in addition a phenotypic differentiation of strain KSS-154-50T from the three most closely related species. Hence, strain KSS-154-50T represents a novel species of the genus Cohnella, for which the name Cohnella lubricantis sp. nov. is proposed. The type strain is KSS-154-50T (=LMG 29763T=CCM 8707T).

  5. Temperature Regulator for Actively Cooled Structures

    NASA Technical Reports Server (NTRS)

    Blosser, Max (Inventor); Kelly, H. Neale (Inventor)

    1995-01-01

    In active cooling of a structure it is beneficial to use a plurality of passages for conducting coolant to various portions of the structure. Since most structures do not undergo isotropic thermal loads it is desirable to allow for variation in coolant flow to each area of the structure. The present invention allows for variable flow by a variation of the area of a portion of each of the coolant passages. Shape memory alloys and bi-material springs are used to produce passages that change flow area as a function of temperature.

  6. Determination of blade-to-coolant heat-transfer coefficients on a forced-convection, water-cooled, single-stage turbine

    NASA Technical Reports Server (NTRS)

    Freche, John C; Schum, Eugene F

    1951-01-01

    Blade-to-coolant convective heat-transfer coefficients were obtained on a forced-convection water-cooled single-stage turbine over a large laminar flow range and over a portion of the transition range between laminar and turbulent flow. The convective coefficients were correlated by the general relation for forced-convection heat transfer with laminar flow. Natural-convection heat transfer was negligible for this turbine over the Grashof number range investigated. Comparison of turbine data with stationary tube data for the laminar flow of heated liquids showed good agreement. Calculated average midspan blade temperatures using theoretical gas-to-blade coefficients and blade-to-coolant coefficients from stationary-tube data resulted in close agreement with experimental data.

  7. Numerical model of the hydrodynamics of the Black Sea and the Sea of Azov with variational initialization of temperature and salinity

    NASA Astrophysics Data System (ADS)

    Zalesny, V. B.; Gusev, A. V.; Moshonkin, S. N.

    2013-11-01

    A numerical primitive-equation model of the hydrodynamics of the Black Sea and the Sea of Azov in σ-coordinates is proposed. The model has a resolution of ˜4 × 4 km in horizontal coordinates with 40-σ levels in the vertical and includes the four-dimensional variational initialization of temperature and salinity fields. A numerical initialization algorithm combines splitting methods and adjoint equations. Flow, temperature, sea level, and salinity fields driven by atmospheric forcing are calculated for the year 2008. The calculations are made in a variational initialization — prediction regime. Temperature and salinity fields are initialized at the end of each month. The optimality system includes forward and adjoint transport-diffusion equations for heat and salt that are linearized on the assimilation interval. Results of three numerical experiments with different sets of assimilated data in comparison with the prediction obtained from the forward model are discussed.

  8. Concerning advantages in using 208Pb as such a FR coolant

    NASA Astrophysics Data System (ADS)

    Khorasanov, G.; Zemskov, E.; Blokhin, A.

    2017-01-01

    In the paper cores of two fast reactors with heavy liquid metal coolant are considered. The first object, RBETS-M, is a project of a medium power, 900 MW, reactor cooled with lead-bismuth. The second object, BRUTS, is a project of an ultra-small power, 0.5 MW, reactor cooled with lead. The results of replacement of their standard coolants with the lead coolant enriched up to 100% with 208Pb are presented. In the RBETS-M core having a large coolant volume share this replacement results in sufficient increasing the share of 238U involved in the fission process and respective decreasing the share of 239Pu and 241Pu burning.

  9. Sodium coolant purification systems for a nuclear power station equipped with a BN-1200 reactor

    NASA Astrophysics Data System (ADS)

    Alekseev, V. V.; Kovalev, Yu. P.; Kalyakin, S. G.; Kozlov, F. A.; Kumaev, V. Ya.; Kondrat'ev, A. S.; Matyukhin, V. V.; Pirogov, E. P.; Sergeev, G. P.; Sorokin, A. P.; Torbenkova, I. Yu.

    2013-05-01

    Both traditional coolant purification methods (by means of traps and sorbents for removing cesium), the use of which supported successful operation of nuclear power installations equipped with fast-neutron reactors with a sodium coolant, and the possibility of removing oxygen from sodium through the use of hot traps are analyzed in substantiating the purification system for a nuclear power station equipped with a BN-1200 reactor. It is shown that a cold trap built into the reactor vessel must be a mandatory component of the reactor plant primary coolant circuit's purification system. The use of hot traps allows oxygen to be removed from the sodium coolant down to permissible concentrations when the nuclear power station operates in its rated mode. The main lines of works aimed at improving the performance characteristics of cold traps are suggested based on the results of performed investigations.

  10. PBF (PER620) interior, basement level. Detail of coolant piping. Date: ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    PBF (PER-620) interior, basement level. Detail of coolant piping. Date: May 2004. INEEL negative no. HD-41-5-2 - Idaho National Engineering Laboratory, SPERT-I & Power Burst Facility Area, Scoville, Butte County, ID

  11. The experience in handling of lead-bismuth coolant contaminated by Polonium-210

    SciTech Connect

    Pankratov, D.V.; Gromov, B.F.; Solodjankin, M.A.

    1993-12-31

    During exploitation of lead-bismuth cooled reactors a wide experience in handling of radioactive coolant containing polonium has been gained. By 1990 total time of this reactor operation has reached approximately 60 reactor years.

  12. Thermal transfer structures coupling electronics card(s) to coolant-cooled structure(s)

    DOEpatents

    David, Milnes P; Graybill, David P; Iyengar, Madhusudan K; Kamath, Vinod; Kochuparambil, Bejoy J; Parida, Pritish R; Schmidt, Roger R

    2014-12-16

    Cooling apparatuses and coolant-cooled electronic systems are provided which include thermal transfer structures configured to engage with a spring force one or more electronics cards with docking of the electronics card(s) within a respective socket(s) of the electronic system. A thermal transfer structure of the cooling apparatus includes a thermal spreader having a first thermal conduction surface, and a thermally conductive spring assembly coupled to the conduction surface of the thermal spreader and positioned and configured to reside between and physically couple a first surface of an electronics card to the first surface of the thermal spreader with docking of the electronics card within a socket of the electronic system. The thermal transfer structure is, in one embodiment, metallurgically bonded to a coolant-cooled structure and facilitates transfer of heat from the electronics card to coolant flowing through the coolant-cooled structure.

  13. 120. COOLANT LINES TO SIS HEAT EXCHANGER No.1 IN AUXILIARY ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    120. COOLANT LINES TO SIS HEAT EXCHANGER No.1 IN AUXILIARY CHAMBER, NOVEMBER 1, 1976 - Shippingport Atomic Power Station, On Ohio River, 25 miles Northwest of Pittsburgh, Shippingport, Beaver County, PA

  14. Design, analysis, and initial testing of a fiber-optic shear gage for three-dimensional, high-temperature flows

    NASA Astrophysics Data System (ADS)

    Orr, Matthew W.

    This investigation concerns the design, analysis, and initial testing of a new, two-component wall shear gage for 3D, high-temperature flows. This gage is a direct-measuring, non-nulling design with a round head surrounded by a small gap. Two flexure wheels are used to allow small motions of the floating head. Fiber-optic displacement sensors measure how far the polished faces of counterweights on the wheels move in relation to a fixed housing as the primary measurement system. No viscous damping was required. The gage has both fiber-optic instrumentation and strain gages mounted on the flexures for validation of the newer fiber optics. The sensor is constructed of Haynes RTM 230RTM, a high-temperature nickel alloy. The gage housing is made of 316 stainless steel. All components of the gage in pure fiber-optic form can survive to a temperature of 1073 K. The bonding methods of the backup strain gages limit their maximum temperature to 473 K. The dynamic range of the gage is from 0--500 Pa (0--10g) and higher shears can be measured by changing the floating head size. Extensive use of finite element modeling was critical to the design and analysis of the gage. Static structural, modal, and thermal analyses were performed on the flexures using the ANSYS finite element package. Static finite element analysis predicted the response of the flexures to a given load, and static calibrations using a direct force method confirmed these results. Finite element modal analysis results were within 16.4% for the first mode and within 30% for the second mode when compared with the experimentally determined modes. Vibration characteristics of the gage were determined from experimental free vibration data after the gage was subjected to an impulse. Uncertainties in the finished geometry make this level of error acceptable. A transient thermal analysis examined the effects of a very high heat flux on the exposed head of the gage. The 100,000 W/m2 heat flux used in this analysis is

  15. Loss-of-coolant accident analyses of the Advanced Neutron Source Reactor

    SciTech Connect

    Chen, N.C.J.; Yoder, G.L. ); Wendel, M.W. )

    1991-01-01

    Currently in the conceptual design stage, the Advanced Neutron Source Reactor (ANSR) will operate at a high heat flux, a high mass flux, an a high degree of coolant subcooling. Loss-of-coolant accident (LOCA) analyses using RELAP5 have been performed as part of an early evaluation of ANSR safety issues. This paper discusses the RELAP5 ANSR conceptual design system model and preliminary LOCA simulation results. Some previous studies were conducted for the preconceptual design. 12 refs., 7 figs.

  16. Power Module Cooling for Future Electric Vehicle Applications: A Coolant Comparison of Oil and PGW

    DTIC Science & Technology

    2006-11-01

    POWER MODULE COOLING FOR FUTURE ELECTRIC VEHICLE APPLICATIONS: A COOLANT COMPARISON OF OIL AND PGW T. E. Salem U. S. Naval Academy 105...and efficient power converters are being developed to support the needs of future ground vehicle systems. This progress is being driven by...2006 2. REPORT TYPE N/A 3. DATES COVERED - 4. TITLE AND SUBTITLE Power Module Cooling For Future Electric Vehicle Applications: A Coolant

  17. Analysis of an AP600 intermediate-size loss-of-coolant accident

    SciTech Connect

    Boyack, B.E.; Lime, J.F.

    1995-09-01

    A postulated double-ended guillotine break of an AP600 direct-vessel-injection line has been analyzed. This event is characterized as an intermediate-break loss-of-coolant accident. Most of the insights regarding the response of the AP600 safety systems to the postulated accident are derived from calculations preformed with the TRAC-PF1/MOD2 code. However, complementary insights derived from a scaled experiment conducted in the ROSA facility, as well as insights based upon calculations by other codes, are also presented. Based upon the calculated and experimental results, the AP600 will not experience a core heat up and will reach a safe shutdown state using only safety-class equipment. Only the early part of the long-term cooling period initiated by In-containment Refueling Water Storage Tank injection was evaluated. Thus, the observation that the core is continuously cooled should be verified for the later phase of the long-term cooling period when sump injection and containment cooling processes are important.

  18. Impact of the propylene glycol-water-borax coolant on material recovery operations

    SciTech Connect

    Duerksen, W.K.; Taylor, P.A.

    1983-05-01

    The reaction of the propylene glycol-water-borax coolant with nitric acid has now been studied in some detail. This document is intended to provide a summary of the results. Findings are summarized under nine headings. Tests have also been conducted to determine if the new coolant would have any adverse effects on the uranium recycle systems. Experiments were scientifically designed after observation of the production operations so that accurate response to the immediate production concerns could be provided. Conclusions from these studies are: formation of glycol nitrates is very improbable; the reaction of concentrated (70%) nitric acid with pure propylene glycol is very violent and hazardous; dilution of the nitric acid-glycol mixture causes a drastic decrease in the rate and intensity of the reaction; the mechanism of the nitric acid propylene glycol reaction is autocatalytic in nitrous acid; no reaction is observed between coolant and 30% nitric acid unless the solution is heated; the coolant reacts fairly vigorously with 55% nitric acid after a concentration-dependent induction time; experiments showed that the dissolution of uranium chips that had been soaked in coolant proceeded at about the same rate as if the chips had not previously contacted glycol; thermodynamic calculations show that the enthalpy change (heat liberated) by the reaction of nitric acid (30%) with propylene glycol is smaller than if the same amount of nitric acid reacted with uranium. Each of these conclusions is briefly discussed. The effect of new coolant on uranium recycle operations is then briefly discussed.

  19. ISS Internal Active Thermal Control System (IATCS) Coolant Remediation Project -2006 Update

    NASA Technical Reports Server (NTRS)

    Morrison, Russell H.; Holt, Mike

    2006-01-01

    The IATCS coolant has experienced a number of anomalies in the time since the US Lab was first activated on Flight 5A in February 2001. These have included: 1) a decrease in coolant pH, 2) increases in inorganic carbon, 3) a reduction in phosphate concentration, 4) an increase in dissolved nickel and precipitation of nickel salts, and 5) increases in microbial concentration. These anomalies represent some risk to the system, have been implicated in some hardware failures and are suspect in others. The ISS program has conducted extensive investigations of the causes and effects of these anomalies and has developed a comprehensive program to remediate the coolant chemistry of the on-orbit system as well as provide a robust and compatible coolant solution for the hardware yet to be delivered. This paper presents a status of the coolant stability over the past year as well as results from destructive analyses of hardware removed from the on-orbit system and the current approach to coolant remediation.

  20. Detailed heat transfer coefficient distributions under an array of impinging jets with coolant extraction

    SciTech Connect

    Huang, Y.; Ekkad, S.V.; Han, J.C.

    1996-12-31

    Jet impingement cooling is a high performance technique for heat transfer enhancement. Local heat transfer distributions are presented for an array of jets impinging on a target plate with a series of coolant extraction holes. The flow enters the pressure channel, impinges on the target plate and exits toward the sides and through the coolant extraction holes. The impingement plate has four rows of 12 jet holes and the target plate has three rows of 11 coolant extraction holes. The jet holes and the coolant extraction holes have the same diameters and are staggered such that the air impinging from the jet hole does not exit directly through the extraction hole. The detailed heat transfer coefficient distributions are measured using a transient technique and liquid crystal coating. Results are presented for a range of jet Reynolds numbers between 4,000 and 20,000. The effect of crossflow is also studied by changing the exit opening of the impingement channel to provide three different spent air exit directions. Heat transfer results for the target plate with coolant extraction are compared with those without coolant extraction at the same flow conditions.