Science.gov

Sample records for added heat load

  1. High heat load synchrotron optics

    SciTech Connect

    Mills, D.M.

    1992-08-01

    Third generation synchrotron radiation sources currently being constructed worldwide will produce x-ray beams of unparalleled power and power density these high heat fluxes coupled with the stringent dimensional requirements of the x-ray optical components pose a prodigious challenge to designers of x-ray optical elements, specifically x-ray mirrors and crystal monochromators. Although certain established techniques for the cooling of high heat flux components can be directly applied to this problem, the thermal management of high heat load x-ray optical components has several unusual aspects that may ultimately lead to unique solutions. This manuscript attempts to summarize the various approaches currently being applied to this undertaking and to point out the areas of research that require further development.

  2. APS high heat load monochromator

    SciTech Connect

    Lee, W.K.; Mills, D.

    1993-02-01

    This document contains the design specifications of the APS high heat load (HHL) monochromator and associated accessories as of February 1993. It should be noted that work is continuing on many parts of the monochromator including the mechanical design, crystal cooling designs, etc. Where appropriate, we have tried to add supporting documentation, references to published papers, and calculations from which we based our decisions. The underlying philosophy behind performance specifications of this monochromator was to fabricate a device that would be useful to as many APS users as possible, that is, the design should be as generic as possible. In other words, we believe that this design will be capable of operating on both bending magnet and ID beamlines (with the appropriate changes to the cooling and crystals) with both flat and inclined crystal geometries and with a variety of coolants. It was strongly felt that this monochromator should have good energy scanning capabilities over the classical energy range of about 4 to 20 keywith Si (111) crystals. For this reason, a design incorporating one rotation stage to drive both the first and second crystals was considered most promising. Separate rotary stages for the first and second crystals can sometimes provide more flexibility in their capacities to carry heavy loads (for heavily cooled first crystals or sagittal benders of second crystals), but their tuning capabilities were considered inferior to the single axis approach.

  3. Positive-ion injector cryogenic heat load

    SciTech Connect

    Zinkann, G.P.; Specht, J.R.; Kedzie, M.; Wiemerslage, G.

    1995-08-01

    A project to improve the temperature profile of the nitrogen heat shield on the PII linac cryostats began. The goal of the project is to reduce the liquid nitrogen consumption and the quiescent cryostat heat load to the helium refrigeration system. In March 1994 additional heat shield components were installed in one PII cryostat. A significant improvement in the quiescent helium system heat load of approximately 10 watts was observed and some improvement in liquid nitrogen consumption was also noted. We plan to extend these improvements to the remaining two cryostats in the next year as access time can be scheduled.

  4. Heat Load Estimator for Smoothing Pulsed Heat Loads on Supercritical Helium Loops

    NASA Astrophysics Data System (ADS)

    Hoa, C.; Lagier, B.; Rousset, B.; Bonnay, P.; Michel, F.

    Superconducting magnets for fusion are subjected to large variations of heat loads due to cycling operation of tokamaks. The cryogenic system shall operate smoothly to extract the pulsed heat loads by circulating supercritical helium into the coils and structures. However the value of the total heat loads and its temporal variation are not known before the plasma scenario starts. A real-time heat load estimator is of interest for the process control of the cryogenic system in order to anticipate the arrival of pulsed heat loads to the refrigerator and finally to optimize the operation of the cryogenic system. The large variation of the thermal loads affects the physical parameters of the supercritical helium loop (pressure, temperature, mass flow) so those signals can be used for calculating instantaneously the loads deposited into the loop. The methodology and algorithm are addressed in the article for estimating the heat load deposition before it reaches the refrigerator. The CEA patented process control has been implemented in a Programmable Logic Controller (PLC) and has been successfully validated on the HELIOS test facility at CEA Grenoble. This heat load estimator is complementary to pulsed load smoothing strategies providing an estimation of the optimized refrigeration power. It can also effectively improve the process control during the transient between different operating modes by adjusting the refrigeration power to the need. This way, the heat load estimator participates to the safe operation of the cryogenic system.

  5. Heat-load simulator for heat sink design

    NASA Technical Reports Server (NTRS)

    Dunleavy, A. M.; Vaughn, T. J.

    1968-01-01

    Heat-load simulator is fabricated from 1/4-inch aluminum plate with a contact surface equal in dimensions and configuration to those of the electronic installation. The method controls thermal output to simulate actual electronic component thermal output.

  6. Residential Variable-Capacity Heat Pumps Sized to Heating Loads

    SciTech Connect

    Munk, Jeffrey D.; Jackson, Roderick K.; Odukomaiya, Adewale; Gehl, Anthony C.

    2014-01-01

    Variable capacity heat pumps are an emerging technology offering significant energy savings potential and improved efficiency. With conventional single-speed systems, it is important to appropriately size heat pumps for the cooling load as over-sizing would result in cycling and insufficient latent capacity required for humidity control. These appropriately sized systems are often under-sized for the heating load and require inefficient supplemental electric resistance heat to meet the heating demand. Variable capacity heat pumps address these shortcomings by providing an opportunity to intentionally size systems for the dominant heating season load without adverse effects of cycling or insufficient dehumidification in the cooling season. This intentionally-sized system could result in significant energy savings in the heating season, as the need for inefficient supplemental electric resistance heat is drastically reduced. This is a continuation of a study evaluating the energy consumption of variable capacity heat pumps installed in two unoccupied research homes in Farragut, a suburb of Knoxville, Tennessee. In this particular study, space conditioning systems are intentionally sized for the heating season loads to provide an opportunity to understand and evaluate the impact this would have on electric resistance heat use and dehumidification. The results and conclusions drawn through this research are valid and specific for portions of the Southeastern and Midwestern United States falling in the mixed-humid climate zone. While other regions in the U.S. do not experience this type of climate, this work provides a basis for, and can help understand the implications of other climate zones on residential space conditioning energy consumption. The data presented here will provide a framework for fine tuning residential building EnergyPlus models that are being developed.

  7. Load-aware Flooding for Streaming over Ad Hoc Networks

    NASA Astrophysics Data System (ADS)

    Utsu, Keisuke; Ishii, Hiroshi

    This paper discusses the streaming of high rate media such as video or audio information over ad hoc networks in disaster situations or for temporary events when it is difficult to use fixed infrastructure. The conventional simple flooding is not applicable for this application because it generates a large number of redundant rebroadcast and heavy traffic load to the network. To restrain redundant rebroadcast messages, several methods have been proposed. But since those studies do not take into account the actual load condition at each node that will affect network efficiency, they cannot achieve both ensuring the high message reachability and reducing redundant rebroadcast. In this paper, we propose two novel load-aware flooding methods using the MAC transmission queue information at each node to make the decision about whether rebroadcast messages should be sent or not. Through network simulations, we evaluate and show the effectiveness of our proposals. The result shows that our proposals achieve both ensuring high message reachability and restraint of redundant rebroadcast comparing with existing methods.

  8. Indirect solar loading of waste heat radiators

    SciTech Connect

    Kirkpatrick, R.C.; Tabor, J.E.; Lindman, E.L.; Cooper, A.J.

    1988-01-01

    Waste heat from space based power systems must ultimately be radiated away into space. The local topology around the radiators must be considered from two stand-points: the scattering of sunlight onto the surfaces of the radiator and the heat load that the radiator may put on near-by components of the system. A view factor code (SNAP) developed at Los Alamos allows the computation of the steady-state radiation environment for complex 3-D geometries. An example of the code's utility is given. 4 refs., 2 figs., 1 tab.

  9. Added effect of heat wave on mortality in Seoul, Korea

    NASA Astrophysics Data System (ADS)

    Lee, Won Kyung; Lee, Hye Ah; Lim, Youn Hee; Park, Hyesook

    2016-05-01

    A heat wave could increase mortality owing to high temperature. However, little is known about the added (duration) effect of heat wave from the prolonged period of high temperature on mortality and different effect sizes depending on the definition of heat waves and models. A distributed lag non-linear model with a quasi-Poisson distribution was used to evaluate the added effect of heat wave on mortality after adjusting for long-term and intra-seasonal trends and apparent temperature. We evaluated the cumulative relative risk of the added wave effect on mortality on lag days 0-30. The models were constructed using nine definitions of heat wave and two relationships (cubic spline and linear threshold model) between temperature and mortality to leave out the high temperature effect. Further, we performed sensitivity analysis to evaluate the changes in the effect of heat wave on mortality according to the different degrees of freedom for time trend and cubic spline of temperature. We found that heat wave had the added effect from the prolonged period of high temperature on mortality and it was considerable in the aspect of cumulative risk because of the lagged influence. When heat wave was defined with a threshold of 98th percentile temperature and ≥2, 3, and 4 consecutive days, mortality increased by 14.8 % (7.5-22.6, 95 % confidence interval (CI)), 18.1 % (10.8-26.0, 95 % CI), 18.1 % (10.7-25.9, 95 % CI), respectively, in cubic spline model. When it came to the definitions of 90th and 95th percentile, the risk increase in mortality declined to 3.7-5.8 % and 8.6-11.3 %, respectively. This effect was robust to the flexibility of the model for temperature and time trend, while the definitions of a heat wave were critical in estimating its relationship with mortality. This finding could help deepen our understanding and quantifying of the relationship between heat wave and mortality and select an appropriate definition of heat wave and temperature model in the future

  10. Added effect of heat wave on mortality in Seoul, Korea.

    PubMed

    Lee, Won Kyung; Lee, Hye Ah; Lim, Youn Hee; Park, Hyesook

    2016-05-01

    A heat wave could increase mortality owing to high temperature. However, little is known about the added (duration) effect of heat wave from the prolonged period of high temperature on mortality and different effect sizes depending on the definition of heat waves and models. A distributed lag non-linear model with a quasi-Poisson distribution was used to evaluate the added effect of heat wave on mortality after adjusting for long-term and intra-seasonal trends and apparent temperature. We evaluated the cumulative relative risk of the added wave effect on mortality on lag days 0-30. The models were constructed using nine definitions of heat wave and two relationships (cubic spline and linear threshold model) between temperature and mortality to leave out the high temperature effect. Further, we performed sensitivity analysis to evaluate the changes in the effect of heat wave on mortality according to the different degrees of freedom for time trend and cubic spline of temperature. We found that heat wave had the added effect from the prolonged period of high temperature on mortality and it was considerable in the aspect of cumulative risk because of the lagged influence. When heat wave was defined with a threshold of 98th percentile temperature and ≥2, 3, and 4 consecutive days, mortality increased by 14.8 % (7.5-22.6, 95 % confidence interval (CI)), 18.1 % (10.8-26.0, 95 % CI), 18.1 % (10.7-25.9, 95 % CI), respectively, in cubic spline model. When it came to the definitions of 90th and 95th percentile, the risk increase in mortality declined to 3.7-5.8 % and 8.6-11.3 %, respectively. This effect was robust to the flexibility of the model for temperature and time trend, while the definitions of a heat wave were critical in estimating its relationship with mortality. This finding could help deepen our understanding and quantifying of the relationship between heat wave and mortality and select an appropriate definition of heat wave and temperature model in the future

  11. Analyzing Design Heating Loads in Superinsulated Buildings

    SciTech Connect

    Arena, Lois

    2015-06-16

    The U.S. Department of Energy’s Building America research team Consortium for Advanced Residential Buildings (CARB) worked with the EcoVillage cohousing community in Ithaca, New York, on the Third Residential EcoVillage Experience neighborhood. This communityscale project consists of 40 housing units—15 apartments and 25 single-family residences. Units range in size from 450 ft2 to 1,664 ft2 and cost from $80,000 for a studio apartment to $235,000 for a three- or four-bedroom single-family home. For the research component of this project, CARB analyzed current heating system sizing methods for superinsulated homes in cold climates to determine if changes in building load calculation methodology should be recommended. Actual heating energy use was monitored and compared to results from the Air Conditioning Contractors of America’s Manual J8 (MJ8) and the Passive House Planning Package software. Results from that research indicate that MJ8 significantly oversizes heating systems for superinsulated homes and that thermal inertia and internal gains should be considered for more accurate load calculations.

  12. Analytical Study on Multi-stream Heat Exchanger Include Longitudinal Heat Conduction and Parasitic Heat Loads

    NASA Astrophysics Data System (ADS)

    Zhu, Weiping; Xie, Xiujuan; Yang, Huihui; Li, Laifeng; Gong, Linghui

    High performance heat exchangers are critical component in many cryogenic systems and its performance is typically very sensitive to longitudinal heat conduction, parasitic heat loads and property variations. This paper gives an analytical study on 1-D model for multi-stream parallel-plate fin heat exchanger by using the method of decoupling transformations. The results obtained in the present paper are valuable for the reference on optimization for heat exchanger design.

  13. Analyzing Design Heating Loads in Superinsulated Buildings

    SciTech Connect

    Arena, Lois

    2015-06-01

    Super-insulated homes offer many benefits including improved comfort, reduced exterior noise penetration, lower energy bills, and the ability to withstand power and fuel outages under much more comfortable conditions than a typical home. While these homes aren't necessarily constructed with excessive mass in the form of concrete floors and walls, the amount of insulation and the increase in the thickness of the building envelope can lead to a mass effect, resulting in the structures ability to store much more heat than a code built home. This results in a very low thermal inertia making the building much less sensitive to drastic temperature swings thereby decreasing the peak heating load demand. During the winter of 2013/2014, CARB monitored the energy use of three homes in climate zone 6 in an attempt to evaluate the accuracy of two different mechanical system sizing methods for low load homes. Based on the results, it is recommended that internal and solar gains be included and some credit for thermal inertia be used in sizing calculations for super insulated homes.

  14. Heat kernels on cone of AdS2 and k-wound circular Wilson loop in AdS5 × S5 superstring

    NASA Astrophysics Data System (ADS)

    Bergamin, R.; Tseytlin, A. A.

    2016-04-01

    We compute the one-loop world-sheet correction to partition function of {{AdS}}5× {{{S}}}5 superstring that should be representing k-fundamental circular Wilson loop in planar limit. The 2d metric of the minimal surface ending on k-wound circle at the boundary is that of a cone of AdS2 with deficit 2π (1-k). We compute the determinants of 2d fluctuation operators by first constructing heat kernels of scalar and spinor Laplacians on the cone using the Sommerfeld formula. The final expression for the k-dependent part of the one-loop correction has simple integral representation but is different from earlier results.

  15. Spallation neutron source cryomodule heat loads and thermal design

    SciTech Connect

    E. F. Daly; V. Ganni; C. H. Rode; W. J. Schneider; K. M. Wilson; M. A. Wiseman

    2002-05-10

    When complete, the Spallation Neutron Source (SNS) will provide a 1 GeV, 2 MW beam for experiments. One portion of the machine's linac consists of over 80 Superconducting Radio Frequency (SRF) 805 MHz cavities housed in a minimum of 23 cryomodules operating at a saturation temperature of 2.1 K. Minimization of the total heat load is critical to machine performance and for efficient operation of the system. The total heat load of the cryomodules consists of the fixed static load and the dynamic load, which is proportional to the cavity performance. The helium refrigerator supports mainly the cryomodule loads and to a lesser extent the distribution system loads. The estimated heat loads and calculated thermal performance are discussed along with two unique features of this design: the helium heat exchanger housed in the cryomodule return end can and the helium gas cooled fundamental power coupler.

  16. D0 Solenoid Upgrade Project: Heat Load Calculations for the Solenoid Chimney

    SciTech Connect

    Rucinski, R.; /Fermilab

    1993-05-26

    This engineering note documents the calculations done to determine the chimney heat loads. These heat load numbers were reported in the D0 solenoid upgrade design report. The heat loads to the LN2 circuit were done by Andrew Stefanik, RDIMechanical Systems group. They were part of his LN2 shield calculations dated 2/23/93. Pages 1 thru 3 of his calculations that apply to the chimney are attached. The heat loads to the LHe circuit were done originally on 12/16/92 and then revised on 12/23/92 to be more conservative. The raw calculations are attached. I include both the original 12/16 version and the 12/23 revised version to document the amount of conservativeness added.

  17. Heat loading limits for solid transuranic wastes storage

    SciTech Connect

    Spatz, T.L.

    1993-07-01

    Heat loading limits have been established for four storage configurations of TRU wastes. The calculations were performed assuming the worst case scenario whereby all the heat generated within a drum was generated within one ``cut`` and that this cut was located in the very center of the drum. Poly-boxes containing one HEPA filter were assumed to have a uniform heat generation throughout the filter. The maximum allowable temperatures were based on the materials in the containers. A comparison between the drum center temperature for a uniform heat load distribution and for the center temperature when the heat load is confined to one cut in the center of the drum is also illustrated. This comparison showed that the heat load of a particular drum can be more than doubled by distributing the sources of heat uniformly throughout the container.

  18. AdS flowing black funnels: Stationary AdS black holes with non-Killing horizons and heat transport in the dual CFT

    NASA Astrophysics Data System (ADS)

    Fischetti, Sebastian; Marolf, Donald; Santos, Jorge

    2013-04-01

    We construct stationary non-equilibrium black funnels locally asymptotic to global AdS4 in vacuum Einstein-Hilbert gravity with negative cosmological constant. These are non-compactly-generated black holes in which a single connected bulk horizon extends to meet the conformal boundary. Thus the induced (conformal) boundary metric has smooth horizons as well. In our examples, the boundary spacetime contains a pair of black holes connected through the bulk by a tubular bulk horizon. Taking one boundary black hole to be hotter than the other (δT !=0) prohibits equilibrium. The result is a so-called flowing funnel, a stationary bulk black hole with a non-Killing horizon that may be said to transport heat toward the cooler boundary black hole. While most of our results are numerical, a semi-analytic fluid/gravity description can be obtained by passing to a one-parameter generalization of the above boundary conditions. In the fluid regime, we find excellent agreement with our numerical solutions. In terms of a dual CFT, our solutions describe heat transport via a large N version of Hawking radiation through a deconfined plasma that couples efficiently to both boundary black holes.

  19. Increased levels of FFA during passive heat loading after a 2-week repeated heat load in Koreans

    NASA Astrophysics Data System (ADS)

    Lee, Jeong Beom; Kim, Tae Wook

    2015-04-01

    The purpose of this study was to determine whether repeated heat load is closely related to circulating levels of free fatty acids (FFA) during repeated passive heat loading (PHL), defined as immersion of the lower body up to an umbilical level in hot water, 42 ± 0.5 °C (three times/week, 30 min/day) for 2 weeks. There were significant correlations between mean body temperature and FFA before and after repeated heat load ( p < 0.001, respectively), and the level of FFA was significantly higher after repeated heat load during PHL ( p < 0.01). The threshold of mean body temperature for lipolysis was lowered by repeated heat load and enhanced lipolysis during PHL. However, caution is needed for diabetic individuals.

  20. Improved Program For Calculation Of Heat-Load Multiplier

    NASA Technical Reports Server (NTRS)

    D'Valentine, Mark

    1995-01-01

    PRM1940 computer program computes heat-load multiplier for use in Power Balance Model (PBM) computer program which calculates hundreds of operating parameters of main engine of space shuttle from relatively few measurement data. PRM1940 is stand-alone program which incorporates only those PBM calculations necessary to compute heat-load multiplier. Developed to accelerate and partly automate calculation of heat-load multiplier. Although programs specific to space shuttle application, also of interest to engineers concerned with monitoring of conditions in turbines, chemical-processing plants, and other high-temperature flow machinery.

  1. Using a cold radiometer to measure heat loads and survey heat leaks

    SciTech Connect

    DiPirro, M.; Tuttle, J.; Hait, T.; Shirron, P.

    2014-01-29

    We have developed an inexpensive cold radiometer for use in thermal/vacuum chambers to measure heat loads, characterize emissivity and specularity of surfaces and to survey areas to evaluate stray heat loads. We report here the results of two such tests for the James Webb Space Telescope to measure heat loads and effective emissivities of 2 major pieces of optical ground support equipment that will be used in upcoming thermal vacuum testing of the Telescope.

  2. Using a Cold Radiometer to Measure Heat Loads and Survey Heat Leaks

    NASA Technical Reports Server (NTRS)

    DiPirro, M.; Tuttle, J.; Hait, T.; Shirron, P.

    2013-01-01

    We have developed an inexpensive cold radiometer for use in thermal/vacuum chambers to measure heat loads, characterize emissivity and specularity of surfaces and to survey areas to evaluate stray heat loads. We report here the results of two such tests for the James Webb Space Telescope to measure heat loads and effective emissivities of2 major pieces of optical ground support equipment that will be used in upcoming thermal vacuum testing of the Telescope.

  3. Using a Cold Radiometer to Measure Heat Loads and Survey Heat Leaks

    NASA Technical Reports Server (NTRS)

    Dipirro, M.; Tuttle, J.; Hait, T.; Shirron, P.

    2014-01-01

    We have developed an inexpensive cold radiometer for use in thermal/vacuum chambers to measure heat loads, characterize emissivity and specularity of surfaces and to survey areas to evaluate stray heat loads. We report here the results of two such tests for the James Webb Space Telescope to measure heat loads and effective emissivities of 2 major pieces of optical ground support equipment that will be used in upcoming thermal vacuum testing of the Telescope.

  4. AdS flowing black funnels: stationary AdS black holes with non-Killing horizons and heat transport in the dual CFT

    NASA Astrophysics Data System (ADS)

    Fischetti, Sebastian; Marolf, Donald; Santos, Jorge E.

    2013-04-01

    We construct stationary non-equilibrium black funnels locally asymptotic to global AdS4 in vacuum Einstein-Hilbert gravity with a negative cosmological constant. These are non-compactly-generated black holes in which a single connected bulk horizon extends to meet the conformal boundary. Thus the induced (conformal) boundary metric has smooth horizons as well. In our examples, the boundary spacetime contains a pair of black holes connected through the bulk by a tubular bulk horizon. Taking one boundary black hole to be hotter than the other (ΔT ≠ 0) prohibits equilibrium. The result is a so-called flowing funnel, a stationary bulk black hole with a non-Killing horizon that may be said to transport heat toward the cooler boundary black hole. While generators of the bulk future horizon evolve toward zero expansion in the far future, they begin at finite affine parameter with infinite expansion on a singular past horizon characterized by power-law divergences with universal exponents. We explore both the horizon generators and the boundary stress tensor in detail. While most of our results are numerical, a semi-analytic fluid/gravity description can be obtained by passing to a one-parameter generalization of the above boundary conditions. The new parameter detunes the temperatures Tbulk BH and Tbndy BH of the bulk and boundary black holes, and we may then take α = {T_{bndy \\ BH}/{T_{bulk \\ BH}} and ΔT small to control the accuracy of the fluid-gravity approximation. In the small α, ΔT regime, we find excellent agreement with our numerical solutions. For our cases the agreement also remains quite good even for α ˜ 0.8. In terms of a dual CFT, our α = 1 solutions describe heat transport via a large N version of Hawking radiation through a deconfined plasma that couples efficiently to both boundary black holes.

  5. 24 CFR 3280.508 - Heat loss, heat gain and cooling load calculations.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... coefficient of heat transmission (Uo) requirement. The annual energy use determination must be based on... Thermal Protection § 3280.508 Heat loss, heat gain and cooling load calculations. (a) Information, values... heat-flow paths (“thermal shorts”) shall be explicitly accounted for in the calculation of...

  6. 24 CFR 3280.508 - Heat loss, heat gain and cooling load calculations.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... coefficient of heat transmission (Uo) requirement. The annual energy use determination must be based on... Thermal Protection § 3280.508 Heat loss, heat gain and cooling load calculations. (a) Information, values... heat-flow paths (“thermal shorts”) shall be explicitly accounted for in the calculation of...

  7. 24 CFR 3280.508 - Heat loss, heat gain and cooling load calculations.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... coefficient of heat transmission (Uo) requirement. The annual energy use determination must be based on... Thermal Protection § 3280.508 Heat loss, heat gain and cooling load calculations. (a) Information, values... heat-flow paths (“thermal shorts”) shall be explicitly accounted for in the calculation of...

  8. 24 CFR 3280.508 - Heat loss, heat gain and cooling load calculations.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... coefficient of heat transmission (Uo) requirement. The annual energy use determination must be based on... Thermal Protection § 3280.508 Heat loss, heat gain and cooling load calculations. (a) Information, values... heat-flow paths (“thermal shorts”) shall be explicitly accounted for in the calculation of...

  9. 24 CFR 3280.508 - Heat loss, heat gain and cooling load calculations.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... coefficient of heat transmission (Uo) requirement. The annual energy use determination must be based on... Thermal Protection § 3280.508 Heat loss, heat gain and cooling load calculations. (a) Information, values... heat-flow paths (“thermal shorts”) shall be explicitly accounted for in the calculation of...

  10. Strategy Guideline. Accurate Heating and Cooling Load Calculations

    SciTech Connect

    Burdick, Arlan

    2011-06-01

    This guide presents the key criteria required to create accurate heating and cooling load calculations and offers examples of the implications when inaccurate adjustments are applied to the HVAC design process. The guide shows, through realistic examples, how various defaults and arbitrary safety factors can lead to significant increases in the load estimate. Emphasis is placed on the risks incurred from inaccurate adjustments or ignoring critical inputs of the load calculation.

  11. Strategy Guideline: Accurate Heating and Cooling Load Calculations

    SciTech Connect

    Burdick, A.

    2011-06-01

    This guide presents the key criteria required to create accurate heating and cooling load calculations and offers examples of the implications when inaccurate adjustments are applied to the HVAC design process. The guide shows, through realistic examples, how various defaults and arbitrary safety factors can lead to significant increases in the load estimate. Emphasis is placed on the risks incurred from inaccurate adjustments or ignoring critical inputs of the load calculation.

  12. Residential heating and cooling loads and costs for the South

    SciTech Connect

    Lau, A. S.; Hyatt, T. D.

    1982-01-01

    This report examines typical residential heating and cooling loads for 24 southern cities and six other US cities. A 1536-square-foot house is examined, with concrete slab floor, frame construction, ventilated attic, and glazing area equivalent to 12% of the floor area. Five basic variations of this house were analyzed: two insulation levels with two compass orientations each, and a sun-tempered case. The building load calculations were based on a non-rigorous methodology typically used within the building community today. The estimated heating and cooling loads and the impact of insulation, orientation, and sun-tempering are illustrated with regional maps. Typical fuel costs and heating systems are also examined and shown to have a major role in determining whether the building design emphasis should be on heating or cooling.

  13. Space Heating Load Estimation Procedure for CHP Systems sizing

    NASA Astrophysics Data System (ADS)

    Vocale, P.; Pagliarini, G.; Rainieri, S.

    2015-11-01

    Due to its environmental and energy benefits, the Combined Heat and Power (CHP) represents certainly an important measure to improve energy efficiency of buildings. Since the energy performance of the CHP systems strongly depends on the fraction of the useful cogenerated heat (i.e. the cogenerated heat that is actually used to meet building thermal demand), in building applications of CHP, it is necessary to know the space heating and cooling loads profile to optimise the system efficiency. When the heating load profile is unknown or difficult to calculate with a sufficient accuracy, as may occur for existing buildings, it can be estimated from the cumulated energy uses by adopting the loads estimation procedure (h-LEP). With the aim to evaluate the useful fraction of the cogenerated heat for different operating conditions in terms of buildings characteristics, weather data and system capacity, the h-LEP is here implemented with a single climate variable: the hourly average dry- bulb temperature. The proposed procedure have been validated resorting to the TRNSYS simulation tool. The results, obtained by considering a building for hospital use, reveal that the useful fraction of the cogenerated heat can be estimated with an average accuracy of ± 3%, within the range of operative conditions considered in the present study.

  14. Born–Infeld AdS black holes as heat engines

    NASA Astrophysics Data System (ADS)

    Johnson, Clifford V.

    2016-07-01

    We study the efficiency of heat engines that perform mechanical work via the pdV terms present in the first law in extended gravitational thermodynamics. We use charged black holes as the working substance, for a particular choice of engine cycle. The context is Einstein gravity with negative cosmological constant and a Born–Infeld nonlinear electrodynamics sector. We compare the results for these ‘holographic’ heat engines to previous results obtained for Einstein–Maxwell black holes, and for the case where there is a Gauss–Bonnet sector.

  15. Incremental cooling load determination for passive direct gain heating systems

    SciTech Connect

    Sullivan, P.W.; Mahone, D.; Fuller, W.; Gruber, J.; Kammerud, R.; Place, W.; Andersson, B.

    1981-05-01

    This paper examines the applicability of the National Association of Home Builders (NAHB) full load compressor hour method for predicting the cooling load increase in a residence, attributable to direct gain passive heating systems. The NAHB method predictions are compared with the results of 200 hour-by-hour simulations using BLAST and the two methods show reasonable agreement. The degree of agreement and the limitations of the NAHB method are discussed.

  16. Daily simulations of urban heat load in Vienna for 2011

    NASA Astrophysics Data System (ADS)

    Hollosi, Brigitta; Zuvela-Aloise, Maja; Koch, Roland

    2014-05-01

    In this study, the dynamical urban climate model MUKLIMO3 (horizontal resolution of 100 m) is uni-directionally coupled with the operational weather forecast model ALARO-ALADIN of the ZAMG (horizontal resolution of 4.8 km) to simulate the development of the urban heat island in Vienna on a daily basis. The aim is to evaluate the performance of the urban climate model applied for climatological studies in a weather prediction mode. The focus of the investigation is on assessment of the urban heat load during day-time. We used the archived daily forecast data for the summer period in 2011 (April - October) as input data for the urban climate model. The high resolution simulations were initialized with vertical profiles of temperature and relative humidity and prevailing wind speed and direction in the rural area near the city in the early morning hours. The model output for hourly temperature and relative humidity has been evaluated against the monitoring data at 9 weather stations in the area of the city. Additionally, spatial gradients in temperature were evaluated by comparing the grid point values with the data collected during a mobile measuring campaign taken on a multi-vehicle bicycle tour on the 7th of July, 2011. The results show a good agreement with observations on a district scale. Particular challenge in the modeling approach is achieving robust and numerically stable model solutions for different weather situation. Therefore, we analyzed modeled wind patterns for different atmospheric conditions in the summer period. We found that during the calm hot days, due to the inhomogeneous surface and complex terrain, the local-scale temperature gradients can induce strong anomalies, which in turn could affect the circulation on a larger scale. However, these results could not be validated due to the lack of observations. In the following years extreme hot conditions are very likely to occur more frequently and with higher intensity. Combining urban climate

  17. Startup analysis for a high temperature gas loaded heat pipe

    NASA Technical Reports Server (NTRS)

    Sockol, P. M.

    1973-01-01

    A model for the rapid startup of a high-temperature gas-loaded heat pipe is presented. A two-dimensional diffusion analysis is used to determine the rate of energy transport by the vapor between the hot and cold zones of the pipe. The vapor transport rate is then incorporated in a simple thermal model of the startup of a radiation-cooled heat pipe. Numerical results for an argon-lithium system show that radial diffusion to the cold wall can produce large vapor flow rates during a rapid startup. The results also show that startup is not initiated until the vapor pressure p sub v in the hot zone reaches a precise value proportional to the initial gas pressure p sub i. Through proper choice of p sub i, startup can be delayed until p sub v is large enough to support a heat-transfer rate sufficient to overcome a thermal load on the heat pipe.

  18. Climatic indicators for estimating residential heating and cooling loads

    SciTech Connect

    Huang, Y.J.; Ritschard, R.; Bull, J.; Chang, L.

    1986-11-01

    An extensive data base of residential energy use generated with the DOE-2.1A simulation code provides an opportunity for correlating building loads predicted by an hourly simulation model to commonly used climatic parameters such as heating and cooling degree-days, and to newer parameters such as insolation-days and latent enthalpy-days. The identification of reliable climatic parameters for estimating cooling loads and the incremental loads for individual building components, such as changing ceiling and wall R-values, infiltration rates or window areas is emphasized.

  19. What caused terrestrial dust loading and climate downturns between 533 and 540 A.D.?

    NASA Astrophysics Data System (ADS)

    Abbott, D. H.; Breger, D. L.; Biscaye, P. E.; Barron, J. A.; Juhl, R. A.; McCafferty, P.

    2013-12-01

    Sn-rich particles, Ni-rich particles and cosmic spherules are found together at four stratigraphic levels in the GISP2 ice core between 360 and 362 meters depth. Using a previously derived calendar-year time scale, these particles span a time of increased dust loading of the Earth's atmosphere between 533 and 540 A.D. The Sn enrichments suggest a cometary source for the dust. The late spring timing of extraterrestrial input best matches the Eta Aquarid meteor shower associated with comet 1P/Halley. The increased flux of cometary dust could explain a modest climate downturn in 533 A.D. The profound global dimming during 536 and 537 A.D. cannot be explained merely by a combination of cometary dust and a modest volcanic eruption. We found tropical marine microfossils at the end 535-start 536 A.D. level that we attribute to a low-latitude explosion in the ocean. This additional source of dust is probably needed to explain the solar dimming in 536-537 A.D. In addition, we found high-latitude marine diatoms and silicoflagellates at a second time horizon, circa 538 A.D. Some of the fossils are pre-Pleistocene in age, as old as Eocene. Both of these fossil-bearing stratigraphic levels contain enrichments of nitrate and ammonium in their supernatant water.

  20. Cellular level loading and heating of superparamagnetic iron oxide nanoparticles.

    PubMed

    Kalambur, Venkat S; Longmire, Ellen K; Bischof, John C

    2007-11-20

    Superparamagnetic iron oxide nanoparticles (NPs) hold promise for a variety of biomedical applications due to their properties of visualization using magnetic resonance imaging (MRI), heating with radio frequency (rf), and movement in an external magnetic field. In this study, the cellular loading (uptake) mechanism of dextran- and surfactant-coated iron oxide NPs by malignant prostate tumor cells (LNCaP-Pro5) has been studied, and the feasibility of traditional rf treatment and a new laser heating method was evaluated. The kinetics of cell loading was quantified using magnetophoresis and a colorimetric assay. The results showed that loading of surfactant-coated iron oxide NPs with LNCaP-Pro5 was saturable with time (at 24 h) and extracellular concentration (11 pg Fe/cell at 0.5 mg Fe/mL), indicating that the particles are taken up by an "adsorptive endocytosis" pathway. Dextran-coated NPs, however, were taken up less efficiently (1 pg Fe/cell at 0.5 mg Fe/mL). Loading did not saturate with concentration suggesting uptake by fluid-phase endocytosis. Magnetophoresis suggests that NP-loaded cells can be held using external magnetic fields in microcirculatory flow velocities in vivo or in an appropriately designed extracorporeal circuit. Loaded cells were heated using traditional rf (260A, 357 kHz) and a new laser method (532 nm, 7 ns pulse duration, 0.03 J/pulse, 20 pulse/s). Iron oxide in water was found to absorb sufficiently strongly at 532 nm such that heating of individual NPs and thus loaded cells (1 pg Fe/cell) was effective (<10% cell survival) after 30 s of laser exposure. Radio frequency treatment required higher loading (>10 pg Fe/cell) and longer duration (30 min) when compared to laser to accomplish cell destruction (50% viability at 10 pg Fe/cell). Scaling calculations show that the pulsed laser method can lead to single-cell (loaded with NPs) treatments (200 degrees C temperature change at the surface of an individual NP) unlike traditional rf heating

  1. Power enhancement of piezoelectric transformers by adding heat transfer equipment.

    PubMed

    Su, Yu-Hao; Liu, Yuan-Ping; Vasic, Dejan; Wu, Wen-Jong; Costa, François; Lee, Chih-Kung

    2012-10-01

    It is known that piezoelectric transformers have several inherent advantages compared with conventional electromagnetic transformers. However, the maximum power capacity of piezoelectric transformers is not as large as electromagnetic transformers in practice, especially in the case of high output current. The theoretical power density of piezoelectric transformers calculated by stress boundary can reach 330 W/cm(3), but no piezoelectric transformer has ever reached such a high power density in practice. The power density of piezoelectric transformers is limited to 33 W/cm(3) in practical applications. The underlying reason is that the maximum passing current of the piezoelectric material (mechanical current) is limited by the temperature rise caused by heat generation. To increase this current and the power capacity, we proposed to add a thermal pad to the piezoelectric transformer to dissipate heat. The experimental results showed that the proposed techniques can increase by 3 times the output current of the piezoelectric transformer. A theoretical-phenomenological model which explains the relationship between vibration velocity and generated heat is also established to verify the experimental results. PMID:23143563

  2. Analysis of hot streak effects on turbine rotor heat load

    SciTech Connect

    Shang, T.; Epstein, A.H.

    1997-07-01

    The influence of inlet hot streak temperature distortion on turbine blade heat load was explored on a transonic axial flow turbine stage test article using a three-dimensional, multiblade row unsteady Euler code. The turbine geometry was the same as that used for a recently reported testing of hot streak influence. Emphasis was placed on elucidating the physical and mechanisms by which hot streaks affect turbine durability. It was found that temperature distortion significantly increases both blade surface heat load nonuniformity and total blade heat load by as much as 10--30% (mainly in the pressure surface), and that the severity of this influence is a strong function of turbine geometry and flow conditions. Three physical mechanisms were identified that drive the heat load nonuniformity: buoyancy, wake convection (the Kerrebrock-Mikolajczak effect), and rotor-stator interactions. The latter can generate significant nonuniformity of the time-averaged relative frame rotor inlet temperature distribution. Dependence of these effects on turbine design variables was investigated to shed light on the design space, which minimizes the adverse effects of hot streaks.

  3. Workshop on high heat load x-ray optics

    SciTech Connect

    Not Available

    1990-01-01

    A workshop on High Heat Load X-Ray Optics'' was held at Argonne National Laboratory on August 3--5, 1989. The object of this workshop was to discuss recent advances in the art of cooling x-ray optics subject to high heat loads from synchrotron beams. The cooling of the first optical element in the intense photon beams that will be produced in the next generation of synchrotron sources is recognized as one of the major challenges that must be faced before one will be able to use these very intense beams in future synchrotron experiments. Considerable advances have been made in this art during the last few years, but much work remains to be done before the heating problem can be said to be completely solved. Special emphasis was placed on recent cooling experiments and detailed finite element'' and finite difference'' calculations comparing experiment with theory and extending theory to optimize performance.

  4. Transient characteristics of a grooved water heat pipe with variable heat load

    NASA Technical Reports Server (NTRS)

    Jang, Jong Hoon

    1990-01-01

    The transient characteristics of a grooved water heat pipe were studied by using variable heat load. First, the effects of the property variations of the working fluid with temperature were investigated by operating the water heat pipe at several different temperatures. The experimental results show that, even for the same heat input profile and heat pipe configuration, the heat pipe transports more heat at higher temperature within the tested temperature range. Adequate liquid return to the evaporator due to decreasing viscosity of the working fluid permits continuous vaporization of water without dry-out. Second, rewetting of the evaporator was studied after the evaporator had experienced dry-out. To rewet the evaporator, the elevation of the condenser end was the most effective way. Without elevating the condenser end, rewetting is not straight-forward even with power turned off unless the heat pipe is kept at isothermal condition for sufficiently long time.

  5. Interaction of adhered metallic dust with transient plasma heat loads

    NASA Astrophysics Data System (ADS)

    Ratynskaia, S.; Tolias, P.; Bykov, I.; Rudakov, D.; De Angeli, M.; Vignitchouk, L.; Ripamonti, D.; Riva, G.; Bardin, S.; van der Meiden, H.; Vernimmen, J.; Bystrov, K.; De Temmerman, G.

    2016-06-01

    The first study of the interaction of metallic dust (tungsten, aluminum) adhered on tungsten substrates with transient plasma heat loads is presented. Experiments were carried out in the Pilot-PSI linear device with transient heat fluxes up to 550 MW m‑2 and in the DIII-D divertor tokamak. The central role of the dust-substrate contact area in heat conduction is highlighted and confirmed by heat transfer simulations. The experiments provide evidence of the occurrence of wetting-induced coagulation, a novel growth mechanism where cluster melting accompanied by droplet wetting leads to the formation of larger grains. The physical processes behind this mechanism are elucidated. The remobilization activity of the newly formed dust and the survivability of tungsten dust on hot surfaces are documented and discussed in the light of implications for ITER.

  6. Helium Refrigerator Design for Pulsed Heat Load in Tokamaks

    SciTech Connect

    Kuendig, A.; Schoenfeld, H.

    2006-04-27

    Nuclear fusion reactors of the Tokamak type will be operated in a pulsed mode requiring the helium refrigerator to remove periodically large heat loads in time steps of approximately one hour. What are the necessary steps for a refrigerator to cope with such load variations?A series of numerical simulations has been performed indicating the possibility of an active refrigerator control with low exergetic losses. A basic comparison is made between the largest existing refrigerator sizes and the size required to service for example the ITER requirements.

  7. Adaptive control in series load PWM induction heating inverters

    NASA Astrophysics Data System (ADS)

    Szelitzky, Tibor; Henrietta Dulf, Eva

    2013-12-01

    Permanent variations of the electric properties of the load in induction heating equipment make difficult to control the plant. To overcome these disadvantages, the authors propose a new approach based on adaptive control methods. For real plants it is enough to present desired performances or start-up variables for the controller, from which the algorithms tune the controllers by itself. To present the advantages of the proposed controllers, comparisons are made to a PI controller tuned through Ziegler-Nichols method.

  8. Numerical Simulation of Wall Heat Load in Combustor Flow

    NASA Astrophysics Data System (ADS)

    Panara, D.; Hase, M.; Krebs, W.; Noll, B.

    2007-09-01

    Due to the major mechanism of NOx generation, there is generally a temperature trade off between improved cycle efficiency, material constraints and low NOx emission. The cycle efficiency is proportional to the highest cycle temperature, but unfortunately also the NOx production increases with increasing combustion temperature. For this reason, the modern combustion chamber design has been oriented towards lean premixed combustion system and more and more attention must be focused on the cooling air management. The challenge is to ensure sufficiently low temperature of the combustion liner with very low amount of film or effusion cooling air. Correct numerical prediction of temperature fields and wall heat load are therefore of critical interest in the modern combustion chamber design. Moreover, lean combustion technology has shown the appearance of thermo-acoustic instabilities which have to be taken into account in the simulation and, more in general, in the design of reliable combustion systems. In this framework, the present investigation addresses the capability of a commercial multiphysics code (ANSYS CFX) to correctly predict the wall heat load and the core flow temperature field in a scaled power generation combustion chamber with a simplified ceramic liner. Comparison are made with the experimental results from the ITS test rig at the University of Karlsruhe [1] and with a previous numerical campaign from [2]. In addition the effect of flow unsteadyness on the wall heat load is discussed showing some limitations of the traditional steady state flow thermal design.

  9. Nonstationary heat and mass transfer with a reduction of the heat load in a heat exchanger with twisted tubes

    NASA Astrophysics Data System (ADS)

    Dzyubenko, B. V.; Ashmantas, L. A.; Baggdonavichyus, A. B.; Segal', M. D.

    1988-04-01

    The results of an investigation of the nonstationary mixing of the heat-transfer agent accompanying the reduction of the heat load in a bundle of twisted tubes are presented, and a generalizing dependence for calculating the effective coefficient of diffusion is derived.

  10. Applications of heat pipes for high thermal load beam lines

    SciTech Connect

    Shu, D.; Mortazavi, P.; Rarback, H.; Howells, M.R.

    1985-01-01

    The high flux beam produced by insertion devices often requires special heat removal techniques. For the optical elements used in such high thermal load beam lines, the required precision demands a highly accurate design. Heat pipe cooling of critical elements of the X-1 beam line at the National Synchrotron Light Source is described. This method reduces vibrations caused by water cooling systems and simplifies the design. In some of these designs, deposited heat must be transferred through unbonded contact interfaces. A pinhole assembly and a beam position monitor designed for the X-1 beam line both transfer heat through such interfaces in an ultrahigh vacuum environment. The fundamental design objective is that of removing the heat with minimal interface thermal resistance. We present our test method and results for measuring the thermal resistance across metallic interfaces as a function of contact pressure. The design of some devices which utilize both heat pipes and thermal contact interfaces will also be described. 12 refs., 8 figs.

  11. Influence of heating load on heat transfer characteristics in micro-pin-fin arrays

    NASA Astrophysics Data System (ADS)

    Guan, Ning; Luan, Tao; Jiang, Guilin; Liu, Zhi-Gang; Zhang, Cheng-Wu

    2016-02-01

    Experimental investigations were carried out to explore the convective heat transfer in micro pin-fins with different aspect ratios, and the influence of heating load on Nusselt numbers in micro pin-fins with liquid water as working fluid were investigated. The mechanism of convective heat transfer in micro pin-fins at different heating load were studied by 3-D numerical investigations, and the relationships of thermal physical properties change, the end wall effect and axial thermal conduction with Nu numbers in micro pin-fins were analysed. It was found that the thickness of boundary layer was decreased as much as 33.3 % attributed to the destructive effect of thermal physical properties change, and convective heat transfer in the micro pin-fin channel was more than 20 % enhanced by the flow disturbance caused by the increase of temperature difference. The discrepancy of Nu in micro pin-fin channel with different aspect ratios reached 34.59 %, and this discrepancy was reduced by the increase of heating load. The maximum value of impact factors of dynamic viscosity and thermal conductivity on the Nu in micro-pin-fins reached 25.02 and 7.68 %, respectively.

  12. Nonstationary heat transfer in a channel containing saturated He II: stepped heat loading

    SciTech Connect

    Shaposhnikov, V.A.; Mikhailov, I.I.; Efimova, L.N.; Romchenko, D.G.

    1988-09-01

    Measurements have been made on the nonstationary temperature distribution in a channel containing saturated superfluid He II under countercurrent conditions with local heat input to the middle of the channel as a stepped function. A numerical method has been developed which incorporates the variable thermophysical parameters for the helium. Those parameters include local heat flux and thermal conductivity related to internal component convection, heat flux density, specific enthalpy and entropy, the Goerter-Mellink friction constant, and the Kapitza conductivity coefficient. Agreement of the variable-property calculations with experiment is evaluated. It is concluded that saturated He II responds to pulse loading as does underheated He II.

  13. Life cycle assessment of base-load heat sources for district heating system options

    SciTech Connect

    Ghafghazi, Saeed; Sowlati, T.; Sokhansanj, Shahabaddine; Melin, Staffan

    2011-03-01

    Purpose There has been an increased interest in utilizing renewable energy sources in district heating systems. District heating systems are centralized systems that provide heat for residential and commercial buildings in a community. While various renewable and conventional energy sources can be used in such systems, many stakeholders are interested in choosing the feasible option with the least environmental impacts. This paper evaluates and compares environmental burdens of alternative energy source options for the base load of a district heating center in Vancouver, British Columbia (BC) using the life cycle assessment method. The considered energy sources include natural gas, wood pellet, sewer heat, and ground heat. Methods The life cycle stages considered in the LCA model cover all stages from fuel production, fuel transmission/transportation, construction, operation, and finally demolition of the district heating system. The impact categories were analyzed based on the IMPACT 2002+ method. Results and discussion On a life-cycle basis, the global warming effect of renewable energy options were at least 200 kgeqCO2 less than that of the natural gas option per MWh of heat produced by the base load system. It was concluded that less than 25% of the upstream global warming impact associated with the wood pellet energy source option was due to transportation activities and about 50% of that was resulted from wood pellet production processes. In comparison with other energy options, the wood pellets option has higher impacts on respiratory of inorganics, terrestrial ecotoxicity, acidification, and nutrification categories. Among renewable options, the global warming impact of heat pump options in the studied case in Vancouver, BC, were lower than the wood pellet option due to BC's low carbon electricity generation profile. Ozone layer depletion and mineral extraction were the highest for the heat pump options due to extensive construction required for these

  14. Performance evaluation of adding ethanol production into an existing combined heat and power plant.

    PubMed

    Starfelt, F; Thorin, E; Dotzauer, E; Yan, J

    2010-01-01

    In this paper, the configuration and performance of a polygeneration system are studied by modelling the integration of a lignocellulosic wood-to-ethanol process with an existing combined heat and power (CHP) plant. Data from actual plants are applied to validate the simulation models. The integrated polygeneration system reaches a total efficiency of 50%, meeting the heating load in the district heating system. Excess heat from the ethanol production plant supplies 7.9 MW to the district heating system, accounting for 17.5% of the heat supply at full heating load. The simulation results show that the production of ethanol from woody biomass is more efficient when integrated with a CHP plant compared to a stand-alone production plant. The total biomass consumption is reduced by 13.9% while producing the same amounts of heat, electricity and ethanol fuel as in the stand-alone configurations. The results showed that another feature of the integrated polygeneration system is the longer annual operating period compared to existing cogeneration. Thus, the renewable electricity production is increased by 2.7% per year. PMID:19758800

  15. Study on transient beam loading compensation for China ADS proton linac injector II

    NASA Astrophysics Data System (ADS)

    Gao, Zheng; He, Yuan; Wang, Xian-Wu; Chang, Wei; Zhang, Rui-Feng; Zhu, Zheng-Long; Zhang, Sheng-Hu; Chen, Qi; Powers, Tom

    2016-05-01

    Significant transient beam loading effects were observed during beam commissioning tests of prototype II of the injector for the accelerator driven sub-critical (ADS) system, which took place at the Institute of Modern Physics, Chinese Academy of Sciences, between October and December 2014. During these tests experiments were performed with continuous wave (CW) operation of the cavities with pulsed beam current, and the system was configured to make use of a prototype digital low level radio frequency (LLRF) controller. The system was originally operated in pulsed mode with a simple proportional plus integral and deviation (PID) feedback control algorithm, which was not able to maintain the desired gradient regulation during pulsed 10 mA beam operations. A unique simple transient beam loading compensation method which made use of a combination of proportional and integral (PI) feedback and feedforward control algorithm was implemented in order to significantly reduce the beam induced transient effect in the cavity gradients. The superconducting cavity field variation was reduced to less than 1.7% after turning on this control algorithm. The design and experimental results of this system are presented in this paper. Supported by National Natural Science Foundation of China (91426303, 11525523)

  16. Recovery of Weak Factor Loadings When Adding the Mean Structure in Confirmatory Factor Analysis: A Simulation Study

    PubMed Central

    Ximénez, Carmen

    2016-01-01

    This article extends previous research on the recovery of weak factor loadings in confirmatory factor analysis (CFA) by exploring the effects of adding the mean structure. This issue has not been examined in previous research. This study is based on the framework of Yung and Bentler (1999) and aims to examine the conditions that affect the recovery of weak factor loadings when the model includes the mean structure, compared to analyzing the covariance structure alone. A simulation study was conducted in which several constraints were defined for one-, two-, and three-factor models. Results show that adding the mean structure improves the recovery of weak factor loadings and reduces the asymptotic variances for the factor loadings, particularly for the models with a smaller number of factors and a small sample size. Therefore, under certain circumstances, modeling the means should be seriously considered for covariance models containing weak factor loadings. PMID:26779071

  17. Utilization of Heat Pump Water Heaters for Load Management

    SciTech Connect

    Boudreaux, Philip R; Jackson, Roderick K; Munk, Jeffrey D; Gehl, Anthony C; Lyne, Christopher T

    2014-01-01

    The Energy Conservation Standards for Residential Water Heaters require residential electric storage water heaters with volumes larger than 55 gallons to have an energy factor greater than 2.0 after April 2015. While this standard will significantly increase the energy efficiency of water heaters, large electric storage water heaters that do not use heat pump technologies may no longer be available. Since utilities utilize conventional large-volume electric storage water heaters for thermal storage in demand response programs, there is a concern that the amended standard will significantly limit demand response capacity. To this end, Oak Ridge National Laboratory partnered with the Tennessee Valley Authority to investigate the load management capability of heat pump water heaters that meet or exceed the forthcoming water heater standard. Energy consumption reduction during peak periods was successfully demonstrated, while still meeting other performance criteria. However, to minimize energy consumption, it is important to design load management strategies that consider the home s hourly hot water demand so that the homeowner has sufficient hot water.

  18. Forced flow supercritical helium in a closed heat transfer loop subjected to pulsed heat loads

    NASA Astrophysics Data System (ADS)

    Hoa, Christine; Bonnay, Patrick; Bon-Mardion, Michel; Charvin, Philippe; Cheynel, Jean-Noel; Girard, Alain; Lagier, Benjamin; Michel, Frederic; Monteiro, Lionel; Poncet, Jean-Marc; Roussel, Pascal; Rousset, Bernard; Vallcorba-Carbonell, Roser

    2012-06-01

    The superconducting magnets of the tokamak JT-60SA are cooled by means of forced flows of supercritical helium at 4.4 K and 0.5 MPa. The closed loops transfer heat from the magnets to the refrigerator through heat exchangers immersed into a saturated liquid helium bath. An experimental loop was designed to represent a 1/20 scaled down mock-up of JT-60SA central solenoid cooling circuits. This design for keeping the same transit times in the helium circuits, aims at observing the thermally induced transients in the closed loop. Indeed, heated section simulates the variable loads coming from the magnet circuits. A series of experiments was performed with pulsed loads in an isochoric configuration of the loop. The cold circulator has been characterized under pulsed operation and its performances are addressed. Mass flow regulations at the interface of the refrigerator were tested to smooth the pulsed loads with the saturated liquid bath acting as a thermal buffer. Knowledge of the pulsed loads effects on the cryogenic components is important in view of a safe operation of the cryogenic system.

  19. Experimental Investigation of Sublimator Performance at Transient Heat Loads

    NASA Technical Reports Server (NTRS)

    Sheth, Rubik B.; Stephen, Ryan A.; Leimkuehler, Thomas O.

    2011-01-01

    Sublimators have been used as heat rejection devices for a variety of space applications including the Apollo Lunar Module and the Extravehicular Mobility Unit (EMU). Sublimators typically operate with steady-state feedwater utilization at or near 100%. However, sublimators are currently being considered to operate in a cyclical topping mode, which represents a new mode of operation for sublimators. Sublimators can be used as a topper during mission phases such as low lunar or low earth orbit. In these mission phases, the sublimator will be repeatedly started and stopped during each orbit to provide supplemental heat rejection for the portion of the orbit where the radiative sink temperature exceeds the system setpoint temperature. This paper will summarize the effort put into understanding sublimator response under a transient heat load. The performance will be assessed by detailing the changes in feedwater utilization due to transient starts and stops during various feedwater timing scenarios. Sublimator start up utilization will be assessed as a possible relationship to transient performance of a sublimator. This paper will also provide recommendations for future sublimator designs and/or feedwater control.

  20. Peroxide test strips detect added hydrogen peroxide in raw milk at levels affecting bacterial load.

    PubMed

    Martin, Nicole H; Friedlander, Adam; Mok, Allen; Kent, David; Wiedmann, Martin; Boor, Kathryn J

    2014-10-01

    Hydrogen peroxide (H2O2) has a long-established history of use as a preservative in milk worldwide. The use of H2O2 to activate the inherent lactoperoxidase enzyme system has dramatically improved the quality of raw dairy products in areas in which cooling is not widely available. In the United States, however, where refrigeration is widely available, the addition of H2O2 to milk is not permitted, with the exception of certain applications prior to cheesemaking and during the preparation of modified whey. Due to the relatively quick deterioration of H2O2 in fluid milk, the detection of raw milk adulterated with the compound can be challenging. In this study we evaluated (i) total aerobic bacterial counts and (ii) ability of peroxide test strips to detect H2O2 in raw milk with various concentrations (0, 100, 300, 500, 700, and 900 ppm) of added H2O2, incubated at both 6 and 21°C for 0, 24, and 48 h. Results showed that at both 6 and 21°C the H2O2 concentration and time had a significant effect on bacterial loads in raw milk. Additionally, commercially available test strips were able to detect H2O2 in raw milk, with predicted probability of >90%, immediately after addition and after 24 and 48 h for the higher concentrations used, offering a viable method for detecting raw milk adulteration with H2O2. PMID:25285503

  1. Particle transport and heat loads in NIO1

    NASA Astrophysics Data System (ADS)

    Fonnesu, N.; Cavenago, M.; Serianni, G.; Veltri, P.

    2016-02-01

    NIO1 is a compact radio frequency ion source designed to generate a 60 kV-135 mA hydrogen negative ion beam and it aims at continuous operation, which implies a detailed thermo-mechanical analysis of the beam-facing components, in particular, the accelerator grids. A 3D analysis of the entire NIO1 beam has been performed for the first time with a fully 3D version of EAMCC, a relativistic particle tracking code for the calculation of the grid power deposition induced by particle impacts. According to the results presented in this paper, secondary and co-extracted electrons cause a non-negligible heat load on the grids, where different high-power density regions, within reasonable sustainable standard limits, are calculated.

  2. Role of fuel chemical properties on combustor radiative heat load

    NASA Technical Reports Server (NTRS)

    Rosfjord, T. J.

    1984-01-01

    In an attempt to rigorously study the fuel chemical property influence on combustor radiative heat load, United Technologies Research Center (UTRC) has conducted an experimental program using 25 test fuels. The burner was a 12.7-cm dia cylindrical device fueled by a single pressure-atomizing injector. Fuel physical properties were de-emphasized by selecting injectors which produced high-atomized, and hence rapidly-vaporizing sprays. The fuels were specified to cover the following wide ranges of chemical properties; hydrogen, 9.1 to 15- (wt) pct; total aromatics, 0 to 100 (vol) pct; and naphthalene, 0 to 30 (vol) pct. They included standard fuels, specialty products and fuel blends. Fuel naphthalene content exhibited the strongest influence on radiation of the chemical properties investigated. Smoke point was a good global indicator of radiation severity.

  3. Role of fuel chemical properties on combustor radiative heat load

    NASA Technical Reports Server (NTRS)

    Rosfjord, T. J.

    1984-01-01

    In an attempt to rigorously study the fuel chemical property influence on combustor radiative heat load, UTRC has conducted an experimental program using 25 test fuels. The burner was a 12.7-cm dia cylindrical device fueled by a single pressure-atomizing injector. Fuel physical properties were de-emphasized by selecting injectors which produced highly-atomized, and hence rapidly-vaporizing sprays. The fuels were specified to cover the following wide ranges of chemical properties: hydrogen, 9.1 to 15- (wt) pct; total aromatics, 0 to 100 (vol) pct; and naphthalene, 0 to 30 (vol) pct. They included standard fuels, specialty products and fuel blends. Fuel naphthalene content exhibited the strongest influence on radiation of the chemical properties investigated. Smoke point was a good global indicator of radiation severity.

  4. Particle transport and heat loads in NIO1.

    PubMed

    Fonnesu, N; Cavenago, M; Serianni, G; Veltri, P

    2016-02-01

    NIO1 is a compact radio frequency ion source designed to generate a 60 kV-135 mA hydrogen negative ion beam and it aims at continuous operation, which implies a detailed thermo-mechanical analysis of the beam-facing components, in particular, the accelerator grids. A 3D analysis of the entire NIO1 beam has been performed for the first time with a fully 3D version of EAMCC, a relativistic particle tracking code for the calculation of the grid power deposition induced by particle impacts. According to the results presented in this paper, secondary and co-extracted electrons cause a non-negligible heat load on the grids, where different high-power density regions, within reasonable sustainable standard limits, are calculated. PMID:26932077

  5. An analysis of representative heating load lines for residential HSPF ratings

    SciTech Connect

    Rice, C. Keith; Shen, Bo; Shrestha, Som S.

    2015-07-01

    This report describes an analysis to investigate representative heating loads for single-family detached homes using current EnergyPlus simulations (DOE 2014a). Hourly delivered load results are used to determine binned load lines using US Department of Energy (DOE) residential prototype building models (DOE 2014b) developed by Pacific Northwest National Laboratory (PNNL). The selected residential single-family prototype buildings are based on the 2006 International Energy Conservation Code (IECC 2006) in the DOE climate regions. The resulting load lines are compared with the American National Standards Institute (ANSI)/Air-Conditioning, Heating, and Refrigeration Institute (AHRI) Standard 210/240 (AHRI 2008) minimum and maximum design heating requirement (DHR) load lines of the heating seasonal performance factor (HSPF) ratings procedure for each region. The results indicate that a heating load line closer to the maximum DHR load line, and with a lower zero load ambient temperature, is more representative of heating loads predicted for EnergyPlus prototype residential buildings than the minimum DHR load line presently used to determine HSPF ratings. An alternative heating load line equation was developed and compared to binned load lines obtained from the EnergyPlus simulation results. The effect on HSPF of the alternative heating load line was evaluated for single-speed and two-capacity heat pumps, and an average HSPF reduction of 16% was found. The alternative heating load line relationship is tied to the rated cooling capacity of the heat pump based on EnergyPlus autosizing, which is more representative of the house load characteristics than the rated heating capacity. The alternative heating load line equation was found to be independent of climate for the six DOE climate regions investigated, provided an adjustable zero load ambient temperature is used. For Region IV, the default DOE climate region used for HSPF ratings, the higher load line results in an ~28

  6. Numerical Model for Conduction-Cooled Current Lead Heat Loads

    SciTech Connect

    White, M.J.; Wang, X.L.; Brueck, H.D.; /DESY

    2011-06-10

    Current leads are utilized to deliver electrical power from a room temperature junction mounted on the vacuum vessel to a superconducting magnet located within the vacuum space of a cryostat. There are many types of current leads used at laboratories throughout the world; however, conduction-cooled current leads are often chosen for their simplicity and reliability. Conduction-cooled leads have the advantage of using common materials, have no superconducting/normal state transition, and have no boil-off vapor to collect. This paper presents a numerical model for conduction-cooled current lead heat loads. This model takes into account varying material and fluid thermal properties, varying thicknesses along the length of the lead, heat transfer in the circumferential and longitudinal directions, electrical power dissipation, and the effect of thermal intercepts. The model is validated by comparing the numerical model results to ideal cases where analytical equations are valid. In addition, the XFEL (X-Ray Free Electron Laser) prototype current leads are modeled and compared to the experimental results from testing at DESY's XFEL Magnet Test Stand (XMTS) and Cryomodule Test Bench (CMTB).

  7. Artist: Ken Hodges Composite image explaining Objective and Motivation for Galileo Probe Heat Loads:

    NASA Technical Reports Server (NTRS)

    1981-01-01

    Artist: Ken Hodges Composite image explaining Objective and Motivation for Galileo Probe Heat Loads: Galileo Probe descending into Jupiters Atmosphere shows heat shield separation with parachute deployed. (Ref. JPL P-19180)

  8. Round Heat-treated Chromium-molybdenum-steel Tubing Under Combined Loads

    NASA Technical Reports Server (NTRS)

    Osgood, William R

    1943-01-01

    The results of tests of round heat-treated chromium-molybdenum-steel tubing are presented. Tests were made on tubing under axial load, bending load, torsional load, combined bending and axial load, combined bending and torsional load, and combined axial, bending, and torsional load. Tensile and compressive tests were made to determine the properties of the material. Formulas are given for the evaluation of the maximum strength of this steel tubing under individual or combined loads. The solution of an example is included to show the procedure to be followed in designing a tubular cantilever member to carry combined loads.

  9. Scaling STI's sapphire cryocooler for applications requiring higher heat loads

    NASA Astrophysics Data System (ADS)

    Karandikar, Abhijit; Fiedler, Andreas

    2012-06-01

    Superconductor Technologies Inc. (STI) developed the Sapphire cryocooler specifically for the SuperLink® product; a high performance superconducting Radio Frequency (RF) front-end receiver used by wireless carriers such as Verizon Wireless and AT&T to improve network cell coverage and data speeds. STI has built and deployed over 6,000 systems operating 24 hours a day (24/7), 7 days a week in the field since 1999. Sapphire is an integrated free piston Stirling cycle cryocooler with a cooling capacity of 5 Watts at 77 Kelvin (K) with less than 100 Watts (W) input power. It has a field-proven Mean Time Between Failure (MTBF) of well over 1 million hours, requires zero maintenance and has logged over 250 million cumulative runtime hours. The Sapphire cooler is built on a scalable technology platform, enabling the design of machines with cooling capacities greater than 1 kilowatt (kW). This scalable platform also extends the same outstanding attributes as the Sapphire cooler, namely high reliability, zero maintenance, and compact size - all at a competitive cost. This paper will discuss emerging applications requiring higher heat loads and these attributes, describe Sapphire, and show a preliminary concept of a scaled machine with a 100 W cooling capacity.

  10. Sensitization of heat-treated Listeria monocytogenes to added lysozyme in milk.

    PubMed Central

    Kihm, D J; Leyer, G J; An, G H; Johnson, E A

    1994-01-01

    Listeria monocytogenes was highly resistant to hen egg white lysozyme in whole milk but was sensitive in media and in phosphate buffer. Methods to sensitize the pathogen to lysozyme in milk were investigated. Treatment of whole milk by cation exchange to remove minerals, particularly Ca2+ and Mg2+, slightly promoted inactivation of L. monocytogenes by lysozyme at 4 degrees C over a period of 6 days. Heat treatment (62.5 degrees C for 15 s) strongly sensitized L. monocytogenes to lysozyme in demineralized milk and in MES [2-(N-morpholino)ethanesulfonic acid] buffer. Addition of Ca2+ or Mg2+ to the demineralized milk restored resistance to lysozyme. Cells were more rapidly heat inactivated at 55 degrees C in demineralized milk containing lysozyme, and addition of Ca2+ to the demineralized milk restored the resistance to heat. The results indicate that minerals or mineral-associated components protect L. monocytogenes from inactivation by lysozyme and heat in milk, probably by increasing cell surface stability. The heat treatment of foods containing added lysozyme can probably play a significant role in producing microbiologically safe foods. Images PMID:7986052

  11. Heat transfer issues in high-heat-load synchrotron x-ray beams

    SciTech Connect

    Khounsary, A.M.; Mills, D.M.

    1994-09-01

    In this paper, a short description of the synchrotron radiation x-ray sources and the associated power loads is given, followed by a brief description of typical synchrotron components and their heat load. It is emphasized that the design goals for most of these components is to limit (a) temperature, (b) stresses, or (c) strains in the system. Each design calls for a different geometry, material selection, and cooling scheme. Cooling schemes that have been utilized so far are primarily single phase and include simple macrochannel cooling, microchannel cooling, contact cooling, pin-post cooling, porous-flow cooling, jet cooling, etc. Water, liquid metals, and various cryogenic coolants have been used. Because the trend in x-ray beam development is towards brighter (i.e., more powerful) beams and assuming that no radical changes in the design of x-ray generating machines occurs in the next few years, it is fair to state that the utilization of various effective cooling schemes and, in particular, two-phase flow (e.g., subcooled boiling) warrants further investigation. This, however, requires a thorough examination of stability and reliability of two-phase flows for high-heat-flux components operating in ultrahigh vacuum with stringent reliability requirements.

  12. Heat Load Sharing in a Capillary Pumped Loop with Multiple Evaporators and Multiple Condensers

    NASA Technical Reports Server (NTRS)

    Ku, Jentung

    2005-01-01

    This paper describes the heat load sharing function among multiple parallel evaporators in a capillary pumped loop (CPL). In the normal mode of operation, the evaporators cool the instruments by absorbing the waste heat. When an instruments is turned off, the attached evaporator can keep it warm by receiving heat from other evaporators serving the operating instruments. This is referred to as heat load sharing. A theoretical basis of heat load sharing is given first. The fact that the wicks in the powered evaporators will develop capillary pressure to force the generated vapor to flow to cold locations where the pressure is lower leads to the conclusion that heat load sharing is an inherent function of a CPL with multiple evaporators. Heat load sharing has been verified with many CPLs in ground tests. Experimental results of the Capillary Pumped Loop 3 (CAPL 3) Flight Experiment are presented in this paper. Factors that affect the amount of heat being shared are discussed. Some constraints of heat load sharing are also addressed.

  13. Dam heat load affects neonatal calves’ bacterial prevalence and innate immunity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Heat stress is known to suppress animal’s immunity, making them more susceptible to bacterial infections. In Indiana, field observations showed that calves have greater morbidity and mortality when they are born after a heat event. Objectives of this study were to determine whether heat load increas...

  14. Effects of Adding Nanoparticles on Boiling and Condensing Heat Transfer inside a horizontal round tube

    NASA Astrophysics Data System (ADS)

    Sheikholeslami, Mohsen; Sadoughi, Mohammadkazem; Shariatmadar, Hamed; Akhavan-Behabadi, Mohammad Ali

    2015-11-01

    An experimental investigation is performed on heat transfer evaluation of a nano-refrigerant flow during condensation and evaporation inside a horizontal round tube. Experiments are carried out for three working fluid types including: i) pure refrigerant (R600a); ii) refrigerant/lubricant (R600a/oil); and iii) nano-refrigerant: refrigerant/lubricant/nanoparticles (R600a/oil/CuO). Nanoparticles are added to the lubricant and their mixture is mixed with pure refrigerant. Therefore, nano-refrigerants (R600a/oil/CuO) are prepared by dispersing CuO nanoparticles with different fractions of 0.5%, 1% and 1.5% in the baseline mixture (R600a/oil). Effects of different factors including vapor quality, mass flux, and nanoparticles on the heat transfer coefficient are examined for both of condensation and evaporation flows, separately. The results shows that maximum heat transfer augmentation of 79% and 83% are achieved by using the refrigerant/lubricant/nanoparticles mixture, in comparison with the pure refrigerant case in condensation and evaporation, respectively which are occurred for nano-refrigerant with 1.5% mass fraction in both of them.

  15. Effects of ventilation behaviour on indoor heat load based on test reference years

    NASA Astrophysics Data System (ADS)

    Rosenfelder, Madeleine; Koppe, Christina; Pfafferott, Jens; Matzarakis, Andreas

    2016-02-01

    Since 2003, most European countries established heat health warning systems to alert the population to heat load. Heat health warning systems are based on predicted meteorological conditions outdoors. But the majority of the European population spends a substantial amount of time indoors, and indoor thermal conditions can differ substantially from outdoor conditions. The German Meteorological Service (Deutscher Wetterdienst, DWD) extended the existing heat health warning system (HHWS) with a thermal building simulation model to consider heat load indoors. In this study, the thermal building simulation model is used to simulate a standardized building representing a modern nursing home, because elderly and sick people are most sensitive to heat stress. Different types of natural ventilation were simulated. Based on current and future test reference years, changes in the future heat load indoors were analyzed. Results show differences between the various ventilation options and the possibility to minimize the thermal heat stress during summer by using an appropriate ventilation method. Nighttime ventilation for indoor thermal comfort is most important. A fully opened window at nighttime and the 2-h ventilation in the morning and evening are more sufficient to avoid heat stress than a tilted window at nighttime and the 1-h ventilation in the morning and the evening. Especially the ventilation in the morning seems to be effective to keep the heat load indoors low. Comparing the results for the current and the future test reference years, an increase of heat stress on all ventilation types can be recognized.

  16. Ad-libitum drinking and performance during a 40-km cycling time trial in the heat.

    PubMed

    Berkulo, Meriam A R; Bol, Susan; Levels, Koen; Lamberts, Robert P; Daanen, Hein A M; Noakes, Timothy D

    2016-01-01

    The aim of this study was to investigate if drinking ad-libitum can counteract potential negative effects of a hypohydrated start caused by fluid restriction during a 40-km time trial (TT) in the heat. Twelve trained males performed one 40-km cycling TT euhydrated (EU: no water during the TT) and two 40-km cycling TTs hypohydrated. During one hypohydrated trial no fluid was ingested (HYPO), during the other trial ad-libitum water ingestion was allowed (FLUID). Ambient temperature was 35.2 ± 0.2 °C, relative humidity 51 ± 3% and airflow 7 m·s(-1). Body mass (BM) was determined at the start of the test, and before and after the TT. During the TT, power output, heart rate (HR), gastrointestinal temperature, mean skin temperature, rating of perceived exertion (RPE), thermal sensation, thermal comfort and thirst sensation were measured. Prior to the start of the TT, BM was 1.2% lower in HYPO and FLUID compared to EU. During the TT, BM loss in FLUID was lower compared to EU and HYPO (1.0 ± 0.8%, 2.7 ± 0.2% and 2.6 ± 0.3%, respectively). Hydration status had no effect on power output (EU: 223 ± 32 W, HYPO: 217 ± 39 W, FLUID: 224 ± 35 W), HR, gastrointestinal temperature, mean skin temperature, RPE, thermal sensation and thermal comfort. Thirst sensation was higher in HYPO than in EU and FLUID. It was concluded that hypohydration did not adversely affect performance during a 40-km cycling TT in the heat. Therefore, whether or not participants consumed fluid during exercise did not influence their TT performance. PMID:25675355

  17. Pushing high-heat-load optics to the limit

    SciTech Connect

    Fernandez, P. B.

    1999-11-08

    A cryogenically cooled silicon monochromator and a water-cooled diamond monochromator have been tested under twice the standard power load conditions at the Advanced Photon Source. Both monochromators performed satisfactorily under these extreme power loads (several hundred watts of incident power and up to 300 W/mm{sup 2} of incident normal peak power density). The experimental data and the parameters derived to predict the performance limits of the cryogenic silicon monochromator are presented.

  18. Design and implementation of a multiaxial loading capability during heating on an engineering neutron diffractometer

    DOE PAGESBeta

    Benafan, O.; Padula, S. A.; Skorpenske, H. D.; An, K.; Vaidyanathan, R.

    2014-10-02

    Here we discuss a gripping capability that was designed, implemented, and tested for in situ neutron diffraction measurements during multiaxial loading and heating on the VULCAN engineering materials diffractometer at the spallation neutron source at Oak Ridge National Laboratory.

  19. Simple Formulas for Stagnation-Point Convective Heat Loads in Lunar Return

    NASA Technical Reports Server (NTRS)

    Grant, Frederick C.

    1961-01-01

    Simple formulas are given for the stagnation-point convective heat 1 loads in lunar return for two operational modes. The two modes of operation analyzed are typical of moderate heating and of nearly minimum heat loads, respectively. The values of the parameters in a simple two- parameter formula for the total-heat load are given in the lift-drag-ratio range of 0.2 to 1.0 and in the peak loading range of 2g to 10g. For vehicles having a lift-drag ratio near 0.5, which is typical of many proposed lunar return vehicles, the nominal mode had about 20 percent more absorption than the nearly minimum mode.

  20. [Physiological evaluation of clothing made of new material for protection against the solar heat load].

    PubMed

    Watanuki, S; Hiraoka, M; Doi, T; Kiyokawa, H

    1992-11-01

    The purpose of this study was to evaluate the effects of clothing made of a new material that is, the polyester staple containing the ceramics and to reflect the solar heat load on physiological responses during rest, exercise (50% VO2max) and recovery on a cycle ergometer. Six young female subjects exposed their back to an artificial solar heat load of an intensity of 680 kcal/m2/h with an air temperature of 30 degrees C. The data were compared to those obtained by wearing clothing made of cotton material. The results were as follows. The cardiac output and oxygen consumption obtained at the end of recovery were increased by solar heat load when the subjects wore cotton material. However, these values showed no significant increase when the subjects wore solar heat reflecting clothing. Furthermore, the cardiac output at the end of submaximal work and recovery were higher for the cotton material compared to the heat reflecting clothing in the solar heat load. The increase of cardiac output for the cotton material may show the increase of skin blood flow for the body heat dissipation. Those results suggest that the solar heat reflecting clothing may decrease the physiological strain like a blood redistribution for the body heat dissipation during exercise in summer sunlight. PMID:1476560

  1. Analysis of the cryogenic system behavior for pulsed heat load in EAST

    SciTech Connect

    Hu, L. B.; Zhuang, M.; Zhou, Z. W.; Xia, G. H.

    2014-01-29

    EAST is the first full superconducting fusion device. The plasma is confined by the magnetic fields generated from a large set of superconducting magnets which are made of cable in-conduit conductor (CICC). In operation, these magnets suffer heat loads from thermal and nuclear radiation from the surrounding components and plasma as well as the eddy currents and the AC losses generated within the magnets, together with the heat conduction through supports and the resistive heat generated at the current lead transiting to room temperature. The cryogenic system of our EAST consists of a 2kW/4K helium refrigerator and a distribution system for the cooling of poloidal field (PF) and toroidal field (TF) coils, structures, thermal shields, buslines and current leads. Pulsed heat load is the main difference between the cryogenic system of a full superconducting Tokamak system and other large scale cryogenic systems. The cryogenic system operates in a pulsed heat loads mode requiring the helium refrigerator to remove periodically large heat loads in time. At the same time, the cryogenic system parameters such as helium cooling superconducting magnets, helium refrigerator and helium distribution system are changing. In this paper, the variation range of the parameters of superconducting magnets and refrigerator has been analyzed in the typical plasma discharge mode. The control scheme for the pulsed loads characteristics of the cryogenic system has been proposed, the implementation of which helps to smooth the pulse loads and to improve the stability of the operation of the cryogenic system.

  2. Modification of titanium surfaces by adding antibiotic-loaded PHB spheres and PEG for biomedical applications.

    PubMed

    Rodríguez-Contreras, Alejandra; Marqués-Calvo, María Soledad; Gil, Francisco Javier; Manero, José María

    2016-08-01

    Novel researches are focused on the prevention and management of post-operative infections. To avoid this common complication of implant surgery, it is preferable to use new biomaterials with antibacterial properties. Therefore, the aim of this work is to develop a method of combining the antibacterial properties of antibiotic-loaded poly(3-hydroxybutyrate) (PHB) nano- and micro-spheres and poly(ethylene glycol) (PEG) as an antifouling agent, with titanium (Ti), as the base material for implants, in order to obtain surfaces with antibacterial activity. The Ti surfaces were linked to both PHB particles and PEG by a covalent bond. This attachment was carried out by firstly activating the surfaces with either Oxygen plasma or Sodium hydroxide. Further functionalization of the activated surfaces with different alkoxysilanes allows the reaction with PHB particles and PEG. The study confirms that the Ti surfaces achieved the antibacterial properties by combining the antibiotic-loaded PHB spheres, and PEG as an antifouling agent. PMID:27318469

  3. Loading-Induced Heat-Shock Response in Bovine Intervertebral Disc Organ Culture.

    PubMed

    Chooi, Wai Hon; Chan, Samantha Chun Wai; Gantenbein, Benjamin; Chan, Barbara Pui

    2016-01-01

    Mechanical loading has been shown to affect cell viability and matrix maintenance in the intervertebral disc (IVD) but there is no investigation on how cells survive mechanical stress and whether the IVD cells perceive mechanical loading as stress and respond by expression of heat shock proteins. This study investigates the stress response in the IVD in response to compressive loading. Bovine caudal disc organ culture was used to study the effect of physiological range static loading and dynamic loading. Cell activity, gene expression and immunofluorescence staining were used to analyze the cell response. Cell activity and cytoskeleton of the cells did not change significantly after loading. In gene expression analysis, significant up-regulation of heat shock protein-70 (HSP70) was observed in nucleus pulposus after two hours of loading. However, the expression of the matrix remodeling genes did not change significantly after loading. Similarly, expressions of stress response and matrix remodeling genes changed with application and removal of the dynamic loading. The results suggest that stress response was induced by physiological range loading without significantly changing cell activity and upregulating matrix remodeling. This study provides direct evidence on loading induced stress response in IVD cells and contributes to our understanding in the mechanoregulation of intervertebral disc cells. PMID:27580124

  4. A system for controlling the boiler heat load

    NASA Astrophysics Data System (ADS)

    Kositsyn, V. Yu.; Rybalev, A. N.; Telichenko, D. A.

    2013-02-01

    The system controlling the load of a coal-fired boiler operating in the configuration with a common steam line that is used at cogeneration stations is considered. An analysis method is proposed, and the mathematical description of the controlled plant is obtained. Results obtained from a study of classic and adaptive control laws are presented.

  5. Additional cooling and heating load improvements in seasonal performance modeling of room and central air conditioners and heat pumps. Topical report, Subtask 3. 2

    SciTech Connect

    Not Available

    1980-04-09

    The study focuses on improving the load modeling technique of Seasonal Performance Model (SPM) in order to estimate a more realistic load for seasonal analysis calculations on an hourly basis. A computer simulation program, Seasonal Performance Model Load (SPMLD), was used to calculate the cooling and heating loads for a typical residence in Caribou, Maine; Columbia, Missouri; and Fort Worth, Texas. The derivation of the SPMLD is described and changes made to improve cooling and heating load estimates are identified. (MCW)

  6. Measurements of SCRF cavity dynamic heat load in horizontal test system

    SciTech Connect

    DeGraff, B.D.; Bossert, R.J.; Pei, L.; Soyars, W.M.; /Fermilab

    2009-11-01

    The Horizontal Test System (HTS) at Fermilab is currently testing fully assembled, dressed superconducting radio frequency (SCRF) cavities. These cavities are cooled in a bath of superfluid helium at 1.8K. Dissipated RF power from the cavities is a dynamic heat load on the cryogenic system. The magnitude of heat flux from these cavities into the helium is also an important variable for understanding cavity performance. Methods and hardware used to measure this dynamic heat load are presented. Results are presented from several cavity tests and testing accuracy is discussed.

  7. Estimation of heat load in waste tanks using average vapor space temperatures

    SciTech Connect

    Crowe, R.D.; Kummerer, M.; Postma, A.K.

    1993-12-01

    This report describes a method for estimating the total heat load in a high-level waste tank with passive ventilation. This method relates the total heat load in the tank to the vapor space temperature and the depth of waste in the tank. Q{sub total} = C{sub f} (T{sub vapor space {minus}} T{sub air}) where: C{sub f} = Conversion factor = (R{sub o}k{sub soil}{sup *}area)/(z{sub tank} {minus} z{sub surface}); R{sub o} = Ratio of total heat load to heat out the top of the tank (function of waste height); Area = cross sectional area of the tank; k{sub soil} = thermal conductivity of soil; (z{sub tank} {minus} z{sub surface}) = effective depth of soil covering the top of tank; and (T{sub vapor space} {minus} T{sub air}) = mean temperature difference between vapor space and the ambient air at the surface. Three terms -- depth, area and ratio -- can be developed from geometrical considerations. The temperature difference is measured for each individual tank. The remaining term, the thermal conductivity, is estimated from the time-dependent component of the temperature signals coming from the periodic oscillations in the vapor space temperatures. Finally, using this equation, the total heat load for each of the ferrocyanide Watch List tanks is estimated. This provides a consistent way to rank ferrocyanide tanks according to heat load.

  8. At What Level of Heat Load Are Age-Related Impairments in the Ability to Dissipate Heat Evident in Females?

    PubMed Central

    Stapleton, Jill M.; Poirier, Martin P.; Flouris, Andreas D.; Boulay, Pierre; Sigal, Ronald J.; Malcolm, Janine; Kenny, Glen P.

    2015-01-01

    Studies have reported that older females have impaired heat loss responses during work in the heat compared to young females. However, it remains unclear at what level of heat stress these differences occur. Therefore, we examined whole-body heat loss [evaporative (HE) and dry heat loss, via direct calorimetry] and changes in body heat storage (∆Hb, via direct and indirect calorimetry) in 10 young (23±4 years) and 10 older (58±5 years) females matched for body surface area and aerobic fitness (VO2peak) during three 30-min exercise bouts performed at incremental rates of metabolic heat production of 250 (Ex1), 325 (Ex2) and 400 (Ex3) W in the heat (40°C, 15% relative humidity). Exercise bouts were separated by 15 min of recovery. Since dry heat gain was similar between young and older females during exercise (p=0.52) and recovery (p=0.42), differences in whole-body heat loss were solely due to HE. Our results show that older females had a significantly lower HE at the end of Ex2 (young: 383±34 W; older: 343±39 W, p=0.04) and Ex3 (young: 437±36 W; older: 389±29 W, p=0.008), however no difference was measured at the end of Ex1 (p=0.24). Also, the magnitude of difference in the maximal level of HE achieved between the young and older females became greater with increasing heat loads (Ex1=10.2%, Ex2=11.6% and Ex3=12.4%). Furthermore, a significantly greater ∆Hb was measured for all heat loads for the older females (Ex1: 178±44 kJ; Ex2: 151±38 kJ; Ex3: 216±25 kJ, p=0.002) relative to the younger females (Ex1: 127±35 kJ; Ex2: 96±45 kJ; Ex3: 146±46 kJ). In contrast, no differences in HE or ∆Hb were observed during recovery (p>0.05). We show that older habitually active females have an impaired capacity to dissipate heat compared to young females during exercise-induced heat loads of ≥325 W when performed in the heat. PMID:25790024

  9. Comparison of ELM heat loads in snowflake and standard divertors

    SciTech Connect

    Rognlien, T D; Cohen, R H; Ryutov, D D; Umansky, M V

    2012-05-08

    An analysis is given of the impact of the tokamak divertor magnetic structure on the temporal and spatial divertor heat flux from edge localized modes (ELMs). Two configurations are studied: the standard divertor where the poloidal magnetic field (B{sub p}) varies linearly with distance (r) from the magnetic null and the snowflake where B{sub p} varies quadratrically with r. Both one and two-dimensional models are used to analyze the effect of the longer magnetic field length between the midplane and the divertor plate for the snowflake that causes a temporal dilation of the ELM divertor heat flux. A second effect discussed is the appearance of a broad region near the null point where the poloidal plasma beta can substantially exceed unity, especially for the snowflake configuration during the ELM; such a condition is likely to drive additional radial ELM transport.

  10. Response of NSTX Liquid Lithium divertor to High Heat Loads

    SciTech Connect

    Abrams, Tyler; Kallman, J; Kaitaa, R; Foley, E L; Grayd, T K; Kugel, H; Levinton, F; McLean, A G; Skinner, C H

    2012-07-18

    Samples of the NSTX Liquid Lithium Divertor (LLD) with and without an evaporative Li coating were directly exposed to a neutral beam ex-situ at a power of ~1.5 MW/m2 for 1-3 seconds. Measurements of front face and bulk sample temperature were obtained. Predictions of temperature evolution were derived from a 1D heat flux model. No macroscopic damage occurred when the "bare" sample was exposed to the beam but microscopic changes to the surface were observed. The Li-coated sample developed a lithium hydroxide (LiOH) coating, which did not change even when the front face temperature exceeded the pure Li melting point. These results are consistent with the lack of damage to the LLD surface and imply that heating alone may not expose pure liquid Li if the melting point of surface impurities is not exceeded. This suggests that flow and heat are needed for future PFCs requiring a liquid Li surface. __________________________________________________

  11. Effects of heat and moisture on fiberglass composite materials in the load carrying and non-load carrying conditions

    NASA Astrophysics Data System (ADS)

    McClurg, Jack Albert

    The objective set forth in this study was to thoroughly document the effects of heat, moisture, and loading conditions on a variety of pultruded unidirectional fiberglass reinforced composite materials. This study incorporated the use of two environmental control chambers and two water immersion tanks in order to provide the necessary range of environmental exposure conditions. A set of specially designed stainless steel loading fixtures was produced in order to introduce the factor of external loading of the specimens while exposed to the predetermined environmental condition and how that would affect the mechanical and physical properties in question. The properties of interest were the flexural strength (determined using the three-point flexural bending method), flexural modulus (determined using the three-point flexural bending method), and glass transition temperature of the material (determined using differential scanning calorimetry). Other data that was noted during the conditioning and testing of the specimens was the break type (flexural tension, compression, shear, etc...), the change in dimensions (prior to exposure vs. after exposure), and the change in weight (prior to exposure vs. after exposure). Using all of the information that was obtained from this study, a more detailed understanding of how and why fiberglass reinforced materials react the way they do when exposed to moisture and elevated temperature was drawn. This study is different from most others in that it explores the interactions of three independent variables (heat, moisture, and loading condition) on three different fiberglass reinforced composite systems (epoxy, vinylester, and polyester resin).

  12. Optimum load distribution between heat sources based on the Cournot model

    NASA Astrophysics Data System (ADS)

    Penkovskii, A. V.; Stennikov, V. A.; Khamisov, O. V.

    2015-08-01

    One of the widespread models of the heat supply of consumers, which is represented in the "Single buyer" format, is considered. The methodological base proposed for its description and investigation presents the use of principles of the theory of games, basic propositions of microeconomics, and models and methods of the theory of hydraulic circuits. The original mathematical model of the heat supply system operating under conditions of the "Single buyer" organizational structure provides the derivation of a solution satisfying the market Nash equilibrium. The distinctive feature of the developed mathematical model is that, along with problems solved traditionally within the bounds of bilateral relations of heat energy sources-heat consumer, it considers a network component with its inherent physicotechnical properties of the heat network and business factors connected with costs of the production and transportation of heat energy. This approach gives the possibility to determine optimum levels of load of heat energy sources. These levels provide the given heat energy demand of consumers subject to the maximum profit earning of heat energy sources and the fulfillment of conditions for formation of minimum heat network costs for a specified time. The practical realization of the search of market equilibrium is considered by the example of a heat supply system with two heat energy sources operating on integrated heat networks. The mathematical approach to the solution search is represented in the graphical form and illustrates computations based on the stepwise iteration procedure for optimization of levels of loading of heat energy sources (groping procedure by Cournot) with the corresponding computation of the heat energy price for consumers.

  13. Characterization of heat loads from mitigated and unmitigated vertical displacement events in DIII-D

    SciTech Connect

    Hollmann, E. M.; Moyer, R. A.; Commaux, N.; Jernigan, T. J.; Eidietis, N. W.; Humphreys, D. A.; Strait, E. J.; Wesley, J. C.; Lasnier, C. J.; Pitts, R. A.; Sugihara, M.; Watkins, J.

    2013-06-15

    Experiments have been conducted on the DIII-D tokamak to study the distribution and repeatability of heat loads and vessel currents resulting from vertical displacement events (VDEs). For unmitigated VDEs, the radiated power fraction appears to be of order 50%, with the remaining power dominantly conducted to the vessel walls. Shot-to-shot scatter in heat loads measured at one toroidal location is not large (<±50%), suggesting that toroidal asymmetries in conducted heat loads are not large. Conducted heat loads are clearly observed during the current quench (CQ) of both mitigated and unmitigated disruptions. Significant poloidal asymmetries in heat loads and radiated power are often observed in the experiments but are not yet understood. Energy dissipated resistively in the conducting walls during the CQ appears to be small (<5%). The mitigating effect of neon massive gas injection (MGI) as a function of MGI trigger delay has also been studied. Improved mitigation is observed as the MGI trigger delay is decreased. For sufficiently early MGI mitigation, close to 100% radiated energy and a reduction of roughly a factor 2 in vessel forces is achieved.

  14. Testing and analysis of load-side immersed heat exchangers for solar domestic hot water systems

    SciTech Connect

    Farrington, R.B.; Bingham, C.E.

    1987-10-01

    This report describes work to determine the performance of load-side heat exchangers for use in residential solar domestic hot water systems. We measured the performance of four heat exchangers: a smooth coil and a finned coil having heat transfer areas of 2.5 m/sup 2/ (26 ft/sup 2/) and those having areas of 1.7 m/sup 2/ (19 ft/sup 2/). A numerical model using the thermal network program MITAS was constructed, and results were compared to the experimental results. Research showed a smooth coil with only 70% of the surface area of a finned coil performed better than the finned coil. Also, load-side heat exchangers can maintain and enhance stratification in storage tanks, permitting the use of control strategies that take advantage of stratified storage tanks to increase system performance. The analytical model, which agreed reasonably well with the experimental results, was used to vary heat exchanger flow rate and area and initial tank temperature for both a smooth- and a finned-coil heat exchanger. Increasing the heat exchanger flow rate and area results in higher heat transfer rates but not necessarily optimal performance. Lower initial tank temperatures resulted in reduced tank stratification. The smooth heat exchanger outperformed the finned heat exchanger with the same outside surface area. 15 refs., 37 figs., 9 tabs.

  15. Dynamic model for electromagnetic field and heating patterns in loaded cylindrical cavities

    SciTech Connect

    Tian, Y.L.; Black, W.M.; Sa`adaldin, H.S.; Ahmad, I.; Silberglitt, R.

    1995-07-01

    An analytical solution for the electromagnetic fields in a cylindrical cavity, partially filled with a cylindrical dielectric has been recently reported. A program based on this solution has been developed and combined with the authors` previous program for heat transfer analysis. The new software has been used to simulate the dynamic temperature profiles of microwave heating and to investigate the role of electromagnetic field in heating uniformity and stability. The effects of cavity mode, cavity dimension, the dielectric properties of loads on electromagnetic field and heating patterns can be predicted using this software.

  16. Detailed heat load calculations for the conceptual design of the Advanced Neutron Source reactor

    SciTech Connect

    Wemple, C.A.

    1993-12-01

    A very detailed MCNP model of the Advanced Neutron Source reactor has been developed at Idaho National Engineering Laboratory. All reactor components inside the reflector vessel were included, and al components were highly segmented. Specific heat loads (watts per gram) have been calculated for each segment in the model, and system-integrated total powers are compared with the design value for the total reactor fission power. The calculated results agree very well with the design values. Axial profiles of the heat loads are provided for all components of the reactor. Individual segment statistical uncertainties were limited wherever possible, and the heat loads for all important reflector components have a standard deviation below 5%.

  17. Performance of an optimally contact-cooled high-heat-load mirror at the APS.

    SciTech Connect

    Cai, Z.; Khounsary, A.; Lai, B.; McNulty, I.; Yun, W.

    1998-11-18

    X-ray undulator beamlines at third-generation synchrotrons facilities use either a monochromator or a mirror as the first optical element. In this paper, the thermal and optical performance of an optimally designed contact-cooled high-heat-load x-ray mirror used as the first optical element on the 2ID undulator beamline at the Advanced Photon Source (APS) is reported. It is shown that this simple and economical mirror design can comfortably handle the high heat load of undulator beamlines and provide good performance with long-term reliability and ease of operation. Availability and advantages of such mirrors can make the mirror-first approach to high-heat-load beamline design an attractive alternative to monochromator-first beamlines in many circumstances.

  18. Combined solar and internal load effects on selection of heat reclaim-economizer HVAC systems

    SciTech Connect

    Sauer, H.J. Jr.; Howell, R.H.; Wang, Z. . Dept. of Mechanical Engineering)

    1990-05-01

    The concern for energy conservation has led to the development and use of heat recovery systems which reclaim the building internal heat before it is discarded in the exhaust air. On the other hand, economizer cycles have been widely used for many years in a variety of types of HVAC systems. Economizer cycles are widely accepted as a means to reduce operating time for chilling equipment when cool outside air is available. It has been suggested that heat reclaim systems should not be used in conjunction with an HVAC system which incorporates an economizer cycle because the economizer operation would result in heat being exhausted which might have been recovered. Others suggest that the economizer cycle can be used economically in a heat recovery system if properly controlled to maintain an overall building heat balance. This study looks at potential energy savings of such combined systems with particular emphasis on the effects of the solar load (amount of glass) and the internal load level (lights, people, appliances, etc.). For systems without thermal storage, annual energy savings of up to 60 percent are predicted with the use of heat reclaim systems in conjunction with economizers when the heat reclaim has priority. These results demonstrate the necessity of complete engineering evaluations if proper selection and operation of combined heat recovery and economizer cycles are to be obtained. This paper includes the basic methodology for making such evaluations.

  19. Cooling-load implications for residential passive-solar-heating systems

    SciTech Connect

    Jones, R.W.; McFarland, R.D.

    1983-01-01

    Ongoing research on quantifying the cooling loads in residential buildings, particularly buildings with passive solar heating systems, is described, along with the computer simulation model used for calculating cooling loads. A sample of interim results is also presented. The objective of the research is to develop a simple analysis method, useful early in design, to estimate the annual cooling energy requirement of a given building.

  20. Calculation of cracking under pulsed heat loads in tungsten manufactured according to ITER specifications

    NASA Astrophysics Data System (ADS)

    Arakcheev, A. S.; Skovorodin, D. I.; Burdakov, A. V.; Shoshin, A. A.; Polosatkin, S. V.; Vasilyev, A. A.; Postupaev, V. V.; Vyacheslavov, L. N.; Kasatov, A. A.; Huber, A.; Mertens, Ph; Wirtz, M.; Linsmeier, Ch; Kreter, A.; Löwenhoff, Th; Begrambekov, L.; Grunin, A.; Sadovskiy, Ya

    2015-12-01

    A mathematical model of surface cracking under pulsed heat load was developed. The model correctly describes a smooth brittle-ductile transition. The elastic deformation is described in a thin-heated-layer approximation. The plastic deformation is described with the Hollomon equation. The time dependence of the deformation and stresses is described for one heating-cooling cycle for a material without initial plastic deformation. The model can be applied to tungsten manufactured according to ITER specifications. The model shows that the stability of stress-relieved tungsten deteriorates when the base temperature increases. This proved to be a result of the close ultimate tensile and yield strengths. For a heat load of arbitrary magnitude a stability criterion was obtained in the form of condition on the relation of the ultimate tensile and yield strengths.

  1. Overall U-values and heating/cooling loads: Manufactured homes

    SciTech Connect

    Conner, C.C.; Taylor, Z.T.

    1992-02-01

    This manual specifies a method for calculating the overall thermal transmittance (also referred to as the overall U-value or U{sub o}), heating load, and cooling load of a manufactured (mobile) home. Rules, examples, and data required by the method are also presented. Compliance with the Department of Housing and Urban Development`s (HUD) U{sub o} and load calculation regulations contained in Sections 3280.506, 3280.510 and 3280.511 of the Manufactured Home Construction and Safety Standards must be demonstrated through the application of the method provided herein.

  2. Overall U-values and heating/cooling loads: Manufactured homes

    SciTech Connect

    Conner, C.C.; Taylor, Z.T.

    1992-02-01

    This manual specifies a method for calculating the overall thermal transmittance (also referred to as the overall U-value or U{sub o}), heating load, and cooling load of a manufactured (mobile) home. Rules, examples, and data required by the method are also presented. Compliance with the Department of Housing and Urban Development's (HUD) U{sub o} and load calculation regulations contained in Sections 3280.506, 3280.510 and 3280.511 of the Manufactured Home Construction and Safety Standards must be demonstrated through the application of the method provided herein.

  3. A Si/Glass Bulk-Micromachined Cryogenic Heat Exchanger for High Heat Loads: Fabrication, Test, and Application Results

    PubMed Central

    Zhu, Weibin; White, Michael J.; Nellis, Gregory F.; Klein, Sanford A.; Gianchandani, Yogesh B.

    2010-01-01

    This paper reports on a micromachined Si/glass stack recuperative heat exchanger with in situ temperature sensors. Numerous high-conductivity silicon plates with integrated platinum resistance temperature detectors (Pt RTDs) are stacked, alternating with low-conductivity Pyrex spacers. The device has a 1 × 1-cm2 footprint and a length of up to 3.5 cm. It is intended for use in Joule–Thomson (J–T) coolers and can sustain pressure exceeding 1 MPa. Tests at cold-end inlet temperatures of 237 K–252 K show that the heat exchanger effectiveness is 0.9 with 0.039-g/s helium mass flow rate. The integrated Pt RTDs present a linear response of 0.26%–0.30%/K over an operational range of 205 K–296 K but remain usable at lower temperatures. In self-cooling tests with ethane as the working fluid, a J–T system with the heat exchanger drops 76.1 K below the inlet temperature, achieving 218.7 K for a pressure of 835.8 kPa. The system reaches 200 K in transient state; further cooling is limited by impurities that freeze within the flow stream. In J–T self-cooling tests with an external heat load, the system reaches 239 K while providing 1 W of cooling. In all cases, there is an additional parasitic heat load estimated at 300–500 mW. PMID:20490284

  4. Surface modifications of W divertor components for EAST during exposure to high heat loads with He

    NASA Astrophysics Data System (ADS)

    Li, C.; Greuner, H.; Yuan, Y.; Zhao, S. X.; Luo, G. N.; Böswirth, B.; Fu, B. Q.; Jia, Y. Z.; Liu, X.; Liu, W.

    2015-08-01

    Flat-type W/Cu plasma-facing components have been developed for the new generation divertor of the Chinese Experimental Advanced Superconducting Tokamak. Surface modifications of such actively water-cooled W components following short and long pulse high heat loading coupled with He particle loads with fluence of 3 × 1022 m-2 have been investigated. An adiabatically loaded W block was investigated as a comparison and exposed to short pulse loads. Blistering was observed on all sample surfaces, but was less pronounced on the components than on the W block, due to the significant lower surface temperature caused by active cooling. For components, longer pulse loads gave rise to a rougher surface. Furthermore, most blisters on components are found to be less than 1 μm in diameter, with just a very few blisters larger than 1 μm, observed only in some near <1 1 1> grains.

  5. Beam heat load due to geometrical and resistive wall impedance in COLDDIAG

    NASA Astrophysics Data System (ADS)

    Casalbuoni, S.; Migliorati, M.; Mostacci, A.; Palumbo, L.; Spataro, B.

    2012-11-01

    One of the still open issues for the development of superconductive insertion devices is the understanding of the heat intake from the electron beam. With the aim of measuring the beam heat load to a cold bore and the hope to gain a deeper understanding in the underlying mechanisms, a cold vacuum chamber for diagnostics (COLDDIAG) was built. It is equipped with the following instrumentation: retarding field analyzers to measure the electron flux, temperature sensors to measure the beam heat load, pressure gauges, and mass spectrometers to measure the gas content. Possible beam heat load sources are: synchrotron radiation, wakefield effects due to geometrical and resistive wall impedance and electron/ion bombardment. The flexibility of the engineering design will allow the installation of the cryostat in different synchrotron light sources. COLDDIAG was first installed in the Diamond Light Source (DLS) in 2011. Due to a mechanical failure of the thermal transition of the cold liner, the cryostat had to be removed after one week of operation. After having implemented design changes in the thermal liner transition, COLDDIAG has been reinstalled in the DLS at the end of August 2012. In order to understand the beam heat load mechanism it is important to compare the measured COLDDIAG parameters with theoretical expectations. In this paper we report on the analytical and numerical computation of the COLDDIAG beam heat load due to coupling impedances deriving from unavoidable step transitions, ports used for pumping and diagnostics, surface roughness, and resistive wall. The results might have an important impact on future technological solutions to be applied to cold bore devices.

  6. Adding a heat bypass improves the thermal characteristics of a 50-micron spaced 8-beam laser diode array

    NASA Astrophysics Data System (ADS)

    Murata, Setsuko; Nakada, Hiroshi

    1992-09-01

    Because heat transfered between closely spaced elements in a compact laser diode array shortens array lifetime and affects the elements' operating characteristics, we evaluated the effect of a heat-bypass structure by measuring the thermal resistance of array elements. We estimated thermal resistance by measuring differences between junction voltage before and after injecting subthreshold current pulses. The thermal resistances due to self heating were more than 20 percent lower after adding the heat-bypass structure. This effect was greatest for elements whose thermal resistance was initially highest, and it was proportional to the number of operating elements. The bypass structure therefore also reduced the thermal resistance resulting from simultaneous operation of all eight elements by more than 40 percent. The resultant reduction in the junction temperature of array elements operating at 100 mW would increase array lifetime at least threefold.

  7. Technology Solutions Case Study: Calculating Design Heating Loads for Superinsulated Buildings

    SciTech Connect

    2015-08-01

    Designing a superinsulated home has many benefits including improved comfort, reduced exterior noise penetration, lower energy bills, and the ability to withstand power and fuel outages under much more comfortable conditions than a typical home. Extremely low heating and cooling loads equate to much smaller HVAC equipment than conventionally required. Sizing the mechanical system to these much lower loads reduces first costs and the size of the distribution system needed. While these homes aren't necessarily constructed with excessive mass in the form of concrete floors and walls, the amount of insulation and the increase in the thickness of the building envelope can lead to a mass effect, resulting in the structures ability to store much more heat than a code built home. This results in a very low thermal inertia making the building much less sensitive to drastic temperature swings thereby decreasing the peak heating load demand. Alternative methods that take this inertia into account along with solar and internal gains result in smaller more appropriate design loads than those calculated using Manual J version 8. During the winter of 2013/2014, the Consortium for Advanced Residential Buildings team monitored the energy use of three homes in climate zone 6 in an attempt to evaluate the accuracy of two different mechanical system sizing methods for low load homes. Based on the results, it is recommended that internal and solar gains be included and some credit for thermal inertia be used in sizing calculations for superinsulated homes.

  8. High Temperature Heat Rejection System for Large Heat Loads; Architecture and Trade Study Results

    NASA Astrophysics Data System (ADS)

    Nikitkin, Michael N.; Allen, Robert W.

    2005-02-01

    Recently, there has been significant interest within the aerospace community to develop space based nuclear power conversion technologies especially for exploring the outer planets of our solar system where the solar energy density is very low. Like all power conversion systems, nuclear power conversion systems operate at efficiencies <100% resulting in the need to reject waste heat to space. Several different HRSs (Heat Rejection Systems) potential designs have been identified for rejecting NEP (Nuclear Electric Power) waste heat and several of them for a CBC (Closed Brayton Cycle) power conversion system are described herein and the results of their initial analyses presented. The analyses presented were performed as part of an initial trade study to recommend a promising HRS for advancement of its TRL (Technical Readiness Level). The trade study effort has concluded that the most preferred HRS for the CBC is the system utilizing simple heat pipes directly connecting the heat source with the heat sink. This system was recommended to be a primary focus during the next phase of the HRS development program.

  9. Study on mitigation of pulsed heat load for ITER cryogenic system

    NASA Astrophysics Data System (ADS)

    Peng, N.; Xiong, L. Y.; Jiang, Y. C.; Tang, J. C.; Liu, L. Q.

    2015-03-01

    One of the key requirements for ITER cryogenic system is the mitigation of the pulsed heat load deposited in the magnet system due to magnetic field variation and pulsed DT neutron production. As one of the control strategies, bypass valves of Toroidal Field (TF) case helium loop would be adjusted to mitigate the pulsed heat load to the LHe plant. A quasi-3D time-dependent thermal-hydraulic analysis of the TF winding packs and TF case has been performed to study the behaviors of TF magnets during the reference plasma scenario with the pulses of 400 s burn and repetition time of 1800 s. The model is based on a 1D helium flow and quasi-3D solid heat conduction model. The whole TF magnet is simulated taking into account thermal conduction between winding pack and case which are cooled separately. The heat loads are given as input information, which include AC losses in the conductor, eddy current losses in the structure, thermal radiation, thermal conduction and nuclear heating. The simulation results indicate that the temperature variation of TF magnet stays within the allowable range when the smooth control strategy is active.

  10. Nuclear heat load calculations for the NBSR cold neutron source using MCNP

    SciTech Connect

    Blau, M. ); Rowe, J.M.; Williams, R.E. )

    1993-01-01

    A liquid-hydrogen (LH2) cold neutron source is being designed for installation in the 20-MW National Bureau of Standards reactor (NBSR) at National Institute of Standards and Technology to replace the D[sub 2]O-ice cold source currently in use. An accurate estimate of the heat deposited in the cold source is needed to ensure that it can be adequately cooled for successful operation. The heat load is caused by the interaction of neutrons and gamma rays with the cold moderator and the walls of the moderator chamber. The Monte Carlo code, MCNP (Version 4.2), was used to model the entire NBSR core and both the existing and the proposed cold sources. The model was used to calculate not only the heat load but also the reactivity and neutron gain of each source.

  11. High Temperature Heat Rejection System for Large Heat Loads; Architecture and Trade Study Results

    NASA Technical Reports Server (NTRS)

    Nilitkin, Michael N.; Allen, Robert W.

    2004-01-01

    To investigate space nuclear reactor technologies, NASA has awarded several contracts under Project Prometheus, the Nuclear Systems Program. The effort described in this paper was performed under one of those contracts (the Brayton NRA) . Like all power conversion systems, nuclear power conversion systems operate at efficiencies less than 100% resulting in the need to reject waste heat to space. Several different HRSs (Heat Rejection Systems) potential designs have been identified for rejecting NEP (Nuclear Electric Power) waste heat and several of them for a CBC (Closed Brayton Cycle) power conversion system are described herein and the results of their initial analyses presented. The analyses presented were performed as part of an initial trade study to recommend a promising HRS for advancement of its TRL.

  12. An evaluation of inside surface heat balance models for cooling load calculations

    SciTech Connect

    Liesen, R.J.; Pedersen, C.O.

    1997-12-31

    The heat balance method is a fundamental procedure that can be used for a specified control volume to describe building physics. With a better understanding of building physics and the cost-effectiveness of computers, these types of procedures are accessible to all practicing engineers. The heat balance method describes the processes using the three fundamental modes of heat transfer: conduction, convection, and radiation. The control volumes naturally divide the building processes into an outside balance, an inside balance, an air balance, and conduction through the building elements. This allows the building heat balance to be solved in a number of fundamental ways. This paper looks at the general formulation of the inside surface heat balance from the conduction through the building elements to the radiant exchange and convection to the air in the zone. Development of many radiant exchange models is shown; these models range from the exact solutions using uniform radiosity networks and exact view factors to mean radiant temperature (MRT) and area-weighted view factors. These radiant exchange models are directly compared to each other for a simple zone with varying aspect ratios. The radiant exchange models are then compared to determine their effect on the cooling load. Finally, other parameters that affect the inside surface heat balance are investigated to determine their sensitivity to the cooling load.

  13. Salt loaded heat pipes: steady-state operation and related heat and mass transport

    NASA Astrophysics Data System (ADS)

    Simakin, A.; Ghassemi, A.

    2003-10-01

    Fluids in the deep-seated zones (3.5-4.5 km) of active geothermal zones are known to have increased salinity and acidity that can enhance interaction with surrounding porous rocks. A possible mechanism for brine generation is the separation of the rising magmatic fluid into a gas-like and a liquid-like component. This work illustrates the main features of this mechanism by investigating the conditions for heat pipe convection of natural brines in hydrothermal systems. The well-established heat pipe regime for convection of two-phase pure water (vapor-liquid) in a porous column is extended to the case of boiling brines. In particular, the NaCl-H 2O system is used to model the 1-D reactive flow with dissolution-precipitation in geothermal reservoirs. The quasi steady-state equations of the conservation of matter, Darcy's law for the gas and liquid phases, and the heat balance equation have been examined while neglecting the temporal variation of porosity. A semi-analytical procedure is used to solve these equations for a two-phase fluid in equilibrium with a solid salt. The solution is in the form of the dependence of liquid volume fraction as a function of temperature for different heat fluxes. The solution is separated into two isolated regions by the temperature T=596°C, at the maximum fluid pressure for three-phase (H-L-V) equilibrium. In the case of unsaturated two-phase flow at the reference permeability of porous rocks (3·10 -16 m 2), the maximum heat flux that can be transferred through the porous column via convection is analytically estimated to be 4.3 W/m 2. This is close to the corresponding value for the three-phase case that is numerically calculated to be 6 W/m 2. Due to dissolution (partial leaching of oxide components by acid condensates) and precipitation of salt at the boiling front, heat transfer in a heat pipe in soluble media occurs in a direction opposite to the associated mass transfer. This can cause deep hydrothermal karsting that is

  14. Method of energy load management using PCM for heating and cooling of buildings

    DOEpatents

    Stovall, T.K.; Tomlinson, J.J.

    1996-03-26

    A method is described for energy load management for the heating and cooling of a building. The method involves utilizing a wallboard as a portion of the building, the wallboard containing about 5 to about 30 wt.% phase change material such that melting of the phase change material occurs during a rise in temperature within the building to remove heat from the air, and a solidification of the phase change material occurs during a lowering of the temperature to dispense heat into the air. At the beginning of either of these cooling or heating cycles, the phase change material is preferably ``fully charged``. In preferred installations one type of wallboard is used on the interior surfaces of exterior walls, and another type as the surface on interior walls. The particular PCM is chosen for the desired wall and room temperature of these locations. In addition, load management is achieved by using PCM-containing wallboards that form cavities of the building such that the cavities can be used for the air handling duct and plenum system of the building. Enhanced load management is achieved by using a thermostat with reduced dead band of about the upper half of a normal dead band of over three degrees. In some applications, air circulation at a rate greater than normal convection provides additional comfort. 7 figs.

  15. Method of energy load management using PCM for heating and cooling of buildings

    DOEpatents

    Stovall, Therese K.; Tomlinson, John J.

    1996-01-01

    A method of energy load management for the heating and cooling of a building. The method involves utilizing a wallboard as a portion of the building, the wallboard containing about 5 to about 30 wt. % a phase change material such that melting of the phase change material occurs during a rise in temperature within the building to remove heat from the air, and a solidification of the phase change material occurs during a lowering of the temperature to dispense heat into the air. At the beginning of either of these cooling or heating cycles, the phase change material is preferably "fully charged". In preferred installations one type of wallboard is used on the interior surfaces of exterior walls, and another type as the surface on interior walls. The particular PCM is chosen for the desired wall and room temperature of these locations. In addition, load management is achieved by using PCM-containing wallboard that form cavities of the building such that the cavities can be used for the air handling duct and plenum system of the building. Enhanced load management is achieved by using a thermostat with reduced dead band of about the upper half of a normal dead band of over three degree. In some applications, air circulation at a rate greater than normal convection provides additional comfort.

  16. Phase change based cooling for high burst mode heat loads with temperature regulation above the phase change temperature

    SciTech Connect

    The United States of America as represented by the United States Department of Energy

    2009-12-15

    An apparatus and method for transferring thermal energy from a heat load is disclosed. In particular, use of a phase change material and specific flow designs enables cooling with temperature regulation well above the fusion temperature of the phase change material for medium and high heat loads from devices operated intermittently (in burst mode). Exemplary heat loads include burst mode lasers and laser diodes, flight avionics, and high power space instruments. Thermal energy is transferred from the heat load to liquid phase change material from a phase change material reservoir. The liquid phase change material is split into two flows. Thermal energy is transferred from the first flow via a phase change material heat sink. The second flow bypasses the phase change material heat sink and joins with liquid phase change material exiting from the phase change material heat sink. The combined liquid phase change material is returned to the liquid phase change material reservoir. The ratio of bypass flow to flow into the phase change material heat sink can be varied to adjust the temperature of the liquid phase change material returned to the liquid phase change material reservoir. Varying the flowrate and temperature of the liquid phase change material presented to the heat load determines the magnitude of thermal energy transferred from the heat load.

  17. Kinetic modeling of divertor heat load fluxes in the Alcator C-Mod and DIII-D tokamaks

    SciTech Connect

    Pankin, A. Y.; Rafiq, T.; Kritz, A. H.; Park, G. Y.; Chang, C. S.; Ku, S.; Brunner, D.; Hughes, J. W.; LaBombard, B.; Terry, J. L.; Groebner, R. J.

    2015-09-15

    The guiding-center kinetic neoclassical transport code, XGC0 [Chang et al., Phys. Plasmas 11, 2649 (2004)], is used to compute the heat fluxes and the heat-load width in the outer divertor plates of Alcator C-Mod and DIII-D tokamaks. The dependence of the width of heat-load fluxes on neoclassical effects, neutral collisions, and anomalous transport is investigated using the XGC0 code. The XGC0 code includes realistic X-point geometry, a neutral source model, the effects of collisions, and a diffusion model for anomalous transport. It is observed that the width of the XGC0 neoclassical heat-load is approximately inversely proportional to the total plasma current I{sub p.} The scaling of the width of the divertor heat-load with plasma current is examined for an Alcator C-Mod discharge and four DIII-D discharges. The scaling of the divertor heat-load width with plasma current is found to be weaker in the Alcator C-Mod discharge compared to scaling found in the DIII-D discharges. The effect of neutral collisions on the 1/I{sub p} scaling of heat-load width is shown not to be significant. Although inclusion of poloidally uniform anomalous transport results in a deviation from the 1/I{sub p} scaling, the inclusion of the anomalous transport that is driven by ballooning-type instabilities results in recovering the neoclassical 1/I{sub p} scaling. The Bohm or gyro-Bohm scalings of anomalous transport do not strongly affect the dependence of the heat-load width on plasma current. The inclusion of anomalous transport, in general, results in widening the width of neoclassical divertor heat-load and enhances the neoclassical heat-load fluxes on the divertor plates. Understanding heat transport in the tokamak scrape-off layer plasmas is important for strengthening the basis for predicting divertor conditions in ITER.

  18. Impact of combined transient plasma/heat loads on tungsten performance below and above recrystallization temperature

    NASA Astrophysics Data System (ADS)

    Loewenhoff, Th.; Bardin, S.; Greuner, H.; Linke, J.; Maier, H.; Morgan, T. W.; Pintsuk, G.; Pitts, R. A.; Riccardi, B.; De Temmerman, G.

    2015-11-01

    The influence of recrystallization on thermal shock resistance has been identified as an issue that may influence the long term performance of ITER tungsten (W) divertor components. To investigate this issue a unique series of experiments has been performed on ITER divertor W monoblock mock-ups in three EU high heat flux facilities: GLADIS (neutral beam), JUDITH 2 (electron beam) and Magnum-PSI (plasma beam). To simulate ITER mitigated edge localised modes, heat fluxes between 0.11 and 0.6 GW m-2 were applied for Δt  <  1 ms. Two different base temperatures, Tbase  =  1200 °C and 1500 °C, were chosen on which ~18 000/100 000 transient events were superimposed representing several full ITER burning plasma discharges in terms of number of transients and particle fluence. An increase in roughening for both e-beam and plasma loaded surfaces was observed when loading during or after recrystallization and when loading at higher temperature. However, regarding the formation of cracks and microstructural modifications the response was different for e-beam and plasma loaded surfaces. The samples loaded in Magnum-PSI did not crack nor show any sign of recrystallization, even at Tbase  =  1500 °C. This could be a dynamic hydrogen flux effect, because pre-loading of samples with hydrogen neutrals (GLADIS) or without hydrogen (e-beam JUDITH 2) did not yield this result. These results show clearly that the loading method used when investigating and qualifying the thermal shock performance of materials for ITER and future fusion reactors can play an important role. This should be properly accounted for and in fact should be the subject of further R&D.

  19. Design and implementation of a multiaxial loading capability during heating on an engineering neutron diffractometer

    NASA Astrophysics Data System (ADS)

    Benafan, O.; Padula, S. A.; Skorpenske, H. D.; An, K.; Vaidyanathan, R.

    2014-10-01

    A gripping capability was designed, implemented, and tested for in situ neutron diffraction measurements during multiaxial loading and heating on the VULCAN engineering materials diffractometer at the spallation neutron source at Oak Ridge National Laboratory. The proposed capability allowed for the acquisition of neutron spectra during tension, compression, torsion, and/or complex loading paths at elevated temperatures. The design consisted of age-hardened, Inconel® 718 grips with direct attachment to the existing MTS load frame having axial and torsional capacities of 100 kN and 400 N.m, respectively. Internal cooling passages were incorporated into the gripping system for fast cooling rates during high temperature experiments up to ˜1000 K. The specimen mounting couplers combined a threaded and hexed end-connection for ease of sample installation/removal without introducing any unwanted loads. Instrumentation of this capability is documented in this work along with various performance parameters. The gripping system was utilized to investigate deformation in NiTi shape memory alloys under various loading/control modes (e.g., isothermal, isobaric, and cyclic), and preliminary results are presented. The measurements facilitated the quantification of the texture, internal strain, and phase fraction evolution in NiTi shape memory alloys under various loading/control modes.

  20. Design and implementation of a multiaxial loading capability during heating on an engineering neutron diffractometer

    SciTech Connect

    Benafan, O.; Padula, S. A.; Skorpenske, H. D.; An, K.; Vaidyanathan, R.

    2014-10-01

    A gripping capability was designed, implemented, and tested for in situ neutron diffraction measurements during multiaxial loading and heating on the VULCAN engineering materials diffractometer at the spallation neutron source at Oak Ridge National Laboratory. The proposed capability allowed for the acquisition of neutron spectra during tension, compression, torsion, and/or complex loading paths at elevated temperatures. The design consisted of age-hardened, Inconel{sup ®} 718 grips with direct attachment to the existing MTS load frame having axial and torsional capacities of 100 kN and 400 N·m, respectively. Internal cooling passages were incorporated into the gripping system for fast cooling rates during high temperature experiments up to ~1000 K. The specimen mounting couplers combined a threaded and hexed end-connection for ease of sample installation/removal without introducing any unwanted loads. Instrumentation of this capability is documented in this work along with various performance parameters. The gripping system was utilized to investigate deformation in NiTi shape memory alloys under various loading/control modes (e.g., isothermal, isobaric, and cyclic), and preliminary results are presented. The measurements facilitated the quantification of the texture, internal strain, and phase fraction evolution in NiTi shape memory alloys under various loading/control modes.

  1. Measuring the Heat Load on the Flight ASTRO-H Soft Xray Spectrometer Dewar

    NASA Technical Reports Server (NTRS)

    DiPirro, M.; Shirron, P.; Yoshida, S.; Kanao, K.; Tsunematsu, S.; Fujimoto, R.; Sneiderman, G.; Kimball, M.; Ezoe, Y.; Ishikawa, K.; Takei, Y.; Mitsuda, K.; Kelley, R.

    2015-01-01

    The Soft Xray Spectrometer (SXS) instrument on-board the ASTRO-H X-ray mission is based on microcalorimeters operating at 50 mK. Low temperature is achieved by use of an adiabatic demagnetization refrigerator (ADR) cyclically operating up to a heat sink at either 1.2 K or 4.5 K. The 1.2 K heat sink is provided by a 40 liter superfluid helium dewar. The parasitic heat to the helium from supports, plumbing, wires, and radiation, and the cyclic heat dumped by the ADR operation determine the liquid helium lifetime. To measure this lifetime we have used various techniques to rapidly achieve thermal equilibrium and then measure the boil-off rate of the helium. We have measured a parasitic heat of 650 microwatts and a cyclic heat of 100 microwatts for a total of 750 microwatts. This closely matches the predicted heat load. Starting with a fill level at launch of more than 33 liters results in a lifetime of greater than 4 years for the liquid helium. The techniques and accuracy for this measurement will be explained in this paper.

  2. An Optimal Control Approach for an Overall Cryogenic Plant Under Pulsed Heat Loads

    NASA Astrophysics Data System (ADS)

    Palaćın, Luis Gómez; Bradu, Benjamin; Viñuela, Enrique Blanco; Maekawa, Ryuji; Chalifour, Michel

    This work deals with the optimal management of a cryogenic plant composed by parallel refrigeration plants, which provide supercritical helium to pulsed heat loads. First, a data reconciliation approach is proposed to estimate precisely the refrigerator variables necessary to deduce the efficiency of each refrigerator. Second, taking into account these efficiencies, an optimal operation of the system is proposed and studied. Finally, while minimizing the power consumption of the refrigerators, the control system maintains stable operation of the cryoplant under pulsed heat loads. The management of the refrigerators is carried out by an upper control layer, which balances the relative production of cooling power in each refrigerator. In addition, this upper control layer deals with the mitigation of malfunctions and faults in the system. The proposed approach has been validated using a dynamic model of the cryoplant developed with EcosimPro software, based on first principles (mass and energy balances) and thermo-hydraulic equations.

  3. The Added Economic and Environmental Value of Solar Thermal Systems in Microgrids with CombinedHeat and Power

    SciTech Connect

    Marnay, Chris; Stadler, Michael; Cardoso, Goncalo; Megel, Olivier; Lai, Judy; Siddiqui, Afzal

    2009-08-15

    The addition of solar thermal and heat storage systems can improve the economic, as well as environmental attraction of micro-generation systems, e.g. fuel cells with or without combined heat and power (CHP) and contribute to enhanced CO2 reduction. However, the interactions between solar thermal collection and storage systems and CHP systems can be complex, depending on the tariff structure, load profile, etc. In order to examine the impact of solar thermal and heat storage on CO2 emissions and annual energy costs, a microgrid's distributed energy resources (DER) adoption problem is formulated as a mixed-integer linear program. The objective is minimization of annual energy costs. This paper focuses on analysis of the optimal interaction of solar thermal systems, which can be used for domestic hot water, space heating and/or cooling, and micro-CHP systems in the California service territory of San Diego Gas and Electric (SDG&E). Contrary to typical expectations, our results indicate that despite the high solar radiation in southern California, fossil based CHP units are dominant, even with forecast 2020 technology and costs. A CO2 pricing scheme would be needed to incent installation of combined solar thermal absorption chiller systems, and no heat storage systems are adopted. This research also shows that photovoltaic (PV) arrays are favored by CO2 pricing more than solar thermal adoption.

  4. Titanium tritide radioisotope heat source development : palladium-coated titanium hydriding kinetics and tritium loading tests.

    SciTech Connect

    Van Blarigan, Peter; Shugard, Andrew D.; Walters, R. Tom

    2012-01-01

    We have found that a 180 nm palladium coating enables titanium to be loaded with hydrogen isotopes without the typical 400-500 C vacuum activation step. The hydriding kinetics of Pd coated Ti can be described by the Mintz-Bloch adherent film model, where the rate of hydrogen absorption is controlled by diffusion through an adherent metal-hydride layer. Hydriding rate constants of Pd coated and vacuum activated Ti were found to be very similar. In addition, deuterium/tritium loading experiments were done on stacks of Pd coated Ti foil in a representative-size radioisotope heat source vessel. The experiments demonstrated that such a vessel could be loaded completely, at temperatures below 300 C, in less than 10 hours, using existing department-of-energy tritium handling infrastructure.

  5. Comparison of the Pharmacokinetics of Nicotine Following Single and Ad Libitum Use of a Tobacco Heating System or Combustible Cigarettes

    PubMed Central

    Picavet, Patrick; Haziza, Christelle; Lama, Nicola; Weitkunat, Rolf

    2016-01-01

    Introduction: We aimed to compare the pharmacokinetics of nicotine between the heat-not-burn Tobacco Heating System 2.1 (THS 2.1) and combustible cigarettes (CCs). We also examined whether the subjective urge to smoke was associated with the pharmacokinetics of nicotine. Methods: This open-label, randomized, two-period, two-sequence crossover study conducted in 28 healthy smokers assessed the pharmacokinetics of nicotine after single and ad libitum use of the THS 2.1 or CCs. During the 7-day confinement period, blood samples were drawn for pharmacokinetic analysis. Subjective effects related to THS 2.1 or CC use were assessed using the Questionnaire of Smoking Urges (QSU-Brief). Results: The nicotine delivery rate was similar with the THS 2.1 and CCs after single and ad libitum use. The time to the maximum nicotine concentration was 8 minutes after single use of the THS 2.1 and CCs. The time to the peak concentration following ad libitum use was similar between the THS 2.1 and CCs. The maximum plasma nicotine concentration after single use of the THS 2.1 was 8.4ng/mL, 70.3% of that obtained with CCs. A transient reduction from baseline in the urge to smoke of 40% was observed 15 minutes after the single use of both the THS 2.1 and CCs. The mean QSU-Brief total scores following single and ad libitum use were similar for the THS 2.1 and CCs. Conclusions: These results suggest that the THS 2.1 effectively delivers nicotine and achieves similar pharmacokinetic profiles to CCs. The THS 2.1 also reduced the urge to smoke similarly to CCs. Implications: Reducing exposure to toxicants and safer delivery of nicotine are among the strategies that may reduce the harm of smoking-related diseases. In the present study, we investigated the pharmacokinetics of nicotine and their effects on the urge to smoke using the THS 2.1. It was developed to replicate the ritual of smoking as closely as possible by providing nicotine in a way that mimics CC smoking, but limits pyrolysis and

  6. The cryogenic cooling program in high-heat-load optics at the Advanced Photon Source

    SciTech Connect

    Rogers, C.S.

    1993-07-01

    This paper describes some of the aspects of the cryogenic optics program at the Advanced Photon Source (APS). A liquid-nitrogen-cooled, high-vacuum, double crystal monochromator is being fabricated at Argonne National Laboratory (ANL). A pumping system capable of delivering a variable flow rate of up to 10 gallons per minute of pressurized liquid nitrogen and removing 5 kilowatts of x-ray power is also being constructed. This specialized pumping system and monochromator will be used to test the viability of cryogenically cooled, high-heat-load synchrotron optics. It has been determined that heat transfer enhancement will be required for optics used with APS insertion devices. An analysis of a porous-matrix-enhanced monochromator crystal is presented. For the particular case investigated, a heat transfer enhancement factor of 5 to 6 was calculated.

  7. Measurements of heat transfer distribution over the surfaces of highly loaded turbine nozzle guide vanes

    NASA Technical Reports Server (NTRS)

    Nealy, D. A.; Mihelc, M. S.; Hylton, L. D.; Gladden, H. J.

    1983-01-01

    The results of an experimental study of aerodynamic (surface velocity) and heat transfer distributions over the surfaces of two different, highly loaded, low-solidity contemporary turbine vane designs are presented. The aerodynamic configurations of the two vanes were carefully selected to emphasize fundamental differences in the character of the solution surface pressure distributions and the consequent effect on surface heat transfer distributions. The experimental measurements were made in moderate-temperature, three-vane cascades under steady-state conditions. The principal independent parameters (Mach number, Reynolds number, turbulence intensity, and wall-to-gas temperature ratio) were varied over ranges consistent with actual engine operation, and the heat matrix was structured to provide an assessment of the independent influence of each parameter. These measurements are intended to serve as verification data for a parallel analytical code development effort. The results of this parallel effort are briefly reviewed, and the principal conclusions to date are summarized.

  8. Initiation of Heated PBX-9501 Explosive When Exposed to Dynamic Loading

    SciTech Connect

    Urtiew, P A; Vandersall, K S; Tarver, C M; Garcia, F

    2005-08-16

    Shock initiation experiments on the heated PBX9501 explosive (95% HMX, 2.5% estane, and 2.5% nitro-plasticizer by weight) were performed at temperatures 150 C and 180 C to obtain in-situ pressure gauge data. A 101 mm diameter propellant driven gas gun was utilized to initiate the PBX9501 explosive and manganin piezo-resistive pressure gauge packages were placed between sample slices to measure time resolved local pressure histories. The run-distance-to-detonation points on the Pop-plot for these experiments showed the sensitivity of the heated material to shock loading. This work shows that heated PBX-9501 is more shock sensitive than it is at ambient conditions. Proper Ignition and Growth modeling parameters were obtained to fit the experimental data. This parameter set will allow accurate code predictions to be calculated for safety scenarios involving PBX9501 explosives at temperatures close to those at which experiments were performed.

  9. Influence of the heater material on the critical heat load at boiling of liquids on surfaces with different sizes

    NASA Astrophysics Data System (ADS)

    Anokhina, E. V.

    2010-05-01

    Data on critical heat loads q cr for the saturated and unsaturated pool boiling of water and ethanol under atmospheric pressure are reported. It is found experimentally that the critical heat load does not necessarily coincide with the heat load causing burnout of the heater, which should be taken into account. The absolute values of q cr for the boiling of water and ethanol on copper surfaces 65, 80, 100, 120, and 200 μm in diameter; tungsten surface 100 μm in diameter; and nichrome surface 100 μm in diameter are obtained experimentally.

  10. Effects of dynamic load on flow and heat transfer of two-phase boiling water in a horizontal pipe

    NASA Astrophysics Data System (ADS)

    Yao, Qiu-Ping; Song, Bao-Yin; Zhao, Mei; Cao, Xi

    2009-07-01

    An experimental investigation was performed to obtain the flow and heat transfer characteristics of single-phase water flow and two-phase pipe boiling water flow under high gravity (Hi-G) in present work. The experiments were conducted on a rotating platform, and boiling two-phase flow state was obtained by means of electric heating. The data were collected specifically in the test section, which was a lucite pipe with inner diameter of 20 mm and length of 400 mm. By changing the parameters, such as rotation speed, inlet temperature, flow rate, and etc., and analyzing the fluid resistance, effective heat and heat transfer coefficient of the experimental data, the effects of dynamic load on the flow and heat transfer characteristics of single phase water and two-phase boiling water flow were investigated and obtained. The two-phase flow patterns under Hi-G condition were obtained with a video camera. The results show that the dynamic load significantly influences the flow characteristic and boiling heat transfer of the two-phase pipe flow. As the direction of the dynamic load and the flow direction are opposite, the greater the dynamic load, the higher the outlet pressure and the flow resistance, and the lower the flow rate, the void fraction, the wall inner surface temperature and the heat transfer capability. Therefore, the dynamic load will block the fluid flow, enhance heat dissipation toward the ambient environment and reduce the heat transfer to the two-phase boiling flow.

  11. Mechanism of heat generation from loading gaseous hydrogen isotopes into palladium nanoparticles

    NASA Astrophysics Data System (ADS)

    Dmitriyeva, Olga

    I have carried out the study of hydrogen isotope reactions in the presence of palladium nanoparticles impregnated into oxide powder. My goal was to explain the mechanisms of heat generation in those systems as a result of exposure to deuterium gas. Some researchers have associated this heating with a nuclear reaction in the Pd lattice. While some earlier experiments showed a correlation between the generation of excess heat and helium production as possible evidence of a nuclear reaction, the results of that research have not been replicated by the other groups and the search for radiation was unsuccessful. Therefore, the unknown origin of the excess heat produced by these systems is of great interest. I synthesized different types of Pd and Pt-impregnated oxide samples similar to those used by other research groups. I used different characterization techniques to confirm that the fabrication method I used is capable of producing Pd nanoparticles on the surface of alumina support. I used a custom built gas-loading system to pressurize the material with hydrogen and deuterium gas while measuring heat output as a result of these pressurizations. My initial study confirmed the excess heat generation in the presence of deuterium. However, the in-situ radiometry and alpha-particle measurements did not show any abnormal increase in counts above the background level. In the absence of nuclear reaction products, I decided to look for a conventional chemical process that could account for the excess heat generation. It was earlier suggested that Pd in its nanoparticle form catalyzes hydrogen/deuterium (H/D) exchange reactions in the material. To prove the chemical nature of the observed phenomena I demonstrated that the reaction can be either exo- or endothermic based on the water isotope trapped in the material and the type of gas provided to the system. The H/D exchange was confirmed by RGA, NMR and FTIR analysis. I quantified the amount of energy that can be released due

  12. Flicker Test as a Load Measurement During the Combined Effect of Heat and Noise.

    PubMed

    Luczak; Kurkus-Rozowska; Sobolewski

    1995-01-01

    This study was a joint physiological and psychological experiment undertaken in order to determine changes in physiological and psychological human functions under the combined influence of heat, noise and physical activity. Seven experimental situations were simulated in a climatic chamber, with different configurations of three independent variables: heat (40 degrees C), noise (98 dB) and physical effort (30% of maximum volume of oxygen uptake--V0&inf2; max). Five psychological variables (critical flicker fusion--CFF, hand tremor, reaction time, subjective climate evaluation and subjective evaluation of the given condition load) and two physiological variables (heart rate and rectal temperature) were monitored. Results indicate that CFF changed (increased) significantly when more than one experimental variable was applied. These changes coincided with significant changes in both subjective climate evaluation and subjective evaluation of a given condition load. There were no significant changes in psychomotor functions (hand tremor and reaction time). None of the observed physiological parameters were above the critical value. The results obtained let us suggest that CFF can be treated as a psychophysical load indicator. PMID:10603547

  13. Reducing the Heat Load on the LCLS 120 Hz RF Gun with RF Pulse Shaping

    SciTech Connect

    Schmerge, J.

    2005-01-31

    The LCLS injector must operate at 120 Hz repetition frequency but to date the maximum operating frequency of an S-band rf gun has been 50 Hz. The high fields desired for the LCLS gun operation limit the repetition frequency due to thermal expansion causing rf detuning and field redistribution. One method of addressing the thermal loading problem is too reduce the power lost on the cavity walls by properly shaping the rf pulse incident on the gun. The idea is to reach the steady state field value in the gun faster than the time constant of the gun would allow when using a flat incident rf pulse. By increasing the incident power by about a factor of three and then decreasing the incident power when the field reaches the desired value in the gun, the field build up time can be decreased by more than a factor of three. Using this technique the heat load is also decreased by more than a factor of three. In addition the rf coupling coefficient can be increased from the typical critically coupled designs to an overcoupled design which also helps reduce the field build up time. Increasing the coupling coefficient from 1 to 2 reduces the heat load by another 25% and still limits the reflected power and coupling hole size to manageable levels.

  14. Tungsten joining with copper alloy and its high heat load performance

    NASA Astrophysics Data System (ADS)

    Liu, Xiang; Lian, Youyun; Chen, Lei; Cheng, Zengkui; Chen, Jiming; Duan, Xuru; Song, Jioupeng; Yu, Yang

    2014-12-01

    W-CuCrZr joining technology by using low activation Cu-Mn filler metal was developed at Southwestern Institute of Physics (SWIP) for the manufacturing of divertor components of fusion experiment devices. In addition, a fast W coating technology by chemical vapor deposition (CVD) was also developed and CVD-W/CuCrZr and CVD-W/C mockups with a W coating thickness of 2 mm were prepared. In order to assess their high heat flux (HHF) performances, a 60 kW Electron-beam Material testing Scenario (EMS-60) equipped with a 150 keV electron beam welding gun was constructed at SWIP. Experimental results indicated that brazed W/CuCrZr mockups can withstand 8 MW/m2 heat flux for 1000 cycles without visible damages and CVD-W/CuCrZr mockups with W-Cu gradient interface can survive 1000 cycles under 11 MW/m2 heat flux. An ultrasonic inspection method for non-destructive tests (NDT) of brazed W/CuCrZr mockups was established and 2 mm defect can be detected. Infinite element analysis and heat load tests indicated that 5 mm defect had less noticeable influence on the heat transfer.

  15. Recrystallization and grain growth induced by ELMs-like transient heat loads in deformed tungsten samples.

    PubMed

    Suslova, A; El-Atwani, O; Sagapuram, D; Harilal, S S; Hassanein, A

    2014-01-01

    Tungsten has been chosen as the main candidate for plasma facing components (PFCs) due to its superior properties under extreme operating conditions in future nuclear fusion reactors such as ITER. One of the serious issues for PFCs is the high heat load during transient events such as ELMs and disruption in the reactor. Recrystallization and grain size growth in PFC materials caused by transients are undesirable changes in the material, since the isotropic microstructure developed after recrystallization exhibits a higher ductile-to-brittle transition temperature which increases with the grain size, a lower thermal shock fatigue resistance, a lower mechanical strength, and an increased surface roughening. The current work was focused on careful determination of the threshold parameters for surface recrystallization, grain growth rate, and thermal shock fatigue resistance under ELM-like transient heat events. Transient heat loads were simulated using long pulse laser beams for two different grades of ultrafine-grained tungsten. It was observed that cold rolled tungsten demonstrated better power handling capabilities and higher thermal stress fatigue resistance compared to severely deformed tungsten. Higher recrystallization threshold, slower grain growth, and lower degree of surface roughening were observed in the cold rolled tungsten. PMID:25366885

  16. Recrystallization and grain growth induced by ELMs-like transient heat loads in deformed tungsten samples

    NASA Astrophysics Data System (ADS)

    Suslova, A.; El-Atwani, O.; Sagapuram, D.; Harilal, S. S.; Hassanein, A.

    2014-11-01

    Tungsten has been chosen as the main candidate for plasma facing components (PFCs) due to its superior properties under extreme operating conditions in future nuclear fusion reactors such as ITER. One of the serious issues for PFCs is the high heat load during transient events such as ELMs and disruption in the reactor. Recrystallization and grain size growth in PFC materials caused by transients are undesirable changes in the material, since the isotropic microstructure developed after recrystallization exhibits a higher ductile-to-brittle transition temperature which increases with the grain size, a lower thermal shock fatigue resistance, a lower mechanical strength, and an increased surface roughening. The current work was focused on careful determination of the threshold parameters for surface recrystallization, grain growth rate, and thermal shock fatigue resistance under ELM-like transient heat events. Transient heat loads were simulated using long pulse laser beams for two different grades of ultrafine-grained tungsten. It was observed that cold rolled tungsten demonstrated better power handling capabilities and higher thermal stress fatigue resistance compared to severely deformed tungsten. Higher recrystallization threshold, slower grain growth, and lower degree of surface roughening were observed in the cold rolled tungsten.

  17. Recrystallization and grain growth induced by ELMs-like transient heat loads in deformed tungsten samples

    PubMed Central

    Suslova, A.; El-Atwani, O.; Sagapuram, D.; Harilal, S. S.; Hassanein, A.

    2014-01-01

    Tungsten has been chosen as the main candidate for plasma facing components (PFCs) due to its superior properties under extreme operating conditions in future nuclear fusion reactors such as ITER. One of the serious issues for PFCs is the high heat load during transient events such as ELMs and disruption in the reactor. Recrystallization and grain size growth in PFC materials caused by transients are undesirable changes in the material, since the isotropic microstructure developed after recrystallization exhibits a higher ductile-to-brittle transition temperature which increases with the grain size, a lower thermal shock fatigue resistance, a lower mechanical strength, and an increased surface roughening. The current work was focused on careful determination of the threshold parameters for surface recrystallization, grain growth rate, and thermal shock fatigue resistance under ELM-like transient heat events. Transient heat loads were simulated using long pulse laser beams for two different grades of ultrafine-grained tungsten. It was observed that cold rolled tungsten demonstrated better power handling capabilities and higher thermal stress fatigue resistance compared to severely deformed tungsten. Higher recrystallization threshold, slower grain growth, and lower degree of surface roughening were observed in the cold rolled tungsten. PMID:25366885

  18. Impact of Groundwater Flow and Energy Load on Multiple Borehole Heat Exchangers.

    PubMed

    Dehkordi, S Emad; Schincariol, Robert A; Olofsson, Bo

    2015-01-01

    The effect of array configuration, that is, number, layout, and spacing, on the performance of multiple borehole heat exchangers (BHEs) is generally known under the assumption of fully conductive transport. The effect of groundwater flow on BHE performance is also well established, but most commonly for single BHEs. In multiple-BHE systems the effect of groundwater advection can be more complicated due to the induced thermal interference between the boreholes. To ascertain the influence of groundwater flow and borehole arrangement, this study investigates single- and multi-BHE systems of various configurations. Moreover, the influence of energy load balance is also examined. The results from corresponding cases with and without groundwater flow as well as balanced and unbalanced energy loads are cross-compared. The groundwater flux value, 10(-7) m/s, is chosen based on the findings of previous studies on groundwater flow interaction with BHEs and thermal response tests. It is observed that multi-BHE systems with balanced loads are less sensitive to array configuration attributes and groundwater flow, in the long-term. Conversely, multi-BHE systems with unbalanced loads are influenced by borehole array configuration as well as groundwater flow; these effects become more pronounced with time, unlike when the load is balanced. Groundwater flow has more influence on stabilizing loop temperatures, compared to array characteristics. Although borehole thermal energy storage (BTES) systems have a balanced energy load function, preliminary investigation on their efficiency shows a negative impact by groundwater which is due to their dependency on high temperature gradients between the boreholes and surroundings. PMID:25227154

  19. Effect of heat treatment temperature on superconducting performance of B 4C added MgB 2/Nb conductors

    NASA Astrophysics Data System (ADS)

    Viljamaa, J.; Kario, A.; Dobročka, E.; Reissner, M.; Kulich, M.; Kováč, P.; Häßler, W.

    2012-02-01

    A previously observed enhancing effect of addition of 10 wt.% of B 4C on critical current density ( Jc) dependence on magnetic flux density ( B) in MgB 2 superconductors is examined here in more detail. Nb sheathed in situ MgB 2 monofilamentary Powder-in-Tube (PIT) samples are prepared with the 10 wt.% addition of boron carbide. The samples are heat treated at different temperatures, namely at 650, 700, 750, and 800 °C for 30 min. The phases and lattice parameters of the samples are studied using X-ray Diffraction (XRD). The amount of B 4C does not decrease from the initial amount with increasing heat treatment temperature ( Tht) but instead increases. This indicates that some of the Mg from the precursor reacts with the Nb sheath. Magnetic Jc( B) characteristics are obtained at several temperatures in external B in a Vibrating Sample Magnetometer (VSM). The magnetic and transport Jc( B) results disagree with each other which can be explained by unsuitability of Nb as the sheath with higher Tht. From these results, also pinning force densities ( Fp) are calculated. No effect on pinning mechanism of B 4C added samples is observed by the heat treatment conditions. Resistance dependencies on temperature are also measured in a Physical Properties Measurement System (PPMS). Mg deficiency with high Tht is supported by these measurements.

  20. Temperature calculations of heat loads in rotating target wheels exposed to high beam currents.

    SciTech Connect

    Greene, J. P.; Gabor, R.; Neubauer, J.

    2000-11-29

    In heavy-ion physics, high beam currents can eventually melt or destroy the target. Tightly focused beams on stationary targets of modest melting point will exhibit short lifetimes. Defocused or wobbled beams are employed to enhance target survival. Rotating targets using large diameter wheels can help overcome target melting and allow for higher beam currents to be used in experiments. The purpose of the calculations in this work is to try and predict the safe maximum beam currents which produce heat loads below the melting point of the target material.

  1. Simultaneous optimization of the cavity heat load and trip rates in linacs using a genetic algorithm

    NASA Astrophysics Data System (ADS)

    Terzić, Balša; Hofler, Alicia S.; Reeves, Cody J.; Khan, Sabbir A.; Krafft, Geoffrey A.; Benesch, Jay; Freyberger, Arne; Ranjan, Desh

    2014-10-01

    In this paper, a genetic algorithm-based optimization is used to simultaneously minimize two competing objectives guiding the operation of the Jefferson Lab's Continuous Electron Beam Accelerator Facility linacs: cavity heat load and radio frequency cavity trip rates. The results represent a significant improvement to the standard linac energy management tool and thereby could lead to a more efficient Continuous Electron Beam Accelerator Facility configuration. This study also serves as a proof of principle of how a genetic algorithm can be used for optimizing other linac-based machines.

  2. Improved High-Heat-Load Graphite Filter Design At CHESS Wiggler Beamlines

    SciTech Connect

    Savino, James J.; Shen Qun; Strieter, Gretchen; Fontes, Ernest; Pauling, Alan K.

    2004-05-12

    Conductively cooled highly-oriented pyrolytic graphite (HOPG) filters have been used at CHESS wiggler beamlines to protect downstream beryllium windows under high heat loads. In the past beam currents above 350 mA have caused excessively high temperatures on the existing HOPG filters, resulting in rapid sublimation of the graphite and drastic shortening of filter lifetimes. A new filter design which eliminates some drawbacks of the existing design is described. The new design utilizes a slotted water jet, which cools a thin, 'compliant' graphite-copper braze joint. Heat-transfer enhancements should enable an installed filter to survive beam currents of 450 mA. Optimization of design features and analysis results are discussed.

  3. Study of Nuclear Decay Data Contribution to Uncertainties in Heat Load Estimations for Spent Fuel Pools

    NASA Astrophysics Data System (ADS)

    Ferroukhi, H.; Leray, O.; Hursin, M.; Vasiliev, A.; Perret, G.; Pautz, A.

    2014-04-01

    At the Paul Scherrer Institut (PSI), a methodology for nuclear data uncertainty propagation in CASMO-5M (C5M) assembly calculations is under development. This paper presents a preliminary application of this methodology to C5M decay heat calculations. Applying a stochastic sampling method, nuclear decay data uncertainties are first propagated for the cooling phase only. Thereafter, the uncertainty propagation is enlarged to gradually account for cross-section as well as fission yield uncertainties during the depletion phase. On that basis, assembly heat load uncertainties as well as total uncertainty for the entire pool are quantified for cooling times up to one year. The relative contributions from the various types of nuclear data uncertainties are in this context also estimated.

  4. Contact-cooled U-monochromators for high heat load x-ray beamlines

    SciTech Connect

    Khounsary, A.; Yun, W.; Trakhtenberg, E.; Xu, S.; Assoufid, L.; Lee, W.K.

    1996-12-31

    This paper describes the design, expected performance, and preliminary test results of a contact-cooled monochromator for use on high heat load x-ray beamlines. The monochromator has a cross section in the shape of the letter U. This monochromator should be suitable for handing heat fluxes up to 5 W/square millimeter. As such, for the present application, it is compatible with the best internally cooled crystal monochromators. There are three key features in the design of this monochromator. First, it is contact cooled, thereby eliminating fabrication of cooling channels, bonding, and undesirable strains in the monochromator due to coolant-manifold-to-crystal-interface. Second, by illuminating the entire length of the crystal and extracting the central part of the reflected beam, sharp slope changes in the beam profile and thus slope errors are avoided. Last, by appropriate cooling of the crystal, tangential slope error can be substantially reduced.

  5. Contact-cooled U-monochromators for high heat load x-ray beamlines

    SciTech Connect

    Khounsary, A.; Yun, W.; Trakhtenberg, E.; Xu, S.; Assoufid, L.; Lee, W.K.

    1996-12-31

    This paper describes the design, expected performance, and preliminary test results of a contact-cooled monochromator for use on high heat load x-ray beamlines. The monochromator has a cross section in the shape of the letter U. This monochromator should be suitable for handling heat fluxes up to 5 W/mm{sup 2}. As such, for the present application, it is compatible with the best internally cooled silicon crystal monochromators operating at room temperature. There are three key features in the design of this monochromator. First, it is contact cooled, thereby eliminating fabrication of cooling channels, bonding, and undesirable strains in the monochromator due to coolant-manifold-to-crystal-interface. Second, by illuminating the entire length of the crystal and extracting the central part of the reflected beam, sharp slope changes in the beam profile and thus slope errors are avoided. Last, by selecting appropriate crystal geometry and cooling locations, tangential slope error can be substantially reduced.

  6. Formation of stored heat by means of bled steam during times of load reduction and its use in peak load times

    NASA Technical Reports Server (NTRS)

    Bitterlich, E.

    1977-01-01

    Technical possibilities and economic advantages of integrating hot water storage systems into power plants fired with fossil fuels are discussed. The systems can be charged during times of load reduction and then used for back-up during peak load periods. Investment costs are higher for such systems than for gas turbine power plants fired with natural gas or light oil installed to meet peak load demand. However, by improving specific heat consumption by about 1,000 kcal/k ohm, which thus reduces the related costs, investment costs will be compensated for, so that power production costs will not increase.

  7. Experimental validation of advanced regulations for superconducting magnet cooling undergoing periodic heat loads

    NASA Astrophysics Data System (ADS)

    Lagier, B.; Rousset, B.; Hoa, C.; Bonnay, P.

    2014-01-01

    Superconducting magnets used in tokamaks undergo periodic heat load caused by cycling plasma operations inducing AC losses, neutrons fluxes and eddy currents in magnet structures. In the cryogenic system of JT60-SA tokamak, the Auxiliary Cold Box (ACB) distributes helium from the refrigerator to the cryogenic users and in particular to the superconducting magnets. ACB comprises a saturated helium bath with immersed heat exchangers, extracting heat from independent cooling loops. The supercritical helium flow in each cooling loop is driven by a cold circulator. In order to safely operate the refrigerator during plasma pulses, the interface between the ACB and the refrigerator shall be as stable as possible, with well-balanced bath inlet and outlet mass flows during cycling operation. The solution presented in this paper relies on a combination of regulations to smooth pulsed heat loads and to keep a constant refrigeration power during all the cycle. Two smoothing strategies are presented, both regulating the outlet mass flow of the bath: the first one using the bath as a thermal buffer and the second one storing energy in the loop by varying the cold circulator speed. The bath outlet mass flow is also controlled by an immersed resistive heater which enables a constant evaporation rate in the bath when power coming from the loops is decreasing. The refrigeration power is controlled so that the compensating power remains within an acceptable margin. Experimental validation is achieved using the HELIOS facility. This facility running at CEA Grenoble since 2010 is a scaled down model of the ACB bath and Central Solenoid magnet cooling loop of the JT60-SA tokamak. Test results show performances and robustness of the regulations.

  8. Experimental validation of advanced regulations for superconducting magnet cooling undergoing periodic heat loads

    SciTech Connect

    Lagier, B.; Rousset, B.; Hoa, C.; Bonnay, P.

    2014-01-29

    Superconducting magnets used in tokamaks undergo periodic heat load caused by cycling plasma operations inducing AC losses, neutrons fluxes and eddy currents in magnet structures. In the cryogenic system of JT60-SA tokamak, the Auxiliary Cold Box (ACB) distributes helium from the refrigerator to the cryogenic users and in particular to the superconducting magnets. ACB comprises a saturated helium bath with immersed heat exchangers, extracting heat from independent cooling loops. The supercritical helium flow in each cooling loop is driven by a cold circulator. In order to safely operate the refrigerator during plasma pulses, the interface between the ACB and the refrigerator shall be as stable as possible, with well-balanced bath inlet and outlet mass flows during cycling operation. The solution presented in this paper relies on a combination of regulations to smooth pulsed heat loads and to keep a constant refrigeration power during all the cycle. Two smoothing strategies are presented, both regulating the outlet mass flow of the bath: the first one using the bath as a thermal buffer and the second one storing energy in the loop by varying the cold circulator speed. The bath outlet mass flow is also controlled by an immersed resistive heater which enables a constant evaporation rate in the bath when power coming from the loops is decreasing. The refrigeration power is controlled so that the compensating power remains within an acceptable margin. Experimental validation is achieved using the HELIOS facility. This facility running at CEA Grenoble since 2010 is a scaled down model of the ACB bath and Central Solenoid magnet cooling loop of the JT60-SA tokamak. Test results show performances and robustness of the regulations.

  9. Analysis of Unsteady Tip and Endwall Heat Transfer in a Highly Loaded Transonic Turbine Stage

    NASA Technical Reports Server (NTRS)

    Shyam, Vikram; Ameri, Ali; Chen, Jen-Ping

    2010-01-01

    In a previous study, vane-rotor shock interactions and heat transfer on the rotor blade of a highly loaded transonic turbine stage were simulated. The geometry consists of a high pressure turbine vane and downstream rotor blade. This study focuses on the physics of flow and heat transfer in the rotor tip, casing and hub regions. The simulation was performed using the Unsteady Reynolds-Averaged Navier-Stokes (URANS) code MSU-TURBO. A low Reynolds number k-epsilon model was utilized to model turbulence. The rotor blade in question has a tip gap height of 2.1 percent of the blade height. The Reynolds number of the flow is approximately 3x10(exp 6) per meter. Unsteadiness was observed at the tip surface that results in intermittent "hot spots". It is demonstrated that unsteadiness in the tip gap is governed by inviscid effects due to high speed flow and is not strongly dependent on pressure ratio across the tip gap contrary to published observations that have primarily dealt with subsonic tip flows. The high relative Mach numbers in the tip gap lead to a choking of the leakage flow that translates to a relative attenuation of losses at higher loading. The efficacy of new tip geometry is discussed to minimize heat flux at the tip while maintaining choked conditions. In addition, an explanation is provided that shows the mechanism behind the rise in stagnation temperature on the casing to values above the absolute total temperature at the inlet. It is concluded that even in steady mode, work transfer to the near tip fluid occurs due to relative shearing by the casing. This is believed to be the first such explanation of the work transfer phenomenon in the open literature. The difference in pattern between steady and time-averaged heat flux at the hub is also explained.

  10. Economizer recirculation for low-load stability in heat recovery steam generator

    SciTech Connect

    Cuscino, R.T.; Shade, R.L. Jr.

    1986-04-15

    An economizer system is described for heating feedwater in a heat recovery steam generator which consists of: at least first and second economizer tube planes; each of the economizer tube planes including a plurality of generally parallel tubes; the tubes being generally vertically disposed; each of the economizer tube planes including a top header and a bottom header; all of the plurality of tubes in each economizer tube plane being connected in parallel to their top and bottom headers whereby parallel feedwater flow through the plurality of tubes between the top and bottom headers is enabled; one of the top and bottom headers being an inlet header; a second of the top and bottom headers being an outlet header; a boiler feed pump; the boiler feed pump being effective for applying a flow of feedwater to the inlet header; means for serially interconnecting the economizer tube planes; the means for serially interconnecting including means for flowing the feedwater upward and downward in tubes of alternating ones of the economizer tube planes between the inlet header and the outlet header; means for conveying heated feedwater from the outlet header to a using process; means for recirculating at least a portion of the heated feedwater from the outlet header to an inlet of the boiler feed pump; and the means for recirculating including means for relating the portion to a steam load in the using process whereby an increased flow is produced through all of the economizer tube planes at values of the steam load below a predetermined value and a condition permitting initiation of reverse flow in any of the tubes is substantially reduced.

  11. Modeling of limiter heat loads and impurity transport in Wendelstein 7-X startup plasmas

    NASA Astrophysics Data System (ADS)

    Effenberg, Florian; Feng, Y.; Frerichs, H.; Schmitz, O.; Hoelbe, H.; Koenig, R.; Krychowiak, M.; Pedersen, T. S.; Bozhenkov, S.; Reiter, D.

    2015-11-01

    The quasi-isodynamic stellarator Wendelstein 7-X starts plasma operation in a limiter configuration. The field consists of closed magnetic flux surfaces avoiding magnetic islands in the plasma boundary. Because of the small size of the limiters and the absence of wall-protecting elements in this phase, limiter heat loads and impurity generation due to plasma surface interaction become a concern. These issues are studied with the 3D fluid plasma edge and kinetic neutral transport code EMC3-Eirene. It is shown that the 3D SOL consists of three separate helical magnetic flux bundles of different field line connection lengths. A density scan at input power of 4MW reveals a strong modulation of the plasma paramters with the connection length. The limiter peak heat fluxes drop from 14 MWm-2 down to 10 MWm-2 with raising the density from 1 ×1018m-3 to 1.9 ×1019m-3, accompanied by an increase of the heat flux channel widths λq. Radiative power losses can help to avoid thermal overloads of the limiters at the upper margin of the heating power. The power removal feasibility of the intrinsic carbon and other extrinsic light impurities via active gas injection is discussed as a preparation of this method for island divertor operation. Work supported in part by start up funds of the Department of Engineering Physics at the University of Wisconsin - Madison, USA and by the U.S. Department of Energy under grant DE-SC0013911.

  12. Climbing performance of Harris' hawks (Parabuteo unicinctus) with added load: Implications for muscle mechanics and for radiotracking

    USGS Publications Warehouse

    Pennycuick, C.J.; Fuller, M.R.; McAllister, L.

    1989-01-01

    Two Harris' hawks were trained to fly along horizontal and climbing flight paths, while carrying loads of various masses, to provide data for estimating available muscle power during short flights. The body mass of both hawks was about 920 g, and they were able to carry loads up to 630 g in horizontal flight. The rate of climb decreased with increasing all-up mass, as also did the climbing power (product of weight and rate of climb). Various assumptions about the aerodynamic power in low-speed climbs led to estimates of the maximum power output of the flight muscles ranging from 41 to 46 W. This, in turn, would imply a stress during shortening of around 210 kPa. The effects of a radio package on a bird that is raising young should be considered in relation to the food load that the forager can normally carry, rather than in relation to its body mass.

  13. Behavior of graphite under heat load and in contact with a hydrogen plasma

    NASA Astrophysics Data System (ADS)

    Bohdansky, J.; Croessmann, C. D.; Linke, J.; McDonald, J. M.; Morse, D. H.; Pontau, A. E.; Watson, R. D.; Whitley, J. B.; Goebel, D. M.; Hirooka, Y.; Leung, K.; Conn, R. W.; Roth, J.; Ottenberger, W.; Kotzlowski, H. E.

    1987-05-01

    Graphite is extensively used in large tokamaks today. In these machines the material is exposed to vacuum, to intense heat loads, and to the edge plasma. The use of graphite in such machines, therefore, depends on the outgassing behavior, the heat shock resistance, and thermochemical properties in a hydrogen plasma. Investigations of these properties made at different laboratories are described here. Experiments conducted at Sandia National Laboratories (SNL), Livermore, and the Max-Planck-Institut für Plasmaphysik (IPP) in Garching showed that the outgassing behavior of fine-grain reactor-grade graphite and carbon fiber composites depends on the pretreatment (manufacturing and/or storage). However, after proper outgassing the samples tested behave similarly in the case of fine-grain graphite, but the outgassing remains high for the carbon fiber composites. Heat shock tests have been made with the Electron Beam Test System (EBTS) at SNL, Albuquerque. Directly cooled graphite samples (FE 159 graphite brazed onto Mo tubes) showed no failure at a heat load of 700 W/cm 2, 20 s; or 10 kW, 1 s. Thermal erosion due to sublimination and particle emission from the graphite surface was observed. This effect is related to the surface temperature and becomes significant at temperatures above 2500°K. Fourteen different types of graphite were tested; the main differences among these samples were the different surface temperatures obtained under the same heating conditions. Cracking due to heat shocks was observed in some of the samples, but none of the carbon fiber composites failed. Thermochemical properties have been tested in the PISCES plasma generator at UCLA for ion energies of around 100 eV. The formation of C-H compounds was observed spectroscopically at sample temperatures of around 600°C. However, this chemical reaction did not lead to erosion as observed in beam experiments but to a drastic change of the surface structure due to redeposition. Carbon-hydrogen lines

  14. Divertor Target Heat Load Reduction by Electrical Biasing, and Application to COMPASS-D

    SciTech Connect

    Fielding, S J; Cohen, R H; Helander, P; Ryutov, D D

    2001-03-07

    A toroidally-asymmetric potential structure in the scrape-off layer (SOL) plasma may be formed by toroidally distributed electrical biasing of the divertor target tiles. The resulting ExB convective motions should increase the plasma radial transport in the SOL and thereby reduce the heat load at the divertor [1]. In this paper we develop theoretical modeling and describe the implementation of this concept to the COMPASS-D divertor. We show that strong magnetic shear near the X-point should cause significant squeezing of the convective cells preventing convection from penetrating above the X-point. This should result in reduced heat load at the divertor target without increasing the radial transport in the portion of the SOL in direct contact with the core plasma, potentially avoiding any confinement degradation. implementation of divertor biasing is in hand on COMPASS-D involving insulation of, and modifications to, the present divertor tiles. Calculations based on measured edge parameters suggest that modest currents {approx} 8 A/tile are required, at up to 150V, to drive the convection. A technical test is preceeding full bias experiments.

  15. Gyrokinetic study of edge blobs and divertor heat-load footprint

    NASA Astrophysics Data System (ADS)

    Chang, C.-S.; Ku, S.-H.; Churchill, M.; Zweben, S.

    2014-10-01

    In an attempt to better understand the complicated physics of the inter-related ``intermittent plasma objects (blobs)'' and divertor heat-load footprint, the full-function gyrokinetic PIC code XGC1 has been used in realistic diverted geometry. Neoclassical and turbulence physics are simulated together self-consistently in the presence of Monte Carlo neutral particles. Blobs are modeled here as electrostatic nonlinear turbulence phenomenon. It is found that the ``blobs'' are generated, together with the ``holes,'' around the steep density gradient region. XGC1 reasserts the previous findings that blobs move out convectively into the scrape-off layer, while the holes move inward toward plasma core. The measured radial width of the divertor heat load, mapped to the outer midplane, is found to be much less than the median radial size of the intermittent plasma objects, but is rather closer to the width of neoclassical orbit excursion from pedestal to divertor, yielding approximately the 1/Ip-type scaling found from our previous pure neoclassical simulation or a heuristic neoclassical argument by Goldston. However, it also shows some spreading by the intermittent turbulence. In ITER plasma edge, where the ion banana width at separatrix becomes negligibly small compared to the meso-scale blob size, blobs may saturate the 1/Ip scaling.

  16. Heat load of a P-doped GaAs photocathode in SRF electron gun

    SciTech Connect

    Wang, E.; Ben-Zvi, I.; Kewisch, J.; Burrill, A.; Rao, T.; Wu, Q.; Jain, A.; Gupta, R.; Holmes, D.

    2010-05-23

    Many efforts were made over the last decades to develop a better polarized electron source for the high energy physics. Several laboratories operate DC guns with the Gallium-Arsenide photo-cathode, which yield a highly polarized electron beam. However, the beam's emittance might well be improved using a Superconducting RF electron gun, which delivers beams of higher brightness than DC guns does, because the field gradient at the cathode is higher. SRF guns with metal cathodes and CsTe cathodes have been tested successfully. To produce polarized electrons, a Gallium-Arsenide photo-cathode must be used: an experiment to do so in a superconducting RF gun is under way at BNL. Since the cathode will be normal conducting, the problem about the heat load stemming from the cathode arises. We present our measurements of the electrical resistance of GaAs at cryogenic temperatures, a prediction of the heat load and the verification by measuring the quality factor of the gun with and without cathode.

  17. Conduit margin heating and deformation during the AD 1886 basaltic Plinian eruption at Tarawera volcano, New Zealand

    NASA Astrophysics Data System (ADS)

    Schauroth, Jenny; Wadsworth, Fabian B.; Kennedy, Ben; von Aulock, Felix W.; Lavallée, Yan; Damby, David E.; Vasseur, Jérémie; Scheu, Bettina; Dingwell, Donald B.

    2016-02-01

    During explosive eruptions, a suspension of gas and pyroclasts rises rapidly within a conduit. Here, we have analysed textures preserved in the walls of a pyroclastic feeder dyke of the AD 1886 Tarawera basaltic Plinian fissure eruption. The samples examined consist of basaltic ash and scoria plastered onto a conduit wall of a coherent rhyolite dome and a welded rhyolitic dome breccia. We examine the textural evidence for the response of the wall material, built of ˜75 vol.% glass and ˜25 vol.% crystals (pore-free equivalent), to mass movement in the adjacent conduit. In the rhyolitic wall material, we quantify the orientation and aspect ratio of biotite crystals as strain markers of simple shear deformation, and interpret juxtaposed regions of vesiculation and vesicle collapse as evidence of conduit wall heating. Systematic changes occur close to the margin: (1) porosity is highly variable, with areas locally vesiculated or densified, (2) biotite crystals are oriented with their long axis parallel to the margin, (3) the biotites have greater aspect ratios close to the margin and (4) the biotite crystals are fractured. We interpret the biotite phenocryst deformation to result from crystal fracture, rotation and cleavage-parallel bookcase translation. These textural observations are inferred to indicate mechanical coupling between the hot gas-ash jet and the conduit wall and reheating of wall rock rhyolite. We couple these observations with a simple 1D conductive heating model to show what minimum temperature the conduit wall needs to reach in order to achieve a temperature above the glass transition throughout the texturally-defined deformed zone. We propose that conduit wall heating and resulting deformation influences conduit margin outgassing and may enhance the intensity of such large basaltic eruptions.

  18. Air-to-Water Heat Pumps With Radiant Delivery in Low-Load Homes

    SciTech Connect

    Backman, C.; German, A.; Dakin, B.; Springer, D.

    2013-12-01

    Space conditioning represents nearly 50% of average residential household energy consumption, highlighting the need to identify alternative cost-effective, energy-efficient cooling and heating strategies. As homes are better built, there is an increasing need for strategies that are particularly well suited for high performance, low load homes. ARBI researchers worked with two test homes in hot-dry climates to evaluate the in-situ performance of air-to-water heat pump (AWHP) systems, an energy efficient space conditioning solution designed to cost-effectively provide comfort in homes with efficient, safe, and durable operation. Two monitoring projects of test houses in hot-dry climates were initiated in 2010 to test this system. Both systems were fully instrumented and have been monitored over one year to capture complete performance data over the cooling and heating seasons. Results are used to quantify energy savings, cost-effectiveness, and system performance using different operating modes and strategies. A calibrated TRNSYS model was developed and used to evaluate performance in various climate regions. This strategy is most effective in tight, insulated homes with high levels of thermal mass (i.e. exposed slab floors).

  19. Air-to-Water Heat Pumps With Radiant Delivery in Low-Load Homes

    SciTech Connect

    Backman, C.; German, A.; Dakin, B.; Springer, D.

    2013-12-01

    Space conditioning represents nearly 50% of average residential household energy consumption, highlighting the need to identify alternative cost-effective, energy-efficient cooling and heating strategies. As homes are better built, there is an increasing need for strategies that are particularly well suited for high performance, low load homes. ARBI researchers worked with two test homes in hot-dry climates to evaluate the in-situ performance of air-to-water heat pump systems, an energy efficient space conditioning solution designed to cost-effectively provide comfort in homes with efficient, safe, and durable operation. Two monitoring projects of test houses in hot-dry climates were initiated in 2010 to test this system. Both systems were fully instrumented and have been monitored over one year to capture complete performance data over the cooling and heating seasons. Results are used to quantify energy savings, cost-effectiveness, and system performance using different operating modes and strategies. A calibrated TRNSYS model was developed and used to evaluate performance in various climate regions. This strategy is most effective in tight, insulated homes with high levels of thermal mass (i.e. exposed slab floors).

  20. Thermal-contact-conductance measurement for high-heat-load optics components at SPring-8

    NASA Astrophysics Data System (ADS)

    Takeuchi, T.; Tanaka, M.; Senba, Y.; Ohashi, H.; Goto, S.

    2011-09-01

    Thermal contact in water-cooling or cryogenic cooling-cooling condition is used for forming a high-heat-load component at the synchrotron radiation beamline. In SPring-8, for example, cryogenic cooling is used for silicon monochromator crystal with an indium insertion metal at the interface between a copper block and a silicon crystal. To reduce the strain on the silicon crystal with a low contact pressure and a high thermal conductivity, we require a silicon-indium-copper system and an alternative insertion material such as a graphite foil. To measure the thermal contact conductance in a quick measurement cycle under various thermal-contact conditions, we improve the thermal-contact-conductance measurement system in terms of the setup facilitation, precise temperature measurement, and thermal insulation around a sample.

  1. High heat load crystal cooling strategies for an APS wiggler beamline

    SciTech Connect

    Beno, M.A.; Knapp, G.S.; Engbretson, M.

    1997-07-01

    High energy wigglers produce extremely high total powers. For example, the insertion device for one beamline of the Basic Energy Sciences Synchrotron Research Center (BESSRC) is an elliptical multipole wiggler (EMPW) which can generate circularly polarized X-rays on axis and produces a total power of {approximately}8 kW. This insertion device will be used to simultaneously provide x-rays to three branch lines, a branch equipped with a normal double crystal monochromator feeding a scattering and spectroscopy station, and two branches with single-bounce horizontally deflecting monochromators for Compton scattering and High Energy Diffraction. The crystal optics for this type of device require substantially different heat load solutions than those used for undulator beamlines. We will discuss how the beam is split and shared among the beamline branch lines and present the crystal cooling strategies employed for both the double-crystal monochromator and horizontally deflecting single-bounce monochromators.

  2. ELM simulation experiments using transient heat and particle load produced by a magnetized coaxial plasma gun

    NASA Astrophysics Data System (ADS)

    Shoda, K.; Sakuma, I.; Iwamoto, D.; Kikuchi, Y.; Fukumoto, N.; Nagata, M.

    2011-10-01

    It is considered that thermal transient events such as type I edge-localized modes (ELMs) and disruptions will limit the lifetime of plasma-facing components (PFCs) in ITER. It is predicted that the heat load onto the PFCs during type I ELMs in ITER is 0.2-2MJ/m2 with pulse length of ~0.1-1ms. We have investigated interaction between transient heat and particle load and the PFCs by using a magnetized coaxial plasma gun (MCPG) at University of Hyogo. In the experiment, a pulsed plasma with duration of ~0.5ms, incident ion energy of ~30eV, and surface absorbed energy density of ~0.3-0.7MJ/m2 was produced by the MCPG. However, no melting occurred on a tungsten surface exposed to a single plasma pulse of ~0.7MJ/m2, while cracks clearly appeared at the edge part of the W surface. Thus, we have recently started to improve the performance of the MCPG in order to investigate melt layer dynamics of a tungsten surface such as vapor cloud formation. In the modified MCPG, the capacitor bank energy for the plasma discharge is increased from 24.5 kJ to 144 kJ. In the preliminary experiments, the plasmoid with duration of ~0.6 ms, incident ion energy of ~ 40 eV, and the surface absorbed energy density of ~2 MJ/m2 was successfully produced at the gun voltage of 6 kV.

  3. Liquid gallium metal cooling for optical elements with high heat loads

    NASA Astrophysics Data System (ADS)

    Smither, Robert K.; Forster, George A.; Kot, Christian A.; Kuzay, Tuncer M.

    1988-04-01

    The intense photon beams from the insertion devices of the Argonne Advanced Photon Source (APS) will have very high total powers, which in some cases will exceed 10 kW, spread over a few cm 2. These high heat loads will require special cooling methods for the optical elements to preserve the quality of the photon beam. A set of finite element analysis calculations were made in three dimensions to determine the temperature distributions and thermal stresses in a single crystal of silicon with heat loads of 2-20 kW. Different geometric arrangements and different cooling fluids (water, gallium, oil, Na, etc.) were considered. These data were then used in a second set of calculations to determine the distortion of the surface of the crystal and the change in the crystal plane spacing for different parts of the surface. The best heat transfer, smallest surface distortions and smallest temperature gradients on the surface of the crystals were obtained when the cooling fluid was allowed to flow through channels in the crystal. The two best fluids for room temperature operation were found to be water and liquid gallium metal. In all cases tried, the variation in temperature across the face of the crystal and the distortion of the surface was at least a factor of two less for the gallium cooling case than for the water cooling case. The water cooling was effective only for very high flow rates. These high flow rates can cause vibrations in the diffraction crystal and in its mount that can seriously degrade the quality of the diffracted photon beam. When the flow rates were decreased the gallium cooling became 3-10 times more effective. This very efficient cooling and the very low vapor pressure for liquid gallium (less than 10 -12 Torr at 100°C) make liquid gallium a very attractive cooling fluid for high vacuum synchrotron applications. A small electromagnetic induction pump for liquid Ga was built to test this cooling method. A pumping volume of 100 cm 3/s was achieved

  4. Water versus carbohydrate-electrolyte fluid replacement during loaded marching under heat stress.

    PubMed

    Byrne, Christopher; Lim, Chin Leong; Chew, Serena Ai Neo; Ming, Elaine Tan Yu

    2005-08-01

    This study compared the effectiveness of carbohydrate-electrolyte (CHO-E) fluid replacement versus water (WAT) on hydration status, physiological and subjective responses, and exercise performance during a 3 x 60-minute loaded (14 kg) treadmill walk in 35 degrees C ambient temperature and 55% humidity. CHO-E did not affect urine loss, plasma volume change (WAT = -3.0 +/- 1.6% vs. CHO-E = -1.1 +/- 1.6%), dehydration (WAT = 0.4 +/- 0.3% vs. CHO-E = 0.4 +/- 0.3% of body mass), or core body temperature (Tc) and heart rate (HR) responses. Endurance time was greater but not significantly different with CHO-E (WAT = 134 +/- 9 vs. CHO-E = 146 +/- 9 minutes). CHO-E increased the frequency of task completion (WAT = 21% vs. CHO-E = 50%), elevated blood glucose, and reduced perceived exertion. CHO-E offers potential to enhance exercise capacity by elevating blood glucose and thereby preventing hypoglycemia, maintaining high rates of carbohydrate oxidation, and/or preventing central fatigue; but provided no additional benefits with regard to hydration status and physiological function during loaded walking under heat stress. PMID:16173217

  5. Tympanic temperature in confined beef cattle exposed to excessive heat load

    NASA Astrophysics Data System (ADS)

    Mader, T. L.; Gaughan, J. B.; Johnson, L. J.; Hahn, G. L.

    2010-11-01

    Angus crossbred yearling steers ( n = 168) were used to evaluate effects on performance and tympanic temperature (TT) of feeding additional potassium and sodium to steers exposed to excessive heat load (maximum daily ambient temperature exceeded 32°C for three consecutive days) during seasonal summer conditions. Steers were assigned one of four treatments: (1) control; (2) potassium supplemented (diet containing 2.10% KHCO3); (3) sodium supplemented (diet containing 1.10% NaCl); or (4) potassium and sodium supplemented (diet containing 2.10% KHCO3 and 1.10% NaCl). Overall, additional KHCO3 at the 2% level or NaCl at the 1% level did not improve performance or heat stress tolerance with these diet formulations. However, the addition of KHCO3 did enhance water intake. Independent of treatment effects, TT of cattle displaying high, moderate, or low levels of stress suggest that cattle that do not adequately cool down at night are prone to achieving greater body temperatures during a subsequent hot day. Cattle that are prone to get hot but can cool at night can keep average tympanic temperatures at or near those of cattle that tend to consistently maintain lower peak and mean body temperatures. In addition, during cooler and moderately hot periods, cattle change TT in a stair-step or incremental pattern, while under hot conditions, average TT of group-fed cattle moves in conjunction with ambient conditions, indicating that thermoregulatory mechanisms are at or near maximum physiological capacity.

  6. Precipitation Behavior in the Heat-Affected Zone of Boron-Added 9Cr-3W-3Co Steel During Post-Weld Heat Treatment and Creep Deformation

    NASA Astrophysics Data System (ADS)

    Liu, Yuan; Tsukamoto, Susumu; Sawada, Kota; Tabuchi, Masaaki; Abe, Fujio

    2015-05-01

    In the previous paper, we demonstrated that the addition of boron was effective in preventing type IV failure due to suppression of grain refinement in the heat-affected zone at the peak temperature of around AC3 (AC3 HAZ). However, some fine prior austenite grains (PAGs) still remained around the coarse PAG boundaries, and these fine PAGs may affect the creep property of the welded joint. In the present study, the effect of these fine PAGs on the creep property of the boron-added 9Cr-3Co-3W steel (B steel) Ac3 HAZ is investigated. Different heat treatments are carried out on B steel base metal to form different Ac3 HAZ-simulated microstructures of coarse PAG with and without fine PAGs. Ac3 HAZ microstructure shows that a lot of M23C6 carbides are formed at the block boundary in the interior of coarse PAG. On the other hand, few M23C6 carbides are formed at the fine PAG boundaries, but a number of μ phases (W6Fe7 type) cover the boundary. The formation of μ phase retards the recovery of dislocation at the fine PAG boundary and contributes to stabilizing the microstructure in the primary and transient creep regions. The μ phase transforms to the Laves phase during creep. As the growth rate of Laves phase is higher than that of M23C6 carbides during creep, the creep strength of fine PAG boundary, which is strengthened only by Laves phase, becomes a little bit lower than the other boundaries strengthened by M23C6 carbides after long-term creep. The mismatch of creep strength between the fine PAG boundary and the matrix should be taken into account to attain an excellent long-term creep property of the B steel welded joint.

  7. Experimental investigation of Mach 3 cruise heating simulations on a representative wing structure for flight loads measurement

    NASA Technical Reports Server (NTRS)

    Fields, R. A.; Olinger, F. V.; Momaghan, R. C.

    1972-01-01

    Radiant heating experiments were performed in the laboratory on an instrumented multispar wing structure to investigate: (1) how accurately the structural temperatures of a Mach 3 cruise-flight profile could be simulated, (2) what the effects of the heating and heating inaccuracies would be on the responses of strain-gage bridges installed on the structure, and (3) how these responses would affect flight loads measurements. Test temperatures throughout the structure agreed well with temperatures calculated for a Mach 3 profile. In addition, temperatures produced by two identical tests were repeatable to less than + or -6 K deg. Thermally induced strain-gage-bridge responses were large enough to be detrimental to a high-speed flight loads program with a goal of establishing aerodynamic loads (exclusive of thermal loads). It was shown that heating simulation can be used effectively for thermal calibration (that is, to provide corrections for a high-temperature environment), and that thermal calibration may not be needed if the simulation data are used to carefully select bridges and load equations.

  8. Sulfur, Chlorine, and Flourine Degassing and Atmospheric Loading by the 1783 - 1784 AD Laki (Skaftar Fires) Eruption in Iceland

    NASA Technical Reports Server (NTRS)

    Thordarson, T.; Self, S.; Hulsebosch, T.; Oskarsson, N.; McPhie, Jocelyn (Editor)

    1996-01-01

    The 1783-1784 Laki tholeiitic basalt fissure eruption in Iceland was one of the greatest atmospheric pollution events of the past 250 years, with widespread effects in the northern hemisphere. The degassing history and volatile budget of this event are determined by measurements of pre-eruption and residual contents of sulfur, chlorine, and fluorine in the products of all phases of the eruption. In fissure eruptions such as Laki, degassing occurs in two stages: by explosive activity or lava fountaining at the vents, and from the lava as it flows away from the vents. Using the measured sulfur concentrations in glass inclusions in phenocrysts and in groundmass glasses of quenched eruption products, we calculate that the total accumulative atmospheric mass loading of sulfur dioxide was 122 Mt over a period of 8 months. This volatile release is sufficient to have generated approximately 250 Mt of H2SO4 aerosols, an amount which agrees with an independent estimate of the Laki aerosol yield based on atmospheric turbidity measurements. Most of this volatile mass (approximately 60 wt.%) was released during the first 1.5 months of activity. The measured chlorine and fluorine concentrations in the samples indicate that the atmospheric loading of hydrochloric acid and hydrofluoric acid was approximately 7.0 and 15.0 Mt, respectively. Furthermore, approximately 75% of the volatile mass dissolved by the Laki magma was released at the vents and carried by eruption columns to altitudes between 6 and 13 km. The high degree of degassing at the vents is attributed to development of a separated two-phase flow in the upper magma conduit, and implies that high-discharge basaltic eruptions such as Laki are able to loft huge quantities of gas to altitudes where the resulting aerosols can reside for months, or even 1-2 years. The atmospheric volatile contribution due to subsequent degassing of the Laki lava flow is only 18 wt.% of the total dissolved in the magma, and these emissions were

  9. Impact on the deuterium retention of simultaneous exposure of tungsten to a steady state plasma and transient heat cycling loads

    NASA Astrophysics Data System (ADS)

    Huber, A.; Sergienko, G.; Wirtz, M.; Steudel, I.; Arakcheev, A.; Brezinsek, S.; Burdakov, A.; Dittmar, T.; Esser, H. G.; Kreter, A.; Linke, J.; Linsmeier, Ch; Mertens, Ph; Möller, S.; Philipps, V.; Pintsuk, G.; Reinhart, M.; Schweer, B.; Shoshin, A.; Terra, A.; Unterberg, B.

    2016-02-01

    The impact on the deuterium retention of simultaneous exposure of tungsten to a steady-state plasma and transient cyclic heat loads has been studied in the linear PSI-2 facility with the main objective of qualifying tungsten (W) as plasma-facing material. The transient heat loads were applied by a high-energy laser, a Nd:YAG laser (λ = 1064 nm) with an energy per pulse of up to 32 J and a duration of 1 ms. A pronounced increase in the D retention by a factor of 13 has been observed during the simultaneous transient heat loads and plasma exposure. These data indicate that the hydrogen clustering is enhanced by the thermal shock exposures, as seen on the increased blister size due to mobilization and thermal production of defects during transients. In addition, the significant increase of the D retention during the simultaneous loads could be explained by an increased diffusion of D atoms into the W material due to strong temperature gradients during the laser pulse exposure and to an increased mobility of D atoms along the shock-induced cracks. Only 24% of the retained deuterium is located inside the near-surface layer (d<4 μm). Enhanced blister formation has been observed under combined loading conditions at power densities close to the threshold for damaging. Blisters are not mainly responsible for the pronounced increase of the D retention.

  10. Manufacturing and high heat flux loading of tungsten coatings on fine grain graphite for the ASDEX-upgrade divertor

    NASA Astrophysics Data System (ADS)

    Deschka, S.; García-Rosales, C.; Hohenauer, W.; Duwe, R.; Gauthier, E.; Linke, J.; Lochter, M.; Malléner, W.; Plöchl, L.; Rödhammer, P.; Salito, A.

    1996-10-01

    Fine grain graphite tiles coated with tungsten layers by plasma spray (PS, thickness 100-550 μm) and physical vapour deposition (PVD, 30-200 μm), respectively, were subjected to thermal loads up to 17 MW/m 2 and 2 s pulse duration. The damage limit was evaluated by increasing the heat flux and the pulse length stepwise. The results proved that PS coatings are capable of withstanding heat loads up to 15 MW/m 2 at 2 s pulse length without any structural changes, and cyclic loading with 1000 cycles at 10 MW/m 2. The highly dense PVD coatings suffered damage by crack formation at slightly lower heat loads, and thin PVD layers failed under cyclic loading with 1000 cycles at 10 MW/m 2 due to thermal fatigue and melting. The good performance of PS coatings is related to their porosity, which provides a crack arresting mechanism, and to their mechanical strength, depending on the density of the PS layer.

  11. Potential Remedies for the High Synchrotron-Radiation-Induced Heat Load for Future Highest-Energy-Proton Circular Colliders.

    PubMed

    Cimino, R; Baglin, V; Schäfers, F

    2015-12-31

    We propose a new method for handling the high synchrotron radiation (SR) induced heat load of future circular hadron colliders (like FCC-hh). FCC-hh are dominated by the production of SR, which causes a significant heat load on the accelerator walls. Removal of such a heat load in the cold part of the machine, as done in the Large Hadron Collider, will require more than 100 MW of electrical power and a major cooling system. We studied a totally different approach, identifying an accelerator beam screen whose illuminated surface is able to forward reflect most of the photons impinging onto it. Such a reflecting beam screen will transport a significant part of this heat load outside the cold dipoles. Then, in room temperature sections, it could be more efficiently dissipated. Here we will analyze the proposed solution and address its full compatibility with all other aspects an accelerator beam screen must fulfill to keep under control beam instabilities as caused by electron cloud formation, impedance, dynamic vacuum issues, etc. If experimentally fully validated, a highly reflecting beam screen surface will provide a viable and solid solution to be eligible as a baseline design in FCC-hh projects to come, rendering them more cost effective and sustainable. PMID:26764998

  12. Material ejection and surface morphology changes during transient heat loading of tungsten as plasma-facing component in fusion devices

    NASA Astrophysics Data System (ADS)

    Suslova, A.; El-Atwani, O.; Harilal, S. S.; Hassanein, A.

    2015-03-01

    We investigated the effect of edge-localized mode like transient heat events on pristine samples for two different grades of deformed tungsten with ultrafine and nanocrystalline grains as potential candidates for plasma-facing components. Pulses from a laser beam with durations ∼1 ms and operating in the near infrared wavelength were used for simulating transient heat loading in fusion devices. We specifically focused on investigating and analysis of different mechanisms for material removal from the sample surface under repetitive transient heat loads. Several techniques were applied for analysing different mechanisms leading to material removal from the W surface under repetitive transient heat loads which include witness plates for collected ejected material, and subsequent analysis using x-ray photoelectron spectroscopy and scanning electron microscopy, visible imaging using fast-gated camera, and evaluating thermal emission from the particles using optical emission spectroscopy. Our results show a significantly improved performance of polycrystalline cold-rolled tungsten compared to tungsten produced using an orthogonal machining process under repetitive transient loads for a wide range of the power densities.

  13. Potential Remedies for the High Synchrotron-Radiation-Induced Heat Load for Future Highest-Energy-Proton Circular Colliders

    NASA Astrophysics Data System (ADS)

    Cimino, R.; Baglin, V.; Schäfers, F.

    2015-12-01

    We propose a new method for handling the high synchrotron radiation (SR) induced heat load of future circular hadron colliders (like FCC-hh). FCC-hh are dominated by the production of SR, which causes a significant heat load on the accelerator walls. Removal of such a heat load in the cold part of the machine, as done in the Large Hadron Collider, will require more than 100 MW of electrical power and a major cooling system. We studied a totally different approach, identifying an accelerator beam screen whose illuminated surface is able to forward reflect most of the photons impinging onto it. Such a reflecting beam screen will transport a significant part of this heat load outside the cold dipoles. Then, in room temperature sections, it could be more efficiently dissipated. Here we will analyze the proposed solution and address its full compatibility with all other aspects an accelerator beam screen must fulfill to keep under control beam instabilities as caused by electron cloud formation, impedance, dynamic vacuum issues, etc. If experimentally fully validated, a highly reflecting beam screen surface will provide a viable and solid solution to be eligible as a baseline design in FCC-hh projects to come, rendering them more cost effective and sustainable.

  14. Study of regeneration system of 300 MW power unit based on nondeaerating heat balance diagram at reduced load

    NASA Astrophysics Data System (ADS)

    Esin, S. B.; Trifonov, N. N.; Sukhorukov, Yu. G.; Yurchenko, A. Yu.; Grigor'eva, E. B.; Snegin, I. P.; Zhivykh, D. A.; Medvedkin, A. V.; Ryabich, V. A.

    2015-09-01

    More than 30 power units of thermal power stations, based on the nondeaerating heat balance diagram, successfully operate in the former Soviet Union. Most of them are power units with a power of 300 MW, equipped with HTGZ and LMZ turbines. They operate according to a variable electric load curve characterized by deep reductions when undergoing night minimums. Additional extension of the range of power unit adjustment makes it possible to maintain the dispatch load curve and obtain profit for the electric power plant. The objective of this research is to carry out estimated and experimental processing of the operating regimes of the regeneration system of steam-turbine plants within the extended adjustment range and under the conditions when the constraints on the regeneration system and its equipment are removed. Constraints concerning the heat balance diagram that reduce the power unit efficiency when extending the adjustment range have been considered. Test results are presented for the nondeaerating heat balance diagram with the HTGZ turbine. Turbine pump and feed electric pump operation was studied at a power unit load of 120-300 MW. The reliability of feed pump operation is confirmed by a stable vibratory condition and the absence of cavitation noise and vibration at a frequency that characterizes the cavitation condition, as well as by oil temperature maintenance after bearings within normal limits. Cavitation performance of pumps in the studied range of their operation has been determined. Technical solutions are proposed on providing a profitable and stable operation of regeneration systems when extending the range of adjustment of power unit load. A nondeaerating diagram of high-pressure preheater (HPP) condensate discharge to the mixer. A regeneration system has been developed and studied on the operating power unit fitted with a deaeratorless thermal circuit of the system for removing the high-pressure preheater heating steam condensate to the mixer

  15. Multi-Objective Optimization of Heat Load and Run Time for CEBAF Linacs Using Genetic Algorithms

    NASA Astrophysics Data System (ADS)

    Reeves, Cody; Terzic, Balsa; Hofler, Alicia

    2014-09-01

    The Continuous Electron Beam Accelerator Facility (CEBAF) consists of two linear accelerators (Linacs) connected by arcs. Within each Linac, there are 200 niobium cavities that use superconducting radio frequency (SRF) to accelerate electrons. The gradients for the cavities are selected to optimize two competing objectives: heat load (the energy required to cool the cavities) and trip rate (how often the beam turns off within an hour). This results in a multidimensional, multi-objective, nonlinear system of equations that is not readily solved by analytical methods. This study improved a genetic algorithm (GA), which applies the concept of natural selection. The primary focus was making this GA more efficient to allow for more cost-effective solutions in the same amount of computation time. Two methods used were constraining the maximum value of the ob-jectives and also utilizing previously simulated solutions as the initial generation. A third method of interest involved refining the GA by combining the two objectives into a single weighted-sum objective, which collapses the set of optimal solutions into a single point. By combining these methods, the GA can be made 128 times as effective, reducing computation time from 30 min to 12 sec. This is crucial for when a cavity must be turned off, a new solution needs to be computed quickly. This work is of particular interest since it provides an efficient algorithm that can be easily adapted to any Linac facility.

  16. Affect of Air Leakage into a Thermal-Vacuum Chamber on Helium Refrigeration Heat Load

    NASA Technical Reports Server (NTRS)

    Garcia, Sam; Meagher, Daniel; Linza, Robert; Saheli, Fariborz; Vargas, Gerardo; Lauterbach, John; Reis, Carl; Ganni, Venkatarao (Rao); Homan, Jonathan

    2008-01-01

    NASA s Johnson Space Center (JSC) Building 32 houses two large thermal-vacuum chambers (Chamber A and Chamber B). Within these chambers are liquid nitrogen shrouds to provide a thermal environment and helium panels which operate at 20K to provide cryopumping. Some amount of air leakage into the chambers during tests is inevitable. This causes "air fouling" of the helium panel surfaces due to the components of the air that adhere to the panels. The air fouling causes the emittance of the helium panels to increase during tests. The increase in helium panel emittance increases the heat load on the helium refrigerator that supplies the 20K helium for those panels. Planning for thermal-vacuum tests should account for this increase to make sure that the helium refrigerator capacity will not be exceeded over the duration of a test. During a recent test conducted in Chamber B a known-size air leak was introduced to the chamber. Emittance change of the helium panels and the affect on the helium refrigerator was characterized. A description of the test and the results will be presented.

  17. Gyrokinetic simulation of edge blobs and divertor heat-load footprint

    NASA Astrophysics Data System (ADS)

    Chang, C. S.; Ku, S.; Hager, R.; Churchill, M.; D'Azevedo, E.; Worley, P.

    2015-11-01

    Gyrokinetic study of divertor heat-load width Lq has been performed using the edge gyrokinetic code XGC1. Both neoclassical and electrostatic turbulence physics are self-consistently included in the simulation with fully nonlinear Fokker-Planck collision operation and neutral recycling. Gyrokinetic ions and drift kinetic electrons constitute the plasma in realistic magnetic separatrix geometry. The electron density fluctuations from nonlinear turbulence form blobs, as similarly seen in the experiments. DIII-D and NSTX geometries have been used to represent today's conventional and tight aspect ratio tokamaks. XGC1 shows that the ion neoclassical orbit dynamics dominates over the blob physics in setting Lq in the sample DIII-D and NSTX plasmas, re-discovering the experimentally observed 1/Ip type scaling. Magnitude of Lq is in the right ballpark, too, in comparison with experimental data. However, in an ITER standard plasma, XGC1 shows that the negligible neoclassical orbit excursion effect makes the blob dynamics to dominate Lq. Differently from Lq 1mm (when mapped back to outboard midplane) as was predicted by simple-minded extrapolation from the present-day data, XGC1 shows that Lq in ITER is about 1 cm that is somewhat smaller than the average blob size. Supported by US DOE and the INCITE program.

  18. Diamond for high-heat-load synchrotron x-ray applications

    SciTech Connect

    Lee, Wah-Keat

    1994-12-31

    Synchrotron facilities worldwide provide scientists with useful radiation in the ultraviolet to the x-ray regime. Third-generation synchrotron sources win deliver photon fluxes in the 10{sup 15} photons/s/0.1%BW range, with brilliance on the order of 10{sup 18} photons/s/0.1%BW/mrad{sup 2}/mm{sup 2}. Along with the increase in flux and brilliance is an increase in the power and power densities of the x-ray beam. Depending on the particular insertion device, the x-ray beam can have total power in excess of 10 kW and peak power, density of more than 400 W/mm{sup 2}. Such high heat loads are a major challenge in the design and fabrication of x-ray beamline components. The superior thermal and mechanical properties of diamond make it a good candidate as material in these components. Single crystal diamonds can be used as x-ray monochromators, while polycrystalline or CVD diamonds can be used in a variety of ways on the front-end beamline components. This paper discusses the issues regarding the feasibility of using diamond in third-generation synchrotron beamline components.

  19. Plasma facing materials performance under ITER-relevant mitigated disruption photonic heat loads

    NASA Astrophysics Data System (ADS)

    Klimov, N. S.; Putrik, A. B.; Linke, J.; Pitts, R. A.; Zhitlukhin, A. M.; Kuprianov, I. B.; Spitsyn, A. V.; Ogorodnikova, O. V.; Podkovyrov, V. L.; Muzichenko, A. D.; Ivanov, B. V.; Sergeecheva, Ya. V.; Lesina, I. G.; Kovalenko, D. V.; Barsuk, V. A.; Danilina, N. A.; Bazylev, B. N.; Giniyatulin, R. N.

    2015-08-01

    PFMs (Plasma-facing materials: ITER grade stainless steel, beryllium, and ferritic-martensitic steels) as well as deposited erosion products of PFCs (Be-like, tungsten, and carbon based) were tested in QSPA under photonic heat loads relevant to those expected from photon radiation during disruptions mitigated by massive gas injection in ITER. Repeated pulses slightly above the melting threshold on the bulk materials eventually lead to a regular, "corrugated" surface, with hills and valleys spaced by 0.2-2 mm. The results indicate that hill growth (growth rate of ∼1 μm per pulse) and sample thinning in the valleys is a result of melt-layer redistribution. The measurements on the 316L(N)-IG indicate that the amount of tritium absorbed by the sample from the gas phase significantly increases with pulse number as well as the modified layer thickness. Repeated pulses significantly below the melting threshold on the deposited erosion products lead to a decrease of hydrogen isotopes trapped during the deposition of the eroded material.

  20. Deemed Savings Estimates for Legacy Air Conditioning and WaterHeating Direct Load Control Programs in PJM Region

    SciTech Connect

    Goldman, Charles

    2007-03-01

    During 2005 and 2006, the PJM Interconnection (PJM) Load Analysis Subcommittee (LAS) examined ways to reduce the costs and improve the effectiveness of its existing measurement and verification (M&V) protocols for Direct Load Control (DLC) programs. The current M&V protocol requires that a PURPA-compliant Load Research study be conducted every five years for each Load-Serving Entity (LSE). The current M&V protocol is expensive to implement and administer particularly for mature load control programs, some of which are marginally cost-effective. There was growing evidence that some LSEs were mothballing or dropping their DLC programs in lieu of incurring the expense associated with the M&V. This project had several objectives: (1) examine the potential for developing deemed savings estimates acceptable to PJM for legacy air conditioning and water heating DLC programs, and (2) explore the development of a collaborative, regional, consensus-based approach for conducting monitoring and verification of load reductions for emerging load management technologies for customers that do not have interval metering capability.

  1. The effect of plasma osmolality and baroreceptor loading status on postexercise heat loss responses.

    PubMed

    Paull, Gabrielle; Dervis, Sheila; Barrera-Ramirez, Juliana; McGinn, Ryan; Haqani, Baies; Flouris, Andreas D; Kenny, Glen P

    2016-03-15

    We examined the separate and combined effects of plasma osmolality and baroreceptor loading status on postexercise heat loss responses. Nine young males completed a 45-min treadmill exercise protocol at 58 ± 2% V̇o2 peak, followed by a 60-min recovery. On separate days, participants received 0.9% NaCl (ISO), 3.0% NaCl (HYP), or no infusion (natural recovery) throughout exercise. In two additional sessions (no infusion), lower-body negative (LBNP) or positive (LBPP) pressure was applied throughout the final 45 min of recovery. Local sweat rate (LSR; ventilated capsule: chest, forearm, upper back, forehead) and skin blood flow (SkBF; laser-Doppler flowmetry: forearm, upper back) were continuously measured. During HYP, upper back LSR was attenuated from end-exercise to 10 min of recovery by ∼0.35 ± 0.10 mg·min(-1)·cm(-2) and during the last 20 min of recovery by ∼0.13 ± 0.03 mg·min(-1)·cm(-2), while chest LSR was lower by 0.18 ± 0.06 mg·min(-1)·cm(-2) at 50 min of recovery compared with natural recovery (all P < 0.05). Forearm and forehead LSRs were not affected by plasma hyperosmolality during HYP (all P > 0.28), which suggests regional differences in the osmotic modulation of postexercise LSR. Furthermore, LBPP application attenuated LSR by ∼0.07-0.28 mg·min(-1)·cm(-2) during the last 30 min of recovery at all sites except the forehead compared with natural recovery (all P < 0.05). Relative to natural recovery, forearm and upper back SkBF were elevated during LBPP, ISO, and HYP by ∼6-10% by the end of recovery (all P < 0.05). We conclude that 1) hyperosmolality attenuates postexercise sweating heterogeneously among skin regions, and 2) baroreceptor loading modulates postexercise SkBF independently of changes in plasma osmolality without regional differences. PMID:26764055

  2. On the influence of the urban heat island on the cooling load of a school building in Athens, Greece

    NASA Astrophysics Data System (ADS)

    Bagiorgas, H. S.; Mihalakakou, G.

    2016-02-01

    The present study investigates the effect of the urban heat island (UHI) phenomenon, measured in the Greater Athens Area (GAA), on the energy consumption of a typical modern school building. The energy performance of the selected building has been calculated using an accurate, extensively validated, transient simulation model for 17 different sites of the GAA, for the summer period. Calculations showed that the urban heat island phenomenon affects remarkably the thermal behavior of the school building, as suburban areas presented much lower cooling loads. The cooling load values fluctuated between 3304.3 kWh for the rural stations and 14,585.1 kWh for the central stations (for the year 2011) or between 3206.5 kWh and 14,208.3 kWh (for the year 2012), respectively. Moreover, the mean monthly cooling load values varied between 0.4-2 kWh/m2 for the rural stations and 4-6.9 kWh/m2 for the central stations, for the selected time period. Furthermore, a neural network model was designed and developed in order to quantify the contribution of various meteorological parameters (such as the mean daily air temperature values, the mean daily solar radiation values, the average wind speed and the urban heat island intensity) to the energy consumption of the building and it was found that the urban heat island intensity is the predominant parameter, influencing remarkably the energy consumption of the typical school building.

  3. Performance of cryogenically cooled, high-heat-load silicon crystal monochromators with porous media augmentation

    SciTech Connect

    Rogers, C.S.; Mills, D.M.; Assoufid, L.; Graber, T.

    1996-09-01

    The performance of two Si crystal x-ray monochromators internally cooled with liquid nitrogen was tested on the F2-wiggler beamline at the Cornell High Energy Synchrotron Source (CHESS). Both crystals were (111)-oriented blocks of rectangular cross section having identical dimensions. Seven 6.4-mm-diameter coolant channels were drilled through the crystals along the beam direction. In one of the crystals, porous Cu mesh inserts were bonded into the channels to enhance the heat transfer. The channels of the second crystal were left as drilled. Symmetric, double-crystal rocking curves were recorded simultaneously for both the first and third order reflections at 8 and 24 keV. The power load on the cooled crystal was adjusted by varying the horizontal beam size using slits. The measured Si(333) rocking curve of the unenhanced crystal at 24 keV at low power was 1.9 arcsec FWHM. The theoretical width is 0.63 arcsec. The difference is due to residual fabrication and mounting strain. For a maximum incident power of 601 W and an average power density of about 10 W/mm{sup 2}, the rocking curve was 2.7 arcsec. The rocking curve width for the enhanced crystal at low power was 2.4 arcsec. At a maximum incident power of 1803 W and an average power density of about 19 W/mm{sup 2}, the rocking curve width was 2.2 arcsec FWHM. The use of porous mesh augmentation is a simple, but very effective, means to improve the performance of cryogenically cooled Si monochromators exposed to high power x-ray beams. {copyright} {ital 1996 American Institute of Physics.}

  4. Numerical study of plasma generation process and internal antenna heat loadings in J-PARC RF negative ion source.

    PubMed

    Shibata, T; Nishida, K; Mochizuki, S; Mattei, S; Lettry, J; Hatayama, A; Ueno, A; Oguri, H; Ohkoshi, K; Ikegami, K; Takagi, A; Asano, H; Naito, F

    2016-02-01

    A numerical model of plasma transport and electromagnetic field in the J-PARC (Japan Proton Accelerator Research Complex) radio frequency ion source has been developed to understand the relation between antenna coil heat loadings and plasma production/transport processes. From the calculation, the local plasma density increase is observed in the region close to the antenna coil. Electrons are magnetized by the magnetic field line with absolute magnetic flux density 30-120 Gauss which leads to high local ionization rate. The results suggest that modification of magnetic configuration can be made to reduce plasma heat flux onto the antenna. PMID:26932010

  5. Experimental creep data for a built-up aluminum/titanium structure subjected to heating and loading

    NASA Technical Reports Server (NTRS)

    Jenkins, J. M.; Montoya, C. A.

    1983-01-01

    Experimental creep, temperature, and strain data resulting from a laboratory experiment on a built-up aluminum/titanium structure are presented. The structure and the experiment are described in detail. A heating and loading experiment lasting approximately six hours is conducted on a test structure. Considerable creep strain resulted from compressive stresses in the heated skin. Large residual stresses were found after the experiment was completed. The residual stresses in the substructure frames were large enough to preclude further cycles of creep experiments with this built-up structure because of concern that the frame webs would buckle.

  6. Measurement of heat load density profile on acceleration grid in MeV-class negative ion accelerator

    NASA Astrophysics Data System (ADS)

    Hiratsuka, Junichi; Hanada, Masaya; Kojima, Atsushi; Umeda, Naotaka; Kashiwagi, Mieko; Miyamoto, Kenji; Yoshida, Masafumi; Nishikiori, Ryo; Ichikawa, Masahiro; Watanabe, Kazuhiro; Tobari, Hiroyuki

    2016-02-01

    To understand the physics of the negative ion extraction/acceleration, the heat load density profile on the acceleration grid has been firstly measured in the ITER prototype accelerator where the negative ions are accelerated to 1 MeV with five acceleration stages. In order to clarify the profile, the peripheries around the apertures on the acceleration grid were separated into thermally insulated 34 blocks with thermocouples. The spatial resolution is as low as 3 mm and small enough to measure the tail of the beam profile with a beam diameter of ˜16 mm. It was found that there were two peaks of heat load density around the aperture. These two peaks were also clarified to be caused by the intercepted negative ions and secondary electrons from detailed investigation by changing the beam optics and gas density profile. This is the first experimental result, which is useful to understand the trajectories of these particles.

  7. Measurement of heat load density profile on acceleration grid in MeV-class negative ion accelerator.

    PubMed

    Hiratsuka, Junichi; Hanada, Masaya; Kojima, Atsushi; Umeda, Naotaka; Kashiwagi, Mieko; Miyamoto, Kenji; Yoshida, Masafumi; Nishikiori, Ryo; Ichikawa, Masahiro; Watanabe, Kazuhiro; Tobari, Hiroyuki

    2016-02-01

    To understand the physics of the negative ion extraction/acceleration, the heat load density profile on the acceleration grid has been firstly measured in the ITER prototype accelerator where the negative ions are accelerated to 1 MeV with five acceleration stages. In order to clarify the profile, the peripheries around the apertures on the acceleration grid were separated into thermally insulated 34 blocks with thermocouples. The spatial resolution is as low as 3 mm and small enough to measure the tail of the beam profile with a beam diameter of ∼16 mm. It was found that there were two peaks of heat load density around the aperture. These two peaks were also clarified to be caused by the intercepted negative ions and secondary electrons from detailed investigation by changing the beam optics and gas density profile. This is the first experimental result, which is useful to understand the trajectories of these particles. PMID:26932019

  8. An In-Depth Look at Ground Source Heat Pumps and Other Electric Loads in Two GreenMax Homes

    SciTech Connect

    Puttagunta, Srikanth; Shapiro, Carl

    2012-04-01

    Building America research team Consortium for Advanced Residential Buildings (CARB) partnered with WPPI Energy to answer key research questions on in-field performance of ground-source heat pumps and lighting, appliance, and miscellaneous loads (LAMELs) through extensive field monitoring at two WPPI GreenMax demonstration homes in Wisconsin. These two test home evaluations provided valuable data on the true in-field performance of various building mechanical systems and LAMELs.

  9. Impact of combined hydrogen plasma and transient heat loads on the performance of tungsten as plasma facing material

    NASA Astrophysics Data System (ADS)

    Wirtz, M.; Bardin, S.; Huber, A.; Kreter, A.; Linke, J.; Morgan, T. W.; Pintsuk, G.; Reinhart, M.; Sergienko, G.; Steudel, I.; De Temmerman, G.; Unterberg, B.

    2015-11-01

    Experiments were performed in three different facilities in order to investigate the impact of combined steady state deuterium plasma exposure and ELM-like thermal shock events on the performance of ultra high purity tungsten. The electron beam facility JUDITH 1 was used to simulate pure thermal loads. In addition the linear plasma devices PSI-2 and Pilot-PSI have been used for successive as well as simultaneous exposure where the transient heat loads were applied by a high energy laser and the pulsed plasma operation, respectively. The results show that the damage behaviour strongly depends on the loading conditions and the sequence of the particle and heat flux exposure. This is due to hydrogen embrittlement and/or a higher defect concentration in the tungsten near surface region due to supersaturation of hydrogen. The different results in terms of damage formation from both linear plasma devices indicate that also the plasma parameters such as particle energy, flux and fluence, plasma impurities and the pulse shape have a strong influence on the damage performance. In addition, the different loading methods such as the scanning with the electron beam in contrast to the homogeneous exposure by the laser leads to an faster increase of the surface roughness due to plastic deformation.

  10. Study on Improving Partial Load by Connecting Geo-thermal Heat Pump System to Fuel Cell Network

    NASA Astrophysics Data System (ADS)

    Obara, Shinya; Kudo, Kazuhiko

    Hydrogen piping, the electric power line, and exhaust heat recovery piping of the distributed fuel cells are connected with network, and operational planning is carried out. Reduction of the efficiency in partial load is improved by operation of the geo-thermal heat pump linked to the fuel cell network. The energy demand pattern of the individual houses in Sapporo was introduced. And the analysis method aiming at minimization of the fuel rate by the genetic algorithm was described. The fuel cell network system of an analysis example assumed connecting the fuel cell co-generation of five houses. When geo-thermal heat pump was introduced into fuel cell network system stated in this paper, fuel consumption was reduced 6% rather than the conventional method

  11. Lava heating and loading of ice sheets on early Mars: Predictions for meltwater generation, groundwater recharge, and resulting landforms

    NASA Astrophysics Data System (ADS)

    Cassanelli, James P.; Head, James W.

    2016-06-01

    Recent modeling studies of the early Mars climate predict a predominantly cold climate, characterized by the formation of regional ice sheets across the highland areas of Mars. Formation of the predicted "icy highlands" ice sheets is coincident with a peak in the volcanic flux of Mars involving the emplacement of the Late Noachian - Early Hesperian ridged plains unit. We explore the relationship between the predicted early Mars "icy highlands" ice sheets, and the extensive early flood volcanism to gain insight into the surface conditions prevalent during the Late Noachian to Early Hesperian transition period. Using Hesperia Planum as a type area, we develop an ice sheet lava heating and loading model. We quantitatively assess the thermal and melting processes involved in the lava heating and loading process following the chronological sequence of lava emplacement. We test a broad range of parameters to thoroughly constrain the lava heating and loading process and outline predictions for the formation of resulting geological features. We apply the theoretical model to a study area within the Hesperia Planum region and assess the observed geology against predictions derived from the ice sheet lava heating and loading model. Due to the highly cratered nature of the Noachian highlands terrain onto which the volcanic plains were emplaced, we predict highly asymmetrical lava loading conditions. Crater interiors are predicted to accumulate greater thicknesses of lava over more rapid timescales, while in the intercrater plains, lava accumulation occurs over longer timescales and does not reach great thicknesses. We find that top-down melting due to conductive heat transfer from supraglacial lava flows is generally limited when the emplaced lava flows are less than ∼10 m thick, but is very significant at lava flow thicknesses of ∼100 m or greater. We find that bottom-up cryosphere and ice sheet melting is most likely to occur within crater interiors where lavas

  12. Theoretical and Experimental Evaluation of the Effect of Adding a Heat-Bypass Structure to a Laser Diode Array

    NASA Astrophysics Data System (ADS)

    Murata, Setsuko; Nakada, Hiroshi; Abe, Tetsuo

    1993-03-01

    Because heat transferred between closely spaced elements in a compact laser diode array shortens array lifetime and affects the elements’ operating characteristics, we theoretically and experimentally evaluated the effect of a heat-bypass structure by calculating and measuring the thermal resistance of array elements. Three-dimensional boundary element analysis showed that the heat bypass reduces the thermal resistance by an amount that is independent of cavity length. Measured junction voltages and wavelengths for a 50-μm-spaced 8-beam laser diode array with 600-μm-long cavities showed that the bypass structure reduces the thermal resistance resulting from simultaneous operation of all eight elements by more than 40%. And that the reduction is greatest for elements whose thermal resistance is highest. The resultant reduction in the junction temperature of array elements operating at 100 mW should increase array lifetime at least threefold.

  13. High-heat-load studies of silicon and diamond monochromators using the APS/CHESS prototype undulator

    SciTech Connect

    Mills, D.M.; Lee, W.K.; Smither, R.K.; Fernandez, P.B.

    1994-09-16

    The results of the latest high-heat-load studies made on the APS/CHESS prototype undulator are summarized. Four different crystals were tested: two slotted, symmetrically cut silicon crystals and a core-drilled, asymmetrically cut silicon crystal and a diamond crystal that was jet cooled using water. The purpose of the silicon crystal tests was to reevaluate the surface power loading at which appreciable degradation of the diffraction efficiency was observed. The diamond tests, allotted only a brief period of time during the testing period, were our first attempt at using diamonds for high-heat-flux x-ray monochromators and were performed primarily to gain first-hand experience with diamond monochromators. Measurements with the silicon crystal at 5 keV reconfirmed our previous measurements of performance degradation at around 4-6 watts/mm{sup 2} using liquid gallium with slotted coolant channels. A value of only 2 watts/mm{sup 2} was observed to cause a degradation of the diffraction performance at 15 keV with the same crystals due to the increased sensitivity to strain because of the reduced Darwin widths. The performance of the asymmetric crystal, with its core-drilled coolant channels, was not found to be as good as that of the slotted crystals. This was probably due to poorer heat transfer properties of the core-drilled geometry in combination with the narrowing of the rocking curves because of the asymmetric cut. Fabrication issues for construction of the gallium-cooled crystals is also discussed. Although the diamonds were only successfully tested at low total power the results were very encouraging and motivated us to accelerate our program on the use of diamonds for high-heat-load monochromators.

  14. Pre-natal heat load affects bacterial levels and innate immunity in neonatal calves

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Heat stress suppresses immunity, making animals more susceptible to bacterial infections. Additionally, field observations suggest that calves have greater morbidity and mortality when they are born after a heat event. However, scientific evidence is still lacking, limiting the development of target...

  15. Construction and testing of a gas-loaded, passive-control, variable-conductance heat pipe

    NASA Technical Reports Server (NTRS)

    Depew, C. A.; Sauerbrey, W. J.; Benson, B. A.

    1973-01-01

    A methanol heat pipe using nitrogen gas for temperature control has been constructed and tested. The system was run over a power ratio of 15 (2 to 30 watts) with the heat source near ambient temperature and with the heat sink at a nominal value of 32 F. Control was obtained with a metal bellows gas reservoir which was actuated by an internal liquid-filled bellows. The liquid bellows was pressurized by expanding liquid methanol which was contained in an auxiliary reservoir in the evaporator heater block. It was demonstrated that the temperature variation of the heat source was reduced from 36 F for the heat pipe with no control to 7 F with the actuated bellows control.

  16. Adipose tissue partitioning of limit-fed beef cattle and beef cattle with ad libitum access to feed differing in adaptation to heat.

    PubMed

    Sprinkle, J E; Ferrell, C L; Holloway, J W; Warrington, B G; Greene, L W; Wu, G; Stuth, J W

    1998-03-01

    We compared fat distribution and lipoprotein lipase (LPL) activity in steers differing in adaptability to the subtropics. Steers were fed a grain diet (3.13 Mcal ME/kg DM) at limited (150 kcal ME x kg[-.75] x d[-1]; .23 kg ADG) or ad libitum levels for 140 d, then slaughtered. Sixteen British- (8 Angus, 8 Hereford; S), 16 Boran- (R), 16 Brahman- (B), and 16 Tuli- (T) cross steers from MARC III composite cows were used. Adipose tissue samples from perirenal, omental, and subcutaneous depots were analyzed for LPL activity. Carcass measurements including omental, external, and seam fat trim from 1/ 2 of the carcass were measured. Subcutaneous fat had greater (P < .05) LPL activity than fat from the other depots. Generally, there were no differences (P > .05) in fat distribution for steers fed at limited levels. Means for ADG, slaughter weights, carcass weights, yield grades, and carcass lipid weights for S and B fed for ad libitum intake were greater (P < .05) than those for T and R. Marbling was greatest (P < .05) for S and did not differ (P > .05) for the other breeds with ad libitum intake. Factor analysis of fat depots for animals with ad libitum intake indicated that Bos taurus cattle differing in adaptation to heat deposited fat differently; S deposited greater (P < .05) proportions of carcass fat and T deposited greater (P < .05) proportions of internal fat. It seems that accumulation of internal fat is detrimental for ADG for Bos taurus cattle. PMID:9535321

  17. Measurement of transformation temperatures and specific heat capacity of tungsten added reduced activation ferritic-martensitic steel

    NASA Astrophysics Data System (ADS)

    Raju, S.; Jeya Ganesh, B.; Rai, Arun Kumar; Mythili, R.; Saroja, S.; Mohandas, E.; Vijayalakshmi, M.; Rao, K. B. S.; Raj, Baldev

    2009-06-01

    The on-heating phase transformation temperatures up to the melting regime and the specific heat capacity of a reduced activation ferritic-martensitic steel (RAFM) with a nominal composition (wt%): 9Cr-0.09C-0.56Mn-0.23V-1W-0.063Ta-0.02N, have been measured using high temperature differential scanning calorimetry. The α -ferrite + carbides → γ-austenite transformation start and finish temperatures, namely A c1, and A c3, are found to be 1104 and 1144 K, respectively for a typical normalized and tempered microstructure. It is also observed that the martensite start ( MS) and finish ( Mf) temperatures are sensitive to the austenitising conditions. Typical MS and Mf values for the 1273 K normalized and 1033 K tempered samples are of the order 714 and 614 K, respectively. The heat capacity CP of the RAFM steel has been measured in the temperature range 473-1273 K, for different normalized and tempered samples. In essence, it is found that the CP of the fully martensitic microstructure is found to be lower than that of its tempered counterpart, and this difference begins to increase in an appreciable manner from about 800 K. The heat capacity of the normalized microstructure is found to vary from 480 to 500 J kg -1 K -1 at 500 K, where as that of the tempered steel is found to be higher by about, 150 J kg -1 K -1.

  18. Effect of Adding a Regenerator to Kornhauser's MIT "Two-Space" (Gas-Spring+Heat Exchanger) Test Rig

    NASA Technical Reports Server (NTRS)

    Ebiana, Asuquo B.; Gidugu, Praveen

    2008-01-01

    This study employed entropy-based second law post-processing analysis to characterize the various thermodynamic losses inside a 3-space solution domain (gas spring+heat exchanger+regenerator) operating under conditions of oscillating pressure and oscillating flow. The 3- space solution domain is adapted from the 2-space solution domain (gas spring+heat exchanger) in Kornhauser's MIT test rig by modifying the heat exchanger space to include a porous regenerator system. A thermal nonequilibrium model which assumes that the regenerator porous matrix and gas average temperatures can differ by several degrees at a given axial location and time during the cycle is employed. An important and primary objective of this study is the development and application of a thermodynamic loss post-processor to characterize the major thermodynamic losses inside the 3-space model. It is anticipated that the experience gained from thermodynamic loss analysis of the simple 3-space model can be extrapolated to more complex systems like the Stirling engine. It is hoped that successful development of loss post-processors will facilitate the improvement of the optimization capability of Stirling engine analysis codes through better understanding of the heat transfer and power losses. It is also anticipated that the incorporation of a successful thermal nonequilibrium model of the regenerator in Stirling engine CFD analysis codes, will improve our ability to accurately model Stirling regenerators relative to current multidimensional thermal-equilibrium porous media models.

  19. Investigation of the impact of transient heat loads applied by laser irradiation on ITER-grade tungsten

    NASA Astrophysics Data System (ADS)

    Huber, A.; Arakcheev, A.; Sergienko, G.; Steudel, I.; Wirtz, M.; Burdakov, A. V.; Coenen, J. W.; Kreter, A.; Linke, J.; Mertens, Ph; Philipps, V.; Pintsuk, G.; Reinhart, M.; Samm, U.; Shoshin, A.; Schweer, B.; Unterberg, B.; Zlobinski, M.

    2014-04-01

    Cracking thresholds and crack patterns in tungsten targets after repetitive ITER-like edge localized mode (ELM) pulses have been studied in recent simulation experiments by laser irradiation. The tungsten specimens were tested under selected conditions to quantify the thermal shock response. A Nd:YAG laser capable of delivering up to 32 J of energy per pulse with a duration of 1 ms at the fundamental wavelength λ = 1064 nm has been used to irradiate ITER-grade tungsten samples with repetitive heat loads. The laser exposures were performed for targets at room temperature (RT) as well as for targets preheated to 400 °C to measure the effects of the ELM-like loading conditions on the formation and development of cracks. The magnitude of the heat loads was 0.19, 0.38, 0.76 and 0.90 MJ m-2 (below the melting threshold) with a pulse duration of 1 ms. The tungsten surface was analysed after 100 and 1000 laser pulses to investigate the influence of material modification by plasma exposures on the cracking threshold. The observed damage threshold for ITER-grade W lies between 0.38 and 0.76 GW m-2. Continued cycling up to 1000 pulses at RT results in enhanced erosion of crack edges and crack edge melting. At the base temperature of 400 °C, the formation of cracks is suppressed.

  20. An investigation of the self-heating phenomenon in viscoelastic materials subjected to cyclic loadings accounting for prestress

    NASA Astrophysics Data System (ADS)

    de Lima, A. M. G.; Rade, D. A.; Lacerda, H. B.; Araújo, C. A.

    2015-06-01

    It has been demonstrated by many authors that the internal damping mechanism of the viscoelastic materials offers many possibilities for practical engineering applications. However, in traditional procedures of analysis and design of viscoelastic dampers subjected to cyclic loadings, uniform, constant temperature is generally assumed and do not take into account the self-heating phenomenon. Moreover, for viscoelastic materials subjected to dynamic loadings superimposed on static preloads, such as engine mounts, these procedures can lead to poor designs or even severe failures since the energy dissipated within the volume of the material leads to temperature rises. In this paper, a hybrid numerical-experimental investigation of effects of the static preloads on the self-heating phenomenon in viscoelastic dampers subjected to harmonic loadings is reported. After presenting the theoretical foundations, the numerical and experimental results obtained in terms of the temperature evolutions at different points within the volume of the viscoelastic material for various static preloads are compared, and the main features of the methodology are discussed.

  1. Displacement analysis of a bend plate test with mechanical loading and laser heating

    SciTech Connect

    Lam, P.S.

    1997-09-01

    The surface displacment of a steel plate caused by a permanent deformation as a result of local yielding was modeled by a finite element analysis. The local yielding occurs when a small area of the plate is heated by a laser beam. The calculated displacments are in good agreement with the preliminary experimental data obtained using a bend specimen with laser heating at the University of Alabama at Huntsville. It has been shown computuationally and optically that the relative displacments are less than 1mm near the laser heated area of the specimen. The results demonstrate that the experimental approach is a feasible technique for determining the residual stress under multiaxial stress field.

  2. Structural response of transient heat loading on a molybdenum surface exposed to low-energy helium ion irradiation

    NASA Astrophysics Data System (ADS)

    Sinclair, G.; Tripathi, J. K.; Diwakar, P. K.; Hassanein, A.

    2016-03-01

    The advancement of fusion reactor engineering is currently inhibited by the lack of knowledge surrounding the stability of plasma facing components (PFCs) in a tokamak environment. During normal operation, events of high heat loading occur periodically where large amounts of energy are imparted onto the PFC surface. Concurrently, irradiation by low-energy helium ions present in the fusion plasma can result in the synthesis of a fibre form nanostructure on the PFC surface, called ‘fuzz’. In order to understand how this heterogeneous structure evolves and deforms in response to transient heat loading, a pulsed Nd:YAG millisecond laser is used to simulate these events on a fuzz form molybdenum (Mo) surface. Performance was analysed by three metrics: nanostructure evolution, particle emission, and improvement in optical properties. Experiments performed at the upper end of the expected range for type-I edge-localized modes (ELMs) found that the helium-induced nanostructure completely disappears after 200 pulses of the laser at 1.5 MJ m-2. In situ mass loss measurements found that the amount of particles leaving the surface increases as energy density increases and the rate of emission increases with pulse count. Finally, optical properties assisted in providing a qualitative indication of fuzz density on the Mo surface; after 400 pulses at 1.5 MJ m-2, the optical reflectivity of the damaged surface is ~90% of that of a mirror polished Mo sample. These findings provide different results than previous studies done with tungsten (W), and further help illustrate the complicated nature of how transient events of high heat loading in a tokamak environment might impact the performance and lifetime of PFCs in ITER and future DEMO devices (Ueda et al 2014 Fusion Eng. Des. 89 901-6).

  3. The updated algorithm of the Energy Consumption Program (ECP): A computer model simulating heating and cooling energy loads in buildings

    NASA Technical Reports Server (NTRS)

    Lansing, F. L.; Strain, D. M.; Chai, V. W.; Higgins, S.

    1979-01-01

    The energy Comsumption Computer Program was developed to simulate building heating and cooling loads and compute thermal and electric energy consumption and cost. This article reports on the new additional algorithms and modifications made in an effort to widen the areas of application. The program structure was rewritten accordingly to refine and advance the building model and to further reduce the processing time and cost. The program is noted for its very low cost and ease of use compared to other available codes. The accuracy of computations is not sacrificed however, since the results are expected to lie within + or - 10% of actual energy meter readings.

  4. The ascending trajectories performance and control to minimize the heat load for the transatmospheric aero-space planes

    NASA Astrophysics Data System (ADS)

    Barlow, J.; Al-Garni, A.

    The goal of airbreathing transatmospheric vehicle (TAV) ascending trajectory performance and control definition is the minimization of heat loads/unit area near the stagnation point, modeling the vehicle as a point-variable mass with drag polar and variable thrust. Initially, the present effort proceeds analytically to define the aerodynamic and thrust controls required for TAV transfer from one specified state to another, while satisfying such equality constraints as constant dynamic pressure and constant rate-of-climb. Extensive numerical optimization algorithms are then applied. An illustrative numerical example is presented.

  5. High-heat-load synchrotron tests of room-temperature, silicon crystal monochromators at the CHESS F-2 wiggler station

    SciTech Connect

    Lee, W.K.; Fernandez, P.B.; Graber, T.; Assoufid, L.

    1995-09-08

    This note summarizes the results of the single crystal monochromator high-heat-load tests performed at the CHESS F-2 wiggler station. The results from two different cooling geometries are presented: (1) the ``pin-post`` crystal and (2) the ``criss-cross`` crystal. The data presented were taken in August 1993 (water-cooled pin-post) and in April 1995 (water- and gallium-cooled pin-post crystal and gallium-cooled criss-cross crystal). The motivation for trying these cooling (or heat exchanger) geometries is to improve the heat transfer efficiency over that of the conventional slotted crystals. Calculations suggest that the pin-post or the microchannel design can significantly improve the thermal performance of the crystal. The pin-post crystal used here was fabricated by Rocketdyne Albuquerque Operations. From the performance of the conventional slotted crystals, it was thought that increased turbulence in the flow pattern may also enhance the heat transfer. The criss-cross crystal was a simple attempt to achieve the increased flow turbulence. The criss-cross crystal was partly fabricated in-house (cutting, etching and polishing) and bonded by RAO. Finally, a performance comparison among all the different room temperature silicon monochromators that have been tested by the APS is presented. The data includes measurements with the slotted crystal and the core-drilled crystals. Altogether, the data presented here were taken at the CHESS F-2 wiggler station between 1991 and 1995.

  6. Assessment of the potential for heat recovery and load leveling on refrigeration systems, volume 1, summary

    NASA Astrophysics Data System (ADS)

    Merriam, R. L.; Lee, W. D.; Carr, J. E.; Boyce, S. E.; Bierenbaum, H. S.

    1980-03-01

    The potential energy savings from refrigerant heat recovery in the residential, commercial and industrial sectors and its impact on electric utilities were assessed. It was concluded that the technology for heat recovery is well established in all sectors and in comparison with solar water heating equivalent energy savings can be achieved at a fraction of the cost. In the absence of barriers, the potential market for heat recovery could be substantial, with an annual energy savings of 0.25 x 10 to the 15th power Btu in 1990. The economic impacts on summer peaking electric utilities were found to be favorable in all regions in central air conditioner applications. Annual net cost savings to the utility were estimated to be $10 to $50 per residential application. In the commercial sector and food processing segment of the industry sector, refrigerant heat recovery could reduce total energy consumption by about 0.28 x 10 to the 15th power Btu, with the major savings from applications in existing buildings.

  7. Artificial Neural Networks: a viable tool to design heat load smoothing strategies for the ITER Toroidal Field coils

    NASA Astrophysics Data System (ADS)

    Froio, A.; Bonifetto, R.; Carli, S.; Quartararo, A.; Savoldi, L.; Zanino, R.

    2015-12-01

    In superconducting tokamaks, cryoplants provide the helium needed to cool the superconducting magnet systems. The evaluation of the heat load from the magnets to the cryoplant is fundamental for the design of the latter and the assessment of suitable strategies to smooth the heat load pulses induced by the pulsed plasma scenarios is crucial for the operation. Here, a simplified thermal-hydraulic model of an ITER Toroidal Field (TF) magnet, based on Artificial Neural Networks (ANNs), is developed and inserted into a detailed model of the ITER TF winding and casing cooling circuits based on the state-of-the-art 4C code, which also includes active controls. The low computational effort requested by such a model allows performing a fast parametric study, to identify the best smoothing strategy during standard plasma operation. The ANNs are trained using 4C simulations, and the predictive capabilities of the simplified model are assessed against 4C simulations, both with and without active smoothing, in terms of accuracy and computational time.

  8. Findings of pre-ELM structures through the observation of divertor heat load patterns at JET with applied n = 2 perturbation fields

    NASA Astrophysics Data System (ADS)

    Rack, M.; Sieglin, B.; Eich, T.; Pearson, J.; Liang, Y.; Balboa, I.; Jachmich, S.; Wingen, A.; Pamela, S. J. P.; EFDA Contributors, JET

    2014-07-01

    Resonant magnetic perturbation experiments at JET with the ITER-like wall have shown the formation of radially propagating pre-ELM structures in the heat flux profile on the outer divertor. These appear a few milliseconds before the major divertor heat load, caused by type-I edge-localized modes (ELMs). The formation of the pre-ELM structures is accompanied by an increase in the Dα emission. For some pronounced examples, the propagation appears to end at the positions where an increased heat load is seen during the ELM crash a few milliseconds later. These observations are presented and discussed along with a comparison of a thermoelectric edge currents model.

  9. Adding heat to the live-high train-low altitude model: a practical insight from professional football

    PubMed Central

    Buchheit, M; Racinais, S; Bilsborough, J; Hocking, J; Mendez-Villanueva, A; Bourdon, P C; Voss, S; Livingston, S; Christian, R; Périard, J; Cordy, J; Coutts, A J

    2013-01-01

    Objectives To examine with a parallel group study design the performance and physiological responses to a 14-day off-season ‘live high-train low in the heat’ training camp in elite football players. Methods Seventeen professional Australian Rules Football players participated in outdoor football-specific skills (32±1°C, 11.5 h) and indoor strength (23±1°C, 9.3 h) sessions and slept (12 nights) and cycled indoors (4.3 h) in either normal air (NORM, n=8) or normobaric hypoxia (14±1 h/day, FiO2 15.2–14.3%, corresponding to a simulated altitude of 2500–3000 m, hypoxic (HYP), n=9). They completed the Yo-Yo Intermittent Recovery level 2 (Yo-YoIR2) in temperate conditions (23±1°C, normal air) precamp (Pre) and postcamp (Post). Plasma volume (PV) and haemoglobin mass (Hbmass) were measured at similar times and 4 weeks postcamp (4WPost). Sweat sodium concentration ((Na+)sweat) was measured Pre and Post during a heat-response test (44°C). Results Both groups showed very large improvements in Yo-YoIR2 at Post (+44%; 90% CL 38, 50), with no between-group differences in the changes (−1%; −9, 9). Postcamp, large changes in PV (+5.6%; −1.8, 5.6) and (Na+)sweat (−29%; −37, −19) were observed in both groups, while Hbmass only moderately increased in HYP (+2.6%; 0.5, 4.5). At 4WPost, there was a likely slightly greater increase in Hbmass (+4.6%; 0.0, 9.3) and PV (+6%; −5, 18, unclear) in HYP than in NORM. Conclusions The combination of heat and hypoxic exposure during sleep/training might offer a promising ‘conditioning cocktail’ in team sports. PMID:24282209

  10. Progress In The Development Of A New High Heat Load X-Ray Tube

    NASA Astrophysics Data System (ADS)

    Iversen, Arthur H.; Whitaker, Stephen

    1988-06-01

    The ongoing development of a new class of liquid cooled rotating anode x-ray tubes capable of high average and high peak power is discussed. Tube performance is characterized by zero wait-times between exposures and essentially no derating from peak instantaneous ratings for any arbitrary exposure sequence. The results of a successful program, which demonstrated proof of principle of the novel heat transfer surface will be described. The design and physics of the heat transfer surface of an experimental tube under construction will be reviewed. Potential benefits of this new tube include higher patient throughput in CT and certain fluoroscopic modalities, and possible longer tube life than conventional designs. New high average power techniques such as slit scanning, energy subtraction, x-ray spectrum optimization and special scatter rejection methods would become more clinically practical.

  11. Numerical Analysis of a Pulse Detonation Cross Flow Heat Load Experiment

    NASA Technical Reports Server (NTRS)

    Paxson, Daniel E.; Naples, Andrew .; Hoke, John L.; Schauer, Fred

    2011-01-01

    A comparison between experimentally measured and numerically simulated, time-averaged, point heat transfer rates in a pulse detonation (PDE) engine is presented. The comparison includes measurements and calculations for heat transfer to a cylinder in crossflow and to the tube wall itself using a novel spool design. Measurements are obtained at several locations and under several operating conditions. The measured and computed results are shown to be in substantial agreement, thereby validating the modeling approach. The model, which is based in computational fluid dynamics (CFD) is then used to interpret the results. A preheating of the incoming fuel charge is predicted, which results in increased volumetric flow and subsequent overfilling. The effect is validated with additional measurements.

  12. Air-To-Water Heat Pumps with Radiant Delivery in Low Load Homes: Tucson, Arizona and Chico, California (Fact Sheet)

    SciTech Connect

    Not Available

    2013-11-01

    Space conditioning represents nearly 50% of average residential household energy consumption, highlighting the need to identify alternative cost-effective, energy-efficient cooling and heating strategies. As homes are better built, there is an increasing need for strategies that are particularly well suited for high performance, low load homes. ARBI researchers worked with two test homes in hot-dry climates to evaluate the in-situ performance of air-to-water heat pump (AWHP) systems, an energy efficient space conditioning solution designed to cost-effectively provide comfort in homes with efficient, safe, and durable operation. Two monitoring projects of test houses in hot-dry climates were initiated in 2010 to test this system. Both systems were fully instrumented and have been monitored over one year to capture complete performance data over the cooling and heating seasons. Results are used to quantify energy savings, cost-effectiveness, and system performance using different operating modes and strategies. A calibrated TRNSYS model was developed and used to evaluate performance in various climate regions. This strategy is most effective in tight, insulated homes with high levels of thermal mass (i.e. exposed slab floors).

  13. Experimental study of ELM-like heat loading on beryllium under ITER operational conditions

    NASA Astrophysics Data System (ADS)

    Spilker, B.; Linke, J.; Pintsuk, G.; Wirtz, M.

    2016-02-01

    The experimental fusion reactor ITER, currently under construction in Cadarache, France, is transferring the nuclear fusion research to the power plant scale. ITER’s first wall (FW), armoured by beryllium, is subjected to high steady state and transient power loads. Transient events like edge localized modes not only deposit power densities of up to 1.0 GW m-2 for 0.2-0.5 ms in the divertor of the machine, but also affect the FW to a considerable extent. Therefore, a detailed study was performed, in which transient power loads with absorbed power densities of up to 1.0 GW m-2 were applied by the electron beam facility JUDITH 1 on beryllium specimens at base temperatures of up to 300 °C. The induced damage was evaluated by means of scanning electron microscopy and laser profilometry. As a result, the observed damage was highly dependent on the base temperatures and absorbed power densities. In addition, five different classes of damage, ranging from ‘no damage’ to ‘crack network plus melting’, were defined and used to locate the damage, cracking, and melting thresholds within the tested parameter space.

  14. Pressure waves in liquid mercury target from pulsed heat loads and the possible way controlling their effects

    SciTech Connect

    Ni, L.; Skala, K.

    1996-06-01

    In ESS project liquid metals are selected as the main target for the pulsed spallation neutron source. Since the very high instantaneous energy is deposited on the heavy molten target in a very short period time, pressure waves are generated. They travel through the liquid and cause high stress in the container. Also, additional stress should be considered in the wall which is the result of direct heating of the target window. These dynamic processes were simulated with computational codes with the static response being analized first. The total resulting dynamic wall stress has been found to have exceeded the design stress for the selected container material. Adding a small amount of gas bubbles in the liquid could be a possible way to reduce the pressure waves.

  15. Divertor heat loads in RMP ELM controlled H-mode plasmas on DIII-D*

    SciTech Connect

    Jakubowski, M; Lasnier, C; Schmitz, O; Evans, T; Fenstermacher, M; Groth, M; Watkins, J; Eich, T; Moyer, R; Wolf, R; Baylor, L; Boedo, J; Burrell, K; Frerichs, H; deGrassie, J; Gohil, P; Joseph, I; Lehnen, M; Leonard, A; Petty, C; Pinsker, R; Reiter, D; Rhodes, T; Samm, U; Snyder, P; Stoschus, H; Osborne, T; Unterberg, B; West, W

    2008-10-13

    In this paper the manipulation of power deposition on divertor targets at DIII-D by application of resonant magnetic perturbations (RMPs) is analyzed. It has been found that heat transport shows a different reaction to the applied RMP depending on the plasma pedestal collisionality. At pedestal electron collisionality above 0.5 the heat flux during the ELM suppressed phase is of the same order as the inter-ELM in the non-RMP phase. Below this collisionality value we observe a slight increase of the total power flux to the divertor. This can be caused by much more negative potential at the divertor surface due to hot electrons reaching the divertor surface from the pedestal area and/or so called pump out effect. In the second part we discuss modification of ELM behavior due to the RMP. It is shown, that the width of the deposition pattern in ELMy H-mode depends linearly on the ELM deposited energy, whereas in the RMP phase of the discharge those patterns seem to be controlled by the externally induced magnetic perturbation. D{sub 2} pellets injected into the plasma bulk during ELM-free RMP H-mode lead in some cases to a short term small transients, which have very similar properties to ELMs in the initial RMP-on phase.

  16. Limitations of liquid nitrogen cooling of high heat load x-ray monochromators

    NASA Astrophysics Data System (ADS)

    Khounsary, Ali; Strons, Philip; Kujala, Naresh; Macrander, Albert

    2012-10-01

    X-ray monochromators, made of single crystals or multilayer coatings, are the most common optical components on many synchrotron beamlines. They intercept the broad-spectrum x-ray (white or pink) beams generated by the radiation source and absorb all but select narrow spectral bands of x-rays, which are diffracted according to Bragg's Law. With some incident beam power in the kW range, minimizing thermally induced deformation detrimental to the performance of the device necessitates the design of optimally cooled monochromators. Monochromator substrate designs have evolved, in parallel with thermal loads of the incident beams, from simple blocks with no cooling, to water cooled (both contact -cooled and internally cooled), and to cryogenically cooled designs where the undesirable thermal distortions are kept in check by operating in a temperature range where the thermomechanical properties of the substrate materials are favorable. Fortuitously, single-crystal silicon at cryogenic temperatures has an exceptionally favorable combination of high thermal conductivity and low thermal expansion coefficient. With further increases in x-ray beam power, partly as a result of the upgrades to the existing synchrotron facilities, the question arises as to the ultimate limits of liquid-nitrogen-cooled silicon monochromators' ability to handle the increased thermal load. In this paper, we describe the difficulties and begin the investigation by using a simple geometric model for a monochromator and obtain analytical solutions for the temperature field. The temperature can be used as a proxy for thermally induced deformation. The significant role of the nonlinear material properties of silicon is examined.

  17. Advantages of the in-situ LTP distortion profile test on high-heat-load mirrors and applications

    SciTech Connect

    Qian, S.; Jark, W.; Sostero, G.; Gambitta, A.; Mazzolini, F.; Savoia, A.

    1996-12-31

    The first in-situ distortion profile measurement of a high heat load mirror by use of the penta-prism LTP is presented. A maximum height distortion of 0.47 micron in tangential direction over a length of 180 mm was measured for an internally water-cooled mirror of a undulator beam line at ELETTRA while exposed to a total emitted power of 600 W (undulator gap 30 mm and current 180 mA). The experiment has an accuracy and repeatability of 0.04 micron. The test schematic and the test equipment are presented. Two measuring methods to scan a penta-prism being installed either outside or inside the vacuum chamber are introduced. Advantages and some possible applications of adopting the penta-prism LTP to make the in-situ profile test are explained.

  18. Experience with bulk tungsten test-limiters under high heat loads: melting and melt layer propagation

    NASA Astrophysics Data System (ADS)

    Sergienko, G.; Bazylev, B.; Hirai, T.; Huber, A.; Kreter, A.; Mertens, Ph; Nedospasov, A.; Philipps, V.; Pospieszczyk, A.; Rubel, M.; Samm, U.; Schweer, B.; Sundelin, P.; Tokar, M.; Wessel, E.

    2007-03-01

    The paper provides an overview of processes and underlying physics governing tungsten melt erosion in the fusion plasma environment. Experiments with three different bulk tungsten test-limiters were performed in TEXTOR: (i) thermally insulated solid plate fixed on a graphite roof-like limiter heated up by the plasma to the melting point, (ii) macro-brush of the ITER-relevant castellated structure and (iii) lamellae structure developed for the JET divertor. The main objectives were to determine the metal surface damage, the formation of the melt layer and its motion in the magnetic field. PHEMOBRID-3D and MEMOS-1.5D numerical codes were used to simulate the experiment with the roof-like test-limiter. Both experiments and simulation showed that the melting of tungsten can lead to a large material redistribution due to thermo-electron emission currents without ejection of molten material to the plasma.

  19. Comparative study of beam losses and heat loads reduction methods in MITICA beam source

    NASA Astrophysics Data System (ADS)

    Sartori, E.; Agostinetti, P.; Dal Bello, S.; Marcuzzi, D.; Serianni, G.; Sonato, P.; Veltri, P.

    2014-02-01

    In negative ion electrostatic accelerators a considerable fraction of extracted ions is lost by collision processes causing efficiency loss and heat deposition over the components. Stripping is proportional to the local density of gas, which is steadily injected in the plasma source; its pumping from the extraction and acceleration stages is a key functionality for the prototype of the ITER Neutral Beam Injector, and it can be simulated with the 3D code AVOCADO. Different geometric solutions were tested aiming at the reduction of the gas density. The parameter space considered is limited by constraints given by optics, aiming, voltage holding, beam uniformity, and mechanical feasibility. The guidelines of the optimization process are presented together with the proposed solutions and the results of numerical simulations.

  20. Comparative study of beam losses and heat loads reduction methods in MITICA beam source

    SciTech Connect

    Sartori, E. Agostinetti, P.; Dal Bello, S.; Marcuzzi, D.; Serianni, G.; Veltri, P.; Sonato, P.

    2014-02-15

    In negative ion electrostatic accelerators a considerable fraction of extracted ions is lost by collision processes causing efficiency loss and heat deposition over the components. Stripping is proportional to the local density of gas, which is steadily injected in the plasma source; its pumping from the extraction and acceleration stages is a key functionality for the prototype of the ITER Neutral Beam Injector, and it can be simulated with the 3D code AVOCADO. Different geometric solutions were tested aiming at the reduction of the gas density. The parameter space considered is limited by constraints given by optics, aiming, voltage holding, beam uniformity, and mechanical feasibility. The guidelines of the optimization process are presented together with the proposed solutions and the results of numerical simulations.

  1. Measurement of strain heat in shock-loaded 304 stainless steel: Implications to powder consolidation

    NASA Astrophysics Data System (ADS)

    Staudhammer, K. P.

    2003-09-01

    Over the past decades there have been numerous papers on the shock response of materials and more specifically towards metal powder compaction and consolidation. In general, the shock process for powdered materials has utilized the traditional pressure-volume shock relationships proportioned to the initial packing densities of the powders. However, this approach and its resulting data are in controversy due to the lack of knowledge of its associated particle strain and strain temperature uncertainties. This paper will describe the current understanding as well as the experimental technique used to obtain the shock response for distended materials. The above parameters are described within a pressure-strain-temperature interdependence. It was found that the experimentally measured strain heat was not only a function of initial packing density but also a function of powder size and distribution.

  2. Inclined monochromator for high heat-load synchrotron x-ray radiation

    DOEpatents

    Khounsary, Ali M.

    1994-01-01

    A double crystal monochromator including two identical, parallel crystals, each of which is cut such that the normal to the diffraction planes of interest makes an angle less than 90 degrees with the surface normal. Diffraction is symmetric, regardless of whether the crystals are symmetrically or asymmetrically cut, enabling operation of the monochromator with a fixed plane of diffraction. As a result of the inclination of the crystal surface, an incident beam has a footprint area which is elongated both vertically and horizontally when compared to that of the conventional monochromator, reducing the heat flux of the incident beam and enabling more efficient surface cooling. Because after inclination of the crystal only a fraction of thermal distortion lies in the diffraction plane, slope errors and the resultant misorientation of the diffracted beam are reduced.

  3. Inclined monochromator for high heat-load synchrotron x-ray radiation

    DOEpatents

    Khounsary, A.M.

    1994-02-15

    A double crystal monochromator is described including two identical, parallel crystals, each of which is cut such that the normal to the diffraction planes of interest makes an angle less than 90 degrees with the surface normal. Diffraction is symmetric, regardless of whether the crystals are symmetrically or asymmetrically cut, enabling operation of the monochromator with a fixed plane of diffraction. As a result of the inclination of the crystal surface, an incident beam has a footprint area which is elongated both vertically and horizontally when compared to that of the conventional monochromator, reducing the heat flux of the incident beam and enabling more efficient surface cooling. Because after inclination of the crystal only a fraction of thermal distortion lies in the diffraction plane, slope errors and the resultant misorientation of the diffracted beam are reduced. 11 figures.

  4. Mitigation of upward and downward vertical displacement event heat loads with upper or lower massive gas injection in DIII-D

    SciTech Connect

    Hollmann, E. M.; Moyer, R. A.; Commaux, N.; Shiraki, D.; Eidietis, N. W.; Parks, P. B.; Lasnier, C. J.

    2015-10-15

    Intentionally triggered upward and downward vertical displacement events (VDEs) leading to disruptions were pre-emptively mitigated with neon massive gas injection (MGI) coming from either above or below the plasma. Global indicators of disruption mitigation effectiveness (conducted heat loads, radiated power, and vessel motion) do not show a clear improvement when mitigating with the gas jet located closer to the VDE impact area. A clear trend of improved mitigation is observed for earlier MGI timing relative to the VDE impact time. The plasma edge magnetic perturbation is seen to lock to a preferential phase during the VDE thermal quench, but this phase is not clearly matched by preliminary attempts to fit to the conducted heat load phase. Clear indications of plasma infra-red (IR) emission are observed both before and during the disruptions. This IR emission can affect calculation of disruption heat loads; here, the time decay of post-disruption IR signals is used to correct for this effect.

  5. Mitigation of upward and downward vertical displacement event heat loads with upper or lower massive gas injection in DIII-D

    SciTech Connect

    Hollmann, E. M.; Commaux, Nicolas J. C.; Eidietis, N. W.; Lasnier, C. J.; Moyer, R. A.; Parks, P. B.; Shiraki, Daisuke

    2015-10-12

    Intentionally triggered upward and downward vertical displacement events (VDEs) leading to disruptions were pre-emptively mitigated with neon massive gas injection (MGI) coming from either above or below the plasma. Global indicators of disruption mitigation effectiveness (conducted heat loads, radiated power, and vessel motion) do not show a clear improvement when mitigating with the gas jet located closer to the VDE impact area. A clear trend of improved mitigation is observed for earlier MGI timing relative to the VDE impact time. The plasma edge magnetic perturbation is seen to lock to a preferential phase during the VDE thermal quench, but this phase is not clearly matched by preliminary attempts to fit to the conducted heat load phase. Clear indications of plasma infra-red (IR) emission are observed both before and during the disruptions. Furthermore, this IR emission can affect calculation of disruption heat loads; here, the time decay of post-disruption IR signals is used to correct for this effect.

  6. THE INFLUENCE OF REPOSITORY THERMAL LOAD ON MULTIPHASE FLOW AND HEAT TRANSFER IN THE UNSATURATED ZONE OF YUCCA MOUNTAIN

    SciTech Connect

    Yu-Shu Wu, Sumit Mukhopadhyay, Keni Zhang, and G. S. Bodvarsson

    2006-04-16

    This paper investigates the impact of proposed repository thermal-loading on mountain-scale flow and heat transfer in the unsaturated fractured rock of Yucca Mountain, Nevada. In this context, a model has been developed to study the coupled thermal-hydrological (TH) processes at the scale of the entire Yucca Mountain. This mountain-scale TH model implements the current geological framework and hydrogeological conceptual models, and incorporates the latest rock thermal and hydrological properties. The TH model consists of a two-dimensional north-south vertical cross section across the entire unsaturated zone model domain and uses refined meshes near and around the proposed repository block, based on the current repository design, drift layout, thermal loading scenario, and estimated current and future climatic conditions. The model simulations provide insights into thermally affected liquid saturation, gas- and liquid-phase fluxes, and elevated water and rock temperature, which in turn allow modelers to predict the changes in water flux driven by evaporation/condensation processes, and drainage between drifts.

  7. Evolution of tungsten degradation under combined high cycle edge-localized mode and steady-state heat loads

    NASA Astrophysics Data System (ADS)

    Loewenhoff, Th; Bürger, A.; Linke, J.; Pintsuk, G.; Schmidt, A.; Singheiser, L.; Thomser, C.

    2011-12-01

    Combined thermal shock and steady-state heat loads (SSHLs) can have an impact on divertor materials and are therefore important for lifetime estimations and evaluations of operational thresholds of divertor components in future fusion devices such as ITER. This paper discusses the results of tests performed in the electron beam facility JUDITH 2 (Forschungszentrum Jülich, Germany) on actively cooled tungsten specimens, loaded with edge-localized mode-like thermal shocks (pulse duration 0.48 ms, power densities 0.14-0.55 GW m-2, frequency 25 Hz and up to 1000 000 pulses) either with or without an additional SSHL of 10 MW m-2. The material showed no damage at 0.14 GW m-2 (independent of the SSHL) for up to 250 000 pulses. At a power density of 0.27 GW m-2 (without SSHL), surface roughening occurred at 100 000 pulses, developing into a crack network at 1000 000 pulses. In general, the additional SSHL resulted in an earlier (in terms of pulse number) and more severe material degradation.

  8. Researching Complex Heat, Air and Moisture Interactions for a Wide-Range of Building Envelope Systems and Environmental Loads

    SciTech Connect

    Karagiozis, A.N.

    2007-05-15

    This document serves as the final report documenting work completed by Oak Ridge National Laboratory (ORNL) and the Fraunhofer Institute in Building Physics (Holzkirchen, Germany) under an international CRADA No. 0575 with Fraunhofer Institute of Bauphysics of the Federal Republic of Germany for Researching Complex Heat, Air and Moisture Interactions for a Wide Range of Building Envelope Systems and Environmental Loads. This CRADA required a multi-faceted approach to building envelope research that included a moisture engineering approach by blending extensive material property analysis, laboratory system and sub-system thermal and moisture testing, and advanced moisture analysis prediction performance. The Participant's Institute for Building physics (IBP) and the Contractor's Buildings Technology Center (BTC) identified potential research projects and activities capable of accelerating and advancing the development of innovative, low energy and durable building envelope systems in diverse climates. This allowed a major leverage of the limited resources available to ORNL to execute the required Department of Energy (DOE) directives in the area of moisture engineering. A joint working group (ORNL and Fraunhofer IBP) was assembled and a research plan was executed from May 2000 to May 2005. A number of key deliverables were produced such as adoption of North American loading into the WUFI-software. in addition the ORNL Weather File Analyzer was created and this has been used to address environmental loading for a variety of US climates. At least 4 papers have been co-written with the CRADA partners, and a chapter in the ASTM Manual 40 on Moisture Analysis and Condensation Control. All deliverables and goals were met and exceeded making this collaboration a success to all parties involves.

  9. Heat Loads at High Temperature Protection Diodes for a Mercury Mission

    NASA Astrophysics Data System (ADS)

    Reul, S.; Zimmermann, W.; Strobl, G. F. X.; La Roche, G.; Baur, C.

    2008-09-01

    In the frame of the BepiColombo project (see Fig. 1) the solar generators have to withstand the environment near Mercury. Thus all components must withstand an solar irradiation of 10 solar constants or 13.67 kW/m2;. Due to manoeuvres it can happen, that e.g. solar cells will be shadowed or all cell interconnections can fail. To prevent the solar cells from operating in reverse a high temperature protection shunt diode is foreseen for each GaInP/GaInAs/Ge solar cell. This paper reports about first computations of the temperature distributions for different load cases with useful assumptions for the generator structure, sizes/shapes, etc. Also the main temperature influencing parameter and some useful consequences for a high temperature design of a solar generator and Si-diodes will be discussed. The work is part of the ESA contract 19739/06/NL/JD. The Si-diode layout is proposed by AZUR SPACE solar power, Heilbronn.

  10. Behaviour of Silicon-Doped CFC Limiter under High Heat Load in TEXTOR-94

    NASA Astrophysics Data System (ADS)

    Huber, A.; Philipps, V.; Hirai, T.; Kirschner, A.; Lehnen, M.; Pospieszczyk, A.; Schweer, B.; Sergienko, G.

    In order to study the impurity production, recycling and power deposition a Si doped CFC test limiter (NS31) was used in TEXTOR-94. The release of impurities (C, Si, O, Cr, CD radicals) was measured spectroscopically. A reduced methane production was found in the Si doped graphite when compared to a pure graphite limiter. A smaller decrease of the carbon fluxes could also be observed. The limiter contained about 1%-1.5% of Si, but a relative Si flux (Si/D) from the Si doped CFC surface between 0.12% and 0.4% has been measured. A chemical erosion of Si due to formation of SiDx has not been observed. Silicon evaporated from the surface at temperatures above 1500°C. This led to an increase of Si concentration and total radiation losses from the plasma. Surface analysis shows the formation of microcracks and holes on the plasma exposed limiter surface. The released Si was deposited in the vicinity of the tangency point of the limiter. Whereas a Si depletion was observed in the area of highest power loading with values reaching in and in-between fibres values of 0.03% and 0.02% respectively.

  11. Heat loads to divertor nearby components from secondary radiation evolved during plasma instabilities

    NASA Astrophysics Data System (ADS)

    Sizyuk, V.; Hassanein, A.

    2015-01-01

    A fundamental issue in tokamak operation related to power exhaust during plasma instabilities is the understanding of heat and particle transport from the core plasma into the scrape-off layer and to plasma-facing materials. During abnormal and disruptive operation in tokamaks, radiation transport processes play a critical role in divertor/edge-generated plasma dynamics and are very important in determining overall lifetimes of the divertor and nearby components. This is equivalent to or greater than the effect of the direct impact of escaped core plasma on the divertor plate. We have developed and implemented comprehensive enhanced physical and numerical models in the upgraded HEIGHTS package for simulating detailed photon and particle transport in the evolved edge plasma during various instabilities. The paper describes details of a newly developed 3D Monte Carlo radiation transport model, including optimization methods of generated plasma opacities in the full range of expected photon spectra. Response of the ITER divertor's nearby surfaces due to radiation from the divertor-developed plasma was simulated by using actual full 3D reactor design and magnetic configurations. We analyzed in detail the radiation emission spectra and compared the emission of both carbon and tungsten as divertor plate materials. The integrated 3D simulation predicted unexpectedly high damage risk to the open stainless steel legs of the dome structure in the current ITER design from the intense radiation during a disruption on the tungsten divertor plate.

  12. Impact of Periodic Unsteadiness on Performance and Heat Load in Axial Flow Turbomachines

    NASA Technical Reports Server (NTRS)

    Sharma, Om P.; Stetson, Gary M.; Daniels, William A,; Greitzer, Edward M.; Blair, Michael F.; Dring, Robert P.

    1997-01-01

    Results of an analytical and experimental investigation, directed at the understanding of the impact of periodic unsteadiness on the time-averaged flows in axial flow turbomachines, are presented. Analysis of available experimental data, from a large-scale rotating rig (LSRR) (low speed rig), shows that in the time-averaged axisymmetric equations the magnitude of the terms representing the effect of periodic unsteadiness (deterministic stresses) are as large or larger than those due to random unsteadiness (turbulence). Numerical experiments, conducted to highlight physical mechanisms associated with the migration of combustor generated hot-streaks in turbine rotors, indicated that the effect can be simulated by accounting for deterministic stress like terms in the time-averaged mass and energy conservation equations. The experimental portion of this program shows that the aerodynamic loss for the second stator in a 1-1/2 stage turbine are influenced by the axial spacing between the second stator leading edge and the rotor trailing edge. However, the axial spacing has little impact on the heat transfer coefficient. These performance changes are believed to be associated with the change in deterministic stress at the inlet to the second stator. Data were also acquired to quantify the impact of indexing the first stator relative to the second stator. For the range of parameters examined, this effect was found to be of the same order as the effect of axial spacing.

  13. A software system used for load distribution at a combined heat and power plant with the complex mix of the equipment and complex schemes of heat and electric power supply

    NASA Astrophysics Data System (ADS)

    Makarch'yan, V. A.; Chernyaev, A. N.; Andryushin, A. V.; Pechenkin, S. P.; Lisitsa, V. I.; Logvinov, E. I.; Molchanov, A. Yu.

    2013-05-01

    The authors describe various approaches to construction of an algorithm for the solution of the problem of load distribution at a combined heat and power (CHP) plant with the complex mix of the equipment and complex schemes of heat and electrical energy supply on the basis of which the software system has been developed. Methods of obtaining energy characteristics of the equipment used for solving the problem of load distribution were studied. The results of the implementation of the software system for load distribution at the CHP-23 plant belonging to OAO Mosenergo are given. Realization of recommendations on maintaining an operational mode of the equipment with due regard for its optimal loading makes it possible to obtain fuel savings of up to 1%.

  14. Heat loads from ICRF and LH wave absorption in the SOL: characterization on JET and implications for the ITER-Like Wall

    SciTech Connect

    Colas, L.; Arnoux, G.; Goniche, M.; Jacquet, Ph.; Mayoral, M.-L.; Brix, M.; Fursdon, M.; Graham, M.; Mailloux, J.; Monakhov, I.; Noble, C.; Sirinelli, A.; Riccardo, V.; Vizvary, Z.; Lerche, E.; Ongena, J.; Petrzilka, V.

    2011-12-23

    Heat loads from ICRF and LH wave absorption in the SOL are characterized on JET from the de-convolution of surface temperatures measured by infrared thermography. The spatial localization, quantitative estimates, parametric dependence and physical origin of the observed heat fluxes are documented. Implications of these observations are discussed for the operation of JET with an ITER-Like Wall, featuring Beryllium tiles with reduced power handling capability.

  15. Building America Case Study: Calculating Design Heating Loads for Superinsulated Buildings, Ithaca, New York; Technology Solutions for New and Existing Homes, Energy Efficiency & Renewable Energy (EERE)

    SciTech Connect

    2015-08-01

    Designing a superinsulated home has many benefits including improved comfort, reduced exterior noise penetration, lower energy bills, and the ability to withstand power and fuel outages under much more comfortable conditions than a typical home. Extremely low heating and cooling loads equate to much smaller HVAC equipment than conventionally required. Sizing the mechanical system to these much lower loads reduces first costs and the size of the distribution system needed. While these homes aren't necessarily constructed with excessive mass in the form of concrete floors and walls, the amount of insulation and the increase in the thickness of the building envelope can lead to a mass effect, resulting in the structures ability to store much more heat than a code built home. This results in a very low thermal inertia making the building much less sensitive to drastic temperature swings thereby decreasing the peak heating load demand. Alternative methods that take this inertia into account along with solar and internal gains result in smaller more appropriate design loads than those calculated using Manual J version 8. During the winter of 2013/2014, CARB monitored the energy use of three homes in climate zone 6 in an attempt to evaluate the accuracy of two different mechanical system sizing methods for low load homes. Based on the results, it is recommended that internal and solar gains be included and some credit for thermal inertia be used in sizing calculations for superinsulated homes.

  16. Effect of high-flux H/He plasma exposure on tungsten damage due to transient heat loads

    NASA Astrophysics Data System (ADS)

    De Temmerman, G.; Morgan, T. W.; van Eden, G. G.; de Kruif, T.; Wirtz, M.; Matejicek, J.; Chraska, T.; Pitts, R. A.; Wright, G. M.

    2015-08-01

    The thermal shock behaviour of tungsten exposed to high-flux plasma is studied using a high-power laser. The cases of laser-only, sequential laser and hydrogen (H) plasma and simultaneous laser plus H plasma exposure are studied. H plasma exposure leads to an embrittlement of the material and the appearance of a crack network originating from the centre of the laser spot. Under simultaneous loading, significant surface melting is observed. In general, H plasma exposure lowers the heat flux parameter (FHF) for the onset of surface melting by ∼25%. In the case of He-modified (fuzzy) surfaces, strong surface deformations are observed already after 1000 laser pulses at moderate FHF = 19 MJ m-2 s-1/2, and a dense network of fine cracks is observed. These results indicate that high-fluence ITER-like plasma exposure influences the thermal shock properties of tungsten, lowering the permissible transient energy density beyond which macroscopic surface modifications begin to occur.

  17. High heat load performance of an inclined crystal monochromator with liquid gallium cooling on the CHESS-ANL undulator

    SciTech Connect

    Macrander, A.T.; Lee, W.K.; Smither, R.K.; Mills, D.M.; Rogers, S.; Khounsary, A.

    1991-11-01

    Results for the performance of a novel double crystal monochromator subjected to high heat loads from an APS prototype undulator at the Cornell High Energy Synchrotron Source (CHESS) are presented. The monochromator was designed to achieve symmetric diffraction from asymmetric planes to spread out the beam footprint thereby lowering the incident power density. Both crystals had (111) oriented surfaces and were arranged such that the beam was diffracted from the (11{bar 1}) planes at 5 KeV. Rocking curves with minimal distortion were obtained at a ring electron current of 96 mA. This corresponded to 370 Watts total power and an peak power density of 48 Watts/mm{sup 2} normal to the incident beam. These results are compared to data obtained from the same crystals in the standard geometry (diffracting planes parallel to surface). The footprint area in the inclined case was three times that of the standard case. We also obtained rocking curve data for the {l_brace}333{r_brace} reflection at 15 KeV for both standard and inclined cases, and these data also showed a minimal distortion for the inclined case. In addition, thermal data were obtained via infrared pyrometry. Not only the diffraction data but also the thermal data revealed a dramatically improved performance for the inclined crystal case.

  18. Comparative failure load values of acrylic resin denture teeth bonded to three different heat cure denture base resins: An in vitro study

    PubMed Central

    Phukela, Sumit Singh; Dua, Amit; Dua, Mahima; Sehgal, Varun; Setya, Gaurav; Dhall, Rupinder Singh

    2016-01-01

    Aim and Objectives: Acrylic teeth are used for fabrication of dentures. Debonding of tooth – denture base bond is routine problem in dental practice. The aim of this study was to comparatively evaluate failure load of acrylic resin denture teeth bonded to three different heat resin. Materials and Methods: Four groups were created out of test samples central incisors (11). Group I: Control, whereas Group II, Group III and Group IV were experimental groups modified with diatoric hole, cingulum ledge lock and Teeth modified with both diatoric hole and cingulum ledge lock, respectively. These test specimens with 3 teeth (2 central [11, 21] and 1, lateral [12] incisors) positioned imitating arrangement of teeth in the conventional denture, prepared by three different heat cure materials (DPI, Trevalon, Acralyn-H). A shear load was applied at cingulum of central incisor (11) at 130° to its long axis using universal tester at a cross head speed of 5 mm/min until failure occurred. Failure load test was conducted and statistical analysis was performed using SPSS 16 software package (IBM Company, New York, U.S). Results: Highest failure load was seen in Group IV specimens, prepared by Trevalon but did not significantly differ from that of DPI. Conclusion: The failure load of bonding denture teeth to three different heat cure materials was notably affected by modifications of ridge lap before processing. The specimens with a combination of diatoric hole and cingulum ledge lock, prepared by Trevalon showed highest failure load but did not significantly vary from that of DPI. The control group prepared by Acralyn-H showed lowest failure load but did not significantly differ from that of DPI. PMID:27195221

  19. Value Added?

    ERIC Educational Resources Information Center

    UCLA IDEA, 2012

    2012-01-01

    Value added measures (VAM) uses changes in student test scores to determine how much "value" an individual teacher has "added" to student growth during the school year. Some policymakers, school districts, and educational advocates have applauded VAM as a straightforward measure of teacher effectiveness: the better a teacher, the better students…

  20. Aerodynamic heating and loading within large open cavities in cone and cone-cylinder-flare models at Mach 6.7

    NASA Technical Reports Server (NTRS)

    Hunt, R. L.

    1974-01-01

    The aerodynamic heating and loading distributions within large cavities exposed by surface openings to hypersonic flow were determined in the 8-foot high-temperature structures tunnel. Cone and cone-cylinder-flare models with cavities having regular and irregular surface-opening shapes were aerothermally tested at various angles of attack up to 30 deg. Tests were conducted at a Mach number of 6.7, a total temperature of 1800 K, a dynamic pressure of 80 kPa, and a stream unit Reynolds number of 6,000,000 per meter. The results showed that the heating rates at internal reattachment were generally lower but of the same order as the corresponding external heating rates; however, other internal heating rates were an order of magnitude lower. The internal flow showed characteristics of being funneled into jets or being dispersed dependent upon the internal surface contour.

  1. Simulation and Analysis of Temperature Distribution and Material Properties Change of a Thermal Heat sink Undergoing Thermal Loading in a Mobile Computer

    NASA Astrophysics Data System (ADS)

    Xavier, A.; Lim, C. S.

    2015-09-01

    This paper is aimed at studying the thermal distribution and its associated effects on a thermal heat sink of a mobile computer (laptop). Possible thermal effects are investigated using Finite-Element Method with the help of a FEM software (Ansys Workbench 14). Physical changes of the structure such as temperature change and deformation are measured and are used as the basis for comparison between models of heat sinks. This paper also attempts to study the effect of thermal loading on the materials found in a heat sink hardware in terms of stresses that may arise due to physical restraints in the hardware as well as provide an optimized solution to reduce its form factor in order to be comparable to an Ultrabook class heat-sink. An optimized solution is made based on a cylindrical fin concept.

  2. Impact of nonlinear 3D equilibrium response on edge topology and divertor heat load in Wendelstein 7-X

    NASA Astrophysics Data System (ADS)

    Suzuki, Y.; Geiger, J.

    2016-06-01

    The impact of the 3D equilibrium response on the plasma edge topology is studied. In Wendelstein 7-X, the island divertor concept is used to assess scenarios for quasi-steady-state operation. However, the boundary islands necessary for the island divertor are strongly susceptible to plasma beta and toroidal current density effects because of the low magnetic shear. The edge magnetic topology for quasi-steady-state operation scenarios is calculated with the HINT-code to study the accompanying changes of the magnetic field structures. Two magnetic configurations have been selected, which had been investigated in self consistent neoclassical transport simulations for low bootstrap current but which use the alternative natural island chains to the standard iota value of 1 (ι b   =  5/5, periodicity), namely, at high-iota (ι b   =  5/4) and at low-iota (ι b   =  5/6). For the high-iota configuration, the boundary islands are robust but the stochasticity around them is enhanced with beta. The addition of toroidal current densities enhances the stochasticity further. The increased stochasticity changes the footprints on in-vessel components with a direct impact on the corresponding heat loads. In the low-iota configuration the boundary islands used for the island divertor are dislocated radially due to the low shear and even show healing effects, i.e. the island width vanishes. In the latter case the plasma changes from divertor to limiter operation. To realize the predicted high-performance quasi-steady-state operation of the transport simulations, further adjustments of the magnetic configuration may be necessary to achieve a proper divertor compatibility of the scenarios.

  3. Loading and heating of a large flat plate at Mach 7 in the Langley 8-foot high-temperature structures tunnel

    NASA Technical Reports Server (NTRS)

    Deveikis, W. D.; Hunt, L. R.

    1973-01-01

    Surface pressure and cold-wall heating rate distributions (wall-temperature to total-temperature ratio approximately 0.2) were obtained on a large, flat calibration panel at a nominal Mach number of 7 in an 8-foot high-temperature structures tunnel. Panel dimensions were 42.5 by 60.0 in. Test objectives were: (1) to map available flat-plate loading and heating provided by the facility and (2) to determine effectiveness of leading-edge bluntness, boundary-layer trips, and aerodynamic fences in generating a uniform, streamwise turbulent flow field over the test surface of a flat-sided panel holder.

  4. Mitigation of upward and downward vertical displacement event heat loads with upper or lower massive gas injection in DIII-D

    DOE PAGESBeta

    Hollmann, E. M.; Commaux, Nicolas J. C.; Eidietis, N. W.; Lasnier, C. J.; Moyer, R. A.; Parks, P. B.; Shiraki, Daisuke

    2015-10-12

    Intentionally triggered upward and downward vertical displacement events (VDEs) leading to disruptions were pre-emptively mitigated with neon massive gas injection (MGI) coming from either above or below the plasma. Global indicators of disruption mitigation effectiveness (conducted heat loads, radiated power, and vessel motion) do not show a clear improvement when mitigating with the gas jet located closer to the VDE impact area. A clear trend of improved mitigation is observed for earlier MGI timing relative to the VDE impact time. The plasma edge magnetic perturbation is seen to lock to a preferential phase during the VDE thermal quench, but thismore » phase is not clearly matched by preliminary attempts to fit to the conducted heat load phase. Clear indications of plasma infra-red (IR) emission are observed both before and during the disruptions. Furthermore, this IR emission can affect calculation of disruption heat loads; here, the time decay of post-disruption IR signals is used to correct for this effect.« less

  5. Adding Value.

    ERIC Educational Resources Information Center

    Orsini, Larry L.; Hudack, Lawrence R.; Zekan, Donald L.

    1999-01-01

    The value-added statement (VAS), relatively unknown in the United States, is used in financial reports by many European companies. Saint Bonaventure University (New York) has adapted a VAS to make it appropriate for not-for-profit universities by identifying stakeholder groups (students, faculty, administrators/support personnel, creditors, the…

  6. Low-cost multi-vehicle air temperature measurements for heat load assessment in local-scale climate applications

    NASA Astrophysics Data System (ADS)

    Zuvela-Aloise, Maja; Weyss, Gernot; Aloise, Giulliano; Mifka, Boris; Löffelmann, Philemon; Hollosi, Brigitta; Nemec, Johana; Vucetic, Visnja

    2014-05-01

    In the recent years there has been a strong interest in exploring the potential of low-cost measurement devices as alternative source of meteorological monitoring data, especially in the urban areas where high-density observations become crucial for appropriate heat load assessment. One of the simple, but efficient approaches for gathering large amount of spatial data is through mobile measurement campaigns in which the sensors are attached to driving vehicles. However, non-standardized data collecting procedure, instrument quality, their response-time and design, variable device ventilation and radiation protection influence the reliability of the gathered data. We investigate what accuracy can be expected from the data collected through low-cost mobile measurements and whether the achieved quality of the data is sufficient for validation of the state-of-the-art local-scale climate models. We tested 5 types of temperature sensors and data loggers: Maxim iButton, Lascar EL-USB-2-LCD+ and Onset HOBO UX100-003 as market available devices and self-designed solar powered Arduino-based data loggers combined with the AOSONG AM2315 and Sensirion SHT21 temperature and humidity sensors. The devices were calibrated and tested in stationary mode at the Austrian Weather Service showing accuracy between 0.1°C and 0.8°C, which was mostly within the device specification range. In mobile mode, the best response-time was found for self-designed device with Arduino-based data logger and Sensirion SHT21 sensor. However, the device lacks the mechanical robustness and should be further improved for broad-range applications. We organized 4 measurement tours: two taking place in urban environment (Vienna, Austria in July 2011 and July 2013) and two in countryside with complex terrain of Mid-Adriatic islands (Hvar and Korcula, Croatia in August 2013). Measurements were taken on clear-sky, dry and hot days. We combined multiple devices attached to bicycle and cars with different

  7. Technology Solutions Case Study: Air-To-Water Heat Pumps with Radiant Delivery in Low Load Homes, Tucson, Arizona and Chico, California

    SciTech Connect

    2013-11-01

    Space conditioning represents nearly 50% of average residential household energy consumption, highlighting the need to identify alternative cost-effective, energy-efficient cooling and heating strategies. As homes are better built, there is an increasing need for strategies that are particularly well suited for high performance, low load homes. ARBI researchers worked with two test homes in hot-dry climates to evaluate the in-situ performance of air-to-water heat pump (AWHP) systems, an energy efficient space conditioning solution designed to cost-effectively provide comfort in homes with efficient, safe, and durable operation. Both systems were fully instrumented and have been monitored over one year to capture complete performance data over the cooling and heating seasons. Results are used to quantify energy savings, cost-effectiveness, and system performance using different operating modes and strategies. This strategy is most effective in tight, insulated homes with high levels of thermal mass (i.e. exposed slab floors).

  8. A novel ultra-high performance liquid chromatography method for the rapid determination of β-lactoglobulin as heat load indicator in commercial milk samples.

    PubMed

    Boitz, Lisa I; Fiechter, Gregor; Seifried, Reinhold K; Mayer, Helmut K

    2015-03-20

    The level of undenatured acid-soluble β-lactoglobulin can be used as an indicator to assess the heat load applied to liquid milk, thus further allowing the discrimination between milk originating from different thermal production processes. In this work, a new UHPLC method for the rapid determination of bovine β-lactoglobulin in 1.8min only (total runtime 3min) is presented using simple UV detection at 205nm. Separation selectivity for possibly co-eluting other major whey proteins (bovine serum albumin, lactoferrin, α-lactalbumin, immunoglobulin G) was verified, and the method validated for the analysis of liquid milk samples regarding linearity (20-560μg/mL, R(2)>0.99), instrumentation precision (RSDs<2.8%), limits of detection and quantification (7 and 23mg/L milk), repeatability of sample work-up (RSDs≤2.6%) and method recovery (103%). In total, 71 commercial liquid milk samples produced using different preservation techniques (e.g., thermal or mechanical treatment), hence featuring different applied heat loads, were profiled for their intrinsic undenatured acid-soluble β-lactoglobulin levels. As expected, pasteurized milk showed the highest concentrations clearly above 3000mg/L due to pasteurization being the mildest thermal treatment, while in contrast, ultra-high temperature heated milk featured the lowest amounts (<200mg/L). For extended shelf life (ESL) milk, quite diverse levels were determined ranging from ∼100 up to 4000mg/L, thus clearly illustrating variable applied heat loads and impacts on the "nativeness" of milk essentially due to the fact that the production technologies used for ESL milk may differ significantly, and are currently not regulated in the EU. PMID:25700725

  9. Fort Gordon energy survey and analysis of boiler and chiller plants, Building 25910, Building 25330 and heating loads. Volume III. Final report

    SciTech Connect

    1995-04-03

    The Trace 600 program was used to generate the heating requirements for each of the building types surveyed during the field study. The data produced from the program was based on several conditions that will be explained here. The weather data for the simulation was based on standard weather tables in the Trace Program for the Augusta area. The design outside dry bulb temperature was 230F, and internal loads such as people, lights, and miscellaneous equipment were not considered. Ventilation and infiltration were considered. Ventilation was defined as 15 cfin/person, infiltration for heating purposes was defined as 0.1 cfm/sf. The report produced heating requirements for the building hourly for five day type conditions. Design, Weekday, Saturday, Sunday, and Monday. The only one column from each building type was selected for the analysis and reporting process. This day type was usually the weekday column. The worst case condition was selected as a conservative approach to providing requirements that may tend toward the high side. Particular attention was paid to the values to assure that the data produced a smooth curve with few spikes and valleys. The information for all twelve months was transferred to Table 3C or 4C for further data reduction. Appendix I contains the Trace output heat load data for Building 25910, North Central Utility Plan Appendix II contains the Trace output data for the South Central Plant Building 25330. The data was used to accumulate the hourly load requirements on each of the two central utility plants.

  10. DIS in AdS

    NASA Astrophysics Data System (ADS)

    Albacete, Javier L.; Kovchegov, Yuri V.; Taliotis, Anastasios

    2009-03-01

    We calculate the total cross section for the scattering of a quark-anti-quark dipole on a large nucleus at high energy for a strongly coupled N = 4 super Yang-Mills theory using AdS/CFT correspondence. We model the nucleus by a metric of a shock wave in AdS5. We then calculate the expectation value of the Wilson loop (the dipole) by finding the extrema of the Nambu-Goto action for an open string attached to the quark and antiquark lines of the loop in the background of an AdS5 shock wave. We find two physically meaningful extremal string configurations. For both solutions we obtain the forward scattering amplitude N for the quark dipole-nucleus scattering. We study the onset of unitarity with increasing center-of-mass energy and transverse size of the dipole: we observe that for both solutions the saturation scale Qs is independent of energy/Bjorken-x and depends on the atomic number of the nucleus as Qs˜A1/3. Finally we observe that while one of the solutions we found corresponds to the pomeron intercept of αP = 2 found earlier in the literature, when extended to higher energy or larger dipole sizes it violates the black disk limit. The other solution we found respects the black disk limit and yields the pomeron intercept of αP = 1.5. We thus conjecture that the right pomeron intercept in gauge theories at strong coupling may be αP = 1.5.

  11. The Influence of Proposed Repository Thermal Load on MultiphaseFlow and Heat Transfer in the Unsaturated Zone of Yucca Mountain

    SciTech Connect

    Wu, Y.-S.; Mukhopadhyay, Sumit; Zhang, Keni; Bodvarsson, G.S.

    2006-02-28

    This paper investigates the impact of proposed repositorythermal-loading on mountain-scale flow and heat transfer in theunsaturated fractured rock of Yucca Mountain, Nevada. In this context, amodel has been developed to study the coupled thermal-hydrological (TH)processes at the scale of the entire Yucca Mountain. This mountain-scaleTH model implements the current geological framework and hydrogeologicalconceptual models, and incorporates the latest rock thermal andhydrological properties. The TH model consists of a two-dimensionalnorth-south vertical cross section across the entire unsaturated zonemodel domain and uses refined meshes near and around the proposedrepository block, based on the current repository design, drift layout,thermal loading scenario, and estimated current and future climaticconditions. The model simulations provide insights into thermallyaffected liquid saturation, gas- and liquid-phase fluxes, and elevatedwater and rock temperature, which in turn allow modelers to predict thechanges in water flux driven by evaporation/condensation processes, anddrainage between drifts.

  12. Micro- and nano-scale damage on the surface of W divertor component during exposure to high heat flux loads with He

    NASA Astrophysics Data System (ADS)

    Li, C.; Greuner, H.; Zhao, S. X.; Böswirth, B.; Luo, G. N.; Zhou, X.; Jia, Y. Z.; Liu, X.; Liu, W.

    2015-11-01

    Micro- and nano-scale surface damage on a W divertor component sample exposed to high heat flux loads generated with He atoms has been investigated through SEM, EBSD, AFM and FIB-SEM. The component sample was supplied by the Institute of Plasma Physics, Chinese Academy of Sciences (ASIPP) and AT&M company, China, and the loading experiment was performed in the GLADIS facility at IPP Garching, Germany. Two typical damage structures were observed on the surface: the first one is characterized by obvious blisters and some grooves formed from ruptured blisters, and the other one is a kind of porous structure accompanying with at least ∼25 nm surface material loss. As the grain orientation is further away from <111>, the damage morphology gradually changes from the former structure to the latter. The possible damage mechanism is discussed.

  13. Evaluation of five biocarriers as supports for immobilized bacteria: Comparative performance during high chemical loading, acid shocking, drying and heat shocking

    SciTech Connect

    Heitkamp, M.A.; Adams, W.J. . Environmental Sciences Center); Camel, V. )

    1993-06-01

    Immobilized bacteria technology (IBT) utilizes inert biocarriers to support high concentrations of chemical-degrading bacteria in reactors designed to provide optimal conditions for microbial activity. This study evaluated IBT performance inpacked bed reactors (PBRs) using a porous inorganic biocarrier (diatomaceous earth), nonporous biocarriers (glass beads), and organic biocarriers having carbon adsorption properties (granular activated carbon) with different porosity. Each reactor was challenged with high chemical loading, acid, dryness, and heat shock conditions. Benchtop PBSs inoculated with a p-nitrophenol (PNP)-degrading Pseudomonas sp. and fed a synthetic waste containing 100 to 1,300 mg/L of PNP showed removal of PNP from effluents within 24 h of start-up. Chemical loading studies showed maximum PNP removal rates of 6.45 to 7.35 kg/m[sup 3]/d for bacteria in PBRs containing diatomaceous earth beads, glass beads, and activated coconut carbon. A lower PNP removal rate of 1.47 kg/m[sup 3]/d was determined for the activated anthracite carbon, and this PBR responded more slowly to increases in chemical loading. The PBR containing bacteria immobilized on activated coconut carbon showed exceptional tolerance to acid shocking, drying, and heat shocking by maintaining PNP removal rates > 85% throughout the entire study. The other biocarriers showed nearly complete loss of PNP degradation during the perturbations, but all recovered high rates of PNP degradation (> 98% removal) within 48 h after an acid shock at pH2, within 8 d after an acid shock at pH 1.0, within 24 h after drying for 72 h, and within 48 h of heat shocking. The resiliency and high chemical removal efficiency demonstrated by immobilized bacteria in this study support the concept of using IBT for the biotreatment of industrial wastes..

  14. Thermo-mechanical properties of silicon, germanium, diamond, beryllium and silicon carbide for high heat load x-ray optics applications

    NASA Astrophysics Data System (ADS)

    Hedayat, Ali; Khounsary, Ali; Mashayek, Farzad

    2012-10-01

    Increased thermal power of the x-ray beams produced at synchrotron radiation facilities such as the Advanced Photon Source at Argonne National Laboratory requires improvements in the thermal management of the components with which the beams interact. Crystals of silicon, germanium, diamond, beryllium, and silicon carbide are important substrate materials in this regard. Accurate physical, thermal, and mechanical properties of these materials, especially at cryogenic temperatures, are needed in the analysis and design of high heat load x-ray components. In this paper, we present a collection of the relevant data, and include curve fits, when possible, for ease of use in the analysis.

  15. The use of solar simulation systems for producing artificial global radiation for the purpose of determining the heat load of rooms

    NASA Technical Reports Server (NTRS)

    Kalt, A. C.

    1975-01-01

    Certain climatic tests which require solar and sky radiation were carried out in the laboratory by using simulated global radiation. The advantages of such a method of measurement and the possibilities and limitations resulting from the simulation of global radiation are described. Experiments concerning the thermal load in rooms were conducted in order to test the procedure. In particular, the heat gain through a window with sunshade is discussed, a venetian blind between the panes of a double-glazed window being used in most cases.

  16. Motion of a ballistic missile angularly misaligned with the flight path upon entering the atmosphere and its effect upon aerodynamic heating, aerodynamic loads, and miss distance

    NASA Technical Reports Server (NTRS)

    Allen, Julian H

    1957-01-01

    An analysis is given of the oscillating motion of a ballistic missile which upon entering the atmosphere is angularly misaligned with respect to the flight path. The history of the motion for some example missiles is discussed from the point of view of the effect of the motion on the aerodynamic heating and loading. The miss distance at the target due to misalignment and to small accidental trim angles is treated. The stability problem is also discussed for the case where the missile is tumbling prior to atmospheric entry.

  17. DIS in AdS

    SciTech Connect

    Albacete, Javier L.; Kovchegov, Yuri V.; Taliotis, Anastasios

    2009-03-23

    We calculate the total cross section for the scattering of a quark-anti-quark dipole on a large nucleus at high energy for a strongly coupled N = 4 super Yang-Mills theory using AdS/CFT correspondence. We model the nucleus by a metric of a shock wave in AdS{sub 5}. We then calculate the expectation value of the Wilson loop (the dipole) by finding the extrema of the Nambu-Goto action for an open string attached to the quark and antiquark lines of the loop in the background of an AdS{sub 5} shock wave. We find two physically meaningful extremal string configurations. For both solutions we obtain the forward scattering amplitude N for the quark dipole-nucleus scattering. We study the onset of unitarity with increasing center-of-mass energy and transverse size of the dipole: we observe that for both solutions the saturation scale Q{sub s} is independent of energy/Bjorken-x and depends on the atomic number of the nucleus as Q{sub s}{approx}A{sup 1/3}. Finally we observe that while one of the solutions we found corresponds to the pomeron intercept of {alpha}{sub P} = 2 found earlier in the literature, when extended to higher energy or larger dipole sizes it violates the black disk limit. The other solution we found respects the black disk limit and yields the pomeron intercept of {alpha}{sub P} = 1.5. We thus conjecture that the right pomeron intercept in gauge theories at strong coupling may be {alpha}{sub P} = 1.5.

  18. Tensile Properties of 7075-T6 and 2024-T3 Aluminum-alloy Sheet Heated at Uniform Temperature Rates Under Constant Load

    NASA Technical Reports Server (NTRS)

    Heimerl, George J; Inge, John E

    1955-01-01

    Results are presented of tests to determine the effect of heating at uniform temperature rates from 0.2 degrees to 100 degrees F. per second on the tensile properties of 7075-T6 d(75s-T6) and 2024-T3 (24s-T3) aluminum-alloy sheet under constant-load conditions. Yield and rupture stresses, obtained under rapid-heating conditions, are compared with results of elevated-temperature stress-strain tests for 1/2-hour exposure. Master yield-and-rupture-stress curves based on linear temperature-rate parameter are presented. Yield and rupture stresses and temperatures may be predicted by means of master curves and the parameter.

  19. Modeling of divertor particle and heat loads during application of resonant magnetic perturbation fields for ELM control in ITER

    NASA Astrophysics Data System (ADS)

    Schmitz, O.; Becoulet, M.; Cahyna, P.; Evans, T. E.; Feng, Y.; Frerichs, H.; Kirschner, A.; Kukushkin, A.; Laengner, R.; Lunt, T.; Loarte, A.; Pitts, R.; Reiser, D.; Reiter, D.; Saibene, G.; Samm, U.

    2013-07-01

    First results from three-dimensional modeling of the divertor heat and particle flux pattern during application of resonant magnetic perturbation fields as ELM control scheme in ITER with the EMC3-Eirene fluid plasma and kinetic neutral transport code are discussed. The formation of a helical magnetic footprint breaks the toroidal symmetry of the heat and particle fluxes. Expansion of the flux pattern as far as 60 cm away from the unperturbed strike line is seen with vacuum RMP fields, resulting in a preferable heat flux spreading. Inclusion of plasma response reduces the radial extension of the heat and particle fluxes and results in a heat flux peaking closer to the unperturbed level. A strong reduction of the particle confinement is found. 3D flow channels are identified as a consistent reason due to direct parallel outflow from inside of the separatrix. Their radial inward expansion and hence the level of particle pump out is shown to be dependent on the perturbation level.

  20. Bubbling AdS3

    NASA Astrophysics Data System (ADS)

    Martelli, Dario; Morales, Jose F.

    2005-02-01

    In the light of the recent Lin, Lunin, Maldacena (LLM) results, we investigate 1/2-BPS geometries in minimal (and next to minimal) supergravity in D = 6 dimensions. In the case of minimal supergravity, solutions are given by fibrations of a two-torus T2 specified by two harmonic functions. For a rectangular torus the two functions are related by a non-linear equation with rare solutions: AdS3 × S3, the pp-wave and the multi-center string. ``Bubbling'', i.e. superpositions of droplets, is accommodated by allowing the complex structure of the T2 to vary over the base. The analysis is repeated in the presence of a tensor multiplet and similar conclusions are reached, with generic solutions describing D1D5 (or their dual fundamental string-momentum) systems. In this framework, the profile of the dual fundamental string-momentum system is identified with the boundaries of the droplets in a two-dimensional plane.

  1. Design of high heat load white-beam slits for wiggler/undulator beamlines at the Advanced Photon Source

    SciTech Connect

    Shu, D.; Tcheskidov, V.; Nian, T.; Haeffner, D.R.; Alp, E.E.; Ryding, D.; Collins, J.; Li, Y.; Kuzay, T.M.

    1994-12-01

    A set of horizontal and vertical white-beam slits has been designed for the Advanced Photon Source wiggler/undulator beamlines at Argonne National Laboratory. While this slit set can handle the high heat flux from on e APS undulator source, it has large enough aperture to be compatible with a wiggler source also. A grazing-incidence, knife-edge configuration has been used in the design to eliminate downstream X-ray scattering. Enhanced heat transfer technology has been used in the water-cooling system. A unique stepping parallelogram driving structure provides precise vertical slit motion with large optical aperture. The full design detail is presented in this paper.

  2. Performance tests of Mn-added aluminum heat pipe with micro-sized inner fins and thermal fluid for cooling electronic device

    NASA Astrophysics Data System (ADS)

    Kim, M. R.; Choi, Y.

    2014-12-01

    Aluminum-5 wt % manganese alloy heat pipe with a nano-fluid of n-butanol and 0.2 wt % carbon nano-tubes was prepared by deep-drawing, and its mechanical and corrosion properties were determined to improve thermal conductivity performance. The heat pipe was designed to have micro-sized inner fins working at temperature higher than 200°C and simultaneously retaining a similar thermal conductivity to that of pure aluminum. The heat pipe formed by aluminum-5 wt % manganese alloys had improved mechanical properties such as 38% micro-hardness, 45.8% yield strength, and 53.5 wt % ultimate tensile strength due to grain size refinement and work hardening effects. The corrosion rate of the aluminum alloy in artificial sea water at room temperature decreased from 0.110 mpy to 0.102 mpy. The nano-fluid of n-butanol and 0.2 wt % carbon nano-tubes improved the thermal conductivity of the heat-pipe by about 250%.

  3. Large-surface-area diamond (111) crystal plates for applications in high-heat-load wavefront-preserving X-ray crystal optics.

    PubMed

    Stoupin, Stanislav; Antipov, Sergey; Butler, James E; Kolyadin, Alexander V; Katrusha, Andrey

    2016-09-01

    Fabrication and results of high-resolution X-ray topography characterization of diamond single-crystal plates with large surface area (10 mm × 10 mm) and (111) crystal surface orientation for applications in high-heat-load X-ray crystal optics are reported. The plates were fabricated by laser-cutting of the (111) facets of diamond crystals grown using high-pressure high-temperature methods. The intrinsic crystal quality of a selected 3 mm × 7 mm crystal region of one of the studied samples was found to be suitable for applications in wavefront-preserving high-heat-load crystal optics. Wavefront characterization was performed using sequential X-ray diffraction topography in the pseudo plane wave configuration and data analysis using rocking-curve topography. The variations of the rocking-curve width and peak position measured with a spatial resolution of 13 µm × 13 µm over the selected region were found to be less than 1 µrad. PMID:27577765

  4. Simulation experiment of interaction of plasma facing materials and transient heat loads in ITER divertor by use of magnetized coaxial plasma gun

    NASA Astrophysics Data System (ADS)

    Nakatsuka, M.; Ando, K.; Higashi, T.; Kikuchi, Y.; Fukumoto, N.; Nagata, M.

    2009-11-01

    Interaction of plasma facing materials and transient head loads such as type I ELMs is one of the critical issues in ITER divertor. The heat load to the ITER divertor during type I ELMs is estimated to be 0.5-3 MJ/m^2 with a pulse length of 0.1-0.5 ms. We have developed a magnetized coaxial plasma gun (MCPG) for the simulation experiment of transient heat load during type I ELMs in ITER divertor. The MCPG has inner and outer electrodes made of stainless steel 304. In addition, the inner electrode is covered with molybdenum so as to suppress the release of impurities from the electrode during the discharge. The diameters of inner and outer electrodes are 0.06 m and 0.14 m, respectively. The power supply for the MCPG is a capacitor bank (7 kV, 1 mF, 25 kJ). The plasma velocity estimated by the time of flight measurement of the magnetic fields was about 50 km/s, corresponding to the ion energy of 15 eV (H) or 30 eV (D). The absorbed energy density of the plasma stream was measured a calorimeter made of graphite. It was found that the absorbed energy density was 0.9 MJ/m^2 with a pulse width of 0.5 ms at the distance of 100 mm from the inner electrode. In the conference, experimental results of plasma exposure on the plasma facing materials in ITER divertor will be shown.

  5. Inclusions and Microstructure of Ce-Added Weld Metal Coarse Grain Heat-Affected Zone in Twin-Wire Submerged-Arc Welding

    NASA Astrophysics Data System (ADS)

    Yu, S. F.; Yan, N.; Chen, Y.

    2016-04-01

    In high heat-input multi-pass twin-wire submerged-arc welding, weld metal of previous pass will be affected by the heat input of subsequent one and form coarse-grained heat-affected zone (CGHAZ). This study focused on the effects of welding thermal cycle on the inclusions and microstructure of Ce-alloyed weld metal CGHAZ. According to the study of inclusions and microstructure of weld metal CGHAZ, it was found that the composition and type of the inclusions did not change under the effect of welding thermal cycle. Although the inclusions were coarsened slightly, the promoting ability to acicular ferrite (AF) was not deprived after thermal cycling. There are three types of AF in weld metal CGHAZ, which include oxy-sulfides of Ce inclusions-promoted AF, home-position-precipitated AF, and sympathetic AF. Results showed more than 80% of microstructure was AF, which greatly benefited the mechanical properties of weld metal CGHAZ, even though granular bainite and M-A constituents were generated.

  6. Inclusions and Microstructure of Ce-Added Weld Metal Coarse Grain Heat-Affected Zone in Twin-Wire Submerged-Arc Welding

    NASA Astrophysics Data System (ADS)

    Yu, S. F.; Yan, N.; Chen, Y.

    2016-06-01

    In high heat-input multi-pass twin-wire submerged-arc welding, weld metal of previous pass will be affected by the heat input of subsequent one and form coarse-grained heat-affected zone (CGHAZ). This study focused on the effects of welding thermal cycle on the inclusions and microstructure of Ce-alloyed weld metal CGHAZ. According to the study of inclusions and microstructure of weld metal CGHAZ, it was found that the composition and type of the inclusions did not change under the effect of welding thermal cycle. Although the inclusions were coarsened slightly, the promoting ability to acicular ferrite (AF) was not deprived after thermal cycling. There are three types of AF in weld metal CGHAZ, which include oxy-sulfides of Ce inclusions-promoted AF, home-position-precipitated AF, and sympathetic AF. Results showed more than 80% of microstructure was AF, which greatly benefited the mechanical properties of weld metal CGHAZ, even though granular bainite and M-A constituents were generated.

  7. Response of lactating cows to methionine or methionine plus lysine added to high protein diets based on alfalfa and heated soybeans.

    PubMed

    Armentano, L E; Bertics, S J; Ducharme, G A

    1997-06-01

    Lactation diets based on wilted alfalfa silage and heated whole soybeans are common in the midwestern US. We examined the milk production response of multiparous Holstein cows to the addition of ruminally protected methionine at two percentages to a basal total mixed ration. An additional total mixed ration included both methionine and lysine supplementation. Sixteen Holstein cows in early lactation were used in a replicated 4 x 4 Latin square design with 21-d periods. Milk production, milk composition, and dry matter intake were determined for the last 5 d of each period. Milk production (41.5 kg/d), dry matter intake (25.9 kg/d), and milk fat concentration (3.26%) were unaffected by the supplementation of amino acids. The addition of methionine increased milk protein concentration and yield linearly. Each gram of methionine increased milk protein yield by 4 g, and milk protein concentration increased from 2.89 to 2.99% with the addition of 10.5 g/d of methionine. The proportion of casein N in total milk N was unaffected by treatment. The addition of lysine did not elicit a response. Total mixed rations based on alfalfa haylage, heated soybeans, and animal proteins were clearly limited by their methionine content but were adequate in their lysine content. PMID:9201591

  8. Entanglement temperature and perturbed AdS3 geometry

    NASA Astrophysics Data System (ADS)

    Levine, G. C.; Caravan, B.

    2016-06-01

    Generalizing the first law of thermodynamics, the increase in entropy density δ S (x ) of a conformal field theory (CFT) is proportional to the increase in energy density, δ E (x ) , of a subsystem divided by a spatially dependent entanglement temperature, TE(x ) , a fixed parameter determined by the geometry of the subsystem, crossing over to thermodynamic temperature at high temperatures. In this paper we derive a generalization of the thermodynamic Clausius relation, showing that deformations of the CFT by marginal operators are associated with spatial temperature variations, δ TE(x ) , and spatial energy correlations play the role of specific heat. Using AdS/CFT duality we develop a relationship between a perturbation in the local entanglement temperature of the CFT and the perturbation of the bulk AdS metric. In two dimensions, we demonstrate a method through which direct diagonalizations of the boundary quantum theory may be used to construct geometric perturbations of AdS3 .

  9. Overview of the results on divertor heat loads in RMP controlled H-modeplasmas on DIII-D

    DOE PAGESBeta

    Jakubowski, M. W.; Evans, T. E.; Fenstermacher, M. E.; Groth, M.; Lasnier, C. J.; Leonard, A. W.; Schmitz, O.; Watkins, J. G.; Eich, T.; Fundamenski, W.; et al

    2009-08-14

    This paper demonstrates the manipulation of power deposition on divertor targets at DIII-D by the application of resonant magnetic perturbations (RMPs) for suppression of large type-I edge localized modes (ELMs) is analysed. We discuss the modification of the ELM characteristics by the RMP applied. It is shown that the width of the deposition pattern in ELMy H-mode depends linearly on the ELM deposited energy, whereas in the RMP phase of the discharge those patterns are controlled by the externally induced magnetic perturbation. It was also found that the manipulation of heat transport due to the application of small, edge RMPmore » depends on the plasma pedestal electron collisionality. We then compare in this analysis RMP and no RMP phases with and without complete ELM suppression. At high , the heat flux during the ELM suppressed phase is of the same order as the inter-ELM and the no-RMP phase. However, below this collisionality value, a slight increase in the total power flux to the divertor is observed during the RMP phase. We surmised that this is most likely caused by a more negative potential at the divertor surface due to hot electrons reaching the divertor surface from the pedestal area along perturbed, open field lines.« less

  10. Overview of the results on divertor heat loads in RMP controlled H-modeplasmas on DIII-D

    SciTech Connect

    Jakubowski, M. W.; Evans, T. E.; Fenstermacher, M. E.; Groth, M.; Lasnier, C. J.; Leonard, A. W.; Schmitz, O.; Watkins, J. G.; Eich, T.; Fundamenski, W.; Moyer, R. A.; Wolf, R. C.; Baylor, L. B.; Boedo, J. A.; Burrell, K. H.; Frerichs, H.; deGrassie, J. S.; Gohil, P.; Joseph, I.; Mordijck, S.; Lehnen, M.; Petty, C. C.; Pinsker, R. I.; Reiter, D.; Rhodes, T. L.; Samm, U.; Schaffer, M. J.; Snyder, P. B.; Stoschus, H.; Osborne, T.; Unterberg, B.; Unterberg, E.

    2009-08-14

    This paper demonstrates the manipulation of power deposition on divertor targets at DIII-D by the application of resonant magnetic perturbations (RMPs) for suppression of large type-I edge localized modes (ELMs) is analysed. We discuss the modification of the ELM characteristics by the RMP applied. It is shown that the width of the deposition pattern in ELMy H-mode depends linearly on the ELM deposited energy, whereas in the RMP phase of the discharge those patterns are controlled by the externally induced magnetic perturbation. It was also found that the manipulation of heat transport due to the application of small, edge RMP depends on the plasma pedestal electron collisionality. We then compare in this analysis RMP and no RMP phases with and without complete ELM suppression. At high , the heat flux during the ELM suppressed phase is of the same order as the inter-ELM and the no-RMP phase. However, below this collisionality value, a slight increase in the total power flux to the divertor is observed during the RMP phase. We surmised that this is most likely caused by a more negative potential at the divertor surface due to hot electrons reaching the divertor surface from the pedestal area along perturbed, open field lines.

  11. Development of lithium and tungsten limiters for test on T-10 tokamak at high heat load condition

    NASA Astrophysics Data System (ADS)

    Lyublinski, I. E.; Vertkov, A. V.; Zharkov, M. Yu; Vershkov, V. A.; Mirnov, S. V.

    2016-04-01

    Application of a complex of powerful (up to 3 MW) ECR plasma heating in T-10 tokamak is pulled down with a problem of the strong plasma pollution at power input more than 2 MW. For the solution of these problems the new W and Li limiters is developed and prepared to implementation. As it is supposed, application of W as a plasma facing material will allow excluding carbon influx into vacuum chamber. An additional Li limiter arranged in a shadow of W one will be used as a Li source for plasma periphery cooling due to a reradiation on Li that will lead to decrease in power deposition on W limiters. Parameters and design of limiters are presented. Plasma facing surface of a limiter is made of capillary-porous system (CPS) with Li. Porous matrix of CPS (W felt) provides stability of liquid Li surface under MHD force effect and an opportunity of its constant renewal due to capillary forces. The necessary Li flux from a Li limiter surface is estimated for maintenance of normal operation mode of W limiters at ECRH power of 3 MW during 400 ms. It is shown, that upgrade of limiters in tokamak T-10 will allow providing of ECR plasma heating with power up to 3 MW at reasonable Li flux.

  12. Prediction of fatigue life of high-heat-load components made of oxygen-free copper by comparing with Glidcop.

    PubMed

    Takahashi, Sunao; Sano, Mutsumi; Watanabe, Atsuo; Kitamura, Hideo

    2013-01-01

    Following a successful study on the prediction of fatigue life of high-heat-load components made of Glidcop, the thermal limitation of oxygen-free copper (OFC), which is used more commonly than Glidcop, has been studied. In addition to its general mechanical properties, the low-cycle-fatigue (LCF) and creep properties of OFC were investigated in detail and compared with those of Glidcop. The breaking mode of OFC, which was observed to be completely different from that of Glidcop in a fatigue fracture experiment, clarified the importance of considering the creep-fatigue interaction. An additional LCF test with compressive strain holding was conducted so that the creep-fatigue life diagram for out-of-phase thermal fatigue could be obtained on the basis of the strain-range partitioning method. The life predicted from elasto-plastic creep analysis agreed well with that determined from the void ratio estimated in the fatigue fracture experiment. PMID:23254657

  13. Prediction of fatigue life of high-heat-load components made of oxygen-free copper by comparing with Glidcop

    PubMed Central

    Takahashi, Sunao; Sano, Mutsumi; Watanabe, Atsuo; Kitamura, Hideo

    2013-01-01

    Following a successful study on the prediction of fatigue life of high-heat-load components made of Glidcop, the thermal limitation of oxygen-free copper (OFC), which is used more commonly than Glidcop, has been studied. In addition to its general mechanical properties, the low-cycle-fatigue (LCF) and creep properties of OFC were investigated in detail and compared with those of Glidcop. The breaking mode of OFC, which was observed to be completely different from that of Glidcop in a fatigue fracture experiment, clarified the importance of considering the creep–fatigue interaction. An additional LCF test with compressive strain holding was conducted so that the creep–fatigue life diagram for out-of-phase thermal fatigue could be obtained on the basis of the strain-range partitioning method. The life predicted from elasto-plastic creep analysis agreed well with that determined from the void ratio estimated in the fatigue fracture experiment. PMID:23254657

  14. External heat transfer predictions in a highly loaded transonic linear turbine guide vane cascade using an upwind biased Navier-Stokes solver

    SciTech Connect

    Gehrer, A.; Jericha, H.

    1999-07-01

    External heat transfer predictions are performed for two-dimensional turbine blade cascades. The Reynolds-averaged Navier-Stokes equations with algebraic (Arnone and Pacciani, 1998), one-equation (Spalart and Allmaras, 1994), and two-equation (low-Re {kappa}-{epsilon}, Biswas and Fukuyama, 1994) turbulence closures are solved with a fully implicit time-marching finite volume method. Comparisons with measurements (Arts et al., 1990; Arts, 1994) for a highly loaded transonic turbine nozzle guide vane cascade show good agreement in some cases, but also reveal problems with transition prediction and turbulence modeling. Special attention has been focused on the low-Re {kappa}-{epsilon} model concerning the influence of the inlet boundary condition for the {epsilon}-equation and problems in the stagnation point region.

  15. Study on Fuel Cell Network System Considering Reduction in Fuel Cell Capacity Using Load Leveling and Heat Release Loss

    NASA Astrophysics Data System (ADS)

    Obara, Shin'ya; Kudo, Kazuhiko

    Reduction in fuel cell capacity linked to a fuel cell network system is considered. When the power demand of the whole network is small, some of the electric power generated by the fuel cell is supplied to a water electrolysis device, and hydrogen and oxygen gases are generated. Both gases are compressed with each compressor and they are stored in cylinders. When the electric demand of the whole network is large, both gases are supplied to the network, and fuel cells are operated by these hydrogen and oxygen gases. Furthermore, an optimization plan is made to minimize the quantity of heat release of the hot water piping that connects each building. Such an energy network is analyzed assuming connection of individual houses, a hospital, a hotel, a convenience store, an office building, and a factory. Consequently, compared with the conventional system, a reduction of 46% of fuel cell capacity is expected.

  16. High heat-flux self-rotating plasma-facing component: Concept and loading test in TEXTOR

    NASA Astrophysics Data System (ADS)

    Terra, A.; Sergienko, G.; Hubeny, M.; Huber, A.; Mertens, Ph.; Philipps, V.

    2015-08-01

    This contribution reports on the concept of a circular self-rotating and temperature self-stabilising plasma-facing component (PFC), and test of a related prototype in TEXTOR tokamak. This PFC uses the Lorentz force induced by plasma current and magnet field (J × B) to create a torque applied on metallic discs which produce a rotational movement. Additional thermionic current, present at high operation temperatures, brings additional temperature stabilisation ability. This self-rotating disk limiter was exposed to plasma in the TEXTOR tokamak under different radial positions to vary the heat flux. This disk structure shows the interesting ability to stabilise its maximum temperature through the fact that the self-induced rotation is modulated by the thermal emission current. It was observed that the rotation speed increased following both the current collected by the limiter, and the temperature of the tungsten disks.

  17. Measurement of strain heat in shock-loaded 304 stainless steel: implications to powder consolidation; oral presentation of full paper

    SciTech Connect

    Staudhammer, Karl P.

    2003-01-01

    Over the past decades there have been numerous papers on the shock response of materials and more specifically towards metal powder compaction and consolidation. In general, the shock process for powdered materials has utilized the traditional pressure-volume shock relationships proportioned to the initial packing densities of the powders. However, this approach and its resulting data are in controversy due to the lack of knowledge of its associated particle strain and strain temperature uncertainties. This paper will describe the current understanding as well as the experimental technique used to obtain the shock response for distended materials. The above parameters are described within a pressure-strain-temperature interdependence. It was found that the experimentally measured strain heat was not only a function of initial packing density but also a function of powder size and distribution.

  18. Radio-frequency triggered heating and drug release using doxorubicin-loaded LSMO nanoparticles for bimodal treatment of breast cancer.

    PubMed

    Kulkarni, Vaishnavi M; Bodas, Dhananjay; Dhoble, Deepa; Ghormade, Vandana; Paknikar, Kishore

    2016-09-01

    Radio-frequency responsive nanomaterials combined with drugs for simultaneous hyperthermia and drug delivery are potential anti-cancer agents. In this study, chitosan coated La0.7Sr0.3MnO3 nanoparticles (C-LSMO NPs) were synthesized and characterized by X-ray diffraction, dynamic light scattering, Fourier transform infra red spectroscopy, vibrating sample magnetometer, scanning electron and atomic force microscopy. Under low radio-frequency (365kHz, RF), C-LSMO NPs (90nm) showed good colloidal stability (+22mV), superparamagnetic nature (15.4 emu/g) and heating capacity (57.4W/g SAR value). Chitosan facilitated doxorubicin entrapment (76%) resulted in DC-LSMO NPs that showed drug release upon a 5min RF exposure. MCF-7 and MDA-MB-231 cancer cells responded to a 5min RF exposure in the presence of bimodal DC-LSMO NPs with a significant decrease in viability to 73% and 88% (Pearson correlation, r=1, P<0.01) respectively, as compared to hyperthermia alone. Internalization of DC-LSMO NPs via the endosomal pathway led to an efficient localization of doxorubicin within the cell nucleus. The ensuing DNA damage, heat shock protein induction, and caspase production triggered apoptotic cell death. Moreover, DC-LSMO NPs successfully restricted the migration of metastatic MDA-MB-231 cancer cells. These data suggest that DC-LSMO NPs are potential bimodal therapeutic agents for cancer treatment and hold promise against disease recurrence and drug resistance. PMID:27337564

  19. Performance, bioenergetic status, and indicators of oxidative stress of environmentally heat-loaded Holstein cows in response to diets inducing milk fat depression.

    PubMed

    Kargar, S; Ghorbani, G R; Fievez, V; Schingoethe, D J

    2015-07-01

    Effects of grain type and dietary oil supplement on production performance, energy balance, metabolic heat production, and markers of liver function of heat-loaded lactating dairy cows were evaluated using 8 multiparous Holstein cows (77.0d in milk) in a duplicated 4×4 Latin square design with a 2×2 factorial arrangement of treatments. Experimental diets contained either ground barley or ground corn supplemented with either fish oil or soybean oil at 2% of dietary dry matter. Mean daily maximum temperature, minimum relative humidity, and maximum temperature-humidity index were 35.3°C, 11.3%, and 77.0, respectively. Dietary treatment did not affect rectal temperature (38.9°C), but respiration rate tended to decrease in cows fed fish oil versus soybean oil. Dry matter intake decreased for the fish oil-supplemented diets (21.1 vs. 24.3kg/d), which was negatively correlated with plasma concentrations of alkaline phosphatase (r=-0.45; n=32) and malondialdehyde (r=-0.26; n=32). Actual milk yield (41.9kg/d) and energy-corrected milk yield (36.6kg/d) were not affected by grain type, whereas feeding fish oil decreased milk yield as compared with soybean oil (40.4 vs. 43.4kg/d). Milk fat depression occurred in all dietary treatments, especially when cows were fed fish oil because of the presence of polyunsaturated FA in the diets. trans-10 C18:1 was negatively correlated with milk fat yield (r=-0.38; n=32). Daily milk cis-9,trans-11 C18:2 secretion was 29.6% less in cows fed barley- versus corn-based diets but 31.8% greater in cows fed fish oil as compared with cows fed soybean oil. Because of a lower dry matter intake, metabolic heat production was decreased in cows fed fish oil relative to cows fed soybean oil. Although feeding fish oil versus soybean oil decreased net energy for both maintenance and lactation, net energy balance remained unchanged across treatments. In vivo plasma lipoperoxidation was greater in cows fed fish oil versus soybean oil, which

  20. Load Frequency Control by use of a Number of Both Heat Pump Water Heaters and Electric Vehicles in Power System with a Large Integration of Renewable Energy Sources

    NASA Astrophysics Data System (ADS)

    Masuta, Taisuke; Shimizu, Koichiro; Yokoyama, Akihiko

    In Japan, from the viewpoints of global warming countermeasures and energy security, it is expected to establish a smart grid as a power system into which a large amount of generation from renewable energy sources such as wind power generation and photovoltaic generation can be installed. Measures for the power system stability and reliability are necessary because a large integration of these renewable energy sources causes some problems in power systems, e.g. frequency fluctuation and distribution voltage rise, and Battery Energy Storage System (BESS) is one of effective solutions to these problems. Due to a high cost of the BESS, our research group has studied an application of controllable loads such as Heat Pump Water Heater (HPWH) and Electric Vehicle (EV) to the power system control for reduction of the required capacity of BESS. This paper proposes a new coordinated Load Frequency Control (LFC) method for the conventional power plants, the BESS, the HPWHs, and the EVs. The performance of the proposed LFC method is evaluated by the numerical simulations conducted on a power system model with a large integration of wind power generation and photovoltaic generation.

  1. Fatigue-test acceleration with flight-by-flight loading and heating to simulate supersonic-transport operation

    NASA Technical Reports Server (NTRS)

    Imig, L. A.; Garrett, L. E.

    1973-01-01

    Possibilities for reducing fatigue-test time for supersonic-transport materials and structures were studied in tests with simulated flight-by-flight loading. In order to determine whether short-time tests were feasible, the results of accelerated tests (2 sec per flight) were compared with the results of real-time tests (96 min per flight). The effects of design mean stress, the stress range for ground-air-ground cycles, simulated thermal stress, the number of stress cycles in each flight, and salt corrosion were studied. The flight-by-flight stress sequences were applied to notched sheet specimens of Ti-8Al-1Mo-1V and Ti-6Al-4V titanium alloys. A linear cumulative-damage analysis accounted for large changes in stress range of the simulated flights but did not account for the differences between real-time and accelerated tests. The fatigue lives from accelerated tests were generally within a factor of two of the lives from real-time tests; thus, within the scope of the investigation, accelerated testing seems feasible.

  2. A molecular dynamics study of the early-time mechanical heating in shock-loaded octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine-based explosives

    NASA Astrophysics Data System (ADS)

    Long, Yao; Chen, Jun

    2014-07-01

    We study the shock-induced hot spot formation mechanism of octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine-based explosives by molecular dynamics, compare different kinds of desensitizers and different shock velocities. A set of programs is written to calculate the physical picture of shock loading. Based on the simulations and analyses, the hot spots are found at the interface and are heated by plastic work in three ways: the interface intrinsic dissipation, the pore collapse, and the coating layer deformation. The work/heat transition rate is proved to be increasing with a loading speed.

  3. Molten salt thermal energy storage for utility peaking loads

    NASA Technical Reports Server (NTRS)

    Ferrara, A.; Haslett, R.; Joyce, J.

    1977-01-01

    This paper considers the use of thermal energy storage (TES) in molten salts to increase the capacity of power plants. Five existing fossil and nuclear electric utility plants were selected as representative of current technology. A review of system load diagrams indicated that TES to meet loads over 95% of peak was a reasonable goal. Alternate TES heat exchanger locations were evaluated, showing that the stored energy should be used either for feedwater heating or to generate steam for an auxiliary power cycle. Specific salts for each concept are recommended. Design layouts were prepared for one plant, and it was shown that a TES tube/shell heat exchanger system could provide about 7% peaking capability at lower cost than adding steam generation capacity. Promising alternate heat exchanger concepts were also identified.

  4. Load calculation and system evaluation for electric vehicle climate control

    SciTech Connect

    Aceves-Saborio, S.; Comfort, W.J. III

    1993-10-27

    Providing air conditioning for electric vehicles (EVs) represents an important challenge, because vapor compression air conditioners, which are common in gasoline powered vehicles, may consume a substantial part of the total energy stored in the EV battery. This report consists of two major parts. The first part is a cooling and heating load calculation for electric vehicles. The second part is an evaluation of several systems that can be used to provide the desired cooling and heating in EVs. Four cases are studied. Short range and full range EVs are each analyzed twice, first with the regular vehicle equipment, and then with a fan and heat reflecting windows, to reduce hot soak. Recent legislation has allowed the use of combustion heating whenever the ambient temperature drops below 5{degrees}C. This has simplified the problem of heating, and made cooling the most important problem. Therefore, systems described in this project are designed for cooling, and their applicability to heating at temperatures above 5{degrees}C is described. If the air conditioner systems cannot be used to cover the whole heating load at 5{degrees}C, then the vehicle requires a complementary heating system (most likely a heat recovery system or electric resistance heating). Air conditioners are ranked according to their overall weight. The overall weight is calculated by adding the system weight and the weight of the battery necessary to provide energy for system operation.

  5. Polarised black holes in AdS

    NASA Astrophysics Data System (ADS)

    Costa, Miguel S.; Greenspan, Lauren; Oliveira, Miguel; Penedones, João; Santos, Jorge E.

    2016-06-01

    We consider solutions in Einstein-Maxwell theory with a negative cosmological constant that asymptote to global AdS 4 with conformal boundary {S}2× {{{R}}}t. At the sphere at infinity we turn on a space-dependent electrostatic potential, which does not destroy the asymptotic AdS behaviour. For simplicity we focus on the case of a dipolar electrostatic potential. We find two new geometries: (i) an AdS soliton that includes the full backreaction of the electric field on the AdS geometry; (ii) a polarised neutral black hole that is deformed by the electric field, accumulating opposite charges in each hemisphere. For both geometries we study boundary data such as the charge density and the stress tensor. For the black hole we also study the horizon charge density and area, and further verify a Smarr formula. Then we consider this system at finite temperature and compute the Gibbs free energy for both AdS soliton and black hole phases. The corresponding phase diagram generalizes the Hawking-Page phase transition. The AdS soliton dominates the low temperature phase and the black hole the high temperature phase, with a critical temperature that decreases as the external electric field increases. Finally, we consider the simple case of a free charged scalar field on {S}2× {{{R}}}t with conformal coupling. For a field in the SU(N ) adjoint representation we compare the phase diagram with the above gravitational system.

  6. ADS Development in Japan

    NASA Astrophysics Data System (ADS)

    Kikuchi, Kenji

    2010-06-01

    Accelerator driven nuclear transmutation system has been pursued to have a clue to the solution of high-level radioactive waste management. The concept consists of super conducting linac, sub-critical reactor and the beam window. Reference model is set up to 800MW thermal power by using 1.5GeV proton beams with considerations multi-factors such as core criticality. Materials damage is simulated by high-energy particle transport codes and so on. Recent achievement on irradiation materials experiment is stated and the differences are pointed out if core burn-up is considered or not. Heat balance in tank-type ADS indicates the temperature conditions of steam generator, the beam widow and cladding materials. Lead-bismuth eutectics demonstration has been conducted. Corrosion depth rate was shown by experiments.

  7. Methodology for consideration of specific features of combined-cycle plants with the optimal sharing of the thermal and the electric loads at combined heat power plants with equipment of a complex configuration

    NASA Astrophysics Data System (ADS)

    Arakelyan, E. K.; Andriushin, A. V.; Burtsev, S. Y.; Andriushin, K. A.; Hurshudyan, S. R.

    2015-05-01

    When a combined-cycle power plant operates as part of a combined heat power plant, the optimal load-sharing among the power-generating units of the station is complicated owing to specific features of operating a combined-cycle power plant, viz., the dependence of its adjustment range values on the outdoor air temperature, degradation of the ecological and economic performance figures under underloading conditions, possibility of load-sharing between the gas turbines, and a high flexibility. A method for optimal sharing of the load among the power-generating plants of combined heat power plants is proposed that takes into consideration the above features of the combined-cycle power plants. The combined heat power plant is divided into "equivalent" units according to the group power supply points. The first step is the intra-unit optimization over the entire variation range of the thermal and electric loads to achieve the best energy performance of the "equivalent" unit. The second step is the optimization of the load-sharing among the "equivalent" units.

  8. Determination of coil defrosting loads. Part 5: Analysis of loads

    SciTech Connect

    Al-Mutawa, N.K.; Sherif, S.A.

    1998-10-01

    This paper (Part 5) provides load analysis for a hot-gas defrosted finned-tube freezer coil for entering air dry-bulb temperatures of {minus}8 F and {minus}13 F. The load analysis covers the total refrigeration load rate, average load sensible heat ratio, defrost heat input, defrost efficiency, and other relevant parameters that lead to the determination of the heat loads due to coil hot-gas defrosting. The intent is to provide some insight into the energy penalty associated with defrosting these types of coils using the hot-gas refrigerant method.

  9. Fracture toughness of the IEA heat of F82H ferritic/martensitic stainless steel as a function of loading mode

    SciTech Connect

    Li, Huaxin; Gelles, D.S.; Hirth, J.P.

    1997-04-01

    Mode I and mixed-mode I/III fracture toughness tests were performed for the IEA heat of the reduced activation ferritic/martensitic stainless steel F82H at ambient temperature in order to provide comparison with previous measurements on a small heat given a different heat treatment. The results showed that heat to heat variations and heat treatment had negligible consequences on Mode I fracture toughness, but behavior during mixed-mode testing showed unexpected instabilities.

  10. Changes in the structure and substructure of tungsten during irradiation by hydrogen plasma flows at the specific energy close to the heat loads on the ITER surface

    NASA Astrophysics Data System (ADS)

    Garkusha, I. E.; Malykhin, S. V.; Makhlai, V. A.; Pugachev, A. T.; Bazdyrieva, S. V.; Aksenov, N. N.

    2014-11-01

    The changes in the structure, the substructure, and the state of stress in the surface layers of tungsten targets and the cracking processes in them are studied in model experiments on irradiation by a hydrogen plasma in a quasi-stationary plasma accelerator QSPA Kh-50, which adequately reproduces the energy density and the edge localized mode (ELM) time in ITER. The plasma heat load is up to 1 MJ m-2, the pulse duration is 0.25 ms, and the maximum number of irradiating pulses of 150. The development of residual macrostresses from compression to tension is analyzed by X-ray diffraction, and their relation to cracking is shown. Irradiation is found to increase the lattice parameter of tungsten in the undeformable section from a 0 ≈ 0.31642 ± 0.00001 (initial state) to 0.31645 ± 0.00001 nm. The changes in the coherent scattering region and microstrains are estimated. The role of point defects and their complexes in the irradiation-assisted processes is established. A qualitative model is proposed to explain these changes.

  11. Thermodynamics of charged Lovelock: AdS black holes

    NASA Astrophysics Data System (ADS)

    Prasobh, C. B.; Suresh, Jishnu; Kuriakose, V. C.

    2016-04-01

    We investigate the thermodynamic behavior of maximally symmetric charged, asymptotically AdS black hole solutions of Lovelock gravity. We explore the thermodynamic stability of such solutions by the ordinary method of calculating the specific heat of the black holes and investigating its divergences which signal second-order phase transitions between black hole states. We then utilize the methods of thermodynamic geometry of black hole spacetimes in order to explain the origin of these points of divergence. We calculate the curvature scalar corresponding to a Legendre-invariant thermodynamic metric of these spacetimes and find that the divergences in the black hole specific heat correspond to singularities in the thermodynamic phase space. We also calculate the area spectrum for large black holes in the model by applying the Bohr-Sommerfeld quantization to the adiabatic invariant calculated for the spacetime.

  12. 14 CFR 23.425 - Gust loads.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Balancing Surfaces § 23.425 Gust loads. (a) Each horizontal surface, other than a main wing, must be... for the conditions specified in paragraph (a) of this section, the initial balancing loads for steady... load resulting from the gusts must be added to the initial balancing load to obtain the total load....

  13. 14 CFR 23.425 - Gust loads.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Balancing Surfaces § 23.425 Gust loads. (a) Each horizontal surface, other than a main wing, must be... for the conditions specified in paragraph (a) of this section, the initial balancing loads for steady... load resulting from the gusts must be added to the initial balancing load to obtain the total load....

  14. [An experimental study on the prediction of heat stress of workers in a hot environment, with special reference to the relation between wearing suits, work load and environmental temperature].

    PubMed

    Yoshino, K; Takano, K; Nagasaka, A; Shigeta, S

    1987-11-01

    Hardly any practical approaches have been made on prediction of appearance of heat-stress hazard, although basic studies have extensively been made, including various heat-stress indices. Hence, in the present paper, an applicational prediction equation is presented with regard to the permissible working time without heat-stress hazard on the basis of experimental results. The purpose of this experiment was to examine the significant correlations between elevated rectal temperature, working conditions such as wearing suits, work load, and environmental temperature. The results obtained can be summarized as follows. (1) A critical level of environmental temperature exists. When this level is exceeded, physiological indices such as rectal temperature rapidly increased. According to experimental results, the critical level was about 30 degrees C and the heavier the work load, the lower was the critical level. (2) Moreover, the heavier the wearing suit, the lower became the temperature level. This finding indicated that it was important to choose a suitable apparel under a hot environment in order to keep the workers safe from heat-stress hazard. (3) A general prediction equation of raising the level of rectal temperature compared with that of initial condition was proposed by analysing each experimental condition (suit, work load, and environmental temperature) by use of second order multiple regression method. This equation showed that elevation of rectal temperature was assumed to be proportional to the logarithm of the working periods. (4) The predicted values by this equation corresponded with the experimental values within +/- 0.2-0.3 degrees C, and the correlation coefficient was 0.96. This equation suggests that heavier suits elevated the rectal temperature about 2-3 degrees C when the work load and environmental temperature were moderate. (5) It is possible to predict the permissible working period by this equation. This may be applied to the working plan

  15. Smeared antibranes polarise in AdS

    NASA Astrophysics Data System (ADS)

    Gautason, Fridrik Freyr; Truijen, Brecht; Van Riet, Thomas

    2015-07-01

    In the recent literature it has been questioned whether the local backreaction of antibranes in flux throats can induce a perturbative brane-flux decay. Most evidence for this can be gathered for D6 branes and D p branes smeared over 6 - p compact directions, in line with the absence of finite temperature solutions for these cases. The solutions in the literature have flat worldvolume geometries and non-compact transversal spaces. In this paper we consider what happens when the worldvolume is AdS and the transversal space is compact. We show that in these circumstances brane polarisation smoothens out the flux singularity, which is an indication that brane-flux decay is prevented. This is consistent with the fact that the cosmological constant would be less negative after brane-flux decay. Our results extend recent results on AdS7 solutions from D6 branes to AdS p+1 solutions from D p branes. We show that supersymmetry of the AdS solutions depend on p non-trivially.

  16. AdS orbifolds and Penrose limits

    SciTech Connect

    Alishahiha, Mohsen; Sheikh-Jabbari, Mohammad M.; Tatar, Radu

    2002-12-09

    In this paper we study the Penrose limit of AdS{sub 5} orbifolds. The orbifold can be either in the pure spatial directions or space and time directions. For the AdS{sub 5}/{Lambda} x S{sup 5} spatial orbifold we observe that after the Penrose limit we obtain the same result as the Penrose limit of AdS{sub 5} x S{sup 5}/{Lambda}. We identify the corresponding BMN operators in terms of operators of the gauge theory on R x S{sup 3}/{Lambda}. The semi-classical description of rotating strings in these backgrounds have also been studied. For the spatial AdS orbifold we show that in the quadratic order the obtained action for the fluctuations is the same as that in S{sup 5} orbifold, however, the higher loop correction can distinguish between two cases.

  17. Experimental investigation of cryogenic oscillating heat pipes

    PubMed Central

    Jiao, A.J.; Ma, H.B.; Critser, J.K.

    2010-01-01

    A novel cryogenic heat pipe, oscillating heat pipe (OHP), which consists of an 4 × 18.5 cm evaporator, a 6 × 18.5 cm condenser, and 10 cm length of adiabatic section, has been developed and experimental characterization conducted. Experimental results show that the maximum heat transport capability of the OHP reached 380W with average temperature difference of 49 °C between the evaporator and condenser when the cryogenic OHP was charged with liquid nitrogen at 48% (v/v) and operated in a horizontal direction. The thermal resistance decreased from 0.256 to 0.112 while the heat load increased from 22.5 to 321.8 W. When the OHP was operated at a steady state and an incremental heat load was added to it, the OHP operation changed from a steady state to an unsteady state until a new steady state was reached. This process can be divided into three regions: (I) unsteady state; (II) transient state; and (III) new steady state. In the steady state, the amplitude of temperature change in the evaporator is smaller than that of the condenser while the temperature response keeps the same frequency both in the evaporator and the condenser. The experimental results also showed that the amplitude of temperature difference between the evaporator and the condenser decreased when the heat load increased. PMID:20585410

  18. Load regulating expansion fixture

    DOEpatents

    Wagner, Lawrence M.; Strum, Michael J.

    1998-01-01

    A free standing self contained device for bonding ultra thin metallic films, such as 0.001 inch beryllium foils. The device will regulate to a predetermined load for solid state bonding when heated to a bonding temperature. The device includes a load regulating feature, whereby the expansion stresses generated for bonding are regulated and self adjusting. The load regulator comprises a pair of friction isolators with a plurality of annealed copper members located therebetween. The device, with the load regulator, will adjust to and maintain a stress level needed to successfully and economically complete a leak tight bond without damaging thin foils or other delicate components.

  19. Load regulating expansion fixture

    DOEpatents

    Wagner, L.M.; Strum, M.J.

    1998-12-15

    A free standing self contained device for bonding ultra thin metallic films, such as 0.001 inch beryllium foils is disclosed. The device will regulate to a predetermined load for solid state bonding when heated to a bonding temperature. The device includes a load regulating feature, whereby the expansion stresses generated for bonding are regulated and self adjusting. The load regulator comprises a pair of friction isolators with a plurality of annealed copper members located therebetween. The device, with the load regulator, will adjust to and maintain a stress level needed to successfully and economically complete a leak tight bond without damaging thin foils or other delicate components. 1 fig.

  20. Heat waves and urban heat islands in Europe: A review of relevant drivers.

    PubMed

    Ward, Kathrin; Lauf, Steffen; Kleinschmit, Birgit; Endlicher, Wilfried

    2016-11-01

    The climate change and the proceeding urbanization create future health challenges. Consequently, more people around the globe will be impaired by extreme weather events, such as heat waves. This study investigates the causes for the emergence of surface urban heat islands and its change during heat waves in 70 European cities. A newly created climate class indicator, a set of meaningful landscape metrics, and two population-related parameters were applied to describe the Surface Urban Heat Island Magnitude (SUHIM) - the mean temperature increase within the urban heat island compared to its surrounding, as well as the Heat Magnitude (HM) - the extra heat load added to the average summer SUHIM during heat waves. We evaluated the relevance of varying urban parameters within linear models. The exemplary European-wide heat wave in July 2006 was chosen and compared to the average summer conditions using MODIS land surface temperature with an improved spatial resolution of 250m. The results revealed that the initial size of the urban heat island had significant influence on SUHIM. For the explanation of HM the size of the heat island, the regional climate and the share of central urban green spaces showed to be critical. Interestingly, cities of cooler climates and cities with higher shares of urban green spaces were more affected by additional heat during heat waves. Accordingly, cooler northern European cities seem to be more vulnerable to heat waves, whereas southern European cities appear to be better adapted. Within the ascertained population and climate clusters more detailed explanations were found. Our findings improve the understanding of the urban heat island effect across European cities and its behavior under heat waves. Also, they provide some indications for urban planners on case-specific adaptation strategies to adverse urban heat caused by heat waves. PMID:27366983

  1. The AdS particle [rapid communication

    NASA Astrophysics Data System (ADS)

    Ghosh, Subir

    2005-09-01

    In this Letter we have considered a relativistic Nambu-Goto model for a particle in AdS metric. With appropriate gauge choice to fix the reparameterization invariance, we recover the previously discussed [S. Ghosh, P. Pal, Phys. Lett. B 618 (2005) 243, arxiv:hep-th/0502192] "exotic oscillator". The Snyder algebra and subsequently the κ-Minkowski spacetime are also derived. Lastly we comment on the impossibility of constructing a non-commutative spacetime in the context of open string where only a curved target space is introduced.

  2. Load cell

    DOEpatents

    Spletzer, Barry L.

    2001-01-01

    A load cell combines the outputs of a plurality of strain gauges to measure components of an applied load. Combination of strain gauge outputs allows measurement of any of six load components without requiring complex machining or mechanical linkages to isolate load components. An example six axis load cell produces six independent analog outputs which can be combined to determine any one of the six general load components.

  3. Load cell

    DOEpatents

    Spletzer, B.L.

    1998-12-15

    A load cell combines the outputs of a plurality of strain gauges to measure components of an applied load. Combination of strain gauge outputs allows measurement of any of six load components without requiring complex machining or mechanical linkages to isolate load components. An example six axis load cell produces six independent analog outputs, each directly proportional to one of the six general load components. 16 figs.

  4. Load cell

    DOEpatents

    Spletzer, Barry L.

    1998-01-01

    A load cell combines the outputs of a plurality of strain gauges to measure components of an applied load. Combination of strain gauge outputs allows measurement of any of six load components without requiring complex machining or mechanical linkages to isolate load components. An example six axis load cell produces six independent analog outputs, each directly proportional to one of the six general load components.

  5. Probing crunching AdS cosmologies

    NASA Astrophysics Data System (ADS)

    Kumar, S. Prem; Vaganov, Vladislav

    2016-02-01

    Holographic gravity duals of deformations of CFTs formulated on de Sitter spacetime contain FRW geometries behind a horizon, with cosmological big crunch singularities. Using a specific analytically tractable solution within a particular single scalar truncation of {N}=8 supergravity on AdS4, we first probe such crunching cosmologies with spacelike radial geodesics that compute spatially antipodal correlators of large dimension boundary operators. At late times, the geodesics lie on the FRW slice of maximal expansion behind the horizon. The late time two-point functions factorise, and when transformed to the Einstein static universe, they exhibit a temporal non-analyticity determined by the maximal value of the scale factor ã max. Radial geodesics connecting antipodal points necessarily have de Sitter energy Ɛ ≲ ã max, while geodesics with Ɛ > ã max terminate at the crunch, the two categories of geodesics being separated by the maximal expansion slice. The spacelike crunch singularity is curved "outward" in the Penrose diagram for the deformed AdS backgrounds, and thus geodesic limits of the antipodal correlators do not directly probe the crunch. Beyond the geodesic limit, we point out that the scalar wave equation, analytically continued into the FRW patch, has a potential which is singular at the crunch along with complex WKB turning points in the vicinity of the FRW crunch. We then argue that the frequency space Green's function has a branch point determined by ã max which corresponds to the lowest quasinormal frequency.

  6. Variable Conductance Heat Pipe Performance after Extended Periods of Freezing

    NASA Astrophysics Data System (ADS)

    Ellis, Michael C.; Anderson, William G.

    2009-03-01

    Radiators operating in lunar or Martian environments must be designed to reject the maximum heat load at the maximum sink temperature, while maintaining acceptable temperatures at lower powers or sink temperatures. Variable Conductance Heat Pipe (VCHP) radiators can passively adjust to these changing conditions. Due to the presence of non-condensable gas (NCG) within each VCHP, the active condensing section adjusts with changes in either thermal load or sink temperature. In a Constant Conductance Heat Pipe (CCHP) without NCG, it is possible for all of the water to freeze in the condenser, by either sublimation or vaporization. With a dry evaporator, startup is difficult or impossible. Several previous studies have shown that adding NCG suppresses evaporator dryout when the condenser is frozen. These tests have been for relatively short durations, with relatively short condensers. This paper describes freeze/thaw experiments involving a VCHP with similar dimensions to the current reactor and cavity cooling radiator heat pipe designs.

  7. AdS3: the NHEK generation

    NASA Astrophysics Data System (ADS)

    Bena, Iosif; Heurtier, Lucien; Puhm, Andrea

    2016-05-01

    It was argued in [1] that the five-dimensional near-horizon extremal Kerr (NHEK) geometry can be embedded in String Theory as the infrared region of an infinite family of non-supersymmetric geometries that have D1, D5, momentum and KK monopole charges. We show that there exists a method to embed these geometries into asymptotically- {AdS}_3× {S}^3/{{Z}}_N solutions, and hence to obtain infinite families of flows whose infrared is NHEK. This indicates that the CFT dual to the NHEK geometry is the IR fixed point of a Renormalization Group flow from a known local UV CFT and opens the door to its explicit construction.

  8. Shadows, currents, and AdS fields

    SciTech Connect

    Metsaev, R. R.

    2008-11-15

    Conformal totally symmetric arbitrary spin currents and shadow fields in flat space-time of dimension greater than or equal to four are studied. A gauge invariant formulation for such currents and shadow fields is developed. Gauge symmetries are realized by involving the Stueckelberg fields. A realization of global conformal boost symmetries is obtained. Gauge invariant differential constraints for currents and shadow fields are obtained. AdS/CFT correspondence for currents and shadow fields and the respective normalizable and non-normalizable solutions of massless totally symmetric arbitrary spin AdS fields are studied. The bulk fields are considered in a modified de Donder gauge that leads to decoupled equations of motion. We demonstrate that leftover on shell gauge symmetries of bulk fields correspond to gauge symmetries of boundary currents and shadow fields, while the modified de Donder gauge conditions for bulk fields correspond to differential constraints for boundary conformal currents and shadow fields. Breaking conformal symmetries, we find interrelations between the gauge invariant formulation of the currents and shadow fields, and the gauge invariant formulation of massive fields.

  9. Heat transfer and core neutronics considerations of the heat pipe cooled thermionic reactor

    NASA Astrophysics Data System (ADS)

    Determan, W. R.; Lewis, Brian

    The authors summarize the results of detailed neutronic and thermal-hydraulic evaluations of the heat pipe cooled thermionic (HPTI) reactor design, identify its key design attributes, and quantify its performance characteristics. The HPTI core uses modular, liquid-metal core heat transfer assemblies to replace the liquid-metal heat transport loop employed by in-core thermionic reactor designs of the past. The nuclear fuel, power conversion, heat transport, and heat rejection functions are all combined into a single modular unit. The reactor/converter assembly uses UN fuel pins to obtain a critical core configuration with in-core safety rods and reflector controls added to complete the subassembly. By thermally bonding the core heat transfer assemblies during the reactor core is coupled neutronically, thermally, and electrically into a modular assembly of individual power sources with cross-tied architecture. A forward-facing heat pipe radiator assembly extends from the reactor head in the shape of a frustum of a cone on the opposite side of the power system from the payload. Important virtues of the concept are the absence of any single-point failures and the ability of the core to effectively transfer the TFE waste heat load laterally to other in-core heat transfer assemblies in the event of multiple failures in either in-core and radiator heat pipes.

  10. Heat transfer and core neutronics considerations of the heat pipe cooled thermionic reactor

    NASA Technical Reports Server (NTRS)

    Determan, W. R.; Lewis, Brian

    1991-01-01

    The authors summarize the results of detailed neutronic and thermal-hydraulic evaluations of the heat pipe cooled thermionic (HPTI) reactor design, identify its key design attributes, and quantify its performance characteristics. The HPTI core uses modular, liquid-metal core heat transfer assemblies to replace the liquid-metal heat transport loop employed by in-core thermionic reactor designs of the past. The nuclear fuel, power conversion, heat transport, and heat rejection functions are all combined into a single modular unit. The reactor/converter assembly uses UN fuel pins to obtain a critical core configuration with in-core safety rods and reflector controls added to complete the subassembly. By thermally bonding the core heat transfer assemblies during the reactor core is coupled neutronically, thermally, and electrically into a modular assembly of individual power sources with cross-tied architecture. A forward-facing heat pipe radiator assembly extends from the reactor head in the shape of a frustum of a cone on the opposite side of the power system from the payload. Important virtues of the concept are the absence of any single-point failures and the ability of the core to effectively transfer the TFE waste heat load laterally to other in-core heat transfer assemblies in the event of multiple failures in either in-core and radiator heat pipes.

  11. Heat pipe cooling system with sensible heat sink

    NASA Technical Reports Server (NTRS)

    Silverstein, Calvin C.

    1988-01-01

    A heat pipe cooling system which employs a sensible heat sink is discussed. With this type of system, incident aerodynamic heat is transported via a heat pipe from the stagnation region to the heat sink and absorbed by raising the temperature of the heat sink material. The use of a sensible heat sink can be advantageous for situations where the total mission heat load is limited, as it is during re-entry, and a suitable radiation sink is not available.

  12. The use of heat pumps in district heat supply

    NASA Astrophysics Data System (ADS)

    Winkens, H. P.

    1985-04-01

    The cost elements of heat pump heat supply stations are examined and the optimum relationship between peak load boiler and heat pump output is shown. The dependence of plant size and temperature on heat generating costs is indicated and the costs of heat distribution and heat transfer are analysed. The possibility of a combined system of chop and heat pumps for the transport of heat over larger distances is shown.

  13. System Measures Loads In Bolts

    NASA Technical Reports Server (NTRS)

    Allison, Sidney G.

    1994-01-01

    Improved technique for ultrasonic nondestructive measurement of loads in bolts involves use of pulsed phase-locked loop interferometer. Provides for correction of errors and for automatic readout of loads in bolts. Actual bolt load measured, using transducers rebonded after bolts tightened. Calibration block and thermometer added. Technique applicable to critical fasteners in aerospace applications, nuclear reactors, petroleum and other chemical processing plants, steel bridges, and other structures.

  14. Bayonet heat exchangers in heat-assisted Stirling heat pump

    SciTech Connect

    Yagyu, S.; Fukuyama, Y.; Morikawa, T.; Isshiki, N.; Satoh, I.; Corey, J.; Fellows, C.

    1998-07-01

    The Multi-Temperature Heat Supply System is a research project creating a city energy system with lower environmental load. This system consists of a gas-fueled internal combustion engine and a heat-assisted Stirling heat pump utilizing shaft power and thermal power in a combination of several cylinders. The heat pump is mainly driven by engine shaft power and is partially assisted by thermal power from engine exhaust heat source. Since this heat pump is operated by proportioning the two energy sources to match the characteristics of the driving engine, the system is expected to produce cooling and heating water at high COP. This paper describes heat exchanger development in the project to develop a heat-assisted Stirling heat pump. The heat pump employs the Bayonet type heat exchangers (BHX Type I) for supplying cold and hot water and (BHX Type II) for absorbing exhaust heat from the driving engine. The heat exchanger design concepts are presented and their heat transfer and flow loss characteristics in oscillating gas flow are investigated. The main concern in the BHX Type I is an improvement of gas side heat transfer and the spirally finned tubes were applied to gas side of the heat exchanger. For the BHX Type II, internal heat transfer characteristics are the main concern. Shell-and-tube type heat exchangers are widely used in Stirling machines. However, since brazing is applied to the many tubes for their manufacturing processes, it is very difficult to change flow passages to optimize heat transfer and loss characteristics once they have been made. The challenge was to enhance heat transfer on the gas side to make a highly efficient heat exchanger with fewer parts. It is shown that the Bayonet type heat exchanger can have good performance comparable to conventional heat exchangers.

  15. Assessing and Reducing Miscellaneous Electric Loads (MELs) in Lodging

    SciTech Connect

    Rauch, Emily M.

    2011-09-01

    Miscellaneous electric loads (MELs) are the loads outside of a building's core functions of heating, ventilating, air conditioning, lighting, and water heating. This report reviews methods to reduce MELs in lodging.

  16. Absorption heat pump system

    DOEpatents

    Grossman, Gershon; Perez-Blanco, Horacio

    1984-01-01

    An improvement in an absorption heat pump cycle is obtained by adding adiabatic absorption and desorption steps to the absorber and desorber of the system. The adiabatic processes make it possible to obtain the highest temperature in the absorber before any heat is removed from it and the lowest temperature in the desorber before heat is added to it, allowing for efficient utilization of the thermodynamic availability of the heat supply stream. The improved system can operate with a larger difference between high and low working fluid concentrations, less circulation losses, and more efficient heat exchange than a conventional system.

  17. ADS pilot program Plan

    NASA Technical Reports Server (NTRS)

    Clauson, J.; Heuser, J.

    1981-01-01

    The Applications Data Service (ADS) is a system based on an electronic data communications network which will permit scientists to share the data stored in data bases at universities and at government and private installations. It is designed to allow users to readily locate and access high quality, timely data from multiple sources. The ADS Pilot program objectives and the current plans for accomplishing those objectives are described.

  18. Fort Carson Building 1860 Biomass Heating Analysis Report

    SciTech Connect

    Hunsberger, Randolph; Tomberlin, Gregg; Gaul, Chris

    2015-09-01

    As part of the Army Net-Zero Energy Installation program, the Fort Carson Army Base requested that NREL evaluate the feasibility of adding a biomass boiler to the district heating system served by Building 1860. We have also developed an Excel-spreadsheet-based decision support tool--specific to the historic loads served by Building 1860--with which users can perform what-if analysis on gas costs, biomass costs, and other parameters. For economic reasons, we do not recommend adding a biomass system at this time.

  19. Cutting Budget Corners While Adding Value.

    ERIC Educational Resources Information Center

    Veile, Craig N.; Carpenter, Mark J.

    2000-01-01

    Discusses how one school district saved money while adding long- term value to its capital improvement project. Planning issues involving square footage requirements, quality of material to be used, and heating and cooling system selection are discussed as are concepts to increase student learning capacity for the same construction dollars. (GR)

  20. Demonstration of the Application of Composite Load Spectra (CLS) and Probabilistic Structural Analysis (PSAM) Codes to SSME Heat Exchanger Turnaround Vane

    NASA Technical Reports Server (NTRS)

    Rajagopal, Kadambi R.; DebChaudhury, Amitabha; Orient, George

    2000-01-01

    This report describes a probabilistic structural analysis performed to determine the probabilistic structural response under fluctuating random pressure loads for the Space Shuttle Main Engine (SSME) turnaround vane. It uses a newly developed frequency and distance dependent correlation model that has features to model the decay phenomena along the flow and across the flow with the capability to introduce a phase delay. The analytical results are compared using two computer codes SAFER (Spectral Analysis of Finite Element Responses) and NESSUS (Numerical Evaluation of Stochastic Structures Under Stress) and with experimentally observed strain gage data. The computer code NESSUS with an interface to a sub set of Composite Load Spectra (CLS) code is used for the probabilistic analysis. A Fatigue code was used to calculate fatigue damage due to the random pressure excitation. The random variables modeled include engine system primitive variables that influence the operating conditions, convection velocity coefficient, stress concentration factor, structural damping, and thickness of the inner and outer vanes. The need for an appropriate correlation model in addition to magnitude of the PSD is emphasized. The study demonstrates that correlation characteristics even under random pressure loads are capable of causing resonance like effects for some modes. The study identifies the important variables that contribute to structural alternate stress response and drive the fatigue damage for the new design. Since the alternate stress for the new redesign is less than the endurance limit for the material, the damage due high cycle fatigue is negligible.

  1. Suspended Load

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The suspended load of rivers and streams consists of the sediments that are kept in the water column by the upward components of the flow velocity. Suspended load may be divided into cohesive and non-cohesive loads which are primarily discriminated by sediment particle size. Non-cohesive sediment ...

  2. Loading an Equidistant Ion Chain in a Ring Shaped Surface Trap and Anomalous Heating Studies with a High Optical Access Trap

    SciTech Connect

    Tabakov, Boyan

    2015-07-01

    Microfabricated segmented surface ion traps are one viable avenue to scalable quantum information processing. At Sandia National Laboratories we design, fabricate, and characterize such traps. Our unique fabrication capabilities allow us to design traps that facilitate tasks beyond quantum information processing. The design and performance of a trap with a target capability of storing hundreds of equally spaced ions on a ring is described. Such a device could aid experimental studies of phenomena as diverse as Hawking radiation, quantum phase transitions, and the Aharonov - Bohm effect. The fabricated device is demonstrated to hold a ~ 400 ion circular crystal, with 9 μm average spacing between ions. The task is accomplished by first characterizing undesired electric fields in the trapping volume and then designing and applying an electric field that substantially reduces the undesired fields. In addition, experimental efforts are described to reduce the motional heating rates in a surface trap by low energy in situ argon plasma treatment that reduces the amount of surface contaminants. The experiment explores the premise that carbonaceous compounds present on the surface contribute to the anomalous heating of secular motion modes in surface traps. This is a research area of fundamental interest to the ion trapping community, as heating adversely affects coherence and thus gate fidelity. The device used provides high optical laser access, substantially reducing scatter from the surface, and thus charging that may lead to excess micromotion. Heating rates for different axial mode frequencies are compared before and after plasma treatment. The presence of a carbon source near the plasma prevents making a conclusion on the observed absence of change in heating rates.

  3. Impact of AD995 alumina rods

    SciTech Connect

    Chhabildas, L.C.; Furnish, M.D.; Reinhart, W.D.; Grady, D.E.

    1997-10-01

    Gas guns and velocity interferometric techniques have been used to determine the loading behavior of an AD995 alumina rod 19 mm in diameter by 75 mm and 150 mm long, respectively. Graded-density materials were used to impact both bare and sleeved alumina rods while the velocity interferometer was used to monitor the axial-velocity of the free end of the rods. Results of these experiments demonstrate that (1) a time-dependent stress pulse generated during impact allows an efficient transition from the initial uniaxial strain loading to a uniaxial stress state as the stress pulse propagates through the rod, and (2) the intermediate loading rates obtained in this configuration lie between split Hopkinson bar and shock-loading techniques.

  4. Performance of a solar augmented heat pump

    NASA Astrophysics Data System (ADS)

    Bedinger, A. F. G.; Tomlinson, J. J.; Reid, R. L.; Chaffin, D. J.

    Performance of a residential size solar augmented heat pump is reported for the 1979-1980 heating season. The facility located in Knoxville, Tennessee, has a measured heat load coefficient of 339.5 watt/C (644 BTU/hr- F). The solar augmented heat pump system consists of 7.4 cu m of one inch diameter crushed limestone. The heat pump is a nominal 8.8 KW (2 1/2 ton) high efficiency unit. The system includes electric resistance heaters to give the option of adding thermal energy to the pebble bed storage during utility off-peak periods, thus offering considerable load management capability. A 15 KW electric resistance duct heater is used to add thermal energy to the pebble bin as required during off-peak periods. Hourly thermal performance and on site weather data was taken for the period November 1, 1979, to April 13, 1980. Thermal performance data consists of heat flow summations for all modes of the system, pebble bed temperatures, and space temperature. Weather data consists of dry bulb temperature, dew point temperature, total global insolation (in the plane of the collector), and wind speed and direction. An error analysis was performed and the least accurate of the measurements was determined to be the heat flow at 5%. Solar system thermal performance factor was measured to be 8.77. The heat pump thermal performance factor was 1.64. Total system seasonal performance factor was measured to be 1.66. Using a modified version of TRNSYS, the thermal performance of this system was simulated. When simulation results were compared with data collected onsite, the predicted heat flow and power consumption generally were within experimental accuracy.

  5. Deployable Heat Pipe Radiator

    NASA Technical Reports Server (NTRS)

    Edelstein, F.

    1975-01-01

    A 1.2- by 1.8-m variable conductance heat pipe radiator was designed, built, and tested. The radiator has deployment capability and can passively control Freon-21 fluid loop temperatures under varying loads and environments. It consists of six grooved variable conductance heat pipes attached to a 0.032-in. aluminum panel. Heat is supplied to the radiator via a fluid header or a single-fluid flexible heat pipe header. The heat pipe header is an artery design that has a flexible section capable of bending up to 90 degrees. Radiator loads as high as 850 watts were successfully tested. Over a load variation of 200 watts, the outlet temperature of the Freon-21 fluid varied by 7 F. An alternate control system was also investigated which used a variable conductance heat pipe header attached to the heat pipe radiator panel.

  6. Heat pipe investigations

    NASA Technical Reports Server (NTRS)

    Marshburn, J. P.

    1972-01-01

    The OAO-C spacecraft has three circular heat pipes, each of a different internal design, located in the space between the spacecraft structural tube and the experiment tube, which are designed to isothermalize the structure. Two of the pipes are used to transport high heat loads, and the third is for low heat loads. The test problems deal with the charging of the pipes, modifications, the mobile tilt table, the position indicator, and the heat input mechanisms. The final results showed that the techniques used were adequate for thermal-vacuum testing of heat pipes.

  7. Comparison of the impact of six heat-load management strategies on thermal responses and milk production of feed-pad and pasture fed dairy cows in a subtropical environment

    NASA Astrophysics Data System (ADS)

    Davison, T. M.; Jonsson, N. N.; Mayer, D. G.; Gaughan, J. B.; Ehrlich, W. K.; McGowan, M. R.

    2016-05-01

    Exposure to hot environments affects milk yield (MY) and milk composition of pasture and feed-pad fed dairy cows in subtropical regions. This study was undertaken during summer to compare MY and physiology of cows exposed to six heat-load management treatments. Seventy-eight Holstein-Friesian cows were blocked by season of calving, parity, milk yield, BW, and milk protein (%) and milk fat (%) measured in 2 weeks prior to the start of the study. Within blocks, cows were randomly allocated to one of the following treatments: open-sided iron roofed day pen adjacent to dairy (CID) + sprinklers (SP); CID only; non-shaded pen adjacent to dairy + SP (NSD + SP); open-sided shade cloth roofed day pen adjacent to dairy (SCD); NSD + sprinkler (sprinkler on for 45 min at 1100 h if mean respiration rate >80 breaths per minute (NSD + WSP)); open-sided shade cloth roofed structure over feed bunk in paddock + 1 km walk to and from the dairy (SCP + WLK). Sprinklers for CID + SP and NSD + SP cycled 2 min on, 12 min off when ambient temperature >26°C. The highest milk yields were in the CID + SP and CID treatments (23.9 L cow-1 day-1), intermediate for NSD + SP, SCD and SCP + WLK (22.4 L cow-1 day-1), and lowest for NSD + WSP (21.3 L cow-1 day-1) (P < 0.05). The highest (P < 0.05) feed intakes occurred in the CID + SP and CID treatments while intake was lowest (P < 0.05) for NSD + WSP and SCP + WLK. Weather data were collected on site at 10-min intervals, and from these, THI was calculated. Nonlinear regression modelling of MY × THI and heat-load management treatment demonstrated that cows in CID + SP showed no decline in MY out to a THI break point value of 83.2, whereas the pooled MY of the other treatments declined when THI >80.7. A combination of iron roof shade plus water sprinkling throughout the day provided the most effective control of heat load.

  8. LoAd: a locally adaptive cortical segmentation algorithm.

    PubMed

    Cardoso, M Jorge; Clarkson, Matthew J; Ridgway, Gerard R; Modat, Marc; Fox, Nick C; Ourselin, Sebastien

    2011-06-01

    Thickness measurements of the cerebral cortex can aid diagnosis and provide valuable information about the temporal evolution of diseases such as Alzheimer's, Huntington's, and schizophrenia. Methods that measure the thickness of the cerebral cortex from in-vivo magnetic resonance (MR) images rely on an accurate segmentation of the MR data. However, segmenting the cortex in a robust and accurate way still poses a challenge due to the presence of noise, intensity non-uniformity, partial volume effects, the limited resolution of MRI and the highly convoluted shape of the cortical folds. Beginning with a well-established probabilistic segmentation model with anatomical tissue priors, we propose three post-processing refinements: a novel modification of the prior information to reduce segmentation bias; introduction of explicit partial volume classes; and a locally varying MRF-based model for enhancement of sulci and gyri. Experiments performed on a new digital phantom, on BrainWeb data and on data from the Alzheimer's Disease Neuroimaging Initiative (ADNI) show statistically significant improvements in Dice scores and PV estimation (p<10(-3)) and also increased thickness estimation accuracy when compared to three well established techniques. PMID:21316470

  9. LoAd: A locally adaptive cortical segmentation algorithm

    PubMed Central

    Cardoso, M. Jorge; Clarkson, Matthew J.; Ridgway, Gerard R.; Modat, Marc; Fox, Nick C.; Ourselin, Sebastien

    2012-01-01

    Thickness measurements of the cerebral cortex can aid diagnosis and provide valuable information about the temporal evolution of diseases such as Alzheimer's, Huntington's, and schizophrenia. Methods that measure the thickness of the cerebral cortex from in-vivo magnetic resonance (MR) images rely on an accurate segmentation of the MR data. However, segmenting the cortex in a robust and accurate way still poses a challenge due to the presence of noise, intensity non-uniformity, partial volume effects, the limited resolution of MRI and the highly convoluted shape of the cortical folds. Beginning with a well-established probabilistic segmentation model with anatomical tissue priors, we propose three post-processing refinements: a novel modification of the prior information to reduce segmentation bias; introduction of explicit partial volume classes; and a locally varying MRF-based model for enhancement of sulci and gyri. Experiments performed on a new digital phantom, on BrainWeb data and on data from the Alzheimer's Disease Neuroimaging Initiative (ADNI) show statistically significant improvements in Dice scores and PV estimation (p<10−3) and also increased thickness estimation accuracy when compared to three well established techniques. PMID:21316470

  10. Innovations Without Added Costs

    ERIC Educational Resources Information Center

    Cereghino, Edward

    1974-01-01

    There is no question that we are in a tight money market, and schools are among the first institutions to feel the squeeze. Therefore, when a plan is offered that provides for innovations without added costs, its something worth noting. (Editor)

  11. What Value "Value Added"?

    ERIC Educational Resources Information Center

    Richards, Andrew

    2015-01-01

    Two quantitative measures of school performance are currently used, the average points score (APS) at Key Stage 2 and value-added (VA), which measures the rate of academic improvement between Key Stage 1 and 2. These figures are used by parents and the Office for Standards in Education to make judgements and comparisons. However, simple…

  12. Introducing ADS Labs

    NASA Astrophysics Data System (ADS)

    Accomazzi, Alberto; Henneken, E.; Grant, C. S.; Kurtz, M. J.; Di Milia, G.; Luker, J.; Thompson, D. M.; Bohlen, E.; Murray, S. S.

    2011-05-01

    ADS Labs is a platform that ADS is introducing in order to test and receive feedback from the community on new technologies and prototype services. Currently, ADS Labs features a new interface for abstract searches, faceted filtering of results, visualization of co-authorship networks, article-level recommendations, and a full-text search service. The streamlined abstract search interface provides a simple, one-box search with options for ranking results based on a paper relevancy, freshness, number of citations, and downloads. In addition, it provides advanced rankings based on collaborative filtering techniques. The faceted filtering interface allows users to narrow search results based on a particular property or set of properties ("facets"), allowing users to manage large lists and explore the relationship between them. For any set or sub-set of records, the co-authorship network can be visualized in an interactive way, offering a view of the distribution of contributors and their inter-relationships. This provides an immediate way to detect groups and collaborations involved in a particular research field. For a majority of papers in Astronomy, our new interface will provide a list of related articles of potential interest. The recommendations are based on a number of factors, including text similarity, citations, and co-readership information. The new full-text search interface allows users to find all instances of particular words or phrases in the body of the articles in our full-text archive. This includes all of the scanned literature in ADS as well as a select portion of the current astronomical literature, including ApJ, ApJS, AJ, MNRAS, PASP, A&A, and soon additional content from Springer journals. Fulltext search results include a list of the matching papers as well as a list of "snippets" of text highlighting the context in which the search terms were found. ADS Labs is available at http://adslabs.org

  13. Stem cell-mediated delivery of SPIO-loaded gold nanoparticles for the theranosis of liver injury and hepatocellular carcinoma

    NASA Astrophysics Data System (ADS)

    Zhao, Jun; Vykoukal, Jody; Abdelsalam, Mohamed; Recio-Boiles, Alejandro; Huang, Qian; Qiao, Yang; Singhana, Burapol; Wallace, Michael; Avritscher, Rony; Melancon, Marites P.

    2014-10-01

    The treatment of liver injuries or hepatocellular carcinoma (HCC) has been hindered by the lack of efficient drug delivery. Even with the help of nanoparticles or other synthetic delivering agents, a large portion of the dose is still sequestered in the reticuloendothelial system. As an alternative, adipose-derived mesenchymal cells (AD-MSCs), which have the capability of homing to the injured liver, can be used as a unique carrier for theranostic agents. Theranostic agents must have the capacity for being non-toxic to host cells during transportation, and for timely activation once they arrive at the injury sites. In this study, we loaded AD-MSCs with superparamagnetic iron oxide-coated gold nanoparticles (SPIO@AuNPs) and tested their effects against liver injury and HCC in cells and in mice. SPIO@AuNP is a non-toxic magnetic resonance (MR)-active contrast agent that can generate heat when irradiated with near-infrared laser. Our results showed that SPIO@AuNPs were successfully transfected into AD-MSCs without compromising either cell viability (P > 0.05) or cell differentiability. In vivo MR imaging and histologic analysis confirmed the active homing of AD-MSCs. Upon laser irradiation, the SPIO@AuNP-loaded AD-MSCs could thermally ablate surrounding HCC tumor cells. SPIO@AuNP-loaded AD-MSCs proved a promising theranostic approach for injured liver and HCC.

  14. Heat exchanger device and method for heat removal or transfer

    DOEpatents

    Koplow, Jeffrey P.

    2012-07-24

    Systems and methods for a forced-convection heat exchanger are provided. In one embodiment, heat is transferred to or from a thermal load in thermal contact with a heat conducting structure, across a narrow air gap, to a rotating heat transfer structure immersed in a surrounding medium such as air.

  15. Heat exchanger device and method for heat removal or transfer

    DOEpatents

    Koplow, Jeffrey P

    2015-03-24

    Systems and methods for a forced-convection heat exchanger are provided. In one embodiment, heat is transferred to or from a thermal load in thermal contact with a heat conducting structure, across a narrow air gap, to a rotating heat transfer structure immersed in a surrounding medium such as air.

  16. Heat exchanger device and method for heat removal or transfer

    DOEpatents

    Koplow, Jeffrey P

    2013-12-10

    Systems and methods for a forced-convection heat exchanger are provided. In one embodiment, heat is transferred to or from a thermal load in thermal contact with a heat conducting structure, across a narrow air gap, to a rotating heat transfer structure immersed in a surrounding medium such as air.

  17. Heat exchanger device and method for heat removal or transfer

    SciTech Connect

    Koplow, Jeffrey P.

    2015-12-08

    Systems and methods for a forced-convection heat exchanger are provided. In one embodiment, heat is transferred to or from a thermal load in thermal contact with a heat conducting structure, across a narrow air gap, to a rotating heat transfer structure immersed in a surrounding medium such as air.

  18. Chemical heat pump and chemical energy storage system

    DOEpatents

    Clark, Edward C.; Huxtable, Douglas D.

    1985-08-06

    A chemical heat pump and storage system employs sulfuric acid and water. In one form, the system includes a generator and condenser, an evaporator and absorber, aqueous acid solution storage and water storage. During a charging cycle, heat is provided to the generator from a heat source to concentrate the acid solution while heat is removed from the condenser to condense the water vapor produced in the generator. Water is then stored in the storage tank. Heat is thus stored in the form of chemical energy in the concentrated acid. The heat removed from the water vapor can be supplied to a heat load of proper temperature or can be rejected. During a discharge cycle, water in the evaporator is supplied with heat to generate water vapor, which is transmitted to the absorber where it is condensed and absorbed into the concentrated acid. Both heats of dilution and condensation of water are removed from the thus diluted acid. During the discharge cycle the system functions as a heat pump in which heat is added to the system at a low temperature and removed from the system at a high temperature. The diluted acid is stored in an acid storage tank or is routed directly to the generator for reconcentration. The generator, condenser, evaporator, and absorber all are operated under pressure conditions specified by the desired temperature levels for a given application. The storage tanks, however, can be maintained at or near ambient pressure conditions. In another form, the heat pump system is employed to provide usable heat from waste process heat by upgrading the temperature of the waste heat.

  19. High capacity demonstration of honeycomb panel heat pipes

    NASA Technical Reports Server (NTRS)

    Tanzer, H. J.; Cerza, M. R., Jr.; Hall, J. B.

    1986-01-01

    High capacity honeycomb panel heat pipes were investigated as heat rejection radiators on future space platforms. Starting with a remnant section of honeycomb panel measuring 3.05-m long by 0.127-m wide that was originally designed and built for high-efficiency radiator fins, features were added to increase thermal transport capacity and thus permit test evaluation as an integral heat transport and rejection radiator. A series of subscale panels were fabricated and reworked to isolate individual enhancement features. Key to the enhancement was the addition of a liquid sideflow that utilizes pressure priming. A prediction model was developed and correlated with measured data, and then used to project performance to large, space-station size radiators. Results show that a honeycomb panel with 5.08-cm sideflow spacing and core modification will meet the design load of a 50 kW space heat rejection system.

  20. Two Virasoro symmetries in stringy warped AdS3

    NASA Astrophysics Data System (ADS)

    Compère, Geoffrey; Guica, Monica; Rodriguez, Maria J.

    2014-12-01

    We study three-dimensional consistent truncations of type IIB supergravity which admit warped AdS3 solutions. These theories contain subsectors that have no bulk dynamics. We show that the symplectic form for these theories, when restricted to the non-dynamical subsectors, equals the symplectic form for pure Einstein gravity in AdS3. Consequently, for each consistent choice of boundary conditions in AdS3, we can define a consistent phase space in warped AdS3 with identical conserved charges. This way, we easily obtain a Virasoro × Virasoro asymptotic symmetry algebra in warped AdS3; two different types of Virasoro × Kač-Moody symmetries are also consistent alternatives.

  1. Deployable heat-pipe radiator

    NASA Technical Reports Server (NTRS)

    Edelstein, F.

    1978-01-01

    Loop temperatures are controlled effectively under varying load conditions. Radiator has four separate pieces of hardware: heat-pipe panel, flexible heat-pipe leader, heat exchanger, fluid header. Single-fluid transport capacities of about 850 watts, corresponding to 51,000 watt-inches, have been achieved in 90 degree bend orientation of heat-pipe header.

  2. 2 MW CW RF load for gyrotrons

    SciTech Connect

    Lawrence Ives, R.; Marsden, David; Mizuhara, Max; Collins, George; Neilson, Jeff; Borchard, Philipp

    2011-07-01

    Final design and assembly are in progress for a 2MW CW RF load for gyrotrons. Such loads are required for testing high power gyrotrons for electron cyclotron heating of fusion plasmas. The research is building on experience with a 1 MW load to increase the power capability, reduce backscattered RF power, and improve the mechanical design. (author)

  3. Hydrogen added after-burner system

    SciTech Connect

    Kanada, Youji; Hayasi, Masaharu; Akaki, Motonobu; Tsuchikawa, Shunzou; Isomura, Akihito

    1996-09-01

    The authors developed a hydrogen-added afterburner system for a new catalyst heating system, which realized large reduction of emissions during start-up at low temperatures when hydrocarbon (HC) emission was rather high. Key development items of this system are a water electrolysis type small size on-board hydrogen supply unit and an engine matching technique for the verification of emission reduction effects.

  4. Leading Change, Adding Value.

    PubMed

    Evans, Nick

    2016-09-12

    Essential facts Leading Change, Adding Value is NHS England's new nursing and midwifery framework. It is designed to build on Compassion in Practice (CiP), which was published 3 years ago and set out the 6Cs: compassion, care, commitment, courage, competence and communication. CiP established the values at the heart of nursing and midwifery, while the new framework sets out how staff can help transform the health and care sectors to meet the aims of the NHS England's Five Year Forward View. PMID:27615573

  5. Dirac operator on fuzzy AdS2

    NASA Astrophysics Data System (ADS)

    Fakhri, Hossein; Imaanpur, Ali

    2003-03-01

    In this article we construct the chirality and Dirac operators on noncommutative AdS2. We also derive the discrete spectrum of the Dirac operator which is important in the study of the spectral triple associated to AdS2. It is shown that the degeneracy of the spectrum present in the commutative AdS2 is lifted in the noncommutative case. The way we construct the chirality operator is suggestive of how to introduce the projector operators of the corresponding projective modules on this space.

  6. An xp model on AdS2 spacetime

    NASA Astrophysics Data System (ADS)

    Molina-Vilaplana, Javier; Sierra, Germán

    2013-12-01

    In this paper we formulate the xp model on the AdS2 spacetime. We find that the spectrum of the Hamiltonian has positive and negative eigenvalues, whose absolute values are given by a harmonic oscillator spectrum, which in turn coincides with that of a massive Dirac fermion in AdS2. We extend this result to generic xp models which are shown to be equivalent to a massive Dirac fermion on spacetimes whose metric depend of the xp Hamiltonian. Finally, we construct the generators of the isometry group SO(2,1) of the AdS2 spacetime, and discuss the relation with conformal quantum mechanics.

  7. National Launch System cycle 1 loads and models data book

    NASA Technical Reports Server (NTRS)

    Bugg, F.; Brunty, J.; Ernsberger, G.; Mcghee, D.; Gagliano, L.; Harrington, F.; Meyer, D.; Blades, E.

    1992-01-01

    This document contains preliminary cycle 1 loads for the National Launch System (NLS) 1 and 2 vehicles. The loads provided and recommended as design loads represent the maximum load expected during prelaunch and flight regimes, i.e., limit loads, except that propellant tank ullage pressure has not been included. Ullage pressure should be added to the loads book values for cases where the addition results in higher loads. The loads must be multiplied by the appropriate factors of safety to determine the ultimate loads for which the structure must be capable.

  8. Supersymmetric warped AdS in extended topologically massive supergravity

    NASA Astrophysics Data System (ADS)

    Deger, N. S.; Kaya, A.; Samtleben, H.; Sezgin, E.

    2014-07-01

    We determine the most general form of off-shell N=(1,1) supergravity field configurations in three dimensions by requiring that at least one off-shell Killing spinor exists. We then impose the field equations of the topologically massive off-shell supergravity and find a class of solutions whose properties crucially depend on the norm of the auxiliary vector field. These are spacelike-squashed and timelike-stretched AdS3 for the spacelike and timelike norms, respectively. At the transition point where the norm vanishes, the solution is null warped AdS3. This occurs when the coefficient of the Lorentz-Chern-Simons term is related to the AdS radius by μℓ=2. We find that the spacelike-squashed AdS3 can be modded out by a suitable discrete subgroup of the isometry group, yielding an extremal black hole solution which avoids closed timelike curves.

  9. An air-Brayton nuclear-hydrogen combined-cycle peak-and base-load electric plant

    SciTech Connect

    Forsberg, Charles W

    2008-01-01

    A combined-cycle power plant is proposed that uses heat from a high-temperature nuclear reactor and hydrogen produced by the high-temperature reactor to meet base-load and peak-load electrical demands. For base-load electricity production, air is compressed; flows through a heat exchanger, where it is heated to between 700 and 900 C; and exits through a high-temperature gas turbine to produce electricity. The heat, via an intermediate heat-transport loop, is provided by a high-temperature reactor. The hot exhaust from the Brayton-cycle turbine is then fed to a heat recovery steam generator that provides steam to a steam turbine for added electrical power production. To meet peak electricity demand, after nuclear heating of the compressed air, hydrogen is injected into the combustion chamber, combusts, and heats the air to 1300 C-the operating conditions for a standard natural-gas-fired combined-cycle plant. This process increases the plant efficiency and power output. Hydrogen is produced at night by electrolysis or other methods using energy from the nuclear reactor and is stored until needed. Therefore, the electricity output to the electric grid can vary from zero (i.e., when hydrogen is being produced) to the maximum peak power while the nuclear reactor operates at constant load. Because nuclear heat raises air temperatures above the auto-ignition temperatures of the hydrogen and powers the air compressor, the power output can be varied rapidly (compared with the capabilities of fossil-fired turbines) to meet spinning reserve requirements and stabilize the grid.

  10. LOADING DEVICE

    DOEpatents

    Ohlinger, L.A.

    1958-10-01

    A device is presented for loading or charging bodies of fissionable material into a reactor. This device consists of a car, mounted on tracks, into which the fissionable materials may be placed at a remote area, transported to the reactor, and inserted without danger to the operating personnel. The car has mounted on it a heavily shielded magazine for holding a number of the radioactive bodies. The magazine is of a U-shaped configuration and is inclined to the horizontal plane, with a cap covering the elevated open end, and a remotely operated plunger at the lower, closed end. After the fissionable bodies are loaded in the magazine and transported to the reactor, the plunger inserts the body at the lower end of the magazine into the reactor, then is withdrawn, thereby allowing gravity to roll the remaining bodies into position for successive loading in a similar manner.

  11. Proposed Framework for Determining Added Mass of Orion Drogue Parachutes

    NASA Technical Reports Server (NTRS)

    Fraire, Usbaldo, Jr.; Dearman, James; Morris, Aaron

    2011-01-01

    The Crew Exploration Vehicle (CEV) Parachute Assembly System (CPAS) project is executing a program to qualify a parachute system for a next generation human spacecraft. Part of the qualification process involves predicting parachute riser tension during system descent with flight simulations. Human rating the CPAS hardware requires a high degree of confidence in the simulation models used to predict parachute loads. However, uncertainty exists in the heritage added mass models used for loads predictions due to a lack of supporting documentation and data. Even though CPAS anchors flight simulation loads predictions to flight tests, extrapolation of these models outside the test regime carries the risk of producing non-bounding loads. A set of equations based on empirically derived functions of skirt radius is recommended as the simplest and most viable method to test and derive an enhanced added mass model for an inflating parachute. This will increase confidence in the capability to predict parachute loads. The selected equations are based on those published in A Simplified Dynamic Model of Parachute Inflation by Dean Wolf. An Ames 80x120 wind tunnel test campaign is recommended to acquire the reefing line tension and canopy photogrammetric data needed to quantify the terms in the Wolf equations and reduce uncertainties in parachute loads predictions. Once the campaign is completed, the Wolf equations can be used to predict loads in a typical CPAS Drogue Flight test. Comprehensive descriptions of added mass test techniques from the Apollo Era to the current CPAS project are included for reference.

  12. Search for SmAd-SmAdscript transitions

    NASA Astrophysics Data System (ADS)

    Wu, Lei; Garland, C. W.; Shashidhar, R.

    1993-03-01

    High-resolution heat capacity measurements have been made on two mixtures of 4-nonyloxybenzoyloxy-4'-cyanoazobenzene (9OBCAB) and 4-nitrophenyl-4'-(4`-n-hexyloxybenzoyloxybenzoate) (6ONPBB). The goal of this work was to establish the thermal behavior near a proposed SmAd-SmAd' transition between two different partial bilayer smectic-A phases. Although nematic-smectic-A transitions with small Cp peaks were observed, there was no calorimetric evidence of smectic-smectic transitions. Any SmAd-SmAd' transition must be first order due to symmetry, and it seems doubtful that true thermodynamic transitions of this type exist.

  13. A consistent and unified picture for critical phenomena of f(R) AdS black holes

    NASA Astrophysics Data System (ADS)

    Mo, Jie-Xiong; Li, Gu-Qiang; Wu, Yu-Cheng

    2016-04-01

    A consistent and unified picture for critical phenomena of charged AdS black holes in f(R) gravity is drawn in this paper. Firstly, we investigate the phase transition in canonical ensemble. We derive the explicit solutions corresponding to the divergence of CQ. The two solutions merge into one when the condition Qc=√(‑1/3R0) is satisfied. The curve of specific heat for Q < Qc has two divergent points and can be divided into three regions. Both the large radius region and the small radius region are thermodynamically stable with positive specific heat while the medium radius region is unstable with negative specific heat. However, when Q > Qc, the specific heat is always positive, implying the black holes are locally stable and no phase transition will take place. Secondly, both the T‑r+ curve and T‑S curve f(R) AdS black holes are investigated and they exhibit Van der Vaals like behavior as the P‑v curve in the former research. Critical physical quantities are obtained and they are consistent with those derived from the specific heat analysis. We carry out numerical check of Maxwell equal area law for the cases Q=0.2Qc, 0.4Qc, 0.6Qc, 0.8Qc. The relative errors are amazingly small and can be negligible. So the Maxwell equal area law holds for T‑S curve of f(R) black holes. Thirdly, we establish geometrothermodynamics for f(R) AdS black hole to examine the phase structure. It is shown that the Legendre invariant scalar curvature fraktur R would diverge exactly where the specific heat diverges. To summarize, the above three perspectives are consistent with each other, thus providing a unified picture which deepens the understanding of critical phenomena of f(R) AdS black holes.

  14. Carbohydrate Loading.

    ERIC Educational Resources Information Center

    Csernus, Marilyn

    Carbohydrate loading is a frequently used technique to improve performance by altering an athlete's diet. The objective is to increase glycogen stored in muscles for use in prolonged strenuous exercise. For two to three days, the athlete consumes a diet that is low in carbohydrates and high in fat and protein while continuing to exercise and…

  15. Cardboard Activity Is "Loaded" with Learning

    ERIC Educational Resources Information Center

    Roman, Harry T.

    2010-01-01

    In this article, the author presents an activity that uses simple paperboard from the back of a pad of paper to illustrate some basic construction principles as students experiment with conducting load tests. The author describes the steps in conducting a load test as well as adding a strut support system. The important lesson here is that…

  16. Ehrenfest's scheme and thermodynamic geometry in Born-Infeld AdS black holes

    NASA Astrophysics Data System (ADS)

    Lala, Arindam; Roychowdhury, Dibakar

    2012-10-01

    In this paper, we analyze the phase transition phenomena in Born-Infeld anti-de Sitter (BI AdS) black holes using Ehrenfest’s scheme of standard thermodynamics. The critical points are marked by the divergences in the heat capacity. In order to investigate the nature of the phase transition, we analytically check both Ehrenfest equations near the critical points. Our analysis reveals that this is indeed a second order phase transition. Finally, we analyze the nature of the phase transition using the state space geometry approach. This is found to be compatible with Ehrenfest’s scheme.

  17. Value Added in English Schools

    ERIC Educational Resources Information Center

    Ray, Andrew; McCormack, Tanya; Evans, Helen

    2009-01-01

    Value-added indicators are now a central part of school accountability in England, and value-added information is routinely used in school improvement at both the national and the local levels. This article describes the value-added models that are being used in the academic year 2007-8 by schools, parents, school inspectors, and other…

  18. 29 CFR 1919.29 - Limitations on safe working loads and proof loads.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 7 2011-07-01 2011-07-01 false Limitations on safe working loads and proof loads. 1919.29 Section 1919.29 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) GEAR CERTIFICATION Certification of Vessels: Tests and Proof Loads; Heat Treatment; Competent Persons...

  19. Per aspirin ad astra...

    PubMed

    Hartung, Thomas

    2009-12-01

    Taking the 110th anniversary of marketing of aspirin as starting point, the almost scary toxicological profile of aspirin is contrasted with its actual use experience. The author concludes that we are lucky that, in 1899, there was no regulatory toxicology. Adding, for the purpose of this article, a fourth R to the Three Rs, i.e. Realism, three reality-checks are carried out. The first one comes to the conclusion that the tools of toxicology are hardly adequate for the challenges ahead. The second one concludes that, specifically, the implementation of the EU REACH system is not feasible with these tools, mainly with regard to throughput. The third one challenges the belief that classical alternative methods, i.e. replacing animal test-based tools one by one, is actually leading to a new toxicology - it appears to change only patches of the patchwork, but not to overcome any inherent limitations other than ethical ones. The perspective lies in the Toxicology for the 21st Century initiatives, which aim to create a new approach from the scratch, by an evidence-based toxicology and a global "Human Toxicology Programme". PMID:20105011

  20. Absorption-heat-pump system

    DOEpatents

    Grossman, G.; Perez-Blanco, H.

    1983-06-16

    An improvement in an absorption heat pump cycle is obtained by adding adiabatic absorption and desorption steps to the absorber and desorber of the system. The adiabatic processes make it possible to obtain the highest temperature in the absorber before any heat is removed from it and the lowest temperature in the desorber before heat is added to it, allowing for efficient utilization of the thermodynamic availability of the heat supply stream. The improved system can operate with a larger difference between high and low working fluid concentrations, less circulation losses, and more efficient heat exchange than a conventional system.

  1. Fundamentals of heat measurement. [heat flux transducers

    NASA Technical Reports Server (NTRS)

    Gerashchenko, O. A.

    1979-01-01

    Various methods and devices for obtaining experimental data on heat flux density over wide ranges of temperature and pressure are examined. Laboratory tests and device fabrication details are supplemented by theoretical analyses of heat-conduction and thermoelectric effects, providing design guidelines and information relevant to further research and development. A theory defining the measure of correspondence between transducer signal and the measured heat flux is established for individual (isolated) heat flux transducers subject to space and time-dependent loading. An analysis of the properties of stacked (series-connected) transducers of various types (sandwich-type, plane, and spiral) is used to derive a similarity theory providing general governing relationships. The transducers examined are used in 36 types of derivative devices involving direct heat loss measurements, heat conduction studies, radiation pyrometry, calorimetry in medicine and industry and nuclear reactor dosimetry.

  2. Distribution of heating in an LVRF bundle due to dysprosium in the central element

    SciTech Connect

    Tsang, K.; Buijs, A.

    2006-07-01

    The computer code MCNP was used to establish the effect of adding dysprosium to the central pin of the proposed BRUCE-B CANFLEX{sup R} Low-Void-Reactivity Fuel (LVRF) on the heat load of the central pin and the heat balance inside the fuel bundle. The Dy generates heat through radiative capture of thermal neutrons, as well as through beta decay of {sup 165}Dy to {sup 165}Ho. We conclude that for fresh fuel, the presence of Dy contributes 26% of the overall heat to the central pin, and 0.5% to the whole fuel bundle. These percentages decrease to 11% and 0.5% at the end-of-life burnup condition. A second, operational quantity is the HPFP ratio (heating-power to fission-power ratio). This ratio is 1.63 for fresh fuel and decreases to 1.19 for fuel at the end-of-life burnup condition. (authors)

  3. Supergravity at the boundary of AdS supergravity

    NASA Astrophysics Data System (ADS)

    Amsel, Aaron J.; Compère, Geoffrey

    2009-04-01

    We give a general analysis of AdS boundary conditions for spin-3/2 Rarita-Schwinger fields and investigate boundary conditions preserving supersymmetry for a graviton multiplet in AdS4. Linear Rarita-Schwinger fields in AdSd are shown to admit mixed Dirichlet-Neumann boundary conditions when their mass is in the range 0≤|m|<1/2lAdS. We also demonstrate that mixed boundary conditions are allowed for larger masses when the inner product is “renormalized” accordingly with the action. We then use the results obtained for |m|=1/lAdS to explore supersymmetric boundary conditions for N=1 AdS4 supergravity in which the metric and Rarita-Schwinger fields are fluctuating at the boundary. We classify boundary conditions that preserve boundary supersymmetry or superconformal symmetry. Under the AdS/CFT dictionary, Neumann boundary conditions in d=4 supergravity correspond to gauging the superconformal group of the three-dimensional CFT describing M2-branes, while N=1 supersymmetric mixed boundary conditions couple the CFT to N=1 superconformal topologically massive gravity.

  4. Design Considerations for Fusible Heat Sink

    NASA Technical Reports Server (NTRS)

    Cognata, Thomas J.; Leimkuehler, Thomas O.; Sheth, Rubik B.

    2011-01-01

    Traditionally radiator designs are based off a passive or flow through design depending on vehicle requirements. For cyclical heat loads, a novel idea of combining a full flow through radiator to a phase change material is currently being investigated. The flow through radiator can be designed for an average heat load while the phase change material can be used as a source of supplemental heat rejections when vehicle heat loads go above the average load. Furthermore, by using water as the phase change material, harmful radiation protection can be provided to the crew. This paper discusses numerous trades conducted to understand the most optimal fusible heat sink design for a particular heat load. Trades include configuration concepts, amount of phase change needed for supplemental heat rejection, and the form of interstitial material needed for optimal performance. These trades were used to culminate to a fusible heat sink design. The paper will discuss design parameters taken into account to develop an engineering development unit.

  5. Low temperature barriers with heat interceptor wells for in situ processes

    DOEpatents

    McKinzie, II, Billy John

    2008-10-14

    A system for reducing heat load applied to a frozen barrier by a heated formation is described. The system includes heat interceptor wells positioned between the heated formation and the frozen barrier. Fluid is positioned in the heat interceptor wells. Heat transfers from the formation to the fluid to reduce the heat load applied to the frozen barrier.

  6. LOADED WAVEGUIDES

    DOEpatents

    Mullett, L.B.; Loach, B.G.; Adams, G.L.

    1958-06-24

    >Loaded waveguides are described for the propagation of electromagnetic waves with reduced phase velocities. A rectangular waveguide is dimensioned so as to cut-off the simple H/sub 01/ mode at the operating frequency. The waveguide is capacitance loaded, so as to reduce the phase velocity of the transmitted wave, by connecting an electrical conductor between directly opposite points in the major median plane on the narrower pair of waveguide walls. This conductor may take a corrugated shape or be an aperature member, the important factor being that the electrical length of the conductor is greater than one-half wavelength at the operating frequency. Prepared for the Second U.N. International ConferThe importance of nuclear standards is duscussed. A brief review of the international callaboration in this field is given. The proposal is made to let the International Organization for Standardization (ISO) coordinate the efforts from other groups. (W.D.M.)

  7. Modelling ELM heat flux deposition on the ITER main chamber wall

    NASA Astrophysics Data System (ADS)

    Kočan, M.; Pitts, R. A.; Lisgo, S. W.; Loarte, A.; Gunn, J. P.; Fuchs, V.

    2015-08-01

    The interaction of ELM filaments with the ITER beryllium first wall panels (FWPs) is studied using a simple ad-hoc fluid model of the filament parallel transport, taking into account the full, three-dimensional structure of the FWPs, including magnetic shadowing effects. The calculated ELM surface heat loads are used as input to the RACLETTE heat transfer code to estimate the FWP surface temperature rise. The results indicate that controlled ELMs in ITER during burning plasma operation (ΔWELM ≈ 0.6 M J) will not lead to melting or significant evaporation of the beryllium surfaces, even in the case of high ELM broadening and the minimum allowable distance between the primary and secondary separatrices. The ELM-averaged steady-state heat load also stays below the maximum power handling capability of the FWPs.

  8. Taking the Heat Off Thermal Loads

    NASA Technical Reports Server (NTRS)

    1998-01-01

    Under an SBIR (Small Business Innovative Research) contract with Goddard Space Flight Center, (NAS5-32730), Frederick A. Costello, Inc., has developed a low cost computer program for integrating thermal modeling with other engineering disciplines. TCON(tm) Concurrent Engineering Software enables graphical user-interface programs to create three dimensional models. This technology reduces time, and facilitates accuracy while performing these applications. TCON(tm) has been sold to NASA and major US industries.

  9. Heat Load on Divertors in NCSX

    NASA Astrophysics Data System (ADS)

    Kaiser, T. B.; Hill, D. N.; Maingi, R.; Monticello, D.; Zarnstorff, M.; Grossman, A.

    2006-10-01

    We have continued our study[1-3] of the effect of divertors in NCSX, using magnetic field data generated by both the PIES and VMEC/MFBE equilibrium codes. Results for comparable equilibria from the two codes agree to within statistical uncertainty. We follow field lines from a surface just outside and conformal with the LCMS until they strike a divertor plate or the first wall, or exceed 1000m in length, with effects of particle scattering mimicked by field-line diffusion. Current candidate divertor designs efficiently collect field lines, allowing fewer than 0.1% to reach the wall. The sensitivity of localized power deposition, assumed to be proportional to the density of field- line strike-points, to adjustments in the divertor configuration is under investigation.1. T.B. Kaiser, et al, Bull. Am. Phys. Soc., 48, paper RP1-20, 2003.2. T.B. Kaiser, et al, Bull. Am. Phys. Soc., 49, paper PP1-73, 2004.3. R. Maingi, et al, EPS Conf. Rome, Italy, paper P5.116, 2006.

  10. Asymptotically AdS spacetimes with a timelike Kasner singularity

    NASA Astrophysics Data System (ADS)

    Ren, Jie

    2016-07-01

    Exact solutions to Einstein's equations for holographic models are presented and studied. The IR geometry has a timelike cousin of the Kasner singularity, which is the less generic case of the BKL (Belinski-Khalatnikov-Lifshitz) singularity, and the UV is asymptotically AdS. This solution describes a holographic RG flow between them. The solution's appearance is an interpolation between the planar AdS black hole and the AdS soliton. The causality constraint is always satisfied. The entanglement entropy and Wilson loops are discussed. The boundary condition for the current-current correlation function and the Laplacian in the IR is examined. There is no infalling wave in the IR, but instead, there is a normalizable solution in the IR. In a special case, a hyperscaling-violating geometry is obtained after a dimensional reduction.

  11. All AdS7 solutions of type II supergravity

    NASA Astrophysics Data System (ADS)

    Apruzzi, Fabio; Fazzi, Marco; Rosa, Dario; Tomasiello, Alessandro

    2014-04-01

    In M-theory, the only AdS7 supersymmetric solutions are AdS7 × S 4 and its orbifolds. In this paper, we find and classify new supersymmetric solutions of the type AdS7 × M 3 in type II supergravity. While in IIB none exist, in IIA with Romans mass (which does not lift to M-theory) there are many new ones. We use a pure spinor approach reminiscent of generalized complex geometry. Without the need for any Ansatz, the system determines uniquely the form of the metric and fluxes, up to solving a system of ODEs. Namely, the metric on M 3 is that of an S 2 fibered over an interval; this is consistent with the Sp(1) R-symmetry of the holographically dual (1,0) theory. By including D8 brane sources, one can numerically obtain regular solutions, where topologically M 3 ≅ S 3.

  12. Worldsheet scattering in AdS3/CFT2

    NASA Astrophysics Data System (ADS)

    Sundin, Per; Wulff, Linus

    2013-07-01

    We confront the recently proposed exact S-matrices for AdS 3/ CFT 2 with direct worldsheet calculations. Utilizing the BMN and Near Flat Space (NFS) expansions for strings on AdS 3 × S 3 × S 3 × S 1 and AdS 3 × S 3 × T 4 we compute both tree-level and one-loop scattering amplitudes. Up to some minor issues we find nice agreement in the tree-level sector. At the one-loop level however we find that certain non-zero tree-level processes, which are not visible in the exact solution, contribute, via the optical theorem, and give an apparent mismatch for certain amplitudes. Furthermore we find that a proposed one-loop modification of the dressing phase correctly reproduces the worldsheet calculation while the standard Hernandez-Lopez phase does not. We also compute several massless to massless processes.

  13. Detailed ultraviolet asymptotics for AdS scalar field perturbations

    NASA Astrophysics Data System (ADS)

    Evnin, Oleg; Jai-akson, Puttarak

    2016-04-01

    We present a range of methods suitable for accurate evaluation of the leading asymptotics for integrals of products of Jacobi polynomials in limits when the degrees of some or all polynomials inside the integral become large. The structures in question have recently emerged in the context of effective descriptions of small amplitude perturbations in anti-de Sitter (AdS) spacetime. The limit of high degree polynomials corresponds in this situation to effective interactions involving extreme short-wavelength modes, whose dynamics is crucial for the turbulent instabilities that determine the ultimate fate of small AdS perturbations. We explicitly apply the relevant asymptotic techniques to the case of a self-interacting probe scalar field in AdS and extract a detailed form of the leading large degree behavior, including closed form analytic expressions for the numerical coefficients appearing in the asymptotics.

  14. New massive gravity and AdS(4) counterterms.

    PubMed

    Jatkar, Dileep P; Sinha, Aninda

    2011-04-29

    We show that the recently proposed Dirac-Born-Infeld extension of new massive gravity emerges naturally as a counterterm in four-dimensional anti-de Sitter space (AdS(4)). The resulting on-shell Euclidean action is independent of the cutoff at zero temperature. We also find that the same choice of counterterm gives the usual area law for the AdS(4) Schwarzschild black hole entropy in a cutoff-independent manner. The parameter values of the resulting counterterm action correspond to a c=0 theory in the context of the duality between AdS(3) gravity and two-dimensional conformal field theory. We rewrite this theory in terms of the gauge field that is used to recast 3D gravity as a Chern-Simons theory. PMID:21635026

  15. Phases of global AdS black holes

    NASA Astrophysics Data System (ADS)

    Basu, Pallab; Krishnan, Chethan; Subramanian, P. N. Bala

    2016-06-01

    We study the phases of gravity coupled to a charged scalar and gauge field in an asymptotically Anti-de Sitter spacetime ( AdS 4) in the grand canonical ensemble. For the conformally coupled scalar, an intricate phase diagram is charted out between the four relevant solutions: global AdS, boson star, Reissner-Nordstrom black hole and the hairy black hole. The nature of the phase diagram undergoes qualitative changes as the charge of the scalar is changed, which we discuss. We also discuss the new features that arise in the extremal limit.

  16. Designing added functions in engineered cementitious composites

    NASA Astrophysics Data System (ADS)

    Yang, En-Hua

    In this dissertation, a new and systematic material design approach is developed for ECC with added functions through material microstructures linkage to composite macroscopic behavior. The thesis research embodies theoretical development by building on previous ECC micromechanical models, and experimental investigations into three specific new versions of ECC with added functions aimed at addressing societal demands of our built infrastructure. Specifically, the theoretical study includes three important ECC modeling elements: Steady-state crack propagation analyses and simulation, predictive accuracy of the fiber bridging constitutive model, and development of the rate-dependent strain-hardening criteria. The first element establishes the steady-state cracking criterion as a fundamental requirement for multiple cracking behavior in brittle matrix composites. The second element improves the accuracy of crack-width prediction in ECC. The third element establishes the micromechanics basis for impact-resistant ECC design. Three new ECCs with added functions were developed and experimentally verified in this thesis research through the enhanced theoretical framework. A green ECC incorporating a large volume of industrial waste was demonstrated to possess reduced crack width and drying shrinkage. The self-healing ECC designed with tight crack width was demonstrated to recover transport and mechanical properties after microcrack damage when exposed to wet and dry cycles. The impact-resistant ECC was demonstrated to retain tensile ductility with increased strength under moderately high strain-rate loading. These new versions of ECC with added functions are expected to contribute greatly to enhancing the sustainability, durability, and safety of civil infrastructure built with ECC. This research establishes the effectiveness of micromechanics-based design and material ingredient tailoring for ECC with added new attributes but without losing its basic tensile ductile

  17. Nanofluid heat capacities

    NASA Astrophysics Data System (ADS)

    Starace, Anne K.; Gomez, Judith C.; Wang, Jun; Pradhan, Sulolit; Glatzmaier, Greg C.

    2011-12-01

    Significant increases in the heat capacity of heat transfer fluids are needed not only to reduce the costs of liquid heating and cooling processes, but also to bring clean energy producing technologies like concentrating solar power (CSP) to price parity with conventional energy generation. It has been postulated that nanofluids could have higher heat capacities than conventional fluids. In this work, nano- and micron-sized particles were added to five base fluids (poly-α olefin, mineral oil, ethylene glycol, a mixture of water and ethylene glycol, and calcium nitrate tetrahydrate), and the resulting heat capacities were measured and compared with those of the neat base fluids and the weighted average of the heat capacities of the components. The particles used were inert metals and metal oxides that did not undergo any phase transitions over the temperature range studied. In the nanofluids studied here, we found no increase in heat capacity upon the addition of the particles larger than the experimental error.

  18. Heat pipe array heat exchanger

    DOEpatents

    Reimann, Robert C.

    1987-08-25

    A heat pipe arrangement for exchanging heat between two different temperature fluids. The heat pipe arrangement is in a ounterflow relationship to increase the efficiency of the coupling of the heat from a heat source to a heat sink.

  19. External artery heat pipe

    NASA Technical Reports Server (NTRS)

    Gernert, Nelson J. (Inventor); Ernst, Donald M. (Inventor); Shaubach, Robert M. (Inventor)

    1989-01-01

    An improved heat pipe with an external artery. The longitudinal slot in the heat pipe wall which interconnects the heat pipe vapor space with the external artery is completely filled with sintered wick material and the wall of the external artery is also covered with sintered wick material. This added wick structure assures that the external artery will continue to feed liquid to the heat pipe evaporator even if a vapor bubble forms within and would otherwise block the liquid transport function of the external artery.

  20. The forecaster's added value

    NASA Astrophysics Data System (ADS)

    Turco, M.; Milelli, M.

    2009-09-01

    skill scores of two competitive forecast. It is important to underline that the conclusions refer to the analysis of the Piemonte operational alert system, so they cannot be directly taken as universally true. But we think that some of the main lessons that can be derived from this study could be useful for the meteorological community. In details, the main conclusions are the following: - despite the overall improvement in global scale and the fact that the resolution of the limited area models has increased considerably over recent years, the QPF produced by the meteorological models involved in this study has not improved enough to allow its direct use, that is, the subjective HQPF continues to offer the best performance; - in the forecast process, the step where humans have the largest added value with respect to mathematical models, is the communication. In fact the human characterisation and communication of the forecast uncertainty to end users cannot be replaced by any computer code; - eventually, although there is no novelty in this study, we would like to show that the correct application of appropriated statistical techniques permits a better definition and quantification of the errors and, mostly important, allows a correct (unbiased) communication between forecasters and decision makers.

  1. Design optimization of ADS plant proposed by JAERI

    NASA Astrophysics Data System (ADS)

    Saito, Shigeru; Tsujimoto, Kazufumi; Kikuchi, Kenji; Kurata, Yuji; Sasa, Toshinobu; Umeno, Makoto; Nishihara, Kenji; Mizumoto, Motoharu; Ouchi, Nobuo; Takei, Hayanori; Oigawa, Hiroyuki

    2006-06-01

    JAERI is conducting R&D on the Accelerator Driven System (ADS) to transmute minor actinides (MAs). The present study discusses the design of the ADS plant and various R&D on the ADS. The reference design of ADS plant in JAERI is the 800 MW, Pb-Bi eutectic (LBE) cooled, tank-type subcritical reactor loaded with (MA+Pu) nitride fuel. LBE is selected as a spallation target material. In our results of the optimization study on the neutronics of the ADS, we have adopted the maximum multiplication factor ( keff) of 0.97. From the results of thermal-hydraulic and structural analysis, the feasibility of the beam window was confirmed for steady state. The R&D activities in JAERI cover the development of superconducting proton linear accelerator, the LBE technology, the irradiation damages of materials, and the reactor physics of the subcritical reactor.

  2. Enhanced Weight based DSR for Mobile Ad Hoc Networks

    NASA Astrophysics Data System (ADS)

    Verma, Samant; Jain, Sweta

    2011-12-01

    Routing in ad hoc network is a great problematic, since a good routing protocol must ensure fast and efficient packet forwarding, which isn't evident in ad hoc networks. In literature there exists lot of routing protocols however they don't include all the aspects of ad hoc networks as mobility, device and medium constraints which make these protocols not efficient for some configuration and categories of ad hoc networks. Thus in this paper we propose an improvement of Weight Based DSR in order to include some of the aspects of ad hoc networks as stability, remaining battery power, load and trust factor and proposing a new approach Enhanced Weight Based DSR.

  3. High heat flux loop heat pipes

    NASA Technical Reports Server (NTRS)

    North, Mark T.; Sarraf, David B.; Rosenfeld, John H.; Maidanik, Yuri F.; Vershinin, Sergey

    1997-01-01

    Loop heat pipes (LHPs) can transport very large thermal power loads over long distances, through flexible, small diameter tubes against gravitational heads. In order to overcome the evaporator limit of LHPs, which is of about 0.07 MW/sq m, work was carried out to improve the efficiency by threefold to tenfold. The vapor passage geometry for the high heat flux conditions is shown. A bidisperse wick material within the circumferential vapor passages was used. Along with heat flux enhancement, several underlying issues were demonstrated, including the fabrication of bidisperse powder with controlled properties and the fabrication of a device geometry capable of replacing vapor passages with bidisperse powder.

  4. Mystery cloud of AD 536

    NASA Technical Reports Server (NTRS)

    Stothers, R. B.

    1984-01-01

    The possible cause of the densest and most persistent dry fog on record, which was observed in Europe and the Middle East during AD 536 and 537, is discussed. The fog's long duration toward the south and the high sulfuric acid signal detected in Greenland in ice cores dated around AD 540 support the theory that the fog was due to the explosion of the Rabaul volcano, the occurrence of which has been dated at about AD 540 by the radiocarbon method.

  5. High Performance Operation Control for Heat Driven Heat Pump System using Metal Hydride

    NASA Astrophysics Data System (ADS)

    Okamoto, Hideyuki; Masuda, Masao; Kozawa, Yoshiyuki

    lt is recognized that COP of heat driven heat pump system using metal hydride is 0.3-0.4 in general. In order to rise COP, we have proposed two kinds of specific operation control; the control of cycle change time according to cold heat load and the control of cooling water temperature according to outside air wet-bulb temperature. The characteristics of the heat pump system using metal hydride have grasped by various experiments and simulations. The validity of the simulation model has been confirmed by comparing with experimental results. As results of the simulations programmed for the actual operation control month by month, yearly COP has risen till 0.5-0.6 for practical scale air-conditioning system without regard for the building use. By the operation control hour by hour, yearly COP has risen till 0.6-0.65. Moreover, in the office building case added 40% sensible heat recovery, yearly COP has risen more than 0.8.

  6. AdS Branes from Partial Breaking of Superconformal Symmetries

    SciTech Connect

    Ivanov, E.A.

    2005-10-01

    It is shown how the static-gauge world-volume superfield actions of diverse superbranes on the AdS{sub d+1} superbackgrounds can be systematically derived from nonlinear realizations of the appropriate AdS supersymmetries. The latter are treated as superconformal symmetries of flat Minkowski superspaces of the bosonic dimension d. Examples include the N = 1 AdS{sub 4} supermembrane, which is associated with the 1/2 partial breaking of the OSp(1|4) supersymmetry down to the N = 1, d = 3 Poincare supersymmetry, and the T-duality related L3-brane on AdS{sub 5} and scalar 3-brane on AdS{sub 5} x S{sup 1}, which are associated with two different patterns of 1/2 breaking of the SU(2, 2|1) supersymmetry. Another (closely related) topic is the AdS/CFT equivalence transformation. It maps the world-volume actions of the codimension-one AdS{sub d+1} (super)branes onto the actions of the appropriate Minkowski (super)conformal field theories in the dimension d.

  7. AdS5 backgrounds with 24 supersymmetries

    NASA Astrophysics Data System (ADS)

    Beck, S.; Gutowski, J.; Papadopoulos, G.

    2016-06-01

    We prove a non-existence theorem for smooth AdS 5 solutions with connected, compact without boundary internal space that preserve strictly 24 supersymmetries. In particular, we show that D = 11 supergravity does not admit such solutions, and that all such solutions of IIB supergravity are locally isometric to the AdS 5 × S 5 maximally supersymmetric background. Furthermore, we prove that (massive) IIA supergravity also does not admit such solutions, provided that the homogeneity conjecture for massive IIA supergravity is valid. In the context of AdS/CFT these results imply that if gravitational duals for strictly mathcal{N}=3 superconformal theories in 4-dimensions exist, they are either singular or their internal spaces are not compact.

  8. NASA Dryden Flight Loads Research Facility

    NASA Technical Reports Server (NTRS)

    Sefic, W. J.

    1981-01-01

    The Dryden Flight Loads Research Facility (NASA) and the associated equipment for simulating the loading and heating of aircraft or their components are described. Particular emphasis is placed on various fail-safe devices which are built into the equipment to minimize the possibility of damage to flight vehicles. The equipment described includes the ground vibration and moment of inertia equipment, the data acquisition system, and the instrumentation available in the facility for measuring load, position, strain, temperature, and acceleration.

  9. Lorentzian AdS geometries, wormholes, and holography

    SciTech Connect

    Arias, Raul E.; Silva, Guillermo A.; Botta Cantcheff, Marcelo

    2011-03-15

    We investigate the structure of two-point functions for the quantum field theory dual to an asymptotically Lorentzian Anti de Sitter (AdS) wormhole. The bulk geometry is a solution of five-dimensional second-order Einstein-Gauss-Bonnet gravity and causally connects two asymptotically AdS spacetimes. We revisit the Gubser-Klebanov-Polyakov-Witten prescription for computing two-point correlation functions for dual quantum field theories operators O in Lorentzian signature and we propose to express the bulk fields in terms of the independent boundary values {phi}{sub 0}{sup {+-}} at each of the two asymptotic AdS regions; along the way we exhibit how the ambiguity of normalizable modes in the bulk, related to initial and final states, show up in the computations. The independent boundary values are interpreted as sources for dual operators O{sup {+-}} and we argue that, apart from the possibility of entanglement, there exists a coupling between the degrees of freedom living at each boundary. The AdS{sub 1+1} geometry is also discussed in view of its similar boundary structure. Based on the analysis, we propose a very simple geometric criterion to distinguish coupling from entanglement effects among two sets of degrees of freedom associated with each of the disconnected parts of the boundary.

  10. Self-dual warped AdS3 black holes

    NASA Astrophysics Data System (ADS)

    Chen, Bin; Ning, Bo

    2010-12-01

    We study a new class of solutions of three-dimensional topological massive gravity. These solutions can be taken as nonextremal black holes, with their extremal counterparts being discrete quotients of spacelike warped AdS3 along the U(1)L isometry. We study the thermodynamics of these black holes and show that the first law is satisfied. We also show that for consistent boundary conditions, the asymptotic symmetry generators form only one copy of the Virasoro algebra with central charge cL=(4νℓ)/(G(ν2+3)), with which the Cardy formula reproduces the black hole entropy. We compute the real-time correlators of scalar perturbations and find a perfect match with the dual conformal field theory (CFT) predictions. Our study provides a novel example of warped AdS/CFT correspondence: the self-dual warped AdS3 black hole is dual to a CFT with nonvanishing left central charge. Moreover, our investigation suggests that the quantum topological massive gravity asymptotic to the same spacelike warped AdS3 in different consistent ways may be dual to different two-dimensional CFTs.

  11. Heat pipe with dual working fluids

    NASA Technical Reports Server (NTRS)

    Shlosinger, A. P. (Inventor)

    1973-01-01

    A heat pipe design is offered that utilizes an auxiliary working fluid. The fluid, although being less efficient than the main working fluid, remains liquid at low heat loads when the main working fluid freezes.

  12. Freezable heat pipe

    DOEpatents

    Ernst, Donald M.; Sanzi, James L.

    1981-02-03

    A heat pipe whose fluid can be repeatedly frozen and thawed without damage to the casing. An additional part is added to a conventional heat pipe. This addition is a simple porous structure, such as a cylinder, self-supporting and free standing, which is dimensioned with its diameter not spanning the inside transverse dimension of the casing, and with its length surpassing the depth of maximum liquid.

  13. Warped AdS3/dipole-CFT duality

    NASA Astrophysics Data System (ADS)

    Song, Wei; Strominger, Andrew

    2012-05-01

    String theory contains solutions with {{SL}}( {{2},{R}} ){{R}} × {{U}}{( {1} )_L} -invariant warped AdS3 (WAdS3) factors arising as continuous deformations of ordinary AdS3 factors. We propose that some of these are holographically dual to the IR limits of nonlocal dipole-deformed 2D D-brane gauge theories, referred to as "dipole CFTs". Neither the bulk nor boundary theories are currently well-understood, and consequences of the proposed duality for both sides is investigated. The bulk entropy-area law suggests that dipole CFTs have (at large N) a high-energy density of states which does not depend on the deformation parameter. Putting the boundary theory on a spatial circle leads to closed timelike curves in the bulk, suggesting a relation of the latter to dipole-type nonlocality.

  14. New boundary conditions for AdS3

    NASA Astrophysics Data System (ADS)

    Compère, Geoffrey; Song, Wei; Strominger, Andrew

    2013-05-01

    New chiral boundary conditions are found for quantum gravity with matter on AdS3. The associated asymptotic symmetry group is generated by a single right-moving U(1) Kac-Moody-Virasoro algebra with {c_R}={3ℓ}/2G . The Kac-Moody zero mode generates global left-moving translations and equals, for a BTZ black hole, the sum of the total mass and spin. The level is positive about the global vacuum and negative in the black hole sector, corresponding to ergosphere formation. Realizations arising in Chern-Simons gravity and string theory are analyzed. The new boundary conditions are shown to naturally arise for warped AdS3 in the limit that the warp parameter is taken to zero.

  15. Observing quantum gravity in asymptotically AdS space

    NASA Astrophysics Data System (ADS)

    Emelyanov, Slava

    2015-12-01

    The question is studied of whether an observer can discover quantum gravity in the semiclassical regime. It is shown that it is indeed possible to probe a certain quantum gravity effect by employing an appropriately designed detector. The effect is related to the possibility of having topologically inequivalent geometries in the path-integral approach at the same time. A conformal field theory (CFT) state which is expected to describe the eternal anti-de Sitter (AdS) black hole in the large-N limit is discussed. It is argued under certain assumptions that the black hole boundary should be merely a patch of the entire AdS boundary. This leads then to a conclusion that that CFT state is the ordinary CFT vacuum restricted to that patch. If existent, the bulk CFT operators can behave as the ordinary semiclassical quantum field theory in the large-N limit in the weak sense.

  16. Semiclassical Virasoro blocks from AdS3 gravity

    NASA Astrophysics Data System (ADS)

    Hijano, Eliot; Kraus, Per; Perlmutter, Eric; Snively, River

    2015-12-01

    We present a unified framework for the holographic computation of Virasoro conformal blocks at large central charge. In particular, we provide bulk constructions that correctly reproduce all semiclassical Virasoro blocks that are known explicitly from conformal field theory computations. The results revolve around the use of geodesic Witten diagrams, recently introduced in [1], evaluated in locally AdS3 geometries generated by backreaction of heavy operators. We also provide an alternative computation of the heavy-light semiclassical block — in which two external operators become parametrically heavy — as a certain scattering process involving higher spin gauge fields in AdS3; this approach highlights the chiral nature of Virasoro blocks. These techniques may be systematically extended to compute corrections to these blocks and to interpolate amongst the different semiclassical regimes.

  17. Lifetime Reliability Prediction of Ceramic Structures Under Transient Thermomechanical Loads

    NASA Technical Reports Server (NTRS)

    Nemeth, Noel N.; Jadaan, Osama J.; Gyekenyesi, John P.

    2005-01-01

    An analytical methodology is developed to predict the probability of survival (reliability) of ceramic components subjected to harsh thermomechanical loads that can vary with time (transient reliability analysis). This capability enables more accurate prediction of ceramic component integrity against fracture in situations such as turbine startup and shutdown, operational vibrations, atmospheric reentry, or other rapid heating or cooling situations (thermal shock). The transient reliability analysis methodology developed herein incorporates the following features: fast-fracture transient analysis (reliability analysis without slow crack growth, SCG); transient analysis with SCG (reliability analysis with time-dependent damage due to SCG); a computationally efficient algorithm to compute the reliability for components subjected to repeated transient loading (block loading); cyclic fatigue modeling using a combined SCG and Walker fatigue law; proof testing for transient loads; and Weibull and fatigue parameters that are allowed to vary with temperature or time. Component-to-component variation in strength (stochastic strength response) is accounted for with the Weibull distribution, and either the principle of independent action or the Batdorf theory is used to predict the effect of multiaxial stresses on reliability. The reliability analysis can be performed either as a function of the component surface (for surface-distributed flaws) or component volume (for volume-distributed flaws). The transient reliability analysis capability has been added to the NASA CARES/ Life (Ceramic Analysis and Reliability Evaluation of Structures/Life) code. CARES/Life was also updated to interface with commercially available finite element analysis software, such as ANSYS, when used to model the effects of transient load histories. Examples are provided to demonstrate the features of the methodology as implemented in the CARES/Life program.

  18. Alday-Maldacena Duality and AdS Plateau Problem

    NASA Astrophysics Data System (ADS)

    Morozov, A.

    A short summary of approximate approach to the study of minimal surfaces in AdS, based on solving Nambu-Goto equations iteratively. Today, after partial denunciation of the BDS conjecture, this looks like the only constructive approach to understanding the ways of its possible modification and thus to saving the Alday-Maldacena duality. Numerous open technical problems are explicitly formulated throughout the text.

  19. 46 CFR 154.178 - Contiguous hull structure: Heating system.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... transverse and longitudinal contiguous hull structure must: (a) Be shown by a heat load calculation to have the heating capacity to meet § 154.174(b)(2) or § 154.176(b)(2); (b) Have stand-by heating to provide 100% of the required heat load and distribution determined under paragraph (a); and (c) Meet Parts...

  20. K-shell and extreme ultraviolet spectroscopic signatures of structured Ar puff Z-pinch loads with high K-shell x-ray yield

    SciTech Connect

    Failor, B. H.; Sze, H. M.; Banister, J. W.; Levine, J. S.; Qi, N.; Apruzese, J. P.; Lojewski, D. Y.

    2007-02-15

    Structured 12-cm-diam Ar gas-puff loads have recently produced Z-pinch implosions with reduced Rayleigh-Taylor instability growth and increased K-shell x-ray yield [H. Sze, J. Banister, B. H. Failor, J. S. Levine, N. Qi, A. L. Velikovich, J. Davis, D. Lojewski, and P. Sincerny, Phys. Rev. Lett. 95, 105001 (2005)]. To better understand the dynamics of these loads, we have measured the extreme ultraviolet (XUV) emission resolved radially, spectrally, and axially. Radial measurements indicated a compressed diameter of {approx_equal}3 mm, consistent with the observed load inductance change and an imploded-mass consisting of a {approx_equal}1.5-mm-diam, hot, K-shell-emitting core and a cooler surrounding blanket. Spectral measurements indicate that, if the load is insufficiently heated, then radiation from the core will rapidly photoheat the outer blanket, producing a strong increase in XUV emission. Also, adding a massive center jet ({>=}20% of load mass) increases the rise and fall times of the XUV emission to {>=}40 ns, consistent with a more adiabatic compression and heating of the load. Axial measurements show that, despite differences in the XUV and K-shell emission time histories, the K-shell x-ray yield is insensitive to axial variations in load mass.

  1. On information loss in AdS3/CFT2

    NASA Astrophysics Data System (ADS)

    Fitzpatrick, A. Liam; Kaplan, Jared; Li, Daliang; Wang, Junpu

    2016-05-01

    We discuss information loss from black hole physics in AdS3, focusing on two sharp signatures infecting CFT2 correlators at large central charge c: `forbidden singularities' arising from Euclidean-time periodicity due to the effective Hawking temperature, and late-time exponential decay in the Lorentzian region. We study an infinite class of examples where forbidden singularities can be resolved by non-perturbative effects at finite c, and we show that the resolution has certain universal features that also apply in the general case. Analytically continuing to the Lorentzian regime, we find that the non-perturbative effects that resolve forbidden singularities qualitatively change the behavior of correlators at times t ˜ S BH , the black hole entropy. This may resolve the exponential decay of correlators at late times in black hole backgrounds. By Borel resumming the 1 /c expansion of exact examples, we explicitly identify `information-restoring' effects from heavy states that should correspond to classical solutions in AdS3. Our results suggest a line of inquiry towards a more precise formulation of the gravitational path integral in AdS3.

  2. Supersymmetric giant graviton solutions in AdS3

    NASA Astrophysics Data System (ADS)

    Mandal, Gautam; Raju, Suvrat; Smedbäck, Mikael

    2008-02-01

    We parametrize all classical probe brane configurations that preserve four supersymmetries in (a) the extremal D1-D5 geometry, (b) the extremal D1-D5-P geometry, (c) the smooth D1-D5 solutions proposed by Lunin and Mathur, and (d) global AdS3×S3×T4/K3. These configurations consist of D1 branes, D5 branes, and bound states of D5 and D1 branes with the property that a particular Killing vector is tangent to the brane world volume at each point. We show that the supersymmetric sector of the D5-brane world volume theory may be analyzed in an effective 1+1 dimensional framework that places it on the same footing as D1 branes. In global AdS and the corresponding Lunin-Mathur solution, the solutions we describe are “bound” to the center of AdS for generic parameters and cannot escape to infinity. We show that these probes only exist on the submanifold of moduli space where the background BNS field and theta angle vanish. We quantize these probes in the near-horizon region of the extremal D1-D5 geometry and obtain the theory of long strings discussed by Seiberg and Witten.

  3. Heat pipe development

    NASA Technical Reports Server (NTRS)

    Bienart, W. B.

    1973-01-01

    The objective of this program was to investigate analytically and experimentally the performance of heat pipes with composite wicks--specifically, those having pedestal arteries and screwthread circumferential grooves. An analytical model was developed to describe the effects of screwthreads and screen secondary wicks on the transport capability of the artery. The model describes the hydrodynamics of the circumferential flow in triangular grooves with azimuthally varying capillary menisci and liquid cross-sections. Normalized results were obtained which give the influence of evaporator heat flux on the axial heat transport capability of the arterial wick. In order to evaluate the priming behavior of composite wicks under actual load conditions, an 'inverted' glass heat pipe was designed and constructed. The results obtained from the analysis and from the tests with the glass heat pipe were applied to the OAO-C Level 5 heat pipe, and an improved correlation between predicted and measured evaporator and transport performance were obtained.

  4. Plutonium Immobilization Project -- Can loading

    SciTech Connect

    Kriikku, E.

    2000-01-18

    The Savannah River Site (SRS) will immobilize excess plutonium in the proposed Plutonium Immobilization Project (PIP). The PIP scope includes unloading transportation containers, preparing the feed streams, converting the metal feed to an oxide, adding the ceramic precursors, pressing the pucks, inspecting pucks, and sintering pucks. The PIP scope also includes loading the pucks into metal cans, sealing the cans, inspecting the cans, loading the cans into magazines, loading magazines into Defense Waste Processing Facility (DWPF) canisters, and transporting the canisters to the DWPF. The DWPF fills the canister with a mixture of high level radioactive waste and glass for permanent storage. Due to the radiation, remote equipment must perform PIP operations in a contained environment.

  5. Three story residence with solar heat--Manchester, New Hampshire

    NASA Technical Reports Server (NTRS)

    1981-01-01

    When heat lost through ducts is counted for accurate performance assessment, solar energy supplied 56 percent of building's space heating load. Average outdoor temperature was 53 degrees F; average indoor temperature was 69 degrees F. System operating modes included heating from solar collectors, storing heat, heating from storage, auxiliary heating with oil fired furnace, summer venting, and hot water preheating.

  6. Axial flow heat exchanger devices and methods for heat transfer using axial flow devices

    DOEpatents

    Koplow, Jeffrey P.

    2016-02-16

    Systems and methods described herein are directed to rotary heat exchangers configured to transfer heat to a heat transfer medium flowing in substantially axial direction within the heat exchangers. Exemplary heat exchangers include a heat conducting structure which is configured to be in thermal contact with a thermal load or a thermal sink, and a heat transfer structure rotatably coupled to the heat conducting structure to form a gap region between the heat conducting structure and the heat transfer structure, the heat transfer structure being configured to rotate during operation of the device. In example devices heat may be transferred across the gap region from a heated axial flow of the heat transfer medium to a cool stationary heat conducting structure, or from a heated stationary conducting structure to a cool axial flow of the heat transfer medium.

  7. DYNAMIC LOADING OF TEFLON AT 200?C

    SciTech Connect

    Urtiew, P A; Forbes, J W; Tarver, C M; Vandersall, K S; Garcia, F

    2007-06-13

    Dynamic loading experiments were performed on inert Teflon (Polytetrafluoroethylene) samples, initially heated to the temperature of 200 C, to test its behavior under these conditions for its use in other heated experiments. Tests were performed in the 100 mm diameter bore propellant driven gas gun with piezo-resistive manganin pressure gauges imbedded into the samples to measure loading pressures. Experimental data provided new information on the shock velocity - particle velocity relationship for the heated material and showed no adverse effect of temperature on the insulating properties of the material.

  8. Hydrogen-or-Fossil-Combustion Nuclear Combined-Cycle Systems for Base- and Peak-Load Electricity Production

    SciTech Connect

    Forsberg, Charles W; Conklin, Jim

    2007-09-01

    A combined-cycle power plant is described that uses (1) heat from a high-temperature nuclear reactor to meet base-load electrical demands and (2) heat from the same high-temperature reactor and burning natural gas, jet fuel, or hydrogen to meet peak-load electrical demands. For base-load electricity production, fresh air is compressed; then flows through a heat exchanger, where it is heated to between 700 and 900 C by heat provided by a high-temperature nuclear reactor via an intermediate heat-transport loop; and finally exits through a high-temperature gas turbine to produce electricity. The hot exhaust from the Brayton-cycle gas turbine is then fed to a heat recovery steam generator that provides steam to a steam turbine for added electrical power production. To meet peak electricity demand, the air is first compressed and then heated with the heat from a high-temperature reactor. Natural gas, jet fuel, or hydrogen is then injected into the hot air in a combustion chamber, combusts, and heats the air to 1300 C-the operating conditions for a standard natural-gas-fired combined-cycle plant. The hot gas then flows through a gas turbine and a heat recovery steam generator before being sent to the exhaust stack. The higher temperatures increase the plant efficiency and power output. If hydrogen is used, it can be produced at night using energy from the nuclear reactor and stored until needed. With hydrogen serving as the auxiliary fuel for peak power production, the electricity output to the electric grid can vary from zero (i.e., when hydrogen is being produced) to the maximum peak power while the nuclear reactor operates at constant load. Because nuclear heat raises air temperatures above the auto-ignition temperatures of the various fuels and powers the air compressor, the power output can be varied rapidly (compared with the capabilities of fossil-fired turbines) to meet spinning reserve requirements and stabilize the electric grid. This combined cycle uses the

  9. Bending AdS waves with new massive gravity

    NASA Astrophysics Data System (ADS)

    Ayón-Beato, Eloy; Giribet, Gaston; Hassaïne, Mokhtar

    2009-05-01

    We study AdS-waves in the three-dimensional new theory of massive gravity recently proposed by Bergshoeff, Hohm, and Townsend. The general configuration of this type is derived and shown to exhibit different branches, with different asymptotic behaviors. In particular, for the special fine tuning m2 = ±1/(2l2), solutions with logarithmic fall-off arise, while in the range m2 > -1/(2l2), spacetimes with Schrödinger isometry group are admitted as solutions. Spacetimes that are asymptotically AdS3, both for the Brown-Henneaux and for the weakened boundary conditions, are also identified. The metric function that characterizes the profile of the AdS-wave behaves as a massive excitation on the spacetime, with an effective mass given by meff2 = m2-1/(2l2). For the critical value m2 = -1/(2l2), the value of the effective mass precisely saturates the Breitenlohner-Freedman bound for the AdS3 space where the wave is propagating on. The analogies with the AdS-wave solutions of topologically massive gravity are also discussed. Besides, we consider the coupling of both massive deformations to Einstein gravity and find the exact configurations for the complete theory, discussing all the different branches exhaustively. One of the effects of introducing the Chern-Simons gravitational term is that of breaking the degeneracy in the effective mass of the generic modes of pure New Massive Gravity, producing a fine structure due to parity violation. Another effect is that the zoo of exact logarithmic specimens becomes considerably enlarged.

  10. ADS/CFT and QCD

    SciTech Connect

    Brodsky, Stanley J.; de Teramond, Guy F.; /Costa Rica U. /SLAC

    2007-02-21

    The AdS/CFT correspondence between string theory in AdS space and conformal .eld theories in physical spacetime leads to an analytic, semi-classical model for strongly-coupled QCD which has scale invariance and dimensional counting at short distances and color confinement at large distances. Although QCD is not conformally invariant, one can nevertheless use the mathematical representation of the conformal group in five-dimensional anti-de Sitter space to construct a first approximation to the theory. The AdS/CFT correspondence also provides insights into the inherently non-perturbative aspects of QCD, such as the orbital and radial spectra of hadrons and the form of hadronic wavefunctions. In particular, we show that there is an exact correspondence between the fifth-dimensional coordinate of AdS space z and a specific impact variable {zeta} which measures the separation of the quark and gluonic constituents within the hadron in ordinary space-time. This connection allows one to compute the analytic form of the frame-independent light-front wavefunctions, the fundamental entities which encode hadron properties and allow the computation of decay constants, form factors, and other exclusive scattering amplitudes. New relativistic lightfront equations in ordinary space-time are found which reproduce the results obtained using the 5-dimensional theory. The effective light-front equations possess remarkable algebraic structures and integrability properties. Since they are complete and orthonormal, the AdS/CFT model wavefunctions can also be used as a basis for the diagonalization of the full light-front QCD Hamiltonian, thus systematically improving the AdS/CFT approximation.

  11. Load calculation and system evaluation for electric vehicle climate control

    SciTech Connect

    Aceves, S.M.; Comfort, W.J. III

    1994-09-12

    This paper presents an analysis of the applicability of alternative systems for electric vehicle (EV) heating and air conditioning (HVAC). The paper consists of two parts. The first part is a cooling and heating load calculation for electric vehicles. The second part is an evaluation of several systems that can provide the desired cooling and heating in EVs. These systems are ranked according to their overall weight The overall weight is calculated by adding the system weight and the weight of the battery necessary to provide energy for system operation. The system with the minimum overall weight is considered to be the best, because minimum vehicle weight decreases the energy required for propulsion, and therefore increases the vehicle range. Three systems are considered as the best choices for EV HVAC. These are, vapor compression, ice storage and adsorption systems. These systems are evaluated, including calculations of system weight, system volume, and COP. The paper also includes a calculation on how the battery energy storage capacity affects the overall system weights and the selection of the optimum system. The results indicate that, at the conditions analyzed in this paper, an ice storage system has the minimum weight of all the systems considered. Vapor compression air conditioners become the system with the minimum weight for battery storage capacities above 230 kJ/kg.

  12. Mass-loading at interplanetary shocks

    NASA Technical Reports Server (NTRS)

    Zank, G. P.

    1992-01-01

    Mass-loading fronts represent a new class of shocks which is found frequently in the solar system, both at the head of comets and upstream of weakly and nonmagnetized planets, and which has not yet been investigated in great detail. Here, a general theoretical description of mass-loading shocks (MLSs) in the heliosphere is presented and the difference between MLSs and classical nonreacting MHD shock are elucidated. It is found that the momentum contribution of added mass within the shock represents a physically important effect, particularly in the shock strength regime observed at Comets Halley and GZ. The mass-loading MHD Rankine-Hugoniot conditions are not tangentially invariant, so mass-loading fronts are subjected to shearing stresses, greatly curtailing the upstream parameter regime for which stable transitions are possible. The existence of fast and slow mode compound mass-loading fronts is predicted. Other forms of mass-loading fronts exist for which no classical MHD counterparts exist.

  13. AMBIPOLAR DIFFUSION HEATING IN TURBULENT SYSTEMS

    SciTech Connect

    Li, Pak Shing; Myers, Andrew; McKee, Christopher F. E-mail: atmyers@berkeley.edu

    2012-11-20

    The temperature of the gas in molecular clouds is a key determinant of the characteristic mass of star formation. Ambipolar diffusion (AD) is considered one of the most important heating mechanisms in weakly ionized molecular clouds. In this work, we study the AD heating rate using two-fluid turbulence simulations and compare it with the overall heating rate due to turbulent dissipation. We find that for observed molecular clouds, which typically have Alfven Mach numbers of {approx}1 and AD Reynolds numbers of {approx}20, about 70% of the total turbulent dissipation is in the form of AD heating. AD has an important effect on the length scale where energy is dissipated: when AD heating is strong, most of the energy in the cascade is removed by ion-neutral drift, with a comparatively small amount of energy making it down to small scales. We derive a relation for the AD heating rate that describes the results of our simulations to within a factor of two. Turbulent dissipation, including AD heating, is generally less important than cosmic-ray heating in molecular clouds, although there is substantial scatter in both.

  14. Ultraviolet asymptotics and singular dynamics of AdS perturbations

    NASA Astrophysics Data System (ADS)

    Craps, Ben; Evnin, Oleg; Vanhoof, Joris

    2015-10-01

    Important insights into the dynamics of spherically symmetric AdS-scalar field perturbations can be obtained by considering a simplified time-averaged theory accurately describing perturbations of amplitude ɛ on time-scales of order 1/ ɛ 2. The coefficients of the time-averaged equations are complicated expressions in terms of the AdS scalar field mode functions, which are in turn related to the Jacobi polynomials. We analyze the behavior of these coefficients for high frequency modes. The resulting asymptotics can be useful for understanding the properties of the finite-time singularity in solutions of the time-averaged theory recently reported in the literature. We highlight, in particular, the gauge dependence of this asymptotics, with respect to the two most commonly used gauges. The harsher growth of the coefficients at large frequencies in higher-dimensional AdS suggests strengthening of turbulent instabilities in higher dimensions. In the course of our derivations, we arrive at recursive relations for the coefficients of the time-averaged theory that are likely to be useful for evaluating them more efficiently in numerical simulations.

  15. Phase transition and thermodynamic geometry of f (R ) AdS black holes in the grand canonical ensemble

    NASA Astrophysics Data System (ADS)

    Li, Gu-Qiang; Mo, Jie-Xiong

    2016-06-01

    The phase transition of a four-dimensional charged AdS black hole solution in the R +f (R ) gravity with constant curvature is investigated in the grand canonical ensemble, where we find novel characteristics quite different from that in the canonical ensemble. There exists no critical point for T -S curve while in former research critical point was found for both the T -S curve and T -r+ curve when the electric charge of f (R ) black holes is kept fixed. Moreover, we derive the explicit expression for the specific heat, the analog of volume expansion coefficient and isothermal compressibility coefficient when the electric potential of f (R ) AdS black hole is fixed. The specific heat CΦ encounters a divergence when 0 <Φ b . This finding also differs from the result in the canonical ensemble, where there may be two, one or no divergence points for the specific heat CQ . To examine the phase structure newly found in the grand canonical ensemble, we appeal to the well-known thermodynamic geometry tools and derive the analytic expressions for both the Weinhold scalar curvature and Ruppeiner scalar curvature. It is shown that they diverge exactly where the specific heat CΦ diverges.

  16. Thermal performance of a multi-evaporator loop heat pipe with thermal masses and thermal electrical coolers

    NASA Technical Reports Server (NTRS)

    Ku, Jentung; Ottenstein, Laura; Birur, Gajanana

    2004-01-01

    This paper describes thermal performance of a loop heat pipe (LHP) with two evaporators and two condensers in ambient testing. Each evaporator has an outer diameter of 15mm and a length of 76mm, and has an integral compensation chamber (CC). An aluminum mass of 500 grams is attached to each evaporator to simulate the instrument mass. A thermal electric cooler (TEC) is installed on each CC to provide heating as well as cooling for CC temperature control. A flow regulator is installed in the condenser section to prevent vapor from going back to the evaporators in the event that one of condenser is fully utilized. Ammonia was used ad the working fluid. Tests conducted included start-up, power cycle, heat load sharing, sink temperature cycle, operating temperature control with TECs, and capillary limit tests. Experimental data showed that the loop could start with a heat load of less than 1OW even with added thermal masses. The loop operated stably with even and uneven evaporator heat loads, and even and uneven condenser sink temperatures. The operating temperature could be controlled within +/-0.5K of the set point temperature using either or both TECs, and the required TEC control heater power was less than 2W under most test conditions. Heat load sharing between the two evaporators was also successfully demonstrated. The loop had a heat transport capability of 120W to 140W, and could recover from a dry-out when the heat load was reduced. The 500-gram aluminum mass on each evaporator had a negligible effect on the loop operation. Existing LHPs servicing the orbiting spacecraft have a single evaporator with an outer diameter of about 25mm. Important performance characteristics demonstrated by this LHP included: 1) Operation of an LHP with 15mm diameter evaporators; 2) Robustness and reliability of an LHP with multiple evaporators and multiple condensers under various test conditions; 3) Heat load sharing among LHP evaporators; 4) Effectiveness of TECs in controlling

  17. Heat Waves

    MedlinePlus

    Heat Waves Dangers we face during periods of very high temperatures include: Heat cramps: These are muscular pains and spasms due ... that the body is having trouble with the heat. If a heat wave is predicted or happening… - ...

  18. Heat emergencies

    MedlinePlus

    Heat emergencies or illnesses are caused by exposure to extreme heat and sun. Heat illnesses can be prevented by ... to regulate the temperature, and make a heat emergency more likely: Drinking alcohol before or during exposure ...

  19. Lunar Base Heat Pump

    NASA Technical Reports Server (NTRS)

    Walker, D.; Fischbach, D.; Tetreault, R.

    1996-01-01

    The objective of this project was to investigate the feasibility of constructing a heat pump suitable for use as a heat rejection device in applications such as a lunar base. In this situation, direct heat rejection through the use of radiators is not possible at a temperature suitable for lde support systems. Initial analysis of a heat pump of this type called for a temperature lift of approximately 378 deg. K, which is considerably higher than is commonly called for in HVAC and refrigeration applications where heat pumps are most often employed. Also because of the variation of the rejection temperature (from 100 to 381 deg. K), extreme flexibility in the configuration and operation of the heat pump is required. A three-stage compression cycle using a refrigerant such as CFC-11 or HCFC-123 was formulated with operation possible with one, two or three stages of compression. Also, to meet the redundancy requirements, compression was divided up over multiple compressors in each stage. A control scheme was devised that allowed these multiple compressors to be operated as required so that the heat pump could perform with variable heat loads and rejection conditions. A prototype heat pump was designed and constructed to investigate the key elements of the high-lift heat pump concept. Control software was written and implemented in the prototype to allow fully automatic operation. The heat pump was capable of operation over a wide range of rejection temperatures and cooling loads, while maintaining cooling water temperature well within the required specification of 40 deg. C +/- 1.7 deg. C. This performance was verified through testing.

  20. New Features in ADS Labs

    NASA Astrophysics Data System (ADS)

    Accomazzi, Alberto; Kurtz, M. J.; Henneken, E. A.; Grant, C. S.; Thompson, D.; Di Milia, G.; Luker, J.; Murray, S. S.

    2013-01-01

    The NASA Astrophysics Data System (ADS) has been working hard on updating its services and interfaces to better support our community's research needs. ADS Labs is a new interface built on the old tried-and-true ADS Abstract Databases, so all of ADS's content is available through it. In this presentation we highlight the new features that have been developed in ADS Labs over the last year: new recommendations, metrics, a citation tool and enhanced fulltext search. ADS Labs has long been providing article-level recommendations based on keyword similarity, co-readership and co-citation analysis of its corpus. We have now introduced personal recommendations, which provide a list of articles to be considered based on a individual user's readership history. A new metrics interface provides a summary of the basic impact indicators for a list of records. These include the total and normalized number of papers, citations, reads, and downloads. Also included are some of the popular indices such as the h, g and i10 index. The citation helper tool allows one to submit a set of records and obtain a list of top 10 papers which cite and/or are cited by papers in the original list (but which are not in it). The process closely resembles the network approach of establishing "friends of friends" via an analysis of the citation network. The full-text search service now covers more than 2.5 million documents, including all the major astronomy journals, as well as physics journals published by Springer, Elsevier, the American Physical Society, the American Geophysical Union, and all of the arXiv eprints. The full-text search interface interface allows users and librarians to dig deep and find words or phrases in the body of the indexed articles. ADS Labs is available at http://adslabs.org

  1. The AdS central charge in string theory

    NASA Astrophysics Data System (ADS)

    Troost, Jan

    2011-11-01

    We evaluate the vacuum expectation value of the central charge operator in string theory in an AdS3 vacuum. Our calculation provides a rare non-zero one-point function on a spherical worldsheet. The evaluation involves the regularization both of a worldsheet ultraviolet divergence (associated to the infinite volume of the conformal Killing group), and a space-time infrared divergence (corresponding to the infinite volume of space-time). The two divergences conspire to give a finite result, which is the classical general relativity value for the central charge, corrected in bosonic string theory by an infinite series of tree level higher derivative terms.

  2. Small black holes in global AdS spacetime

    NASA Astrophysics Data System (ADS)

    Jokela, Niko; Pönni, Arttu; Vuorinen, Aleksi

    2016-04-01

    We study the properties of two-point functions and quasinormal modes in a strongly coupled field theory holographically dual to a small black hole in global anti-de Sitter spacetime. Our results are seen to smoothly interpolate between known limits corresponding to large black holes and thermal AdS space, demonstrating that the Son-Starinets prescription works even when there is no black hole in the spacetime. Omitting issues related to the internal space, the results can be given a field theory interpretation in terms of the microcanonical ensemble, which provides access to energy densities forbidden in the canonical description.

  3. Entanglement entropy and duality in AdS4

    NASA Astrophysics Data System (ADS)

    Bakas, Ioannis; Pastras, Georgios

    2015-07-01

    Small variations of the entanglement entropy δS and the expectation value of the modular Hamiltonian δE are computed holographically for circular entangling curves in the boundary of AdS4, using gravitational perturbations with general boundary conditions in spherical coordinates. Agreement with the first law of thermodynamics, δS = δE, requires that the line element of the entangling curve remains constant. In this context, we also find a manifestation of electric-magnetic duality for the entanglement entropy and the corresponding modular Hamiltonian, following from the holographic energy-momentum/Cotton tensor duality.

  4. Fake gaps in AdS3/CFT2

    NASA Astrophysics Data System (ADS)

    Belin, Alexandre; Castro, Alejandra; Hung, Ling-Yan

    2015-11-01

    We discuss properties of interpolating geometries in three dimensional gravity in the presence of a chiral anomaly. This anomaly, which introduces an unbalance between left and right central charges, is protected under RG flows. For this simple reason it is impossible to gap a system with such an anomaly. Our goal is to discuss how holography captures this basic and robust feature. We demonstrate the absence of a mass gap by analysing the linearized spectrum and holographic entanglement entropy of these backgrounds in the context of AdS3/CFT2.

  5. Pure Spinors in AdS and Lie Algebra Cohomology

    NASA Astrophysics Data System (ADS)

    Mikhailov, Andrei

    2014-10-01

    We show that the BRST cohomology of the massless sector of the Type IIB superstring on AdS5 × S 5 can be described as the relative cohomology of an infinite-dimensional Lie superalgebra. We explain how the vertex operators of ghost number 1, which correspond to conserved currents, are described in this language. We also give some algebraic description of the ghost number 2 vertices, which appears to be new. We use this algebraic description to clarify the structure of the zero mode sector of the ghost number two states in flat space, and initiate the study of the vertices of the higher ghost number.

  6. Internal structure of charged AdS black holes

    NASA Astrophysics Data System (ADS)

    Bhattacharjee, Srijit; Sarkar, Sudipta; Virmani, Amitabh

    2016-06-01

    When an electrically charged black hole is perturbed, its inner horizon becomes a singularity, often referred to as the Poisson-Israel mass inflation singularity. Ori constructed a model of this phenomenon for asymptotically flat black holes, in which the metric can be determined explicitly in the mass inflation region. In this paper we implement the Ori model for charged AdS black holes. We find that the mass function inflates faster than the flat space case as the inner horizon is approached. Nevertheless, the mass inflation singularity is still a weak singularity: Although spacetime curvature becomes infinite, tidal distortions remain finite on physical objects attempting to cross it.

  7. Improved solar heating systems

    DOEpatents

    Schreyer, J.M.; Dorsey, G.F.

    1980-05-16

    An improved solar heating system is described in which the incident radiation of the sun is absorbed on collector panels, transferred to a storage unit and then distributed as heat for a building and the like. The improvement is obtained by utilizing a storage unit comprising separate compartments containing an array of materials having different melting points ranging from 75 to 180/sup 0/F. The materials in the storage system are melted in accordance with the amount of heat absorbed from the sun and then transferred to the storage system. An efficient low volume storage system is provided by utilizing the latent heat of fusion of the materials as they change states in storing ad releasing heat for distribution.

  8. Advanced heat pump

    NASA Astrophysics Data System (ADS)

    Ashley, Joseph L.; Matthews, John D.

    1989-09-01

    This patent application discloses a heat pump which includes a first packed bed of liquid desiccant for removing moisture from outside air in the heating mode of operation, and a pump for transferring the moisture laden desiccant to a second packed bed which humidifies condenser heated inside air by adding water vapor to the air. The first packed bed, by removing moisture from the outside air before it passes through the heat pump's evaporator coils, prevents frost from forming on the coils. In the cooling mode of operation the second packed bed of liquid desiccant removes water vapor from the air inside of the building. The moisture laden desiccant is then transferred to the first packed bed by a second pump where condenser heat transfers the moisture from the desiccant to outside air.

  9. Introducing ADS 2.0

    NASA Astrophysics Data System (ADS)

    Accomazzi, Alberto; Kurtz, M. J.; Henneken, E. A.; Grant, C. S.; Thompson, D.; Luker, J.; Chyla, R.; Murray, S. S.

    2014-01-01

    In the spring of 1993, the Smithsonian/NASA Astrophysics Data System (ADS) first launched its bibliographic search system. It was known then as the ADS Abstract Service, a component of the larger Astrophysics Data System effort which had developed an interoperable data system now seen as a precursor of the Virtual Observatory. As a result of the massive technological and sociological changes in the field of scholarly communication, the ADS is now completing the most ambitious technological upgrade in its twenty-year history. Code-named ADS 2.0, the new system features: an IT platform built on web and digital library standards; a new, extensible, industrial strength search engine; a public API with various access control capabilities; a set of applications supporting search, export, visualization, analysis; a collaborative, open source development model; and enhanced indexing of content which includes the full-text of astronomy and physics publications. The changes in the ADS platform affect all aspects of the system and its operations, including: the process through which data and metadata are harvested, curated and indexed; the interface and paradigm used for searching the database; and the follow-up analysis capabilities available to the users. This poster describes the choices behind the technical overhaul of the system, the technology stack used, and the opportunities which the upgrade is providing us with, namely gains in productivity and enhancements in our system capabilities.

  10. Critical gravity on AdS2 spacetimes

    NASA Astrophysics Data System (ADS)

    Myung, Yun Soo; Kim, Yong-Wan; Park, Young-Jai

    2011-09-01

    We study the critical gravity in two-dimensional anti-de Sitter (AdS2) spacetimes, which was obtained from the cosmological topologically massive gravity (TMGΛ) in three dimensions by using the Kaluza-Klein dimensional reduction. We perform the perturbation analysis around AdS2, which may correspond to the near-horizon geometry of the extremal Banados, Teitelboim, and Zanelli (BTZ) black hole obtained from the TMGΛ with identification upon uplifting three dimensions. A massive propagating scalar mode δF satisfies the second-order differential equation away from the critical point of K=l, whose solution is given by the Bessel functions. On the other hand, δF satisfies the fourth-order equation at the critical point. We exactly solve the fourth-order equation, and compare it with the log gravity in two dimensions. Consequently, the critical gravity in two dimensions could not be described by a massless scalar δFml and its logarithmic partner δFlog⁡4th.

  11. Conserved charges in timelike warped AdS3 spaces

    NASA Astrophysics Data System (ADS)

    Donnay, L.; Fernández-Melgarejo, J. J.; Giribet, G.; Goya, A.; Lavia, E.

    2015-06-01

    We consider the timelike version of warped anti-de Sitter space (WAdS), which corresponds to the three-dimensional section of the Gödel solution of four-dimensional cosmological Einstein equations. This geometry presents closed timelike curves (CTCs), which are inherited from its four-dimensional embedding. In three dimensions, this type of solution can be supported without matter provided the graviton acquires mass. Here, among the different ways to consistently give mass to the graviton in three dimensions, we consider the parity-even model known as new massive gravity (NMG). In the bulk of timelike WAdS3 space, we introduce defects that, from the three-dimensional point of view, represent spinning massive particlelike objects. For this type of source, we investigate the definition of quasilocal gravitational energy as seen from infinity, far beyond the region where the CTCs appear. We also consider the covariant formalism applied to NMG to compute the mass and the angular momentum of spinning particlelike defects and compare the result with the one obtained by means of the quasilocal stress tensor. We apply these methods to special limits in which the WAdS3 solutions coincide with locally AdS3 and locally AdS2×R spaces. Finally, we make some comments about the asymptotic symmetry algebra of asymptotically WAdS3 spaces in NMG.

  12. Primordial fluctuations from complex AdS saddle points

    NASA Astrophysics Data System (ADS)

    Hertog, Thomas; van der Woerd, Ellen

    2016-02-01

    One proposal for dS/CFT is that the Hartle-Hawking (HH) wave function in the large volume limit is equal to the partition function of a Euclidean CFT deformed by various operators. All saddle points defining the semiclassical HH wave function in cosmology have a representation in which their interior geometry is part of a Euclidean AdS domain wall with complex matter fields. We compute the wave functions of scalar and tensor perturbations around homogeneous isotropic complex saddle points, turning on single scalar field matter only. We compare their predictions for the spectra of CMB perturbations with those of a different dS/CFT proposal based on the analytic continuation of inflationary universes to real asymptotically AdS domain walls. We find the predictions of both bulk calculations agree to first order in the slow roll parameters, but there is a difference at higher order which, we argue, is a signature of the HH state of the fluctuations.

  13. Study of heat dissipation process from heat sink using lensless Fourier transform digital holographic interferometry.

    PubMed

    Kumar, Varun; Shakher, Chandra

    2015-02-20

    This paper presents the results of experimental investigations about the heat dissipation process of plate fin heat sink using digital holographic interferometry. Visual inspection of reconstructed phase difference maps of the air field around the heat sink with and without electric power in the load resistor provides qualitative information about the variation of temperature and the heat dissipation process. Quantitative information about the temperature distribution is obtained from the relationship between the digitally reconstructed phase difference map of ambient air and heated air. Experimental results are presented for different current and voltage in the load resistor to investigate the heat dissipation process. The effect of fin spacing on the heat dissipation performance of the heat sink is also investigated in the case of natural heat convection. From experimental data, heat transfer parameters, such as local heat flux and convective heat transfer coefficients, are also calculated. PMID:25968185

  14. Influence of coagulation factor x on in vitro and in vivo gene delivery by adenovirus (Ad) 5, Ad35, and chimeric Ad5/Ad35 vectors.

    PubMed

    Greig, Jenny A; Buckley, Suzanne Mk; Waddington, Simon N; Parker, Alan L; Bhella, David; Pink, Rebecca; Rahim, Ahad A; Morita, Takashi; Nicklin, Stuart A; McVey, John H; Baker, Andrew H

    2009-10-01

    The binding of coagulation factor X (FX) to the hexon of adenovirus (Ad) 5 is pivotal for hepatocyte transduction. However, vectors based on Ad35, a subspecies B Ad, are in development for cancer gene therapy, as Ad35 utilizes CD46 (which is upregulated in many cancers) for transduction. We investigated whether interaction of Ad35 with FX influenced vector tropism using Ad5, Ad35, and Ad5/Ad35 chimeras: Ad5/fiber(f)35, Ad5/penton(p)35/f35, and Ad35/f5. Surface plasmon resonance (SPR) revealed that Ad35 and Ad35/f5 bound FX with approximately tenfold lower affinities than Ad5 hexon-containing viruses, and electron cryomicroscopy (cryo-EM) demonstrated a direct Ad35 hexon:FX interaction. The presence of physiological levels of FX significantly inhibited transduction of vectors containing Ad35 fibers (Ad5/f35, Ad5/p35/f35, and Ad35) in CD46-positive cells. Vectors were intravenously administered to CD46 transgenic mice in the presence and absence of FX-binding protein (X-bp), resulting in reduced liver accumulation for all vectors. Moreover, Ad5/f35 and Ad5/p35/f35 efficiently accumulated in the lung, whereas Ad5 demonstrated poor lung targeting. Additionally, X-bp significantly reduced lung genome accumulation for Ad5/f35 and Ad5/p35/f35, whereas Ad35 was significantly enhanced. In summary, vectors based on the full Ad35 serotype will be useful vectors for selective gene transfer via CD46 due to a weaker FX interaction compared to Ad5. PMID:19603000

  15. Thermal Performance of a Multi-Evaporator Loop Heat Pipe with Thermal Masses and Thermoelectric Coolers

    NASA Technical Reports Server (NTRS)

    Ku, Jen-Tung; Ottenstein, Laura; Birur, Gajanana

    2004-01-01

    This paper describes thermal performance of a loop heat pipe (LHP) with two evaporators and two condensers in ambient testing. Each evaporator has an outer diameter of 15mm and a length of 76mm, and has an integral compensation chamber (CC). An aluminum mass of 500 grams is attached to each evaporator to simulate the instrument mass. A thermoelectric cooler (TEC) is installed on each CC to provide heating as well as cooling for CC temperature control. A flow regulator is installed in the condenser section to prevent vapor from going back to the evaporators in the event that one of the condensers is fully utilized. Ammonia was used as the working fluid. Tests conducted included start-up, power cycle, heat load sharing, sink temperature cycle, operating temperature control with TECs, and capillary limit tests. Experimental data showed that the loop could start with a heat load of less than 10W even with added thermal masses. The loop operated stably with even and uneven evaporator heat loads, and even and uneven condenser sink temperatures. The operating temperature could be controlled within +/- 0.5K of the set point temperature using either or both TECs, and the required TEC control heater power was less than 2W under most test conditions. Heat load sharing between the two evaporators was also successfully demonstrated. The loop had a heat transport capability of 120W to 140W, and could recover from a dry-out when the heat load was reduced. The 500-gram aluminum mass on each evaporator had a negligible effect on the loop operation. Existing LHPs servicing orbiting spacecraft have a single evaporator with an outer diameter of about 25mm. Important performance characteristics demonstrated by this LHP included: 1) Operation of an LHP with 15mm diameter evaporators; 2) Robustness and reliability of an LHP with multiple evaporators and multiple condensers under various test conditions; 3) Heat load sharing among LHP evaporators; 4) Effectiveness of TECs in controlling

  16. Aerosol Best Estimate Value-Added Product

    SciTech Connect

    Flynn, C; Turner, D; Koontz, A; Chand, D; Sivaraman, C

    2012-07-19

    The objective of the Aerosol Best Estimate (AEROSOLBE) value-added product (VAP) is to provide vertical profiles of aerosol extinction, single scatter albedo, asymmetry parameter, and Angstroem exponents for the atmospheric column above the Central Facility at the ARM Southern Great Plains (SGP) site. We expect that AEROSOLBE will provide nearly continuous estimates of aerosol optical properties under a range of conditions (clear, broken clouds, overcast clouds, etc.). The primary requirement of this VAP was to provide an aerosol data set as continuous as possible in both time and height for the Broadband Heating Rate Profile (BBHRP) VAP in order to provide a structure for the comprehensive assessment of our ability to model atmospheric radiative transfer for all conditions. Even though BBHRP has been completed, AEROSOLBE results are very valuable for environmental, atmospheric, and climate research.

  17. Load carriage, human performance, and employment standards.

    PubMed

    Taylor, Nigel A S; Peoples, Gregory E; Petersen, Stewart R

    2016-06-01

    The focus of this review is on the physiological considerations necessary for developing employment standards within occupations that have a heavy reliance on load carriage. Employees within military, fire fighting, law enforcement, and search and rescue occupations regularly work with heavy loads. For example, soldiers often carry loads >50 kg, whilst structural firefighters wear 20-25 kg of protective clothing and equipment, in addition to carrying external loads. It has long been known that heavy loads modify gait, mobility, metabolic rate, and efficiency, while concurrently elevating the risk of muscle fatigue and injury. In addition, load carriage often occurs within environmentally stressful conditions, with protective ensembles adding to the thermal burden of the workplace. Indeed, physiological strain relates not just to the mass and dimensions of carried objects, but to how those loads are positioned on and around the body. Yet heavy loads must be borne by men and women of varying body size, and with the expectation that operational capability will not be impinged. This presents a recruitment conundrum. How do employers identify capable and injury-resistant individuals while simultaneously avoiding discriminatory selection practices? In this communication, the relevant metabolic, cardiopulmonary, and thermoregulatory consequences of loaded work are reviewed, along with concomitant impediments to physical endurance and mobility. Also emphasised is the importance of including occupation-specific clothing, protective equipment, and loads during work-performance testing. Finally, recommendations are presented for how to address these issues when evaluating readiness for duty. PMID:27277563

  18. Adding value to your work.

    PubMed

    Chambers, D W

    1998-01-01

    Dentists and many staff enjoy characteristics of work associated with high levels of satisfaction and performance. Although value can be added to oral health care professionals' jobs through enlargement, enrichment, rotations, and autonomous work groups, there are limits to these techniques. Controlling work performance by means of rewards is risky. Probably the most effective means of adding value to jobs is through the Quality of Work Life approach, concentrating on job design and placement to make work meaningful and autonomous and to provide feedback. PMID:9697373

  19. Receiver-Based Ad Hoc On Demand Multipath Routing Protocol for Mobile Ad Hoc Networks

    PubMed Central

    Al-Nahari, Abdulaziz; Mohamad, Mohd Murtadha

    2016-01-01

    Decreasing the route rediscovery time process in reactive routing protocols is challenging in mobile ad hoc networks. Links between nodes are continuously established and broken because of the characteristics of the network. Finding multiple routes to increase the reliability is also important but requires a fast update, especially in high traffic load and high mobility where paths can be broken as well. The sender node keeps re-establishing path discovery to find new paths, which makes for long time delay. In this paper we propose an improved multipath routing protocol, called Receiver-based ad hoc on demand multipath routing protocol (RB-AOMDV), which takes advantage of the reliability of the state of the art ad hoc on demand multipath distance vector (AOMDV) protocol with less re-established discovery time. The receiver node assumes the role of discovering paths when finding data packets that have not been received after a period of time. Simulation results show the delay and delivery ratio performances are improved compared with AOMDV. PMID:27258013

  20. Receiver-Based Ad Hoc On Demand Multipath Routing Protocol for Mobile Ad Hoc Networks.

    PubMed

    Al-Nahari, Abdulaziz; Mohamad, Mohd Murtadha

    2016-01-01

    Decreasing the route rediscovery time process in reactive routing protocols is challenging in mobile ad hoc networks. Links between nodes are continuously established and broken because of the characteristics of the network. Finding multiple routes to increase the reliability is also important but requires a fast update, especially in high traffic load and high mobility where paths can be broken as well. The sender node keeps re-establishing path discovery to find new paths, which makes for long time delay. In this paper we propose an improved multipath routing protocol, called Receiver-based ad hoc on demand multipath routing protocol (RB-AOMDV), which takes advantage of the reliability of the state of the art ad hoc on demand multipath distance vector (AOMDV) protocol with less re-established discovery time. The receiver node assumes the role of discovering paths when finding data packets that have not been received after a period of time. Simulation results show the delay and delivery ratio performances are improved compared with AOMDV. PMID:27258013

  1. Underworld and multi-basin heat flow

    NASA Astrophysics Data System (ADS)

    Quenette, S. M.; O'Neill, C.; Moresi, L. N.; Danis, C. R.; Mansour, J.

    2011-12-01

    We present an over arching method for non-linear heat flow assessments of large, multi-basin systems. Our example is the Sydney-, Gunnedah-, Bowen basins (Danis et al 2011), which covers an area of 800kms by 1900kms and depth of 5kms, on the east coast of Australia. It is used as a baseline towards further fluid and structural geodynamics oriented analysis. In contrast to reservoir scale geothermal models - basin, multi-basin and towards lithosphere scale models exhibit their own challenges in terms of physical/rheological behaviour and computational tractability. For instance we model a non-linear heat flow by means of temperature dependent conductivity, as indicated by Clauser and Huenges (1995), which allows crystalline basement rocks, such as granites, to show for example a significant decrease in conductivity from ambient temperature up to around 400C, dropping from around 3 mK**(units) to around 2. For this modelling, a specialisation of the geodynamics code 'Underworld' (Moresi et al 2007) called Underworld-GT is used. A toolbox is added to the otherwise un-touched Underworld code adding geothermal workflow and context to Underworld. A particular novel feature is the ability to load stratigraphic layers, and/or GoCAD or GeoModeller voxel sets as the constraining geological geometry, whilst allowing the heat assessment models to scale from 1 process to 1000s. Another is the ability to prescribe synthetic drill holes, and its use in stochastic-oriented assessments of model parameters. Following the Underworld platform's approach and its simple PDE abstraction layer, these model configurations from a baseline for further additions to the governing equations such as fluid flow and structure, enabling a bridge between reservoir and continental scale dynamics, albeit with their own computational challenges.

  2. Phase-Change Heat-Storage Module

    NASA Technical Reports Server (NTRS)

    Mulligan, James C.

    1989-01-01

    Heat-storage module accommodates momentary heating or cooling overload in pumped-liquid heat-transfer system. Large heat-storage capacity of module provided by heat of fusion of material that freezes at or near temperature desired to maintain object to be heated or cooled. Module involves relatively small penalties in weight, cost, and size and more than compensates by enabling design of rest of system to handle only average load. Latent heat of fusion of phase-change material provides large heat-storage capacity in small volume.

  3. Psychometric examination and validation of the aggressive driving scale (ADS).

    PubMed

    Zhang, Yiqi; Houston, Rebecca; Wu, Changxu

    2016-07-01

    Aggressive driving behavior is an important cause of traffic accidents. Based on the recent view that aggressive driving is one way that trait aggression manifests itself, a growing research area has focused on the development of scales to assess aggressive driving. The aggressive driving scale (ADS) analyzed in the present study consists of 24 items. A sample of 276 participants was analyzed to obtain the factor structure and reliability of the ADS and 67 of them participated in the behavioral experiment in order to examine the construct and predictive validity of the scale. Results indicated a 3-factor structure (interference with other drivers, violations/risk taking, and anger/aggression expression behavior) with high item loadings. The ADS had high internal consistency and test-retest reliability. Construct validity of the ADS was established as the ADS subscale scores correlated significantly with trait measures of anger and aggression. Predictive validity of the ADS was verified as most items were significantly correlated with behavioral measures derived from a driving simulator. The ADS was a significant predictor of behavioral measures both in the simulated environment (i.e., frequency of driving off the road, red light running behavior, frequency of colliding with a vehicle, frequency and distance of over speeding, frequency and distance of central crossing) and reported real world situations (i.e., annual moving violations and accidents). These results suggest that the ADS is a reliable and valid tool in evaluating aggressive driving behavior as the current study provides behavioral support for the effectiveness of the ADS in measuring aggressive driving behavior. Aggr. Behav. 42:313-323, 2016. © 2016 Wiley Periodicals, Inc. PMID:26848038

  4. Heat pipe radiator. [for spacecraft waste heat rejection

    NASA Technical Reports Server (NTRS)

    Swerdling, B.; Alario, J.

    1973-01-01

    A 15,000 watt spacecraft waste heat rejection system utilizing heat pipe radiator panels was investigated. Of the several concepts initially identified, a series system was selected for more in-depth analysis. As a demonstration of system feasibility, a nominal 500 watt radiator panel was designed, built and tested. The panel, which is a module of the 15,000 watt system, consists of a variable conductance heat pipe (VCHP) header, and six isothermalizer heat pipes attached to a radiating fin. The thermal load to the VCHP is supplied by a Freon-21 liquid loop via an integral heat exchanger. Descriptions of the results of the system studies and details of the radiator design are included along with the test results for both the heat pipe components and the assembled radiator panel. These results support the feasibility of using heat pipes in a spacecraft waste heat rejection system.

  5. Basic investigations on heat pumps, volume 2

    NASA Astrophysics Data System (ADS)

    Dick, H. G.; Nguyen, D. D.; Paul, J.; Reichelt, J.; Renz, M.; Tolle, A.

    1980-12-01

    Computer programs that determine the basic characteristics of heat pumps for different refrigerants and the interference between refrigerant and oil, and especially reciprocating compressors for heat pumps, are presented. The influence of electric-motor cooling, lubrication, different refrigerants, speed control and partial-load behavior of heat exchangers are emphasized. Mixtures of solvents and refrigerants for absorption heat pumps were studied and additional measurements for heat pump operation were carried out.

  6. Higher-derivative superparticle in AdS3 space

    NASA Astrophysics Data System (ADS)

    Kozyrev, Nikolay; Krivonos, Sergey; Lechtenfeld, Olaf

    2016-03-01

    Employing the coset approach we construct component actions for a superparticle moving in AdS3 with N =(2 ,0 ), D =3 supersymmetry partially broken to N =2 , d =1 . These actions may contain higher time-derivative terms, which are chosen to possess the same (super)symmetries as the free superparticle. In terms of the nonlinear-realization superfields, the component actions always take a simpler form when written in terms of covariant Cartan forms. We also consider in detail the reduction to the nonrelativistic case and construct the corresponding action of a Newton-Hooke superparticle and its higher-derivative generalizations. The structure of these higher time-derivative generalizations is completely fixed by invariance under the supersymmetric Newton-Hooke algebra extended by two central charges.

  7. Aspects of warped AdS3/CFT2 correspondence

    NASA Astrophysics Data System (ADS)

    Chen, Bin; Zhang, Jia-Ju; Zhang, Jian-Dong; Zhong, De-Liang

    2013-04-01

    In this paper we apply the thermodynamics method to investigate the holographic pictures for the BTZ black hole, the spacelike and the null warped black holes in three-dimensional topologically massive gravity (TMG) and new massive gravity (NMG). Even though there are higher derivative terms in these theories, the thermodynamics method is still effective. It gives consistent results with the ones obtained by using asymptotical symmetry group (ASG) analysis. In doing the ASG analysis we develop a brute-force realization of the Barnich-Brandt-Compere formalism with Mathematica code, which also allows us to calculate the masses and the angular momenta of the black holes. In particular, we propose the warped AdS3/CFT2 correspondence in the new massive gravity, which states that quantum gravity in the warped spacetime could holographically dual to a two-dimensional CFT with {c_R}={c_L}=24 /{Gm{β^2√{{2( {21-4{β^2}} )}}}}.

  8. Vortex hair on AdS black holes

    NASA Astrophysics Data System (ADS)

    Gregory, Ruth; Gustainis, Peter C.; Kubizňák, David; Mann, Robert B.; Wills, Danielle

    2014-11-01

    We analyse vortex hair for charged rotating asymptotically AdS black holes in the abelian Higgs model. We give analytical and numerical arguments to show how the vortex interacts with the horizon of the black hole, and how the solution extends to the boundary. The solution is very close to the corresponding asymptotically flat vortex, once one transforms to a frame that is non-rotating at the boundary. We show that there is a Meissner effect for extremal black holes, with the vortex flux being expelled from sufficiently small black holes. The phase transition is shown to be first order in the presence of rotation, but second order without rotation. We comment on applications to holography.

  9. An investigation of AdS2 backreaction and holography

    NASA Astrophysics Data System (ADS)

    Engelsöy, Julius; Mertens, Thomas G.; Verlinde, Herman

    2016-07-01

    We investigate a dilaton gravity model in AdS2 proposed by Almheiri and Polchinski [1] and develop a 1d effective description in terms of a dynamical boundary time with a Schwarzian derivative action. We show that the effective model is equivalent to a 1d version of Liouville theory, and investigate its dynamics and symmetries via a standard canonical framework. We include the coupling to arbitrary conformal matter and analyze the effective action in the presence of possible sources. We compute commutators of local operators at large time separation, and match the result with the time shift due to a gravitational shockwave interaction. We study a black hole evaporation process and comment on the role of entropy in this model.

  10. On thermodynamics of charged AdS black holes in extended phases space via M2-branes background

    NASA Astrophysics Data System (ADS)

    Chabab, M.; El Moumni, H.; Masmar, K.

    2016-06-01

    Motivated by a recent work on asymptotically AdS_4 black holes in M-theory, we investigate both thermodynamics and the thermodynamical geometry of Reissner-Nordstrom-AdS black holes from M2-branes. More precisely, we study AdS black holes in AdS4× S7, with the number of M2-branes interpreted as a thermodynamical variable. In this context, we calculate various thermodynamical quantities including the chemical potential, and examine their phase transitions along with the corresponding stability behaviors. In addition, we also evaluate the thermodynamical curvatures of the Weinhold, Ruppeiner, and Quevedo metrics for M2-branes geometry to study the stability of such a black object. We show that the singularities of these scalar curvature's metrics reproduce similar stability results to those obtained by the phase transition diagram via the heat capacities in different ensembles either when the number of the M2 branes or the charge is held fixed. Also, we note that all results derived in Belhaj et al. (Eur Phys J C 76(2):73, 2016) are recovered in the limit of the vanishing charge.

  11. Heat Without Heat

    NASA Astrophysics Data System (ADS)

    Lubkin, Elihu

    1997-04-01

    Logic of the Second Law of Thermodynamics demands acquisition of naked entropy. Accordingly, the leanest liaison between systems is not a diathermic membrane, it is a purely informational tickler, leaking no appreciable energy. The subsystem here is a thermodynamic universe, which gets `heated' entropically, yet without gaining calories. Quantum Mechanics graciously supports that(Lubkin, E. and Lubkin, T., International Journal of Theoretical Physics,32), 933-943 (1993) (at a cost of about 1 bit) through entanglement---across this least permeable of membranes---with what is beyond that universe. Heat without heat(Also v. forthcoming Proceedings of the 4th Drexel University Conference of September 1994) is the aspirin for Boltzmann's headache, conserving entropy in mechanical isolation, even while increasing entropy in thermodynamic isolation.

  12. Systematics of Coupling Flows in AdS Backgrounds

    SciTech Connect

    Goldberger, Walter D.; Rothstein, Ira Z.

    2003-03-18

    We give an effective field theory derivation, based on the running of Planck brane gauge correlators, of the large logarithms that arise in the predictions for low energy gauge couplings in compactified AdS}_5 backgrounds, including the one-loop effects of bulk scalars, fermions, and gauge bosons. In contrast to the case of charged scalars coupled to Abelian gauge fields that has been considered previously in the literature, the one-loop corrections are not dominated by a single 4D Kaluza-Klein mode. Nevertheless, in the case of gauge field loops, the amplitudes can be reorganized into a leading logarithmic contribution that is identical to the running in 4D non-Abelian gauge theory, and a term which is not logarithmically enhanced and is analogous to a two-loop effect in 4D. In a warped GUT model broken by the Higgs mechanism in the bulk,we show that the matching scale that appears in the large logarithms induced by the non-Abelian gauge fields is m_{XY}^2/k where m_{XY} is the bulk mass of the XY bosons and k is the AdS curvature. This is in contrast to the UV scale in the logarithmic contributions of scalars, which is simply the bulk mass m. Our results are summarized in a set of simple rules that can be applied to compute the leading logarithmic predictions for coupling constant relations within a given warped GUT model. We present results for both bulk Higgs and boundary breaking of the GUT gauge

  13. Holography beyond conformal invariance and AdS isometry?

    SciTech Connect

    Barvinsky, A. O.

    2015-03-15

    We suggest that the principle of holographic duality be extended beyond conformal invariance and AdS isometry. Such an extension is based on a special relation between functional determinants of the operators acting in the bulk and on its boundary, provided that the boundary operator represents the inverse propagators of the theory induced on the boundary by the Dirichlet boundary value problem in the bulk spacetime. This relation holds for operators of a general spin-tensor structure on generic manifolds with boundaries irrespective of their background geometry and conformal invariance, and it apparently underlies numerous O(N{sup 0}) tests of the AdS/CFT correspondence, based on direct calculation of the bulk and boundary partition functions, Casimir energies, and conformal anomalies. The generalized holographic duality is discussed within the concept of the “double-trace” deformation of the boundary theory, which is responsible in the case of large-N CFT coupled to the tower of higher-spin gauge fields for the renormalization group flow between infrared and ultraviolet fixed points. Potential extension of this method beyond the one-loop order is also briefly discussed.

  14. Holography beyond conformal invariance and AdS isometry?

    NASA Astrophysics Data System (ADS)

    Barvinsky, A. O.

    2015-03-01

    We suggest that the principle of holographic duality be extended beyond conformal invariance and AdS isometry. Such an extension is based on a special relation between functional determinants of the operators acting in the bulk and on its boundary, provided that the boundary operator represents the inverse propagators of the theory induced on the boundary by the Dirichlet boundary value problem in the bulk spacetime. This relation holds for operators of a general spin-tensor structure on generic manifolds with boundaries irrespective of their background geometry and conformal invariance, and it apparently underlies numerous O( N 0) tests of the AdS/CFT correspondence, based on direct calculation of the bulk and boundary partition functions, Casimir energies, and conformal anomalies. The generalized holographic duality is discussed within the concept of the "double-trace" deformation of the boundary theory, which is responsible in the case of large- N CFT coupled to the tower of higher-spin gauge fields for the renormalization group flow between infrared and ultraviolet fixed points. Potential extension of this method beyond the one-loop order is also briefly discussed.

  15. Islands of stability and recurrence times in AdS

    NASA Astrophysics Data System (ADS)

    Green, Stephen R.; Maillard, Antoine; Lehner, Luis; Liebling, Steven L.

    2015-10-01

    We study the stability of anti-de Sitter (AdS) spacetime to spherically symmetric perturbations of a real scalar field in general relativity. Further, we work within the context of the "two time framework" (TTF) approximation, which describes the leading nonlinear effects for small amplitude perturbations, and is therefore suitable for studying the weakly turbulent instability of AdS—including both collapsing and noncollapsing solutions. We have previously identified a class of quasiperiodic (QP) solutions to the TTF equations, and in this paper we analyze their stability. We show that there exist several families of QP solutions that are stable to linear order, and we argue that these solutions represent islands of stability in TTF. We extract the eigenmodes of small oscillations about QP solutions, and we use them to predict approximate recurrence times for generic noncollapsing initial data in the full (non-TTF) system. Alternatively, when sufficient energy is driven to high-frequency modes, as occurs for initial data far from a QP solution, the TTF description breaks down as an approximation to the full system. Depending on the higher order dynamics of the full system, this often signals an imminent collapse to a black hole.

  16. Heat transfer during evaporation on a small surface (Review)

    NASA Astrophysics Data System (ADS)

    Tolubinskii, V. I.; Antonenko, V. A.; Kudritskii, G. R.; Ostrovskii, Iu. N.

    Experimental data in the literature on the intensity of heat transfer and critical heat loads associated with the boiling of a liquid on a small surface are examined. Various methods for intensifying heat transfer are discussed. Expressions are presented for calculating heat transfer coefficients and critical heat flux densities.

  17. Effects of dehydration and heat stress on food intake and dry matter digestibility in East African ruminants.

    PubMed

    Maloiy, G M O; Kanui, T I; Towett, P K; Wambugu, S N; Miaron, J O; Wanyoike, M M

    2008-10-01

    Comparative investigations were made between wild and domestic ruminants from arid and semi-arid regions and those species from non-arid areas in an attempt to evaluate the adaptations of these ruminants in terms of the effects of heat stress and dehydration on food intake and digestibility. The effect of (a) an intermittent heat load (a daily light cycle of 12 h at 22 degrees C and 12 h at 40 degrees C) compared to 22 degrees C throughout the day and (b) dehydration level of 15% weight loss, with and without the heat load, on the intake and digestibility of a poor quality hay was investigated in the Grant's gazelle, Oryx, the domestic Turkana goats, fat-tailed sheep, zebu cattle, Thomson's gazelle and wildebeest. The intermittent heat load with water available ad libitum depressed the food intake of zebu cattle and Turkana goats by more than 40%. It had no significant effect on the food intake of the other species. The Thomson's and Grants gazelle, oryx, wildebeest and fat-tailed sheep appear well adapted to withstanding a periodic heat load. Dehydration at 22 degrees C caused a marked depression on food intake of all the species investigated. Dehydration together with a heat load caused no further reduction in the food intake by the Grants's gazelle, oryx, and goats but it did cause a further reduction in the intake in the other species. The small non-domestic ruminants (i.e. Grant's and Thomson's gazelle) appear much more digestive efficient than any of their domestic counterpart. PMID:18644247

  18. Turbine modifications for district heating

    SciTech Connect

    Sawhney, H.S.; Oliker, I.; Silaghy, F.J.

    1983-01-01

    This paper discusses the technical and economic feasibilities of retrofitting existing turbine-generators and replacing existing turbine-generators with specially designed district heating units. Topics considered include turbine retrofit options (approach and design criteria, district heating equipment), new district heating turbines (approach and design criteria, turbine selection), and heat generation costs. The conclusions of the analysis include: no technical barrier was discovered for converting the Potomac River Power Plant to a cogeneration facility, additional equipment required for the district heating operation is of conventional design, the existing steam turbines and associated system components can be retrofitted for district heating operation, the modified units retain the flexibility of producing 100% electric power output when the district heating load is disconnected, the district heating system uses indirect heating of water by extraction steam (the purity of which is not degraded), about three and a half times more heat can be extracted from units designed specifically for cogeneration than from modified units, and the described methodology can be used for the assessment of retrofitting existing units to cogeneration operation for power plants located close to heat load centers.

  19. Symplastic phloem loading in poplar.

    PubMed

    Zhang, Cankui; Han, Lu; Slewinski, Thomas L; Sun, Jianlei; Zhang, Jing; Wang, Zeng-Yu; Turgeon, Robert

    2014-09-01

    Sap is driven through phloem sieve tubes by an osmotically generated pressure gradient between source and sink tissues. In many plants, source pressure results from thermodynamically active loading in which energy is used to transfer sucrose (Suc) from mesophyll cells to the phloem of leaf minor veins against a concentration gradient. However, in some species, almost all trees, correlative evidence suggests that sugar migrates passively through plasmodesmata from mesophyll cells into the sieve elements. The possibility of alternate loading mechanisms has important ramifications for the regulation of phloem transport and source-sink interactions. Here, we provide experimental evidence that, in gray poplar (Populus tremula × Populus alba), Suc enters the phloem through plasmodesmata. Transgenic plants were generated with yeast invertase in the cell walls to prevent Suc loading by this route. The constructs were driven either by the constitutive 35S promoter or the minor vein-specific galactinol synthase promoter. Transgenic plants grew at the same rate as the wild type without symptoms of loading inhibition, such as accumulation of carbohydrates or leaf chlorosis. Rates of photosynthesis were normal. In contrast, alfalfa (Medicago sativa) plants, which have limited numbers of plasmodesmata between mesophyll and phloem, displayed typical symptoms of loading inhibition when transformed with the same DNA constructs. The results are consistent with passive loading of Suc through plasmodesmata in poplar. We also noted defense-related symptoms in leaves of transgenic poplar when the plants were abruptly exposed to excessively high temperatures, adding to evidence that hexose is involved in triggering the hypersensitive response. PMID:25056922

  20. Scattering States in AdS/CFT

    SciTech Connect

    Fitzpatrick, A.Liam; Kaplan, Jared; /SLAC

    2012-02-14

    We show that suitably regulated multi-trace primary states in large N CFTs behave like 'in' and 'out' scattering states in the flat-space limit of AdS. Their transition matrix elements approach the exact scattering amplitudes for the bulk theory, providing a natural CFT definition of the flat space S-Matrix. We study corrections resulting from the AdS curvature and particle propagation far from the center of AdS, and show that AdS simply provides an IR regulator that disappears in the flat space limit.

  1. An Evaluation of the HVAC Load Potential for Providing Load Balancing Service

    SciTech Connect

    Lu, Ning

    2012-09-30

    This paper investigates the potential of providing aggregated intra-hour load balancing services using heating, ventilating, and air-conditioning (HVAC) systems. A direct-load control algorithm is presented. A temperature-priority-list method is used to dispatch the HVAC loads optimally to maintain consumer-desired indoor temperatures and load diversity. Realistic intra-hour load balancing signals were used to evaluate the operational characteristics of the HVAC load under different outdoor temperature profiles and different indoor temperature settings. The number of HVAC units needed is also investigated. Modeling results suggest that the number of HVACs needed to provide a {+-}1-MW load balancing service 24 hours a day varies significantly with baseline settings, high and low temperature settings, and the outdoor temperatures. The results demonstrate that the intra-hour load balancing service provided by HVAC loads meet the performance requirements and can become a major source of revenue for load-serving entities where the smart grid infrastructure enables direct load control over the HAVC loads.

  2. ADS's Dexter Data Extraction Applet

    NASA Astrophysics Data System (ADS)

    Demleitner, M.; Accomazzi, A.; Eichhorn, G.; Grant, C. S.; Kurtz, M. J.; Murray, S. S.

    The NASA Astrophysics Data System (ADS) now holds 1.3 million scanned pages, containing numerous plots and figures for which the original data sets are lost or inaccessible. The availability of scans of the figures can significantly ease the regeneration of the data sets. For this purpose, the ADS has developed Dexter, a Java applet that supports the user in this process. Dexter's basic functionality is to let the user manually digitize a plot by marking points and defining the coordinate transformation from the logical to the physical coordinate system. Advanced features include automatic identification of axes, tracing lines and finding points matching a template. This contribution both describes the operation of Dexter from a user's point of view and discusses some of the architectural issues we faced during implementation.

  3. Realizing "value-added" metrology

    NASA Astrophysics Data System (ADS)

    Bunday, Benjamin; Lipscomb, Pete; Allgair, John; Patel, Dilip; Caldwell, Mark; Solecky, Eric; Archie, Chas; Morningstar, Jennifer; Rice, Bryan J.; Singh, Bhanwar; Cain, Jason; Emami, Iraj; Banke, Bill, Jr.; Herrera, Alfredo; Ukraintsev, Vladamir; Schlessinger, Jerry; Ritchison, Jeff

    2007-03-01

    The conventional premise that metrology is a "non-value-added necessary evil" is a misleading and dangerous assertion, which must be viewed as obsolete thinking. Many metrology applications are key enablers to traditionally labeled "value-added" processing steps in lithography and etch, such that they can be considered integral parts of the processes. Various key trends in modern, state-of-the-art processing such as optical proximity correction (OPC), design for manufacturability (DFM), and advanced process control (APC) are based, at their hearts, on the assumption of fine-tuned metrology, in terms of uncertainty and accuracy. These trends are vehicles where metrology thus has large opportunities to create value through the engineering of tight and targetable process distributions. Such distributions make possible predictability in speed-sorts and in other parameters, which results in high-end product. Additionally, significant reliance has also been placed on defect metrology to predict, improve, and reduce yield variability. The necessary quality metrology is strongly influenced by not only the choice of equipment, but also the quality application of these tools in a production environment. The ultimate value added by metrology is a result of quality tools run by a quality metrology team using quality practices. This paper will explore the relationships among present and future trends and challenges in metrology, including equipment, key applications, and metrology deployment in the manufacturing flow. Of key importance are metrology personnel, with their expertise, practices, and metrics in achieving and maintaining the required level of metrology performance, including where precision, matching, and accuracy fit into these considerations. The value of metrology will be demonstrated to have shifted to "key enabler of large revenues," debunking the out-of-date premise that metrology is "non-value-added." Examples used will be from critical dimension (CD

  4. Solar thermal heating and cooling. A bibliography with abstracts

    NASA Technical Reports Server (NTRS)

    Arenson, M.

    1979-01-01

    This bibliographic series cites and abstracts the literature and technical papers on the heating and cooling of buildings with solar thermal energy. Over 650 citations are arranged in the following categories: space heating and cooling systems; space heating and cooling models; building energy conservation; architectural considerations, thermal load computations; thermal load measurements, domestic hot water, solar and atmospheric radiation, swimming pools; and economics.

  5. 29 CFR 1919.36 - Heat treatment.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 29 Labor 7 2013-07-01 2013-07-01 false Heat treatment. 1919.36 Section 1919.36 Labor Regulations...) GEAR CERTIFICATION Certification of Vessels: Tests and Proof Loads; Heat Treatment; Competent Persons § 1919.36 Heat treatment. (a) The annealing of wrought iron gear required by this part shall...

  6. 29 CFR 1919.36 - Heat treatment.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 7 2011-07-01 2011-07-01 false Heat treatment. 1919.36 Section 1919.36 Labor Regulations...) GEAR CERTIFICATION Certification of Vessels: Tests and Proof Loads; Heat Treatment; Competent Persons § 1919.36 Heat treatment. (a) The annealing of wrought iron gear required by this part shall...

  7. 29 CFR 1919.36 - Heat treatment.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 7 2010-07-01 2010-07-01 false Heat treatment. 1919.36 Section 1919.36 Labor Regulations...) GEAR CERTIFICATION Certification of Vessels: Tests and Proof Loads; Heat Treatment; Competent Persons § 1919.36 Heat treatment. (a) The annealing of wrought iron gear required by this part shall...

  8. 29 CFR 1919.36 - Heat treatment.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 7 2012-07-01 2012-07-01 false Heat treatment. 1919.36 Section 1919.36 Labor Regulations...) GEAR CERTIFICATION Certification of Vessels: Tests and Proof Loads; Heat Treatment; Competent Persons § 1919.36 Heat treatment. (a) The annealing of wrought iron gear required by this part shall...

  9. 29 CFR 1919.36 - Heat treatment.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 7 2014-07-01 2014-07-01 false Heat treatment. 1919.36 Section 1919.36 Labor Regulations...) GEAR CERTIFICATION Certification of Vessels: Tests and Proof Loads; Heat Treatment; Competent Persons § 1919.36 Heat treatment. (a) The annealing of wrought iron gear required by this part shall...

  10. Heat Treatment Procedure Qualification -- Final Technical Report

    SciTech Connect

    Robert C. Voigt

    2004-10-15

    Heat treatment practices used by steel foundries have been carefully studied as part of comprehensive heat treatment procedure development trials. These studies highlight the relationships between critical heat treatment process control parameters and heat treatment success. Foundry heat treatment trials to develop heat treatment procedure qualification have shed light on the relationship between heat treatment theory and current practices. Furnace load time-temperature profiles in steel foundries exhibit significant differences depending on heat treatment equipment, furnace loading practice, and furnace maintenance. Time-temperature profiles of the furnace control thermocouples can be very different from the time-temperature profiles observed at the center of casting loads in the furnace. Typical austenitrization temperatures and holding times used by steel foundries far exceed what is required for transformation to austenite. Quenching and hardenability concepts were also investigated. Heat treatment procedure qualification (HTPQ) schema to demonstrate heat treatment success and to pre-qualify other alloys and section sizes requiring lesser hardenability have been developed. Tempering success is dependent on both tempering time and temperature. As such, furnace temperature uniformity and control of furnace loading during tempering is critical to obtain the desired mechanical properties. The ramp-up time in the furnace prior to the establishment of steady state heat treatment conditions contributes to the extent of heat treatment performed. This influence of ramp-up to temperature during tempering has been quantified.

  11. Heat Treatment Procedure Qualification for Steel Castings

    SciTech Connect

    Mariol Charles; Nicholas Deskevich; Vipin Varkey; Robert Voigt; Angela Wollenburg

    2004-04-29

    Heat treatment practices used by steel foundries have been carefully studied as part of comprehensive heat treatment procedure qualification development trials. These studies highlight the relationships between critical heat treatment process control parameters and heat treatment success. Foundry heat treatment trials to develop heat treatment procedure qualifications have shed light on the relationship between heat treatment theory and current practices. Furnace load time-temperature profiles in steel foundries exhibit significant differences depending on heat treatment equipment, furnace loading practice, and furnace maintenance. Time-temperature profiles of furnace control thermocouples can be very different from the time-temperature profiles observed at the center of casting loads in the furnace. Typical austenitization temperatures and holding times used by steel foundries far exceed what is required for transformation to austenite. Quenching and hardenability concepts were also investigated. Heat treatment procedure qualification (HTPQ) schema to demonstrate heat treatment success and to pre-qualify other alloys and section sizes requiring lesser hardenability have been developed. Tempering success is dependent on both tempering time and temperature. As such, furnace temperature uniformity and control of furnace loading during tempering is critical to obtain the desired mechanical properties. The ramp-up time in the furnace prior to the establishment of steady state heat treatment conditions contributes to the extent of heat treatment performed. This influence of ramp-up to temperature during tempering has been quantified.

  12. Missing top of the AdS resonance structure

    NASA Astrophysics Data System (ADS)

    Yang, I.-Sheng

    2015-03-01

    We study a massless scalar field in AdSd +1 with a nonlinear coupling ϕN and not limited to spherical symmetry. The free-field-eigenstate spectrum is strongly resonant, and it is commonly believed that the nonlinear coupling leads to energy transfer between eigenstates. We prove that when N d is even, the most efficient resonant channels to transfer energy are always absent. In particular, for N =3 this means no energy transfer at all. For N =4 , this effectively kills half of the channels, leading to the same set of extra conservation laws recently derived for gravitational interactions within spherical symmetry.

  13. Magnetic mass in 4D AdS gravity

    NASA Astrophysics Data System (ADS)

    Araneda, René; Aros, Rodrigo; Miskovic, Olivera; Olea, Rodrigo

    2016-04-01

    We provide a fully covariant expression for the diffeomorphic charge in four-dimensional anti-de Sitter gravity, when the Gauss-Bonnet and Pontryagin terms are added to the action. The couplings of these topological invariants are such that the Weyl tensor and its dual appear in the on-shell variation of the action and such that the action is stationary for asymptotic (anti-)self-dual solutions in the Weyl tensor. In analogy with Euclidean electromagnetism, whenever the self-duality condition is global, both the action and the total charge are identically vanishing. Therefore, for such configurations, the magnetic mass equals the Ashtekhar-Magnon-Das definition.

  14. Canonical energy and hairy AdS black holes

    NASA Astrophysics Data System (ADS)

    Hyun, Seungjoon; Park, Sang-A.; Yi, Sang-Heon

    2016-08-01

    We propose the modified version of the canonical energy which was introduced originally by Hollands and Wald. Our construction depends only on the Euler-Lagrange expression of the system and thus is independent of the ambiguity in the Lagrangian. After some comments on our construction, we briefly mention on the relevance of our construction to the boundary information metric in the context of the AdS/CFT correspondence. We also study the stability of three-dimensional hairy extremal black holes by using our construction.

  15. Plutonium immobilization -- Can loading

    SciTech Connect

    Kriikku, E.

    2000-02-17

    The Savannah River Site (SRS) will immobilize excess plutonium in the proposed Plutonium Immobilization Project (PIP). The PIP adds the excess plutonium to ceramic pucks, loads the pucks into cans, and places the cans into DWPF canisters. This paper discusses the PIP process steps, the can loading conceptual design, can loading equipment design, and can loading work completed.

  16. Heat Recovery in Building Envelopes

    SciTech Connect

    Sherman, Max H.; Walker, Iain S.

    2001-01-01

    Infiltration has traditionally been assumed to contribute to the energy load of a building by an amount equal to the product of the infiltration flow rate and the enthalpy difference between inside and outside. Application of such a simple formula may produce an unreasonably high contribution because of heat recovery within the building envelope. Previous laboratory and simulation research has indicated that such heat transfer between the infiltrating air and walls may be substantial. In this study, Computational Fluid Dynamics was used to simulate sensible heat transfer in typical envelope constructions. The results show that the traditional method may over-predict the infiltration energy load by up to 95 percent at low leakage rates. A simplified physical model has been developed and used to predict the infiltration heat recovery based on the Peclet number of the flow and the fraction of the building envelope active in infiltration heat recovery.

  17. Detection of Periodic Beacon Loads in Electrical Distribution Substation Data

    SciTech Connect

    Hammerstrom, Donald J.; Guttromson, Ross T.; Lu, Ning; Boyd, Paul A.; Trudnowski, Daniel; Chassin, David P.; Bonebrake, Christopher A.; Shaw, James M.

    2006-05-31

    This research explores methods for identifying a whether a load is sending a signal to the utility SCADA system. Such a system can identify whether various loads are signialing using existing SCADA infrastructure, that is, without added, high cost communications infrastructure.

  18. Solar-powered Rankine heat pump for heating and cooling

    NASA Technical Reports Server (NTRS)

    Rousseau, J.

    1978-01-01

    The design, operation and performance of a familyy of solar heating and cooling systems are discussed. The systems feature a reversible heat pump operating with R-11 as the working fluid and using a motor-driven centrifugal compressor. In the cooling mode, solar energy provides the heat source for a Rankine power loop. The system is operational with heat source temperatures ranging from 155 to 220 F; the estimated coefficient of performance is 0.7. In the heating mode, the vapor-cycle heat pump processes solar energy collected at low temperatures (40 to 80 F). The speed of the compressor can be adjusted so that the heat pump capacity matches the load, allowing a seasonal coefficient of performance of about 8 to be attained.

  19. The ADS All Sky Survey

    NASA Astrophysics Data System (ADS)

    Goodman, Alyssa

    We will create the first interactive sky map of astronomers' understanding of the Universe over time. We will accomplish this goal by turning the NASA Astrophysics Data System (ADS), widely known for its unrivaled value as a literature resource, into a data resource. GIS and GPS systems have made it commonplace to see and explore information about goings-on on Earth in the context of maps and timelines. Our proposal shows an example of a program that lets a user explore which countries have been mentioned in the New York Times, on what dates, and in what kinds of articles. By analogy, the goal of our project is to enable this kind of exploration-on the sky-for the full corpus of astrophysical literature available through ADS. Our group's expertise and collaborations uniquely position us to create this interactive sky map of the literature, which we call the "ADS All-Sky Survey." To create this survey, here are the principal steps we need to follow. First, by analogy to "geotagging," we will "astrotag," the ADS literature. Many "astrotags" effectively already exist, thanks to curation efforts at both CDS and NED. These efforts have created links to "source" positions on the sky associated with each of the millions of articles in the ADS. Our collaboration with ADS and CDS will let us automatically extract astrotags for all existing and future ADS holdings. The new ADS Labs, which our group helps to develop, includes the ability for researchers to filter article search results using a variety of "facets" (e.g. sources, keywords, authors, observatories, etc.). Using only extracted astrotags and facets, we can create functionality like what is described in the Times example above: we can offer a map of the density of positions' "mentions" on the sky, filterable by the properties of those mentions. Using this map, researchers will be able to interactively, visually, discover what regions have been studied for what reasons, at what times, and by whom. Second, where

  20. Cappuccino and Specific Heat versus Heat of Vaporization

    ERIC Educational Resources Information Center

    Hidden, Frits; Boomsma, Jorn; Schins, Anton; van den Berg, Ed

    2012-01-01

    A cappuccino is prepared by adding about 50 mL frothing, foaming milk to a cup of espresso. Whole milk is best for foaming and the ideal milk temperature when adding it to the espresso is 65 [degrees]C. The espresso itself may be warmer than that. During the heating the milk should not burn, as that would spoil the taste. The best way is to heat…

  1. Frozen yogurt with added inulin and isomalt.

    PubMed

    Isik, U; Boyacioglu, D; Capanoglu, E; Erdil, D Nilufer

    2011-04-01

    The objective of this study was to produce a frozen yogurt containing low fat and no added sugar. Samples containing 5% polydextrose, 0.065% aspartame and acesulfame-K mixture, and different levels of inulin and isomalt (5.0, 6.5, and 8.0%) were produced at pilot scale and analyzed for their physical and chemical properties including proximate composition, viscosity, acidity, overrun, melting rate, heat shock stability, as well as sensory characteristics, and viability of lactic acid bacteria. With the addition of inulin and isomalt, viscosity increased by 19 to 52% compared with that of sample B (reduced-fat control). The average calorie values of samples substituted with sweeteners were about 43% lower than that of original sample. Low-calorie frozen yogurt samples melted about 33 to 48% slower than the reduced-fat control sample at 45 min. Based on quantitative descriptive profile test results, statistically significant differences among products were observed for hardness, iciness, foamy melting, whey separation, and sweetness characteristics. The results of principal component analysis showed that the sensory properties of the sample containing 6.5% inulin and 6.5% isomalt were similar to those of control. Lactic acid bacteria counts of frozen yogurt were found to be between 8.12 and 8.49 log values, 3 mo after the production. The overall results showed that it is possible to produce an attractive frozen yogurt product with the incorporation of inulin and isomalt with no added sugar and reduced fat. PMID:21426952

  2. SPECIFIC HEAT INDICATOR

    DOEpatents

    Horn, F.L.; Binns, J.E.

    1961-05-01

    Apparatus for continuously and automatically measuring and computing the specific heat of a flowing solution is described. The invention provides for the continuous measurement of all the parameters required for the mathematical solution of this characteristic. The parameters are converted to logarithmic functions which are added and subtracted in accordance with the solution and a null-seeking servo reduces errors due to changing voltage drops to a minimum. Logarithmic potentiometers are utilized in a unique manner to accomplish these results.

  3. Distributed vs. centralized heating

    SciTech Connect

    Mehrotra, P.; Sood, P.

    1983-04-01

    Decentralization of the steam system in an industrial plant can dramatically reduce energy waste and operating costs. The approach (1) utilizes high-pressure gas piping to properly selected and located heat sources such as fluid heaters, boilers, and ovens, (2) replaces stream with a high-temperature fluid heat-transfer medium and/or hot water, and (3) provides a high- or low-pressure steam source near those users that must use stream. In a case study of a 50-year-old Chicago building housing a felt and rubber products plant, a steam profile revealed that 48% of the energy supplied to the boiler was wasted through flue gases, steam leakage, condensate drain, and transmission heat losses; 42% was used to provide ventilation preheat and transmission heat losses in winter; and 10% was actually for process heat. The Chicago plant installed instantaneous water heaters, a gas-fired fluid heater, six air-to-air heat exchangers, infrared heaters for the plant perimeter, and a low-pressure steam boiler for office heating, cutting gas consumption over 30%. Decisions about decentralization should consider the age of the plant, diversity of use, load factor, operation variations of production sections, and uncertainity of production planning.

  4. A sublimation heat engine

    NASA Astrophysics Data System (ADS)

    Wells, Gary G.; Ledesma-Aguilar, Rodrigo; McHale, Glen; Sefiane, Khellil

    2015-03-01

    Heat engines are based on the physical realization of a thermodynamic cycle, most famously the liquid-vapour Rankine cycle used for steam engines. Here we present a sublimation heat engine, which can convert temperature differences into mechanical work via the Leidenfrost effect. Through controlled experiments, quantified by a hydrodynamic model, we show that levitating dry-ice blocks rotate on hot turbine-like surfaces at a rate controlled by the turbine geometry, temperature difference and solid material properties. The rotational motion of the dry-ice loads is converted into electric power by coupling to a magnetic coil system. We extend our concept to liquid loads, generalizing the realization of the new engine to both sublimation and the instantaneous vapourization of liquids. Our results support the feasibility of low-friction in situ energy harvesting from both liquids and ices. Our concept is potentially relevant in challenging situations such as deep drilling, outer space exploration or micro-mechanical manipulation.

  5. High Power Disk Loaded Guide Load

    SciTech Connect

    Farkas, Z.D.; /SLAC

    2006-02-22

    A method to design a matching section from a smooth guide to a disk-loaded guide, using a variation of broadband matching, [1, 2] is described. Using this method, we show how to design high power loads. The load consists of a disk-loaded coaxial guide operating in the TE{sub 01}-mode. We use this mode because it has no electric field terminating on a conductor, has no axial currents, and has no current at the cylinder-disk interface. A high power load design that has -35 dB reflection and a 200 MHz, -20 dB bandwidth, is presented. It is expected that it will carry the 600 MW output peak power of the pulse compression network. We use coaxial geometry and stainless steel material to increase the attenuation per cell.

  6. The inside outs of AdS3/CFT2: exact AdS wormholes with entangled CFT duals

    NASA Astrophysics Data System (ADS)

    Mandal, Gautam; Sinha, Ritam; Sorokhaibam, Nilakash

    2015-01-01

    We present the complete family of solutions of 3D gravity (Λ < 0) with two asymptotically AdS exterior regions. The solutions are constructed from data at the two boundaries, which correspond to two independent and arbitrary stress tensors T R , , and T L , . The two exteriors are smoothly joined on to an interior region through a regular horizon. We find CFT duals of these geometries which are entangled states of two CFT's. We compute correlators between general operators at the two boundaries and find perfect agreement between CFT and bulk calculations. We calculate and match the CFT entanglement entropy (EE) with the holographic EE which involves geodesics passing through the wormhole. We also compute a holographic, non-equilibrium entropy for the CFT using properties of the regular horizon. The construction of the bulk solutions here uses an exact version of Brown-Henneaux type diffeomorphisms which are asymptotically nontrivial and transform the CFT states by two independent unitary operators on the two sides. Our solutions provide an infinite family of explicit examples of the ER=EPR relation of Maldacena and Susskind [1].

  7. Fabrication and test of a variable conductance heat pipe

    NASA Technical Reports Server (NTRS)

    Lehtinen, A. M.

    1978-01-01

    A variable conductance heat pipe (VCHP) with feedback control was fabricated with a reservoir-condenser volume ratio of 10 and an axially grooved action section. Tests of the heat transport capability were greater than or equal to the analytical predictions for the no gas case. When gas was added, the pipe performance degraded by 18% at zero tilt as was expected. The placement of the reservoir heater and the test fixture cooling fins are believed to have caused a superheated vapor condition in the reservoir. Erroneously high reservoir temperature indications resulted from this condition. The observed temperature gradients in the reservoir lend support to this theory. The net result was higher than predicted reservoir temperatures. Also, significant increases in minimum heat load resulted for controller set point temperatures higher than 0 C. At 30 C, control within the tolerance band was maintained, but high reservoir heater power was required. Analyses showed that control is not possible for reasonably low reservoir heater power. This is supported by the observation of a significant reservoir heat leak through the condenser.

  8. Role of Liver X Receptor in AD Pathophysiology

    PubMed Central

    Sandoval-Hernández, Adrián G.; Buitrago, Luna; Moreno, Herman; Cardona-Gómez, Gloria Patricia; Arboleda, Gonzalo

    2015-01-01

    Alzheimer's disease (AD) is the major cause of dementia worldwide. The pharmacological activation of nuclear receptors (Liver X receptors: LXRs or Retinoid X receptors: RXR) has been shown to induce overexpression of the ATP-Binding Cassette A1 (ABCA1) and Apolipoprotein E (ApoE), changes that are associated with improvement in cognition and reduction of amyloid beta pathology in amyloidogenic AD mouse models (i.e. APP, PS1: 2tg-AD). Here we investigated whether treatment with a specific LXR agonist has a measurable impact on the cognitive impairment in an amyloid and Tau AD mouse model (3xTg-AD: 12-months-old; three months treatment). The data suggests that the LXR agonist GW3965 is associated with increased expression of ApoE and ABCA1 in the hippocampus and cerebral cortex without a detectable reduction of the amyloid load. We also report that most cells overexpressing ApoE (86±12%) are neurons localized in the granular cell layer of the hippocampus and entorhinal cortex. In the GW3965 treated 3xTg-AD mice we also observed reduction in astrogliosis and increased number of stem and proliferating cells in the subgranular zone of the dentate gyrus. Additionally, we show that GW3965 rescued hippocampus long term synaptic plasticity, which had been disrupted by oligomeric amyloid beta peptides. The effect of GW3965 on synaptic function was protein synthesis dependent. Our findings identify alternative functional/molecular mechanisms by which LXR agonists may exert their potential benefits as a therapeutic strategy against AD. PMID:26720273

  9. Role of Liver X Receptor in AD Pathophysiology.

    PubMed

    Sandoval-Hernández, Adrián G; Buitrago, Luna; Moreno, Herman; Cardona-Gómez, Gloria Patricia; Arboleda, Gonzalo

    2015-01-01

    Alzheimer's disease (AD) is the major cause of dementia worldwide. The pharmacological activation of nuclear receptors (Liver X receptors: LXRs or Retinoid X receptors: RXR) has been shown to induce overexpression of the ATP-Binding Cassette A1 (ABCA1) and Apolipoprotein E (ApoE), changes that are associated with improvement in cognition and reduction of amyloid beta pathology in amyloidogenic AD mouse models (i.e. APP, PS1: 2tg-AD). Here we investigated whether treatment with a specific LXR agonist has a measurable impact on the cognitive impairment in an amyloid and Tau AD mouse model (3xTg-AD: 12-months-old; three months treatment). The data suggests that the LXR agonist GW3965 is associated with increased expression of ApoE and ABCA1 in the hippocampus and cerebral cortex without a detectable reduction of the amyloid load. We also report that most cells overexpressing ApoE (86±12%) are neurons localized in the granular cell layer of the hippocampus and entorhinal cortex. In the GW3965 treated 3xTg-AD mice we also observed reduction in astrogliosis and increased number of stem and proliferating cells in the subgranular zone of the dentate gyrus. Additionally, we show that GW3965 rescued hippocampus long term synaptic plasticity, which had been disrupted by oligomeric amyloid beta peptides. The effect of GW3965 on synaptic function was protein synthesis dependent. Our findings identify alternative functional/molecular mechanisms by which LXR agonists may exert their potential benefits as a therapeutic strategy against AD. PMID:26720273

  10. Staged regenerative sorption heat pump

    NASA Technical Reports Server (NTRS)

    Jones, Jack A. (Inventor)

    1995-01-01

    A regenerative adsorbent heat pump process and system for cooling and heating a space. A sorbent is confined in a plurality of compressors of which at least four are first stage and at least four are second stage. The first stage operates over a first pressure region and the second stage over a second pressure region which is higher than the first. Sorbate from the first stage enters the second stage. The sorbate loop includes a condenser, expansion valve, evaporator and the compressors. A single sorbate loop can be employed for single-temperature-control such as air conditioning and heating. Two sorbate loops can be used for two-temperature-control as in a refrigerator and freezer. The evaporator temperatures control the freezer and refrigerator temperatures. Alternatively the refrigerator temperature can be cooled by the freezer with one sorbate loop. A heat transfer fluid is circulated in a closed loop which includes a radiator and the compressors. Low temperature heat is exhausted by the radiator. High temperature heat is added to the heat transfer fluid entering the compressors which are desorbing vapor. Heat is transferred from compressors which are sorbing vapor to the heat transfer fluid, and from the heat transfer fluid to the compressors which are desorbing vapor. Each compressor is subjected to the following phases, heating to its highest temperature, cooling down from its highest temperature, cooling to its lowest temperature, and warming up from its lowest temperature. The phases are repeated to complete a cycle and regenerate heat.

  11. Heat stress increases insulin sensitivity in pigs

    PubMed Central

    Sanz Fernandez, M Victoria; Stoakes, Sara K; Abuajamieh, Mohannad; Seibert, Jacob T; Johnson, Jay S; Horst, Erin A; Rhoads, Robert P; Baumgard, Lance H

    2015-01-01

    Proper insulin homeostasis appears critical for adapting to and surviving a heat load. Further, heat stress (HS) induces phenotypic changes in livestock that suggest an increase in insulin action. The current study objective was to evaluate the effects of HS on whole-body insulin sensitivity. Female pigs (57 ± 4 kg body weight) were subjected to two experimental periods. During period 1, all pigs remained in thermoneutral conditions (TN; 21°C) and were fed ad libitum. During period 2, pigs were exposed to: (i) constant HS conditions (32°C) and fed ad libitum (n = 6), or (ii) TN conditions and pair-fed (PFTN; n = 6) to eliminate the confounding effects of dissimilar feed intake. A hyperinsulinemic euglycemic clamp (HEC) was conducted on d3 of both periods; and skeletal muscle and adipose tissue biopsies were collected prior to and after an insulin tolerance test (ITT) on d5 of period 2. During the HEC, insulin infusion increased circulating insulin and decreased plasma C-peptide and nonesterified fatty acids, similarly between treatments. From period 1 to 2, the rate of glucose infusion in response to the HEC remained similar in HS pigs while it decreased (36%) in PFTN controls. Prior to the ITT, HS increased (41%) skeletal muscle insulin receptor substrate-1 protein abundance, but did not affect protein kinase B or their phosphorylated forms. In adipose tissue, HS did not alter any of the basal or stimulated measured insulin signaling markers. In summary, HS increases whole-body insulin-stimulated glucose uptake. PMID:26243213

  12. Multiplexer/Demultiplexer Loading Tool (MDMLT)

    NASA Technical Reports Server (NTRS)

    Brewer, Lenox Allen; Hale, Elizabeth; Martella, Robert; Gyorfi, Ryan

    2012-01-01

    The purpose of the MDMLT is to improve the reliability and speed of loading multiplexers/demultiplexers (MDMs) in the Software Development and Integration Laboratory (SDIL) by automating the configuration management (CM) of the loads in the MDMs, automating the loading procedure, and providing the capability to load multiple or all MDMs concurrently. This loading may be accomplished in parallel, or single MDMs (remote). The MDMLT is a Web-based tool that is capable of loading the entire International Space Station (ISS) MDM configuration in parallel. It is able to load Flight Equivalent Units (FEUs), enhanced, standard, and prototype MDMs as well as both EEPROM (Electrically Erasable Programmable Read-Only Memory) and SSMMU (Solid State Mass Memory Unit) (MASS Memory). This software has extensive configuration management to track loading history, and the performance improvement means of loading the entire ISS MDM configuration of 49 MDMs in approximately 30 minutes, as opposed to 36 hours, which is what it took previously utilizing the flight method of S-Band uplink. The laptop version recently added to the MDMLT suite allows remote lab loading with the CM of information entered into a common database when it is reconnected to the network. This allows the program to reconfigure the test rigs quickly between shifts, allowing the lab to support a variety of onboard configurations during a single day, based on upcoming or current missions. The MDMLT Computer Software Configuration Item (CSCI) supports a Web-based command and control interface to the user. An interface to the SDIL File Transfer Protocol (FTP) server is supported to import Integrated Flight Loads (IFLs) and Internal Product Release Notes (IPRNs) into the database. An interface to the Monitor and Control System (MCS) is supported to control the power state, and to enable or disable the debug port of the MDMs to be loaded. Two direct interfaces to the MDM are supported: a serial interface (debug port) to

  13. Simulated Reentry Heating by Torching

    NASA Technical Reports Server (NTRS)

    Harvey, Gale A.

    2008-01-01

    The two first order reentry heating parameters are peak heating flux (W/square cm) and peak heat load (kJ/square cm). Peak heating flux (and deceleration, gs) is higher for a ballistic reentry and peak heat load is higher for a lifting reentry. Manned vehicle reentries are generally lifting reentries at nominal 1-5 gs so that personnel will not be crushed by high deceleration force. A few off-nominal manned reentries have experienced 8 or more gs with corresponding high heating flux (but below nominal heat load). The Shuttle Orbiter reentries provide about an order of magnitude difference in peak heating flux at mid-bottom (TPS tiles, approximately 6 W/square cm or 5 BTU/square ft - sec) and leading edge (RCC, approximately 60 W/square cm or 50 BTU/square ft- sec). Orion lunar return and Mars sample lander are of the same order of magnitude as orbiter leading edge peak heat loads. Flight temperature measurements are available for some orbiter TPS tile and RCC locations. Return-to-Flight on-orbit tile-repair-candidate-material-heating performance was evaluated by matching propane torch heating of candidate-materials temperatures at several depths to orbiter TPS tile flight-temperatures. Char and ash characteristics, heat expansion, and temperature histories at several depths of the cure-in-place ablator were some of the TPS repair material performance characteristics measured. The final char surface was above the initial surface for the primary candidate (silicone based) material, in contrast to a receded surface for the Apollo-type ablative heat shield material. Candidate TPS materials for Orion CEV (LEO and lunar return), and for Mars sample lander (MSL) are now being evaluated. Torching of a candidate ablator material, PICA, was performed to match the ablation experienced by the STARDUST PICA heat shield. Torching showed that the carbon fiberform skeleton in a sample of PICA was inhomogeneous in that sample, and allowed measurements (of the clumps and voids) of

  14. Simulated Reentry Heating by Torching

    NASA Technical Reports Server (NTRS)

    Harvey, Gale A.

    2008-01-01

    The two first order reentry heating parameters are peak heating flux (W/cm2) and peak heat load (kJ/cm2). Peak heating flux (and deceleration, gs) is higher for a ballistic reentry and peak heat load is higher for a lifting reentry. Manned vehicle reentries are generally lifting reentries at nominal 1-5 gs so that personnel will not be crushed by high deceleration force. A few off-nominal manned reentries have experienced 8 or more gs with corresponding high heating flux (but below nominal heat load). The Shuttle Orbiter reentries provide about an order of magnitude difference in peak heating flux at mid-bottom (TPS tiles, approximately 6 W/cm2 or 5 BTU/ft2- sec) and leading edge (RCC, approximately 60 W/cm2 or 50 BTU/ft2- sec). Orion lunar return and Mars sample lander are of the same order of magnitude as orbiter leading edge peak heat loads. Flight temperature measurements are available for some orbiter TPS tile and RCC locations. Return-to-Flight on-orbit tile-repair-candidate-material-heating performance was evaluated by matching propane torch heating of candidate-materials temperatures at several depths to orbiter TPS tile flight-temperatures. Char and ash characteristics, heat expansion, and temperature histories at several depths of the cure-in-place ablator were some of the TPS repair material performance characteristics measured. The final char surface was above the initial surface for the primary candidate (silicone based) material, in contrast to a receded surface for the Apollo-type ablative heat shield material. Candidate TPS materials for Orion CEV (LEO and lunar return), and for Mars sample lander are now being evaluated. Torching of a candidate ablator material, PICA, was performed to match the ablation experienced by the STARDUST PICA heat shield. Torching showed that the carbon fiberform skeleton in a sample of PICA was inhomogeneous in that sample, and allowed measurements (of the clumps and voids) of the inhomogeneity. Additional reentry

  15. Complete Initial Scoping Tests on the Incorporation of Novel Loaded Iodine Getters into GCM.

    SciTech Connect

    Nenoff, Tina M.; Garino, Terry J.; Croes, Kenneth James

    2015-08-18

    This study encompasses initial scoping tests on the incorporation of a novel iodine loaded getter material into the Sandia developed low temperature sintering glass ceramic material (GCM) waste form. In particular, we studied the PNNL Ag-I-Aerogel. Optical microscopy indicates inhomogenous samples based on particle sizes and variations in color (AgI vs Ag/AgO on silica). TGA/MS data when heated in air indicates loss of iodine and organics (CO2) between 250-450°C a total of ~15wt% loss, with additional / small iodine loss when during 550°C hold for 1 hr. TGA/MS data when heated in N2 indicates less organic and slightly less iodine loss below 550°C, with no loss of iodine in 550°C 1 hour hold. Furthermore, a substantial mass loss of sulfur containing compounds is observed (m/e of 34 and 36) between 150 – 550°C in both air and N2 sintering atmospheres. In an effort to capture iodine lost to volatilization during heating (at temps below glass sintering temperature of 550°C), we added 5 wt% Ag flake to the AgIaerogel. Resulting data indicates the iodine is retained with the addition of the Ag flake, resulting in only a small iodine loss (< 1wt%) at ~350°C. No method of curtailing loss of sulfur containing compounds due to heating was successful in this scoping study.

  16. 1-loop partition function in AdS 3/ CFT 2

    NASA Astrophysics Data System (ADS)

    Chen, Bin; Wu, Jie-qiang

    2015-12-01

    The 1-loop partition function of the handlebody solutions in the AdS3 gravity have been derived some years ago using the heat kernel techniques and the method of images. In the semiclassical limit, such partition function should correspond to the order O( c 0) part in the partition function of dual conformal field theory(CFT) on the boundary Riemann surface. The higher genus partition function could be computed by the multi-point functions in the Riemann sphere via sewing prescription. In the large central charge limit, the CFT is effectively free in the sense that to the leading order of c the multi-point function is further simplified to be a summation over the products of two-point functions of single-particle states. Correspondingly in the bulk, the graviton is freely propagating without interaction. Furthermore the product of the two-point functions may define the links, each of which is in one-to-one correspondence with the conjugacy class of the Schottky group of the Riemann surface. Moreover, the value of a link is determined by the multiplier of the element in the conjugacy class. This allows us to reproduce exactly the gravitational 1-loop partition function. The proof can be generalized to the higher spin gravity and its dual CFT.

  17. Buffer storage of thermal energy using the reaction heat of the system calcium oxide/calcium hydroxide

    NASA Astrophysics Data System (ADS)

    Lehmann, B.

    1986-12-01

    The reaction heat of the system CaO/Ca(OH)2 was investigated as storage effect for thermal energy. The heat from the chemical system is used as a buffer facility for thermal energy, i.e., sensible heat is stored without thermal losses to the environment. In the forward reaction by adding water to the CaO, sensible heat is released, which can be used for heating houses or water, and for generation of steam for industrial purposes. The necessary heat to be fed to the Ca(OH)2 in order to run the reaction inversely can be supplied by solar collector, high temperature reactors, geothermal energy, or combustion of wastes. Heat at temperatures less than 450 C has to be furnished for the loading phase of the reaction. The discharging reaction delivers temperatures up to 400 C. A gas loop was designed, built, and operated to test this kind of heat storage. The quantities which determine the storage and release of energy were deduced and documented. Pressure drops and storage mass behavior are discussed.

  18. Direct heating surface combustor

    NASA Technical Reports Server (NTRS)

    Beremand, D. G.; Shire, L. I.; Mroz, T. S. (Inventor)

    1978-01-01

    The combustor utilizes a non-adiabatic flame to provide low-emission combustion for gas turbines. A fuel-air mixture is directed through a porous wall, the other side of which serves as a combustion surface. A radiant heat sink disposed adjacent to and spaced from the combustion surface controls the combustor flame temperature in order to prevent the formation of oxides of nitrogen. A secondary air flow cools the heat sink. Additionally, up to 100% of secondary air flow is mixed with the combustion products at the direct heating surface combustor to dilute such products thereby reducing exit temperature. However, if less than 100% secondary air is mixed to the combustor, the remainder may be added to the combustion products further downstream.

  19. Heat pipe life and processing study

    NASA Technical Reports Server (NTRS)

    Antoniuk, D.; Luedke, E. E.

    1979-01-01

    The merit of adding water to the reflux charge in chemically and solvent cleaned aluminum/slab wick/ammonia heat pipes was evaluated. The effect of gas in the performance of three heat pipe thermal control systems was found significant in simple heat pipes, less significant in a modified simple heat pipe model with a short wickless pipe section. Use of gas data for the worst and best heat pipes of the matrix in a variable conductance heat pipe model showed a 3 C increase in the source temperature at full on condition after 20 and 246 years, respectively.

  20. Load sensing system

    DOEpatents

    Sohns, Carl W.; Nodine, Robert N.; Wallace, Steven Allen

    1999-01-01

    A load sensing system inexpensively monitors the weight and temperature of stored nuclear material for long periods of time in widely variable environments. The system can include an electrostatic load cell that encodes weight and temperature into a digital signal which is sent to a remote monitor via a coaxial cable. The same cable is used to supply the load cell with power. When multiple load cells are used, vast