Science.gov

Sample records for added heat load

  1. Simplified Methodology for Calculating Building Heating Loads.

    DTIC Science & Technology

    1980-11-01

    an inexpensive, accurate, and reliable simplified methodology , termed the "Modified Bin Method ", for 2 calculating building heating loads. In doing so...I AD-AI01 725 AIR FORCE INST OF TECH WRIGMT-PATTERSON AFB OH F/6 13/1 SIMPLIFIED METHODOLOGY FOR CALCULATING BUILDING HEATING LOADS.(U) NOV 80 S 0...University The Graduate School ," Department of Architectural Engineering 4, Simplified Methodology for Calculating Building Heating Loads, -A /. ’.- A

  2. Quantum load balancing in ad hoc networks

    NASA Astrophysics Data System (ADS)

    Hasanpour, M.; Shariat, S.; Barnaghi, P.; Hoseinitabatabaei, S. A.; Vahid, S.; Tafazolli, R.

    2017-06-01

    This paper presents a novel approach in targeting load balancing in ad hoc networks utilizing the properties of quantum game theory. This approach benefits from the instantaneous and information-less capability of entangled particles to synchronize the load balancing strategies in ad hoc networks. The quantum load balancing (QLB) algorithm proposed by this work is implemented on top of OLSR as the baseline routing protocol; its performance is analyzed against the baseline OLSR, and considerable gain is reported regarding some of the main QoS metrics such as delay and jitter. Furthermore, it is shown that QLB algorithm supports a solid stability gain in terms of throughput which stands a proof of concept for the load balancing properties of the proposed theory.

  3. 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.

  4. 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.

  5. Added sugar, glycemic index and load in colon cancer risk.

    PubMed

    Galeone, Carlotta; Pelucchi, Claudio; La Vecchia, Carlo

    2012-07-01

    There is a growing body of in-vivo evidences that sucrose-rich diets cause mutations in the rat colon epithelium, with several biological mechanism hypothesized, but epidemiological studies have yielded conflicting results. In order to provide a quantification of the magnitude of the risk of colon cancer for high intake of added sugar, high dietary glycemic index and glycemic load, we performed a meta-analysis based on a systematic review of the literature to date. Recent epidemiological data indicate a lack of association between high intake of added sugar, high-glycemic index and glycemic load diets and risk of colon cancer. There is no consistent evidence from epidemiological studies, although a modest excess risk emerged in case-control studies, that added sugars, dietary glycemic index and glycemic load are associated with increased risk of colon cancer, independently from their effect on energy intake, overweight, obesity and diabetes, which are related to excess colon cancer risk.

  6. 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.

  7. 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.

  8. Position paper -- Tank heat loading. Revision 1

    SciTech Connect

    Groth, B.D.

    1995-01-11

    The purpose of this paper is to provide an update to Project W-236A, Multi-function Waste Tank Facility (MWTF), Project File documentation on the selection of the heat removal capability that MWTF Tank Ventilation Systems will be designed to remove. Further scale model mixing tests, as well as greater understanding of the mission of the tanks and the radionuclide heat load, have shown the current heat removal capabilities to be over-designed. Using the latest available information will decrease the amount of conservatism currently in the design. It is important to note that this paper is not for defining the tank mixer pump requirements, but is to be only used for defining and defending the nominal and extreme case heat generation rate that the ventilation system and other heat removal systems will be designed to remove. There are three main heat loads in the tanks of which two can be controlled to a certain extent through operational considerations. These two are mixing pump heat and heat of chemical addition. The third heat source is radionuclide content which can only be controlled by what wastes are pumped to the tank and whether it is diluted prior to pumping. Other heat loads such as transfer pumps were considered to be negligible. In addition, chemical addition is considered a transient situation that is rarely performed and will be treated as such.

  9. 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.

  10. 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.

  11. Isolating Added Mass Load Components of CPAS Main Clusters

    NASA Technical Reports Server (NTRS)

    Ray, Eric S.

    2017-01-01

    The current simulation for the Capsule Parachute Assembly System (CPAS) lacks fidelity in representing added mass for the 116 ft Do ringsail Main parachute. The availability of 3-D models of inflating Main canopies allowed for better estimation the enclosed air volume as a function of time. This was combined with trajectory state information to estimate the components making up measured axial loads. A proof-of-concept for an alternate simulation algorithm was developed based on enclosed volume as the primary independent variable rather than drag area growth. Databases of volume growth and parachute drag area vs. volume were developed for several flight tests. Other state information was read directly from test data, rather than numerically propagated. The resulting simulated peak loads were close in timing and magnitude to the measured loads data. However, results are very sensitive to data curve fitting and may not be suitable for Monte Carlo simulations. It was assumed that apparent mass was either negligible or a small fraction of enclosed mass, with little difference in results.

  12. 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

  13. 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

  14. 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.

  15. Heat Load on the NCSX First Wall

    NASA Astrophysics Data System (ADS)

    Kaiser, T. B.; Monticello, D. N.; Hill, D. N.; Umansky, M. V.

    2003-10-01

    We have used magnetic field data generated by the PIES 3D MHD equilibrium code(M50 coil set) and a new vacuum field code(Michael Drevlak Max Planck Institute for Plasma Physics, Greifswald, Germany, private communication), together with the latest numerical model of the first wall (Art Brooks, PPPL, private communication) to compute wall heat loading in the National Compact Stellarator Experiment (NCSX) as a function of position. Field lines originating just outside the last closed magnetic surface are followed until they intersect the wall by integrating the field-line equations of motion in cylindrical coordinates using the LSODE integrator. Magnetic field values are interpolated with arbitrary-order splines. The local (nonuniform) heat flux is estimated from the density and incidence angle of escaping field lines.

  16. 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.

  17. 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.

  18. 24 CFR 3280.508 - Heat loss, heat gain and cooling load calculations.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 24 Housing and Urban Development 5 2013-04-01 2013-04-01 false Heat loss, heat gain and cooling load calculations. 3280.508 Section 3280.508 Housing and Urban Development Regulations Relating to... Thermal Protection § 3280.508 Heat loss, heat gain and cooling load calculations. (a) Information,...

  19. 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.

  20. 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.

  1. 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.

  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. 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.

  5. High particle and heat load material testing device

    NASA Astrophysics Data System (ADS)

    Sadovskiy, Ya; Begrambekov, L.; Shigin, P.; Ayrapetov, A.; Bidlevich, O.; Grunin, A.; Utkov, N.

    2017-01-01

    A brief overview of the high heat flux material testing facilities is presented which forms background for a new small-scale laboratory device capable of high heat flux material testing. The scheme of the device is presented and its working principles are described. High heat and particle loads are achieved by focusing of either electron or ion beam on the sample being tested. The sample is fixed to an actively cooled copper table. Experiments with hydrogen ion beam irradiation of an MPG-8 graphite sample are presented, in which heat loads of 270 MW/m2 were achieved. SEM images of the sample surface after testing are presented.

  6. Transient behavior of heat pipe with thermal energy storage under pulse heat loads

    NASA Astrophysics Data System (ADS)

    Chang, Ming-, Jr.

    1991-02-01

    Future space missions will require thermal transport devices with the ability to handle transient pulse heat loads. A novel design of a high-temperature axially grooved heat pipe (HP) which incorporates thermal energy storage (TES) to migrate pulse heat loads was presented. A phase-change material (PCM) which is encapsulated in cylindrical containers was used for the thermal energy storage. The transient response of the HP/TES system under two different types of pulse heat loads was studied analytically. The first type is pulse heat loads applied at the heat pipe evaporator, the second type is reversed-pulse heat loads applied at the condenser. In this research, a new three-dimensional alternating-direction-implicit (ADI) method was developed to model the heat conduction through the heat pipe wall and wicks, including the liquid flow in grooves. A very important characteristic of this new ADI method is that it is consistent with physical considerations. Compared with the well-known Brian's and Douglas's ADI methods, this new ADI method had higher accuracy and requires less computer storage. In the numerical solution of heat transfer problems with phase change (Stefan-type problem), a modified Pham's method which includes features from enthalpy and heat capacity methods was used to simulate the melting and solidification processes of the PCG. The vapor flow was assumed quasi-steady and one-dimensional, and was coupled with the evaporation and condensation on the heat pipe inside wall surface and the surfaces of the PCM containers. The transient responses of three different HP/TES configurations were compared: (1) a heat pipe with a large empty cylinder installed in the vapor core, (2) a heat pipe with a large PCM cylinder, and (3) a heat pipe with six small PCM cylinders. From the numerical results, it was found that the PCM is very effective in mitigrating the adverse effect of pulse heat loads. The six small PCM cylinders are more efficient than the large PCM

  7. 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.

  8. Cooling Load Estimation in the Building Based On Heat Sources

    NASA Astrophysics Data System (ADS)

    Chairani; Sulistyo, S.; Widyawan

    2017-05-01

    Heating, ventilation and air conditioning (HVAC) is the largest source of energy consumption. In this research, we discuss cooling load in the room by considering the different heat source and the number of occupancy. Energy cooling load is affected by external and internal heat sources. External cooling load in this discussion include convection outdoor/exterior using the DOE-2 algorithm, calculation of heat using Thermal Analysis Research Program (TARP), and Conduction Transfer Function (CTF). The internal cooling load is calculated based on the activity of the occupants in the office, a number of occupants, heat gain from lighting, and heat gain from electrics equipment. Weather data used is Surakarta weather and design day used is Jakarta design day. We use the ASHRAE standard for building materials and the metabolic of occupants while on the activity. The results show that the number of occupancies have an influence of cooling load. A large number of occupancy will cause the cooling load is great as well.

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

    NASA Astrophysics Data System (ADS)

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

    1983-11-01

    The quantification of 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 the design, to estimate the annual cooling energy requirement of a given building.

  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. Concept for meeting the whole house heating load using a pulse combustion space heater

    SciTech Connect

    West, J.L.; Thrasher, W.H.; Brand, L.R.

    1985-08-01

    Documentation of a method to provide heat to an entire structure by means of an added pulse combustion space heating appliance installed in one room shows that a highly efficient space-heating appliance is an economically viable alternative. Case studies show the value of the approach and the problems associated with its use. Data show the fraction of the furnace load met by the space heater in the normal operating mode. Space heater effectiveness varies with room configurations. The study also found a higher degree of comfort with the combination of appliances than with the central furnace alone. 5 figures, 3 tables.

  13. 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.

  14. 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.

  15. Effects of dark energy on the efficiency of charged AdS black holes as heat engines

    NASA Astrophysics Data System (ADS)

    Liu, Hang; Meng, Xin-He

    2017-08-01

    In this paper, we study the heat engine where a charged AdS black hole surrounded by dark energy is the working substance and the mechanical work is done via the PdV term in the first law of black hole thermodynamics in the extended phase space. We first investigate the effects of a kind of dark energy (quintessence field in this paper) on the efficiency of the RN-AdS black holes as the heat engine defined as a rectangular closed path in the P- V plane. We get the exact efficiency formula and find that the quintessence field can improve the heat engine efficiency, which will increase as the field density ρ _q grows. At some fixed parameters, we find that a larger volume difference between the smaller black holes(V_1) and the bigger black holes(V_2 ) will lead to a lower efficiency, while the bigger pressure difference P_1-P_4 will make the efficiency higher, but it is always smaller than 1 and will never be beyond the Carnot efficiency, which is the maximum value of the efficiency constrained by thermodynamics laws; this is consistent to the heat engine in traditional thermodynamics. After making some special choices for the thermodynamical quantities, we find that the increase of the electric charge Q and the normalization factor a can also promote the heat engine efficiency, which would infinitely approach the Carnot limit when Q or a goes to infinity.

  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. Analysis of sweeping heat loads on divertor plate materials

    SciTech Connect

    Hassanein, A.

    1991-12-31

    The heat flux on the divertor plate of a fusion reactor is probably one of the most limiting constraints on its lifetime. The current heat flux profile on the outer divertor plate of a device like ITER is highly peaked with narrow profile. The peak heat flux can be as high as 30--40 MW/m{sup 2} with full width at half maximum (FWHM) is in the order of a few centimeters. Sweeping the separatrix along the divertor plate is one of the options proposed to reduce the thermomechanical effects of this highly peaked narrow profile distribution. The effectiveness of the sweeping process is investigated parametrically for various design values. The optimum sweeping parameters of a particular heat load will depend on the design of the divertor plate as well as on the profile of such a heat load. In general, moving a highly peaked heat load results in substantial reduction of the thermomechanical effects on the divertor plate. 3 refs., 8 figs.

  18. Analysis of sweeping heat loads on divertor plate materials

    SciTech Connect

    Hassanein, A.

    1991-01-01

    The heat flux on the divertor plate of a fusion reactor is probably one of the most limiting constraints on its lifetime. The current heat flux profile on the outer divertor plate of a device like ITER is highly peaked with narrow profile. The peak heat flux can be as high as 30--40 MW/m{sup 2} with full width at half maximum (FWHM) is in the order of a few centimeters. Sweeping the separatrix along the divertor plate is one of the options proposed to reduce the thermomechanical effects of this highly peaked narrow profile distribution. The effectiveness of the sweeping process is investigated parametrically for various design values. The optimum sweeping parameters of a particular heat load will depend on the design of the divertor plate as well as on the profile of such a heat load. In general, moving a highly peaked heat load results in substantial reduction of the thermomechanical effects on the divertor plate. 3 refs., 8 figs.

  19. 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.

  20. Particle loading rates for HVAC filters, heat exchangers, and ducts.

    PubMed

    Waring, M S; Siegel, J A

    2008-06-01

    The rate at which airborne particulate matter deposits onto heating, ventilation, and air-conditioning (HVAC) components is important from both indoor air quality (IAQ) and energy perspectives. This modeling study predicts size-resolved particle mass loading rates for residential and commercial filters, heat exchangers (i.e. coils), and supply and return ducts. A parametric analysis evaluated the impact of different outdoor particle distributions, indoor emission sources, HVAC airflows, filtration efficiencies, coils, and duct system complexities. The median predicted residential and commercial loading rates were 2.97 and 130 g/m(2) month for the filter loading rates, 0.756 and 4.35 g/m(2) month for the coil loading rates, 0.0051 and 1.00 g/month for the supply duct loading rates, and 0.262 g/month for the commercial return duct loading rates. Loading rates are more dependent on outdoor particle distributions, indoor sources, HVAC operation strategy, and filtration than other considered parameters. The results presented herein, once validated, can be used to estimate filter changing and coil cleaning schedules, energy implications of filter and coil loading, and IAQ impacts associated with deposited particles. The results in this paper suggest important factors that lead to particle deposition on HVAC components in residential and commercial buildings. This knowledge informs the development and comparison of control strategies to limit particle deposition. The predicted mass loading rates allow for the assessment of pressure drop and indoor air quality consequences that result from particle mass loading onto HVAC system components.

  1. Long-Haul Truck Sleeper Heating Load Reduction Package for Rest Period Idling

    SciTech Connect

    Lustbader, Jason Aaron; Kekelia, Bidzina; Tomerlin, Jeff; Kreutzer, Cory J.; Yeakel, Skip; Adelman, Steven; Luo, Zhiming; Zehme, John

    2016-04-05

    Annual fuel use for sleeper cab truck rest period idling is estimated at 667 million gallons in the United States, or 6.8% of long-haul truck fuel use. Truck idling during a rest period represents zero freight efficiency and is largely done to supply accessory power for climate conditioning of the cab. The National Renewable Energy Laboratory's CoolCab project aims to reduce heating, ventilating, and air conditioning (HVAC) loads and resulting fuel use from rest period idling by working closely with industry to design efficient long-haul truck thermal management systems while maintaining occupant comfort. Enhancing the thermal performance of cab/sleepers will enable smaller, lighter, and more cost-effective idle reduction solutions. In addition, if the fuel savings provide a one- to three-year payback period, fleet owners will be economically motivated to incorporate them. For candidate idle reduction technologies to be implemented by original equipment manufacturers and fleets, their effectiveness must be quantified. To address this need, several promising candidate technologies were evaluated through experimentation and modeling to determine their effectiveness in reducing rest period HVAC loads. Load reduction strategies were grouped into the focus areas of solar envelope, occupant environment, conductive pathways, and efficient equipment. Technologies in each of these focus areas were investigated in collaboration with industry partners. The most promising of these technologies were then combined with the goal of exceeding a 30% reduction in HVAC loads. These technologies included 'ultra-white' paint, advanced insulation, and advanced curtain design. Previous testing showed more than a 35.7% reduction in air conditioning loads. This paper describes the overall heat transfer coefficient testing of this advanced load reduction technology package that showed more than a 43% reduction in heating load. Adding an additional layer of advanced insulation with a

  2. Long-Haul Truck Sleeper Heating Load Reduction Package for Rest Period Idling: Preprint

    SciTech Connect

    Lustbader, Jason; Kekelia, Bidzina; Tomerlin, Jeff; Kreutzer, Cory; Adelman, Steve; Yeakel, Skip; Luo, Zhiming; Zehme, John

    2016-03-24

    Annual fuel use for sleeper cab truck rest period idling is estimated at 667 million gallons in the United States, or 6.8% of long-haul truck fuel use. Truck idling during a rest period represents zero freight efficiency and is largely done to supply accessory power for climate conditioning of the cab. The National Renewable Energy Laboratory's CoolCab project aims to reduce heating, ventilating, and air conditioning (HVAC) loads and resulting fuel use from rest period idling by working closely with industry to design efficient long-haul truck thermal management systems while maintaining occupant comfort. Enhancing the thermal performance of cab/sleepers will enable smaller, lighter, and more cost-effective idle reduction solutions. In addition, if the fuel savings provide a one- to three-year payback period, fleet owners will be economically motivated to incorporate them. For candidate idle reduction technologies to be implemented by original equipment manufacturers and fleets, their effectiveness must be quantified. To address this need, several promising candidate technologies were evaluated through experimentation and modeling to determine their effectiveness in reducing rest period HVAC loads. Load reduction strategies were grouped into the focus areas of solar envelope, occupant environment, conductive pathways, and efficient equipment. Technologies in each of these focus areas were investigated in collaboration with industry partners. The most promising of these technologies were then combined with the goal of exceeding a 30% reduction in HVAC loads. These technologies included 'ultra-white' paint, advanced insulation, and advanced curtain design. Previous testing showed more than a 35.7% reduction in air conditioning loads. This paper describes the overall heat transfer coefficient testing of this advanced load reduction technology package that showed more than a 43% reduction in heating load. Adding an additional layer of advanced insulation with a

  3. 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.

  4. 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.

  5. Cryogenic heat loads analysis from SST-1 plasma experiments

    NASA Astrophysics Data System (ADS)

    Bairagi, N.; Tanna, V. L.; Pradhan, S.

    2017-02-01

    Cryogenic heat load analysis is an important aspect for stable operation of Tokamaks employing large scale superconducting magnets. Steady State Superconducting Tokamak (SST-1) at IPR is equipped with superconducting magnets system (SCMS) comprising sixteen numbers of modified ‘D’ shaped toroidal field (TF) and nine poloidal field (PF) superconducting coils which are wound using NbTi/Cu based cable-in conduit conductor (CICC). SST-1 magnets operation has flexibility to cool either in two-phase with sub-cooling, two-phase without sub-cooling or single phase (supercritical) helium using a dedicated 1.3 kW helium refrigerator cum liquefier (HRL). Here, we report gross heat losses for integrated TF superconducting magnets of SST-1 during the plasma campaign using cryogenic helium supply/return thermodynamic data from cryoplant. Heat loads mainly comprising of steady state as well as transient loads are smoothly absorbed by SST-1 cryogenic helium plant during plasma experiments. The corresponding heat produced in the coils is totally released to the helium flowing through the TF coils, which in turn is dumped into liquid helium stored in main control Dewar. These results are very useful reference for heat loss analysis for TF as well as PF coils and provides database for future operation of SST-1 machine.

  6. 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.

  7. The effect of nanoparticles added to heated micropolar fluid

    NASA Astrophysics Data System (ADS)

    Nering, Konrad; Rup, Kazimierz

    2016-10-01

    This paper presents an analysis of momentum, angular momentum and heat transfer during the unsteady natural convection in micropolar nanofluids. Presented phenomena are modelled in the vicinity of a vertical plate and heat flux which rises suddenly at a given moment, using the boundary layer concept. Differential equations of angular momentum conservation are used according to the theory of micropolar fluids developed by Eringen. Finite difference method is used to solve the equations for conservation of mass, energy, momentum and angular momentum. Selected nanofluids treated as single phase fluids contain small particles with diameter size d = 10 nm and d = 38.4 nm. In particular, two ethylene glycol based nanofluids and one water-based nanofluid are analysed. Volume fraction of these solutions is 6%. First ethylene glycol solution contain Al2 O3 nanoparticles (d = 38.4 nm), and the second ethylene glycol solution contained Cu nanoparticles (d = 10 nm). Water based nanofluid contain Al2 O3 nanoparticles (d = 38.4 nm). As a result of solving conservation equations, unsteady velocity field (U, V), temperature (T), microrotation component normal to (x, y) plane (N), velocity gradient ∂U/∂Y and temperature gradient ∂T/∂Y are obtained. These results are compared to theoretical and experimental results presented in literature. At the end of this paper, heat transfer enhancement for analysed nanofluids is estimated.

  8. 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.

  9. 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.

  10. Dynamic Loading of Carrara Marble in a Heated State

    NASA Astrophysics Data System (ADS)

    Wong, Louis Ngai Yuen; Li, Zhihuan; Kang, Hyeong Min; Teh, Cee Ing

    2017-06-01

    Useable land is a finite space, and with a growing global population, countries have been exploring the use of underground space as a strategic resource to sustain the growth of their society and economy. However, the effects of impact loading on rocks that have been heated, and hence the integrity of the underground structure, are still not fully understood and has not been included in current design standards. Such scenarios include traffic accidents and explosions during an underground fire. This study aims to provide a better understanding of the dynamic load capacity of Carrara marble at elevated temperatures. Dynamic uniaxial compression tests are performed on Carrara marble held at various temperatures using a split-Hopkinson Pressure Bar (SHPB) setup with varying input force. A customized oven is included in the SHPB setup to allow for testing of the marble specimens in a heated state. After the loading test, a three-wave analysis is performed to obtain the dynamic stress-strain curve of the specimen under loading. The fragments of the failed specimens were also collected and dry-sieved to obtain the particle size distribution. The results reveal that the peak stress of specimens that have been heated is negatively correlated with the heating temperature. However, the energy absorbed by the specimens at peak stress at all temperatures is similar, indicating that a significant amount of energy is dissipated via plastic deformation. Generally, fragment size is also found to show a negative correlation with heating temperature and loading pressure. However, in some cases this relationship does not hold true, probably due to the occurrence of stress shadowing. Linear Elastic Fracture Mechanics has been found to be generally applicable to specimens tested at low temperatures; but at higher temperatures, Elastic-Plastic Fracture Mechanics will give a more accurate prediction. Another contribution of this study is to show that other than the peak stress of the

  11. Surface heat loads on the ITER divertor vertical targets

    NASA Astrophysics Data System (ADS)

    Gunn, J. P.; Carpentier-Chouchana, S.; Escourbiac, F.; Hirai, T.; Panayotis, S.; Pitts, R. A.; Corre, Y.; Dejarnac, R.; Firdaouss, M.; Kočan, M.; Komm, M.; Kukushkin, A.; Languille, P.; Missirlian, M.; Zhao, W.; Zhong, G.

    2017-04-01

    The heating of tungsten monoblocks at the ITER divertor vertical targets is calculated using the heat flux predicted by three-dimensional ion orbit modelling. The monoblocks are beveled to a depth of 0.5 mm in the toroidal direction to provide magnetic shadowing of the poloidal leading edges within the range of specified assembly tolerances, but this increases the magnetic field incidence angle resulting in a reduction of toroidal wetted fraction and concentration of the local heat flux to the unshadowed surfaces. This shaping solution successfully protects the leading edges from inter-ELM heat loads, but at the expense of (1) temperatures on the main loaded surface that could exceed the tungsten recrystallization temperature in the nominal partially detached regime, and (2) melting and loss of margin against critical heat flux during transient loss of detachment control. During ELMs, the risk of monoblock edge melting is found to be greater than the risk of full surface melting on the plasma-wetted zone. Full surface and edge melting will be triggered by uncontrolled ELMs in the burning plasma phase of ITER operation if current models of the likely ELM ion impact energies at the divertor targets are correct. During uncontrolled ELMs in pre-nuclear deuterium or helium plasmas at half the nominal plasma current and magnetic field, full surface melting should be avoided, but edge melting is predicted.

  12. 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.

  13. 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.

  14. Investigation of LLD Test Sample Performance Under High Heat Loads

    NASA Astrophysics Data System (ADS)

    Abrams, Tyler; Jaworski, M. A.; Kaita, R.; Kallman, J.; Foley, E.; Gray, T.; Kugel, H.; Levinton, F.

    2010-11-01

    A small prototype sample of the NSTX Liquid Lithium Divertor (LLD) was exposed to a MSE-LIF diagnostic neutral beam at a power of ˜10 MW/m^2 for 1-3 seconds. Calibrated infrared measurements of front face temperature and thermocouple measurements of bulk sample temperature were obtained. Predictions of temperature evolution were derived from a simple 1D heat flux model and compared with experimental data. These results demonstrated the effective heat load handling of a thin stainless steel liner with porous Mo coating on a copper heat sink, suggesting usefulness as NSTX-Upgrade PFCs. A novel method of measuring the resistance of the lithium films inside NSTX was also developed, the initial results of which will be presented.

  15. 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.

  16. Comparison of measured and predicted sensible heating and cooling loads for six test buildings

    SciTech Connect

    Burch, D.M.; Walton, G.N.; Licitra, B.A.; Cavanaugh, K.

    1986-06-01

    Hourly sensible heating and cooling loads for six test buildings were predicted using two computer programs, called TARP and EMPS. The predicted loads were compared to corresponding measured loads for winter heating, spring heating, and summer cooling periods. Both computer programs predicted the general trends of the measured data.

  17. Impact of Heat Wave Definitions on the Added Effect of Heat Waves on Cardiovascular Mortality in Beijing, China.

    PubMed

    Dong, Wentan; Zeng, Qiang; Ma, Yue; Li, Guoxing; Pan, Xiaochuan

    2016-09-21

    Heat waves are associated with increased mortality, however, few studies have examined the added effect of heat waves. Moreover, there is limited evidence for the influence of different heat wave definitions (HWs) on cardiovascular mortality in Beijing, the capital of China. The aim of this study was to find the best HW definitions for cardiovascular mortality, and we examined the effect modification by an individual characteristic on cardiovascular mortality in Beijing, a typical northern city in China. We applied a Poisson generalized additive approach to estimate the differences in cardiovascular mortality during heat waves (using 12 HWs) compared with non-heat-wave days in Beijing from 2006 to 2009. We also validated the model fit by checking the residuals to ensure that the autocorrelation was successfully removed. In addition, the effect modifications by individual characteristics were explored in different HWs. Our results showed that the associations between heat waves and cardiovascular mortality differed from different HWs. HWs using the 93th percentile of the daily average temperature (27.7 °C) and a duration ≥5 days had the greatest risk, with an increase of 18% (95% confidence interval (CI): 6%, 31%) in the overall population, 24% (95% CI: 10%, 39%) in an older group (ages ≥65 years), and 22% (95% CI: 3%, 44%) in a female group. The added effect of heat waves was apparent after 5 consecutive heat wave days for the overall population and the older group. Females and the elderly were at higher risk than males and younger subjects (ages <65 years). Our findings suggest that heat wave definitions play a significant role in the relationship between heat wave and cardiovascular mortality. Using a suitable definition may have implications for designing local heat early warning systems and protecting the susceptible populations during heat waves.

  18. Impact of Heat Wave Definitions on the Added Effect of Heat Waves on Cardiovascular Mortality in Beijing, China

    PubMed Central

    Dong, Wentan; Zeng, Qiang; Ma, Yue; Li, Guoxing; Pan, Xiaochuan

    2016-01-01

    Heat waves are associated with increased mortality, however, few studies have examined the added effect of heat waves. Moreover, there is limited evidence for the influence of different heat wave definitions (HWs) on cardiovascular mortality in Beijing, the capital of China. The aim of this study was to find the best HW definitions for cardiovascular mortality, and we examined the effect modification by an individual characteristic on cardiovascular mortality in Beijing, a typical northern city in China. We applied a Poisson generalized additive approach to estimate the differences in cardiovascular mortality during heat waves (using 12 HWs) compared with non-heat-wave days in Beijing from 2006 to 2009. We also validated the model fit by checking the residuals to ensure that the autocorrelation was successfully removed. In addition, the effect modifications by individual characteristics were explored in different HWs. Our results showed that the associations between heat waves and cardiovascular mortality differed from different HWs. HWs using the 93th percentile of the daily average temperature (27.7 °C) and a duration ≥5 days had the greatest risk, with an increase of 18% (95% confidence interval (CI): 6%, 31%) in the overall population, 24% (95% CI: 10%, 39%) in an older group (ages ≥65 years), and 22% (95% CI: 3%, 44%) in a female group. The added effect of heat waves was apparent after 5 consecutive heat wave days for the overall population and the older group. Females and the elderly were at higher risk than males and younger subjects (ages <65 years). Our findings suggest that heat wave definitions play a significant role in the relationship between heat wave and cardiovascular mortality. Using a suitable definition may have implications for designing local heat early warning systems and protecting the susceptible populations during heat waves. PMID:27657103

  19. 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

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

    USGS Publications Warehouse

    Abbott, Dallas H.; Breger, Dee; Biscaye, Pierre E.; Barron, John A.; Juhl, Robert A.; McCafferty, Patrick

    2014-01-01

    Sn-rich particles, Ni-rich particles, and cosmic spherules are found together at four discrete stratigraphic levels within the 362-360 m depth interval of the Greenland Ice Sheet Project 2 (GISP2) ice core (72.6°N, 38.5°W, elevation: 3203 m). Using a previously derived calendar-year time scale, these particles span a time of increased dust loading of Earth's atmosphere between A.D. 533 and 540. The Sn-rich and Ni-rich particles contain an average of 10–11 wt% C. Their high C contents coupled with local enrichments in the volatile elements I, Zn, Cu, and Xe 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. An increased flux of cometary dust might explain a modest climate downturn in A.D. 533. Both cometary dust and volcanic sulfate probably contributed to the profound global dimming during A.D. 536 and 537 but may be insufficient sources of fine aerosols. We found tropical marine microfossils and aerosol-sized CaCO3 particles at the end A.D. 535–start A.D. 536 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 during A.D. 536 and 537. Although there has been no extinction documented at A.D. 536, our results are relevant because mass extinctions may also have multiple drivers. Detailed examinations of fine particles at and near extinction horizons can help to determine the relative contributions of cosmic and volcanic drivers to mass extinctions.

  1. Heat Exposure and Hypohydration Exacerbate Physiological Strain During Load Carrying.

    PubMed

    Adams, Elizabeth L; Casa, Douglas J; Huggins, Robert A; DeMartini, Julie K; Stearns, Rebecca L; Kennedy, Rachel M; DiStefano, Lindsay J; Armstrong, Lawrence E; Maresh, Carl M

    2017-02-01

    Heat exposure and hypohydration induce physiological and psychological strain during exercise; however, it is unknown if the separate effects of heat exposure and hypohydration are synergistic when co-occurring during loaded exercise. This study compared separate and combined effects of heat exposure and hypohydration on physiological strain, mood state, and visual vigilance during loaded exercise. Twelve males (mean±SD; age, 20±2 years; body mass, 74.0±8.2 kg; maximal oxygen uptake, 57.0±6.0 mLkg-1min-1) completed 4 trials under the following conditions: euhydrated temperate (EUT), hypohydrated temperate (HYT), euhydrated hot (EUH), and hypohydrated hot (HYH). Exercise was 90 min of treadmill walking (∼50% VO2 max, 5% grade) while carrying a 45 lb rucksack. Profile of Mood States and the Scanning Visual Vigilance Test were completed pre and post exercise. The separate effects of heat exposure (EUH) and hypohydration (HYT) on post-exercise Tre were similar (38.25±0.63°C vs. 38.22±0.29°C, respectively, p>0.05), while in combination (HYH), post-exercise Tre was far greater (39.32±0.43°C). Increase in Tre per 1% body mass loss (BML) for HYH (vs. EUH) was greater than HYT (vs. EUT) (0.32°C vs. 0.04°C, respectively, p=0.02); HR increase per 1% BML for HYH (vs. EUH) was 7 bpm compared to HYT (vs. EUT) at 3 bpm (p=0.30). HYH induced greater mood disturbance (post-pre exercise) (35±21 units) compared to other conditions (EUT=3±9 units; HYT=3±16 units; EUH=16±26 units; p<0.001). No differences occurred in visual vigilance (p>0.05). Independently, heat exposure and hypohydration induced similar physiological strain during loaded exercise; when combined, heat exposure with hypohydration, synergistically exacerbated physiological strain and mood disturbance.

  2. Influence of heat wave definitions to the added effect of heat waves on daily mortality in Nanjing, China.

    PubMed

    Chen, Kai; Bi, Jun; Chen, Jin; Chen, Xiaodong; Huang, Lei; Zhou, Lian

    2015-02-15

    Few studies have explored the added effect of heat waves, especially in China. Moreover, no prior studies have assessed whether the choice of heat wave definitions affected this added effect. This study compared the associations between heat waves defined by different heat wave definitions (HWs) and cause-specific mortality in warm season in Nanjing, China. A distributed lag model was applied to evaluate the differences in daily mortality during heat-wave days (defined using 15 HWs) compared with non-heat-wave days in Nanjing, during 2007 to 2013. For different HWs, model fits were examined by the Akaike Information Criterion for quasi-Poisson and effects were compared by stratified analysis and bootstrapping. In addition, we explored the effect modifications by individual characteristics under different HWs. Different HWs resulted in considerable differences in associations between heat waves and mortality. Heat waves defined as ≥4 consecutive days with daily average temperature >98th percentile had the best model fit and were associated with an increase of 24.6% (95% CI: 15.6%, 34.3%) total mortality, 46.9% (95% CI: 33.0%, 62.3%) cardiovascular mortality, 32.0% (95% CI: 8.5%, 60.5%) respiratory mortality, 51.3% (95% CI: 23.4%, 85.6%) stroke mortality, 63.4% (95% CI: 41.5%, 88.8%) ischemic heart disease mortality, and 47.6% (95% CI: 14.5%, 90.3%) chronic obstructive pulmonary disease mortality at lag day 2. Under different HWs, added effects of heat waves on mortality were higher for females versus males, the elderly versus young residents, and people with low education versus those with high education. Results were less sensitive to the inclusion of air pollutants. Heat wave definition plays a critical role in the relationship between heat waves and mortality. Selecting an appropriate definition of heat waves is therefore important to design local heat warning systems and to reduce the burden of disease during heat waves. Copyright © 2014 Elsevier B.V. All

  3. Ambient temperature and added heat wave effects on hospitalizations in California from 1999 to 2009.

    PubMed

    Sherbakov, Toki; Malig, Brian; Guirguis, Kristen; Gershunov, Alexander; Basu, Rupa

    2017-09-28

    Investigators have examined how heat waves or incremental changes in temperature affect health outcomes, but few have examined both simultaneously. We utilized distributed lag nonlinear models (DLNM) to explore temperature associations and evaluate possible added heat wave effects on hospitalizations in 16 climate zones throughout California from May through October 1999-2009. We define heat waves as a period when daily mean temperatures were above the zone- and month-specific 95th percentile for at least two consecutive days. DLNMs were used to estimate climate zone-specific non-linear temperature and heat wave effects, which were then combined using random effects meta-analysis to produce an overall estimate for each. With higher temperatures, admissions for acute renal failure, appendicitis, dehydration, ischemic stroke, mental health, non-infectious enteritis, and primary diabetes were significantly increased, with added effects from heat waves observed for acute renal failure and dehydration. Higher temperatures also predicted statistically significant decreases in hypertension admissions, respiratory admissions, and respiratory diseases with secondary diagnoses of diabetes, though heat waves independently predicted an added increase in risk for both respiratory types. Our findings provide evidence that both heat wave and temperature exposures can exert effects independently. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. A new heat load index for feedlot cattle.

    PubMed

    Gaughan, J B; Mader, T L; Holt, S M; Lisle, A

    2008-01-01

    The ability to predict the effects of extreme climatic variables on livestock is important in terms of welfare and performance. An index combining temperature and humidity (THI) has been used for more than 4 decades to assess heat stress in cattle. However, the THI does not include important climatic variables such as solar load and wind speed (WS, m/s). Likewise, it does not include management factors (the effect of shade) or animal factors (genotype differences). Over 8 summers, a total of 11,669 Bos taurus steers, 2,344 B. taurus crossbred steers, 2,142 B. taurus x Bos indicus steers, and 1,595 B. indicus steers were used to develop and test a heat load index (HLI) for feedlot cattle. A new HLI incorporating black globe (BG) temperature ( degrees C), relative humidity (RH, decimal form), and WS was initially developed by using the panting score (PS) of 2,490 Angus steers. The HLI consists of 2 parts based on a BG temperature threshold of 25 degrees C: HLI(BG>25) = 8.62 + (0.38 x RH) + (1.55 x BG) - (0.5 x WS) + e((2.4-WS)), and HLI(BG<25) = 10.66 + (0.28 x RH) + (1.3 x BG) - WS, where e is the base of the natural logarithm. A threshold HLI above which cattle of different genotypes gain body heat was developed for 7 genotypes. The threshold for unshaded black B. taurus steers was 86, and for unshaded B. indicus (100%) the threshold was 96. Threshold adjustments were developed for factors such as coat color, health status, access to shade, drinking water temperature, and manure management. Upward and downward adjustments are possible; upward adjustments occur when cattle have access to shade (+3 to +7) and downward adjustments occur when cattle are showing clinical signs of disease (-5). A related measure, the accumulated heat load (AHL) model, also was developed after the development of the HLI. The AHL is a measure of the animal's heat load balance and is determined by the duration of exposure above the threshold HLI. The THI and THI-hours (hours above a THI

  5. 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.

  6. 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.

  7. 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.

  8. 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

  9. 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.

  10. Particle transport and heat loads in NIO1

    SciTech Connect

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

    2016-02-15

    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.

  11. A New High Heat Load X-Ray Tube

    NASA Astrophysics Data System (ADS)

    Iversen, Arthur H.; Whitaker, Stephen

    1984-06-01

    A new class of internally liquid cooled rotating anode x-ray tubes capable of high average and high peak power is proposed for medical applications. The principles of this new tube design are discussed and estimated performance levels are compared to levels attainable with conventional solid rotating anode medical x-ray tubes and with existing liquid cooled rotating anode x-ray tubes. Performance improvements of the proposed tube include essentially unlimited anode Heat Unit loading, and anode cooling rates, peak and continuous, that are more than an order of magnitude greater than is currently available. The new tube would enable present high average power demanding procedures such as CT and digital and conventional vascular angiography to be performed more efficiently and with higher patient throughput. New imaging techniques requiring even higher average power levels such as energy subtraction, slit scanning, x-ray spectrum optimization and special scatter rejection methods would become more clinically practical.

  12. 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.

  13. Methodology for adding glycemic index and glycemic load values to 24-hour dietary recall database

    PubMed Central

    Olendzki, Barbara C.; Ma, Yunsheng; Culver, Annie L.; Ockene, Ira S.; Griffith, Jennifer A.; Hafner, Andrea R.; Hebert, James R.

    2006-01-01

    Objectives We describe a method of adding the glycemic index (GI) and glycemic load (GL) values to the nutrient database of the 24-hour dietary recall interview (24HR), a widely used dietary assessment. We also calculated daily GI and GL values from the 24HR. Methods Subjects were 641 healthy adults from central Massachusetts who completed 9067 24HRs. The 24HR-derived food data were matched to the International Table of Glycemic Index and Glycemic Load Values. The GI values for specific foods not in the table were estimated against similar foods according to physical and chemical factors that determine GI. Mixed foods were disaggregated into individual ingredients. Results Of 1261 carbohydrate-containing foods in the database, GI values of 602 foods were obtained from a direct match (47.7%), accounting for 22.36% of dietary carbohydrate. GI values from 656 foods (52.1%) were estimated, contributing to 77.64% of dietary carbohydrate. The GI values from three unknown foods (0.2%) could not be assigned. The average daily GI was 84 (SD 5.1, white bread as referent) and the average GL was 196 (SD 63). Conclusion Using this methodology for adding GI and GL values to nutrient databases, it is possible to assess associations between GI and/or GL and body weight and chronic disease outcomes (diabetes, cancer, heart disease). This method can be used in clinical and survey research settings where 24HRs are a practical means for assessing diet. The implications for using this methodology compel a broader evaluation of diet with disease outcomes. PMID:17029903

  14. 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).

  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. Heat Loads Due to Small Penetrations in Multilayer Insulation Blankets

    NASA Technical Reports Server (NTRS)

    Johnson, W. L.; Heckle, K. W.; Fesmire, J. E.

    2017-01-01

    The main penetrations (supports and piping) through multilayer insulation systems for cryogenic tanks have been previously addressed by heat flow measurements. Smaller penetrations due to fasteners and attachments are now experimentally investigated. The use of small pins or plastic garment tag fasteners to each the handling and construction of multilayer insulation (MLI) blankets goes back many years. While it has long been understood that penetrations and other discontinuities degrade the performance of the MLI blanket, quantification of this degradation has generally been lumped into gross performance multipliers (often called degradation factors or scale factors). Small penetrations contribute both solid conduction and radiation heat transfer paths through the blanket. The conduction is down the stem of the structural element itself while the radiation is through the hole formed during installation of the pin or fastener. Analytical models were developed in conjunction with MLI perforation theory and Fouriers Law. Results of the analytical models are compared to experimental testing performed on a 10 layer MLI blanket with approximately 50 small plastic pins penetrating the test specimen. The pins were installed at 76-mm spacing inches in both directions to minimize the compounding of thermal effects due to localized compression or lateral heat transfer. The testing was performed using a liquid nitrogen boil-off calorimeter (Cryostat-100) with the standard boundary temperatures of 293 K and 78 K. Results show that the added radiation through the holes is much more significant than the conduction down the fastener. The results are shown to be in agreement with radiation theory for perforated films.

  17. 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)

  18. 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

  19. 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.

  20. High Heat Load Diamond Monochromator Project at ESRF

    NASA Astrophysics Data System (ADS)

    Van aerenbergh, P.; Detlefs, C.; Härtwig, J.; Lafford, T. A.; Masiello, F.; Roth, T.; Schmid, W.; Wattecamps, P.; Zhang, L.

    2010-06-01

    Due to its outstanding thermal properties, diamond is an attractive alternative to silicon as a monochromator material for high intensity X-ray beams. To date, however, the practical applications have been limited by the small size and relatively poor crystallographic quality of the crystals available. The ESRF Diamond Project Group has studied the perfection of diamonds in collaboration with industry and universities. The group has also designed and tested different stress-free mounting techniques to integrate small diamonds into larger X-ray optical elements. We now propose to develop a water-cooled Bragg-Bragg double crystal monochromator using diamond (111) crystals. It will be installed on the ESRF undulator beamline, ID06, for testing under high heat load. This monochromator will be best suited for the low energy range, typically from ˜3.4 keV to 15 keV, due to the small size of the diamonds available and the size of the beam footprint. This paper presents stress-free mounting techniques studied using X-ray diffraction imaging, and their thermal-mechanical analysis by finite element modelling, as well as the status of the ID06 monochromator project.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. Automatic ID heat load generation in ANSYS code

    SciTech Connect

    Wang, Zhibi

    1992-04-30

    Detailed power density profiles are critical in the execution of a thermal analysis using a finite element (FE) code such as ANSYS. Unfortunately, as yet there is no easy way to directly input the precise power profiles into ANSYS. A straight-forward way to do this is to hand-calculate the power of each node or element and then type the data into the code. Every time a change is made to the FE model, the data must be recalculated and reentered. One way to solve this problem is to generate a set of discrete data, using another code such as PHOTON2, and curve-fit the data. Using curve-fitted formulae has several disadvantages. It is time consuming because of the need to run a second code for generation of the data, curve-fitting, and doing the data check, etc. Additionally, because there is no generality for different beamlines or different parameters, the above work must be repeated for each case. And, errors in the power profiles due to curve-fitting result in errors in the analysis. To solve the problem once and for all and with the capability to apply to any insertion device (ID), a program for ED power profile was written in ANSYS Parametric Design Language (APDL). This program is implemented as an ANSYS command with input parameters of peak magnetic field, deflection parameter, length of ID, and distance from the source. Once the command is issued, all the heat load will be automatically generated by the code.

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

    USDA-ARS?s Scientific Manuscript database

    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...

  7. Transient characteristics of a gas-loaded liquid metal heat pipe with a long adiabatic section

    NASA Astrophysics Data System (ADS)

    Ponnappan, R.; Boehman, L. I.; Mahefkey, E. T.

    An area of major concern for high-temperature liquid metal heat pipes used in waste heat rejection systems of spaceborne power plants is the behavior of these devices under transient load conditions during the startup, the shutdown, and the operational variation of thermal loads. This paper considers the transient characteristics of a gas-loaded liquid metal heat pipe pertaining only to the startup from the frozen state. The approach used was to test a specially designed and fabricated 2-m-long sodium heat pipe under simulated heat input and rejection conditions. Both vacuum and gas-filled mode performances were obtained for comparison purposes. It was demonstrated that gas-loading did not adversely affect the priming of the long adiabatic artery groove. The startup from the liquid state was smoother than from the frozen state. Test results are presented on transient temperature profiles at specified axial locations and under different conditions.

  8. Effect of load intensity on heating in a polymer-bonded explosive

    NASA Astrophysics Data System (ADS)

    Kim, Seokpum; Miller, Christopher; Horie, Yasuyuki; Zhou, Min

    2015-06-01

    The ignition behavior of a HMX/Estane polymer-bonded explosive under impact loading with flyer velocities of 200 - 1600 m/s is analyzed using a cohesive finite element method (CFEM) which accounts for large deformation, microcracking, and frictional heating. The formulation admits loading in both the shock and non-shock regimes. The study focuses on the changes in heating mechanisms as the load intensity increases. The heating in the microstructures is quantified in terms of the overall energy dissipation as well as hotspot clustering and density. It is found that microstructural attributes such as volume fraction of HMX, grain surface area, and clustering of grains significantly influence heating and the hotspot development, therefore, the ignition behavior of the materials. In addition, a shift in the dominant heating mechanism is seen as load intensity is increased from that of a non-shock nature to shock. Microstructure-performance relations are obtained.

  9. 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.

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

    PubMed

    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.

  11. Effect of Heat Treatment on the Structure and Properties of Explosion Welded Bimetal Kh20N80 + AD1

    NASA Astrophysics Data System (ADS)

    Shmorgun, V. G.; Arisova, V. N.; Slautin, O. V.; Taube, A. O.; Bakuntseva, V. M.

    2017-05-01

    Results of a study of the effect of heat treatment on the microhardness, structure and phase composition of diffusion zone in explosion-welded `refractory nickel alloy Kh20N80 + aluminum alloy AD1' bimetal are presented.

  12. Computation Method of Heat Loads in Cryogenic Parts of High Temperature Superconductor Synchronous Machines

    NASA Astrophysics Data System (ADS)

    Taku, Seigo; Maki, Naoki

    High temperature superconductor (HTS) synchronous machines are expected to have higher efficiency and smaller size than normal conductor synchronous machines, and are being developed mainly in USA and Germany. This paper describes a computation method of heat loads in cryogenic parts of HTS synchronous machines, and the evaluation study results of heat loads in HTS synchronous motors for blowers, in which Bi-2223 are used at 30K, using the computation method. From the evaluated heat loads, the required capacity of the refrigerator for HTS synchronous machines may be determined.

  13. Influence of transition metals added during sporulation on heat resistance of Clostridium botulinum 113B spores.

    PubMed Central

    Kihm, D J; Hutton, M T; Hanlin, J H; Johnson, E A

    1990-01-01

    Sporulation of Clostridium botulinum 113B in a complex medium supplemented with certain transition metals (Fe, Mn, Cu, or Zn) at 0.01 to 1.0 mM gave spores that were increased two to sevenfold in their contents of the added metals. The contents of calcium, magnesium, and other metals in the purified spores were relatively unchanged. Inclusion of sodium citrate (3 g/liter) in the medium enhanced metal accumulation and gave consistency in the transition metal contents of independent spore crops. In citrate-supplemented media, C. botulinum formed spores with very high contents of Zn (approximately 1% of the dry weight). Spores containing an increased content of Fe (0.1 to 0.2%) were more susceptible to thermal killing than were native spores or spores containing increased Zn or Mn. The spores formed with added Fe or Cu also appeared less able to repair heat-induced injuries than the spores with added Mn or Zn. Fe-increased spores appeared to germinate and outgrow at a higher frequency than did native and Mn-increased spores. This study shows that C. botulinum spores can be sensitized to increased thermal destruction by incorporation of Fe in the spores. PMID:2180370

  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. Exertional Heat Injury: Effects of Adding Cold (4°C) Intravenous Saline to Prehospital Protocol.

    PubMed

    Mok, Gordon; DeGroot, David; Hathaway, Nathanael E; Bigley, Daniel P; McGuire, Christopher S

    This article reviews current prehospital treatment for heat casualties and introduces a retrospective study on the addition of cold (4 °C) intravenous (IV) saline to prehospital treatment and its effect on morbidity. The study is a retrospective cohort reviewing electronic medical records of 290 heat casualties admitted to Martin Army Community Hospital, Ft. Benning, GA, comparing two treatment groups; U.S. Army Training and Doctrine Command (ice-sheeting and ambient temperature IV saline) versus Benning (ice-sheeting and cold IV saline). U.S. Army Training and Doctrine Command group significantly differed from Benning group on a number of measures, the median length of stay in the hospital was 3 and 2 d, respectively (P < 0.0001); pCr were 1.8 to 1.4 mg·dL, respectively (difference of 0.4 mg·dL pCr, P < 0.0001). However, creatine phosphokinase, aspartate aminotransferase, and alanine aminotransferase were not significantly different across groups. Findings demonstrate that adding cold IV saline to ice-sheeting as a protocol reduces the length of hospitalization of heat casualties and lowers their peak creatinine values.

  16. Heating and thermal squeezing in parametrically driven oscillators with added noise.

    PubMed

    Batista, Adriano A

    2012-11-01

    In this paper we report a theoretical model based on Green's functions, Floquet theory, and averaging techniques up to second order that describes the dynamics of parametrically driven oscillators with added thermal noise. Quantitative estimates for heating and quadrature thermal noise squeezing near and below the transition line of the first parametric instability zone of the oscillator are given. Furthermore, we give an intuitive explanation as to why heating and thermal squeezing occur. For small amplitudes of the parametric pump the Floquet multipliers are complex conjugate of each other with a constant magnitude. As the pump amplitude is increased past a threshold value in the stable zone near the first parametric instability, the two Floquet multipliers become real and have different magnitudes. This creates two different effective dissipation rates (one smaller and the other larger than the real dissipation rate) along the stable manifolds of the first-return Poincaré map. We also show that the statistical average of the input power due to thermal noise is constant and independent of the pump amplitude and frequency. The combination of these effects causes most of heating and thermal squeezing. Very good agreement between analytical and numerical estimates of the thermal fluctuations is achieved.

  17. Quantitative evaluation of wall heat loads by lost fast ions in the Large Helical Device

    NASA Astrophysics Data System (ADS)

    Morimoto, Junki; Suzuki, Yasuhiro; Seki, Ryosuke

    2016-10-01

    In fusion plasmas, fast ions are produced by neutral beam injections (NBI), ion cyclotron heating (ICH) and fusion reactions. Some of fast ions are lost from fusion plasmas because of some kinds of drift and instability. These lost fast ions may cause damages on plasma facing components such as divertors and diagnostic instruments in fusion reactors. Therefore, wall heat loads by lost fast ions in the Large Helical Device (LHD) is under investigation. For this purpose, we have been developing the Monte-Carlo code for the quantitative evaluation of wall heat loads based on following the guiding center orbits of fast ions. Using this code, we investigate wall heat loads and hitting points of lost fast ions produced by NBI in LHD. Magnetic field configurations, which depend on beta values, affect orbits of fast ions and wall heat loads. Therefore, the wall heat loads by fast ions in equilibrium magnetic fields including finite beta effect and magnetic islands are quantitatively evaluated. The differences of wall heat loads and particle deposition patterns for cases of the vacuum field and various beta equilibrium fields will be presented at the meeting.

  18. 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.

    2014-10-02

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

    DOE PAGES

    Benafan, O.; Padula, S. A.; Skorpenske, H. D.; ...

    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.

  20. Determination Of Heat Load By Wet Bulb Globe Temperature In Working Environment

    NASA Astrophysics Data System (ADS)

    Králiková, Ružena; Maďoranová, Marieta

    2015-07-01

    Thermal load on people in general depends on the heat production in the human organism as a result of physical activity as well as environmental conditions which are affected by transfer of heat between human and the surrounding area. The resulting effect of metabolic exchanges which occur in work activities is the thermal load of organism. The paper deals with the evaluation of microclimatic conditions of the working environment of workers, who are exposed to the hot environment during their work.

  1. Results of high heat flux tests of tungsten divertor targets under plasma heat loads expected in ITER and tokamaks (review)

    NASA Astrophysics Data System (ADS)

    Budaev, V. P.

    2016-12-01

    Heat loads on the tungsten divertor targets in the ITER and the tokamak power reactors reach 10MW m-2 in the steady state of DT discharges, increasing to 0.6-3.5 GW m-2 under disruptions and ELMs. The results of high heat flux tests (HHFTs) of tungsten under such transient plasma heat loads are reviewed in the paper. The main attention is paid to description of the surface microstructure, recrystallization, and the morphology of the cracks on the target. Effects of melting, cracking of tungsten, drop erosion of the surface, and formation of corrugated and porous layers are observed. Production of submicron-sized tungsten dust and the effects of the inhomogeneous surface of tungsten on the plasma-wall interaction are discussed. In conclusion, the necessity of further HHFTs and investigations of the durability of tungsten under high pulsed plasma loads on the ITER divertor plates, including disruptions and ELMs, is stressed.

  2. Optimal Cooling Load and COP Relationship of a Four-Heat-Reservoir Endoreversible Absorption Refrigeration Cycle

    NASA Astrophysics Data System (ADS)

    Chen, Lingen; Zheng, Tong; Sun, Fengrui; Wu, Chih

    2004-06-01

    On the basis of a four-heat-reservoir endoreversible absorption refrigeration cycle model, another linear heat transfer law [i.e., the heat-flux] is adopted, the fundamental optimal relation between the coefficient of performance (COP) and the cooling load, as well as the maximum cooling load and the corresponding COP of the cycle coupled to constant-temperature heat reservoirs are derived by using finite-time thermodynamics or thermodynamic optimization. The optimal distribution of the heat-transfer surface areas is also obtained. Moreover, the effects of the cycle parameters on the COP and the cooling load of the cycle are studied by detailed numerical examples. The results obtained herein are of importance to the optimal design and performance improvement of an absorption refrigeration cycle.

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

    NASA Astrophysics Data System (ADS)

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

    2014-01-01

    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.

  4. 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.

  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. Trained humans can exercise safely in extreme dry heat when drinking water ad libitum.

    PubMed

    Nolte, Heinrich W; Noakes, Timothy D; Van Vuuren, Bernard

    2011-09-01

    Guidelines to establish safe environmental exercise conditions are partly based on thermal prescriptive zones. Yet there are reports of self-paced human athletic performances in extreme heat. Eighteen participants undertook a 25-km route march in a dry bulb temperature reaching 44.3°C. The mean (± s) age of the participants was 26.0 ± 3.7 years. Their mean ad libitum water intake was 1264 ± 229 mL · h(-1). Predicted sweat rate was 1789 ± 267 mL · h(-1). Despite an average body mass loss of 2.73 ± 0.98 kg, plasma osmolality and serum sodium concentration did not change significantly during exercise. Total body water fell 1.47 kg during exercise. However, change in body mass did not accurately predict changes in total body water as a 1:1 ratio. There was a significant relationship (negative slope) between post-exercise serum sodium concentration and changes in both body mass and percent total body water. There was no relationship between percent body mass loss and peak exercise core temperature (39 ± 0.9°C) or exercise time. We conclude that participants maintained plasma osmolality, serum sodium concentration, and safe core temperatures by (1) adopting a pacing strategy, (2) high rates of ad libitum water intake, and (3) by a small reduction in total body water to maintain serum sodium concentration. Our findings support the hypothesis that humans are the mammals with the greatest capacity for exercising in extreme heat.

  7. Coronal Loops Heating in the Atmosphere of the Ad Leo Red Dwarf

    NASA Astrophysics Data System (ADS)

    Zaitsev, V. V.; Kronshtadtov, P. V.

    2016-08-01

    We study the possible origin of long-lasting soft X-ray flares on the AD Leo star, which were observed onboard the Extreme Ultraviolet Explorer (EUVE) spacecraft for the period of 1993-2000 [1]. These flares have relatively long rise and decay times of the radiation intensity ( τ R ≈ 104 s and τ d ≈ 5 · 103, respectively), as well as a relatively large emission measure EM ≈ 1051cm-3, which exceeds by 1-3 orders of magnitude the emission measure of soft X-ray flares on the Sun. Assuming that the radiation appears in magnetic loops and basing on the observed values of the emission measure and radiation decay time, the authors of [1] determined the typical length overline{l}≈ 1.5\\cdot {10}^{10} cm , electron number density overline{n}≈ 3\\cdot {10}^{11}c{m}^{-3} , and plasma temperature overline{T}≈ 2.5\\cdot 107 K of the loops. This paper considers plasma heating due to dissipation of the electric currents in the coronal magnetic loops of the star induced by the photospheric convection. The large inductance of the loop as an equivalent electric circuit determines the long time of the current rise in the source and explains the observed time of plasma heating and the rise time of the X-ray radiation intensity. It is shown that the parameters of the X-ray sources in the AD Leo atmosphere agree with the parameters calculated under the assumption of simultaneous emission of a great number of loops (about 50) with electric currents greater than 1013 A, which exceeds the electric currents in the solar coronal magnetic loops by 1-3 orders of magnitude. Such an exceeding can be related to the higher photospheric convection velocities on the late-type stars compared with the Sun.

  8. 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.

  9. Studies of air traffic forecasts, airspace load and the effect of ADS-B via satellites on flight times

    NASA Astrophysics Data System (ADS)

    Zhong, Z. W.; Ridhwan Salleh, Saiful; Chow, W. X.; Ong, Z. M.

    2016-10-01

    Air traffic forecasting is important as it helps stakeholders to plan their budgets and facilities. Thus, three most commonly used forecasting models were compared to see which model suited the air passenger traffic the best. General forecasting equations were also created to forecast the passenger traffic. The equations could forecast around 6.0% growth from 2015 onwards. Another study sought to provide an initial work for determining a theoretical airspace load with relevant calculations. The air traffic was simulated to investigate the current airspace load. Logical and reasonable results were obtained from the modelling and simulations. The current utilization percentages for airspace load per hour and the static airspace load in the interested airspace were found to be 6.64% and 11.21% respectively. Our research also studied how ADS-B would affect the time taken for aircraft to travel. 6000 flights departing from and landing at the airport were studied. New flight plans were simulated with improved flight paths due to the implementation of ADS-B, and flight times of all studied flights could be improved.

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

    PubMed Central

    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

  11. 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.

  12. 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

  13. 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.

  14. Dependence of Dynamic Tensile Strength of Longyou Sandstone on Heat-Treatment Temperature and Loading Rate

    NASA Astrophysics Data System (ADS)

    Yao, Wei; Xu, Ying; Wang, Wei; Kanopolous, Patrick

    2016-10-01

    As a material for famous historical underground rock caverns, Longyou sandstone (LS) may fail under the combination of high loading rate and high temperature. The thermal damage induced by various heat-treatment temperatures (150, 250, 350, 450, 600 and 850 °C) is first characterized by X-ray Micro-computed tomography (CT) method. The damage variable derived from the average CT value for heat-treated LS specimen and reference specimen without heat treatment was used to quantify the thermal damage. The dynamic tensile strengths of these LS samples under different dynamic loading rates (ranging from 24 to 540 GPa/s) were then obtained using the split Hopkinson pressure bar (SHPB) system. The dynamic tensile strength of LS increases with the loading rate at a given heat-treatment temperature, and the tensile strength at the same loading rate decreases with the heat-treatment temperature except for 450 °C. Based on the experimental data, an empirical equation was established to relate the dynamic tensile strength of LS to the loading rate and the heat-treatment temperature.

  15. Calorimetric measurement of heat load in full non-inductive LHCD plasmas on TRIAM-1M

    NASA Astrophysics Data System (ADS)

    Hanada, K.; Shinoda, N.; Sugata, T.; Sasaki, K.; Zushi, H.; Nakamura, K.; Sato, K. N.; Sakamoto, M.; Idei, H.; Hasegawa, M.; Kawasaki, S.; Nakashima, H.; Higashijima, A.; Triam Group

    2007-06-01

    Calorimetric measurements using the temperature increment of cooling-water were carried out to estimate the heat load distribution on the plasma facing components (PFCs) in the limiter discharges on TRIAM-1M. Line averaged electron density, ne, and LH power, PLH, dependences of the heat load on PFCs were measured. The heat load on the limiters was proportional to ne1.5 in the range of ne = 0.2-1.0 × 1019 m-3 and PLH1 in the range of PLH = 0.005-0.09 MW. For PLH > 0.1 MW, the plasma transition to an enhanced current drive (ECD) mode appeared and the ne dependences on the heat load on the limiter moderated. This indicates that the heat flux to scrape-off layer (SOL) region was reduced due to the improvement of the plasma confinement. The up-down asymmetry of the heat load on the vacuum vessel was enhanced in the ECD mode, which may be caused by the increasing of the direct loss of energetic electrons.

  16. Diffusion-controlled startup of a gas-loaded liquid-metal heat pipe

    NASA Astrophysics Data System (ADS)

    Ponnappan, R.; Boehman, L. I.; Mahefkey, E. T.

    1990-07-01

    Liquid-metal heat pipes have exhibited difficulties starting up from a frozen-state. Inert gas loading is a possible solution to the frozen-state startup problem. The present study deals with the diffusion-controlled startup analysis and testing of an argon-loaded, 2-m-long, stainless steel-sodium heat pipe of the double-walled type with artery channel and long adiabatic section. A two-dimensional, quasi-steady state, binary vapor-gas diffusion model determined the energy transport rate of vapor at the diffusion front. The analytical solution to the diffusion problem provided the vapor flux, which in turn was used in the one-dimensional transient thermal model of the heat pipe to predict the time rate-of-change of temperature and position of the hot front. The experimental test results successfully demonstrated the startup of a gas-loaded sodium heat pipe and validated the diffusion model of the startup.

  17. Thermally determining flow and/or heat load distribution in parallel paths

    SciTech Connect

    Chainer, Timothy J.; Iyengar, Madhusudan K.; Parida, Pritish R.

    2016-12-13

    A method including obtaining calibration data for at least one sub-component in a heat transfer assembly, wherein the calibration data comprises at least one indication of coolant flow rate through the sub-component for a given surface temperature delta of the sub-component and a given heat load into said sub-component, determining a measured heat load into the sub-component, determining a measured surface temperature delta of the sub-component, and determining a coolant flow distribution in a first flow path comprising the sub-component from the calibration data according to the measured heat load and the measured surface temperature delta of the sub-component.

  18. How to match an acoustical load to a thermoacoustic heat engine?

    NASA Astrophysics Data System (ADS)

    Zhang, L. M.; Chen, Y. Y.; Luo, E. C.

    2014-01-01

    The efficient operation of a thermoacoustic prime mover and its acoustic load depends on whether they match each other. In this paper, a numerical simulation of RC-type and RL-type acoustic loads driven by a traveling-wave thermoacoustic engine with constant heating temperature was carried out. It is found that the dependence of the output acoustic power and efficiency on the acoustic load is quite complicated and unique. There are several critical acoustic loads which can characterize the unique output performance of the acoustic heat engine. In addition, a trade-off between net acoustic power and thermal efficiency needs to be made. This work is helpful to provide guidance on how to design an efficiently loaded thermoacoustic engine.

  19. Comfort air temperature influence on heating and cooling loads of a residential building

    NASA Astrophysics Data System (ADS)

    Stanciu, C.; Șoriga, I.; Gheorghian, A. T.; Stanciu, D.

    2016-08-01

    The paper presents the thermal behavior and energy loads of a two-level residential building designed for a family of four, two adults and two students, for different inside comfort levels reflected by the interior air temperature. Results are intended to emphasize the different thermal behavior of building elements and their contribution to the building's external load. The most important contributors to the building thermal loss are determined. Daily heating and cooling loads are computed for 12 months simulation in Bucharest (44.25°N latitude) in clear sky conditions. The most important aspects regarding sizing of thermal energy systems are emphasized, such as the reference months for maximum cooling and heating loads and these loads’ values. Annual maximum loads are encountered in February and August, respectively, so these months should be taken as reference for sizing thermal building systems, in Bucharest, under clear sky conditions.

  20. 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.

  1. Induction of denitrification in a pilot-scale trickling filter by adding nitrate at high loading rate.

    PubMed

    Vanhooren, H; De Pauw, D; Vanrolleghem, P A

    2003-01-01

    Oxygen transferred from the liquid phase into a biofilm can be used for aerobic degradation of organic matter and for nitrification. A second possible pathway for the removal of organic matter is denitrification in anoxic zones deeper in the biofilm. At high organic loading rates with insufficient oxygen supply to the biofilm, denitrification could be induced by providing the biofilm with external nitrate. This possibility was tested in a pilot-scale trickling filter by adding a pulse of nitrate to a highly loaded trickling filter. The experiment showed that denitrification can indeed be induced by adding nitrate at high loading conditions and that this way a considerably increased substrate removal capacity can be obtained. The fact that denitrification occurred was confirmed by the increased production of CO2 from bioconversion processes, without a major change of the O2 consumption. The simplified mixed-culture biofilm model developed by Rauch et al. was extended for the description of off-gas measurements and was able to describe the results of the experiment very well.

  2. 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.

  3. 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.

  4. 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. __________________________________________________

  5. Lactating red squirrels experiencing high heat load occupy less insulated nests.

    PubMed

    Guillemette, Christina U; Fletcher, Quinn E; Boutin, Stan; Hodges, Ryan M; McAdam, Andrew G; Humphries, Murray M

    2009-04-23

    The heat dissipation limit hypothesis suggests that the capacity for lactating mammals to transfer energy to their offspring through milk may be constrained by limits on heat dissipation, particularly in species that raise offspring in well-insulated nests. We tested a prediction of this hypothesis by evaluating whether lactating free-ranging red squirrels (Tamiasciurus hudsonicus) occupy less insulated nests when experiencing conditions that increase heat load. In support of the hypothesis, when climate normal ambient temperatures were warm, squirrels supporting large litter masses of furred offspring occupied nests of lower insulative value. These results support the heat dissipation limit hypothesis and suggest that free-ranging mammals may select nests based on their insulative value, not only to reduce heat loss in cold conditions but also to dissipate heat during periods of heat stress.

  6. High performance microchannel heat exchanger for cooling high heat load x-ray optical elements

    SciTech Connect

    Choi, U.S.; Rogers, C.S.; Mills, D.M.

    1992-01-01

    Analysis has been carried out to demonstrate that a liquid nitrogen cooled microchannel heat exchanger can be designed to maximize the heat transfer from silicon to the working fluid. The results show that the performance of the liquid nitrogen cooled microchannel heat exchanger is significantly enhanced by approximately three times over flowing water through microchannels.

  7. High performance microchannel heat exchanger for cooling high heat load x-ray optical elements

    SciTech Connect

    Choi, U.S.; Rogers, C.S.; Mills, D.M.

    1992-12-01

    Analysis has been carried out to demonstrate that a liquid nitrogen cooled microchannel heat exchanger can be designed to maximize the heat transfer from silicon to the working fluid. The results show that the performance of the liquid nitrogen cooled microchannel heat exchanger is significantly enhanced by approximately three times over flowing water through microchannels.

  8. Modeling of pulsed heat load in a cryogenic SHe loop using Artificial Neural Networks

    NASA Astrophysics Data System (ADS)

    Savoldi Richard, L.; Bonifetto, R.; Carli, S.; Grand Blanc, M.; Zanino, R.

    2013-10-01

    The pulsed heat load to the cryoplant is an important issue in the design and operation of tokamaks adopting superconducting (SC) magnets for the magnetic confinement, as the International Thermonuclear Experimental Reactor (ITER). The smoothing of the heat load during plasma operation is being addressed by experiments, e.g. in the HELIOS facility at CEA Grenoble, and simulations. The assessment of the operation of the cryoplant mainly requires the knowledge of the evolution of the heat load to the liquid helium (LHe) baths that are used as interfaces/buffers between the magnets cooling loops and the cryoplant itself. In this paper, an innovative approach based on Artificial Neural Networks (ANNs) is presented, leading to a simplified but fast model of the transient heat load from the magnets to the LHe baths. An ANN model is developed for the HELIOS loop and the resulting network is trained using detailed transient simulations performed with the 4C code, which was previously extensively validated against experimental data from HELIOS. The predictive capability of the (simplified) ANN model is then demonstrated by considering another, independent dataset, not used during the ANN training, and comparing the evolution of the heat load to the LHe bath computed by the ANNs with that obtained from the (detailed) 4C model.

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

    NASA Astrophysics Data System (ADS)

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

    2013-06-01

    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.

  10. 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.

  11. 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.

  12. 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.

  13. An evaluation of enhanced cooling techniques for high-heat load absorbers.

    SciTech Connect

    Sharma, S.; Doose, C.; Rotela, E.; Barickowski, A.

    2002-10-28

    Many components of the storage ring and front ends in the third generation of light sources are subjected to high heat loads from intense x-rays. Temperature rises and thermal stresses in these components must be kept within acceptable limits of critical heat flux and low-cycle fatigue failure. One of the design solutions is to improve heat transfer to the cooling water either by increasing water velocity in the cooling channels or by using inserts, such as porous media, twisted tapes and wire springs. In this paper we present experimental and analytical results to compare various enhanced cooling techniques for conditions specific to heating from an x-ray fan.

  14. The effect of wall mass on winter heating loads and indoor comfort: An experimental study

    SciTech Connect

    Bruch, D.M.; Krintz, D.F.; Spain, R.S.

    1984-01-01

    Six test buildings were extensively instrumented for measuring heating loads and indoor comfort and were exposed to a winter heating season and an intermediate heating season. The test buildings were 20 x 20 ft. (6.1 x 6.1 m) one-room buildings constructed at Gaithersburg, MD. The buildings had the same floor plan and orientation, and were identical, except for the wall construction, which was as follows: insulated lightweight wood frame; uninsulated lightweight wood frame; insulated masonry with outside mass; uninsulated masonry; log; and insulated masonry with inside mass. The construction of the buildings generally was selected to be representative of current practice. During the winter season, when some space heating was supplied each hour of the test, measured heating loads were predicted with a steady-state heat-transfer model that did not include the effect of thermal mass, thereby indicating no thermal mass effect. The indoor comfort was not affected by wall mass. During the intermediate heating season, when solar window and occupancy heat gains caused the indoor temperatures to float above the thermostat set temperatures during warm day periods, a significant thermal mass effect was observed. Heavyweight buildings were observed to consume less heating energy than comparable lightweight, buildings having equivalent wall thermal resistance. The effect was greater when wall mass was positioned, inside as opposed to outside, the wall insulation. Wall mass was observed to reduce overheating considerably during warm day periods.

  15. Erosion of newly developed CFCs and Be under disruption heat loads

    NASA Astrophysics Data System (ADS)

    Nakamura, K.; Akiba, M.; Araki, M.; Dairaku, M.; Sato, K.; Suzuki, S.; Yokoyama, K.; Linke, J.; Duwe, R.; Bolt, H.; Roedig, M.

    1996-10-01

    An evaluation of the erosion under disruption heat loads is very important to the lifetime prediction of divertor armour tiles of next fusion devices such as ITER. In particular, erosion data on CFCs (carbon fiber reinforced composites) and beryllium (Be) as the armour materials is urgently required in the ITER design. For CFCs, high heat flux experiments on the newly developed CFCs with high thermal conductivity have been performed under the heat flux of around 800-2000 MW/m 2 and the pulse length of 2-5 ms in JAERI electron beam irradiation systems (JEBIS). As a result, the weight losses of B 4C doped CFCs after heating were almost same to those of the non doped CFC up to 5 wt% boron content. For Be, we have carried out our first disruption experiments on S65/C grade Be specimens in the Juelich divertor test facility in hot cells (JUDITH) facility as a frame work of the J—EU collaboration. The heating conditions were heat loads of 1250-5000 MW/m 2 for 2-8 ms, and the heated area was 3 × 3 mm 2. As a result, the protuberances of the heated area of Be were observed under the lower heat flux.

  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. Water flow calorimetry measurements of heat loads for a volume production H/sup -/ source

    SciTech Connect

    Purgalis, P.; Ackerman, G.; Kwan, J.; Wells, R.P.

    1987-10-01

    The design of volume-production H/sup -/ sources requires the knowledge of heat loads on the source components. The arc and filament heater power input to a 20 cm diameter x 23 cm long source can be 50 kW or higher, practically all of which is absorbed in the cooling water. Water flow calorimetry measurements were made to determine the heat loads on the bucket walls, grid no. 1, and magnetic filter rods. The measurements are presented for two different filament locations, for three different values of arc power, and for three values of source gas pressure. 1 ref., 4 figs., 2 tabs.

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

    PubMed

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

    2010-02-01

    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 x 1-cm(2) 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.

  19. 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

  20. 24 CFR 3280.508 - Heat loss, heat gain and cooling load calculations.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... and data necessary for heat loss and heat gain determinations must be taken from the 1997 ASHRAE... be in accordance with the fundamental principles of the 1997 ASHRAE Handbook of Fundamentals, Inch... the residential window U values contained in Chapter 29, Table 5 of the 1997 ASHRAE Handbook...

  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. Dietary glycemic load, added sugars, and carbohydrates as risk factors for pancreatic cancer: the Multiethnic Cohort Study.

    PubMed

    Nöthlings, Ute; Murphy, Suzanne P; Wilkens, Lynne R; Henderson, Brian E; Kolonel, Laurence N

    2007-11-01

    Because elevated blood glucose concentrations have been shown to be associated with greater risk of pancreatic cancer, a high dietary glycemic load, which is based on an empirical measure of blood glucose response after food consumption, has been hypothesized as a pancreatic cancer risk factor. However, results so far are scarce and inconsistent. We analyzed data for 162 150 participants in the Hawaii-Los Angeles Multiethnic Cohort Study to investigate associations between glycemic load, dietary carbohydrates, sucrose, fructose, total sugars, and added sugars and the risk of pancreatic cancer. Dietary intake was assessed at baseline by using a quantitative food-frequency questionnaire. During 8 y of follow-up, 434 incident pancreatic cancer cases occurred. Glycemic load and added sugars were not significantly associated with pancreatic cancer risk. The risk increased with higher intakes of total sugars, fructose, and sucrose, and the association with fructose was significant when the highest and lowest quartiles were compared (relative risk: 1.35; 95% CI: 1.02, 1.80; P for trend = 0.046). A significant association was found with fruit and juices intake (1.37; 1.02, 1.84; P for trend = 0.04) but not with soda intake. Statistical evidence of a significant interaction with body mass index was present only for sucrose intake (P = 0.04). A comparison of the highest and lowest quartiles of sucrose intake in overweight or obese participants gave a relative risk of 1.46 (0.95-2.25; P for trend = 0.04), but the comparison was not significant in normal-weight participants. High fructose and sucrose intakes may play a role in pancreatic cancer etiology. Conditions such as overweight or obesity in which a degree of insulin resistance may be present may also be important.

  4. Effect of the load size on the efficiency of microwave heating under stop flow and continuous flow conditions.

    PubMed

    Patil, Narendra G; Rebrov, Evgeny V; Eränen, Kari; Benaskar, Faysal; Meuldijk, Jan; Mikkola, Jyri-Pekka; Hessel, Volker; Hulshof, Lumbertus A; Murzin, Dmitry Yu; Schouten, Jaap C

    2012-01-01

    A novel heating efficiency analysis of the microwave heated stop-flow (i.e. stagnant liquid) and continuous-flow reactors has been presented. The thermal losses to the surrounding air by natural convection have been taken into account for heating efficiency calculation of the microwave heating process. The effect of the load diameter in the range of 4-29 mm on the heating efficiency of ethylene glycol was studied in a single mode microwave cavity under continuous flow and stop-flow conditions. The variation of the microwave absorbing properties of the load with temperature was estimated. Under stop-flow conditions, the heating efficiency depends on the load diameter. The highest heating efficiency has been observed at the load diameter close to the half wavelength of the electromagnetic field in the corresponding medium. Under continuous-flow conditions, the heating efficiency increased linearly. However, microwave leakage above the propagation diameter restricted further experimentation at higher load diameters. Contrary to the stop-flow conditions, the load temperature did not raise monotonously from the inlet to outlet under continuous-flow conditions. This was due to the combined effect of lagging convective heat fluxes in comparison to volumetric heating. This severely disturbs the uniformity of the electromagnetic field in the axial direction and creates areas of high and low field intensity along the load Length decreasing the heating efficiency as compared to stop-flow conditions.

  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. Results of high heat flux tests of tungsten divertor targets under plasma heat loads expected in ITER and tokamaks (review)

    SciTech Connect

    Budaev, V. P.

    2016-12-15

    Heat loads on the tungsten divertor targets in the ITER and the tokamak power reactors reach ~10MW m{sup −2} in the steady state of DT discharges, increasing to ~0.6–3.5 GW m{sup −2} under disruptions and ELMs. The results of high heat flux tests (HHFTs) of tungsten under such transient plasma heat loads are reviewed in the paper. The main attention is paid to description of the surface microstructure, recrystallization, and the morphology of the cracks on the target. Effects of melting, cracking of tungsten, drop erosion of the surface, and formation of corrugated and porous layers are observed. Production of submicron-sized tungsten dust and the effects of the inhomogeneous surface of tungsten on the plasma–wall interaction are discussed. In conclusion, the necessity of further HHFTs and investigations of the durability of tungsten under high pulsed plasma loads on the ITER divertor plates, including disruptions and ELMs, is stressed.

  7. Response of boar sperm to the treatment with cholesterol-loaded cyclodextrins added prior to cryopreservation.

    PubMed

    Blanch, E; Tomás, C; Graham, J K; Mocé, E

    2012-12-01

    Cryopreserved boar sperm is not used extensively for artificial insemination, owing to the poor fertility rates of the sperm after freezing and thawing. The sperm membrane is damaged as the cells are cooled from body temperature to 5°C (cold shock), as well as during the freeze-thaw process. Increasing the cholesterol content of boar sperm membranes could help them survive cryopreservation, similar to sperm from other species that are cold shock sensitive. The aim of this study was to determine the optimal cholesterol-loaded cyclodextrin (CLC) concentration to use for boar sperm cryopreservation, and the influence of CLCs on the cryosurvival of sperm from boars classified as good or poor freezers. Treating boar sperm with 1 mg of CLC/120 × 10(6) sperm slightly improved (p < 0.05) the percentage of viable sperm after freezing-thawing. On the other hand, sperm, from both good and poor freezers, responded similarly to CLC treatment. Nevertheless, additional studies will be needed to study the effect of this treatment on other parameters of sperm quality.

  8. Infrared testing for engine blades crack defects with laser scanning automatic heat loading

    NASA Astrophysics Data System (ADS)

    Bai, Fengming; Song, Nuan; Wang, Lixiao

    2008-12-01

    In this paper, automatic scanning infrared laser nondestructive testing methods, such as aero-engine blades crack detection of defects; Use of thermal heating differential equations and leaves the surface temperature distribution in the infrared detection system to allow resolution under discussion laser scanning heating infrared detection engine blades crack defects. The method can be nondestructive testing of metal parts of the internal defects, such as micro-cracks, loose, porosity and so on, like the thin parts more effective. First introduced in the infrared detection system works as using laser scans of the work piece to be seized automatic heating pretreatment, to detect internal defects part of the nature and characteristics of purpose. The paper also build a two-dimensional analysis model of detected objects because of defective parts and non-defective parts of the geometry and physical properties of heat there is an obvious difference in surface temperature caused by the different response, therefore, can discuss affect of the temperature distribution of information, to determine the appropriate method. Discuss and analysis interaction between the loading heat flux density, length and depth of defects, and do some heat transfer analysis to measured the surface temperature distribution. Through load a constant heat flow to blades, the infrared detection system can obtain the surface temperature field of existence the temperature difference, which blades cracks determine the existence and its location.

  9. 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.

  10. Thermal response of actively cooled tungsten monoblocks to inhomogeneous surface heat loading

    NASA Astrophysics Data System (ADS)

    Patil, Y.; Khirwadkar, S. S.; Krishnan, D.

    2017-04-01

    Tungsten (W) monoblocks of the Plasma Facing Unit (PFU) are exposed to the inhomogeneous heat loads arises due to exponentially decaying power flux along Scrap of Layer (SOL) away from the separatrix as well as fabrication tolerances and misalignment of divertor targets in poloidal and toroidal directions. Thermal and structural analysis of a tungsten monoblock under such inhomogeneous heat loads are need to be investigated. The paper presents the results of Finite Element Analysis (FEA) performed on a tungsten monoblock loaded by inhomogeneous surface heat flux 10 MW/m2 on the plasma wetted area of tungsten monoblock and 4 MW/m2 on the shaded area with magnetically shadowed fraction of the monoblock length (Lshad) variation from 20% to 95% by a step of 15%. The other case is the total incident heat flux 20 MW/m2 on the plasma wetted area of tungsten monoblock and no heat flux on the shaded area of a tungsten monoblock with Lshad variation from 20% to 95% by a step of 15%. FEA concluded that when Lshad is increased from 20% to 95% the total power to the monoblock decreases and the peak surface temperature decreases.

  11. 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.

  12. Influence of an eccentric load added at the back of the head on head-neck posture.

    PubMed

    Pavan, Esteban E; Frigo, Carlo A; Pedotti, Antonio

    2013-09-01

    A biomechanical study of the head-neck complex in seated subjects was conducted to verify whether a slight load, applied at the back of the head, could beneficially affect the head-neck posture, one of the factors of postural neck pain. An eccentric load of 0.5 kg was applied to the subjects' head by means of a special cap. A group of asymptomatic subjects (n=10, 28.9±12.1 yrs), and a group of subjects that had experienced mild, occasional neck pain (n=10, 39.6±18.4 yrs) were compared. They were analyzed while maintaining a still posture that was periodically perturbed to avoid habituation. A 3D motion analyzer and reflective markers placed over the head, the neck and the trunk, were used to compute head inclination and translation and head/neck flexion angle in different conditions: before, during and after having had the load applied for 15 min. Although the moment induced by the load was extensor, a forward-oriented movement of the head was observed in both groups. However, the forward displacement, in relation to the initial position, was smaller in the mild neck pain group than in the asymptomatic group (5.7±4.7 mm vs. 8.9±5.5 mm, P<0.05 and 2.6±5.9 mm vs. 11.0±9.0 mm after 15 min, P<0.05). After removing the load, the mild neck pain subjects assumed a retracted position (-3.8±2.7 mm) while the asymptomatic subjects stayed protracted (+3.5±5.1 mm, P<0.01). These unexpected findings suggest that a slight load added to the head can influence the postural control mechanisms and, in symptomatic subjects, lead to a new strategy aimed at a reduction of the neck extensor muscle contraction. Copyright © 2013 Elsevier B.V. All rights reserved.

  13. 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.

  14. 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.

  15. Erosion simulation of first wall beryllium armour under ITER transient heat loads

    NASA Astrophysics Data System (ADS)

    Bazylev, B.; Janeschitz, G.; Landman, I.; Pestchanyi, S.; Loarte, A.

    2009-04-01

    The beryllium is foreseen as plasma facing armour for the first wall in the ITER in form of Be-clad blanket modules in macrobrush design with brush size about 8-10 cm. In ITER significant heat loads during transient events (TE) are expected at the main chamber wall that may leads to the essential damage of the Be armour. The main mechanisms of metallic target damage remain surface melting and melt motion erosion, which determines the lifetime of the plasma facing components. Melting thresholds and melt layer depth of the Be armour under transient loads are estimated for different temperatures of the bulk Be and different shapes of transient loads. The melt motion damages of Be macrobrush armour caused by the tangential friction force and the Lorentz force are analyzed for bulk Be and different sizes of Be-brushes. The damage of FW under radiative loads arising during mitigated disruptions is numerically simulated.

  16. The Evaluation of the Heat Loading from Steady, Transient, and Off-Normal Conditions in ARIES Power Plants

    SciTech Connect

    C.E. Kessel, M.S. Tillack and J. Blanchard

    2012-09-07

    The heat loading on plasma facing components (PFCs) provides a critical limitation for design and operation of the first wall, divertor, and other special components. Power plants will have high power entering the scrape-off layer and transporting to the first wall and divertor. Although the design for steady heat loads is understood, the approach for transient and offnormal loading is not. The characterization of heat loads developed for ITER1 can be applied to power plants to better develop the operating space of viable solutions and point to research focus areas.

  17. 24 CFR 3280.508 - Heat loss, heat gain and cooling load calculations.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... Floor Systems 23.15Pipes 23.17Tanks, Vessels, and Equipment 23.18Refrigerated Rooms and Buildings 24.18Mechanical and Industrial Systems 25.19Commercial Building Envelope Leakage 27.9Calculation of Heat Loss from... consistent with the calculation procedures provided in the document, Overall U-values and...

  18. 24 CFR 3280.508 - Heat loss, heat gain and cooling load calculations.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... one-half the nominal insulation level of the surrounding building component. (d) High efficiency... Floor Systems 23.15Pipes 23.17Tanks, Vessels, and Equipment 23.18Refrigerated Rooms and Buildings 24.18Mechanical and Industrial Systems 25.19Commercial Building Envelope Leakage 27.9Calculation of Heat Loss...

  19. 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

  20. Localized Fast-Ion Induced Heat Loads in Test Blanket Module Mockup Experiments on DIII-D

    NASA Astrophysics Data System (ADS)

    Kramer, G. J.; Budny, R. V.; Ellis, R. A.; Nazikian, R.; McLean, A. G.; Brooks, N. H.; Schaffer, M. J.; van Zeeland, M. A.; Heidbrink, W. W.; Kurki-Suonio, T.; Koskela, T.; Shinohara, K.; Snipes, J. A.; Spong, D. A.

    2012-10-01

    Localized hot spots can be created in ITER on the Test Blanket Modules (TBMs) because the ferritic steel of the TBMs distorts the local magnetic field near the modules and alters fast ion confinement. Predicting the TBM heat load levels is important for assessing their effects on the ITER first wall. Experiments in DIII-D were carried out with a mock-up of the ITER TBM ferromagnetic error field to provide data for validation of fast-ion orbit following codes. The front surface temperature of the protective TBM tiles was imaged directly with a calibrated infrared camera and heat loads were extracted. The detailed spot sizes and measured heat loads are compared with results from heat load calculations performed with a suite of orbit following codes. The codes reproduce the hot spots well, thereby validating the codes and giving confidence in predictions for fast-ion heat loads in ITER.

  1. 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.

  2. Dielectric-loaded coaxial-slot antenna for interstitial microwave hyperthermia: longitudinal control of heating patterns.

    PubMed

    Hamada, L; Saito, K; Yoshimura, H; Ito, K

    2000-01-01

    In this paper, the microwave interstitial antenna with the dielectric load in part near the tip is introduced to realize the tip-heating and to improve the dependence of the heating patterns on the insertion depth. Numerical simulations using the Finite Difference Time Domain (FDTD) method have been conducted at the frequency of 915 MHz for four different configurations of the coaxial-slot antenna inserted into a catheter: the media between the antenna and the catheter are (a) no, (b) a thin air layer, (c) a thin dielectric layer, and (d) a thin air layer and a dielectric load in part near the tip. The diameter of the antenna including the catheter is sufficiently small for minimally invasive therapy. Comparison of the SARs for the four configurations makes it clear that the dielectric-loaded antenna can realize the best tip-heating and suppress the hot spot near the surface of the human body. Dependence of the SAR distributions on the insertion depth of the antenna has also been examined. It is found from the investigation that the dielectric-loaded antenna has little dependence on the insertion depth.

  3. 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.

  4. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2015-09-01

    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 Ip. 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/Ip 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/Ip scaling, the inclusion of the anomalous transport that is driven by ballooning-type instabilities results in recovering the neoclassical 1/Ip 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.

  6. 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.

  7. Effects of adding injection-compression to rapid heat cycle molding on the structure of a light guide plate

    NASA Astrophysics Data System (ADS)

    Hong, Seokkwan; Min, Inki; Yoon, Kyunghwan; Kang, Jeongjin

    2014-01-01

    This study investigates the effects of adding injection-compression to rapid heat cycle molding (RHCM) (rapid heat cycle injection-compression molding (RICM)) on the physical quality and optical anisotropy of a molded light guide plate (LGP). Transcription ratio of microstructure, uniformity of part thickness and birefringence were experimentally evaluated on a 7 inch LGP of nominal thickness of 1.12 mm (including a microstructure array of 30 µm diameter and 14 µm height). The designed mold was equipped with rapid heating and compressing facilities and a microstructured nickel stamper was fabricated by UV LIGA process. In addition, to investigate the efficacy of RICM, experiments involving conventional injection molding (CIM), ICM, and RHCM were conducted in parallel with RICM using the same mold. RHCM and RICM yielded excellent transcription ratios for the microstructure, while CIM and RICM provided high thickness uniformity and low birefringence. Thus, RICM obtains high transcription ratio of microstructure, uniform thickness and low birefringence.

  8. Quasi-steady state thermal resistance of a flexible copper-water heat pipe subjected to transient acceleration loading

    SciTech Connect

    Thomas, S.K.; Yerkes, K.L.

    1996-12-31

    The thermal performance of a flexible copper-water heat pipe is investigated to determine its quasi-steady state characteristics under varying acceleration loadings. This was accomplished by attaching the heat pipe to a centrifuge table, where the imposed angular velocity was sinusoidal in nature. It was found that the thermal resistance of the heat pipe is a function of the acceleration frequency, heat input, condenser temperature, and dryout condition prior to changing the frequency. The objective of the present experimental study is to determine the potential performance characteristics of heat pipes used as heat sinks in transient acceleration environments typical of those seen in high-performance aircraft. In addition, this research will enable heat pipe designers to re-examine the effects of accelerations loading with respect to heat pipe wick and containment structures, so that new wicks and heat pipe shells can be developed and designed specifically for exploitation of the phenomena which occur in transient acceleration fields.

  9. Heat acclimation decreases the growth hormone response to acute constant-load exercise in the heat.

    PubMed

    Oöpik, Vahur; Timpmann, Saima; Kreegipuu, Kairi; Unt, Eve; Tamm, Maria

    2014-02-01

    The major objective of this study was to elucidate the effect of heat acclimation on blood growth hormone (GH) response to moderate intensity exhausting exercise in the heat. In addition, the potential relationship between inter-individual differences in GH response to exercise and variability in exercise-induced sweat loss was investigated. Twenty young men completed three exercise tests on a treadmill: H1 (walk at 60% VO₂peak until exhaustion at 42 °C), N (walk at 22 °C; duration equal to H1) and H2 (walk until exhaustion at 42 °C after a 10-day heat acclimation program). Core temperature (T(c)) was recorded continuously and venous blood samples were taken before, during and after each exercise test. Exercise-induced sweat production was calculated on the basis of body mass change taking into account water intake and the volume of blood samples drawn. Lower pre-exercise T(c), lower rate of rise in T(c) during exercise, and prolonged time to exhaustion in H2 compared with H1 revealed that the subjects successfully achieved an acclimated state. Overall, serum GH level was higher in H1 compared with both N and H2 (p<0.001) but did not differ between the two latter trials (p>0.05). T(c) correlated with serum GH concentration (r=0.615, p<0.01). Analysis of the individual data revealed a group (n=9) possessing a threshold-like pattern of the relationship between T(c) and blood GH response, whereas a plateau-like pattern was evident in the rest of the subjects (n=11). Both sweat production (r=0.596; p<0.001) and the rate of sweat production (r=0.457; p<0.001) correlated with the growth hormone area under the curve. Heat acclimation decreases the GH response to moderate intensity exhausting exercise in the heat. GH may have a modest stimulating effect on whole-body sweat production during exercise. © 2013.

  10. 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.

  11. 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.

  12. Impact of wheat-Leymus racemosus added chromosomes on wheat adaptation and tolerance to heat stress.

    PubMed

    Mohammed, Yasir Serag Alnor; Tahir, Izzat Sidahmed Ali; Kamal, Nasrein Mohamed; Eltayeb, Amin Elsadig; Ali, Abdelbagi Mukhtar; Tsujimoto, Hisashi

    2014-03-01

    Adaptation of wheat (Triticum aestivum L.) to high temperatures could be improved by introducing alien genes from wild relatives. We evaluated the responses of wheat-Leymus racemosus chromosome introgression lines to high temperature to determine their potentiality for developing improved wheat cultivars. Introgression lines and their parent Chinese Spring were evaluated in a growth chamber at the seedling stage and in the field at the reproductive stage in two heat-stressed environments in Sudan. Optimum and late planting were used to ensure exposure of the plants to heat stress at the reproductive stage. The results revealed the impact of several Leymus chromosomes in improving wheat adaptation and tolerance to heat. Three lines possessed enhanced adaptation, whereas two showed high heat tolerance. Two addition lines showed a large number of kernels per spike, while one possessed high yield potential. Grain yield was correlated negatively with the heat susceptibility index, days to heading and maturity and positively with kernel number per spike and triphenyl tetrazolium chloride assay under late planting. The findings suggest that these genetic stocks could be used as a bridge to introduce the valuable Leymus traits into a superior wheat genetic background, thus helping maximize wheat yield in heat-stressed environments.

  13. Comparing Two Opacity Models in Monte Carlo Radiative Heat Transfer: Computational Efficiency and Parallel Load Balancing

    NASA Astrophysics Data System (ADS)

    Cleveland, Mathew A.; Palmer, Todd S.

    2013-09-01

    Thermal heating from radiative heat transfer can have a significant effect on combustion systems. A variety of models have been developed to represent the strongly varying opacities found in combustion gases (Goutiere et al., 2000). This work evaluates the computational efficiency and load balance issues associated with two opacity models implemented in a 3D parallel Monte Carlo solver: the spectral-line-based weighted sum of gray gases (SLW) (Denison and Webb, 1993) and the spectral line-by-line (LBL) (Wang and Modest, 2007) opacity models. The parallel performance of the opacity models is evaluated using the Su and Olson (1999) frequency-dependent semi-analytic benchmark problem. Weak scaling, strong scaling, and history scaling studies were performed and comparisons were made for each opacity model. Comparisons of load balance sensitivities to these types of scaling were also evaluated. It was found that the SLW model has some attributes that might be valuable in a select set of parallel problems.

  14. 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.

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

    PubMed

    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.

  16. 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.

  17. 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.

  18. Effect of added caffeic acid and tyrosol on the fatty acid and volatile profiles of camellia oil following heating.

    PubMed

    Haiyan, Zhong; Bedgood, Danny R; Bishop, Andrea G; Prenzler, Paul D; Robards, Kevin

    2006-12-13

    Camellia oil is widely used in some parts of the world partly because of its high oxidative stability. The effect of heating a refined camellia oil for 1 h at 120 degrees C or 2 h at 170 degrees C with exogenous antioxidant, namely, caffeic acid and tyrosol, was studied. Parameters used to assess the effect of heating were peroxide and K values, volatile formation, and fatty acid profile. Of these, volatile formation was the most sensitive index of change as seen in the number of volatiles and the total area count of volatiles in gas chromatograms. Hexanal was generally the dominant volatile in treated and untreated samples with a concentration of 2.13 and 5.34 mg kg(-1) in untreated oils heated at 120 and 170 degrees C, respectively. The hexanal content was significantly reduced in heated oils to which tyrosol and/or caffeic acid had been added. Using volatile formation as an index of oxidation, tyrosol was the more effective antioxidant of these compounds. This is contradictory to generally accepted antioxidant structure-activity relationships. Changes in fatty acid profiles after heating for up to 24 h at 180 degrees C were not significant.

  19. 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.

  20. Load following characteristics of SiGe/GaP thermoelectric generators and their response to external heating

    SciTech Connect

    El-Genk, M.S.; Seo, J.T.; Buksa, J.J.

    1987-03-01

    This paper discusses the load following characteristics of SiGe/GaP thermoelectric (TE) generators during both steady-state and transient changes of the external load. It also investigates the performance of TE generators as they are subjected to an external heating at their cold shoes. Results show that TE generators are load following within a narrow range of external load values and that external heating impairs their performance. The load following behavior of TE generators was found to be independent of the rate of changing the external load (steady state or ramp). For a constant hot shoe temperature, external heating of the TE generators caused their cold shoe temperature to rise and consequently increased the rate of heat rejection by radiation and decreased the electric power output. Because of the enhancement in the heat rejection by radiation during the external heating of the TE generators, a large heating rate is required for the generators to cease operation. The tolerance of TE generators to external heating can effectively be increased by initially raising the TE cold shoe temperature.

  1. Simulation of MLI concerning the influence of an additional heat load on intermediate layers

    SciTech Connect

    Funke, Thomas; Golle, Steffen; Haberstroh, Christoph

    2014-01-29

    Multilayer insulation (MLI) is commonly used in most cryogenic devices such as LHe cryostats or storage vessels. Numerical and experimental studies of such insulation systems are known from literature. The temperature distribution of intermediate layers has been investigated as well. Experiments using temperature sensors, for example thermocouples, to determine the temperature of intermediate layers had been described. Naturally such wiring causes additional heat load on the respective layer and influences the equilibrium temperature. A mathematical model of heat transfer through MLI has been developed to investigate the temperature distribution across the MLI layers. The model comprises a combination of radiation, residual gas conduction and conductive heat flux. An analysis for variable cold and warm boundary temperatures and various residual gases and pressures is carried out. In addition to the model an experimental test rig will be built for the verification of the model. The paper presents the influence of an additional heat load on an intermediate layer on the temperature distribution and on the overall thermal performance of MLI.

  2. Oligonol Supplementation Affects Leukocyte and Immune Cell Counts after Heat Loading in Humans

    PubMed Central

    Lee, Jeong Beom; Shin, Young Oh

    2014-01-01

    Oligonol is a low-molecular-weight form of polyphenol and has antioxidant and anti-inflammatory activity, making it a potential promoter of immunity. This study investigates the effects of oligonol supplementation on leukocyte and immune cell counts after heat loading in 19 healthy male volunteers. The participants took a daily dose of 200 mg oligonol or a placebo for 1 week. After a 2-week washout period, the subjects were switched to the other study arm. After each supplement, half-body immersion into hot water was made, and blood was collected. Then, complete and differential blood counts were performed. Flow cytometry was used to enumerate and phenotype lymphocyte subsets. Serum concentrations of interleukin (IL)-1β and IL-6 in blood samples were analyzed. Lymphocyte subpopulation variables included counts of total T cells, B cells, and natural killer (NK) cells. Oligonol intake attenuated elevations in IL-1β (an 11.1-fold change vs. a 13.9-fold change immediately after heating; a 12.0-fold change vs. a 12.6-fold change 1h after heating) and IL-6 (an 8.6-fold change vs. a 9.9-fold change immediately after heating; a 9.1-fold change vs. a 10.5-fold change 1h after heating) immediately and 1 h after heating in comparison to those in the placebo group. Oligonol supplementation led to significantly higher numbers of leukocytes (a 30.0% change vs. a 21.5% change immediately after heating; a 13.5% change vs. a 3.5% change 1h after heating) and lymphocytes (a 47.3% change vs. a 39.3% change immediately after heating; a 19.08% change vs. a 2.1% change 1h after heating) relative to those in the placebo group. Oligonol intake led to larger increases in T cells, B cells, and NK cells at rest (p < 0.05, p < 0.05, and p < 0.001, respectively) and immediately after heating (p < 0.001) in comparison to those in the placebo group. In addition, levels of T cells (p < 0.001) and B cells (p < 0.001) were significantly higher 1 h after heating in comparison to those in the

  3. 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.

  4. Modelling of powder consolidation using electro heating assisted by mechanical loading

    NASA Astrophysics Data System (ADS)

    Knyazeva, A.; Sorokova, S.

    2017-01-01

    The model of the process of reactive sintering assisted by mechanical loading is suggested. The conjugate heat exchange of powder mixture is taken into account. The powder mixture motion is described as viscous liquid with effective viscosity. Mechanical sub problem is one dimensional because friction near the wall is assumed negligible small. Conjugate thermal conductivity problem includes thermal conduction equations for various materials (reactive mixture and walls of the camber. Heat release is possible due to external electrical heating, viscous dissipation and chemical reactions. Kinetical equations correspond to detailed reaction scheme. The problem is solved numerically with special algorithm. As a result the composition of the mixture is obtained for different time moments. The final composition is not uniform.

  5. Present Status of High-Heat-Load Components for SPring-8 Front Ends

    SciTech Connect

    Takahashi, Sunao; Sano, Mutsumi; Mochizuki, Tetsuro; Watanabe, Atsuo

    2004-05-12

    We tried to investigate the damage of high-heat-load components (HHLC) for SPring-8 front ends, which had been operating for about 5 years. In case of the absorber and the XY-slit, utilizing the inclined-incidence technology with the advanced material of GlidCop, the change of the mechanical property of GlidCop and the damage of welded joints, where the maximum equivalent tensile stress appeared, were examined. Although any remarkable damage was not observed, a change of the elongation was detected along the irradiated body of the absorber. As for the pre-slit, utilizing the volumetric heating technology with a low-Z material, it was confirmed by a heating test that the soundness of the brazed joint between the low-Z material and a cooling holder was maintained.

  6. Using Simulink Simulation to Evaluate Load Following Characteristics of SOFC Generator with Heat Exchanger Considering Heat Balance

    NASA Astrophysics Data System (ADS)

    Tuyen, Nguyen Duc; Fujita, Goro; Yokoyama, Ryuichi; Koyanagi, Kaoru; Funabashi, Toshihisa; Nomura, Masakatsu

    That ever increasing electricity consumption, progress in power deregulation, and rising public awareness for environment have created more interest in fuel cell distributed generation. Among different types of fuel cells, solid oxide fuel cells (SOFCs) manifest themselves as great potential applications due to many advantages such as low emission, high efficiency, and high power rating. On the other hand, SOFC systems are beneficial because they can convert fuel such as natural gas (almost CH4) which is supplied by widespread systems in many countries into electricity efficiently using internal reforming. In facts, the load demand changes flexibly and fuel cell life time decreases by rapid thermal change. Its lifetime may be extended by maintaining in appropriate temperature. Therefore, it is important to acquire the load following performance as well as control of operation temperature. This paper addresses components of the simple SOFC power unit model with heat exchanger (HX) included. Typical dynamical submodels are used to follow the variation of load demand at a local location that considers temperature characteristics using the Matlab-SIMULINK program.

  7. 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.

  8. 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

  9. Absorption, by humans, of beta-carotene from fortified soybean oil added to rice: effect of heat treatment.

    PubMed

    Dutra-de-Oliveira, J E; Fávaro, R M; Leonardo, I R; Jordão Júnior, A A; Vannucchi, H

    1998-08-01

    This study was carried out to evaluate the absorption of beta-carotene in humans when rice is prepared with refined cooking soybean oil fortified with beta-carotene and to assess the effect of heat treatment on its bioavailability. Sixteen healthy adults subjects participated in two experimental trials. Studies were carried out during two experimental periods of 11 days with a 12-day interval between them. Beta carotene was added to the soybean cooking oil and rice was cooked with it or it was added to the rice after cooking. Experimental diets included these two kinds of rice during the first day and fasting blood samples were collected on different days. All of the test diets were low in carotenoids. Plasma carotenoids were measured by HPLC method. beta-carotene absorption was calculated through postabsorptive peak rise in plasma beta-carotene and the total area under the absorption curve was determined by the trapezoidal method for the 11-day period. Absorption of carotene from heated or unheated fortified soybean oil were similar. Peak plasma carotene rise was different in men and women, p < 0.05 (0.66 +/- 0.097 vs. 1.04 +/- 0.117 mumol/l, respectively). Plasma alpha-carotene and retinol showed no variation. Results demonstrate that beta-carotene added to soybean oil used in the preparation of rice is absorbed, heated or not, and could be a practical source of provitamin A. Developing countries looking for strategies to increase vitamin A intake could use fortification of vegetable oils with synthetic beta-carotene as a simple method.

  10. On the Henry constant and isosteric heat at zero loading in gas phase adsorption.

    PubMed

    Do, D D; Nicholson, D; Do, H D

    2008-08-01

    The Henry constant and the isosteric heat of adsorption at zero loading are commonly used as indicators of the strength of the affinity of an adsorbate for a solid adsorbent. It is assumed that (i) they are observable in practice, (ii) the Van Hoff's plot of the logarithm of the Henry constant versus the inverse of temperature is always linear and the slope is equal to the heat of adsorption, and (iii) the isosteric heat of adsorption at zero loading is either constant or weakly dependent on temperature. We show in this paper that none of these three points is necessarily correct, first because these variables might not be observable since they are outside the range of measurability; second that the linearity of the Van Hoff plot breaks down at very high temperature, and third that the isosteric heat versus loading is a strong function of temperature. We demonstrate these points using Monte Carlo integration and Monte Carlo simulation of adsorption of various gases on a graphite surface. Another issue concerning the Henry constant is related to the way the adsorption excess is defined. The most commonly used equation is the one that assumes that the void volume is the volume extended all the way to a boundary passing through the centres of the outermost solid atoms. With this definition the Henry constant can become negative at high temperatures. Although adsorption at these temperatures may not be practical because of the very low value of the Henry constant, it is more useful to define the Henry constant in such a way that it is always positive at all temperatures. Here we propose the use of the accessible volume; the volume probed by the adsorbate when it is in nonpositive regions of the potential, to calculate the Henry constant.

  11. 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

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

    PubMed

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

    2016-05-01

    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. 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). 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 8.4 ng/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. 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. 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 combustion by heating tobacco at a much lower temperature

  13. 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.

  14. Risk Assessment of Heating, Ventilating, and Air-Conditioning Strategies in Low-Load Homes

    SciTech Connect

    Poerschke, Andrew

    2016-02-17

    "Modern, energy efficient homes conforming to the Zero Energy Ready Home standard face the challenge of meeting high customer expectations for comfort. Traditional heating, ventilation, and air conditioning (HVAC) sizing and control strategies may be insufficient to adequately condition each zone due to unique load patterns in each room caused by a number of factors. These factors include solar heat gains, occupant-related gains, and gains associated with appliances and electronics. Because of shrinking shell loads, these intermittent factors are having an increasingly significant impact on the thermal load in each zone. Consequently, occupant comfort can be compromised. To evaluate the impact of climate and house geometry, as well as HVAC system and control strategies on comfort conditions, IBACOS analyzed the results of 99 TRNSYS multiple-zone simulations. The results of this analysis indicate that for simple-geometry and single-story plans, a single zone and thermostat can adequately condition the entire house. Demanding house geometry and houses with multiple stories require the consideration of multiple thermostats and multiple zones.

  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

    2014-11-04

    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.

  16. Preservation of (-)-epigallocatechin-3-gallate antioxidant properties loaded in heat treated β-lactoglobulin nanoparticles.

    PubMed

    Li, Bo; Du, Wenkai; Jin, Jianchang; Du, Qizhen

    2012-04-04

    (-)-Epigallocatechin-3-gallate (EGCG) was loaded in heat treated β-lactoglobulin (β-Lg) for the preservation of antioxidant activity. The effects of pH (2.5-7.0), the heating temperature of β-Lg (30-85 °C), the molar ratio of β-Lg to EGCG (1:2-1:32), and the β-Lg concentration (1-10 mg/mL) on the properties of β-Lg-EGCG complexes were studied. All four factors significantly influenced the particle size, the ζ-potential, and the entrapment efficiency of EGCG and EGCG loading in β-Lg particles. A stable and clear solution system could be obtained at pH 6.4-7.0. The highest protection of EGCG antioxidant activity was obtained with β-Lg heated at 85 °C and the molar ratio of 1:2 (β-Lg: EGCG). β-Lg-EGCG complexes were found to have the same secondary structure as native β-Lg.

  17. Behavior of Brazed W/Cu Mockup Under High Heat Flux Loads

    NASA Astrophysics Data System (ADS)

    Chen, Lei; Lian, Youyun; Liu, Xiang

    2014-03-01

    In order to transfer the heat from the armor to the coolant, tungsten has to be connected with a copper heat sink. The joint technology is the most critical issue for manufacturing plasma facing components. Consequently, the reliability of the joints should be verified by a great number of high-heat-flux (HHF) tests to simulate the real load conditions. W/Cu brazed joint technology with sliver free filler metal CuMnNi has been developed at Southwestern Institute of Physics (SWIP). Screening and thermal fatigue tests of one small-scale flat tile W/CuCrZr mockup were performed on a 60 kW electron-beam Material testing scenario (EMS-60) constructed recently at SWIP. The module successfully survived screening test with the absorbed power density (Pabs) of 2 MW/m2 to 10 MW/m2 and the following 1000 cycles at Pabs of 7.2 MW/m2 without hot spots and overheating zones during the whole test campaign. Metallurgy and SEM observations did not find any cracks at both sides and the interface, indicating a good bonding of W and CuCrZr alloy. In addition, finite element simulations by ANSYS 12.0 under experimental load conditions were performed and compared with experimental results.

  18. Modelling reduction of urban heat load in Vienna by modifying surface properties of roofs

    NASA Astrophysics Data System (ADS)

    Žuvela-Aloise, Maja; Andre, Konrad; Schwaiger, Hannes; Bird, David Neil; Gallaun, Heinz

    2017-01-01

    The study examines the potential of urban roofs to reduce the urban heat island (UHI) effect by changing their reflectivity and implementing vegetation (green roofs) using the example of the City of Vienna. The urban modelling simulations are performed based on high-resolution orography and land use data, climatological observations, surface albedo values from satellite imagery and registry of the green roof potential in Vienna. The modelling results show that a moderate increase in reflectivity of roofs (up to 0.45) reduces the mean summer temperatures in the densely built-up environment by approximately 0.25 °C. Applying high reflectivity materials (roof albedo up to 0.7) leads to average cooling in densely built-up area of approximately 0.5 °C. The green roofs yield a heat load reduction in similar order of magnitude as the high reflectivity materials. However, only 45 % of roof area in Vienna is suitable for greening and the green roof potential mostly applies to industrial areas in city outskirts and is therefore not sufficient for substantial reduction of the UHI effect, particularly in the city centre which has the highest heat load. The strongest cooling effect can be achieved by combining the green roofs with high reflectivity materials. In this case, using 50 or 100 % of the green roof potential and applying high reflectivity materials on the remaining surfaces have a similar cooling effect.

  19. 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

  20. 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.

  1. Investigation of various methods for heat load measurement of ITER prototype cryoline

    NASA Astrophysics Data System (ADS)

    Shah, N. D.; Sarkar, B.; Choukekar, K.; Bhattacharya, R.; Kumar, Uday

    2014-01-01

    The cold testing of ITER prototype cryoline (PTCL) is part of technical qualification procedure for multi process pipe ITER cryolines. The detailed plan has been developed for the warm and cold testing of PTCL, which includes pressure and leak test at room temperature followed by cooldown of all the process pipes of PTCL to nominal operating temperature using cold helium. The test infrastructure, which primarily includes 80 K system to supply helium at 30 grams per second (g/s), 6.5 bar and liquid helium Dewar of 5000 liter capacity to supply vapor helium at maximum 1.4 bar and 6 g/s in a controlled manner is at advanced stage of realization. The detailed scheme and methodology for PTCL heat load measurement at 4.5 K and 80 K temperature level using small flow rate and enthalpy difference has been already developed as Plan-A. However, in order to be sure on the measurement of Plan-A, it has been realized to develop back-up plan to ensure the correctness of the measurements. The in-built flexibility of the test infrastructure supports the back-up methods for heat load measurement of PTCL using the same infrastructure. The back-up methods foreseen as Plan-B includes (i) filling the process pipes with low temperature helium gas and evaluating time bound temperature increase and (ii) measuring temperature difference for various heater power using existing electric heaters and extrapolating the results. The present paper details both the plans for the heat load measurement at 4.5 K and 80 K temperature level including the comparison between the two.

  2. Volume loading augments cutaneous vasodilatation and cardiac output of heat stressed older adults.

    PubMed

    Gagnon, Daniel; Romero, Steven A; Ngo, Hai; Sarma, Satyam; Cornwell, William K; Poh, Paula Y S; Stoller, Douglas; Levine, Benjamin D; Crandall, Craig G

    2017-08-21

    Age-related changes in cutaneous microvascular and cardiac functions limit the extent of cutaneous vasodilatation and the increase in cardiac output that healthy older adults can achieve during passive heat stress. However, it is unclear if these age-related changes in microvascular and cardiac functions maximally restrain the levels of cutaneous vasodilatation and cardiac output that healthy older adults can achieve during heat stress. We observed that rapid volume loading, performed during passive heat stress, augments both cutaneous vasodilatation and cardiac output in healthy older humans. These findings demonstrate that the microcirculation of healthy aged skin can further dilate during passive heat exposure, despite peripheral limitations to vasodilatation. Furthermore, healthy older humans can augment cardiac output when cardiac pre-load is increased during heat stress. Primary ageing markedly attenuates cutaneous vasodilatation and the increase in cardiac output during passive heating. However, it remains unclear if these responses are maximally restrained by age-related changes in cutaneous microvascular and cardiac functions. We hypothesized that rapid volume loading performed during heat stress would increase cardiac output in older adults without parallel increases in cutaneous vasodilatation. Twelve young (Y: 26 ± 5 years) and ten older (O: 69 ± 3 years) healthy adults were passively heated until core temperature increased by 1.5°C. Cardiac output (thermodilution), forearm vascular conductance (FVC, venous occlusion plethysmography) and cutaneous vascular conductance (CVC, laser-Doppler) were measured before and after rapid infusion of warmed saline (15 mL kg(-1) , ∼7 min). While heat stressed, but prior to saline infusion, cardiac output (O: 6.8 ± 0.4 vs. Y: 9.4 ± 0.6 L min(-1) ), FVC (O: 0.08 ± 0.01 vs. Y: 0.17 ± 0.02 mL (100 mL min(-1)  mmHg(-1) )(-1) ), and CVC (O: 1.29 ± 0.34 vs. Y: 1.93 ± 0.30

  3. 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.

  4. Thermomechanical analysis of a compact-design high heat load crotch absorber

    SciTech Connect

    Sheng, I.C.; Sharma, S.; Rotela, R.; Howell, J.

    1995-07-01

    The Advanced Photon Source (APS) is a third-generation synchrotron facility built to generate extremely powerful x-rays. x-ray absorbers in the APS dipole vacuum chambers, known as crotch absorbers, are subjected to a very high power density of 750 Watt/mm{sup 2} at 300 mA of beam current. In the compact design of the APS crotch absorbers, this high heat load is handled by a combination of optimized geometry, fins for power dispersion and cooling efficiency, and a material with high fatigue strength (Glidcop). The basic design and the results of detailed thermomechanical finite element analysis are presented in this paper.

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

    DOE PAGES

    Terzić, Balša; Hofler, Alicia S.; Reeves, Cody J.; ...

    2014-10-15

    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.

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

    NASA Astrophysics Data System (ADS)

    Greene, John P.; Gabor, Rachel; Neubauer, Janelle

    2001-07-01

    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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. Henry constant and isosteric heat at zero-loading for gas adsorption in carbon nanotubes.

    PubMed

    Do, D D; Do, H D; Wongkoblap, A; Nicholson, D

    2008-12-28

    The Henry constant and the isosteric heat of adsorption at zero loading in a carbon nanotube bundle are studied with Monte Carlo integration for the adsorption of gases over a range of temperatures. The spacing between nanotubes in a bundle is determined from the minimization of potential energy of interaction between these tubes. We study different tube configurations with bundles of 2, 3, 4 and 7 tubes. Depending on the configuration it is found that the spacing is of between 0.31 to 0.333 nm, and this falls within the range reported in the literature. The Henry constant has been carefully defined so that it will not become negative at high temperatures. This is done with the aid of accessible volume, rather than the usual absolute void volume. We show that linearity of the van't Hoff plot for the Henry constant is not strictly followed. Furthermore the slope of this plot is not equal to the isosteric heat of adsorption at zero loading, which is found to be a strong function of temperature. From the results we find that the Henry constant and the heat of adsorption depend on the tube configuration. In general the adsorption in the cusp interstices is strongest followed by that inside the tube and finally on the outer surface. However for very small tubes adsorption occurs inside the tube first. For molecules with orientation, the behaviour is even more interesting and the shape of the isosteric heat versus temperature depends on the degree of orientation, tube configuration and the domain of adsorption (interstices, inside the tube and on the outer surface).

  12. 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.

  13. Heat load behaviors of plasma sprayed tungsten coatings on copper alloys with different compliant layers

    NASA Astrophysics Data System (ADS)

    Chong, F. L.; Chen, J. L.; Li, J. G.; Hu, D. Y.; Zheng, X. B.

    2008-04-01

    Plasma sprayed tungsten (PS-W) coatings with the compliant layers of titanium (Ti), nickel-chromium-aluminum (NiCrAl) alloys and W/Cu mixtures were fabricated on copper alloys, and their properties of the porosity, oxygen content, thermal conductivity and bonding strength were measured. High heat flux tests of actively cooled W coatings were performed by means of an electron beam facility. The results indicated that APS-W coating showed a poorer heat transfer capability and thermo-mechanical properties than VPS-W coating, and the compliant layers improved W coating performance under the heat flux load. Among three compliant layers, W/Cu was the preferable because of its better effects on heat removal and stress alleviating. The optimization of W/Cu compliant layer found that 0.1 mm and 25 vol.%W was optimum compliant layer structure for 1 mm W coating, which induced a 23% reduction of the maximum stress compared to the sharp interface, and the plastic strain was reduced to 0.01% from 1.55%.

  14. 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.

  15. A degree-day method for residential heating load calculations specifically incorporating the utilization of solar gains

    SciTech Connect

    Lucas, R.G.; Pratt, R.G.

    1990-09-01

    A simple and well known method of estimating residential heating loads is the variable base degree-day method, in which the steady-state heat loss rate (UA) is multiplied by the degree-days based from the balance temperature of the structure. The balance temperature is a function of the UA as well as the average rate of internal heat gains, reflecting the displacement of the heating requirements by these gains. Currently, the heat gains from solar energy are lumped with those from appliances to estimate an average rate over the day. This ignores the effects of the timing of the gains from solar energy, which are more highly concentrated during daytime hours, hence more frequently exceeding the required space heat and less utilizable than the gains from appliances. Simulations or specialized passive solar energy calculation methods have previously been required to account for this effect. This paper presents curves of the fraction of the absorbed solar energy utilized for displacement of space heat, developed by comparing heating loads calculated using a variable base degree-day method (ignoring solar gains) to heating loads from a large number of detailed DOE-2 simulations. The difference in the loads predicted by the two methods can be interpreted as the utilized solar gains. The solar utilization decreases as the thermal integrity increases, as expected, and the solar utilizations are similar across climates. They can be used to estimate the utilized fraction of the absorbed solar energy and, with the load predicted by the variable base degree-day calculation, form a modified degree-day method that closely reproduces the loads predicted by the DOE-2 simulation model and is simple enough for hand calculations. 6 refs., 6 figs., 2 tabs.

  16. Physiological responses of Australian Merino wethers exposed to high heat load.

    PubMed

    Alhidary, I A; Shini, S; Al Jassim, R A M; Gaughan, J B

    2012-01-01

    Twelve 9-mo-old Merino wethers (30.4 ± 3.2 kg of BW) were used in a crossover study to investigate the heat tolerance of Australian Merino sheep by testing their physiological responses to repeated heat loads that occurred during summer months. Wethers were randomly divided into 2 groups of 6 wethers each, housed individually in an environmental chamber, and subjected to 2 d of thermoneutral conditions (TNC) followed by either 7 d of TNC (maximum temperature of 24°C, minimum temperature of 16°C) or 7 d of hot conditions (maximum temperature of 38°C, minimum temperature of 28°C), and then 2 d of TNC. These treatments were applied in 2 replicates, with each replicate in a separate environmental chamber. Rectal temperature (RT) and respiration rate were measured daily at 0600, 0800, 1000, 1200, 1400, 1600, and 1800 h. Feed and water intakes were measured daily, and wethers were weighed on d 1 and 11. Blood samples were collected from each whether on d 2 and 6, and serum was assayed for concentrations of creatine, glucose, total protein, cholesterol, NEFA, calcium, sodium, and potassium. Exposure to a high ambient temperature resulted in an 0.8°C increase in RT (P < 0.001), an increase in respiration rate (P < 0.001) by 66 breaths/min, and a 2.7 L/d increase in water intake (P < 0.0001). Feed intake decreased by 22% (P < 0.0001), BW decreased by 5.2% (P < 0.03), and creatine concentration was reduced (P < 0.05). No differences (P > 0.05) between treatments were observed for any of the remaining serum variables. These results indicate that Australian Merino sheep were able to maintain RT within the normal range during exposure to a prolonged increase in heat and that they recovered quickly from the negative effect of heat stress within 2 d of conditions returning to TNC. It would appear that they have a high heat tolerance, and further studies are needed to examine the effects of a greater heat load to determine the temperature-humidity index thresholds for

  17. 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.

  18. 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.

  19. Divertor target heat load reduction by electrical biasing, and application to COMPASS-D

    NASA Astrophysics Data System (ADS)

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

    2001-03-01

    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 E× B convective motions should increase the plasma radial transport in the SOL and thereby reduce the heat load at the divertor [R.H. Cohen, D.D. Ryutov, Nucl. Fus. 37 (1997) 621]. In this paper, we develop theoretical modelling and describe the implementation of this concept to the COMPASS-D divertor. We show that a 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 ˜8 A/tile are required, at up to 150 V, to drive the convection. A technical test is preceding full bias experiments.

  20. Coupled Kinetic-MHD Simulations of Divertor Heat Load with ELM Perturbations

    NASA Astrophysics Data System (ADS)

    Cummings, Julian; Chang, C. S.; Park, Gunyoung; Sugiyama, Linda; Pankin, Alexei; Klasky, Scott; Podhorszki, Norbert; Docan, Ciprian; Parashar, Manish

    2010-11-01

    The effect of Type-I ELM activity on divertor plate heat load is a key component of the DOE OFES Joint Research Target milestones for this year. In this talk, we present simulations of kinetic edge physics, ELM activity, and the associated divertor heat loads in which we couple the discrete guiding-center neoclassical transport code XGC0 with the nonlinear extended MHD code M3D using the End-to-end Framework for Fusion Integrated Simulations, or EFFIS. In these coupled simulations, the kinetic code and the MHD code run concurrently on the same massively parallel platform and periodic data exchanges are performed using a memory-to-memory coupling technology provided by EFFIS. The M3D code models the fast ELM event and sends frequent updates of the magnetic field perturbations and electrostatic potential to XGC0, which in turn tracks particle dynamics under the influence of these perturbations and collects divertor particle and energy flux statistics. We describe here how EFFIS technologies facilitate these coupled simulations and discuss results for DIII-D, NSTX and Alcator C-Mod tokamak discharges.

  1. Oxide segregation and melting behavior of transient heat load exposed beryllium

    NASA Astrophysics Data System (ADS)

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

    2016-10-01

    In the experimental fusion reactor ITER, beryllium will be applied as first wall armor material. However, the ITER-like wall project at JET already experienced that the relatively low melting temperature of beryllium can easily be exceeded during plasma operation. Therefore, a detailed study was carried out on S-65 beryllium under various transient, ITER-relevant heat loads that were simulated in the electron beam facility JUDITH 1. Hereby, the absorbed power densities were in the range of 0.15-1.0 GW m-2 in combination with pulse durations of 1-10 ms and pulse numbers of 1-1000. In metallographic cross sections, the emergence of a transition region in a depth of ~70-120 µm was revealed. This transition region was characterized by a strong segregation of oxygen at the grain boundaries, determined with energy dispersive x-ray spectroscopy element mappings. The oxide segregation strongly depended on the maximum temperature reached at the end of the transient heat pulse in combination with the pulse duration. A threshold for this process was found at 936 °C for a pulse duration of 10 ms. Further transient heat pulses applied to specimens that had already formed this transition region resulted in the overheating and melting of the material. The latter occurred between the surface and the transition region and was associated with a strong decrease of the thermal conductivity due to the weakly bound grains across the transition region. Additionally, the transition region caused a partial separation of the melt layer from the bulk material, which could ultimately result in a full detachment of the solidified beryllium layers from the bulk armor. Furthermore, solidified beryllium filaments evolved in several locations of the loaded area and are related to the thermally induced crack formation. However, these filaments are not expected to account for an increase of the beryllium net erosion.

  2. 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).

  3. 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).

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

    PubMed

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

    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.

  5. Assessing heat load in drylot dairy cattle: Refining on-farm sampling methodology.

    PubMed

    Tresoldi, Grazyne; Schütz, Karin E; Tucker, Cassandra B

    2016-11-01

    Identifying dairy cattle experiencing heat stress and adopting appropriate mitigation strategies can improve welfare and profitability. However, little is known about how cattle use heat abatement resources (shade, sprayed water) on drylot dairies. It is also unclear how often we need to observe animals to measure high heat load, or the relevance of specific aspects of this response, particularly in terms of panting. Our objectives were to describe and determine sampling intervals to measure cattle use of heat abatement resources, respiration rate (RR) and panting characteristics (drooling, open mouth, protruding tongue), and to evaluate the relationship between the latter 2. High-producing cows were chosen from 4 drylots (8 cows/dairy, n=32) and observed for at least 5.9h (1000 to 1800h, excluding milking) when air temperature, humidity, and the combined index averaged 33°C, 30%, and 79, respectively. Use of heat abatement resources was recorded continuously; RR and the presence and absence of each panting characteristic were recorded every 5min. From the observed values, estimates using the specified sub-sampling intervals were calculated for heat abatement resource use (1, 5, 10, 15, 20, 30, 60, 90, and 120min), and for RR and panting (10, 15, 20, 30, 60, 90, and 120min). Estimates and observed values were compared using linear regression. Sampling intervals were considered accurate if they met 3 criteria: R(2)≥0.9, intercept=0, and slope=1. The relationship between RR and each panting characteristic was analyzed using mixed models. Cows used shade (at corral or over feed bunk) and feed bunk area (where water was sprayed) for about 90 and 50% of the observed time, respectively, and used areas with no cooling for 2min at a time, on average. Cows exhibited drooling (34±4% of observations) more often than open mouth and protruding tongue (11±3 and 8±3% of observations, respectively). Respiration rate varied depending on the presence of panting (with vs

  6. Method to Estimate Long-term Change of Heat and Electric Power Daily Load Curves in Japan

    NASA Astrophysics Data System (ADS)

    Oda, Takuya; Akisawa, Atushi; Kashiwagi, Takao

    The rapid spread of CHP systems will put pressure on the regional power system to requiring an examination of the power and heat output of CHP systems. When considering the country-wide potential of the CHP system one should examine such system in coordination with the grid power system. It is essential to calculate the heat and power demand at end-use level. In the paper, annual heat and power demands of end-use sectors are forecast to the year 2025 based on 20 year data. Regression analysis is used. Estimated annual demands are divided into the seasonal hourly demands considering demand characteristics. Daily load curves of heat and power demands are determined for the Japanese end-use sectors, and the annual changes of such demands are shown by duration curves of heat to power ratios. Moreover, the grid power daily load curves are computed numerically from the estimated heat and power demands at manufacturing, residential and commercial sectors. Such load curves also consider self-generated power at manufacturing industry and own consumption of the grid power. Estimating heat and power demands allow for a joint analysis between the power system and the future phasing in of CHP systems.

  7. 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.

  8. Measuring temperature in the lens during experimental heat load indirectly as light scattering increase rate

    NASA Astrophysics Data System (ADS)

    Yu, Zhaohua; Talebizadeh, Nooshin; Kronschläger, Martin; Söderberg, Per

    2017-01-01

    The current study aims to experimentally estimate the temperature in the lens due to heat load indirectly from the measurement of increases in the rate of temperature-induced light scattering. The lens was extracted from Sprague-Dawley rats and put into a temperature-controlled cuvette filled with a balanced salt solution. Altogether, 80 lenses were equally divided into four temperature groups. Each lens was exposed for 5 min to temperature depending on the group to which it belonged while the intensity of forward light scattering was recorded. The inclination coefficients of light scattering increase at the temperature of 37°C, 40°C, 43°C, and 46°C were estimated as a CI(0.95), 3.1±0.8, 4.4±0.8, 5.5±0.9, and 7.0±0.8×10-4 tEDC/s, respectively. The Arrhenius equation implies that the natural logarithm of the inclination coefficient is linearly dependent on the inverse of the temperature. The proportionality constant and the intercept were 9.6±2.4×10 K and 22.8±7.7, respectively. The activation energy was 8.0±2.0×101 kJ·mol-1. The current experiment implies that if averaging 20 measurements of inclination coefficients in a new experiment at constant heat load, the confidence limits for predicted temperature correspond to ± 1.9°C. With the proportionality constant and the intercept estimated in the current experiment, the in vivo temperature in the lens can be determined retrospectively with sufficient resolution.

  9. Extent and economic effect of heat loads on dairy cattle production in Australia.

    PubMed

    Mayer, D G; Davison, T M; McGowan, M R; Young, B A; Matschoss, A L; Hall, A B; Goodwin, P J; Jonsson, N N; Gaughan, J B

    1999-12-01

    To investigate the extent of heat load problems, caused by the combination of excessive temperature and humidity, in Holstein-Friesian cows in Australia. Also, to outline how milk production losses and consequent costs from this can be estimated and minimised. Long-term meteorological data for Australia were analysed to determine the distribution of hot conditions over space and time. Fifteen dairy production regions were identified for higher-resolution data analysis. Both the raw meteorological data and their integration into a temperature-humidity thermal index were compiled onto a computer program. This mapping software displays the distribution of climatic patterns, both Australia-wide and within the selected dairying regions. Graphical displays of the variation in historical records for 200 locations in the 15 dairying regions are also available. As a separate study, production data from research stations, on-farm trials and milk factory records were statistically analysed and correlated with the climatic indices, to estimate production losses due to hot conditions. Both milk yields and milk constituents declined with increases in the temperature-humidity index. The onset and rate of this decline are dependent on a number of factors, including location, level of production, adaptation, and management regime. These results have been integrated into a farm-level economic analysis for managers of dairy properties. By considering the historical patterns of hot conditions over time and space, along with expected production losses, managers of dairy farms can now conduct an economic evaluation of investment strategies to alleviate heat loads. These strategies include the provision of sprinklers, shade structures, or combinations of these.

  10. 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.

  11. 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

  12. α-Tocopherol-loaded niosome prepared by heating method and its release behavior.

    PubMed

    Basiri, Ladan; Rajabzadeh, Ghadir; Bostan, Aram

    2017-04-15

    α-Tocopherol-loaded niosome was developed using modified heating method. The influence of surfactants (Span60 and Tween60) in different mole ratios, presence or absence of cholesterol (Chol) and dicetyl phosphate (DCP) as well as different concentration of α-tocopherol (α-TOC) on mean size, polydispersity index, zeta potential and entrapment efficiency (EE) was evaluated. The results showed that α-TOC loaded niosomes exhibited a small mean size (73.85±0.6-186±0.58nm), narrow size distribution and high EE (61.13±0.52-98.92±0.92). By decreasing the HLB, the EE and stability of the niosomes increased. The DCP and Chol improved the physicochemical properties of niosomes. 3:1 mole ratio of Span 60:Tween 60, 4mg/ml of α-TOC and 25:12.5:2.5 mole ratio of surfactant:Chol:DCP was the optimum formulation in the encapsulation of α-TOC applying niosome system. The niosomes had sustained release profile in the simulated gastric and intestinal fluid.

  13. Recrystallization and grain growth behavior of rolled tungsten under VDE-like short pulse high heat flux loads

    NASA Astrophysics Data System (ADS)

    Yuan, Y.; Greuner, H.; Böswirth, B.; Krieger, K.; Luo, G.-N.; Xu, H. Y.; Fu, B. Q.; Li, M.; Liu, W.

    2013-02-01

    Short pulse heat loads expected for vertical displacement events (VDEs) in ITER were applied in the high heat flux (HHF) test facility GLADIS at IPP-Garching onto samples of rolled W. Pulsed neutral beams with the central heat flux of 23 MW/m2 were applied for 0.5, 1.0 and 1.5 s, respectively. Rapid recrystallization of the adiabatically loaded 3 mm thick samples was observed when the pulse duration was up to 1.0 s. Grains grew markedly following recrystallization with increasing pulse length. The recrystallization temperature and temperature dependence of the recrystallized grain size were also investigated. The results showed that the recrystallization temperature of the W grade was around 2480 °C under the applied heat loading condition, which was nearly 1150 °C higher than the conventional recrystallization temperature, and the grains were much finer. A linear relationship between the logarithm of average grain size (ln d) and the inverse of maximum surface temperature (1/Tmax) was found and accordingly the activation energy for grain growth in temperature evolution up to Tmax in 1.5 s of the short pulse HHF load was deduced to be 4.1 eV. This provided an effective clue to predict the structure evolution under short pulse HHF loads.

  14. 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.

  15. Effect of wall mass on the peak sensible heating and cooling loads of a single-family residence

    SciTech Connect

    Burch, D.M.; Walton, G.N.; Licitra, B.A.; Cavanaugh, K.; Klein, M.D.

    1986-10-01

    The effect of wall mass on the peak sensible heating and cooling loads of a single-family residence was investigated using a sophisticated computer program called the Thermal Analysis Research Program (TARP). The computer simulation accuracy was verified by comparing its predicted sensible heating and cooling loads to measured values for six test buildings each having different wall constructions at the National Bureau of Standards. Good agreement was obtained for the load comparisons. The computer program subsequently was used to simulate the performance of identical houses each having the following three insulated-wall constructions: wood frame, conventional masonry (outside wall mass), and innovative masonry (inside wall mass). When the house was operated with fixed thermostat settings, the effect of wall mass on the peak sensible heating and cooling loads was found to be less than 11% for the climatic regions analyzed. Operating the typical house with a 10/sup 0/F (5.6/sup 0/C) night temperature setback during an 8-hour night period caused the daily peak sensible heating loads to be approximately twice those without setback.

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

    PubMed

    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.

  17. 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.

  18. 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.

  19. Revised Heating Load Line Analysis: Addendum to ORNL/TM-2015/281

    SciTech Connect

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

    2016-07-01

    The original heating load line analysis of ORNL TM-2015/281 was modified to incorporate two adjustments of (1) removing mechanical ventilation and (2) resizing the heat pump units based on new criteria. This resulted in a lowering of the HLL slope factor from the originally rounded 1.3 level to 1.15 in DOE Region IV and V while leaving unchanged the zero-load ambient at a rounded value of 55 F. For the other four DOE regions, the zero-load ambients dropped by 1 to 2 F from those found earlier and the rounded HLL slope factors ranged from 1.05 to 1.3. The average rounded HLL slope factor over all six DOE regions is 1.15. Effects of the revised slope factor on rated HSPFs (Region IV) for single- and two-capacity units dropped from 16% in the original work to 12.6% in this report. For VS units, the HSPF reductions of 14 to 25% in the original report were lowered to a range of 9 to 21%. As in the original report, for VS units that do not limit minimum speed operation below 47 F ambient, the average HSPF reduction for the cases evaluated is approximately the same as for single- and two-capacity units. For VS units that do limit minimum speed operation below 47 F ambient, the lower 1.15 slope factor of this report generally results in small overpredictions of rated HSPF by 1 to 3% compared to functional HSPF. An exception is minimum-speed-limited VS units where the minimum speed COP at 47 F is higher than that at 62 F; one such unit was found to have an HSPF overprediction of over 14% with the 1.15 HLL slope factor level. For such VS exception cases, a default HSPF penalty should be considered. For the more typical VS units that limit minimum speed operation, use of a 1.15 slope factor for rated HSPF was found to still acceptably limit the HSPF error. If slope factors lower than 1.15 are used for HSPF ratings, some means should be considered to appropriately derate the HSPFs for VS units which limit minimum speed operation below 47 F ambient.

  20. Enhancement of urban heat load through social inequalities on an example of a fictional city King's Landing

    NASA Astrophysics Data System (ADS)

    Žuvela-Aloise, M.

    2017-03-01

    The numerical model MUKLIMO_3 is used to simulate the urban climate of an imaginary city as an illustrative example to demonstrate that the residential areas with deprived socio-economic conditions can exhibit an enhanced heat load at night, and thus more disadvantageous environmental conditions, compared with the areas of higher socio-economic status. The urban climate modelling simulations differentiate between orographic, natural landscape, building and social effects, where social differences are introduced by selection of location, building type and amount of vegetation. The model results show that the increase of heat load can be found in the areas inhabited by the poor population as a combined effect of natural and anthropogenic factors. The unfavourable location in the city and the building type, consisting of high density, low housing with high fraction of pavement and small amount of vegetation contribute to the formation of excessive heat load. This abstract example shows that the enhancement of urban heat load can be linked to the concept of a socially stratified city and is independent of the historical development of any specific city.

  1. 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.

  2. Enhancement of urban heat load through social inequalities on an example of a fictional city King's Landing

    NASA Astrophysics Data System (ADS)

    Žuvela-Aloise, M.

    2016-08-01

    The numerical model MUKLIMO_3 is used to simulate the urban climate of an imaginary city as an illustrative example to demonstrate that the residential areas with deprived socio-economic conditions can exhibit an enhanced heat load at night, and thus more disadvantageous environmental conditions, compared with the areas of higher socio-economic status. The urban climate modelling simulations differentiate between orographic, natural landscape, building and social effects, where social differences are introduced by selection of location, building type and amount of vegetation. The model results show that the increase of heat load can be found in the areas inhabited by the poor population as a combined effect of natural and anthropogenic factors. The unfavourable location in the city and the building type, consisting of high density, low housing with high fraction of pavement and small amount of vegetation contribute to the formation of excessive heat load. This abstract example shows that the enhancement of urban heat load can be linked to the concept of a socially stratified city and is independent of the historical development of any specific city.

  3. Enhancement of urban heat load through social inequalities on an example of a fictional city King's Landing.

    PubMed

    Žuvela-Aloise, M

    2017-03-01

    The numerical model MUKLIMO_3 is used to simulate the urban climate of an imaginary city as an illustrative example to demonstrate that the residential areas with deprived socio-economic conditions can exhibit an enhanced heat load at night, and thus more disadvantageous environmental conditions, compared with the areas of higher socio-economic status. The urban climate modelling simulations differentiate between orographic, natural landscape, building and social effects, where social differences are introduced by selection of location, building type and amount of vegetation. The model results show that the increase of heat load can be found in the areas inhabited by the poor population as a combined effect of natural and anthropogenic factors. The unfavourable location in the city and the building type, consisting of high density, low housing with high fraction of pavement and small amount of vegetation contribute to the formation of excessive heat load. This abstract example shows that the enhancement of urban heat load can be linked to the concept of a socially stratified city and is independent of the historical development of any specific city.

  4. 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.

  5. 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.

  6. Sex difference in the heat shock response to high external load resistance training in older humans.

    PubMed

    Njemini, Rose; Forti, Louis Nuvagah; Mets, Tony; Van Roie, Evelien; Coudyzer, Walter; Beyer, Ingo; Delecluse, Christophe; Bautmans, Ivan

    2017-07-01

    Literature reports on the effects of resistance training on heat shock protein70 (Hsp70) adaptation in older subjects are scarce. Moreover, the optimum training load required to obtain a beneficial adaptation profile is lacking. Therefore, the aim of this study was to determine the effects of resistance training at various external loads on extracellular Hsp70 (eHsp70) resting levels in older humans. Fifty-six community-dwelling older (68±5years) volunteers were randomized to 12weeks of resistance training (3×/week) at either high-resistance (HIGH, 8 males, 10 females, 2×10-15 repetitions at 80% 1RM), low resistance (LOW, 9 Males, 10 Females, 1×80-100 repetitions at 20% 1RM), or mixed low resistance (LOW+, 9 Males, 10 Females, 1×60 repetitions at 20% 1RM followed by 1×10-20 repetitions at 40% 1RM). Serum was available from 48 out of the 56 participants at baseline and after 12weeks for determination of eHsp70. Mid-thigh muscle volume (computed tomography), muscle strength (1RM & Biodex dynamometer) and physical functioning (including 6min walk distance [6MWD]) were assessed. There was a sex-related dichotomy in the heat shock response to high external load training. We observed a significant decrease in eHsp70 concentration in the HIGH group for female, but not male, subjects. At baseline, men had a larger muscle volume, leg press and leg extension 1RM compared to women (all p<0.001). Also, the 6MWD was significantly higher in men compared to women at baseline. However, this difference disappeared when correcting for height. Moreover, the overall functional performance and physical activity scores were similar in men and women. None of the participants' characteristics nor any of the outcome variables differed between groups at baseline. There was a significant increase in the strength and physical performance parameters in both men and women post-exercise (all p<0.05). Females in the HIGH group clearly demonstrated a larger gain in leg press 1RM and the

  7. Passive heat loading links lipolysis and regulation of fibroblast growth factor-21 in humans.

    PubMed

    Lee, Jeong-Beom; Kim, Tae-Wook

    2014-10-01

    There is relativley little information on the serum biomarkers of heat stress. Therefore, the goal of this study was to verify the effect of passive heat loading (PHL) on the expression of fibroblast growth factor-21 (FGF21) and free fatty acids (FFAs). Four PHL protocols based on intensity (39 °C vs. 43 °C, leg immersion, 30 min) and type (leg vs. half immersion, 42 °C, 30 min) were used. Each protocol was applied on a 2 day cycle to 12 healthy adult males (age, 22.4 ± 2.9 years; height, 174.1 ± 4.6 cm; weight, 71.3 ± 5.6 kg; body mass index, 23.1 ± 3.0). The subjects were categorized into two groups according to the study design (randomized, with a parallel trial). Body temperature, FGF21 and FFAs were determined prior to PH L, immediately and 60 min after PHL. Body temperature was significant higher (43 °C) than the 39 °C measured under identical PHL type (leg immersion). PHL was effective for the expression of FGF21 and for lipolysis. The quantitative levels of FGF21 and FFA increased with increasing temperature (39 °C<42 °C<43 °C). A significant difference in the quantitative levels of FGF21 and FFAs was also evident based on the type of PHL (legloading temperature of 43 °C is more effective for expressing FGF21 and for lipolysis than temperatures of 39 °C and 42 °C, and half immersion is more effective than leg immersion at 42 °C. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. 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

  9. Lesson from Tungsten Leading Edge Heat Load Analysis in KSTAR Divertor

    NASA Astrophysics Data System (ADS)

    Hong, Suk-Ho; Pitts, Richard Anthony; Lee, Hyeong-Ho; Bang, Eunnam; Kang, Chan-Soo; Kim, Kyung-Min; Kim, Hong-Tack; ITER Organization Collaboration; Kstar Team Team

    2016-10-01

    An important design issue for the ITER tungsten (W) divertor and in fact for all such components using metallic plasma-facing elements and which are exposed to high parallel power fluxes, is the question of surface shaping to avoid melting of leading edges. We have fabricated a series of tungsten blocks with a variety of leading edge heights (0.3, 0.6, 1.0, and 2.0 mm), from the ITER worst case to heights even beyond the extreme value tested on JET. They are mounted into adjacent, inertially cooled graphite tile installed in the central divertor region of KSTAR, within the field of view of an infra-red (IR) thermography system with a spatial resolution to 0.4 mm/pixel. Adjustment of the outer divertor strike point position is used to deposit power on the different blocks in different discharges. The measured power flux density on flat regions of the surrounding graphite tiles is used to obtain the parallel power flux, q|| impinging on the various W blocks. Experiments have been performed in Type I ELMing H-mode with Ip = 600 kA, BT = 2 T, PNBI = 3.5 MW, leading to a hot attached divertor with typical pulse lengths of 10 s. Three dimensional ANSYS simulations using q|| and assuming geometric projection of the heat flux are found to be consistent with the observed edge loading. This research was partially supported by Ministry of Science, ICT, and Future Planning under KSTAR project.

  10. Thermal shock and fatigue resistance of tungsten materials under transient heat loading

    NASA Astrophysics Data System (ADS)

    Zhang, Xiaoxin; Yan, Qingzhi; Lang, Shaoting; Xia, Min; Liu, Xiang; Ge, Changchun

    2014-12-01

    Transient heat loading tests were performed on rolled pure tungsten (PW) and lanthanum oxide doped tungsten (WL10) as well as swaged + rolled potassium doped tungsten (W-K) samples using an electron beam. In thermal shock tests, the cracking threshold was 0.44-0.66, 0.17-0.22 and 0.44-0.66 GW/m2 for PW, WL10 and W-K, respectively. The melting threshold was over 1.1 GW/m2 for PW and W-K while 0.66-0.88 GW/m2 for WL10. In thermal fatigue tests, the obvious roughening threshold was over 1000 cycles for PW and WL10 while 1-100 cycles for W-K. The cracking threshold was 100-1000 cycles for PW, 1-100 cycles for WL10 and over 1000 cycles for W-K alloy. WL10 displayed worse thermal and fatigue resistance while W-K exhibited better properties compared with PW, which was attributed to differences in thermal-mechanical properties of the three tungsten alloys, in addition to the size and number density of La2O3 particles and potassium bubbles.

  11. 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.

  12. Impact of remanent magnetic field on the heat load of original CEBAF cryomodule

    SciTech Connect

    Ciovati, Gianluigi; Cheng, Guangfeng; Drury, Michael; Fischer, John; Geng, Rongli

    2016-11-22

    The heat load of the original cryomodules for the CEBAF accelerator is ~50% higher than the target value of 100 W at 2.07 K for refurbished cavities operating at an accelerating gradient of 12.5 MV/m. This issue is due to the quality factor of the cavities being ~50% lower in the cryomodule than when tested in a vertical cryostat, even at low RF field. Previous studies were not conclusive about the origin of the additional losses. We present the results of a systematic study of the additional losses in a five-cell cavity from a decommissioned cryomodule after attaching components, which are part of the cryomodule, such as the cold tuner, the He tank and the cold magnetic shield, prior to cryogenic testing in a vertical cryostat. Flux-gate magnetometers and temperature sensors are used as diagnostic elements. Different cool-down procedures and tests in different residual magnetic fields were investigated during the study. Here, three flux-gate magnetometers attached to one of the cavities installed in the refurbished cryomodule C50-12 confirmed the hypothesis of high residual magnetic field as a major cause for the increased RF losses.

  13. Impact of remanent magnetic field on the heat load of original CEBAF cryomodule

    DOE PAGES

    Ciovati, Gianluigi; Cheng, Guangfeng; Drury, Michael; ...

    2016-11-22

    The heat load of the original cryomodules for the CEBAF accelerator is ~50% higher than the target value of 100 W at 2.07 K for refurbished cavities operating at an accelerating gradient of 12.5 MV/m. This issue is due to the quality factor of the cavities being ~50% lower in the cryomodule than when tested in a vertical cryostat, even at low RF field. Previous studies were not conclusive about the origin of the additional losses. We present the results of a systematic study of the additional losses in a five-cell cavity from a decommissioned cryomodule after attaching components, whichmore » are part of the cryomodule, such as the cold tuner, the He tank and the cold magnetic shield, prior to cryogenic testing in a vertical cryostat. Flux-gate magnetometers and temperature sensors are used as diagnostic elements. Different cool-down procedures and tests in different residual magnetic fields were investigated during the study. Here, three flux-gate magnetometers attached to one of the cavities installed in the refurbished cryomodule C50-12 confirmed the hypothesis of high residual magnetic field as a major cause for the increased RF losses.« less

  14. Limiter heat loads during the first operation of the W7-X stellarator

    NASA Astrophysics Data System (ADS)

    Wurden, Glen; Niemann, Holger; Jakubowski, Marcin; Bozhenkov, Sergey; Biedermann, Christoph; Marsen, Stefan; Effenberg, Florian; Stephey, Laurie; Schmitz, Oliver; W7-X Team

    2016-10-01

    During the first operational phase (OP1.1) of the new W7-X stellarator, five poloidal graphite limiters served as the main boundary for the plasma. There was a dedicated set of diagnostics to observe the performance of the temporary poloidal limiters and infer basic transport behavior of the 3-D helical SOL plasma. We describe IR imaging of the limiters, which resulted in observations of 1) heat flux determination as a function of time and space, 2) total energy into the limiters, 3) high-frequency helical patterns of energy bursts onto the limiters, 4) changes in surface emissivity, and 5) detection of UFO's (small-to-large dusts). These measurements were made in 2 magnetic configuration discharges (differing iota), and in ones where the power loads to the limiters were systematically modified by the use of trim coils. Observed power fractions on the limiters ranged from 40% to 20% of the 0.6 to 4 MW ECRH input powers. Acknowledgement: Funded under DOE LANS Contract DE-AC5026NA25396 and DE-SC0014210, and within the EUROfusion Consortium under Euratom Grant 633053.

  15. 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.

  16. Thermal Fatigue Life of Glidcop Al-15 High-Heat-Load Components

    SciTech Connect

    Jin, J. F.; Xiao, W. L.; Chen, H. B.

    2010-05-21

    Shanghai Synchrotron Radiation Facility (SSRF) is a third-generation of synchrotron radiation light source and is presently under construction as a large scale national scientific project in China. Depending on the outstanding thermal and mechanical performance, Glidcop Al-15, a dispersion strengthened copper alloy, is chosen to serve for the high-heat-load components at beam line front end in SSRF. Present study is to investigate the thermal fatigue lives of critical SSRF components. A nonlinear finite element method (FEM) is used to simulate the nonlinear three dimensional stress-strain fields of the critical component-Mask2 at SSRF beam line. The method consists of transient temperature analyses followed by elastic-plastic stress analyses. Then, a critical plane approach is used to predict the thermal fatigue life of mask2. The critical plane approach is appropriate for estimating service life of critical SSRF components since the results are in good consistent with the experimental ones taken at the Advanced Photon Source (APS).

  17. Investigation of vacuum properties of CuCrZr alloy for high-heat-load absorber

    NASA Astrophysics Data System (ADS)

    Shueh, C.; Chan, C. K.; Chang, C. C.; Sheng, I. C.

    2017-01-01

    The Taiwan Photon Source (TPS) uses high-heat-load (HHL) absorbers to protect downstream ultrahigh-vacuum chambers from overheating. In this work, we propose to use the CuCrZr alloy (ASTM C18150) for the HHL absorber body and the ConFlat flanges. We use the throughput method to measure the thermal outgassing rate and a helium leak detector to verify the vacuum seal between the CuCrZr alloy and stainless-steel flanges. The measured outgassing rate of the CuCrZr alloy was 5.8×10-10 Pa m/s after 72 h of pumping and decreased to 2.0 × 10-10 Pa m/s after 100 h of pumping. The leak rate through the vacuum seal between a CuCrZr flange and a stainless-steel flange was less than 1 × 10-10 Pa m3/s even after mounting and unmounting the flanges ten times and baking them at 250 °C. These results indicate that CuCrZr alloy is suitable for integrating HHL components with ConFlat CuCrZr flanges for the absorption of the synchrotron radiation generated by the TPS.

  18. 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.

  19. 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.

  20. Influence of heat flux loading patterns on the surface cracking features of tungsten armor under ELM-like thermal shocks

    NASA Astrophysics Data System (ADS)

    Li, Muyuan; Werner, Ewald; You, Jeong-Ha

    2015-02-01

    In this work, the influence of different high heat flux (HHF) loading patterns on the surface cracking of tungsten was investigated under edge-localized mode (ELM)-like thermal loads. Two numerical approaches were employed, namely, the extended finite element method (XFEM) and the virtual crack tip extension (VCE) method. Comparative assessment of initial cracking and crack growth was conducted for six HHF loading patterns (combinations of three spatial and two temporal variants) assuming the same deposited energy for all cases. A ramp pulse with a longer duration leads to slightly lower temperatures and stresses in comparison to a constant pulse with a shorter duration, and no significant difference in cracking appears for these two temporal loading scenarios. In the central part of the loading area, cracks propagate perpendicularly to the surface and the final length of these cracks is dependent on the applied power density. For both triangular and uniformly distributed HHF loadings, cracks initiated near the position, where the peak stress occurred at the surface, tend to kink from the initial vertical paths and then grow parallel to the surface. The driving force for this type of crack propagation is larger under uniform than triangular loading.

  1. Preliminary study on heat load using calorimetric measurement during long-pulse high-performance discharges on EAST

    NASA Astrophysics Data System (ADS)

    Liu, Y. K.; Hamada, N.; Hanada, K.; Gao, X.; Liu, H. Q.; Yu, Y. W.; Qian, J. P.; Yang, L.; Xu, T. J.; Jie, Y. X.; Yao, Y.; Wang, S. S.; Xu, J. C.; Yang, Z. D.; Li, G. S.; EAST Team

    2017-04-01

    Experimental Advanced Superconducting Tokamak (EAST) aims to demonstrate steady-state advanced high-performance H-mode plasmas with an ITER-like configuration, plasma control and heating schemes. The plasma-facing components in EAST are actively cooled, providing good conditions for researching long-pulse and high-energy discharges. A long-pulse high-performance plasma discharge (#59892 discharge) of up to 103 s with a core electron temperature of up to 4.5 keV was sustained with an injected energy exceeding 0.22 GJ in the 2015–2016 experimental campaign. A calorimetric measurement utilizing the temperature increment of cooling water is carried out to calculate the heat load on the strike point region of the lower divertor during long-pulse discharges in EAST. For the long-pulse and high-energy discharges, the comparison of the measurement results for the heat load measured by divertor Langmuir probes and the calorimetry diagnostic indicates that most of the heat load is delivered to the divertor panels as plasma, not radiation, and charge exchange neutrals. The ratio of the heat load on the strike point region of the lower divertor to the total injected energy is on average 42.5% per discharge with the lower single null divertor configuration. If the radiated energy loss measured by the fast bolometer diagnostic is taken into consideration, the ratio is found to be 61.6%. The experimental results and the analysis of the physics involved in these discharges are reported and discussed.

  2. Effects of Properties on S45C Carbon Steel by Electroless NiP Adding Al2O3 Powder of Composite Deposition and Various Heat Treatments

    NASA Astrophysics Data System (ADS)

    Chang, Shih-Hsien; Liang, Cheng; Chang, Chih-Chung

    2014-06-01

    This research studies the effects on the surface microstructure and mechanical properties of S45C carbon steel via electroless Ni-P, by adding αAl2O3 powder via composite deposition and various heat treatments. The plating specimens were treated with pH5 and pH8 baths heated to 350°C and 300°C, respectively, and soaked for 1 hr. Meanwhile, two different particle sizes of Al2O3 powder were added to the electroless Ni-P plating: 0.3 μm of αAl2O3 and 0.05 μm of γAl2O3 powder, respectively. The experimental results show that, after 1 hr of heat treatment at 300°C, the optimal hardness for the specimens using the pH8 of Ni-P with αAl2O3 and γAl2O3 added by composite deposition are HV0.05 1237 and HV0.05 1145, respectively. All of the specimens underwent the main precipitate phase of Ni3P after heat treatment.

  3. 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

  4. 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.

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

    NASA Astrophysics Data System (ADS)

    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.

  6. 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.

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

    SciTech Connect

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

    2016-02-15

    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.

  8. Augmented supraspinal fatigue following constant-load cycling in the heat.

    PubMed

    Goodall, S; Charlton, K; Hignett, C; Prichard, J; Barwood, M; Howatson, G; Thomas, K

    2015-06-01

    The development of central fatigue is prominent following exercise-induced hyperthermia, but the contribution of supraspinal fatigue is not well understood. Seven endurance-trained cyclists (mean ± SD peak O2 uptake, 62.0 ± 5.6 mL/kg/min) completed two high-intensity constant-load cycling trials (296 ± 34 W) to the limit of tolerance in a hot (34 °C, 20% relative humidity) and, on a separate occasion, for the same duration, a control condition (18 °C, 20% relative humidity). Core body temperature (Tc ) was measured throughout. Before and immediately after each trial, twitch responses to supramaximal femoral nerve and transcranial magnetic stimulation were obtained from the knee extensors to assess neuromuscular and corticospinal function, respectively. Exercise time was 11.4 ± 2.6 min. Peak Tc was higher in the hot compared with control (38.36 ± 0.43 °C vs 37.86 ± 0.36 °C; P = 0.035). Post-exercise reductions in maximal voluntary contraction force (13 ± 9% vs 9 ± 5%), potentiated twitch force (16 ± 12% vs 21 ± 13%) and voluntary activation (9 ± 7% vs 7 ± 7%) were similar in hot and control trials, respectively. However, cortical voluntary activation declined more in the hot compared with the control (8 ± 3% vs 3 ± 2%; P = 0.001). Exercise-induced hyperthermia elicits significant central fatigue of which a large portion can be attributed to supraspinal fatigue. These data indicate that performance decrements in the heat might initially originate in the brain.

  9. Development and applications of rectangular box-type explosively bonded structures for high-heat-load beamline components

    NASA Astrophysics Data System (ADS)

    Shu, D.; Chang, J.; Kuzay, T. M.; Brasher, D. G.

    2001-07-01

    Explosive bonding technology is a good choice to join dissimilar materials, such as 304L stainless steel and GlidCop AL-15, and is used extensively in making the advanced photon source (APS) high-heat-load beamline and front-end components. It is a bonding method in which the controlled energy of a detonating explosive is used to create a metallurgical bond between two or more similar or dissimilar materials. In recent years, special explosive bonding units with rectangular box-type joints were developed for the APS new high-heat-load beamline components. Based on this new technique, the box form of the component could be built in two halves first, then welded together. Therefore, beamline designers have more freedom to optimize the cooling surface geometry.

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

    SciTech Connect

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

    2016-02-15

    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.

  11. 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.

  12. Experimental Investigation of Heat Transfer in Separated Flow on a Highly Loaded LP Turbine Cascade

    DTIC Science & Technology

    2003-03-01

    W Q e Q c Q f c Fig. 5 Heat-rate balance of a glue-on hot-film sensor The forced convective heat flux fcQ can be determined from the heat-rate...constant in x-direction, fcQ results in: )cTw(TAhfc Q −= (10) The heat generation rate by an electrical current I of the hot- film with a resistance Rw

  13. 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.

  14. 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

  15. Numerical study of oscillatory flow and heat transfer in a loaded thermoacoustic stack

    SciTech Connect

    Worlikar, A.S.; Knio, O.M.

    1999-01-01

    A thermoacoustic refrigerator may be idealized as consisting of a straight resonance tube housing a stack of parallel plates and heat exchangers, and an acoustic source. Among the advantages of thermoacoustic refrigerators are the simplicity of their design and the fact that they naturally avoid the need for harmful refrigerants such as chlorofluorocarbons (CFCs). The operation of these devices is based on exploiting the well-known thermoacoustic effect to induce a temperature difference across the stack and to transport heat from one end of the plate to the other. Heat exchangers are then used to transfer energy from the thermoacoustic refrigerator to hot and cold reservoirs. A two-dimensional, low-Mach-number computational model is used to analyze the unsteady flow and temperature fields in the neighborhood of an idealized stack/heat exchanger configuration. The model relies on a vorticity-based formulation of the mass, momentum, and energy equations in the low-Mach-number, short-stack limit. The stack and heat exchangers are assumed to consist of flat plates of equal thickness. The heat exchanger plates are assumed isothermal and in perfect thermal contact with the stack plates. The simulations are used to study the effect of heat exchanger size and operating conditions on the heat transfer and stack performance. Computed results show that optimum stack performance is achieved when the length of the heat exchanger is nearly equal to the peak-to-peak particle displacement. Numerical estimates of the mean enthalpy flux within the channel are in good agreement with the predictions of linear theory. However, the results reveal that a portion of the heat exchangers is ineffective due to reverse heat transfer. Details of the energy flux density around the heat exchangers are visualized, and implications regarding heat exchanger design and model extension are discussed.

  16. Curcumin-loaded guanidine functionalized PEGylated I3ad mesoporous silica nanoparticles KIT-6: practical strategy for the breast cancer therapy.

    PubMed

    Ma'mani, Leila; Nikzad, Safoora; Kheiri-Manjili, Hamidreza; Al-Musawi, Sharafaldin; Saeedi, Mina; Askarlou, Sonia; Foroumadi, Alireza; Shafiee, Abbas

    2014-08-18

    In this research, we have synthesized guanidine functionalized PEGylated mesoporous silica nanoparticles as a novel and efficient drug delivery system (DDS). For this purpose, guanidine functionalized PEGylated I3ad mesoporous silica nanoparticle KIT-6 [Gu@PEGylated KIT-6] was utilized as a promising system for the effective delivery of curcumin into the breast cancer cells. The modified mesoporous silica nanoparticles (MSNs) was fully characterized by different techniques such as transmission and scanning electron microscopy (TEM & SEM), N2 adsorption-desorption measurement, thermal gravimetric analysis (TGA), X-ray powder diffraction (XRD), and dynamic light scattering (DLS). The average particle size of [Gu@PEGylated KIT-6] and curcumin loaded [Gu@PEGylated KIT-6] nanoparticles were about 60 and 70 nm, respectively. This new system exhibited high drug loading capacity, sustained drug release profile, and high and long term anticancer efficacy in human cancer cell lines. It showed pH-responsive controlled characteristics and highly programmed release of curcumin leading to the satisfactory results in in vitro breast cancer therapy. Our results depicted that the pure nanoparticles have no cytotoxicity against human breast adenocarcinoma cells (MCF-7), mouse breast cancer cells (4T1), and human mammary epithelial cells (MCF10A). Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  17. Effects of added surfactant on swelling and molecular transport in drug-loaded tablets based on hydrophobically modified poly(acrylic acid).

    PubMed

    Knöös, Patrik; Wahlgren, Marie; Topgaard, Daniel; Ulvenlund, Stefan; Piculell, Lennart

    2014-08-14

    A combination of NMR chemical shift imaging and self-diffusion experiments is shown to give a detailed molecular picture of the events that occur when tablets of hydrophobically modified poly(acrylic acid) loaded with a drug (griseofulvin) swell in water in the presence or absence of surfactant (sodium octylbenzenesulfonate). The hydrophobic substituents on the polymer bind and trap the surfactant molecules in mixed micelles, leading to a slow effective surfactant transport that occurs via a small fraction of individually dissolved surfactant molecules in the water domain. Because of the efficient binding of surfactant, the penetrating water is found to diffuse past the penetrating surfactant into the polymer matrix, pushing the surfactant front outward as the matrix swells. The added surfactant has little effect on the transport of drug because both undissolved solid drug and surfactant-solubilized drug function as reservoirs that essentially follow the polymer as it swells. However, the added surfactant nevertheless has a strong indirect effect on the release of griseofulvin, through the effect of the surfactant on the solubility and erosion of the polymer matrix. The surfactant effectively solubilizes the hydrophobically modified polymer, making it fully miscible with water, leading to a more pronounced swelling and a slower erosion of the polymer matrix.

  18. 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

  19. The effects of compressor speed and electronic expansion valve opening on the optimum design of inverter heat pump at various heating loads

    SciTech Connect

    Hwang, Y.; Kim, Y.; Park, J.; Kim, C.

    1999-07-01

    The experiments to design the optimum operation point of an inverter heat pump were performed by varying compressor speed and expansion valve opening for various heating loads. At the indoor temperatures of {minus}5 {approximately} 15C and outdoor temperatures of {minus}10 {approximately} 25 C, the compressor driving frequencies were varied 10 {approximately} 120 Hz and 80 {approximately} 200 pulse for the expansion valve opening while the speed of the indoor and outdoor fans were fixed. From the results of this study, the optimum combination of compressor driving frequency and expansion valve opening were found to exist if indoor and outdoor temperatures are settled though the operation point is changed by the preferable factor among capacity, comfort and power saving.

  20. 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.

  1. Containment loads due to direct containment heating and associated hydrogen behavior: Analysis and calculations with the CONTAIN code

    SciTech Connect

    Williams, D C; Bergeron, K D; Carroll, D E; Gasser, R D; Tills, J L; Washington, K E

    1987-05-01

    One of the most important unresolved issues governing risk in many nuclear power plants involves the phenomenon called direct containment heating (DCH), in which it is postulated that molten corium ejected under high pressure from the reactor vessel is dispersed into the containment atmosphere, thereby causing sufficient heating and pressurization to threaten containment integrity. Models for the calculation of potential DCH loads have been developed and incorporated into the CONTAIN code for severe accident analysis. Using CONTAIN, DCH scenarios in PWR plants having three different representative containment types have been analyzed: Surry (subatmospheric large dry containment), Sequoyah (ice condenser containment), and Bellefonte (atmospheric large dry containment). A large number of parameter variation and phenomenological uncertainty studies were performed. Response of DCH loads to these variations was found to be quite complex; often the results differ substantially from what has been previously assumed concerning DCH. Containment compartmentalization offers the potential of greatly mitigating DCH loads relative to what might be calculated using single-cell representations of containments, but the actual degree of mitigation to be expected is sensitive to many uncertainties. Dominant uncertainties include hydrogen combustion phenomena in the extreme environments produced by DCH scenarios, and factors which affect the rate of transport of DCH energy to the upper containment. In addition, DCH loads can be aggravated by rapid blowdown of the primary system, co-dispersal of moderate quantities of water with the debris, and quenching of de-entrained debris in water; these factors act by increasing steam flows which, in turn, accelerates energy transport. It may be noted that containment-threatening loads were calculated for a substantial portion of the scenarios treated for some of the plants considered.

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

    USDA-ARS?s Scientific Manuscript database

    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...

  3. 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.

  4. 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.

  5. Pulse Mitigation and Heat Transfer Enhancement Techniques. Volume 4. Transient Behavior of Heat Pipe With Thermal Energy Storage Under Pulse Heat Loads

    DTIC Science & Technology

    1992-08-01

    the remarkable properties of the heat pipe have become appreciated, and serious developmental work is still taking place. A heat pipe consists of a...transient liquid flow model requires knowledge of the saturation dependence of the capillary flow properties , which can only be determined by experiment...their discretization equations which are physically unrealistic. In light of the above observation, an improved ADI method is proposed. The

  6. 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.

  7. 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).

  8. Divertor heat load in ASDEX Upgrade L-mode in presence of external magnetic perturbation

    NASA Astrophysics Data System (ADS)

    Faitsch, M.; Sieglin, B.; Eich, T.; Herrmann, A.; Suttrop, W.; the ASDEX Upgrade Team

    2017-09-01

    Power exhaust is one of the major challenges for a future fusion device. Applying a non-axisymmetric external magnetic perturbation is one technique that is studied in order to mitigate or suppress large edge localized modes which accompany the high confinement regime in tokamaks. The external magnetic perturbation induces breaking in the axisymmetry of a tokamak and leads to a 2D heat flux pattern on the divertor target. The 2D heat flux pattern at the outer divertor target is studied on ASDEX Upgrade in stationary L-mode discharges. The amplitude of the 2D characteristic of the heat flux depends on the alignment between the field lines at the edge and the vacuum response of the applied magnetic perturbation spectrum. The 2D characteristic reduces with increasing density. The increasing divertor broadening, S, with increasing density is proposed as the main actuator. This is supported by a generic model using field line tracing and the vacuum field approach that is in quantitative agreement with the measured heat flux. The perturbed heat flux, averaged over a full toroidal rotation of the magnetic perturbation, is identical to the non-perturbed heat flux without magnetic perturbation. The transport qualifiers, power fall-off length {λ }q and divertor broadening, S, are the same within the uncertainty compared to the unperturbed reference. No additional cross field transport is observed.

  9. Ultra-wideband coaxial hybrid coupler for load resilient ion cyclotron range of frequency heating at fusion plasmas

    SciTech Connect

    Kim, H. J.; Bae, Y. S.; Yang, H. L.; Kwak, J.-G.; Wang, S. J.; Kim, B. K.; Choi, J. J.

    2012-06-25

    We designed a high power and ultra-wideband two-section 3 dB coaxial hybrid coupler for load resilient ion cyclotron range of frequency heating by configuring asymmetric impedance matching using a three-dimensional simulation code, hfss. By adjusting the characteristic impedances of main and coupled lines of the hybrid coupler, we realized that the bandwidth of the proposed circuit is not only wider than that of a conventional three-section coupler, but also that the bandwidth is almost twice as wide compared to the conventional two-section hybrid coupler while maintaining the identical overall size.

  10. 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.

  11. 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.

  12. Allowable aperture size of the front end for the high-heat-load undulator beamlines of SPring-8.

    PubMed

    Oura, M; Sakae, H; Sakurai, Y; Kitamura, H

    1998-05-01

    A systematic study to determinine the allowable aperture size of the front end for the SPring-8 high-heat-load undulator beamlines has been performed, from the viewpoint of protecting the front-end Be window from thermomechanical failure, and based on the results of ANSYS finite-element analyses. These results have revealed that the allowable aperture size of the front end ranges approximately from 1.06 mm(2) to 3.2 mm(2) depending on the K-parameter and the filter thickness.

  13. Criteria for the diagnosis of heat-related deaths: National Association of Medical Examiners. Position paper. National Association of Medical Examiners Ad Hoc Committee on the Definition of Heat-Related Fatalities.

    PubMed

    Donoghue, E R; Graham, M A; Jentzen, J M; Lifschultz, B D; Luke, J L; Mirchandani, H G

    1997-03-01

    The National Association of Medical Examiners Ad Hoc Committee on the Definition of Heat-Related Fatalities recommends the following definition of "heat-related death": a death in which exposure to high ambient temperature either caused the death or significantly contributed to it. The committee also recommends that the diagnosis of heat-related death be based on a history of exposure to high ambient temperature and the reasonable exclusion of other causes of hyperthermia. The diagnosis may be established from the circumstances surrounding the death, investigative reports concerning environmental temperature, and/or measured antemortem body temperature at the time of collapse. In cases where the measured antemortem body temperature at the time of collapse was > or = 105 degrees F (> or = 40.6 degrees C), the cause of death should be certified as heat stroke or hyperthermia. Deaths may also be certified as heat stroke or hyperthermia with lower body temperatures when cooling has been attempted prior to arrival at the hospital and/or when there is a clinical history of mental status changes and elevated liver and muscle enzymes. In cases where the antemortem body temperature cannot be established but the environmental temperature at the time of collapse was high, an appropriate heat-related diagnosis should be listed as the cause of death or as a significant contributing condition.

  14. 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.

  15. Effect of ad Libitum Ice-Slurry and Cold-Fluid Ingestion on Cycling Time-Trial Performance in the Heat.

    PubMed

    Maunder, Ed; Laursen, Paul B; Kilding, Andrew E

    2017-01-01

    To compare the physiological and performance effects of ad libitum cold-fluid (CF) and ice-slurry (IS) ingestion on cycling time-trial (TT) performance in the heat. Seven well-trained male triathletes and cyclists completed 2 maximaleffort 40-km cycling TTs in hot (35°C) and humid (60% relative humidity) conditions. In randomized order, participants ingested CF or IS (initial temperatures 4°C and -1°C, respectively) ad libitum during exercise. At each 5-km interval, time elapsed, power output, rectal and skin temperature, heart rate, and perceptual measures were recorded. The actual CF and IS temperatures during the 40-km TT were determined post hoc. Performance time (2.5% ± 2.6%, ES = 0.27) and mean power (-2.2% ± 3.2%, ES = -0.15) were likely worse in the IS trial. Differences in thermoregulatory and cardiovascular measures were largely unclear between trials, while feeling state was worse in the later stages of the IS trial (ES = -0.31 to -0.95). Fluid-ingestion volume was very likely lower in the IS trial (-29.7% ± 19.4%, ES = -0.97). The temperatures of CF and IS increased by 0.37°C/min and 0.02°C/min, respectively, over the mean TT duration. Ad libitum ingestion of CF resulted in improved 40-km cycling TT performance compared with IS. Participants chose greater fluid-ingestion rates in the CF trial than in the IS trial and had improved feeling state. These findings suggest that ad libitum CF ingestion is preferable to IS during cycling TTs under conditions of environmental heat stress.

  16. An Electrothermal Plasma Source Developed for Simulation of Transient Heat Loads in Future Large Fusion Devices

    NASA Astrophysics Data System (ADS)

    Gebhart, Trey; Baylor, Larry; Winfrey, Leigh

    2016-10-01

    The realization of fusion energy requires materials that can withstand high heat and particle fluxes at the plasma material interface. In this work, an electrothermal (ET) plasma source has been designed as a possible transient heat flux source for a linear plasma material interaction device. An ET plasma source operates in the ablative arc regime, which is driven by a DC capacitive discharge. The current travels through the 4mm bore of a boron nitride liner and subsequently ablates and ionizes the liner material. This results in a high density plasma with a large unidirectional bulk flow out of the source exit. The pulse length for the ET source has been optimized using a pulse forming network to have a duration of 1ms at full-width half maximum. The peak currents and maximum source energies seen in this system are 2kA and 5kJ. The goal of this work is to show that the ET source produces electron densities and heat fluxes that are comparable to transient events in future large magnetic confinement fusion devices. Heat flux, plasma temperature, and plasma density were determined for each test shot using infrared imaging and optical spectroscopy techniques. This work will compare the ET source output (heat flux, temperature, and density) with and without an applied magnetic field. Research sponsored by the Laboratory Directed Research and Development Program of Oak Ridge National Laboratory, managed by UT-Battelle, LLC, for the U. S. Department of Energy.

  17. 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.

  18. Engineering for high heat loads on ALS (Advanced Light Source) beamlines

    SciTech Connect

    DiGennaro, R.; Swain, T.

    1989-08-01

    This paper discussed general thermal engineering problems and specific categories of thermal design issues for high photon flux beam lines at the LBL Advanced Light Source: thermal distortion of optical surfaces and elevated temperatures of thermal absorbers receiving synchrotron radiation. A generic design for water-cooled heat absorbers is described for use with ALS photon shutters, beam defining apertures, and heat absorbing masks. Also, results of in- situ measurements of thermal distortion of a water-cooled mirror in a synchrotron radiation beam line are compared with calculated performance estimates. 17 refs., 2 figs.

  19. 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.

  20. Studies on the Startup Transients and Performance of a Gas Loaded Sodium Heat Pipe

    DTIC Science & Technology

    1989-06-01

    calculated using Eq. (88). 0cal " P p Alcoolant (88) Coolant flow rate, V - 2.3 liters/minute; specific gravity, p 1.0; and specific heat, C = 4.2 J...Steady State Calorimetric Test Data 151 mmmma 0mmr mmmmm mm ----- Eq. (88), QCal = 161.07 ( Alcoolant ) watts. 1here was good agreement between Qi (power

  1. Vehicle Exhaust Waste Heat Recovery Model with Integrated Thermal Load Leveling

    DTIC Science & Technology

    2015-08-01

    24. Ethylene Glycol Heat-Transfer Fluid. The Engineering Toolbox; n.d. [accessed 9/1/2014]. http://www.engineeringtoolbox.com/ ethylene - glycol ...water:ethylene glycol mixture;24 the coolant mass flow rate ?̇? is taken as 0.15 kg/s, equal to the midpoint of flow rates

  2. The antioxidants in oils heated at frying temperature, whether natural or added, could protect against postprandial oxidative stress in obese people.

    PubMed

    Perez-Herrera, Aleyda; Rangel-Zuñiga, Oriol A; Delgado-Lista, Javier; Marin, Carmen; Perez-Martinez, Pablo; Tasset, Inmaculada; Tunez, Isaac; Quintana-Navarro, Gracia M; Lopez-Segura, Fernando; Luque de Castro, Maria D; Lopez-Miranda, Jose; Camargo, Antonio; Perez-Jimenez, Francisco

    2013-06-15

    We have investigated the effects of the intake of oils heated at frying temperature in order to find an oil model for deep-frying that prevents postprandial oxidative stress. Twenty obese people received four breakfasts following a randomised crossover design consisting of different oils (virgin olive oil (VOO), sunflower oil (SFO), and a mixed seed oil (SFO/canola oil) with added dimethylpolysiloxane (SOX) or natural antioxidants from olives (SOP)), which were subjected to 20 heating cycles. The intake of SFO-breakfast reduced plasma GSH levels and the GSH/GSSG ratio, increased protein carbonyl levels, and induced a higher gene expression of the different NADPH-oxidase subunits, Nrf2-Keap1 activation, gene expression of the antioxidant enzymes in peripheral blood mononuclear cells and antioxidant plasma activities than the intake of the breakfasts prepared with VOO, SOP and SOX. Oils with phenolic compounds, whether natural (VOO) or artificially added (SOP), or with artificial antioxidant (SOX), could reduce postprandial oxidative stress compared with sunflower oil.

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

    SciTech Connect

    None, None

    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).

  4. Melt layer erosion of pure and lanthanum doped tungsten under VDE-like high heat flux loads

    NASA Astrophysics Data System (ADS)

    Yuan, Y.; Greuner, H.; Böswirth, B.; Luo, G.-N.; Fu, B. Q.; Xu, H. Y.; Liu, W.

    2013-07-01

    Heat loads expected for VDEs in ITER were applied in the neutral beam facility GLADIS at IPP Garching. Several ˜3 mm thick rolled pure W and W-1 wt% La2O3 plates were exposed to pulsed hydrogen beams with a central heat flux of 23 MW/m2 for 1.5-1.8 s. The melting thresholds are determined, and melt layer motion as well as material structure evolutions are shown. The melting thresholds of the two W grades are very close in this experimental setup. Lots of big bubbles with diameters from several μm to several 10 μm in the re-solidified layer of W were observed and they spread deeper with increasing heat flux. However, for W-1 wt% La2O3, no big bubbles were found in the corrugated melt layer. The underlying mechanisms referred to the melt layer motion and bubble issues are tentatively discussed based on comparison of the erosion characteristics between the two W grades.

  5. 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.

  6. 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

  7. 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.

  8. The temperature of water ingested ad libitum does not influence performance during a 40-km self-paced cycling trial in the heat.

    PubMed

    De Carvalho, M V; De Andrade, M T; Ramos, G P; Maia-Lima, A; Pereira, E R; Mendes, T T; Marins, J C; Amorim, F T; Silami-Garcia, E

    2015-12-01

    The aim of the present study was to evaluate the effects of the temperature of ingested water on performance during a 40-km self-paced cycling trial in the heat (35º C and 60% relative humidity). The study was randomized, counterbalanced, crossover and single-blinded. Ten well-trained male cycling athletes (cyclists, mountain bikers or triathletes) who were non-acclimatized to heat were subjected to four experimental situations divided into two sets. In the first set, the participants performed two trials, during which they were given either cold (10º C) or warm water (37º C) ad libitum. In these situations, the volume and timing of the water ingestion (when each bolus was ingested) were recorded and replicated in the second set, but the water temperature was reversed. The performance times were unaffected by the water intake volume (P=0.425), but the water at a temperature of 37º C tended to induce lower performance times (P=0.078) during the trials (AL10=93.0±3.5 min; AL37=94.4±4.1 min; SC10=93.4±4.0; SC37=97.4±4.3 min). The water intake was greater when the water was cold (P<0.05), but the temperature did not affect the heat storage rate, rectal temperature, mean skin temperature, heart rate, blood glucose level, sweat loss, sweat rate, perceived exertion rate or plasma volume changes. However, a significant reduction in the plasma volume change from pre- to postexercise was observed (P<0.01). The performance, thermoregulatory, cardiovascular and metabolic responses during a 40-km self-paced cycling trial in the heat were unaffected by different water temperatures.

  9. Results from the US/USSR exchange for heat load material studies of simulated tokamak disruptions

    NASA Astrophysics Data System (ADS)

    Gahl, J. M.; Crawford, J. F.; McDonald, J. M.; McGrath, R. T.; Zakharov, A.

    This paper presents recent results from exchange I.2 of the US/USSR Exchange Program of Cooperation for Magnetic Confinement Fusion. Previous results from this exchange demonstrated much lower than expected ablation of graphites when the graphites were exposed to disruption like heat fluxes delivered by plasma gun sources. This lower than expected ablation has been accounted for by the 'vapor shielding' effect. Vapor shielding occurs when material is ablated from the surface of the graphite target early in the plasma pulse. This ablated material then shields the surface of the target from the rest of the incoming plasma pulse. Vapor shielding has been inferred from diagnostics and ablation data at all participating laboratories, and clear evidence of the effect has been found by laser interferometry at Kurchatov (Troitsk) in the 2MK-200 machine. Recent results from Kurchatov on the 2MK-200 and MKT experiments continue to indicate that the erosion of graphite exposed to disruption like heat fluxes is much lower than expected. Work from the University of New Mexico on the PLAIDS experiment confirms earlier important work conducted on the VIKA experiment at Efremov. This is particularly interesting in that PLAIDS and VIA have very similar plasma pulse characteristics.

  10. 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.

  11. Estimation of the dust production rate from the tungsten armour after repetitive ELM-like heat loads

    NASA Astrophysics Data System (ADS)

    Pestchanyi, S.; Garkusha, I.; Makhlaj, V.; Landman, I.

    2011-12-01

    Experimental simulations for the erosion rate of tungsten targets under ITER edge-localized mode (ELM)-like surface heat loads of 0.75 MJ m-2 causing surface melting and of 0.45 MJ m-2 without melting have been performed in the QSPA-Kh50 plasma accelerator. Analytical considerations allow us to conclude that for both energy deposition values the erosion mechanism is solid dust ejection during surface cracking under the action of thermo-stress. Tungsten influx into the ITER containment of NW~5×1018 W per medium size ELM of 0.75 MJ m-2 and 0.25 ms time duration has been estimated. The radiation cooling power of Prad=150-300 MW due to such influx of tungsten is intolerable: it should cool the ITER core to 1 keV within a few seconds.

  12. Fatigue life prediction for high-heat-load components made of GlidCop by elastic-plastic analysis.

    PubMed

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

    2008-03-01

    A procedure to predict the fatigue fracture life of high-heat-load components made of GlidCop has been successfully established. This method is based upon the Manson-Coffin equation with a cumulative linear damage law. This prediction was achieved by consolidating the results of experiments and analyses, and considered the effects of environment and creep. A low-cycle-fatigue test for GlidCop was conducted so that environment-dependent Delta(t)-N(f) diagrams for any temperature could be prepared. A special test piece was designed to concentrate the strain in a central area locally, resulting in the low-cycle-fatigue fracture. The experiments were carried out by repeatedly irradiating a test piece with an electron beam. The results of the experiment confirmed that the observed fatigue life was within a factor of two when compared with the predicted fatigue life, yet located on the safer side.

  13. High-heat-load monochromator options for the RIXS beamline at the APS with the MBA lattice

    SciTech Connect

    Liu, Zunping Gog, Thomas Stoupin, Stanislav A.; Upton, Mary H.; Ding, Yang; Kim, Jung-Ho; Casa, Diego M.; Said, Ayman H.; Carter, Jason A.; Navrotski, Gary

    2016-07-27

    With the MBA lattice for APS-Upgrade, tuning curves of 2.6 cm period undulators meet the source requirements for the RIXS beamline. The high-heat-load monochromator (HHLM) is the first optical white beam component. There are four options for the HHLM such as diamond monochromators with refrigerant of either water or liquid nitrogen (LN{sub 2}), and silicon monochromators of either direct or indirect cooling system. Their performances are evaluated at energy 11.215 keV (Ir L-III edge). The cryo-cooled diamond monochromator has similar performance as the water-cooled diamond monochromator because GaIn of the Cu-GaIn-diamond interface becomes solid. The cryo-cooled silicon monochromators perform better, not only in terms of surface slope error due to thermal deformation, but also in terms of thermal capacity.

  14. Influence of Column Axial Load and Heat Affected Zone on the Strength of Aluminium Column Web in Tension

    PubMed Central

    De Matteis, Gianfranco; Sarracco, Gianluca; Brando, Giuseppe; Mazzolani, Federico M.

    2014-01-01

    The component method for aluminium joints has been recently introduced in some codes and guidelines. Nevertheless, it is still in need of some development and improvement, as in some cases it was obtained by adapting the existing formulations that are valid for steel. The current paper presents the main outcomes of a parametric analysis carried out by means of finite element (FE) numerical models for determining the influence of both column axial load and heat affected zone—in the case of welded details—on the structural response of the column web in a tension component. The proposed study integrates previous research carried out by the authors, where the influence of the assumed alloy was investigated and interpreted by corrective parameters expressed as a function of both the material strain hardening and ductility. PMID:28788636

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

    DOE PAGES

    Hollmann, E. M.; Commaux, N.; Eidietis, N. W.; ...

    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 current channel is seen to lock to a preferential phase during the VDE thermal quench, but this phasemore » is not clearly matched by preliminary attempts to fit to the conducted heat load phase. Finally, clear indications of plasma infra-red emission are observed both before and during the disruptions; this infrared emission can affect calculation of disruption heat loads.« less

  16. 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, N.; Eidietis, N. W.; Lasnier, C. J.; Moyer, R. A.; Parks, P. B.; Shiraki, D.

    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 current channel 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. Finally, clear indications of plasma infra-red emission are observed both before and during the disruptions; this infrared emission can affect calculation of disruption heat loads.

  17. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2015-10-01

    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.

  19. 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.

  20. Load-dependent heat development, thermal effects, duration, and soft tissue preservation in piezosurgical implant site preparation: an experimental ex vivo study.

    PubMed

    Stelzle, Florian; Neukam, Friedrich Wilhelm; Nkenke, Emeka

    2012-01-01

    Piezoelectric surgery is meant to be a gentle method for implant site preparation (ISP). However, the application of load and its influence on heat development over time and effects on soft tissue are unknown. Therefore, this study sought to evaluate heat development in the bone and the duration of the procedure according to load application, as well as preservation of the sinus floor mucosa during piezoelectric ISP. One hundred twenty implant sites (6 mm deep x 3 mm wide) were prepared in the calvaria of ex vivo pig heads using piezoelectric surgery. The load applied to the working tip was increased in 100-g intervals up to 1,000 g. The bone temperature was measured, and thermal effects were analyzed histomorphometrically. The duration of each ISP was recorded. Another 12 ISPs were performed at the lateral wall of the maxillary sinus in the vicinity of the sinus floor mucosa, and sites were checked for perforation. Temperature and histologic effects of heat demonstrated a significant positive correlation with the applied load. The duration of ISP was significantly negatively correlated with load application. The maximum temperature generated by piezoelectric surgery was 64.5°C (load of 901 to 1,000 g). At a load of 401 to 500 g, the average temperature was 40.2°C ± 3.3°C, the average thermal damage extended 115.9 ± 16.3 Μm beyond the ISP area, and the maximum temperature did not exceed 47°C. The average duration of ISP using this load interval was 45.5 ± 9.4 seconds. Two perforations of the sinus floor mucosa were detected. In the present setting, the applied load during piezoelectric ISP should not exceed 500 g to prevent temperatures above 47°C in the bony implant socket. With a load of 400 to 500 g, ISP took 40 to 50 seconds.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. Fundamental studies of heat load and thermal-structure analysis of large space structures

    NASA Technical Reports Server (NTRS)

    Thornton, E. A.

    1983-01-01

    Investigation of the basic requirements for modeling slender member shadowing effects on thermally induced deformation continues. The theoretical formulation is complete and computer programming is underway. The basic requirements for thermal finite elements to model heat transfer in orbiting structures were also studied. The need for planar isothermal elements to model large space structures' antenna meshes was established. Finite Element approaches for modeling space structure cable and membrane components with thermal effects is underway. Three levels of structural modeling and analysis were identified: (1) a linear-elastic small deflection analysis that does not permit cable slackening; (2) a linear-elastic analysis that includes stress stiffening (the ANSYS program), but not large deflections; and (3) full nonlinear large deflection analysis with stress stiffening. Methods of determining cable initial tensions are currently being evaluated.

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

    PubMed

    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.

  7. 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.

  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. Simulation and analysis of the response of carbon-fiber composites and pyrolytic graphites to off-normal high heat loads

    SciTech Connect

    van der Laan, J.G.; Klippel, H.T.; van der Stad, R.C.L.; Bakker, C. )

    1991-07-01

    The response of plasma-facing materials to off-normal high heat loads expected in Next European Torus/International Thermonuclear Experimental Reactor (NET/ITER) disruptions has been studied by both experimental and numerical simulations. Experiments have been performed on a number of pyrolytic graphites and carbon-fiber composites. The measured erosion is compared with numerical predictions by a transient heat load code. The effect of variations in thermophysical material parameters on thermal erosion behavior is discussed. Cracking is observed on the surface of pyrolytic graphites, even below the erosion threshold.

  10. Cyclic heat load testing of improved CFC/Cu bonding for the W 7-X divertor targets

    NASA Astrophysics Data System (ADS)

    Greuner, H.; Böswirth, B.; Boscary, J.; Chaudhuri, P.; Schlosser, J.; Friedrich, T.; Plankensteiner, A.; Tivey, R.

    2009-04-01

    Extensive high heat flux cycling testing of pre-series targets was performed in the neutral beam facility GLADIS to establish the industrial process for the manufacturing of 890 targets, which will be needed for the installation of the WENDELSTEIN 7-X divertor. The targets are manufactured of flat tiles of CFC NB31 as plasma facing material bonded by an Active Metal Casting copper interlayer onto a water-cooled CuCrZr structure. Based on the results of the 3D thermo-mechanical FEM analysis of the CFC/Cu interface, an additional set of 17 full-scale pre-series elements including three design variations was manufactured by PLANSEE SE. The insertion of an additional plastically compliant copper interlayer between the cooling structure and the Active Metal Casting interlayer showed the best results. No critical tile detachment was observed during >5000 cycles at 10 MW/m 2. These results demonstrated the sufficient life time of the component for the expected heat load in operation.

  11. MEASURED SPACE CONDITIONING PERFORMANCE OFA VERTICAL-BORE GROUND SOURCE HEAT PUMP (GSHP) OVER TWELVE MONTHS UNDER SIMULATED OCCUPANCY LOADS

    SciTech Connect

    Ally, Moonis Raza; Munk, Jeffrey D; Baxter, Van D; Gehl, Anthony C

    2014-01-01

    This paper presents monthly performance metrics of a 7.56 kW (2.16 ton) GSHP serving the space conditioning loads of a 251m2 (2700ft2) residential home with a phase change material in its envelope, and a single vertical-bore 94.5m (310 ft) ground loop. The same ground loop also serviced a ground source heat pump water heater. Envelope characteristics are discussed briefly in the context of reducing thermal losses. Data on entering water temperatures, energy extracted from the ground, energy delivered/removed, compressor electricity use, COP, GSHP run times (low and high compressor stages), and the impact of fan and pump energy consumption on efficiency are presented for each month. Both practical as well as research and development issues are discussed. The findings suggest that GSHPs represent a practical technology option to reduce source energy reduction and greenhouse emissions under the IECC 2012 Standard, as well as the European Union (EU) 2020 target of generating over 25% of heat consumed in the EU from renewable energy.

  12. 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%.

  13. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2011-12-01

    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. Development of a Novel Method for the Exploration of the Thermal Response of Superfluid Helium Cooled Superconducting Cables to Pulse Heat Loads

    NASA Astrophysics Data System (ADS)

    Winkler, T.; Koettig, T.; van Weelderen, R.; Bremer, J.; ter Brake, H. J. M.

    Management of transient heat deposition in superconducting magnets and its extraction from the aforementioned is becoming increasingly important to bring high energy particle accelerator performance to higher beam energies and intensities. Precise knowledge of transient heat deposition phenomena in the magnet cables will permit to push the operation of these magnets as close as possible to their current sharing limit, without unduly provoking magnet quenches. With the prospect of operating the Large Hadron Collider at CERN at higher beam energies and intensities an investigation into the response to transient heat loads of LHC magnets, operating in pressurized superfluid helium, is being performed. The more frequently used approach mimics the cable geometry by resistive wires and uses Joule-heating to deposit energy. Instead, to approximate as closely as possible the real magnet conditions, a novel method for depositing heat in cable stacks made out of superconducting magnet-cables has been developed. The goal is to measure the temperature difference as a function of time between the cable stack and the superfluid helium bath depending on heat load and heat pulse length. The heat generation in the superconducting cable and precise measurement of small temperature differences are major challenges. The functional principle and experimental set-up are presented together with proof of principle measurements.

  16. 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.

  17. Inter-model, analytical, and experimental validation of a heat balance based residential cooling load calculation procedure

    NASA Astrophysics Data System (ADS)

    Xiao, Dongyi

    Scope and method of study. A systematic validation of the ASHRAE heat balance based residential cooling load calculation procedure (RHB) has been performed with inter-model comparison, analytical verification and experimental validation. The inter-model validation was performed using ESP-r as the reference model. The testing process was automated through parametric generation and simulation of large sets of test cases for both RHB and ESP-r. The house prototypes covered include a simple Shoebox prototype and a real 4-bedroom house prototype. An analytical verification test suite for building fabric models of whole building energy simulation programs has been developed. The test suite consists of a series of sixteen tests covering convection, conduction, solar irradiation, long-wave radiation, infiltration and ground-coupled floors. Using the test suite, a total of twelve analytical tests have been done with the RHB procedure. The experimental validation has been conducted using experimental data collected from a Cardinal Project house located in Fort Wayne, Indiana. During the diagnostic process of the experimental validation, comparisons have also been made between ESP-r simulation results and experimental data. Findings and conclusions. It is concluded RHB is acceptable as a design tool on a typical North American house. Analytical tests confirmed the underlying mechanisms for modeling basic heat transfer phenomena in building fabric. The inter-model comparison showed that the differences found between RHB and ESP-r can be traced to the differences in sub-models used by RHB and ESP-r. It also showed that the RHB-designed systems can meet the design criteria and that the RHB temperature swing option is helpful in reducing system over-sizing. The experimental validation demonstrated that the systems designed with the method will have adequate size to meet the room temperatures specified in the design, whether or not swing is utilized. However, actual system

  18. MO-F-CAMPUS-J-04: Radiation Heat Load On the MR System of the Elekta Atlantic System

    SciTech Connect

    Towe, S; Roberts, D; Overweg, J; Van Lanen, E

    2015-06-15

    Purpose: The Elekta Atlantic system combines a digital linear accelerator system with a 1.5T Philips MRI machine.This study aimed to assess the energy deposited within the cryostat system when the radiation beam passes through the cryostat. The cryocooler on the magnet has a cooling capacity which is about 1 Watt in excess of the cryogenic heat leak into the magnet’s cold mass. A pressure-controlled heater inside the magnet balances the excess refrigeration power such that the helium pressure in the tank is kept slightly above ambient air pressure. If radiation power is deposited in the cold mass then this heater will need less power to maintain pressure equilibrium and if the radiation heat load exceeds the excess cryocooler capacity the pressure will rise. Methods: An in-house CAD based Monte Carlo code based on Penelope was used to model the entire MR-Linac system to quantify the heat load on the magnet’s cold mass. These results were then compared to experimental results obtained from an Elekta Atlantic system installed in UMC-Utrecht. Results: For a field size of 25 cm x 22 cm and a dose rate of 107 mu.min-1, the energy deposited by the radiation beam led to a reduction in heater power from 1.16 to 0.73 W. Simulations predicted a reduction to 0.69 W which is in good agreement. For the worst case field size (largest) and maximum dose rate the cryostat cooler capacity was exceeded. This resulted in a pressure rise within the system but was such that continuous irradiation for over 12 hours would be required before the magnet would start blowing off helium. Conclusion: The study concluded that the Atlantic system does not have to be duty cycle restricted, even for the worst case non-clinical scenario and that there are no adverse effects on the MR system. Stephen Towe and David Roberts Both work for Elekta; Ezra Van Lanen works for Philips Healthcare; Johan Overweg works for Philips Innovative Technologies.

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

    SciTech Connect

    Sizyuk, V. Hassanein, A.

    2015-01-15

    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.

  20. 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.

  1. Impact of heat stress on conception rate of dairy cows in the moderate climate considering different temperature-humidity index thresholds, periods relative to breeding, and heat load indices.

    PubMed

    Schüller, L K; Burfeind, O; Heuwieser, W

    2014-05-01

    The objectives of this retrospective study were to investigate the relationship between temperature-humidity index (THI) and conception rate (CR) of lactating dairy cows, to estimate a threshold for this relationship, and to identify periods of exposure to heat stress relative to breeding in an area of moderate climate. In addition, we compared three different heat load indices related to CR: mean THI, maximum THI, and number of hours above the mean THI threshold. The THI threshold for the influence of heat stress on CR was 73. It was statistically chosen based on the observed relationship between the mean THI at the day of breeding and the resulting CR. Negative effects of heat stress, however, were already apparent at lower levels of THI, and 1 hour of mean THI of 73 or more decreased the CR significantly. The CR of lactating dairy cows was negatively affected by heat stress both before and after the day of breeding. The greatest negative impact of heat stress on CR was observed 21 to 1 day before breeding. When the mean THI was 73 or more in this period, CR decreased from 31% to 12%. Compared with the average maximum THI and the total number of hours above a threshold of more than or 9 hours, the mean THI was the most sensitive heat load index relating to CR. These results indicate that the CR of dairy cows raised in the moderate climates is highly affected by heat stress. Copyright © 2014 Elsevier Inc. All rights reserved.

  2. Effect of dry heat and steam sterilization on load-deflection characteristics of β-titanium wires: An in vitro study

    PubMed Central

    Alavi, Shiva; Sinaee, Neda

    2012-01-01

    Background: Sterilization techniques could affect the characteristics of orthodontic wires. The aim of the present study was to evaluate the effect of steam and dry heat sterilization techniques on load-deflection behavior of five types of β-titanium alloy wires. Materials and Methods: The samples consisted of 30 straight lengths of five types of β-titanium alloy wires: Titanium Molybdenum Alloy (TMA) Low Friction (TMAL), TMA Low Friction Colored (HONE), Resolve (RES), BetaForce (BETA), and BETA CNA (CNA). Thirty wire segments were divided into three groups of 10. Group 1 was the control group and the group 2 samples were sterilized by dry heat in an oven (60 minutes at 160°C) and group 3 by steam in an autoclave (15 minutes at 121°C). Then all the wire samples underwent a three-point bending test in a testing machine to evaluate load-deflection properties. Data was analyzed by repeated measures ANOVA and Scheffé's test (α = 0.05). Results: The results showed that dry heat sterilization significantly increased force levels during both loading and unloading of CNA, BETA and RES and during loading of HONE (P < 0.05). Steam sterilization significantly increased force levels during both loading and unloading of BETA and during unloading of HONE (P < 0.05), with no effects on the load-deflection characteristics of TMAL, CNA and RES (P > 0.05). Conclusion: It appears dry heat sterilization increases stiffness of RES, BETA, CNA and HONE but autoclave sterilization did not have any effect on load-deflection characteristics of most of the β-titanium wires tested, indicating that clinicians who want to provide maximum safety for their patients can autoclave TMAL, RES and CNA before applying them. PMID:23559917

  3. 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.

  4. Near-infrared dye loaded polymeric nanoparticles for cancer imaging and therapy and cellular response after laser-induced heating

    PubMed Central

    Lei, Tingjun; Fernandez-Fernandez, Alicia; Manchanda, Romila; Huang, Yen-Chih

    2014-01-01

    Summary Background: In the past decade, researchers have focused on developing new biomaterials for cancer therapy that combine imaging and therapeutic agents. In our study, we use a new biocompatible and biodegradable polymer, termed poly(glycerol malate co-dodecanedioate) (PGMD), for the synthesis of nanoparticles (NPs) and loading of near-infrared (NIR) dyes. IR820 was chosen for the purpose of imaging and hyperthermia (HT). HT is currently used in clinical trials for cancer therapy in combination with radiotherapy and chemotherapy. One of the potential problems of HT is that it can up-regulate hypoxia-inducible factor-1 (HIF-1) expression and enhance vascular endothelial growth factor (VEGF) secretion. Results: We explored cellular response after rapid, short-term and low thermal dose laser-IR820-PGMD NPs (laser/NPs) induced-heating, and compared it to slow, long-term and high thermal dose heating by a cell incubator. The expression levels of the reactive oxygen species (ROS), HIF-1 and VEGF following the two different modes of heating. The cytotoxicity of NPs after laser/NP HT resulted in higher cell killing compared to incubator HT. The ROS level was highly elevated under incubator HT, but remained at the baseline level under the laser/NP HT. Our results show that elevated ROS expression inside the cells could result in the promotion of HIF-1 expression after incubator induced-HT. The VEGF secretion was also significantly enhanced compared to laser/NP HT, possibly due to the promotion of HIF-1. In vitro cell imaging and in vivo healthy mice imaging showed that IR820-PGMD NPs can be used for optical imaging. Conclusion: IR820-PGMD NPs were developed and used for both imaging and therapy purposes. Rapid and short-term laser/NP HT, with a low thermal dose, does not up-regulate HIF-1 and VEGF expression, whereas slow and long term incubator HT, with a high thermal dose, enhances the expression of both transcription factors. PMID:24778954

  5. Integrated core-edge tokamak simulations using a novel coordinate system for divertor detachment and heat-load studies

    NASA Astrophysics Data System (ADS)

    Leddy, Jarrod; Dudson, Ben; Romanelli, Michele

    2015-11-01

    Simulating tokamak edge plasmas can often be difficult due to the X-point and divertor region having a different geometry than the rest of the plasma. For edge simulations, a field-aligned coordinate system is normally utilized so that the elongated structures along the field line can be resolved using less grid points while maintaining high resolution perpendicular to the field line. This introduces a singularity at the X-point and constrains the radial coordinate and the poloidal projection of the field-aligned coordinate to be orthogonal. We propose a new coordinate system that relaxes this constraint to allow arbitrary geometries to be matched in the poloidal plane while maintaining a field-aligned coordinate. This is useful at the divertor plate where field lines are not perpendicular to the surface and at the X-point where a close approach is desired. We implement a collisional two-fluid turbulence model using BOUT + + to simulate an isolated divertor leg and investigate the effect of divertor plate angle on detachment and heat loads. We then couple edge simulations in BOUT + + with CENTORI, a core plasma fluid code, to study the evolution of the full plasma with these improved boundary conditions. This work has received funding from the RCUK Energy Programme [grant number EP/I501045].

  6. 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.

  7. Pioneering Heat Pump Project

    SciTech Connect

    Aschliman, Dave; Lubbehusen, Mike

    2015-06-30

    This project was initiated at a time when ground coupled heat pump systems in this region were limited in size and quantity. There were economic pressures with costs for natural gas and electric utilities that had many organizations considering ground coupled heat pumps; The research has added to the understanding of how ground temperatures fluctuate seasonally and how this affects the performance and operation of the heat pumps. This was done by using a series of temperature sensors buried within the middle of one of the vertical bore fields with sensors located at various depths below grade. Trending of the data showed that there is a lag in ground temperature with respect to air temperatures in the shoulder months, however as full cooling and heating season arrives, the heat rejection and heat extraction from the ground has a significant effect on the ground temps; Additionally it is better understood that while a large community geothermal bore field serving multiple buildings does provide a convenient central plant to use, it introduces complexity of not being able to easily model and predict how each building will contribute to the loads in real time. Additional controllers and programming were added to provide more insight into this real time load profile and allow for intelligent shedding of load via a dry cooler during cool nights in lieu of rejecting to the ground loop. This serves as a means to ‘condition’ the ground loop and mitigate thermal creep of the field, as is typically observed; and It has been observed when compared to traditional heating and cooling equipment, there is still a cost premium to use ground source heat pumps that is driven mostly by the cost for vertical bore holes. Horizontal loop systems are less costly to install, but do not perform as well in this climate zone for heating mode

  8. 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.

  9. Effect of volume loading on the Frank–Starling relation during reductions in central blood volume in heat-stressed humans

    PubMed Central

    Bundgaard-Nielsen, M; Wilson, T E; Seifert, T; Secher, N H; Crandall, C G

    2010-01-01

    During reductions in central blood volume while heat stressed, a greater decrease in stroke volume (SV) for a similar decrease in ventricular filling pressure, compared to normothermia, suggests that the heart is operating on a steeper portion of a Frank–Starling curve. If so, volume loading of heat-stressed individuals would shift the operating point to a flatter portion of the heat stress Frank–Starling curve thereby attenuating the reduction in SV during subsequent decreases in central blood volume. To investigate this hypothesis, right heart catheterization was performed in eight males from whom pulmonary capillary wedge pressure (PCWP), central venous pressure and SV (via thermodilution) were obtained while central blood volume was reduced via lower-body negative pressure (LBNP) during normothermia, whole-body heating (increase in blood temperature ∼1°C), and during whole-body heating after intravascular volume expansion. Volume expansion was accomplished by administration of a combination of a synthetic colloid (HES 130/0.4, Voluven) and saline. Before LBNP, SV was not affected by heating (122 ± 30 ml; mean ±s.d.) compared to normothermia (110 ± 20 ml; P= 0.06). However, subsequent volume loading increased SV to 143 ± 29 ml (P= 0.003). LBNP provoked a larger decrease in SV relative to the decrease in PCWP during heating (8.6 ± 1.9 ml mmHg−1) compared to normothermia (4.5 ± 3.0 ml mmHg−1, P= 0.02). After volume loading while heat stressed, the reduction in the SV to PCWP ratio during LBNP was comparable to that observed during normothermia (4.8 ± 2.3 ml mmHg−1; P= 0.78). These data support the hypothesis that a Frank–Starling mechanism contributes to compromised blood pressure control during simulated haemorrhage in heat-stressed individuals, and extend those findings by showing that volume infusion corrects this deficit by shifting the operating point to a flatter portion of the heat stress Frank–Starling curve. PMID:20603336

  10. Effect of volume loading on the Frank-Starling relation during reductions in central blood volume in heat-stressed humans.

    PubMed

    Bundgaard-Nielsen, M; Wilson, T E; Seifert, T; Secher, N H; Crandall, C G

    2010-09-01

    During reductions in central blood volume while heat stressed, a greater decrease in stroke volume (SV) for a similar decrease in ventricular filling pressure, compared to normothermia, suggests that the heart is operating on a steeper portion of a Frank-Starling curve. If so, volume loading of heat-stressed individuals would shift the operating point to a flatter portion of the heat stress Frank-Starling curve thereby attenuating the reduction in SV during subsequent decreases in central blood volume. To investigate this hypothesis, right heart catheterization was performed in eight males from whom pulmonary capillary wedge pressure (PCWP), central venous pressure and SV (via thermodilution) were obtained while central blood volume was reduced via lower-body negative pressure (LBNP) during normothermia, whole-body heating (increase in blood temperature 1 degrees C), and during whole-body heating after intravascular volume expansion. Volume expansion was accomplished by administration of a combination of a synthetic colloid (HES 130/0.4, Voluven) and saline. Before LBNP, SV was not affected by heating (122 +/- 30 ml; mean +/- s.d.) compared to normothermia (110 +/- 20 ml; P = 0.06). However, subsequent volume loading increased SV to 143 +/- 29 ml (P = 0.003). LBNP provoked a larger decrease in SV relative to the decrease in PCWP during heating (8.6 +/- 1.9 ml mmHg(1)) compared to normothermia (4.5 +/- 3.0 ml mmHg(1), P = 0.02). After volume loading while heat stressed, the reduction in the SV to PCWP ratio during LBNP was comparable to that observed during normothermia (4.8 +/- 2.3 ml mmHg(1); P = 0.78). These data support the hypothesis that a Frank-Starling mechanism contributes to compromised blood pressure control during simulated haemorrhage in heat-stressed individuals, and extend those findings by showing that volume infusion corrects this deficit by shifting the operating point to a flatter portion of the heat stress Frank-Starling curve.

  11. 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.

  12. 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.

  13. Hairy AdS solitons

    NASA Astrophysics Data System (ADS)

    Anabalón, Andrés; Astefanesei, Dumitru; Choque, David

    2016-11-01

    We construct exact hairy AdS soliton solutions in Einstein-dilaton gravity theory. We examine their thermodynamic properties and discuss the role of these solutions for the existence of first order phase transitions for hairy black holes. The negative energy density associated to hairy AdS solitons can be interpreted as the Casimir energy that is generated in the dual filed theory when the fermions are antiperiodic on the compact coordinate.

  14. Effect of drug loading on the transformation of vesicular into cubic nanoparticles during heat treatment of aqueous monoolein/poloxamer dispersions.

    PubMed

    Wörle, Gert; Siekmann, Britta; Bunjes, Heike

    2006-06-01

    Colloidal dispersions of the pre-equilibrated cubic phase in the monoolein/poloxamer 407/water system, which are under investigation as potential drug carriers, often contain a considerable fraction of undesired non-cubic particles, particularly when prepared with high concentrations of poloxamer. Recent investigations revealed that the non-cubic particles can be transformed into particles of cubic internal structure by heat treatment. The present study investigates the effect of drug loading on the non-cubic to cubic transformation process during autoclaving of the dispersions. The results indicate that the process can also proceed in dispersions loaded with different concentrations of ubidecarenone, tocopheryl acetate, betamethasone-17-valerate, chloramphenicol or miconazole. At low concentration, none of the drugs had pronounced influence on the autoclaved dispersions whereas with increasing drug concentration different effects were observed. Depending on the type of drug no effects (betamethasone-17-valerate), increasing particle size of the dispersions (chloramphenicol, miconazole) or phase separation upon autoclaving (high load of miconazole) was observed. Except for loading with high amounts of chloramphenicol, which led to the formation of cubic phase particles already without additional heat treatment, the properties of the thermally untreated dispersions were virtually unaffected by drug incorporation.

  15. Effects of acute heat exposure on prosencephalic c-Fos expression in normohydrated, water-deprived and salt-loaded rats.

    PubMed

    Santana, Rejane; de De Castro E Silva, Emilio; Reis de Oliveira, Irismar; Fregoneze, Josmara B

    2007-04-13

    In the present study, the distribution pattern of c-Fos protein immunoreactivity (Fos-IR) in prosencephalic areas of the brain involved in thermoregulatory and osmoregulatory responses was investigated, in rats exposed or not exposed to a hyperthermic environment, under three different conditions: normohydration, dehydration induced by water deprivation and hyperosmolarity induced by an acute intragastric salt load. Normohydrated, water-deprived or salt-loaded male Wistar rats (270+/-30 g) were submitted or not to acute heat exposure (33 degrees C for 45 min). A separate group of animals was submitted to the same experimental protocol and had blood samples collected before and after the heating period to measure serum osmolarity and sodium. The brains were processed for c-Fos immunohistochemistry using the avidin-biotin peroxidase method. After analyzing Fos-IR in the brains of animals in the present study, three different types of prosencephalic areas were identified: (1) those that respond to hydrational and to heat conditions, with an interaction between these two factors (PaMP and SON); (2) those that respond to hydrational and to heat conditions, but with no interaction between these factors (MnPO, LSV and OVLT); and (3) those that respond only to hydrational status (SFO and PaLM).

  16. Analytical assessment of the intense heat load of whipping cream, coffee cream, and condensed milk at retail in Austria and Germany.

    PubMed

    Boitz, Lisa I; Mayer, Helmut K

    2016-01-01

    Time temperature integrators (TTIs) are useful tools in estimating the heat load applied on differently processed dairy products. The objective of this study was to analyze and assess three TTIs - lactulose, furosine, and acid-soluble β-lactoglobulin (β-Lg) - in 70 high heated dairy products at retail in Austria and Germany comprising whipping cream, coffee cream/milk, and condensed milk products. While β-Lg was not appropriate to evaluate the heat load of these products, furosine and especially lactulose increased with rising intensity of heat treatment, and are appropriate to distinguish between several heating categories analyzed. Pasteurized (n = 8) and "heat treated" (n = 5) whipping cream samples showed lowest furosine (48 ± 14/ 45 ± 19 mg.100 g(-1) protein) and low lactulose (29 ± 10/57 ± 28 mg.L(-1)) concentrations, followed by ESL whipping cream (n = 10), ESL coffee cream (n = 1), and UHT whipping cream (n = 10) (furosine = 72 ± 37/71/161 ± 30 mg.100 g(-1) protein; lactulose = 56 ± 41/161/195 ± 39 mg.L(-1)), respectively. Sterilized condensed milk samples (n = 14) showed the highest concentrations of both TTIs and could be clearly separated from UHT treated samples (n = 5) (furosine = 491 ± 196/216 ± 46 mg.100 g(-1) protein; lactulose = 1997 ± 658/409 ± 161 mg.L(-1)), whereas the so-called heat-treated samples (n = 9) had a heat load in between showing an extreme range of variation for both TTIs.

  17. 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).

  18. [A study of the effects of physical load on umpires during the national high school baseball games--the effects of physical load on umpires at the Koshien stadium in a summer-heat environment].

    PubMed

    Kurakake, S; Nakaji, S; Sugawara, K; Okamura, N; Oshita, Y; Umeda, T

    1998-01-01

    This study attempted to measure the physical load on national high school baseball umpires during games played at Koshien stadium under extremely hot and humid conditions in the summer. Thirty-one umpires participated in this study. Thirteen of them were evaluated twice while eighteen were evaluated only once. The factors used to determine physical load were the following: body weight, oral temperature, blood pressure, heart rate, and serum biochemical elements. These were measured before and after the games. Heart rate was measured at one-minute intervals. The results were as follows. 1) All the games were played under conditions of extremely high temperatures--32.1 degrees celsius dry-bulb, 27.0 degrees celsius wet-bulb, 36.8 degrees celsius black-globe, 29.5 degrees--WBGT which are likely to cause heat-related illnesses. 2) The physical load of baseball umpires during the game showed a 1.69 percent decrease in average body weight due to perspiration, a 0.43 degrees C increase in oral temperature and an increase in heart rate. An examination of the serum biochemical elements showed that muscle deviation enzymes changed due to muscular activity and blood condensed due to perspiration. The physical load levels of baseball umpires were influenced by extreme heat and physical activity during the game. 3) There were no observable differences in either the amount of physical activity or the extreme heat environment among the umpires of different field positions. But the chief umpire's physical load showed a greater decrease in body weight, more blood condensation due to perspiration as a result of the heavier equipment he wore, more muscular activity and higher energy consumption than his counterparts on the bases. 4) The umpire's heart rates were higher during games than before games. The moment they were on the playing field. Their heart rates rose to an average of 134. It remained above 115 for about two hours, apparently caused by physical activity and heart load.

  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,…

  20. 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

  1. Adding Vitamin E-TPGS to the Formulation of Genexol-PM: Specially Mixed Micelles Improve Drug-Loading Ability and Cytotoxicity against Multidrug-Resistant Tumors Significantly

    PubMed Central

    Fan, Zhuoyang; Chen, Cheng; Pang, Xiaoying; Yu, Zhou; Qi, Yang; Chen, Xinyi; Liang, Huihui; Fang, Xiaoling; Sha, Xianyi

    2015-01-01

    Genexol-PM, produced by Samyang Company (Korea) is an excellent preparation of paclitaxel (PTX) for clinical cancer treatment. However, it cannot resolve the issue of multidrug resistance (MDR)—a significant problem in the administration of PTX to cancer patients. To increase the efficacy of Genexol-PM against MDR tumors, a mixed micelle capable of serving as a vehicle for PTX was developed, and two substances were chosen as carrier materials: 1) Polyethylene glycol–polylactic acid (PEG-PLA), the original vehicle of Genexol-PM. 2) Vitamin E-TPGS, an inhibitor of P-glycoprotein (P-gp). P-gp has been proven to be the main cause of MDR. In vitro evaluation indicated that the mixed micelle was an ideal PTX delivery system for the treatment of MDR tumors; the mixed micelle also showed a significantly better drug-loading coefficient than Genexol-PM. PMID:25831130

  2. The effect of glucose when added to a fat load on the response of glucagon-like peptide-1 (GLP-1) and apolipoprotein B-48 in the postprandial phase.

    PubMed

    Zemánková, K; Mrázková, J; Piťha, J; Kovář, J

    2015-01-01

    Increased and prolonged postprandial lipemia has been identified as a risk factor of cardiovascular disease. However, there is no consensus on how to test postprandial lipemia, especially with respect to the composition of an experimental meal. To address this question of how glucose, when added to a fat load, affects the selected parameters of postprandial lipemia, we carried out a study in 30 healthy male volunteers. Men consumed an experimental meal containing either 75 g of fat + 25 g of glucose (F+G meal) or 75 g of fat (F meal) in a control experiment. Blood was taken before the meal and at selected time points within the following 8 h. Glucose, when added to a fat load, induced an increase of glycemia and insulinemia and, surprisingly, a 20 % reduction in the response of both total and active glucagon-like peptide-1 (GLP-1) concentration. The addition of glucose did not affect the magnitude of postprandial triglyceridemia and TRL-C and TRL-TG concentrations but stimulated a faster response of chylomicrons to the test meal, evaluated by changes in apolipoprotein B-48 concentrations. The addition of glucose induced the physiological response of insulin and the lower response of GLP-1 to the test meal during the early postprandial phase, but had no effect on changes of TRL-cholesterol and TRL-TG within 8 h after the meal.

  3. Conceptual design of a latent heat thermal energy storage subsystem for a saturated steam solar receiver and load

    NASA Astrophysics Data System (ADS)

    Dilauro, G. F.; Rice, R. E.

    1982-02-01

    The conceptual design of a tube intensive latent heat thermal energy storage (TES) subsystem which utilized a eutectic mixture of sodium hydroxide and sodium nitrate as the phase change material (PCM) was developed. The charging and discharging of the unit is accomplished by the same serpentine tube bundle heat exchanger in which heat transfer is augmented by aluminum channels acting as fins. Every tenth channel is made of steel to provide tube support.

  4. 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.

  5. 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.

  6. 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..

  7. Detailed heat load calculations at the beginning, middle, and end of cycle for the conceptual design of the Advanced Neutron Source Reactor

    SciTech Connect

    Wemple, C. A.; Schnitzler, B. G.

    1995-04-01

    The Advanced Neutron Source (ANS) is a world-class research reactor and experimental center for neutron research, presently being designed at the Oak Ridge National Laboratory (ORNL). The reactor consists of a 330-MW(f) highly enriched uranium core, which is cooled, moderated, and reflected with heavy water. When completed, it will be the preeminent ultrahigh neutron flux reactor in the world, with facilities for research programs in biology, materials science, chemistry, fundamental and nuclear physics, and analytical chemistry. Irradiation facilities are provided for a variety of isotope production capabilities, as well as materials irradiation. The ANS reactor design, at the time of this report, has completed the conceptual design phase and entered the advanced conceptual design phase. This report is part of an effort to fully document the analysis methods and results for the conceptual design. It details the methods used to perform heat load calculations on the ANS reactor design, describes the model used, and gives the resulting heat loads in all components of the reactor, in both a differential (by segment) and integral (by component) fashion. These heat load data are provided at three times within the ANS fuel cycle - at beginning (0 days), middle (8.5 days), and end (17 days) of cycle. The remainder of the report is dedicated to this description. In Chapter 2, some necessary background on the reactor design is provided. Chapters 3 and 4 give details of the depletion methods used and revisions to previous MCNP models. Chapter 5 analyzes the results of these calculations, and Chapter 6 provides a summary and conclusions.

  8. 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.

  9. 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.

  10. 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.

  11. Modeling the recovery of heat-treated Bacillus licheniformis Ad978 and Bacillus weihenstephanensis KBAB4 spores at suboptimal temperature and pH using growth limits.

    PubMed

    Trunet, C; Mtimet, N; Mathot, A-G; Postollec, F; Leguerinel, I; Sohier, D; Couvert, O; Carlin, F; Coroller, L

    2015-01-01

    The apparent heat resistance of spores of Bacillus weihenstephanensis and Bacillus licheniformis was measured and expressed as the time to first decimal reduction (δ value) at a given recovery temperature and pH. Spores of B. weihenstephanensis were produced at 30°C and 12°C, and spores of B. licheniformis were produced at 45°C and 20°C. B. weihenstephanensis spores were then heat treated at 85°C, 90°C, and 95°C, and B. licheniformis spores were heat treated at 95°C, 100°C, and 105°C. Heat-treated spores were grown on nutrient agar at a range of temperatures (4°C to 40°C for B. weihenstephanensis and 15°C to 60°C for B. licheniformis) or a range of pHs (between pH 4.5 and pH 9.5 for both strains). The recovery temperature had a slight effect on the apparent heat resistance, except very near recovery boundaries. In contrast, a decrease in the recovery pH had a progressive impact on apparent heat resistance. A model describing the heat resistance and the ability to recover according to the sporulation temperature, temperature of treatment, and recovery temperature and pH was proposed. This model derived from secondary mathematical models for growth prediction. Previously published cardinal temperature and pH values were used as input parameters. The fitting of the model with apparent heat resistance data obtained for a wide range of spore treatment and recovery conditions was highly satisfactory.

  12. 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…

  13. 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.

  14. Effects of fuel load and moisture content on fire behaviour and heating in masticated litter-dominated fuels

    Treesearch

    Jesse K. Kreye; Leda N. Kobziar; Wayne C. Zipperer

    2013-01-01

    Mechanical fuels treatments are being used in fire-prone ecosystems where fuel loading poses a hazard, yetlittle research elucidating subsequent fire behaviour exists, especially in litter-dominated fuelbeds. To address this deficiency, we burned constructed fuelbeds from masticated sites in pine flatwoods forests in northern Florida...

  15. 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.

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

    SciTech Connect

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

    2016-08-10

    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. In conclusion, 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.

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

    DOE PAGES

    Stoupin, Stanislav; Antipov, Sergey; Butler, James E.; ...

    2016-08-10

    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 configurationmore » and data analysis using rocking-curve topography. In conclusion, 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.« less

  18. Control of Advanced Reactor-Coupled Heat Exchanger System: Incorporation of Reactor Dynamics in System Response to Load Disturbances

    DOE PAGES

    Skavdahl, Isaac; Utgikar, Vivek; Christensen, Richard; ...

    2016-05-24

    We present an alternative control schemes for an Advanced High Temperature Reactor system consisting of a reactor, an intermediate heat exchanger, and a secondary heat exchanger (SHX) in this paper. One scheme is designed to control the cold outlet temperature of the SHX (Tco) and the hot outlet temperature of the intermediate heat exchanger (Tho2) by manipulating the hot-side flow rates of the heat exchangers (Fh/Fh2) responding to the flow rate and temperature disturbances. The flow rate disturbances typically require a larger manipulation of the flow rates than temperature disturbances. An alternate strategy examines the control of the cold outletmore » temperature of the SHX (Tco) only, since this temperature provides the driving force for energy production in the power conversion unit or the process application. The control can be achieved by three options: (1) flow rate manipulation; (2) reactor power manipulation; or (3) a combination of the two. The first option has a quicker response but requires a large flow rate change. The second option is the slowest but does not involve any change in the flow rates of streams. The final option appears preferable as it has an intermediate response time and requires only a minimal flow rate change.« less

  19. Inframetrics infrared scanner upgraded to a 12-bit digital thermography system for heat load measurements at nuclear fusion experiments

    NASA Astrophysics Data System (ADS)

    Denner, T.

    1999-01-01

    A commercially available Inframetrics Scanner (Modell 760) has been upgraded to 12-bit resolution in order to derive heat fluxes on tokamak devices (TEXTOR-94). The temperature resolution is high enough to detect—at the same camera settings—the small sawtoothing heat flux modulation and the large disruptive heat fluxes. Eight new boards have been developed and installed at TEXTOR-94 to perform the measurement, transmit the data from the experiment to the control room, and store the data in a PC. To ensure reliable data transmission, the data stream (1.1 MSPS) is transferred via optical fibers from the camera to the PC in the control room. The PC receives timing information from the TEXTOR-94 timing system such that a synchronization of the camera clock and the experimental clock is guaranteed. The new system includes a time reference to correct a small frequency drift of the original Inframetrics scanner. This feature permits to compare the heat flux with signals from other TEXTOR-94 diagnostics during fast events like disruptions for which the camera can also be operated in the fast line scan mode.

  20. Design and optimisation of low heat load liquid helium cryostat to house cryogenic current comparator in antiproton decelerator at CERN

    NASA Astrophysics Data System (ADS)

    Lees, A.; Koettig, T.; Fernandes, M.; Tan, J.

    2017-02-01

    The Cryogenic Current Comparator (CCC) is installed in the low-energy Antiproton Decelerator (AD) at CERN to make an absolute measurement of the beam intensity. Operating below 4.2 K, it is based on a superconducting quantum interference device (SQUID) and employs a superconducting niobium shield to supress magnetic field components not linked to the beam current. The AD contains no permanent cryogenic infrastructure so the local continuous liquefaction of helium using a pulse-tube is required; limiting the available cooling power to 0.69 W at 4.2K. Due to the sensitivity of the SQUID to variations in magnetic fields, the CCC is highly sensitive to mechanical vibration which is limited to a minimum by the support systems of the cryostat. This article presents the cooling system of the cryostat and discusses the design challenges overcome to minimise the transmission of vibration to the CCC while operating within the cryogenic limits imposed by the cooling system.

  1. Window U-value effects on residential cooling load

    SciTech Connect

    Sullivan, R.; Frost, K.; Arasteh, D.; Selkowitz, S.

    1993-09-01

    This paper presents the results of a study investigating the effects of window U-value changes on residential cooling loads. We used the DOE-2. I D energy analysis simulation program to analyze the hourly, daily, monthly, and annual cooling loads as a function of window U-value. The performance of a prototypical single-story house was examined in three locations: hot and humid, Miami FL; hot and dry, Phoenix AZ; and a heating-dominated location with a mildly hot and humid summer, Madison WI. Our results show that when comparing windows with identical orientation, size, and shading coefficient, higher U-value windows often yield lower annual cooling loads, but lower U-value windows yield lower peak cooling loads. This occurs because the window with the higher U-value conducts more heat from inside the residence to the outside during morning and evening hours when the outside air temperature is often lower than the inside air temperature; and, a lower U-value window conducts less heat from outside to inside during summer afternoon peak cooling hours. The absolute effects are relatively small when compared to total annual cooling which is typically dominated by window solar heat gain effects, latent loads, and intemal loads. The U-value effect on cooling is also small when compared to both the effects of U-value and solar heat gain on heating load. Our modeling assumed that U-value and solar heat gain could be independently controlled. In fact, reducing window conductance to the levels used in this study implies adding a second glazing layer which always reduces solar heat gain, thus reducing annual cooling. Thus, when we compare realistic options, e.g., single pane clear to double pane clear, or single pane tinted to double pane tinted, the double pane unit shows lower annual cooling, as well as lower peak loads.

  2. Micro-chemical analysis of high heat loaded CFC-Cu interfaces from Tore Supra and Wendelstein 7-X

    NASA Astrophysics Data System (ADS)

    Höschen, T.; Linsmeier, Ch; Greuner, H.; Missirlian, M.

    2011-12-01

    A comparison of high-heat-flux tested carbon-fiber reinforced carbon (CFC)/Cu materials of Tore Supra and Wendelstein 7-X plasma-facing components is made in order to understand the different fatigue behavior of the bonding interfaces, in particular for the Tore Supra materials. The elemental distribution around the bonding layer and the chemical composition of the active element titanium are characterized by secondary ion mass spectrometry and x-ray photoelectron spectroscopy. The results show that the improved bonding of the Wendelstein 7-X target elements compared to the Tore Supra pump limiter elements is due to a modified silicon and titanium distribution at the bonding interface. However, the difference in fatigue behavior between the two Tore Supra components cannot be attributed to the bonding interface, since the elemental distribution and chemistry of these components are identical and no degradation is observed after an extended heat flux exposure.

  3. Nonlocal size dependency in nonlinear instability of axially loaded exponential shear deformable FG-CNT reinforced nanoshells under heat conduction

    NASA Astrophysics Data System (ADS)

    Sahmani, S.; Fattahi, A. M.

    2017-05-01

    The present study deals with size-dependent nonlinear instability characteristics of functionally graded carbon nanotube (FG-CNT) reinforced composite shells at nanoscale subjected to axial compression combined with through-thickness heat conduction. To take size dependency into account, Eringen's nonlocal continuum elasticity is incorporated to a novel shear deformation shell theory including a refined exponential distribution for transverse shear strain. In addition to the uniform distribution (UD) of CNT reinforcements, three FG patterns are also considered, namely FG-A, FG-V and FG-X. Also, on the basis of polynomial series, the temperature variation due to the through-thickness heat conduction is estimated. Via a perturbation-based boundary layer-type solving procedure, explicit expressions for nonlocal equilibrium curves are proposed relevant to the prebuckling and postbuckling regimes of FG-CNT exponential shear deformable nanoshells with temperature-dependent and temperature-independent material properties. It is observed that by taking the nonlocality size effect into consideration, the influence of the through-thickness heat conduction on the nonlinear axial instability response of FG-CNT reinforced nanoshells becomes more significant.

  4. 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.

  5. 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.

  6. Overview of the Results on Divertor Heat Loads in RMP Controlled H-mode Plasmas 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.; Elch, T.; 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.; Unterberg, E. A.; West, W. P.

    2009-01-01

    n this paper 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 nu(e)*. We compare in this analysis RMP and no RMP phases with and without complete ELM suppression. At high nu(e)* > 0.5, 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. 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.

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

    DOE PAGES

    Jakubowski, M. W.; Evans, T. E.; Fenstermacher, M. 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 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

  8. 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.

  9. 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.

  10. 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

  11. 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

  12. 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.

  13. 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.

  14. 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.

  15. The role of heat treatment on microstructure and mechanical properties of Ti-13Zr-13Nb alloy for biomedical load bearing applications.

    PubMed

    Majumdar, P; Singh, S B; Chakraborty, M

    2011-10-01

    The suitability of heat treated Ti-13Zr-13Nb (TZN) alloy for biomedical load bearing applications has been investigated. Depending upon the heat treatment conditions, the microstructure of TZN alloy mainly consists of α, β or α" martensite phases. In general, for all the deformation and solution treatment temperatures the variation of the hardness and tensile strength with cooling rate is similar. The elastic modulus of TZN alloy decreases with an increase in cooling rate from the solution treatment temperature. Relatively fine α+β microstructure increases the hardness and tensile strength. The presence of martensite and/or retained β in the microstructure decreases the hardness and elastic modulus and increases the ductility substantially whereas higher amount of α phase in the matrix increases the elastic modulus. Decomposition of martensite and retained β into α phase during aging increases the hardness, elastic modulus and tensile strength and decreases the ductility. Among the samples studied, the aged TZN sample, which was deformed and solution treated at 800 °C followed by water quenching, is a promising candidate for the application as implant material.

  16. Monthly average clear-sky broadband irradiance database for worldwide solar heat gain and building cooling load calculations

    SciTech Connect

    Gueymard, Christian A.; Thevenard, Didier

    2009-11-15

    This paper establishes the formulation of a new clear-sky solar radiation model appropriate for algorithms calculating cooling loads in buildings. The aim is to replace the ASHRAE clear-sky model of 1967, whose limitations are well known and are reviewed. The new model is derived in two steps. The first step consists of obtaining a reference irradiance dataset from the REST2 model, which uses a high-performance, validated, two-band clear-sky algorithm. REST2 requires detailed inputs about atmospheric conditions such as aerosols, water vapor, ozone, and ground albedo. The development of global atmospheric datasets used as inputs to REST2 is reviewed. For the most part, these datasets are derived from space observations to guarantee universality and accuracy. In the case of aerosols, point-source terrestrial measurements were also used as ground truthing of the satellite data. The second step of the model consists of fits derived from a REST2-based reference irradiance dataset. These fits enable the derivation of compact, but relatively accurate expressions, for beam and diffuse clear-sky irradiance. The fitted expressions require the tabulation of only two pseudo-optical depths for each month of the year. The resulting model, and its tabulated data, are expected to be incorporated in the 2009 edition of the ASHRAE Handbook of Fundamentals. (author)

  17. Joule-Thomson expansion of the charged AdS black holes

    NASA Astrophysics Data System (ADS)

    Ökcü, Özgür; Aydıner, Ekrem

    2017-01-01

    In this paper, we study Joule-Thomson effects for charged AdS black holes. We obtain inversion temperatures and curves. We investigate similarities and differences between van der Waals fluids and charged AdS black holes for the expansion. We obtain isenthalpic curves for both systems in the T- P plane and determine the cooling-heating regions.

  18. Rennet-induced coagulation of raw and heated camel and cow milk gels determined by instrumental techniques: effects of added calcium and phosphate.

    PubMed

    Karoui, Romdhane; Kamal, Mohammad

    2017-09-01

    The potentiality of the front-face fluorescence spectroscopy and rheological measurements combined with chemometric tools to characterise the structure evolution during coagulation of raw and preheated camel and cow milk at 50 and 70 °C with/without added calcium and phosphate was evaluated. Tryptophan and vitamin A fluorescence spectra were collected during the gelation of milk at 0, 10, 20, 30, 40, and 45 min after the addition of rennet-induced coagulation. In parallel, the storage modulus (G'), loss modulus (G″) and tan delta (tan δ) were determined using low amplitude oscillation shear analysis. The principal component analysis (PCA) applied to the normalised tryptophan spectra allowed the gels made with camel milk to be differentiated from those of cow milk on the one hand, and to monitor protein structure modifications during the gelation, on the other hand. The common components and specific weights analysis (CCSWA) applied jointly to the fluorescence and rheological data sets permitted a clear separation of raw milk gels from those preheated at 50 and 70 °C. The front-face fluorescence spectroscopy method coupled with multi-variate statistical analyses showed a high capacity for studying changes in the micelle structure throughout the rennet-induced coagulation process. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  19. 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.

  20. 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.

  1. 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 .

  2. Development of fundamental power coupler for C-ADS superconducting elliptical cavities

    NASA Astrophysics Data System (ADS)

    Gu, Kui-Xiang; Bing, Feng; Pan, Wei-Min; Huang, Tong-Ming; Ma, Qiang; Meng, Fan-Bo

    2017-06-01

    5-cell elliptical cavities have been selected for the main linac of the China Accelerator Driven sub-critical System (C-ADS) in the medium energy section. According to the design, each cavity should be driven with radio frequency (RF) energy up to 150 kW by a fundamental power coupler (FPC). As the cavities work with high quality factor and high accelerating gradient, the coupler should keep the cavity from contamination in the assembly procedure. To fulfil the requirements, a single-window coaxial type coupler was designed with the capabilities of handling high RF power, class 10 clean room assembly, and heat load control. This paper presents the coupler design and gives details of RF design, heat load optimization and thermal analysis as well as multipacting simulations. In addition, a primary high power test has been performed and is described in this paper. Supported by China ADS Project (XDA03020000) and National Natural Science Foundation of China (11475203)

  3. Energy Corner: Heat Reclamation Rescues Wasted Heat.

    ERIC Educational Resources Information Center

    Daugherty, Thomas

    1982-01-01

    Heat reclamation systems added to pre-existing central heating systems provide maximum savings at minimum cost. The benefits of a particular appliance marketed under the brand name "Energizer" are discussed. (Author/MLF)

  4. Energy Corner: Heat Reclamation Rescues Wasted Heat.

    ERIC Educational Resources Information Center

    Daugherty, Thomas

    1982-01-01

    Heat reclamation systems added to pre-existing central heating systems provide maximum savings at minimum cost. The benefits of a particular appliance marketed under the brand name "Energizer" are discussed. (Author/MLF)

  5. 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.

  6. Orientifolded locally AdS3 geometries

    NASA Astrophysics Data System (ADS)

    Loran, F.; Sheikh-Jabbari, M. M.

    2011-01-01

    Continuing the analysis of [Loran F and Sheikh-Jabbari M M 2010 Phys. Lett. B 693 184-7], we classify all locally AdS3 stationary axi-symmetric unorientable solutions to AdS3 Einstein gravity and show that they are obtained by applying certain orientifold projection on AdS3, BTZ or AdS3 self-dual orbifold, respectively, O-AdS3, O-BTZ and O-SDO geometries. Depending on the orientifold fixed surface, the O-surface, which is either a space-like 2D plane or a cylinder, or a light-like 2D plane or a cylinder, one can distinguish four distinct cases. For the space-like orientifold plane or cylinder cases, these geometries solve AdS3 Einstein equations and are hence locally AdS3 everywhere except at the O-surface, where there is a delta-function source. For the light-like cases, the geometry is a solution to Einstein equations even at the O-surface. We discuss the causal structure for static, extremal and general rotating O-BTZ and O-SDO cases as well as the geodesic motion on these geometries. We also discuss orientifolding Poincaré patch AdS3 and AdS2 geometries as a way to geodesic completion of these spaces and comment on the 2D CFT dual to the O-geometries.

  7. [Studies on thermoregulative performance of disabled persons with congenital maldevelopment of the limbs and acquired loss of limbs during defined physical work and passive heat load (author's transl)].

    PubMed

    Engel, P; Hildebrandt, G; Pihera, A; Rode, F W

    1978-01-01

    Comparative studies were conducted in 20 persons without hands (amputated a long time ago) and in fifteen juveniles (12--15 years) with dysemlia (phocomelia or ectromelia), tested in each case against groups of non-disabled persons of corresponding age. All persons under examination had to perform the same, graded treadmill work under thermoconstant condition (30 degrees C, 45% rel. humidity). These tests pointed towards the existence of a particularly economic mode of thermoregulation in persons with dysmelia obviously involving adaptive processes of energy metabolism as well, whereas such adaptation does not take place--not even in the course of many years--in disabled persons with acquired loss of limbs. The persons with congenital dysmelia showed lower temperatures of the interior of the body, less sweat loss, and on the average a lower uptake of oxygen than non-disabled persons of the same age, whereas higher temperatures of the interior of the body, greater sweat loss, and a higher oxygen uptake were measured in the persons whose arms had been amputated a long time ago (ie persons without hands). Under passive heat load (40 degrees C, 30 min.) the amputated persons showed a corresponding thermoregulative performance as during physical work, in comparison to the non-disabled persons.

  8. Overall Design of the ADS Injector I Cryogenic System in China

    NASA Astrophysics Data System (ADS)

    Li, Shaopeng; Ge, Rui; Zhang, Zhuo; Liu, Yaping; Sang, Minjing; Bian, Lin; Han, Ruixiong; Zhang, Jiehao; Sun, Liangrui; Xu, Miaofu; Ye, Rui; Zhang, Jianqin

    The accelerator driven sub-critical system (ADS) in China is a kind of transmutation machine to minimize nuclear waste. As one of the important parts in ADS, injector will be built at IHEP,CAS. Injector I needs two cryomodules operating at 2K cryogenic environment to realize a 10MeVproton beam energy. Each cryomodule includes seven spoke cavities and sevensuperconducting magnets. This paper describes the overall design of the cryogenic system, including the cooling flow chart, heat loads estimation, the structure of the operation cryomodule and some of the key components.

  9. Warped AdS3 black holes

    NASA Astrophysics Data System (ADS)

    Anninos, Dionysios; Li, Wei; Padi, Megha; Song, Wei; Strominger, Andrew

    2009-03-01

    Three dimensional topologically massive gravity (TMG) with a negative cosmological constant -l-2 and positive Newton constant G admits an AdS3 vacuum solution for any value of the graviton mass μ. These are all known to be perturbatively unstable except at the recently explored chiral point μl = 1. However we show herein that for every value of μl ≠ 3 there are two other (potentially stable) vacuum solutions given by SL(2,Bbb R) × U(1)-invariant warped AdS3 geometries, with a timelike or spacelike U(1) isometry. Critical behavior occurs at μl = 3, where the warping transitions from a stretching to a squashing, and there are a pair of warped solutions with a null U(1) isometry. For μl > 3, there are known warped black hole solutions which are asymptotic to warped AdS3. We show that these black holes are discrete quotients of warped AdS3 just as BTZ black holes are discrete quotients of ordinary AdS3. Moreover new solutions of this type, relevant to any theory with warped AdS3 solutions, are exhibited. Finally we note that the black hole thermodynamics is consistent with the hypothesis that, for μl > 3, the warped AdS3 ground state of TMG is holographically dual to a 2D boundary CFT with central charges c_R-formula and c_L-formula.

  10. Warped AdS3 black holes

    NASA Astrophysics Data System (ADS)

    Song, Wei; Anninos, Dionysios; Li, Wei; Padi, Megha; Strominger, Andrew

    2009-03-01

    Three dimensional topologically massive gravity (TMG) with a negative cosmological constant -ell-2 and positive Newton constant G admits an AdS3 vacuum solution for any value of the graviton mass μ. These are all known to be perturbatively unstable except at the recently explored chiral point μell = 1. However we show herein that for every value of μell ≠ 3 there are two other (potentially stable) vacuum solutions given by SL(2,Bbb R) × U(1)-invariant warped AdS3 geometries, with a timelike or spacelike U(1) isometry. Critical behavior occurs at μell = 3, where the warping transitions from a stretching to a squashing, and there are a pair of warped solutions with a null U(1) isometry. For μell > 3, there are known warped black hole solutions which are asymptotic to warped AdS3. We show that these black holes are discrete quotients of warped AdS3 just as BTZ black holes are discrete quotients of ordinary AdS3. Moreover new solutions of this type, relevant to any theory with warped AdS3 solutions, are exhibited. Finally we note that the black hole thermodynamics is consistent with the hypothesis that, for μell > 3, the warped AdS3 ground state of TMG is holographically dual to a 2D boundary CFT with central charges c_R-formula and c_L-formula.

  11. 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.

  12. 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

  13. Segmented strings in AdS 3

    NASA Astrophysics Data System (ADS)

    Callebaut, Nele; Gubser, Steven S.; Samberg, Andreas; Toldo, Chiara

    2015-11-01

    We study segmented strings in flat space and in AdS 3. In flat space, these well known classical motions describe strings which at any instant of time are piecewise linear. In AdS 3, the worldsheet is composed of faces each of which is a region bounded by null geodesics in an AdS 2 subspace of AdS 3. The time evolution can be described by specifying the null geodesic motion of kinks in the string at which two segments are joined. The outcome of collisions of kinks on the worldsheet can be worked out essentially using considerations of causality. We study several examples of closed segmented strings in AdS 3 and find an unexpected quasi-periodic behavior. We also work out a WKB analysis of quantum states of yo-yo strings in AdS 5 and find a logarithmic term reminiscent of the logarithmic twist of string states on the leading Regge trajectory.

  14. Axion wormholes in AdS compactifications

    NASA Astrophysics Data System (ADS)

    Hertog, Thomas; Trigiante, Mario; Van Riet, Thomas

    2017-06-01

    We find regular axionic Euclidean wormhole solutions in Type IIB string theory compactified on {AdS}_5× {S}^5/{Z}_k . AdS/CFT enables a precise derivation of the axion content of the Euclidean theory, placing the string theory embedding of the wormholes on firm footing. This further sharpens the paradox posed by these solutions.

  15. Heat pump systems

    SciTech Connect

    Sauer, H.J.; Howell, R.H.

    1983-01-01

    This book was written as a reference and textbook on heat pumps. Economics, thermodynamics, heat transfer, design, selection, and operating practices are covered in detail. Specific methods, and solutions rather than broad generalizations are emphasized. Includes problems, bibliographies, and a subject index. For applied science collections in public, college and appropriate special libraries. Contents: Thermodynamics, Heat pump systems and applications. Heat pump components. Heating and cooling loads. Energy use determination. Reliability, maintenance, and service. Advances in heat pumps. Appendices. Index.

  16. 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.

  17. 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.

  18. AD-1 in flight

    NASA Technical Reports Server (NTRS)

    1980-01-01

    on its last flight on August 7, 1982, was NASA Research Pilot Thomas C. McMurtry. The AD-1 flew a total of 79 times during the research program. The aircraft was constructed by the Ames Industrial Co., Bohemia, NY, under a $240, 000 fixed-price contract. NASA specified the design based on a geometric configuration provided by the Boeing company. The Rutan Aircraft Factory, Mojave, CA, provided the detailed design and loads analysis for the vehicle. The aircraft was 38.8 feet long and 6.75 feet high with a wing span of 32.3 feet, unswept. It was constructed of plastic reinforced with fiberglass and weighed 1,450 pounds,empty. The vehicle was powered by two small turbojet engines, each producing 220 pounds of thrust at sea level. Due to safety concerns, the aircraft was limited to speeds of 170 mph.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. AdS duals of matrix strings

    NASA Astrophysics Data System (ADS)

    Morales, Jose F.; Samtleben, Henning

    2003-06-01

    We review recent work on the holographic duals of type II and heterotic matrix string theories described by warped AdS3 supergravities. In particular, we compute the spectra of Kaluza-Klein primaries for type I, II supergravities on warped AdS3 × S7 and match them with the primary operators in the dual two-dimensional gauge theories. The presence of non-trivial warp factors and dilaton profiles requires a modification of the familiar dictionary between masses and 'scaling' dimensions of fields and operators. We present these modifications for the general case of domain wall/QFT correspondences between supergravities on warped AdSd+1 × Sq geometries and super Yang-Mills theories with 16 supercharges.

  5. 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.

  6. The effect of load on heat production, thermal effects and expenditure of time during implant site preparation - an experimental ex vivo comparison between piezosurgery and conventional drilling.

    PubMed

    Stelzle, Florian; Frenkel, Carsten; Riemann, Max; Knipfer, Christian; Stockmann, Philipp; Nkenke, Emeka

    2014-02-01

    Piezoelectric surgery (PS) is meant to be a gentle osteotomy method. The aim of this study was to compare piezosurgical vs. conventional drilling methods for implant site preparation (ISP) - focusing on load-dependent thermal effect on hard tissue and the expenditure of ISP time. Three hundred and sixty ISP were performed on ex vivo pig heads using piezosurgery, spiral burs (SB) and trephine burs (TB). The load applied was increased from 0 to 1000 g in 100-g intervals. Temperature within the bone was measured with a thermocouple, and duration was recorded with a stop watch. Thermal effects were histomorphometrically analysed. Twelve ISPs per technique were performed at the lateral wall of the maxillary sinus. PS yields the highest mean temperatures (48.6 ± 3.4°C) and thermal effects (200.7 ± 44.4 μm), both at 900-1000 g. Duration is reduced with a plus of load and significantly longer in either case for PS (P < 0.05). There is a correlation of the applied load with all other examined factors for PS and TB. Temperature and histological effects decrease for SB beyond 500 g. PS yields significantly higher temperatures and thermal tissue alterations on load levels higher than 500 g and is significantly slower for ISP compared to SB and TB. For ISP with PS, a maximum load of 400 g should be maintained. © 2012 John Wiley & Sons A/S.

  7. AdS2 D-branes in Lorentzian AdS3

    NASA Astrophysics Data System (ADS)

    Deliduman, Cemsinan

    2003-09-01

    The boundary states for two dimensional anti de Sitter (AdS2) Dirichlet-branes (D-branes) in Lorentzian AdS3 space-time are presented. AdS2 D-branes are algebraically defined by twisted Dirichlet boundary conditions and are located on twisted conjugacy classes of SL(2,R). Using the free-field representation of symmetry currents in the SL(2,R) Wess-Zumino-Novikov-Witten model, the twisted Dirichlet gluing conditions among currents are translated to matching conditions among free fields and then to boundary conditions among the modes of free fields. The Ishibashi states are written as coherent states on AdS3 in the free field formalism and it is shown that twisted Dirichlet boundary conditions are satisfied on them. The tree-level amplitude of propagation of closed strings between two AdS2 D-branes is evaluated and by comparing it with the characters of sl^(2,R) Kac-Moody algebra it is shown that only states in the principal continuous series representation of sl^(2,R) Kac-Moody algebra contribute to the amplitude and thus they are the only ones that couple to AdS2 D-branes. The form of the character of sl^(2,R) principal continuous series and the boundary condition among the zero modes are used to determine the physical boundary states for AdS2 D-branes.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. Thermodynamics and Stability of Five Dimensional AdS Reissner-Nordstrom Black Hole

    NASA Astrophysics Data System (ADS)

    Saadat, Hassan

    2012-01-01

    In this paper we consider five dimensional AdS Reissner-Nordstrom black hole and calculate thermodynamical variables such as entropy, specific heat and free energy. In that case we can obtain stability conditions of the black hole and fix black hole charge and mass for phase transition.

  13. 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.

  14. 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.

  15. An AdS Crunch in Supergravity

    NASA Astrophysics Data System (ADS)

    Hertog, Thomas

    2004-12-01

    We review some properties of N=8 gauged supergravity in four dimensions with modified, but AdS invariant boundary conditions on the m2 = -2 scalars. There is a one-parameter class of asymptotic conditions on these fields and the metric components, for which the full AdS symmetry group is preserved. The generators of the asymptotic symmetries are finite, but acquire a contribution from the scalar fields. For a large class of such boundary conditions, we find there exist black holes with scalar hair that are specified by a single conserved charge. Since Schwarschild-AdS is a solution too for all boundary conditions, this provides an example of black hole non-uniqueness. We also show there exist solutions where smooth initial data evolve to a big crunch singularity. This opens up the possibility of using the dual conformal field theory to obtain a fully quantum description of the cosmological singularity, and we report on a preliminary study of this.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  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. Heat exchanger device and method for heat removal or transfer

    DOEpatents

    Koplow, Jeffrey P [San Ramon, CA

    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.

  2. Heat exchanger device and method for heat removal or transfer

    DOEpatents

    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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. AdS2 holographic dictionary

    NASA Astrophysics Data System (ADS)

    Cvetič, Mirjam; Papadimitriou, Ioannis

    2016-12-01

    We construct the holographic dictionary for both running and constant dilaton solutions of the two dimensional Einstein-Maxwell-Dilaton theory that is obtained by a circle reduction from Einstein-Hilbert gravity with negative cosmological constant in three dimensions. This specific model ensures that the dual theory has a well defined ultraviolet completion in terms of a two dimensional conformal field theory, but our results apply qualitatively to a wider class of two dimensional dilaton gravity theories. For each type of solutions we perform holographic renormalization, compute the exact renormalized one-point functions in the presence of arbitrary sources, and derive the asymptotic symmetries and the corresponding conserved charges. In both cases we find that the scalar operator dual to the dilaton plays a crucial role in the description of the dynamics. Its source gives rise to a matter conformal anomaly for the running dilaton solutions, while its expectation value is the only non trivial observable for constant dilaton solutions. The role of this operator has been largely overlooked in the literature. We further show that the only non trivial conserved charges for running dilaton solutions are the mass and the electric charge, while for constant dilaton solutions only the electric charge is non zero. However, by uplifting the solutions to three dimensions we show that constant dilaton solutions can support non trivial extended symmetry algebras, including the one found by Compère, Song and Strominger [1], in agreement with the results of Castro and Song [2]. Finally, we demonstrate that any solution of this specific dilaton gravity model can be uplifted to a family of asymptotically AdS2 × S 2 or conformally AdS2 × S 2 solutions of the STU model in four dimensions, including non extremal black holes. The four dimensional solutions obtained by uplifting the running dilaton solutions coincide with the so called `subtracted geometries', while those obtained

  8. 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.

  9. 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.

    2016-12-01

    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.

  10. 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)

  11. 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)

  12. 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.

  13. 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.

  14. AdS2 holographic dictionary

    DOE PAGES

    Cvetic, Mirjam; Papadimitriou, Ioannis

    2016-12-02

    Here, we construct the holographic dictionary for both running and constant dilaton solutions of the two dimensional Einstein-Maxwell-Dilaton theory that is obtained by a circle reduction from Einstein-Hilbert gravity with negative cosmological constant in three dimensions. This specific model ensures that the dual theory has a well defined ultraviolet completion in terms of a two dimensional conformal field theory, but our results apply qualitatively to a wider class of two dimensional dilaton gravity theories. For each type of solutions we perform holographic renormalization, compute the exact renormalized one-point functions in the presence of arbitrary sources, and derive the asymptotic symmetriesmore » and the corresponding conserved charges. In both cases we find that the scalar operator dual to the dilaton plays a crucial role in the description of the dynamics. Its source gives rise to a matter conformal anomaly for the running dilaton solutions, while its expectation value is the only non trivial observable for constant dilaton solutions. The role of this operator has been largely overlooked in the literature. We further show that the only non trivial conserved charges for running dilaton solutions are the mass and the electric charge, while for constant dilaton solutions only the electric charge is non zero. However, by uplifting the solutions to three dimensions we show that constant dilaton solutions can support non trivial extended symmetry algebras, including the one found by Compère, Song and Strominger, in agreement with the results of Castro and Song. Finally, we demonstrate that any solution of this specific dilaton gravity model can be uplifted to a family of asymptotically AdS2 × S2 or conformally AdS2 × S2 solutions of the STU model in four dimensions, including non extremal black holes. As a result, the four dimensional solutions obtained by uplifting the running dilaton solutions coincide with the so called ‘subtracted geometries

  15. Thermal stability analysis of nonlinearly charged asymptotic AdS black hole solutions

    NASA Astrophysics Data System (ADS)

    Dehghani, M.; Hamidi, S. F.

    2017-08-01

    In this paper, the four-dimensional nonlinearly charged black hole solutions have been considered in the presence of the power Maxwell invariant electrodynamics. Two new classes of anti-de Sitter (AdS) black hole solutions have been introduced according to different amounts of the parameters in the nonlinear theory of electrodynamics. The conserved and thermodynamical quantities of either of the black hole classes have been calculated from geometrical and thermodynamical approaches, separately. It has been shown that the first law of black hole thermodynamics is satisfied for either of the AdS black hole solutions we just obtained. Through the canonical and grand canonical ensemble methods, the black hole thermal stability or phase transitions have been analyzed by considering the heat capacities with the fixed black hole charge and fixed electric potential, respectively. It has been found that the new AdS black holes are stable if some simple conditions are satisfied.

  16. AD(H)D.

    PubMed

    Harrison, Christopher; Charles, Janice; Britt, Helena

    2008-06-01

    The BEACH program (Bettering the Evaluation and Care of Health) shows that management of attention deficit (hyperactivity) disorder (AD(H)D) was rare in general practice, occurring only six times per 1,000 encounters with children aged 5-17 years, between April 2000 and December 2007. This suggests that general practitioners manage AD(H)D about 46,000 times for this age group nationally each year.

  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. 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)

  19. 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.

  20. 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.

  1. 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

  2. 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.

  3. Adding and Deleting Images

    EPA Pesticide Factsheets

    Images are added via the Drupal WebCMS Editor. Once an image is uploaded onto a page, it is available via the Library and your files. You can edit the metadata, delete the image permanently, and/or replace images on the Files tab.

  4. The Waubonsee Ad Hocracy.

    ERIC Educational Resources Information Center

    Waubonsee Community Coll., Sugar Grove, IL.

    The Waubonsee Community College Ad Hocracy model of governance incorporates the concept of a streamlined, flexible organizational structure which allows for voluntary participation in problem-solving and decision-making. Central to this model is the concept of open meetings which provide for the consideration of all views and the reaching of…

  5. 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…

  6. 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…

  7. 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.

  8. ADS in a Nutshell

    NASA Astrophysics Data System (ADS)

    Demleitner, M.; Eichhorn, G.; Grant, C. S.; Accomazzi, A.; Murray, S. S.; Kurtz, M. J.

    1999-05-01

    The bibliographic databases maintained by the NASA Astrophysics Data System are updated approximately biweekly with records gathered from over 125 sources all over the world. Data are either sent to us electronically, retrieved by our staff via semi-automated procedures, or entered in our databases through supervised OCR procedures. PERL scripts are run on the data to convert them from their incoming format to our standard format so that they can be added to the master database at SAO. Once new data has been added, separate index files are created for authors, objects, title words, and text word, allowing these fields to be searched for individually or in combination with each other. During the indexing procedure, discipline-specific knowledge is taken into account through the use of rule-based procedures performing string normalization, context-sensitive word translation, and synonym and stop word replacement. Once the master text and index files have been updated at SAO, an automated procedure mirrors the changes in the database to the ADS mirror site via a secure network connection. The use of a public domain software tool called rsync allows incremental updating of the database files, with significant savings in the amount of data being transferred. In the past year, the ADS Abstract Service databases have grown by approximately 30%, including 50% growth in Physics, 25% growth in Astronomy and 10% growth in the Instrumentation datasets. The ADS Abstract Service now contains over 1.4 million abstracts (475K in Astronomy, 430K in Physics, 510K in Instrumentation, and 3K in Preprints), 175,000 journal abstracts, and 115,000 full text articles. In addition, we provide links to over 40,000 electronic HTML articles at other sites, 20,000 PDF articles, and 10,000 postscript articles, as well as many links to other external data sources.

  9. 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.

  10. Rotary Joint for Heat Transfer

    NASA Technical Reports Server (NTRS)

    Shauback, R.

    1986-01-01

    Rotary joint exchanges heat between two heat pipes - one rotating and one stationary. Joint accommodates varying heat loads with little temperature drop across interface. According to concept, heat pipe enters center of disklike stationary section of joint. There, wicks in central artery of heat pipe separate into multiple strands that lead to concentric channels on rotaryinterface side of stationary disk. Thin layer of liquid sodium/potassium alloy carries heat from one member of rotary joint to other. Liquid conducts heat efficiently while permitting relative motion between members. Polypropylene rings contain liquid without interfering with rotation.

  11. Beam-induced radiation heating on the superconducting undulator at the advanced photon source

    NASA Astrophysics Data System (ADS)

    Boon, Laura Elizabeth

    2014-09-01

    In January 2013 the Advanced Photon Source (APS), a 7 GeV synchrotron X-ray source, commissioned a Superconducting Undulator (SCU). The superconducting magnet is thermally isolated from the beam vacuum chamber, which absorbs the beam-induced heating. Previous beam induced heat load studies at other laboratories had not included a robust calculation of radiation heating from the upstream dipole magnet. The mitigation of the radiation heating mechanism, and production of photoelectrons to seed an electron cloud was studied for this thesis. An analytical model was developed to predict the radiation heat load on the SCU chamber. This model was benchmarked with ray tracings and simulations. Results from this synchrotron radiation model were used to guide the design of the installed SCU beam chamber. A 3D Monte-Carlo simulation on synchrotron radiation on the beam chamber was developed. The model considered the effect of diffuse scattering and complex chamber geometries. It was found that a simulation assuming no photon scattering gave a power that agreed within 0.4% of the analytical model. Comparison between analytical calculations and measured temperature rise on the installed SCU show the analytical model agrees with the measured temperature rise within 20%. Previous models of similar superconducting devices in accelerators have reached at best 200% difference between the measured and modeled heat load. The beam heat load model presented in this thesis represents a significant improvement in modeling of superconducting devices in high energy particle accelerators. In addition to heating the SCU chamber, absorbed photons produce photoelectrons which seed electron clouds, another source of beam induced heating. Measurements of the technical aluminum samples show peaks in the quantum efficiency for photon energies equal to the K edges of oxygen, carbon, and aluminum. These results can be added to electron cloud simulation codes to improve simulation results.

  12. 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.

  13. 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.

  14. Air-cooled heat exchangers: Conventional and unconventional

    SciTech Connect

    Kals, W. )

    1994-08-01

    Wet-surface air-cooled heat exchangers, presently thought of as unconventional, should be considered for applications where fin-tube air coolers are not used. Wet-Surface coolers have advantages where fin-tube exchangers may not supply enough duty, especially during hot weather. They can also cool to temperatures below the capability of cooling water exchangers. Air-cooled heat exchangers made their first appearance in petroleum refineries and chemical processing plants in the US thirty years ago. Their rapidly increasing use is due to the desire of plant designers and operators to avoid problems associated with cooling water. With air as the cooling medium, process heat is surrendered directly to the atmosphere. No additional thermal load is added to existing cooling towers. The paper describes air-cooled exchangers, design features, applications, and limitations.

  15. 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.

  16. IPLS: Interactive Pallet Loading System.

    DTIC Science & Technology

    1981-06-01

    AD-AI01 410 FLOR IDA UNIV GAINESVILLE DEPT OF INDUSTRIAL AND SYS--ETC F/6 15/5 IPLS. INTERACTIVE PALLET LOADING SYSTEM.(U) .JN 81 T J HODGSON. N0OCIA...76-C 0096 UNCLASSIFIEDRR69L * unuuuu L~EhEEEE / IPL SINTERACTIVE PALLET LOADING SYSTEM Research Report No. 8]-9 by Thorn J. Hodgson June, 1981...COVEREo IPLS: INTERACTIVE PALLET LOADING SyS Technical / j ’.l e P a t . | - f F O M IN G O R G . R E P O R T N U M B E R--81-9 7. AuTmo, .. s

  17. 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.

  18. Transportability Tests of Various Combat Configured Loads (CCLs) on the Palletized Loading System (PLS) Truck/Trailer

    DTIC Science & Technology

    1992-01-01

    AD-A259 615 FINAL REPORT JANUARY 1992 REPORT NO. 91-02 TRANSPORTABILITY TESTS OF VARIOUS COMBAT CONFIGURED LOADS (CCLs) ON THE PALLETIZED LOADING...Transportability Test of Various Combat Configured Loads (CCLs) on the Palletized Loading System (PLS) Tuck/Trailer 12. PERSONAL AUTHOR(S) A. C...Transportation Engineering Division (SMCAC-DET), to test various Combat Configured Loads (CCLs) on the Palletized Loading System (PLS) truck/trailer. The test

  19. Partition functions with spin in AdS2 via quasinormal mode methods

    NASA Astrophysics Data System (ADS)

    Keeler, Cynthia; Lisbão, Pedro; Ng, Gim Seng

    2016-10-01

    We extend the results of [1], computing one loop partition functions for massive fields with spin half in AdS2 using the quasinormal mode method proposed by Denef, Hartnoll, and Sachdev [2]. We find the finite representations of SO(2, 1) for spin zero and spin half, consisting of a highest weight state | h> and descendants with non-unitary values of h. These finite representations capture the poles and zeroes of the one loop determinants. Together with the asymptotic behavior of the partition functions (which can be easily computed using a large mass heat kernel expansion), these are sufficient to determine the full answer for the one loop determinants. We also discuss extensions to higher dimensional AdS2 n and higher spins.

  20. Travelers' Health: Problems with Heat and Cold

    MedlinePlus

    ... predisposing factor in heat illness. Dehydration also reduces exercise performance, decreases time to exhaustion, and increases internal heat load. Temperature and heart rate increase in direct proportion to the level of ...

  1. Design and fabrication of heat resistant multilayers

    SciTech Connect

    Thorne, J.M.; Knight, L.V.; Peterson, B.G.; Perkins, R.T.; Gray, K.J.

    1986-01-01

    Many promising applications of multilayer x-ray optical elements subject them to intense radiation. This paper discusses the selection of optimal pairs of materials to resist heat damage and presents simulations of multilayer performance under extreme heat loadings.

  2. [New methods for determining the relative load due to physical effort of the human body].

    PubMed

    Szubert, Józef; Szubert, Sławomir; Koszada-Włodarczyk, Wiesława; Bortkiewicz, Alicja

    2014-01-01

    The relative physical load (% VO2max) is the quotient of oxygen uptake (Vo2) during physical effort and maximum oxygen uptake (VO2max) by the human body. For this purpose the stress test must be performed. The relative load shows a high correlation with minute ventilation, cardiac output, heart rate, stroke volume, increased concentrations of catecholamines in the blood, inner temperature, weight, height and human body surface area. The relative load is a criterion for the maximum workloads admissible for healthy and sick workers. Besides, the classification of effort can be more precise when based on the relative load than on the energy output. Based on our own and international empirical evidence and the laws of heat transfer and fluid mechanics, a model of temperature control system has been developed, involving the elements of human cardiovascular and respiratory systems. Using this model, we have been able to develop our own methods of determining the relative load, applying only the body core temperature (Tw) or heart rate within one minute (HR), body mass (m), height (H), and body surface area (AD) instead of VO,max. The values of the relative physical load (% VO2max) obtained by using our own methods do not differ significantly from those obtained by other methods and by other researchers. The developed methods for determining the relative physical load (% VO2max) do not require the exercise test to be performed, therefore, they may be considered (after verification in an experimental study) a feasible alternative to current methods.

  3. 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.

  4. 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.

  5. Fundamental heat transfer experiments of heat pipes for turbine cooling

    SciTech Connect

    Yamawaki, S.; Yoshida, T.; Taki, M.; Mimura, F.

    1998-07-01

    Fundamental heat transfer experiments were carried out for three kinds of heat pipes that may be applied to turbine cooling in future aero-engines. In the turbine cooling system with a heat pipe, heat transfer rate and start-up time of the heat pipe are the most important performance criteria to evaluate and compare with conventional cooling methods. Three heat pipes are considered, called heat pipe A, B, and C, respectively. All heat pipes have a stainless steel shell and nickel sintered powder metal wick. Sodium (Na) was the working fluid for heat pipes A and B; heat pipe C used eutectic sodium-potassium (NaK). Heat pipes B and C included noncondensible gas for rapid start-up. There were fins on the cooling section of heat pipes. In the experiments, an infrared image furnace supplied heat to the heat pipe simulating turbine blade surface conditions. In the results, heat pipe B demonstrated the highest heat flux of 17 to 20 W/cm{sup 2}. The start-up time was about 6 minutes for heat pipe B and about 6 minutes for heat pipe A. Thus, adding noncondensible gas effectively reduced start-up time. Although NaK is a liquid phase at room temperature, the start-up time of heat pipe C (about 7 to 8 minutes) was not shorter than the heat pipe B. The effect of a gravitational force on heat pipe performance was also estimated by inclining the heat pipe at an angle of 90 deg. There was no significant gravitational dependence on heat transport for heat pipes including noncondensible gas.

  6. AdS cycles in eternally inflating background

    NASA Astrophysics Data System (ADS)

    Liu, Zhi-Guo; Piao, Yun-Song

    2014-09-01

    In the eternally inflating background, the bubbles with AdS vacua will crunch. However, this crunch might be followed by a bounce. It is generally thought that the bubble universe may be cyclic, which will go through a sequence of AdS crunches, until the field inside the bubble finally lands at a dS minimum. However, we show that due to the amplification of field fluctuation, the bubble universe going through AdS cycles will inevitably fragment within two or three cycles. We discuss its implication to the eternal inflation scenario.

  7. The DEMO wall load challenge

    NASA Astrophysics Data System (ADS)

    Wenninger, R.; Albanese, R.; Ambrosino, R.; Arbeiter, F.; Aubert, J.; Bachmann, C.; Barbato, L.; Barrett, T.; Beckers, M.; Biel, W.; Boccaccini, L.; Carralero, D.; Coster, D.; Eich, T.; Fasoli, A.; Federici, G.; Firdaouss, M.; Graves, J.; Horacek, J.; Kovari, M.; Lanthaler, S.; Loschiavo, V.; Lowry, C.; Lux, H.; Maddaluno, G.; Maviglia, F.; Mitteau, R.; Neu, R.; Pfefferle, D.; Schmid, K.; Siccinio, M.; Sieglin, B.; Silva, C.; Snicker, A.; Subba, F.; Varje, J.; Zohm, H.

    2017-04-01

    For several reasons the challenge to keep the loads to the first wall within engineering limits is substantially higher in DEMO compared to ITER. Therefore the pre-conceptual design development for DEMO that is currently ongoing in Europe needs to be based on load estimates that are derived employing the most recent plasma edge physics knowledge. An initial assessment of the static wall heat load limit in DEMO infers that the steady state peak heat flux limit on the majority of the DEMO first wall should not be assumed to be higher than 1.0 MW m‑2. This compares to an average wall heat load of 0.29 MW m‑2 for the design {\\tt {EU}}{\\tt {~}}{\\tt {DEMO1}}{\\tt {~2015}} assuming a perfect homogeneous distribution. The main part of this publication concentrates on the development of first DEMO estimates for charged particle, radiation, fast particle (all static) and disruption heat loads. Employing an initial engineering wall design with clear optimization potential in combination with parameters for the flat-top phase (x-point configuration), loads up to 7 MW m‑2 (penalty factor for tolerances etc not applied) have been calculated. Assuming a fraction of power radiated from the x-point region between 1/5 and 1/3, peaks of the total power flux density due to radiation of 0.6–0.8 MW m‑2 are found in the outer baffle region. This first review of wall loads, and the associated limits in DEMO clearly underlines a significant challenge that necessitates substantial engineering efforts as well as a considerable consolidation of the associated physics basis.

  8. 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.

  9. 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.

  10. Activity of bone cement loaded with daptomycin alone or in combination with gentamicin or PEG600 against Staphylococcus epidermidis biofilms.

    PubMed

    Peñalba Arias, Patricio; Furustrand Tafin, Ulrika; Bétrisey, Bertrand; Vogt, Sebastian; Trampuz, Andrej; Borens, Olivier

    2015-02-01

    Daptomycin is a promising candidate for local treatment of bone infection due to its activity against multi-resistant staphylococci. We investigated the activity of antibiotic-loaded PMMA against Staphylococcus epidermidis biofilms using an ultra-sensitive method bacterial heat detection method (microcalorimetry). PMMA cylinders loaded with daptomycin alone or in combination with gentamicin or PEG600, vancomycin and gentamicin were incubated with S. epidermidis-RP62A in tryptic soy broth (TSB) for 72 h. Cylinders were thereafter washed and transferred in microcalorimetry ampoules pre-filled with TSB. Bacterial heat production, proportional to the quantity of biofilm on the PMMA, was measured by isothermal microcalorimetry at 37 °C. Heat detection time was considered time to reach 20 μW. Experiments were performed in duplicate. The heat detection time was 5.7-7.0 h for PMMA without antibiotics. When loaded with 5% of daptomycin, vancomycin or gentamicin, detection times were 5.6-16.4 h, 16.8-35.7 h and 4.7-6.2 h, respectively. No heat was detected when 5% gentamicin or 0.5% PEG600 was added to the daptomycin-loaded PMMA. The study showed that vancomycin was superior to daptomycin and gentamicin in inhbiting staphylococcal adherence in vitro. However, PMMA loaded with daptomycin combined with gentamicin or PEG600 completely inhibited S. epidermidis-biofilm formation. PMMA loaded with these combinations may represent effective strategies for local treatment in the presence of multi-resistant staphylococci. Copyright © 2014 Elsevier Ltd. All rights reserved.

  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. 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. 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…

  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. 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…

  17. Cooling loads in laboratories

    SciTech Connect

    Wilkins, C.K.; Cook, M.R.

    1999-07-01

    The heating, ventilating, and air-conditioning (HVAC) system for a laboratory must be designed with consideration for safety, air cleanliness, and space temperature. The primary safety concern is to ensure proper coordination between fume hood exhaust and makeup air supply. Air cleanliness is maintained by properly filtering supply air, by delivering adequate room air changes, and by ensuring proper pressure relationships between the laboratory and adjacent spaces. Space temperature is maintained by supplying enough cooling air to offset the amount of heat generated in the room. Each of these factors must be considered, and the one that results in the largest ventilation rate is used to establish the supply and exhaust airflows. The project described in this paper illustrates a case where cooling load is the determining factor in the sizing of the air systems.

  18. Supersymmetry of AdS and flat IIB backgrounds

    NASA Astrophysics Data System (ADS)

    Beck, S.; Gutowski, J.; Papadopoulos, G.

    2015-02-01

    We present a systematic description of all warped AdS n × w M 10- n and IIB backgrounds and identify the a priori number of supersymmetries N preserved by these solutions. In particular, we find that the AdS n backgrounds preserve for n ≤ 4 and for 4 < n ≤ 6 supersymmetries and for suitably restricted. In addition under some assumptions required for the applicability of the maximum principle, we demonstrate that the Killing spinors of AdS n backgrounds can be identified with the zero modes of Dirac-like operators on M 10- n establishing a new class of Lichnerowicz type theorems. Furthermore, we adapt some of these results to backgrounds with fluxes by taking the AdS radius to infinity. We find that these backgrounds preserve for 2 < n ≤ 4 and for 4 < n ≤ 7 supersymmetries. We also demonstrate that the Killing spinors of AdS n × w M 10- n do not factorize into Killing spinors on AdS n and Killing spinors on M 10- n .

  19. [Value-Added--Adding Economic Value in the Food Industry].

    ERIC Educational Resources Information Center

    Welch, Mary A., Ed.

    1989-01-01

    This booklet focuses on the economic concept of "value added" to goods and services. A student activity worksheet illustrates how the steps involved in processing food are examples of the concept of value added. The booklet further links food processing to the idea of value added to the Gross National Product (GNP). Discussion questions,…

  20. Duplex Stirling gas fired heating only heat pump

    NASA Astrophysics Data System (ADS)

    Beale, W.

    1982-03-01

    In phase I the Duplex Stirling Gas fired Heat Pump was analyzed with the aid of the Sunpower third order simulation and optimization code and found to show heating COP of 1.7 at the rating point of 8 C (17 F) with a heat delivery of 10 kW. Also it was found that a direct heat exchange between working fluid and source and sink air was consistent with high COP in the heat pump, thus eliminating the need for an intermediate heat transfer fluid and its associated pumps and controls. Further, it was demonstrated in the simulation that the heat engine power output could be matched to the heat pump load over the range of source temperatures without need of complex control systems. Cost estimates, along with COP figures from the analysis indicated a payback time of 2 to 4 years in completion with existing combustion heating systems in northern climates.