Science.gov

Sample records for absorbed heat load

  1. High heat-load absorbers for the APS storage ring

    SciTech Connect

    Sharma, S.; Rotela, E.; Barcikowski, A.

    2000-07-21

    The power density of the dipole x-rays in the 7-GeV APS storage ring is 261 watts/mrad at 300 mA of beam current. An array of absorbers is used in the ring to shield its vacuum chambers and diagnostics components in the path of these intense x-rays. This paper describes some of the unique absorber designs that were developed to handle the requirements of high power density and UHV compatibility with no water-to-vacuum joints.

  2. Nonventing, Regenerable, Lightweight Heat Absorber

    NASA Technical Reports Server (NTRS)

    Izenson, Michael G.; Chen, Weibo

    2008-01-01

    A lightweight, regenerable heat absorber (RHA), developed for rejecting metabolic heat from a space suit, may also be useful on Earth for short-term cooling of heavy protective garments. Unlike prior space-suit-cooling systems, a system that includes this RHA does not vent water. The closed system contains water reservoirs, tubes through which water is circulated to absorb heat, an evaporator, and an absorber/radiator. The radiator includes a solution of LiCl contained in a porous material in titanium tubes. The evaporator cools water that circulates through a liquid-cooled garment. Water vapor produced in the evaporator enters the radiator tubes where it is absorbed into the LiCl solution, releasing heat. Much of the heat of absorption is rejected to the environment via the radiator. After use, the RHA is regenerated by heating it to a temperature of 100 C for about 2 hours to drive the absorbed water back to the evaporator. A system including a prototype of the RHA was found to be capable of maintaining a temperature of 20 C while removing heat at a rate of 200 W for 6 hours.

  3. Load limiting energy absorbing lightweight debris catcher

    NASA Technical Reports Server (NTRS)

    Kahn, Jon B. (Inventor); Schneider, William C. (Inventor)

    1991-01-01

    In the representative embodiment of the invention disclosed, a load limiting, energy absorbing net is arranged to overlay a normally-covered vent opening in the rear bulkhead of the space orbiter vehicle. Spatially-disposed flexible retainer straps are extended from the net and respectively secured to bulkhead brackets spaced around the vent opening. The intermediate portions of the straps are doubled over and stitched together in a pattern enabling the doubled-over portions to progressively separate at a predicable load designed to be well below the tensile capability of the straps as the stitches are successively torn apart by the forces imposed on the retainer members whenever the cover plate is explosively separated from the bulkhead and propelled into the net. By arranging these stitches to be successively torn away at a load below the strap strength in response to forces acting on the retainers that are less than the combined strength of the retainers, this tearing action serves as a predictable compact energy absorber for safely halting the cover plate as the retainers are extended as the net is deployed. The invention further includes a block of an energy-absorbing material positioned in the net for receiving loose debris produced by the explosive release of the cover plate.

  4. Energy absorber for sodium-heated heat exchanger

    DOEpatents

    Essebaggers, J.

    1975-12-01

    A heat exchanger is described in which water-carrying tubes are heated by liquid sodium and in which the results of accidental contact between the water and the sodium caused by failure of one or more of the water tubes is minimized. An energy absorbing chamber contains a compressible gas and is connected to the body of flowing sodium by a channel so that, in the event of a sodium-water reaction, products of the reaction will partially fill the energy absorbing chamber to attenuate the rise in pressure within the heat exchanger.

  5. Vertical-plane pendulum absorbers for minimizing helicopter vibratory loads

    NASA Technical Reports Server (NTRS)

    Amer, K. B.; Neff, J. R.

    1974-01-01

    The use of pendulum dynamic absorbers mounted on the blade root and operating in the vertical plane to minimize helicopter vibratory loads was discussed. A qualitative description was given of the concept of the dynamic absorbers and some results of analytical studies showing the degree of reduction in vibratory loads attainable are presented. Operational experience of vertical plane dynamic absorbers on the OH-6A helicopter is also discussed.

  6. Method of absorbance correction in a spectroscopic heating value sensor

    SciTech Connect

    Saveliev, Alexei; Jangale, Vilas Vyankatrao; Zelepouga, Sergeui; Pratapas, John

    2013-09-17

    A method and apparatus for absorbance correction in a spectroscopic heating value sensor in which a reference light intensity measurement is made on a non-absorbing reference fluid, a light intensity measurement is made on a sample fluid, and a measured light absorbance of the sample fluid is determined. A corrective light intensity measurement at a non-absorbing wavelength of the sample fluid is made on the sample fluid from which an absorbance correction factor is determined. The absorbance correction factor is then applied to the measured light absorbance of the sample fluid to arrive at a true or accurate absorbance for the sample fluid.

  7. MSAT boom joint testing and load absorber design

    NASA Technical Reports Server (NTRS)

    Klinker, D. H.; Shuey, K.; St.clair, D. R.

    1994-01-01

    Through a series of component and system-level tests, the torque margin for the MSAT booms is being determined. The verification process has yielded a number of results and lessons that can be applied to many other types of deployable spacecraft mechanisms. The MSAT load absorber has proven to be an effective way to provide high energy dissipation using crushable honeycomb. Using two stages of crushable honeycomb and a fusible link, a complex crush load profile has been designed and implemented. The design features of the load absorber lend themselves to use in other spacecraft applications.

  8. High heat load synchrotron optics

    SciTech Connect

    Mills, D.M.

    1992-08-01

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

  9. Generator-absorber-heat exchange heat transfer apparatus and method and use thereof in a heat pump

    DOEpatents

    Phillips, Benjamin A.; Zawacki, Thomas S.; Marsala, Joseph

    1994-11-29

    Numerous embodiments and related methods for generator-absorber heat exchange (GAX) are disclosed, particularly for absorption heat pump systems. Such embodiments and related methods use the working solution of the absorption system for the heat transfer medium.

  10. 21-PWR WASTE PACKAGE WITH ABSORBER PLATES LOADING CURVE EVALUATION

    SciTech Connect

    J.M. Scaglione

    2004-12-17

    The objective of this calculation is to evaluate the required minimum burnup as a function of initial pressurized water reactor (PWR) assembly enrichment that would permit loading of spent nuclear fuel into the 21 PWR waste package with absorber plates design as provided in Attachment IV. This calculation is an example of the application of the methodology presented in the ''Disposal Criticality Analysis Methodology Topical Report'' (YMP 2003). The scope of this calculation covers a range of enrichments from 0 through 5.0 weight percent U-235, and a burnup range of 0 through 45 GWd/MTU. Higher burnups were not necessary because 45 GWd/MTU was high enough for the loading curve determination. This activity supports the validation of the use of burnup credit for commercial spent nuclear fuel applications. The intended use of these results will be in establishing PWR waste package configuration loading specifications. Limitations of this evaluation are as follows: (1) The results are based on burnup credit for actinides and selected fission products as proposed in YMP (2003, Table 3-1) and referred to as the ''Principal Isotopes''. Any change to the isotope listing will have a direct impact on the results of this report. (2) The results are based on 1.5 wt% Gd in the Ni-Gd Alloy material and having no tuff inside the waste package. If the Gd loading is reduced or a process to introduce tuff inside the waste package is defined, then this report would need to be reevaluated based on the alternative materials. This calculation is subject to the ''Quality Assurance Requirements and Description'' (QARD) (DOE 2004) because it concerns engineered barriers that are included in the ''Q-List'' (BSC 2004k, Appendix A) as items important to safety and waste isolation.

  11. 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.

  12. Tunable microwave metamaterial absorbers using varactor-loaded split loops

    NASA Astrophysics Data System (ADS)

    Zhu, Jinfeng; Li, Delong; Yan, Shuang; Cai, Yijun; Huo Liu, Qing; Lin, Timothy

    2015-12-01

    Currently, implementation of active circuit elements within metamaterials is an effective way to make them electrically tunable. We combine varactors with split copper loops in a metamaterial absorber in order to obtain an electrically tunable microwave response. This absorber has a compact planar structure and a simplified back feeding network. Flexible frequency tunability of the microwave reflection in the range of 5-6 GHz is experimentally achieved. The design, simulation, and experimental results are systematically presented. The proposed method is scalable for developing active metamaterial absorbers based on metal loops, and shows a promising potential of active metamaterial absorbers for extensive microwave applications.

  13. Generator-absorber-heat exchange heat transfer apparatus and method and use thereof in a heat pump

    DOEpatents

    Phillips, Benjamin A.; Zawacki, Thomas S.

    1996-12-03

    Numerous embodiments and related methods for generator-absorber heat exchange (GAX) are disclosed, particularly for absorption heat pump systems. Such embodiments and related methods use the working solution of the absorption system for the heat transfer medium. A combination of weak and rich liquor working solution is used as the heat transfer medium.

  14. Reprint of : Thermoelectricity without absorbing energy from the heat sources

    NASA Astrophysics Data System (ADS)

    Whitney, Robert S.; Sánchez, Rafael; Haupt, Federica; Splettstoesser, Janine

    2016-08-01

    We analyze the power output of a quantum dot machine coupled to two electronic reservoirs via thermoelectric contacts, and to two thermal reservoirs - one hot and one cold. This machine is a nanoscale analogue of a conventional thermocouple heat-engine, in which the active region being heated is unavoidably also exchanging heat with its cold environment. Heat exchange between the dot and the thermal reservoirs is treated as a capacitive coupling to electronic fluctuations in localized levels, modeled as two additional quantum dots. The resulting multiple-dot setup is described using a master equation approach. We observe an "exotic" power generation, which remains finite even when the heat absorbed from the thermal reservoirs is zero (in other words the heat coming from the hot reservoir all escapes into the cold environment). This effect can be understood in terms of a non-local effect in which the heat flow from heat source to the cold environment generates power via a mechanism which we refer to as Coulomb heat drag. It relies on the fact that there is no relaxation in the quantum dot system, so electrons within it have a non-thermal energy distribution. More poetically, one can say that we find a spatial separation of the first-law of thermodynamics (heat to work conversion) from the second-law of thermodynamics (generation of entropy). We present circumstances in which this non-thermal system can generate more power than any conventional macroscopic thermocouple (with local thermalization), even when the latter works with Carnot efficiency.

  15. Thermoelectricity without absorbing energy from the heat sources

    NASA Astrophysics Data System (ADS)

    Whitney, Robert S.; Sánchez, Rafael; Haupt, Federica; Splettstoesser, Janine

    2016-01-01

    We analyze the power output of a quantum dot machine coupled to two electronic reservoirs via thermoelectric contacts, and to two thermal reservoirs - one hot and one cold. This machine is a nanoscale analogue of a conventional thermocouple heat-engine, in which the active region being heated is unavoidably also exchanging heat with its cold environment. Heat exchange between the dot and the thermal reservoirs is treated as a capacitive coupling to electronic fluctuations in localized levels, modeled as two additional quantum dots. The resulting multiple-dot setup is described using a master equation approach. We observe an "exotic" power generation, which remains finite even when the heat absorbed from the thermal reservoirs is zero (in other words the heat coming from the hot reservoir all escapes into the cold environment). This effect can be understood in terms of a non-local effect in which the heat flow from heat source to the cold environment generates power via a mechanism which we refer to as Coulomb heat drag. It relies on the fact that there is no relaxation in the quantum dot system, so electrons within it have a non-thermal energy distribution. More poetically, one can say that we find a spatial separation of the first-law of thermodynamics (heat to work conversion) from the second-law of thermodynamics (generation of entropy). We present circumstances in which this non-thermal system can generate more power than any conventional macroscopic thermocouple (with local thermalization), even when the latter works with Carnot efficiency.

  16. Analysis of heat-pipe absorbers in evacuated-tube solar collectors

    NASA Astrophysics Data System (ADS)

    Hull, J. R.; Schertz, W. W.; Allen, J. W.

    1986-02-01

    Heat transfer in evacuated-tube solar collectors with heat-pipe absorbers is compared with that for similar collectors with flow-through absorbers. In systems that produce hot water or other heated fluids, the heat-pipe absorber suffers a heat transfer penalty compared with the flow-through absorber, but in many cases the penalty can be minimized by proper design at the heat-pipe condenser and system manifold. The heat transfer penalty decreases with decreasing collector heat loss coefficient, suggesting that evacuated tubes with optical concentration are more appropriate for use with heat pipes than evacuated or nonevacuated flat-plate collectors. When the solar collector is used to drive an absorption chiller, the heat-pipe absorber has better heat transfer characteristics than the flow-through absorbers.

  17. WECS - load controlled pitch - variable load conversion to heat. Final report

    SciTech Connect

    Secord, N.

    1983-11-26

    Load control circuitry was developed such that excess energy from a windmill, that would normally go back to the utility, be absorbed in thermal storage to heat domestic hot water. Also, associated with this objective is the development of instrumentation to measure the power curve of the windmill as a function of windspeed. An Enertech 4KW windmill and related equipment was used to meet this objective.

  18. Cooling solutions for high heat load optics

    SciTech Connect

    Morris, D.; Harding, G.H.; Cox, M.P.; Lunt, D.

    1996-09-01

    Heat loads on optical components at third-generation synchrotron sources, such as the APS, present beamline designers with difficult and complex engineering problems. A number of solutions have been proposed, such as pin-post water cooling, cryogenic cooling, and liquid gallium cooling. This paper describes both a cryogenic cooling system and a liquid gallium pumping system that have been developed specifically for the APS high heat load beamlines. Also presented is a potential solution for the first mirrors on high heat load beamlines, based on liquid gallium internal cooling of a silicon carbide mirror. {copyright} {ital 1996 American Institute of Physics.}

  19. Generator-absorber-heat exchange heat transfer apparatus and method and use thereof in a heat pump

    DOEpatents

    Phillips, Benjamin A.; Zawacki, Thomas S.

    1998-07-21

    Numerous embodiments and related methods for generator-absorber heat exchange (GAX) are disclosed, particularly for absorption heat pump systems. Such embodiments and related methods use, as the heat transfer medium, the working fluid of the absorption system taken from the generator at a location where the working fluid has a rich liquor concentration.

  20. Generator-absorber-heat exchange heat transfer apparatus and method and use thereof in a heat pump

    DOEpatents

    Phillips, B.A.; Zawacki, T.S.

    1998-07-21

    Numerous embodiments and related methods for generator-absorber heat exchange (GAX) are disclosed, particularly for absorption heat pump systems. Such embodiments and related methods use, as the heat transfer medium, the working fluid of the absorption system taken from the generator at a location where the working fluid has a rich liquor concentration. 5 figs.

  1. 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.

  2. Tuned vibration absorbers with nonlinear viscous damping for damped structures under random load

    NASA Astrophysics Data System (ADS)

    Shum, K. M.

    2015-06-01

    The classical problem for the application of a tuned vibration absorber is to minimize the response of a structural system, such as displacement, velocity, acceleration or to maximize the energy dissipated by tuned vibration absorber. The development of explicit optimal absorber parameters is challenging for a damped structural system since the fixed points no longer exist in the frequency response curve. This paper aims at deriving a set of simple design formula of tuned vibration absorber with nonlinear viscous damping based on the frequency tuning for harmonic load for a damped structural system under white noise excitation. The vibration absorbers being considered include tuned mass damper (TMD) and liquid column vibration absorber (LCVA). Simple approximate expression for the standard deviation velocity response of tuned vibration absorber for damped primary structure is also derived in this study to facilitate the estimation of the damping coefficient of TMD with nonlinear viscous damping and the head loss coefficient of LCVA. The derived results indicate that the higher the structural inherent damping the smaller the supplementary damping provided by a tuned vibration absorber. Furthermore, the optimal damping of tuned vibration absorber is shown to be independent of structural damping when it is tuned using the frequency tuning for harmonic load. Finally, the derived closed-form expressions are demonstrated to be capable of predicting the optimal parameters of tuned vibration absorbers with sufficient accuracy for preliminary design of tuned vibration absorbers with nonlinear viscous damping for a damped primary structure.

  3. 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.

  4. 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.

  5. Efficient thermoelectric cooling of concentrated heat loads

    NASA Astrophysics Data System (ADS)

    Hershberger, Jeff; Smythe, Robert; Gu, Xiaoyi; Hill, Richard F.

    2013-02-01

    An efficiency improvement of 87% is demonstrated in cooling of concentrated heat loads when using thermoelectric coolers (TECs) constructed with thermally conductive printed circuit boards (TCPCBs) as compared to traditional ceramic-based TECs. Laser diodes and infrared detectors must be actively cooled but are smaller than typical TECs. As a result, heat spreading must occur between the optical component and the semiconductor pellets near the edge of the TEC. Typically, TECs based on aluminum nitride circuit boards are chosen and in some cases an AlN plate is added between the optical component and the TEC. To address this, TECs have been developed that replace the ceramic circuit boards with laminated TCPCBs containing a thick copper backing. The copper backing improves heat spreading within the TEC. A study was conducted to quantify differences in coefficient of performance (COP, heat pumped divided by electrical power consumed) when cooling concentrated heat loads. A heat source 3 mm wide was cooled by TECs ~12 mm wide, comparing ceramic-based and TCPCB-based TECs of otherwise identical design. With a fixed hot side temperature and heat load, each TEC was powered to achieve a desired temperature at the heat source. Ceramic-based and TCPCB-based TECs exhibited COPs of 0.235 and 0.440 respectively, an 87% improvement. Further improvements are achievable: adding a thick copper plate between the heat source and the TEC resulted in a COP of ~0.59 for both TEC types.

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

    SciTech Connect

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

    2014-01-01

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

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

    PubMed

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

    2007-11-20

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

  8. The Synergism Between Heat and Mass Transfer Additive and Advanced Surfaces in Aqueous LiBr Horizontal Tube Absorbers

    SciTech Connect

    Miller, W.A.

    1999-03-24

    Experiments were conducted in a laboratory to investigate the absorption of water vapor into a falling-film of aqueous lithium bromide (LiBr). A mini-absorber test stand was used to test smooth tubes and a variety of advanced tube surfaces placed horizontally in a single-row bundle. The bundle had six copper tubes; each tube had an outside diameter of 15.9-mm and a length of 0.32-m. A unique feature of the stand is its ability to operate continuously and support testing of LiBr brine at mass fractions {ge} 0.62. The test stand can also support testing to study the effect of the failing film mass flow rate, the coolant mass flow rate, the coolant temperature, the absorber pressure and the tube spacing. Manufacturers of absorption chillers add small quantities of a heat and mass transfer additive to improve the performance of the absorbers. The additive causes surface stirring which enhances the transport of absorbate into the bulk of the film. Absorption may also be enhanced with advanced tube surfaces that mechanically induce secondary flows in the falling film without increasing the thickness of the film. Several tube geometry's were identified and tested with the intent of mixing the film and renewing the interface with fresh solution from the tube wall. Testing was completed on a smooth tube and several different externally enhanced tube surfaces. Experiments were conducted over the operating conditions of 6.5 mm Hg absorber pressure, coolant temperatures ranging from 20 to 35 C and LiBr mass fractions ranging from 0.60 through 0.62. Initially the effect of tube spacing was investigated for the smooth tube surface, tested with no heat and mass transfer additive. Test results showed the absorber load and the mass absorbed increased as the tube spacing increased because of the improved wetting of the tube bundle. However, tube spacing was not a critical factor if heat and mass transfer additive was active in the mini-absorber. The additive dramatically affected

  9. Generator-Absorber heat exchange transfer apparatus and method using an intermediate liquor

    DOEpatents

    Phillips, Benjamin A.; Zawacki, Thomas S.

    1996-11-05

    Numerous embodiments and related methods for generator-absorber heat exchange (GAX) are disclosed, particularly for absorption heat pump systems. Such embodiments and related methods use the working solution of the absorption system for the heat transfer medium where the working solution has an intermediate liquor concentration.

  10. 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.

  11. Nano-porous-water Absorbents for Solid-absorbebt Heat Pump System

    NASA Astrophysics Data System (ADS)

    Mizota, Tadato; Nakayama, Noriaki

    Zeolite-water heat-pump system has been developed in these 25 years. Recently, an instant beer-cooling system has appeared by using the zeolite heat pump system as a commercial product. It takes so long time for the development since the first proposal. The most serious problem through the development has been of the ability of absorbents. Themaximum heat exchange capacity to date exceeds 1MJ•kg-1 for Mg89-A, which is comparable to the energy storage capacity of modern alkaline-ion batteries in weight-bases. But it needs high temperature heat sources more than 200°C for the activation. Absorbents useful at lower temperatures are thus desirable for effective use of various kinds of lower temperature heat sources Various nano-porous materials as well as zeolites now under investigation as candidates of heat-pump absorbents, such as silica-gels, allophane, imogolite, hydrotalcite, etc.

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

    NASA Technical Reports Server (NTRS)

    Ku, Jentung

    2005-01-01

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

  13. Reducing heat loss from the energy absorber of a solar collector

    DOEpatents

    Chao, Bei Tse; Rabl, Ari

    1976-01-01

    A device is provided for reducing convective heat loss in a cylindrical radiant energy collector. It includes a curved reflective wall in the shape of the arc of a circle positioned on the opposite side of the exit aperture from the reflective side walls of the collector. Radiant energy exiting the exit aperture is directed by the curved wall onto an energy absorber such that the portion of the absorber upon which the energy is directed faces downward to reduce convective heat loss from the absorber.

  14. Ultrabroadband Microwave Metamaterial Absorber Based on Electric SRR Loaded with Lumped Resistors

    NASA Astrophysics Data System (ADS)

    Zhao, Jingcheng; Cheng, Yongzhi

    2016-10-01

    An ultrabroadband microwave metamaterial absorber (MMA) based on an electric split-ring resonator (ESRR) loaded with lumped resistors is presented. Compared with an ESRR MMA, the composite MMA (CMMA) loaded with lumped resistors offers stronger absorption over an extremely extended bandwidth. The reflectance simulated under different substrate loss conditions indicates that incident electromagnetic (EM) wave energy is mainly consumed by the lumped resistors. The simulated surface current and power loss density distributions further illustrate the mechanism underlying the observed absorption. Further simulation results indicate that the performance of the CMMA can be tuned by adjusting structural parameters of the ESRR and lumped resistor parameters. We fabricated and measured MMA and CMMA samples. The CMMA yielded below -10 dB reflectance from 4.4 GHz to 18 GHz experimentally, with absorption bandwidth and relative bandwidth of 13.6 GHz and 121.4%, respectively. This ultrabroadband microwave absorber has potential applications in the electromagnetic energy harvesting and stealth fields.

  15. 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.

  16. The 3D heat flux density distribution on a novel parabolic trough wavy absorber

    NASA Astrophysics Data System (ADS)

    Demagh, Yassine; Kabar, Yassine; Bordja, Lyes; Noui, Samira

    2016-05-01

    The non-uniform concentrated solar flux distribution on the outer surface of the absorber pipe can lead to large circumferential gradient temperature and high concentrated temperature of the absorber pipe wall, which is one of the primary causes of parabolic trough solar receiver breakdown. In this study, a novel shape of the parabolic trough absorber pipe is proposed as a solution to well homogenize the solar flux distribution, as well as, the temperature in the absorber wall. The conventional straight absorber located along the focal line of the parabola is replaced by wavy one (invention patent by Y. Demagh [1]) for which the heat flux density distribution on the outer surface varies in both axial and azimuthal directions (3D) while it varies only in the azimuthal direction on the former (2D). As far as we know, there is not previous study which has used a longitudinally wavy pipe as an absorber into the parabolic trough collector unit.

  17. 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... Thermal Protection § 3280.508 Heat loss, heat gain and cooling load calculations. (a) Information, values and data necessary for heat loss and heat gain determinations must be taken from the 1997...

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

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 24 Housing and Urban Development 5 2014-04-01 2014-04-01 false Heat loss, heat gain and cooling... Thermal Protection § 3280.508 Heat loss, heat gain and cooling load calculations. (a) Information, values and data necessary for heat loss and heat gain determinations must be taken from the 1997...

  19. 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.

  20. Effect of Index of Refraction on Radiation Characteristics in a Heated Absorbing, Emitting, and Scattering Layer

    NASA Technical Reports Server (NTRS)

    Siegel, R.; Spuckler, C. M.

    1992-01-01

    The effect of the index of refraction on the temperature distribution and radiative heat flux in semitransparent materials, such as some ceramics, is investigated analytically. In the case considered here, a plane layer of a ceramic material is subjected to external radiative heating incident on each of its surfaces; the material emits, absorbs, and isotropically scatters radiation. It is shown that, for radiative equilibrium in a gray layer with diffuse interfaces, the temperature distribution and radiative heat flux for any index of refraction can be obtained in a simple manner from the results for an index of refraction of unity.

  1. A kHz heat-load shutter for white-beam experiments at synchrotron sources.

    PubMed

    Gembicky, Milan; Adachi, Shin Ichi; Coppens, Philip

    2007-05-01

    A heat-load shutter capable of frequencies from one to several tens of kHz and window times from 10 micros up to 1 ms is described. In the current configuration the water-cooled shutter absorbs approximately 99% of the heat generated by the white beam. It has been successfully used for extended periods synchronized with a Jülich pulse-selector operating at 946 Hz. The temperature of the pulse-selector remained constant during a three-day continuous operation. Flexibility is provided by the interchangeability of the chopper disc.

  2. A study of heat transfer for two layered composite inclined plate crotch absorbers

    SciTech Connect

    Choi, M.

    1989-11-01

    Since a copper plate (Z=29) absorbs most of the photon energy very near the surface, the temperature of the surface becomes very high despite of having a high thermal conductivity. On the other hand, a beryllium plate( Z=4) can diffuse the intense radiation throughout the depth of its plate by allowing photons to penetrate, but has a low thermal conductivity (about half of that of a copper). As an effort to combine both merits of Be and Cu, a Be-Cu composite absorber was developed and has been successfully used in CESR. They analyzed composite the heat transfer problem numerically for the case of a vertically located Be-Cu composite cylinder which results in symmetry with respect to the center of photon beam and allows them to consider only half a domain. In this note, an inclined absorber with two layered metal plates is considered and a full domain solution is sought to study the asymmetric heating due to the inclined photon beam penetration heating. An analytical solution for heat transfer is obtained for a full domain using the Fourier integral transformation and of particular interests are the effects of different thickness ratios of two materials and different inclination angles.

  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

    NASA Astrophysics Data System (ADS)

    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.

  5. 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.

  6. 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.

  7. WECS-load controlled pitch-variable load conversion to heat

    NASA Astrophysics Data System (ADS)

    Secord, N. W.

    1982-03-01

    Installing a 4 kW windmill and instrumentation on a 100-ft. free-standing lattice tower, developing load control circuitry that will store excess energy in a 1000-gallon electrically heated water tank which will also provides domestic heat via a heat exchanger, and developing a torque controlled pitching hub and blade system are described. Project status and costs are discussed.

  8. Do Different Colors Absorb Heat Better? Grades PreK-2.

    ERIC Educational Resources Information Center

    Rushton, Erik; Ryan, Emily; Swift, Charles

    In this activity, students test whether the color of a material affects how much heat it absorbs. An ice cube is placed in a box made of colored paper (one box per color; white, yellow, red, and black) which is then placed in the sun. Students predict which color will melt the ice cube first and record the order and time required for the ice cubes…

  9. Hemostatic absorbable gelatin sponge loaded with 5-fluorouracil for treatment of tumors

    PubMed Central

    Sun, Wei; Chen, Yinghui; Yuan, Weien

    2013-01-01

    Background Surgical tumor resection is the main treatment for tumors however the treatment process often results in massive bleeding and tumor cell residue. The main aim of this research was to address problems such as bleeding, systemic chemotherapy side effects while enhancing quality of life, and increasing drug concentrations at the tumor site by developing a novel formulation with local long-term efficacy for treatment of tumors and to stop bleeding. Methods 5-Fluorouracil (5-FU) was suspended in an ethyl acetate solution of poly D,L-lactide-co-glycolic acid (PLGA) and a vacuum drying method was applied. The hemostatic gelatin sponge loaded with 5-FU was prepared by absorption of the suspension. The in vitro and in vivo characteristics of the hemostatic gelatin sponge loaded with 5-FU (5-FU-HAGS) were investigated. Results 5-FU-HAGS (hemostatic absorbable gelatin sponge loaded with 5-fluorouracil) was successfully produced with controlled release of the content and was reproducibly suitable for local tumor treatment as an implant to stop bleeding. The encapsulation efficiency of 5-FU-HAGS was above 98%. The in vitro 5-FU release kinetic profile matched a near zero-order equation for 20 days. The in vivo 5-FU plasma concentration was at a more stable level than when 5-FU solution was administered by subcutaneous injection. Bleeding can be stopped more effectively by coating a piece of blank gelatin sponge. The survival ratio of tumor-bearing mice using a 5-FU-HAGS subcutaneous implant was higher when compared to mice given a subcutaneous injection of 5-FU solution. Conclusion The 5-FU-HAGS system is a potential and effective way of enhancing the survival ratio and improving the quality of life of tumor-bearing mice. PMID:23626465

  10. Lumbar load attenuation for rotorcraft occupants using a design methodology for the seat impact energy-absorbing system

    NASA Astrophysics Data System (ADS)

    Moradi, Rasoul; Beheshti, Hamid K.; Lankarani, Hamid M.

    2012-12-01

    Aircraft occupant crash-safety considerations require a minimum cushion thickness to limit the relative vertical motion of the seat-pelvis during high vertical impact loadings in crash landings or accidents. In military aircraft and helicopter seat design, due to the potential for high vertical accelerations in crash scenarios, the seat system must be provided with an energy absorber to attenuate the acceleration level sustained by the occupants. Because of the limited stroke available for the seat structure, the design of the energy absorber becomes a trade-off problem between minimizing the stroke and maximizing the energy absorption. The available stroke must be used to prevent bottoming out of the seat as well as to absorb maximum impact energy to protect the occupant. In this study, the energy-absorbing system in a rotorcraft seat design is investigated using a mathematical model of the occupant/seat system. Impact theories between interconnected bodies in multibody mechanical systems are utilized to study the impact between the seat pan and the occupant. Experimental responses of the seat system and the occupant are utilized to validate the results from this study for civil and military helicopters according to FAR 23 and 25 and MIL-S-58095 requirements. A model for the load limiter is proposed to minimize the lumbar load for the occupant by minimizing the relative velocity between the seat pan and the occupant's pelvis. The modified energy absorber/load limiter is then implemented for the seat structure so that it absorbs the energy of impact in an effective manner and below the tolerable limit for the occupant in a minimum stroke. Results show that for a designed stroke, the level of occupant lumbar spine injury would be significantly attenuated using this modified energy-absorber system.

  11. 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.

  12. 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.

  13. Development and Testing of a Refractory Millimeter-Wave Absorbent Heat Exchanger

    NASA Technical Reports Server (NTRS)

    Lambot, Thomas; Myrabo, Leik; Murakami, David; Parkin, Kevin

    2014-01-01

    Central to the Millimeter-Wave Thermal Launch System (MTLS) is the millimeter-wave absorbent heat exchanger. We have developed metallic and ceramic variants, with the key challenge being the millimeter-wave absorbent coatings for each. The ceramic heat exchanger came to fruition first, demonstrating for the first time 1800 K peak surface temperatures under illumination by a 110 GHz Gaussian beam. Absorption efficiencies of up to 80 are calculated for mullite heat exchanger tubes and up to 50 are calculated for alumina tubes. These are compared with estimates based on stratified layer and finite element analyses. The problem of how to connect the 1800 K end of the ceramic tubes to a graphite outlet manifold and nozzle is solved by press fitting, or by threading the ends of the ceramic tubes and screwing them into place. The problem of how to connect the ceramic tubes to a metallic or nylon inlet pipe is solved by using soft compliant PTFE and PVC tubes that accommodate thermal deformations of the ceramic tubes during startup and operation. We show the resulting heat exchangers in static tests using argon and helium as propellants.

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

    SciTech Connect

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

    1982-01-01

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

  15. Fe-, Co-, and Ni-Loaded Porous Activated Carbon Balls as Lightweight Microwave Absorbents.

    PubMed

    Li, Guomin; Wang, Liancheng; Li, Wanxi; Xu, Yao

    2015-11-16

    Porous activated carbon ball (PACB) composites impregnated with iron, cobalt, nickel and/or their oxides were synthesized through a wet chemistry method involving PACBs as the carrier to load Fe(3+), Co(2+), and Ni(2+) ions and a subsequent carbothermal reduction at different annealing temperatures. The results show that the pyrolysis products of nitrates and/or the products from the carbothermal reduction are embedded in the pores of the PACBs, with different distributions, resulting in different crystalline phases. The as-prepared PACB composites possessed high specific surface areas of 791.2-901.5 m(2)  g(-1) and low densities of 1.1-1.3 g cm(-3). Minimum reflection loss (RL) values of -50.1, -20.6, and -20.4 dB were achieved for Fe-PACB (annealed at 500 °C), Co-PACB (annealed at 800 °C), and Ni-PACB (annealed at 800 °C) composites, respectively. Moreover, the influence of the amount of the magnetic components in the PACB composites on the microwave-absorbing performances was investigated, further confirming that the dielectric loss was the primary contributor to microwave absorption. PMID:26373310

  16. 24 CFR 3280.508 - Heat loss, heat gain and cooling load calculations.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... Thermal Protection § 3280.508 Heat loss, heat gain and cooling load calculations. (a) Information, values... Loads—Manufactured Homes—February 1992-PNL 8006, HUD User No. 0005945. (c) Areas where the insulation... heat-flow paths (“thermal shorts”) shall be explicitly accounted for in the calculation of...

  17. WECS-Load controlled pitch-variable load conversion to heat

    SciTech Connect

    Not Available

    1982-03-29

    The planned work described consists of installing a 4 kW windmill and instrumentation on a 100-ft. free-standing lattice tower, developing load control circuitry that will store excess energy in a 1000-gallon electrically heated water tank which will also heat domestic via a heat exchanger, and developing a torque controlled pitching hub and blade system. Project status and costs are discussed. (LEW)

  18. 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.

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

    NASA Astrophysics Data System (ADS)

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

    1981-05-01

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

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

    NASA Technical Reports Server (NTRS)

    Sockol, P. M.

    1973-01-01

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

  1. Analysis of the effect of different absorber materials and loading on the shielding effectiveness of a metallic enclosure

    NASA Astrophysics Data System (ADS)

    Parr, S.; Karcoon, H.; Dickmann, S.; Rambousky, R.

    2015-11-01

    Metallic rooms as part of a complex system, like a ship, are necessarily connected electromagnetically via apertures and cables to the outside. Therefore, their electromagnetic shielding effectiveness (SE) is limited by ventilation openings, cable feed-throughs and door gaps. Thus, electronic equipment inside these rooms is susceptible to outer electromagnetic threats like IEM (Intentional Electromagnetic Interference). Dielectric or magnetic absorber inside such a screened room can be used in order to prevent the SE from collapsing at the resonant frequencies. In this contribution, the effect of different available absorber materials is compared, as well as other properties like weight and workability. Furthermore, parameter variations of the absorber as well as the effect of loading in form of metallic and dielectric structures on the SE are analyzed.

  2. A concentrated solar cavity absorber with direct heat transfer through recirculating metallic particles

    NASA Astrophysics Data System (ADS)

    Sarker, M. R. I.; Saha, Manabendra; Beg, R. A.

    2016-07-01

    A recirculating flow solar particle cavity absorber (receiver) is modeled to investigate the flow behavior and heat transfer characteristics of a novel developing concept. It features a continuous recirculating flow of non-reacting metallic particles (black silicon carbide) with air which are used as a thermal enhancement medium. The aim of the present study is to numerically investigate the thermal behavior and flow characteristics of the proposed concept. The proposed solar particle receiver is modeled using two phase discrete particle model (DPM), RNG k-flow model and discrete ordinate (DO) radiation model. Numerical analysis is carried out considering a solar receiver with only air and the mixture of non-reacting particles and air as a heat transfer as well as heat carrying medium. The parametric investigation is conducted considering the incident solar flux on the receiver aperture and changing air flow rate and recirculation rate inside the receiver. A stand-alone feature of the recirculating flow solar particle receiver concept is that the particles are directly exposed to concentrated solar radiation monotonously through recirculating flow inside the receiver and results in efficient irradiation absorption and convective heat transfer to air that help to achieve high temperature air and consequently increase in thermal efficiency. This paper presents, results from the developed concept and highlights its flow behavior and potential to enhance the heat transfer from metallic particles to air by maximizing heat carrying capacity of the heat transfer medium. The imposed milestones for the present system will be helpful to understand the radiation absorption mechanism of the particles in a recirculating flow based receiver, the thermal transport between the particles, the air and the cavity, and the fluid dynamics of the air and particle in the cavity.

  3. Effect of Index of Refraction on Radiation Characteristics in a Heated Absorbing, Emitting, and Scattering Layer

    NASA Technical Reports Server (NTRS)

    Siegel, R.; Spuckler, C. M.

    1992-01-01

    The index of refraction can considerably influence the temperature distribution and radiative heat flow in semitransparent materials such as some ceramics. For external radiant heating, the refractive index influences the amount of energy transmitted into the interior of the material. Emission within a material depends on the square of its refractive index, and hence this emission can be many times that for a biackbody radiating into a vacuum. Since radiation exiting through an interface into a vacuum cannot exceed that of a blackbody, there is extensive reflection at the internal surface of an interface, mostly by total internal reflection. This redistributes energy within the layer and tends to make its temperature distribution more uniform. The purpose of the present analysis is to show that, for radiative equilibrium in a gray layer with diffuse interfaces, the temperature distribution and radiative heat flux for any index of refraction can be obtained very simply from the results for an index of refraction of unity. For the situation studied here, the layer is subjected to external radiative heating incident on each of its surfaces. The material emits, absorbs, and isotropically scatters radiation. For simplicity the index of refraction is unity in the medium surrounding the layer. The surfaces of the layer are assumed diffuse. This is probably a reasonable approximation for a ceramic layer that has not been polished. When transmitted radiation or radiation emitted from the interior reaches the inner surface of an interface, the radiation is diffused and some of it thereby placed into angular directions for which there is total internal reflection. This provides a trapping effect for retaining energy within the layer and tends to equalize its temperature distribution. An analysis of temperature distributions in absorbing-emitting layers, including index of refraction effects, was developed by Gardon (1958) to predict cooling and heat treating of glass plates

  4. The Development of a Conical Composite Energy Absorber for Use in the Attenuation of Crash/Impact Loads

    NASA Technical Reports Server (NTRS)

    Littell, Justin D.

    2014-01-01

    A design for a novel light-weight conical shaped energy absorbing (EA) composite subfloor structure is proposed. This composite EA is fabricated using repeated alternating patterns of a conical geometry to form long beam structures which can be implemented as aircraft subfloor keel beams or frame sections. The geometrical features of this conical design, along with the hybrid composite materials used in the manufacturing process give a strength tailored to achieve a constant 25-40 g sustained crush load, small peak crush loads and long stroke limits. This report will discuss the geometrical design and fabrication methods, along with results from static and dynamic crush testing of 12-in. long subcomponents.

  5. Ablation loading of solid target through foam absorber on ABC laser at ENEA-Frascati

    NASA Astrophysics Data System (ADS)

    De Angelis, R.; Consoli, F.; Gus'kov, S. Yu.; Rupasov, A. A.; Andreoli, P.; Cristofari, G.; Di Giorgio, G.; Giulietti, D.; Cantono, G.; Kalal, M.

    2016-03-01

    This work reports an experimental characterization of the efficiency of energy transmission of porous laser absorbers as a function of their density and thickness. In this campaign the foams were deposited on different metal substrates, which finally absorbed the energy deposited by the laser on the bulk of the porous material. The dimensions of the craters produced on the substrate can be related to the energy transmitted through the foams.

  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. Measurements of absorbed heat flux and water-side heat transfer coefficient in water wall tubes

    NASA Astrophysics Data System (ADS)

    Taler, Jan; Taler, Dawid; Kowal, Andrzej

    2011-04-01

    The tubular type instrument (flux tube) was developed to identify boundary conditions in water wall tubes of steam boilers. The meter is constructed from a short length of eccentric tube containing four thermocouples on the fire side below the inner and outer surfaces of the tube. The fifth thermocouple is located at the rear of the tube on the casing side of the water-wall tube. The boundary conditions on the outer and inner surfaces of the water flux-tube are determined based on temperature measurements at the interior locations. Four K-type sheathed thermocouples of 1 mm in diameter, are inserted into holes, which are parallel to the tube axis. The non-linear least squares problem is solved numerically using the Levenberg-Marquardt method. The heat transfer conditions in adjacent boiler tubes have no impact on the temperature distribution in the flux tubes.

  8. Capturing the Energy Absorbing Mechanisms of Composite Structures under Crash Loading

    NASA Astrophysics Data System (ADS)

    Wade, Bonnie

    As fiber reinforced composite material systems become increasingly utilized in primary aircraft and automotive structures, the need to understand their contribution to the crashworthiness of the structure is of great interest to meet safety certification requirements. The energy absorbing behavior of a composite structure, however, is not easily predicted due to the great complexity of the failure mechanisms that occur within the material. Challenges arise both in the experimental characterization and in the numerical modeling of the material/structure combination. At present, there is no standardized test method to characterize the energy absorbing capability of composite materials to aide crashworthy structural design. In addition, although many commercial finite element analysis codes exist and offer a means to simulate composite failure initiation and propagation, these models are still under development and refinement. As more metallic structures are replaced by composite structures, the need for both experimental guidelines to characterize the energy absorbing capability of a composite structure, as well as guidelines for using numerical tools to simulate composite materials in crash conditions has become a critical matter. This body of research addresses both the experimental characterization of the energy absorption mechanisms occurring in composite materials during crushing, as well as the numerical simulation of composite materials undergoing crushing. In the experimental investigation, the specific energy absorption (SEA) of a composite material system is measured using a variety of test element geometries, such as corrugated plates and tubes. Results from several crush experiments reveal that SEA is not a constant material property for laminated composites, and varies significantly with the geometry of the test specimen used. The variation of SEA measured for a single material system requires that crush test data must be generated for a range of

  9. Laser heating of an absorbing and conducting media applied to laser flash property measurements

    SciTech Connect

    Gritzo, L.A.; Anderson, E.E.

    1993-12-31

    The laser flash technique is widely used for determining the thermal diffusivity of a sample. In this work, the temperature distribution throughout the sample is investigated, identifying localized, highly-heated regions near the front surface of the sample as a function of: (1) pulse duration, (2) incident beam uniformity, and (3) sample opacity. These high-temperature regions result in an increase in the uncertainty due to temperature-dependent properties, an increase in the heat loss from the sample, and an increased risk of sample damage. The temperature within a semi-transparent media is also investigated in order to establish a regime for which the media can reasonably be considered as opaque. This analysis illustrates that, for same total energy deposition, treatment of the incident energy as a continuous heat source, as opposed to an infinitesimal pulse of energy, results in a factor of 2 increase in the front surface temperature during heating. Also, for the same total energy deposition and approximate beam size, use of a Gaussian intensity distribution increases the front surface temperature during heating by more than a factor of 2 as compared to the use of a uniform temperature distribution. By analyzing the front surface temperature of an absorbing and conducting semi-transparent sample subjected to a Gaussian intensity distribution, it is concluded that the media can be treated as opaque, (i.e. the energy can be applied as a boundary condition) for {var_epsilon} = kd > 50, where k is the extinction coefficient and d is the beam diameter. For materials with a sufficiently small absorption coefficient and thermal diffusivity, a closed-form solution suitable for design use is presented for the front-surface temperature at a location coincident with the beam centerline.

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

    NASA Astrophysics Data System (ADS)

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

    2016-06-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2016-06-01

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

  12. Helium Refrigerator Design for Pulsed Heat Load in Tokamaks

    SciTech Connect

    Kuendig, A.; Schoenfeld, H.

    2006-04-27

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

  13. White-Light-Induced Collective Heating of Gold Nanocomposite/Bombyx mori Silk Thin Films with Ultrahigh Broadband Absorbance.

    PubMed

    Tsao, Shao Hsuan; Wan, Dehui; Lai, Yu-Sheng; Chang, Ho-Ming; Yu, Chen-Chieh; Lin, Keng-Te; Chen, Hsuen-Li

    2015-12-22

    This paper describes a systematic investigation of the phenomenon of white-light-induced heating in silk fibroin films embedded with gold nanoparticles (Au NPs). The Au NPs functioned to develop an ultrahigh broadband absorber, allowing white light to be used as a source for photothermal generation. With an increase of the Au content in the composite films, the absorbance was enhanced significantly around the localized surface plasmon resonance (LSPR) wavelength, while non-LSPR wavelengths were also increased dramatically. The greater amount of absorbed light increased the rate of photoheating. The optimized composite film exhibited ultrahigh absorbances of approximately 95% over the spectral range from 350 to 750 nm, with moderate absorbances (>60%) at longer wavelengths (750-1000 nm). As a result, the composite film absorbed almost all of the incident light and, accordingly, converted this optical energy to local heat. Therefore, significant temperature increases (ca. 100 °C) were readily obtained when we irradiated the composite film under a light-emitting diode or halogen lamp. Moreover, such composite films displayed linear light-to-heat responses with respect to the light intensity, as well as great photothermal stability. A broadband absorptive film coated on a simple Al/Si Schottky diode displayed a linear, significant, stable photo-thermo-electronic effect in response to varying the light intensity.

  14. Tunable wideband absorber based on resistively loaded lossy high-impedance surface

    NASA Astrophysics Data System (ADS)

    Dang, Ke-Zheng; Shi, Jia-Ming; Wang, Jia-Chun; Lin, Zhi-Dan; Wang, Qi-Chao

    2015-10-01

    A lossy high-impedance surface comprised of two layers of resistive frequency selective surfaces is employed to design a tunable electromagnetic absorber. The tunability is realized through changing the composite unit cell by moving the top layer mechanically. To explain the absorbing mechanism, an equivalent circuit model with an interacting coefficient is proposed. Then, simulations and measurements are carried out and agree well with each other. Results show that the complex structure with a thickness less than λ0/4 is able to achieve a wideband absorption in a frequency range from 5.90 GHz to 19.73 GHz. Moreover, it is tunable in the operation frequency band.

  15. 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.

  16. Amplification of the snow melting effect on the heat wave over the Eurasia by absorbing aerosols

    NASA Astrophysics Data System (ADS)

    Kim, M. K.; Kim, K. M.; Lau, W. K. M.; Sang, J.; Yasunari, T. J.

    2015-12-01

    In this study, we present the potential impact of snow darkening effect on the Eurasian heat wave by absorbing aerosols using the NASA GEOS-5 Model experiments with aerosol tracers and a state-of-the-art snow darkening module for the land surface. Results show that snow darkening effect (SDE) can have a significant influence on not only the intensity but also the duration of heatwave during snow melting season, i.e., late spring season over the mid-western Eurasia and early summer season over the central northern Eurasia. During the early snow melting season surface air temperature is significantly increased by 3-6K due to early snow melting and enhanced solar radiation. Moreover enhanced evaporation induced by surface energy surplus during the early melting season leads to the new equilibrium level with lower soil moisture over the Eurasia since snow melting season, and thereby provide favorable condition for severe droughts and heat wave over the large parts of the Eurasia. This finding suggests that the SDE may play an important role in amplifying the snow melting effect on large-scale heat wave over the Eurasia. Energy and water balance at the surface supporting this findings are also discussed from evaporation-precipitation recycling point of view.

  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. Physiological effects of solar heat load in a fighter cockpit.

    PubMed

    Nunneley, S A; Myhre, L G

    1976-09-01

    The use of bubble canopies to improve vision in fighter aircraft exposes the cockpit to a high radiant heat load. Incoming sunlight increases the heat stress on crewmembers, both by raising air temperature and by directly heating exposed skin and clothing. An F-15 aircraft at Edwards AFB was modified to permit cockpit ventilation by external ground carts. Eight volunteers from the Test Pilot School were studied during 1-h periods in the closed cockpit, in sun and in shade. Mean cockpit air temperatures were 35.2 degrees C in shade and 51.9 degrees C in sun with PH2O less than 10 torr. The corresponding WBGT's were 22.6 and 36.4 degrees C. Sunlight added significantly to overall heat stress, as indicated by a rising heart rate and evaporative weight loss of 284 g/m2 - h (shade value was 109 g/m2 - hr). Mean skin temperatures were 34.3 degrees C in shade and 35.8 degrees C in sun. Particularly high skin temperatures were observed on the chest, the forehead and the top of the head under the helmet. The legs remained cool due to the flow of conditioned air, and this may explain why rectal temperature showed no meaningful change. Heat stress, which alone poses no physiological hazard, may cause crew performance decrements as well as diminishing acceleration tolerance. Possible means of eliminating or ameliorating these effects are discussed.

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

    SciTech Connect

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

    1988-09-01

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

  20. 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

  1. Theoretical investigation of crack formation in tungsten after heat loads

    NASA Astrophysics Data System (ADS)

    Arakcheev, A. S.; Huber, A.; Wirtz, M.; Sergienko, G.; Steudel, I.; Burdakov, A. V.; Coenen, J. W.; Kreter, A.; Linke, J.; Mertens, Ph.; Shoshin, A. A.; Unterberg, B.; Vasilyev, A. A.

    2015-08-01

    Transient events such as ELMs in large plasma devices lead to significant heat load on plasma-facing components (PFCs). ELMs cause mechanical damage of PFCs (e.g. cracks). The cracks appear due to stresses caused by thermal extension. Analytical calculations of the stresses are carried out for tungsten. The model only takes into account the basic features of solid body mechanics without material modifications (e.g. fatigue or recrystallization). The numerical results of the model demonstrate good agreement with experimental data obtained at the JUDITH-1, PSI-2 and GOL-3 facilities.

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

    NASA Astrophysics Data System (ADS)

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

    2011-10-01

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

  3. 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.

  4. Waters of Hydration of Cupric Hydrates: A Comparison between Heating and Absorbance Methods

    ERIC Educational Resources Information Center

    Barlag, Rebecca; Nyasulu, Frazier

    2011-01-01

    The empirical formulas of four cupric hydrates are determined by measuring the absorbance in aqueous solution. The Beer-Lambert Law is verified by constructing a calibration curve of absorbance versus known Cu[superscript 2+](aq) concentration. A solution of the unknown hydrate is prepared by using 0.2-0.3 g of hydrate, and water is added such…

  5. Electromagnetic property of SiO2-coated carbonyl iron/polyimide composites as heat resistant microwave absorbing materials

    NASA Astrophysics Data System (ADS)

    Wang, Hongyu; Zhu, Dongmei; Zhou, Wancheng; Luo, Fa

    2015-02-01

    Heat resistant microwave absorbing materials were prepared by compression molding method, using polyimide resin as matrix and SiO2 coated carbonyl iron (CI) as filler. The SiO2 coated CI particles were prepared by Stober process. The microwave absorbing properties and the effect of heat treatment on the electromagnetic properties of SiO2 coated CI/polyimide composites were investigated. When the content of SiO2 coated CI is 60 wt%, the value of minimum reflection loss decreases from -25 dB to -33 dB with the thickness increases from 1.5 mm to 2.1 mm. According to the thermal-gravimetric analyses (TGA) curves, the polyimide matrix can be used at 300 °C for long time. The complex permittivity of the composites slightly increases while the complex permeability almost keeps constant after heat treatment at 300 °C for 10 h, which indicating that the composites can be used at elevated temperature as microwave absorbing materials at the same time have good heat resistance and microwave absorption.

  6. Enhanced spatial near-infrared modulation of graphene-loaded perfect absorbers using plasmonic nanoslits.

    PubMed

    Cai, Yijun; Zhu, Jinfeng; Liu, Qing Huo; Lin, Timothy; Zhou, Jianyang; Ye, Longfang; Cai, Zhiping

    2015-12-14

    Modulating spatial near-infrared light for ultra-compact electro-optic devices is a critical issue in optical communication and imaging applications. To date, spatial near-infrared modulators based on graphene have been reported, but they showed limited modulation effects due to the relatively weak light-graphene interaction. In combination with graphene and metallic nanoslits, we design a kind of ultrathin near-infrared perfect absorber with enhanced spatial modulation effects and independence on a wide range of incident angles. The modulated spectral shift of central wavelength is up to 258.2 nm in the near-infrared range, which is more promising in applications than state-of-the-art devices. The modulation enhancement is attributed to the plasmonic nanoslit mode, in which the optical electric field is highly concentrated in the deep subwavelength scale and the light-graphene interaction is significantly strengthened. The physical insight is deeply revealed by a combination of equivalent circuit and electromagnetic field analysis. The design principles are not only crucial for spatial near-infrared modulators, but also provide a key guide for developing active near-infrared patch nanoantennas based on graphene.

  7. Experimental validation of a magnetorheological energy absorber design optimized for shock and impact loads

    NASA Astrophysics Data System (ADS)

    Singh, Harinder J.; Hu, Wei; Wereley, Norman M.; Glass, William

    2014-12-01

    A linear stroke adaptive magnetorheological energy absorber (MREA) was designed, fabricated and tested for intense impact conditions with piston velocities up to 8 m s-1. The performance of the MREA was characterized using dynamic range, which is defined as the ratio of maximum on-state MREA force to the off-state MREA force. Design optimization techniques were employed in order to maximize the dynamic range at high impact velocities such that MREA maintained good control authority. Geometrical parameters of the MREA were optimized by evaluating MREA performance on the basis of a Bingham-plastic analysis incorporating minor losses (BPM analysis). Computational fluid dynamics and magnetic FE analysis were conducted to verify the performance of passive and controllable MREA force, respectively. Subsequently, high-speed drop testing (0-4.5 m s-1 at 0 A) was conducted for quantitative comparison with the numerical simulations. Refinements to the nonlinear BPM analysis were carried out to improve prediction of MREA performance.

  8. Synchrotron Heating by a Fast Radio Burst in a Self-absorbed Synchrotron Nebula and Its Observational Signature

    NASA Astrophysics Data System (ADS)

    Yang, Yuan-Pei; Zhang, Bing; Dai, Zi-Gao

    2016-03-01

    Fast radio bursts (FRBs) are mysterious transient sources. If extragalactic, as suggested by their relative large dispersion measures, their brightness temperatures must be extremely high. Some FRB models (e.g., young pulsar model, magnetar giant flare model, or supra-massive neutron star collapse model) suggest that they may be associated with a synchrotron nebula. Here we study a synchrotron-heating process by an FRB in a self-absorbed synchrotron nebula. If the FRB frequency is below the synchrotron self-absorption frequency of the nebula, electrons in the nebula would absorb FRB photons, leading to a harder electron spectrum and enhanced self-absorbed synchrotron emission. In the meantime, the FRB flux is absorbed by the nebula electrons. We calculate the spectra of FRB-heated synchrotron nebulae, and show that the nebula spectra would show a significant hump in several decades near the self-absorption frequency. Identifying such a spectral feature would reveal an embedded FRB in a synchrotron nebula.

  9. Simulation and performance analysis of an ammonia-water absorption heat pump based on the generator-absorber heat exchange (GAX) cycle

    SciTech Connect

    Grossman, G.; DeVault, R.C.; Creswick, F.A.

    1995-02-01

    A computer simulation has been conducted to investigate the performance of an absorption heat pump, based on the Generator-Absorber Heat Exchange (GAX) cycle employing ammonia-water as the working fluid pair. The particular feature of this cycle is the ability to recover heat from the absorber and employ it to partially heat the generator, thus improving the COP. In the present study, a detailed simulation has been conducted of one of the preferred configurations for the cycle. A modular computer code for flexible simulation of absorption systems (ABSIM) was employed. Performance parameters, including COP and capacity, were investigated as functions of different operating parameters over a wide range of conditions in both the cooling and heating mode. The effect of the ambient temperature, the rectifier performance, the flowrate in the GAX heat transfer loop and the refrigerant flow control were investigated. COP`s on the order of 1.0 for cooling and 2.0 for heating have been calculated.

  10. 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.

  11. 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.

  12. Particle transport and heat loads in NIO1.

    PubMed

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

    2016-02-01

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

  13. Particle transport and heat loads in NIO1.

    PubMed

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

    2016-02-01

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

  14. 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.

  15. 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

  16. 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).

  17. Heat load characteristics and new design using one-coil model superconducting magnets

    NASA Astrophysics Data System (ADS)

    Jizo, Yoshihiro; Akagi, Hidenari; Yamaguchi, Takashi; Terai, Motoaki; Shinobu, Masatoshi

    Superconducting magnets (SCM) for Maglev trains are vibrated by the electromagnetic force arising from the magnetic field of higher harmonics, which is due to the arrangement of the ground coils. The heat load within the liquid helium temperature region increases by the vibration of the magnets. This paper reports a heat load generation estimation mechanism due to the above-mentioned vibration, as well as effective measures of reducing heat load generation. In addition, we show how a one-coil type SCM can reduce the heat load generation in electromagnetic disturbance tests.

  18. 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)

  19. The effect of using a heat recovery absorber on the performance and operating cost of the solar ammonia absorption cycles

    SciTech Connect

    Saghiruddin; Siddiqui, M.A.

    1997-02-01

    Economic analysis of ordinary and evacuated tubular type flat-plate collectors have been carried out for operating absorption cycles with and without heat recovery absorber. Water-ammonia, NaSCN-NH{sub 3} and LiNO{sub 3}-NH{sub 3} have been selected as the working fluids in the cycles. Use of a heat recovery absorber, in addition to the primary absorber in the conventional absorption cycles, lead to improvement in the system performances by about 20--30% in the H{sub 2}O-NH{sub 3} and 33--36% in the NaSCN-NH{sub 3} and LiNO{sub 3}-NH{sub 3} mixtures. Subsequently, there is a considerable amount of reduction in the cost of the solar collector required to operate them. For the set of operating conditions, in this theoretical study, the cost reduces to about 25% in the H{sub 2}O-NH{sub 3} and 30% in the NaSCN and LiNO{sub 3}-NH{sub 3} cycles.

  20. Heat localization for targeted tumor treatment with nanoscale near-infrared radiation absorbers.

    PubMed

    Xie, Bin; Singh, Ravi; Torti, F M; Keblinski, Pawel; Torti, Suzy

    2012-09-21

    Focusing heat delivery while minimizing collateral damage to normal tissues is essential for successful nanoparticle-mediated laser-induced thermal cancer therapy. We present thermal maps obtained via magnetic resonance imaging characterizing laser heating of a phantom tissue containing a multiwalled carbon nanotube inclusion. The data demonstrate that heating continuously over tens of seconds leads to poor localization (∼ 0.5 cm) of the elevated temperature region. By contrast, for the same energy input, heat localization can be reduced to the millimeter rather than centimeter range by increasing the laser power and shortening the pulse duration. The experimental data can be well understood within a simple diffusive heat conduction model. Analysis of the model indicates that to achieve 1 mm or better resolution, heating pulses of ∼2 s or less need to be used with appropriately higher heating power. Modeling these data using a diffusive heat conduction analysis predicts parameters for optimal targeted delivery of heat for ablative therapy.

  1. Heat localization for targeted tumor treatment with nanoscale near-infrared radiation absorbers

    NASA Astrophysics Data System (ADS)

    Xie, Bin; Singh, Ravi; Torti, F. M.; Keblinski, Pawel; Torti, Suzy

    2012-09-01

    Focusing heat delivery while minimizing collateral damage to normal tissues is essential for successful nanoparticle-mediated laser-induced thermal cancer therapy. We present thermal maps obtained via magnetic resonance imaging characterizing laser heating of a phantom tissue containing a multiwalled carbon nanotube inclusion. The data demonstrate that heating continuously over tens of seconds leads to poor localization (∼ 0.5 cm) of the elevated temperature region. By contrast, for the same energy input, heat localization can be reduced to the millimeter rather than centimeter range by increasing the laser power and shortening the pulse duration. The experimental data can be well understood within a simple diffusive heat conduction model. Analysis of the model indicates that to achieve 1 mm or better resolution, heating pulses of ∼2 s or less need to be used with appropriately higher heating power. Modeling these data using a diffusive heat conduction analysis predicts parameters for optimal targeted delivery of heat for ablative therapy.

  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. Sound Absorbers

    NASA Astrophysics Data System (ADS)

    Fuchs, H. V.; Möser, M.

    Sound absorption indicates the transformation of sound energy into heat. It is, for instance, employed to design the acoustics in rooms. The noise emitted by machinery and plants shall be reduced before arriving at a workplace; auditoria such as lecture rooms or concert halls require a certain reverberation time. Such design goals are realised by installing absorbing components at the walls with well-defined absorption characteristics, which are adjusted for corresponding demands. Sound absorbers also play an important role in acoustic capsules, ducts and screens to avoid sound immission from noise intensive environments into the neighbourhood.

  4. 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.

  5. 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.

  6. Study and characterization of porous copper oxide produced by electrochemical anodization for radiometric heat absorber.

    PubMed

    Ben Salem, Sonia; Achour, Zahra Ben; Thamri, Kamel; Touayar, Oualid

    2014-01-01

    The aim of this work is to optimize the different parameters for realization of an absorbing cavity to measure the incident absolute laser energy. Electrochemical oxidation is the background process that allowed the copper blackening. A study of the blackened surface quality was undertaken using atomic force microscopy (AFM) analysis and ultraviolet-visible-infrared spectrophotometry using a Shimadzu spectrophotometer. A two-dimensional and three-dimensional visualization by AFM of the formed oxide coating showed that the copper surfaces became porous after electrochemical etching with different roughness. This aspect is becoming more and more important with decreasing current density anodization. In a 2 mol L(-1) of NaOH solution, at a temperature of 90°C, and using a 16 mA cm(2) constant density current, the copper oxide formed has a reflectivity of around 3% in the spectral range between 300 and 1,800 nm. Using the 'mirage effect' technique, the obtained Cu2O diffusivity and thermal conductivity are respectively equal to (11.5 ± 0.5) 10 to 7 m(2) s(-1) and (370 ± 20) Wm(-1) K(-1). This allows us to consider that our Cu2O coating is a good thermal conductor. The results of the optical and thermal studies dictate the choice of the cavity design. The absorbing cavity is a hollow cylinder machined to its base at an angle of 30°. If the included angle of the plane is 30° and the interior surface gives specular reflection, an incoming ray parallel to the axis will undergo five reflections before exit. So the absorption of the surface becomes closely near 0.999999. PMID:25349555

  7. Study and characterization of porous copper oxide produced by electrochemical anodization for radiometric heat absorber

    NASA Astrophysics Data System (ADS)

    Ben Salem, Sonia; Achour, Zahra Ben; Thamri, Kamel; Touayar, Oualid

    2014-10-01

    The aim of this work is to optimize the different parameters for realization of an absorbing cavity to measure the incident absolute laser energy. Electrochemical oxidation is the background process that allowed the copper blackening. A study of the blackened surface quality was undertaken using atomic force microscopy (AFM) analysis and ultraviolet-visible-infrared spectrophotometry using a Shimadzu spectrophotometer. A two-dimensional and three-dimensional visualization by AFM of the formed oxide coating showed that the copper surfaces became porous after electrochemical etching with different roughness. This aspect is becoming more and more important with decreasing current density anodization. In a 2 mol L -1 of NaOH solution, at a temperature of 90°C, and using a 16 mA cm2 constant density current, the copper oxide formed has a reflectivity of around 3% in the spectral range between 300 and 1,800 nm. Using the `mirage effect' technique, the obtained Cu2O diffusivity and thermal conductivity are respectively equal to (11.5 ± 0.5) 10 to 7 m2 s-1 and (370 ± 20) Wm-1 K-1. This allows us to consider that our Cu2O coating is a good thermal conductor. The results of the optical and thermal studies dictate the choice of the cavity design. The absorbing cavity is a hollow cylinder machined to its base at an angle of 30°. If the included angle of the plane is 30° and the interior surface gives specular reflection, an incoming ray parallel to the axis will undergo five reflections before exit. So the absorption of the surface becomes closely near 0.999999.

  8. 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.; 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.

  9. 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.

  10. Relations for local radiative heat transfer between rectangular boundaries of an absorbing-emitting medium

    NASA Technical Reports Server (NTRS)

    Siegel, R.

    1993-01-01

    An analytical solution was obtained by Siegel (1991, 1992) for local boundary heat fluxes by a radiating medium at uniform temperature in a 2D rectangular region. It is shown here that, after local fluxes from the medium to the walls have been evaluated, it is very easy to compute local fluxes arriving from the adjacent and opposite walls. This extends the previous analysis and provides convenient relations to include radiation from a black boundary, each side of the rectangle being at a different uniform temperature. The final expressions are helpful in performing spectral calculations that must be made for many spectral bands.

  11. 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.

  12. 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.

  13. 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.

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

    PubMed

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

    2016-01-01

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

  15. 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

  16. 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)

  17. A system for controlling the boiler heat load

    NASA Astrophysics Data System (ADS)

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

    2013-02-01

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

  18. Preliminary Investigation of the Heat Shock Resistant Properties of Molybdenum Disilicide Blades Under Centrifugal Load

    NASA Technical Reports Server (NTRS)

    Long, Roger A; Frenche, John C

    1952-01-01

    An investigation to determine the heat-shock resistant properties of two molybdenum disilicide turbine blades under centrifugal loads imposed by turbine rotation is presented. Molybdenum disilicide turbine blades fabricated by hot-pressing techniques withstood heat-shock conditions under blade centrifugal stresses up to 5350 pounds per square inch. Additional development is required before the heat-shock resistant properties of molybdenum disilicide are satisfactory for turbine-blade application.

  19. At what level of heat load are age-related impairments in the ability to dissipate heat evident in females?

    PubMed

    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.

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

    SciTech Connect

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

    2009-11-01

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

  1. 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.

  2. Effects of the South Asian Absorbing Haze on the Northeast Monsoon and Surface-Air Heat Exchange.

    NASA Astrophysics Data System (ADS)

    Chung, Chul Eddy; Ramanathan, V.; Kiehl, Jeffrey T.

    2002-09-01

    The effects of the south Asian haze on the regional climate are assessed using the National Center for Atmospheric Research Community Climate Model version 3 (CCM3) at the T42/L18 resolution. This haze, as documented during the Indian Ocean Experiment (INDOEX) campaign (1995-2000), consists mainly of anthropogenic aerosols, and spans over most of south Asia and the north Indian Ocean. It reduces the net solar flux at the surface by as much as 20-40 W m2 on a monthly mean basis and heats the lowest 3-km atmosphere by as much as 0.4-0.8 K day1, which enhances the solar heating of this layer by 50%-100%. This widespread haze layer is a seasonal phenomenon limited to the dry period between November and May.The imposed haze radiative forcing leads to several large and statistically significant climate changes during the dry monsoon season, which include cooling of the land surface, and warming of the atmosphere. These temperature change features lead to the stabilization of the boundary layer that results in a reduction of evaporation and sensible heat flux from the land. The dynamical response to the aerosol forcing is surprisingly large. The aerosol forcing weakens the north-south temperature gradient in the lower level, which results in an enhancement of the area mean low-level convergence and a northward shift of the ITCZ. The increase in low-level convergence leads to increased convective rainfall and latent heat release, which in turn leads to a further increase in low-level convergence. This positive feedback between the low-level convergence and deep convective heating increases the average precipitation over the haze area by as much as 20%. The ocean surface undergoes a suppression of evaporation. Because of this decreased evaporation accompanied by the increase in the haze-area precipitation, the precipitation over the rest of the Tropics decreases, with a large fraction of this decrease concentrated over the Indonesian and the western Pacific warm pool region

  3. 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.

  4. 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.

  5. 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. __________________________________________________

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

    NASA Astrophysics Data System (ADS)

    McClurg, Jack Albert

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

  7. 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.

  8. 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.

  9. Heat load tests of superconducting magnets vibrated electromagnetically for the Maglev train

    NASA Astrophysics Data System (ADS)

    Ohmori, J.; Nakao, H.; Yamashita, T.; Sanada, Y.; Shudou, M.; Kawai, M.; Fujita, M.; Terai, M.; Miura, A.

    Superconducting magnets on Maglev trains vibrate due to harmonic ripples of electromagnetic flux generated by ground coils. Heat load caused by vibration in the magnet amounted to several tens of watts in the electromagnetic vibration test. This was mainly because a.c. loss was induced in the helium vessel housing the superconducting coil, due to relative vibration between the aluminium thermal shield and the coil. The heat load caused by vibration should be strictly restricted to less than 4W due to limited cryogenic refrigeration capacity. The heat load was tested using electromagnetic flux ripples for a superconducting magnet model of one coil which corresponds to 1/4 of an actual magnet. The flux ripples simulated the 6th harmonic of the actual ground levitation coil. Some ideas to reduce the heat load were tried for the magnet model, such as applying high resistance thermal radiation shielding, increasing rigidity of the vacuum vessel, and using high purity copper plating on the helium vessel. These ideas proved effective, and the maximum heat load due to vibration was held to less than 4 W per magnet for the one coil magnet model.

  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. Biaxial Mechanical Evaluation of Absorbable and Nonabsorbable Synthetic Surgical Meshes Used for Hernia Repair: Physiological Loads Modify Anisotropy Response.

    PubMed

    Cordero, A; Hernández-Gascón, B; Pascual, G; Bellón, J M; Calvo, B; Peña, E

    2016-07-01

    The aim of this study was to obtain information about the mechanical properties of six meshes commonly used for hernia repair (Surgipro(®), Optilene(®), Infinit(®), DynaMesh(®), Ultrapro™ and TIGR(®)) by planar biaxial tests. Stress-stretch behavior and equibiaxial stiffness were evaluated, and the anisotropy was determined by testing. In particular, equibiaxial test (equal simultaneous loading in both directions) and biaxial test (half of the load in one direction following the Laplace law) were selected as a representation of physiologically relevant loads. The majority of the meshes displayed values in the range of 8 and 18 (N/mm) in each direction for equibiaxial stiffness (tangent modulus under equibiaxial load state in both directions), while a few achieved 28 and 50 (N/mm) (Infinit (®) and TIGR (®)). Only the Surgipro (®) mesh exhibited planar isotropy, with similar mechanical properties regardless of the direction of loading, and an anisotropy ratio of 1.18. Optilene (®), DynaMesh (®), Ultrapro (®) and TIGR (®) exhibited moderate anisotropy with ratios of 1.82, 1.84, 2.17 and 1.47, respectively. The Infinit (®) scaffold exhibited very high anisotropy with a ratio of 3.37. These trends in material anisotropic response changed during the physiological state in the human abdominal wall, i.e. T:0.5T test, which the meshes were loaded in one direction with half the load used in the other direction. The Surgipro (®) mesh increased its anisotropic response (Anis[Formula: see text] = 0.478) and the materials that demonstrated moderate and high anisotropic responses during multiaxial testing presented a quasi-isotropic response, especially the Infinit(®) mesh that decreased its anisotropic response from 3.369 to 1.292. PMID:26620778

  12. Biaxial Mechanical Evaluation of Absorbable and Nonabsorbable Synthetic Surgical Meshes Used for Hernia Repair: Physiological Loads Modify Anisotropy Response.

    PubMed

    Cordero, A; Hernández-Gascón, B; Pascual, G; Bellón, J M; Calvo, B; Peña, E

    2016-07-01

    The aim of this study was to obtain information about the mechanical properties of six meshes commonly used for hernia repair (Surgipro(®), Optilene(®), Infinit(®), DynaMesh(®), Ultrapro™ and TIGR(®)) by planar biaxial tests. Stress-stretch behavior and equibiaxial stiffness were evaluated, and the anisotropy was determined by testing. In particular, equibiaxial test (equal simultaneous loading in both directions) and biaxial test (half of the load in one direction following the Laplace law) were selected as a representation of physiologically relevant loads. The majority of the meshes displayed values in the range of 8 and 18 (N/mm) in each direction for equibiaxial stiffness (tangent modulus under equibiaxial load state in both directions), while a few achieved 28 and 50 (N/mm) (Infinit (®) and TIGR (®)). Only the Surgipro (®) mesh exhibited planar isotropy, with similar mechanical properties regardless of the direction of loading, and an anisotropy ratio of 1.18. Optilene (®), DynaMesh (®), Ultrapro (®) and TIGR (®) exhibited moderate anisotropy with ratios of 1.82, 1.84, 2.17 and 1.47, respectively. The Infinit (®) scaffold exhibited very high anisotropy with a ratio of 3.37. These trends in material anisotropic response changed during the physiological state in the human abdominal wall, i.e. T:0.5T test, which the meshes were loaded in one direction with half the load used in the other direction. The Surgipro (®) mesh increased its anisotropic response (Anis[Formula: see text] = 0.478) and the materials that demonstrated moderate and high anisotropic responses during multiaxial testing presented a quasi-isotropic response, especially the Infinit(®) mesh that decreased its anisotropic response from 3.369 to 1.292.

  13. FEM study of recrystallized tungsten under ELM-like heat loads

    NASA Astrophysics Data System (ADS)

    Du, J.; Yuan, Y.; Wirtz, M.; Linke, J.; Liu, W.; Greuner, H.

    2015-08-01

    FEM thermal analysis has been performed on rolled tungsten plate loaded with heat load of 23 MW/m2 for 1.5 s. Gradient temperature field is generated due to the Gaussian shape beam profile. Recrystallization and grain growth of various scales were found at different areas of the sample depending on the localized thermal field. FEM thermal-mechanical analyses have been performed on the recrystallized tungsten exposed to ELMs-like heat loads. The analyzed load conditions were 0.38 and 1.14 GW/m2 with different base temperatures. Material deterioration due to recrystallization was implemented by adopting decreased yield stress, tangent modulus, strength coefficient and ductility coefficients. Life time predicted by adopting strain life criterion indicates grain growth from 5 μm to 100 μm causes the life decrease of 80%. This result is gained by pure mathematical calculation based on the empiric assumptions of material properties.

  14. A 31 mW, 280 fs passively mode-locked fiber soliton laser using a high heat-resistant SWNT/P3HT saturable absorber coated with siloxane.

    PubMed

    Ono, Takato; Hori, Yuichiro; Yoshida, Masato; Hirooka, Toshihiko; Nakazawa, Masataka; Mata, Junji; Tsukamoto, Jun

    2012-10-01

    We report a substantial increase in the heat resistance in a connector-type single-wall carbon nanotube (SWNT) saturable absorber by sealing SWNT/P3HT composite with siloxane. By applying the saturable absorber to a passively mode-locked Er fiber laser, we successfully demonstrated 280 fs, 31 mW pulse generation with a fivefold improvement in heat resistance.

  15. 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

  16. 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.

  17. Mixed double-diffusive convection in gas-loaded heat pipes

    SciTech Connect

    Peterson, P.F. ); Tien, C.L. )

    1990-02-01

    This study examines mixed double-diffusive convection in gas-loaded heat pipes and two-phase thermosyphons. The numerical simulation and experiments show that steady, laminar natural convection due to the combined effects of temperature and concentration gradients can greatly redistribute the noncondensable gas within the condenser. This change of the gas distribution, however, does not significantly alter the overall condensation heat transfer. This interesting result implies that even with natural convection present, much simpler integral models can still be applied with confidence for the design of variable-conductance heat pipes and thermosyphons.

  18. 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.

  19. 24 CFR 3280.508 - Heat loss, heat gain and cooling load calculations.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ....18Mechanical and Industrial Systems 25.19Commercial Building Envelope Leakage 27.9Calculation of Heat Loss from... generally accepted engineering practices. The general requirement is to demonstrate that the home...

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

    NASA Astrophysics Data System (ADS)

    Nikitkin, Michael N.; Allen, Robert W.

    2005-02-01

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

  1. 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.

  2. 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.

  3. Experimental temperature distribution and heat load characteristics of rotating heat pipes

    NASA Technical Reports Server (NTRS)

    Daniels, T. C.; Williams, R. J.

    1978-01-01

    Experimental results show conclusively that the presence of a small quantity of a noncondensable gas (NCG) mixed with the working fluid has a considerable effect on the condensation process in a rotating heat pipe. The temperature distribution in the condenser shows the blanketing effect of the NCG and the ratio of the molecular weight of the working fluid to that of the NCG has a very definite effect on the shape of this distribution. Some of the effects are quite similar to the well-established data on stationary heat pipes.

  4. 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.

  5. 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.

  6. 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.

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

    DOEpatents

    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.

  8. Internal absorber solar collector

    DOEpatents

    Sletten, Carlyle J.; Herskovitz, Sheldon B.; Holt, F. S.; Sletten, E. J.

    1981-01-01

    Thin solar collecting panels are described made from arrays of small rod collectors consisting of a refracting dielectric rod lens with an absorber imbedded within it and a reflecting mirror coated on the back side of the dielectric rod. Non-tracking collector panels on vertical walls or roof tops receive approximately 90% of solar radiation within an acceptance zone 60.degree. in elevation angle by 120.degree. or more in the azimuth sectors with a collector concentration ratio of approximately 3.0. Miniaturized construction of the circular dielectric rods with internal absorbers reduces the weight per area of glass, plastic and metal used in the collector panels. No external parts or insulation are needed as heat losses are low due to partial vacuum or low conductivity gas surrounding heated portions of the collector. The miniature internal absorbers are generally made of solid copper with black selective surface and the collected solar heat is extracted at the collector ends by thermal conductivity along the absorber rods. Heat is removed from end fittings by use of liquid circulants. Several alternate constructions are provided for simplifying collector panel fabrication and for preventing the thermal expansion and contraction of the heated absorber or circulant tubes from damaging vacuum seals. In a modified version of the internal absorber collector, oil with temperature dependent viscosity is pumped through a segmented absorber which is now composed of closely spaced insulated metal tubes. In this way the circulant is automatically diverted through heated portions of the absorber giving higher collector concentration ratios than theoretically possible for an unsegmented absorber.

  9. ITER-relevant transient heat loads on tungsten exposed to plasma and beryllium

    NASA Astrophysics Data System (ADS)

    Yu, J. H.; Doerner, R. P.; Dittmar, T.; Höschen, T.; Schwarz-Selinger, T.; Baldwin, M. J.

    2014-04-01

    Tungsten (W) is presently the most attractive plasma facing material for future fusion reactors. Off-normal transient events such as edge localized modes and disruptions are simulated with a pulsed laser system in the PISCES-B facility, providing pulses with 1-10 ms duration with absorbed heat flux factors up to ˜90 MJ m-2 s-1/2. This paper characterizes surface morphology changes and damage thresholds under transient heating on W exposed to He plasma or D plasma with and without Be coatings. W is damaged in the form of grain growth, surface roughening, melting and cracking. With a Be coating on the order of μm thick, the laser pulse produces a variety of Be surface changes including Be-W alloying, vaporization of the Be layer, melting and delamination.

  10. 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.

  11. 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.

  12. 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.

  13. Methods for absorbing neutrons

    DOEpatents

    Guillen, Donna P.; Longhurst, Glen R.; Porter, Douglas L.; Parry, James R.

    2012-07-24

    A conduction cooled neutron absorber may include a metal matrix composite that comprises a metal having a thermal neutron cross-section of at least about 50 barns and a metal having a thermal conductivity of at least about 1 W/cmK. Apparatus for providing a neutron flux having a high fast-to-thermal neutron ratio may include a source of neutrons that produces fast neutrons and thermal neutrons. A neutron absorber positioned adjacent the neutron source absorbs at least some of the thermal neutrons so that a region adjacent the neutron absorber has a fast-to-thermal neutron ratio of at least about 15. A coolant in thermal contact with the neutron absorber removes heat from the neutron absorber.

  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

    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.

  16. 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.

  17. 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.

  18. 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.

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

    SciTech Connect

    Rogers, C.S.

    1993-07-01

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

  20. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2009-11-01

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

  2. Oligonol supplementation affects leukocyte and immune cell counts after heat loading in humans.

    PubMed

    Lee, Jeong Beom; Shin, Young Oh

    2014-06-24

    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. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2009-07-01

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

  5. 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

  6. 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.

  7. 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.

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

    PubMed

    Luczak; Kurkus-Rozowska; Sobolewski

    1995-01-01

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

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

    SciTech Connect

    Schmerge, J.

    2005-01-31

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

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

    NASA Astrophysics Data System (ADS)

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

    2014-11-01

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

  11. 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

  12. 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.

  13. 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.

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

    PubMed

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

    2015-01-01

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

  15. Numerical heat transfer study in a scattering, absorbing and emitting semi-transparent porous medium in a cylindrical enclosure

    NASA Astrophysics Data System (ADS)

    Timoumi, M.; Chérif, B.; Sifaoui, M. S.

    2005-12-01

    In this paper, heat transfer problem through a semi-transparent porous medium in a cylindrical enclosure is investigated. The governing equations for this problem and the boundary conditions are non-linear differential equations depending on the dimensionless radial coordinate, Planck number N, scattering albedo ω, walls emissivity and thermal conductivity ratio kr. The set of differential equations are solved by a numerical technique taken from the IMSL MATH/LIBRARY. Various results are obtained for the dimensionless temperature profiles in the solid and fluid phases and the radiative heat flux. The effects of some radiative properties of the medium on the heat transfer rate are examined.

  16. Growth of micro-crystals in solution by in-situ heating via continuous wave infrared laser light and an absorber

    NASA Astrophysics Data System (ADS)

    Pathak, Shashank; Dharmadhikari, Jayashree A.; Thamizhavel, A.; Mathur, Deepak; Dharmadhikari, Aditya K.

    2016-01-01

    We report on growth of micro-crystals such as sodium chloride (NaCl), copper sulphate (CuSO4), potassium di-hydrogen phosphate (KDP) and glycine (NH2CH2COOH) in solution by in-situ heating using continuous wave Nd:YVO4 laser light. Crystals are grown by adding single walled carbon nanotubes (SWNT). The SWNTs absorb 1064 nm light and act as an in-situ heat source that vaporizes the solvent producing microcrystals. The temporal dynamics of micro-crystal growth is investigated by varying experimental parameters such as SWNT bundle size and incident laser power. We also report crystal growth without SWNT in an absorbing medium: copper sulphate in water. Even though the growth dynamics with SWNT and copper sulphate are significantly different, our results indicate that bubble formation is necessary for nucleation. Our simple method may open up new vistas for rapid growth of seed crystals especially for examining the crystallizability of inorganic and organic materials.

  17. An investigation on the effect of varying the load, mesh and simulation parameters in microwave heating applications.

    PubMed

    Ehlers, Richard A; Metaxas, Ricky A C

    2007-01-01

    The paper attempts to provide a generic proposal on the influence of various microwave load parameters based on results accumulated during an investigation using a specific microwave multimode heating cavity configuration. The results have been obtained by numerical analysis using the Finite Element Method within a 3-D environment. The load parameters considered were dielectric constant, loss factor, load thickness and load position. Load material properties are typical of those used in industrial relevant applications. Of the four load parameters investigated, the configuration with a high loss factor was seen to dominate the load impact regardless of load thickness, load position or dielectric constant. With decreasing loss factor or increasing load thickness, the influence of the dielectric constant increases. Minor adjustments in the load position (10%) is generally seen to have minimal impact for all load properties considered. The paper also investigates the numerical impact of varying load properties. As the dielectric constant increases, which requires a higher number of mesh elements, so does the average iterations per numerical cycle. The number of numerical cycles and time to reach a convergence is also seen to be inversely proportional to the load loss factor.

  18. Inner cladding influence on large mode area photonic crystal fiber properties under severe heat load

    NASA Astrophysics Data System (ADS)

    Coscelli, Enrico; Poli, Federica; Dauliat, Romain; Darwich, Dia; Cucinotta, Annamaria; Selleri, Stefano; Schuster, Kay; Benoît, Aurélien; Jamier, Raphael; Roy, Philippe

    2016-03-01

    Constant innovations of fiber technology over the last twenty years has fueled a huge improvement of the performances of fiber lasers. Further power scaling of fiber lasers is currently hindered by the phenomenon of transverse mode instabilities, a sudden deterioration of output beam quality occurring beyond a certain power threshold due to energy transfer from the fiber fundamental mode to high-order modes. Several studies have pinpointed a thermal origin for this phenomenon. A possible solution is to implement fiber designs capable of providing a robust single-mode operation even under severe heat load, in order to prevent such coupling. In this paper the effects on the propagating modes of the change of the inner cladding size and microstructuration in double-cladding photonic crystal fibers under heating condition are discussed, and related to field confinement and single-mode regime.

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

    SciTech Connect

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

    2004-05-12

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

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

    NASA Astrophysics Data System (ADS)

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

    2014-04-01

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

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. Characterization of the heat loading of Nd-doped YAG, YOS, YLF, and GGG excited at diode pumping wavelengths

    SciTech Connect

    Comaskey, B.; Moran, B.D.; Albrecht, G.F.; Beach, R.J.

    1995-07-01

    The parameter {xi} (xi) is proposed as an alternate to the traditional solid-state laser media heating parameter, {chi} (chi). {xi} is the ratio of heat produced to energy absorbed, and {chi} is the ratio of heat produced to the maximum stored energy in the upper laser level. The parameter {xi} is particularly relevant to diode pumped systems. The authors demonstrate an experimental {xi} characterization based on the determination of the steady state cooling rate (hence heating rate) of small sample crystals subjected to pump laser heating. Using measured fluorescent lifetimes of the samples and near zero doping (intrinsic) values, the doping independent (zero doping or zero quenching) parameters {xi}{phi} and {xi}{phi} are determined. The results for all samples are in excellent agreement with calculations based solely on energy defect and nonradiative quenching of the upper level.

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

    NASA Astrophysics Data System (ADS)

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

    2012-10-01

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

  9. 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).

  10. 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).

  11. Metal-shearing energy absorber

    NASA Technical Reports Server (NTRS)

    Fay, R. J.; Wittrock, E. P.

    1971-01-01

    Device, consisting of tongue of thin aluminum alloy strip, pull tab, slotted steel plate which serves as cutter, and steel buckle, absorbs mechanical energy when its ends are subjected to tensile loading. Device is applicable as auxiliary shock absorbing anchor for automobile and airplane safety belts.

  12. 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.

  13. 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

  14. MIC mitigation in a 100 MW district heating peak load unit.

    PubMed

    Olesen, B H; Lorenzen, J; Kjellerup, B V; Odum, S; Nielsen, P H; Frølund, B

    2004-01-01

    During inspection of AISI316 stainless steel plate heat exchangers in a district heating peak load unit, localised corrosion attacks along with indications of microbiological activity were found on the boiler side beneath patches of sturdy black deposits. Bacteria and sulphide were detected within black deposits. Thorough investigation of the boiler system revealed several incidents of localised corrosion on low alloy steel along with deposits of organic matter and bacteria primarily in places with stagnant water or places operating at a low flow rate. A relatively large amount of bacteria was detected within the system, primarily in deposits and around corrosion sites. The observations suggested the combination of deposits and bacterial activity, being the major reason for the observed corrosion. Prior to the investigation, the boiler system had operated with cat-/anion-exchanged, de-aerated water for 3 years, during which the water fulfilled strict chemical limits set to minimise corrosion. Based on these findings, the system has been modified in order to minimise the risk of microbiologically influenced corrosion and a monitoring program for fouling and corrosion has been established.

  15. Study of material response on simulated ITER disruptive plasma heat load with variable duration

    SciTech Connect

    Litunovsky, V.N.; Ovchinnikov, I.B.; Drozdov, A.A.; Kuznetsov, V.E.; Ljublin, B.V.; Titov, V.A.

    1995-12-31

    The damage of divertor elements during off-normal events (disruptions and giant ELMs) will determine sufficiently the life-time of ITER divertor. The strategy of the solution of a problem of the reliable prediction of divertor components disruptive damages is contained in collection of information on both natural disruptions in existing Tokamaks and simulated ones, and also development of codes for modelling of the experiments and divertor life-time damage. Some results of the study of material response on plasma high heat flux load are given in the report. High power long pulse plasma accelerator of VIKA facility is used as source of plasma high heat flux (w{sub p} {le} 30 MJ/m{sup 2}). The peculiarity of described experiments in variation of rectangular like pulse duration of plasma stream ({tau}{sub p} = 0.09; 0.18; 0.27; 0.36 ms). Some data of plasma parameters in a plasma-material interaction zone are given. The growth of both mass losses and crater depth with irradiation increase is fixed for Al and Cu. As a preliminary result one can mark a tendency to decreasing both crack length for hot (T = 300 C) irradiated Al sample and mass losses for W irradiated at T = 1,000 C.

  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. Optimization of a muon collider interaction region with respect to detector backgrounds and the heat load to the cryogenic systems

    SciTech Connect

    Johnstone, C.J.; Mokhov, N.V.

    1996-10-16

    In a 2 X 2 TeV {mu}{sup +}{mu}{sup -} Collider almost 15 MW of power is deposited in the machine and detector components due to the unavoidable {mu}{r_arrow}{ital e{nu}{nu}{anti {nu}}} decays. The resulting heat load to the cryogenic systems and the background levels in the collider detectors significantly exceed those in any existing or designed hadron and {ital e}{sup +}{ital e}{sup -} colliders. This paper shows that by carefully designing the final focus system, by embedding shielding and by taking other protective measures the heat load and backgrounds can be mitigated by several orders of magnitude.

  19. Liquid Cryogen Absorber for MICE

    SciTech Connect

    Baynham, D.E.; Bish, P.; Bradshaw, T.W.; Cummings, M.A.; Green,M.A.; Ishimoto, S.; Ivaniouchenkov, I.; Lau, W.; Yang, S.Q.; Zisman, M.S.

    2005-08-20

    The Muon Ionization Cooling Experiment (MICE) will test ionization cooling of muons. In order to have effective ionization cooling, one must use an absorber that is made from a low-z material. The most effective low z materials for ionization cooling are hydrogen, helium, lithium hydride, lithium and beryllium, in that order. In order to measure the effect of material on cooling, several absorber materials must be used. This report describes a liquid-hydrogen absorber that is within a pair of superconducting focusing solenoids. The absorber must also be suitable for use with liquid helium. The following absorber components are discussed in this report; the absorber body, its heat exchanger, the hydrogen system, and the hydrogen safety. Absorber cooling and the thin windows are not discussed here.

  20. Mechanical energy absorber

    NASA Technical Reports Server (NTRS)

    Wesselski, Clarence J. (Inventor)

    1993-01-01

    An energy absorbing system for controlling the force where a moving object engages a stationary stop and where the system utilized telescopic tubular members, energy absorbing diaphragm elements, force regulating disc springs, and a return spring to return the telescoping member to its start position after stroking is presented. The energy absorbing system has frusto-conical diaphragm elements frictionally engaging the shaft and are opposed by a force regulating set of disc springs. In principle, this force feedback mechanism serves to keep the stroking load at a reasonable level even if the friction coefficient increases greatly. This force feedback device also serves to desensitize the singular and combined effects of manufacturing tolerances, sliding surface wear, temperature changes, dynamic effects, and lubricity.

  1. Countercurrent flow absorber and desorber

    DOEpatents

    Wilkinson, William H.

    1984-01-01

    Countercurrent flow absorber and desorber devices are provided for use in absorption cycle refrigeration systems and thermal boosting systems. The devices have increased residence time and surface area resulting in improved heat and mass transfer characteristics. The apparatuses may be incorporated into open cycle thermal boosting systems in which steam serves both as the refrigerant vapor which is supplied to the absorber section and as the supply of heat to drive the desorber section of the system.

  2. Countercurrent flow absorber and desorber

    DOEpatents

    Wilkinson, W.H.

    1984-10-16

    Countercurrent flow absorber and desorber devices are provided for use in absorption cycle refrigeration systems and thermal boosting systems. The devices have increased residence time and surface area resulting in improved heat and mass transfer characteristics. The apparatuses may be incorporated into open cycle thermal boosting systems in which steam serves both as the refrigerant vapor which is supplied to the absorber section and as the supply of heat to drive the desorber section of the system. 9 figs.

  3. 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.

  4. 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.

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

    PubMed

    Cimino, R; Baglin, V; Schäfers, F

    2015-12-31

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

  6. 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.

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

    PubMed

    Cimino, R; Baglin, V; Schäfers, F

    2015-12-31

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

  8. 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.

  9. 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

  10. High heat load x-ray optics research and development at the Advanced Photon Source -- An overview

    SciTech Connect

    Lee, Wah-Keat; Mills, D.M.

    1993-09-01

    Insertion devices at third generation synchrotron radiation sources such as the APS are capable of producing x-ray beams with total power in excess of 7 kilowatts or power densities of 150 watts/mm{sup 2} at a typical location of the optical components. Optical elements subjected to these types of heat fluxes will suffer considerably unless carefully designed to withstand these unprecedented power loadings. At the Advanced Photon Source (APS), we have an aggressive R&D program aimed at investigating possible methods to mitigate thermal distortions. The approaches being studied include, improved heat exchangers, use of liquid gallium and liquid nitrogen as coolants, novel crystal geometries, power filtering, and replacement of silicon with diamond for crystal monochromators. This paper will provide an overview of the high heat load x-ray optics program at the APS.

  11. 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.

  12. 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.

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

    SciTech Connect

    Lee, Wah-Keat

    1994-12-31

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

  14. Absorbed dose water calorimeter

    SciTech Connect

    Domen, S.R.

    1982-01-26

    An absorbed dose water calorimeter that takes advantage of the low thermal diffusivity of water and the water-imperviousness of polyethylene film. An ultra-small bead thermistor is sandwiched between two thin polyethylene films stretched between insulative supports in a water bath. The polyethylene films insulate the thermistor and its leads, the leads being run out from between the films in insulated sleeving and then to junctions to form a wheatstone bridge circuit. Convection barriers may be provided to reduce the effects of convection from the point of measurement. Controlled heating of different levels in the water bath is accomplished by electrical heater circuits provided for controlling temperature drift and providing adiabatic operation of the calorimeter. The absorbed dose is determined from the known specific heat of water and the measured temperature change.

  15. 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.

  16. Counterflow absorber for an absorption refrigeration system

    DOEpatents

    Reimann, Robert C.

    1984-01-01

    An air-cooled, vertical tube absorber for an absorption refrigeration system is disclosed. Strong absorbent solution is supplied to the top of the absorber and refrigerant vapor is supplied to the bottom of the absorber to create a direct counterflow of refrigerant vapor and absorbent solution in the absorber. The refrigeration system is designed so that the volume flow rate of refrigerant vapor in the tubes of the absorber is sufficient to create a substantially direct counterflow along the entire length of each tube in the absorber. This provides several advantages for the absorber such as higher efficiency and improved heat transfer characteristics, and allows improved purging of non-condensibles from the absorber.

  17. 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. PMID:25943667

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

    SciTech Connect

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

    1996-09-01

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

  19. Thermal analysis of the crotch absorber in APS

    SciTech Connect

    Sheng, I.C.; Howell, J.

    1992-10-01

    A crotch absorber design for use in the Advanced Photon source (APS) has been proposed and analyzed. the absorber is placed downstream of sectors S2 and S4 in the curved storage ring chamber and will be subjected to a peak power of 120 W/mm{sup 2} per 100mA synchrotron radiation. A beryllium ring is brazed on the GlidCop cooling cylinder in order to diffuse the concentrated bending magnet heating. One concentric water channel and two annular return water channels are arranged in the GlidCop cylinder to enhance the cooling. A Bodner-Partom thermoviscoplastic constitutive equation and a modified Manson-Coffin fatigue relation are proposed to simulate the cyclic thermal loading, as well as to predict the thermal fatigue life of the crotch absorber. Results of temperature and stress using finite element computations are displayed and series of e-beam welder tests and microstructure measurements are reported.

  20. Thermal analysis of the crotch absorber in APS

    SciTech Connect

    Sheng, I.C.; Howell, J.

    1992-01-01

    A crotch absorber design for use in the Advanced Photon source (APS) has been proposed and analyzed. the absorber is placed downstream of sectors S2 and S4 in the curved storage ring chamber and will be subjected to a peak power of 120 W/mm{sup 2} per 100mA synchrotron radiation. A beryllium ring is brazed on the GlidCop cooling cylinder in order to diffuse the concentrated bending magnet heating. One concentric water channel and two annular return water channels are arranged in the GlidCop cylinder to enhance the cooling. A Bodner-Partom thermoviscoplastic constitutive equation and a modified Manson-Coffin fatigue relation are proposed to simulate the cyclic thermal loading, as well as to predict the thermal fatigue life of the crotch absorber. Results of temperature and stress using finite element computations are displayed and series of e-beam welder tests and microstructure measurements are reported.

  1. 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.

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

    PubMed

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

    2016-02-01

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

  3. 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.

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

    PubMed

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

    2016-02-01

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

  5. 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.

  6. Electrospun novel super-absorbent based on polysaccharide-polyvinyl alcohol-montmorillonite clay nanocomposites.

    PubMed

    Islam, Md Shahidul; Rahaman, Md Saifur; Yeum, Jeong Hyun

    2015-01-22

    A novel super-absorbent material was fabricated by electrospinning the natural polysaccharide pullulan (PULL) with polyvinyl alcohol (PVA) and montmorillonite (MMT) clay to form nonwoven webs, which were then heat treated. Transmission electron microscopy (TEM) micrographs, X-ray diffraction (XRD) patterns, and Fourier transform infrared (FTIR) analysis of the novel super-absorbent nanofibers suggest the coexistence of PULL, PVA, and MMT through the exfoliation of MMT layers in the super-absorbent nanofiber composite. The heat-treated PULL/PVA/MMT webs loaded with 5 wt% MMT electrospun nanofibers exhibited a water absorbency of 143.42 g g(-1) in distilled water and a water absorbency of 39.75 g g(-1) in a 0.9 wt% NaCl solution. Under extremely dry conditions, the PULL/PVA/MMT webs exhibited the ability to retain 43% distilled water and 38% saline water after being exposed to the atmosphere for one week. The heat treatment improved the crystallinity of the electrospun PULL/PVA/MMT super-absorbent webs and thus made the webs highly stable in aqueous environments. Overall, the addition of MMT resulted in improved thermal stability and mechanical properties and increased the water absorbency of the PULL/PVA/MMT composite. PMID:25439870

  7. Electrospun novel super-absorbent based on polysaccharide-polyvinyl alcohol-montmorillonite clay nanocomposites.

    PubMed

    Islam, Md Shahidul; Rahaman, Md Saifur; Yeum, Jeong Hyun

    2015-01-22

    A novel super-absorbent material was fabricated by electrospinning the natural polysaccharide pullulan (PULL) with polyvinyl alcohol (PVA) and montmorillonite (MMT) clay to form nonwoven webs, which were then heat treated. Transmission electron microscopy (TEM) micrographs, X-ray diffraction (XRD) patterns, and Fourier transform infrared (FTIR) analysis of the novel super-absorbent nanofibers suggest the coexistence of PULL, PVA, and MMT through the exfoliation of MMT layers in the super-absorbent nanofiber composite. The heat-treated PULL/PVA/MMT webs loaded with 5 wt% MMT electrospun nanofibers exhibited a water absorbency of 143.42 g g(-1) in distilled water and a water absorbency of 39.75 g g(-1) in a 0.9 wt% NaCl solution. Under extremely dry conditions, the PULL/PVA/MMT webs exhibited the ability to retain 43% distilled water and 38% saline water after being exposed to the atmosphere for one week. The heat treatment improved the crystallinity of the electrospun PULL/PVA/MMT super-absorbent webs and thus made the webs highly stable in aqueous environments. Overall, the addition of MMT resulted in improved thermal stability and mechanical properties and increased the water absorbency of the PULL/PVA/MMT composite.

  8. Comments on liquid hydrogen absorbers for MICE

    SciTech Connect

    Green, Michael A.

    2003-02-01

    This report describes the heat transfer problems associatedwith a liquid hydrogen absorber for the MICE experiment. This reportdescribes a technique for modeling heat transfer from the outside world,to the abosrber case and in its vacuum vessel, to the hydrogen and theninto helium gas at 14 K. Also presented are the equation for freeconvection cooling of the liquid hydrogen in the absorber.

  9. Influence of carbon black and indium tin oxide absorber particles on laser transmission welding

    NASA Astrophysics Data System (ADS)

    Aden, Mirko; Mamuschkin, Viktor; Olowinsky, Alexander

    2015-06-01

    For laser transmission welding of polypropylene carbon black and indium tin oxide (ITO) are used as absorber particles. Additionally, the colorant titanium dioxide is mixed to the absorbing part, while the transparent part is kept in natural state. The absorption coefficients of ITO and carbon black particles are obtained, as well as the scattering properties of polypropylene loaded with titanium dioxide (TiO2). At similar concentrations the absorption coefficient of ITO is an order of magnitude smaller than that of carbon black. Simulations of radiation propagation show that the penetration depth of laser light is smaller for carbon black. Therefore, the density of the released heat is higher. Adding TiO2 changes the distribution of heat in case of ITO, whereas for carbon black the effect is negligible. Thermal simulations reveal the influence of the two absorbers and TiO2 on the heat affected zone. The results of the thermal simulations are compared to tensile test results.

  10. 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

  11. Heat loads in inboard limited L-mode plasmas in TCV

    NASA Astrophysics Data System (ADS)

    Nespoli, F.; Labit, B.; Furno, I.; Canal, G. P.; Fasoli, A.

    2015-08-01

    Infrared thermography is used in TCV to measure the heat flux deposited onto the graphite tiles of the inner wall. The heat flux radial profile is found to be well described by the sum of a main parallel component and a non negligible cross-field component. The latter accounts for about 20% of the deposited heat flux. The parallel component shows an enhancement around the contact point in all discharges under consideration. Main plasma parameters, such as density, current, elongation and triangularity have been varied, allowing for empirical scalings of the heat fluxes.

  12. A bottom-up engineering estimate of the aggregate heating andcooling loads of the entire U.S. building stock

    SciTech Connect

    Huang, Yu Joe; Brodrick, Jim

    2000-08-01

    A recently completed project for the U.S. Department of Energy's (DOE) Office of Building Equipment combined DOE-2 results for a large set of prototypical commercial and residential buildings with data from the Energy Information Administration (EIA) residential and commercial energy consumption surveys (RECS, CBECS) to estimate the total heating and cooling loads in U.S. buildings attributable to different shell components such as windows, roofs, walls, etc., internal processes, and space-conditioning systems. This information is useful for estimating the national conservation potentials for DOE's research and market transformation activities in building energy efficiency. The prototypical building descriptions and DOE-2 input files were developed from 1986 to 1992 to provide benchmark hourly building loads for the Gas Research Institute (GRI) and include 112 single-family, 66 multi-family, and 481 commercial building prototypes. The DOE study consisted of two distinct tasks : (1) perform DOE-2 simulations for the prototypical buildings and develop methods to extract the heating and cooling loads attributable to the different building components; and (2) estimate the number of buildings or floor area represented by each prototypical building based on EIA survey information. These building stock data were then multiplied by the simulated component loads to derive aggregated totals by region, vintage, and building type. The heating and cooling energy consumption of the national building stock estimated by this bottom-up engineering approach was found to agree reasonably well with estimates from other sources, although significant differences were found for certain end-uses. The main added value from this study, however, is the insight it provides about the contributing factors behind this energy consumption, and what energy savings can be expected from efficiency improvements for different building components by region, vintage, and building type.

  13. Load-deflection characteristics of nickel-titanium alloy wires after clinical recycling and dry heat sterilization.

    PubMed

    Kapila, S; Haugen, J W; Watanabe, L G

    1992-08-01

    The desirable mechanical properties of nickel-titanium alloy wires and their relatively high cost has prompted many clinicians to recycle these wires. Clinical recycling exposes the wires to several weeks or months of mechanical stresses and elements of the oral environment, as well as sterilization between uses. In a previous study it was noted that clinical recycling combined with cold sterilization alters the load-deflection characteristics and surface topography of nickel-titanium wires. Whether similar changes in mechanical properties occur in wires subjected to repeated clinical use and dry heat sterilization is not yet clear. The purpose of this investigation was to determine the effects of in vivo recycling interposed by dry heat sterilization (together referred to as clinical recycling, CR) on the load-deflection characteristics of nickel-titanium alloy wires. To differentiate the effects of dry heat sterilization (DHS) from those of CR on the behavior of these wires, a series of wires were also subjected to DHS only. Two types of nickel-titanium wires, namely Nitinol and NiTi were subjected to a three-point bending test in an as-received condition (T0), after one cycle (T1), and two cycles (T2) of DHS or CR. Ten wires comprised each subsample. Statistical analyses were done by one-factor repeated measures analysis of variance and Scheffe F test. Both DHS alone, as well as CR, produced significant changes in the loading and unloading characteristics of Nitinol and NiTi wires. However, the changes in the load-deflection characteristics of these wires after DHS only were relatively small, and the clinical significance of these changes is open to question.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1636628

  14. 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.

  15. 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.

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  17. 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.

  18. 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.

  19. 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).

  20. 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.

  1. 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.

  2. 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.

  3. Energy absorber uses expanded coiled tube

    NASA Technical Reports Server (NTRS)

    Johnson, E. F.

    1972-01-01

    Mechanical shock mitigating device, based on working material to its failure point, absorbs mechanical energy by bending or twisting tubing. It functions under axial or tangential loading, has no rebound, is area independent, and is easy and inexpensive to build.

  4. 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.

  5. INVESTIGATION OF A TEST LOOP FOR THE COOLING SYSTEM OF THE ITER TF COIL UNDER PULSED HEAT LOAD

    SciTech Connect

    Rousset, B.; Girard, A.; Maze, S.; Poncet, J. M.; Roussel, P.; Murdoch, D.; Sanmarti, M.

    2008-03-16

    CEA is involved in the design of the cooling scheme of the future ITER tokamak. Pulsed operation of ITER will result in heat load variations (which refrigerators have difficulties to cope with). A load smoothing device has been proposed by the ITER team which needs to be validated. To do this, a scaled-down experiment (hereafter also called model) has been proposed and studied in the framework of an EFDA sub-task. This paper presents the test loop dimensioning and the preliminary design for constructing the model. The choice of the relevant design criteria had to be defined so as to obtain in fine a geometric ratio between the ITER system and the model. It is shown that this ratio is then applicable for the mass flow rates as well as the different volumes (heat exchanger, pipes,...) existing on ITER and on the proposed experimental model. Details of the scaling, model design and 3D views corresponding to this preliminary study are presented in this paper.

  6. 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.

  7. Sonofusion: Heat and ^4He Created by Cavitationally Induced Loading of Metal Foils

    NASA Astrophysics Data System (ADS)

    Stringham, Roger

    2003-03-01

    Helium four was produced in a vacuum tight system and measured by mass spectrometry with no measurable accompanying radiation. This fusion product from a piezo driven, acoustic reactor forces deuterons into a metallic foil. We believe the reaction is the result of the adiabatic collapse of transient bubbles in D_2O. The collapse process forms high-density plasma jets that are further z-pinched and then implanted into the foil lattices where the DD fusion takes place. With no evidence of long range radiation, the mc^2 energy was converted to heat. The reactor gases were analyzed at levels as high as 500 ppm of ^4He, which is 100 times that found in air. The SEM, Scanning Electron Microscope, photos of target foil surfaces show evidence of violent activity identified as ejecta sites varying in size from 100 to 10000 nm in diameter. The ^4He, radiation, excess heat, and SEM measurements support the DD fusion explanation.

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

    SciTech Connect

    Not Available

    2013-11-01

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

  9. TPX/TFTR Neutral Beam energy absorbers

    SciTech Connect

    Dahlgren, F.; Wright, K.; Kamperschroer, J.; Grisham, L.; Lontai, L.; Peters, C.; VonHalle, A.

    1993-11-01

    The present beam energy absorbing surfaces on the TFTR Neutral Beams such as Ion Dumps, Calorimeters, beam defining apertures, and scrapers, are simple water cooled copper plates which wee designed to absorb (via their thermal inertia) the incident beam power for two seconds with a five minute coal down interval between pulses. These components are not capable of absorbing the anticipated beam power loading for 1000 second TPX pulses and will have to be replaced with an actively cooled design. While several actively cooled energy absorbing designs were considered,, the hypervapotron elements currently being used on the JET beamlines were chosen due to their lower cooling water demands and reliable performance on JET.

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

    SciTech Connect

    Gahl, J.M.; Crawford, J.F.; McDonald, J.M.; McGrath, R.T.; Zakharov, A.; Tserevitinov, S.; Barabash, V.; Guseva, M.

    1992-08-01

    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.

  11. 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.

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

    SciTech Connect

    Gahl, J.M.; Crawford, J.F. ); McDonald, J.M.; McGrath, R.T. ); Zakharov, A. ); Tserevitinov, S. ); Barabash, V. ); Guseva, M. (Gosudarstvennyj Komitet po Ispol'zovaniy

    1992-01-01

    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.

  13. 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.

  14. Absorber coatings' degradation

    SciTech Connect

    Moore, S.W.

    1984-01-01

    This report is intended to document some of the Los Alamos efforts that have been carried out under the Department of Energy (DOE) Active Heating and Cooling Materials Reliability, Maintainability, and Exposure Testing program. Funding for these activities is obtained directly from DOE although they represent a variety of projects and coordination with other agencies. Major limitations to the use of solar energy are the uncertain reliability and lifetimes of solar systems. This program is aimed at determining material operating limitations, durabilities, and failure modes such that materials improvements can be made and lifetimes can be extended. Although many active and passive materials and systems are being studied at Los Alamos, this paper will concentrate on absorber coatings and degradation of these coatings.

  15. Development of 300 °C heat resistant boron-loaded resin for neutron shielding

    NASA Astrophysics Data System (ADS)

    Morioka, Atsuhiko; Sakurai, Shinji; Okuno, Koichi; Sato, Satoshi; Verzirov, Yury; Kaminaga, Atsushi; Nishitani, Takeo; Tamai, Hiroshi; Kudo, Yusuke; Yoshida, Shigeru; Matsukawa, Makoto

    2007-08-01

    A new neutron shielding material resistant to temperatures up to 300 °C is developed, consisting of a phenol-based resin with 6 wt% boron. The resin will be applied around the vacuum vessel of the DD plasma device to suppress the streaming neutrons and to reduce the nuclear heating of the superconducting coils. The neutron shielding performance of the newly developed resin, examined by the 252Cf neutron source, is almost the same as that of polyethylene, which is not effective above 100 °C. The new resin maintains its mechanical strength in the high temperature region. The outgas of CO 2, NH 3 and H 2O from the resin have been measured, however, the neutron shielding performance of the resin after 200 °C baking was almost the same as that before baking. Thirteen kinds of organic gases have been observed at ˜300 °C.

  16. 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.

  17. 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.

  18. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2014-02-01

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

  20. 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.; 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 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

  1. 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.

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

    SciTech Connect

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

    2015-10-12

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

  3. 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.

  4. 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.

  5. 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.

  6. The Cooling of a Liquid Absorber using a Small Cooler

    SciTech Connect

    Baynham, D.E.; Bradshaw, T.W.; Green, M.A.; Ishimoto, S.; Liggins, N.

    2005-08-24

    This report discusses the use of small cryogenic coolers for cooling the Muon Ionization Cooling Experiment (MICE) liquid cryogen absorbers. Since the absorber must be able contain liquid helium as well liquid hydrogen, the characteristics of the available 4.2 K coolers are used here. The issues associated with connecting two-stage coolers to liquid absorbers are discussed. The projected heat flows into an absorber and the cool-down of the absorbers using the cooler are presented. The warm-up of the absorber is discussed. Special hydrogen safety issues that may result from the use of a cooler on the absorbers are also discussed.

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

    NASA Astrophysics Data System (ADS)

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

    2008-09-01

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

  8. 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.

  9. 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.

  10. Energy-Absorbing, Lightweight Wheels

    NASA Technical Reports Server (NTRS)

    Waydo, Peter

    2003-01-01

    Improved energy-absorbing wheels are under development for use on special-purpose vehicles that must traverse rough terrain under conditions (e.g., extreme cold) in which rubber pneumatic tires would fail. The designs of these wheels differ from those of prior non-pneumatic energy-absorbing wheels in ways that result in lighter weights and more effective reduction of stresses generated by ground/wheel contact forces. These wheels could be made of metals and/or composite materials to withstand the expected extreme operating conditions. As shown in the figure, a wheel according to this concept would include an isogrid tire connected to a hub via spring rods. The isogrid tire would be a stiff, lightweight structure typically made of aluminum. The isogrid aspect of the structure would both impart stiffness and act as a traction surface. The hub would be a thin-walled body of revolution having a simple or compound conical or other shape chosen for structural efficiency. The spring rods would absorb energy and partially isolate the hub and the supported vehicle from impact loads. The general spring-rod configuration shown in the figure was chosen because it would distribute contact and impact loads nearly evenly around the periphery of the hub, thereby helping to protect the hub against damage that would otherwise be caused by large loads concentrated onto small portions of the hub.

  11. 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.

  12. 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.

  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. Modeling Laser-Tissue Interactions: Implementing the Heat Diffusion Equation and Wave Equation to Simulate Thermal Interactions of Absorber Distributions in Biological Tissues

    NASA Astrophysics Data System (ADS)

    Barrera, Frederick; Ahmed, Elharith; Nash, Patrick; Sardar, Dhiraj

    2011-03-01

    The tracking of photons through turbid media (e.g. tissues) has been studied extensively from an experimental vantage point. These turbid media are difficult to characterize- since their components are exceedingly variegated- and thus present many challenges to clinicians who require models which precisely predict the location and time evolution of energy deposition. Furthermore, the interaction of the turbid media sample with the source of radiation typically involves many dynamic mechanisms (e.g. photothermal etc.) Using diffuse light transport, and an electromagnetic wave approach (e.g. Maxwell's equations), an analysis of thermal energy distribution in tissues is performed. Assuming a highly absorbing chromophore model of melanocytes in tissues, a comparison of the variation of thermal energy is determined for different collections of melanocyte spatial distributions. This work was funded by NIH/NIGMS MBRS-RISE GM60655.

  15. 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

  16. 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.

  17. 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.

  18. RF-Thermal-Structural Analysis of a Waveguide Higher Order Mode Absorber

    SciTech Connect

    G. Cheng; E. F. Daly; R. A. Rimmer; M. Stirbet; L. Vogel; H. Wang; K. M. Wilson

    2007-07-03

    For an ongoing high current cryomodule project, a total of 5 higher order mode (HOM) absorbers are required per cavity. The load is designed to absorb Radio Frequency (RF) heat induced by HOMs in a 748.5MHz cavity. Each load is targeted at a 4 kW dissipation capability. Water cooling is employed to remove the heat generated in ceramic tiles and by surface losses on the waveguide walls. A sequentially coupled RF-thermal-structural analysis was developed in ANSYS to optimize the HOM load design. Frequency-dependent dielectric material properties measured from samples and RF power spectrum calculated by the beam-cavity interaction codes were considered. The coupled field analysis capability of ANSYS avoided mapping of results between separate RF and thermal/structural simulation codes. For verification purposes, RF results obtained from ANSYS were compared to those from MAFIA, HFSS, and Microwave Studio. Good agreement was reached and this confirms that multiple-field coupled analysis is a desirable choice in analysis of HOM loads. Similar analysis could be performed on other particle accelerator components where distributed RF heating and surface current induced losses are inevitable.

  19. Heat pipe nuclear reactor for space power

    NASA Technical Reports Server (NTRS)

    Koening, D. R.

    1976-01-01

    A heat-pipe-cooled nuclear reactor has been designed to provide 3.2 MWth to an out-of-core thermionic conversion system. The reactor is a fast reactor designed to operate at a nominal heat-pipe temperature of 1675 K. Each reactor fuel element consists of a hexagonal molybdenum block which is bonded along its axis to one end of a molybdenum/lithium-vapor heat pipe. The block is perforated with an array of longitudinal holes which are loaded with UO2 pellets. The heat pipe transfers heat directly to a string of six thermionic converters which are bonded along the other end of the heat pipe. An assembly of 90 such fuel elements forms a hexagonal core. The core is surrounded by a thermal radiation shield, a thin thermal neutron absorber, and a BeO reflector containing boron-loaded control drums.

  20. Effect of heating rate on evaporative heat loss in the microwave-exposed mouse

    SciTech Connect

    Gordon, C.J.

    1982-08-01

    Mice were exposed to microwave radiation at 2.450 MHz at varying intensities and heat loads to determine if the animals thermoregulate or temperature regulate in conditions of varying heat load. The mice were exposed to whole-body doses of microwave radiation and power not reflected back was regarded as absorbed by the mouse. Incident powers of three to six watts were used, resulting in specific absorption rates of 47.4-93.4 W/kg. Deep body temperatures and the evaporated heat loss were monitored, and results demonstrated that mice thermoregulate, i.e., dissipate heat loads through evaporative heat loss at a rate which is modeled numerically. It is concluded that a significant portion of the microwave energy is deposited internally.

  1. Composition for absorbing hydrogen

    DOEpatents

    Heung, Leung K.; Wicks, George G.; Enz, Glenn L.

    1995-01-01

    A hydrogen absorbing composition. The composition comprises a porous glass matrix, made by a sol-gel process, having a hydrogen-absorbing material dispersed throughout the matrix. A sol, made from tetraethyl orthosilicate, is mixed with a hydrogen-absorbing material and solidified to form a porous glass matrix with the hydrogen-absorbing material dispersed uniformly throughout the matrix. The glass matrix has pores large enough to allow gases having hydrogen to pass through the matrix, yet small enough to hold the particles dispersed within the matrix so that the hydrogen-absorbing particles are not released during repeated hydrogen absorption/desorption cycles.

  2. Composition for absorbing hydrogen

    DOEpatents

    Heung, L.K.; Wicks, G.G.; Enz, G.L.

    1995-05-02

    A hydrogen absorbing composition is described. The composition comprises a porous glass matrix, made by a sol-gel process, having a hydrogen-absorbing material dispersed throughout the matrix. A sol, made from tetraethyl orthosilicate, is mixed with a hydrogen-absorbing material and solidified to form a porous glass matrix with the hydrogen-absorbing material dispersed uniformly throughout the matrix. The glass matrix has pores large enough to allow gases having hydrogen to pass through the matrix, yet small enough to hold the particles dispersed within the matrix so that the hydrogen-absorbing particles are not released during repeated hydrogen absorption/desorption cycles.

  3. Simulation of localized fast-ion heat loads in test blanket module simulation experiments on DIII-D

    NASA Astrophysics Data System (ADS)

    Kramer, G. J.; McLean, A.; Brooks, N.; Budny, R. V.; Chen, X.; Heidbrink, W. W.; Kurki-Suonio, T.; Nazikian, R.; Koskela, T.; Schaffer, M. J.; Shinohara, K.; Snipes, J. A.; Van Zeeland, M. A.

    2013-12-01

    Infrared imaging of hot spots induced by localized magnetic perturbations using the test blanket module (TBM) mock-up on DIII-D is in good agreement with beam-ion loss simulations. The hot spots were seen on the carbon protective tiles surrounding the TBM as they reached temperatures over 1000 °C. The localization of the hot spots on the protective tiles is in fair agreement with fast-ion loss simulations using a range of codes: ASCOT, SPIRAL and OFMCs while the codes predicted peak heat loads that are within 30% of the measured ones. The orbit calculations take into account the birth profile of the beam ions as well as the scattering and slowing down of the ions as they interact with the localized TBM field. The close agreement between orbit calculations and measurements validate the analysis of beam-ion loss calculations for ITER where ferritic material inside the tritium breeding TBMs is expected to produce localized hot spots on the first wall.

  4. 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.

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

    PubMed Central

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

    2016-01-01

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

  6. Durability of Polymeric Glazing and Absorber Materials

    SciTech Connect

    Jorgensen, G.; Terwilliger, K.; Bingham, C.; Milbourne, M.

    2005-01-01

    The Solar Heating and Lighting Program has set the goal of reducing the cost of solar water heating systems by at least 50%. An attractive approach to such large cost reduction is to replace glass and metal parts with less-expensive, lighter-weight, more-integrated polymeric components. The key challenge with polymers is to maintain performance and assure requisite durability for extended lifetimes. The objective of this task is to quantify lifetimes through measurement of the optical and mechanical stability of candidate polymeric glazing and absorber materials. Polycarbonate sheet glazings, as proposed by two industry partners, have been tested for resistance to UV radiation with three complementary methods. Incorporation of a specific 2-mil thick UV-absorbing screening layer results in glazing lifetimes of at least 15 years; improved screens promise even longer lifetimes. Proposed absorber materials were tested for creep and embrittlement under high temperature, and appear adequate for planned ICS absorbers.

  7. Structured Metal Film as Perfect Absorber

    NASA Astrophysics Data System (ADS)

    Xiong, Xiang; Jiang, Shang-Chi; Peng, Ru-Wen; Wang, Mu

    2014-03-01

    With standing U-shaped resonators, fish-spear-like resonator has been designed for the first time as the building block to assemble perfect absorbers. The samples have been fabricated with two-photon polymerization process and FTIR measurement results support the effectiveness of the perfect absorber design. In such a structure the polarization-dependent resonance occurs between the tines of the spears instead of the conventional design where the resonance occurs between the metallic layers separated by a dielectric interlayer. The incident light neither transmits nor reflects back which results in unit absorbance. The power of light is trapped between the tines of spears and finally be absorbed. The whole structure is covered with a continuous metallic layer with good thermo-conductance, which provides an excellent approach to deal with heat dissipation, is enlightening in exploring metamaterial absorbers.

  8. Porous absorber for solar air heaters

    SciTech Connect

    Finch, J.A.

    1980-09-10

    A general discussion of the factors affecting solar collector performance is presented. Bench scale tests done to try to determine the heat transfer characteristics of various screen materials are explained. The design, performance, and evaluation of a crude collector with a simple screen stack absorber is treated. The more sophisticated absorber concept, and its first experimental approximation is examined. A short summary of future plans for the collector concept is included. (MHR)

  9. Fast microwave assisted pyrolysis of biomass using microwave absorbent.

    PubMed

    Borges, Fernanda Cabral; Du, Zhenyi; Xie, Qinglong; Trierweiler, Jorge Otávio; Cheng, Yanling; Wan, Yiqin; Liu, Yuhuan; Zhu, Rongbi; Lin, Xiangyang; Chen, Paul; Ruan, Roger

    2014-03-01

    A novel concept of fast microwave assisted pyrolysis (fMAP) in the presence of microwave absorbents was presented and examined. Wood sawdust and corn stover were pyrolyzed by means of microwave heating and silicon carbide (SiC) as microwave absorbent. The bio-oil was characterized, and the effects of temperature, feedstock loading, particle sizes, and vacuum degree were analyzed. For wood sawdust, a temperature of 480°C, 50 grit SiC, with 2g/min of biomass feeding, were the optimal conditions, with a maximum bio-oil yield of 65 wt.%. For corn stover, temperatures ranging from 490°C to 560°C, biomass particle sizes from 0.9mm to 1.9mm, and vacuum degree lower than 100mmHg obtained a maximum bio-oil yield of 64 wt.%. This study shows that the use of microwave absorbents for fMAP is feasible and a promising technology to improve the practical values and commercial application outlook of microwave based pyrolysis. PMID:24518438

  10. Fast microwave assisted pyrolysis of biomass using microwave absorbent.

    PubMed

    Borges, Fernanda Cabral; Du, Zhenyi; Xie, Qinglong; Trierweiler, Jorge Otávio; Cheng, Yanling; Wan, Yiqin; Liu, Yuhuan; Zhu, Rongbi; Lin, Xiangyang; Chen, Paul; Ruan, Roger

    2014-03-01

    A novel concept of fast microwave assisted pyrolysis (fMAP) in the presence of microwave absorbents was presented and examined. Wood sawdust and corn stover were pyrolyzed by means of microwave heating and silicon carbide (SiC) as microwave absorbent. The bio-oil was characterized, and the effects of temperature, feedstock loading, particle sizes, and vacuum degree were analyzed. For wood sawdust, a temperature of 480°C, 50 grit SiC, with 2g/min of biomass feeding, were the optimal conditions, with a maximum bio-oil yield of 65 wt.%. For corn stover, temperatures ranging from 490°C to 560°C, biomass particle sizes from 0.9mm to 1.9mm, and vacuum degree lower than 100mmHg obtained a maximum bio-oil yield of 64 wt.%. This study shows that the use of microwave absorbents for fMAP is feasible and a promising technology to improve the practical values and commercial application outlook of microwave based pyrolysis.

  11. Thermal radiation absorbed by dairy cows in pasture

    NASA Astrophysics Data System (ADS)

    da Silva, Roberto Gomes; Guilhermino, Magda Maria; de Morais, Débora Andréia E. Façanha

    2010-01-01

    The goal of the present paper was to assess a method for estimating the thermal radiation absorbed by dairy cows (0.875 Holstein-0.125 Guzerath) on pasture. A field test was conducted with 472 crossbred dairy cows in three locations of a tropical region. The following environmental data were collected: air temperature, partial vapour pressure, wind speed, black globe temperature, ground surface temperature and solar radiation. Average total radiation absorbed by animals was calculated as {R_{abs}} = 640.0 ± 3.1 W.{m^{ - 2}} . Absorbed short-wave radiation (solar direct, diffuse and reflected) averaged 297.9 ± 2.7 W m-2; long wave (from the sky and from terrestrial surfaces) averaged 342.1 ± 1.5 W m-2. It was suggested that a new environmental measurement, the effective radiant heat load (ERHL), could be used to assess the effective mean radiant temperature ( {T_{mr}^* } ) . Average T_{mr}^* was 101.4 ± 1.2°C, in contrast to the usual mean radiant temperature, {T_{mr}} = 65.1 ± 0.5° C . Estimates of T_{mr}^* were considered as more reliable than those of T mr in evaluating the thermal environment in the open field, because T mr is almost totally associated only with long wave radiation.

  12. Modelling Absorbent Phenomena of Absorbent Structure

    NASA Astrophysics Data System (ADS)

    Sayeb, S.; Ladhari, N.; Ben Hassen, M.; Sakli, F.

    Absorption, retention and strike through time, as evaluating criteria of absorbent structures quality were studied. Determination of influent parameters on these criteria were realized by using the design method of experimental sets. In this study, the studied parameters are: Super absorbent polymer (SAP)/fluff ratio, compression and the porosity of the non woven used as a cover stock. Absorption capacity and retention are mostly influenced by SAP/fluff ratio. However, strike through time is affected by compression. Thus, a modelling of these characteristics in function of the important parameter was established.

  13. Externally tuned vibration absorber

    DOEpatents

    Vincent, Ronald J.

    1987-09-22

    A vibration absorber unit or units are mounted on the exterior housing of a hydraulic drive system of the type that is powered from a pressure wave generated, e.g., by a Stirling engine. The hydraulic drive system employs a piston which is hydraulically driven to oscillate in a direction perpendicular to the axis of the hydraulic drive system. The vibration absorbers each include a spring or other resilient member having one side affixed to the housing and another side to which an absorber mass is affixed. In a preferred embodiment, a pair of vibration absorbers is employed, each absorber being formed of a pair of leaf spring assemblies, between which the absorber mass is suspended.

  14. 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.

  15. 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.

  16. 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.

  17. Durability of Polymeric Glazing and Absorber Materials

    SciTech Connect

    Jorgensen, G.; Terwilliger, K.; Bingham, C.; Lindquist, C.; Milbourne, M.

    2005-11-01

    The Solar Heating and Lighting Program has set the goal of reducing the cost of solar water heating systems by at least 50%. An attractive approach to such large cost reduction is to replace glass and metal parts with less-expensive, lighter-weight, more-integrated polymeric components. The key challenge with polymers is to maintain performance and assure requisite durability for extended lifetimes. We have begun evaluation of several new UV-screened polycarbonate sheet glazing constructions. This has involved interactions with several major polymer industry companies to obtain improved candidate samples. Proposed absorber materials were tested for UV resistance, and appear adequate for unglazed ICS absorbers.

  18. Advanced neutron absorber materials

    DOEpatents

    Branagan, Daniel J.; Smolik, Galen R.

    2000-01-01

    A neutron absorbing material and method utilizing rare earth elements such as gadolinium, europium and samarium to form metallic glasses and/or noble base nano/microcrystalline materials, the neutron absorbing material having a combination of superior neutron capture cross sections coupled with enhanced resistance to corrosion, oxidation and leaching.

  19. 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, Nicolas J. C.; Eidietis, N. W.; Lasnier, C. J.; Moyer, R. A.; Parks, P. B.; Shiraki, Daisuke

    2015-10-12

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

  20. Absorbing Outflows in AGN

    NASA Technical Reports Server (NTRS)

    Mathur, Smita

    2002-01-01

    The goal of this program was a comprehensive multiwavelength study of absorption phenomena in active galactic nuclei (AGN). These include a variety of associated absorption systems: X-ray warm absorbers, X-ray cold absorbers. UV absorbers with high ionization lines, MgII absorbers, red quasars and BALQSOs. The aim is to determine the physical conditions in the absorbing outflows, study their inter-relations and their role in AGN. We designed several observing programs to achieve this goal: X-ray spectroscopy, UV spectroscopy, FLAY spectroscopy and X-ray imaging. We were very successful towards achieving the goal over the five year period as shown through following observing programs and papers. Copies of a few papers are attached with this report.

  1. Unglazed transpired solar collector having a low thermal-conductance absorber

    DOEpatents

    Christensen, Craig B.; Kutscher, Charles F.; Gawlik, Keith M.

    1997-01-01

    An unglazed transpired solar collector using solar radiation to heat incoming air for distribution, comprising an unglazed absorber formed of low thermal-conductance material having a front surface for receiving the solar radiation and openings in the unglazed absorber for passage of the incoming air such that the incoming air is heated as it passes towards the front surface of the absorber and the heated air passes through the openings in the absorber for distribution.

  2. [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.

  3. 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

  4. 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).

  5. 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.

  6. Harnessing snap-through instability for shape-recoverable energy-absorbing structure

    NASA Astrophysics Data System (ADS)

    Kang, Sung; Shan, Sicong; Raney, Jordan; Wang, Pai; Candido, Francisco; Lewis, Jennifer; Bertoldi, Katia

    2015-03-01

    Energy absorbing materials and structures are used in numerous areas for maintaining structural integrity, protection and comfort. To absorb/dissipate energy from shock/vibration, one generally relies on processes such as plastic deformation and damping as the case of metal foams and suspensions. Because plastic deformation and damping induce irreversible change in the energy-absorbing systems such as shape changes and degradation of damping elements by heat dissipation, it would be desirable to develop a new energy-absorption mechanism with reversibility. Furthermore, it would be desirable to implement energy-absorption mechanisms whose behavior is not affected by the rate of loading. Here, we report a shape-recoverable system that absorbs energy without degradation by harnessing multistability in elastic structures. Using numerical simulations, we investigate geometrical parameters that determine the onset of the snap-through and multi-stability. We subsequently manufacture structures with different geometrical parameters and sizes using a scalable direct-write 3D printing approach. We experimentally demonstrate reversible energy-absorption in these structures at strain rates over three orders of magnitudes, with reduced peak acceleration under impact by up to one order of magnitude compared with control samples. Our findings can open new opportunities for scalable design and manufacturing of energy-absorbing materials and structures.

  7. Lipid-absorbing Polymers

    NASA Technical Reports Server (NTRS)

    Marsh, H. E., Jr.; Wallace, C. J.

    1973-01-01

    The removal of bile acids and cholesterol by polymeric absorption is discussed in terms of micelle-polymer interaction. The results obtained with a polymer composed of 75 parts PEO and 25 parts PB plus curing ingredients show an absorption of 305 to 309%, based on original polymer weight. Particle size effects on absorption rate are analyzed. It is concluded that crosslinked polyethylene oxide polymers will absorb water, crosslinked polybutadiene polymers will absorb lipids; neither polymer will absorb appreciable amounts of lipids from micellar solutions of lipids in water.

  8. Thin film absorber for a solar collector

    DOEpatents

    Wilhelm, William G.

    1985-01-01

    This invention pertains to energy absorbers for solar collectors, and more particularly to high performance thin film absorbers. The solar collectors comprising the absorber of this invention overcome several problems seen in current systems, such as excessive hardware, high cost and unreliability. In the preferred form, the apparatus features a substantially rigid planar frame with a thin film window bonded to one planar side of the frame. An absorber in accordance with the present invention is comprised of two thin film layers that are sealed perimetrically. In a preferred embodiment, thin film layers are formed from a metal/plastic laminate. The layers define a fluid-tight planar envelope of large surface area to volume through which a heat transfer fluid flows. The absorber is bonded to the other planar side of the frame. The thin film construction of the absorber assures substantially full envelope wetting and thus good efficiency. The window and absorber films stress the frame adding to the overall strength of the collector.

  9. 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.

  10. 14 CFR 27.475 - Tires and shock absorbers.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Tires and shock absorbers. 27.475 Section... AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Strength Requirements Ground Loads § 27.475 Tires and shock... be in their static position and the shock absorbers to be in their most critical position....

  11. 14 CFR 27.475 - Tires and shock absorbers.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Tires and shock absorbers. 27.475 Section... AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Strength Requirements Ground Loads § 27.475 Tires and shock... be in their static position and the shock absorbers to be in their most critical position....

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

    SciTech Connect

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

    2006-02-28

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

  13. 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.

  14. Thermal loading considerations for synchrotron radiation mirrors

    SciTech Connect

    Holdener, F.R.; Berglin, E.J.; Fuchs, B.A.; Humpal, H.H.; Karpenko, V.P.; Martin, R.W.; Tirsell, K.G.

    1986-03-26

    Grazing incidence mirrors used to focus synchrotron radiation beams through small distant apertures have severe optical requirements. The surface distortion due to heat loading of the first mirror in a bending magnet beam line is of particular concern when a large fraction of the incident beam is absorbed. In this paper we discuss mirror design considerations involved in minimizing the thermal/mechanical loading on vertically deflecting first surface mirrors required for SPEAR synchrotron radiation beam lines. Topics include selection of mirror material and cooling method, the choice of SiC for the substrate, optimization of the thickness, and the design of the mirror holder and cooling mechanism. Results obtained using two-dimensional, finite-element thermal/mechanical distortion analysis are presented for the case of a 6/sup 0/ grazing incidence SiC mirror absorbing up to 260 W at Beam Line VIII on the SPEAR ring. Test descriptions and results are given for the material used to thermally couple this SiC mirror to a water-cooled block. The interface material is limited to applications for which the equivalent normal heat load is less than 20 W/cm/sup 2/.

  15. 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..

  16. Solar Heating And Cooling Of Buildings (SHACOB): Requirements definition and impact analysis-2. Volume 3: Customer load management systems

    NASA Astrophysics Data System (ADS)

    Cretcher, C. K.; Rountredd, R. C.

    1980-11-01

    Customer Load Management Systems, using off-peak storage and control at the residences, are analyzed to determine their potential for capacity and energy savings by the electric utility. Areas broadly representative of utilities in the regions around Washington, DC and Albuquerque, NM were of interest. Near optimum tank volumes were determined for both service areas, and charging duration/off-time were identified as having the greatest influence on tank performance. The impacts on utility operations and corresponding utility/customer economics were determined in terms of delta demands used to estimate the utilities' generating capacity differences between the conventional load management, (CLM) direct solar with load management (DSLM), and electric resistive systems. Energy differences are also determined. These capacity and energy deltas are translated into changes in utility costs due to penetration of the CLM or DSLM systems into electric resistive markets in the snapshot years of 1990 and 2000.

  17. Unidirectional perfect absorber

    PubMed Central

    Jin, L.; Wang, P.; Song, Z.

    2016-01-01

    This study proposes a unidirectional perfect absorber (UPA), which we realized with a two-arm Aharonov-Bohm interferometer, that consists of a dissipative resonator side-coupled to a uniform resonator array. The UPA has reflection-less full absorption on one direction, and reflectionless full transmission on the other, with an appropriate magnetic flux and coupling, detuning, and loss of the side-coupled resonator. The magnetic flux controls the transmission, the left transmission is larger for magnetic flux less than one-half flux quantum; and the right transmission is larger for magnetic flux between one-half and one flux quantum. Besides, a perfect absorber (PA) can be realized based on the UPA, in which light waves from both sides, with arbitrary superposition of the ampli- tude and phase, are perfectly absorbed. The UPA is expected to be useful in the design of novel optical devices. PMID:27615125

  18. Unidirectional perfect absorber

    NASA Astrophysics Data System (ADS)

    Jin, L.; Wang, P.; Song, Z.

    2016-09-01

    This study proposes a unidirectional perfect absorber (UPA), which we realized with a two-arm Aharonov-Bohm interferometer, that consists of a dissipative resonator side-coupled to a uniform resonator array. The UPA has reflection-less full absorption on one direction, and reflectionless full transmission on the other, with an appropriate magnetic flux and coupling, detuning, and loss of the side-coupled resonator. The magnetic flux controls the transmission, the left transmission is larger for magnetic flux less than one-half flux quantum; and the right transmission is larger for magnetic flux between one-half and one flux quantum. Besides, a perfect absorber (PA) can be realized based on the UPA, in which light waves from both sides, with arbitrary superposition of the ampli- tude and phase, are perfectly absorbed. The UPA is expected to be useful in the design of novel optical devices.

  19. Unidirectional perfect absorber.

    PubMed

    Jin, L; Wang, P; Song, Z

    2016-01-01

    This study proposes a unidirectional perfect absorber (UPA), which we realized with a two-arm Aharonov-Bohm interferometer, that consists of a dissipative resonator side-coupled to a uniform resonator array. The UPA has reflection-less full absorption on one direction, and reflectionless full transmission on the other, with an appropriate magnetic flux and coupling, detuning, and loss of the side-coupled resonator. The magnetic flux controls the transmission, the left transmission is larger for magnetic flux less than one-half flux quantum; and the right transmission is larger for magnetic flux between one-half and one flux quantum. Besides, a perfect absorber (PA) can be realized based on the UPA, in which light waves from both sides, with arbitrary superposition of the ampli- tude and phase, are perfectly absorbed. The UPA is expected to be useful in the design of novel optical devices. PMID:27615125

  20. Unidirectional perfect absorber.

    PubMed

    Jin, L; Wang, P; Song, Z

    2016-09-12

    This study proposes a unidirectional perfect absorber (UPA), which we realized with a two-arm Aharonov-Bohm interferometer, that consists of a dissipative resonator side-coupled to a uniform resonator array. The UPA has reflection-less full absorption on one direction, and reflectionless full transmission on the other, with an appropriate magnetic flux and coupling, detuning, and loss of the side-coupled resonator. The magnetic flux controls the transmission, the left transmission is larger for magnetic flux less than one-half flux quantum; and the right transmission is larger for magnetic flux between one-half and one flux quantum. Besides, a perfect absorber (PA) can be realized based on the UPA, in which light waves from both sides, with arbitrary superposition of the ampli- tude and phase, are perfectly absorbed. The UPA is expected to be useful in the design of novel optical devices.

  1. Beam Pipe HOM Absorber for 750 MHz RF Cavity Systems

    SciTech Connect

    Johnson, Rolland; Neubauer, Michael

    2014-10-29

    This joint project of Muons, Inc., Cornell University and SLAC was supported by a Phase I and Phase II grant monitored by the SBIR Office of Science of the DOE. Beam line HOM absorbers are a critical part of future linear colliders. The use of lossy materials at cryogenic temperatures has been incorporated in several systems. The design in beam pipes requires cylinders of lossy material mechanically confined in such a way as to absorb the microwave energy from the higher-order modes and remove the heat generated in the lossy material. Furthermore, the potential for charge build-up on the surface of the lossy material requires the conductivity of the material to remain consistent from room temperature to cryogenic temperatures. In this program a mechanical design was developed that solved several design constraints: a) fitting into the existing Cornell load vacuum component, b) allowing the use of different material compositions, c) a thermal design that relied upon the compression of the lossy ceramic material without adding stress. Coating experiments were performed that indicated the design constraints needed to fully implement this approach for solving the charge build-up problem inherent in using lossy ceramics. In addition, the ACE3P program, used to calculate the performance of lossy cylinders in beam pipes in general, was supported by this project. Code development and documentation to allow for the more wide spread use of the program was a direct result of this project was well.

  2. Cyclodextrins: a new efficient absorbent to treat waste gas streams.

    PubMed

    Blach, Philippe; Fourmentin, Sophie; Landy, David; Cazier, Fabrice; Surpateanu, Gheorghe

    2008-01-01

    Volatile Organic Compounds (VOCs) in the air provoke health and environmental concerns. This paper focuses on the absorption method to treat industrial polluted air loaded with VOCs. The key variable of this treatment being the choice of a suitable liquid absorbent, the aim of this research work is to investigate the effectiveness and the regeneration of a new potential family of absorbent: cyclodextrins (CDs). All CDs derivatives tested are able to decrease the Henry's law constant of toluene: a reduction of volatility up to 95% may be obtained, depending on CD nature and concentration. Moreover, absorption experiments show that beta-CD, which presents the highest absorption ability, is 250 time more efficient than water. The absorption efficiency is not totally correlated with static experiments, suggesting that, in addition to Henry's law constants and inclusion compounds stability, toluene diffusion into such solutions has to be taken into account. It is also to be noted that salt and pH variations seem to have little influence on the absorption capacity of CDs, which may be of great interest for industrial applications. Finally, since production of solid compounds was not observed during these experiments and since temperature decreases the capture ability in a drastic way, regeneration of the washing solution can be achieved by heating the solution in combination with air stripping.

  3. Ferrite HOM Absorber for the RHIC ERL

    SciTech Connect

    Hahn,H.; Choi, E.M.; Hammons, L.

    2008-10-01

    A superconducting Energy Recovery Linac is under construction at Brookhaven National Laboratory to serve as test bed for RHIC upgrades. The damping of higher-order modes in the superconducting five-cell cavity for the Energy-Recovery linac at RHIC is performed exclusively by two ferrite absorbers. The ferrite properties have been measured in ferrite-loaded pill box cavities resulting in the permeability values given by a first-order Debye model for the tiled absorber structure and an equivalent permeability value for computer simulations with solid ring dampers. Measured and simulated results for the higher-order modes in the prototype copper cavity are discussed. First room-temperature measurements of the finished niobium cavity are presented which confirm the effective damping of higher-order modes in the ERL. by the ferrite absorbers.

  4. Absorber Materials at Room and Cryogenic Temperatures

    SciTech Connect

    F. Marhauser, T.S. Elliott, A.T. Wu, E.P. Chojnacki, E. Savrun

    2011-09-01

    We recently reported on investigations of RF absorber materials at cryogenic temperatures conducted at Jefferson Laboratory (JLab). The work was initiated to find a replacement material for the 2 Kelvin low power waveguide Higher Order Mode (HOM) absorbers employed within the original cavity cryomodules of the Continuous Electron Beam Accelerator Facility (CEBAF). This effort eventually led to suitable candidates as reported in this paper. Furthermore, though constrained by small funds for labor and resources, we have analyzed a variety of lossy ceramic materials, several of which could be usable as HOM absorbers for both normal conducting and superconducting RF structures, e.g. as loads in cavity waveguides and beam tubes either at room or cryogenic temperatures and, depending on cooling measures, low to high operational power levels.

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

    PubMed

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

    2016-09-01

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

  6. 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.

  7. Manufacture of thick VPS W coatings on relatively large CuZrCr substrate and its steady high heat load performance

    NASA Astrophysics Data System (ADS)

    Deng, Chunming; Liu, Min; Yang, Zhenxiao; Deng, Changguang; Zhou, Kesong; Kuang, Ziqi; Zhang, Jifu

    2014-12-01

    W material is considered as one of potential Plasma Facing Materials (PFMs) for its high melting point, excellent stability at elevated temperature, good thermal conductivity, excellent anti-plasma sputtering and low Tritium retention. Functionally graded W/Cu coating was applied on CuCrZr substrate (250 mm × 120 mm × 30 mm) with compositionally gradient W/Cu as bond coat (0.4-0.6 mm) and 1.5 mm thick W coating as top coat via Vacuum Plasma Spraying (VPS) for continuous deposition of 5 h. Microstructure, chemical composition, porosity and adhesive strength for as sprayed thick W coating on the CuCrZr substrate were characterized by means of SEM, ICP-MS, Mercury Intrusion Porosimeter and tensile strength tester. The steady high heat load (HHL) performance for W/Cu functional gradient coating was evaluated by high energy electron beam. The results showed that thick VPS W coated CuCrZr substrate can withstand the steady high heat load at the electron beam power density of 9 MW/m2 for 1000 cycles.

  8. Neutron Absorbing Alloys

    DOEpatents

    Mizia, Ronald E.; Shaber, Eric L.; DuPont, John N.; Robino, Charles V.; Williams, David B.

    2004-05-04

    The present invention is drawn to new classes of advanced neutron absorbing structural materials for use in spent nuclear fuel applications requiring structural strength, weldability, and long term corrosion resistance. Particularly, an austenitic stainless steel alloy containing gadolinium and less than 5% of a ferrite content is disclosed. Additionally, a nickel-based alloy containing gadolinium and greater than 50% nickel is also disclosed.

  9. Solar concentrator/absorber

    NASA Technical Reports Server (NTRS)

    Von Tiesenhausen, G. F.

    1976-01-01

    Collector/energy converter, consisting of dual-slope optical concentrator and counterflow thermal energy absorber, is attached to multiaxis support structure. Efficient over wide range of illumination levels, device may be used to generate high temperature steam, serve as solar powered dryer, or power absorption cycle cooler.

  10. Methods for applying microchannels to separate methane using liquid absorbents, especially ionic liquid absorbents from a mixture comprising methane and nitrogen

    DOEpatents

    Tonkovich, Anna Lee Y.; Litt, Robert D.; Dongming, Qiu; Silva, Laura J.; Lamont, Micheal Jay; Fanelli, Maddalena; Simmons, Wayne W.; Perry, Steven

    2011-10-04

    Methods of using microchannel separation systems including absorbents to improve thermal efficiency and reduce parasitic power loss. Energy is typically added to desorb methane and then energy or heat is removed to absorb methane using a working solution. The working solution or absorbent may comprise an ionic liquid, or other fluids that demonstrate a difference in affinity between methane and nitrogen in a solution.

  11. The Potential of Combined Heat and Power Generation, Wind Power Generation and Load Management Techniques for Cost Reduction in Small Electricity Supply Systems.

    NASA Astrophysics Data System (ADS)

    Bass, Jeremy Hugh

    Available from UMI in association with The British Library. Requires signed TDF. An evaluation is made of the potential fuel and financial savings possible when a small, autonomous diesel system sized to meet the demands of an individual, domestic consumer is adapted to include: (1) combined heat and power (CHP) generation, (2) wind turbine generation, (3) direct load control. The potential of these three areas is investigated by means of time-step simulation modelling on a microcomputer. Models are used to evaluate performance and a Net Present Value analysis used to assess costs. A cost/benefit analysis then enables those areas, or combination of areas, that facilitate and greatest savings to be identified. The modelling work is supported by experience gained from the following: (1) field study of the Lundy Island wind/diesel system, (2) laboratory testing of a small diesel generator set, (3) study of a diesel based CHP unit, (4) study of a diesel based direct load control system, (5) statistical analysis of data obtained from the long-term monitoring of a large number of individual household's electricity consumption. Rather than consider the consumer's electrical demand in isolation, a more flexible approach is adopted, with consumer demand being regarded as the sum of primarily two components: a small, electricity demand for essential services and a large, reschedulable demand for heating/cooling. The results of the study indicate that: (1) operating a diesel set in a CHP mode is the best strategy for both financial and fuel savings. A simple retrofit enables overall conversion efficiencies to be increased from 25% to 60%, or greater, at little cost. (2) wind turbine generation in association with direct load control is a most effective combination. (3) a combination of both the above areas enables greatest overall financial savings, in favourable winds resulting in unit energy costs around 20% of those of diesel only operation.

  12. Model Development and Experimental Validation of the Fusible Heat Sink Design for Exploration Vehicles

    NASA Technical Reports Server (NTRS)

    Cognata, Thomas J.; Leimkuehler, Thomas O.; Sheth, Rubik B.; Le,Hung

    2012-01-01

    The Fusible Heat Sink is a novel vehicle heat rejection technology which combines a flow through radiator with a phase change material. The combined technologies create a multi-function device able to shield crew members against Solar Particle Events (SPE), reduce radiator extent by permitting sizing to the average vehicle heat load rather than to the peak vehicle heat load, and to substantially absorb heat load excursions from the average while constantly maintaining thermal control system setpoints. This multi-function technology provides great flexibility for mission planning, making it possible to operate a vehicle in hot or cold environments and under high or low heat load conditions for extended periods of time. This paper describes the model development and experimental validation of the Fusible Heat Sink technology. The model developed was intended to meet the radiation and heat rejection requirements of a nominal MMSEV mission. Development parameters and results, including sizing and model performance will be discussed. From this flight-sized model, a scaled test-article design was modeled, designed, and fabricated for experimental validation of the technology at Johnson Space Center thermal vacuum chamber facilities. Testing showed performance comparable to the model at nominal loads and the capability to maintain heat loads substantially greater than nominal for extended periods of time.

  13. Model Development and Experimental Validation of the Fusible Heat Sink Design for Exploration Vehicles

    NASA Technical Reports Server (NTRS)

    Cognata, Thomas J.; Leimkuehler, Thomas; Sheth, Rubik; Le, Hung

    2013-01-01

    The Fusible Heat Sink is a novel vehicle heat rejection technology which combines a flow through radiator with a phase change material. The combined technologies create a multi-function device able to shield crew members against Solar Particle Events (SPE), reduce radiator extent by permitting sizing to the average vehicle heat load rather than to the peak vehicle heat load, and to substantially absorb heat load excursions from the average while constantly maintaining thermal control system setpoints. This multi-function technology provides great flexibility for mission planning, making it possible to operate a vehicle in hot or cold environments and under high or low heat load conditions for extended periods of time. This paper describes the modeling and experimental validation of the Fusible Heat Sink technology. The model developed was intended to meet the radiation and heat rejection requirements of a nominal MMSEV mission. Development parameters and results, including sizing and model performance will be discussed. From this flight-sized model, a scaled test-article design was modeled, designed, and fabricated for experimental validation of the technology at Johnson Space Center thermal vacuum chamber facilities. Testing showed performance comparable to the model at nominal loads and the capability to maintain heat loads substantially greater than nominal for extended periods of time.

  14. Metasurface Broadband Solar Absorber

    PubMed Central

    Azad, Abul K.; Kort-Kamp, Wilton J. M.; Sykora, Milan; Weisse-Bernstein, Nina R.; Luk, Ting S.; Taylor, Antoinette J.; Dalvit, Diego A. R.; Chen, Hou-Tong

    2016-01-01

    We demonstrate a broadband, polarization independent, wide-angle absorber based on a metallic metasurface architecture, which accomplishes greater than 90% absorptance in the visible and near-infrared range of the solar spectrum, and exhibits low absorptivity (emissivity) at mid- and far-infrared wavelengths. The complex unit cell of the metasurface solar absorber consists of eight pairs of gold nano-resonators that are separated from a gold ground plane by a thin silicon dioxide spacer. Our experimental measurements reveal high-performance absorption over a wide range of incidence angles for both s- and p-polarizations. We also investigate numerically the frequency-dependent field and current distributions to elucidate how the absorption occurs within the metasurface structure. PMID:26828999

  15. Metasurface Broadband Solar Absorber.

    PubMed

    Azad, Abul K; Kort-Kamp, Wilton J M; Sykora, Milan; Weisse-Bernstein, Nina R; Luk, Ting S; Taylor, Antoinette J; Dalvit, Diego A R; Chen, Hou-Tong

    2016-01-01

    We demonstrate a broadband, polarization independent, wide-angle absorber based on a metallic metasurface architecture, which accomplishes greater than 90% absorptance in the visible and near-infrared range of the solar spectrum, and exhibits low absorptivity (emissivity) at mid- and far-infrared wavelengths. The complex unit cell of the metasurface solar absorber consists of eight pairs of gold nano-resonators that are separated from a gold ground plane by a thin silicon dioxide spacer. Our experimental measurements reveal high-performance absorption over a wide range of incidence angles for both s- and p-polarizations. We also investigate numerically the frequency-dependent field and current distributions to elucidate how the absorption occurs within the metasurface structure.

  16. Metasurface Broadband Solar Absorber

    DOE PAGES

    Azad, Abul K.; Kort-Kamp, Wilton J. M.; Sykora, Milan; Weisse-Bernstein, Nina R.; Luk, Ting S.; Taylor, Antoinette J.; Dalvit, Diego A. R.; Chen, Hou-Tong

    2016-02-01

    Here, we demonstrate a broadband, polarization independent, wide-angle absorber based on a metallic metasurface architecture, which accomplishes greater than 90% absorptance in the visible and near-infrared range of the solar spectrum, and exhibits low absorptivity (emissivity) at mid- and far-infrared wavelengths. The complex unit cell of the metasurface solar absorber consists of eight pairs of gold nano-resonators that are separated from a gold ground plane by a thin silicon dioxide spacer. Moreover, our experimental measurements reveal high-performance absorption over a wide range of incidence angles for both s- and p-polarizations. We also investigate numerically the frequency-dependent field and current distributionsmore » to elucidate how the absorption occurs within the metasurface structure.« less

  17. Metasurface Broadband Solar Absorber.

    PubMed

    Azad, Abul K; Kort-Kamp, Wilton J M; Sykora, Milan; Weisse-Bernstein, Nina R; Luk, Ting S; Taylor, Antoinette J; Dalvit, Diego A R; Chen, Hou-Tong

    2016-01-01

    We demonstrate a broadband, polarization independent, wide-angle absorber based on a metallic metasurface architecture, which accomplishes greater than 90% absorptance in the visible and near-infrared range of the solar spectrum, and exhibits low absorptivity (emissivity) at mid- and far-infrared wavelengths. The complex unit cell of the metasurface solar absorber consists of eight pairs of gold nano-resonators that are separated from a gold ground plane by a thin silicon dioxide spacer. Our experimental measurements reveal high-performance absorption over a wide range of incidence angles for both s- and p-polarizations. We also investigate numerically the frequency-dependent field and current distributions to elucidate how the absorption occurs within the metasurface structure. PMID:26828999

  18. Ionized Absorbers in AGN

    NASA Technical Reports Server (NTRS)

    Mathur, S.

    1999-01-01

    As a part of this program, we observed three AGN:PKS2251 + 113, PG0043 = 039 and PLH909. Two objects show signatures of absorbtion in their UV spectra. Based on our earlier modeling of X-ray warm absorbents, we expected to observe X-ray observation in these objects. The third, PLH909, is known to have soft excess in EINSTEIN data. Attachment: "Exploratory ASCA observation of broad absorption line quasi-stellar objects".

  19. Solar absorber material reflectivity measurements at temperature

    SciTech Connect

    Bonometti, J.A.; Hawk, C.W.

    1999-07-01

    Assessment of absorber shell material properties at high operating temperatures is essential to the full understanding of the solar energy absorption process in a solar thermal rocket. A review of these properties, their application and a new experimental methodology to measure them at high temperatures is presented. The direct application for the research is absorber cavity development for a Solar Thermal Upper Stage (STUS). High temperature measurements, greater than 1,000 Kelvin, are difficult to obtain for incident radiation upon a solid surface that forms an absorber cavity in a solar thermal engine. The basic material properties determine the amount of solar energy that is absorbed, transmitted or reflected and are dependent upon the material's temperature. This investigation developed a new approach to evaluate the material properties (i.e., reflectivity, absorptive) of the absorber wall and experimentally determined them for rhenium and niobium sample coupons. The secular reflectivity was measured both at room temperature and at temperatures near 1,000 Kelvin over a range of angles from 0 to 90 degrees. The same experimental measurements were used to calculate the total reflectivity of the sample by integrating the recorded intensities over a hemisphere. The test methodology used the incident solar energy as the heating source while directly measuring the reflected light (an integrated value over all visible wavelengths). Temperature dependence on total reflectivity was found to follow an inverse power function of the material's temperature.

  20. Thermal Loading of a Direct Drive Target Rarefied Gas

    SciTech Connect

    Christensen, B.R.; Raffray, A.R.; Tillack, M.S.

    2005-05-15

    In an inertial fusion energy (IFE) power plant, each fusion micro-explosion ({approx}10 Hz) causes thermal and structural loads on the IFE reactor wall and driver optics. The loading on the wall must remain sufficiently low to ensure that economic and safety constraints are met.One proposed method for decreasing the intensity of the wall loading is to fill the reaction chamber with a gas, such as Xe, at low density. The gas will absorb much of the radiation and ion energy from the fusion event, and then slowly release it to the chamber wall. Unfortunately the protective gas introduces major heat loads on the direct drive target. The thermal loading of a target, during injection, largely determines the viability of that target upon reaching chamber center. Thus, the density of the gas must be carefully selected to ensure that a target will survive injection.The objective of this work is to quantify and characterize the heat flux resulting from the interaction of the target and the protective gas. The loading of the target is modeled using DS2V, a commercial DSMC (Direct Simulation Monte Carlo) program. Using DS2V, this work explores the effect of the protective gas density, temperature, sticking (condensation) and accommodation coefficients on the heat flux to the target.

  1. Optimization of a Mu2e production solenoid heat and radiation shield using MARS15

    SciTech Connect

    Pronskikh, V.S.; Mokhov, N.V.; /Fermilab

    2011-02-01

    A Monte-Carlo study of several Mu2e Production Solenoid (PS) absorber (heat shield) versions using the MARS15 code has been performed. Optimizations for material as well as cost (amount of tungsten) have been carried out. Studied are such quantities as the number of displacements per atom (DPA) in the helium-cooled solenoid superconducting coils, power density and dynamic heat load in various parts of the PS and its surrounding structures. Prompt dose, residual dose, secondary particle flux are also simulated in the PS structures and the experimental hall. A preliminary choice of the PS absorber design is made on the ground of these studies.

  2. High speed interference heating loads and pressure distributions resulting from elevon deflections. [shock wave interaction effects on hypersonic aircraft surfaces

    NASA Technical Reports Server (NTRS)

    Johnson, C. B.; Kaufman, L. G., III

    1979-01-01

    Effects of elevon-induced three-dimensional shock-wave turbulent boundary-layer interactions on hypersonic aircraft surfaces are analyzed. Detailed surface pressure and heating rate distributions obtained on wing-elevon-fuselage models representative of aft portions of hypersonic aircraft are compared with analytical and experimental results from other sources. Examples are presented that may be used to evaluate the adequacy of current theoretical methods for estimating the effects of three-dimensional shock-wave turbulent boundary-layer interactions on hypersonic aircraft surfaces.

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

    SciTech Connect

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

    2009-08-14

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

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

    2009-08-14

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

  5. Direct fired heat exchanger

    DOEpatents

    Reimann, Robert C.; Root, Richard A.

    1986-01-01

    A gas-to-liquid heat exchanger system which transfers heat from a gas, generally the combustion gas of a direct-fired generator of an absorption machine, to a liquid, generally an absorbent solution. The heat exchanger system is in a counterflow fluid arrangement which creates a more efficient heat transfer.

  6. A heat flow calorimeter

    NASA Technical Reports Server (NTRS)

    Johnston, W. V.

    1973-01-01

    Reaction mechanism for nickel-cadmium cell is not known well enough to allow calculation of heat effects. Calorimeter can measure heat absorbed or evolved in cell, by determining amount of external heat that must be supplied to calorimeter to maintain constant flow isothermal heat sink.

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

    PubMed

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

    2013-01-01

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

  8. 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.

  9. 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.

  10. Heat cascading regenerative sorption heat pump

    NASA Technical Reports Server (NTRS)

    Jones, Jack A. (Inventor)

    1995-01-01

    A simple heat cascading regenerative sorption heat pump process with rejected or waste heat from a higher temperature chemisorption circuit (HTCC) powering a lower temperature physisorption circuit (LTPC) which provides a 30% total improvement over simple regenerative physisorption compression heat pumps when ammonia is both the chemisorbate and physisorbate, and a total improvement of 50% or more for LTPC having two pressure stages. The HTCC contains ammonia and a chemisorbent therefor contained in a plurality of canisters, a condenser-evaporator-radiator system, and a heater, operatively connected together. The LTPC contains ammonia and a physisorbent therefor contained in a plurality of compressors, a condenser-evaporator-radiator system, operatively connected together. A closed heat transfer circuit (CHTC) is provided which contains a flowing heat transfer liquid (FHTL) in thermal communication with each canister and each compressor for cascading heat from the HTCC to the LTPC. Heat is regenerated within the LTPC by transferring heat from one compressor to another. In one embodiment the regeneration is performed by another CHTC containing another FHTL in thermal communication with each compressor. In another embodiment the HTCC powers a lower temperature ammonia water absorption circuit (LTAWAC) which contains a generator-absorber system containing the absorbent, and a condenser-evaporator-radiator system, operatively connected together. The absorbent is water or an absorbent aqueous solution. A CHTC is provided which contains a FHTL in thermal communication with the generator for cascading heat from the HTCC to the LTAWAC. Heat is regenerated within the LTAWAC by transferring heat from the generator to the absorber. The chemical composition of the chemisorbent is different than the chemical composition of the physisorbent, and the absorbent. The chemical composition of the FHTL is different than the chemisorbent, the physisorbent, the absorbent, and ammonia.

  11. Absorber for terahertz radiation management

    DOEpatents

    Biallas, George Herman; Apeldoorn, Cornelis; Williams, Gwyn P.; Benson, Stephen V.; Shinn, Michelle D.; Heckman, John D.

    2015-12-08

    A method and apparatus for minimizing the degradation of power in a free electron laser (FEL) generating terahertz (THz) radiation. The method includes inserting an absorber ring in the FEL beam path for absorbing any irregular THz radiation and thus minimizes the degradation of downstream optics and the resulting degradation of the FEL output power. The absorber ring includes an upstream side, a downstream side, and a plurality of wedges spaced radially around the absorber ring. The wedges form a scallop-like feature on the innermost edges of the absorber ring that acts as an apodizer, stopping diffractive focusing of the THz radiation that is not intercepted by the absorber. Spacing between the scallop-like features and the shape of the features approximates the Bartlett apodization function. The absorber ring provides a smooth intensity distribution, rather than one that is peaked on-center, thereby eliminating minor distortion downstream of the absorber.

  12. Spacesuit Evaporator-Absorber-Radiator (SEAR)

    NASA Technical Reports Server (NTRS)

    Hodgson, Ed; Izenson, Mike; Chan, Weibo; Bue, Grant C.

    2012-01-01

    For decades advanced spacesuit developers have pursued a regenerable, robust nonventing system for heat rejection. Toward this end, this paper investigates linking together two previously developed technologies, namely NASA s Spacesuit Water Membrane Evaporator (SWME), and Creare s Lithium Chloride Absorber Radiator (LCAR). Heat from a liquid cooled garment is transported to SWME that provides cooling through evaporation. This water vapor is then captured by solid LiCl in the LCAR with a high enthalpy of absorption, resulting in sufficient temperature lift to reject heat to space by radiation. After the sortie, the LCAR would be heated up and dried in a regenerator to drive off and recover the absorbed evaporant. A engineering development prototype was built and tested in vacuum conditions at a sink temperature of 250 K. The LCAR was able to stably reject 75 W over a 7-hour period. A conceptual design of a full-scale radiator is proposed. Excess heat rejection above 240 W would be accomplished through venting of the evaporant. Loop closure rates were predicted for various exploration environment scenarios.

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

    NASA Astrophysics Data System (ADS)

    Obara, Shin'ya; Kudo, Kazuhiko

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

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

    SciTech Connect

    Ni, L.; Skala, K.

    1996-06-01

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

  15. 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

  16. 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

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

    PubMed

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

    2016-09-01

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

  18. Corrosion resistant neutron absorbing coatings

    DOEpatents

    Choi, Jor-Shan; Farmer, Joseph C; Lee, Chuck K; Walker, Jeffrey; Russell, Paige; Kirkwood, Jon; Yang, Nancy; Champagne, Victor

    2013-11-12

    A method of forming a corrosion resistant neutron absorbing coating comprising the steps of spray or deposition or sputtering or welding processing to form a composite material made of a spray or deposition or sputtering or welding material, and a neutron absorbing material. Also a corrosion resistant neutron absorbing coating comprising a composite material made of a spray or deposition or sputtering or welding material, and a neutron absorbing material.

  19. Corrosion resistant neutron absorbing coatings

    DOEpatents

    Choi, Jor-Shan; Farmer, Joseph C.; Lee, Chuck K.; Walker, Jeffrey; Russell, Paige; Kirkwood, Jon; Yang, Nancy; Champagne, Victor

    2012-05-29

    A method of forming a corrosion resistant neutron absorbing coating comprising the steps of spray or deposition or sputtering or welding processing to form a composite material made of a spray or deposition or sputtering or welding material, and a neutron absorbing material. Also a corrosion resistant neutron absorbing coating comprising a composite material made of a spray or deposition or sputtering or welding material, and a neutron absorbing material.

  20. Underwater acoustic omnidirectional absorber

    NASA Astrophysics Data System (ADS)

    Naify, Christina J.; Martin, Theodore P.; Layman, Christopher N.; Nicholas, Michael; Thangawng, Abel L.; Calvo, David C.; Orris, Gregory J.

    2014-02-01

    Gradient index media, which are designed by varying local element properties in given geometry, have been utilized to manipulate acoustic waves for a variety of devices. This study presents a cylindrical, two-dimensional acoustic "black hole" design that functions as an omnidirectional absorber for underwater applications. The design features a metamaterial shell that focuses acoustic energy into the shell's core. Multiple scattering theory was used to design layers of rubber cylinders with varying filling fractions to produce a linearly graded sound speed profile through the structure. Measured pressure intensity agreed with predicted results over a range of frequencies within the homogenization limit.

  1. Solar radiation absorbing material

    DOEpatents

    Googin, John M.; Schmitt, Charles R.; Schreyer, James M.; Whitehead, Harlan D.

    1977-01-01

    Solar energy absorbing means in solar collectors are provided by a solar selective carbon surface. A solar selective carbon surface is a microporous carbon surface having pores within the range of 0.2 to 2 micrometers. Such a surface is provided in a microporous carbon article by controlling the pore size. A thermally conductive substrate is provided with a solar selective surface by adhering an array of carbon particles in a suitable binder to the substrate, a majority of said particles having diameters within the range of about 0.2-10 microns.

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

    NASA Technical Reports Server (NTRS)

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

    1973-01-01

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

  3. Effects of potential models on the adsorption of ethane and ethylene on graphitized thermal carbon black. Study of two-dimensional critical temperature and isosteric heat versus loading.

    PubMed

    Do, D D; Do, H D

    2004-12-01

    Adsorption of ethylene and ethane on graphitized thermal carbon black and in slit pores whose walls are composed of graphene layers is studied in detail to investigate the packing efficiency, the two-dimensional critical temperature, and the variation of the isosteric heat of adsorption with loading and temperature. Here we used a Monte Carlo simulation method with a grand canonical Monte Carlo ensemble. A number of two-center Lennard-Jones (LJ) potential models are investigated to study the impact of the choice of potential models in the description of adsorption behavior. We chose two 2C-LJ potential models in our investigation of the (i) UA-TraPPE-LJ model of Martin and Siepmann for ethane and Wick et al. for ethylene and (ii) AUA4-LJ model of Ungerer et al. for ethane and Bourasseau et al. for ethylene. These models are used to study the adsorption of ethane and ethylene on graphitized thermal carbon black. It is found that the solid-fluid binary interaction parameter is a function of adsorbate and temperature, and the adsorption isotherms and heat of adsorption are well described by both the UA-TraPPE and AUA models, although the UA-TraPPE model performs slightly better. However, the local distributions predicted by these two models are slightly different. These two models are used to explore the two-dimensional condensation for the graphitized thermal carbon black, and these values are 110 K for ethylene and 120 K for ethane.

  4. Heat load estimation in the duct and blanket module region of the HNB during various operating scenarios of the ITER machine

    NASA Astrophysics Data System (ADS)

    Singh, M. J.; Boilson, D.; Hemsworth, R.; Dlougach, E.; Geli, F.; Chareyre, J.; Urbani, M.; Krylov, A.; Panasenkov, A.; Lisgo, S.; Pitts, R.; Roccella, M.

    2013-02-01

    The neutral beam heating and current drive system in ITER consists of 3 beam lines (2 present plus one future upgrade) with each beam line designed to deliver 40 A of accelerated deuterium beams at 1 MeV with a 25% duty cycle. The beam line is coupled to the vacuum vessel port of the tokamak through a series of front end components and a connecting duct. The edge of the beam line and the walls of the vacuum vessel up to the blanket aperture are lined with duct liners to protect them from heat loads from the direct and re-ionised beam interception during the transport of the neutral beam. The direct interception of the beam is due to the inherent divergence of the beam or its halo component. The re-ionised beam consists of ions born due to the interaction of the accelerated neutral beam with the back ground gas all along the beam line, after the neutraliser exit. The motion of these ions is also affected by the electric field of the residual ion dump (RID) and the magnetic field from the tokamak during its various phases of operation. A systematic study to assess the heat loads during the neutral beam transport on the different front end components, the various regions of the duct and the blanket modules is necessary to ascertain the proper thermo-mechanical design of these components. The beam transmission code "BTR" has been used for that purpose. Simulations have been carried out of the gas profile along the neutral beam line considering gas flux from the ion source, the neutraliser, the RID (due to the dumped ion beams) and the flow of the gas from the tokamak to the duct. The re-ionisation losses have been estimated to be 13.8 % for the region between the exit of the neutraliser and the blanket module edge. The magnetic fields for the various operating scenarios of the tokamak like the start of the burn (SOB), end of burn (EOB), X point formation (XPF), XPF + 20 s, EOB + disruption have been simulated for the 15 MA DT scenario. The beamlet divergence has been

  5. A simple model for calculating the performance of a lithium-bromide/water coil absorber

    SciTech Connect

    Seewald, J.S.; Perez-Blanco, H.

    1994-12-31

    The performance of an absorber is of paramount importance when considering the overall performance of an absorption-cycle heat pump. Thus, a thorough understanding of the absorption process and a means of predicting the performance of an absorber are useful. For these reasons, a model of the absorption process in a simple absorber, using lithium-bromide and water as the working fluids, was developed. Subsequently, the model was applied to a particular absorber through the use of a computer program. Using this program, the effect on absorber performance due to the variance of several parameters was analyzed. The results of the absorber performance simulations are also presented.

  6. Investigations on Absorber Materials at Cryogenic Temperatures

    SciTech Connect

    Marhauser, Frank; Elliott, Thomas; Rimmer, Robert

    2009-05-01

    In the framework of the 12 GeV upgrade project for the Continuous Electron Beam Accelerator Facility (CEBAF) improvements are being made to refurbish cryomodules housing Thomas Jefferson National Accelerator Facility's (JLab) original 5-cell cavities. Recently we have started to look into a possible simplification of the existing Higher Order Mode (HOM) absorber design combined with the aim to find alternative material candidates. The absorbers are implemented in two HOM-waveguides immersed in the helium bath and operate at 2 K temperature. We have built a cryogenic setup to perform measurements on sample load materials to investigate their lossy characteristics and variations from room temperature down to 2 K. Initial results are presented in this paper.

  7. Dual broadband metamaterial absorber.

    PubMed

    Kim, Young Ju; Yoo, Young Joon; Kim, Ki Won; Rhee, Joo Yull; Kim, Yong Hwan; Lee, YoungPak

    2015-02-23

    We propose polarization-independent and dual-broadband metamaterial absorbers at microwave frequencies. This is a periodic meta-atom array consisting of metal-dielectric-multilayer truncated cones. We demonstrate not only one broadband absorption from the fundamental magnetic resonances but additional broadband absorption in high-frequency range using the third-harmonic resonance, by both simulation and experiment. In simulation, the absorption was over 90% in 3.93-6.05 GHz, and 11.64-14.55 GHz. The corresponding experimental absorption bands over 90% were 3.88-6.08 GHz, 9.95-10.46 GHz and 11.86-13.84 GHz, respectively. The origin of absorption bands was elucidated. Furthermore, it is independent of polarization angle owing to the multilayered circular structures. The design is scalable to smaller size for the infrared and the visible ranges.

  8. Thermally induced nonlinear optical absorption in metamaterial perfect absorbers

    SciTech Connect

    Guddala, Sriram Kumar, Raghwendra; Ramakrishna, S. Anantha

    2015-03-16

    A metamaterial perfect absorber consisting of a tri-layer (Al/ZnS/Al) metal-dielectric-metal system with top aluminium nano-disks was fabricated by laser-interference lithography and lift-off processing. The metamaterial absorber had peak resonant absorbance at 1090 nm and showed nonlinear absorption for 600ps laser pulses at 1064 nm wavelength. A nonlinear saturation of reflectance was measured to be dependent on the average laser power incident and not the peak laser intensity. The nonlinear behaviour is shown to arise from the heating due to the absorbed radiation and photo-thermal changes in the dielectric properties of aluminium. The metamaterial absorber is seen to be damage resistant at large laser intensities of 25 MW/cm{sup 2}.

  9. Thermally induced nonlinear optical absorption in metamaterial perfect absorbers

    NASA Astrophysics Data System (ADS)

    Guddala, Sriram; Kumar, Raghwendra; Ramakrishna, S. Anantha

    2015-03-01

    A metamaterial perfect absorber consisting of a tri-layer (Al/ZnS/Al) metal-dielectric-metal system with top aluminium nano-disks was fabricated by laser-interference lithography and lift-off processing. The metamaterial absorber had peak resonant absorbance at 1090 nm and showed nonlinear absorption for 600ps laser pulses at 1064 nm wavelength. A nonlinear saturation of reflectance was measured to be dependent on the average laser power incident and not the peak laser intensity. The nonlinear behaviour is shown to arise from the heating due to the absorbed radiation and photo-thermal changes in the dielectric properties of aluminium. The metamaterial absorber is seen to be damage resistant at large laser intensities of 25 MW/cm2.

  10. High-Capacity Heat-Pipe Evaporator

    NASA Technical Reports Server (NTRS)

    Oren, J. A.; Duschatko, R. J.; Voss, F. E.; Sauer, L. W.

    1989-01-01

    Heat pipe with cylindrical heat-input surface has higher contact thermal conductance than one with usual flat surface. Cylindrical heat absorber promotes nearly uniform flow of heat into pipe at all places around periphery of pipe, helps eliminate hotspots on heat source. Lugs in aluminum pipe carry heat from outer surface to liquid oozing from capillaries of wick. Liquid absorbs heat, evaporates, and passes out of evaporator through interlug passages.

  11. Chemical heat pump

    DOEpatents

    Greiner, Leonard

    1980-01-01

    A chemical heat pump system is disclosed for use in heating and cooling structures such as residences or commercial buildings. The system is particularly adapted to utilizing solar energy, but also increases the efficiency of other forms of thermal energy when solar energy is not available. When solar energy is not available for relatively short periods of time, the heat storage capacity of the chemical heat pump is utilized to heat the structure as during nighttime hours. The design also permits home heating from solar energy when the sun is shining. The entire system may be conveniently rooftop located. In order to facilitate installation on existing structures, the absorber and vaporizer portions of the system may each be designed as flat, thin wall, thin pan vessels which materially increase the surface area available for heat transfer. In addition, this thin, flat configuration of the absorber and its thin walled (and therefore relatively flexible) construction permits substantial expansion and contraction of the absorber material during vaporization and absorption without generating voids which would interfere with heat transfer. The heat pump part of the system heats or cools a house or other structure through a combination of evaporation and absorption or, conversely, condensation and desorption, in a pair of containers. A set of automatic controls change the system for operation during winter and summer months and for daytime and nighttime operation to satisfactorily heat and cool a house during an entire year. The absorber chamber is subjected to solar heating during regeneration cycles and is covered by one or more layers of glass or other transparent material. Daytime home air used for heating the home is passed at appropriate flow rates between the absorber container and the first transparent cover layer in heat transfer relationship in a manner that greatly reduce eddies and resultant heat loss from the absorbant surface to ambient atmosphere.

  12. LBNF Hadron Absorber: Mechanical Design and Analysis for 2.4MW Operation

    SciTech Connect

    Hartsell, B.; Anderson, K.; Hylen, J.; Sidorov, V.; Tariq, S.

    2015-06-01

    Fermilab’s Long-Baseline Neutrino Facility (LBNF) requires an absorber, essentially a large beam dump consisting of actively cooled aluminum and steel blocks, at the end of the decay pipe to stop leftover beam particles and provide radiation protection to people and groundwater. At LBNF’s final beam power of 2.4 MW and assuming the worst case condition of a 204 m long helium filled decay pipe, the absorber is required to handle a heat load of about 750 kW. This results in significant thermal management challenges which have been mitigated by the addition of an aluminum ‘spoiler’ and ‘sculpting’ the central portion of the aluminum core blocks. These thermal effects induce structural stresses which can lead to fatigue and creep considerations. Various accident conditions are considered and safety systems are planned to monitor operation and any accident pulses. Results from these thermal and structural analyses will be presented as well as the mechanical design of the absorber. The design allows each of the core blocks to be remotely removed and replaced if necessary. A shielded remote handling structure is incorporated to hold the hadron monitor when it is removed from the beam.

  13. Infrared bolometers with silicon nitride micromesh absorbers

    NASA Technical Reports Server (NTRS)

    Bock, J. J.; Turner, A. D.; DelCastillo, H. M.; Beeman, J. W.; Lange, A. E.; Mauskopf, P. D.

    1996-01-01

    Sensitive far infrared and millimeter wave bolometers fabricated from a freestanding membrane of low stress silicon nitride are reported. The absorber, consisting of a metallized silicon nitride micromesh thermally isolated by radial legs of silicon nitride, is placed in an integrating cavity to efficiently couple to single mode or multiple mode infrared radiation. This structure provides low heat capacity, low thermal conduction and minimal cross section to energetic particles. A neutron transmutation doped Ge thermister is bump bonded to the center of the device and read out with evaporated Cr-Au leads. The limiting performance of the micromesh absorber is discussed and the recent results obtained from a 300 mK cold stage are summarized.

  14. Broadband patterned magnetic microwave absorber

    SciTech Connect

    Li, Wei; Wu, Tianlong; Wang, Wei; Guan, Jianguo; Zhai, Pengcheng

    2014-07-28

    It is a tough task to greatly improve the working bandwidth for the traditional flat microwave absorbers because of the restriction of available material parameters. In this work, a simple patterning method is proposed to drastically broaden the absorption bandwidth of a conventional magnetic absorber. As a demonstration, an ultra-broadband microwave absorber with more than 90% absorption in the frequency range of 4–40 GHz is designed and experimentally realized, which has a thin thickness of 3.7 mm and a light weight equivalent to a 2-mm-thick flat absorber. In such a patterned absorber, the broadband strong absorption is mainly originated from the simultaneous incorporation of multiple λ/4 resonances and edge diffraction effects. This work provides a facile route to greatly extend the microwave absorption bandwidth for the currently available absorbing materials.

  15. Liquid Hydrogen Absorber for MICE

    SciTech Connect

    Ishimoto, S.; Suzuki, S.; Yoshida, M.; Green, Michael A.; Kuno, Y.; Lau, Wing

    2010-05-30

    Liquid hydrogen absorbers for the Muon Ionization Cooling Experiment (MICE) have been developed, and the first absorber has been tested at KEK. In the preliminary test at KEK we have successfully filled the absorber with {approx}2 liters of liquid hydrogen. The measured hydrogen condensation speed was 2.5 liters/day at 1.0 bar. No hydrogen leakage to vacuum was found between 300 K and 20 K. The MICE experiment includes three AFC (absorber focusing coil) modules, each containing a 21 liter liquid hydrogen absorber made of aluminum. The AFC module has safety windows to separate its vacuum from that of neighboring modules. Liquid hydrogen is supplied from a cryocooler with cooling power 1.5 W at 4.2 K. The first absorber will be assembled in the AFC module and installed in MICE at RAL.

  16. Electrochemically regenerable carbon dioxide absorber

    NASA Technical Reports Server (NTRS)

    Woods, R. R.; Marshall, R. D.; Schubert, F. H.; Heppner, D. B.

    1979-01-01

    Preliminary designs were generated for two electrochemically regenerable carbon dioxide absorber concepts. Initially, an electrochemically regenerable absorption bed concept was designed. This concept incorporated the required electrochemical regeneration components in the absorber design, permitting the absorbent to be regenerated within the absorption bed. This hardware was identified as the electrochemical absorber hardware. The second hardware concept separated the functional components of the regeneration and absorption process. This design approach minimized the extravehicular activity component volume by eliminating regeneration hardware components within the absorber. The electrochemical absorber hardware was extensively characterized for major operating parameters such as inlet carbon dioxide partial pressure, process air flow rate, operational pressure, inlet relative humidity, regeneration current density and absorption/regeneration cycle endurance testing.

  17. 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.

  18. Electromagnetic power absorber

    NASA Technical Reports Server (NTRS)

    Iwasaki, R.

    1977-01-01

    Device has reflection coefficient of order of few tenths of percent and is designed to maintain isothermal temperature distribution in high-power microwave and laser applications. Rigid tile functions over broad temperature range and serves as blackbody radiometric standard. Tile modules allow assembly of compact and economical custom-design configurations. Epoxy surface of tiles is insulated with styrofoam against environmental changes and is not subject to convective heat loss. Technique also prevents moisture accumulation and serves as infrared radiation shield.

  19. Fabrication and microwave absorbing properties of NixPy nanotubes

    NASA Astrophysics Data System (ADS)

    Wang, Haoran; Wan, Lei; Chen, Yaqiong; Hu, Wenbin; Liu, Lei; Zhong, Cheng; Deng, Yida

    2015-06-01

    Materials possessing microwave absorbing properties have been a researching hotspot for their important applications amid a high frequency electromagnetic waves environment. This paper focuses on the preparation of a series of NixPy(x:y = 2.65-2.73) nanotubes (NTs) and their corresponding microwave absorbing properties. After being heat-treated, different NixPy phases would appear, without damaging their initial hollow morphologies. These processes were accompanied with the alteration of related physical properties. Low enough minimum reflection loss (RL) has been achieved in all of these samples, with -48.63 dB as the lowest one being obtained at the non-heat-treated sample. Besides, a large proportion of the microwave frequency band could be covered on the 450 °C heat-treated sample (over a 4.5 GHz bandwidth). These are indicative of the superior microwave absorbing nature of NixPy NTs.

  20. Schlieren photography to study sound interaction with highly absorbing materials.

    PubMed

    Declercq, Nico F; Degrieck, Joris; Leroy, Oswald

    2005-06-01

    Strong absorption of sound is often caused by the conversion of sound energy into heat. When this happens, it is not possible to study the interaction of sound with the absorbing material by means of reflected sound characteristics, because there is no reflected sound. Detecting for example the distance that sound travels in a strongly absorbing material, can be done by heat detection systems. However, the presence of temperature detectors in such materials interferes with the sound field and is therefore not really suitable. Infrared measurements are a possible option. Another option is the use of Schlieren photography for simultaneous visualization of sound and heat. This technique is briefly outlined with a 3 MHz sound beam incident on a highly absorbing sponge. PMID:15950023

  1. 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.

  2. Plants absorb heavy metals

    SciTech Connect

    Parry, J.

    1995-02-01

    Decontamination of heavy metals-polluted soils remains one of the most intractable problems of cleanup technology. Currently available techniques include extraction of the metals by physical and chemical means, such as acid leaching and electroosmosis, or immobilization by vitrification. There are presently no techniques for cleanup which are low cost and retain soil fertility after metals removal. But a solution to the problem could be on the horizon. A small but growing number of plants native to metalliferous soils are known to be capable of accumulating extremely high concentrations of metals in their aboveground portions. These hyperaccumulators, as they are called, contain up to 1,000 times larger metal concentrations in their aboveground parts than normal species. Their distribution is global, including many different families of flowering plants of varying growth forms, from herbaceous plants to trees. Hyperaccumulators absorb metals they do not need for their own nutrition. The metals are accumulated in the leaf and stem vacuoles, and to a lesser extent in the roots.

  3. Spacesuit Evaporator-Absorber-Radiator (SEAR)

    NASA Technical Reports Server (NTRS)

    Bue, Grant C.; Hodgson, Ed; Izenso, Mike; Chan, Weibo; Cupples, Scott

    2011-01-01

    For decades advanced spacesuit developers have pursued a regenerable, robust non-venting system for heat rejection. Toward this end, this paper investigates linking together two previously developed technologies, namely NASA's Spacesuit Water Membrane Evaporator (SWME), and Creare's lithium chloride Heat Pump Radiator (HPR). Heat from a liquid cooled garment is transported to SWME that provides cooling through evaporation. The SEAR is evacuated at the onset of operations and thereafter, the water vapor absorption rate of the HPR maintains a low pressure environment for the SWME to evaporate effectively. This water vapor captured by solid LiCl in the HPR with a high enthalpy of absorption, results in sufficient temperature lift to reject most of the heat to space by radiation. After the sortie, the HPR would be heated up in a regenerator to drive off and recover the absorbed evaporant. A one-fourth scale prototype was built and tested in vacuum conditions at a sink temperature of 250 K. The HPR was able to stably reject 60 W over a 7-hour period. A conceptual design of a full-scale radiator is proposed. Excess heat rejection above 240 W would be accomplished through venting of the evaporant. Loop closure rates were predicted for various exploration environment scenarios.

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

    NASA Astrophysics Data System (ADS)

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

    2014-11-01

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

  5. Leaf absorbance and photosynthesis

    NASA Technical Reports Server (NTRS)

    Schurer, Kees

    1994-01-01

    The absorption spectrum of a leaf is often thought to contain some clues to the photosynthetic action spectrum of chlorophyll. Of course, absorption of photons is needed for photosynthesis, but the reverse, photosynthesis when there is absorption, is not necessarily true. As a check on the existence of absorption limits we measured spectra for a few different leaves. Two techniques for measuring absorption have been used, viz. the separate determination of the diffuse reflectance and the diffuse transmittance with the leaf at a port of an integrating sphere and the direct determination of the non-absorbed fraction with the leaf in the sphere. In a cross-check both methods yielded the same results for the absorption spectrum. The spectrum of a Fuchsia leaf, covering the short-wave region from 350 to 2500 nm, shows a high absorption in UV, blue and red, the well known dip in the green and a steep fall-off at 700 nm. Absorption drops to virtually zero in the near infrared, with subsequent absorptions, corresponding to the water absorption bands. In more detailed spectra, taken at 5 nm intervals with a 5 nm bandwidth, differences in chlorophyll content show in the different depths of the dip around 550 nm and in a small shift of the absorption edge at 700 nm. Spectra for Geranium (Pelargonium zonale) and Hibiscus (with a higher chlorophyll content) show that the upper limit for photosynthesis can not be much above 700 nm. No evidence, however, is to be seen of a lower limit for photosynthesis and, in fact, some experiments down to 300 nm still did not show a decrease of the absorption although it is well recognized that no photosynthesis results with 300 nm wavelengths.

  6. Hydraulic shock absorber

    SciTech Connect

    Tanaka, T.

    1987-03-03

    This patent describes a hydraulic shock absorber including a piston reciprocating in a cylinder, a piston upper chamber and a piston lower chamber which are oil-tightly separated by the piston, piston ports formed through the piston in a circle for communicating the piston upper chamber with the piston lower chamber, and return ports formed outside of the piston ports in a circle for communicating the piston upper chamber with the piston lower chamber. It also includes a sheet ring-like non-return valve provided above the piston and fitted to a piston rod, valve holes formed through the non-return valve in opposed relation with the piston ports. A ring-like non-return valve stopper fixed to the piston rod on an upper side of the non-return valve with a small spaced defined between the non-return valve and the non-return valve stopper, and a spring is interposed between the non-return valve and the non-return valve stopper for normally urging the non-return valve to an upper surface of the piston. Movement of the piston to the piston upper chamber allows oil to flow from the piston upper chamber through the piston ports to the piston lower chamber, while the return ports are closed by the non-return valve to generate a vibration damping force by resistance upon pass of the oil through the piston parts. The improvement described here comprises a groove formed in an upper surface of the piston facing the non-return valve and aligned with the valve holes, the groove being in the circle where the piston ports lie and being in communication with the piston ports.

  7. The broadband dynamic vibration absorber

    NASA Astrophysics Data System (ADS)

    Hunt, J. B.; Nissen, J.-C.

    1982-08-01

    The limited effectiveness of the linear passive dynamic vibration absorber is described. This is followed by an analysis producing the response of a primary system when a non-linear softening Belleville spring is used in the absorber. It is shown that the suppression bandwidth can be doubled by this means.

  8. A circuit method to integrate metamaterial and graphene in absorber design

    NASA Astrophysics Data System (ADS)

    Wang, Zuojia; Zhou, Min; Lin, Xiao; Liu, Huixia; Wang, Huaping; Yu, Faxin; Lin, Shisheng; Li, Erping; Chen, Hongsheng

    2014-10-01

    We theoretically investigate a circuit analog approach to integrate graphene and metamaterial in electromagnetic wave absorber design. In multilayer graphene-metamaterial (GM) absorbers, ultrathin metamaterial elements are theoretically modeled as equivalent loads which attached to the junctions between two transmission lines. Combining with the benefits of tunable chemical potential in graphene, an optimized GM absorber is proposed as a proof of the circuit method. Numerical simulation results demonstrate the effectiveness of the circuit analytical model. The operating frequency of the GM absorber can be varied in terahertz frequency, indicating the potential applications of the GM absorber in sensors, modulators, and filters.

  9. Solar-Heated Gasifier

    NASA Technical Reports Server (NTRS)

    Qader, S. A.

    1985-01-01

    Catalytic coal and biomass gasifer system heated by solar energy. Sunlight from solar concentrator focused through quartz window onto ceramic-honeycomb absorber surface, which raises temperature of reactant steam, fluidizing gas, and reactor walls.

  10. Interaction of inhalational anaesthetics with CO2 absorbents.

    PubMed

    Baum, Jan A; Woehlck, Harvey J

    2003-03-01

    We review the currently available carbon dioxide absorbents: sodium hydroxide lime (=soda lime), barium hydroxide lime, potassium-hydroxide-free soda lime, calcium hydroxide lime and non-caustic lime. In general, all of these carbon dioxide absorbents are liable to react with inhalational anaesthetics. However, there is a decreasing reactivity of the different absorbents with inhalational anaesthetics: barium hydroxide lime > soda lime > potassium-hydroxide-free soda lime > calcium hydroxide lime and non-caustic lime. Gaseous compounds generated by the reaction of the anaesthetics with desiccated absorbents are those that threaten patients. All measures are comprehensively described to--as far as possible--prevent any accidental drying out of the absorbent. Whether or not compound A, a gaseous compound formed by the reaction of sevoflurane with normally hydrated absorbents, is still a matter of concern is discussed. Even after very high loading with this compound, during long-lasting low-flow sevoflurane anaesthesias, no clinical or laboratory signs of renal impairment were observed in any of the surgical patients. Finally, guidelines for the judicious use of different absorbents are given. PMID:12751549

  11. An absorbed dose calorimeter for IMRT dosimetry

    NASA Astrophysics Data System (ADS)

    Duane, S.; Aldehaybes, M.; Bailey, M.; Lee, N. D.; Thomas, C. G.; Palmans, H.

    2012-10-01

    A new calorimeter for dosimetry in small and complex fields has been built. The device is intended for the direct determination of absorbed dose to water in moderately small fields and in composite fields such as IMRT treatments, and as a transfer instrument calibrated against existing absorbed dose standards in conventional reference conditions. The geometry, materials and mode of operation have been chosen to minimize detector perturbations when used in a water phantom, to give a reasonably isotropic response and to minimize the effects of heat transfer when the calorimeter is used in non-reference conditions in a water phantom. The size of the core is meant to meet the needs of measurement in IMRT treatments and is comparable to the size of the air cavity in a type NE2611 ionization chamber. The calorimeter may also be used for small field dosimetry. Initial measurements in reference conditions and in an IMRT head and neck plan, collapsed to gantry angle zero, have been made to estimate the thermal characteristics of the device, and to assess its performance in use. The standard deviation (estimated repeatability) of the reference absorbed dose measurements was 0.02 Gy (0.6%).

  12. ABSORBING WIPP BRINES: A TRU WASTE DISPOSAL STRATEGY

    SciTech Connect

    Yeamans, D. R.; Wrights, R. S.

    2002-02-25

    Los Alamos National Laboratory (LANL) has completed experiments involving 15 each, 250- liter experimental test containers of transuranic (TRU) heterogeneous waste immersed in two types of brine similar to those found in the underground portion of the Waste Isolation Pilot Plant (WIPP). To dispose of the waste without removing the brine from the test containers, LANL added commercially available cross-linked polyacrylate granules to absorb the 190 liters of brine in each container, making the waste compliant for shipping to the WIPP in a Standard Waste Box (SWB). Prior to performing the absorption, LANL and the manufacturer of the absorbent conducted laboratory and field tests to determine the ratio of absorbent to brine that would fully absorb the liquid. Bench scale tests indicated a ratio of 10 parts Castile brine to one part absorbent and 6.25 parts Brine A to one part absorbent. The minimum ratio of absorbent to brine was sought because headspace in the containers was limited. However, full scale testing revealed that the ratio should be adjusted to be about 15% richer in absorbent. Additional testing showed that the absorbent would not apply more than 13.8 kPa pressure on the walls of the vessel and that the absorbent would still function normally at that pressure and would not degrade in the approximately 5e-4 Sv/hr radioactive field produced by the waste. Heat generation from the absorption was minimal. The in situ absorption created a single waste stream of 8 SWBs whereas the least complicated alternate method of disposal would have yielded at least an additional 2600 liters of mixed low level liquid waste plus about two cubic meters of mixed low level solid waste, and would have resulted in higher risk of radiation exposure to workers. The in situ absorption saved $311k in a combination of waste treatment, disposal, material and personnel costs compared to the least expensive alternative and $984k compared to the original plan.

  13. Absorbing WIPP brines : a TRU waste disposal strategy.

    SciTech Connect

    Yeamans, D. R.; Wright, R.

    2002-01-01

    Los Alamos National Laboratory (LANL) has completed experiments involving 15 each, 250-liter experimental test containers of transuranic (TRU) heterogeneous waste immersed in two types of brine similar to those found in the underground portion of the Waste Isolation Pilot Plant (WIPP). To dispose of the waste without removing the brine from the test containers, LANL added commercially available cross-linked polyacrylate granules to absorb the 190 liters of brine in each container, making the waste compliant for shipping to the WlPP in a Standard Waste Box (SWB). Prior to performing the absorption, LANL and the manufacturer of the absorbent conducted laboratory and field tests to determine the ratio of absorbent to brine that would fully absorb the liquid. Bench scale tests indicated a ratio of 10 parts Castile brine to one part absorbent and 6.25 parts Brine A to one part absorbent. The minimum ratio of absorbent to brine was sought because headspace in the containers was limited. However, full scale testing revealed that the ratio should be adjusted to be about 15% richer in absorbent. Additional testing showed that the absorbent would not apply more than 13.8 kPa pressure on the walls of the vessel and that the absorbent would still function normally at that pressure and would not degrade in the approximately 5e-4 Sv/hr radioactive field produced by the waste. Heat generation from the absorption was minimal. The in situ absorption created a single waste stream of 8 SWBs whereas the least complicated alternate method of disposal would have yielded at least an additional 2600 liters of mixed low level liquid waste plus about two cubic meters of mixed low level solid waste, and would have resulted in higher risk of radiation exposure to workers. The in situ absorption saved $3 1 lk in a combination of waste treatment, disposal, material and personnel costs compared to the least expensive alternative and $984k compared to the original plan.

  14. Absorbent product to absorb fluids. [for collection of human wastes

    NASA Technical Reports Server (NTRS)

    Dawn, F. S.; Correale, J. V. (Inventor)

    1982-01-01

    A multi-layer absorbent product for use in contact with the skin to absorb fluids is discussed. The product utilizes a water pervious facing layer for contacting the skin, overlayed by a first fibrous wicking layer, the wicking layer preferably being of the one-way variety in which fluid or liquid is moved away from the facing layer. The product further includes a first container section defined by inner and outer layer of a water pervious wicking material between which is disposed a first absorbent mass. A second container section defined by inner and outer layers between which is disposed a second absorbent mass and a liquid impermeable/gas permeable layer. Spacesuit applications are discussed.

  15. Self-Regulating Shock Absorber

    NASA Technical Reports Server (NTRS)

    Wesselski, Clarence J.

    1995-01-01

    Mechanical shock absorber keeps frictional damping force within tolerable limit. Its damping force does not increase with coefficient of friction between energy-absorbing components; rather, frictional damping force varies only slightly. Relatively insensitive to manufacturing variations and environmental conditions altering friction. Does not exhibit high breakaway friction and consequent sharp increase followed by sharp decrease in damping force at beginning of stroking. Damping force in absorber does not vary appreciably with speed of stroking. In addition, not vulnerable to leakage of hydraulic fluid.

  16. Optimisation of shock absorber process parameters using failure mode and effect analysis and genetic algorithm

    NASA Astrophysics Data System (ADS)

    Mariajayaprakash, Arokiasamy; Senthilvelan, Thiyagarajan; Vivekananthan, Krishnapillai Ponnambal

    2013-07-01

    The various process parameters affecting the quality characteristics of the shock absorber during the process were identified using the Ishikawa diagram and by failure mode and effect analysis. The identified process parameters are welding process parameters (squeeze, heat control, wheel speed, and air pressure), damper sealing process parameters (load, hydraulic pressure, air pressure, and fixture height), washing process parameters (total alkalinity, temperature, pH value of rinsing water, and timing), and painting process parameters (flowability, coating thickness, pointage, and temperature). In this paper, the process parameters, namely, painting and washing process parameters, are optimized by Taguchi method. Though the defects are reasonably minimized by Taguchi method, in order to achieve zero defects during the processes, genetic algorithm technique is applied on the optimized parameters obtained by Taguchi method.

  17. Investigation of a Shock Absorber for Safeguard of Fuel Assemblies Failure

    SciTech Connect

    Karalevicius, Renatas; Dundulis, Gintautas; Rimkevicius, Sigitas; Uspuras, Eugenijus

    2006-07-01

    The Ignalina NPP has two reactors. The Unit 1 was shut down, therefore the special equipment was designed for transportation of the fuel from Unit 1 to Unit 2. The fuel-loaded basket can drop during transportation. The special shock absorber was designed in order to avoid failure of fuel assemblies during transportation. In case of drop of fuel loaded basket, the failure of fuel assemblies can occur. This shock absorber was studied by scaled experiments at Lithuanian Energy Institute. Static and dynamic investigations of shock absorber are presented in this paper, including dependency of axial force versus axial compression. The finite element codes BRIGADE/Plus and ABAQUS/Explicit were used for analysis. Static simulation was used to optimize the dimensions of shock absorber. Dynamic analysis shows that shock absorber is capable to withstand the dynamic load for successful force suppression function in case of an accident. (authors)

  18. Thin-film absorber for a solar collector

    SciTech Connect

    Wilhelm, W.G.

    1982-02-09

    This invention pertains to energy absorbers for solar collectors, and more particularly to high performance thin film absorbers. The solar collectors comprising the absorber of this invention overcome several problems seen in current systems, such as excessive hardware, high cost and unreliability. In the preferred form, the apparatus features a substantially rigid planar frame with a thin film window bonded to one planar side of the frame. An absorber in accordance with the present invention is comprised of two thin film layers that are sealed perimetrically. In a preferred embodiment, thin film layers are formed from a metal/plastic laminate. The layers define a fluid-tight planar envelope of large surface area to volume through which a heat transfer fluid flows. The absorber is bonded to the other planar side of the frame. The thin film construction of the absorber assures substantially full envelope wetting and thus good efficiency. The window and absorber films stress the frame adding to the overall strength of the collector.

  19. Heat dissipation in water-cooled reflectors

    NASA Technical Reports Server (NTRS)

    Kozai, Toyoki

    1994-01-01

    The energy balance of a lamp varies with the thermal and optical characteristics of the reflector. The photosynthetic radiation efficiency of lamps, defined as input power divided by photosynthetically active radiation (PAR, 400-700 nm) emitted from the lamp ranges between 0.17 and 0.26. The rest of the energy input is wasted as longwave (3000 nm and over) and non-PAR shortwave radiation (from 700 nm to 3000 nm), convective, and conductive heat from the lamp, reflector, and ballast, and simply for increasing the cooling load. Furthermore, some portion of the PAR is uselessly absorbed by the inner walls, shelves, vessels, etc. and some portion of the PAR received by the plantlets is converted into sensible and latent heat. More than 98% of the energy input is probably converted into heat, with only less than 2% of the energy input being converted into chemical energy as carbohydrates by photosynthesis. Therefore, it is essential to reduce the generation of heat in the culture room in order to reduce the cooling load. Through use of a water-cooled reflector, the generation of convective and conductive heat and longwave radiation from the reflector can be reduced, without reduction of PAR.

  20. Solar heat receiver

    DOEpatents

    Hunt, Arlon J.; Hansen, Leif J.; Evans, David B.

    1985-01-01

    A receiver for converting solar energy to heat a gas to temperatures from 700.degree.-900.degree. C. The receiver is formed to minimize impingement of radiation on the walls and to provide maximum heating at and near the entry of the gas exit. Also, the receiver is formed to provide controlled movement of the gas to be heated to minimize wall temperatures. The receiver is designed for use with gas containing fine heat absorbing particles, such as carbon particles.

  1. Solar heat receiver

    DOEpatents

    Hunt, A.J.; Hansen, L.J.; Evans, D.B.

    1982-09-29

    A receiver is described for converting solar energy to heat a gas to temperatures from 700 to 900/sup 0/C. The receiver is formed to minimize impingement of radiation on the walls and to provide maximum heating at and near the entry of the gas exit. Also, the receiver is formed to provide controlled movement of the gas to be heated to minimize wall temperatures. The receiver is designed for use with gas containing fine heat absorbing particles, such as carbon particles.

  2. Americium Transmutation Feasibility When Used as Burnable Absorbers - 12392

    SciTech Connect

    Barbaras, Sean A.; Knight, Travis W.

    2012-07-01

    The use of plutonium in Mixed Oxide (MOX) fuel in traditional Pressurized Water Reactor (PWR) assemblies leads to greater americium production which is not addressed in MOX recycling. The transuranic nuclides (TRU) contribute the most to the radiotoxicity of nuclear waste and a reduction of the TRU stockpile would greatly reduce the overall radiotoxicity of what must be managed. Am-241 is a TRU of particular concern because it is the dominant contributor of total radiotoxicity for the first 1000 years in a repository. This research explored the feasibility of transmuting Am-241 by using varying amounts in MOX rods being used in place of burnable absorbers and evaluated with respect to the impact on incineration and transmutation of transuranics in MOX fuel as well as the impact on safety. This research concludes that the addition of americium to a non-uniform fuel assembly is a viable method of transmuting Am-241, holding down excess reactivity in the core while serving as a burnable poison, as well as reducing the radiotoxicity of high level waste that must be managed. The use of Am/MOX hybrid fuel assemblies to transmute americium was researched using multiple computer codes. Am-241 was shown in this study to be able to hold down excess reactivity at the beginning of cycle and shape the power distribution in the core with assemblies of varying americium content loaded in a pattern similar to the traditional use of assemblies with varying amounts of burnable absorbers. The feasibility, safety, and utility of using americium to create an Am/MOX hybrid non-uniform core were also evaluated. The core remained critical to a burnup of 22,000 MWD/MTM. The power coefficient of reactivity as well as the temperature and power defects were sufficiently negative to provide a prompt feedback mechanism in case of a transient and prevent a power excursion, thus ensuring inherent safety and protection of the core. As shown here as well as many other studies, this non

  3. Development of flat-plate solar collectors for the heating and cooling of buildings: Executive summary

    NASA Technical Reports Server (NTRS)

    1978-01-01

    An efficient, low cost, flat-plate solar collector was developed. Computer aided mathematical models of the heat process in the collector were used in defining absorber panel configuration; determining insulation thickness; and in selecting the number, spacing, and material of the covers. Prototypes were built and performance tested. Data from simulated operation of the collector are compared with predicted loads from a number of locations to determine the degree of solar utilization.

  4. Integration of regenerative shock absorber into vehicle electric system

    NASA Astrophysics Data System (ADS)

    Zhang, Chongxiao; Li, Peng; Xing, Shaoxu; Kim, Junyoung; Yu, Liangyao; Zuo, Lei

    2014-03-01

    Regenerative/Energy harvesting shock absorbers have a great potential to increase fuel efficiency and provide suspension damping simultaneously. In recent years there's intensive work on this topic, but most researches focus on electricity extraction from vibration and harvesting efficiency improvement. The integration of electricity generated from regenerative shock absorbers into vehicle electric system, which is very important to realize the fuel efficiency benefit, has not been investigated. This paper is to study and demonstrate the integration of regenerative shock absorber with vehicle alternator, battery and in-vehicle electrical load together. In the presented system, the shock absorber is excited by a shaker and it converts kinetic energy into electricity. The harvested electricity flows into a DC/DC converter which realizes two functions: controlling the shock absorber's damping and regulating the output voltage. The damping is tuned by controlling shock absorber's output current, which is also the input current of DC/DC converter. By adjusting the duty cycles of switches in the converter, its input impedance together with input current can be adjusted according to dynamic damping requirements. An automotive lead-acid battery is charged by the DC/DC converter's output. To simulate the working condition of combustion engine, an AC motor is used to drive a truck alternator, which also charges the battery. Power resistors are used as battery's electrical load to simulate in-vehicle electrical devices. Experimental results show that the proposed integration strategy can effectively utilize the harvested electricity and power consumption of the AC motor is decreased accordingly. This proves the combustion engine's load reduction and fuel efficiency improvement.

  5. 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.

  6. 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.

  7. Progress on the MICE Liquid Absorber Cooling and CryogenicDistribution System

    SciTech Connect

    Green, M.A.; Baynham, E.; Bradshaw, T.; Drumm, P.; Ivanyushenkov,Y.; Ishimoto, S.; Cummings, M.A.C.; Lau, W.W.; Yang, S.Q.

    2005-05-13

    This report describes the progress made on the design of the cryogenic cooling system for the liquid absorber for the international Muon Ionization Cooling Experiment (MICE). The absorber consists of a 20.7-liter vessel that contains liquid hydrogen (1.48 kg at 20.3 K) or liquid helium (2.59 kg at 4.2 K). The liquid cryogen vessel is located within the warm bore of the focusing magnet for the MICE. The purpose of the magnet is to provide a low beam beta region within the absorber. For safety reasons, the vacuum vessel for the hydrogen absorber is separated from the vacuum vessel for the superconducting magnet and the vacuum that surrounds the RF cavities or the detector. The absorber thin windows separate the liquid in the absorber from the absorber vacuum. The absorber vacuum vessel also has thin windows that separate the absorber vacuum space from adjacent vacuum spaces. Because the muon beam in MICE is of low intensity, there is no beam heating in the absorber. The absorber can use a single 4 K cooler to cool either liquid helium or liquid hydrogen within the absorber.

  8. Carbon Absorber Retrofit Equipment (CARE)

    SciTech Connect

    Klein, Eric

    2015-12-23

    During Project DE-FE0007528, CARE (Carbon Absorber Retrofit Equipment), Neumann Systems Group (NSG) designed, installed and tested a 0.5MW NeuStream® carbon dioxide (CO2) capture system using the patented NeuStream® absorber equipment and concentrated (6 molal) piperazine (PZ) as the solvent at Colorado Springs Utilities’ (CSU’s) Martin Drake pulverized coal (PC) power plant. The 36 month project included design, build and test phases. The 0.5MW NeuStream® CO2 capture system was successfully tested on flue gas from both coal and natural gas combustion sources and was shown to meet project objectives. Ninety percent CO2 removal was achieved with greater than 95% CO2product purity. The absorbers tested support a 90% reduction in absorber volume compared to packed towers and with an absorber parasitic power of less than 1% when configured for operation with a 550MW coal plant. The preliminary techno-economic analysis (TEA) performed by the Energy and Environmental Research Center (EERC) predicted an over-the-fence cost of $25.73/tonne of CO2 captured from a sub-critical PC plant.

  9. Mushroom plasmonic metamaterial infrared absorbers

    NASA Astrophysics Data System (ADS)

    Ogawa, Shinpei; Fujisawa, Daisuke; Hata, Hisatoshi; Uetsuki, Mitsuharu; Misaki, Koji; Kimata, Masafumi

    2015-01-01

    There has been a considerable amount of interest in the development of various types of electromagnetic wave absorbers for use in different wavelength ranges. In particular, infrared (IR) absorbers with wavelength selectivity can be applied to advanced uncooled IR sensors, which would be capable of identifying objects through their radiation spectrum. In the present study, mushroom plasmonic metamaterial absorbers (MPMAs) for the IR wavelength region were designed and fabricated. The MPMAs consist of a periodic array of thin metal micropatches connected to a thin metal plate with narrow silicon (Si) posts. A Si post height of 200 nm was achieved by isotropic XeF2 etching of a thin Si layer sandwiched between metal plates. This fabrication procedure is relatively simple and is consistent with complementary metal oxide semiconductor technology. The absorption spectra of the fabricated MPMAs were experimentally measured. In addition, theoretical calculations of their absorption properties were conducted using rigorous coupled wave analysis. Both the calculated and measured absorbance results demonstrated that these MPMAs can realize strong selective absorption at wavelengths beyond the period of the array by varying the micropatch width. Absorbance values greater than 90% were achieved. Dual- or single-mode absorption can also be selected by varying the width of the Si posts. Pixel structures using such MPMAs could be used as high responsivity, high resolution and fast uncooled IR sensors.

  10. Additive manufacturing of RF absorbers

    NASA Astrophysics Data System (ADS)

    Mills, Matthew S.

    The ability of additive manufacturing techniques to fabricate integrated electromagnetic absorbers tuned for specific radio frequency bands within structural composites allows for unique combinations of mechanical and electromagnetic properties. These composites and films can be used for RF shielding of sensitive electromagnetic components through in-plane and out-of-plane RF absorption. Structural composites are a common building block of many commercial platforms. These platforms may be placed in situations in which there is a need for embedded RF absorbing properties along with structural properties. Instead of adding radar absorbing treatments to the external surface of existing structures, which adds increased size, weight and cost; it could prove to be advantageous to integrate the microwave absorbing properties directly into the composite during the fabrication process. In this thesis, a method based on additive manufacturing techniques of composites structures with prescribed electromagnetic loss, within the frequency range 1 to 26GHz, is presented. This method utilizes screen printing and nScrypt micro dispensing to pattern a carbon based ink onto low loss substrates. The materials chosen for this study will be presented, and the fabrication technique that these materials went through to create RF absorbing structures will be described. The calibration methods used, the modeling of the RF structures, and the applications in which this technology can be utilized will also be presented.

  11. Mushroom plasmonic metamaterial infrared absorbers

    SciTech Connect

    Ogawa, Shinpei Fujisawa, Daisuke; Hata, Hisatoshi; Uetsuki, Mitsuharu; Misaki, Koji; Kimata, Masafumi

    2015-01-26

    There has been a considerable amount of interest in the development of various types of electromagnetic wave absorbers for use in different wavelength ranges. In particular, infrared (IR) absorbers with wavelength selectivity can be applied to advanced uncooled IR sensors, which would be capable of identifying objects through their radiation spectrum. In the present study, mushroom plasmonic metamaterial absorbers (MPMAs) for the IR wavelength region were designed and fabricated. The MPMAs consist of a periodic array of thin metal micropatches connected to a thin metal plate with narrow silicon (Si) posts. A Si post height of 200 nm was achieved by isotropic XeF{sub 2} etching of a thin Si layer sandwiched between metal plates. This fabrication procedure is relatively simple and is consistent with complementary metal oxide semiconductor technology. The absorption spectra of the fabricated MPMAs were experimentally measured. In addition, theoretical calculations of their absorption properties were conducted using rigorous coupled wave analysis. Both the calculated and measured absorbance results demonstrated that these MPMAs can realize strong selective absorption at wavelengths beyond the period of the array by varying the micropatch width. Absorbance values greater than 90% were achieved. Dual- or single-mode absorption can also be selected by varying the width of the Si posts. Pixel structures using such MPMAs could be used as high responsivity, high resolution and fast uncooled IR sensors.

  12. Development of flat-plate solar collectors for the heating and cooling of buildings

    NASA Technical Reports Server (NTRS)

    Ramsey, J. W.; Borzoni, J. T.; Holland, T. H.

    1975-01-01

    The relevant design parameters in the fabrication of a solar collector for heating liquids were examined. The objective was to design, fabricate, and test a low-cost, flat-plate solar collector with high collection efficiency, high durability, and requiring little maintenance. Computer-aided math models of the heat transfer processes in the collector assisted in the design. The preferred physical design parameters were determined from a heat transfer standpoint and the absorber panel configuration, the surface treatment of the absorber panel, the type and thickness of insulation, and the number, spacing and material of the covers were defined. Variations of this configuration were identified, prototypes built, and performance tests performed using a solar simulator. Simulated operation of the baseline collector configuration was combined with insolation data for a number of locations and compared with a predicted load to determine the degree of solar utilization.

  13. A novel self-locked energy absorbing system

    NASA Astrophysics Data System (ADS)

    Chen, Yuli; Qiao, Chuan; Qiu, Xinming; Zhao, Shougen; Zhen, Cairu; Liu, Bin

    2016-02-01

    Metallic thin-walled round tubes are widely used as energy absorption elements. However, lateral splash of the round tubes under impact loadings reduces the energy absorption efficiency and may cause secondary damage. Therefore, it is necessary to assemble and fasten round tubes together by boundary constraints and/or fasteners between tubes, which increases the time and labor cost and affects the mechanical performance of round tubes. In an effort to break through this limitation, a novel self-locked energy-absorbing system has been proposed in this paper. The proposed system is made up of thin-walled tubes with dumbbell-shaped cross section, which are specially designed to interlock with each other and thus provide lateral constraint under impact loadings. Both finite element simulations and impact experiment demonstrated that without boundary constraints or fasteners between tubes, the proposed self-locked energy-absorbing system can still effectively attenuate impact loads while the round tube systems fail to carry load due to the lateral splashing of tubes. Furthermore, the geometric design for a single dumbbell-shaped tube and the stacking arrangement for the system are discussed, and a general guideline on the structural design of the proposed self-locked energy absorbing system is provided.

  14. Radiation in an Emitting and Absorbing Medium: A Gridless Approach

    SciTech Connect

    GRITZO,LOUIS A.; STRICKLAND,JAMES H.; DESJARDIN,PAUL E.

    2000-07-27

    A gridless technique for the solution of the integral form of the radiative heat flux equation for emitting and absorbing media is presented. Treatment of non-uniform absorptivity and gray boundaries is included. As part of this work, the authors have developed fast multipole techniques for extracting radiative heat flux quantities from the temperature fields of one-dimensional and three-dimensional geometries. Example calculations include those for one-dimensional radiative heat transfer through multiple flame sheets, a three-dimensional enclosure with black walls, and an axisymmetric enclosure with black walls.

  15. Performance of a Multifunctional Space Evaporator- Absorber-Radiator (SEAR)

    NASA Technical Reports Server (NTRS)

    Izenson, Michael G.; Chen, Weibo; Bue, Grant; Quinn, Gregory

    2013-01-01

    The Space Evaporator-Absorber-Radiator (SEAR) is a nonventing thermal control subsystem that combines a Space Water Membrane Evaporator (SWME) with a Lithium Chloride Absorber Radiator (LCAR). The LCAR is a heat pump radiator that absorbs water vapor produced in the SWME. Because of the very low water vapor pressure at equilibrium with lithium chloride solution, the LCAR can absorb water vapor at a temperature considerably higher than the SWME, enabling heat rejection by thermal radiation from a relatively small area radiator. Prior SEAR prototypes used a flexible LCAR that was designed to be installed on the outer surface of a portable life support system (PLSS) backpack. This paper describes a SEAR subsystem that incorporates a very compact LCAR. The compact, multifunctional LCAR is built in the form of thin panels that can also serve as the PLSS structural shell. We designed and assembled a 2 sq ft prototype LCAR based on this design and measured its performance in thermal vacuum tests when supplied with water vapor by a SWME. These tests validated our models for SEAR performance and showed that there is enough area available on the PLSS backpack shell to enable heat rejection from the LCAR.

  16. Performance of a Multifunctional Space Evaporator-Absorber-Radiator (SEAR)

    NASA Technical Reports Server (NTRS)

    Izenson, Michael G.; Chen, Weibo; Phillips, Scott; Chepko, Ariane; Bue, Grant; Quinn, Gregory

    2014-01-01

    The Space Evaporator-Absorber-Radiator (SEAR) is a nonventing thermal control subsystem that combines a Space Water Membrane Evaporator (SWME) with a Lithium Chloride Absorber Radiator (LCAR). The LCAR is a heat pump radiator that absorbs water vapor produced in the SWME. Because of the very low water vapor pressure at equilibrium with lithium chloride solution, the LCAR can absorb water vapor at a temperature considerably higher than the SWME, enabling heat rejection sufficient for most EVA activities by thermal radiation from a relatively small area radiator. Prior SEAR prototypes used a flexible LCAR that was designed to be installed on the outer surface of a portable life support system (PLSS) backpack. This paper describes a SEAR subsystem that incorporates a very compact LCAR. The compact, multifunctional LCAR is built in the form of thin panels that can also serve as the PLSS structural shell. We designed and assembled a 2 ft² prototype LCAR based on this design and measured its performance in thermal vacuum tests when supplied with water vapor by a SWME. These tests validated our models for SEAR performance and showed that there is enough area available on the PLSS backpack shell to enable rejection of metabolic heat from the LCAR. We used results of these tests to assess future performance potential and suggest approaches for integrating the SEAR system with future space suits.

  17. Damage tolerant light absorbing material

    DOEpatents

    Lauf, Robert J.; Hamby, Jr., Clyde; Akerman, M. Alfred; Seals, Roland D.

    1993-01-01

    A light absorbing article comprised of a composite of carbon-bonded carbon fibers, prepared by: blending carbon fibers with a carbonizable organic powder to form a mixture; dispersing the mixture into an aqueous slurry; vacuum molding the aqueous slurry to form a green article; drying and curing the green article to form a cured article; and, carbonizing the cured article at a temperature of at least about 1000.degree. C. to form a carbon-bonded carbon fiber light absorbing composite article having a bulk density less than 1 g/cm.sup.3.

  18. Damage tolerant light absorbing material

    DOEpatents

    Lauf, R.J.; Hamby, C. Jr.; Akerman, M.A.; Seals, R.D.

    1993-09-07

    A light absorbing article comprised of a composite of carbon-bonded carbon fibers, is prepared by: blending carbon fibers with a carbonizable organic powder to form a mixture; dispersing the mixture into an aqueous slurry; vacuum molding the aqueous slurry to form a green article; drying and curing the green article to form a cured article; and, carbonizing the cured article at a temperature of at least about 1000 C to form a carbon-bonded carbon fiber light absorbing composite article having a bulk density less than 1 g/cm[sup 3]. 9 figures.

  19. Waveform-Dependent Absorbing Metasurfaces

    NASA Astrophysics Data System (ADS)

    Wakatsuchi, Hiroki; Kim, Sanghoon; Rushton, Jeremiah J.; Sievenpiper, Daniel F.

    2013-12-01

    We present the first use of a waveform-dependent absorbing metasurface for high-power pulsed surface currents. The new type of nonlinear metasurface, composed of circuit elements including diodes, is capable of storing high-power pulse energy to dissipate it between pulses, while allowing propagation of small signals. Interestingly, the absorbing performance varies for high-power pulses but not for high-power continuous waves (CW’s), since the capacitors used are fully charged up. Thus, the waveform dependence enables us to distinguish various signal types (i.e., CW or pulse) even at the same frequency, which potentially creates new kinds of microwave technologies and applications.

  20. High-Efficiency Absorber for Damping the Transverse Wake Fields

    SciTech Connect

    Novokhatski, A.; Seeman, J.; Weathersby, S.; /SLAC

    2007-02-28

    Transverse wake fields generated by intense beams may propagate long distances in the vacuum chamber and dissipate power in different shielded elements such as bellows, vacuum valves or vacuum pumps. Induced heating in these elements may be high enough to deteriorate vacuum conditions. We have developed a broadband water-cooled bellows-absorber to capture and damp these harmful transverse fields without impacting the longitudinal beam impedance. Experimental results at the PEP-II SLAC B-factory demonstrate high efficiency of this device. This absorber may be useful in other machines like synchrotron light sources or International Linear Collider.

  1. High-efficiency absorber for damping transverse wakefields

    NASA Astrophysics Data System (ADS)

    Novokhatski, A.; Seeman, J.; Weathersby, S.

    2007-04-01

    Transverse wakefields generated by intense beams may propagate long distances in a vacuum chamber and dissipate power in different shielded elements such as bellows, vacuum valves, or vacuum pumps. Induced heating in these elements may be high enough to deteriorate vacuum conditions. We have developed a broadband water-cooled bellows absorber to capture and damp these harmful transverse fields without impacting the longitudinal beam impedance. Experimental results at the PEP-II SLAC B-factory demonstrate a high efficiency for this device. This absorber may be useful in super B-factories, the International Linear Collider, the Large Hadron Collider, or synchrotron light sources.

  2. Single-phase Stefan problem in selectively absorbing medium

    NASA Astrophysics Data System (ADS)

    Sleptsov, S. D.; Rubtsov, N. A.; Savvinova, N. A.

    2016-01-01

    The thermal state of a translucent selectively absorbing medium was studied by the methods of numerical simulation at different values of the optical properties of boundaries and heat transfer from the left surface in approximation of one-phase Stefan problem. The temperature fields and densities of resultant radiation fluxes as well as the thermal state of the left boundary and dynamics of layer reduction in the melting process were analyzed. The processes of phase transition in a flat layer of selective and gray absorbing media and emitting media were compared, and their fundamental differences were shown.

  3. Study of the antifungal potential of novel cellulose/copper composites as absorbent materials for fruit juices.

    PubMed

    Llorens, Amparo; Lloret, Elsa; Picouet, Pierre; Fernandez, Avelina

    2012-08-17

    Cellulose/copper composites with antifungal properties have been synthesized by physical/chemical methods. Physical treatments by heat or by a combination of heat and UV radiation provided composites with metallic copper and excellent interfacial adhesion; in contrast, chemical reduction with borohydride generated small although partially aggregated copper oxide nanoparticles. Copper micro/nano-particles and copper ions (Cu(2+)) were released from the cellulose matrix at an adequate rate to achieve a strong antimicrobial activity against Saccharomyces cerevisiae in in vitro experiments. Moreover, the copper oxide composites showed an excellent antifungal activity in pineapple and melon juice, reducing about 4 log cycles the loads of spoilage-related yeasts and moulds. The metallic copper composites reduced in 4 log cycles the load of yeasts and moulds in pineapple juice, although their antifungal activity was weaker in contact with melon juice. Copper loaded absorbent materials could be selectively implemented during the shelf-life of minimally processed fruits to reduce the number of spoilage-related microorganisms in the drip.

  4. Recent developments of smart electromagnetic absorbers based polymer-composites at gigahertz frequencies

    NASA Astrophysics Data System (ADS)

    Idris, Fadzidah Mohd.; Hashim, Mansor; Abbas, Zulkifly; Ismail, Ismayadi; Nazlan, Rodziah; Ibrahim, Idza Riati

    2016-05-01

    The rapid increase in electromagnetic interference has received a serious attention from researchers who responded by producing a variety of radar absorbing materials especially at high gigahertz frequencies. Ongoing investigation is being carried out in order to find the best absorbing materials which can fulfill the requirements for smart absorbing materials which are lightweight, broad bandwidth absorption, stronger absorption etc. Thus, to improve the absorbing capability, several important parameters need to be taken into consideration such as filler type, loading level, type of polymer matrix, physical thickness, grain sizes, layers and bandwidth. Therefore, this article introduces the electromagnetic wave absorption mechanisms and then reveals and reviews those parameters that enhance the absorption performance.

  5. CO2 Capture with Liquid-to-Solid Absorbents: CO2 Capture Process Using Phase-Changing Absorbents

    SciTech Connect

    2010-10-01

    IMPACCT Project: GE and the University of Pittsburgh are developing a unique CO2 capture process in which a liquid absorbent, upon contact with CO2, changes into a solid phase. Once in solid form, the material can be separated and the CO2 can be released for storage by heating. Upon heating, the absorbent returns to its liquid form, where it can be reused to capture more CO2. The approach is more efficient than other solventbased processes because it avoids the heating of extraneous solvents such as water. This ultimately leads to a lower cost of CO2 capture and will lower the additional cost to produce electricity for coal-fired power plants that retrofit their facilities to include this technology.

  6. Design of electromagnetic shock absorbers for automotive suspensions

    NASA Astrophysics Data System (ADS)

    Amati, Nicola; Festini, Andrea; Tonoli, Andrea

    2011-12-01

    Electromechanical dampers seem to be a valid alternative to conventional shock absorbers for automotive suspensions. They are based on linear or rotative electric motors. If they are of the DC-brushless type, the shock absorber can be devised by shunting its electric terminals with a resistive load. The damping force can be modified by acting on the added resistance. To supply the required damping force without exceeding in size and weight, a mechanical or hydraulic system that amplifies the speed is required. This paper illustrates the modelling and design of such electromechanical shock absorbers. This paper is devoted to describe an integrated design procedure of the electrical and mechanical parameters with the objective of optimising the device performance. The application to a C class front suspension car has shown promising results in terms of size, weight and performance.

  7. Load cell

    DOEpatents

    Spletzer, B.L.

    1998-12-15

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

  8. 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.

  9. 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.

  10. Oil and fat absorbing polymers

    NASA Technical Reports Server (NTRS)

    Marsh, H. E., Jr. (Inventor)

    1977-01-01

    A method is described for forming a solid network polymer having a minimal amount of crosslinking for use in absorbing fats and oils. The polymer remains solid at a swelling ratio in oil or fat of at least ten and provides an oil absorption greater than 900 weight percent.

  11. 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.

  12. High-Capacity Spacesuit Evaporator Absorber Radiator (SEAR)

    NASA Technical Reports Server (NTRS)

    Izenson, Michael G.; Chen, Weibo; Phillips, Scott; Chepko, Ariane; Bue, Grant; Quinn, Gregory

    2015-01-01

    Future human space exploration missions will require advanced life support technology that can operate across a wide range of applications and environments. Thermal control systems for space suits and spacecraft will need to meet critical requirements for water conservation and multifunctional operation. This paper describes a Space Evaporator Absorber Radiator (SEAR) that has been designed to meet performance requirements for future life support systems. A SEAR system comprises a lithium chloride absorber radiator (LCAR) for heat rejection coupled with a space water membrane evaporator (SWME) for heat acquisition. SEAR systems provide heat pumping to minimize radiator size, thermal storage to accommodate variable environmental conditions, and water absorption to minimize use of expendables. We have built and tested a flight-like, high-capacity LCAR, demonstrated its performance in thermal vacuum tests, and explored the feasibility of an ISS demonstration test of a SEAR system. The new LCAR design provides the same cooling capability as prior LCAR prototypes while enabling over 30% more heat absorbing capacity. Studies show that it should be feasible to demonstrate SEAR operation in flight by coupling with an existing EMU on the space station.

  13. High-Capacity Spacesuit Evaporator Absorber Radiator (SEAR)

    NASA Technical Reports Server (NTRS)

    Izenson, Michael G.; Chen, Weibo; Phillips, Scott; Chepko, Ariane; Bue, Grant; Quinn, Gregory

    2014-01-01

    Future human space exploration missions will require advanced life support technology that can operate across a wide range of applications and environments. Thermal control systems for space suits and spacecraft will need to meet critical requirements for water conservation and adaptability to highly variable thermal environments. This paper describes a Space Evaporator Absorber Radiator (SEAR) that has been designed to meet performance requirements for future life support systems. A SEAR system comprises a lithium chloride absorber radiator (LCAR) for heat rejection coupled with a space water membrane evaporator (SWME) for heat acquisition. SEAR systems provide heat pumping to minimize radiator size, thermal storage to accommodate variable environmental conditions, and water absorption to minimize use of expendables. We have built and tested a flightlike, high-capacity LCAR, demonstrated its performance in thermal vacuum tests, and explored the feasibility of an ISS demonstration test of a SEAR system. The new LCAR design provides the same cooling capability as prior LCAR prototypes while enabling over 30% more heat absorbing capacity. Studies show that it should be feasible to demonstrate SEAR operation in flight by coupling with an existing EMU on the space station.

  14. A simple model for the design of vertical tube absorbers

    SciTech Connect

    Patnaik, V.; Perez-Blanco, H.; Ryan, W.A.

    1993-08-01

    The absorption of water vapor in aqueous solutions of lithium bromide is modelled for a falling-film, vertical-tube absorber. The model is based on the solution of three ordinary differential equations to calculate solution bulk and interface concentration and temperature distributions and the coolant temperature distribution. The heat and mass transfer coefficients employed in the equations are extracted from the literature. In this way, the model incorporates recent information on wavy-laminar flows. Under certain conditions, the solution exhibits instabilities in the entrance region of the absorber tube, which are corrected by the introduction of a dampening factor incorporating relevant thermophysical properties. The usefulness of the model for generating absorber performance charts is demonstrated.

  15. Electrically tunable metasurface absorber based on dissipating behavior of embedded varactors

    NASA Astrophysics Data System (ADS)

    Luo, Zhangjie; Long, Jiang; Chen, Xing; Sievenpiper, Daniel

    2016-08-01

    An electrically tunable metasurface that absorbs continuous electromagnetic (EM) surface waves is proposed by taking advantage of varactor diodes embedded in the surface. On the one hand, the varactors perform as the main dissipating components due to their parasitic series resistance; on the other hand, they function as the tuning elements because the dissipation is highly dependent on their capacitance. Therefore, the absorption of the surface can be tuned by the direct current biasing voltage across the varactors, which is validated numerically and experimentally in this letter. This absorbing mechanism of the surface differs from prior surface-wave absorbers and can lead to greater flexibility for absorbing metasurfaces. In this work, a power-dependent absorbing performance is achieved by loading microwave power sensors. If incorporated with other types of sensors, the absorption could potentially be controlled by corresponding physical variables such as light, pressure, or temperature, thus giving rise to various absorbing applications in a complex EM environment.

  16. Periodic Architecture for High Performance Shock Absorbing Composites

    PubMed Central

    Misra, Abha; Kumar, Praveen

    2013-01-01

    A novel composite architecture consisting of a periodic arrangement of closely-spaced spheres of a stiff material embedded in a soft matrix is proposed for extremely high damping and shock absorption capacity. Efficacy of this architecture is demonstrated by compression loading a composite, where multiple steel balls were stacked upon each other in a polydimethylsiloxane (PDMS) matrix, at a low strain-rate of 0.05 s−1 and a very high strain-rate of >2400 s−1. The balls slide over each other upon loading, and revert to their original position when the load is removed. Because of imposition of additional strains into the matrix via this reversible, constrained movement of the balls, the composite absorbs significantly larger energy and endures much lesser permanent damage than the monolithic PDMS during both quasi-static and impact loadings. During the impact loading, energy absorbed per unit weight for the composite was ~8 times larger than the monolithic PDMS. PMID:23792699

  17. Innovative energy absorbing devices based on composite tubes

    NASA Astrophysics Data System (ADS)

    Tiwari, Chandrashekhar

    Analytical and experimental study of innovative load limiting and energy absorbing devices are presented here. The devices are based on composite tubes and can be categorized in to two groups based upon the energy absorbing mechanisms exhibited by them, namely: foam crushing and foam fracturing. The device based on foam crushing as the energy absorbing mechanism is composed of light weight elastic-plastic foam filling inside an angle ply composite tube. The tube is tailored to have a high Poisson’s ratio (>20). Upon being loaded the device experiences large transverse contraction resulting in rapid decrease in diameter. At a certain axial load the foam core begins to crush and energy is dissipated. This device is termed as crush tube device. The device based upon foam shear fracture as the energy absorbing mechanism involves an elastic-plastic core foam in annulus of two concentric extension-twist coupled composite tubes with opposite angles of fibers. The core foam is bonded to the inner and outer tube walls. Upon being loaded axially, the tubes twist in opposite directions and fracture the core foam in out of plane shear and thus dissipate the energy stored. The device is termed as sandwich core device (SCD). The devices exhibit variations in force-displacement characteristics with changes in design and material parameters, resulting in wide range of energy absorption capabilities. A flexible matrix composite system was selected, which was composed of high stiffness carbon fibers as reinforcements in relatively low stiffness polyurethane matrix, based upon large strain to failure capabilities and large beneficial elastic couplings. Linear and non-linear analytical models were developed encapsulating large deformation theory of the laminated composite shells (using non-linear strain energy formulation) to the fracture mechanics of core foam and elastic-plastic deformation theory of the foam filling. The non-linear model is capable of including material and

  18. Digital Alloy Absorber for Photodetectors

    NASA Technical Reports Server (NTRS)

    Hill, Cory J. (Inventor); Ting, David Z. (Inventor); Gunapala, Sarath D. (Inventor)

    2016-01-01

    In order to increase the spectral response range and improve the mobility of the photo-generated carriers (e.g. in an nBn photodetector), a digital alloy absorber may be employed by embedding one (or fraction thereof) to several monolayers of a semiconductor material (insert layers) periodically into a different host semiconductor material of the absorber layer. The semiconductor material of the insert layer and the host semiconductor materials may have lattice constants that are substantially mismatched. For example, this may performed by periodically embedding monolayers of InSb into an InAsSb host as the absorption region to extend the cutoff wavelength of InAsSb photodetectors, such as InAsSb based nBn devices. The described technique allows for simultaneous control of alloy composition and net strain, which are both key parameters for the photodetector operation.

  19. Mesoporous silicate MCM-41 containing organic ultraviolet ray absorbents: Preparation, photostability and in vitro release

    NASA Astrophysics Data System (ADS)

    Ambrogi, V.; Perioli, L.; Marmottini, F.; Latterini, L.; Rossi, C.; Costantino, U.

    2007-05-01

    The mesoporous silicate MCM-41 was studied for its properties to adsorb and to influence the photostability and the release of three organic ultraviolet (UV) ray absorbents, namely benzophenone-3 (B3), benzophenone-2 (B2) and p-aminobenzoic acid (PABA). MCM-41 microcrystals have been loaded with the UV absorbents obtaining a good loading w/w percentage. The loaded samples have been characterized by chemical and thermal analyses, X-ray diffraction, N2 adsorption isotherms. Photochemical studies demonstrated that the UV-shielding properties of B2 were maintained whereas in other cases a small reduction of sunscreen protection range was noticed. B3 and B2 release from loaded MCM-41 formulations were studied and compared to those obtained from formulations containing free UV ray absorbent; no remarkable differences were observed in the release profiles.

  20. Inferring Absorbing Organic Carbon Content from AERONET Data

    NASA Technical Reports Server (NTRS)

    Arola, A.; Schuster, G.; Myhre, G.; Kazadzis, S.; Dey, S.; Tripathi, S. N.

    2011-01-01

    Black carbon, light-absorbing organic carbon (often called brown carbon) and mineral dust are the major light-absorbing aerosols. Currently the sources and formation of brown carbon aerosol in particular are not well understood. In this study we estimated globally the amount of light absorbing organic carbon and black carbon from AERONET measurements. We find that the columnar absorbing organic carbon (brown carbon) levels in biomass burning regions of South-America and Africa are relatively high (about 15-20 magnesium per square meters during biomass burning season), while the concentrations are significantly lower in urban areas in US and Europe. However, we estimated significant absorbing organic carbon amounts from the data of megacities of newly industrialized countries, particularly in India and China, showing also clear seasonality with peak values up to 30-35 magnesium per square meters during the coldest season, likely caused by the coal and biofuel burning used for heating. We also compared our retrievals with the modeled organic carbon by global Oslo CTM for several sites. Model values are higher in biomass burning regions than AERONET-based retrievals, while opposite is true in urban areas in India and China.

  1. Measurements of Light Absorbing Particles on Tropical South American Glaciers

    NASA Astrophysics Data System (ADS)

    Schmitt, C. G.; All, J.; Schwarz, J. P.; Arnott, W. P.; Warthon, J.; Andrade, M.; Celestian, A. J.; Hoffmann, D.; Cole, R. J.; Lapham, E.; Horodyskyj, U. N.; Froyd, K. D.; Liao, J.

    2014-12-01

    Glaciers in the tropical Andes have been losing mass rapidly in recent decades. In addition to the documented increase in temperature, increases in light absorbing particulates deposited on glaciers could be contributing to the observed glacier loss. Here we present results of measurements of light absorbing particles from glaciers in Peru and Bolivia. Samples have been collected by American Climber Science Program volunteers and scientists at altitudes up to 6770 meters. Collected snow samples were melted and filtered in the field. A new inexpensive technique, the Light Absorption Heating Method (LAHM) has been developed for analysis of light absorbing particles collected on filters. Results from LAHM analysis are calibrated using filters with known amounts of fullerene soot, a common industrial surrogate for black carbon (BC). For snow samples collected at the same field location LAHM analysis and measurements from the Single Particle Soot Photometer (SP2) instrument are well correlated (r2 = 0.92). Co-located SP2 and LAHM filter analysis suggest that BC could be the dominant absorbing component of the light absorbing particles in some areas.

  2. Conical solar absorber/thruster for space propulsion

    SciTech Connect

    Strumpf, H.J.; Borghese, J.B.; Keating, R.F.

    1995-11-01

    Solar-powered space propulsion uses solar heating of a propellant such as hydrogen to impart thrust to a rocket when the hydrogen exists through an appropriately designed nozzle. Because of the low molecular weight of hydrogen, exhaust velocities, and hence specific impulses, can potentially be much greater than for chemical combustion of fuel. A very efficient solar thermal absorber design has been developed. The design consists of two interwound helical coils of rhenium tubing, through which the propellant flows to be heated before being exhausted out a rhenium nozzle. The conical absorbing surface is configured to conform to the extreme solar rays from a solar concentrator; i.e., the receiver apex angle is designed to match the concentrator apex angle. This shape helps to minimize the amount of reflected or emitted energy lost through the receiver aperture.

  3. Radiative cooling of solar absorbers using a visibly transparent photonic crystal thermal blackbody

    PubMed Central

    Zhu, Linxiao; Raman, Aaswath P.; Fan, Shanhui

    2015-01-01

    A solar absorber, under the sun, is heated up by sunlight. In many applications, including solar cells and outdoor structures, the absorption of sunlight is intrinsic for either operational or aesthetic considerations, but the resulting heating is undesirable. Because a solar absorber by necessity faces the sky, it also naturally has radiative access to the coldness of the universe. Therefore, in these applications it would be very attractive to directly use the sky as a heat sink while preserving solar absorption properties. Here we experimentally demonstrate a visibly transparent thermal blackbody, based on a silica photonic crystal. When placed on a silicon absorber under sunlight, such a blackbody preserves or even slightly enhances sunlight absorption, but reduces the temperature of the underlying silicon absorber by as much as 13 °C due to radiative cooling. Our work shows that the concept of radiative cooling can be used in combination with the utilization of sunlight, enabling new technological capabilities. PMID:26392542

  4. Radiative cooling of solar absorbers using a visibly transparent photonic crystal thermal blackbody.

    PubMed

    Zhu, Linxiao; Raman, Aaswath P; Fan, Shanhui

    2015-10-01

    A solar absorber, under the sun, is heated up by sunlight. In many applications, including solar cells and outdoor structures, the absorption of sunlight is intrinsic for either operational or aesthetic considerations, but the resulting heating is undesirable. Because a solar absorber by necessity faces the sky, it also naturally has radiative access to the coldness of the universe. Therefore, in these applications it would be very attractive to directly use the sky as a heat sink while preserving solar absorption properties. Here we experimentally demonstrate a visibly transparent thermal blackbody, based on a silica photonic crystal. When placed on a silicon absorber under sunlight, such a blackbody preserves or even slightly enhances sunlight absorption, but reduces the temperature of the underlying silicon absorber by as much as 13 °C due to radiative cooling. Our work shows that the concept of radiative cooling can be used in combination with the utilization of sunlight, enabling new technological capabilities.

  5. Radiative cooling of solar absorbers using a visibly transparent photonic crystal thermal blackbody.

    PubMed

    Zhu, Linxiao; Raman, Aaswath P; Fan, Shanhui

    2015-10-01

    A solar absorber, under the sun, is heated up by sunlight. In many applications, including solar cells and outdoor structures, the absorption of sunlight is intrinsic for either operational or aesthetic considerations, but the resulting heating is undesirable. Because a solar absorber by necessity faces the sky, it also naturally has radiative access to the coldness of the universe. Therefore, in these applications it would be very attractive to directly use the sky as a heat sink while preserving solar absorption properties. Here we experimentally demonstrate a visibly transparent thermal blackbody, based on a silica photonic crystal. When placed on a silicon absorber under sunlight, such a blackbody preserves or even slightly enhances sunlight absorption, but reduces the temperature of the underlying silicon absorber by as much as 13 °C due to radiative cooling. Our work shows that the concept of radiative cooling can be used in combination with the utilization of sunlight, enabling new technological capabilities. PMID:26392542

  6. Waste glass as absorbent for thin layer chromatography (TLC).

    PubMed

    Pant, Deepak

    2009-07-01

    This study shows that glass powder of 200-300 mesh size range can be used as an absorbent for thin layer chromatography without adding any binder provided its uniformity is improved by a suitable thermal treatment. For this purpose TLC plates of the said mesh size range glass powder are heated thermally in a muffle furnace at a temperature of 650 degrees C for a period of 3 h. PMID:19375296

  7. Solar heating system

    DOEpatents

    Schreyer, James M.; Dorsey, George F.

    1982-01-01

    An improved solar heating system in which the incident radiation of the sun is absorbed on collector panels, transferred to a storage unit and then distributed as heat for a building and the like. The improvement is obtained by utilizing a storage unit comprising separate compartments containing an array of materials having different melting points ranging from 75.degree. to 180.degree. F. The materials in the storage system are melted in accordance with the amount of heat absorbed from the sun and then transferred to the storage system. An efficient low volume storage system is provided by utilizing the latent heat of fusion of the materials as they change states in storing and releasing heat for distribution.

  8. Improved solar heating systems

    DOEpatents

    Schreyer, J.M.; Dorsey, G.F.

    1980-05-16

    An improved solar heating system is described in which the incident radiation of the sun is absorbed on collector panels, transferred to a storage unit and then distributed as heat for a building and the like. The improvement is obtained by utilizing a storage unit comprising separate compartments containing an array of materials having different melting points ranging from 75 to 180/sup 0/F. The materials in the storage system are melted in accordance with the amount of heat absorbed from the sun and then transferred to the storage system. An efficient low volume storage system is provided by utilizing the latent heat of fusion of the materials as they change states in storing ad releasing heat for distribution.

  9. Chemical heat pump

    DOEpatents

    Greiner, Leonard

    1984-01-01

    A chemical heat pump system is disclosed for use in heating and cooling structures such as residences or commercial buildings. The system is particularly adapted to utilizing solar energy, but also increases the efficiency of other forms of thermal energy when solar energy is not available. When solar energy is not available for relatively short periods of time, the heat storage capacity of the chemical heat pump is utilized to heat the structure, as during nighttime hours. The design also permits home heating from solar energy when the sun is shining. The entire system may be conveniently rooftop located. In order to faciliate installation on existing structures, the absorber and vaporizer portions of the system may each be designed as flat, thin wall, thin pan vessels which materially increase the surface area available for heat transfer. In addition, this thin, flat configuration of the absorber and its thin walled (and therefore relatively flexible) construction permits substantial expansion and contraction of the absorber material during vaporization and absorption without generating voids which would interfere with heat transfer.

  10. Chemical heat pump

    DOEpatents

    Greiner, Leonard

    1981-01-01

    A chemical heat pump system is disclosed for use in heating and cooling structures such as residences or commercial buildings. The system is particularly adapted to utilizing solar energy, but also increases the efficiency of other forms of thermal energy when solar energy is not available. When solar energy is not available for relatively short periods of time, the heat storage capacity of the chemical heat pump is utilized to heat the structure, as during nighttime hours. The design also permits home heating from solar energy when the sun is shining. The entire system may be conveniently rooftop located. In order to facilitate installation on existing structures, the absorber and vaporizer portions of the system may each be designed as flat, thin wall, thin pan vessels which materially increase the surface area available for heat transfer. In addition, this thin, flat configuration of the absorber and its thin walled (and therefore relatively flexible) construction permits substantial expansion and contraction of the absorber material during vaporization and absorption without generating voids which would interfere with heat transfer.

  11. Chemical heat pump

    DOEpatents

    Greiner, Leonard

    1984-01-01

    A chemical heat pump system is disclosed for use in heating and cooling structures such as residences or commercial buildings. The system is particularly adapted to utilizing solar energy, but also increases the efficiency of other forms of thermal energy when solar energy is not available. When solar energy is not available for relatively short periods of time, the heat storage capacity of the chemical heat pump is utilized to heat the structure, as during nighttime hours. The design also permits home heating from solar energy when the sun is shining. The entire system may be conveniently rooftop located. In order to facilitate intallation on existing structures, the absorber and vaporizer portions of the system may each be designed as flat, thin wall, thin pan vessels which materially increase the surface area available for heat transfer. In addition, this thin, flat configuration of the absorber and its thin walled (and therefore relatively flexible) construction permits substantial expansion and contraction of the absorber material during vaporization and absorption without generating voids which would interfere with heat transfer.

  12. Chemical heat pump

    DOEpatents

    Greiner, Leonard

    1984-01-01

    A chemical heat pump system is disclosed for use in heating and cooling structures such as residences or commercial buildings. The system is particularly adapted to utilizing solar energy, but also increases the efficiency of other forms of thermal energy when solar energy is not available. When solar energy is not available for relatively short periods of time, the heat storage capacity of the chemical heat pump is utilized to heat the structure, as during nighttime hours. The design also permits home heating from solar energy when the sun is shining. The entire system may be conveniently rooftop located. In order to facilitate installation on existing structures, the absorber and vaporizer portions of the system may each be designed as flat, thin wall, thin pan vessels which materially increase the surface area available for heat transfer. In addition, this thin, flat configuration of the absorber and its thin walled (and therefore relatively flexible) construction permits substantial expansion and contraction of the absorber material during vaporization and absorption without generating voids which would interfere with heat transfer.

  13. 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.

  14. Vapor shielding models and the energy absorbed by divertor targets during transient events

    NASA Astrophysics Data System (ADS)

    Skovorodin, D. I.; Pshenov, A. A.; Arakcheev, A. S.; Eksaeva, E. A.; Marenkov, E. D.; Krasheninnikov, S. I.

    2016-02-01

    The erosion of divertor targets caused by high heat fluxes during transients is a serious threat to ITER operation, as it is going to be the main factor determining the divertor lifetime. Under the influence of extreme heat fluxes, the surface temperature of plasma facing components can reach some certain threshold, leading to an onset of intense material evaporation. The latter results in formation of cold dense vapor and secondary plasma cloud. This layer effectively absorbs the energy of the incident plasma flow, turning it into its own kinetic and internal energy and radiating it. This so called vapor shielding is a phenomenon that may help mitigating the erosion during transient events. In particular, the vapor shielding results in saturation of energy (per unit surface area) accumulated by the target during single pulse of heat load at some level Emax. Matching this value is one of the possible tests to verify complicated numerical codes, developed to calculate the erosion rate during abnormal events in tokamaks. The paper presents three very different models of vapor shielding, demonstrating that Emax depends strongly on the heat pulse duration, thermodynamic properties, and evaporation energy of the irradiated target material. While its dependence on the other shielding details such as radiation capabilities of material and dynamics of the vapor cloud is logarithmically weak. The reason for this is a strong (exponential) dependence of the target material evaporation rate, and therefore the "strength" of vapor shield on the target surface temperature. As a result, the influence of the vapor shielding phenomena details, such as radiation transport in the vapor cloud and evaporated material dynamics, on the Emax is virtually completely masked by the strong dependence of the evaporation rate on the target surface temperature. However, the very same details define the amount of evaporated particles, needed to provide an effective shielding to the target, and

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. Improving the laboratory monitoring of absorbent oil

    SciTech Connect

    V.S. Shved; S.S. Sychev; I.V. Safina; S.A. Klykov

    2009-05-15

    The performance of absorbent coal tar oil is analyzed as a function of the constituent and group composition. The qualitative and quantitative composition of the oil that ensures the required absorbent properties is determined. Operative monitoring may be based on absorbent characteristics that permit regulation of the beginning and end of regeneration.

  20. Impacts of Snow Darkening by Absorbing Aerosols on Eurasian Climate

    NASA Technical Reports Server (NTRS)

    Kim, Kyu-Myong; Lau, William K M.; Yasunari, Teppei J.; Kim, Maeng-Ki; Koster, Randal D.

    2016-01-01

    The deposition of absorbing aerosols on snow surfaces reduces snow-albedo and allows snowpack to absorb more sunlight. This so-called snow darkening effect (SDE) accelerates snow melting and leads to surface warming in spring. To examine the impact of SDE on weather and climate during late spring and early summer, two sets of NASA GEOS-5 model simulations with and without SDE are conducted. Results show that SDE-induced surface heating is particularly pronounced in Eurasian regions where significant depositions of dust transported from the North African deserts, and black carbon from biomass burning from Asia and Europe occur. In these regions, the surface heating due to SDE increases surface skin temperature by 3-6 degrees Kelvin near the snowline in spring. Surface energy budget analysis indicates that SDE-induced excess heating is associated with a large increase in surface evaporation, subsequently leading to a significant reduction in soil moisture, and increased risks of drought and heat waves in late spring to early summer. Overall, we find that rainfall deficit combined with SDE-induced dry soil in spring provide favorable condition for summertime heat waves over large regions of Eurasia. Increased frequency of summer heat waves with SDE and the region of maximum increase in heat-wave frequency are found along the snow line, providing evidence that early snowmelt by SDE may increase the risks of extreme summer heat wave. Our results suggest that climate models that do not include SDE may significantly underestimate the effect of global warming over extra-tropical continental regions.

  1. Porcelain enamel neutron absorbing material

    SciTech Connect

    Iverson, Daniel C.

    1990-01-01

    A porcelain enamel composition as a neutron absorbing material can be prepared of a major proportion by weight of a cadmium compound and a minor proportion of compounds of boron, lithium and silicon. These compounds in the form of a porcelain enamel coating or layer on several alloys has been found to be particularly effective in enhancing the nuclear safety of equipment for use in the processing and storage of fissile material. The composition of the porcelain enamel coating can be tailored to match the coefficient of thermal expansion of the equipment to be coated and excellent coating adhesion can be achieved.

  2. Porcelain enamel neutron absorbing material

    SciTech Connect

    Iverson, Daniel C.

    1990-02-06

    A porcelain enamel composition as a neutron absorbing material can be prepared of a major proportion by weight of a cadmium compound and a minor proportion of compounds of boron, lithium and silicon. These compounds in the form of a porcelain enamel coating or layer on several alloys has been found to be particularly effective in enhancing the nuclear safety of equipment for use in the processing and storage of fissile material. The composition of the porcelain enamel coating can be tailored to match the coefficient of thermal expansion of the equipment to be coated and excellent coating adhesion can be achieved.

  3. Porcelain enamel neutron absorbing material

    DOEpatents

    Iverson, D.C.

    1987-11-20

    A porcelain enamel composition as a neutron absorbing material can be prepared of a major proportion by weight of a cadmium compound and a minor proportion of compound of boron, lithium and silicon. These compounds in the form of a porcelain enamel coating or layer on several alloys has been found to be particularly effective in enhancing the nuclear safety of equipment for use in the processing and storage of fissile material. The composition of the porcelain enamel coating can be tailored to match the coefficient of thermal expansion of the equipment to be coated and excellent coating adhesion can be achieved. 2 figs.

  4. Development of 2 underseat energy absorbers for application to crashworthy passenger seats for general aviation aircraft

    NASA Technical Reports Server (NTRS)

    Warrick, J. C.; Desjardins, S. P.

    1979-01-01

    This report presents the methodology and results of a program conducted to develop two underseat energy absorber (E/A) concepts for application to nonadjustable crashworthy passenger seats for general aviation aircraft. One concept utilizes an inflated air bag, and the other, a convoluted sheet metal bellows. Prototypes of both were designed, built, and tested. Both concepts demonstrated the necessary features of an energy absorber (load-limiter); however, the air bag concept is particularly encouraging because of its light weight. Several seat frame concepts also were investigated as a means of resisting longitudinal and lateral loads and of guiding the primary vertical stroke of the underseat energy absorber. Further development of a seat system design using the underseat energy absorbers is recommended because they provide greatly enhanced crash survivability as compared with existing general aviation aircraft seats.

  5. Technology Solutions Case Study: Advanced Boiler Load Monitoring Controls, Chicago, Illinois

    SciTech Connect

    2014-09-01

    Most of Chicago’s older multifamily housing stock is heated by centrally metered steam or hydronic systems. The cost of heat is typically absorbed into the owner’s operating cost and is then passed to tenants. Central boilers typically have long service lifetimes; the incentive for retrofit system efficiency upgrades is greater than equipment replacement for the efficiency-minded owner. System improvements as the “low-hanging fruit” are familiar, from improved pipe insulation to aftermarket controls such as outdoor temperature reset (OTR) or lead/lag controllers for sites with multiple boilers. Beyond these initial system efficiency upgrades are an emerging class of Advanced Load Monitoring (ALM) aftermarket controllers that dynamically respond to the boiler load, with claims of 10% to 30% of fuel savings over a heating season. In this project, the Building America team Partnership for Advanced Residential Retrofit (PARR) installed and monitored an ALM aftermarket controller, the M2G from Greffen Systems, at two Chicago area multifamily buildings with existing OTR control. Results show that energy savings depend on the degree to which boilers are oversized for their load, represented by cycling rates. Also, savings vary over the heating season with cycling rates, with greater savings observed in shoulder months. Over the monitoring period, oversized boilers at one site showed reductions in cycling and energy consumption in line with prior laboratory studies, while less oversized boilers at another site showed muted savings.

  6. Energy Absorbing Seat System for an Agricultural Aircraft

    NASA Technical Reports Server (NTRS)

    Kellas, Sotiris; Jones, Lisa E. (Technical Monitor)

    2002-01-01

    A task was initiated to improve the energy absorption capability of an existing aircraft seat through cost-effective retrofitting, while keeping seat-weight increase to a minimum. This task was undertaken as an extension of NASA ongoing safety research and commitment to general aviation customer needs. Only vertical crash scenarios have been considered in this task which required the energy absorbing system to protect the seat occupant in a range of crash speeds up to 31 ft/sec. It was anticipated that, the forward and/or side crash accelerations could be attenuated with the aid of airbags, the technology of which is currently available in automobiles and military helicopters. Steps which were followed include, preliminary crush load determination, conceptual design of cost effective energy absorbers, fabrication and testing (static and dynamic) of energy absorbers, system analysis, design and fabrication of dummy seat/rail assembly, dynamic testing of dummy seat/rail assembly, and finally, testing of actual modified seat system with a dummy occupant. A total of ten full scale tests have been performed including three of the actual aircraft seat. Results from full-scale tests indicated that occupant loads were attenuated successfully to survivable levels.

  7. The Double Absorbing Boundary method

    NASA Astrophysics Data System (ADS)

    Hagstrom, Thomas; Givoli, Dan; Rabinovich, Daniel; Bielak, Jacobo

    2014-02-01

    A new approach is devised for solving wave problems in unbounded domains. It has common features to each of two types of existing techniques: local high-order Absorbing Boundary Conditions (ABC) and Perfectly Matched Layers (PML). However, it is different from both and enjoys relative advantages with respect to both. The new method, called the Double Absorbing Boundary (DAB) method, is based on truncating the unbounded domain to produce a finite computational domain Ω, and on applying a local high-order ABC on two parallel artificial boundaries, which are a small distance apart, and thus form a thin non-reflecting layer. Auxiliary variables are defined on the two boundaries and inside the layer bounded by them, and participate in the numerical scheme. The DAB method is first introduced in general terms, using the 2D scalar time-dependent wave equation as a model. Then it is applied to the 1D Klein-Gordon equation, using finite difference discretization in space and time, and to the 2D wave equation in a wave guide, using finite element discretization in space and dissipative time stepping. The computational aspects of the method are discussed, and numerical experiments demonstrate its performance.

  8. Corrosion control in alkanolamine gas treating: Absorber corrosion

    SciTech Connect

    Helle, H.P.E.

    1995-12-01

    Even in 1980, when corrosion in alkanolamine units was rampant, over 50% of all acid gas purification systems was based on alkanolamine absorbents. Over the years the control of corrosion has gradually become firmer. This paper examines the reasons for corrosion and provides insight in one particular aspect of corrosion in alkanolamine units, absorber corrosion. Three factors are identified, solvent degradation, local stagnancy and exceeding the units capacity. Solvent degradation increases the corrosivity of the solvent proper by the formation of complexing compounds such as diamines. Local stagnancy allows the solvent loading level to approach equilibrium which creates a corrosive environment. Exceeding the unit`s capacity will achieve essentially the same but on a larger scale. The corrosion enhancement by interaction of a total of 12 factors is made visual and clarified. The paper examines step by step the means to prevent a number of the factors arising. Guidelines are given for design of the absorber and absorber internals, the molarity of the solvent, inhibition and the benefits and handicaps of filming inhibitors.

  9. The study on the heat transfer characteristics of oxygen fuel combustion boiler

    NASA Astrophysics Data System (ADS)

    Wu, Haibo; Liu, Zhaohui; Liao, Haiyan

    2016-10-01

    According to 350MW and 600MW boilers, under oxygen fuel condition, through the reasonable control of the primary and secondary flow and the correct option and revision of mathematical model, the temperature distribution, heat flux distribution and absorption heat distribution, etc. was obtained which compared with those under air condition. Through calculation, it is obtained that the primary and secondary flow mixed well, good tangentially fired combustion in furnace was formed, the temperature under air condition obviously higher than the temperature under O26 condition. The adiabatic flame temperature of wet cycle was slightly higher than that of dry cycle. The maximum heat load appeared on the waterwall around the burner area. The heat load gradually decreased along the furnace height up and down in burner area. The heat absorption capacity of the furnace under O26 was lower than that under the air condition. The heat absorption capacity of the platen heating surface under O26 was equal to that under air condition. And the heat absorbing capacity of waterwall under O26 was about7%~12% less than that under air condition.

  10. Measurements of bremsstrahlung production and x-ray cryostat heating in VENUS

    SciTech Connect

    Lyneis, C.; Leitner, D.; Todd, D.; Virostek, S.; Loew, T.; Heinen, A.; Tarvainen, O.

    2006-03-15

    The VENUS superconducting electron cyclotron resonance (ECR) ion source is designed to operate at 28 GHz with up to 10 kW of rf power. Most of this power is absorbed by the plasma electrons and then dumped onto the plasma chamber wall. The distribution of heating and bremsstrahlung production is highly nonuniform and reflects the geometry of the magnetic confinement fields. The nonuniform distribution of electron losses to the wall results in localized heating on the aluminum chamber walls, which can lead to burnout. In addition, part of the bremsstrahlung produced by the collision of the hot-electrons with the walls is absorbed by the cold mass of the superconducting magnet leading to an additional heat load in the cryostat in the order of several watts. Therefore a new plasma chamber has been installed that incorporates a high-Z tantalum shield to reduce the cryostat heating and enhance water cooling to minimize the chance of burnout. In order to better understand the heat load, the spectrum of the bremsstrahlung has been carefully measured as a function of rf power, magnetic confinement, and rf frequency. In addition, the distribution of electron heating in VENUS magnetic field has been simulated with a three-dimensional computer code [H. Heinen and H. J. Andra, Proceedings of the 14th International Workshop on ECR Sources (CERN, Geneva, 1999), 224; H. J. Andra and A. Heinen, Proceedings of the 15th International Workshop on ECR lon Sources, ECRIS'02 (Jyvaeskylae, Finland 2002), 85.] to better understand the heat load distribution on the plasma chamber wall. The new plasma chamber design, results of the bremsstrahlung measurements, and the effectiveness of the high-Z shielding are described.

  11. A polarization-independent broadband terahertz absorber

    SciTech Connect

    Shi, Cheng; Zang, XiaoFei E-mail: ymzhu@usst.edu.cn; Wang, YiQiao; Chen, Lin; Cai, Bin; Zhu, YiMing E-mail: ymzhu@usst.edu.cn

    2014-07-21

    A highly efficient broadband terahertz absorber is designed, fabricated, and experimentally as well as theoretically evaluated. The absorber comprises a heavily doped silicon substrate and a well-designed two-dimensional grating. Due to the destructive interference of waves and diffraction, the absorber can achieve over 95% absorption in a broad frequency range from 1 to 2 THz and for angles of incidence from 0° to 60°. Such a terahertz absorber is also polarization-independent due to its symmetrical structure. This omnidirectional and broadband absorber have potential applications in anti-reflection coatings, imaging systems, and so on.

  12. Heat and mass exchanger

    DOEpatents

    Lowenstein, Andrew; Sibilia, Marc J.; Miller, Jeffrey A.; Tonon, Thomas

    2007-09-18

    A mass and heat exchanger includes at least one first substrate with a surface for supporting a continuous flow of a liquid thereon that either absorbs, desorbs, evaporates or condenses one or more gaseous species from or to a surrounding gas; and at least one second substrate operatively associated with the first substrate. The second substrate includes a surface for supporting the continuous flow of the liquid thereon and is adapted to carry a heat exchange fluid therethrough, wherein heat transfer occurs between the liquid and the heat exchange fluid.

  13. Recovery act. Development of design and simulation tool for hybrid geothermal heat pump system

    SciTech Connect

    Wang, Shaojie; Ellis, Dan

    2014-05-29

    The ground source heat pump (GSHP) system is one of the most energy efficient HVAC technologies in the current market. However, the heat imbalance may degrade the ability of the ground loop heat exchanger (GLHX) to absorb or reject heat. The hybrid GSHP system, which combines a geothermal well field with a supplemental boiler or cooling tower, can balance the loads imposed on the ground loop heat exchangers to minimize its size while retaining superior energy efficiency. This paper presents a recent simulation-based study with an intention to compare multiple common control strategies used in hybrid GSHP systems, including fixed setpoint, outside air reset, load reset, and wetbulb reset. A small office in Oklahoma City conditioned by a hybrid GSHP system was simulated with the latest version of eQUEST 3.7[1]. The simulation results reveal that the hybrid GSHP system has the excellent capability to meet the cooling and heating setpoints during the occupied hours, balance thermal loads on the ground loop, as well as improve the thermal comfort of the occupants with the undersized well field.

  14. Comparison of the impact of six heat-load management strategies on thermal responses and milk production of feed-pad and pasture fed dairy cows in a subtropical environment

    NASA Astrophysics Data System (ADS)

    Davison, T. M.; Jonsson, N. N.; Mayer, D. G.; Gaughan, J. B.; Ehrlich, W. K.; McGowan, M. R.

    2016-05-01

    Exposure to hot environments affects milk yield (MY) and milk composition of pasture and feed-pad fed dairy cows in subtropical regions. This study was undertaken during summer to compare MY and physiology of cows exposed to six heat-load management treatments. Seventy-eight Holstein-Friesian cows were blocked by season of calving, parity, milk yield, BW, and milk protein (%) and milk fat (%) measured in 2 weeks prior to the start of the study. Within blocks, cows were randomly allocated to one of the following treatments: open-sided iron roofed day pen adjacent to dairy (CID) + sprinklers (SP); CID only; non-shaded pen adjacent to dairy + SP (NSD + SP); open-sided shade cloth roofed day pen adjacent to dairy (SCD); NSD + sprinkler (sprinkler on for 45 min at 1100 h if mean respiration rate >80 breaths per minute (NSD + WSP)); open-sided shade cloth roofed structure over feed bunk in paddock + 1 km walk to and from the dairy (SCP + WLK). Sprinklers for CID + SP and NSD + SP cycled 2 min on, 12 min off when ambient temperature >26°C. The highest milk yields were in the CID + SP and CID treatments (23.9 L cow-1 day-1), intermediate for NSD + SP, SCD and SCP + WLK (22.4 L cow-1 day-1), and lowest for NSD + WSP (21.3 L cow-1 day-1) (P < 0.05). The highest (P < 0.05) feed intakes occurred in the CID + SP and CID treatments while intake was lowest (P < 0.05) for NSD + WSP and SCP + WLK. Weather data were collected on site at 10-min intervals, and from these, THI was calculated. Nonlinear regression modelling of MY × THI and heat-load management treatment demonstrated that cows in CID + SP showed no decline in MY out to a THI break point value of 83.2, whereas the pooled MY of the other treatments declined when THI >80.7. A combination of iron roof shade plus water sprinkling throughout the day provided the most effective control of heat load.

  15. Self-assembly of highly efficient, broadband plasmonic absorbers for solar steam generation.

    PubMed

    Zhou, Lin; Tan, Yingling; Ji, Dengxin; Zhu, Bin; Zhang, Pei; Xu, Jun; Gan, Qiaoqiang; Yu, Zongfu; Zhu, Jia

    2016-04-01

    The study of ideal absorbers, which can efficiently absorb light over a broad range of wavelengths, is of fundamental importance, as well as critical for many applications from solar steam generation and thermophotovoltaics to light/thermal detectors. As a result of recent advances in plasmonics, plasmonic absorbers have attracted a lot of attention. However, the performance and scalability of these absorbers, predominantly fabricated by the top-down approach, need to be further improved to enable widespread applications. We report a plasmonic absorber which can enable an average measured absorbance of ~99% across the wavelengths from 400 nm to 10 μm, the most efficient and broadband plasmonic absorber reported to date. The absorber is fabricated through self-assembly of metallic nanoparticles onto a nanoporous template by a one-step deposition process. Because of its efficient light absorption, strong field enhancement, and porous structures, which together enable not only efficient solar absorption but also significant local heating and continuous stream flow, plasmonic absorber-based solar steam generation has over 90% efficiency under solar irradiation of only 4-sun intensity (4 kW m(-2)). The pronounced light absorption effect coupled with the high-throughput self-assembly process could lead toward large-scale manufacturing of other nanophotonic structures and devices.

  16. Fractional absorption of active absorbable algal calcium (AAACa) and calcium carbonate measured by a dual stable-isotope method

    Technology Transfer Automated Retrieval System (TEKTRAN)

    With the use of stable isotopes, this study aimed to compare the bioavailability of active absorbable algal calcium (AAACa), obtained from oyster shell powder heated to a high temperature, with an additional heated seaweed component (Heated Algal Ingredient, HAI), with that of calcium carbonate. In ...

  17. Thermal Performance of a Dual-Channel, Helium-Cooled, Tungsten Heat Exchanger

    SciTech Connect

    YOUCHISON,DENNIS L.; NORTH,MART T.

    2000-11-22

    Helium-cooled, refractory heat exchangers are now under consideration for first wall and divertor applications. These refractory devices take advantage of high temperature operation with large delta-Ts to effectively handle high heat fluxes. The high temperature helium can then be used in a gas turbine for high-efficiency power conversion. Over the last five years, heat removal with helium was shown to increase dramatically by using porous metal to provide a very large effective surface area for heat transfer in a small volume. Last year, the thermal performance of a bare-copper, dual-channel, helium-cooled, porous metal divertor mock-up was evaluated on the 30 kW Electron Beam Test System at Sandia National Laboratories. The module survived a maximum absorbed heat flux of 34.6 MW/m{sup 2} and reached a maximum surface temperature of 593 C for uniform power loading of 3 kW absorbed on a 2-cm{sup 2} area. An impressive 10 kW of power was absorbed on an area of 24 cm{sup 2}. Recently, a similar dual-module, helium-cooled heat exchanger made almost entirely of tungsten was designed and fabricated by Thermacore, Inc. and tested at Sandia. A complete flow test of each channel was performed to determine the actual pressure drop characteristics. Each channel was equipped with delta-P transducers and platinum RTDs for independent calorimetry. One mass flow meter monitored the total flow to the heat exchanger, while a second monitored flow in only one of the channels. The thermal response of each tungsten module was obtained for heat fluxes in excess of 5 MW/m{sup 2} using 50 C helium at 4 MPa. Fatigue cycles were also performed to assess the fracture toughness of the tungsten modules. A description of the module design and new results on flow instabilities are also presented.

  18. Laser-heated thruster

    NASA Technical Reports Server (NTRS)

    Kemp, N. H.; Lewis, P. F.

    1980-01-01

    The development of a computer program for the design of the thrust chamber for a CW laser heated thruster was examined. Hydrodgen was employed as the propellant gas and high temperature absorber. The laser absorption coefficient of the mixture/laser radiation combination is given in temperature and species densities. Radiative and absorptive properties are given to determine radiation from such gas mixtures. A computer code for calculating the axisymmetric channel flow of a gas mixture in chemical equilibrium, and laser energy absorption and convective and radiative heating is described. It is concluded that: (1) small amounts of cesium seed substantially increase the absorption coefficient of hydrogen; (2) cesium is a strong radiator and contributes greatly to radiation of cesium seeded hydrogen; (3) water vapor is a poor absorber; and (4) for 5.3mcm radiation, both H2O/CO and NO/CO seeded hydrogen mixtures are good absorbers.

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

    SciTech Connect

    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.

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

    SciTech Connect

    Koplow, Jeffrey P.

    2015-12-08

    Systems and methods for a forced-convection heat exchanger are provided. In one embodiment, heat is transferred to or from a thermal load in thermal contact with a heat conducting structure, across a narrow air gap, to a rotating heat transfer structure immersed in a surrounding medium such as air.

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

    SciTech Connect

    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.

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

    DOEpatents

    Koplow, Jeffrey P.

    2012-07-24

    Systems and methods for a forced-convection heat exchanger are provided. In one embodiment, heat is transferred to or from a thermal load in thermal contact with a heat conducting structure, across a narrow air gap, to a rotating heat transfer structure immersed in a surrounding medium such as air.

  3. Finned-absorber solar collector

    NASA Technical Reports Server (NTRS)

    1980-01-01

    Report presents results of performance evaluation. Tests are part of continuing study of solar-heating systems and components for NASA and Department of Energy. Test data are presented as graphs and tables. Report also summarizes test procedures and mathematical analysis of results.

  4. Amplification of ENSO effects on Indian summer monsoon by absorbing aerosols

    NASA Astrophysics Data System (ADS)

    Kim, Maeng-Ki; Lau, William K. M.; Kim, Kyu-Myong; Sang, Jeong; Kim, Yeon-Hee; Lee, Woo-Seop

    2016-04-01

    In this study, we present observational evidence, based on satellite aerosol measurements and MERRA reanalysis data for the period 1979-2011, indicating that absorbing aerosols can have strong influence on seasonal-to-interannual variability of the Indian summer monsoon rainfall, including amplification of ENSO effects. We find a significant correlation between ENSO (El Nino Southern Oscillation) and aerosol loading in April-May, with La Nina (El Nino) conditions favoring increased (decreased) aerosol accumulation over northern India, with maximum aerosol optical depth over the Arabian Sea and Northwestern India, indicative of strong concentration of dust aerosols transported from West Asia and Middle East deserts. Composite analyses based on a normalized aerosol index (NAI) show that high concentration of aerosol over northern India in April-May is associated with increased moisture transport, enhanced dynamically induced warming of the upper troposphere over the Tibetan Plateau, and enhanced rainfall over northern India and the Himalayan foothills during May-June, followed by a subsequent suppressed monsoon rainfall over all India, consistent with the elevated heat pump (EHP) hypothesis (Lau et al. in Clim Dyn 26:855-864, 2006. doi: 10.1007/s00382-006-0114-z). Further analyses from sub-sampling of ENSO years, with normal (<1-σ), and abnormal (>1-σ) NAI over northern India respectively show that the EHP may lead to an amplification of the Indian summer monsoon response to ENSO forcing, particularly with respect to the increased rainfall over the Himalayan foothills, and the warming of the upper troposphere over the Tibetan Plateau. Our results suggest that absorbing aerosol, particular desert dusts can strongly modulate ENSO influence, and possibly play important roles as a feedback agent in climate change in Asian monsoon regions.

  5. Warming of the Arctic lower stratosphere by light absorbing particles

    NASA Astrophysics Data System (ADS)

    Baumgardner, D.; Kok, G.; Raga, G.

    2004-03-01

    Recent measurements of light absorbing particles in the Arctic lower stratosphere show significantly higher mass concentrations of black carbon than were measured in 1992. The difference is primarily a result of measurements with a more quantitative and accurate technique than was previously used. We attribute the large amount of light absorbing material to transport from lower latitude, tropospheric sources rather than increases in aircraft emissions. The calculated heating rate in this aerosol layer, as compared to an atmosphere consisting of only gases, increases by 12% during the winter. This is a result of light absorption by the particles and could perturb the altitude of the local tropopause and affect tropospheric/stratospheric exchange processes.

  6. Development of a prototype regeneration carbon dioxide absorber. [for use in EVA conditions

    NASA Technical Reports Server (NTRS)

    Patel, P. S.; Baker, B. S.

    1977-01-01

    A prototype regenerable carbon dioxide absorber was developed to maintain the environmental quality of the portable life support system. The absorber works on the alkali metal carbonate-bicarbonate solid-gas reaction to remove carbon dioxide from the atmosphere. The prototype sorber module was designed, fabricated, and tested at simulated extravehicular activity conditions to arrive at optimum design. The unit maintains sorber outlet concentration below 5 mm Hg. An optimization study was made with respect to heat transfer, temperature control, sorbent utilization, sorber life and regenerability, and final size of the module. Important parameters influencing the capacity of the final absorber unit were identified and recommendations for improvement were made.

  7. Foam-based optical absorber for high-power laser radiometry

    SciTech Connect

    Ramadurai, Krishna; Cromer, Christopher L.; Li, Xiaoyu; Mahajan, Roop L.; Lehman, John H

    2007-12-01

    We report damage threshold measurements of novel absorbers comprised of either liquid-cooled silicon carbide or vitreous carbon foams. The measurements demonstrate damage thresholds up to 1.6x104 W/cm2 at an incident circular spot size of 2 mm with an absorbance of 96% at 1.064 {mu}m. We present a summary of the damage threshold as a function of the water flow velocity and the absorbance measurements. We also present a qualitative description of a damage mechanism based on a two-phase heat transfer between the foam and the flowing water.

  8. Magnetic field effects on microwave absorbing materials

    NASA Technical Reports Server (NTRS)

    Goldberg, Ira; Hollingsworth, Charles S.; Mckinney, Ted M.

    1991-01-01

    The objective of this program was to gather information to formulate a microwave absorber that can work in the presence of strong constant direct current (DC) magnetic fields. The program was conducted in four steps. The first step was to investigate the electrical and magnetic properties of magnetic and ferrite microwave absorbers in the presence of strong magnetic fields. This included both experimental measurements and a literature survey of properties that may be applicable to finding an appropriate absorbing material. The second step was to identify those material properties that will produce desirable absorptive properties in the presence of intense magnetic fields and determine the range of magnetic field in which the absorbers remain effective. The third step was to establish ferrite absorber designs that will produce low reflection and adequate absorption in the presence of intense inhomogeneous static magnetic fields. The fourth and final step was to prepare and test samples of such magnetic microwave absorbers if such designs seem practical.

  9. Carbon Dioxide Absorption Heat Pump

    NASA Technical Reports Server (NTRS)

    Jones, Jack A. (Inventor)

    2002-01-01

    A carbon dioxide absorption heat pump cycle is disclosed using a high pressure stage and a super-critical cooling stage to provide a non-toxic system. Using carbon dioxide gas as the working fluid in the system, the present invention desorbs the CO2 from an absorbent and cools the gas in the super-critical state to deliver heat thereby. The cooled CO2 gas is then expanded thereby providing cooling and is returned to an absorber for further cycling. Strategic use of heat exchangers can increase the efficiency and performance of the system.

  10. Crash-Energy Absorbing Composite Structure and Method of Fabrication

    NASA Technical Reports Server (NTRS)

    Kellas, Sotiris (Inventor); Carden, Huey D. (Inventor)

    1998-01-01

    A stand-alone, crash-energy absorbing structure and fabrication method are provided. A plurality of adjoining rigid cells are each constructed of resin-cured fiber reinforcement and are arranged in a geometric configuration. The geometric configuration of cells is integrated by means of continuous fibers wrapped thereabout in order to maintain the cells in the geometric configuration. The cured part results in a net shape, stable structure that can function on its own with no additional reinforcement and can withstand combined loading while crushing in a desired direction.

  11. Absorbent product and articles made therefrom

    NASA Technical Reports Server (NTRS)

    Dawn, F. S.; Correale, J. V. (Inventor)

    1982-01-01

    A multilayer absorbent product for use in contact with the skin to absorb fluids is described. The product has a water pervious facing layer for contacting the skin, and a first fibrous wicking layer overlaying the water pervious layer. A first container section is defined by inner and outer layers of a water pervious wicking material in between a first absorbent mass and a second container section defined by inner and outer layers of a water pervious wicking material between what is disposed a second absorbent mass, and a liquid impermeable/gas permeable layer overlaying the second fibrous wicking layer.

  12. Advanced Reflector and Absorber Materials (Fact Sheet)

    SciTech Connect

    Not Available

    2010-08-01

    Fact sheet describing NREL CSP Program capabilities in the area of advanced reflector and absorber materials: evaluating performance, determining degradation rates and lifetime, and developing new coatings.

  13. Device for absorbing mechanical shock

    DOEpatents

    Newlon, Charles E.

    1980-01-01

    This invention is a comparatively inexpensive but efficient shock-absorbing device having special application to the protection of shipping and storage cylinders. In a typical application, two of the devices are strapped to a cylinder to serve as saddle-type supports for the cylinder during storage and to protect the cylinder in the event it is dropped during lifting or lowering operations. In its preferred form, the invention includes a hardwood plank whose grain runs in the longitudinal direction. The basal portion of the plank is of solid cross-section, whereas the upper face of the plank is cut away to form a concave surface fittable against the sidewall of a storage cylinder. The concave surface is divided into a series of segments by transversely extending, throughgoing relief slots. A layer of elastomeric material is positioned on the concave face, the elastomer being extrudable into slots when pressed against the segments by a preselected pressure characteristic of a high-energy impact. The compressive, tensile, and shear properties of the hardwood and the elastomer are utilized in combination to provide a surprisingly high energy-absorption capability.

  14. Device for absorbing mechanical shock

    DOEpatents

    Newlon, C.E.

    1979-08-29

    This invention is a comparatively inexpensive but efficient shock-absorbing device having special application to the protection of shipping and storage cylinders. In a typical application, two of the devices are strapped to a cylinder to serve as saddle-type supports for the cylinder during storage and to protect the cylinder in the event it is dropped during lifting or lowering operations. In its preferred form, the invention includes a hardwood plank whose grain runs in the longitudinal direction. The basal portion of the plank is of solid cross-section, whereas the upper face of the plank is cut away to form a concave surface fittable against the sidewall of a storage cylinder. The concave surface is divided into a series of segments by transversely extending, throughgoing relief slots. A layer of elastomeric material is positioned on the concave face, the elastomer being extrudable into slots when pressed against the segments by a preselected pressure characteristic of a high-energy impact. The compressive, tensile, and shear properties of the hardwood and the elastomer are utilized in combination to provide a surprisingly high energy-absorption capability.

  15. Self-assembly of highly efficient, broadband plasmonic absorbers for solar steam generation

    PubMed Central

    Zhou, Lin; Tan, Yingling; Ji, Dengxin; Zhu, Bin; Zhang, Pei; Xu, Jun; Gan, Qiaoqiang; Yu, Zongfu; Zhu, Jia

    2016-01-01

    The study of ideal absorbers, which can efficiently absorb light over a broad range of wavelengths, is of fundamental importance, as well as critical for many applications from solar steam generation and thermophotovoltaics to light/thermal detectors. As a result of recent advances in plasmonics, plasmonic absorbers have attracted a lot of attention. However, the performance and scalability of these absorbers, predominantly fabricated by the top-down approach, need to be further improved to enable widespread applications. We report a plasmonic absorber which can enable an average measured absorbance of ~99% across the wavelengths from 400 nm to 10 μm, the most efficient and broadband plasmonic absorber reported to date. The absorber is fabricated through self-assembly of metallic nanoparticles onto a nanoporous template by a one-step deposition process. Because of its efficient light absorption, strong field enhancement, and porous structures, which together enable not only efficient solar absorption but also significant local heating and continuous stream flow, plasmonic absorber–based solar steam generation has over 90% efficiency under solar irradiation of only 4-sun intensity (4 kW m−2). The pronounced light absorption effect coupled with the high-throughput self-assembly process could lead toward large-scale manufacturing of other nanophotonic structures and devices. PMID:27152335

  16. Water-heating dehumidifier

    DOEpatents

    Tomlinson, John J.

    2006-04-18

    A water-heating dehumidifier includes a refrigerant loop including a compressor, at least one condenser, an expansion device and an evaporator including an evaporator fan. The condenser includes a water inlet and a water outlet for flowing water therethrough or proximate thereto, or is affixed to the tank or immersed into the tank to effect water heating without flowing water. The immersed condenser design includes a self-insulated capillary tube expansion device for simplicity and high efficiency. In a water heating mode air is drawn by the evaporator fan across the evaporator to produce cooled and dehumidified air and heat taken from the air is absorbed by the refrigerant at the evaporator and is pumped to the condenser, where water is heated. When the tank of water heater is full of hot water or a humidistat set point is reached, the water-heating dehumidifier can switch to run as a dehumidifier.

  17. Laser-heated thruster

    NASA Technical Reports Server (NTRS)

    Kemp, N. H.; Krech, R. H.

    1980-01-01

    The development of computer codes for the thrust chamber of a rocket of which the propellant gas is heated by a CW laser beam was investigated. The following results are presented: (1) simplified models of laser heated thrusters for approximate parametric studies and performance mapping; (3) computer programs for thrust chamber design; and (3) shock tube experiment to measure absorption coefficients. Two thrust chamber design programs are outlined: (1) for seeded hydrogen, with both low temperature and high temperature seeds, which absorbs the laser radiation continuously, starting at the inlet gas temperature; and (2) for hydrogen seeded with cesium, in which a laser supported combustion wave stands near the gas inlet, and heats the gas up to a temperature at which the gas can absorb the laser energy.

  18. 21 CFR 872.6050 - Saliva absorber.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Saliva absorber. 872.6050 Section 872.6050 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6050 Saliva absorber. (a) Identification. A...

  19. 21 CFR 872.6050 - Saliva absorber.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Saliva absorber. 872.6050 Section 872.6050 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6050 Saliva absorber. (a) Identification. A...

  20. 21 CFR 872.6050 - Saliva absorber.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Saliva absorber. 872.6050 Section 872.6050 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6050 Saliva absorber. (a) Identification. A...