Sample records for joule heating

  1. Joule-Thomson expander and heat exchanger

    NASA Technical Reports Server (NTRS)

    Norman, R. H.

    1976-01-01

    The Joule-Thomson Expander and Heat Exchanger Program was initiated to develop an assembly (JTX) which consists of an inlet filter, counterflow heat exchanger, Joule-Thomson expansion device, and a low pressure jacket. The program objective was to develop a JTX which, when coupled to an open cycle supercritical helium refrigerating system (storage vessel), would supply superfluid helium (He II) at 2 K or less for cooling infrared detectors.

  2. High-latitude Joule heating response to IMF inputs

    Microsoft Academic Search

    M. McHarg; F. Chun; D. Knipp; G. Lu; B. Emery; A. Ridley

    2005-01-01

    We evaluate the response of the high-latitude Joule heating to orientation and magnitude of the interplanetary magnetic field (IMF). Approximately 9000 individual Joule heating patterns derived from data assimilation for the northern hemisphere were used to develop averaged and hemispherically integrated Joule power maps for the northern hemisphere north of 40° magnetic latitude. Hemispherically integrated Joule heating increases with IMF

  3. Memristor Physics Driven by Joule Heating

    NASA Astrophysics Data System (ADS)

    Hjalmarson, Harold; McLain, Michael; Mamaluy, Denis; Gao, Xujiao

    2014-03-01

    Switching in bipolar memristive devices involves the growth of conductive filaments following the application of a voltage pulse that causes heating. This Joule heating by the electric field is a large contributor to the migration of atoms and vacancies. In this talk, the results of continuum calculations will be used to describe the switching of tantalum oxide devices. The continuum calculations include the effects of Joule heating, chemical species migration, ionizing radiation and chemical reactions. These calculations will be focused on the temporal evolution of a conductive filament in a simple structure. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  4. Optimal joule heating of the subsurface

    DOEpatents

    Berryman, James G. (Danville, CA); Daily, William D. (Livermore, CA)

    1994-01-01

    A method for simultaneously heating the subsurface and imaging the effects of the heating. This method combines the use of tomographic imaging (electrical resistance tomography or ERT) to image electrical resistivity distribution underground, with joule heating by electrical currents injected in the ground. A potential distribution is established on a series of buried electrodes resulting in energy deposition underground which is a function of the resistivity and injection current density. Measurement of the voltages and currents also permits a tomographic reconstruction of the resistivity distribution. Using this tomographic information, the current injection pattern on the driving electrodes can be adjusted to change the current density distribution and thus optimize the heating. As the heating changes conditions, the applied current pattern can be repeatedly adjusted (based on updated resistivity tomographs) to affect real time control of the heating.

  5. Welding dissimilar metal microwires by Joule heating

    NASA Astrophysics Data System (ADS)

    Sunagawa, Takuya; Tohmyoh, Hironori

    2015-06-01

    In this paper we report on the Joule heat welding of dissimilar metal microwires. The current required for successful welding was investigated. Various combinations of 25 µm diameter Cu, Au and Al microwires were welded together using this technique. The welded dissimilar metal wire systems were then cut by supplying a higher current, and it was found that the position at which the wires cut was not at the midpoint, i.e., the position of the weld, of the wire system. This is because the temperature distributions formed in the dissimilar metal systems were asymmetrical. The positions at which the wires cut were in good agreement with those predicted by a heat conduction model. The lower limit for successful welding of the dissimilar metal microwire system was found to be determined by the lower of the two currents required to cut microwires of the individual materials.

  6. Nanometric crystallization of amorphous ribbons by DC Joule heating

    NASA Astrophysics Data System (ADS)

    Morón, C.; Maganto, F.; García, A.

    2004-05-01

    We report the results of studies on the development of nanocrystalline phase by DC Joule heating. Structural and magnetic properties, after various annealing conditions, are reported. We show that DC Joule heating is an effective technique for control of nanometric crystallization and it is also compared with respect to conventional heat treatment and laser annealing. In Fe 73.5Nb 3Cu 1Si 13.5B 9, the average grain size of Joule heated samples is significantly lower than in the furnace and laser annealed alloy.

  7. Observations of joule and particle heating in the auroral zone

    NASA Technical Reports Server (NTRS)

    Banks, P. M.

    1977-01-01

    Observational data from the Chatanika, Alaska incoherent scatter radar have been used to deduce atmospheric heating rates associated with particle precipitation and joule dissipation. During periods when Chatanika is in the vicinity of the auroral oval the height-integrated heat input to the lower thermosphere can be as large as 100 ergs per sq cm per sec with joule and particle heating rates of comparable magnitude. Altitude profiles of these heat inputs are also obtained, showing that the energy liberated by joule dissipation tends to peak at a substantially higher altitude (about 130 km) than that due to particles (100-120 km). As a consequence, it follows that joule heating can be expected to provide a rapid means for creating thermospheric disturbances. It is also pointed out that joule and particle heating are permanent features of the auroral oval and polar cap. As such, expansion of the auroral oval leads to an increase in the total global heating and, hence, to the close relationship between magnetic disturbances and thermospheric perturbation.

  8. Non-joule heating of ice in an electric field.

    PubMed

    Petrenko, Victor F; Ryzhkin, Ivan A

    2011-06-16

    We theoretically predict and calculate non-Joule heating/cooling caused by a direct electric current in ordinary crystalline ice Ih. The cause of this effect is related to partial ordering/disordering occurring in the proton subsystem of ice when protons either drift or diffuse in the ice. Depending on relative directions of the electric current and the configuration vector of ice, the non-Joule effect can be either positive, that is, heat generation, or negative, that is, heat absorption, and its absolute magnitude is usually comparable with that of normal Joule heating. The magnitude of this phenomenon is also approximately inversely proportional to the ice temperature and, thus, is more pronounced at low temperatures. PMID:21671671

  9. Physical and numerical modeling of Joule-heated melters

    Microsoft Academic Search

    L. L. Eyler; R. J. Skarda; R. S. Crowder III; D. S. Trent; C. R. Reid; D. L. Lessor

    1985-01-01

    The Joule-heated ceramic-lined melter is an integral part of the high level waste immobilization process under development by the US Department of Energy. Scaleup and design of this waste glass melting furnace requires an understanding of the relationships between melting cavity design parameters and the furnace performance characteristics such as mixing, heat transfer, and electrical requirements. Developing empirical models of

  10. Nonlinear phenomena in multiferroic nanocapacitor: Joule heating and electromechanical effects

    SciTech Connect

    Kim, Yunseok [ORNL; Kumar, Amit [ORNL; Tselev, Alexander [ORNL; Kravchenko, Ivan I [ORNL; Kalinin, Sergei V [ORNL; Jesse, Stephen [ORNL

    2011-01-01

    We demonstrate an approach for probing nonlinear electromechanical responses in BiFeO3 thin film nanocapacitors using half-harmonic band excitation piezoresponse force microscopy (PFM). Nonlinear PFM images of nanocapacitor arrays show clearly visible clusters of capacitors associated with variations of local leakage current through the BiFeO3 film. Strain spectroscopy measurements and finite element modeling point to significance of the Joule heating and show that the thermal effects caused by the Joule heating can provide nontrivial contributions to the nonlinear electromechanical responses in ferroic nanostructures. This approach can be further extended to unambiguous mapping of electrostatic signal contributions to PFM and related techniques.

  11. Analytical and Numerical Study of Joule Heating Effects on Electrokinetically Pumped Continuous Flow PCR Chips

    E-print Network

    Le Roy, Robert J.

    Analytical and Numerical Study of Joule Heating Effects on Electrokinetically Pumped Continuous, and the potential for integration.1-3 Joule heating is inevitable when electrokinetic pumping is used Form: December 8, 2007 Joule heating is an inevitable phenomenon for microfluidic chips involving

  12. Joule Heating and Anomalous Resistivity in the Solar Corona

    E-print Network

    Steven R. Spangler

    2008-12-22

    Recent radioastronomical observations of Faraday rotation in the solar corona can be interpreted as evidence for coronal currents, with values as large as $2.5 \\times 10^9$ Amperes (Spangler 2007). These estimates of currents are used to develop a model for Joule heating in the corona. It is assumed that the currents are concentrated in thin current sheets, as suggested by theories of two dimensional magnetohydrodynamic turbulence. The Spitzer result for the resistivity is adopted as a lower limit to the true resistivity. The calculated volumetric heating rate is compared with an independent theoretical estimate by Cranmer et al (2007). This latter estimate accounts for the dynamic and thermodynamic properties of the corona at a heliocentric distance of several solar radii. Our calculated Joule heating rate is less than the Cranmer et al estimate by at least a factor of $3 \\times 10^5$. The currents inferred from the observations of Spangler (2007) are not relevant to coronal heating unless the true resistivity is enormously increased relative to the Spitzer value. However, the same model for turbulent current sheets used to calculate the heating rate also gives an electron drift speed which can be comparable to the electron thermal speed, and larger than the ion acoustic speed. It is therefore possible that the coronal current sheets are unstable to current-driven instabilities which produce high levels of waves, enhance the resistivity and thus the heating rate.

  13. Acceleration of runaway electrons and Joule heating in solar flares

    NASA Technical Reports Server (NTRS)

    Holman, G. D.

    1984-01-01

    The electric field acceleration of electrons out of a thermal plasma and the simultaneous Joule heating of the plasma are studied. Acceleration and heating timescales are derived and compared, and upper limits are obtained on the acceleration volume and the rate at which electrons can be accelerated. These upper limits, determined by the maximum magnetic field strength observed in flaring regions, place stringent restrictions upon the acceleration process. The role of the plasma resistivity in these processes is examined, and possible sources of anomalous resistivity are summarized. The implications of these results for the microwave and hard X-ray emission from solar flares are examined.

  14. Physical and numerical modeling of Joule-heated melters

    NASA Astrophysics Data System (ADS)

    Eyler, L. L.; Skarda, R. J.; Crowder, R. S., III; Trent, D. S.; Reid, C. R.; Lessor, D. L.

    1985-10-01

    The Joule-heated ceramic-lined melter is an integral part of the high level waste immobilization process under development by the US Department of Energy. Scaleup and design of this waste glass melting furnace requires an understanding of the relationships between melting cavity design parameters and the furnace performance characteristics such as mixing, heat transfer, and electrical requirements. Developing empirical models of these relationships through actual melter testing with numerous designs would be a very costly and time consuming task. Additionally, the Pacific Northwest Laboratory (PNL) has been developing numerical models that simulate a Joule-heated melter for analyzing melter performance. This report documents the method used and results of this modeling effort. Numerical modeling results are compared with the more conventional, physical modeling results to validate the approach. Also included are the results of numerically simulating an operating research melter at PNL. Physical Joule-heated melters modeling results used for qualiying the simulation capabilities of the melter code included: (1) a melter with a single pair of electrodes and (2) a melter with a dual pair (two pairs) of electrodes. The physical model of the melter having two electrode pairs utilized a configuration with primary and secondary electrodes. The principal melter parameters (the ratio of power applied to each electrode pair, modeling fluid depth, electrode spacing) were varied in nine tests of the physical model during FY85. Code predictions were made for five of these tests. Voltage drops, temperature field data, and electric field data varied in their agreement with the physical modeling results, but in general were judged acceptable.

  15. Physical and numerical modeling of Joule-heated melters

    SciTech Connect

    Eyler, L.L.; Skarda, R.J.; Crowder, R.S. III; Trent, D.S.; Reid, C.R.; Lessor, D.L.

    1985-10-01

    The Joule-heated ceramic-lined melter is an integral part of the high level waste immobilization process under development by the US Department of Energy. Scaleup and design of this waste glass melting furnace requires an understanding of the relationships between melting cavity design parameters and the furnace performance characteristics such as mixing, heat transfer, and electrical requirements. Developing empirical models of these relationships through actual melter testing with numerous designs would be a very costly and time consuming task. Additionally, the Pacific Northwest Laboratory (PNL) has been developing numerical models that simulate a Joule-heated melter for analyzing melter performance. This report documents the method used and results of this modeling effort. Numerical modeling results are compared with the more conventional, physical modeling results to validate the approach. Also included are the results of numerically simulating an operating research melter at PNL. Physical Joule-heated melters modeling results used for qualiying the simulation capabilities of the melter code included: (1) a melter with a single pair of electrodes and (2) a melter with a dual pair (two pairs) of electrodes. The physical model of the melter having two electrode pairs utilized a configuration with primary and secondary electrodes. The principal melter parameters (the ratio of power applied to each electrode pair, modeling fluid depth, electrode spacing) were varied in nine tests of the physical model during FY85. Code predictions were made for five of these tests. Voltage drops, temperature field data, and electric field data varied in their agreement with the physical modeling results, but in general were judged acceptable. 14 refs., 79 figs., 17 tabs.

  16. Joule heating of the Jovian ionosphere by corotation enforcement currents

    NASA Astrophysics Data System (ADS)

    Nishida, A.; Watanabe, Y.

    1981-11-01

    A simple magnetodisk model is used to estimate the Joule heating rate, for several causes of departure from the corotation during whose enforcement heat is deposited on the Jovian magnetosphere. Following compression or expansion of the magnetosphere, the magnetospheric plasma sub- or super-rotates due to conservation of angular momentum and thermal energy is deposited in the ionosphere at a rate of 10 to the 12th W for 100,000 sec while rotational speed is adjusted toward the corotation with the planet. Day-night asymmetry in trajectory of rotational motion of plasma, due to magnetospheric configuration asymmetry, may also produce energy dissipation of a similar magnitude as the rotational speed is adjusted. The corotation enforcement current therefore deposits as much heat as the dynamo current from Io, and plays an important role in the energetics and dynamics of the Jovian magnetosphere.

  17. Nanoscale Joule heating, Peltier cooling and current crowding at graphenemetal contacts

    E-print Network

    King, William P.

    Nanoscale Joule heating, Peltier cooling and current crowding at graphene­metal contacts Kyle L, but also to reveal Peltier cooling and current crowding at graphene­metal contacts. These effects are key the presence of Joule heating9­11, current crowding12­16 and thermoelectric heating and cooling17 . Comparison

  18. Experience with a joule heated ceramic melter while converting simulated high-level waste to glass

    Microsoft Academic Search

    1976-01-01

    Development of a joule heated ceramic melter, sponsored by the Energy Research and Development Administration, has been progressing for nearly three years. In January 1975, a ceramic lined, direct joule heated glass melter was started up and operated continuously for nearly eleven months. During this period, process testing was completed both while feeding simulated high-level waste calcine and while feeding

  19. Joule heating and nitric oxide in the thermosphere C. A. Barth,1

    E-print Network

    Bailey, Scott

    Joule heating and nitric oxide in the thermosphere C. A. Barth,1 G. Lu,2 and R. G. Roble2 Received] The effect of Joule heating on the density of nitric oxide in the thermosphere was studied using observations from the Student Nitric Oxide Explorer (SNOE) satellite and model calculations from the Thermospheric

  20. Refractory electrodes for joule heating and methods of using same

    DOEpatents

    Lamar, D.A.; Chapman, C.C.; Elliott, M.L.

    1998-05-12

    A certain group of electrically conductive refractory materials presently known for use in high temperature applications as throat constructions, melter sidewalls, forehearth, stacks, port sills, hot face lining for slagging coal gasifiers, slag runners, and linings for nuclear waste encapsulation furnaces may be used as electrodes permitting joule heating at temperatures in excess of 1,200 C in excess of about 4400 hours even in the presence of transition group element(s). More specifically, the invention is an electrode for melting earthen materials, wherein the electrode is made from an electrically conductive refractory material, specifically at least one metal oxide wherein the metal is selected from the group consisting of chrome, ruthenium, rhodium, tin and combinations thereof. 2 figs.

  1. Polycrystalline silicon thin-film transistors fabricated by rapid Joule heating method

    Microsoft Academic Search

    Y. Kaneko; N. Andoh; T. Sameshima

    2003-01-01

    We report n- and p-channel polycrystalline silicon thin film transistors (poly-Si TFTs) fabricated with a rapid joule heating method. Crystallization of 50-nm-thick silicon films and activation of phosphorus and boron atoms were successfully achieved by rapid heat diffusion via 300-nm-thick SiO2 intermediate layers from joule heating induced by electrical current flowing in chromium strips. The effective carrier mobility and the

  2. Toward reversing Joule heating with a phonon-absorbing heterobarrier

    NASA Astrophysics Data System (ADS)

    Shin, Seungha; Kaviany, Massoud

    2015-02-01

    Using a graded heterobarrier placed along an electron channel, phonons emitted in Joule heating are recycled in situ by increasing the entropy of phonon-absorbing electrons. The asymmetric electric potential distribution created by alloy grading separates the phonon absorption and emission regions, and emission in the larger effective-mass region causes momentum relaxation with smaller electron kinetic energy loss. These lead to smaller overall phonon emission and simultaneous potential-gain and self-cooling effects. Larger potential is gained with lower current and higher optical-phonon temperature. The self-consistent Monte Carlo simulations complying with the lateral momentum conservation combined with the entropy analysis are applied to a GaAs:Al electron channel with a graded heterobarrier, and under ideal lateral thermal isolation from surroundings, the phonon recycling efficiency reaches 25% of the reversible limit at 350 K, and it increases with temperature. The lateral momentum contributes to the transmission across the barrier, so partially nonconserving lateral momentum electron scattering (rough interface) can improve efficiency.

  3. Joule heating in ferromagnetic nanostripes with a notch

    NASA Astrophysics Data System (ADS)

    Ramos, Eduardo; López, Cristina; Akerman, Johanna; Muñoz, Manuel; Prieto, José L.

    2015-06-01

    The temperature in a ferromagnetic nanostripe with a notch subject to Joule heating has been studied in detail. We first performed an experimental real-time calibration of the temperature versus time as a 100 ns current pulse was injected into a Permalloy nanostripe. This calibration was repeated for different pulse amplitudes and stripe dimensions and the set of experimental curves were fitted with a computer simulation using the Fourier thermal conduction equation. The best fit of these experimental curves was obtained by including the temperature-dependent behavior of the electrical resistivity of the Permalloy and of the thermal conductivity of the substrate (Si O2 ). Notably, a nonzero interface thermal resistance between the metallic nanostripe and the substrate was also necessary to fit the experimental curves. We found this parameter pivotal to understand our results and the results from previous works. The higher current density in the notch, together with the interface thermal resistance, allows a considerable increase of the temperature in the notch, creating a large horizontal thermal gradient. This gradient, together with the high temperature in the notch and the larger current density close to the edges of the notch, can be very influential in experiments studying the current assisted domain wall motion.

  4. Experience with a joule heated ceramic melter while converting simulated high-level waste to glass

    Microsoft Academic Search

    1976-01-01

    Development of a joule-heated ceramic melter, sponsored by the Energy Research and Development Administration, has been progressing for nearly 3 years. In January 1975, a ceramic-lined, direct joule-heated glass melter was started up and operated continuously for nearly 11 months. During this period, process testing was completed both while feeding simulated high-level waste calcine and while feeding simulated high-level liquid

  5. Convective behaviour of a uniformly Joule-heated liquid pool in a rectangular cavity

    Microsoft Academic Search

    G. Sugilal; P. K. Wattal; K. Iyer

    2005-01-01

    A two-dimensional mathematical model has been developed to study the interaction between gravitational body force and self-induced electromagnetic body force in a Joule-heated liquid pool in a rectangular cavity, with an aspect ratio of 2. The Joule heating of the liquid pool in the cavity is accomplished by passing a large alternating current employing a pair of plate electrodes immersed

  6. Hybrid joule heating/electro-osmosis process for extracting contaminants from soil layers

    DOEpatents

    Carrigan, Charles R.; Nitao, John J.

    2003-06-10

    Joule (ohmic) heating and electro-osmosis are combined in a hybrid process for removal of both water-soluble contaminants and non-aqueous phase liquids from contaminated, low-permeability soil formations that are saturated. Central to this hybrid process is the partial desaturation of the formation or layer using electro-osmosis to remove a portion of the pore fluids by induction of a ground water flow to extraction wells. Joule heating is then performed on a partially desaturated formation. The joule heating and electro-osmosis operations can be carried out simultaneously or sequentially if the desaturation by electro-osmosis occurs initially. Joule heating of the desaturated formation results in a very effective transfer or partitioning of liquid state contaminants to the vapor phase. The heating also substantially increases the vapor phase pressure in the porous formation. As a result, the contaminant laden vapor phase is forced out into soil layers of a higher permeability where other conventional removal processes, such as steam stripping or ground water extraction can be used to capture the contaminants. This hybrid process is more energy efficient than joule heating or steam stripping for cleaning low permeability formations and can share electrodes to minimize facility costs.

  7. Calculating Hemispheric Power and Joule Heating using Defense Meteorological Satellite Program (DMSP) F13 data

    NASA Astrophysics Data System (ADS)

    Khan, M.; Emery, B. A.; Maute, A. I.

    2013-12-01

    Thermosphere Ionosphere Electrodynamics General Circulation Model (TIEGCM) simulates the thermosphere-ionosphere with self consistent electrodynamics. The Weimer 2005 ion convection model can be used with a parameterized model of the aurora based on the electron auroral hemispheric power. The spatial location and radius of the auroral model is adjusted with respect to the Weimer 2005 boundary for zero electric potential, but the resulting Joule heating may be an under or over estimation of the real magnetosphere-ionosphere energy transfer. To improve the auroral model so that the resulting Joule heating is relatively realistic is the ultimate aim of this project. To this end, we achieve a number of sub-goals using data from the DMSP-F13, which is in a dawn-dusk orbit. We use data from the Ion Drift Meter (IDM) to quantify the relative positions of the convection reversal boundary (CRB), the cross-track ion drift (Vy) sunward peaks, and the equatorward boundary of zero velocities (or zero electric potential) and compare them to Weimer 2005 positions for the same orbits. The electric field is estimated only from the cross-track ion velocity Vy in the dawn-dusk orbits, while the along-track ion velocity Vx is ignored. We also calculate auroral Pederson conductance using the auroral electron energy flux and mean electron energy measurements from the DMSP Special Sensor Precipitating Electron and Ion Spectrometer (SSJ/4). The hemispheric power is estimated from the electron energy flux. The Joule heating is approximately the product of the Pedersen conductance and the square of the electric field, where we include Pedersen conductance from EUV and from the aurora to estimate EUV Joule heating and particle Joule heating. Our results for a range of Bz Interplanetary Magnetic Fields (IMF Bz) values show that the hemispheric power is largest in the morning sector where the aurora is widest. The aurora mostly lies in the sunward ion flow region and thus the integrated particle Joule heating in the sunward ion flow region is higher than in the anti-sunward ion flow located in the polar cap. Thus, for the TIEGCM, the poleward edge of the aurora should be placed close to the Weimer CRB. However, the integrated total Joule heating is higher for anti-sunward ion flow in the polar cap compared to the integrated total Joule heating for the equatorward sunward ion flow, which points out the relative importance of the anti-sunward ion drifts. As for the spatially integrated total Joule heating, the values are approximately the same in the dawn and dusk regions.

  8. Joule heating and nitric oxide in the thermosphere, 2 Charles A. Barth1

    E-print Network

    Bailey, Scott

    Joule heating and nitric oxide in the thermosphere, 2 Charles A. Barth1 Received 14 April 2010. The heating leads to an increase in the density of nitric oxide at 140 km in the thermosphere. On some occasions, the increased nitric oxide diffuses downward to the 110 km level causing the nitric oxide density

  9. A continuum-atomistic method for incorporating Joule heating into classical molecular dynamics simulations

    E-print Network

    Brenner, Donald W.

    -scale molecular dynamics (MD) simulation is not to model electron dynamics, but rather to numerically solveA continuum-atomistic method for incorporating Joule heating into classical molecular dynamics dynamics (MD) simulations. When coupled to a continuum thermostat, the method allows resistive heating

  10. Diffusion, Fluxes, Friction Forces, and Joule Heating in Two-Temperature Multicomponent Magnetohydrodynamics

    NASA Technical Reports Server (NTRS)

    Chang, C. H.

    1999-01-01

    The relationship between Joule heating, diffusion fluxes, and friction forces has been studied for both total and electron thermal energy equations, using general expressions for multicomponent diffusion in two-temperature plasmas with the velocity dependent Lorentz force acting on charged species in a magnetic field. It is shown that the derivation of Joule heating terms requires both diffusion fluxes and friction between species which represents the resistance experienced by the species moving at different relative velocities. It is also shown that the familiar Joule heating term in the electron thermal energy equation includes artificial effects produced by switching the convective velocity from the species velocity to the mass-weighted velocity, and thus should not be ignored even when there is no net energy dissipation.

  11. Effect of Joule heating on isoelectric focusing of proteins in a microchannel.

    PubMed

    Yoo, Kisoo; Shim, Jaesool; Dutta, Prashanta

    2014-11-01

    Electric field-driven separation and purification techniques, such as isoelectric focusing (IEF) and isotachophoresis, generate heat in the system that can affect the performance of the separation process. In this study, a new mathematical model is presented for IEF that considers the temperature rise due to Joule heating. We used the model to study focusing phenomena and separation performance in a microchannel. A finite volume-based numerical technique is developed to study temperature-dependent IEF. Numerical simulation for narrow range IEF (6?Joule heating in the system for a nominal electric field of 100?V/cm. For the no Joule heating case, constant properties are used, while for the Joule heating case, temperature-dependent titration curves and thermo-physical properties are used. Our numerical results show that the temperature change due to Joule heating has a significant impact on the final focusing points of proteins, which can lower the separation performance considerably. In the absence of advection and any active cooling mechanism, the temperature increase is the highest at the mid-section of a microchannel. We also found that the maximum temperature in the system is a strong function of the [Formula: see text] value of the carrier ampholytes. Simulation results are also obtained for different values of applied electric fields in order to find the optimum working range considering the simulation time and buffer temperature. Moreover, the model is extended to study IEF in a straight microchip where pH is formed by supplying H(+) and OH(-), and the thermal analysis shows that the heat generation is negligible in ion supplied IEF. PMID:25553199

  12. Size-dependent joule heating of gold nanoparticles using capacitively coupled radiofrequency fields

    Microsoft Academic Search

    Christine H. Moran; Sean M. Wainerdi; Tonya K. Cherukuri; Carter Kittrell; Benjamin J. Wiley; Nolan W. Nicholas; Steven A. Curley; John S. Kanzius; Paul Cherukuri

    2009-01-01

    Capacitively coupled shortwave radiofrequency fields (13.56 MHz) resistively heat low concentrations (?1 ppm) of gold nanoparticles\\u000a with a thermal power dissipation of ?380 kW\\/g of gold. Smaller diameter gold nanoparticles (< 50 nm) heat at nearly twice\\u000a the rate of larger diameter gold nanoparticles (?50 nm), which is attributed to the higher resistivity of smaller gold nanostructures.\\u000a A Joule heating

  13. A JOULE-HEATED MELTER TECHNOLOGY FOR THE TREATMENT AND IMMOBILIZATION OF LOW-ACTIVITY WASTE

    Microsoft Academic Search

    KELLY SE

    2011-01-01

    This report is one of four reports written to provide background information regarding immobilization technologies remaining under consideration for supplemental immobilization of Hanford's low-activity waste. This paper provides the reader a general understanding of joule-heated ceramic lined melters and their application to Hanford's low-activity waste.

  14. Off-gas characteristics of liquid-fed joule-heated ceramic melters

    Microsoft Academic Search

    R. W. Goles; G. J. Sevigny

    1982-01-01

    The off gas characteristics of liquid fed joule heated ceramic meters were investigated as a function of melter operational condition and simulated waste feed composition. The identity and behavior patterns of gaseous emissions, the characteristics of melter generated aerosols, the nature and magnitude of melter effluent losses and the factors affecting melter operational performance were established.

  15. Off-gas characteristics of liquid-fed joule-heated ceramic melters

    NASA Astrophysics Data System (ADS)

    Goles, R. W.; Sevigny, G. J.

    1982-06-01

    The off gas characteristics of liquid fed joule heated ceramic meters were investigated as a function of melter operational condition and simulated waste feed composition. The identity and behavior patterns of gaseous emissions, the characteristics of melter generated aerosols, the nature and magnitude of melter effluent losses and the factors affecting melter operational performance were established.

  16. A model for Joule heating-induced dispersion in microchip electrophoresis

    E-print Network

    Lin, Qiao

    A model for Joule heating-induced dispersion in microchip electrophoresis Yi Wang,a Qiao Lin processes that commonly occur in microchip electrophoresis. This model, which is given in terms microfluidic components, microchip electrophoresis is a key technology to enable lab-on-a-chip microsystems

  17. Electrothermal coupling analysis of current crowding and Joule heating in flip-chip packages

    Microsoft Academic Search

    Yi-shao Lai; Chin-li Kao

    2006-01-01

    Solder bumps serve as electrical paths as well as structural support in a flip-chip package assembly. Owing to the differences of feature sizes and electric resistivities between a solder bump and its adjacent traces, current densities around the regions where traces connect the solder bump increase in a significant amount. This current crowding effect along with the induced Joule heating

  18. Experimental evidence in support of Joule heating associated with geomagnetic activity

    NASA Technical Reports Server (NTRS)

    Devries, L. L.

    1971-01-01

    High resolution accelerometer measurements in the altitude region 140 to 300 km from a satellite in a near-polar orbit during a period of extremely high geomagnetic activity indicate that Joule heating is the primary source of energy for atmospheric heating associated with geomagnetic activity. This conclusion is supported by the following observational evidence: (1) There is an atmospheric response in the auroral zone which is nearly simulataneous with the onset of geomagnetic activity, with no significant response in the equatorial region until several hours later; (2) The maximum heating occurs at geographic locations near the maximum current of the auroral electrojet; and (3) There is evidence of atmospheric waves originating near the auroral zone at altitudes where Joule heating would be expected to occur. An analysis of atmospheric response time to this heat shows time delays are apparently independent of altitude but are strongly dependent upon geomagnetic latitude.

  19. Joule heat generation in thermionic cathodes of high-pressure arc discharges

    SciTech Connect

    Benilov, M. S.; Cunha, M. D. [Departamento de Fisica, CCCEE, Universidade da Madeira, Largo do Municipio, 9000 Funchal (Portugal)

    2013-02-14

    The nonlinear surface heating model of plasma-cathode interaction in high-pressure arcs is extended to take into account the Joule effect inside the cathode body. Calculation results are given for different modes of current transfer to tungsten cathodes of different configurations in argon plasmas of atmospheric or higher pressures. Special attention is paid to analysis of energy balances of the cathode and the near-cathode plasma layer. In all the cases, the variation of potential inside the cathode is much smaller than the near-cathode voltage drop. However, this variation can be comparable to the volt equivalent of the energy flux from the plasma to the cathode and then the Joule effect is essential. Such is the case of the diffuse and mixed modes on rod cathodes at high currents, where the Joule heating causes a dramatic change of thermal and electrical regimes of the cathode. The Joule heating has virtually no effect over characteristics of spots on rod and infinite planar cathodes.

  20. Modeling Joule Heating Effect on Lunar O2 Generation via Electrolytic Reduction.

    NASA Technical Reports Server (NTRS)

    Dominquez, Jesus; Poizeau, Sophie; Sibille, Laurent

    2009-01-01

    Kennedy Space Center is leading research work on lunar O2 generation via electrolytic reduction of regolith; the metal oxide present in the regolith is dissociated in oxygen anions and metal cations leading to the generation of gaseous oxygen at the anode and liquid metal at the cathode. Electrical resistance of molten regolith is high, leading to heating of the melt when electrical current is applied between the electrodes (Joule heating). The authors have developed a 3D model using a rigorous approach for two coupled physics (thermal and electrical potential) to not only study the effect of Joule heating on temperature distribution throughout the molten regolith but also to evaluate and optimize the design of the electrolytic cells. This paper presents the results of the thermal analysis performed on the model and used to validate the design of the electrolytic cell.

  1. Micro-scale heat-exchangers for Joule-Thomson cooling.

    SciTech Connect

    Gross, Andrew John

    2014-01-01

    This project focused on developing a micro-scale counter flow heat exchangers for Joule-Thomson cooling with the potential for both chip and wafer scale integration. This project is differentiated from previous work by focusing on planar, thin film micromachining instead of bulk materials. A process will be developed for fabricating all the devices mentioned above, allowing for highly integrated micro heat exchangers. The use of thin film dielectrics provides thermal isolation, increasing efficiency of the coolers compared to designs based on bulk materials, and it will allow for wafer-scale fabrication and integration. The process is intended to implement a CFHX as part of a Joule-Thomson cooling system for applications with heat loads less than 1mW. This report presents simulation results and investigation of a fabrication process for such devices.

  2. Wavelet method to study the electric field and Joule heating at substorm related nightside reconnection site

    NASA Astrophysics Data System (ADS)

    Nanan, Balan

    The electric field components in the spin plane (Edusk ) and in the plane perpendicular to XGSE (Esigma ) and their Joule heating effects at substorm related nightside magnetic reconnection site are studied using the Electric Field Wavemeter(EFW) data from Cluster spacecraft during 03:00-05:00 UT on 27th August 2001. The electric field data are also subjected to complex Morlet wavelet transform technique to investigate the nature of Edusk and Esigma at magnetic reconnection during 03:25-04:33UT from C4 data. Edusk is found to be higher than Esigma , and after magnetic reconnection also the Joule heating effect at the reconnection site remains higher in Edusk than in Esigma when substorm related nightside reconnection site at geomagnetotail is considered as a constant voltage generator. From this study it is also found that the phase and real part of the spectrum reveal period doubling; amplitude and power spectra also show chaotic nature at the reconnection site.

  3. Joule heating effects on particle immobilization in insulator-based dielectrophoretic devices

    PubMed Central

    Gallo-Villanueva, Roberto C.; Sano, Michael B.; Lapizco-Encinas, Blanca H.; Davalos, Rafael V.

    2014-01-01

    In this work, the temperature effects due to Joule heating obtained by application of a DC electric potential were investigated for a microchannel with cylindrical insulating posts employed for insulator based dielectrophoresis (iDEP). The conductivity of the suspending medium, the local electric field, and the gradient of the squared electric field, which directly affect the magnitude of the dielectrophoretic force exerted on particles, were computationally simulated employing COMSOL Multiphysics. It was observed that a temperature gradient is formed along the microchannel which redistributes the conductivity of the suspending medium leading to an increase of the dielectrophoretic force towards the inlet of the channel while decreasing towards the outlet. Experimental results are in good agreement with simulations on the particle trapping zones anticipated. This study demonstrates the importance of considering Joule heating effects when designing iDEP systems. PMID:24002905

  4. The neutron star in Cassiopeia A: equation of state, superfluidity, and Joule heating

    E-print Network

    Bonanno, A; Burgio, G F; Urpin, V

    2013-01-01

    The thermomagnetic evolution of the young neutron star in Cassiopea A is studied by considering fast neutrino emission processes. In particular, we consider neutron star models obtained from the equation of state computed in the framework of the Brueckner-Bethe-Goldstone many-body theory and variational methods, and models obtained with the Akmal-Pandharipande-Ravenhall equation of state. It is shown that it is possible to explain a fast cooling regime as the one observed in the neutron star in Cassiopea A if the Joule heating produced by dissipation of the small-scale magnetic field in the crust is taken into account. We thus argue that it is difficult to put severe constraints on the superfluid gap if the Joule heating is considered.

  5. Experimental joule-heated ceramic melter for converting radioactive waste to glass

    Microsoft Academic Search

    Chismar

    1978-01-01

    A small electric melter was developed to implement studies for converting radioactive waste to glass at the Savannah River Laboratory (SRL). The ceramic-lined, joule-heated melter has been in operation for ten months. During this period, simulated, high-level-waste, calcined materials and frit were processed at rates of 2 to 15 g\\/min. The melt chamber is 7.6-cm wide, 22.9-cm long and 7.6-cm

  6. Experimental joule-heated ceramic melter for converting radioactive waste to glass

    Microsoft Academic Search

    Chismar

    1978-01-01

    A small electric melter was developed to implement studies for converting radioactive waste to glass at the Savannah River Laboratory (SRL). The ceramic-lined, joule-heated melter has been in operation for ten months. During this period, simulated high-level waste, calcined materials, and frit were processed at rates of 2 to 15 g\\/min. The melt chamber is 7.6 cm wide, 22.9 cm

  7. Solar Wind Effect on Joule Heating in the High-Latitude Ionosphere

    NASA Astrophysics Data System (ADS)

    Cai, L.; Aikio, A. T.; Nygren, T. J.

    2014-12-01

    The interplanetary magnetic field (IMF) carried by solar wind affects strongly several key parameters in the high-latitude ionosphere. In this study, the solar wind effect on those parameters especially on Joule heating is conducted statistically based on the simultaneous measurements by the EISCAT radars in Tromsø (TRO, 66.6° cgmLat, mainly within the auroral oval on the nightside), and on Svalbard (ESR, 75.4º cgmLat, mostly within the polar cap). The most important findings are as follows: (i) At TRO, the decrease in Joule heating in the afternoon-evening sector due to neutral winds reported by Aikio et al. [2012] requires southward IMF conditions and a sufficiently high solar wind electric field. The increase in the morning sector takes place for all IMF directions within a region where the upper-E neutral wind has a large equatorward component and the F-region plasma flow is directed eastward. (ii) At ESR, an afternoon hot spot of joule heating centred typically at 14-15 MLT is observed during all IMF conditions. Enhanced Pedersen conductances within the hot spot region are observed only for the IMF Bz+/By- conditions, and the corresponding convection electric field values within the hot spot are smaller than during the other IMF conditions. Hence, the hot spot represents a region of persistent magnetopsheric electromagnetic energy input. (iii) For the southward IMF conditions, the MLT-integrated Joule heating rate without neutral winds for By- is twice the value for By+ at TRO. This can plausibly be explained by the higher average solar wind electric field values for By-.

  8. Restrictions on linear heat capacities from Joule-Brayton maximum-work cycle efficiency

    NASA Astrophysics Data System (ADS)

    Angulo-Brown, F.; Gonzalez-Ayala, Julian; Arias-Hernandez, L. A.

    2014-02-01

    This paper discusses the possibility of using the Joule-Brayton cycle to determine the accessible value range for the coefficients a and b of the heat capacity at constant pressure Cp, expressed as Cp=a+bT (with T the absolute temperature) by using the Carnot theorem. This is made for several gases which operate as the working fluids. Moreover, the landmark role of the Curzon-Ahlborn efficiency for this type of cycle is established.

  9. Statistics of Joule heating in the auroral zone and polar cap using Astrid-2 satellite Poynting flux

    NASA Astrophysics Data System (ADS)

    Olsson, A.; Janhunen, P.; Karlsson, T.; Ivchenko, N.; Blomberg, L.

    2004-12-01

    We make a statistical study of ionospheric Joule heating with the Poynting flux method using six months of Astrid-2/EMMA electric and magnetic field data during 1999 (solar maximum year). For the background magnetic field we use the IGRF model. Our results are in agreement with earlier statistical satellite studies using both the ?PE2 method and the Poynting flux method. We present a rather comprehensive set of fitted Joule heating formulas expressing the Joule heating in given magnetic local time (MLT) and invariant latitude (ILAT) range under given solar illumination conditions as a function of the Kp index, the AE index, the Akasofu epsilon parameter and the solar wind kinetic energy flux. The study thus provides improved and more detailed estimates of the statistical Joule heating. Such estimates are necessary building blocks for future quantitative studies of the power budget in the magnetosphere and in the nightside auroral region.

  10. Statistical properties of Joule heating rate, electric field and conductances at high latitudes

    NASA Astrophysics Data System (ADS)

    Aikio, A. T.; Selkälä, A.

    2009-07-01

    Statistical properties of Joule heating rate, electric field and conductances in the high latitude ionosphere are studied by a unique one-month measurement made by the EISCAT incoherent scatter radar in Tromsø (66.6 cgmlat) from 6 March to 6 April 2006. The data are from the same season (close to vernal equinox) and from similar sunspot conditions (about 1.5 years before the sunspot minimum) providing an excellent set of data to study the MLT and Kp dependence of parameters with high temporal and spatial resolution. All the parameters show a clear MLT variation, which is different for low and high Kp conditions. Our results indicate that the response of morning sector conductances and conductance ratios to increased magnetic activity is stronger than that of the evening sector. The co-location of Pedersen conductance maximum and electric field maximum in the morning sector produces the largest Joule heating rates 03-05 MLT for Kp?3. In the evening sector, a smaller maximum occurs at 18 MLT. Minimum Joule heating rates in the nightside are statistically observed at 23 MLT, which is the location of the electric Harang discontinuity. An important outcome of the paper are the fitted functions for the Joule heating rate as a function of electric field magnitude, separately for four MLT sectors and two activity levels (Kp<3 and Kp?3). In addition to the squared electric field, the fit includes a linear term to study the possible anticorrelation or correlation between electric field and conductance. In the midday sector, positive correlation is found as well as in the morning sector for the high activity case. In the midnight and evening sectors, anticorrelation between electric field and conductance is obtained, i.e. high electric fields are associated with low conductances. This is expected to occur in the return current regions adjacent to auroral arcs as a result of ionosphere-magnetosphere coupling, as discussed by Aikio et al. (2004) In addition, a part of the anticorrelation may come from polarization effects inside high-conductance regions, e.g. auroral arcs. These observations confirm the speculated effect of small scale electrodynamics, which is not included in most of the global modeling efforts of Joule heating rate.

  11. Measurements and Electrical Equivalent Model of Polymer PTC as a Function of Joule Heating Energy

    NASA Astrophysics Data System (ADS)

    Abubaker, Zawam; Maeyama, Mitsuaki

    In this paper, experiments were conducted to study the electrical I-V characteristics of the polymer Positive Temperature Coefficient (PTC)resistor as a function of joule heating due to I2R. More than 80short-circuit tests were carried out on four samples (rated 60V/40A), and the results show that all PTC samples tripped when the thresholdinput energy nearly equaled 20 J. We propose a new mathematical modelfor the PTC in the fault current condition, a PTC-TACS (Transient Analysis of Control Systems) model, by using the Electro-Magnetic Transient Program (EMTP), which is a function of the input joule heatingenergy. A comparison between the experimental results and EMTPsimulation results has shown that the PTC-TACS model is valid and veryeffective to investigate the PTC under fault current conditions inelectrical circuits and to design an over-current limiter based on PTCmaterials for industrial applications. In the discussion about radiationpower loss in case that the applied voltage is greater than 50V or thetripped time is less than 4ms, it is shown that the radiation powerloss can be neglected and the PTC resistance can be expressed only bythe input joule heating energy.

  12. Imaging Joule Heating in an 80 nm Wide Titanium Nanowire by Thermally Modulated Fluorescence

    NASA Astrophysics Data System (ADS)

    Saïdi, E.; Labéguerie-Egéa, J.; Billot, L.; Lesueur, J.; Mortier, M.; Aigouy, L.

    2013-09-01

    A fluorescent erbium/ytterbium co-doped fluoride nanocrystal glued at the end of a sharp atomic force microscope tungsten tip was used as a nanoscale thermometer. The thermally induced fluorescence quenching enabled observation of the heating and measurement of the temperature distribution in a Joule-heated 80 nm wide and 2 ?m long titanium nanowire fabricated on an oxidized silicon substrate. The measurements have been carried out in an alternating heating mode by applying a modulated current on the device at low frequency. The heating is found to be inhomogeneous along the wire, and the temperature in its center increases quadratically with the applied current. Heat appears to be confined mainly along the wire, with weak lateral diffusion along the substrate and in the lateral metallic pads. The lateral resolution of this thermal measurement technique is better than 250 nm. It could also be used to study thermally induced defects in nanodevices.

  13. Simple and strong: twisted silver painted nylon artificial muscle actuated by Joule heating

    NASA Astrophysics Data System (ADS)

    Mirvakili, Seyed M.; Rafie Ravandi, Ali; Hunter, Ian W.; Haines, Carter S.; Li, Na; Foroughi, Javad; Naficy, Sina; Spinks, Geoffrey M.; Baughman, Ray H.; Madden, John D. W.

    2014-03-01

    Highly oriented nylon and polyethylene fibres shrink in length when heated and expand in diameter. By twisting and then coiling monofilaments of these materials to form helical springs, the anisotropic thermal expansion has recently been shown to enable tensile actuation of up to 49% upon heating. Joule heating, by passing a current through a conductive coating on the surface of the filament, is a convenient method of controlling actuation. In previously reported work this has been done using highly flexible carbon nanotube sheets or commercially available silver coated fibres. In this work silver paint is used as the Joule heating element at the surface of the muscle. Up to 29% linear actuation is observed with energy and power densities reaching 840 kJ m-3 (528 J kg-1) and 1.1 kW kg-1 (operating at 0.1 Hz, 4% strain, 1.4 kg load). This simple coating method is readily accessible and can be applied to any polymer filament. Effective use of this technique relies on uniform coating to avoid temperature gradients.

  14. Solar wind effect on Joule heating in the high-latitude ionosphere

    NASA Astrophysics Data System (ADS)

    Cai, L.; Aikio, A. T.; Nygrén, T.

    2014-12-01

    The effect of solar wind on several electrodynamic parameters, measured simultaneously by the European Incoherent Scatter (EISCAT) radars in Tromsø (TRO, 66.6° cgmLat) and on Svalbard (ESR, 75.4° cgmLat), has been evaluated statistically. The main emphasis is on Joule heating rate QJ, which has been estimated by taking into account the neutral wind. In addition, a generally used proxy QE, which is the Pedersen conductance times the electric field squared, has been calculated. The most important findings are as follows. (i) The decrease in Joule heating in the afternoon-evening sector due to winds reported by Aikio et al. (2012) requires southward interplanetary magnetic field (IMF) conditions and a sufficiently high solar wind electric field. The increase in the morning sector takes place for all IMF directions within a region where the upper E neutral wind has a large equatorward component and the F region plasma flow is directed eastward. (ii) At ESR, an afternoon hot spot of Joule heating centered typically at 14-15 magnetic local time (MLT) is observed during all IMF conditions. Enhanced Pedersen conductances within the hot spot region are observed only for the IMF Bz + /By- conditions, and the corresponding convection electric field values within the hot spot are smaller than during the other IMF conditions. Hence, the hot spot represents a region of persistent magnetospheric electromagnetic energy input, and the median value is about 3 mW/m2. (iii) For the southward IMF conditions, the MLT-integrated QE for By- is twice the value for By+ at TRO. This can plausibly be explained by the higher average solar wind electric field values for By-.

  15. Restrictions on linear heat capacities from Joule-Brayton maximum-work cycle efficiency.

    PubMed

    Angulo-Brown, F; Gonzalez-Ayala, Julian; Arias-Hernandez, L A

    2014-02-01

    This paper discusses the possibility of using the Joule-Brayton cycle to determine the accessible value range for the coefficients a and b of the heat capacity at constant pressure C(p), expressed as C(p) = a + bT (with T the absolute temperature) by using the Carnot theorem. This is made for several gases which operate as the working fluids. Moreover, the landmark role of the Curzon-Ahlborn efficiency for this type of cycle is established. PMID:25353449

  16. A study of Joule heating-induced breakdown of carbon nanotube interconnects.

    PubMed

    Santini, C A; Vereecken, P M; Volodin, A; Groeseneken, G; De Gendt, S; Haesendonck, C Van

    2011-09-30

    We investigate breakdown of carbon nanotube (CNT) interconnects induced by Joule heating in air and under high vacuum conditions (10(-5) mbar). A CNT with a diameter of 18 nm, which is grown by chemical vapor deposition to connect opposing titanium nitride (TiN) electrodes, is able to carry an electrical power up to 0.6 mW before breaking down under vacuum, with a corresponding maximum current density up to 8 × 10(7) A cm(-2) (compared to 0.16 mW and 2 × 10(7) A cm(-2) in air). Decoration with electrochemically deposited Ni particles allows protection of the CNT interconnect against oxidation and improvement of the heat release through the surrounding environment. A CNT decorated with Ni particles is able to carry an increased electrical power of about 1.5 mW before breaking down under vacuum, with a corresponding maximum current density as high as 1.2 × 10(8) A cm(-2). The Joule heating produced along the current carrying CNT interconnect is able to melt the Ni particles and promotes the formation of titanium carbon nitride which improves the electrical contact between the CNT and the TiN electrodes. PMID:21891859

  17. Polycrystalline silicon thin-film transistors fabricated by Joule-heating-induced crystallization

    NASA Astrophysics Data System (ADS)

    Hong, Won-Eui; Ro, Jae-Sang

    2015-01-01

    Joule-heating-induced crystallization (JIC) of amorphous silicon (a-Si) films is carried out by applying an electric pulse to a conductive layer located beneath or above the films. Crystallization occurs across the whole substrate surface within few tens of microseconds. Arc instability, however, is observed during crystallization, and is attributed to dielectric breakdown in the conductor/insulator/transformed polycrystalline silicon (poly-Si) sandwich structures at high temperatures during electrical pulsing for crystallization. In this study, we devised a method for the crystallization of a-Si films while preventing arc generation; this method consisted of pre-patterning an a-Si active layer into islands and then depositing a gate oxide and gate electrode. Electric pulsing was then applied to the gate electrode formed using a Mo layer. The Mo layer was used as a Joule-heat source for the crystallization of pre-patterned active islands of a-Si films. JIC-processed poly-Si thin-film transistors (TFTs) were fabricated successfully, and the proposed method was found to be compatible with the standard processing of coplanar top-gate poly-Si TFTs.

  18. Impact of Joule Heating and pH on Biosolids Electro-Dewatering.

    PubMed

    Navab-Daneshmand, Tala; Beton, Raphaël; Hill, Reghan J; Frigon, Dominic

    2015-05-01

    Electro-dewatering (ED) is a novel technology to reduce the overall costs of residual biosolids processing, transport, and disposal. In this study, we investigated Joule heating and pH as parameters controlling the dewaterability limit, dewatering rate, and energy efficiency. Temperature-controlled electrodes revealed that Joule heating enhances water removal by increasing evaporation and electro-osmotic flow. High temperatures increased the dewatering rate, but had little impact on the dewaterability limit and energy efficiency. Analysis of horizontal layers after 15-min ED suggests electro-osmotic flow reversal, as evidenced by a shifting of the point of minimum moisture content from the anode toward the cathode. This flow reversal was also confirmed by the pH at the anode being below the isoelectric point, as ascertained by pH titration. The important role of pH on ED was further studied by adding acid/base solutions to biosolids prior to ED. An acidic pH reduced the biosolids charge while simultaneously increasing the dewatering efficiency. Thus, process optimization depends on trade-offs between speed and efficiency, according to physicochemical properties of the biosolids microstructure. PMID:25494946

  19. Nanoscale Joule heating, Peltier cooling and current crowding at graphene-metal contacts.

    PubMed

    Grosse, Kyle L; Bae, Myung-Ho; Lian, Feifei; Pop, Eric; King, William P

    2011-05-01

    The performance and scaling of graphene-based electronics is limited by the quality of contacts between the graphene and metal electrodes. However, the nature of graphene-metal contacts remains incompletely understood. Here, we use atomic force microscopy to measure the temperature distributions at the contacts of working graphene transistors with a spatial resolution of ~ 10 nm (refs 5-8), allowing us to identify the presence of Joule heating, current crowding and thermoelectric heating and cooling. Comparison with simulation enables extraction of the contact resistivity (150-200 ? µm²) and transfer length (0.2-0.5 µm) in our devices; these generally limit performance and must be minimized. Our data indicate that thermoelectric effects account for up to one-third of the contact temperature changes, and that current crowding accounts for most of the remainder. Modelling predicts that the role of current crowding will diminish and the role of thermoelectric effects will increase as contacts improve. PMID:21460825

  20. MHD Mixed Convective Peristaltic Motion of Nanofluid with Joule Heating and Thermophoresis Effects

    PubMed Central

    Shehzad, Sabir Ali; Abbasi, Fahad Munir; Hayat, Tasawar; Alsaadi, Fuad

    2014-01-01

    The primary objective of present investigation is to introduce the novel aspect of thermophoresis in the mixed convective peristaltic transport of viscous nanofluid. Viscous dissipation and Joule heating are also taken into account. Problem is modeled using the lubrication approach. Resulting system of equations is solved numerically. Effects of sundry parameters on the velocity, temperature, concentration of nanoparticles and heat and mass transfer rates at the wall are studied through graphs. It is noted that the concentration of nanoparticles near the boundaries is enhanced for larger thermophoresis parameter. However reverse situation is observed for an increase in the value of Brownian motion parameter. Further, the mass transfer rate at the wall significantly decreases when Brownian motion parameter is assigned higher values. PMID:25391147

  1. MHD mixed convective peristaltic motion of nanofluid with Joule heating and thermophoresis effects.

    PubMed

    Shehzad, Sabir Ali; Abbasi, Fahad Munir; Hayat, Tasawar; Alsaadi, Fuad

    2014-01-01

    The primary objective of present investigation is to introduce the novel aspect of thermophoresis in the mixed convective peristaltic transport of viscous nanofluid. Viscous dissipation and Joule heating are also taken into account. Problem is modeled using the lubrication approach. Resulting system of equations is solved numerically. Effects of sundry parameters on the velocity, temperature, concentration of nanoparticles and heat and mass transfer rates at the wall are studied through graphs. It is noted that the concentration of nanoparticles near the boundaries is enhanced for larger thermophoresis parameter. However reverse situation is observed for an increase in the value of Brownian motion parameter. Further, the mass transfer rate at the wall significantly decreases when Brownian motion parameter is assigned higher values. PMID:25391147

  2. Tailored Electrical Driving as a Means of Controlling Heat Distribution and Convection Patterns in Joule-Heated Waste Glass Melters

    SciTech Connect

    Fort, James A.; Lessor, Delbert L.

    2004-01-01

    The ability to control melter convection patterns may provide a means of mitigating gas layer buildup under the cold cap, enhancing the heat transfer to the batch, and possible accelerating batch reactions, thereby increasing melt rate and glass throughput. Other operational benefits could result from such control. Convective patterns in an electrically heated melter are dominated by the distribution of Joule heat and thermal boundary conditions for a given melter design and geometry. We believe that control of electrical driving, in particular control of the interaction of electrical fields connected to distinct electrode pairs, can be used to vary the distribution of Joule heat generation. The under-investigated aspect of electrical driving control is the effect of waveform “overlap” of the driving voltages, the “overlap” in the case of harmonic driving being determined by the relative phase. For electrical driving using waveforms chopped by Silicon Controlled Rectifiers (SCRs), the chopping influences the "overlap." This control can provide a means of controlling melt convection. The objective of the present investigation is to test that hypothesis, verifying that such control can be observed for a numerical model of a simple melter geometry.

  3. Residual resistance of 2D and 3D structures and Joule heat release.

    PubMed

    Gurevich, V L; Kozub, V I

    2011-06-22

    We consider a residual resistance and Joule heat release in 2D nanostructures as well as in ordinary 3D conductors. We assume that elastic scattering of conduction electrons by lattice defects is predominant. Within a rather intricate situation in such systems we discuss in detail two cases. (1) The elastic scattering alone (i.e. without regard of inelastic mechanisms of scattering) leads to a transition of the mechanical energy (stored by the electrons under the action of an electric field) into heat in a traditional way. This process can be described by the Boltzmann equation where it is possible to do the configuration averaging over defect positions in the electron-impurity collision term. The corresponding conditions are usually met in metals. (2) The elastic scattering can be considered with the help of the standard electron-impurity collision integral only in combination with some additional averaging procedure (possibly including inelastic scattering or some mechanisms of electron wavefunction phase destruction). This situation is typical for degenerate semiconductors with a high concentration of dopants and conduction electrons. Quite often, heat release can be observed via transfer of heat to the lattice, i.e. via inelastic processes of electron-phonon collisions and can take place at distances much larger than the size of the device. However, a direct heating of the electron system can be registered too by, for instance, local measurements of the current noise or direct measurement of an electron distribution function. PMID:21628783

  4. Numerical analysis of the electrical failure of a metallic nanowire mesh due to Joule heating

    PubMed Central

    2013-01-01

    To precisely examine the electrical failure behavior of a metallic nanowire mesh induced by Joule heating (i.e., melting), a previously developed numerical method was modified with regard to the maximum temperature in the mesh and the electrical resistivity of the nanowire. A sample case of an Ag nanowire mesh under specific working conditions was analyzed with highly accurate numerical results. By monitoring the temperature in the mesh, the current required to trigger the melting of a mesh segment (i.e., the melting current) could be obtained. The melting process of a mesh equipped with a current source during actual operation was predicted on the basis of the obtained relationship between the melting current and the corresponding melting voltage in the numerical melting process. Local unstable and stable melting could be precisely identified for both the current-controlled and voltage-controlled current sources in the present example. PMID:23992528

  5. Ozone generation by negative corona discharge: the effect of Joule heating

    NASA Astrophysics Data System (ADS)

    Yanallah, K.; Pontiga, F.; Fernández-Rueda, A.; Castellanos, A.; Belasri, A.

    2008-10-01

    Ozone generation in pure oxygen using a wire-to-cylinder corona discharge reactor is experimentally and numerically investigated. Ozone concentration is determined by means of direct UV spectroscopy and the effects of Joule heating and ozone decomposition on the electrodes are analysed for different discharge gaps. The numerical model combines the physical processes in the corona discharge with the chemistry of ozone formation and destruction. The chemical kinetics model and the electrical model are coupled through Poisson's equation, and the current-voltage (CV) characteristic measured in experiments is used as input data to the numerical simulation. The numerical model is able to predict the radial distributions of electrons, ions, atoms and molecules for each applied voltage of the CV characteristic. In particular, the evolution of ozone density inside the discharge cell has been investigated as a function of current intensity and applied voltage.

  6. Modeling principles applied to the simulation of a joule-heated glass melter

    SciTech Connect

    Routt, K.R.

    1980-05-01

    Three-dimensional conservation equations applicable to the operation of a joule-heated glass melter were rigorously examined and used to develop scaling relationships for modeling purposes. By rigorous application of the conservation equations governing transfer of mass, momentum, energy, and electrical charge in three-dimensional cylindrical coordinates, scaling relationships were derived between a glass melter and a physical model for the following independent and dependent variables: geometrical size (scale), velocity, temperature, pressure, mass input rate, energy input rate, voltage, electrode current, electrode current flux, total power, and electrical resistance. The scaling relationships were then applied to the design and construction of a physical model of the semiworks glass melter for the Defense Waste Processing Facility. The design and construction of such a model using glycerine plus LiCl as a model fluid in a one-half-scale Plexiglas tank is described.

  7. Current-controlled negative differential resistance due to Joule heating in TiO2

    NASA Astrophysics Data System (ADS)

    Alexandrov, A. S.; Bratkovsky, A. M.; Bridle, B.; Savel'ev, S. E.; Strukov, D. B.; Stanley Williams, R.

    2011-11-01

    We show that Joule heating causes current-controlled negative differential resistance (CC-NDR) in TiO2 by constructing an analytical model of the voltage-current V(I) characteristic based on polaronic transport for Ohm's Law and Newton's Law of Cooling and fitting this model to experimental data. This threshold switching is the "soft breakdown" observed during electroforming of TiO2 and other transition-metal-oxide based memristors, as well as a precursor to "ON" or "SET" switching of unipolar memristors from their high to their low resistance states. The shape of the V(I) curve is a sensitive indicator of the nature of the polaronic conduction.

  8. Electron kinetics and non-Joule heating in near-collisionless inductively coupled plasmas V. I. Kolobov

    E-print Network

    Economou, Demetre J.

    Electron kinetics and non-Joule heating in near-collisionless inductively coupled plasmas V. I of Houston, Houston, Texas 77204-4792 Received 1 July 1996 Electron kinetics in an inductively coupled plasma for the manufacturing of ultra-large- scale integrated circuits 1 . Inductively coupled plasma ICP sources

  9. MHD Mixed Convection with Joule Heating Effect in a Lid-Driven Cavity with a Heated Semi-Circular Source Using the Finite Element Technique

    Microsoft Academic Search

    M. M. Rahman; Hakan F. Öztop; N. A. Rahim; R. Saidur; Khaled Al-Salem

    2011-01-01

    A computational fluid dynamics simulation of heat transfer characteristics on the conjugate effect of Joule heating and magnetic field acting normal to the lid-driven cavity with a heated semi-circular source on one wall under constant temperature is investigated. The left wall of the cavity moves in an upward (case I) or downward (case II) direction, and buoyancy forces are also

  10. Influence of Newtonian heating on three dimensional MHD flow of couple stress nanofluid with viscous dissipation and Joule heating.

    PubMed

    Ramzan, Muhammad

    2015-01-01

    The present exploration discusses the influence of Newtonian heating on the magnetohydrodynamic (MHD) three dimensional couple stress nanofluid past a stretching surface. Viscous dissipation and Joule heating effects are also considered. Moreover, the nanofluid model includes the combined effects of thermophoresis and Brownian motion. Using an appropriate transformation, the governing non linear partial differential equations are converted into nonlinear ordinary differential equations. Series solutions using Homotopy Analysis method (HAM) are computed. Plots are presented to portrait the arising parameters in the problem. It is seen that an increase in conjugate heating parameter results in considerable increase in the temperature profile of the stretching wall. Skin friction coefficient, local Nusselt and local Sherwood numbers tabulated and analyzed. Higher values of conjugate parameter, Thermophoresis parameter and Brownian motion parameter result in enhancement of temperature distribution. PMID:25874800

  11. Heat transfer analysis for magnetohydrodynamics axisymmetric flow between stretching disks in the presence of viscous dissipation and Joule heating

    NASA Astrophysics Data System (ADS)

    Khan, N.; Sajid, M.; Mahmood, T.

    2015-05-01

    The investigation of heat transfer analysis on steady MHD axi-symmetric flow between two infinite stretching disks in the presence of viscous dissipation and Joule heating is basic objective of this paper. Attention has been focused to acquire the similarity solutions of the equations governing the flow and thermal fields. The transformed boundary value problem is solved analytically using homotopy analysis method. The series solutions are developed and the convergence of these solutions is explicitly discussed. The analytical expressions for fluid velocity, pressure and temperature are constructed and analyzed for various set of parameter values. The numerical values for skin friction coefficient and the Nusselt number are presented in tabular form. Particular attention is given to the variations of Prandtl and Eckert numbers. We examined that the dimensionless temperature field is enhanced when we increase the values of Eckert number and Prandtl number.

  12. Effect of concurrent joule heat and charge trapping on RESET for NbAlO fabricated by atomic layer deposition

    PubMed Central

    2013-01-01

    The RESET process of NbAlO-based resistive switching memory devices fabricated by atomic layer deposition is investigated at low temperatures from 80 to 200 K. We observed that the conduction mechanism of high resistance state changed from hopping conduction to Frenkel-Poole conduction with elevated temperature. It is found that the conductive filament rupture in RRAM RESET process can be attributed not only to the Joule heat generated by internal current flow through a filament but also to the charge trap/detrapping effect. The RESET current decreases upon heating. Meanwhile, the energy consumption also decreases exponentially. This phenomenon indicates the temperature-related charge trap/detrapping process which contributes to the RESET besides direct Joule heat. PMID:23421401

  13. Consistent melting behavior induced by Joule heating between Ag microwire and nanowire meshes

    PubMed Central

    2014-01-01

    The melting behavior of an Ag microwire mesh induced by Joule heating was numerically investigated and compared with that of the corresponding Ag nanowire mesh with the same structure but different geometrical and physical properties of the wire itself. According to the relationship of melting current and melting voltage during the melting process, a similar repetitive zigzag pattern in melting behavior was discovered in both meshes. On this basis, a dimensionless parameter defined as figure of merit was proposed to characterize the current-carrying ability of the mesh. The consistent feature of figure of merit in both meshes indicates that the melting behavior of the Ag nanowire mesh can be predicted from the present results of the corresponding Ag microwire mesh with the same structure but made from a different wire (e.g., different size, different material) through simple conversion. The present findings can provide fundamental insight into the reliability analysis on the metallic nanowire mesh-based transparent conductive electrode. PMID:24910578

  14. Incineration\\/vitrification of simulated low-level institutional wastes in a joule-heated glass melter

    Microsoft Academic Search

    J. L. Buelt; K. H. Oma

    1981-01-01

    The purpose of this study was to determine the feasibility of reducing the volume of low-level institutional wastes by incineration and then converting the residual solids into glass with a single-step process. Experimental test results with simulated waste show that a joule-heated ceramic melter originally developed for high-level waste vitrification can be used for the low-level waste volume reduction process.

  15. Vitrification of Hanford wastes in a joule-heated ceramic melter and evaluation of resultant canisterized product

    Microsoft Academic Search

    C. C. Chapman; J. L. Buelt; S. C. Slate; Y. B. Katayama; L. R. Bunnell

    1979-01-01

    Experience gained in the week-long vitrification test and characterization of the glass produced in the run support the following conclusions: The Hanford waste simulated in this test can be readily vitrified in a joule-heated ceramic melter. Physical properties of the molten glass were entirely compatible with melter operation. The average feed rate of 106 kg\\/h is high enough to make

  16. Off-gas characteristics of defense waste vitrification using liquid-fed Joule-heated ceramic melters

    Microsoft Academic Search

    R. W. Goles; G. J. Sevigny

    1983-01-01

    Off-gas and effluent characterization studies have been established as part of a PNL Liquid-Fed Ceramic Melter development program supporting the Savannah River Laboratory Defense Waste Processing Facility (SRL-DWPF). The objectives of these studies were to characterize the gaseous and airborne emission properties of liquid-fed joule-heated melters as a function of melter operational parameters and feed composition. All areas of off-gas

  17. Modified data analysis for thermal conductivity measurements of polycrystalline silicon microbridges using a steady state Joule heating technique.

    PubMed

    Sayer, Robert A; Piekos, Edward S; Phinney, Leslie M

    2012-12-01

    Accurate knowledge of thermophysical properties is needed to predict and optimize the thermal performance of microsystems. Thermal conductivity is experimentally determined by measuring quantities such as voltage or temperature and then inferring a thermal conductivity from a thermal model. Thermal models used for data analysis contain inherent assumptions, and the resultant thermal conductivity value is sensitive to how well the actual experimental conditions match the model assumptions. In this paper, a modified data analysis procedure for the steady state Joule heating technique is presented that accounts for bond pad effects including thermal resistance, electrical resistance, and Joule heating. This new data analysis method is used to determine the thermal conductivity of polycrystalline silicon (polysilicon) microbridges fabricated using the Sandia National Laboratories SUMMiT V™ micromachining process over the temperature range of 77-350 K, with the value at 300 K being 71.7 ± 1.5 W/(m K). It is shown that making measurements on beams of multiple lengths is useful, if not essential, for inferring the correct thermal conductivity from steady state Joule heating measurements. PMID:23278015

  18. Rapid concentration of deoxyribonucleic acid via Joule heating induced temperature gradient focusing in poly-dimethylsiloxane microfluidic channel.

    PubMed

    Ge, Zhengwei; Wang, Wei; Yang, Chun

    2015-02-01

    This paper reports rapid microfluidic electrokinetic concentration of deoxyribonucleic acid (DNA) with the Joule heating induced temperature gradient focusing (TGF) by using our proposed combined AC and DC electric field technique. A peak of 480-fold concentration enhancement of DNA sample is achieved within 40s in a simple poly-dimethylsiloxane (PDMS) microfluidic channel of a sudden expansion in cross-section. Compared to a sole DC field, the introduction of an AC field can reduce DC field induced back-pressure and produce sufficient Joule heating effects, resulting in higher concentration enhancement. Within such microfluidic channel structure, negative charged DNA analytes can be concentrated at a location where the DNA electrophoretic motion is balanced with the bulk flow driven by DC electroosmosis under an appropriate temperature gradient field. A numerical model accounting for a combined AC and DC field and back-pressure driven flow effects is developed to describe the complex Joule heating induced TGF processes. The experimental observation of DNA concentration phenomena can be explained by the numerical model. PMID:25597807

  19. Joule Heating, Particle Precipitation and Dynamical Heating as Possible Tidal Sources in the Antarctic Winter Lower Thermosphere

    NASA Astrophysics Data System (ADS)

    Fong, W.; Chu, X.; Lu, X.; Chen, C.; Yu, Z.; Fuller-Rowell, T. J.; Richmond, A. D.; Codrescu, M.

    2014-12-01

    Winter temperature tides observed by lidar at McMurdo (77.8°S, 166.7°E), Antarctica, show less than 3 K diurnal and semidiurnal tidal amplitude below 100 km. However, above 100 km, the diurnal and semidiurnal tidal amplitudes grow super-exponentially and can reach at least 15 K near 110 km, which are exceeding that of the freely propagating tides originating from the lower atmosphere. Such fast growth exists for all Kp index cases and diurnal amplitude increases to 15?30 K at 110 km with larger Kp indices corresponding to larger tidal amplitudes and faster growth rates. Combining with the slopes of diurnal tidal phases being steeper above 100 km, and the tidal phases barely changing with altitude from 100 to 106 km, it indicates that in-situ tidal sources may exist near or above 100 km. In this paper, we utilize the coupled thermosphere ionosphere plasmasphere electrodynamics (CTIPe) model to investigate possible sources/mechanisms that lead to the fast amplitude growth of tides in the polar winter region. Joule heating, particle precipitation, and dynamical heating are likely to be the dominant thermospheric tidal sources, according to CTIPe model. Interestingly, the CTIPe tidal amplitudes induced by these sources form a concentric pattern with its center located at the geomagnetic pole, implying that the geomagnetic activity may play an important role. Furthermore, dynamical heating, which includes adiabatic heating/cooling and vertical advection, is likely to be the explanation of the fast growth of diurnal tidal amplitudes even under quiet condition of geomagnetic activity as observed by lidar. We also found that the tides propagating from the lower atmosphere is a minor factor for the fast increase of thermospheric diurnal tides in Antarctica.

  20. Thermodynamic analysis of the reverse Joule–Brayton cycle heat pump for domestic heating

    E-print Network

    White, Alexander

    2009-03-20

    of the RJB cycle have been proposed, whilst Braun et al. [6] have analysed an air cycle heat pump for drying applications. The RJB cycle also finds application in aircraft cooling and air liquefaction, either as an open or a closed cycle device, and a number... in turbo Brayton technology for low temperature applications,” Cryogenics, vol. 39, pp. 989–995, 1999. [16] J. He, Y. Xin, and X. He, “Performance optimization of quantum Brayton refrigeration cycle working with spin systems,” Applied Energy, vol. 84, pp...

  1. Transformation temperatures and shape memory characteristics of a Ti-45Ni-5Cu(at %) alloy annealed by Joule heating

    NASA Astrophysics Data System (ADS)

    Kang, Seok-Won; Cho, Gyu-Bong; Yang, Seung-Yong; Liu, Yinong; Yang, Hong; Miyazaki, Shuichi; Nam, Tae-Hyun

    2010-05-01

    A temperature gradient of 75-188 K was developed in a Ti-45Ni-5Cu(at %) alloy wire with 30 mm length by Joule heating, depending on electrical power. The shape change rate increased from 0.022 to 0.045% K-1 on increasing the electrical power from 4.8 to 6.2 W. The change in the stress required for the B2-B19' transformation increased from 60 to 103 MPa on increasing the electrical power from 4.8 to 10.1 W.

  2. Short Time-Scale Enhancements to the Global Thermosphere Temperature and Nitric Oxide Content Resulting From Ionospheric Joule Heating

    NASA Astrophysics Data System (ADS)

    Weimer, D. R.; Mlynczak, M. G.; Hunt, L. A.; Sutton, E. K.

    2014-12-01

    The total Joule heating in the polar ionosphere can be derived from an empirical model of the electric fields and currents, using input measurements of the solar wind velocity and interplanetary magnetic field (IMF). In the thermosphere, measurements of the neutral density from accelerometers on the CHAMP and GRACE satellites are used to derive exospheric temperatures, showing that enhanced ionospheric energy dissipation produces elevated temperatures with little delay.Using the total ionospheric heating, changes in the global mean exosphere temperature as a function of time can be calculated with a simple differential equation. The results compare very well with the CHAMP and GRACE measurement. A critical part of the calculation is the rate at which the thermosphere cools after the ionospheric heating is reduced. It had been noted previously that events with significant levels of heating subsequently cool at a faster rate, and this cooling was attributed to enhanced nitric oxide emissions. This correlation with nitric oxide has been confirmed with very high correlations with measurements of nitric oxide emissions in the thermosphere, from the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument on the Thermosphere Ionosphere Mesosphere Energetics and Dynamics (TIMED) satellite. These measurements were used in a recent improvement in the equations that calculate the thermosphere temperature. The global nitric oxide cooling rates are included in this calculation, and the predicted levels of nitric oxide, derived from the ionosphere heating model, match the SABER measurements very well, having correlation coefficients on the order of 0.9.These calculations are used to govern the sorting of measurements CHAMP and GRACE measurements, on the basis of the global temperature enhancements due to Joule heating, as well as various solar indices, and season. Global maps of the exospheric temperature are produced from these sorted data.

  3. On the influence of Joule heating induced nanocrystallization on structural and magnetic properties of Co64Fe21B15 alloy

    E-print Network

    Paris-Sud XI, Université de

    ]. In the eighties, in addition to conventional furnace treatment having heating rate of the order of 0.1 to 1 K/s) allowing the sample to crystallize at higher temperatures with respect to furnace annealing with attractive physical properties starting from amorphous ribbons. Among these, dc Joule heating is a convenient

  4. Joule Thomson refrigerator

    NASA Technical Reports Server (NTRS)

    Chan, Chung K. (inventor); Gatewood, John R. (inventor)

    1988-01-01

    A bi-directional Joule Thomson refrigerator is described, which is of simple construction at the cold end of the refrigerator. Compressed gas flowing in either direction through the Joule Thomson expander valve and becoming liquid, is captured in a container in direct continuous contact with the heat load. The Joule Thomson valve is responsive to the temperature of the working fluid near the valve, to vary the flow resistance through the valve so as to maintain a generally constant flow mass between the time that the refrigerator is first turned on and the fluid is warm, and the time when the refrigerator is near its coldest temperature and the fluid is cold. The valve is operated by differences in thermal coefficients of expansion of materials to squeeze and release a small tube which acts as the expander valve.

  5. Heat treatment of whole milk by the direct joule effect--experimental and numerical approaches to fouling mechanisms.

    PubMed

    Fillaudeau, L; Winterton, P; Leuliet, J C; Tissier, J P; Maury, V; Semet, F; Debreyne, P; Berthou, M; Chopard, F

    2006-12-01

    The development of alternative technologies such as the direct Joule effect to pasteurize and sterilize food products is of great scientific and industrial interest. Our objective was 1) to gain insight into the ability to ensure ultra-high-temperature treatment of milk and 2) to investigate the links among thermal, hydraulic, and electrical phenomena in relation to fouling in a direct Joule effect heater. The ohmic heater [OH; E perpendicular to v (where E is the electrical field and v is the velocity); P (power) = 15 kW] was composed of 5 flat rectangular cells [e (space between the plate and electrode) = 15 mm, w (wall) = 76 mm, and L (length of the plate in plate heat exchanger or electrode) = 246 mm]--3 active cells to ensure heating and 2 (at the extremities) for electrical insulation and the recovery of leakage currents. In the first step, the thermal performance of the OH was investigated vs. the flow regimen [50 < Re (Reynolds number) < 5,000], supplied power (0 < P < 15 kW), and electrical conductivity of fluids (0.1 < sigma(20 degrees C) < 2 S/m) under clean conditions with model fluids. This protocol enabled a global thermal approach (thermal and electrical balance, modeling of the temperature profile of a fluid) and local analysis of the wall temperature of the electrode. An empirical correlation was established to estimate the temperature gradient, T(w)-T(b) (where T(w) is the wall temperature and T(b) is the product temperature) under clean conditions (without fouling) and was used to define operating conditions for pure-volume and direct-resistance heating. In the second step, the ability of OH to ensure the ultra-high-temperature treatment of whole milk was investigated and compared with a plate heat exchanger. Special care was taken to investigate the heat transfer phenomena occurring over a range of temperatures from 105 to 138 degrees C. This temperature range corresponds to the part of the process made critical by protein and mineral fouling. The objectives were 1) to demonstrate the ability of an OH to ensure heat treatment of milk, 2) to study the thermal and hydraulic performance with an increasing power and temperature difference between the inlet and outlet of the OH, 3) to define and validate a criterion to follow heat dissipation efficiency, and 4) to compare the fouling propensity with the different configurations. A heat dissipation coefficient, Rh(CO), was defined and validated to monitor the fouling propensity through global electrical and thermal parameters. Finally, a numerical simulation was developed to analyze heat profiles (wall, deposit, bulk). Because of an increasing Joule effect in the static deposit, the simulation showed how wall overheating would definitively cause fouling to spiral out of control. PMID:17106078

  6. Remote Joule heating by a carbon nanotube Kamal H. Baloch1, Norvik Voskanian1, Merijntje Bronsgeest2 and John Cumings1

    E-print Network

    Li, Teng

    -scale metallic indium islands thermally evaporated onto the back side of an electron-transparent silicon nitride the remote Joule heating of a silicon nitride substrate by a single multi- walled carbon nanotube. At least this phase transition as a change in contrast of the islands. When the indium islands reversibly melt

  7. The Joule heat production rate and the particle energy injection rate as a function of the geomagnetic indices AE and AL

    Microsoft Academic Search

    B.-H. Ahn; S.-I. Akasofu; Y. Kamide

    1983-01-01

    Magnetic records from 71 stations were employed to determine the distribution of electric fields and currents in the polar ionosphere for March 17, 18, and 19, 1978. Hourly distribution maps of the Joule heat production rate, the particle energy injection rate, and their sum over the entire polar region on the three days were calculated. For constructing the hourly distribution

  8. Experimental evaluation of an adaptive Joule–Thomson cooling system including silicon-microfabricated heat exchanger and microvalve components

    PubMed Central

    Zhu, Weibin; Park, Jong M.; White, Michael J.; Nellis, Gregory F.; Gianchandani, Yogesh B.

    2011-01-01

    This article reports the evaluation of a Joule–Thomson (JT) cooling system that combines two custom micromachined components—a Si/glass-stack recuperative heat exchanger and a piezoelectrically actuated expansion microvalve. With the microvalve controlling the flow rate, this system can modulate cooling to accommodate varying refrigeration loads. The perforated plate Si/glass heat exchanger is fabricated with a stack of alternating silicon plates and Pyrex glass spacers. The microvalve utilizes a lead zirconate titanate actuator to push a Si micromachined valve seat against a glass plate, thus modulating the flow passing through the gap between the valve seat and the glass plate. The fabricated heat exchanger has a footprint of 1×1?cm2 and a length of 35 mm. The size of the micromachined piezoelectrically actuated valve is about 1×1×1?cm3. In JT cooling tests, the temperature of the system was successfully controlled by adjusting the input voltage of the microvalve. When the valve was fully opened (at an input voltage of ?30 V), the system cooled down to a temperature as low as 254.5 K at 430 kPa pressure difference between inlet and outlet at steady state and 234 K at 710 kPa in a transient state. The system provided cooling powers of 75 mW at 255 K and 150 mW at 258 K. Parasitic heat loads at 255 K are estimated at approximately 700 mW. PMID:21552354

  9. Physical modeling of joule heated ceramic glass melters for high level waste immobilization

    Microsoft Academic Search

    M. S. Quigley; D. K. Kreid

    1979-01-01

    It was not shown that the isothermal boundary conditions imposed by this study established prototypic heat losses through the boundaries of the model. Prototype wall temperatures and heat fluxes should be measured to provide better verification of the accuracy of the physical model. A complete set of measurements covering power input, heat balances, wall temperatures, glass temperatures, and glass properties

  10. Off-gas characteristics of defense waste vitrification using liquid-fed Joule-heated ceramic melters

    SciTech Connect

    Goles, R.W.; Sevigny, G.J.

    1983-09-01

    Off-gas and effluent characterization studies have been established as part of a PNL Liquid-Fed Ceramic Melter development program supporting the Savannah River Laboratory Defense Waste Processing Facility (SRL-DWPF). The objectives of these studies were to characterize the gaseous and airborne emission properties of liquid-fed joule-heated melters as a function of melter operational parameters and feed composition. All areas of off-gas interest and concern including effluent characterization, emission control, flow rate behavior and corrosion effects have been studied using alkaline and formic-acid based feed compositions. In addition, the behavioral patterns of gaseous emissions, the characteristics of melter-generated aerosols and the nature and magnitude of melter effluent losses have been established under a variety of feeding conditions with and without the use of auxiliary plenum heaters. The results of these studies have shown that particulate emissions are responsible for most radiologically important melter effluent losses. Melter-generated gases have been found to be potentially flammable as well as corrosive. Hydrogen and carbon monoxide present the greatest flammability hazard of the combustibles produced. Melter emissions of acidic volatile compounds of sulfur and the halogens have been responsible for extensive corrosion observed in melter plenums and in associated off-gas lines and processing equipment. The use of auxiliary plenum heating has had little effect upon melter off-gas characteristics other than reducing the concentrations of combustibles.

  11. Conceptual design of a joule-heated ceramic melter for the DOE Fernald silos 1, 2, and 3 wastes

    SciTech Connect

    Robinson, R.A.; Janke, D.S.; Peters, R. [Battelle Pacific Northwest Lab., Richland, WA (United States); Fekete, L. [Parsons, Fairfield, OH (United States)

    1992-06-01

    Vitrification of nuclear wastes has been under investigation since the mid-1950s. Most of the international communities experience has been with vitrification of high level nuclear wastes. In the US, this technology was developed by Battelle scientists at the DOEs Pacific Northwest Laboratories located at their Hanford site. Based on Laboratory and pilot-scale testing conducted at Hanford in the early 1970s, the DOE has constructed high level nuclear waste vitrification facilities at both Savannah River, South Carolina, and West Valley, New York, and is finalizing the design of a similar treatment facility at Hanford. Although these systems were designed to be fully remote due to the extreme radioactive hazards associated with this type of nuclear waste, technology transfer was successfully applied to the design of a vitrification process for the K-65 and uranium metal oxide wastes in a semi-remote operation at Fernald. This paper describes a conceptual design of a joule-heated, slurry-fed ceramic melter that was developed for vitrification of the DOE K-65 and metal oxide low level wastes at Fernald, Ohio.

  12. Effect of current crowding and Joule heating on electromigration-induced failure in flip chip composite solder joints tested at room temperature

    NASA Astrophysics Data System (ADS)

    Nah, J. W.; Suh, J. O.; Tu, K. N.

    2005-07-01

    The electromigration of flip chip solder joints consisting of 97Pb-3Sn and 37Pb-63Sn composite solders was studied under high current densities at room temperature. The mean time to failure and failure modes were found to be strongly dependent on the change in current density. The composite solder joints did not fail after 1month stressed at 4.07×104A/cm2, but failed after just 10h of current stressing at 4.58×104A/cm2. At a slightly higher current stressing of 5.00×104A/cm2, the composite solder joints failed after only 0.6h due to melting. Precipitation and growth of Cu6Sn5 at the cathode caused the Cu under bump metallurgy to be quickly consumed and resulted in void formation at the contact area. The void reduced the contact area and displaced the electrical path, affecting the current crowding and Joule heating inside the solder bump. Significant Joule heating inside solder bumps can cause melting of the solder and quick failure. The effect of void propagation on current crowding and Joule heating was confirmed by simulation.

  13. Effect of Joule heating and thermal radiation in flow of third grade fluid over radiative surface.

    PubMed

    Hayat, Tasawar; Shafiq, Anum; Alsaedi, Ahmed

    2014-01-01

    This article addresses the boundary layer flow and heat transfer in third grade fluid over an unsteady permeable stretching sheet. The transverse magnetic and electric fields in the momentum equations are considered. Thermal boundary layer equation includes both viscous and Ohmic dissipations. The related nonlinear partial differential system is reduced first into ordinary differential system and then solved for the series solutions. The dependence of velocity and temperature profiles on the various parameters are shown and discussed by sketching graphs. Expressions of skin friction coefficient and local Nusselt number are calculated and analyzed. Numerical values of skin friction coefficient and Nusselt number are tabulated and examined. It is observed that both velocity and temperature increases in presence of electric field. Further the temperature is increased due to the radiation parameter. Thermal boundary layer thickness increases by increasing Eckert number. PMID:24454694

  14. Effect of Joule Heating and Thermal Radiation in Flow of Third Grade Fluid over Radiative Surface

    PubMed Central

    Hayat, Tasawar; Shafiq, Anum; Alsaedi, Ahmed

    2014-01-01

    This article addresses the boundary layer flow and heat transfer in third grade fluid over an unsteady permeable stretching sheet. The transverse magnetic and electric fields in the momentum equations are considered. Thermal boundary layer equation includes both viscous and Ohmic dissipations. The related nonlinear partial differential system is reduced first into ordinary differential system and then solved for the series solutions. The dependence of velocity and temperature profiles on the various parameters are shown and discussed by sketching graphs. Expressions of skin friction coefficient and local Nusselt number are calculated and analyzed. Numerical values of skin friction coefficient and Nusselt number are tabulated and examined. It is observed that both velocity and temperature increases in presence of electric field. Further the temperature is increased due to the radiation parameter. Thermal boundary layer thickness increases by increasing Eckert number. PMID:24454694

  15. Iron Phosphate Glass for Vitrifying Hanford AZ102 LAW in Joule Heated and Cold Crucible Induction Melters

    SciTech Connect

    Day, Delbert E.; Brow, R. K.; Ray, C. S.; Kim, Cheol-Woon; Reis, Signo T.; Vienna, John D.; Peeler, David K.; Johnson, Fabienne; Hansen, E. K.; Sevigny, Gary J.; Soelberg, Nicolas R.; Pegg, Ian L.; Gan, Hao

    2012-01-05

    An iron phosphate composition for vitrifying a high sulfate (~17 wt%) and high alkali (~80 wt%) low activity Hanford waste, known as AZ102 LAW, has been developed for processing in a Joule Heated Melter (JHM) or a Cold Crucible Induction Melter (CCIM). This composition produced a glass waste form, designated as MS26AZ102F-2, with a waste loading of 26 wt% of the AZ102 which corresponded to a total alkali and sulfate (SO3) content of 21 and 4.2 wt%, respectively. A slurry (7M Na) of MS26AZ102F-2 simulant was melted continuously at temperatures between 1030 and 1090°C for 10 days in a small JHM at PNNL and for 7 days in a CCIM at INL. The as-cast glasses produced in both melters and in trial laboratory experiments along with their CCC-treated counterparts met the DOE LAW requirements for the Product Consistency Test (PCT) and the Vapor Hydration Test (VHT). These glass waste forms retained up to 77 % of the SO3 (3.3 wt%), 100% of the Cesium, and 33 to 44% of the rhenium, surrogate for Tc-99, all of which either exceeded or were comparable to the retention limit for these species in borosilicate glass nuclear waste form. Analyses of commercial K-3 refractory lining and the Inconel 693 metal electrodes used in JHM indicated only minimum corrosion of these components by the iron phosphate glass. This is the first time that an iron phosphate composition (slurry feed) was melted continuously in the JHM and CCIM, thereby, demonstrating that iron phosphate glasses can be used as alternative hosts for vitrifying nuclear waste.

  16. Application of High-Speed Infrared Imaging to Study Transient Joule Heating in Station Class Zinc Oxide Surge Arresters

    SciTech Connect

    Dinwiddie, R. B.; Wang, H.; Johnnerfelt, B.

    2004-03-15

    Zinc Oxide based surge arresters are widely used to safeguard and improve reliability of the electrical power delivering and transmission systems. The primary application of surge arresters is to protect valuable components such as transformers from lightning strikes and switching transients in the transmission lines. Metal-oxide-varistor blocks (MOV, e.g. ZnO) are used in surge arrester assemblies. ORNL has developed an advanced infrared imaging technique to monitor the joule heating during transient heating of small varistors. In a recent short-term R&D effort, researchers from ABB and ORNL have expanded the use of IR imaging to larger station-class arrester blocks. An on-site visit to the ABB facility demonstrated that the use of IR imaging is not only feasible but also has the potential to improve arrester quality and reliability. The ASEA Brown Bower (ABB) Power and Technology & Development Company located at Greensburg PA having benefited from collaborative R&D cooperation with ORNL. ABB has decided a follow-on CRADA project is very important. While the previous efforts to study surge arresters included broader studies of IR imaging and computer modeling, ABB has recognized the potential of IR imaging, decided to focus on this particular area. ABB plans to use this technique to systematically study the possible defects in the arrester fabrication process. ORNL will improve the real-time monitoring capability and provide analysis of the infrared images. More importantly, the IR images will help us understand transient heating in a ceramic material from the scientific standpoint. With the improved IR imaging ABB and ORNL will employ the IR system to visualize manufacturing defects that could not be detected otherwise. The proposed on-site tests at ABB Power Technology & Development processing facility will identify the defects and also allow quick adjustments to be made since the resulting products can be inspected immediately. ABB matched the DOE $50K funding with $50K funds-in to ORNL. ABB also provided about $75K in-kind effort for on-site testing, and R&D to improve the fabrication process.

  17. Numerical calculation and experimental research on crack arrest by detour effect and joule heating of high pulsed current in remanufacturing

    NASA Astrophysics Data System (ADS)

    Yu, Jing; Zhang, Hongchao; Deng, Dewei; Hao, Shengzhi; Iqbal, Asif

    2014-07-01

    The remanufacturing blanks with cracks were considered as irreparable. With utilization of detour effect and Joule heating of pulsed current, a technique to arrest the crack in martensitic stainless steel FV520B is developed. According to finite element theory, the finite element(FE) model of the cracked rectangular specimen is established firstly. Then, based on electro-thermo-structure coupled theory, the distributions of current density, temperature field, and stress field are calculated for the instant of energizing. Furthermore, the simulation results are verified by some corresponding experiments performed on high pulsed current discharge device of type HCPD-I. Morphology and microstructure around the crack tip before and after electro pulsing treatment are observed by optical microscope(OM) and scanning electron microscope(SEM), and then the diameters of fusion zone and heat affected zone(HAZ) are measured in order to contrast with numerical calculation results. Element distribution, nano-indentation hardness and residual stress in the vicinity of the crack tip are surveyed by energy dispersive spectrometer(EDS), scanning probe microscopy(SPM) and X-ray stress gauge, respectively. The results show that the obvious partition and refined grain around the crack tip can be observed due to the violent temperature change. The contents of carbon and oxygen in fusion zone and HAZ are higher than those in matrix, and however the hardness around the crack tip decreases. Large residual compressive stress is induced in the vicinity of the crack tip and it has the same order of magnitude for measured results and numerical calculation results that is 100 MPa. The relational curves between discharge energies and diameters of the fusion zone and HAZ are obtained by experiments. The difference of diameter of fusion zone between measured and calculated results is less than 18.3%. Numerical calculation is very useful to define the experimental parameters. An effective method to prevent further extension of the crack is presented and can provide a reference for the compressor rotor blade remanufacturing.

  18. Iron Phosphate Glass for Vitrifying Hanford AZ102 LAW in Joule Heated and Cold Crucible Induction Melters - 12240

    SciTech Connect

    Day, Delbert E.; Brow, Richard K.; Ray, Chandra S.; Reis, Signo T. [Missouri University of Science and Technology, 1870 Miner Circle, Rolla, MO 65409 (United States); Kim, Cheol-Woon [MO-SCI Corporation, 4040 HyPoint North, Rolla, MO 65401 (United States); Vienna, John D.; Sevigny, Gary [Pacific North West National Laboratory, Battelle Blvd., Richland, WA 99352 (United States); Peeler, David; Johnson, Fabienne C.; Hansen, Eric K. [Savannah River National Laboratory, Savannah River Site, 999-W, Aiken, SC 29803 (United States); Soelberg, Nick [Idaho National Laboratory, 2525 Fremont Avenue, Idaho Falls, ID 83415 (United States); Pegg, Ian L.; Gan, Hao [Catholic University of America, 620 Michigan Avenue, N.E., Washington, DC 20064 (United States)

    2012-07-01

    An iron phosphate composition for vitrifying a high sulfate (?17 wt%) and high alkali (?80 wt%) Hanford low activity waste (LAW), known as AZ-102 LAW, has been developed for processing in a Joule Heated Melter (JHM) or a Cold Crucible Induction Melter (CCIM). This composition produced a glass waste form, designated as MS26AZ102F-2, with a waste loading of 26 wt% of the AZ-102 which corresponded to a total alkali and sulfate (represented as SO{sub 3}) content of 21 and 4.4 wt%, respectively. A slurry (7 M Na{sup +}) of MS26AZ102F-2 simulant was melted continuously at temperatures between 1030 and 1090 deg. C for 10 days in a small JHM at PNNL and for 70 hours in a CCIM at INL. The as-cast glasses produced in both melters and in trial laboratory experiments along with their canister centerline cooled (CCC) counterparts met the requirements for the Product Consistency Test (PCT) and the Vapor Hydration Test (VHT) responses in the Hanford Tank Waste Treatment and Immobilization Plant (WTP) Contract. These glass waste forms retained up to 77 % of the SO{sub 3} (3.3 wt%), 100% of the Cesium, and 33 to 44% of the rhenium (used as a surrogate for Tc) all of which either exceeded or were comparable to the retention limit for these species in borosilicate glass nuclear waste form. Analyses of commercial K-3 refractory lining and the Inconel 693 metal electrodes used in JHM indicated only minimum corrosion of these components by the iron phosphate glass. This is the first time that an iron phosphate composition was melted continuously in a slurry fed JHM and in the US, thereby, demonstrating that iron phosphate glasses can be used as alternative hosts for vitrifying nuclear waste. The following conclusions are drawn from the results of the present work. (1) An iron phosphate composition, designated as MS26AZ102F-2, containing 26 wt% of the simulated high sulfate (17 wt%), high alkali (80 wt%) Hanford AZ-102 LAW meets all the criteria for processing in a JHM and CCIM. This composition produces a homogeneous glass with a density of 2.80 ± 0.04 g/cm{sup 3} after melting between 1000 and 1050 deg. C for 3 to 5 h. (2) This is the first time that an iron phosphate glass was melted in the JHM continuously for 10 days achieving a specific melting rate of 1010 kg/m2/day and in the CCIM for 70 hrs with a melting rate of 664 kg/m{sup 2}/day. (3) The analyzed (ICP-AES) compositions for all the glasses prepared under several melting conditions are in excellent agreement with the target composition. The variation of melting conditions include: (i) use of small scale/short melting time to large scale/long melting time (300 g to 80 kg, 4 h to 10 days) operations including melting in the JHM and CCIM, (ii) use of dry or wet (slurry) melter feed, (iii) addition of reductant (sugar) in the batch, and (iv) bubbling the melt with air. (4) The chemical durability as measured by PCT and VHT for the quenched and CCC-treated waste forms prepared from laboratory, JHM or CCIM melting exceeds the DOE requirements for LAW. (5) Depending upon the melting time (4 h to 10 days), the average concentration of SO{sub 3} in the MS26AZ102F-2 iron phosphate glass waste form varies from about 1.78 (RSM) to 3.74 (laboratory melt) wt% which corresponds to an SO{sub 3} retention of 41 to 86% when melted between 1030 at 1050 deg. C in air. (6) The retention of SO{sub 3} in the glass was reduced when a reductant (sugar) was added to the slurry. (7) The retention of other problem components like Cesium and Rhenium/Tc-99 is also high; from 92 to 100% for Cs{sub 2}O under different melting conditions, and from 66 to 33% for Re{sub 2}O{sub 7} for melts processed from 3 to 5 hours and up to 10 days. (8) Corrosion tests on Inconel 693 and K-3 refractory at temperatures between 1000 and 1050 deg. C indicate that both materials should be suitable for melting iron phosphate glasses. (9) The viscosity and electrical conductivity of the MS26AZ102F-2 melt are within the acceptable limits for RSM and CCIM processing. (10)This work has shown that iron phosphate compositions are a pot

  19. Joule heating effect on oxide whisker growth induced by current stressing in Cu/Sn-58Bi/Cu solder joint

    NASA Astrophysics Data System (ADS)

    He, Hongwen; Cao, Liqiang; Wan, Lixi; Zhao, Haiyan; Xu, Guangchen; Guo, Fu

    2012-08-01

    The electromigration test was conducted in Cu/Sn-58Bi/Cu solder joint with high current density of 104 A/ cm2. Results showed that a large number of whiskers with natural weed appearance were observed at the cathode side in such a short current stressing time. Furthermore, some secondary whiskers were attached to the primary whiskers, which has never been reported before. We presumed the vapor-solid (VS) mechanism to explain the oxide whiskers growth, which was quite different from the traditional theory that the compressive stress took on the driving force. In conclusion, due to the over-Joule heating effect, the metal oxide whiskers were synthesized in bulk quantities by thermal evaporation of Sn oxide and Bi oxide.

  20. Joule-Heated Ceramic-Lined Melter to Vitrify Liquid Radioactive Wastes Containing Am241 Generated From MOX Fuel Fabrication in Russia

    SciTech Connect

    Smith, E C; Bowan II, B W; Pegg, I; Jardine, L J

    2004-11-16

    The governments of the United Stated of America and the Russian Federation (RF) signed an Agreement September 1, 2000 to dispose of weapons plutonium that has been designated as no longer required for defense purposes. The Agreement declares that each country will disposition 34MT of excess weapons grade plutonium from their stockpiles. The preferred disposition technology is the fabrication of mixed oxide (MOx) fuel for use or burning in pressurized water reactors to destroy the plutonium. Implementation of this Agreement will require the conversion of plutonium metal to oxide and the fabrication of MOx fuel within the Russian Federation. The MOx fuel fabrication and metal to oxide conversion processes will generate solid and liquid radioactive wastes containing trace amounts of plutonium, neptunium, americium, and uranium requiring treatment, storage, and disposal. Unique to the Russian MOx fuel fabrication facility's flow-sheet is a liquid waste stream with high concentrations ({approx}1 g/l) of {sup 241}Am and non radioactive silver. The silver is used to dissolve PuO{sub 2} feed materials to the MOx fabrication facility. Technical solutions are needed to treat and solidify this liquid waste stream. Alternative treatment technologies for this liquid waste stream are being evaluated by a Russian engineering team. The technologies being evaluated include borosilicate and phosphate vitrification alternatives. The evaluations are being performed at a conceptual design level of detail under a Lawrence Livermore National Laboratory (LLNL) contract with the Russian organization TVEL using DOE NA-26 funding. As part of this contract, the RF team is evaluating the technical and economic feasibility of the US borosilicate glass vitrification technology based on a Duratek melter to solidify this waste stream into a form acceptable for storage and geologic disposal. The composition of the glass formed from treating the waste is dictated by the concentration of silver and americium it contains. Silver is widely used as an additive in glass making. However, its solubility is known to be limited in borosilicate glasses. Further, silver, which is present as a nitrate salt in the waste, can be easily reduced to molten silver in the melting process. Molten silver, if formed, would be difficult to reintroduce into the glass matrix and could pose operating difficulties for the glass melter. This will place a limitation on the waste loading of the melter feed material to prevent the separation of silver from the waste within the melter. If the silver were recovered in the MOx fabrication process, which is currently under consideration, the composition of the glass would likely be limited only by the thermal heat load from the incorporated {sup 241}Am. The resulting mass of glass used to encapsulate the waste could then be reduced by a factor of approximately three. The vitrification process used to treat the waste stream is proposed to center on a joule-heated ceramic lined slurry fed melter. Glass furnaces of this type are used in the United States to treat high-level waste (HLW) at the: Defense Waste Processing Facility, West Valley Demonstration Project, and to process the Hanford tank waste. The waste will initially be blended with glass-forming chemicals, which are primarily sand and boric acid. The resulting slurry is pumped to the melter for conversion to glass. The melter is a ceramic lined metal box that contains a molten glass pool heated by passing electric current through the glass. Molten glass from the melter is poured into canisters to cool and solidify. They are then sealed and decontaminated to form the final waste disposal package. Emissions generated in the melter from the vitrification process are treated by an off-gas system to remove radioactive contamination and destroy nitrogen oxides (NOx).

  1. Watt and joule balances

    NASA Astrophysics Data System (ADS)

    Robinson, Ian A.

    2014-04-01

    The time is fast approaching when the SI unit of mass will cease to be based on a single material artefact and will instead be based upon the defined value of a fundamental constant—the Planck constant—h . This change requires that techniques exist both to determine the appropriate value to be assigned to the constant, and to measure mass in terms of the redefined unit. It is important to ensure that these techniques are accurate and reliable to allow full advantage to be taken of the stability and universality provided by the new definition and to guarantee the continuity of the world's mass measurements, which can affect the measurement of many other quantities such as energy and force. Up to now, efforts to provide the basis for such a redefinition of the kilogram were mainly concerned with resolving the discrepancies between individual implementations of the two principal techniques: the x-ray crystal density (XRCD) method [1] and the watt and joule balance methods which are the subject of this special issue. The first three papers report results from the NRC and NIST watt balance groups and the NIM joule balance group. The result from the NRC (formerly the NPL Mk II) watt balance is the first to be reported with a relative standard uncertainty below 2 × 10-8 and the NIST result has a relative standard uncertainty below 5 × 10-8. Both results are shown in figure 1 along with some previous results; the result from the NIM group is not shown on the plot but has a relative uncertainty of 8.9 × 10-6 and is consistent with all the results shown. The Consultative Committee for Mass and Related Quantities (CCM) in its meeting in 2013 produced a resolution [2] which set out the requirements for the number, type and quality of results intended to support the redefinition of the kilogram and required that there should be agreement between them. These results from NRC, NIST and the IAC may be considered to meet these requirements and are likely to be widely debated prior to a decision on redefinition. The CCM had already recognized that agreement was close and has set in place a process whereby redefinition can take place by 2018. The final decision will be in the hands of the Conférence Générale des Poids et Mesures (CGPM) but the results reported here should aid a positive decision. Figure 1. Figure 1. Results from recent measurements of the Planck constant. The reference for the results h 90 is derived from the conventional values of the Josephson constant K J-90 and the von Klitzing constant R K-90. The factor of ten improvement in uncertainty of the NRC watt balance result, over that achieved by the same apparatus at NPL a few years earlier, can be understood as a factor of five improvement arising from the elimination of an effect discovered at NPL that could not be eliminated before shipment to Canada and a factor of two arising from the considerable improvements made by NRC. Once the kilogram has been redefined, the watt and joule balances will complete their transitions from instruments that are primarily of interest to the electrical community for determining the SI electrical units from the mechanical units, to the principal methods by which an individual National Measurement Institute (NMI) can make an independent determination of the SI unit of mass and thereby contribute to the maintenance of national and international mass scales. This special issue gives an introduction to the diversity of techniques which are required for the operation of watt and joule balances. However it does not contain a review of existing balances; this was a deliberate decision, as a number of such review papers have been published in the past five years [3-7] and it was felt that it was not yet time for another. The first technique considered is that of gravimetry; the watt balance measures the weight Mg of a mass M , and to convert the measured weight into a mass, the value of the acceleration due to gravity g must be known, at the time of the weighing and at the centre of gravity of the mass. The paper by Liard and his co-au

  2. Direct Observation of Nanoscale Peltier and Joule Effects at Metal-Insulator Domain Walls in Vanadium Dioxide Nanobeams

    E-print Network

    Wu, Junqiao

    localized alternating Peltier heating and cooling as well as Joule heating concentrated at the M-I domainDirect Observation of Nanoscale Peltier and Joule Effects at Metal- Insulator Domain Walls the monoclinic phase identification. KEYWORDS: Vanadium dioxide, thermoreflectance microscopy, Peltier effect

  3. Direct observation of nanometer-scale Joule and Peltier effects in phase change memory devices

    NASA Astrophysics Data System (ADS)

    Grosse, Kyle L.; Xiong, Feng; Hong, Sungduk; King, William P.; Pop, Eric

    2013-05-01

    We measure power dissipation in phase change memory (PCM) devices by scanning Joule expansion microscopy (SJEM) with ˜50 nm spatial and 0.2 K temperature resolution. The temperature rise in the Ge2Sb2Te5 (GST) is dominated by Joule heating, but at the GST-TiW contacts it is a combination of Peltier and current crowding effects. Comparison of SJEM and electrical measurements with simulations of the PCM devices uncovers a thermopower of ˜350 ?V K-1 and a contact resistance of ˜2.0 × 10-8 ? m2 (to TiW) for 25 nm thick films of face centered-cubic crystalline GST. Knowledge of such nanometer-scale Joule, Peltier, and current crowding effects is essential for energy-efficient design of future PCM technology.

  4. Elevated-pressure mixed-coolants Joule Thomson cryocooling

    NASA Astrophysics Data System (ADS)

    Maytal, B.-Z.; Nellis, G. F.; Klein, S. A.; Pfotenhauer, J. M.

    2006-01-01

    This paper explores the potential of mixed coolants at elevated pressures for Joule-Thomson cryocooling. A numerical model of a Joule-Thomson cryocooler is developed that is capable of simulating operation with mixtures of up to 9 components consisting of hydrocarbons, non-flammable halogenated refrigerants, and inert gases. The numerical model is integrated with a genetic optimization algorithm, which has a high capability for convergence in an environment of discontinuities, constraints and local optima. The genetic optimization algorithm is used to select the optimal mixture compositions that separately maximizes following two objective functions at each elevated pressure for 80, 90 and 95 K cryocooling: the molar specific cooling capacity (the highest attainable is 3200 J/mol) and the produced cooling capacity per thermal conductance which is a measure of the compactness of the recuperator. The optimized cooling capacity for a non-flammable halogenated refrigerant mixture is smaller than for a hydrocarbon mixture; however, the cooling capacity of the two types of mixtures approach one another as pressure becomes higher. The coefficient of performance, the required heat transfer area and the effect of the number of components in the mixture is investigated as a function of the pressure. It is shown that mixtures with more components provide a higher cooling capacity but require larger recuperative heat exchangers. Optimized mixtures for 90 K cryocooling have similar cooling capacity as those for 80 K. Optimized compactness for 80 K is about 50% higher than can be achieved by pure nitrogen. For 90 K, no mixture provides a more compact recuperator than can be achieved using pure argon. The results are discussed in the context of potential applications for closed and open cycle cryocoolers.

  5. The JOULE Experiment: Observations of Small-Scale Structure in the Auroral Oval During a Substorm Event

    NASA Astrophysics Data System (ADS)

    Larsen, M. F.; Bishop, R.; Zhan, T.; Pfaff, R.; Stegies, C.; Knudsen, D.; Clemmons, J.; Hecht, J.; Hysell, D.; Bahcivan, H.; Bristow, W.

    2003-12-01

    The JOULE experiment was carried out at the Poker Flat Research Range in Alaska on March 27, 2003, during a substorm event in the postmidnight sector. The objective of the experiment was to measure the electric fields and the Joule heating over a range of scale sizes from approximately 1000 km to a few tens of meters with the specific goal of obtaining estimates of the contributions of the small-scale fluctuations in the forcing to the overall Joule heating rates. The instrumentation included the SuperDARN radars covering the Alaska sector which represented the largest scales, an imaging coherent scatter radar covering the intermediate scales, and two instrumented rockets covering the smallest scales. In addition, chemical tracer releases provided information about the E-region wind profiles and the horizontal gradients in the winds across the auroral oval. An overview of the experiment, the substorm event, and the measurements will be presented.

  6. Mega-joule experiment area study, 1989

    SciTech Connect

    Slaughter, D.; Oirth, C.; Woodworth, J.

    1995-03-09

    This document contains Chapters 3 and 4 from the Mega-Joule Experiment Area Study, 1989. Water frost on the first containment wall is studied in detail in Chapter 3. Considered topics are the computer modeling of frost ablation and shock propagation and the experimental characterization of water frost. The latter is broken down into: frost crystal morphology, experiment configuration, growth rate results, density results, thermal conductivity, crush strength of frost, frost integrity, frost response to simulated soft x-rays. Chapter 4 presents information on surrounding shielding and structures to include: cryogenic spheres for first wall and coolant containment; shield tank concerning primary neutron and gamma ray shielding; and secondary shielding.

  7. Improving Control in a Joule-Thomson Refrigerator

    NASA Technical Reports Server (NTRS)

    Borders, James; Pearson, David; Prina, Mauro

    2005-01-01

    A report discusses a modified design of a Joule-Thomson (JT) refrigerator under development to be incorporated into scientific instrumentation aboard a spacecraft. In most other JT refrigerators (including common household refrigerators), the temperature of the evaporator (the cold stage) is kept within a desired narrow range by turning a compressor on and off as needed. This mode of control is inadequate for the present refrigerator because a JT-refrigerator compressor performs poorly when the flow from its evaporator varies substantially, and this refrigerator is required to maintain adequate cooling power. The proposed design modifications include changes in the arrangement of heat exchangers, addition of a clamp that would afford a controlled heat leak from a warmer to a cooler stage to smooth out temperature fluctuations in the cooler stage, and incorporation of a proportional + integral + derivative (PID) control system that would regulate the heat leak to maintain the temperature of the evaporator within a desired narrow range while keeping the amount of liquid in the evaporator within a very narrow range in order to optimize the performance of the compressor. Novelty lies in combining the temperature- and cooling-power-regulating controls into a single control system.

  8. Nanometer-scale temperature imaging for independent observation of Joule and Peltier effects in phase change memory devices.

    PubMed

    Grosse, Kyle L; Pop, Eric; King, William P

    2014-09-01

    This paper reports a technique for independent observation of nanometer-scale Joule heating and thermoelectric effects, using atomic force microscopy (AFM) based measurements of nanometer-scale temperature fields. When electrical current flows through nanoscale devices and contacts the temperature distribution is governed by both Joule and thermoelectric effects. When the device is driven by an electrical current that is both periodic and bipolar, the temperature rise due to the Joule effect is at a different harmonic than the temperature rise due to the Peltier effect. An AFM tip scanning over the device can simultaneously measure all of the relevant harmonic responses, such that the Joule effect and the Peltier effect can be independently measured. Here we demonstrate the efficacy of the technique by measuring Joule and Peltier effects in phase change memory devices. By comparing the observed temperature responses of these working devices, we measure the device thermopower, which is in the range of 30 ± 3 to 250 ± 10 ?V K(-1). This technique could facilitate improved measurements of thermoelectric phenomena and properties at the nanometer-scale. PMID:25273761

  9. The Joule-Thomson effect in cesium vapor

    Microsoft Academic Search

    I. I. Novikov; V. V. Roshchupkin; M. M. Liakhovitskii

    1977-01-01

    The paper reports results of the measurement of the Joule-Thomson coefficient in cesium vapor near the saturation line in the temperature range 768-1234 K and the pressure range of about 0 to 790,000 Pa. The experimental apparatus and technique of measurement are described and attention is given to data reduction procedures. The Joule-Thomson coefficient is studied as a function of

  10. Proceeding of the 1st International Forum on Heat Transfer

    E-print Network

    Maruyama, Shigeo

    was heated by Joule-heating in vacuum, ethanol gas was introduced into the chamber at 1.0 Torr and then SWNTs. Moreover, extremely high thermal conductivity along the tube axis is one of the interesting properties by Joule-heating in vacuum while monitoring the temperature with a thermocouple fixed on the silicon

  11. Offgas emissions from slurry-fed Joule-heated melters

    SciTech Connect

    Overcamp, T.J.; Harden, J.M. [Clemson Univ., Anderson, SC (United States); Cicero, C.A.; Bickford, D.F. [Westinghouse Savannah River Company, Aiken, SC (United States)

    1996-12-31

    This paper reports on total particulate emissions from surrogate testing on a variety of DOE surrogate wastewater sludges and on decontamination factors of specific metals from tests on surrogate sludge from the West End Treatment Facility (WETF) at the Oak Ridge Reservation (ORR). The majority of the data were taken on tests using the Envitco EV-16 refractory-lined melter. Several WETF tests were run in the Stir-Melter WV-0.25 melter.

  12. An analysis of electrothermodynamic heating and cooling

    E-print Network

    Honea, Mark Stephen

    1998-01-01

    , albeit at the expense of the Joule heating within the conductor. This investigation explores the dynamic nature of thermoelectrically cooled/heated regions in effort to gain a greater understanding of the transient application of thermoelectricity...

  13. Development of a Numerical Model to Predict In-Plane Heat Generation Patterns During Induction Processing of Carbon Fiber-Reinforced Prepreg Stacks

    Microsoft Academic Search

    HEE JUNE KIM; SHRIDHAR YARLAGADDA; NICHOLAS B. SHEVCHENKO; BRUCE K. FINK; JOHN W. GILLESPIE JR.

    2003-01-01

    A numerical model is proposed to describe in-plane heat generation spatial response during induction processing of carbon fiber-reinforced thermoplastics. The model is based on a unified approach that considers three possible heating mechanisms: fiber heating (Joule losses in fiber), noncontact junction heating (dielectric hysteresis), and contact junction heating (Joule losses at junctions). A lumped meshing scheme is used to construct

  14. Coils and the Electromagnet Used in the Joule Balance at the NIM

    E-print Network

    Zhang, Zhonghua; Han, Bing; Lu, Yunfeng; Li, Shisong; Xu, Jinxin; Wang, Gang

    2015-01-01

    In the joule balance developed at National Institute of Metrology (NIM), the dynamic phase of a watt balance is replaced by the mutual inductance measurement in an attempt to provide an alternative method for the kg redefinition. But for this method a rather large current in the exciting coil, is needed to offer the necessary magnetic field in the force weighing phase, and the coil heating becomes an important uncertainty source. To reduce coil heating, a new coil system, in which a ferromagnetic material is used to increase the magnetic field was designed recently. But adopting the ferromagnetic material brings the difficulty from the nonlinear characteristic of material. This problem can be removed by measuring the magnetic flux linkage difference of the suspended coil at two vertical positions directly to replace the mutual inductance parameter. Some systematic effects of this magnet are discussed.

  15. Design of a valved moving magnet type linear compressor for a Joule-Thomson cryocooler

    NASA Astrophysics Data System (ADS)

    Wang, W. W.; Wang, L. Y.; Gan, Z. H.

    2014-01-01

    For temperatures around 4-6 K, Joule-Thomson (J-T) cryocoolers can achieve a higher efficiency than Stirling or pulse tube cryocoolers thus have been widely used in space. It is crucial for a J-T compressor to obtain a relatively high pressure ratio. With this concept, a valved moving magnet type linear compressor has been designed. This paper describes the design method and component structure of the linear compressor in detail. The electromagnetic force of linear motor, stiffness and stress distribution of flexure springs were calculated based on finite element method (FEM). System resonance was specially considered to achieve a high efficiency, and system vibration and heat dissipation problems were discussed. The design goal of the linear compressor is to achieve an efficiency of 80% and a lifetime longer than 5 years.

  16. A 2.5-Kelvin Gifford-McMahon/Joule-Thomson Cooler for Cavity Maser Applications

    NASA Astrophysics Data System (ADS)

    Britcliffe, M.; Hanson, T.; Fernandez, J.

    2001-07-01

    A 2.5-K cooler suitable for cooling cavity maser amplifiers is described. The device combines a 4-K Gifford-McMahon (GM) refrigerator with a Joule-Thomson (JT) circuit to provide 180 mW of cooling at 2.5 K. The device is compact and can operate in any physical orientation. A commercial two-stage GM cooler pre-cools the helium JT circuit flow. The JT circuit can be simplified as compared with existing systems. Only two counter flow heat exchangers are necessary. The 4-K GM operating temperature also allows the use of a single-stage compressor for the JT circuit. The JT circuit operates with a supply pressure of only 110 kPa. A commercial scroll vacuum pump is used as a compressor. The simplified system can be fabricated for less than the cost of current 4.5-K maser coolers

  17. Simultaneous Thermal Imaging of Peltier and Joule Effects B. Vermeersch and A. Shakouri

    E-print Network

    Simultaneous Thermal Imaging of Peltier and Joule Effects B. Vermeersch and A. Shakouri Baskin dependence. Estab- lished techniques employ two distinct runs of data averaging: one with forward and one with reverse supply polarity. Post processing of the two images provides the Peltier and Joule terms, based

  18. Animal Physiology 1 Lecture 22 & 23. Thermoregulation: Dealing with Heat and

    E-print Network

    Creel, Scott

    ) Thyroid hormones control deposition and use of brown fat. Hcond: Heat gained or lost by conduction thing. Heat is form of energy, so it is measured in units of joules (or calories). If a given amount

  19. Joule-Thomson cryocooler with neon and nitrogen mixture using commercial air-conditioning compressors

    NASA Astrophysics Data System (ADS)

    Lee, Jisung; Oh, Haejin; Baek, Seungwhan; Lee, Cheonkyu; Jeong, Sangkwon

    2014-01-01

    A 2-stage mixed refrigerant (MR) Joule-Thomson (JT) cryocooler was designed for cooling high temperature superconducting cable below 70 K. The low temperature cycle was to operate with neon-nitrogen mixture, and the required compression ratio was approximately 24 when the suction pressure was 100 kPa. The high compression ratio of 24, the low pressure of 100 kPa at compressor suction, and the working fluid with high heat of compression were challenging issues to existing typical compression systems. We developed an innovative compression system with commercial oil-lubricated air-conditioning compressors. They were 2-stage rotary compressors originally designed for R410Aand connected in series. The compressors were modified to accommodate effective intercooling at every stage to alleviate compressor overheating problem. Additionally, fine-grade three-stage oil filters, an adsorber, and driers were installed at the discharge line to avoid a potential clogging problem from oil mist and moisture at low temperature sections. The present compression system was specifically demonstrated with a neon-nitrogen MR JT cryocooler. The operating pressure ratio was able to meet the designed specifications, and the recorded no-load mini mum temperature was 63.5 K . Commercial air-conditioning compressors were successfully applied to the high-c ompression ratio MR JT cryocooler with adequate modification using off-the-shelf components.

  20. Integrated Heat Switch/Oxide Sorption Compressor

    NASA Technical Reports Server (NTRS)

    Bard, Steven

    1989-01-01

    Thermally-driven, nonmechanical compressor uses container filled with compressed praseodymium cerium oxide powder (PrCeOx) to provide high-pressure flow of oxygen gas for driving closed-cycle Joule-Thomson-expansion refrigeration unit. Integrated heat switch/oxide sorption compressor has no moving parts except check valves, which control flow of oxygen gas between compressor and closed-cycle Joule-Thomson refrigeration system. Oxygen expelled from sorbent at high pressure by evacuating heat-switch gap and turning on heater.

  1. Experimental Investigation for 100-Joule-class TEA CO2 Laser and Gas Interaction

    NASA Astrophysics Data System (ADS)

    Dou, Zhiguo; Yao, Honglin; Wang, Jun; Wen, Ming; Wang, Peng; Yang, Jan; Li, Chong

    2006-05-01

    Impulse coupling coefficient Cm is one of the most important performance parameters in laser propulsion. Cm is the impulse increment of lightcraft that per joule laser beam energy acts on. The TEA CO2 laser, whose single pulse energy is 100-Joule-class and wavelength is 10.6?m, is adopted by experimental research. In experimental environment cabin, the parabolic lightcraft is fixed on impact pendulum. Using Air, N2, He, CO2, N2-He and N2-CO2, different Cm is obtained. Experimental results indicate that Cm of the mixed gas is improved through changing gas component ratio.

  2. Transonic Heating Effects in the Auroral Thermosphere

    NASA Astrophysics Data System (ADS)

    Balthazor, R. L.; Wilford, C.; Thom, S.; Denton, M. H.; Pryse, E.

    2003-12-01

    We review substantial recent developments to the CTIP coupled thermosphere-ionosphere-plasmasphere model, using observations from the Aberystwyth ionospheric tomographic imaging chain and the IMAGE satellite to benchmark and validate the model results. Thermospheric heating in auroral regions has classically been viewed as a combination of Joule Heating (macroscopic frictional heating from the ionosphere), Lorentz forcing (microscopic momentum transfer from ions) and particle precipitation. Of these, it has been shown that above about 110 km, Joule Heating is the dominant energy transfer mechanism. However, ion velocities during disturbed times often approach or exceed the neutral sound speed. We investigate shock front heating through modelling using the improved CTIP model and compare these with in-situ satellite observation. We conclude that shock heating may be a significant contribution to the auroral thermosphere-ionosphere energy balance.

  3. Direct observation of nanoscale Peltier and Joule effects at metal-insulator domain walls in vanadium dioxide nanobeams.

    PubMed

    Favaloro, Tela; Suh, Joonki; Vermeersch, Bjorn; Liu, Kai; Gu, Yijia; Chen, Long-Qing; Wang, Kevin X; Wu, Junqiao; Shakouri, Ali

    2014-05-14

    The metal to insulator transition (MIT) of strongly correlated materials is subject to strong lattice coupling, which brings about the unique one-dimensional alignment of metal-insulator (M-I) domains along nanowires or nanobeams. Many studies have investigated the effects of stress on the MIT and hence the phase boundary, but few have directly examined the temperature profile across the metal-insulating interface. Here, we use thermoreflectance microscopy to create two-dimensional temperature maps of single-crystalline VO2 nanobeams under external bias in the phase coexisting regime. We directly observe highly localized alternating Peltier heating and cooling as well as Joule heating concentrated at the M-I domain boundaries, indicating the significance of the domain walls and band offsets. Utilizing the thermoreflectance technique, we are able to elucidate strain accumulation along the nanobeam and distinguish between two insulating phases of VO2 through detection of the opposite polarity of their respective thermoreflectance coefficients. Microelasticity theory was employed to predict favorable domain wall configurations, confirming the monoclinic phase identification. PMID:24735496

  4. The 30 MHz imaging radar observations of auroral irregularities during the JOULE campaign

    Microsoft Academic Search

    H. Bahcivan; D. L. Hysell; M. F. Larsen; R. F. Pfaff

    2005-01-01

    Coherent backscatter from the auroral electrojet was observed by a 30 MHz imaging radar in Anchorage during the Joint Observations of Upper Latitude Electrodynamics (JOULE) campaign conducted from the Poker Flat Research Range in the spring of 2003. The observations were made at the same time that ionospheric electric fields and plasma number densities were measured in situ by instruments

  5. JouleQuest: An Accurate Power Model for the StarCore DSP Platform

    Microsoft Academic Search

    Ashish Mathur; Sourav Roy; Rajat Bhatia; Arup Chakraborty; Vijay Bhargava; Jatin Bhartia

    2007-01-01

    This paper describes the design, validation and integration of JouleQuest: a comprehensive power estimation framework for the StarCore DSP platform. The goal of this work is to provide a power model coupled to a fast platform simulator, that can accurately predict the power variability on the platform. The power consumption model for the DSP core is an instruction level model

  6. Cherish every Joule: Maximizing throughput with an eye on network-wide energy consumption

    E-print Network

    Hou, Y. Thomas

    Cherish every Joule: Maximizing throughput with an eye on network-wide energy consumption Canming: {jcm, yshi, thou, wjlou}@vt.edu Abstract Conserving network-wide energy consumption is becoming of wireless networks, the concern of energy consumption is becoming in- creasingly important for network

  7. Studies of heat source driven natural convection

    Microsoft Academic Search

    F. A. Kulacki; A. A. Emara

    1975-01-01

    Natural convection energy transport in a horizontal layer of internally heated fluid was measured for Rayleigh numbers from 1890 to 2.17 x 10 to the 12th power. The fluid layer is bounded below by a rigid zero-heat-flux surface and above by a rigid constant-temperature surface. Joule heating by an alternating current passing horizontally through the layer provides the uniform volumetric

  8. JTMIX - CRYOGENIC MIXED FLUID JOULE-THOMSON ANALYSIS PROGRAM

    NASA Technical Reports Server (NTRS)

    Jones, J. A.

    1994-01-01

    JTMIX was written to allow the prediction of both ideal and realistic properties of mixed gases in the 65-80K temperature range. It allows mixed gas J-T analysis for any fluid combination of neon, nitrogen, various hydrocarbons, argon, oxygen, carbon monoxide, carbon dioxide, and hydrogen sulfide. When used in conjunction with the NIST computer program DDMIX, JTMIX has accurately predicted order-of-magnitude increases in J-T cooling capacities when various hydrocarbons are added to nitrogen, and it predicts nitrogen normal boiling point depressions to as low as 60K when neon is added. JTMIX searches for heat exchanger "pinch points" that can result from insolubility of various components in each other. These points result in numerical solutions that cannot exist. The length of the heat exchanger is searched for such points and, if they exist, the user is warned and the temperatures and heat exchanger effectiveness are corrected to provide a real solution. JTMIX gives very good correlation (within data accuracy) to mixed gas data published by the USSR and data taken by APD for the U.S. Naval Weapons Lab. Data taken at JPL also confirms JTMIX for all cases tested. JTMIX is written in Turbo C for IBM PC compatible computers running MS-DOS. The National Institute of Standards and Technology's (NIST, Gaithersburg, MD, 301-975-2208) computer code DDMIX is required to provide mixed-fluid enthalpy data which is input into JTMIX. The standard distribution medium for this program is a 5.25 inch 360K MS-DOS format diskette. JTMIX was developed in 1991 and is a copyrighted work with all copyright vested in NASA.

  9. Experimental joule-heated ceramic melter for converting radioactive waste to glass

    Microsoft Academic Search

    P. H. Chrismar

    1978-01-01

    A small electric melter was developed to implement studies for converting radioactive waste to glass at the Savannah River Laboratory (SRL). During its 10 months of operation, the ceramic-lined, jouleheated melter processed simulated, high-level-waste, calcined materials and frit at rates of 2 to 15 g\\/min. The melt chamber is 7.6 cm wide, 22.9 cm long and 7.6 cm deep. The

  10. Nanoscale Joule heating, Peltier cooling and current crowding at graphene-metal contacts

    Microsoft Academic Search

    Kyle L. Grosse; Myung-Ho Bae; Feifei Lian; Eric Pop; William P. King

    2011-01-01

    The performance and scaling of graphene-based electronics is limited by the quality of contacts between the graphene and metal electrodes. However, the nature of graphene-metal contacts remains incompletely understood. Here, we use atomic force microscopy to measure the temperature distributions at the contacts of working graphene transistors with a spatial resolution of ~10 nm (refs 5, , , 8), allowing

  11. Investigation of neon-nitrogen mixed refrigerant Joule-Thomson cryocooler operating below 70 K with precooling at 100 K

    NASA Astrophysics Data System (ADS)

    Lee, Jisung; Oh, Haejin; Jeong, Sangkwon

    2014-05-01

    There has been two-stage mixed refrigerant (MR) Joule-Thomson (JT) refrigeration cycle suggested for cooling high temperature superconductor (HTS) electric power cable below 70 K. As the continuation effort of realizing the actual system, we fabricated and tested a small scale neon and nitrogen MR JT cryocooler to investigate the refrigeration characteristics and performance. The compression system of the refrigeration circuit was accomplished by modifying commercially available air-conditioning rotary compressors. Compressors stably operated at the maximum compression ratio of 31 when the suction pressure was 77 kPa. The achieved lowest temperature was 63.6 K when the heating load was 35.9 W. The measured Carnot efficiency of the present system was 6.5% which was lower than that of the designed goal of 17.4%. The low efficiency of compressor (34.5%), and the pressure drop at the compressor suction were the main reasons for this efficiency degradation. The feasibility and usefulness of neon and nitrogen MR JT refrigeration cycle was validated that the achieved minimum temperature was 63.6 K even though the pressure after the expansion was maintained by 130 kPa. The comparison between the measurement and calculation showed that each stream temperature of refrigeration cycle were predictable within 3% error by Peng-Robinson equation of state (EOS).

  12. A theoretical study on heat production in squid giant axon.

    PubMed

    Nogueira, R de A; Conde Garcia, E A

    1983-09-01

    The heat produced by action currents during the upstroke of the action potential in the squid axon has been calculated. Equations were developed and it was demonstrated that the phase plane area, obtained from nerve action potential upstroke, is a measure of the heat liberated at the axoplasmic level. Assuming the Hodgkin and Huxley model, it was possible to show that the axoplasmic heat is a constant fraction of the total Joule heating. PMID:6314059

  13. The development of a proff of principle superfluid Joule-Thomson refrigerator for cooling below 1 Kelvin

    E-print Network

    Miller, Franklin K., 1970-

    2005-01-01

    A new type of sub-Kelvin refrigerator, the superfluid Joule-Thomson refrigerator, has been developed and its performance has been experimentally verified. This refrigerator uses a liquid superfluid mixture of He and 4He ...

  14. Superfluid Joule–Thomson Refrigeration, a New Concept for Cooling Below 2 Kelvin

    Microsoft Academic Search

    J. G. Brisson

    2000-01-01

    A new type of sub-Kelvin refrigerator, the superfluid Joule–Thomson refrigerator is discussed. The refrigerator uses the circulation of the 3He component of a liquid 3He–4He mixture through a throttle to provide cooling to temperatures of 0.5 K. A simple analytical model is developed to predict the cooling power for this refrigerator as function of temperature. In addition, cooling power predictions

  15. Design and optimization of a two-stage 28 K Joule-Thomson microcooler

    Microsoft Academic Search

    H. S. Cao; A. V. Mudaliar; J. H. Derking; P. P. P. M. Lerou; H. J. Holland; D. R. Zalewski; S. Vanapalli; H. J. M. ter Brake

    Micro Joule-Thomson (JT) coolers made from glass wafers have been investigated for many years at the University of Twente. After successful realization of a single-stage JT microcooler with a cooling capacity of about 10 mW at 100 K, a two-stage microcooler is being researched to attain a lower temperature of about 30 K. By maximizing the coefficient of performance (COP)

  16. JouleTrack: a web based tool for software energy profiling

    Microsoft Academic Search

    Amit Sinha; Anantha P. Chandrakasan

    2001-01-01

    A software energy estimation methodology is presented that avoids explicit characterization of instruction energy consumption and pre-dicts energy consumption to within 3% accuracy for a set of bench-mark programs evaluated on the StrongARM SA-1100 and Hitachi SH-4 microprocessors. The tool, JouleTrack, is available as an online resource and has various estimation levels. It also isolates the switch-ing and leakage components

  17. Local heating-induced plastic deformation in resistive switching devices

    Microsoft Academic Search

    W. Jiang; R. J. Kamaladasa; Y. M. Lu; A. Vicari; R. Berechman; P. A. Salvador; J. A. Bain; Y. N. Picard; M. Skowronski

    2011-01-01

    Resistive switching is frequently associated with local heating of the switching structure. The mechanical effect of such heating on Pt\\/SrTiO3 (001) Schottky barriers and on Pt\\/SrZrO3\\/SrRuO3\\/SrTiO3 switching devices was examined. The extent and magnitude of Joule heating was assessed using IR microscopy at power dissipation levels similar to what others have reported during electroforming. Lines aligned along the [100] and

  18. One-Joule-per-Pulse Q-Switched 2-micron Solid State Laser

    NASA Technical Reports Server (NTRS)

    Yu, Jirong; Trieu, Bo C.; Modlin, Ed A.; Singh, Upendra N.; Kavaya, Michael J.; Chen, Songsheng; Bai, Yingxin; Petzar, Pual J.; Petros, Mulugeta

    2005-01-01

    Q-switched output of 1.1 J per pulse at 2-micron wavelength has been achieved in a diode pumped Ho:Tm:LuLF laser using a side-pumped rod configuration in a Master-Oscillator-Power-Amplifier (MOPA) architecture. This is the first time that a 2-micron laser has broken the Joule per pulse barrier for Q-switched operation. The total system efficiency reaches 5% and 6.2% for single and double pulse operation, respectively. The system produces excellent 1.4 times of transform limited beam quality.

  19. A joule-class, TEM00 spatial profile, narrow-linewidth laser system

    NASA Astrophysics Data System (ADS)

    Vaupel, Andreas; Bodnar, Nathan; Hemmer, Micha"l.; Richardson, Martin

    2011-02-01

    A Joule-class, narrow-linewidth amplifier line delivering 20 ns pulses with a TEM00 spatial profile is presented. A Q-switched Nd:YAG oscillator with an intra-cavity volume Bragg grating (VBG) is used to seed the amplifier line. A series of flashlamp-pumped Nd:YAG amplifiers consisting of a double-pass and two single-pass amplifiers boost the energy of the 21 ns pulses to 480 mJ. The presented amplifier line will be used for fundamental studies including remote Raman spectroscopy and ns filamentation.

  20. Investigation of two-phase heat transfer coefficients of argon-freon cryogenic mixed refrigerants

    NASA Astrophysics Data System (ADS)

    Baek, Seungwhan; Lee, Cheonkyu; Jeong, Sangkwon

    2014-11-01

    Mixed refrigerant Joule Thomson refrigerators are widely used in various kinds of cryogenic systems these days. Although heat transfer coefficient estimation for a multi-phase and multi-component fluid in the cryogenic temperature range is necessarily required in the heat exchanger design of mixed refrigerant Joule Thomson refrigerators, it has been rarely discussed so far. In this paper, condensation and evaporation heat transfer coefficients of argon-freon mixed refrigerant are measured in a microchannel heat exchanger. A Printed Circuit Heat Exchanger (PCHE) with 340 ?m hydraulic diameter has been developed as a compact microchannel heat exchanger and utilized in the experiment. Several two-phase heat transfer coefficient correlations are examined to discuss the experimental measurement results. The result of this paper shows that cryogenic two-phase mixed refrigerant heat transfer coefficients can be estimated by conventional two-phase heat transfer coefficient correlations.

  1. Transient response of perforated plate matrix heat exchangers

    Microsoft Academic Search

    P. Ramesh; G. Venkatarathnam

    1998-01-01

    Perforated plate matrix heat exchangers are used in a number of applications such as helium liquefiers, Joule–Thompson cryocoolers operating with pure fluids and mixtures, etc. The time taken for cool down of cryocoolers is very critical in many applications, for example, those used in mobile applications (e.g. missiles). In this paper we study the effect of different parameters on the

  2. Thermodynamical calculation of metal heating in nanosecond exploding wire and foil experiments

    Microsoft Academic Search

    G. S. Sarkisov; S. E. Rosenthal; K. W. Struve

    2007-01-01

    A method of thermodynamical calculation of thin metal wire heating during its electrical explosion is discussed. The technique is based on a calculation of Joule energy deposition taking into account the current wave form and the temperature dependence of the resistivity and heat capacity of the metal. Comparing the calculation to a set of exploding tungsten wire experiments demonstrates good

  3. Heterogeneous nanometer-scale Joule and Peltier effects in sub-25 nm thin phase change memory devices

    NASA Astrophysics Data System (ADS)

    Grosse, Kyle L.; Pop, Eric; King, William P.

    2014-09-01

    We measure heterogeneous power dissipation in phase change memory (PCM) films of 11 and 22 nm thin Ge2Sb2Te5 (GST) by scanning Joule expansion microscopy (SJEM), with sub-50 nm spatial and ˜0.2 K temperature resolution. The heterogeneous Joule and Peltier effects are explained using a finite element analysis (FEA) model with a mixture of hexagonal close-packed and face-centered cubic GST phases. Transfer length method measurements and effective media theory calculations yield the GST resistivity, GST-TiW contact resistivity, and crystal fraction of the GST films at different annealing temperatures. Further comparison of SJEM measurements and FEA modeling also predicts the thermopower of thin GST films. These measurements of nanometer-scale Joule, thermoelectric, and interface effects in PCM films could lead to energy-efficient designs of highly scaled PCM technology.

  4. Local heating-induced plastic deformation in resistive switching devices

    NASA Astrophysics Data System (ADS)

    Jiang, W.; Kamaladasa, R. J.; Lu, Y. M.; Vicari, A.; Berechman, R.; Salvador, P. A.; Bain, J. A.; Picard, Y. N.; Skowronski, M.

    2011-09-01

    Resistive switching is frequently associated with local heating of the switching structure. The mechanical effect of such heating on Pt/SrTiO3 (001) Schottky barriers and on Pt/SrZrO3/SrRuO3/SrTiO3 switching devices was examined. The extent and magnitude of Joule heating was assessed using IR microscopy at power dissipation levels similar to what others have reported during electroforming. Lines aligned along the [100] and [010] directions were observed spreading laterally around the locally heated area imaged by IR. Atomic force microscopy, transmission electron microscopy. and electron channeling contrast imaging suggest these lines are slip lines due to the plastic deformation induced by the local compressive stresses created by Joule heating. The deformation pattern is identical to that produced by nanoindentation. The implications of deformation for resistive switching systems are discussed.

  5. Overview of the ARGOS X-ray framing camera for Laser MegaJoule

    SciTech Connect

    Trosseille, C., E-mail: clement.trosseille@cea.fr; Aubert, D.; Auger, L.; Bazzoli, S.; Brunel, P.; Burillo, M.; Chollet, C.; Jasmin, S.; Maruenda, P.; Moreau, I.; Oudot, G.; Raimbourg, J.; Soullié, G.; Stemmler, P.; Zuber, C. [CEA, DAM, DIF, F-91297 Arpajon (France); Beck, T. [CEA, DEN, CADARACHE, F-13108 St Paul lez Durance (France); Gazave, J. [CEA, DAM, CESTA, F-33116 Le Barp (France)

    2014-11-15

    Commissariat à l’Énergie Atomique et aux Énergies Alternatives has developed the ARGOS X-ray framing camera to perform two-dimensional, high-timing resolution imaging of an imploding target on the French high-power laser facility Laser MegaJoule. The main features of this camera are: a microchannel plate gated X-ray detector, a spring-loaded CCD camera that maintains proximity focus in any orientation, and electronics packages that provide remotely-selectable high-voltages to modify the exposure-time of the camera. These components are integrated into an “air-box” that protects them from the harsh environmental conditions. A miniaturized X-ray generator is also part of the device for in situ self-testing purposes.

  6. Ohmic heating, line tying, and preionization in Hanbit

    Microsoft Academic Search

    J. S. Hong; A. C. England; M. Kwon; J. H. Choi

    2003-01-01

    Initial attempts have been made at Ohmic (Joule) heating, stabilization, and preionization in Hanbit using an electron-emitting hot cathode in conjunction with a reflex discharge. The hot cathode was constructed using a set of LaB6 discs heated internally with current through carbon rods. The cathode was mounted in the cusp section of Hanbit on magnetic field lines connected to the

  7. X-ray characterization of high energy density plasmas produced in mega-joule laser experiments on the National Ignition Facility

    NASA Astrophysics Data System (ADS)

    Glenzer, Siegfried

    2010-03-01

    With completion of the National Ignition Facility (NIF) at the Lawrence Livermore National Laboratory the quest for producing a burning fusion plasma has begun. The goal of these experiments is to compress matter to densities and temperatures higher than the interior of the sun to initiate nuclear fusion and burn of hydrogen isotopes. In the first indirect-drive hohlraum experiments on NIF, we have demonstrated symmetric capsule implosions at unprecedented conditions of mega-joule laser energies. 192 simultaneously fired laser beams heat ignition hohlraums to radiation temperatures of 3.3 million Kelvin compressing 2-millimeter capsules by the soft x rays produced inside the hohlraum. In these experiments, symmetry and velocity of the implosion are measured by imaging the 9 keV capsule x-ray emission on a temporally resolving 2-D detector. In addition, x-ray radiography and scattering techniques are being developed for measuring the density and temperature of the implosion. The experiments indicate conditions suitable for compressing deuterium-tritium filled capsules with the goal to produce burning fusion plasmas in the laboratory.

  8. Experimental investigation on mixed refrigerant Joule–Thomson cryocooler with flammable and non-flammable refrigerant mixtures

    Microsoft Academic Search

    N. S. Walimbe; K. G. Narayankhedkar; M. D. Atrey

    2010-01-01

    The mixed refrigerant Joule–Thomson (MR J–T) cryocoolers have a wide application area covering the temperature range from 80K to 200K. The significant advantages of the system are simplicity of its design and working reliability with high level performance. The present paper discusses the experimental results of MR J–T cooler with different flammable and non-flammable mixture compositions. The work highlights the

  9. Development of a low-noise 10 K J-T (Joule-Thomson) refrigeration system. Technical report (Final)

    Microsoft Academic Search

    1987-01-01

    This report summarizes work done on the development of a low-noise Joule-Thomson, microminiature refrigeration system designed for 10 K operation. Topics discussed include: calculation of phase diagram of mixtures of certain hydrocarbon gases with nitrogen using the Benedict-Webb-Rubin equation of state; the setup of a magnetron-enhanced sputtering system to allow sputtering a layer of adhesive on the glass substrates with

  10. Use of a Joule-Thomson micro-refrigerator to cool a radio-frequency coil for magnetic resonance microscopy

    Microsoft Academic Search

    A. C. Wright; H. K. Song; D. M. Elliott; F. W. Wehrli

    2005-01-01

    A method is described for cryogenically cooling a rf detector coil, as used in high-resolution magnetic resonance imaging (MRI), to enhance image signal-to-noise ratio (SNR). By incorporating the rf coil into a Joule-Thomson micro-refrigerator, the coil is precision-cooled to 70 K using only a source of high-pressure nitrogen gas at room temperature, avoiding the need for liquid cryogens. The rf

  11. Statistical spatio-temporal properties of the Laser MegaJoule speckle

    SciTech Connect

    Le Cain, A.; Sajer, J. M. [CEA, DAM, CESTA, BP 2, F-33114 Le Barp (France); Riazuelo, G. [CEA, DAM, DIF, F-91297 Arpajon (France)

    2012-10-15

    This paper investigates a statistical model to describe the spatial and temporal properties of hot spots generated by the superimposition of multiple laser beams. In the context of the Laser MegaJoule design, we introduce the formula for contrasts, trajectories and velocities of the speckle pattern. Single bundle of four beams, two-cones and three-cones configurations are considered. Statistical properties of the speckle in the zone where all the beams overlap are studied with different configurations of polarizations. These properties are shown to be very different from the case of one single bundle of four beams. The configuration of polarization has only a slight effect in the two-cones or three cones configuration. Indeed, the impact of the double polarization smoothing is reduced in the area in which all the beams overlap, while it is much more significant when they split. Moreover, the size of the hot-spots decreases as the number of laser beams increases, but we show that their velocity decreases. As a matter of fact, the maximal velocity of hot spots is found to be only about 10{sup -5} of the velocity of light and the integrated contrast is about 15% when the beams overlap.

  12. Visco Jet Joule-Thomson Device Characterization Tests in Liquid Methane

    NASA Technical Reports Server (NTRS)

    Jurns, John M.

    2009-01-01

    Joule-Thomson (J-T) devices have been identified as critical components for Thermodynamic Vent Systems (TVS) planned for future space exploration missions. Lee Visco Jets (The Lee Company) (Ref. 4) are one type of J-T device that may be used for LCH4 propellant systems. Visco Jets have been previously tested and characterized in LN2 and LH2 (Refs. 6 and 7), but have not been characterized in LOX or LCH4. Previous Visco Jet tests with LH2 resulted in clogging of the Visco Jet orifice under certain conditions. It has been postulated that this clogging was due to the presence of neon impurities in the LH2 that solidified in the orifices. Visco Jets therefore require testing in LCH4 to verify that they will not clog under normal operating conditions. This report describes a series of tests that were performed at the NASA Glenn Research Center to determine if Visco Jets would clog under normal operating conditions with LCH4 propellant. Test results from this program indicate that no decrease in flow rate was observed for the Visco Jets tested, and that current equation used for predicting flow rate appears to under-predict actual flow at high Lohm ratings.

  13. Investigation of pressure drop in capillary tube for mixed refrigerant Joule-Thomson cryocooler

    NASA Astrophysics Data System (ADS)

    Ardhapurkar, P. M.; Sridharan, Arunkumar; Atrey, M. D.

    2014-01-01

    A capillary tube is commonly used in small capacity refrigeration and air-conditioning systems. It is also a preferred expansion device in mixed refrigerant Joule-Thomson (MR J-T) cryocoolers, since it is inexpensive and simple in configuration. However, the flow inside a capillary tube is complex, since flashing process that occurs in case of refrigeration and air-conditioning systems is metastable. A mixture of refrigerants such as nitrogen, methane, ethane, propane and iso-butane expands below its inversion temperature in the capillary tube of MR J-T cryocooler and reaches cryogenic temperature. The mass flow rate of refrigerant mixture circulating through capillary tube depends on the pressure difference across it. There are many empirical correlations which predict pressure drop across the capillary tube. However, they have not been tested for refrigerant mixtures and for operating conditions of the cryocooler. The present paper assesses the existing empirical correlations for predicting overall pressure drop across the capillary tube for the MR J-T cryocooler. The empirical correlations refer to homogeneous as well as separated flow models. Experiments are carried out to measure the overall pressure drop across the capillary tube for the cooler. Three different compositions of refrigerant mixture are used to study the pressure drop variations. The predicted overall pressure drop across the capillary tube is compared with the experimentally obtained value. The predictions obtained using homogeneous model show better match with the experimental results compared to separated flow models.

  14. Multilayer cloud monitoring by micro-Joule lidar based on photon counting receiver and diode laser

    NASA Astrophysics Data System (ADS)

    Pershin, S. M.; Lyash, A. N.; Makarov, V. S.; Hamal, K.; Prochazka, I.; Sopko, B.

    2009-05-01

    Multilayers clouds layer's horizons have been detected in strong snowing condition by using the micro-Joule eye-safe lidar. Lidar is based on the 1 ?J (30 ns length) pulsed diode laser, which operates with high repetition rate (up to 10 kHz) and silica (Si) photon counting receiver (Single Photon Avalanche Diode, SPAD) from Czech Technical University. Note that the unique low avalanche voltage of Czech SPAD (~ 26-28 Volts), low power consumption (~ 0.2 Watts), the wide (-100 to 20 °C) temperature operation and low weight (~ 0.94 kg) were the main arguments to involve this lidar version into the NASA Mars Polar Lander mission a decade ago in 1999. The Geiger (photon counting) mode of SPAD operation and laser high repetition rate allow us to apply the specifically statistical approach to the development of the remote sensing return, which is scattered by aerosol and other inhomogeneous along the sounding trace. To get of reliable signal-to-noise ratio (SNR) we have to use a few hundred or thousand laser pulses because the probability of the photon scattered by sounding object is smaller than unit. As a role a Poison statistics is used to development of the remote sensing return.

  15. Turbulent resistive heating of solar coronal arches

    NASA Technical Reports Server (NTRS)

    Benford, G.

    1983-01-01

    The possibility that coronal heating occurs by means of anomalous Joule heating by electrostatic ion cyclotron waves is examined, with consideration given to currents running from foot of a loop to the other. It is assumed that self-fields generated by the currents are absent and currents follow the direction of the magnetic field, allowing the plasma cylinder to expand radially. Ion and electron heating rates are defined within the cylinder, together with longitudinal conduction and convection, radiation and cross-field transport, all in terms of Coulomb and turbulent effects. The dominant force is identified as electrostatic ion cyclotron instability, while ion acoustic modes remain stable. Rapid heating from an initial temperature of 10 eV to 100-1000 eV levels is calculated, with plasma reaching and maintaining a temperature in the 100 eV range. Strong heating is also possible according to the turbulent Ohm's law and by resistive heating.

  16. An experimental, theoretical and numerical investigation of corona wind heat transfer enhancement

    E-print Network

    Owsenek, Brian Leonard

    1993-01-01

    as 70 W/m2K are reported. Joule heating of the air is measured, and found to generate a temperature increases of up to 3'C. The optimum needle and wire heights are found, and the trends in wire-plate performance are examined. A numerical procedure...

  17. Physical Properties of AU and AL Thin Films Measured by Resistive Heating

    Microsoft Academic Search

    F. Avilés; O. Ceh; A. I. Oliva

    2005-01-01

    The electrical resistivity (rho), resistive thermal coefficient (alphar), thermal expansion coefficient (alphat) and stress (sigma) of Al and Au thin films deposited by thermal evaporation were measured while films were heated by Joule effect. Electrical resistivity measured by the four-probe technique was simultaneously measured with surface film temperature in real time. Au films show important variations in the alphar and

  18. FY 2009 Annual Report of Joule Software Metric SC GG 3.1/2.5.2, Improve Computational Science Capabilities

    SciTech Connect

    Kothe, Douglas B [ORNL; Roche, Kenneth J [ORNL; Kendall, Ricky A [ORNL

    2010-01-01

    The Joule Software Metric for Computational Effectiveness is established by Public Authorizations PL 95-91, Department of Energy Organization Act, and PL 103-62, Government Performance and Results Act. The U.S. Office of Management and Budget (OMB) oversees the preparation and administration of the President s budget; evaluates the effectiveness of agency programs, policies, and procedures; assesses competing funding demands across agencies; and sets the funding priorities for the federal government. The OMB has the power of audit and exercises this right annually for each federal agency. According to the Government Performance and Results Act of 1993 (GPRA), federal agencies are required to develop three planning and performance documents: 1.Strategic Plan: a broad, 3 year outlook; 2.Annual Performance Plan: a focused, 1 year outlook of annual goals and objectives that is reflected in the annual budget request (What results can the agency deliver as part of its public funding?); and 3.Performance and Accountability Report: an annual report that details the previous fiscal year performance (What results did the agency produce in return for its public funding?). OMB uses its Performance Assessment Rating Tool (PART) to perform evaluations. PART has seven worksheets for seven types of agency functions. The function of Research and Development (R&D) programs is included. R&D programs are assessed on the following criteria: Does the R&D program perform a clear role? Has the program set valid long term and annual goals? Is the program well managed? Is the program achieving the results set forth in its GPRA documents? In Fiscal Year (FY) 2003, the Department of Energy Office of Science (DOE SC-1) worked directly with OMB to come to a consensus on an appropriate set of performance measures consistent with PART requirements. The scientific performance expectations of these requirements reach the scope of work conducted at the DOE national laboratories. The Joule system emerged from this interaction. Joule enables the chief financial officer and senior DOE management to track annual performance on a quarterly basis. Joule scores are reported as success, goal met (green light in PART), mixed results, goal partially met (yellow light in PART), and unsatisfactory, goal not met (red light in PART). Joule links the DOE strategic plan to the underlying base program targets.

  19. Conceptual design of a joule-heated ceramic melter for the DOE Fernald silos 1, 2, and 3 wastes

    Microsoft Academic Search

    R. A. Robinson; D. S. Janke; R. Peters; L. Fekete

    1992-01-01

    Vitrification of nuclear wastes has been under investigation since the mid-1950s. Most of the international communities experience has been with vitrification of high level nuclear wastes. In the US, this technology was developed by Battelle scientists at the DOEs Pacific Northwest Laboratories located at their Hanford site. Based on Laboratory and pilot-scale testing conducted at Hanford in the early 1970s,

  20. Vitrification of high-level radioactive waste in a small-scale joule-heated ceramic melter

    Microsoft Academic Search

    M. J. Plodinec; G. B. Woolsey

    1981-01-01

    Direct feeding of actual liquid-waste slurries to the small melter is discussed. The liquid-feeding tests demonstrated that addition of premelted glass frit to the waste slurry reduces the amount of material volatilized. Results of these tests are in accord with results of large-scale tests with actual waste.

  1. Development of glasses for the vitrification of high level liquid waste (HLLW) in a joule heated ceramic melter

    Microsoft Academic Search

    B. Luckscheiter; M. Nesovic

    1996-01-01

    A vitrification process was developed at Forschungszentrum Karlsruhe, Institut für Nukleare Entsorgungstechnik (INE), for solidifying in borosilicate glasses High Level Waste (HLW) solutions from the nuclear fuel cycle. To optimise melter operation the glass melt should have a flat viscosity curve and a relatively high specific electrical resistance of ?6.5 ?·cm at 1150°C. Further requirements are: no liquid-liquid immiscibility and

  2. Industrial operation of Joule heated ceramic melters Type EP500 and Pamela for vitrification of high radiaoctive waste

    Microsoft Academic Search

    A. S. Polyakov; A. P. Suslov; V. I. Osnovin

    1993-01-01

    During the operation of a nuclear reactor radioactive fission products are formed. In the reprocessing process most of this radioactive inventory ends up as high-level liquid waste (HLLW), steel tanks being used for interim storage. Certainty, tank storage is not a long-term solution for isolating these wastes from the biosphere. There is, therefore, a demand for producing solid waste packages

  3. Vitrification of high-level radioactive waste in a small-scale joule-heated ceramic melter

    NASA Astrophysics Data System (ADS)

    Plodinec, M. J.; Woolsey, G. B.

    1981-11-01

    Direct feeding of actual liquid-waste slurries to the small melter is discussed. The liquid-feeding tests demonstrated that addition of premelted glass frit to the waste slurry reduces the amount of material volatilized. Results of these tests are in accord with results of large-scale tests with actual waste.

  4. Experimental and numerical investigation into the joule heating effect for electrokinetically driven microfluidic chips utilizing total internal reflection fluorescence microscopy

    Microsoft Academic Search

    Lung-Ming Fu; Jing-Hui Wang; Wen-Bo Luo; Che-Hsin Lin

    2009-01-01

    This paper presents a detection scheme for analyzing the temperature distribution nearby the channel wall in a microfluidic\\u000a chip utilizing a temperature-dependent fluorescence dye. An advanced optical microscope system—total internal reflection fluorescence\\u000a microscope (TIRFM) is used for measuring the temperature distribution on the channel wall at the point of electroosmotic flow\\u000a in an electrokinetically driven microfluidic chip. In order to

  5. High-resolution spatial mapping of the temperature distribution of a Joule self-heated graphene nanoribbon

    E-print Network

    Heinz, Tony F.

    nanoribbon Young-Jun Yu, Melinda Y. Han, Stéphane Berciaud, Alexandru B. Georgescu, Tony F. Heinz et al Chaos 22, 033149 (2012) Investigating and understanding fouling in a planar setup using ultrasonic information on Appl. Phys. Lett. Journal Homepage: http://apl.aip.org/ Journal Information: http://apl.aip.org/about/about_the_journal

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

    Microsoft Academic Search

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

    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

  7. Dimensional Analysis of Thermoelectric Modules Under Constant Heat Flux

    NASA Astrophysics Data System (ADS)

    Suzuki, Ryosuke O.; Fujisaka, Takeyuki; Ito, Keita O.; Meng, Xiangning; Sui, Hong-Tao

    2015-01-01

    Thermoelectric power generation is examined in the case of radiative heating. A constant heat flux is assumed in addition to consideration of the Seebeck effect, Peltier effect, and Joule heating with temperature-dependent material properties. Numerical evaluations are conducted using a combination of the finite-volume method and an original simultaneous solver for the heat transfer, thermoelectric, and electric transportation phenomena. Comparison with experimental results shows that the new solver could work well in the numerical calculations. The calculations predict that the Seebeck effect becomes larger for longer thermoelectric elements because of the larger temperature difference. The heat transfer to the cold surface is critical to determine the junction temperatures under a constant heat flux from the hot surface. The negative contribution from Peltier cooling and heating can be minimized when the current is smaller for longer elements. Therefore, a thicker TE module can generate more electric power even under a constant heat flux.

  8. Variation of TMA Optical Spectra With Altitude as Observed During the JOULE-2 and HEX-2 Rocket Experiments

    NASA Astrophysics Data System (ADS)

    Hampton, D. L.; Conde, M.; Craven, J. D.

    2007-12-01

    During the JOULE-2 and HEX-2 rocket experiments a total of 7 rockets releasing tri-methyl aluminum (TMA) were launched from the Poker Flat Research Range. Four of the TMA trails were observed with a video imaging spectrograph located at Poker Flat: two during the JOULE-2 experiment in the 400 to 650 nm wavelength range, and two during the HEX-2 experiment in the 615 nm to 890 nm wavelength range. The spectrograph has an angular extent of about 10 degrees along the slit and a spectral resolution of 8 nm. The spectra show that the TMA emissions comprise a broadband continuum, with no significant narrowband emission or molecular band structure apparent. When spectra are compared for TMA released at different altitudes, the continuum shows no difference between 400 nm and 600 nm. However, at wavelengths longer than 650 nm, spectra from 100 km altitude show 20 to 40% greater intensity than spectra from 90 km, when normalized at 615 nm. Proposed mechanisms for photon production in TMA generally invoke a catalytic cycle of chemiluminescence reactions between AlO and O, O2, and in some cases OH and H2O. We report the quantitative variation in spectrum with altitude for TMA in these two releases, ongoing work to use (rarely calibrated) literature data on AlO chemiluminescent reactions to determine the most likely mechanism for photon production in TMA releases, and speculate on whether the spectrum of a TMA release can help reveal geophysical information in the upper atmosphere.

  9. Technology, applications and modelling of ohmic heating: a review.

    PubMed

    Varghese, K Shiby; Pandey, M C; Radhakrishna, K; Bawa, A S

    2014-10-01

    Ohmic heating or Joule heating has immense potential for achieving rapid and uniform heating in foods, providing microbiologically safe and high quality foods. This review discusses the technology behind ohmic heating, the current applications and thermal modeling of the process. The success of ohmic heating depends on the rate of heat generation in the system, the electrical conductivity of the food, electrical field strength, residence time and the method by which the food flows through the system. Ohmic heating is appropriate for processing of particulate and protein rich foods. A vast amount of work is still necessary to understand food properties in order to refine system design and maximize performance of this technology in the field of packaged foods and space food product development. Various economic studies will also play an important role in understanding the overall cost and viability of commercial application of this technology in food processing. Some of the demerits of the technology are also discussed. PMID:25328171

  10. Instability Heating of the HDZP

    NASA Astrophysics Data System (ADS)

    Lovberg, R. H.; Riley, R. A.; Shlachter, J. S.

    1994-03-01

    We present a model of dense Z-Pinch heating. For pinches of sufficiently small diameter and high current, direct ion heating by m = 0 instabilities becomes the principal channel for power input. This process is particularly important in the present generation of dense micro-pinches (e.g., HDZP-II) where instability growth times are much smaller than current risetimes, and a typical pinch diameter is several orders smaller than that of the chamber. Under these conditions, m = 0 formation is not disruptive: the large Ez field reconnects the instability cusps externally, after which the ingested magnetic flux decays into turbulent kinetic energy of the plasma. The continuous process is analogous to boiling of a heated fluid. A simple analysis shows that an equivalent resistance Rt = l/4?NMi (?0/?)3/2 I/r appears in the driving circuit, where I is the pinch current, N is the line density, l is the pinch length, mi is the ion mass, and r is the pinch radius. A corresponding heating term has been added to the ion energy equation in a 0-D, self-similar simulation, which had been written previously to estimate fusion yields and radial expansion of D2 fiber pinches. The simulation results agree well with the experimental results from HDZP-II, where the assumption of only joule heating produced gross disagreement. Turbulent ion heating should be the dominant process in any simple pinch carrying meg-ampere current and having submillimeter radius.

  11. Ionospheric heating with oblique HF waves

    SciTech Connect

    Field, E.C.; Bloom, R.M.

    1990-10-01

    This paper presents calculations of ionospheric electron density perturbations and ground-level signal changes produced by intense oblique high-frequency (HF) transmitters. Our analysis takes into account radio field focusing at caustics, the consequent joule-heating of the surrounding plasma, heat conduction, diffusion, and recombination processes--these being the effects of a powerful oblique modifying, wave. It neglects whatever plasma instabilities might occur. We then seek effects on a secondary 'test wave that is propagated along the same path as the first. Our calculations predict ground-level field-strength reductions of several dB in the test wave for modifying waves having ERP in the 85-to-90 dBW range. These field-strength changes are similar in sign, magnitude, and location to ones measured in Soviet experiments. Our results are sensitive to the the model ionosphere assumed, so future experiments should employ the widest possible range of frequencies and propagation conditions. An effective power of 90 dBW seems to be a sort of threshold that, if exceeded, results in substantial rather than small signal changes. Our conclusions are based solely on joule-heating and subsequent defocusing of waves passing through caustic regions.

  12. Empirically corrected HEAT method for calculating atomization energies

    SciTech Connect

    Brand, Holmann V [Los Alamos National Laboratory

    2008-01-01

    We describe how to increase the accuracy ofthe most recent variants ofthe HEAT method for calculating atomization energies of molecules by means ofextremely simple empirical corrections that depend on stoichiometry and the number ofunpaired electrons in the molecule. Our corrections reduce the deviation from experiment for all the HEAT variants. In particular, our corrections reduce the average absolute deviation and the root-mean-square deviation ofthe 456-QP variant to 0.18 and 0.23 kJoule/mol (i.e., 0.04 and 0.05 kcallmol), respectively.

  13. Experimental investigation on mixed refrigerant Joule-Thomson cryocooler with flammable and non-flammable refrigerant mixtures

    NASA Astrophysics Data System (ADS)

    Walimbe, N. S.; Narayankhedkar, K. G.; Atrey, M. D.

    2010-10-01

    The mixed refrigerant Joule-Thomson (MR J-T) cryocoolers have a wide application area covering the temperature range from 80 K to 200 K. The significant advantages of the system are simplicity of its design and working reliability with high level performance. The present paper discusses the experimental results of MR J-T cooler with different flammable and non-flammable mixture compositions. The work highlights the use of pressure-enthalpy and temperature-enthalpy diagrams for these mixtures to support the experimental results. A record lowest temperature of 65 K and a cooling capacity of 6 W at 80 K are obtained for a single stage MR J-T system starting at 300 K. Further, using a mixture of minimum flammable refrigerants, temperatures below 100 K is achieved.

  14. Use of a Joule-Thomson micro-refrigerator to cool a radio-frequency coil for magnetic resonance microscopy

    NASA Astrophysics Data System (ADS)

    Wright, A. C.; Song, H. K.; Elliott, D. M.; Wehrli, F. W.

    2005-01-01

    A method is described for cryogenically cooling a rf detector coil, as used in high-resolution magnetic resonance imaging (MRI), to enhance image signal-to-noise ratio (SNR). By incorporating the rf coil into a Joule-Thomson micro-refrigerator, the coil is precision-cooled to 70K using only a source of high-pressure nitrogen gas at room temperature, avoiding the need for liquid cryogens. The rf coil is insulated by a glass vacuum dewar that permits its use in proximity to biological tissues. Design and operation of the cryogenic system are described and its performance is demonstrated in a 1.5T clinical MRI scanner with images of a water phantom and a sheep intervertebral disc specimen. SNR gains of two to three times were obtained, compared to a similar coil at room temperature. The potential of this technology for local high-resolution MRI is discussed.

  15. Aerothermal Heating Predictions for Mars Microprobe

    NASA Technical Reports Server (NTRS)

    Mitcheltree, R. A.; DiFulvio, M.; Horvath, T. J.; Braun, R. D.

    1998-01-01

    A combination of computational predictions and experimental measurements of the aerothermal heating expected on the two Mars Microprobes during their entry to Mars are presented. The maximum, non-ablating, heating rate at the vehicle's stagnation point (at alpha = 0 degrees) is predicted for an undershoot trajectory to be 194 Watts per square centimeters with associated stagnation point pressure of 0.064 atm. Maximum stagnation point pressure occurs later during the undershoot trajectory and is 0.094 atm. From computations at seven overshoot-trajectory points, the maximum heat load expected at the stagnation point is near 8800 Joules per square centimeter. Heat rates and heat loads on the vehicle's afterbody are much lower than the forebody. At zero degree angle-of-attack, heating over much of the hemi-spherical afterbody is predicted to be less than 2 percent of the stagnation point value. Good qualitative agreement is demonstrated for forebody and afterbody heating between CFD calculations at Mars entry conditions and experimental thermographic phosphor measurements from the Langley 20-Inch Mach 6 Air Tunnel. A novel approach which incorporates six degree-of-freedom trajectory simulations to perform a statistical estimate of the effect of angle-of-attack, and other off-nominal conditions, on heating is included.

  16. Plate Fin Heat Exchanger Model with Axial Conduction and Variable Properties

    Microsoft Academic Search

    B. J. Hansen; M. J. White; A. Klebaner

    2011-01-01

    Future superconducting radio frequency (SRF) cavities, as part of Project X at Fermilab, will be cooled to superfluid helium temperatures by a cryogenic distribution system supplying cold supercritical helium. To reduce vapor fraction during the final Joule-Thomson (J-T) expansion into the superfluid helium cooling bath, counter-flow, plate-fin heat exchangers will be utilized. Due to their compact size and ease of

  17. Assessment of Zr–V–Fe getter alloy for gas-gap heat switches

    Microsoft Academic Search

    M Prina; J. G Kulleck; R. C Bowman

    2002-01-01

    A commercial Zr–V–Fe alloy (i.e. SAES Getters trade name alloy St-172) has been assessed as reversible hydrogen storage material for use in actuators of gas-gap heat switches. For applications involving hydride compressors in closed-cycle Joule–Thomson sorption cryocoolers, the actuator need to produce a conducting (i.e. ON) state pressure above 670 Pa and an insulating (i.e. OFF) state pressure below 0.13

  18. New flow boiling heat transfer model for hydrocarbons evaporating inside horizontal tubes

    SciTech Connect

    Chen, G. F.; Gong, M. Q.; Wu, J. F.; Zou, X. [Key Laboratory of Cryogenics, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, P.O. Box 2711, 35, Beijing, 100190 (China); Wang, S. [Key Laboratory of Cryogenics, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, P.O. Box 2711, 35, Beijing, 100190 (China); University of Chinese Academy of Science, No. 19 YuQuan Road, Beijing, 100049 (China)

    2014-01-29

    Hydrocarbons have high thermodynamic performances, belong to the group of natural refrigerants, and they are the main components in mixture Joule-Thomson low temperature refrigerators (MJTR). New evaluations of nucleate boiling contribution and nucleate boiling suppression factor in flow boiling heat transfer have been proposed for hydrocarbons. A forced convection heat transfer enhancement factor correlation incorporating liquid velocity has also been proposed. In addition, the comparisons of the new model and other classic models were made to evaluate its accuracy in heat transfer prediction.

  19. Numerical Studies of Fluid Leakage from a Geologic DisposalReservoir for CO2 Show Self-Limiting Feedback between Fluid Flow and HeatTransfer

    SciTech Connect

    Pruess, Karsten

    2005-03-22

    Leakage of CO2 from a hypothetical geologic storage reservoir along an idealized fault zone has been simulated, including transitions between supercritical, liquid, and gaseous CO2. We find strong non-isothermal effects due to boiling and Joule-Thomson cooling of expanding CO2. Leakage fluxes are limited by limitations in conductive heat transfer to the fault zone. The interplay between multiphase flow and heat transfer effects produces non-monotonic leakage behavior.

  20. Analytical Models for Flowing-Fluid Temperature Distribution in Single-Phase Oil Reservoirs Accounting for Joule-Thomson Effect 

    E-print Network

    Chevarunotai, Natasha

    2014-11-13

    temperature alteration in the reservoir. In this study, we developed a robust analytical model to estimate the flowing-fluid-temperature distribution in the reservoir accounting for J-T heating or cooling effect. All significant heat-transfer mechanisms...

  1. Heating with waste heat

    SciTech Connect

    Beabout, R.W.

    1986-09-02

    Most of the power consumed in the gaseous diffusion process is converted into heat of compression, which is removed from the process gas and rejected into the atmosphere by recirculating cooling water over cooling towers. The water being handled through the X-333 and X-330 Process Buildings can be heated to 140 to 150/sup 0/F for heating use. The Gas Centrifuge Enrichment Plant is provided with a recirculating heating water (RHW) system which uses X-330 water and wasted heat. The RHW flow is diagrammed. (DLC)

  2. Plate Fin Heat Exchanger Model with Axial Conduction and Variable Properties

    E-print Network

    Hansen, B J; Klebaner, A; 10.1063/1.4706971

    2012-01-01

    Future superconducting radio frequency (SRF) cavities, as part of Project X at Fermilab, will be cooled to superfluid helium temperatures by a cryogenic distribution system supplying cold supercritical helium. To reduce vapor fraction during the final Joule-Thomson (J-T) expansion into the superfluid helium cooling bath, counter-flow, plate-fin heat exchangers will be utilized. Due to their compact size and ease of fabrication, plate-fin heat exchangers are an effective option. However, the design of compact and high-effectiveness cryogenic heat exchangers operating at liquid helium temperatures requires consideration of axial heat conduction along the direction of flow, in addition to variable fluid properties. Here we present a numerical model that includes the effects of axial conduction and variable properties for a plate fin heat exchanger. The model is used to guide design decisions on heat exchanger material choice and geometry. In addition, the J-T expansion process is modeled with the heat exchanger ...

  3. Numerical Examination of the Performance of a Thermoelectric Cooler with Peltier Heating and Cooling

    NASA Astrophysics Data System (ADS)

    Kim, Chang Nyung; Kim, Jeongho

    2015-05-01

    There has recently been much progress in the development of materials with higher thermoelectric performance, leading to the design of thermoelectric devices for generation of electricity and for heating or cooling. Local heating can be achieved by current flow through an electric resistance, and local heating and cooling can be performed by Peltier heating and cooling. In this study, we developed computer software that can be used to predict the Seebeck and Peltier effects for thermoelectric devices. The temperature, electric potential, heat flow, electric current, and coefficient of performance were determined, with the objective of investigating the Peltier effect in a thermoelectric device. In addition to Peltier heating and cooling, Joule and Thomson heating were quantitatively evaluated for the thermoelectric device.

  4. Vitrification of intermediate level radioactive waste by induction heating

    SciTech Connect

    Sobolev, I.A.; Dmitriyev, S.A.; Lifanov, F.A.; Stefanovsky, S.V.; Kobelev, A.P.; Kornev, V.I.; Knyazev, O.A.; Tsveshko, O.N. [SIA Radon, Moscow (Russian Federation)

    1995-12-31

    Vitrification of intermediate level liquid and solid radioactive wastes is an effective method of their immobilization. A new type of melter -- cold crucible -- suitable for production of high fusible materials has been developed. No refractories and internal electrodes are used in this melter. Based on the preliminary experience of SIA Radon with lab-scale and pilot plants, the full-scale plants for vitrification of liquid and solid radioactive wastes have been constructed. The main process variables such as melt capacity, melting ratio, cesium volatilization as well as materials properties have been determined. Advantages of cold crucible over Joule heated ceramic melter have been shown. Process flow sheets have been described.

  5. Ionospheric heating with oblique high-frequency waves

    SciTech Connect

    Field, E.C. Jr.; Bloom, R.M. (Pacific-Sierra Research Corp., Los Angeles, CA (USA)); Kossey, P.A. (Air Force Geophysical Lab., Bedford, MA (USA))

    1990-12-01

    This paper presents calculations of ionospheric electron temperature and density perturbations and ground-level signal changes produced by intense oblique high-frequency (HF) radio waves. The analysis takes into account focusing at caustics, the consequent Joule heating of the surrounding plasma, heat conduction, diffusion, and recombination processes, these being the effects of a powerful oblique modifying wave. It neglects whatever plasma instabilities might occur. The authors then seek effects on a secondary test wave that is propagated along the same path as the first. The calculations predict ground-level field strength reductions of several decibels in the test wave for modifying waves having effective radiated power (ERP) in the 85- to 90-dBW range. These field strength changes are similar in sign, magnitude, and location to ones measured in Soviet experiments. The location of the signal change is sensitive to the frequency and the model ionosphere assumed; so future experiments should employ the widest possible range of frequencies and propagation conditions. An ERP of 90 dBW seems to be a sort of threshold that, if exceeded, might result in substantial rather than small signal changes. The conclusions are based solely on Joule heating and subsequent refraction of waves passing through caustic regions.

  6. Experimental study of a mixed refrigerant Joule-Thomson cryocooler using a commercial air-conditioning scroll compressor

    NASA Astrophysics Data System (ADS)

    Lee, Jisung; Lee, Kyungsoo; Jeong, Sangkwon

    2013-05-01

    Mixed refrigerant Joule-Thomson (MR J-T) cryocoolers have been used to create cryogenic temperatures and are simple, efficient, cheap, and durable. However, compressors for MR J-T cryocoolers still require optimization. As the MR J-T cryocooler uses a commercial scroll compressor developed for air-conditioning systems, compressor overheating due to the use of less optimized refrigerants may not be negligible, and could cause compressor malfunction due to burn-out of scroll tip seals. Therefore, in the present study, the authors propose procedures to optimize compressor operation to avoid the overheating issue when the MR J-T cryocooler is used with a commercial oil lubricated scroll compressor, and the present experimental results obtained for a MR J-T cryocooler. A single stage 1.49 kW (2 HP) scroll compressor designed for R22 utilizing a mixture of nitrogen and hydrocarbons was used in the present study. As was expected, compressor overheating and irreversible high temperatures at a compressor discharge port were found at the beginning of compressor operation, which is critical, and hence, the authors used a water injection cooling system for the compressor to alleviate temperature overshooting. In addition, a portion of refrigerant in the high-pressure stream was by-passed into the compressor suction port. This allowed an adequate compression ratio, prevented excessive temperature increases at the compressor discharge, and eventually enabled the MR J-T cryocooler to operate stably at 121 K. The study shows that commercial oil lubricated scroll compressors can be used for MR J-T cryocooling systems if care is exercised to avoid compressor overheating.

  7. Localized heating and thermal characterization of high electrical resistivity silicon-on-insulator sensors using nematic liquid crystals

    NASA Astrophysics Data System (ADS)

    Elibol, Oguz H.; Reddy, Bobby; Bashir, Rashid

    2008-09-01

    We present a method for localized heating of media at the surface of silicon-on-insulator field-effect sensors via application of an ac voltage across the channel and the substrate and compare this technique with standard Joule heating via the application of dc voltage across the source and drain. Using liquid crystals as the medium to enable direct temperature characterization, our results show that under comparable bias conditions, heating of the medium using an alternating field results in a greater increase in temperature with a higher spatial resolution. These features are very attractive as devices are scaled to the nanoscale dimensions.

  8. Hydrogen evolution in nickel-water heat pipes.

    NASA Technical Reports Server (NTRS)

    Anderson, W. T.

    1973-01-01

    A study was made of the evolution of hydrogen gas in nickel-water heat pipes for the purpose of investigating methods of accelerated life testing. The data were analyzed in terms of a phenomenological corrosion model of heat pipe degradation which incorporates corrosion and oxidation theory and contains parameters which can be determined by experiment. The gas was evolved with a linear time dependence and an exponential temperature dependence with an activation energy of 1.03 x 10 to the minus 19th joules. A flow-rate dependence of the gas evolution was found in the form of a threshold. The results were used to predict usable lifetimes of heat pipes operated at normal operating conditions from results taken under accelerated operating conditions.

  9. Multi-meter fiber-delivery and pulse self-compression of milli-Joule femtosecond laser and fiber-aided laser-micromachining.

    PubMed

    Debord, B; Alharbi, M; Vincetti, L; Husakou, A; Fourcade-Dutin, C; Hoenninger, C; Mottay, E; Gérôme, F; Benabid, F

    2014-05-01

    We report on damage-free fiber-guidance of milli-Joule energy-level and 600-femtosecond laser pulses into hypocycloid core-contour Kagome hollow-core photonic crystal fibers. Up to 10 meter-long fibers were used to successfully deliver Yb-laser pulses in robustly single-mode fashion. Different pulse propagation regimes were demonstrated by simply changing the fiber dispersion and gas. Self-compression to ~50 fs, and intensity-level nearing petawatt/cm(2) were achieved. Finally, free focusing-optics laser-micromachining was also demonstrated on different materials. PMID:24921775

  10. Characterization of off-gases from a small-scale, joule-heated ceramic melter for nuclear waste vitrification. [Ru, Cl, F, ¹³⁷Cs

    Microsoft Academic Search

    G. B. Woolsey; E. L. Wilhite

    1980-01-01

    This paper confirmed with actual nuclear waste the thermodynamic predictions of the fate of some of the semivolatiles in off-gas. Ruthenium behaves erratically and it is postulated that it migrates as a finely divided solid, rather than as a volatile oxide. Provisions for handling these waste off-gasses will be incorporated in the design of facilities for vitrifying SRP waste.

  11. Joule-Heated Ceramic-Lined Melter to Vitrify Liquid Radioactive Wastes Containing Am241 Generated From MOX Fuel Fabrication in Russia

    Microsoft Academic Search

    E C Smith; B W Bowan II; I Pegg; L J Jardine

    2004-01-01

    The governments of the United Stated of America and the Russian Federation (RF) signed an Agreement September 1, 2000 to dispose of weapons plutonium that has been designated as no longer required for defense purposes. The Agreement declares that each country will disposition 34MT of excess weapons grade plutonium from their stockpiles. The preferred disposition technology is the fabrication of

  12. Use of Optical and Imaging Techniques for Inspection of Off-Line Joule-Heated Melter at the West Valley Demonstration Project

    SciTech Connect

    Plodinec, M. J.; Jang, P-R; Long, Z.; Monts, D. L.; Philip, T.; Su, Y.

    2003-02-25

    The West Valley melter has been taken out of service. Its design is the direct ancestor of the current melter design for the Hanford Waste Treatment Plant. Over its eight years of service, the West Valley melter has endured many of the same challenges that the Hanford melter will encounter with feeds that are similar to many of the Hanford double shell tank wastes. Thus, inspection of the West Valley melter prior to its disposal could provide valuable--even crucial--information to the designers of the melters to be used at the Hanford Site, particularly if quantitative information can be obtained. The objective of Mississippi State University's Diagnostic Instrumentation and Analysis Laboratory's (DIAL) efforts is to develop, fabricate, and deploy inspection tools for the West Valley melter that will (i) be remotely operable in the West Valley process cell; (ii) provide quantitative information on melter refractory wear and deposits on the refractory; and (iii) indicate areas of heterogeneity (e.g., deposits) requiring more detailed characterization. A collaborative arrangement has been established with the West Valley Demonstration Project (WVDP) to inspect their melter.

  13. Optical cell with periodic resistive heating for the measurement of heat, mass, and thermal diffusions in liquid mixtures

    SciTech Connect

    Hartung, M.; Koehler, W. [Physikalisches Institut, Universitaet Bayreuth, D-95440 Bayreuth (Germany)

    2007-08-15

    A new technique for the measurement of heat, mass, and thermal diffusions in liquids has been developed. Similar to laser induced dynamic gratings, a temperature grating is created in the sample. Thermal expansion transforms the temperature into a refractive-index grating, which is read by diffraction of a readout laser beam. In a multicomponent mixture an additional concentration grating is formed by thermal diffusion driven by the temperature gradients of the temperature grating. Differently to laser induced dynamic grating experiments we use Joule heating instead of optical heating. For that purpose we have built cuvettes which have a grating of transparent conducting strips on the inner side of one of their windows. If heated by an electric current a temperature grating will build up in the sample. Both the heat equation and the extended diffusion equation have been solved in two dimensions to allow for quantitative data analysis. Our apparatus and method of analysis have been validated by measurements of heat, mass, and thermal diffusions in pure and binary liquids. Heat diffusion can be correctly determined as was shown for pure toluene, pure dodecane, and the symmetric mixture of isobutylbenzene dodecane. Mass and thermal diffusions were studied in the three symmetric mixtures of dodecane, isobutylbenzene, and tetralin. The obtained diffusion and Soret coefficients agree with the literature values within the experimental errors. Uncompensated transient heating effects limit the resolution of the experimental technique.

  14. Heat Pipes

    ERIC Educational Resources Information Center

    Lewis, J.

    1975-01-01

    Describes the construction, function, and applications of heat pipes. Suggests using the heat pipe to teach principles related to heat transfer and gives sources for obtaining instructional kits for this purpose. (GS)

  15. Coronal heating

    NASA Technical Reports Server (NTRS)

    Wentzel, D. G.

    1981-01-01

    Theoretical arguments for coronal heating that take into account coronal structure are reviewed. Heating by the dissipation of electrical currents and heating by dissipation of waves are discussed. Loop structures in the solar corona are described.

  16. Heat pumps

    Microsoft Academic Search

    Heap

    1983-01-01

    An updated version of the 1979 first edition of this work for designers, specifiers, suppliers, installers, and users of heat pumps. Its aim is to assist in the reassessment of energy costs and cost relativities of the various applications of heat pumps. It presents the development of the heat pump markets, research into advanced heat pump systems, and development of

  17. Heat loss through connecting thermistor wires in a three-body graphite calorimeter

    NASA Astrophysics Data System (ADS)

    Radu, D.; Guerra, A. S.; Ionita, C.; Astefanoaei, I.

    2010-06-01

    The main aim of this paper is to calculate the small but significant amount of heat lost from a graphite calorimeter absorber through connecting thermistor wires during electrical calibration. Taking into account the electro-thermal interaction between the heating thermistor and its surrounding environment, a more realistic approach to the problem was developed and estimative numerical results were obtained. It was found that the wires contribute about 0.01% in extracting heat from the calorimeter core (which corresponds to a correction factor kwcore = 0.9999). The total correction factor for heat loss through the connecting thermistor wires during the electrical calibration of the calorimeter (the total combined effect of the heater and the sensor leads due to conduction, radiation and Joule effect) was determined: kw = 0.9989.

  18. Steady state heat transfer experimental studies of LHC superconducting cables operating in cryogenic environment of superfluid helium

    E-print Network

    Santandrea, Dario; Tuccillo, Raffaele; Granieri, Pier Paolo.

    The heat management is a basic and fundamental aspect of the superconducting magnets used in the CERN Large Hadron Collider. Indeed, the coil temperature must be kept below the critical value, despite the heat which can be generated or deposited in the magnet during the normal operations. Therefore, this thesis work aims at determining the heating power which can be extracted from the superconducting cables of the LHC, specially through their electrical insulation which represents the main thermal barrier. An experimental measurement campaign in superfluid helium bath was performed on several samples reproducting the main LHC magnets. The heating power was generated in the sample by Joule heating and the temperature increase was measured by means of Cernox bare chip and thermocouples. An innovative instrumentation technique which also includes the in-situ calibration of the thermocouples was developed. A thorough uncertainty analysis on the overall measurement chain concluded the experimental setup. The prese...

  19. A novel thin-film temperature and heat-flux microsensor for heat transfer measurements in microchannels.

    PubMed

    Hamadi, David; Garnier, Bertrand; Willaime, Herve; Monti, Fabrice; Peerhossaini, Hassan

    2012-02-01

    Temperature and heat-flux measurement at the microscale for convective heat-transfer studies requires highly precise, minimally intrusive sensors. For this purpose, a new generic temperature and heat-flux sensor was designed, calibrated and tested. The sensor allows measurement of temperature and heat flux distributions along the direction of flow. It is composed of forty gold thermoresistances, 85 nm thick, deposited on both sides of a borosilicate substrate. Their sensitivities are about 37.8 ?V K(-1), close to those of a K-type wire thermocouple. Using a thermoelectrical model, temperature biases due to the Joule effect were calculated using the current crossing each thermoresistance and the heat-transfer coefficient. Finally, heat-transfer measurements were performed with deionized water flowing in a straight PDMS microchannel for various Reynolds numbers. The Nusselt number was obtained for microchannels of 50 to 10 ?m span. The results were found to be in good agreement with classical Nu-Re macroscopic correlations. PMID:22179553

  20. Waste heat

    SciTech Connect

    Moore, N.L.

    1985-07-01

    This is a survey of waste heat recovery in US industry. Future prospects depend on the price of fossil fuels. Fuel and energy consumption in the year 2000 is summarized. Areas of greatest growth in waste heat recovery will be in high-temperature recuperation, heat pumps and cogeneration. (DLC)

  1. Heat pumps

    Microsoft Academic Search

    R. D. Heap

    1979-01-01

    With increasing energy costs and changing cost relativities, potential heat pump applications deserve a thorough reassessment. Such a reassessment is the objective of this book. The topics covered include the general, historical, and theoretical background material; vapor compression equipment; general aspects of system design, with particular reference to the design of space heating systems employing heat pumps; domestic, commercial, and

  2. Ionosphere/thermosphere heating determined from dynamic magnetosphere-ionosphere/thermosphere coupling

    NASA Astrophysics Data System (ADS)

    Tu, Jiannan; Song, Paul; Vasyli?nas, Vytenis M.

    2011-09-01

    Ionosphere/thermosphere heating driven by magnetospheric convection is investigated through a three-fluid inductive (including Faraday's law) approach to describing magnetosphere-ionosphere/thermosphere coupling, for a 1-D stratified ionosphere/thermosphere in this initial study. It is shown that the response of the ionosphere/thermosphere and thus the heating is dynamic and height-dependent. The heating is essentially frictional in nature rather than Joule heating as commonly assumed. The heating rate reaches a quasi-steady state after about 25 Alfvén travel times. During the dynamic period, the heating can be enhanced and displays peaks at multiple times due to wave reflections. The dynamic heating rate can be more than twice greater than the quasi-steady state value. The heating is strongest in the E-layer but the heating rate per unit mass is concentrated around the F-layer peak height. This implies a potential mechanism of driving O+ upflow from O+ rich F-layer. It is shown that the ionosphere/thermosphere heating caused by the magnetosphere-ionosphere coupling can be simply evaluated through the relative velocity between the plasma and neutrals without invoking field-aligned currents, ionospheric conductance, and electric field. The present study provides understanding of the dynamic magnetosphere-ionosphere/thermosphere coupling from the ionospheric/thermospheric view in addition to magnetospheric perspectives.

  3. Multiphysics Modeling for Dimensional Analysis of a Self-Heated Molten Regolith Electrolysis Reactor for Oxygen and Metals Production on the Moon and Mars

    NASA Technical Reports Server (NTRS)

    Dominguez, Jesus; Sibille, Laurent

    2010-01-01

    The technology of direct electrolysis of molten lunar regolith to produce oxygen and molten metal alloys has progressed greatly in the last few years. The development of long-lasting inert anodes and cathode designs as well as techniques for the removal of molten products from the reactor has been demonstrated. The containment of chemically aggressive oxide and metal melts is very difficult at the operating temperatures ca. 1600 C. Containing the molten oxides in a regolith shell can solve this technical issue and can be achieved by designing a self-heating reactor in which the electrolytic currents generate enough Joule heat to create a molten bath.

  4. Mathematical Modeling of Magneto Pulsatile Blood Flow Through a Porous Medium with a Heat Source

    NASA Astrophysics Data System (ADS)

    Sharma, B. K.; Sharma, M.; Gaur, R. K.; Mishra, A.

    2015-05-01

    In the present study a mathematical model for the hydro-magnetic non-Newtonian blood flow in the non-Darcy porous medium with a heat source and Joule effect is proposed. A uniform magnetic field acts perpendicular to the porous surface. The governing non-linear partial differential equations have been solved numerically by applying the explicit finite difference Method (FDM). The effects of various parameters such as the Reynolds number, hydro-magnetic parameter, Forchheimer parameter, Darcian parameter, Prandtl number, Eckert number, heat source parameter, Schmidt number on the velocity, temperature and concentration have been examined with the help of graphs. The present study finds its applications in surgical operations, industrial material processing and various heat transfer operations.

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

    PubMed

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

    2010-02-01

    This paper reports on a micromachined Si/glass stack recuperative heat exchanger with in situ temperature sensors. Numerous high-conductivity silicon plates with integrated platinum resistance temperature detectors (Pt RTDs) are stacked, alternating with low-conductivity Pyrex spacers. The device has a 1 x 1-cm(2) footprint and a length of up to 3.5 cm. It is intended for use in Joule-Thomson (J-T) coolers and can sustain pressure exceeding 1 MPa. Tests at cold-end inlet temperatures of 237 K-252 K show that the heat exchanger effectiveness is 0.9 with 0.039-g/s helium mass flow rate. The integrated Pt RTDs present a linear response of 0.26%-0.30%/K over an operational range of 205 K-296 K but remain usable at lower temperatures. In self-cooling tests with ethane as the working fluid, a J-T system with the heat exchanger drops 76.1 K below the inlet temperature, achieving 218.7 K for a pressure of 835.8 kPa. The system reaches 200 K in transient state; further cooling is limited by impurities that freeze within the flow stream. In J-T self-cooling tests with an external heat load, the system reaches 239 K while providing 1 W of cooling. In all cases, there is an additional parasitic heat load estimated at 300-500 mW. PMID:20490284

  6. 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

  7. Measurements of ions emission using ToF method and CR39 SSNTD in a Small Plasma Focus device of Hundreds of Joules

    NASA Astrophysics Data System (ADS)

    Moreno, José; Pedreros, José; Soto, Leopoldo

    2014-05-01

    Ion beam emission in plasma focus (PF) discharges was originally investigated to explain the strong forward anisotropy observed in the neutron emission when D2 is used as filling gas in the PF devices. Several properties of emitted deuteron beam, including its angular distribution and energy spectra in PF devices operating at energies from 1kJ to 1MJ, have been measured. At present there is a growing interest in the development of very small PF devices operating under 1kJ. As part of the very low energy (< 1kJ) PF devices physics characterization program carried out at the Chilean Nuclear Energy Commission, the charged particle emission is being studied when hydrogen (H2) and mixture (H2+ %Ar) is used as filling gas in the PF device. The experiments have been performed in a plasma focus device of 400 joules (PF-400J). In order to estimate the ion beam energy spectrum and its ionization degree, by means of the time of flight method, a graphite collector system operating in the bias ion collector mode was constructed. On the other hand, measurements of the energy and flux of the ions have been corroborated using CR39 SSNTD. Preliminary results mainly show the presence of hydrogen ions with an average energy of 40keV. Also, in some cases, copper (from anode) and aluminum (from insulator) ions with energies lower than 1keV have been observed.

  8. Heat Transfer

    NSDL National Science Digital Library

    Integrated Teaching and Learning Program,

    Students explore heat transfer and energy efficiency using the context of energy efficient houses. They gain a solid understanding of the three types of heat transfer: radiation, convection and conduction, which are explained in detail and related to the real world. They learn about the many ways solar energy is used as a renewable energy source to reduce the emission of greenhouse gasses and operating costs. Students also explore ways in which a device can capitalize on the methods of heat transfer to produce a beneficial result. They are given the tools to calculate the heat transferred between a system and its surroundings.

  9. Energy-Saving Sintering of Electrically Conductive Powders by Modified Pulsed Electric Current Heating Using an Electrically Nonconductive Die

    NASA Astrophysics Data System (ADS)

    Ito, Mikio; Kawahara, Kenta; Araki, Keita

    2014-04-01

    Sintering of Cu and thermoelectric Ca3Co4O9 was tried using a modified pulsed electric current sintering (PECS) process, where an electrically nonconductive die was used instead of a conventional graphite die. The pulsed electric current flowed through graphite punches and sample powder, which caused the Joule heating of the powder compact itself, resulting in sintering under smaller power consumption. Especially for the Ca3Co4O9 powder, densification during sintering was also accelerated by this modified PECS process.

  10. Heat Problems.

    ERIC Educational Resources Information Center

    Connors, G. Patrick

    Heat problems and heat cramps related to jogging can be caused by fluid imbalances, medications, dietary insufficiency, vomiting or diarrhea, among other factors. If the condition keeps reoccurring, the advice of a physician should be sought. Some preventive measures that can be taken include: (1) running during the cooler hours of the day; (2)…

  11. Heat stroke.

    PubMed

    Leon, Lisa R; Bouchama, Abderrezak

    2015-04-01

    Heat stroke is a life-threatening condition clinically diagnosed as a severe elevation in body temperature with central nervous system dysfunction that often includes combativeness, delirium, seizures, and coma. Classic heat stroke primarily occurs in immunocompromised individuals during annual heat waves. Exertional heat stroke is observed in young fit individuals performing strenuous physical activity in hot or temperature environments. Long-term consequences of heat stroke are thought to be due to a systemic inflammatory response syndrome. This article provides a comprehensive review of recent advances in the identification of risk factors that predispose to heat stroke, the role of endotoxin and cytokines in mediation of multi-organ damage, the incidence of hypothermia and fever during heat stroke recovery, clinical biomarkers of organ damage severity, and protective cooling strategies. Risk factors include environmental factors, medications, drug use, compromised health status, and genetic conditions. The role of endotoxin and cytokines is discussed in the framework of research conducted over 30 years ago that requires reassessment to more clearly identify the role of these factors in the systemic inflammatory response syndrome. We challenge the notion that hypothalamic damage is responsible for thermoregulatory disturbances during heat stroke recovery and highlight recent advances in our understanding of the regulated nature of these responses. The need for more sensitive clinical biomarkers of organ damage is examined. Conventional and emerging cooling methods are discussed with reference to protection against peripheral organ damage and selective brain cooling. PMID:25880507

  12. An Experimental Study of Near Wake Structure Behind Two Circular Cylinders with Heat Addition

    NASA Astrophysics Data System (ADS)

    Laughlin, George; Kumar, Sanjay; Cantu, Cesar

    2008-11-01

    In this study, we present flow visualization data on the effect of heat addition on the near wake structure behind two identical circular cylinders separated in the span-wise direction perpendicular to the flow at Re = 350. Flow visualization is done using the hydrogen bubble technique. The spacing between the two cylinders is T/D = 1.7, where T = center-to-center spacing and D = cylinder diameter. The gap flow is known to be intermittently bi-stable at this spacing, which is clearly demonstrated in the study. The present study focuses on the response of the gap flow to the heat release in one cylinder. The study shows clearly that the gap flow deflects towards the heated cylinder resulting in a narrower wake behind the heated cylinder as compared to the wake behind the unheated cylinder. The response of the gap-flow is further demonstrated by turning the heat off on one cylinder and switching the heat on the other cylinder resulting in the gap flow deflection as well. The cylinders in the present experiments are heated by joule heating with an estimated wall temperature difference of 30^oC in water at the given Reynolds number resulting in Richardson number of about 0.2 in the present experiments.

  13. Heat collector

    DOEpatents

    Merrigan, Michael A. (Santa Cruz, NM)

    1984-01-01

    A heat collector and method suitable for efficiently and cheaply collecting solar and other thermal energy are provided. The collector employs a heat pipe in a gravity-assist mode and is not evacuated. The collector has many advantages, some of which include ease of assembly, reduced structural stresses on the heat pipe enclosure, and a low total materials cost requirement. Natural convective forces drive the collector, which after startup operates entirely passively due in part to differences in molecular weights of gaseous components within the collector.

  14. Thermodynamical calculation of metal heating in nanosecond exploding wire and foil experiments

    SciTech Connect

    Sarkisov, G. S.; Rosenthal, S. E.; Struve, K. W. [Ktech Corporation, 10800 Gibson Boulevard, Albuquerque, New Mexico 87123 (United States); Sandia National Laboratories, Albuquerque, New Mexico 87110 (United States)

    2007-04-15

    A method of thermodynamical calculation of thin metal wire heating during its electrical explosion is discussed. The technique is based on a calculation of Joule energy deposition taking into account the current wave form and the temperature dependence of the resistivity and heat capacity of the metal. Comparing the calculation to a set of exploding tungsten wire experiments demonstrates good agreement up to the time of melting. Good agreement is also demonstrated with resistive magnetohydrodynamics simulation. A similar thermodynamical calculation for Mo, Ti, Ni, Fe, Al, and Cu shows good agreement with experimental data. The thermodynamical technique is useful for verification of the voltage measurements in exploding wire experiments. This technique also shows good agreement with an exploding W foil experiment.

  15. Thermodynamical calculation of metal heating in nanosecond exploding wire and foil experiments.

    PubMed

    Sarkisov, G S; Rosenthal, S E; Struve, K W

    2007-04-01

    A method of thermodynamical calculation of thin metal wire heating during its electrical explosion is discussed. The technique is based on a calculation of Joule energy deposition taking into account the current wave form and the temperature dependence of the resistivity and heat capacity of the metal. Comparing the calculation to a set of exploding tungsten wire experiments demonstrates good agreement up to the time of melting. Good agreement is also demonstrated with resistive magnetohydrodynamics simulation. A similar thermodynamical calculation for Mo, Ti, Ni, Fe, Al, and Cu shows good agreement with experimental data. The thermodynamical technique is useful for verification of the voltage measurements in exploding wire experiments. This technique also shows good agreement with an exploding W foil experiment. PMID:17477658

  16. Temperature Control at DBS Electrodes using Heat Sink: Experimentally Validated FEM Model of DBS lead Architecture

    PubMed Central

    Elwassif, Maged M.; Datta, Abhishek; Rahman, Asif; Bikson, Marom

    2012-01-01

    There is a growing interest in the use of Deep Brain Stimulation for the treatment of medically refractory movement disorders and other neurological and psychiatric conditions. The extent of temperature increases around DBS electrodes during normal operation (joule heating and increased metabolic activity) or coupling with an external source (e.g. MRI) remains poorly understood and methods to mitigate temperature increases are being actively investigated. We developed a heat transfer finite element method simulation of DBS incorporating the realistic architecture of Medtronic 3389 leads. The temperature changes were analyzed considering different electrode configurations, stimulation protocols, and tissue properties. The heat-transfer model results were then validated using micro-thermocouple measurements during DBS lead stimulation in a saline bath. FEM results indicate that lead design (materials and geometry) may have a central role in controlling temperature rise by conducting heat. We show how modifying lead design can effectively control temperature increases. The robustness of this heat-sink approach over complimentary heat-mitigation technologies follows from several features: 1) it is insensitive to the mechanisms of heating (e.g. nature of magnetic coupling); 2) does not interfere with device efficacy; and 3) can be practically implemented in a broad range of implanted devices without modifying the normal device operations or the implant procedure. PMID:22764359

  17. Parametric investigation of heating due to magnetic fluid hyperthermia in a tumor with blood perfusion

    NASA Astrophysics Data System (ADS)

    Liangruksa, Monrudee; Ganguly, Ranjan; Puri, Ishwar K.

    2011-03-01

    Magnetic fluid hyperthermia (MFH) is a cancer treatment that can selectively elevate the tumor temperature without significantly damaging the surrounding healthy tissue. Optimal MFH design requires a fundamental parametric investigation of the heating of soft materials by magnetic fluids. We model the problem of a spherical tumor and its surrounding healthy tissue that are heated by exciting a homogeneous dispersion of magnetic nanoparticles infused only into the tumor with an external AC magnetic field. The key dimensionless parameters influencing thermotherapy are the Péclet, Fourier, and Joule numbers. Analytical solutions for transient and steady hyperthermia provide correlations between these parameters and the portions of tumor and healthy tissue that are subjected to a threshold temperature beyond which they are damaged. Increasing the ratio of the Fourier and Joule numbers also increases the tumor temperature, but doing so can damage the healthy tissue. Higher magnetic heating is required for larger Péclet numbers due to the larger convection heat loss that occurs through blood perfusion. A comparison of the model predictions with previous experimental data for MFH applied to rabbit tumors shows good agreement. The optimal MFH conditions are identified based on two indices, the fraction IT of the tumor volume in which the local temperature is above a threshold temperature and the ratio IN of the damaged normal tissue volume to the tumor tissue volume that also lies above it. The spatial variation in the nanoparticle concentration is also considered. A Gaussian distribution provides efficacy while minimizing the possibility of generating a tumor hot spot. Varying the thermal properties of tumor and normal tissue alters ITand IN but the nature of the temperature distribution remains unchanged.

  18. Heat pipe waste heat recovery boilers

    Microsoft Academic Search

    D. A. Littwin; J. McCurley

    1981-01-01

    The use of heat pipes as transport devices in waste heat recovery boilers is examined. Test results show that heat pipes can efficiently extract heat from the hot gas stream and transfer it inside the pressure vessel for the steam generation process. The benefits of incorporating heat pipes into the design of waste heat recovery boilers include a highly compact

  19. Latent heat in soil heat flux measurements

    Microsoft Academic Search

    J. L. Heitman; R. Horton; T. J. Sauer; T. S. Ren; X. Xiao

    2010-01-01

    The surface energy balance includes a term for soil heat flux. Soil heat flux is difficult to measure because it includes conduction and convection heat transfer processes. Accurate representation of soil heat flux is an important consideration in many modeling and measurement applications. Yet, there remains uncertainty about what comprises soil heat flux and how surface and subsurface heat fluxes

  20. Dynamics of Quantal Heating in Electron Systems with Discrete Spectra

    NASA Astrophysics Data System (ADS)

    Mayer, William; Dietrich, Scott; Vitkalov, Sergey; Bykov, Alexey

    2015-03-01

    The temporal evolution of quantal Joule heating of 2D electrons in GaAs quantum well placed in quantizing magnetic fields is studied using a difference frequency method. The method is based on measurements of the electron conductivity oscillating at the beat frequency f =f1 -f2 between two microwaves applied to 2D system at frequencies f1 and f2. The method provides direct access to the dynamical characteristics of the heating and yields the inelastic scattering time ?in of 2D electrons. The obtained ?in is strongly temperature dependent, varying from 0.13 ns at 5.5K to 1 ns at 2.4K in magnetic field B=0.333T. When temperature T exceeds the Landau level separation the relaxation rate 1 /?in is proportional to T2, indicating the electron-electron interaction as the dominant mechanism limiting the quantal heating. At lower temperatures the rate tends to be proportional to T3, indicating considerable contribution from electron-phonon scattering. This work was supported by the National Science Foundation (DMR 1104503), the Russian Foundation for Basic Research (project no.14-02-01158) and the Ministry of Education and Science of the Russian Federation.

  1. Dynamics of quantal heating in electron systems with discrete spectra

    NASA Astrophysics Data System (ADS)

    Dietrich, Scott; Mayer, William; Vitkalov, Sergey; Bykov, A. A.

    2015-05-01

    The temporal evolution of quantal Joule heating of two-dimensional (2D) electrons in a GaAs quantum well placed in quantizing magnetic fields is studied using a difference-frequency method. The method is based on measurements of the electron conductivity oscillating at the beat frequency f =f1-f2 between two microwaves applied to the 2D system at frequencies f1 and f2. The method provides direct access to the dynamical characteristics of the heating and yields the inelastic-scattering time ?i n of 2D electrons. The obtained ?i n is strongly temperature dependent, varying from 0.13 ns at 5.5 K to 1 ns at 2.4 K in magnetic field B =0.333 T . When the temperature T exceeds the Landau-level separation, the relaxation rate 1 /?i n is proportional to T2, indicating electron-electron interaction as the dominant mechanism limiting the quantal heating. At lower temperatures, the rate tends to be proportional to T3, indicating considerable contribution from electron-phonon scattering.

  2. Apprehending Joule Thieves with Cinder

    E-print Network

    Rumble, Stephen M.

    Energy is the critical limiting resource to mobile computing devices. Correspondingly, an operating system must track, provision, and ration how applications consume energy. The emergence of third-party application stores ...

  3. Apprehending Joule Thieves With Cinder

    E-print Network

    Levis, Philip

    Effectively rate limited maps #12;19 Throttle Games 20 KJ 1 W 0 J wumpus roguespacewar #12;20 Downloaded Apps time/Standby time rationing ­ Phone calls (total talk time, 911) ­ "Games & Widgets" folder ­ Email J wumpus roguespacewar 1 W 0 J iFoo 250 mW #12;22 Limits on Background Apps User's expectations

  4. Flash Heating

    NASA Astrophysics Data System (ADS)

    Taylor, G. J.

    2000-03-01

    Meteorites contain millimeter-sized objects called chondrules. They were melted in the solar nebula, the cloud of gas and dust in which the Sun and planets formed. Numerous experiments on rock powders have been done to understand the melting process and the cooling rates chondrules experienced. Most meteorite specialists believe that chondrules formed by flash heating, with almost instantaneous melting, though the length of time they remained molten is uncertain. Can conventional laboratory furnaces heat rock powders rapidly enough to flash melt them? Susan Maharaj and Roger Hewins (Rutgers University, New Brunswick) tested this idea by inserting tiny wires of pure elements (which have precise melting temperatures) into compressed rock powders about 3.5 mm in diameter, and placing the samples into a furnace heated to a range of temperatures. They found that at 1600 C, a sample took only six seconds to reach 1538 C. When placed into a furnace at 1500 C, samples took ten seconds to reach 1495 C. This shows that the flash heating process can be studied in conventional laboratory furnaces.

  5. Heating asymmetry induced by tunneling current flow in magnetic tunnel junctions

    NASA Astrophysics Data System (ADS)

    Gapihan, E.; Hérault, J.; Sousa, R. C.; Dahmane, Y.; Dieny, B.; Vila, L.; Prejbeanu, I. L.; Ducruet, C.; Portemont, C.; Mackay, K.; Nozières, J. P.

    2012-05-01

    In this work, exchange bias was used as a probe to characterise the temperature profile induced by the inelastic relaxation of electrons tunnelling across a MgO barrier. Thermally assisted magnetic random access memory (TA-MRAM) cells comprising a magnetic tunnel junction (MTJ) with a reference pinned layer and a FeMn exchange biased storage layer were used. The pinning direction of the ferromagnetic storage layer is reversed when heated above the blocking temperature of the antiferromagnetic layer (FeMn). The power density required to reach this blocking temperature in the FeMn layer depends on the current polarity, indicating that the heat source term associated with the current flowing through the barrier depends itself on the current direction in contrast to simple Joule heating. This effect is due to the mechanism of energy dissipation in tunnelling. The tunnelling itself is ballistic i.e., without dissipation. However, after tunnelling, the hot electrons very quickly relax to the Fermi energy thereby loosing their excess energy in the receiving electrode. Therefore, the heat is essentially generated on one side of the barrier so that the whole profile of temperature throughout the pillar depends on the current direction. Full 3D thermal simulations also confirmed the temperature profile asymmetry. The proper choice of heating current direction (i.e., voltage polarity applied to the MTJ) can yield a reduction of about 10% in the heating power density required to enable writing in thermally assisted MRAM cells.

  6. Waste Heat Recovery from High Temperature Off-Gases from Electric Arc Furnace

    SciTech Connect

    Nimbalkar, Sachin U [ORNL; Thekdi, Arvind [E3M Inc; Keiser, James R [ORNL; Storey, John Morse [ORNL

    2014-01-01

    This article presents a study and review of available waste heat in high temperature Electric Arc Furnace (EAF) off gases and heat recovery techniques/methods from these gases. It gives details of the quality and quantity of the sensible and chemical waste heat in typical EAF off gases, energy savings potential by recovering part of this heat, a comprehensive review of currently used waste heat recovery methods and potential for use of advanced designs to achieve a much higher level of heat recovery including scrap preheating, steam production and electric power generation. Based on our preliminary analysis, currently, for all electric arc furnaces used in the US steel industry, the energy savings potential is equivalent to approximately 31 trillion Btu per year or 32.7 peta Joules per year (approximately $182 million US dollars/year). This article describes the EAF off-gas enthalpy model developed at Oak Ridge National Laboratory (ORNL) to calculate available and recoverable heat energy for a given stream of exhaust gases coming out of one or multiple EAF furnaces. This Excel based model calculates sensible and chemical enthalpy of the EAF off-gases during tap to tap time accounting for variation in quantity and quality of off gases. The model can be used to estimate energy saved through scrap preheating and other possible uses such as steam generation and electric power generation using off gas waste heat. This article includes a review of the historical development of existing waste heat recovery methods, their operations, and advantages/limitations of these methods. This paper also describes a program to develop and test advanced concepts for scrap preheating, steam production and electricity generation through use of waste heat recovery from the chemical and sensible heat contained in the EAF off gases with addition of minimum amount of dilution or cooling air upstream of pollution control equipment such as bag houses.

  7. Geothermal district heating systems

    NASA Astrophysics Data System (ADS)

    Budney, G. S.; Childs, F.

    1982-06-01

    Ten district heating demonstration projects and their present status are described. The projects are Klamath County YMCA, Susanville District Heating, Klamath Falls District Heating, Reno Salem Plaza Condominium, El Centro Community Center Heating/Cooling, Haakon School and Business District Heating, St. Mary's Hospital, Diamond Ring Ranch, Pagosa Springs District Heating, and Boise District Heating.

  8. Waste heat recovery using heat pipe heat exchanger for heating automobile using exhaust gas

    Microsoft Academic Search

    Feng Yang; Xiugan Yuan; Guiping Lin

    2003-01-01

    The feasibility of using heat pipe heat exchangers for heating applying automotive exhaust gas is studied and the calculation method is developed. Practical heat pipe heat exchanger is set up for heating HS663, a large bus. Simple experiments are carried out to examine the performance of the heat exchanger. It is shown that the experimental results, which indicate the benefit

  9. Emerging heat pipe applications

    Microsoft Academic Search

    A. Basuilis; D. J. Formiller

    1978-01-01

    The article discusses the application of heat pipes in various industrial, military, and space projects. Several types of heat pipes are described, including simple cylindrical heat pipes, switching heat pipes, thermal diodes, variable conductance heat pipes, and vapor chambers. Potential future applications of heat pipes are identified in the fields of electronics, spacecraft thermal control, heat pipe recovery systems, and

  10. Ceramic heat pipe heat exchangers

    Microsoft Academic Search

    W. A. Ranken

    1976-01-01

    High-temperature strength, resistance to corrosive atmospheres, and moderate cost combine to make ceramic materials an obvious choice for construction of high-temperature thermal energy recuperator systems. Despite these advantages, ceramic recuperators are steadily being replaced by metallic units at considerable sacrifice in maximum air or fuel preheat temperatures and hence in recovery efficiency. By constructing a recuperator from ceramic heat pipes,

  11. Geothermal heating

    SciTech Connect

    Aureille, M.

    1982-01-01

    The aim of the study is to demonstrate the viability of geothermal heating projects in energy and economic terms and to provide nomograms from which an initial estimate may be made without having to use data-processing facilities. The effect of flow rate and temperature of the geothermal water on drilling and on the network, and the effect of climate on the type of housing are considered.

  12. Heat Transfer

    NSDL National Science Digital Library

    Ms. Leslie Van (Montgomery Blair High School)

    2006-04-01

    In this inquiry activity students explore how heat transfers from one substance to another This inquiry activity was developed by a K-12 science teacher in the American Physiological SocietyÂ?s 2006 Frontiers in Physiology Program. The NSES Standards addressed by this activity are current as of the year of development. For more information on the Frontiers in Physiology Program, please visit www.frontiersinphys.org.

  13. Industrial Waste Heat Recovery Using Heat Pipes

    E-print Network

    Ruch, M. A.

    1981-01-01

    For almost a decade now, heat pipes with secondary finned surfaces have been utilized in counter flow heat exchangers to recover sensible energy from industrial exhaust gases. Over 3,000 such heat exchangers are now in service, recovering...

  14. Industrial Waste Heat Recovery Using Heat Pipes 

    E-print Network

    Ruch, M. A.

    1981-01-01

    For almost a decade now, heat pipes with secondary finned surfaces have been utilized in counter flow heat exchangers to recover sensible energy from industrial exhaust gases. Over 3,000 such heat exchangers are now in service, recovering...

  15. Heat pipe heat exchanger design considerations

    Microsoft Academic Search

    K. T. Feldman; D. C. Lu

    1976-01-01

    Typical heat pipe heat exchangers (HPHX) are described, along with their advantages, uses, and some problems in HPHX design, and a computer HPHX analysis program is discussed with required input data. The computer program is being developed for analysis of heat exchange performance by finned-tube HPHX and thread-puddle-artery heat pipes. Copper-water heat pipes and carbon steel-Dowtherm A heat pipes are

  16. Dynamic response characteristics of thermoelectric generator predicted by a three-dimensional heat-electricity coupled model

    NASA Astrophysics Data System (ADS)

    Meng, Jing-Hui; Zhang, Xin-Xin; Wang, Xiao-Dong

    2014-01-01

    The practical application environments of thermoelectric generators (TEGs) always change, which make a requirement for studying the dynamic response characteristics of TEGs. This work develops a complete, three-dimensional and transient model to investigate this issue. The model couples the energy and electric potential equations. Seebeck effect, Peltier effect, Thomson effect, Joule heating and Fourier heat conduction are taken into account in this model. Dynamic output power and conversion efficiency of the TEG, which are caused by variations of the hot end temperature, cold end temperature and load current, are studied. The response hysteresis of the output power to the hot end and cold end temperatures, the overshoot or undershoot of the conversion efficiency are found and attributed to the delay of thermal diffusion. However, the output power is synchronous with the load current due to much faster electric response than thermal response.

  17. Regenerative Hydride Heat Pump

    NASA Technical Reports Server (NTRS)

    Jones, Jack A.

    1992-01-01

    Hydride heat pump features regenerative heating and single circulation loop. Counterflow heat exchangers accommodate different temperatures of FeTi and LaNi4.7Al0.3 subloops. Heating scheme increases efficiency.

  18. Uniform and Non-uniform Thermoelement Subject to Lateral Heat Convection

    NASA Astrophysics Data System (ADS)

    Hameed, Amar Hasan; Kafafy, Raed

    2013-03-01

    A general energy equation of quasi-one-dimensional heat flow in a longitudinal thermoelement (TE) of a curved side that is subjected to an electric field and convection heat transfer on the curved surface is developed. The energy equation is solved for the temperature distribution in two cases; uniform cross-section TE and non-uniform cross-section TE. Analytical solutions for a uniform cross-section TE with uniform electrical and thermophysical properties are obtained, whereas numerical solutions are provided for a non-uniform cross-section TE. Two parameters playing a vital role in the thermal performance of the TE are identified: the heat resistance ratio ( HRR) and the energy growing ratio ( EGR). The HRR represents the ratio of the longitudinal conduction maximum thermal resistance to the lateral convection maximum thermal resistance. The EGR represents the ratio of Joule's electrical heating to Fourier's heat conduction. The effects of varying these two parameters, as well as the TE geometry, have been thoroughly investigated.

  19. Integrated Heat Pump (IHP) System Development - Air-Source IHP Control Strategy and Specifications and Ground-Source IHP Conceptual Design

    SciTech Connect

    Murphy, Richard W [ORNL; Rice, C Keith [ORNL; Baxter, Van D [ORNL

    2007-05-01

    The integrated heat pump (IHP), as one appliance, can provide space cooling, heating, ventilation, and dehumidification while maintaining comfort and meeting domestic water heating needs in near-zero-energy home (NZEH) applications. In FY 2006 Oak Ridge National Laboratory (ORNL) completed development of a control strategy and system specification for an air-source IHP. The conceptual design of a ground-source IHP was also completed. Testing and analysis confirm the potential of both IHP concepts to meet NZEH energy services needs while consuming 50% less energy than a suite of equipment that meets current minimum efficiency requirements. This report is in fulfillment of an FY06 DOE Building Technologies (BT) Joule Milestone.

  20. Nonlinear radiation heat transfer effects in the natural convective boundary layer flow of nanofluid past a vertical plate: a numerical study.

    PubMed

    Mustafa, Meraj; Mushtaq, Ammar; Hayat, Tasawar; Ahmad, Bashir

    2014-01-01

    The problem of natural convective boundary layer flow of nanofluid past a vertical plate is discussed in the presence of nonlinear radiative heat flux. The effects of magnetic field, Joule heating and viscous dissipation are also taken into consideration. The governing partial differential equations are transformed into a system of coupled nonlinear ordinary differential equations via similarity transformations and then solved numerically using the Runge-Kutta fourth-fifth order method with shooting technique. The results reveal an existence of point of inflection for the temperature distribution for sufficiently large wall to ambient temperature ratio. Temperature and thermal boundary layer thickness increase as Brownian motion and thermophoretic effects intensify. Moreover temperature increases and heat transfer from the plate decreases with an increase in the radiation parameter. PMID:25251242

  1. Nonlinear Radiation Heat Transfer Effects in the Natural Convective Boundary Layer Flow of Nanofluid Past a Vertical Plate: A Numerical Study

    PubMed Central

    Mustafa, Meraj; Mushtaq, Ammar; Hayat, Tasawar; Ahmad, Bashir

    2014-01-01

    The problem of natural convective boundary layer flow of nanofluid past a vertical plate is discussed in the presence of nonlinear radiative heat flux. The effects of magnetic field, Joule heating and viscous dissipation are also taken into consideration. The governing partial differential equations are transformed into a system of coupled nonlinear ordinary differential equations via similarity transformations and then solved numerically using the Runge–Kutta fourth-fifth order method with shooting technique. The results reveal an existence of point of inflection for the temperature distribution for sufficiently large wall to ambient temperature ratio. Temperature and thermal boundary layer thickness increase as Brownian motion and thermophoretic effects intensify. Moreover temperature increases and heat transfer from the plate decreases with an increase in the radiation parameter. PMID:25251242

  2. Heat exchanger

    DOEpatents

    Brackenbury, P.J.

    1983-12-08

    A heat exchanger comparising a shell attached at its open end to one side of a tube sheet and a detachable head connected to the other side of said tube sheet. The head is divided into a first and second chamber in fluid communication with a nozzle inlet and nozzle outlet, respectively, formed in said tube sheet. A tube bundle is mounted within said shell and is provided with inlets and outlets formed in said tube sheet in communication with said first and second chambers, respectively.

  3. Heat pumps. Second edition

    Microsoft Academic Search

    D. A. Reay; D. B. A. Mac Michael

    1986-01-01

    This book provides a revised and extended account of the design, manufacture and use of heat pumps in industrial and domestic applications. Topics covered include the following: history of the heat pump; heat pump theory; practical design; design problem areas; heat pump applications domestic; heat pumps in commercial and municipal buildings; and heat pump applications in industry.

  4. Water heating system

    Microsoft Academic Search

    Yoshino

    1984-01-01

    A water heating system comprising an outdoor heat exchanger including a heat collection chamber, solar collector panels, collector fins, an evaporator for passing refrigerant therethrough to perform the heat exchange between the refrigerant and the heat transferred from the panels and fins to evaporate the refrigerant. The panels, fins and evaporator are incorporated integrally in the heat collection chamber. A

  5. Heat recovery method

    SciTech Connect

    Richarts, F.

    1985-04-16

    Heat is recovered by combining a heat transfer system including heat exchangers interconnected in a circulatory system, with a heat pump system. The heat pump system is preferably operated in accordance with the Lorenz-Principle. It is not necessary to divide the heat carrier circuit of the heat pump into two or three separate circulatory circuits. The heat carrier circuit of the heat pump can thus continue to operate unchanged even if the heat pump is switched off. For this purpose the warm heat carrier coming from a discharge fluid cooler, is heated further in a condenser of the heat pump and the cold heat carrier coming from a preheater or cooler group, is cooled further in an evaporator of the heat pump.

  6. Heat exchange system for recycling waste heat

    Microsoft Academic Search

    A. A. Giuffre; A. F. Giuffre

    1982-01-01

    Design of heat exchange system for recycling waste heat, such as that leaving a building stack or flue, to supply heat where needed, such as to incoming fresh air or to tempered stored water of the building water storage system, wherein the building has a source of heat at a constant temperature (such as a furnace, a cooking facility, or

  7. Geothermal heat pumps for heating and cooling

    SciTech Connect

    Garg, S.C.

    1994-03-01

    Naval Facilities Engineering Service Center (NFESC) has been tasked by Naval Shore Facilities Energy Office to evaluate the NAS Patuxent River ground-source heat pump (GHP) installation. A large part of a building`s energy consumption consists of heating and air conditioning for occupant comfort. The space heating requirements are normally met by fossil-fuel-fired equipment or electric resistance heating. Cooling is provided by either air conditioners or heat pumps, both using electricity as an energy source.

  8. Geothermal heat pumps for heating and cooling

    NASA Astrophysics Data System (ADS)

    Garg, Suresh C.

    1994-03-01

    Naval Facilities Engineering Service Center (NFESC) has been tasked by Naval Shore Facilities Energy Office to evaluate the NAS Patuxent River ground-source heat pump (GHP) installation. A large part of a building's energy consumption consists of heating and air conditioning for occupant comfort. The space heating requirements are normally met by fossil-fuel-fired equipment or electric resistance heating. Cooling is provided by either air conditioners or heat pumps, both using electricity as an energy source.

  9. Thulium-170 heat source

    SciTech Connect

    Walter, C.E.; Van Konynenburg, R.; Van Sant, J.H.

    1992-01-21

    This patent describes an isotopic heat source. It comprises; at least one isotopic fuel stack, comprising alternating layers of: thulium oxide; and a low atomic weight diluent for thulium oxide; a heat block defining holes into which the fuel stacks can be placed; at least one heat pipe for heat removal, with the heat pipe being positioned in the heat block in thermal connection with the fuel stack; and a structural container surrounding the heat block.

  10. Nonazeotropic Heat Pump

    NASA Technical Reports Server (NTRS)

    Ealker, David H.; Deming, Glenn

    1991-01-01

    Heat pump collects heat from water circulating in heat-rejection loop, raises temperature of collected heat, and transfers collected heat to water in separate pipe. Includes sealed motor/compressor with cooling coils, evaporator, and condenser, all mounted in outer housing. Gradients of temperature in evaporator and condenser increase heat-transfer efficiency of vapor-compression cycle. Intended to recover relatively-low-temperature waste heat and use it to make hot water.

  11. Operation of an ADR Using Helium Exchange Gas as a Substitute for a Failed Heat Switch

    NASA Technical Reports Server (NTRS)

    Shirron, P.; DiPirro, M.; Kimball, M.; Sneiderman, G.; Porter, F. S.; Kilbourne, C.; Kelley, R.; Fujimoto, R.; Yoshida, S.; Takei, Y.; Mitsuda, K.

    2014-01-01

    The Soft X-ray Spectrometer (SXS) is one of four instruments on the Japanese Astro-H mission, which is currently planned for launch in late 2015. The SXS will perform imaging spectroscopy in the soft X-ray band (0.3-12 keV) using a 6 6 pixel array of microcalorimeters cooled to 50 mK. The detectors are cooled by a 3-stage adiabatic demagnetization refrigerator (ADR) that rejects heat to either a superfluid helium tank (at 1.2 K) or to a 4.5 K Joule-Thomson (JT) cryocooler. Four gas-gap heat switches are used in the assembly to manage heat flow between the ADR stages and the heat sinks. The engineering model (EM) ADR was assembled and performance tested at NASA/GSFC in November 2011, and subsequently installed in the EM dewar at Sumitomo Heavy Industries, Japan. During the first cooldown in July 2012, a failure of the heat switch that linked the two colder stages of the ADR to the helium tank was observed. Operation of the ADR requires some mechanism for thermally linking the salt pills to the heat sink, and then thermally isolating them. With the failed heat switch unable to perform this function, an alternate plan was devised which used carefully controlled amounts of exchange gas in the dewar's guard vacuum to facilitate heat exchange. The process was successfully demonstrated in November 2012, allowing the ADR to cool the detectors to 50 mK for hold times in excess of 10 h. This paper describes the exchange-gas-assisted recycling process, and the strategies used to avoid helium contamination of the detectors at low temperature.

  12. Heat-Of-Reaction Chemical Heat Pumps--Possible Configurations 

    E-print Network

    Kirol, L. D.

    1986-01-01

    Chemical heat pumps utilize working fluids which undergo reversible chemical changes. Mechanically driven reactive heat pump cycles or, alternatively, heat driven heat pumps in which either heat engine or heat pump working fluid is reactive...

  13. Probing fast heating in magnetic tunnel junction structures with exchange bias

    NASA Astrophysics Data System (ADS)

    Papusoi, C.; Sousa, R.; Herault, J.; Prejbeanu, I. L.; Dieny, B.

    2008-10-01

    Heat diffusion in a magnetic tunnel junction (MTJ) having a ferromagnetic/antiferromagnetic free layer is investigated. The MTJ is heated by an electric current pulse of power PHP, flowing through the junction in current perpendicular to the plane (CPP) geometry, via Joule heat dissipation in the tunnel barrier. According to a proposed one-dimensional (1D) model of heat diffusion, when an electric voltage is applied to the MTJ, the free layer experiences a transient temperature regime, characterized by an exponential increase of its temperature TAF with a time constant ?TR, followed by a steady temperature regime characterized by TAF=TRT+?PHP, where TRT is the room temperature and ? is a constant. Magnetic transport measurements of exchange bias HEX acting on the free layer allow the determination of ? and ?TR. The experimental values of ? and ?TR are in agreement with those calculated using the 1D model and an estimation of the MTJ thermodynamic parameters based on the Dulong Petit and Widemann Franz laws.

  14. Transient heat transfer analysis of superconducting magnetic levitating flywheel rotor operating in vacuum

    SciTech Connect

    Mochida, A.; Kudo, K.; Higasa, H.

    1999-07-01

    In the present study, transient temperature rise is analyzed in a flywheel type power storage system operated in vacuum environment. The flywheel rotor is levitated by high-temperature-superconducting magnetic bearing to reduce the bearing loss. Though the superconductor is cooled by liquid nitrogen, the temperature of the whole system rises due to Joule heating in the coils of the bearings and the motor during the operation. If the temperature should reach the critical temperature of the permanent magnet used for the magnetic bearings after long time operation, the magnetic bearings lose their effect. The heat generated in the levitated rotor diffuses within it by heat conduction and finally emitted to its surrounding solid materials by thermal radiation from the rotor surfaces across vacuum layer. Numerical simulation is carried out calculating the transient radiative-conductive heat transfer and time-dependent profiles of temperature within the rotor are obtained. The results are compared with the experimentally obtained temperatures by measured a test model of 1kWh power storage and the measured profiles of the temperature rise of the rotor fit very well with the calculated ones. Using this simulation tool, the effects of the surface emissivity of the materials of the rotor and the stator, the temperature of the surrounding casings and the thermal conductivity of the materials on the temperature profiles in the system are estimated.

  15. The LUCIA project: towards 100 joules nanosecond pulses, kW averaged power, based on ytterbium diode pumped solid state laser

    Microsoft Academic Search

    J.-C. Chanteloup; G. Bourdet; A. Migus

    2002-01-01

    Summary form only given. We show that diode pumped Yb:YAG lasers are particularly good candidates for femtosecond pulse applications, because centimeter-scale size aperture YAG crystals are easily available, their heat generation is reduced relative to Nd:YAG and high power laser diodes are available at the required pump wavelength. We designed the LUCIA laser system to consist of: an oscillator delivering

  16. Solar heating apparatus

    Microsoft Academic Search

    Trihey

    1976-01-01

    Solar heating apparatus is presented for heating a heat transfer medium comprising a support structure, a light absorbing surface arranged to transmit heat to a heat transfer medium, focusing means mounted on said support structure for focusing solar energy upon the light absorbing surface, and tracking means for tracking movement of the sun and moving the focusing means relative to

  17. Heat pipe technology

    NASA Technical Reports Server (NTRS)

    1972-01-01

    A bibliography of heat pipe technology to provide a summary of research projects conducted on heat pipes is presented. The subjects duscussed are: (1) heat pipe applications, (2) heat pipe theory, (3) design and fabrication, (4) testing and operation, (5) subject and author index, and (6) heat pipe related patents.

  18. Reverse cycle heat pump

    Microsoft Academic Search

    Harnish

    1977-01-01

    A reverse cycle heat pump is provided with a heat exchanger which provides refrigerant subcooling with no thermodynamic losses. The heat exchanger is arranged such that it is operative only during the heating cycle to permit optimum charging of the system and allow operation during the cooling cycle with no excess refrigerant in the system accumulator. The heat exchanger is

  19. Heat transport and solidification in the electromagnetic casting of aluminum alloys. Part 2: Development of a mathematical model and comparison with experimental results

    SciTech Connect

    Prasso, D.C. [Intel Corp., Aloha, OR (United States); Evans, J.W. [Univ. of California, Berkeley, CA (United States). Dept. of Materials Science and Mineral Engineering; Wilson, I.J. [Reynolds Metals Co., Muscle Shoals, AL (United States)

    1995-12-01

    In this second article of a two-part series, a mathematical model for heat transport and solidification of aluminum in electromagnetic casting is developed. The model is a three-dimensional one but involves a simplified treatment of convective heat transport in the liquid metal pool. Heat conduction in the solid was thought to play a dominant role in heat transport, and the thermal properties of the two alloys used in measurements reported in Part 1 (AA 5182 and 3104) were measured independently for input to the model. Heat transfer into the water sprays impacting the sides of the ingot was approximated using a heat-transfer coefficient from direct chill casting; because this heat-transfer step appears not to be rate determining for solidification and cooling of most of the ingot, there is little inaccuracy involved in this approximation. Joule heating was incorporated into some of the computations, which were carried out using the finite element software FIDAP. There was good agreement between the computed results and extensive thermocouple measurements (reported in Part 1) made on a pilot-scale caster at Reynolds Metals Company (Richmond, VA).

  20. Heat Pump for High School Heat Recovery 

    E-print Network

    Huang, K.; Wang, H.; Zhou, X.

    2006-01-01

    The heat pump system used for recycling and reusing waste heat in s high school bathroom was minutely analyzed in its coefficient of performance, onetime utilization ratio of energy, economic property and so on. The results showed that this system...

  1. Alternative heat sources for heat pumps

    NASA Astrophysics Data System (ADS)

    1984-09-01

    Solar assisted, water source, and ground source heat pumps are described as alternatives to air to air heat pumps for use in a broader range of climates. Publications for further information on these systems are listed.

  2. Heat Pump for High School Heat Recovery

    E-print Network

    Huang, K.; Wang, H.; Zhou, X.

    2006-01-01

    The heat pump system used for recycling and reusing waste heat in s high school bathroom was minutely analyzed in its coefficient of performance, onetime utilization ratio of energy, economic property and so on. The results showed that this system...

  3. Babies and heat rashes

    MedlinePLUS

    Heat rashes and babies; Prickly heat rash; Red miliaria ... To avoid heat rash , keep your baby cool and dry during warm weather. Some helpful suggestions: During the hot season, dress your baby in lightweight, soft, cotton clothing. Cotton ...

  4. Regenerative adsorbent heat pump

    NASA Technical Reports Server (NTRS)

    Jones, Jack A. (Inventor)

    1991-01-01

    A regenerative adsorbent heat pump process and system is provided which can regenerate a high percentage of the sensible heat of the system and at least a portion of the heat of adsorption. A series of at least four compressors containing an adsorbent is provided. A large amount of heat is transferred from compressor to compressor so that heat is regenerated. The process and system are useful for air conditioning rooms, providing room heat in the winter or for hot water heating throughout the year, and, in general, for pumping heat from a lower temperature to a higher temperature.

  5. Heat-of-reaction chemical heat pumps: Possible configurations

    Microsoft Academic Search

    L. D. Kirol

    1986-01-01

    Chemical heat pumps utilize working fluids which undergo reversible chemical changes. Mechanically driven reactive heat pump cycles or, alternatively, heat driven heat pumps in which either heat engine or heat pump working fluid is reactive, are considered. As such, chemical heat pumps can be classified by: (1) drive (electric drive, waste heat drive, or prime energy drive), (2) operating mode

  6. Rotary magnetic heat pump

    DOEpatents

    Kirol, L.D.

    1987-02-11

    A rotary magnetic heat pump constructed without flow seals or segmented rotor accomplishes recuperation and regeneration by using split flow paths. Heat exchange fluid pumped through heat exchangers and returned to the heat pump splits into two flow components: one flowing counter to the rotor rotation and one flowing with the rotation. 5 figs.

  7. Heat release rate calorimetry

    Microsoft Academic Search

    Edwin E. Smith

    1996-01-01

    A simple, theoretically sound method for eliminating the effects of internal heat absorption on rate of heat release is described for the Ohio State University (OSU) Release Rate apparatus. By monitoring the temperature of metal walls and calculating the heat loss to surroundings caused by changes in wall temperature due to heat absorption, a complete energy balance on the system

  8. Rotary magnetic heat pump

    DOEpatents

    Kirol, Lance D. (Shelly, ID)

    1988-01-01

    A rotary magnetic heat pump constructed without flow seals or segmented rotor accomplishes recuperation and regeneration by using split flow paths. Heat exchange fluid pumped through heat exchangers and returned to the heat pump splits into two flow components: one flowing counter to the rotor rotation and one flowing with the rotation.

  9. Loop heat pipes

    Microsoft Academic Search

    Yu. F. Maydanik

    2005-01-01

    Loop heat pipes (LHPs) are two-phase heat-transfer devices with capillary pumping of a working fluid. They possess all the main advantages of conventional heat pipes, but owing to the original design and special properties of the capillary structure are capable of transferring heat efficiency for distances up to several meters at any orientation in the gravity field, or to several

  10. Nature's Heat Exchangers.

    ERIC Educational Resources Information Center

    Barnes, George

    1991-01-01

    Discusses the heat-transfer systems of different animals. Systems include heat conduction into the ground, heat transferred by convection, heat exchange in lizards, fish and polar animals, the carotid rete system, electromagnetic radiation from animals and people, and plant and animal fiber optics. (MDH)

  11. Solar Heating Equipment

    NASA Technical Reports Server (NTRS)

    1981-01-01

    Solar Unlimited, Inc.'s suncatcher line includes a variety of solar arrays, derived from NASA's satellite program: water heating only, partial home heating, or water and whole house central heating. Solar Unlimited developed a set of vigorous requirements to avoid problems common to solar heating technologies.

  12. Solar heat pump

    NASA Astrophysics Data System (ADS)

    Hermanson, R.

    Brief discussions of the major components of a solar powered, chemical ground source heat pump are presented. The components discussed are the solar collectors and the chemical heat storage battery. Sodium sulfide is the medium used for heat storage. Catalog information which provides a description of all of the heat pump systems is included.

  13. Ceramic heat pipe development

    NASA Astrophysics Data System (ADS)

    Merrigan, M.

    1980-12-01

    Progress in developing ceramic heat pipe recuperators for recovering heat from industrial processing furnaces is reported. Information is included on the design, materials procurement, fabrication, materials testing, performance testing, performance and cost of ceramic heat pipes, especially tungsten-coated silicon carbide and Sic-W-Mo heat pipes.

  14. Ceramic heat pipe development

    Microsoft Academic Search

    M. Merrigan

    1980-01-01

    Progress in developing ceramic heat pipe recuperators for recovering heat from industrial processing furnaces is reported. Information is included on the design, materials procurement, fabrication, materials testing, performance testing, performance and cost of ceramic heat pipes, especially tungsten-coated silicon carbide and Sic-W-Mo heat pipes.

  15. Improved heat exhaust and the characteristics of the high Tc superconducting terahertz emitter

    NASA Astrophysics Data System (ADS)

    Kashiwagi, T.; Yamamoto, T.; Kitamura, T.; Asanuma, K.; Yasui, T.; Shibano, Y.; Watanabe, C.; Nakade, K.; Saiwai, Y.; Kubo, H.; Sakamoto, K.; Katsuragawa, T.; Tsujimoto, M.; Yoshizaki, R.; Minami, H.; Klemm, R. A.; Kadowaki, K.

    2015-03-01

    In our previous study it is known that THz emitting efficiency improves greatly when the stand-alone type of mesa structure is used for the THz emitting device. The principle reason for that lies in the heat removal from the mesa, in which a gigantic amount of heat is generated while the mesa is in the resistive state. Recently, we developed a new device structure based on the stand-alone type of mesa structure of Bi2212 single crystal in order to make high exhaust of Joule heating. The results show that although the power is comparable and is not significantly increased, very wide the radiation frequencies ranging from 0.3 to 1.6 THz were obtained. We will discuss the details of the radiation characteristics of this one. This study has been supported by CREST-JST. TK is also supported by the Matsuda grant and JST A-STEP. This work is in part performed in collaboration with Dr. Wai Kwok and his group in Argonne National Lab.

  16. Dual mode heat exchanger

    NASA Astrophysics Data System (ADS)

    Altoz, F. E.

    1985-12-01

    The invention comprises a compact, light weight, dual mode heat transfer device. The dual mode heat transfer device provides for air cooling of heat dissipating electronic components at moderate aircraft speeds and when available ambient air is below a preselected temperature. At elevated aircraft speeds when the ambient air temperature is above the preselected temperature a coolant liquid is converted to steam or vapor in order to cool the heat dissipating electronic components. A preferred embodiment of the invention includes a cold plate for conducting heat away from the heat dissipating components and radiator fins for dissipating cold plate heat to a air cooling flow.

  17. Thulium-170 heat source

    SciTech Connect

    Walter, C.E.; Van Konynenburg, R.; VanSant, J.H.

    1990-09-06

    An isotopic heat source is formed using stacks of thin individual layers of a refractory isotopic fuel, preferably thulium oxide, alternating with layers of a low atomic weight diluent, preferably graphite. The graphite serves several functions: to act as a moderator during neutron irradiation, to minimize bremsstrahlung radiation, and to facilitate heat transfer. The fuel stacks are inserted into a heat block, which is encased in a sealed, insulated and shielded structural container. Heat pipes are inserted in the heat block and contain a working fluid. The heat pipe working fluid transfers heat from the heat block to a heat exchanger for power conversion. Single phase gas pressure controls the flow of the working fluid for maximum heat exchange and to provide passive cooling.

  18. Thulium-170 heat source

    DOEpatents

    Walter, Carl E. (Pleasanton, CA); Van Konynenburg, Richard (Livermore, CA); VanSant, James H. (Tracy, CA)

    1992-01-01

    An isotopic heat source is formed using stacks of thin individual layers of a refractory isotopic fuel, preferably thulium oxide, alternating with layers of a low atomic weight diluent, preferably graphite. The graphite serves several functions: to act as a moderator during neutron irradiation, to minimize bremsstrahlung radiation, and to facilitate heat transfer. The fuel stacks are inserted into a heat block, which is encased in a sealed, insulated and shielded structural container. Heat pipes are inserted in the heat block and contain a working fluid. The heat pipe working fluid transfers heat from the heat block to a heat exchanger for power conversion. Single phase gas pressure controls the flow of the working fluid for maximum heat exchange and to provide passive cooling.

  19. Heat Treating Apparatus

    DOEpatents

    De Saro, Robert (Annandale, NJ); Bateman, Willis (Sutton Colfield, GB)

    2002-09-10

    Apparatus for heat treating a heat treatable material including a housing having an upper opening for receiving a heat treatable material at a first temperature, a lower opening, and a chamber therebetween for heating the heat treatable material to a second temperature higher than the first temperature as the heat treatable material moves through the chamber from the upper to the lower opening. A gas supply assembly is operatively engaged to the housing at the lower opening, and includes a source of gas, a gas delivery assembly for delivering the gas through a plurality of pathways into the housing in countercurrent flow to movement of the heat treatable material, whereby the heat treatable material passes through the lower opening at the second temperature, and a control assembly for controlling conditions within the chamber to enable the heat treatable material to reach the second temperature and pass through the lower opening at the second temperature as a heated material.

  20. Thermoelectric heat exchange element

    DOEpatents

    Callas, James J. (Peoria, IL); Taher, Mahmoud A. (Peoria, IL)

    2007-08-14

    A thermoelectric heat exchange module includes a first substrate including a heat receptive side and a heat donative side and a series of undulatory pleats. The module may also include a thermoelectric material layer having a ZT value of 1.0 or more disposed on at least one of the heat receptive side and the heat donative side, and an electrical contact may be in electrical communication with the thermoelectric material layer.

  1. Heat Integrate Heat Engines in Process Plants

    E-print Network

    Hindmarsh, E.; Boland, D.; Townsend, D. W.

    but not across the pinch. As the Figures illustrate, this appropriate integra tion leads to substantial reductions in utility re quirements over the inappropriately integrated case, Figure 9. Inappropriate integration means the heat 480 ESL-IE-86... Press. i (9) Linnhoff, B. and Hindmarsh, E., "The Pilch Design Method for Heat Exchanger Networkds, "Chern. Eng. Sci., 745-763, 1983. (10) Hindmarsh, E. and Townsend, D.W., "Heat'Integra tion and Distillation Systems into Tota~ Flow sheets - A...

  2. Experimental Research on Solar Assisted Heat Pump Heating System with Latent Heat Storage 

    E-print Network

    Han, Z.; Zheng, M.; Liu, W.; Wang, F.

    2006-01-01

    Assisted Heat Pump Heating System with Latent Heat Storage. In this system, solar energy is the major heat source for a heat pump, and the supplementary heat source is soil. The disagreement in time between the space heat load and heat collected by solar...

  3. The heat pipe heat exchangers: Design, technology and applications

    Microsoft Academic Search

    S. Chadourne

    1991-01-01

    The Heat Pipe Heat Exchanger (HPHE) is a relatively new and very attractice heat exchanger type. For a good understanding of this very special heat exchanger, a minimum knowledge of the heat pipes is required. The heat pipe and thermosyphon basic theory (including the calculation of the thermal limits) is summarized. Some information concerning the heat pipe technological aspects is

  4. Numerical study of heat pipe application in heat recovery systems

    Microsoft Academic Search

    Song Lin; John Broadbent; Ryan McGlen

    2005-01-01

    Heat pipes are two-phase heat transfer devices with extremely high effective thermal conductivity. They can be cylindrical or planar in structure. Heat pipes can be embedded in a metal cooling plate, which is attached to the heat source, and can also be assembled with a fin stack for fluid heat transfer. Due to the high heat transport capacity, heat exchangers

  5. Fluid heating system with storage of electric heat

    Microsoft Academic Search

    McKenney

    1981-01-01

    A heating system includes a heat storage tank containing a heat transfer fluid (Water) electrically heated to a high temperature. A tube\\/shell heat exchanger having a pair of fluid flow paths arranged in counter flow relationship is provided for extraction of heat from storage tank by the circulation of the heat transfer fluid therethrough. Conduit means connect the outlet of

  6. Heat storage device

    SciTech Connect

    Gawron, K.; Mahdjuri, F.; Schroder, J.

    1980-09-02

    A heat storage device is described that is comprised of a closed reservoir within which is positioned a flexible closed container of smaller volume. The flexible container encloses a liquefiable heat-accumulating material; and the reservoir is provided with a heat-transport medium outside of the flexible container. The heat-transport medium always remains in the liquid phase and, upon solidification and shrinkage of the heat-accumulating material, fills the spaces thus formed between the flexible container and the reservoir wall in order to maintain adequate transfer of heat.

  7. Heat transfer system

    DOEpatents

    McGuire, Joseph C. (Richland, WA)

    1982-01-01

    A heat transfer system for a nuclear reactor. Heat transfer is accomplished within a sealed vapor chamber which is substantially evacuated prior to use. A heat transfer medium, which is liquid at the design operating temperatures, transfers heat from tubes interposed in the reactor primary loop to spaced tubes connected to a steam line for power generation purposes. Heat transfer is accomplished by a two-phase liquid-vapor-liquid process as used in heat pipes. Condensible gases are removed from the vapor chamber through a vertical extension in open communication with the chamber interior.

  8. Heat transfer system

    DOEpatents

    Not Available

    1980-03-07

    A heat transfer system for a nuclear reactor is described. Heat transfer is accomplished within a sealed vapor chamber which is substantially evacuated prior to use. A heat transfer medium, which is liquid at the design operating temperatures, transfers heat from tubes interposed in the reactor primary loop to spaced tubes connected to a steam line for power generation purposes. Heat transfer is accomplished by a two-phase liquid-vapor-liquid process as used in heat pipes. Condensible gases are removed from the vapor chamber through a vertical extension in open communication with the chamber interior.

  9. Heat Wave Safety Checklist

    MedlinePLUS

    ... heat has caused more deaths than all other weather events, including floods. A heat wave is a ... stroke include hot, red skin which may be dry or moist; changes in consciousness; vomiting; and high ...

  10. Monogroove liquid heat exchanger

    NASA Technical Reports Server (NTRS)

    Brown, Richard F. (Inventor); Edelstein, Fred (Inventor)

    1990-01-01

    A liquid supply control is disclosed for a heat transfer system which transports heat by liquid-vapor phase change of a working fluid. An assembly (10) of monogroove heat pipe legs (15) can be operated automatically as either heat acquisition devices or heat discharge sources. The liquid channels (27) of the heat pipe legs (15) are connected to a reservoir (35) which is filled and drained by respective filling and draining valves (30, 32). Information from liquid level sensors (50, 51) on the reservoir (35) is combined (60) with temperature information (55) from the liquid heat exchanger (12) and temperature information (56) from the assembly vapor conduit (42) to regulate filling and draining of the reservoir (35), so that the reservoir (35) in turn serves the liquid supply/drain needs of the heat pipe legs (15), on demand, by passive capillary action (20, 28).

  11. Specifying Waste Heat Boilers 

    E-print Network

    Ganapathy, V.

    1992-01-01

    Waste heat boilers or Heat Recovery Steam Generators (HRSGs) as they are often called are used to recover energy from waste gas streams in chemical plants, refineries, kilns, incineration systems and cogeneration and combined cycle plants...

  12. Heat pump advances

    Microsoft Academic Search

    1989-01-01

    This article describes new heat pump units that offer increased comfort as well as energy savings. Hydrotech 2000, a high-efficiency air-source heat pump developed by Carrier Corporation and the Electric Power Research Institute, combines domestic water heating with air conditioning; in addition, the system's compressor and blower use variable-speed motors. This reduces electric consumption by matching the heat pump's output

  13. Abrasion resistant heat pipe

    DOEpatents

    Ernst, D.M.

    1984-10-23

    A specially constructed heat pipe is described for use in fluidized bed combustors. Two distinct coatings are spray coated onto a heat pipe casing constructed of low thermal expansion metal, each coating serving a different purpose. The first coating forms aluminum oxide to prevent hydrogen permeation into the heat pipe casing, and the second coating contains stabilized zirconium oxide to provide abrasion resistance while not substantially affecting the heat transfer characteristics of the system.

  14. Abrasion resistant heat pipe

    DOEpatents

    Ernst, Donald M. (Leola, PA)

    1984-10-23

    A specially constructed heat pipe for use in fluidized bed combustors. Two distinct coatings are spray coated onto a heat pipe casing constructed of low thermal expansion metal, each coating serving a different purpose. The first coating forms aluminum oxide to prevent hydrogen permeation into the heat pipe casing, and the second coating contains stabilized zirconium oxide to provide abrasion resistance while not substantially affecting the heat transfer characteristics of the system.

  15. 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.

  16. Solar heat receiver

    DOEpatents

    Hunt, Arlon J. (Oakland, CA); Hansen, Leif J. (Berkeley, CA); Evans, David B. (Orinda, CA)

    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.

  17. Mass and Heat Recovery 

    E-print Network

    Hindawai, S. M.

    2010-01-01

    uses. Figure (1) showing the mass and heat recovery system (MHRS) layout . This layout can divided to four (4) sections : 1. Mass and heat collection (MHC) . 2. Mass and heat storage unit (MHSU) . 3. Heat recovery unit (HRU) . 4. Mass... recovery unit (MRU) . ESL-IC-10-10-56 Proceedings of the Tenth International Conference for Enhanced Building Operations, Kuwait, October 26-28, 2010 - 2 - ESL-IC-10-10-56 Proceedings of the Tenth International Conference for Enhanced...

  18. Heat Transfer Guest Editorial

    E-print Network

    Kandlikar, Satish

    Journal of Heat Transfer Guest Editorial We are indeed delighted in bringing out this special issue was showcased in diverse areas such as traditional heat and mass transfer, lab-on-chip, sensors, biomedical applica- tions, micromixers, fuel cells, and microdevices. Selected papers in the field of heat transfer

  19. Champagne Heat Pump

    NASA Technical Reports Server (NTRS)

    Jones, Jack A.

    2004-01-01

    The term champagne heat pump denotes a developmental heat pump that exploits a cycle of absorption and desorption of carbon dioxide in an alcohol or other organic liquid. Whereas most heat pumps in common use in the United States are energized by mechanical compression, the champagne heat pump is energized by heating. The concept of heat pumps based on other absorption cycles energized by heat has been understood for years, but some of these heat pumps are outlawed in many areas because of the potential hazards posed by leakage of working fluids. For example, in the case of the water/ammonia cycle, there are potential hazards of toxicity and flammability. The organic-liquid/carbon dioxide absorption/desorption cycle of the champagne heat pump is similar to the water/ammonia cycle, but carbon dioxide is nontoxic and environmentally benign, and one can choose an alcohol or other organic liquid that is also relatively nontoxic and environmentally benign. Two candidate nonalcohol organic liquids are isobutyl acetate and amyl acetate. Although alcohols and many other organic liquids are flammable, they present little or no flammability hazard in the champagne heat pump because only the nonflammable carbon dioxide component of the refrigerant mixture is circulated to the evaporator and condenser heat exchangers, which are the only components of the heat pump in direct contact with air in habitable spaces.

  20. Heat pumps in distillation

    Microsoft Academic Search

    1976-01-01

    The methods used and results obtained in evaluating the economics of substituting heat pumps for conventional distillation process design are presented. From this study it was concluded that: heat pumps have extensive applicability to distillation whenever direct refrigeration or chilled water are required for condensation; heat pumps have limited, but very real ranges of applicability when reboiler temperatures are above

  1. Waste heat recovery boiler

    Microsoft Academic Search

    E. Yanai; T. Kuribayashi

    1987-01-01

    A waste heat recovery boiler is described which utilizes an exhaust gas of a gas turbine and generates steam for driving a steam turbine. The improvement wherein at least two denitrating devices for removing NO\\/sub x\\/ components in the exhaust gas therefrom are disposed inside the waste heat recovery boiler. The waste heat recovery boiler is equipped with fuel economizers

  2. Heat Loss Calculation Exercise

    NSDL National Science Digital Library

    Garrison, Kirk

    This class exercise from Kirk Garrison is intended for construction students learning about home insulation and heating. The class will learn to calculate heat loss in a home by using an online home heat loss calculator. This exercise document includes student worksheets. This document may be downloaded in PDF file format.

  3. Solar heated anaerobic digestor

    Microsoft Academic Search

    Rhoades

    1980-01-01

    A solar heated anaerobic digestor is provided, adapted to utilize organic material capable of decomposing to produce methane gas and a liquid fertilizer. The sealed anaerobic digestor is wrapped with a layer of heat absorptive material followed by a series of abutting removable panels of insulative material. Insulative panels may be temporarily removed to expose the heat absorptive material to

  4. Heated graphite cylinder electrodes

    Microsoft Academic Search

    Jian-Jun Sun; Liang Guo; De-Feng Zhang; Wen-Hui Yin; Guo-Nan Chen

    2007-01-01

    A new heated graphite cylinder electrode (HGCE) has been successfully fabricated, which arrangement is similar to that of the heated metal (Pt or Au) wire electrode invented by Grundler. The cylinders’ diameters range from ca. 95 to 300?m obtained by grinding the commercial available pencil graphite. HGCEs demonstrate rapid responses to the heating up and high thermal stability during being

  5. Heat pipe technology issues

    Microsoft Academic Search

    M. A. Merrigan

    1984-01-01

    Critical high temperature, high power applications in space nuclear power designs are near the current state of the art of heat pipe technology in terms of power density, operating temperature, and lifetime. Recent heat pipe development work at Los Alamos National Laboratory involved performance testing of typical space reactor heat pipe designs to power levels in excess of 19 kW\\/cm(2)

  6. Roles of Clathrate Hydrates in Crustal Heating and Volatile Storage/Release on Earth, Mars, and Beyond

    NASA Astrophysics Data System (ADS)

    Kargel, J. S.; Beget, J.; Furfaro, R.; Prieto-Ballesteros, O.; Palmero-Rodriguez, J. A.

    2007-12-01

    Clathrate hydrates are stable through much of the Solar System. These materials and hydrate-like amorphous associations of water with N2, CO, CH4, CO2, O2 and other molecules could, in fact, constitute the bulk of the non-rock components of some icy satellites, comets, and Kuiper Belt Objects. CO2 clathrate is thermodynamically stable at the Martian South Pole surface and could form a significant fraction of both Martian polar caps and icy permafrost distributed across one-third of the Martian surface. CH4 clathrate is the largest clathrate material in Earth's permafrost and cold seafloor regions, and it may be a major volatile reservoir on Mars, too. CO2 clathrate is less abundant on Earth but it might store most of Mars' CO2 inventory and thus may be one of the critical components in the climate system of that planet, just as CH4 clathrate is for Earth. These ice-like phases not only store biologically, geologically, and climatologically important gases, but they also are natural thermal insulators. Thus, they retard the conductive flow of geothermal heat, and thick accumulations of them can modify geotherms, cause brines to exist where otherwise they would not, and induce low-grade metamorphism of upper crustal rocks underlying the insulating bodies. This mechanism of crustal heating may be especially important in assisting hydrogeologic activity on Mars, gas-rich carbonaceous asteroids, icy satellites, and Kuiper Belt Objects. These worlds, compared to Earth, are comparatively energy starved and frozen but may partly make up for their deficit of joules by having large accumulations of joule-conserving hydrates. Thick, continuous layers of clathrate may seal in gases and produce high gas fugacities in aquifers underlying the clathrates, thus producing gas-rich reservoirs capable of erupting violently. This may have happened repeatedly in Earth history, with global climatic consequences for abrupt climate change. We have hypothesized that such eruptions may have occurred during interglacial epochs and formed super-size maar craters in Bering Land Bridge National Preserve (Alaska). On Mars, clathrates and gas-saturated aquifers apparently played some role in the largest flood- and debris-flow-forming events in that planet's history, with vast consequences for landform development and resurfacing. This heating phenomenon also has possible implications for carbon sequestration as a means of climate change mediation on Earth; besides other concerns about their long-term stability, artificial hydrates produced by carbon dioxide pumping onto the seafloor might heat up and become unstable over time due to normal background radiogenic heat flux.

  7. High heat flux loop heat pipes

    NASA Technical Reports Server (NTRS)

    North, Mark T.; Sarraf, David B.; Rosenfeld, John H.; Maidanik, Yuri F.; Vershinin, Sergey

    1997-01-01

    Loop heat pipes (LHPs) can transport very large thermal power loads over long distances, through flexible, small diameter tubes against gravitational heads. In order to overcome the evaporator limit of LHPs, which is of about 0.07 MW/sq m, work was carried out to improve the efficiency by threefold to tenfold. The vapor passage geometry for the high heat flux conditions is shown. A bidisperse wick material within the circumferential vapor passages was used. Along with heat flux enhancement, several underlying issues were demonstrated, including the fabrication of bidisperse powder with controlled properties and the fabrication of a device geometry capable of replacing vapor passages with bidisperse powder.

  8. The use of heat pumps in district heat supply

    NASA Astrophysics Data System (ADS)

    Winkens, H. P.

    1985-04-01

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

  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. Solar heated anaerobic digestor

    SciTech Connect

    Rhoades, D.

    1980-09-09

    A solar heated anaerobic digestor is provided, adapted to utilize organic material capable of decomposing to produce methane gas and a liquid fertilizer. The sealed anaerobic digestor is wrapped with a layer of heat absorptive material followed by a series of abutting removable panels of insulative material. Insulative panels may be temporarily removed to expose the heat absorptive material to solar radiation and may be replaced when the solar radiation diminishes. A layer of transparent material wrapped in outwardly spaced relation around the insulatng panels is capable of transmitting solar radiation while providing protection against environmental elements. Additional heating means extending into the digestor provide auxiliary heat as required.

  11. Urban heat island

    NASA Technical Reports Server (NTRS)

    Kim, Hongsuk H.

    1991-01-01

    The phenomenon of urban heat island was investigated by the use of LANDSAT Thematic Mapper data sets collected over the metropolitan area of Washington DC (U.S.). By combining the retrieved spectral albedos and temperatures, urban modification on radiation budgets of five surface categories were analyzed. The surface radiation budget imagery of the area show that urban heating is attributable to a large heat flux from the rapidly heating surfaces of asphalt, bare soil and short grass. In summer, symptoms of diurnal heating begin to appear by mid morning and can be about 10 degrees warmer than nearby woodlands in summer.

  12. Electromagnetic heating of Io

    NASA Astrophysics Data System (ADS)

    Colburn, D. S.

    1980-12-01

    The electromagnetic heating of the Io interior is considered as an alternative to tidal dissipation to account for the observed volcanic activity. The characteristics of the time-varying magnetic field of Jupiter as seen from Io are discussed, and the range of possible rock conductivities is examined. Interior heating due to the transverse electric and transverse magnetic modes is calculated. It is found that the TM mode appears to be insignificant as a heating source due to the high conductivity of the ionosphere, even when TM heating is concentrated in local hot regions. The TE mode is a more promising source of heating, although electromagnetic heating by either mode does not appear significant in comparison with other heat sources at present.

  13. 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.

  14. Miniature Heat Pipes

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Small Business Innovation Research contracts from Goddard Space Flight Center to Thermacore Inc. have fostered the company work on devices tagged "heat pipes" for space application. To control the extreme temperature ranges in space, heat pipes are important to spacecraft. The problem was to maintain an 8-watt central processing unit (CPU) at less than 90 C in a notebook computer using no power, with very little space available and without using forced convection. Thermacore's answer was in the design of a powder metal wick that transfers CPU heat from a tightly confined spot to an area near available air flow. The heat pipe technology permits a notebook computer to be operated in any position without loss of performance. Miniature heat pipe technology has successfully been applied, such as in Pentium Processor notebook computers. The company expects its heat pipes to accommodate desktop computers as well. Cellular phones, camcorders, and other hand-held electronics are forsible applications for heat pipes.

  15. Active microchannel heat exchanger

    DOEpatents

    Tonkovich, Anna Lee Y. (Pasco, WA) [Pasco, WA; Roberts, Gary L. (West Richland, WA) [West Richland, WA; Call, Charles J. (Pasco, WA) [Pasco, WA; Wegeng, Robert S. (Richland, WA) [Richland, WA; Wang, Yong (Richland, WA) [Richland, WA

    2001-01-01

    The present invention is an active microchannel heat exchanger with an active heat source and with microchannel architecture. The microchannel heat exchanger has (a) an exothermic reaction chamber; (b) an exhaust chamber; and (c) a heat exchanger chamber in thermal contact with the exhaust chamber, wherein (d) heat from the exothermic reaction chamber is convected by an exothermic reaction exhaust through the exhaust chamber and by conduction through a containment wall to the working fluid in the heat exchanger chamber thereby raising a temperature of the working fluid. The invention is particularly useful as a liquid fuel vaporizer and/or a steam generator for fuel cell power systems, and as a heat source for sustaining endothermic chemical reactions and initiating exothermic reactions.

  16. Nanofluid heat capacities

    NASA Astrophysics Data System (ADS)

    Starace, Anne K.; Gomez, Judith C.; Wang, Jun; Pradhan, Sulolit; Glatzmaier, Greg C.

    2011-12-01

    Significant increases in the heat capacity of heat transfer fluids are needed not only to reduce the costs of liquid heating and cooling processes, but also to bring clean energy producing technologies like concentrating solar power (CSP) to price parity with conventional energy generation. It has been postulated that nanofluids could have higher heat capacities than conventional fluids. In this work, nano- and micron-sized particles were added to five base fluids (poly-? olefin, mineral oil, ethylene glycol, a mixture of water and ethylene glycol, and calcium nitrate tetrahydrate), and the resulting heat capacities were measured and compared with those of the neat base fluids and the weighted average of the heat capacities of the components. The particles used were inert metals and metal oxides that did not undergo any phase transitions over the temperature range studied. In the nanofluids studied here, we found no increase in heat capacity upon the addition of the particles larger than the experimental error.

  17. Heat tube device

    NASA Technical Reports Server (NTRS)

    Khattar, Mukesh K. (inventor)

    1990-01-01

    The present invention discloses a heat tube device through which a working fluid can be circulated to transfer heat to air in a conventional air conditioning system. The heat tube device is disposable about a conventional cooling coil of the air conditioning system and includes a plurality of substantially U-shaped tubes connected to a support structure. The support structure includes members for allowing the heat tube device to be readily positioned about the cooling coil. An actuatable adjustment device is connected to the U-shaped tubes for allowing, upon actuation thereof, for the heat tubes to be simultaneously rotated relative to the cooling coil for allowing the heat transfer from the heat tube device to air in the air conditioning system to be selectively varied.

  18. Heat Recovery from Coal Gasifiers

    E-print Network

    Wen, H.; Lou, S. C.

    1981-01-01

    and convection waste heat boilers. Medium level waste heat leaving fixed bed type gasifiers can be recovered more economically by convection type boilers or shell and tube heat exchangers. An economic analysis for the steam generation and process heat exchanger...

  19. Lunar base heat pump

    NASA Technical Reports Server (NTRS)

    Goldman, Jeffrey H.; Tetreault, R.; Fischbach, D.; Walker, D.

    1994-01-01

    A heat pump is a device which elevates the temperature of a heat flow by a means of an energy input. By doing this, the heat pump can cause heat to transfer faster from a warm region to a cool region, or it can cause heat to flow from a cool region to a warmer region. The second case is the one which finds vast commercial applications such as air conditioning, heating, and refrigeration. Aerospace applications of heat pumps include both cases. The NASA Johnson Space Center is currently developing a Life Support Systems Integration Facility (LSSIF, previously SIRF) to provide system-level integration, operational test experience, and performance data that will enable NASA to develop flight-certified hardware for future planetary missions. A high lift heat pump is a significant part of the TCS hardware development associated with the LSSIF. The high lift heat pump program discussed here is being performed in three phases. In Phase 1, the objective is to develop heat pump concepts for a lunar base, a lunar lander, and for a ground development unit for the SIRF. In Phase 2, the design of the SIRF ground test unit is being performed, including identification and evaluation of safety and reliability issues. In Phase 3, the SIRF unit will be manufactured, tested, and delivered to the NASA Johnson Space Center.

  20. Optimization of Heat Exchangers

    SciTech Connect

    Ivan Catton

    2010-10-01

    The objective of this research is to develop tools to design and optimize heat exchangers (HE) and compact heat exchangers (CHE) for intermediate loop heat transport systems found in the very high temperature reator (VHTR) and other Generation IV designs by addressing heat transfer surface augmentation and conjugate modeling. To optimize heat exchanger, a fast running model must be created that will allow for multiple designs to be compared quickly. To model a heat exchanger, volume averaging theory, VAT, is used. VAT allows for the conservation of mass, momentum and energy to be solved for point by point in a 3 dimensional computer model of a heat exchanger. The end product of this project is a computer code that can predict an optimal configuration for a heat exchanger given only a few constraints (input fluids, size, cost, etc.). As VAT computer code can be used to model characteristics )pumping power, temperatures, and cost) of heat exchangers more quickly than traditional CFD or experiment, optimization of every geometric parameter simultaneously can be made. Using design of experiment, DOE and genetric algorithms, GE, to optimize the results of the computer code will improve heat exchanger disign.

  1. Heat pump system

    DOEpatents

    Swenson, Paul F.; Moore, Paul B.

    1983-06-21

    An air heating and cooling system for a building includes an expansion type refrigeration circuit and a vapor power circuit. The refrigeration circuit includes two heat exchangers, one of which is communicated with a source of indoor air from the building and the other of which is communicated with a source of air from outside the building. The vapor power circuit includes two heat exchangers, one of which is disposed in series air flow relationship with the indoor refrigeration circuit heat exchanger and the other of which is disposed in series air flow relationship with the outdoor refrigeration circuit heat exchanger. Fans powered by electricity generated by a vapor power circuit alternator circulate indoor air through the two indoor heat exchangers and circulate outside air through the two outdoor heat exchangers. The system is assembled as a single roof top unit, with a vapor power generator and turbine and compressor thermally insulated from the heat exchangers, and with the indoor heat exchangers thermally insulated from the outdoor heat exchangers.

  2. Heat pump system

    DOEpatents

    Swenson, Paul F. (Shaker Heights, OH); Moore, Paul B. (Fedhaven, FL)

    1983-01-01

    An air heating and cooling system for a building includes an expansion type refrigeration circuit and a vapor power circuit. The refrigeration circuit includes two heat exchangers, one of which is communicated with a source of indoor air from the building and the other of which is communicated with a source of air from outside the building. The vapor power circuit includes two heat exchangers, one of which is disposed in series air flow relationship with the indoor refrigeration circuit heat exchanger and the other of which is disposed in series air flow relationship with the outdoor refrigeration circuit heat exchanger. Fans powered by electricity generated by a vapor power circuit alternator circulate indoor air through the two indoor heat exchangers and circulate outside air through the two outdoor heat exchangers. The system is assembled as a single roof top unit, with a vapor power generator and turbine and compressor thermally insulated from the heat exchangers, and with the indoor heat exchangers thermally insulated from the outdoor heat exchangers.

  3. Laser heated thermoluminescence dosimetry

    SciTech Connect

    Justus, B.L.; Huston, A.L. [Naval Research Laboratory, Washington, DC (United States)

    1996-06-01

    We report a novel laser-heated thermoluminescence dosimeter that is radically different from previous laser-heated dosimeters. The dosimeter is a semiconductor and metal ion doped silica glass that has excellent optical transparency. The high optical quality of the glass essentially eliminates laser power loss due to light scattering. This efficient utilization of the laser power permits operation of the dosimeter without strong absorption of the laser, as is required in traditional laser-heated dosimetry. Our laser-heated dosimeter does not rely on the diffusion of heat from a separate, highly absorbing substrate, but operates via intimate, localized heating within the glass dosimeter due to the absorption of the laser light by rare earth ion dopants in the glass. Following absorption of the laser light, the rare earth ions transfer energy to the surrounding glass via nonradiative relaxation processes, resulting in rapid, localized temperature increases sufficient to release all the filled traps near the ions. As the heat diffuses radially away from the rare earth ions the temperature plummets dramatically on a manometer distance scale and the release of additional filled traps subsides. A key distinguishing feature of this laser-heated dosimeter is the ability to read the dose information more than once. While laser-heating provides complete information about the radiation exposure experienced by the glass due to the release of locally heated traps, the process leaves the remaining filled bulk traps undisturbed. The bulk traps can be read using traditional bulk heating methods and can provide a direct determination of an accumulated dose, measured following any number of laser-heated readouts. Laser-heated dosimetry measurements have been performed using a solid state diode laser for the readout following radiation exposure with a {sup 60}Co source.

  4. Silicon Heat Pipe Array

    NASA Technical Reports Server (NTRS)

    Yee, Karl Y.; Ganapathi, Gani B.; Sunada, Eric T.; Bae, Youngsam; Miller, Jennifer R.; Beinsford, Daniel F.

    2013-01-01

    Improved methods of heat dissipation are required for modern, high-power density electronic systems. As increased functionality is progressively compacted into decreasing volumes, this need will be exacerbated. High-performance chip power is predicted to increase monotonically and rapidly with time. Systems utilizing these chips are currently reliant upon decades of old cooling technology. Heat pipes offer a solution to this problem. Heat pipes are passive, self-contained, two-phase heat dissipation devices. Heat conducted into the device through a wick structure converts the working fluid into a vapor, which then releases the heat via condensation after being transported away from the heat source. Heat pipes have high thermal conductivities, are inexpensive, and have been utilized in previous space missions. However, the cylindrical geometry of commercial heat pipes is a poor fit to the planar geometries of microelectronic assemblies, the copper that commercial heat pipes are typically constructed of is a poor CTE (coefficient of thermal expansion) match to the semiconductor die utilized in these assemblies, and the functionality and reliability of heat pipes in general is strongly dependent on the orientation of the assembly with respect to the gravity vector. What is needed is a planar, semiconductor-based heat pipe array that can be used for cooling of generic MCM (multichip module) assemblies that can also function in all orientations. Such a structure would not only have applications in the cooling of space electronics, but would have commercial applications as well (e.g. cooling of microprocessors and high-power laser diodes). This technology is an improvement over existing heat pipe designs due to the finer porosity of the wick, which enhances capillary pumping pressure, resulting in greater effective thermal conductivity and performance in any orientation with respect to the gravity vector. In addition, it is constructed of silicon, and thus is better suited for the cooling of semiconductor devices.

  5. Reversible oxygen vacancies doping in (La0.7,Sr0.3)MnO3 microbridges by combined self-heating and electromigration

    NASA Astrophysics Data System (ADS)

    Manca, Nicola; Pellegrino, Luca; Marré, Daniele

    2015-05-01

    Combination of electric fields and Joule self-heating is used to change the oxygen stoichiometry and promote oxygen vacancy drift in a freestanding (La,Sr)MnO3 thin film microbridge placed in controlled atmosphere. By controlling the local oxygen vacancies concentration, we can reversibly switch our (La,Sr)MnO3-based microbridges from metallic to insulating behavior on timescales lower than 1 s and with small applied voltages (<5 V). The strong temperature gradients given by the microbridge geometry strongly confine the motion of oxygen vacancies, limiting the modified region within the free-standing area. Multiple resistive states can be set by selected current pulses that determine different oxygen vacancies profiles within the device. Qualitative analysis of device operation is also provided with the support of finite element analysis.

  6. Plasma heat pump and heat engine

    SciTech Connect

    Avinash, K. [Centre for Space Plasma and Aeronomic Research, University of Alabama, Huntsville, Alabama 35899 (United States) and Department of Physics and Astrophysics, University of Delhi, Delhi 110007 (India)

    2010-08-15

    A model system where cold charged particles are locally confined in a volume V{sub P} within a warm plasma of volume V (V{sub P}<heat and vice versa. Two applications of this theory are, first we propose a pumping device which heats plasmas by an adiabatic/isothermal compression of fields. Heating power ranging from a few hundred watts to a few kilowatts is possible with the present day technology. Second, we discuss the feasibility of constructing an electrostatic heat engine which converts plasma heat into mechanical work via plasma electric fields. Effects of P{sub E} are shown to be observable in colloidal solutions.

  7. Waste heat recovery using heat pipe heat exchanger (HPHE) for surgery rooms in hospitals

    Microsoft Academic Search

    S. H. Noie-Baghban; G. R. Majideian

    2000-01-01

    Research has been carried out on the theory, design and construction of heat pipes, especially their use in heat pipe heat exchangers for energy recovery, reduction of air pollution and environmental conservation. A heat pipe heat exchanger has been designed and constructed for heat recovery in hospital and laboratories, where the air must be changed up to 40 times per

  8. Hybrid cycle power plant with heat accumulator for storing heat exchange fluid transferring heat between cycles

    Microsoft Academic Search

    Pacault

    1976-01-01

    An installation for producing motive power, operating on a hybrid cycle of gas and vapor such as steam is described. The installation has a heat accumulator for storing a heat-exchange fluid which can also act as a fluid fuel for a heat source adapted to heat the fluid of the heat accumulator. Heat can be drawn from the accumulator in

  9. Electrohydrodynamic heat pipe experiments

    NASA Technical Reports Server (NTRS)

    Jones, T. B.; Perry, M. P.

    1974-01-01

    Experiments with two electrohydrodynamic heat pipes are reported. Both devices employ an electromechanical flow structure for axial liquid flow and a capillary wicking structure for (1) collection of condensed liquid at the cooled end and (2) distribution of this liquid at the heated end. One device has circumferential grooving for the capillary structure and the other has feltmetal wicking. The experiments successfully demonstrate the electrohydrodynamic heat pipe concept. Compatibility of the two circumferential wick structures with an axial electromechanical flow structure is also demonstrated. A significant mismatch of the capillary groove and electrohydrodynamic pumping capabilities results in severe hydrodynamic burn-out limiting in the first heat pipe. Both devices have very poor over-all thermal conductances of the order of 1-2 W/deg C, reflecting the generally poor heat-transfer properties of the dielectric working fluids required in electrohydrodynamic heat pipes.

  10. Water-heating dehumidifier

    DOEpatents

    Tomlinson, John J. (Knoxville, TN)

    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.

  11. What's waste heat worth

    SciTech Connect

    Campagne, W.V.L.

    1982-07-01

    An evaluation technique to determine the monetary revenue, in dollars, of a waste heat recovery project is introduced. This evaluation technique shows how to translate the heat transferred from a donor stream (waste heat) to a recipient stream, into a dollar loss for the donor and a dollar gain for the recipient. It is this ratio of dollar gain over dollar loss which reflects the fuel recovery ratio, and which determines the efficiency of the waste heat recovery. This evaluation technique is based on the premise that waste heat recovery can be equated to potential steam savings and thus, the fuel value in dollars of the waste heat as a function of its temperature can be related to that of steam. 4 refs.

  12. Heat illness in Cyprus.

    PubMed

    Bricknell, M C

    1994-06-01

    Heat illness in the Armed Forces is an emotive issue. No specific service-wide system currently exists to monitor the incidence of heat illness. Within British Forces Cyprus medical policy guidelines for physical activity at various Wet Bulb Globe Temperature (WBGT) readings were issued in 1988. A local system for reporting heat casualties was introduced in August 1989. This paper examined retrospectively the reports of heat illness casualties from August 1988 to December 1992 in Cyprus. There was a reduction in reported incidents causing heat casualties over the period studied from 18 incidents in 1990 to 8 in 1992. There was also a reduction in the maximum recorded WBGT reading for each incident. From these results it would seem that there may have been a reduction in preventable heat casualties attributable to commanders following the WBGT guidelines. PMID:8907832

  13. Heat-pipe Earth.

    PubMed

    Moore, William B; Webb, A Alexander G

    2013-09-26

    The heat transport and lithospheric dynamics of early Earth are currently explained by plate tectonic and vertical tectonic models, but these do not offer a global synthesis consistent with the geologic record. Here we use numerical simulations and comparison with the geologic record to explore a heat-pipe model in which volcanism dominates surface heat transport. These simulations indicate that a cold and thick lithosphere developed as a result of frequent volcanic eruptions that advected surface materials downwards. Declining heat sources over time led to an abrupt transition to plate tectonics. Consistent with model predictions, the geologic record shows rapid volcanic resurfacing, contractional deformation, a low geothermal gradient across the bulk of the lithosphere and a rapid decrease in heat-pipe volcanism after initiation of plate tectonics. The heat-pipe Earth model therefore offers a coherent geodynamic framework in which to explore the evolution of our planet before the onset of plate tectonics. PMID:24067709

  14. Induction Heating Systems

    NASA Technical Reports Server (NTRS)

    1991-01-01

    Induction heating technology, a magnetic non-deforming process, was developed by Langley researchers to join plastic and composite components in space. Under NASA license, Inductron Corporation uses the process to produce induction heating systems and equipment for numerous applications. The Torobonder, a portable system, comes with a number of interchangeable heads for aircraft repair. Other developments are the E Heating Head, the Toroid Joining Gun, and the Torobrazer. These products perform bonding applications more quickly, safely and efficiently than previous methods.

  15. NCSX Plasma Heating Methods

    SciTech Connect

    H.W. Kugel; D. Spong; R. Majeski; M. Zarnstorff

    2003-02-28

    The NCSX (National Compact Stellarator Experiment) has been designed to accommodate a variety of heating systems, including ohmic heating, neutral-beam injection, and radio-frequency. Neutral beams will provide one of the primary heating methods for NCSX. In addition to plasma heating, beams are also expected to provide a means for external control over the level of toroidal plasma rotation velocity and its profile. The plan is to provide 3 MW of 50 keV balanced neutral-beam tangential injection with pulse lengths of 500 msec for initial experiments, and to be upgradeable to pulse lengths of 1.5 sec. Subsequent upgrades will add 3 MW of neutral-beam injection. This Chapter discusses the NCSX neutral-beam injection requirements and design issues, and shows how these are provided by the candidate PBX-M (Princeton Beta Experiment-Modification) neutral-beam injection system. In addition, estimations are given for beam-heating efficiencies, scaling of heating efficiency with machine size an d magnetic field level, parameter studies of the optimum beam-injection tangency radius and toroidal injection location, and loss patterns of beam ions on the vacuum chamber wall to assist placement of wall armor and for minimizing the generation of impurities by the energetic beam ions. Finally, subsequent upgrades could add an additional 6 MW of radio-frequency heating by mode-conversion ion-Bernstein wave (MCIBW) heating, and if desired as possible future upgrades, the design also will accommodate high-harmonic fast-wave and electron-cyclotron heating. The initial MCIBW heating technique and the design of the radio-frequency system lend themselves to current drive, so that if current drive became desirable for any reason only minor modifications to the heating system described here would be needed. The radio-frequency system will also be capable of localized ion heating (bulk or tail), and possibly ion-Bernstein-wave-generated sheared flows.

  16. NCSX Plasma Heating Methods

    SciTech Connect

    Kugel, H. W.; Spong, D.; Majeski, R.; Zarnstorff, M.

    2008-01-18

    The National Compact Stellarator Experiment (NCSX) has been designed to accommodate a variety of heating systems, including ohmic heating, neutral beam injection, and radio-frequency (rf). Neutral beams will provide one of the primary heating methods for NCSX. In addition to plasma heating, neutral beams are also expected to provide a means for external control over the level of toroidal plasma rotation velocity and its profile. The experimental plan requires 3 MW of 50-keV balanced neutral beam tangential injection with pulse lengths of 500 ms for initial experiments, to be upgradeable to pulse lengths of 1.5 s. Subsequent upgrades will add 3MW of neutral beam injection (NBI). This paper discusses the NCSX NBI requirements and design issues and shows how these are provided by the candidate PBX-M NBI system. In addition, estimations are given for beam heating efficiencies, scaling of heating efficiency with machine size and magnetic field level, parameter studies of the optimum beam injection tangency radius and toroidal injection location, and loss patterns of beam ions on the vacuum chamber wall to assist placement of wall armor and for minimizing the generation of impurities by the energetic beam ions. Finally, subsequent upgrades could add an additional 6 MW of rf heating by mode conversion ion Bernstein wave (MCIBW) heating, and if desired as possible future upgrades, the design also will accommodate high-harmonic fast-wave and electron cyclotron heating. The initial MCIBW heating technique and the design of the rf system lend themselves to current drive, so if current drive became desirable for any reason, only minor modifications to the heating system described here would be needed. The rf system will also be capable of localized ion heating (bulk or tail), and possiblyIBW-generated sheared flows.

  17. Heating steels in vacuum

    Microsoft Academic Search

    Marmer

    1983-01-01

    It is recommended that high-strength and corrosion-resistant steels be heated in an electric vacuum furnace. Absence of oxidation and decarburization, decrease in the deformation of the part, increase in service life, plus safety, and nontoxicity in the shop, are cited as advantages. Annealing, carburizing, hardening, brazing, and sintering--all detailed-can be more efficiently accomplished in vacuum heating. As vacuum heating requires

  18. Industrial Heat Recovery - 1982 

    E-print Network

    Csathy, D.

    1982-01-01

    limit, for natural circulation boil ers, is the available static head which determines the total resistance of the circulating system. For higher pressure boilers, taller, narrow boilers (with fewer tubes and More static head) are nreferrable from... 2000 psi~ Heat Flux When the heat flux reaches the point at which there is a departure from nucleate boiling, the tube wall temperature will rise sharply and subsequent tube failure may result. This critical heat flux is a function of several...

  19. Heat pipe technology issues

    SciTech Connect

    Merrigan, M.A.

    1984-04-01

    Critical high temperature, high power applications in space nuclear power designs are near the current state of the art of heat pipe technology in terms of power density, operating temperature, and lifetime. Recent heat pipe development work at Los Alamos National Laboratory has involved performance testing of typical space reactor heat pipe designs to power levels in excess of 19 kW/cm/sup 2/ axially and 300 W/cm/sup 2/ radially at temperatures in the 1400 to 1500 K range. Operation at conditions in the 10 kW/cm/sup 2/ range has been sustained for periods of up to 1000 hours without evidence of performance degradation. The effective length for heat transport in these heat pipes was from 1.0 to 1.5 M. Materials used were molybdenum alloys with lithium employed as the heat pipe operating fluid. Shorter, somewhat lower power, molybdenum heat pipes have been life tested at Los Alamos for periods of greater than 25,000 hours at 1700 K with lithium and 20,000 hours at 1500/sup 0/K with sodium. These life test demonstrations and the attendant performance limit investigations provide an experimental basis for heat pipe application in space reactor design and represent the current state-of-the-art of high temperature heat pipe technology.

  20. Heat rejection system

    DOEpatents

    Smith, Gregory C. (Richland, WA); Tokarz, Richard D. (Richland, WA); Parry, Jr., Harvey L. (Richland, WA); Braun, Daniel J. (Richland, WA)

    1980-01-01

    A cooling system for rejecting waste heat consists of a cooling tower incorporating a plurality of coolant tubes provided with cooling fins and each having a plurality of cooling channels therein, means for directing a heat exchange fluid from the power plant through less than the total number of cooling channels to cool the heat exchange fluid under normal ambient temperature conditions, means for directing water through the remaining cooling channels whenever the ambient temperature rises above the temperature at which dry cooling of the heat exchange fluid is sufficient and means for cooling the water.

  1. Solar heated anaerobic digester

    SciTech Connect

    Rhoades, D.

    1980-09-09

    The title digester is adapted to utilize organic waste material capable of decomposing to produce CH/sub 4/ and a liquid fertilizer. The sealed anaerobic digester is wrapped with a layer of heat-absorptive material followed by a series of abutting removable panels of insulative material. Insulative panels may be temporarily removed to expose the heat-absorptive material to solar radiation and may be replaced when the solar radiation diminishes. A layer of transparent material wrapped in outwardly spaced relation around the insulating panels is capable of transmitting solar radiation while providing protection against environmental elements. Additional heating means extending into the digester provide auxiliary heat as required.

  2. Heat Capacity Analysis Report

    SciTech Connect

    A. Findikakis

    2004-11-01

    The purpose of this report is to provide heat capacity values for the host and surrounding rock layers for the waste repository at Yucca Mountain. The heat capacity representations provided by this analysis are used in unsaturated zone (UZ) flow, transport, and coupled processes numerical modeling activities, and in thermal analyses as part of the design of the repository to support the license application. Among the reports that use the heat capacity values estimated in this report are the ''Multiscale Thermohydrologic Model'' report, the ''Drift Degradation Analysis'' report, the ''Ventilation Model and Analysis Report, the Igneous Intrusion Impacts on Waste Packages and Waste Forms'' report, the ''Dike/Drift Interactions report, the Drift-Scale Coupled Processes (DST and TH Seepage) Models'' report, and the ''In-Drift Natural Convection and Condensation'' report. The specific objective of this study is to determine the rock-grain and rock-mass heat capacities for the geologic stratigraphy identified in the ''Mineralogic Model (MM3.0) Report'' (BSC 2004 [DIRS 170031], Table 1-1). This report provides estimates of the heat capacity for all stratigraphic layers except the Paleozoic, for which the mineralogic abundance data required to estimate the heat capacity are not available. The temperature range of interest in this analysis is 25 C to 325 C. This interval is broken into three separate temperature sub-intervals: 25 C to 95 C, 95 C to 114 C, and 114 C to 325 C, which correspond to the preboiling, trans-boiling, and postboiling regimes. Heat capacity is defined as the amount of energy required to raise the temperature of a unit mass of material by one degree (Nimick and Connolly 1991 [DIRS 100690], p. 5). The rock-grain heat capacity is defined as the heat capacity of the rock solids (minerals), and does not include the effect of water that exists in the rock pores. By comparison, the rock-mass heat capacity considers the heat capacity of both solids and pore water. For temperatures in the trans-boiling regime (95 C to 114 C), the additional energy required to vaporize the pore water is accounted for in the rock-mass heat capacity. The rock-grain heat capacities are intended to be used in models and analyses that explicitly account for the thermodynamic effects of the water within the rock porosity. The rock-mass heat capacities are intended to be used in models and analyses that do not explicitly account for these thermodynamic effects, particularly boiling. The term specific heat is often used synonymously with heat capacity; however, the latter term is used throughout this document.

  3. Heat flux measurements

    NASA Technical Reports Server (NTRS)

    Liebert, Curt H.; Weikle, Donald H.

    1989-01-01

    A new automated, computer controlled heat flux measurement facility is described. Continuous transient and steady-state surface heat flux values varying from about 0.3 to 6 MW/sq m over a temperature range of 100 to 1200 K can be obtained in the facility. An application of this facility is the development of heat flux gauges for continuous fast transient surface heat flux measurement on turbine blades operating in space shuttle main engine turbopumps. The facility is useful for durability testing at fast temperature transients.

  4. Microtube strip heat exchanger

    SciTech Connect

    Doty, F.D.

    1991-07-08

    During the last quarter, Doty Scientific, Inc. (DSI) continued to make progress on the microtube strip (MTS) heat exchanger. DSI completed a heat exchanger stress analysis of the ten-module heat exchanger bank; and, performed a shell-side flow inhomogeneity analysis of the three-module heat exchanger bank. The company produced 50 tubestrips using an in-house CNC milling machine and began pressing them onto tube arrays. DSI revised some of the tooling required to encapsulate a tube array and press tubestrips into the array to improve some of the prototype tooling. 2 refs., 4 figs.

  5. External artery heat pipe

    NASA Technical Reports Server (NTRS)

    Gernert, Nelson J. (Inventor); Ernst, Donald M. (Inventor); Shaubach, Robert M. (Inventor)

    1989-01-01

    An improved heat pipe with an external artery. The longitudinal slot in the heat pipe wall which interconnects the heat pipe vapor space with the external artery is completely filled with sintered wick material and the wall of the external artery is also covered with sintered wick material. This added wick structure assures that the external artery will continue to feed liquid to the heat pipe evaporator even if a vapor bubble forms within and would otherwise block the liquid transport function of the external artery.

  6. To Heat or Not to Heat?

    NSDL National Science Digital Library

    CREAM GK-12 Program, Engineering Education Research Center, College of Engineering and Architecture,

    Students are introduced to various types of energy with a focus on thermal energy and types of heat transfer as they are challenged to design a better travel thermos that is cost efficient, aesthetically pleasing and meets the design objective of keeping liquids hot. They base their design decisions on material properties such thermal conductivity, cost and function. These engineering and science concepts are paired with student experiences to build an understanding of heat transfer as it plays a role in their day-to-day lives. While this introduction only shows the top-level concepts surrounding the mathematics associated with heat transfer; the skills become immediately useful as students apply what they know to solve an engineering challenge.

  7. Heat transfer characteristics of a radical heat pipe

    NASA Astrophysics Data System (ADS)

    Kaminaga, Fumito; Okamoto, Yoshizo; Yotsukura, Terumitsu; Ito, Haruhiko; Saito, Takasi; Amezawa, Hiroo

    1990-03-01

    Heat transfer characteristics of a newly designed heat pipe which transports thermal energy in a radial direction of the heat pipe are examined experimentally, using Freon R-113 working fluid. The heat pipe produces a much higher overall heat transmission than the current heat pipe due to a direct contact condensation instead of a filmwise condensation. An unheated vapor space above a heated section and a higher charge rate over 70 percent are required to use it in a wide range of heat flux. A normal screen wick presents an insufficient capillary force to pump up the working fluid to the heated section against the gravity force.

  8. Tidal Heating in Enceladus

    NASA Astrophysics Data System (ADS)

    Meyer, Jennifer; Wisdom, J.

    2007-07-01

    The heating in Enceladus in an equilibrium resonant configuration with other saturnian satellites can be estimated independently of the physical properties of Enceladus. Our results update the values obtained for the equilibrium tidal heating found by Lissauer et al. (1984) and Peale (2003). We find that equilibrium tidal heating cannot account for the heat that is observed to be coming from Enceladus, and current heating rates are even less for conventional estimates of the Love number for Enceladus. Even allowing for a much larger dynamic Love number, as can occur in viscoelastic models (Ross and Schubert, 1989), the equilibrium tidal heating is less than the heat observed to be coming from Enceladus. One resolution is that the tidal equilibrium is unstable and that the system oscillates about equilibrium. Yoder (1981) suggested that Enceladus might oscillate about equilibrium if the Q of Enceladus is stress dependent. An alternate suggestion was made by Ojakangas and Stevenson (1986), who emphasized the possible temperature dependence of Q. In these models Enceladus would now be releasing heat stored during a recent high eccentricity phase. However, we have shown that the Ojakangas and Stevenson model does not produce oscillations for parameters appropriate for Enceladus. Other low-order resonance configurations are possible for the saturnian satellites in the past. These include the 3:2 Mimas-Enceladus and the 3:4 Enceladus-Tethys resonances. The latter resonance has no equilibrium because the orbits are diverging, and the former has an equilibrium heating rate of only 0.48 GW. So equilibrium heating at past resonances is no more successful at explaining past resurfacing events than equilibrium heating is at explaining the present activity.

  9. Planetary heat flow measurements.

    PubMed

    Hagermann, Axel

    2005-12-15

    The year 2005 marks the 35th anniversary of the Apollo 13 mission, probably the most successful failure in the history of manned spaceflight. Naturally, Apollo 13's scientific payload is far less known than the spectacular accident and subsequent rescue of its crew. Among other instruments, it carried the first instrument designed to measure the flux of heat on a planetary body other than Earth. The year 2005 also should have marked the launch of the Japanese LUNAR-A mission, and ESA's Rosetta mission is slowly approaching comet Churyumov-Gerasimenko. Both missions carry penetrators to study the heat flow from their target bodies. What is so interesting about planetary heat flow? What can we learn from it and how do we measure it?Not only the Sun, but all planets in the Solar System are essentially heat engines. Various heat sources or heat reservoirs drive intrinsic and surface processes, causing 'dead balls of rock, ice or gas' to evolve dynamically over time, driving convection that powers tectonic processes and spawns magnetic fields. The heat flow constrains models of the thermal evolution of a planet and also its composition because it provides an upper limit for the bulk abundance of radioactive elements. On Earth, the global variation of heat flow also reflects the tectonic activity: heat flow increases towards the young ocean ridges, whereas it is rather low on the old continental shields. It is not surprising that surface heat flow measurements, or even estimates, where performed, contributed greatly to our understanding of what happens inside the planets. In this article, I will review the results and the methods used in past heat flow measurements and speculate on the targets and design of future experiments. PMID:16286290

  10. Lunar Base Heat Pump

    NASA Technical Reports Server (NTRS)

    Walker, D.; Fischbach, D.; Tetreault, R.

    1996-01-01

    The objective of this project was to investigate the feasibility of constructing a heat pump suitable for use as a heat rejection device in applications such as a lunar base. In this situation, direct heat rejection through the use of radiators is not possible at a temperature suitable for lde support systems. Initial analysis of a heat pump of this type called for a temperature lift of approximately 378 deg. K, which is considerably higher than is commonly called for in HVAC and refrigeration applications where heat pumps are most often employed. Also because of the variation of the rejection temperature (from 100 to 381 deg. K), extreme flexibility in the configuration and operation of the heat pump is required. A three-stage compression cycle using a refrigerant such as CFC-11 or HCFC-123 was formulated with operation possible with one, two or three stages of compression. Also, to meet the redundancy requirements, compression was divided up over multiple compressors in each stage. A control scheme was devised that allowed these multiple compressors to be operated as required so that the heat pump could perform with variable heat loads and rejection conditions. A prototype heat pump was designed and constructed to investigate the key elements of the high-lift heat pump concept. Control software was written and implemented in the prototype to allow fully automatic operation. The heat pump was capable of operation over a wide range of rejection temperatures and cooling loads, while maintaining cooling water temperature well within the required specification of 40 deg. C +/- 1.7 deg. C. This performance was verified through testing.

  11. Heat pipe heat exchangers as energy recovery devices

    Microsoft Academic Search

    Ruch

    1976-01-01

    Counterflow heat exchangers comprised of a bundle of heat pipes with secondary finned surfaces attached offer attractive advantages as energy recovery units. With no moving parts and wide design flexibility, these heat pipe heat exchangers are finding ever increasing usage in air-to-air heat recovery. Three general classes of applications can be identified: using energy recovery from process exhaust to regenerate

  12. Proceedings of Heat Transfer 2003: ASME Summer Heat Transfer Conference

    E-print Network

    Kandlikar, Satish

    Proceedings of Heat Transfer 2003: ASME Summer Heat Transfer Conference Las Vegas, Nevada, USA July 21-23, 2003 HT2003-47449 HEAT TRANSFER FROM A MOVING AND EVAPORATING MENISCUS ON A HEATED SURFACE meniscus with complete evaporation of water without any meniscus break-up. The experimental heat transfer

  13. 24 CFR 3280.506 - Heat loss/heat gain.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...Development 5 2010-04-01 2010-04-01 false Heat loss/heat gain. 3280.506 Section 3280.506 Housing and...SAFETY STANDARDS Thermal Protection § 3280.506 Heat loss/heat gain. The manufactured home heat...

  14. 24 CFR 3280.506 - Heat loss/heat gain.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...Development 5 2011-04-01 2011-04-01 false Heat loss/heat gain. 3280.506 Section 3280.506 Housing and...SAFETY STANDARDS Thermal Protection § 3280.506 Heat loss/heat gain. The manufactured home heat...

  15. IMPLEMENTING GROUND SOURCE HEAT PUMP AND GROUND LOOP HEAT EXCHANGER

    E-print Network

    IMPLEMENTING GROUND SOURCE HEAT PUMP AND GROUND LOOP HEAT EXCHANGER MODELS IN THE ENERGYPLUS #12;ii IMPLEMENTING GROUND SOURCE HEAT PUMP AND GROUND LOOP HEAT EXCHANGER MODELS IN THE ENERGYPLUS............................................................... 2 1.3. Overview of the Parameter Estimation Water-to-Water Heat Pump Model ........... 5 1

  16. Heat pipes and use of heat pipes in furnace exhaust

    DOEpatents

    Polcyn, Adam D. (Pittsburgh, PA)

    2010-12-28

    An array of a plurality of heat pipe are mounted in spaced relationship to one another with the hot end of the heat pipes in a heated environment, e.g. the exhaust flue of a furnace, and the cold end outside the furnace. Heat conversion equipment is connected to the cold end of the heat pipes.

  17. Heat Transfer Discussion: "Heat Transfer and Wall

    E-print Network

    Kandlikar, Satish

    flow boiling curve extending from the single-phase region at point C to the fully developed boiling During Subcooled Flow Nucleate Boiling­A Review" (Warrier, G.R., and Dhir, V.K., 2006, Journal of Heat in the partial boiling region, along with Eqs. 13 - 14 . The authors of 1 further state that Kandlikar 3 in 1998

  18. Vacuum powered heat exchanger

    SciTech Connect

    Ruffolo, R.F.

    1986-06-24

    In an internal combustion engine including an oil lubrication system, a liquid cooling system, and an improved air intake system is described. The improved air intake system comprises: a housing including a first opening in one end, which opening is open to the atmosphere and a second opening comprising an air outlet opening in the other end open to the air intake manifold of the engine, a heat exchanger positioned in the first opening. The heat exchanger consists of a series of coils positioned in the flow path of the atmospheric air as it enters the housing, the heat exchanger being fluidly connected to either the engine lubrication system or the cooling system to provide a warm heat source for the incoming air to the housing, acceleration means positioned in the housing downstream of the heat exchanger, the acceleration means comprising a honeycomb structure positioned across the air intake flow path. The honey-comb structure includes a multitude of honey combed mini-venturi cells through which the heated air flows in an accelerated mode, a removable air filter positioned between the heat exchanger and the acceleration means and a single opening provided in the housing through which the air filter can be passed and removed, and additional openings in the housing positioned downstream of the heat exchanger and upstream of the air filter, the additional openings including removable flaps for opening and closing the openings to control the temperature of the air flowing through the housing.

  19. DHE (Downhole Heat Exchangers)

    Microsoft Academic Search

    G. Culver

    1990-01-01

    The use of downhole heat exchangers (DHE) for residential or commercial space and domestic water heating and other applications has several desirable features. Systems are nearly or completely passive -- that is, no or very little geothermal water or steam is produced from the well either reducing or completely eliminating surface environmental concerns and the need for disposal systems or

  20. Modelling microwave heating

    Microsoft Academic Search

    James M Hill; Timothy R Marchant

    1996-01-01

    Although microwave radiation is best known for heating food in the kitchen, in recent years it has found new applications in many industrial processes, such as those involving melting, smelting, sintering, drying, and joining. Heating by microwave radiation constitutes a highly coupled nonlinear problem giving rise to new and unexpected physical behavior, the best known of which is the appearance

  1. Microwave heating of foodstuffs

    Microsoft Academic Search

    M. E. C. Oliveira; A. S. Franca

    2002-01-01

    The temperature distribution in a product submitted to microwave radiation is governed by the interaction and absorption of radiation by the medium and the accompanying transport processes due to the dissipation of electromagnetic energy into heat. Thus, modeling of microwave heating involves coupling the models for microwave power absorption and temperature distribution inside the product. In this study, a model

  2. Battery heating system

    Microsoft Academic Search

    C. Silvertown; W. Sinclair

    1980-01-01

    A battery heating system is comprised of a number of storage batteries and an alternator driven by a variable speed prime mover connected to supply ac heating current to the batteries. The system is arranged so that the ac current is substantially constant over the working speed range of the prime mover.

  3. Heat and Motion.

    ERIC Educational Resources Information Center

    Pearlman, Norman

    Unlike many elementary presentations on heat, this monograph is not restricted to explaining thermal behavior in only macroscopic terms, but also developes the relationships between thermal properties and atomic behavior. "It relies at the start on intuition about heat at the macroscopic level. Familiarity with the particle model of mechanics,…

  4. Plumbing and Heating Curriculum.

    ERIC Educational Resources Information Center

    EASTCONN Regional Educational Services Center, North Windham, CT.

    Theory and experience in the following areas are included in this plumbing curriculum: (1) plumbing fixtures and heating; (2) city water service; (3) fixture roughing; (4) venting; and (5) solar heating systems. The plumbing program manual includes the following sections: (1) general objectives for grades 10, 11, and 12; (2) a list of 33 major…

  5. Acoustic Heating Peter Ulmschneider

    E-print Network

    Ulmschneider, Peter

    Acoustic Heating Peter Ulmschneider lnstitut fiir Theoretische Astrophysik der Universitat Heidelberg Im Neuenheimer Feld 561, 6900 Heidelberg 1, Federal Republic of Germany. Abstract. Acoustic shock waves are a viable and prevalent heating mechanism both in early- and in late-type stars. Acoustic

  6. Microchannel heat sink assembly

    DOEpatents

    Bonde, Wayne L. (Livermore, CA); Contolini, Robert J. (Pleasanton, CA)

    1992-01-01

    The present invention provides a microchannel heat sink with a thermal range from cryogenic temperatures to several hundred degrees centigrade. The heat sink can be used with a variety of fluids, such as cryogenic or corrosive fluids, and can be operated at a high pressure. The heat sink comprises a microchannel layer preferably formed of silicon, and a manifold layer preferably formed of glass. The manifold layer comprises an inlet groove and outlet groove which define an inlet manifold and an outlet manifold. The inlet manifold delivers coolant to the inlet section of the microchannels, and the outlet manifold receives coolant from the outlet section of the microchannels. In one embodiment, the manifold layer comprises an inlet hole extending through the manifold layer to the inlet manifold, and an outlet hole extending through the manifold layer to the outlet manifold. Coolant is supplied to the heat sink through a conduit assembly connected to the heat sink. A resilient seal, such as a gasket or an O-ring, is disposed between the conduit and the hole in the heat sink in order to provide a watetight seal. In other embodiments, the conduit assembly may comprise a metal tube which is connected to the heat sink by a soft solder. In still other embodiments, the heat sink may comprise inlet and outlet nipples. The present invention has application in supercomputers, integrated circuits and other electronic devices, and is suitable for cooling materials to superconducting temperatures.

  7. Introductory heat-transfer

    NASA Technical Reports Server (NTRS)

    Widener, Edward L.

    1992-01-01

    The objective is to introduce some concepts of thermodynamics in existing heat-treating experiments using available items. The specific objectives are to define the thermal properties of materials and to visualize expansivity, conductivity, heat capacity, and the melting point of common metals. The experimental procedures are described.

  8. Heat Transfer Technical Brief

    E-print Network

    Banerjee, Debjyoti

    % higher heat flux at Leidenfrost point (film boiling regime) compared to control experiments. HoweverJournal of Heat Transfer Technical Brief Pool Boiling Experiments on Multiwalled Carbon Nanotube with verti- cally aligned multiwalled carbon nanotubes (MWCNT) "forests" and were used for pool boiling

  9. Basic Comfort Heating Principles.

    ERIC Educational Resources Information Center

    Dempster, Chalmer T.

    The material in this beginning book for vocational students presents fundamental principles needed to understand the heating aspect of the sheet metal trade and supplies practical experience to the student so that he may become familiar with the process of determining heat loss for average structures. Six areas covered are: (1) Background…

  10. Applying industrial heat pumps

    Microsoft Academic Search

    1993-01-01

    Industry uses as little as 20% of the heat content of the fuels it burns. Much of the remainder escapes to the environment and is lost. Capturing this waste heat from industrial processes or refrigeration equipment could cut a plant's operating costs, extend global energy supplies, and reduce emissions. Today, more than 1500 U.S. plants in a wide range of

  11. Heat storage material

    SciTech Connect

    Mita, N.; Murai, Y.; Sato, A.

    1982-01-05

    A heat storage material having a melting point in the range of 90* to 100* C is described. It is excellent in that it is neither corrosiv inflammable nor toxic. The heat storage material comprises a mixture of dimethyl terephthalate and one member selected from the group consisting of dimethyl fumarate and dihydroanthracene.

  12. Solar heat transport fluid

    NASA Technical Reports Server (NTRS)

    1978-01-01

    The progress made in the development and delivery of noncorrosive fluid subsystems is discussed. These subsystems are to be compatible with closed-loop solar heating or combined heating and hot water systems. They are also to be compatible with both metallic and non-metallic plumbing systems. The performance testing of a number of fluids is described.

  13. Heat Shield in Pieces

    NASA Technical Reports Server (NTRS)

    2005-01-01

    This image from NASA's Mars Exploration Rover Opportunity shows the remains of the rover's heat shield, broken into two key pieces, the main piece on the left side and a broken-off flank piece near the middle of the image. The heat shield impact site is identified by the circle of red dust on the right side of the picture. In this view, Opportunity is approximately 20 meters (66 feet) away from the heat shield, which protected it while hurtling through the martian atmosphere.

    In the far left of the image, a meteorite called 'Heat Shield Rock,' sits nearby, The Sun is reflecting off the silver-colored underside of the internal thermal blankets of the heat shield.

    The rover spent 36 sols investigating how the severe heating during entry through the atmosphere affected the heat shield. The most obvious is the fact that the heat shield inverted upon impact.

    This is an approximately true-color rendering of the scene acquired around 1:22 p.m. local solar time on Opportunity sol 324 (Dec. 21, 2004) in an image mosaic using panoramic filters at wavelengths of 750, 530, and 430 nanometers.

  14. Passive Vaporizing Heat Sink

    NASA Technical Reports Server (NTRS)

    Knowles, TImothy R.; Ashford, Victor A.; Carpenter, Michael G.; Bier, Thomas M.

    2011-01-01

    A passive vaporizing heat sink has been developed as a relatively lightweight, compact alternative to related prior heat sinks based, variously, on evaporation of sprayed liquids or on sublimation of solids. This heat sink is designed for short-term dissipation of a large amount of heat and was originally intended for use in regulating the temperature of spacecraft equipment during launch or re-entry. It could also be useful in a terrestrial setting in which there is a requirement for a lightweight, compact means of short-term cooling. This heat sink includes a hermetic package closed with a pressure-relief valve and containing an expendable and rechargeable coolant liquid (e.g., water) and a conductive carbon-fiber wick. The vapor of the liquid escapes when the temperature exceeds the boiling point corresponding to the vapor pressure determined by the setting of the pressure-relief valve. The great advantage of this heat sink over a melting-paraffin or similar phase-change heat sink of equal capacity is that by virtue of the =10x greater latent heat of vaporization, a coolant-liquid volume equal to =1/10 of the paraffin volume can suffice.

  15. Scraped Surface Heat Exchangers

    Microsoft Academic Search

    Chetan S. Rao; Richard W. Hartel

    2006-01-01

    Scraped surface heat exchangers (SSHEs) are commonly used in the food, chemical, and pharmaceutical industries for heat transfer, crystallization, and other continuous processes. They are ideally suited for products that are viscous, sticky, that contain particulate matter, or that need some degree of crystallization. Since these characteristics describe a vast majority of processed foods, SSHEs are especially suited for pumpable

  16. Solar heated anaerobic digester

    Microsoft Academic Search

    Rhoades

    1980-01-01

    The title digester is adapted to utilize organic waste material capable of decomposing to produce CHâ and a liquid fertilizer. The sealed anaerobic digester is wrapped with a layer of heat-absorptive material followed by a series of abutting removable panels of insulative material. Insulative panels may be temporarily removed to expose the heat-absorptive material to solar radiation and may be

  17. Heat pipe development status

    SciTech Connect

    Merrigan, M.A.

    1984-01-01

    Test heat pipes have been operated in the 1400 K to 1700 K range for periods in excess of 20,000 hours with the objective of understanding and controlling corrosion and failure mechanisms. The results of a post test analysis of one of these heat pipes that was operated for 25,216 hours at 1700 K are reviewed and the implications for heat pipe lifetime discussed. An in-process report of an investigation of transient heat pipe behavior is presented. This investigation is being conducted as a result of restart problems encountered during life test of a 2 m. radiation cooled heat pipe. The results of a series of shut-down tests from power and temperature are given and probable causes of the restart problem discussed.

  18. Heat flux microsensor measurements

    NASA Astrophysics Data System (ADS)

    Terrell, J. P.; Hager, J. M.; Onishi, S.; Diller, T. E.

    1992-12-01

    A thin-film heat flux sensor has been fabricated on a stainless steel substrate. The thermocouple elements of the heat flux sensor were nickel and nichrome, and the temperature resistance sensor was platinum. The completed heat flux microsensor was calibrated at the AEDC radiation facility. The gage output was linear with heat flux with no apparent temperature effect on sensitivity. The gage was used for heat flux measurements at the NASA Langley Vitiated Air Test Facility. Vitiated air was expanded to Mach 3.0 and hydrogen fuel was injected. Measurements were made on the wall of a diverging duct downstream of the injector during all stages of the hydrogen combustion tests. Because the wall and the gage were not actively cooled, the wall temperature reached over 1000 C (1900 F) during the most severe test.

  19. Heat flux microsensor measurements

    NASA Technical Reports Server (NTRS)

    Terrell, J. P.; Hager, J. M.; Onishi, S.; Diller, T. E.

    1992-01-01

    A thin-film heat flux sensor has been fabricated on a stainless steel substrate. The thermocouple elements of the heat flux sensor were nickel and nichrome, and the temperature resistance sensor was platinum. The completed heat flux microsensor was calibrated at the AEDC radiation facility. The gage output was linear with heat flux with no apparent temperature effect on sensitivity. The gage was used for heat flux measurements at the NASA Langley Vitiated Air Test Facility. Vitiated air was expanded to Mach 3.0 and hydrogen fuel was injected. Measurements were made on the wall of a diverging duct downstream of the injector during all stages of the hydrogen combustion tests. Because the wall and the gage were not actively cooled, the wall temperature reached over 1000 C (1900 F) during the most severe test.

  20. Waste heat recovery boiler

    SciTech Connect

    Yanai, E.; Kuribayashi, T.

    1987-09-15

    A waste heat recovery boiler is described which utilizes an exhaust gas of a gas turbine and generates steam for driving a steam turbine. The improvement wherein at least two denitrating devices for removing NO/sub x/ components in the exhaust gas therefrom are disposed inside the waste heat recovery boiler. The waste heat recovery boiler is equipped with fuel economizers for preheating feed water by the exhaust gas, rear and front evaporators for evaporating the pre-heated feed water, a superheater for heating the vaporized feed water and generating the driving steam for the steam turbine, all of the constituent members being disposed sequentially from a downstream side to an upstream side of the exhaust gas, and wherein the denitrating devices are disposed between at least two evaporators and between the front evaporator and the superheater.

  1. Heat Flow Measurement

    NASA Technical Reports Server (NTRS)

    1993-01-01

    Heat gauges are used to measure heat flow in industrial activities. They must periodically be certified by instruments designed to provide a heat flux measurement standard. CSTAR, a NASA CCDS, and REMTECH have developed a portable heat flux checker/calibrator. The Q-CHEC can be carried to the heat gauge for certification, reducing out of service time for the gauge and eliminating the need for a replacement gauge during certification. It can provide an "end-to-end" check of the instrumentation measurement system or be used as a standalone calibrator. Because Q-CHEC offers on-site capability to detect and eliminate measurement errors, measurements do not have to be repeated, and money is saved.

  2. Heat Pipe Systems

    NASA Technical Reports Server (NTRS)

    1993-01-01

    The heat pipe was developed to alternately cool and heat without using energy or any moving parts. It enables non-rotating spacecraft to maintain a constant temperature when the surface exposed to the Sun is excessively hot and the non Sun-facing side is very cold. Several organizations, such as Tropic-Kool Engineering Corporation, joined NASA in a subsequent program to refine and commercialize the technology. Heat pipes have been installed in fast food restaurants in areas where humid conditions cause materials to deteriorate quickly. Moisture removal was increased by 30 percent in a Clearwater, FL Burger King after heat pipes were installed. Relative humidity and power consumption were also reduced significantly. Similar results were recorded by Taco Bell, which now specifies heat pipe systems in new restaurants in the Southeast.

  3. Two-Year Community College Chemistry: Joules.

    ERIC Educational Resources Information Center

    Bardole, Ellen, Ed.; Bardole, Jay, Ed.

    1978-01-01

    Describes a forensic science course designed to give criminal justice students the knowledge and technology of science to solve a crime. The article includes a listing of topic areas, suggestions for the presentation of the content material, and an outline of the content and design. (MA)

  4. Air circuit with heating pump

    Microsoft Academic Search

    H. Holik; H. J. Bauder; H. Brugger; A. Reinhart; K. H. Spott

    1980-01-01

    A pump which draws energy from exhaust air from a paper drying process to heat up the blow air was studied. The use of a heat pump instead of a steam heated exchanger can reduce primary energy consumption for blown air heating by more than half and the costs for air heating up to half. The amortization times for the

  5. Modular axial grooved heat pipes

    Microsoft Academic Search

    H. Koch; H. Kreeb; M. Perdu

    1976-01-01

    A modular axial grooved heat pipe system operable between 100 and 400 K was developed. Accent was placed on typical space application problems such as assembly of two heat pipes (interface problems), circular heat pipes, construction of radiators, long life behavior, and cryogenic heat pipes. Results of performance tests on this heat pipe system designed for a space radiator to

  6. A Heat Flux Instrument for Measuring Venus Surface Heat Flow

    NASA Astrophysics Data System (ADS)

    Pauken, M.; Smrekar, S.

    2015-04-01

    An instrument has been developed to measure the surface heat flow on Venus. Heat flow measurement would provide a better understanding of the evolutionary development of Venus. The instrument uses a semiconductor thermopile to measure heat flow.

  7. Economic Options for Upgrading Waste Heat 

    E-print Network

    Erickson, D. C.

    1983-01-01

    There are at least six major types of equipment that upgrade waste heat: (1) thermocompressor; (2) electric drive compressor heat pump; (3) absorption heat pump; (4) high temperature heat powered compressor heat pump; (5) reverse absorption heat...

  8. Progress in heat pipe and porous heat exchanger technology

    Microsoft Academic Search

    A. V. Luikov; L. L. Vasiliev

    1975-01-01

    This is a review of the papers presented at the 1st International Heat Pipe Conference held in Stuttgart, 15-17 October 1973. The review deals with heat pipe application in different branches of technology, heat- and mass-transfer processes in heat pipes, design of variable-conductance heat pipes, optimization of their parameters, operation of heat pipes under weightlessness and in the field of

  9. Analysis and application of the heat pipe heat exchanger

    Microsoft Academic Search

    T. H. Sun; R. C. Prager

    1978-01-01

    Heat pipe heat exchangers offer many advantages over more conventional heat exchangers, particularly for gas-to-gas application. Proper application of these devices depends on the conditions imposed by the process from which waste heat is to be recovered, and some of the more common constraints are analyzed. The overall operation of heat pipe heat exchangers is best studied using effectiveness-NTU calculations,

  10. Mechanical behavior of nanocrystalline Fe-Hf-B ribbons

    NASA Astrophysics Data System (ADS)

    Chiriac, Horia; Hison, Cornelia

    2003-01-01

    Investigation of annealing type (furnace annealing, direct current (DC) Joule heating, furnace pre-annealing followed by DC Joule heating) influence on the mechanical behavior (brittleness) of Fe-Hf-B nanocrystalline ribbons is presented. The results show a win of two orders of magnitude in terms of brittleness for furnace pre-annealing followed by DC Joule heating with respect to furnace annealing or DC Joule heating.

  11. Prototype solar heating and combined heating and cooling systems

    NASA Technical Reports Server (NTRS)

    1977-01-01

    Eight prototype solar heating and combined heating and cooling systems are being developed. The effort includes development, manufacture, test, installation, maintenance, problem resolution, and performance evaluation.

  12. Fireplace heating unit

    SciTech Connect

    Henderson, L.L.

    1982-10-19

    An efficient heating unit for ready installation in any standard fireplace includes a refractory lined fire box contained within an outer shell to form a heat exchanger between hot gaseous fuel combustion products and living space air entering the jacket space between the walls of the fire box and the outer shell in a continuous convection cycle. Heated air re-enters the living space through a grill above the fire box and fire box flue maze. The flue maze or manifold forms a radiator of great surface area which projects into the living space immediately below the heated air grill and the maze is vented into the chimney by two nonadjustable and one adjustable vents which are sealed from the air passages of the heat exchanger. Lockable and adjustably vented doors at the front of the fire box are provided. A three piece face plate formed of thin metal having thermal contact with both the fire box and heat exchanger shell maximizes heat radiation into the living space.

  13. Integrating preconcentrator heat controller

    DOEpatents

    Bouchier, Francis A. (Albuquerque, NM); Arakaki, Lester H. (Edgewood, NM); Varley, Eric S. (Albuquerque, NM)

    2007-10-16

    A method and apparatus for controlling the electric resistance heating of a metallic chemical preconcentrator screen, for example, used in portable trace explosives detectors. The length of the heating time-period is automatically adjusted to compensate for any changes in the voltage driving the heating current across the screen, for example, due to gradual discharge or aging of a battery. The total deposited energy in the screen is proportional to the integral over time of the square of the voltage drop across the screen. Since the net temperature rise, .DELTA.T.sub.s, of the screen, from beginning to end of the heating pulse, is proportional to the total amount of heat energy deposited in the screen during the heating pulse, then this integral can be calculated in real-time and used to terminate the heating current when a pre-set target value has been reached; thereby providing a consistent and reliable screen temperature rise, .DELTA.T.sub.s, from pulse-to-pulse.

  14. Heat exchangers and the performance of heat pumps – Analysis of a heat pump database

    Microsoft Academic Search

    D. S. Kim; I. Moretti; M. Monsberger

    2011-01-01

    Heat pumping is a highly energy-efficient technology that could help reduce energy and environmental problems. The efficiency of a heat pump greatly depends on the individual and integral performance of the components inside. In this study, heat pump performance is investigated with a special focus on heat exchangers. Experimental data obtained from comprehensive heat pump measurements performed at the Austrian

  15. Parallel and Perpendicular Heating of Solar Wind Protons by Kinetic Waves as Inferred from WIND Observations

    NASA Astrophysics Data System (ADS)

    He, J.; Wang, L.; Tu, C. Y.; Marsch, E.

    2014-12-01

    The solar wind may be heated non-adiabatically by Joule dissipation of coherent current structures or by wave-particle interaction with kinetic waves. In high-speed solar wind, where current structures of tangential-discontinuity type are rare and Alfven-like waves are abundant, wave-particle interaction may be a promising candidate for the heating mechanism. Here we address how the solar wind protons are heated parallel and perpendicularly based on the observations of proton velocity distributions and kinetic wave fluctuations from the WIND spacecraft. It is shown that solar wind protons consist of anisotropic core and beam populations with a relative field-aligned drift speed of ~VA between them. Both quasi-parallel left-handed Alfven-cyclotron waves (LH-ACWs) and quasi-perpendicular right-handed Alfven-cyclotron waves / kinetic Alfven waves (RH-ACWs/KAWs) are also identified. It seems that the proton velocity distribution contours may be shaped by left-cyclotron resonance with quasi-parallel LH-ACWs for its anisotropic core components, Landau resonance with quasi-perpendicular KAWs for its beam drift, and right-cyclotron resonance with quasi-perpendicular RH-ACWs for its anisotropic beam component. Plasma instability is also investigated from the data, which shows that the core component anisotropy is usually unstable and may be responsible for the observed LH-ACWs with enhanced fluctuations; whereas the beam drift is stable and no RH-fast/whistler waves are observed. Moreover, the solar wind protons are observed, with the unprecedented cadence of 3s, to be highly dynamic in their velocity distributions with an apparent alternation between the stretching and contracting of the drifted beam, which may be connected with amplitude intermittency of associated waves.

  16. Measuring the Heats of Water.

    ERIC Educational Resources Information Center

    Hunt, James L.; Tegart, Tracy L.

    1994-01-01

    Uses common equipment (tea kettle and vacuum bottles) to precisely measure the specific heat, latent heat of fusion, and latent heat of vaporization of water. Provides descriptions for all three experiments. (MVL)

  17. Optimization of Heat Exchanger Cleaning 

    E-print Network

    Siegell, J. H.

    1986-01-01

    The performance of heat integration systems is quantified in terms of the amount of heat that is recovered. This decreases with time due to increased fouling of the heat exchange surface. Using the "Total Fouling Related Expenses (TFRE)" approach...

  18. Industrial Heat Pump Design Options 

    E-print Network

    Gilbert, J. S.

    1985-01-01

    %! This paper discusses ways to use heat pumps in new process and retrofit designs, including methods to overcome problems in heat exchange fouling and high lift applications. Examples of actual designs and a simple approximation of installed heat pump cost...

  19. Complex Compound Chemical Heat Pumps

    E-print Network

    Rockenfeller, U.; Langeliers, J.; Horn, G.

    Complex-compound solid-vapor fluid pairs can be used in heat of reaction heat pumps for temperature amplifier (TA) as well as heat amplifier (HA) cycle configurations. This report describes the conceptual hardware design for complex compound...

  20. Analysis of orbital heat transfer

    NASA Technical Reports Server (NTRS)

    Buna, T.

    1974-01-01

    Graphical representation of orbital heat balance in form of polar diagrams is obtained from integral expressions of orbital heat transfer whereby quantities of heat are represented as areas swept by ""thermal radii.''

  1. Molecular heat pump

    E-print Network

    Dvira Segal; Abraham Nitzan

    2005-10-11

    We propose a novel molecular device that pumps heat against a thermal gradient. The system consists of a molecular element connecting two thermal reservoirs that are characterized by different spectral properties. The pumping action is achieved by applying an external force that periodically modulates molecular levels. This modulation affects periodic oscillations of the internal temperature of the molecule and the strength of its coupling to each reservoir resulting in a net heat flow in the desired direction. The heat flow is examined in the slow and fast modulation limits and for different modulation waveforms, thus making it possible to optimize the device performance.

  2. Waste heat recovery system

    SciTech Connect

    Smith, E.M.; Cornelison, R.C.

    1989-10-24

    This patent describes a waste heat recovery system. It comprises a conduit for conveying an exhaust gas stream; a boiler assembly connected to the conduit including a heat recovery steam generator through which the exhaust gas if flowed, and characterized by a high temperature stream tube heat exchanger and, at a downstream location relative thereto, a water-tube boiler; an ammonia gas injector for injecting ammonia gas into the exhaust gas stream and located upstream of the water-tube boiler in juxtaposition to the exhaust gas source; and a low temperature selective catalytic reduction unit located downstream of the water-tube boiler.

  3. Fluctuation relation for heat.

    PubMed

    Noh, Jae Dong; Park, Jong-Min

    2012-06-15

    We present a fluctuation relation for heat dissipation in a nonequilibrium system. A nonequilibrium work is known to obey the fluctuation theorem in any time interval t. Heat, which differs from work by an energy change, is shown to satisfy a modified fluctuation relation. Modification is brought about by the correlation between heat and energy change during nonequilibrium processes whose effect may not be negligible even in the t?? limit. The fluctuation relation is derived for overdamped Langevin equation systems, and tested in a linear diffusion system. PMID:23004252

  4. Heat transfer in pipes

    NASA Astrophysics Data System (ADS)

    Burbach, T.

    1985-04-01

    The heat transfer from hot water to a cold copper pipe in laminar and turbulent flow condition is determined. The mean flow through velocity in the pipe, relative test length and initial temperature in the vessel were varied extensively during tests. Measurements confirm Nusselt's theory for large test lengths in laminar range. A new equation is derived for heat transfer for large starting lengths which agrees satisfactorily with measurements for large starting lengths. Test results are compared with the new Prandtl equation for heat transfer and correlated well. Test material for 200- and to 400-diameter test length is represented at four different vessel temperatures.

  5. Heat transfer in pipes

    NASA Technical Reports Server (NTRS)

    Burbach, T.

    1985-01-01

    The heat transfer from hot water to a cold copper pipe in laminar and turbulent flow condition is determined. The mean flow through velocity in the pipe, relative test length and initial temperature in the vessel were varied extensively during tests. Measurements confirm Nusselt's theory for large test lengths in laminar range. A new equation is derived for heat transfer for large starting lengths which agrees satisfactorily with measurements for large starting lengths. Test results are compared with the new Prandtl equation for heat transfer and correlated well. Test material for 200- and to 400-diameter test length is represented at four different vessel temperatures.

  6. Entry aerodynamics and heating

    NASA Technical Reports Server (NTRS)

    Olstad, W.

    1974-01-01

    An overview of the problems of entry aerodynamics and heating is given with emphasis on survival of the probe, predictability of performance, and reliability of performance. Technological challenges to performance prediction are considered and include: turbulent heat transfer, radiation blockage, chemical state of the shock layer, afterbody heat transfer, asymmetric ablation, and real-gas aerodynamics. It is indicated that various obstacles must be overcome in order to achieve technology readiness. These obstacles are considered to be: extrapolations from ground tests to flight; lack of flight experience; lack of parametric data; and uncertain knowledge of atmospherics.

  7. Graphite-Fiber Heat Radiators

    NASA Technical Reports Server (NTRS)

    Phillips, Wayne M.

    1995-01-01

    Heat radiators of proposed type feature thermally conductive fibers protruding from metallic surfaces to provide increased heat-dissipation surface areas. Free of leaks and more reliable than radiators incorporating heat pipes. Also lightweight and relatively inexpensive. Radial graphite fibers carry heat away from spherical shell and radiate heat into space. Radiators prove useful on Earth in special industrial and scientific applications involving dissipation of heat in vacuum or in relatively still air.

  8. Improved Thin, Flexible Heat Pipes

    NASA Technical Reports Server (NTRS)

    Rosenfeld, John H.; Gernert, Nelson J.; Sarraf, David B.; Wollen, Peter J.; Surina, Frank C.; Fale, John E.

    2004-01-01

    Flexible heat pipes of an improved type are fabricated as layers of different materials laminated together into vacuum- tight sheets or tapes. In comparison with prior flexible heat pipes, these flexible heat pipes are less susceptible to leakage. Other advantages of these flexible heat pipes, relative to prior flexible heat pipes, include high reliability and greater ease and lower cost of fabrication. Because these heat pipes are very thin, they are highly flexible. When coated on outside surfaces with adhesives, these flexible heat pipes can be applied, like common adhesive tapes, to the surfaces of heat sinks and objects to be cooled, even if those surfaces are curved.

  9. WM '04 Conference, February 29 March 4, 2004, Tucson, AZ WM-4010 VITRIFICATION OF LOW AND INTERMEDIATE LEVEL WASTE: TECHNOLOGY

    E-print Network

    Sheffield, University of

    -fed Joule heated ceramic melters (JHCM) were used later replaced by cold crucible high frequency induction melters (CCM). #12;WM '04 Conference, February 29 ­ March 4, 2004, Tucson, AZ WM-4010 JOULE HEATED CERAMIC for a reference liquid radioactive waste with total salt content about 200 g/l [2- 5]. Fig. 1 Joule heated ceramic

  10. Evidence of thermal heating in the low temperature resistive switching of V2O3 microbridges

    NASA Astrophysics Data System (ADS)

    Menghini, Mariela; Dillemans, Leander; Levrie, Karen; Homm, Pia; Su, Chen-Yi; Lieten, Ruben; Smets, Tomas; Locquet, Jean-Pierre

    2014-03-01

    Vanadium sesquioxide (V2O3) is a strongly correlated material that exhibits a metal-insulator-transition (MIT) at low temperatures. The electrical triggering of this transition could result in an exciting new category of applications, such as resistive switching-based memories and field-effect transistors. We have fabricated V2O3 microbridges by combining MBE growth with UV lithography and etching.The MIT is studied in microbridges with different length/width aspect ratios. We found that the size of the MIT is largest for the widest and shortest microbridges. We discuss the influence of device processing in the observed behavior. We have also measured voltage-current characteristics (VIs) of the microbridges at different temperatures across the MIT. At intermediate temperatures we observe a sudden change to a more resistive state while the current is swept continuously. The only way to switch back to an insulating state is by thermal cycling. At sufficiently low and high temperatures the VIs are smooth. We have estimated the power transferred to the device by the applied current in order to understand this behavior in terms of local Joule heating. The distribution of size of the resistance jumps and the values of voltage and current at which these jumps occur are studied as a function of width and length of the microbridge.

  11. Methane heat transfer investigation

    NASA Technical Reports Server (NTRS)

    1984-01-01

    Future high chamber pressure LOX/hydrocarbon booster engines require copper base alloy main combustion chamber coolant channels similar to the SSME to provide adequate cooling and reusable engine life. Therefore, it is of vital importance to evaluate the heat transfer characteristics and coking thresholds for LNG (94% methane) cooling, with a copper base alloy material adjacent to he fuel coolant. High pressure methane cooling and coking characteristics recently evaluated at Rocketdyne using stainless steel heated tubes at methane bulk temperatures and coolant wall temperatures typical of advanced engine operation except at lower heat fluxes as limited by the tube material. As expected, there was no coking observed. However, coking evaluations need be conducted with a copper base surface exposed to the methane coolant at higher heat fluxes approaching those of future high chamber pressure engines.

  12. Liquid Phase Heating Systems 

    E-print Network

    Mordt, E. H.

    1979-01-01

    Temperature Water (HTW) central district heating systems are far superior to steam systems in large, spread out installations such as airports, universities and office complexes. Water, pressurized to keep it in the liquid state, is distributed at 400o...

  13. Light vs. Heat Bulbs

    NSDL National Science Digital Library

    Office of Educational Partnerships,

    Students measure the light output and temperature (as a measure of heat output) for three types of light bulbs to identify why some light bulbs are more efficient (more light with less energy) than others.

  14. Advanced heat pump cycle

    SciTech Connect

    Groll, E.A.; Radermacher, R.

    1993-07-01

    The desorption and absorption process of a vapor compression heat pump with a solution circuit (VCHSC) proceeds at gliding temperature intervals, which can be adjusted over a wide range. In case that the gliding temperature intervals in the desorber and the absorber overlap, a modification of the VCHSC employing a desorber/absorber heat exchange (DAHX) can be introduced, which results in an extreme reduction of the pressure ratio. Although the DAHX-cycle has features of a two-stage cycle, it still requires only one solution pump, one separator and one compressor. Such a cycle for the working pair ammonia/water is built in the Energy Laboratory of the Center for Environmental Energy Engineering at the University of Maryland. The experimental results obtained with the research plant are discussed and compared to those calculated with a simulation program. The possible temperature lift between heat source and heat sink depending on the achievable COP are presented.

  15. Mechanical Compression Heat Pumps 

    E-print Network

    Apaloo, T. L.; Kawamura, K.; Matsuda, J.

    1986-01-01

    to develop, design and test compressors built to meet the needs of the mechanically demanding industrial heat pump applications which often require high compression ratios and temperatures in excess of 200 degrees F. This paper will review the theoretical...

  16. Heat leak measurements facility

    SciTech Connect

    Gonczy, J.D.; Kuchnir, M.; Nicol, T.H.; Niemann, R.C.; Powers, R.J.

    1985-09-01

    Heat leak measurements of superconducting magnet suspension systems, and multilayer insulation (MLI) systems are important for the optimum design of magnet cryostats. For this purpose, a cryogenic test facility was developed having a versatile functional end in which test components of differing geometrical configurations can be installed and evaluated. This paper details the test facility design and operating parameters. Experimental results of heat leak measurements to 4.5 K obtained on a post type support system having heat intercepts at 10 K and 80 K are presented. Included are measurements obtained while operating the 10 K intercept at temperatures above 10 K, i.e., in the 10-40 K range. Also reported is a description of the test facility conversion for a heat load study of several MLI systems with variations of MLI installation technique. The results of the first MLI system tested are presented.

  17. Heat Treatment Assistant Professor

    E-print Network

    Cambridge, University of

    growth. Heat treatment of aluminum, copper, magnesium, titanium and nickel alloys. Temper designations working, non-uniform cooling from high temperature during casting and welding (stress relief annealing) 6

  18. Heating steels in vacuum

    SciTech Connect

    Marmer, E.N.

    1983-03-01

    It is recommended that high-strength and corrosion-resistant steels be heated in an electric vacuum furnace. Absence of oxidation and decarburization, decrease in the deformation of the part, increase in service life, plus safety, and nontoxicity in the shop, are cited as advantages. Annealing, carburizing, hardening, brazing, and sintering--all detailed-can be more efficiently accomplished in vacuum heating. As vacuum heating requires certain surface conditions, the compositions of residual mediums is studied. The microrelief and surface finish obtained after vacuum heating is determined. Annealing in a vacuum is compared to annealing in air, a depletion in manganese indicating a greater savings by use of vacuum. Ductility is also tested. The gas of special purity nitrogen is recommended for best results. In general, then, use of electric vacuum furnaces is recommended.

  19. Investment casting heat transfer

    NSDL National Science Digital Library

    Powell, Adam C., IV

    2004-12-15

    Calculate temperature profile and Biot number in mixed conduction and convection/radiation heat transfer from liquid metal through a ceramic mold to the environment, and suggest a design change to reduce the probability of shattering due to thermal stress.

  20. Methane heat transfer investigation

    NASA Technical Reports Server (NTRS)

    Cook, R. T.

    1984-01-01

    Future high chamber pressure LOX/hydrocarbon booster engines require copper-base alloy main combustion chamber coolant channels similar to the SSME to provide adequate cooling and resuable engine life. Therefore, it is of vital importance to evaluate the heat transfer characteristics and coking thresholds for LNG (94% methane) cooling, with a copper-base alloy material adjacent to the fuel coolant. High-pressure methane cooling and coking characteristics were recently evaluated using stainless-steel heated tubes at methane bulk temperatures and coolant wall temperatures typical of advanced engine operation except at lower heat fluxes as limited by the tube material. As expected, there was no coking observed. However, coking evaluations need be conducted with a copper-base surface exposed to the methane coolant at higher heat fluxes approaching those of future high chamber pressure engines.

  1. Opportunity's Heat Shield Scene

    NASA Technical Reports Server (NTRS)

    2005-01-01

    This image from NASA's Mars Exploration Rover Opportunity reveals the scene of the rover's heat shield impact. In this view, Opportunity is approximately 130 meters (427 feet) away from the device that protected it while hurtling through the martian atmosphere.

    The rover spent 36 sols investigating how the severe heating during entry through the atmosphere affected the heat shield. The most obvious is the fact that the heat shield inverted upon impact.

    This is the panoramic camera team's best current attempt at generating a true-color view of what this scene would look like if viewed by a human on Mars. It was generated from a mathematical combination of six calibrated, left-eye panoramic camera images acquired around 1:50 p.m. local solar time on Opportunity's sol 322 (Dec. 19, 2004) using filters ranging in wavelengths from 430 to 750 nanometers.

  2. Hurricanes as Heat Engines

    NSDL National Science Digital Library

    My NASA Data

    In this activity, students examine the effects of hurricanes on sea surface temperature using NASA data. They examine authentic sea surface temperature data to explore how hurricanes extract heat energy from the ocean surface.

  3. Solar heat transport fluid

    NASA Technical Reports Server (NTRS)

    1978-01-01

    The progress made on the development and delivery of noncorrosive fluid subsystems is reported. These subsystems are to be compatible with closed-loop solar heating or combined heating and hot water systems. They are also to be compatible with both metallic and non-metallic plumbing systems. At least 100 gallons of each type of fluid recommended by the contractor will be delivered under the contract. The performance testing of a number of fluids is described.

  4. Microtube strip heat exchanger

    NASA Astrophysics Data System (ADS)

    Doty, F. D.

    1990-12-01

    Doty Scientific (DSI) believes their microtube-strip heat exchanger will contribute significantly to the following: (1) the closed Brayton cycles being pursued at MIT, NASA, and elsewhere; (2) reverse Brayton cycle cryocoolers, currently being investigated by NASA for space missions, being applied to MRI superconducting magnets; and (3) high-efficiency cryogenic gas separation schemes for CO2 removal from exhaust stacks. The goal of this current study is to show the potential for substantial progress in high-effectiveness, low-cost, gas-to-gas heat exchangers for diverse applications at temperatures from below 100 K to above 1000 K. To date, the highest effectiveness measured is about 98 percent and relative pressure drops below 0.1 percent with a specific conductance of about 45 W/kgK are reported. During the pre-award period DSI built and tested a 3-module heat exchanger bank using 103-tube microtube strip (MTS) modules. To add to their analytical capabilities, DSI has acquired computational fluid dynamics (CFD) software. This report describes the pre-award work and the status of the ten tasks of the current project, which are: analyze flow distribution and thermal stresses within individual modules; design a heat exchanger bank of ten modules with 400 microtube per module; obtain production quality tubestrip die and AISI 304 tubestrips; obtain production quality microtubing; construct revised MTS heat exchanger; construct dies and fixtures for prototype heat exchanger; construct 100 MTS modules; assemble 8 to 10 prototype MTS heat exchangers; test prototype MTS heat exchanger; and verify test through independent means.

  5. Microtube Strip Heat Exchanger

    SciTech Connect

    Doty, F.D.

    1990-12-27

    Doty Scientific (DSI) believes their Microtube-Strip Heat Exchanger will contribute significantly to (a) the closed Brayton cycles being pursued at MIT, NASA, and elsewhere; (b) reverse Brayton cycle cryocoolers, currently being investigated by NASA for space missions, being applied to MRI superconducting magnets; and (c) high-efficiency cryogenic gas separation schemes for CO{sub 2} removal from exhaust stacks. The goal of this current study is to show the potential for substantial progress in high-effectiveness, low-cost, gas-to-gas heat exchangers for diverse applications at temperatures from below 100 K to above 1000 K. To date, the highest effectiveness measured is about 98%, and relative pressure drops below 0.1% with a specific conductance of about 45 W/kgK are reported. During the pre-award period DSI built and tested a 3-module heat exchanger bank using 103-tube microtube strip (MTS) modules. To add to their analytical capabilities, DSI has acquired computational fluid dynamics (CFD) software. This report describes the pre-award work and the status of the ten tasks of the current project, which are: analyze flow distribution and thermal stresses within individual modules; design a heat exchanger bank of ten modules with 400 microtube per module; obtain production quality tubestrip die and AISI 304 tubestrips; obtain production quality microtubing; construct revised MTS heat exchanger; construct dies and fixtures for prototype heat exchanger; construct 100 MTS modules; assemble 8-10 prototype MTS heat exchangers; test prototype MTS heat exchanger; and verify test through independent means. 7 refs., 9 figs. 1 tab. (CK)

  6. Freezable heat pipe

    DOEpatents

    Ernst, Donald M. (Leola, PA); Sanzi, James L. (Lancaster, PA)

    1981-02-03

    A heat pipe whose fluid can be repeatedly frozen and thawed without damage to the casing. An additional part is added to a conventional heat pipe. This addition is a simple porous structure, such as a cylinder, self-supporting and free standing, which is dimensioned with its diameter not spanning the inside transverse dimension of the casing, and with its length surpassing the depth of maximum liquid.

  7. Computational heat transfer

    NASA Astrophysics Data System (ADS)

    Jaluria, Yogesh; Torrance, Kenneth E.

    Numerical approaches to heat-transfer problems are examined in an introductory text for senior and graduate engineering students. The emphasis is on the application of physical criteria in selecting the computational method. Chapters are devoted to the mathematics of the governing equations, finite differences, and finite elements; the simulation of transport processes; numerical methods for convective and radiative heat transfer; and combined modes and process applications. Graphs, diagrams, flow charts, problems, tables of material parameters, and sample computer programs are provided.

  8. Microchannel heat exchanger optimization

    Microsoft Academic Search

    G. M. Harpole; J. E. Eninger

    1991-01-01

    A complete two-dimensional flow\\/thermal model of the micro-channel cooler is developed. Optimization of the design parameters with this model is demonstrated for the case of a 1 kW\\/cm2 heat flux with the top surface at 25°C. For this case, pure water could be used as the coolant, or 92% water\\/8% methanol (-5°C freezing point) if the heat is to be

  9. Heat Switches for ADRs

    NASA Technical Reports Server (NTRS)

    DiPirro, M. J.; Shirron, P. J.

    2014-01-01

    Heat switches are key elements in the cyclic operation of Adiabatic Demagnetization Refrigerators (ADRs). Several of the types of heat switches that have been used for ADRs are described in this paper. Key elements in selection and design of these switches include not only ON/OFF switching ratio, but also method of actuation, size, weight, and structural soundness. Some of the trade-off are detailed in this paper.

  10. Externally heated thermal battery

    Microsoft Academic Search

    Louis Pracchia; Ronald F. Vetter; Darwin Rosenlof

    1991-01-01

    A thermal battery activated by external heat comprising an anode (e.g., composed of a lithium-aluminum alloy), a cathode (e.g., composed of iron disulfide), and an electrolyte (e.g., a lithium chloride-potassium chloride eutectic) with the electrolyte inactive at ambient temperature but activated by melting at a predetermined temperature when exposed to external heating is presented. The battery can be used as

  11. Geo-heat center

    SciTech Connect

    Lienau, P.J.; Fornes, A.O.

    1983-01-01

    A summary is presented of the Geo-Heat Center from its origin in 1974. The GHC has been involved in a number of studies and projects. A few of these are: construction of a greenhouse based on geothermal applications, an aquaculture project raising freshwater Malaysian prawns, an investigation of ground water characteristics and corrosion problems associated with the use of geothermal waters, and the assessment of the potential utilization of direct-heat applications of geothermal energy for an agribusiness.

  12. Hurricanes as Heat Engines

    NSDL National Science Digital Library

    Susan Byrne

    2000-05-03

    As water vapor evaporates from the warm ocean surface, it is forced upward in the convective clouds that surround the eyewall and rainband regions of a storm. As the water vapor cools and condenses from a gas back to a liquid state, it releases latent heat. The release of latent heat warms the surrounding air, making it lighter and thus promoting more vigorous cloud development.

  13. Protuberance heating test program

    NASA Technical Reports Server (NTRS)

    Sieker, W. D.

    1966-01-01

    Results are presented of the protuberance heating test program. Four general protuberance shapes on a flat plate were tested. Presentation and evaluation of the data both on the protuberance and in the wake regions are made. The test program is an extension of the general protuberance heat transfer test. The additional series of tests was conducted to define the extent of wake heating and to assess the effects of Reynolds number variation on heating both on and around the protuberances. The protuberance models were mounted near the forward end of a six-foot instrumented test plate with stringers that simulated interstage and skirt structure of the Saturn S-4B stage. The tests were performed at Mach numbers of 2.49, 3.51, and 4.44. Reynolds numbers per foot of 3 million and 1.5 million were used for the two lower Mach numbers and 3 million for a Mach number of 4.44. The test Mach numbers simulated the Saturn S-4B flight conditions during the most severe aerodynamic heating period. The test Reynolds numbers were somewhat higher than the flight values, but lower values could not be used because of tunnel and instrumentation limitations. Oil flow runs were made on two representative models at various combinations of Mach number and Reynolds number to help define the extent of wake heating.

  14. Intrinsically irreversible heat engine

    DOEpatents

    Wheatley, J.C.; Swift, G.W.; Migliori, A.

    1984-01-01

    A class of heat engines based on an intrinsically irreversible heat transfer process is disclosed. In a typical embodiment the engine comprises a compressible fluid that is cyclically compressed and expanded while at the same time being driven in reciprocal motion by a positive displacement drive means. A second thermodynamic medium is maintained in imperfect thermal contact with the fluid and bears a broken thermodynamic symmetry with respect to the fluid. The second thermodynamic medium is a structure adapted to have a low fluid flow impedance with respect to the compressible fluid, and which is further adapted to be in only moderate thermal contact with the fluid. In operation, thermal energy is pumped along the second medium due to a phase lag between the cyclical heating and cooling of the fluid and the resulting heat conduction between the fluid and the medium. In a preferred embodiment the engine comprises an acoustical drive and a housing containing a gas which is driven at a resonant frequency so as to be maintained in a standing wave. Operation of the engine at acoustic frequencies improves the power density and coefficient of performance. The second thermodynamic medium can be coupled to suitable heat exchangers to utilize the engine as a simple refrigeration device having no mechanical moving parts. Alternatively, the engine is reversible in function so as to be utilizable as a prime mover by coupling it to suitable sources and sinks of heat.

  15. Intrinsically irreversible heat engine

    DOEpatents

    Wheatley, John C. (Los Alamos, NM); Swift, Gregory W. (Los Alamos, NM); Migliori, Albert (Santa Fe, NM)

    1984-01-01

    A class of heat engines based on an intrinsically irreversible heat transfer process is disclosed. In a typical embodiment the engine comprises a compressible fluid that is cyclically compressed and expanded while at the same time being driven in reciprocal motion by a positive displacement drive means. A second thermodynamic medium is maintained in imperfect thermal contact with the fluid and bears a broken thermodynamic symmetry with respect to the fluid. the second thermodynamic medium is a structure adapted to have a low fluid flow impedance with respect to the compressible fluid, and which is further adapted to be in only moderate thermal contact with the fluid. In operation, thermal energy is pumped along the second medium due to a phase lag between the cyclical heating and cooling of the fluid and the resulting heat conduction between the fluid and the medium. In a preferred embodiment the engine comprises an acoustical drive and a housing containing a gas which is driven at a resonant frequency so as to be maintained in a standing wave. Operation of the engine at acoustic frequencies improves the power density and coefficient of performance. The second thermodynamic medium can be coupled to suitable heat exchangers to utilize the engine as a simple refrigeration device having no mechanical moving parts. Alternatively, the engine is reversible in function so as to be utilizable as a prime mover by coupling it to suitable sources and sinks of heat.

  16. Chimney heat exchanger

    SciTech Connect

    Whiteley, I.C.

    1981-09-01

    A heat exchanger for installation on the top of a chimney of a building includes a housing having a lower end receiving the top of the chimney and an upper end with openings permitting the escape of effluent from the chimney and a heat exchanger assembly disposed in the housing including a central chamber and a spirally arranged duct network defining an effluent spiral path between the top of the chimney and the central chamber and a fresh air spiral path between an inlet disposed at the lower end of the housing and the central chamber, the effluent and fresh air spiral paths being in heat exchange relationship such that air passing through the fresh air spiral path is heated by hot effluent gases passing upward through the chimney and the effluent spiral path for use in heating the building. A pollution trap can be disposed in the central chamber of the heat exchanger assembly for removing pollutants from the effluent, the pollution trap including a rotating cage carrying pumice stones for absorbing pollutants from the effluent with the surface of the pumice gradually ground off to reveal fresh stone as the cage rotates.

  17. The use of refuse heat assisted by heat transformers

    NASA Astrophysics Data System (ADS)

    Mostofizadeh, C.

    1980-08-01

    The principle of heat transformation from lower temperatures to higher temperatures is investigated. The heat transformer works like an absorption refrigerator and can increase the temperature by 30 K. A testing plant was set up, and measurements show the utility of heat transformers. The construction and mode of operation of the heat transformer are described.

  18. First university owned district heating system using biomass heat

    E-print Network

    Northern British Columbia, University of

    used for core campus heating. To demonstrate syngas production and biomass campus heating Main CampusHighlights · First university owned district heating system using biomass heat · Capacity: 15 MMBtu/hr · Fuel: Local wood residue · Integrated research laboratory · LEED Gold building Biomass Gasification

  19. Heat transfer in SiC compact heat exchanger

    Microsoft Academic Search

    Y. Takeuchi; K. Noborio; Y. Yamamoto; S. Konishi

    2010-01-01

    For development of a compact SiC heat exchanger, numerical heat transfer analysis was conducted to investigate its performance for a wide range of thermal media, liquid LiPb and helium gas, flow rates. The numerical model used was based on the heat exchanger test module developed by the authors. Within the authors’ experimental range, the heat quantity transferred from high temperature

  20. Heat source and heating load operation optimization control technology

    Microsoft Academic Search

    Tao Ji; Shuying Zeng; Kun Liu; Changming Li; Ying Sun

    2011-01-01

    A heat source and heating load energy-saving operation optimization control system, which is suitable for boiler straightly providing type heating system is developed. Studied the relationship of flow and heat load in the quality - flow adjusting process and illustrated with piping supply and return water temperature function expression corresponding to the flow optimization coefficient. According to the outdoor temperature

  1. Solar air heating system for combined DHW and space heating

    E-print Network

    Solar air heating system for combined DHW and space heating solar air collector PV-panel fannon-return valve DHW tank mantle cold waterhot water roof Solar Energy Centre Denmark Danish Technological Institute SEC-R-29 #12;Solar air heating system for combined DHW and space heating Søren Østergaard Jensen

  2. Heat pumps in complex heat and power systems: Final report

    Microsoft Academic Search

    E. Hindmarsh; S. M. Ranade

    1989-01-01

    This report documents the results of an investigation into the placement of heat pumps in complex heat and power systems. The primary goal of this project was the development of a systematic procedure for determining the appropriate integration of heat pumps in industrial sites. Pinch technology, heat pump theory and site utility system theory form the foundation of this work.

  3. Heat Transfer Derivation of differential equations for heat transfer conduction

    E-print Network

    Veress, Alexander

    Heat Transfer Derivation of differential equations for heat transfer conduction without convection/(hftF). T is the temperature, in C or F. dT=dx is the temperature gradient, in C/m or F/ft. This equation states that the heat sign in the above equation states heat flow is positive in the direction opposite the direction

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

    DOEpatents

    Koplow, Jeffrey P

    2013-12-10

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

  5. Heat transfer mechanisms in thin film with laser heat source

    Microsoft Academic Search

    Shuichi Torii; Wen-Jei Yang

    2005-01-01

    The present study deals with the effect of laser radiation on the propagation phenomenon of a thermal wave in a very thin film subjected to a symmetrical heating on both sides. Pulsating laser heating is modelled as an internal heat source with various time characteristics. The Cattaneo heat flux law together with the energy conservation equation is solved by a

  6. Heat and liquid recovery using open cycle heat pump system

    Microsoft Academic Search

    Fox

    1985-01-01

    The present invention relates to the recovery of heat and\\/or condensable liquid from a gaseous environment utilizing an open cycle heat pump system. The open cycle heat pump system is employed to alter the temperature of a gas by compression, expansion, heat exchange, and combinations thereof, to condense selected vapors carried in the gaseous environment for removal from the gas.

  7. Heat and liquid recovery using open cycle heat pump system

    Microsoft Academic Search

    Fox

    1981-01-01

    The present invention relates to the recovery of heat and\\/or condensable liquid from a gaseous environment utilizing an open cycle heat pump system. The open cycle heat pump system is employed to alter the temperature of a gas by compression, expansion, heat exchange, and combinations thereof, to condense selected vapors carried in the gaseous environment for removal from the gas.

  8. Sulfur heat pipes for 600 K space heat rejection systems

    Microsoft Academic Search

    John H. Rosenfeld; G. Yale Eastman; James E. Lindemuth

    1992-01-01

    A preliminary investigation was performed to study the use of sulfur heat pipes in a lightweight space radiator for waste heat rejection at 600 K. Several space power concepts have a need for heat rejection at 600 K. Heat pipes have been shown in previous studies to be useful in reducing the mass of radiators; however, few high-performance, lightweight working

  9. Heat pipe design for space power heat rejection applications

    Microsoft Academic Search

    M. A. Merrigan

    1986-01-01

    Heat pipe radiators represent the current state-of-the-art in heat rejection systems for space power applications. Design trends in high temperature systems are to higher power applications with necessarily larger radiators. In these systems the usable length of radiation loaded heat pipe elements and the temperature distribution for long heat pipe elements are both of concern. The work reported herein is

  10. Thermal measurements and flow visualization of heat convection in a tilted channel

    NASA Astrophysics Data System (ADS)

    Tisserand, Jean-Christophe; Creyssels, Mathieu; Riedinger, Xavier; Castaing, Bernard; Chillà, Francesca

    2010-05-01

    Convection is the most important heat transport mechanism. We can find it not only in many natural situations such as stars, planet's atmosphere but also in half-natural situations such as industrial plants. Furthermore, the Rayleigh-Benard system, in which a fluid is cooled from above and heated from below, is one of the most studied systems in thermal convection. Nevertheless, in this configuration, the neighborhood of the plates controls the heat transfer. Therefore, we have to make a system in which the flow forgets the cold and the hot plate. We have built a vertical long channel which links two chambers : the hot one at the lower end and the cold one at the upper end. Moreover, this channel, which is hanged to a structure, can be tilted from an angle of 0 degree to 90 degrees. The experimental facility used for this purpose is a square channel with an inner area of 5*5 cm² m and with a height of 20 cm. The cell is filled with water and is heated at the bottom by Joule effect. At the top, the temperature is regulated by a thermal bath and the mean temperature of the bulk is 25°C . It is worth noticing that this configuration could correspond to heat pipes (without phase transformation) used in thermalisation systems or could model a vertical access pit of an underground carry. In this paper, we want to highlight how the thermal convection in the bulk of the channel is. In the first part, the paper will be focused on the visualization of the flow into the channel thanks to particle image velocimetry (PIV) technique. We look at the mean velocity field (transverse and axial components) , the fluctuations of the mean velocity field and the shear Reynolds stress. Besides, we analyze how the influence of the power supply and the dependance of the tilt angle are. At last, we will interpret the PIV measurements in terms of turbulent viscosity and effective heat conduction and we will deduce from the PIV measurements the axial mean profile of temperature. Then, in a second part, we present new thermal measurements. Thanks to a new sensor inserted into the channel and which is not too intrusive, we have measured the axial mean profile of temperature for several tilt angle and several different power supplies. At last, in a third part, a model which allows to account for the competition between stratification and turbulence will be developed.

  11. Heating system with vapour compressor heat pump and vertical U-tube ground heat exchanger

    NASA Astrophysics Data System (ADS)

    Hanuszkiewicz-Drapa?a, Ma?gorzata; Sk?adzie?, Jan

    2010-10-01

    In the paper a heating system with a vapour compressor heat pump and vertical U-tube ground heat exchanger for small residential house is considered. A mathematical model of the system: heated object - vapour compressor heat pump - ground heat exchanger is presented shortly. The system investigated is equipped, apart from the heat pump, with the additional conventional source of heat. The processes taking place in the analyzed system are of unsteady character. The model consists of three elements; the first containing the calculation model of the space to be heated, the second - the vertical U-tube ground heat exchanger with the adjoining area of the ground. The equations for the elements of vapour compressor heat pump form the third element of the general model. The period of one heating season is taken into consideration. The results of calculations for two variants of the ground heat exchanger are presented and compared. These results concern variable in time parameters at particular points of the system and energy consumption during the heating season. This paper presents the mutual influence of the ground heat exchanger subsystem, elements of vapour compressor heat pump and heated space.

  12. Heat Pipe Thermal Conditioning Panel

    NASA Technical Reports Server (NTRS)

    Saaski, E. W.

    1973-01-01

    The development, fabrication, and evaluation of heat pipe thermal conditioning panels are discussed. The panels were designed and fabricated to be compatible with several planned NASA space vehicles, in terms of panel size, capacity, temperature gradients, and integration with various heat exchangers and electronic components. It was satisfactorily demonstrated that the heat pipe thermal conditioning panel meets the thermal efficiency and heat transport requirements.

  13. High-temperature heating array

    NASA Technical Reports Server (NTRS)

    Christensen, H. E.; Cox, B. G.

    1976-01-01

    Heating array for thermally conditioning reusable surface insulation panels of thermal protection systems is capable of heating samples to 2500 F at pressures ranging from 0.5 to 760 torr. System uses low cost, easily replaceable graphite heating elements, which give more uniform heating than quartz lamps.

  14. Water chemistry of heating networks

    Microsoft Academic Search

    M. K. Bogatyreva; N. I. Serebryannikov; T. K. Margulova; O. I. Martynova

    1979-01-01

    The reliability and efficiency of district heating equipment are inseparably connected with the water chemistry of the heating networks. Losses of water in the heating networks are made up by makeup water the quality of which must meet certain demands. In selecting the system of water treatment of makeup water for the heating networks one must take into account both

  15. Heat simulation via Scilab programming

    NASA Astrophysics Data System (ADS)

    Hasan, Mohammad Khatim; Sulaiman, Jumat; Karim, Samsul Arifin Abdul

    2014-07-01

    This paper discussed the used of an open source sofware called Scilab to develop a heat simulator. In this paper, heat equation was used to simulate heat behavior in an object. The simulator was developed using finite difference method. Numerical experiment output show that Scilab can produce a good heat behavior simulation with marvellous visual output with only developing simple computer code.

  16. Modular solar powered heat pump

    Microsoft Academic Search

    1980-01-01

    Disclosed is a solar powered heat pump useful for both heating and cooling building space and for providing refrigeration. The device operates on a chemical effect (adsorption) intermittent heat pump cycle in which the moderately high temperature heat generated by insolation is used to drive the desorber. The device has inherent thermal storage, can be factory built, sealed, and tested,

  17. Short duration heat transfer measurements

    Microsoft Academic Search

    T. Arts; C. Camci

    1985-01-01

    Shock tunnels, blowdown cascades, and isentropic light piston compression tubes used to study heat transfer and aerodynamic phenomena in turbine components are described. Thin film heat transfer gages, calorimeter gages, and optical measurements methods are presented. Compression tube investigations of convective heat transfer on a flat plate, with and without film cooling; and convective heat transfer on a high pressure

  18. Flat-plate heat pipe

    NASA Technical Reports Server (NTRS)

    Marcus, B. D.; Fleischman, G. L. (inventors)

    1977-01-01

    Flat plate (vapor chamber) heat pipes were made by enclosing metal wicking between two capillary grooved flat panels. These heat pipes provide a unique configuration and have good capacity and conductance capabilities in zero gravity. When these flat plate vapor chamber heat pipes are heated or cooled, the surfaces are essentially isothermal, varying only 3 to 5 C over the panel surface.

  19. Industrial heat pump assessment study

    Microsoft Academic Search

    R. N. Chappell; S. J. Priebe; G. L. Wilfert

    1989-01-01

    This report summarizes preliminary studies that assess the potential of industrial heat pumps for reduction of process heating requirements in industries receiving power from the Bonneville Power Administration (BPA). This project was initiated at the request of BPA to determine the potential of industrial heat pumps in BPA's service area. Working from known heat pump principles and from a list

  20. Heat Recovery from Coal Gasifiers 

    E-print Network

    Wen, H.; Lou, S. C.

    1981-01-01

    is presented. Steam generated from the waste heat boiler is used to drive steam turbines for power generation or air compressors for the oxygen plant. Low level heat recovered by process heat exchangers is used to heat product gas or support the energy...

  1. Shuttle reentry aerodynamic heating test

    NASA Technical Reports Server (NTRS)

    Pond, J. E.; Mccormick, P. O.; Smith, S. D.

    1971-01-01

    The research for determining the space shuttle aerothermal environment is reported. Brief summaries of the low Reynolds number windward side heating test, and the base and leeward heating and high Reynolds number heating test are included. Also discussed are streamline divergence and the resulting effect on aerodynamic heating, and a thermal analyzer program that is used in the Thermal Environment Optimization Program.

  2. Rotary Joint for Heat Transfer

    NASA Technical Reports Server (NTRS)

    Shauback, R.

    1986-01-01

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

  3. Overshooting by differential heating

    NASA Astrophysics Data System (ADS)

    Andrássy, R.; Spruit, H. C.

    2015-06-01

    On the long nuclear time scale of stellar main-sequence evolution, even weak mixing processes can become relevant for redistributing chemical species in a star. We investigate a process of "differential heating", which occurs when a temperature fluctuation propagates by radiative diffusion from the boundary of a convection zone into the adjacent radiative zone. The resulting perturbation of the hydrostatic equilibrium causes a flow that extends some distance from the convection zone. We study a simplified differential-heating problem with a static temperature fluctuation imposed on a solid boundary. The astrophysically relevant limit of a high Reynolds number and a low Péclet number (high thermal diffusivity) turns out to be interestingly non-intuitive. We derive a set of scaling relations for the stationary differential heating flow. A numerical method adapted to a high dynamic range in flow amplitude needed to detect weak flows is presented. Our two-dimensional simulations show that the flow reaches a stationary state and confirm the analytic scaling relations. These imply that the flow speed drops abruptly to a negligible value at a finite height above the source of heating. We approximate the mixing rate due to the differential heating flow in a star by a height-dependent diffusion coefficient and show that this mixing extends about 4% of the pressure scale height above the convective core of a 10 M? zero-age main sequence star. Appendix A is available in electronic form at http://www.aanda.org

  4. Heat sensitive immunoliposomes

    SciTech Connect

    Sullivan, S.M.

    1985-01-01

    Heat sensitive immunoliposomes were prepared with derivatized antibody. The liposomes are able to bind specifically to target cells and to release their encapsulated contents upon brief heating. Monoclonal anti-H2K/sup K/ was covalently derivatized with palmitoyl-N-hydroxysuccinimide. The palmitoyl antibody was injected at a controlled rate into a suspension of fused unilamellar dipalmitoylphosphati-dylcholine liposomes maintained at a constant temperature. Injection of palmitoyl antibody into a liposome suspension containing 50 mM carboxyfluorescein at 41/sup 0/C resulted in simultaneous antibody incorporation and entrapment of dye. The immunoliposomes were able to release entrapped dye upon heating. Furthermore, this ability was retained when the immunoliposomes were found to the target cells. /sup 3/H-Uridine was entrapped in the heat sensitive immunoliposomes to examine the cellular uptake properties of entrapped contents upon release. The release of uridine from bound heat sensitive immunoliposomes exhibited very similar properties to those obtained for carboxyfluorescein release. The rate of uridine uptake for immunoliposome released uridine was 5 fold greater than bare liposome released uridine and 10 fold greater than that obtained for free uridine. Nucleoside uptake inhibitors were able to inhibit uptake of free uridine and uridine released from immunoliposomes showing the release to be extracellular and uridine uptake was mediated by the nucleoside transporter. These results show that a high local concentration of nucleosides released from immunoliposomes bound to their respective target cell can enhance cellular uptake thus promoting efficient drug delivery.

  5. Heat distribution ceramic processing method

    DOEpatents

    Tiegs, Terry N. (Lenoir City, TN); Kiggans, Jr., James O. (Oak Ridge, TN)

    2001-01-01

    A multi-layered heat distributor system is provided for use in a microwave process. The multi-layered heat distributors includes a first inner layer of a high thermal conductivity heat distributor material, a middle insulating layer and an optional third insulating outer layer. The multi-layered heat distributor system is placed around the ceramic composition or article to be processed and located in a microwave heating system. Sufficient microwave energy is applied to provide a high density, unflawed ceramic product.

  6. Artificial muscles on heat

    NASA Astrophysics Data System (ADS)

    McKay, Thomas G.; Shin, Dong Ki; Percy, Steven; Knight, Chris; McGarry, Scott; Anderson, Iain A.

    2014-03-01

    Many devices and processes produce low grade waste heat. Some of these include combustion engines, electrical circuits, biological processes and industrial processes. To harvest this heat energy thermoelectric devices, using the Seebeck effect, are commonly used. However, these devices have limitations in efficiency, and usable voltage. This paper investigates the viability of a Stirling engine coupled to an artificial muscle energy harvester to efficiently convert heat energy into electrical energy. The results present the testing of the prototype generator which produced 200 ?W when operating at 75°C. Pathways for improved performance are discussed which include optimising the electronic control of the artificial muscle, adjusting the mechanical properties of the artificial muscle to work optimally with the remainder of the system, good sealing, and tuning the resonance of the displacer to minimise the power required to drive it.

  7. Overshooting by differential heating

    E-print Network

    Andrássy, R

    2015-01-01

    On the long nuclear time scale of stellar main-sequence evolution, even weak mixing processes can become relevant for redistributing chemical species in a star. We investigate a process of "differential heating," which occurs when a temperature fluctuation propagates by radiative diffusion from the boundary of a convection zone into the adjacent radiative zone. The resulting perturbation of the hydrostatic equilibrium causes a flow that extends some distance from the convection zone. We study a simplified differential-heating problem with a static temperature fluctuation imposed on a solid boundary. The astrophysically relevant limit of a high Reynolds number and a low P\\'eclet number (high thermal diffusivity) turns out to be interestingly non-intuitive. We derive a set of scaling relations for the stationary differential heating flow. A numerical method adapted to a high dynamic range in flow amplitude needed to detect weak flows is presented. Our two-dimensional simulations show that the flow reaches a sta...

  8. 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.

  9. Externally heated thermal battery

    NASA Astrophysics Data System (ADS)

    Pracchia, Louis; Vetter, Ronald F.; Rosenlof, Darwin

    1991-04-01

    A thermal battery activated by external heat comprising an anode (e.g., composed of a lithium-aluminum alloy), a cathode (e.g., composed of iron disulfide), and an electrolyte (e.g., a lithium chloride-potassium chloride eutectic) with the electrolyte inactive at ambient temperature but activated by melting at a predetermined temperature when exposed to external heating is presented. The battery can be used as a sensor or to ignite pyrotechnic and power electronic devices in a system for reducing the hazard of ordnance exposed to detrimental heating. A particular application is the use of the battery to activate a squib to function in conjunction with one or more other components to vent an ordnance case in order to prevent its explosion in a fire.

  10. Heat flow in Oklahoma

    SciTech Connect

    Cranganu, C.; Deming, D. (Univ. of Oklahoma, Norman, OK (United States))

    1996-01-01

    Oklahoma is one area in which terrestrial heat flow data are sparse. The thermal state of the southern mid-continent, however, is a key to understanding several important geologic problems. These include thermal anomalies associated with Paleozoic fluid migrations and the formation of Mississippi Valley-type lead-zinc deposits, the thermal evolution of the Arkoma and Anadarko sedimentary basins, and the history of hydrocarbon generation and overpressuring in the Anadarko Basin. In the late 1920s, the American Petroleum Institute made a set of equilibrium temperature logs in idle oil wells. These temperature data are generally regarded as being high quality, accurate estimates of rock temperature and they cover the entire central part of Oklahoma. Average thermal gradients in the API survey range from 14 to 43 [sup 0]C/km (average 31.2 [sup 0]C/km) over depth intervals that extend from the surface to a an average depth of 961 m. Geothermal gradients decrease from NNE to SSW. The observed change in thermal gradients could be due to a number of factors. The change in thermal gradients could simply reflect changes in lithology and thermal conductivity. Alternatively, the variation in thermal gradients could be indicative of a change in heat flow related perhaps to variations in the concentration of radioactive heat-producing elements in the crust or heat transport by one or more regional groundwater flow systems. We are proceeding to reduce ambiguity in interpretation by estimating heat flow from thermal conductivity measurements on drill cuttings and heat production from available gamma-ray logs which penetrate basement rocks.

  11. Heat flow in Oklahoma

    SciTech Connect

    Cranganu, C.; Deming, D. [Univ. of Oklahoma, Norman, OK (United States)

    1996-12-31

    Oklahoma is one area in which terrestrial heat flow data are sparse. The thermal state of the southern mid-continent, however, is a key to understanding several important geologic problems. These include thermal anomalies associated with Paleozoic fluid migrations and the formation of Mississippi Valley-type lead-zinc deposits, the thermal evolution of the Arkoma and Anadarko sedimentary basins, and the history of hydrocarbon generation and overpressuring in the Anadarko Basin. In the late 1920s, the American Petroleum Institute made a set of equilibrium temperature logs in idle oil wells. These temperature data are generally regarded as being high quality, accurate estimates of rock temperature and they cover the entire central part of Oklahoma. Average thermal gradients in the API survey range from 14 to 43 {sup 0}C/km (average 31.2 {sup 0}C/km) over depth intervals that extend from the surface to a an average depth of 961 m. Geothermal gradients decrease from NNE to SSW. The observed change in thermal gradients could be due to a number of factors. The change in thermal gradients could simply reflect changes in lithology and thermal conductivity. Alternatively, the variation in thermal gradients could be indicative of a change in heat flow related perhaps to variations in the concentration of radioactive heat-producing elements in the crust or heat transport by one or more regional groundwater flow systems. We are proceeding to reduce ambiguity in interpretation by estimating heat flow from thermal conductivity measurements on drill cuttings and heat production from available gamma-ray logs which penetrate basement rocks.

  12. Heat Shields for Aerobrakes

    NASA Technical Reports Server (NTRS)

    Pitts, W. C.; Murbach, M. S.

    1987-01-01

    Performances of three types of heat protectors predicted. Estimates of expected performances of heat shields for conical drag brake presented in paper. Drag brakes, or aerobrakes, being considered as devices for slowing space vehicles when they return to Space Shuttle altitudes from higher satellite altitudes after supply missions. Aerobrakes add less weight than do retro-rockets for same purpose and consume no fuel. Paper provides general information on sensitivity of performance to thermal and physical properties of materials used in aerobrakes. Information useful to both designers of brakes and developers of materials for brake fabrication on aerospace structures.

  13. Acoustical heat pumping engine

    DOEpatents

    Wheatley, John C. (Los Alamos, NM); Swift, Gregory W. (Los Alamos, NM); Migliori, Albert (Santa Fe, NM)

    1983-08-16

    The disclosure is directed to an acoustical heat pumping engine without moving seals. A tubular housing holds a compressible fluid capable of supporting an acoustical standing wave. An acoustical driver is disposed at one end of the housing and the other end is capped. A second thermodynamic medium is disposed in the housing near to but spaced from the capped end. Heat is pumped along the second thermodynamic medium toward the capped end as a consequence both of the pressure oscillation due to the driver and imperfect thermal contact between the fluid and the second thermodynamic medium.

  14. Specifying Waste Heat Boilers

    E-print Network

    Ganapathy, V.

    .Hence the gas tlow should always be given in mass units so that the HRSG design basis is consistent. b.gas analysis Exhaust gas analysis should be stated for several reasons.The gas enthalpy or specific heat and hence the duty or HRSG 220 ESL-IE-92... variations in surface area can be more glaring when extended surfaces are used.Use of finned tubes reduces the overall heat transfer coefficient.Engineers should be concerned with the product of UxS and not S alone.Hence specifications should NOT call...

  15. Optical heat flux gauge

    DOEpatents

    Noel, Bruce W. (Espanola, NM); Borella, Henry M. (Santa Barbara, CA); Cates, Michael R. (Oak Ridge, TN); Turley, W. Dale (Santa Barbara, CA); MacArthur, Charles D. (Clayton, OH); Cala, Gregory C. (Dayton, OH)

    1991-01-01

    A heat flux gauge comprising first and second thermographic phosphor layers separated by a layer of a thermal insulator, wherein each thermographic layer comprises a plurality of respective thermographic sensors in a juxtaposed relationship with respect to each other. The gauge may be mounted on a surface with the first thermographic phosphor in contact with the surface. A light source is directed at the gauge, causing the phosphors to luminesce. The luminescence produced by the phosphors is collected and its spectra analyzed in order to determine the heat flux on the surface. First and second phosphor layers must be different materials to assure that the spectral lines collected will be distinguishable.

  16. Precision Heating Process

    NASA Technical Reports Server (NTRS)

    1992-01-01

    A heat sealing process was developed by SEBRA based on technology that originated in work with NASA's Jet Propulsion Laboratory. The project involved connecting and transferring blood and fluids between sterile plastic containers while maintaining a closed system. SEBRA markets the PIRF Process to manufacturers of medical catheters. It is a precisely controlled method of heating thermoplastic materials in a mold to form or weld catheters and other products. The process offers advantages in fast, precise welding or shape forming of catheters as well as applications in a variety of other industries.

  17. Solar industrial process heat

    SciTech Connect

    Lumsdaine, E.

    1981-04-01

    The aim of the assessment reported is to candidly examine the contribution that solar industrial process heat (SIPH) is realistically able to make in the near and long-term energy futures of the United States. The performance history of government and privately funded SIPH demonstration programs, 15 of which are briefly summarized, and the present status of SIPH technology are discussed. The technical and performance characteristics of solar industrial process heat plants and equipment are reviewed, as well as evaluating how the operating experience of over a dozen SIPH demonstration projects is influencing institutional acceptance and economoc projections. Implications for domestic energy policy and international implications are briefly discussed. (LEW)

  18. Residential CO 2 heat pump system for combined space heating and hot water heating

    Microsoft Academic Search

    Jørn Stene

    2005-01-01

    A theoretical and experimental study has been carried out for a residential brine-to-water CO2 heat pump system for combined space heating and hot water heating. A 6.5kW prototype heat pump unit was constructed and extensively tested in order to document the performance and to study component and system behaviour over a wide range of operating conditions. The CO2 heat pump

  19. Solitons and ionospheric heating

    NASA Technical Reports Server (NTRS)

    Weatherall, J. C.; Goldman, M. V.; Sheerin, J. P.; Nicholson, D. R.; Payne, G. L.; Hansen, P. J.

    1982-01-01

    It is noted that for parameters characterizing the Platteville ionospheric heating facility, the Langmuir wave evolution at the exact reflection point of the heater wave involves an oscillating two-stream instability followed by a collisionally damped three-dimensional soliton collapse. The result gives an alternative explanation for certain experimental observations.

  20. Electricity from waste heat

    NASA Astrophysics Data System (ADS)

    Larjola, Jaakko; Lindgren, Olli; Vakkilainen, Esa

    In industry and in ships, large amounts of waste heat with quite a high release temperature are produced: examples are combustion gases and the exhaust gases of ceramic kilns. Very often they cannot be used for heating purposes because of long transport distances or because there is no local district heating network. Thus, a practical solution would be to convert this waste heat into electric power. This conversion may be carried out using an ORC-plant (Organic Rankine Cycle). There are probably some twenty ORC-plants in commercial use in the world. They are, however, usually based on conventional power plant technology, and are rather expensive, complicated and may have significant maintenance expenses. In order to obviate these problems, a project was started at Lappeenranta University of Technology at the beginning of 1981 to develop a high-speed, hermetic turbogenerator as the prime mover of the ORC. With this new technology the whole ORC-plant is quite simple, with only one moving part in the power system. It is expected to require very little maintenance, and the calculations made give for it significantly lower specific price than for the conventional technology ORC-plant. Two complete prototypes of the new technology ORC-plant have been built, one to the laboratory, other to industrial use. The nominal output of both is 100 kW electricity. Calculated amortization times for the new ORC-plant range from 2.1 to 6.

  1. Intrinsically irreversible heat engines

    SciTech Connect

    Wheatley, J.C.

    1982-01-01

    The concept of an intrinsically irreversible heat engine is examined as a means of obtaining temperatures near absolute zero. These engines use the irreversible process of thermal conduction to achieve the necessary phasing between temperature changes and motion of a primary medium and therefore have only one moving mechanical element. (GHT)

  2. Urban Heat Island

    NSDL National Science Digital Library

    NASA GSFC

    While this MPEG could have been better designed to show how and why urban areas absorb more heat than surrounding vegetated areas, there is value in seeing enhanced convection over the city, cloud formation favored by increased condensation nuclei, and increased showers downwind of the city.

  3. Sudurnes Regional Heating Corp.

    SciTech Connect

    Lienau, P.J. [ed.

    1996-11-01

    The Svartsengi geothermal area is close to the town of Grindavik on the Rekjanes peninsula and is part of an active fissure swarm, lined with crater-rows and open fissures and faults. The high-temperature area has an area of 2 sq. km and shows only limited signs of geothermal activity at the surface. The reservoir, however, contains lots of energy and at least 8 wells supply the Svartsengi Power Plant with steam. The steam is not useable for domestic heating purposes so that heat exchangers are used to heat cold groundwater with the steam. Some steam is also used for producing 16.4 MW{sub e} of electrical power. The article shows the distribution system piping hot water to nine towns and the Keflavik International Airport. The effluent brine from the Svartsengi Plant is disposed of into a surface pond, called the Blue Lagoon, popular to tourists and people suffering from psoriasis and other forms of eczema seeking therapeutic effects from the silica rich brine. This combined power plant and regional district heating system (cogeneration) is an interesting and unique design for the application of geothermal energy.

  4. Stop Heat from Escaping

    NSDL National Science Digital Library

    2014-09-18

    One way to conserve energy in a building is to use adequate insulation. Insulation helps keep the hot or cool air inside or outside of a building. Inefficient heating and cooling of buildings is a leading residential and industrial source of wasteful energy use. In this activity, students act as engineers and determine which type of insulation would conserve the most energy.

  5. Heating element support clip

    DOEpatents

    Sawyer, W.C.

    1995-08-15

    An apparatus for supporting a heating element in a channel formed in a heater base is disclosed. A preferred embodiment includes a substantially U-shaped tantalum member. The U-shape is characterized by two substantially parallel portions of tantalum that each have an end connected to opposite ends of a base portion of tantalum. The parallel portions are each substantially perpendicular to the base portion and spaced apart a distance not larger than a width of the channel and not smaller than a width of a graphite heating element. The parallel portions each have a hole therein, and the centers of the holes define an axis that is substantially parallel to the base portion. An aluminum oxide ceramic retaining pin extends through the holes in the parallel portions and into a hole in a wall of the channel to retain the U-shaped member in the channel and to support the graphite heating element. The graphite heating element is confined by the parallel portions of tantalum, the base portion of tantalum, and the retaining pin. A tantalum tube surrounds the retaining pin between the parallel portions of tantalum. 6 figs.

  6. Heating element support clip

    DOEpatents

    Sawyer, William C. (Salida, CA)

    1995-01-01

    An apparatus for supporting a heating element in a channel formed in a heater base is disclosed. A preferred embodiment includes a substantially U-shaped tantalum member. The U-shape is characterized by two substantially parallel portions of tantalum that each have an end connected to opposite ends of a base portion of tantalum. The parallel portions are each substantially perpendicular to the base portion and spaced apart a distance not larger than a width of the channel and not smaller than a width of a graphite heating element. The parallel portions each have a hole therein, and the centers of the holes define an axis that is substantially parallel to the base portion. An aluminum oxide ceramic retaining pin extends through the holes in the parallel portions and into a hole in a wall of the channel to retain the U-shaped member in the channel and to support the graphite heating element. The graphite heating element is confined by the parallel portions of tantalum, the base portion of tantalum, and the retaining pin. A tantalum tube surrounds the retaining pin between the parallel portions of tantalum.

  7. Enhanced Condensation Heat Transfer

    NASA Astrophysics Data System (ADS)

    Rose, John Winston

    The paper gives some personal observations on various aspects of enhanced condensation heat transfer. The topics discussed are external condensation (horizontal low-finned tubes and wire-wrapped tubes), internal condensation (microfin tubes and microchannels) and Marangoni condensation of binary mixtures.

  8. Industrial Waste Heat Recovery 

    E-print Network

    Ward, M. E.; Solomon, N. G.; Tabb, E. S.

    1980-01-01

    was that the upper material temperature limit of 1500oF is state-of-the-art for recuperators operating in an oxidizing environment produced by the com-bustion of Diesel No.2. A full size counter axial flow metal heat exchanger test module has successfully completed...

  9. Heat and temperature

    NSDL National Science Digital Library

    Edward A. Zobel

    1997-01-01

    Knowing the difference between heat and temperature is important if one is to have a clear understanding of energy. In this section we will define both terms and reach an understanding of how they are related ideas, but not identical ideas.

  10. Phytosanitary Heat Treatments

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This book chapter by Neil Heather and Guy Hallman, in “Pest Management and Phytosanitary Trade Barriers,” CABI Press, deals with disinfestations of food commodities. Disinfestation of food commodities with heat to satisfy phytosanitary requirements has the advantage of freedom from chemical residue...

  11. Heat pipe thermal switch

    NASA Technical Reports Server (NTRS)

    Wolf, D. A. (inventor)

    1983-01-01

    A thermal switch for controlling the dissipation of heat between a body is described. The thermal switch is comprised of a flexible bellows defining an expansible vapor chamber for a working fluid located between an evaporation and condensation chamber. Inside the bellows is located a coiled retaining spring and four axial metal mesh wicks, two of which have their central portions located inside of the spring while the other two have their central portions located between the spring and the side wall of the bellows. The wicks are terminated and are attached to the inner surfaces of the outer end walls of evaporation and condensation chambers respectively located adjacent to the heat source and heat sink. The inner surfaces of the end walls furthermore include grooves to provide flow channels of the working fluid to and from the wick ends. The evaporation and condensation chambers are connected by turnbuckles and tension springs to provide a set point adjustment for setting the gap between an interface plate on the condensation chamber and the heat sink.

  12. Photovoltaic Roof Heat Flux

    NASA Astrophysics Data System (ADS)

    Samady, Mezhgan Frishta

    Solar panels were mounted with different designs onto 1:800 scale building models while temperature and radiation were measured. While there have been other studies aimed at finding the optimal angles for solar panels [9], in this study both the angle and the mounting method were tested. The three PV mounting designs that were considered to provide the most insulation to a building's rooftop were flush, offset (control), and angled. The solar panel offset height became a key component for rooftop insulation as well as the performance of the actual solar panel. Experimental results were given to verify the thermal behavior of the heat loads from the different designs of the photovoltaic panel. From the results, the angled PV design needed 16Z more heat extraction than the offset and flush PV design needed 60% more heat extracted than the offset. In addition to the heat transfer analysis, thermal models were performed to incorporate main atmospheric conditions which were based on the effects of PV mounting structure.

  13. Wastewater heat recovery apparatus

    DOEpatents

    Kronberg, James W. (108 Independent Blvd., Aiken, SC 29801)

    1992-01-01

    A heat recovery system with a heat exchanger and a mixing valve. A drain trap includes a heat exchanger with an inner coiled tube, baffle plate, wastewater inlet, wastewater outlet, cold water inlet, and preheated water outlet. Wastewater enters the drain trap through the wastewater inlet, is slowed and spread by the baffle plate, and passes downward to the wastewater outlet. Cold water enters the inner tube through the cold water inlet and flows generally upward, taking on heat from the wastewater. This preheated water is fed to the mixing valve, which includes a flexible yoke to which are attached an adjustable steel rod, two stationary zinc rods, and a pivoting arm. The free end of the arm forms a pad which rests against a valve seat. The rods and pivoting arm expand or contract as the temperature of the incoming preheated water changes. The zinc rods expand more than the steel rod, flexing the yoke and rotating the pivoting arm. The pad moves towards the valve seat as the temperature of the preheated water rises, and away as the temperature falls, admitting a variable amount of hot water to maintain a nearly constant average process water temperature.

  14. Thermal performances of heat exchangers applicable to waste-heat recovery systems

    Microsoft Academic Search

    Shou-Shing Hsieh; Chihng-Tsung Liauh; Wen-Sun Han

    1988-01-01

    Results are presented and discussed for the quantitative evaluation of the heat exchangers applied to waste-heat recovery systems for two types of conventional heat exchangers: compact cross-flow heat exchangers, and heat-pipe heat exchangers. The effects of the different alignments on the heat transfer rate of heat pipe heat exchangers are also studied.

  15. Aerodynamic heated steam generating apparatus

    SciTech Connect

    Kim, K.

    1986-08-12

    An aerodynamic heated steam generating apparatus is described which consists of: an aerodynamic heat immersion coil steam generator adapted to be located on the leading edge of an airframe of a hypersonic aircraft and being responsive to aerodynamic heating of water by a compression shock airstream to produce steam pressure; an expansion shock air-cooled condensor adapted to be located in the airframe rearward of and operatively coupled to the aerodynamic heat immersion coil steam generator to receive and condense the steam pressure; and an aerodynamic heated steam injector manifold adapted to distribute heated steam into the airstream flowing through an exterior generating channel of an air-breathing, ducted power plant.

  16. Modeling of Heat Transfer in Geothermal Heat Exchangers

    E-print Network

    Cui, P.; Man, Y.; Fang, Z.

    2006-01-01

    Ground-coupled heat pump (GCHP) systems have been gaining increasing popularity for space conditioning in residential and commercial buildings. The geothermal heat exchanger (GHE) is devised for extraction or injection of thermal energy from...

  17. Urban Sewage Delivery Heat Transfer System (2): Heat Transfer 

    E-print Network

    Zhang, C.; Wu, R.; Li, X.; Li, G.; Zhuang, Z.; Sun, D.

    2006-01-01

    The thimble delivery heat-transfer (TDHT) system is one of the primary modes to utilize the energy of urban sewage. Using the efficiency-number of transfer units method ( ), the heat-transfer efficiencies of the parallel-flow ...

  18. Modeling of Heat Transfer in Geothermal Heat Exchangers 

    E-print Network

    Cui, P.; Man, Y.; Fang, Z.

    2006-01-01

    Ground-coupled heat pump (GCHP) systems have been gaining increasing popularity for space conditioning in residential and commercial buildings. The geothermal heat exchanger (GHE) is devised for extraction or injection of thermal energy from...

  19. Waste-heat recovery in batch processes using heat storage

    Microsoft Academic Search

    S. Stoltze; J. Mikkelsen; B. Lorentzen; P. M. Petersen; B. Qvale

    1995-01-01

    The waste-heat recovery in batch processes has been studied using the pinch-point method. The aim of the work has been to investigate theoretical and practical approaches to the design of heat-exchanger networks, including heat storage, for waste-heat recovery in batch processes. The study is limited to the incorporation of energy-storage systems based on fixed-temperature variable-mass stores. The background for preferring

  20. Control of heat source in a heat conduction problem

    NASA Astrophysics Data System (ADS)

    Lyashenko, V.; Kobilskaya, E.

    2014-11-01

    The mathematical model of thermal processes during the heat treatment of a moving axisymmetric environment, for example wire. is considered. The wire is heated by internal constantly or periodically operating heat source. It is presented in the form of initial-boundary value problem for the unsteady heat equation with internal constantly or periodically operating heat source. The purpose of the work is the definition of control parameter of temperature field of a moving area, which is heated by internal heat source. The control parameters are determined by solving a nonlocal problem for the heat equation. The problem of getting an adequate temperature distribution throughout the heating area is considered. Therefore, a problem of heat source control is solved, in particular, control by electric current. Control of the heat source allows to maintain the necessary, from a technological point of view, temperature in the heating area. In this paper, to find additional information about the source of heat. The integral condition is used in the control problem. Integral condition, which is considered in the work, determines the energy balance of the heating zone and connects the desired temperature distribution in the internal points of area with temperatures at the boundaries. Control quality in an extremum formulation of the problem is assessed using the quadratic functional. In function space, from a physical point of view, proposed functional is the absolute difference between the actual emission of energy and absorbed energy in the heating zone. The absorbed energy is calculated by solving of the boundary value problem. Methods of determining the control parameters of temperature field are proposed. The resulting problem is solved by iterative methods. At different physical conditions, numerical calculations are carried out, control parameters of the heat treatment process are obtained.