Science.gov

Sample records for heat shock-triggered released

  1. Heat shock triggers rapid protein phosphorylation in soybean seedings

    SciTech Connect

    Krishnan, H.B.; Pueppke, S.G.

    1987-10-29

    Heat shock arrests the synthesis of many cellular proteins and simultaneously initiates expression of a unique set of proteins, termed heat shock proteins. We have found that heat shock rapidly triggers phosphorylation of a set of proteins in soybean seedlings. Although the kinetics of phosphorylation and the heat shock response are similar, the major identified phosphorylation products do not comigrate with heat shock proteins on polyacrylamide gels. Cadmium, which is known to induce the heat shock response, stimulates phosphorylation of the same set of proteins. The rapidity of phosphorylation suggests that it may play a pivotal role in sensing and transducing elevated temperature stress in plants.

  2. Resistance heating releases structural adhesive

    NASA Technical Reports Server (NTRS)

    Glemser, N. N.

    1967-01-01

    Composite adhesive package bonds components together for testing and enables separation when testing is completed. The composite of adhesives, insulation and a heating element separate easily when an electrical current is applied.

  3. Passive ice freezing-releasing heat pipe

    DOEpatents

    Gorski, Anthony J.; Schertz, William W.

    1982-01-01

    A heat pipe device has been developed which permits completely passive ice formation and periodic release of ice without requiring the ambient temperature to rise above the melting point of water. This passive design enables the maximum amount of cooling capacity to be stored in the tank.

  4. Rankine vortex evolution in a gas with heat release source

    NASA Astrophysics Data System (ADS)

    Zavershinskii, I. P.; Klimov, A. I.; Molevich, N. E.; Porfir'ev, D. P.

    2009-04-01

    The influence of a heat release source with temperature-dependent power on the stability of a Rankine vortex has been studied. A condition for the formation of a radially convergent swirling flow with increasing vorticity is found for a medium with a positive feedback between nonequilibrium heat release perturbations and the pressure at the vortex core.

  5. Transient pipe flow derived by periodic heat release

    NASA Astrophysics Data System (ADS)

    Wang, Yi-Zun; Celik, Ismail

    The heat release resulting from chemical reactions in a combustor/tail pipe system usually induces an instability in the gas flow. This instability may lead to a stable periodic motion under certain combinations of combustion heat release and combustor geometry. This paper reports a numerical study of the unsteady (periodic) gas flow which is driven by a periodic heat release prescribed empirically. The one-dimensional transient equations of motion and energy are derived by integration from the more general two-dimensional equations. The combustion heat release is added to the energy equation as a source term. These equations are solved using the explicit, predictor-corrector method of MacCormack. Some predictions are compared with measurements. The effects of the wall friction, heat transfer, and the amplitude and frequency of combustion heat release on the velocity and pressure waves are investigated. The results indicate that pulsation amplitude is a strong function of the heat release rate and it shows a maximum near an equivalence ratio value of one, where the heat release is near its maximum; this is in conformity with the experimental data. A method for calculating the natural operation frequency of pulse combustor is suggested.

  6. Spatially resolved heat release rate measurements in turbulent premixed flames

    SciTech Connect

    Ayoola, B.O.; Kaminski, C.F.; Balachandran, R.; Mastorakos, E.; Frank, J.H.

    2006-01-01

    Heat release rate is a fundamental property of great importance for the theoretical and experimental elucidation of unsteady flame behaviors such as combustion noise, combustion instabilities, and pulsed combustion. Investigations of such thermoacoustic interactions require a reliable indicator of heat release rate capable of resolving spatial structures in turbulent flames. Traditionally, heat release rate has been estimated via OH or CH radical chemiluminescence; however, chemiluminescence suffers from being a line-of-sight technique with limited capability for resolving small-scale structures. In this paper, we report spatially resolved two-dimensional measurements of a quantity closely related to heat release rate. The diagnostic technique uses simultaneous OH and CH{sub 2}O planar laser-induced fluorescence (PLIF), and the pixel-by-pixel product of the OH and CH{sub 2}O PLIF signals has previously been shown to correlate well with local heat release rates. Results from this diagnostic technique, which we refer to as heat release rate imaging (HR imaging), are compared with traditional OH chemiluminescence measurements in several flames. Studies were performed in lean premixed ethylene flames stabilized between opposed jets and with a bluff body. Correlations between bulk strain rates and local heat release rates were obtained and the effects of curvature on heat release rate were investigated. The results show that the heat release rate tends to increase with increasing negative curvature for the flames investigated for which Lewis numbers are greater than unity. This correlation becomes more pronounced as the flame gets closer to global extinction.

  7. The meridional scale of baroclinic waves with latent heat release

    NASA Technical Reports Server (NTRS)

    Tang, Chung-Muh

    1988-01-01

    The control on the meridional scale of a class of the baroclinic waves exercised by latent heat release is analyzed. A meridional-scale equation is derived, in which the dry model and the moist model without the meridional variation of the baroclinic waves are revealed. It is shown that, in the dry model the stability analysis cannot determine the meridional scale of the baroclinic waves. When latent heat release is included, the meridional variation of the waves either vanishes or is finite. When the waves have the meridional variation with latent heat release, the growth rate increases as the heating increases for a given Froude number, and there are two modes - the first mode has a small ascending region and a large descending region, while the second mode has a small descending region and a large ascending region.

  8. Hanford production reactor heat releases 1951--1971

    SciTech Connect

    Kannberg, L.D.

    1992-04-01

    The purpose of this report is to document and detail the thermal releases from the Hanford nuclear production reactors during the period 1951 through 1971, and to put these releases in historical perspective with respect to changing Columbia River flows and temperatures. This information can also be used as a foundation for further ecological evaluations. When examining Hanford production reactor thermal releases to the Columbia River all related factors affecting the releases and the characteristics of the river should be considered. The major considerations in the present study were the characteristics of the releases themselves (primarily coolant flow rate, temperatures, discharge facilities, period of operation, and level of operation) and the characteristics of the river in that reach (primarily flow rate, temperature and mixing characteristics; the effects of dam construction were also taken into account). In addition, this study addressed ecological effects of thermal releases on aquatic species. Accordingly, this report includes discussion of the reactor cooling system, historical heat releases, thermal mixing and transport studies, hydroelectric power development, and ecologic effects of Hanford production reactor heat releases on salmon and trout. Appendix A contains reactor operating statistics, and Appendix B provide computations of heat added to the Columbia River between Priest Rapids Dam and Richland, Washington.

  9. Heat release rate from the combustion of uranium

    SciTech Connect

    Solbrig, C.W.

    1995-07-01

    Fuel treatment is planned at the Argonne National Laboratory on EBR-II spent fuel. The electrochemical treatment process is carried out in a cell with an argon atmosphere to prevent any reaction. The amount of fuel processed at any time is limited by the amount of energy which could be released by metal combustion if air is inadvertently allowed into the cell since the heat release would increase the cell pressure. The cell pressure is required to be below atmospheric even if combustion occurs to ensure no cell gas/aerosol is released to the environment. Metal fires can release large amounts of heat. In certain configurations such as fine particulate, metal can be pyrophoric at room temperature. When the metal is a nuclear fuel, it is important to be able to predict the reaction/heat release rate if the metal is inadvertently exposed to air. A realistic combustion model is needed to predict heat release rates for the many different flow and transport configurations which exist in the various fuel processing steps. A model for the combustion of uranium is developed here which compares satisfactorily to experimental data.

  10. Passive ice freezing-releasing heat pipe. [Patent application

    DOEpatents

    Gorski, A.J.; Schertz, W.W.

    1980-09-29

    A heat pipe device has been developed which permits completely passive ice formation and periodic release of ice without requiring the ambient temperature to rise above the melting point of water. This passive design enables the maximum amount of cooling capacity to be stored in the tank.

  11. Evaluation of Heat Induced Methane Release from Methane Hydrates

    NASA Astrophysics Data System (ADS)

    Leeman, J.; Elwood-Madden, M.; Phelps, T. J.; Rawn, C. J.

    2010-12-01

    Clathrates, or gas hydrates, structurally are guest gas molecules populating a cavity in a cage of water molecules. Gas hydrates naturally occur on Earth under low temperature and moderate pressure environments including continental shelf, deep ocean, and permafrost sediments. Large quantities of methane are trapped in hydrates, providing significant near-surface reserves of carbon and energy. Thermodynamics predicts that hydrate deposits may be destabilized by reducing the pressure in the system or raising the temperature. However, the rate of methane release due to varying environmental conditions remains relatively unconstrained and complicated by natural feedback effects of clathrate dissociation. In this study, hydrate dissociation in sediment due to localized increases in temperature was monitored and observed at the mesoscale (>20L) in a laboratory environment. Experiments were conducted in the Seafloor Process Simulator (SPS) at Oak Ridge National Laboratory (ORNL) to simulate heat induced dissociation. The SPS, containing a column of Ottawa sand saturated with water containing 25mg/L Sno-Max to aid nucleation, was pressurized and cooled well into the hydrate stability field. A fiber optic distributed sensing system (DSS) was embedded at four depths in the sediment column. This allowed the temperature strain value (a proxy for temperature) of the system to be measured with high spatial resolution to monitor the clathrate formation/dissociation processes. A heat exchanger embedded in the sediment was heated using hot recirculated ethylene glycol and the temperature drop across the exchanger was measured. These experiments indicate a significant and sustained amount of heat is required to release methane gas from hydrate-bearing sediments. Heat was consumed by hydrate dissociated in a growing sphere around the heat exchanger until steady state was reached. At steady state all heat energy entering the system was consumed in maintaining the temperature profile

  12. Satellite-observed latent heat release in a tropical cyclone

    NASA Technical Reports Server (NTRS)

    Adler, R. F.; Rodgers, E. B.

    1977-01-01

    The latent heat release (LHR) and the distribution of rainfall rate of a tropical cyclone as it grows from a tropical disturbance to a typhoon were determined from Nimbus 5 Electrically Scanning Microwave Radiometer data. The LHR (calculated over a circular area of 4 deg latitude radius) increased during the development and intensification of the storm from a magnitude of 2.7 x 10 to the fourteenth W (in the disturbance stage) to 8.8 x 10 to the fourteenth W (typhoon stage). The latter value corresponds to a mean rainfall rate of 2.0 mm/h. The more intense the cyclone and the greater the LHR, the greater the percentage contribution of the larger rainfall rates to the LHR. As a cyclone intensifies, the higher rainfall rates tend to concentrate toward the center of the circulation.

  13. Radio Heating of Lunar Soil to Release Gases

    NASA Technical Reports Server (NTRS)

    Chui, Talso; Penanen, Konstantin

    2006-01-01

    A report proposes the development of a system to collect volatile elements and compounds from Lunar soil for use in supporting habitation and processing into rocket fuel. Prior exploratory missions revealed that H2, He, and N2 are present in Lunar soil and there are some indications that water ice may also be present. The proposed system would include a shroud that would be placed on the Lunar surface. Inside the shroud would be a radio antenna aimed downward. The antenna would be excited at a suitably high power and at a frequency chosen to optimize the depth of penetration of radio waves into the soil. The radio waves would heat the soil, thereby releasing volatiles bound to soil particles. The escaping volatiles would be retained by the shroud and collected by condensation in a radiatively cooled vessel connected to the shroud. It has been estimated that through radio-frequency heating at a power of 10 kW for one day, it should be possible to increase the temperature of a soil volume of about 1 cubic m by about 200 C -- an amount that should suffice for harvesting a significant quantity of volatile material.

  14. Propagation of blast waves with exponential heat release and internal heat conduction and thermal radiation

    NASA Astrophysics Data System (ADS)

    Gretler, W.; Wehle, P.

    1993-09-01

    The problem of reactive blast waves in a combustible gas mixture, where the heat release at the detonation front decays exponentially with the distance from the center, is analyzed. The central theme of the paper is on the propagation of reactive blast into a uniform, quiescent, counterpressure atmosphere of a perfect gas with constant specific heats. The limiting cases of Chapman-Jouguet detonation waves are considered in the phenomenon of point explosion. In order to deal with this problem, the governing equations including thermal radiation and heat conduction were solved by the method of characteristics using a problem-specific grid and a series expansion as start solution. Numerical results for the distribution of the gas-dynamic parameters inside the flow field are shown and discussed.

  15. [Relationships between reactive oxygen metabolism and endodormancy release of peach bud under short-term heating].

    PubMed

    Wang, Xiao-di; Wang, Hai-bo; Gao, Dong-sheng; Li, Jiang; Wang, Bao-liang; Liu, Feng-zhi

    2010-11-01

    Taking the 6-year-old peach "Shuguang" as test object, this paper studied the effects of short-term heating at 40 degrees C, 45 degrees C, and 50 degrees C on the bud livability, bud burst, reactive oxygen content, and activities of related enzymes in peach bud, aimed to investigate the regulation effect of short-term heating on the endodormancy release of peach bud. The results indicated that the effects of short-tern heating on the endodormancy release of peach bud were advanced by the postponement of treatment date, the increase of treatment temperature, and the prolonging of treatment time. On November 30, the regulation effect of heating at 40 degrees C was negative. Comparing with those under no-heating (CK), the date of endodormancy release was postponed, the bud burst, the O2-* and * OH production rates, the H2O2 content, and the activities of CAT and POD were lowered, and the SOD activity was improved. It was adverse under heating at 45 degrees C and 50 degrees C. On December 10, heating at 40 degrees C nearly had no obvious effect on the endodormancy release, while heating at 45 degrees C and 50 degrees C had the same effect as that on November 30, with the former being more superior to the latter. Correlation analysis indicated that the rapid increase of reactive oxygen might be the critical reason for the endodormancy release of peach bud. PMID:21360995

  16. Retrieved Vertical Profiles of Latent Heat Release Using TRMM Rainfall Products

    NASA Technical Reports Server (NTRS)

    Tao, W.-K.; Lang, S.; Olson, W. S.; Meneghini, R.; Yang, S.; Simpson, J.; Kummerow, C.; Smith, E.

    2000-01-01

    This paper represents the first attempt to use TRMM rainfall information to estimate the four dimensional latent heating structure over the global tropics for February 1998. The mean latent heating profiles over six oceanic regions (TOGA COARE IFA, Central Pacific, S. Pacific Convergence Zone, East Pacific, Indian Ocean and Atlantic Ocean) and three continental regions (S. America, Central Africa and Australia) are estimated and studied. The heating profiles obtained from the results of diagnostic budget studies over a broad range of geographic locations are used to provide comparisons and indirect validation for the heating algorithm estimated heating profiles. Three different latent heating algorithms, the Goddard Convective-Stratiform (CSH) heating, the Goddard Profiling (GPROF) heating, and the Hydrometeor heating (HH) are used and their results are intercompared. The horizontal distribution or patterns of latent heat release from the three different heating retrieval methods are quite similar. They all can identify the areas of major convective activity (i.e., a well defined ITCZ in the Pacific, a distinct SPCZ) in the global tropics. The magnitude of their estimated latent heating release is also not in bad agreement with each other and with those determined from diagnostic budget studies. However, the major difference among these three heating retrieval algorithms is the altitude of the maximum heating level. The CSH algorithm estimated heating profiles only show one maximum heating level, and the level varies between convective activity from various geographic locations. These features are in good agreement with diagnostic budget studies. By contrast, two maximum heating levels were found using the GPROF heating and HH algorithms. The latent heating profiles estimated from all three methods can not show cooling between active convective events. We also examined the impact of different TMI (Multi-channel Passive Microwave Sensor) and PR (Precipitation Radar

  17. Decomposition Kinetics for Mass Loss and Heat Released for HMX

    SciTech Connect

    Weese, R K; Burnham, A K

    2004-07-27

    Nucleation-growth kinetic expressions are derived for thermal decomposition of HMX from a variety of types of data, including mass loss for isothermal and constant rate heating in an open pan, and heat flow for isothermal and constant rate heating in open and closed pans. Conditions are identified in which thermal runaway is small to nonexistent, which typically means temperatures less than 255 C and heating rates less than 1 C/min. Activation energies are typically in the 140 to 150 kJ/mol regime for open pan experiments and about 160 kJ/mol for sealed pan experiments. The reaction clearly displays more than one process, and most likely three processes, which are most clearly evident in open pan experiments. The reaction is accelerated for closed pan experiments, and one global reaction appears to fit the data well.

  18. Effects of heat release on the large-scale structure in turbulent mixing layers

    NASA Astrophysics Data System (ADS)

    McMurtry, P. A.; Riley, J. J.; Metcalfe, R. W.

    1989-02-01

    The effects of chemical heat release on the large-scale structure in a chemically reacting turbulent mixing layer have been studied using three-dimensional time-dependent simulations. Moderate heat release is found to slow the development of the large-scale structures and to shift their wavelengths to larger scales. The results suggest that previously unexplained anomalies observed in the mean velocity profiles of reacting jets and mixing layers may be the result of vorticity generation by baroclinic torques.

  19. The direct simulation of high-speed mixing-layers without and with chemical heat release

    NASA Technical Reports Server (NTRS)

    Sekar, B.; Mukunda, H. S.; Carpenter, M. H.

    1991-01-01

    A direct numerical simulation of high speed reacting and non-reacting flows for H2-air systems is presented. The calculations are made for a convective Mach number of 0.38 with hyperbolic tangent initial profile and finite rate chemical reactions. A higher-order numerical method is used in time accurate mode to time advance the solution to a statistical steady state. About 600 time slices of all the variables are then stored for statistical analysis. It is shown that most of the problems of high-speed combustion with air are characterized by relatively weak heat release. The present study shows that: (1) the convective speed is reduced by heat release by about 10 percent at this convective Mach number M(sub c) = 0.38; (2) the variation of the mean and rms fluctuation of temperature can be explained on the basis of temperature fluctuation between the flame temperature and the ambient; (3) the growth rate with heat release is reduced by 7 percent; and (4) the entrainment is reduced by 25 percent with heat release. These differences are small in comparison with incompressible flow dynamics, and are argued to be due to the reduced importance of heat release in comparison with the large enthalpy gradients resulting from the large-scale vortex dynamics. It is finally suggested that the problems of reduced mixing in high-speed flows are not severely complicated by heat release.

  20. Cold Heat Release Characteristics of Solidified Oil Droplet-Water Solution Latent Heat Emulsion by Air Bubbles

    NASA Astrophysics Data System (ADS)

    Inaba, Hideo; Morita, Shin-Ichi

    The present work investigates the cold heat-release characteristics of the solidified oil droplets (tetradecane, C14H30, freezing point 278.9 K)/water solution emulsion as a latent heat-storage material having a low melting point. An air bubbles-emulsion direct-contact heat exchange method is selected for the cold heat-results from the solidified oil droplet-emulsion layer. This type of direct-contact method results in the high thermal efficiency. The diameter of air bubbles in the emulsion increases as compared with that in the pure water. The air bubbles blown from a nozzle show a strong mixing behavior during rising in the emulsion. The temperature effectiveness, the sensible heat release time and the latent heat release time have been measured as experimental parameters. The useful nondimensional emulsion level equations for these parameters have been derived in terms of the nondimensional emalsion level expressed the emulsion layer dimensions, Reynolds number for air flow, Stefan number and heat capacity ratio.

  1. Fragmentation of condensed material by isochoric heating and release

    SciTech Connect

    Glenn, L.A.

    1983-03-01

    A model is suggested to describe the mechanics of fragmentation when a liquid or solid body disassembles under intense isochoric heating. The model is based on the concept that surface area created in the fragmentation process is governed by an equilibrium balance of the surface energy and a local inertial or kinetic energy. An expression is derived for the resulting fragment size as a function of the initial size, the specific energy deposited, and thermomechanical properties of the material. The theory is applied to calculate the blanket break-up due to neutron heating in the HYLIFE and Cascade Chamber inertial confinement fusion reactors.

  2. Heat release effects on the instability of parallel shear layers

    SciTech Connect

    Hegde, U.

    1994-01-01

    The influence of time-dependent heat addition on the linear instablity of shear layers is of considerable interest in understanding the dynamic behavior of reacting flows and combustion-turbulence interactions. The approach is based upon the Bernoulli enthalpy aeroacoustics theory, which utilizes the specific enthalpy and specific entropy as the primary thermodynamic variables. In addition, velocity oscillations are split into Helmoholtz decomposition theorem.

  3. Adsorption and release of ofloxacin from acid- and heat-treated halloysite.

    PubMed

    Wang, Qin; Zhang, Junping; Zheng, Yue; Wang, Aiqin

    2014-01-01

    Halloysite nanotube is an ideal vehicle of the controlled release of drugs. In this study, we systematically investigated the effects of acid- and heat-treatments on the physicochemical properties, structure and morphology of halloysite by XRD, FTIR, SEM and TEM. Afterwards, the adsorption and in vitro release properties of halloysite for cationic ofloxacin (OFL) were evaluated. The results indicate that HCl treatment has no influence on the crystal structure of halloysite, whereas it becomes amorphous after calcined at temperature higher than 500 °C. Both acid- and heat-treatments have no evident influence on the tubular structure of halloysite. OFL was adsorbed onto halloysite via electrostatic interaction between protonated OFL and negative halloysite surface, cation exchange as well as electrostatic interaction between the OFL-Al(3+) complexes and the negative halloysite surface. Acid-treatment facilitates the release of the adsorbed OFL compared with the natural halloysite in spite of a slight decrease of adsorption capacity. However, heat-treatment results in a sharp decrease of adsorption capacity for OFL owning to the OFL-promoted dissolution of aluminum and the disappearance of the porous structure. Although heat-treatment also facilitates release of the adsorbed OFL, the amount of OFL released is in fact less than the natural halloysite owing to the very low adsorption capacity. Thus, acid-activation is an effective protocol to improve the adsorption and release of halloysite for cationic drug molecules. PMID:24060930

  4. Direct numerical simulations of a reacting mixing layer with chemical heat release

    NASA Technical Reports Server (NTRS)

    Mcmurtry, P. A.; Jou, W.-H.; Metcalfe, R. W.; Riley, J. J.

    1985-01-01

    In order to study the coupling between chemical heat release and fluid dynamics, direct numerical simulations of a chemically reacting mixing layer with heat release are performed. The fully compressible equations as well as an approximate set of equations that is asymptotically valid for low-Mach-number flows are treated. These latter equations have the computational advantage that high-frequency acoustic waves have been filtered out, allowing much larger time steps to be taken in the numerical solution procedure. A detailed derivation of these equations along with an outline of the numerical solution technique is given. Simulation results indicate that the rate of chemical product formed, the thickness of the mixing layer, and the amount of mass entrained into the layer all decrease with increasing rates of heat release.

  5. Multifractal and statistical analyses of heat release fluctuations in a spark ignition engine.

    PubMed

    Sen, Asok K; Litak, Grzegorz; Kaminski, Tomasz; Wendeker, Mirosław

    2008-09-01

    Using multifractal and statistical analyses, we have investigated the complex dynamics of cycle-to-cycle heat release variations in a spark ignition engine. Three different values of the spark advance angle (Delta beta) are examined. The multifractal complexity is characterized by the singularity spectrum of the heat release time series in terms of the Holder exponent. The broadness of the singularity spectrum gives a measure of the degree of mutifractality or complexity of the time series. The broader the spectrum, the richer and more complex is the structure with a higher degree of multifractality. Using this broadness measure, the complexity in heat release variations is compared for the three spark advance angles (SAAs). Our results reveal that the heat release data are most complex for Delta beta=30 degrees followed in order by Delta beta=15 degrees and 5 degrees. In other words, the complexity increases with increasing SAA. In addition, we found that for all the SAAs considered, the heat release fluctuations behave like an antipersistent or a negatively correlated process, becoming more antipersistent with decreasing SAA. We have also performed a statistical analysis of the heat release variations by calculating the kurtosis of their probability density functions (pdfs). It is found that for the smallest SAA considered, Delta beta=5 degrees, the pdf is nearly Gaussian with a kurtosis of 3.42. As the value of the SAA increases, the pdf deviates from a Gaussian distribution and tends to be more peaked with larger values of kurtosis. In particular, the kurtosis has values of 3.94 and 6.69, for Delta beta=15 degrees and 30 degrees, respectively. A non-Gaussian density function with kurtosis in excess of 3 is indicative of intermittency. A larger value of kurtosis implies a higher degree of intermittency. PMID:19045453

  6. WATRE: a computer program for analyzing water and gas release from heated concrete

    SciTech Connect

    Claybrook, S.W.

    1983-05-16

    The capabilities of the WATRE computer code for calculating water and CO/sub 2/ release from heated concrete have been significantly enhanced. The governing finite difference equations have been recast in implicit form to reduce time step limitations and increase computational efficiency. The water release model has been validated by comparison with data from several experiments. The CO/sub 2/ model has also been implemented and validation is in progress.

  7. The Effect of Spray Initial Conditions on Heat Release and Emissions in LDI CFD Calculations

    NASA Technical Reports Server (NTRS)

    Iannetti, Anthony C.; Liu, Nan-Suey; Davoudzadeh, Farhad

    2008-01-01

    The mass and velocity distribution of liquid spray has a primary effect on the combustion heat release process. This heat release process then affects emissions like nitrogen oxides (NOx) and carbon monoxide (CO). Computational Fluid Dynamics gives the engineer insight into these processes, but various setup options exist (number of droplet groups, and initial droplet temperature) for spray initial conditions. This paper studies these spray initial condition options using the National Combustion Code (NCC) on a single swirler lean direct injection (LDI) flame tube. Using laminar finite rate chemistry, comparisons are made against experimental data for velocity measurements, temperature, and emissions (NOx, CO).

  8. Americium and plutonium release behavior from irradiated mixed oxide fuel during heating

    NASA Astrophysics Data System (ADS)

    Sato, I.; Suto, M.; Miwa, S.; Hirosawa, T.; Koyama, S.

    2013-06-01

    The release behavior of Pu and Am was investigated under the reducing atmosphere expected in sodium cooled fast reactor severe accidents. Irradiated Pu and U mixed oxide fuels were heated at maximum temperatures of 2773 K and 3273 K. EPMA, γ-ray spectrometry and α-ray spectrometry for released and residual materials revealed that Pu and Am can be released more easily than U under the reducing atmosphere. The respective release rate coefficients for Pu and Am were obtained as 3.11 × 10-4 min-1 and 1.60 × 10-4 min-1 at 2773 K under the reducing atmosphere with oxygen partial pressure less than 0.02 Pa. Results of thermochemical calculations indicated that the main released chemical forms would likely be PuO for Pu and Am for Am under quite low oxygen partial pressure.

  9. Laser induced heating of PMMA microspheres for remote drug release: a FEM simulation model

    NASA Astrophysics Data System (ADS)

    Vilhena, Henrique; Coelho, João. M. P.; Rebordão, José M.

    2014-08-01

    We present a model in which polymeric spherical microstructures embedded with a light absorbing dye are shown to attain the phase transition temperature necessary for the release of a drug contained in its polymeric matrix into the surrounding medium. By numerically solving the heat diffusion equation and considering a Gaussian near-infrared source it is shown that heating is mostly confined to the particle although limited heat transfer occurs out into the surrounding medium. The influence of different operational parameters is analyzed. Based on the results, we elaborate on the experimental implementation of this kind of remotely operated drug delivery systems.

  10. Impact of Dissociation and Sensible Heat Release on Pulse Detonation and Gas Turbine Engine Performance

    NASA Technical Reports Server (NTRS)

    Povinelli, Louis A.

    2001-01-01

    A thermodynamic cycle analysis of the effect of sensible heat release on the relative performance of pulse detonation and gas turbine engines is presented. Dissociation losses in the PDE (Pulse Detonation Engine) are found to cause a substantial decrease in engine performance parameters.

  11. Clean Photothermal Heating and Controlled Release from Near-Infrared Dye Doped Nanoparticles without Oxygen Photosensitization.

    PubMed

    Guha, Samit; Shaw, Scott K; Spence, Graeme T; Roland, Felicia M; Smith, Bradley D

    2015-07-21

    The photothermal heating and release properties of biocompatible organic nanoparticles, doped with a near-infrared croconaine (Croc) dye, were compared with analogous nanoparticles doped with the common near-infrared dyes ICG and IR780. Separate formulations of lipid-polymer hybrid nanoparticles and liposomes, each containing Croc dye, absorbed strongly at 808 nm and generated clean laser-induced heating (no production of (1)O2 and no photobleaching of the dye). In contrast, laser-induced heating of nanoparticles containing ICG or IR780 produced reactive (1)O2, leading to bleaching of the dye and also decomposition of coencapsulated payload such as the drug doxorubicin. Croc dye was especially useful as a photothermal agent for laser-controlled release of chemically sensitive payload from nanoparticles. Solution state experiments demonstrated repetitive fractional release of water-soluble fluorescent dye from the interior of thermosensitive liposomes. Additional experiments used a focused laser beam to control leakage from immobilized liposomes with very high spatial and temporal precision. The results indicate that fractional photothermal leakage from nanoparticles doped with Croc dye is a promising method for a range of controlled release applications. PMID:26149326

  12. Combustion heat release effects on asymmetric vortex shedding from bluff bodies

    NASA Astrophysics Data System (ADS)

    Cross, Caleb Nathaniel

    2011-07-01

    This thesis describes an investigation of oscillatory combustion processes due to vortex shedding from bluff body flame holders. The primary objective of this study was to elucidate the influence of combustion process heat release upon the Benard-von Karman (BVK) instability in reacting bluff body wakes. For this purpose, spatial and temporal heat release distributions in bluff body-stabilized combustion of liquid Jet-A fuel with high-temperature, vitiated air were characterized over a wide range of operating conditions. Two methods of fuel injection were investigated. In the first method, referred to as close-coupled fuel injection, the fuel was supplied via discrete liquid jets injected perpendicular to the cross-flowing air stream just upstream of the bluff body trailing edge, thereby limiting fuel and air mixing prior to burning. The fuel was introduced well upstream (˜0.5 m) of the bluff body in the second fuel injection mode, resulting in a well-evaporated and mixed reactants stream. The resulting BVK heat release dynamics were compared between these fuel injection modes in order to investigate their dependence upon the spatial distributions of fuel-air ratio and heat release in the reacting wake. When close-coupled fuel injection was used, the BVK heat release dynamics increased in amplitude with increasing global equivalence ratio, reaching a maximum just before globally rich blow out of the combustion process occurred. This was due to a decrease in fuel entrainment into the near-wake as the fuel spray penetrated further into the cross-flow, which reduced the local heat release and equivalence ratio (indicated by CH* and C2*/CH* chemiluminescence, respectively). As a result, the density gradient across the near-wake reaction zone decreased, resulting in less damping of vorticity due to dilatation. In addition, unburned reactants were entrained into the recirculation zone due to the injection of discrete liquid fuel jets in close proximity to the wake. This

  13. Model Scramjet Inlet Unstart Induced by Mass Addition and Heat Release

    NASA Astrophysics Data System (ADS)

    Im, Seong-Kyun; Baccarella, Damiano; McGann, Brendan; Liu, Qili; Wermer, Lydiy; Do, Hyungrok

    2015-11-01

    The inlet unstart phenomena in a model scramjet are investigated at an arc-heated hypersonic wind tunnel. The unstart induced by nitrogen or ethylene jets at low or high enthalpy Mach 4.5 freestream flow conditions are compared. The jet injection pressurizes the downstream flow by mass addition and flow blockage. In case of the ethylene jet injection, heat release from combustion increases the backpressure further. Time-resolved schlieren imaging is performed at the jet and the lip of the model inlet to visualize the flow features during unstart. High frequency pressure measurements are used to provide information on pressure fluctuation at the scramjet wall. In both of the mass and heat release driven unstart cases, it is observed that there are similar flow transient and quasi-steady behaviors of unstart shockwave system during the unstart processes. Combustion driven unstart induces severe oscillatory flow motions of the jet and the unstart shock at the lip of the scramjet inlet after the completion of the unstart process, while the unstarted flow induced by solely mass addition remains relatively steady. The discrepancies between the processes of mass and heat release driven unstart are explained by flow choking mechanism.

  14. Combustion instability and active control: Alternative fuels, augmentors, and modeling heat release

    NASA Astrophysics Data System (ADS)

    Park, Sammy Ace

    Experimental and analytical studies were conducted to explore thermo-acoustic coupling during the onset of combustion instability in various air-breathing combustor configurations. These include a laboratory-scale 200-kW dump combustor and a 100-kW augmentor featuring a v-gutter flame holder. They were used to simulate main combustion chambers and afterburners in aero engines, respectively. The three primary themes of this work includes: 1) modeling heat release fluctuations for stability analysis, 2) conducting active combustion control with alternative fuels, and 3) demonstrating practical active control for augmentor instability suppression. The phenomenon of combustion instabilities remains an unsolved problem in propulsion engines, mainly because of the difficulty in predicting the fluctuating component of heat release without extensive testing. A hybrid model was developed to describe both the temporal and spatial variations in dynamic heat release, using a separation of variables approach that requires only a limited amount of experimental data. The use of sinusoidal basis functions further reduced the amount of data required. When the mean heat release behavior is known, the only experimental data needed for detailed stability analysis is one instantaneous picture of heat release at the peak pressure phase. This model was successfully tested in the dump combustor experiments, reproducing the correct sign of the overall Rayleigh index as well as the remarkably accurate spatial distribution pattern of fluctuating heat release. Active combustion control was explored for fuel-flexible combustor operation using twelve different jet fuels including bio-synthetic and Fischer-Tropsch types. Analysis done using an actuated spray combustion model revealed that the combustion response times of these fuels were similar. Combined with experimental spray characterizations, this suggested that controller performance should remain effective with various alternative fuels

  15. 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

  16. Heat release and flame structure measurements of self-excited acoustically-driven premixed methane flames

    SciTech Connect

    Kopp-Vaughan, Kristin M.; Tuttle, Steven G.; Renfro, Michael W.; King, Galen B.

    2009-10-15

    An open-open organ pipe burner (Rijke tube) with a bluff-body ring was used to create a self-excited, acoustically-driven, premixed methane-air conical flame, with equivalence ratios ranging from 0.85 to 1.05. The feed tube velocities corresponded to Re = 1780-4450. Coupled oscillations in pressure, velocity, and heat release from the flame are naturally encouraged at resonant frequencies in the Rijke tube combustor. This coupling creates sustainable self-excited oscillations in flame front area and shape. The period of the oscillations occur at the resonant frequency of the combustion chamber when the flame is placed {proportional_to}1/4 of the distance from the bottom of the tube. In this investigation, the shape of these acoustically-driven flames is measured by employing both OH planar laser-induced fluorescence (PLIF) and chemiluminescence imaging and the images are correlated to simultaneously measured pressure in the combustor. Past research on acoustically perturbed flames has focused on qualitative flame area and heat release relationships under imposed velocity perturbations at imposed frequencies. This study reports quantitative empirical fits with respect to pressure or phase angle in a self-generated pressure oscillation. The OH-PLIF images were single temporal shots and the chemiluminescence images were phase averaged on chip, such that 15 exposures were used to create one image. Thus, both measurements were time resolved during the flame oscillation. Phase-resolved area and heat release variations throughout the pressure oscillation were computed. A relation between flame area and the phase angle before the pressure maximum was derived for all flames in order to quantitatively show that the Rayleigh criterion was satisfied in the combustor. Qualitative trends in oscillating flame area were found with respect to feed tube flow rates. A logarithmic relation was found between the RMS pressure and both the normalized average area and heat release rate

  17. The effects of latent heat release on the waves with Ekman pumping

    NASA Technical Reports Server (NTRS)

    Tang, C. M.

    1984-01-01

    The problem of the effects of the latent heat release on the waves with both upper and lower boundary frictional effects is investigated. The influence of the vertical shear of the basic wind in these models will be investigated. These investigations will shed some light on the method of solution to the problem of including the effect of Ekman pumping on the moist baroclinic waves in the model of Tang and Fichtl.

  18. Activated platelets release sphingosine 1-phosphate and induce hypersensitivity to noxious heat stimuli in vivo

    PubMed Central

    Weth, Daniela; Benetti, Camilla; Rauch, Caroline; Gstraunthaler, Gerhard; Schmidt, Helmut; Geisslinger, Gerd; Sabbadini, Roger; Proia, Richard L.; Kress, Michaela

    2015-01-01

    At the site of injury activated platelets release various mediators, one of which is sphingosine 1-phosphate (S1P). It was the aim of this study to explore whether activated human platelets had a pronociceptive effect in an in vivo mouse model and whether this effect was based on the release of S1P and subsequent activation of neuronal S1P receptors 1 or 3. Human platelets were prepared in different concentrations (105/μl, 106/μl, 107/μl) and assessed in mice with different genetic backgrounds (WT, S1P1fl/fl, SNS-S1P1−/−, S1P3−/−). Intracutaneous injections of activated human platelets induced a significant, dose-dependent hypersensitivity to noxious thermal stimulation. The degree of heat hypersensitivity correlated with the platelet concentration as well as the platelet S1P content and the amount of S1P released upon platelet activation as measured with LC MS/MS. Despite the significant correlations between S1P and platelet count, no difference in paw withdrawal latency (PWL) was observed in mice with a global null mutation of the S1P3 receptor or a conditional deletion of the S1P1 receptor in nociceptive primary afferents. Furthermore, neutralization of S1P with a selective anti-S1P antibody did not abolish platelet induced heat hypersensitivity. Our results suggest that activated platelets release S1P and induce heat hypersensitivity in vivo. However, the platelet induced heat hypersensitivity was caused by mediators other than S1P. PMID:25954148

  19. The heat released during catalytic turnover enhances the diffusion of an enzyme.

    PubMed

    Riedel, Clement; Gabizon, Ronen; Wilson, Christian A M; Hamadani, Kambiz; Tsekouras, Konstantinos; Marqusee, Susan; Pressé, Steve; Bustamante, Carlos

    2015-01-01

    Recent studies have shown that the diffusivity of enzymes increases in a substrate-dependent manner during catalysis. Although this observation has been reported and characterized for several different systems, the precise origin of this phenomenon is unknown. Calorimetric methods are often used to determine enthalpies from enzyme-catalysed reactions and can therefore provide important insight into their reaction mechanisms. The ensemble averages involved in traditional bulk calorimetry cannot probe the transient effects that the energy exchanged in a reaction may have on the catalyst. Here we obtain single-molecule fluorescence correlation spectroscopy data and analyse them within the framework of a stochastic theory to demonstrate a mechanistic link between the enhanced diffusion of a single enzyme molecule and the heat released in the reaction. We propose that the heat released during catalysis generates an asymmetric pressure wave that results in a differential stress at the protein-solvent interface that transiently displaces the centre-of-mass of the enzyme (chemoacoustic effect). This novel perspective on how enzymes respond to the energy released during catalysis suggests a possible effect of the heat of reaction on the structural integrity and internal degrees of freedom of the enzyme. PMID:25487146

  20. The heat released during catalytic turnover enhances the diffusion of an enzyme

    SciTech Connect

    Riedel, Clement; Gabizon, Ronen; Wilson, Christian A. M.; Hamadani, Kambiz; Tsekouras, Konstantinos; Marqusee, Susan; Pressé, Steve; Bustamante, Carlos

    2014-12-10

    Recent studies have shown that the diffusivity of enzymes increases in a substrate-dependent manner during catalysis. Although this observation has been reported and characterized for several different systems, the precise origin of this phenomenon is unknown. Calorimetric methods are often used to determine enthalpies from enzyme-catalysed reactions and can therefore provide important insight into their reaction mechanisms. The ensemble averages involved in traditional bulk calorimetry cannot probe the transient effects that the energy exchanged in a reaction may have on the catalyst. Here we obtain single-molecule fluorescence correlation spectroscopy data and analyse them within the framework of a stochastic theory to demonstrate a mechanistic link between the enhanced diffusion of a single enzyme molecule and the heat released in the reaction. We propose that the heat released during catalysis generates an asymmetric pressure wave that results in a differential stress at the protein-solvent interface that transiently displaces the centre-of-mass of the enzyme (chemoacoustic effect). We find this novel perspective on how enzymes respond to the energy released during catalysis suggests a possible effect of the heat of reaction on the structural integrity and internal degrees of freedom of the enzyme.

  1. The heat released during catalytic turnover enhances the diffusion of an enzyme

    DOE PAGESBeta

    Riedel, Clement; Gabizon, Ronen; Wilson, Christian A. M.; Hamadani, Kambiz; Tsekouras, Konstantinos; Marqusee, Susan; Pressé, Steve; Bustamante, Carlos

    2014-12-10

    Recent studies have shown that the diffusivity of enzymes increases in a substrate-dependent manner during catalysis. Although this observation has been reported and characterized for several different systems, the precise origin of this phenomenon is unknown. Calorimetric methods are often used to determine enthalpies from enzyme-catalysed reactions and can therefore provide important insight into their reaction mechanisms. The ensemble averages involved in traditional bulk calorimetry cannot probe the transient effects that the energy exchanged in a reaction may have on the catalyst. Here we obtain single-molecule fluorescence correlation spectroscopy data and analyse them within the framework of a stochastic theorymore » to demonstrate a mechanistic link between the enhanced diffusion of a single enzyme molecule and the heat released in the reaction. We propose that the heat released during catalysis generates an asymmetric pressure wave that results in a differential stress at the protein-solvent interface that transiently displaces the centre-of-mass of the enzyme (chemoacoustic effect). We find this novel perspective on how enzymes respond to the energy released during catalysis suggests a possible effect of the heat of reaction on the structural integrity and internal degrees of freedom of the enzyme.« less

  2. The heat released during catalytic turnover enhances the diffusion of an enzyme

    PubMed Central

    Riedel, Clement; Gabizon, Ronen; Wilson, Christian A. M.; Hamadani, Kambiz; Tsekouras, Konstantinos; Marqusee, Susan; Pressé, Steve; Bustamante, Carlos

    2015-01-01

    Recent studies have shown that the diffusivity of enzymes increases in a substrate-dependent manner during catalysis1,2. Although this observation has been reported and characterized for several different systems3–10, the precise origin of this phenomenon is unknown. Calorimetric methods are often used to determine enthalpies from enzyme-catalysed reactions and can therefore provide important insight into their reaction mechanisms11,12. The ensemble averages involved in traditional bulk calorimetry cannot probe the transient effects that the energy exchanged in a reaction may have on the catalyst. Here we obtain single-molecule fluorescence correlation spectroscopy data and analyse them within the framework of a stochastic theory to demonstrate a mechanistic link between the enhanced diffusion of a single enzyme molecule and the heat released in the reaction. We propose that the heat released during catalysis generates an asymmetric pressure wave that results in a differential stress at the protein–solvent interface that transiently displaces the centre-of-mass of the enzyme (chemoacoustic effect). This novel perspective on how enzymes respond to the energy released during catalysis suggests a possible effect of the heat of reaction on the structural integrity and internal degrees of freedom of the enzyme. PMID:25487146

  3. Species production and heat release rates in two-layered natural gas fires

    SciTech Connect

    Zukoski, E.E.; Morehart, J.H.; Kubota, T.; Toner, S.J. )

    1991-02-01

    A fire burning in an enclosure with restricted ventilation will result in the accumulation of a layer of warm products of combustion mixed with entrained air adjacent to the ceiling. For many conditions, the depth of this layer will extend to occupy a significant fraction of the volume of the room. Eventually, the interface between this vitiated ceiling layer and the uncontaminated environment below will position itself so that a large portion of the combustion processes occur in this vitiated layer. A description is given of experimental work concerning the rates of formation of product species and heat release in a turbulent, buoyant natural gas diffusion flame burning in this two-layered configuration. The enclosure was modeled by placing a hood above a burner so that it accumulated the plume gases, and the unsteady development of the ceiling layer was modeled by the direct addition of air into the upper portion of the hood. Measurements of the composition of these gases allowed the computation of stoichiometries and heat release rates. These investigations showed that the species produced in the flame depend primarily on the stoichiometry of the gases present in the ceiling layer and weakly on the temperature of the layer, but are independent of the fuel pair ratio of the mass transported into the layer by the plume. Heat release rates in the fires were compared to a theoretical limit based on a stoichiometric reaction of fuel and air with excess components left unchanged by the combustion.

  4. Mechanisms by which heat release affects the flow field in a chemically reacting, turbulent mixing layer

    NASA Astrophysics Data System (ADS)

    Riley, J. J.; Metcalfe, R. W.; McMurtry, P. A.

    1987-01-01

    The mechanisms by which heat release affects the fluid dynamics in a turbulent reacting mixing layer are studied by direct numerical simulation. In agreement with previous laboratory experiments, the heat release is observed to lower the rate at which the mixing layer grows and to reduce the rate at which chemical products are formed. The baroclinic torque and thermal expansion in the mixing layer are shown to produce changes in the flame vortex structure that act to produce more diffuse vortices than in the constant density case, resulting in lower rotation rates of fluid elements. Previously unexplained anomalies observed in the mean velocity profiles of reacting jets and mixing layers are shown to result from vorticity generation by baroclinic torques. The density reductions also lower the generation rates of turbulent kinetic energy and the turbulent shear stresses, resulting in less turbulent mixing of fluid elements. Calculations of the energy in the various wave numbers show that the heat release has a stabilizing effect on the growth rates of individual modes. A linear stability analysis of a simlified model problem confirms this, showing that low density fluid in the mixing region will result in a shift of the frequency of the unstable modes to lower wave numbers (longer wavelengths). The growth rates of the unstable modes decrease, contributing to the slower growth of the mixing layer.

  5. Heat-Induced Release of Epigenetic Silencing Reveals the Concealed Role of an Imprinted Plant Gene

    PubMed Central

    Sanchez, Diego H.; Paszkowski, Jerzy

    2014-01-01

    Epigenetic mechanisms suppress the transcription of transposons and DNA repeats; however, this suppression can be transiently released under prolonged heat stress. Here we show that the Arabidopsis thaliana imprinted gene SDC, which is silent during vegetative growth due to DNA methylation, is activated by heat and contributes to recovery from stress. SDC activation seems to involve epigenetic mechanisms but not canonical heat-shock perception and signaling. The heat-mediated transcriptional induction of SDC occurs particularly in young developing leaves and is proportional to the level of stress. However, this occurs only above a certain window of absolute temperatures and, thus, resembles a thermal-sensing mechanism. In addition, the re-silencing kinetics during recovery can be entrained by repeated heat stress cycles, suggesting that epigenetic regulation in plants may conserve memory of stress experience. We further demonstrate that SDC contributes to the recovery of plant biomass after stress. We propose that transcriptional gene silencing, known to be involved in gene imprinting, is also co-opted in the specific tuning of SDC expression upon heat stress and subsequent recovery. It is therefore possible that dynamic properties of the epigenetic landscape associated with silenced or imprinted genes may contribute to regulation of their expression in response to environmental challenges. PMID:25411840

  6. Combustion heat release effects on asymmetric vortex shedding from bluff bodies

    NASA Astrophysics Data System (ADS)

    Cross, Caleb Nathaniel

    2011-07-01

    This thesis describes an investigation of oscillatory combustion processes due to vortex shedding from bluff body flame holders. The primary objective of this study was to elucidate the influence of combustion process heat release upon the Benard-von Karman (BVK) instability in reacting bluff body wakes. For this purpose, spatial and temporal heat release distributions in bluff body-stabilized combustion of liquid Jet-A fuel with high-temperature, vitiated air were characterized over a wide range of operating conditions. Two methods of fuel injection were investigated. In the first method, referred to as close-coupled fuel injection, the fuel was supplied via discrete liquid jets injected perpendicular to the cross-flowing air stream just upstream of the bluff body trailing edge, thereby limiting fuel and air mixing prior to burning. The fuel was introduced well upstream (˜0.5 m) of the bluff body in the second fuel injection mode, resulting in a well-evaporated and mixed reactants stream. The resulting BVK heat release dynamics were compared between these fuel injection modes in order to investigate their dependence upon the spatial distributions of fuel-air ratio and heat release in the reacting wake. When close-coupled fuel injection was used, the BVK heat release dynamics increased in amplitude with increasing global equivalence ratio, reaching a maximum just before globally rich blow out of the combustion process occurred. This was due to a decrease in fuel entrainment into the near-wake as the fuel spray penetrated further into the cross-flow, which reduced the local heat release and equivalence ratio (indicated by CH* and C2*/CH* chemiluminescence, respectively). As a result, the density gradient across the near-wake reaction zone decreased, resulting in less damping of vorticity due to dilatation. In addition, unburned reactants were entrained into the recirculation zone due to the injection of discrete liquid fuel jets in close proximity to the wake. This

  7. Near-Infrared-Induced Heating of Confined Water in Polymeric Particles for Efficient Payload Release

    PubMed Central

    2015-01-01

    Near-infrared (NIR) light-triggered release from polymeric capsules could make a major impact on biological research by enabling remote and spatiotemporal control over the release of encapsulated cargo. The few existing mechanisms for NIR-triggered release have not been widely applied because they require custom synthesis of designer polymers, high-powered lasers to drive inefficient two-photon processes, and/or coencapsulation of bulky inorganic particles. In search of a simpler mechanism, we found that exposure to laser light resonant with the vibrational absorption of water (980 nm) in the NIR region can induce release of payloads encapsulated in particles made from inherently non-photo-responsive polymers. We hypothesize that confined water pockets present in hydrated polymer particles absorb electromagnetic energy and transfer it to the polymer matrix, inducing a thermal phase change. In this study, we show that this simple and highly universal strategy enables instantaneous and controlled release of payloads in aqueous environments as well as in living cells using both pulsed and continuous wavelength lasers without significant heating of the surrounding aqueous solution. PMID:24717072

  8. Liquid-Phase Heat-Release Rates of the Systems Hydrazine-Nitric Acid and Unsymmetrical Dimethylhydrazine-Nitric Acid

    NASA Technical Reports Server (NTRS)

    Somogyi, Dezso; Feiler, Charles E.

    1960-01-01

    The initial rates of heat release produced by the reactions of hydrazine and unsymmetrical dimethylhydrazine with nitric acid were determined in a bomb calorimeter under conditions of forced mixing. Fuel-oxidant weight ratio and injection velocity were varied. The rate of heat release apparently depended on the interfacial area between the propellants. Above a narrow range of injection velocities representing a critical amount of interfacial area, the rates reached a maximum and were almost constant with injection velocity. The maximum rate for hydrazine was about 70 percent greater than that for unsymmetrical dimethylhydrazine. The total heat released did not vary with mixture ratio over the range studied.

  9. Acetylcholine released from cholinergic nerves contributes to cutaneous vasodilation during heat stress

    NASA Technical Reports Server (NTRS)

    Shibasaki, Manabu; Wilson, Thad E.; Cui, Jian; Crandall, Craig G.

    2002-01-01

    Nitric oxide (NO) contributes to active cutaneous vasodilation during a heat stress in humans. Given that acetylcholine is released from cholinergic nerves during whole body heating, coupled with evidence that acetylcholine causes vasodilation via NO mechanisms, it is possible that release of acetylcholine in the dermal space contributes to cutaneous vasodilation during a heat stress. To test this hypothesis, in seven subjects skin blood flow (SkBF) and sweat rate were simultaneously monitored over three microdialysis membranes placed in the dermal space of dorsal forearm skin. One membrane was perfused with the acetylcholinesterase inhibitor neostigmine (10 microM), the second membrane was perfused with the NO synthase inhibitor N(G)-nitro-l-arginine methyl ester (l-NAME; 10 mM) dissolved in the aforementioned neostigmine solution (l-NAME(Neo)), and the third membrane was perfused with Ringer solution as a control site. Each subject was exposed to approximately 20 min of whole body heating via a water-perfused suit, which increased mean body temperature from 36.4 +/- 0.1 to 37.5 +/- 0.1 degrees C (P < 0.05). After the heat stress, SkBF at each site was normalized to its maximum value, identified by administration of 28 mM sodium nitroprusside. Mean body temperature threshold for cutaneous vasodilation was significantly lower at the neostigmine-treated site relative to the other sites (neostigmine: 36.6 +/- 0.1 degrees C, l-NAME(Neo): 37.1 +/- 0.1 degrees C, control: 36.9 +/- 0.1 degrees C), whereas no significant threshold difference was observed between the l-NAME(Neo)-treated and control sites. At the end of the heat stress, SkBF was not different between the neostigmine-treated and control sites, whereas SkBF at the l-NAME(Neo)-treated site was significantly lower than the other sites. These results suggest that acetylcholine released from cholinergic nerves is capable of modulating cutaneous vasodilation via NO synthase mechanisms early in the heat stress but

  10. Nonlinear traveling waves in a two-layer system with heat release/consumption at the interface

    NASA Astrophysics Data System (ADS)

    Simanovskii, Ilya B.; Viviani, Antonio; Dubois, Frank; Legros, Jean-Claude

    2016-06-01

    The influence of an interfacial heat release and heat consumption on nonlinear convective flows, developed under the joint action of buoyant and thermocapillary effects in a laterally heated two-layer system with periodic boundary conditions, is investigated. Regimes of traveling waves and modulated traveling waves have been obtained. It is found that rather intensive heat sinks at the interface can lead to the change of the direction of the waves' propagation.

  11. Heat-Driven Release of a Drug Molecule From Carbon Nanotubes

    NASA Astrophysics Data System (ADS)

    Chaban, Vitaly; Prezhdo, Oleg

    2011-03-01

    Hydrophobicity and ability to absorb light that penetrates through living tissues make carbon nanotubes (CNTs) promising intracellular drug delivery agents. Following insertion of a drug molecule into a CNT, the latter is delivered into a tissue, is heated by near infrared radiation, and releases the drug. In order to assess the feasibility of this scheme, we investigate the rates of energy transfer between CNT, water and the drug molecule, and study the temperature and concentration dependence of the diffusion coefficient of the drug molecule inside CNTs. We use ciprofloxacin (CIP) as a sample drug: direct penetration of CIP through cell membranes is problematic due to its high polarity. The simulations show that a heated CNT rapidly deposits its energy to CIP and water. All estimated timescales for the vibrational energy exchange between CNT, CIP and water are less than 10 ps at 298 K. As the system temperature grows from 278 K to 363 K, the diffusion coefficient of the confined CIP increases 5-7 times, depending on CIP concentration. The diffusion coefficient slightly drops with increasing CIP concentration. This effect is more pronounced at higher temperatures. The simulations support the idea that optical heating of CNTs can assist in releasing encapsulated drugs.

  12. 75 FR 61521 - NUREG/CR-7010, Cable Heat Release, Ignition, and Spread in Tray Installations During Fire...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-05

    ...The Nuclear Regulatory Commission has issued for public comment a document entitled: ``NUREG/CR-7010, Cable Heat Release, Ignition, and Spread in Tray Installations During Fire (CHRISTIFIRE) Volume 1: Horizontal Trays, Draft Report for...

  13. Fluctuation-induced heat release from temperature-quenched nuclear spins near a quantum critical point.

    PubMed

    Kim, Y H; Kaur, N; Atkins, B M; Dalal, N S; Takano, Y

    2009-12-11

    At a quantum critical point (QCP)--a zero-temperature singularity in which a line of continuous phase transition terminates--quantum fluctuations diverge in space and time, leading to exotic phenomena that can be observed at nonzero temperatures. Using a quantum antiferromagnet, we present calorimetric evidence that nuclear spins frozen in a high-temperature nonequilibrium state by temperature quenching are annealed by quantum fluctuations near the QCP. This phenomenon, with readily detectable heat release from the nuclear spins as they are annealed, serves as an excellent marker of a quantum critical region around the QCP and provides a probe of the dynamics of the divergent quantum fluctuations. PMID:20366226

  14. WATRE: a program for computing water and gas released from heated concrete

    SciTech Connect

    Claybrook, S.W.; Muhlestein, L.D.

    1985-01-01

    The WATRE computer program calculates the rate and quantity of water and carbon dioxide gas released from heated concrete. Recent development efforts have improved the numerical solution scheme, resulting in increased computational efficiency. The WATRE model is presented and the numerical procedure used to solve the governing equations is outlined. Validation of the WATRE model by comparison with extensive experimental data is emphasized. Results of a sensitivity study which investigated the effects that changes in input data have on WATRE calculations are also discussed.

  15. Rotating magnetic macrospheres as heating mechanism for remote controlled drug release

    NASA Astrophysics Data System (ADS)

    Steinke, Franziska; Andrä, Wilfried; Heide, Rainer; Werner, Christoph; Bellemann, Matthias Erich

    2007-04-01

    A permanent magnetic macrosphere (diameter: 5 mm) spherically seated in an oil bearing inside an experimental capsule (comparable to a hard gelatine capsule size 2) is turned by a rotating magnetic field ( H ⩽ 5 kA/m; frequency ν⩽500 Hz) and causes a temperature rise up to about 60 °C. In order to find further possible improvements, the experimental results were compared to theoretical expectations. First experiments using improved thermal isolation yielded temperatures of about 100 °C. The heating can be used as a mechanism to remotely release drugs in the gastrointestinal tract.

  16. Combustion Gases And Heat Release Analysis During Flame And Flameless Combustion Of Wood Pellets

    NASA Astrophysics Data System (ADS)

    Horváth, Jozef; Wachter, Igor; Balog, Karol

    2015-06-01

    With the growing prices of fossil fuels, alternative fuels produced of biomass come to the fore. They are made of waste materials derived from the processing of wood and wood materials. The main objective of this study was to analyse the fire-technical characteristics of wood pellets. The study analysed three dust samples acquired from wood pellets made of various types of wood biomass. Wood pellet dust is produced when manipulating with pellets. During this process a potentially hazardous situations may occur. Biomass is chemically composed mostly of hemicellulose, cellulose and lignin. During straining of the biomass by heat flux, combustion initiation occurs. Also, there was a change in the composition of material throughout combustion gases production, and the amount of heat generated by a flame or flameless combustion. Measurement of fire characteristics was conducted according to ISO 5660-1 standard using a cone calorimeter. Two samples of wood pellet dust were tested under the heat flux of 35 kW.m-2 and 50 kW.m-2. The process of combustion, the time to ignition, the carbon monoxide concentration and the amount of released heat were observed.

  17. A chlorine disinfectant for excess argon released from K-felsspar during step heating

    NASA Astrophysics Data System (ADS)

    Harrison, T. Mark; Heizler, Matthew T.; Lovera, Oscar M.; Chen, Wenji; Grove, Marty

    1994-05-01

    The release of excess 40Ar ( 40Ar E) from virtually all alkali feldspars at low temperatures ( < 800°C) during 40Ar/39Ar step-heating experiments obscures potentially valuable age and thermal history information. We report a method that takes advantage of the differential release of 40Ar E between contiguous isothermal heating steps, due to the decrepitation of fluid inclusions, and which permits derivation of a correction for the contaminating argon. Differences in age and Cl/K between successive temperature pairs commonly yield a single, well-correlated array on a Δ( 40Ar∗/K) versus Δ( Cl/K) plot that identifies the Cl-correlated composition of 40Ar E ( 40Ar E/Cl) affecting that sample. Eighteen of the twenty K-feldspar samples we have measured yield a single 40Ar E/Cl component, that varies from 1.1 × 10 -3 to 4.2 × 10 -6, making possible recovery of otherwise unobtainable thermochronological information. The upper bound on the 40Ar E/Cl distribution of ˜ 10 -3 may reflect Ar saturation of pore fluids, or the maximum duration between deuteric alteration and cooling below Ar closure in K-feldspar.

  18. Towards Measurement of the Time-resolved Heat Release of Protein Conformation Dynamics

    NASA Technical Reports Server (NTRS)

    Puchalla, Jason; Adamek, Daniel; Austin, Robert

    2004-01-01

    We present a way to observe time-resolved heat release using a laminar flow diffusional mixer coupled with a highly sensitive infrared camera which measures the temperature change of the solvent. There are significant benefits to the use of laminar flow mixers for time-resolved calorimetry: (1) The thermal signal can be made position and time- stationary to allow for signal integration; (2) Extremely small volumes (nl/s) of sample are required for a measurement; (3) The same mixing environment can be observed spectroscopically to obtain state occupation information; (4) The mixer allows one to do out of equilibrium dynamic studies. The hope is that these measurements will allow us probe the non-equilibrium thermodynamics as a protein moves along a free energy trajectory from one state to another.

  19. Influence of heat pre-treatment on BSA tryptic hydrolysis and peptide release.

    PubMed

    Arrutia, Fátima; Puente, Ángela; Riera, Francisco A; Menéndez, Carlos; González, Ulises A

    2016-07-01

    In contrast with other food proteins, such as β-lactoglobulin or caseins, intensely studied for bioactive peptide production, relatively little attention has been paid to serum albumin, the main blood protein, even though blood disposal is a severe problem for meat processors. In this study, serum albumin was hydrolysed with trypsin after several heat treatments and using different enzyme concentrations. The degree of hydrolysis reached and the peptide sequences released over time were evaluated. Large differences in enzyme-to-substrate ratios (1:50, 1:100 and 1:200) led to similar degree of hydrolysis values (31.92±1.43%, 31.08±3.09% and 26.21±0.71%), and did not alter the number of peptides released. However, thermal treatment enhanced significantly (p<0.05) both the degree of hydrolysis (up to 50.41±1.90%) and the number and amount of the majority of peptides obtained, all with potential bioactivity (28 peptides in the native hydrolysate, 39 in the thermally treated). PMID:26920264

  20. Light or Heat? The Origin of Cargo Release from Nanoimpeller Particles Containing Upconversion Nanocrystals under IR Irradiation.

    PubMed

    Dong, Juyao; Zink, Jeffrey I

    2015-09-01

    Nanoimpellers are mesoporous silica nanoparticles that contain azobenzene derivatives bonded inside the pores and rely on the continuous photoisomerization of multiple azobenzenes to release cargo under near UV irradiation. A recent study employs upconversion nanocrystal embedded particles to replace UV light with IR light to stimulate nanoimpellers. However, the photothermal effect of IR irradiation and its likely contribution to the observed release behavior are not examined. It is found that, in the absence of upconversion nanocrystals, the azobenzene co-condensed silica particles still respond to 980 nm illumination, which increases the nanoparticle temperature by 25 °C in 15 min, experimentally measured by an encapsulated nanothermometer. After suppressing the heating, the IR irradiation does not initiate the release, indicating that optical heating, not upconverted light, is responsible for the triggered cargo release. The results are explained by numerical analyses. PMID:26034008

  1. Extracellular Release and Signaling by Heat Shock Protein 27: Role in Modifying Vascular Inflammation

    PubMed Central

    Batulan, Zarah; Pulakazhi Venu, Vivek Krishna; Li, Yumei; Koumbadinga, Geremy; Alvarez-Olmedo, Daiana Gisela; Shi, Chunhua; O’Brien, Edward R.

    2016-01-01

    Heat shock protein 27 (HSP27) is traditionally viewed as an intracellular chaperone protein with anti-apoptotic properties. However, recent data indicate that a number of heat shock proteins, including HSP27, are also found in the extracellular space where they may signal via membrane receptors to alter gene transcription and cellular function. Therefore, there is increasing interest in better understanding how HSP27 is released from cells, its levels and composition in the extracellular space, and the cognate cell membrane receptors involved in effecting cell signaling. In this paper, the knowledge to date, as well as some emerging paradigms about the extracellular function of HSP27 is presented. Of particular interest is the role of HSP27 in attenuating atherogenesis by modifying lipid uptake and inflammation in the plaque. Moreover, the abundance of HSP27 in serum is an emerging new biomarker for ischemic events. Finally, HSP27 replacement therapy may represent a novel therapeutic opportunity for chronic inflammatory disorders, such as atherosclerosis. PMID:27507972

  2. Low effective activation energies for oxygen release from metal oxides: evidence for mass-transfer limits at high heating rates.

    PubMed

    Jian, Guoqiang; Zhou, Lei; Piekiel, Nicholas W; Zachariah, Michael R

    2014-06-01

    Oxygen release from metal oxides at high temperatures is relevant to many thermally activated chemical processes, including chemical-looping combustion, solar thermochemical cycles and energetic thermite reactions. In this study, we evaluated the thermal decomposition of nanosized metal oxides under rapid heating (~10(5) K s(-1)) with time-resolved mass spectrometry. We found that the effective activation-energy values that were obtained using the Flynn-Wall-Ozawa isoconversional method are much lower than the values found at low heating rates, indicating that oxygen transport might be rate-determining at a high heating rate. PMID:24619858

  3. Performance and efficiency evaluation and heat release study of a direct-injection stratified-charge rotary engine

    NASA Technical Reports Server (NTRS)

    Nguyen, H. L.; Addy, H. E.; Bond, T. H.; Lee, C. M.; Chun, K. S.

    1987-01-01

    A computer simulation which models engine performance of the Direct Injection Stratified Charge (DISC) rotary engines was used to study the effect of variations in engine design and operating parameters on engine performance and efficiency of an Outboard Marine Corporation (OMC) experimental rotary combustion engine. Engine pressure data were used in a heat release analysis to study the effects of heat transfer, leakage, and crevice flows. Predicted engine data were compared with experimental test data over a range of engine speeds and loads. An examination of methods to improve the performance of the rotary engine using advanced heat engine concepts such as faster combustion, reduced leakage, and turbocharging is also presented.

  4. Effect of chemical heat release in a temporally evolving mixing layer

    NASA Technical Reports Server (NTRS)

    Higuera, F. J.; Moser, R. D.

    1994-01-01

    Two-dimensional numerical simulations of a temporally evolving mixing layer with an exothermic infinitely fast diffusion flame between two unmixed reactants have been carried out in the limit of zero Mach number to study the effect of the heat release on the early stages of the evolution of the flow. Attention has been directed to relatively large values of the oxidizer-to-fuel mass stoichiometric ratio typical of hydrocarbon flames, and initial vorticity distributions thicker than the temperature and species distributions have been chosen to mimic the situation at the outlet of a jet. The results show that, during the stages of the evolution covered by the present simulations, enhancement of combustion occurs by local stretching of the flame without much augmentation of its area. The rate of product generation depends strongly on the initial conditions, which suggests the possibility of controlling the combustion by acting on the flow. Rollup and vortex amalgamation still occur in these reacting flows but are very much affected by the production of new vorticity by baroclinic torques. These torques lead to counter rotating vortex pairs around the flame and, more importantly, in thin layers of light fluid that leave the vicinity of the flame when the Kelvin-Helmholtz instability begins to develop. Propelled by the vortex pairs, these layers wind around, split on reaching high pressure regions, and originate new vortex pairs in a process that ends up building large-scale vortices with a vorticity distribution more complex than for a constant density fluid.

  5. Stabilizing Alginate Confinement and Polymer Coating of CO-Releasing Molecules Supported on Iron Oxide Nanoparticles To Trigger the CO Release by Magnetic Heating.

    PubMed

    Meyer, Hajo; Winkler, Felix; Kunz, Peter; Schmidt, Annette M; Hamacher, Alexandra; Kassack, Matthias U; Janiak, Christoph

    2015-12-01

    Maghemite (Fe2O3) iron oxide nanoparticles (IONPs) were synthesized, modified with covalent surface-bound CO-releasing molecules of a tri(carbonyl)-chlorido-phenylalaninato-ruthenium(II) complex (CORM), and coated with a dextran polymer. The time- and temperature-dependent CO release from this CORM-3 analogue was followed by a myoglobin assay. A new measurement method for the myoglobin assay was developed, based on confining "water-soluble" polymer-coated Dextran500k@CORM@IONP particles in hollow spheres of nontoxic and easily prepared calcium alginate. Dropping a mixture of Dextran500k@CORM@IONP and sodium alginate into a CaCl2 solution leads to stable hollow spheres of Ca(2+) cross-linked alginate which contain the Dextran500k@CORM@IONP particles. This "alginate-method" (i) protects CORM-3 analogues from rapid CO-displacement reactions with a protein, (ii) enables a spatial separation of the CORM from its surrounding myoglobin assay with the alginate acting as a CO-permeable membrane, and (iii) allows the use of substances with high absorptivity (such as iron oxide nanoparticles) in the myoglobin assay without interference in the optical path of the UV cell. Embedding the CORM@IONP nanoparticles in the alginate vessel represents a compartmentation of the reactive component and allows for close contact with, yet facile separation from, the surrounding myoglobin assay. The half-life of the CO release from Dextran500k@CORM@IONP particles surrounded by alginate was determined to be 890 ± 70 min at 20 °C. An acceleration of the CO release occurs at higher temperature with a half-life of 172 ± 27 min at 37 °C and 45 ± 7 min at 50 °C. The CO release can be triggered in an alternating current magnetic field (31.7 kA m(-1), 247 kHz, 39.9 mT) through local magnetic heating of the susceptible iron oxide nanoparticles. With magnetic heating at 20 °C in the bulk solution, the half-life of CO release from Dextran500k@CORM@IONP particles decreased to 155 ± 18 min

  6. Numerical simulations on influence of urban land cover expansion and anthropogenic heat release on urban meteorological environment in Pearl River Delta

    NASA Astrophysics Data System (ADS)

    Zhang, Ning; Wang, Xuemei; Chen, Yan; Dai, Wei; Wang, Xueyuan

    2015-08-01

    Urbanization is an extreme way in which human being changes the land use/land cover of the earth surface, and anthropogenic heat release occurs at the same time. In this paper, the anthropogenic heat release parameterization scheme in the Weather Research and Forecasting model is modified to consider the spatial heterogeneity of the release; and the impacts of land use change and anthropogenic heat release on urban boundary layer structure in the Pearl River Delta, China, are studied with a series of numerical experiments. The results show that the anthropogenic heat release contributes nearly 75 % to the urban heat island intensity in our studied period. The impact of anthropogenic heat release on near-surface specific humidity is very weak, but that on relative humidity is apparent due to the near-surface air temperature change. The near-surface wind speed decreases after the local land use is changed to urban type due to the increased land surface roughness, but the anthropogenic heat release leads to increases of the low-level wind speed and decreases above in the urban boundary layer because the anthropogenic heat release reduces the boundary layer stability and enhances the vertical mixing.

  7. Release behavior of non-network proteins and its relationship to the structure of heat-induced soy protein gels.

    PubMed

    Wu, Chao; Hua, Yufei; Chen, Yeming; Kong, Xiangzhen; Zhang, Caimeng

    2015-04-29

    Heat-induced soy protein gels were prepared by heating protein solutions at 12%, 15% ,or 18% for 0.5, 1.0, or 2.0 h. The release of non-network proteins from gel slices was conducted in 10 mM pH 7.0 sodium phosphate buffer. SDS-PAGE and diagonal electrophoresis demonstrated that the released proteins consisted of undenatured AB subunits and denatured proteins including monomers of A polypeptides, disulfide bond linked dimers, trimers, and polymers of A polypeptides, and an unidentified 15 kDa protein. SEC-HPLC analysis of non-network proteins revealed three major protein peaks, with molecular weights of approximately 253.9, 44.8, and 9.7 kDa. The experimental data showed that the time-dependent release of the three fractions from soy protein gels fit Fick's second law. An increasing protein concentration or heating time resulted in a decrease in diffusion coefficients of non-network proteins. A power law expression was used to describe the relationship between non-network protein diffusion coefficient and molecular weight, for which the exponent (α) shifted to higher value with an increase in protein concentration or heating time, indicating that a more compact gel structure was formed. PMID:25842998

  8. Smoothing HCCI heat release with vaporization-cooling-induced thermal stratification using ethanol.

    SciTech Connect

    Dec, John E.; Sjoberg, Carl-Magnus G.

    2010-12-01

    Ethanol and ethanol/gasoline blends are being widely considered as alternative fuels for light-duty automotive applications. At the same time, HCCI combustion has the potential to provide high efficiency and ultra-low exhaust emissions. However, the application of HCCI is typically limited to low and moderate loads because of unacceptably high heat-release rates (HRR) at higher fueling rates. This work investigates the potential of lowering the HCCI HRR at high loads by using partial fuel stratification to increase the in-cylinder thermal stratification. This strategy is based on ethanol's high heat of vaporization combined with its true single-stage ignition characteristics. Using partial fuel stratification, the strong fuel-vaporization cooling produces thermal stratification due to variations in the amount of fuel vaporization in different parts of the combustion chamber. The low sensitivity of the autoignition reactions to variations of the local fuel concentration allows the temperature variations to govern the combustion event. This results in a sequential autoignition event from leaner and hotter zones to richer and colder zones, lowering the overall combustion rate compared to operation with a uniform fuel/air mixture. The amount of partial fuel stratification was varied by adjusting the fraction of fuel injected late to produce stratification, and also by changing the timing of the late injection. The experiments show that a combination of 60-70% premixed charge and injection of 30-40 % of the fuel at 80{sup o}CA before TDC is effective for smoothing the HRR. With CA50 held fixed, this increases the burn duration by 55% and reduces the maximum pressure-rise rate by 40%. Combustion stability remains high but engine-out NO{sub x} has to be monitored carefully. For operation with strong reduction of the peak HRR, ISNO{sub x} rises to around 0.20 g/kWh for an IMEP{sub g} of 440 kPa. The single-cylinder HCCI research engine was operated naturally aspirated

  9. Assessment of Heat Resistance of Bacterial Spores from Food Product Isolates by Fluorescence Monitoring of Dipicolinic Acid Release

    PubMed Central

    Kort, Remco; O'Brien, Andrea C.; van Stokkum, Ivo H. M.; Oomes, Suus J. C. M.; Crielaard, Wim; Hellingwerf, Klaas J.; Brul, Stanley

    2005-01-01

    This study is aimed at the development and application of a convenient and rapid optical assay to monitor the wet-heat resistance of bacterial endospores occurring in food samples. We tested the feasibility of measuring the release of the abundant spore component dipicolinic acid (DPA) as a probe for heat inactivation. Spores were isolated from the laboratory type strain Bacillus subtilis 168 and from two food product isolates, Bacillus subtilis A163 and Bacillus sporothermodurans IC4. Spores from the lab strain appeared much less heat resistant than those from the two food product isolates. The decimal reduction times (D values) for spores from strains 168, A163, and IC4 recovered on Trypticase soy agar were 1.4, 0.7, and 0.3 min at 105°C, 120°C, and 131°C, respectively. The estimated Z values were 6.3°C, 6.1°C, and 9.7°C, respectively. The extent of DPA release from the three spore crops was monitored as a function of incubation time and temperature. DPA concentrations were determined by measuring the emission at 545 nm of the fluorescent terbium-DPA complex in a microtiter plate fluorometer. We defined spore heat resistance as the critical DPA release temperature (Tc), the temperature at which half the DPA content has been released within a fixed incubation time. We found Tc values for spores from Bacillus strains 168, A163, and IC4 of 108°C, 121°C, and 131°C, respectively. On the basis of these observations, we developed a quantitative model that describes the time and temperature dependence of the experimentally determined extent of DPA release and spore inactivation. The model predicts a DPA release rate profile for each inactivated spore. In addition, it uncovers remarkable differences in the values for the temperature dependence parameters for the rate of spore inactivation, DPA release duration, and DPA release delay. PMID:16000762

  10. Re-examining the roles of surface heat flux and latent heat release in a "hurricane-like" polar low over the Barents Sea

    NASA Astrophysics Data System (ADS)

    Kolstad, Erik W.; Bracegirdle, Thomas J.; Zahn, Matthias

    2016-07-01

    Polar lows are intense mesoscale cyclones that occur at high latitudes in both hemispheres during winter. Their sometimes evidently convective nature, fueled by strong surface fluxes and with cloud-free centers, have led to some polar lows being referred to as "arctic hurricanes." Idealized studies have shown that intensification by hurricane development mechanisms is theoretically possible in polar winter atmospheres, but the lack of observations and realistic simulations of actual polar lows have made it difficult to ascertain if this occurs in reality. Here the roles of surface heat fluxes and latent heat release in the development of a Barents Sea polar low, which in its cloud structures showed some similarities to hurricanes, are studied with an ensemble of sensitivity experiments, where latent heating and/or surface fluxes of sensible and latent heat were switched off before the polar low peaked in intensity. To ensure that the polar lows in the sensitivity runs did not track too far away from the actual environmental conditions, a technique known as spectral nudging was applied. This was shown to be crucial for enabling comparisons between the different model runs. The results presented here show that (1) no intensification occurred during the mature, postbaroclinic stage of the simulated polar low; (2) surface heat fluxes, i.e., air-sea interaction, were crucial processes both in order to attain the polar low's peak intensity during the baroclinic stage and to maintain its strength in the mature stage; and (3) latent heat release played a less important role than surface fluxes in both stages.

  11. Numerical Study on the Heat Release Distributions of a Supersonic Combustor with Three-Dimensional "Swallowtail" Cavity

    NASA Astrophysics Data System (ADS)

    Wang, Chun; Sun, Xiaofeng; Yao, Xuanyu; Jiang, Zonglin

    Hypersonic air-breathing propulsion has been a focus technology in hypersonic aviation in the past decades [1]. Three-dimensional cavity may act as the flame holder of a Scramjet engine in air-breathing hypersonic propulsion. An interesting three-dimensional cavity is "swallowtail" cavity which has a special inner shape like a swallowtail. With three-dimensional cavity in supersonic chamber, threedimensional vortexes may be organized optimally, and the exchange of mass, momentum and energy between cavity flow and supersonic flow may be enhanced to provide better performance of mixing and combustion[2]. Also, three-dimensional cavity may avoid the sharp heat release in local region of chamber and suppress the subsonic combustion oscillation induced by the cavity in a supersonic combustor. It is necessary to study the heat release distribution of a supersonic combustor with three-dimensional cavity.

  12. The Effects of Fuel Stratification and Heat Release Rate Shaping in Reactivity Controlled Compression Ignition (RCCI) Combustion

    NASA Astrophysics Data System (ADS)

    DelVescovo, Dan A.

    Low temperature combustion strategies have demonstrated high thermal efficiency with low emissions of pollutants, including oxides of nitrogen and particulate matter. One such combustion strategy, called Reactivity Controlled Compression Ignition (RCCI), which involves the port injection of a low reactivity fuel such as gasoline, ethanol, or natural gas, and a direct injection of a high reactivity fuel, such as diesel, has demonstrated excellent control over the heat release event due to the introduction of in-cylinder stratification of equivalence ratio and reactivity. The RCCI strategy is inherently fuel flexible, however the direct injection strategy needs to be tailored to the combination of premixed and direct injected fuels. Experimental results demonstrate that, when comparing different premixed fuels, matching combustion phasing with premixed mass percentage or SOI timing is not sufficient to retain baseline efficiency and emissions results. If the bulk characteristics of the heat release event can be matched, however, then the efficiency and emissions can be maintained. A 0-D methodology for predicting the required fuel stratification for a desired heat release for kinetically-controlled stratified-charge combustion strategies is proposed and validated with 3-D reacting and non-reacting CFD simulations performed with KIVA3Vr2 in this work. Various heat release rate shapes, phasing, duration, and premixed and DI fuel chemistries are explored using this analysis. This methodology provides a means by which the combustion process of a stratified-charge, kinetically-controlled combustion strategy could be optimized for any fuel combination, assuming that the fuel chemistry is well characterized.

  13. Changes in body core temperatures and heat balance after an abrupt release of lower body negative pressure in humans

    NASA Astrophysics Data System (ADS)

    Tanabe, Minoru; Shido, Osamu

    1994-03-01

    Changes in body core temperature ( T cor) and heat balance after an abrupt release of lower body negative pressure (LBNP) were investigated in 5 volunteers under the following conditions: (1) an ambient temperature ( T a) of 20 °C or (2) 35 °C, and (3) T a of 25 °C with a leg skin temperature of 30°C or (4) 35°C. The leg skin temperature was controlled with water perfusion devices wound around the legs. Rectal ( T re), tympanic ( T ty) and esophageal ( T es) temperatures, skin temperatures (7 sites) and oxygen consumption were measured. The intensity of LBNP was adjusted so that the amount of blood pooled in the legs was the same under all conditions. When a thermal balance was attained during LBNP, application of LBNP was suddenly halted. The skin temperatures increased significantly after the release of LBNP under all conditions, while oxygen consumption hardly changed. The release of LBNP caused significant falls in T cor s under conditions (1) and (3), but lowered T cor s very slightly under conditions (2) and (4). The changes in T es were always more rapid and greater than those of T ty and T re. The falls in T ty and T re appeared to be explained by changes in heat balance, whereas the sharp drop of T es could not be explained especially during the first 8 min after the release of LBNP. The results suggest that a fall in T cor after a release of LBNP is attributed to an increase in heat loss due to reflexive skin vasodilation and is dependent on the temperature of venous blood returning from the lower body. It is presumed that T es may not be an appropriate indicator for T cor when venous return changes rapidly.

  14. The pH effect of solvent in silanization on fluoride released and mechanical properties of heat-cured acrylic resin containing fluoride-releasing filler.

    PubMed

    Nakornchai, Natha; Arksornnukit, Mansuang; Kamonkhantikul, Krid; Takahashi, Hidekazu

    2016-01-01

    This study aimed to evaluate the effect of an acidic-adjusted pH of solvent in silanization on the amount of fluoride released and mechanical properties of heat-cured acrylic resin containing a silanized fluoride-releasing filler. The experimental groups were divided into 4 groups; non-silanized, acidic-adjusted pH, non-adjusted pH, and no filler as control. For fluoride measurement, each specimen was placed in deionized water which was changed every day for 7 days, every week for 7 weeks and measured. The flexural strength and flexural modulus were evaluated after aging for 48 h, 1, and 2 months. Two-way ANOVA indicated significant differences among groups, storage times, and its interaction in fluoride measurement and flexural modulus. For flexural strength, there was significant difference only among groups. Acidic-adjusted pH of solvent in silanization enhanced the amount of fluoride released from acrylic resin, while non-adjusted pH of solvent exhibited better flexural strength of acrylic resin. PMID:27252000

  15. Two-time correlation of heat release rate and spectrum of combustion noise from turbulent premixed flames

    NASA Astrophysics Data System (ADS)

    Liu, Yu

    2015-09-01

    The spectral characteristics of combustion noise are dictated by the temporal correlation of the overall change of heat release rate fluctuations which has not received sufficient attention in prior studies. In this work, the two-time correlation of the volumetric heat release rate fluctuations within the flame brush and its role in modeling combustion noise spectrum are investigated by analyzing direct numerical simulation (DNS) data of turbulent premixed V-flames. This two-time correlation can be well represented by Gaussian-type functions and it captures the slow global variation of the fluctuating heat release rate and hence the low-frequency noise sources of unsteady combustion. The resulting correlation model is applied to predict the far-field noise spectrum from test open flames, and different reference time scales are used to scale this correlation from the DNS data to the test flames. The comparison between predictions and measurements indicates that the correlation models of all reference time scales are capable of reproducing the essential spectral shape including the low- and high-frequency dependencies. Reasonable agreement in the peak frequency, peak sound pressure level, and the Strouhal number scaling of peak frequency is also achieved for two turbulent time scales. A promising convective time scale shows great potential for characterizing the spectral features, yet its predictive capabilities are to be further verified through a longer DNS signal of a bounded flame configuration.

  16. Neuronal Serotonin Release Triggers the Heat Shock Response in C. elegans in the Absence of Temperature Increase

    PubMed Central

    Tatum, Marcus C.; Ooi, Felicia K.; Chikka, Madhusudana Rao; Chauve, Laetitia; Martinez-Velazquez, Luis A.; Steinbusch, Harry W.M.; Morimoto, Richard I.; Prahlad, Veena

    2016-01-01

    Summary Background Cellular mechanisms aimed at repairing protein damage and maintaining homeostasis, widely understood to be triggered by the damage itself, have recently been shown to be under cell nonautonomous control in the metazoan C. elegans. The heat shock response (HSR) is one such conserved mechanism, activated by cells upon exposure to proteotoxic conditions such as heat. Previously, we had shown that this conserved cytoprotective response is regulated by the thermosensory neuronal circuitry of C. elegans. Here, we investigate the mechanisms and physiological relevance of neuronal control. Results By combining optogenetic methods with live visualization of the dynamics of the heat shock transcription factor (HSF1), we show that excitation of the AFD thermosensory neurons is sufficient to activate HSF1 in another cell, even in the absence of temperature increase. Excitation of the AFD thermosensory neurons enhances serotonin release. Serotonin release elicited by direct optogenetic stimulation of serotonergic neurons activates HSF1 and upregulates molecular chaperones through the metabotropic serotonin receptor SER-1. Consequently, excitation of serotonergic neurons alone can suppress protein misfolding in C. elegans peripheral tissue. Conclusions These studies imply that thermosensory activity coupled to serotonergic signaling is sufficient to activate the protective HSR prior to frank proteotoxic damage. The ability of neurosensory release of serotonin to control cellular stress responses and activate HSF1 has powerful implications for the treatment of protein conformation diseases. PMID:25557666

  17. Characteristics of cyclic heat release variability in the transition from spark ignition to HCCI in a gasoline engine

    SciTech Connect

    Sen, Asok K; Litak, Grzegorz; Edwards, Kevin Dean; FINNEY, Charles E A; Daw, C Stuart; Wagner, Robert M

    2011-01-01

    We study selected examples of previously published cyclic heat-release measurements from a single-cylinder gasoline engine as stepwise valve timing adjustments were made to shift from spark ignited (SI) combustion to homogeneous charge compression ignition (HCCI). Wavelet analysis of the time series, combined with conventional statistics and multifractal analysis, revealed previously undocumented features in the combustion variability as the shift occurred. In the spark-ignition combustion mode, the heat-release variations were very small in amplitude and exhibited more persistent low-frequency oscillations with intermittent high-frequency bursts. In the HCCI combustion mode, the amplitude of the heat-release variations again was small and involved mainly low-frequency oscillations. At intermediate states between SI and HCCI, a wide range of very large-amplitude oscillations occurred, including both persistent low-frequency periodicities and intermittent high-frequency bursts. It appears from these results that real-time wavelet decomposition of engine cylinder pressure measurements may be useful for on-board tracking of SI HCCI combustion regime shifts.

  18. Flow-flame interactions causing acoustically coupled heat release fluctuations in a thermo-acoustically unstable gas turbine model combustor

    SciTech Connect

    Steinberg, A.M.; Boxx, I.; Stoehr, M.; Meier, W.; Carter, C.D.

    2010-12-15

    A detailed analysis of the flow-flame interactions associated with acoustically coupled heat-release rate fluctuations was performed for a 10 kW, CH{sub 4}/air, swirl stabilized flame in a gas turbine model combustor exhibiting self-excited thermo-acoustic oscillations at 308 Hz. High-speed stereoscopic particle image velocimetry, OH planar laser induced fluorescence, and OH* chemiluminescence measurements were performed at a sustained repetition rate of 5 kHz, which was sufficient to resolve the relevant combustor dynamics. Using spatio-temporal proper orthogonal decomposition, it was found that the flow-field contained several simultaneous periodic motions: the reactant flux into the combustion chamber periodically oscillated at the thermo-acoustic frequency (308 Hz), a helical precessing vortex core (PVC) circumscribed the burner nozzle at 515 Hz, and the PVC underwent axial contraction and extension at the thermo-acoustic frequency. The global heat release rate fluctuated at the thermo-acoustic frequency, while the heat release centroid circumscribed the combustor at the difference between the thermo-acoustic and PVC frequencies. Hence, the three-dimensional location of the heat release fluctuations depended on the interaction of the PVC with the flame surface. This motivated the compilation of doubly phase resolved statistics based on the phase of both the acoustic and PVC cycles, which showed highly repeatable periodic flow-flame configurations. These include flames stabilized between the inflow and inner recirculation zone, large-scale flame wrap-up by the PVC, radial deflection of the inflow by the PVC, and combustion in the outer recirculation zones. Large oscillations in the flame surface area were observed at the thermo-accoustic frequency that significantly affected the total heat-release oscillations. By filtering the instantaneous reaction layers at different scales, the importance of the various flow-flame interactions affecting the flame area was

  19. Numerical simulation of unsteady heat release of low frequency instabilities in a dump combustor

    NASA Astrophysics Data System (ADS)

    Laverdant, A.

    The influence of combustion instabilities on heat transfer is investigated using an adaptation of KIVA code. A simulation of low-frequency instabilities observed on a small burner is described. It is shown that the turbulence is distributed in the flame zone, and the heat transfer increases by acoustic pulsation emitted from the entrance plane of the cavity.

  20. Study of Cold Heat Energy Release Characteristics of Flowing Ice Water Slurry in a Pipe

    NASA Astrophysics Data System (ADS)

    Inaba, Hideo; Horibe, Akihiko; Ozaki, Koichi; Yokota, Maki

    This paper has dealt with melting heat transfer characteristics of ice water slurry in an inside tube of horizontal double tube heat exchanger in which a hot water circulated in an annular gap between the inside and outside tubes. Two kinds of heat exchangers were used; one is made of acrylic resin tube for flow visualization and the other is made of stainless steel tube for melting heat transfer measurement. The result of flow visualization revealed that ice particles flowed along the top of inside tube in the ranges of small ice packing factor and low ice water slurry velocity, while ice particles diffused into the whole of tube and flowed like a plug built up by ice particles for large ice packing factor and high velocity. Moreover, it was found that the flowing ice plug was separated into numbers of small ice clusters by melting phenomenon. Experiments of melting heat transfer were carried out under some parameters of ice packing factor, ice water slurry flow rate and hot water temperature. Consequently, the correlation equation of melting heat transfer was derived as a function of those experimental parameters.

  1. National Athletic Trainers' Association Releases New Guidelines for Exertional Heat Illnesses: What School Nurses Need to Know.

    PubMed

    VanScoy, Rachel M; DeMartini, Julie K; Casa, Douglas J

    2016-05-01

    Exertional heat illnesses (EHI) occur in various populations and settings. Within a school setting, there are student athletes who take part in physical activity where the risk of EHI is increased. The National Athletic Trainers' Association (NATA) released an updated position statement on EHI in September of 2015. This article is a summary of the position statement. The sports medicine team, including school nurses and athletic trainers, provides quality health care to these physically active individuals. Thus, it is important for school nurses to understand the prevention, recognition, and treatment of EHI. PMID:26941054

  2. Small Heat Shock Proteins Can Release Light Dependence of Tobacco Seed during Germination1[OPEN

    PubMed Central

    Koo, Hyun Jo; Park, Soo Min; Kim, Keun Pill; Suh, Mi Chung; Lee, Mi Ok; Lee, Seong-Kon; Xinli, Xia

    2015-01-01

    Small heat shock proteins (sHSPs) function as ATP-independent molecular chaperones, and although the production and function of sHSPs have often been described under heat stress, the expression and function of sHSPs in fundamental developmental processes, such as pollen and seed development, have also been confirmed. Seed germination involves the breaking of dormancy and the resumption of embryo growth that accompany global changes in transcription, translation, and metabolism. In many plants, germination is triggered simply by imbibition of water; however, different seeds require different conditions in addition to water. For small-seeded plants, like Arabidopsis (Arabidopsis thaliana), lettuce (Lactuca sativa), tomato (Solanum lycopersicum), and tobacco (Nicotiana tabacum), light is an important regulator of seed germination. The facts that sHSPs accumulate during seed development, sHSPs interact with various client proteins, and seed germination accompanies synthesis and/or activation of diverse proteins led us to investigate the role of sHSPs in seed germination, especially in the context of light dependence. In this study, we have built transgenic tobacco plants that ectopically express sHSP, and the effect was germination of the seeds in the dark. Administering heat shock to the seeds also resulted in the alleviation of light dependence during seed germination. Subcellular localization of ectopically expressed sHSP was mainly observed in the cytoplasm, whereas heat shock-induced sHSPs were transported to the nucleus. We hypothesize that ectopically expressed sHSPs in the cytoplasm led the status of cytoplasmic proteins involved in seed germination to function during germination without additional stimulus and that heat shock can be another signal that induces seed germination. PMID:25604531

  3. Novel analytical method to measure formaldehyde release from heated hair straightening cosmetic products: Impact on risk assessment.

    PubMed

    Galli, Corrado Lodovico; Bettin, Federico; Metra, Pierre; Fidente, Paola; De Dominicis, Emiliano; Marinovich, Marina

    2015-08-01

    Hair straightening cosmetic products may contain formaldehyde (FA). In Europe, FA is permitted for use in personal care products at concentrations ⩽ 0.2g/100g. According to the Cosmetic Ingredient Review (CIR) Expert Panel products are safe when formalin (a 37% saturated solution of FA in water) concentration does not exceed 0.2g/100g (0.074 g/100g calculated as FA). The official method of reference does not discriminate between "free" FA and FA released into the air after heating FA donors. The method presented here captures and collects the FA released into the air from heated cosmetic products by derivatization with 2,4-dinitrophenylhydrazine and final analysis by UPLC/DAD instrument. Reliable data in terms of linearity, recovery, repeatability and sensitivity are obtained. On a total of 72 market cosmetic products analyzed, 42% showed FA concentrations very close to or above the threshold value (0.074 g/100g calculated as FA) suggested by the Cosmetic Ingredient Review committee, whereas 11 products, negative using the official method of reference, were close to or above the threshold value (0.074 g/100g calculated as FA). This may pose a health problem for occasional users and professional hair stylists. PMID:26003512

  4. Mass spectrometric analysis of the volatiles released by heating or crushing rocks

    NASA Technical Reports Server (NTRS)

    Barker, C.; Sommer, M. A.

    1973-01-01

    Vacuum extraction with subsequent mass spectrometric analysis of evolved volatiles was selected as the analytical procedure. The high-vacuum gas-handling system was constructed of stainless steel. The system was completely free from mercury, grease, or volatile organic materials. The furnace for heating the samples is discussed together with the high-vacuum crusher, the mass spectrometer, and approaches for water determination. The analytical procedure is considered, giving attention to the extraction of volatiles, adsorption studies, and the analysis of volatiles.

  5. Free fatty acids released from phospholipids are the major heat-stable hemolytic factor of Entamoeba histolytica trophozoites.

    PubMed Central

    Said-Fernández, S; López-Revilla, R

    1988-01-01

    The major hemolytic activity of Entamoeba histolytica trophozoites is located in a vesicular fraction called P30 and known to be due to heat-labile and heat-stable hemolytic components whose effect increases up to 100 times during preincubation at 36 degrees C. The heat-stable hemolytic activity (HSHA) was found in the chloroform-methanol extract of preincubated P30, whose partition with 2 M KCl yielded a lipid fraction, an interphase, and an aqueous phase. HSHA was detected only in the lipid fraction, where it amounted to 59% of the chloroform-methanol extract activity and increased 50% when supplemented with the interphase material; it was accounted for by the free fatty acids, whose potency increased 33% with the interphase material, and was blocked by delipidated bovine serum albumin. A parallel increase in free fatty acids and lysophospholipids and a corresponding decrease in phospholipids were observed during P30 preincubation. Most of the phospholipase activity of trophozoite homogenates was also found in P30. Therefore, most of the HSHA generated during preincubation was due to free fatty acids released from phospholipids by a P30 phospholipase that may contribute significantly to E. histolytica cytopathogenicity and virulence. Images PMID:2894362

  6. The application of satellite data to study the effects of latent heat release on cyclones

    NASA Technical Reports Server (NTRS)

    Clark, J. H. E.

    1984-01-01

    Generalized energetics were studied for nonlinear inviscid symmetric instability (SI). It was found that the linear theory fails to predict the stability in certain cases where the basic state is transitional between stability and instability. The initial growth of the SI perturbations can be fairly well approximated by linear theory, but the long time nonlinear evaluations will be bonded energetically if the SI region is finite. However, a further extension of the energetics to conditional symmetric instability (CSI) shows that the nonlinear evolution of circulation will energetically depend much more on the precipitation in a complicated way. By treating the latent heat as a source which is implicitly related to the motion field, the existence, uniqueness and stability of steady viscous (CSI) circulations are studied. Viscous CSI circulations are proved to be unique and asymptotically stable when the heat sources are weak and less sensitive to the motion perturbations. By considering the fact that moist updrafts are narrow and using eddy viscosity of 0(1,000 m squared/s) the stability criterion suggests that some frontal rainbands were probably dominated by the CSI mechanism even in their mature quasi-steady stage.

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

    NASA Astrophysics Data System (ADS)

    Obara, Shin'ya; Kudo, Kazuhiko

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

  8. Photodynamic therapy-induced cell surface expression and release of heat shock proteins: relevance for tumor response.

    PubMed

    Korbelik, Mladen; Sun, Jinghai; Cecic, Ivana

    2005-02-01

    Almost instantaneously after the treatment of mouse SCCVII tumor cells with Photofrin-based photodynamic therapy (PDT), a fraction (15-25%) of total cellular heat shock protein 70 (HSP70) became exposed at the cell surface. The level of this surface-expressed HSP70 then remained unchanged for the next 6 hours and persisted at lower levels even at 18 hours after PDT. A similar induction of surface HSP70 expression was found with PDT-treated human umbilical vein endothelial cells. The same analysis for several other HSPs revealed the induced surface expression of HSP60 and GRP94, but not GRP78, on PDT-treated SCCVII cells. A fraction of total HSP70 existing in SCCVII cells at the time of PDT treatment was promptly (within 1 hour) released from cells after high treatment doses, whereas even lower PDT doses induced a substantial HSP70 release at later time intervals. Macrophages coincubated with PDT-treated SCCVII cells displayed elevated levels of both HSP70 and GRP94 on their surface and were stimulated to produce tumor necrosis factor alpha, whose production was inhibited by the presence of antibodies against either HSP70, Toll-like receptors 2 and 4, or specific NF-kappaB inhibitor in the coincubation medium. The induction of cell surface expression and release of HSPs by PDT may represent an important event in the response of tumors to this treatment modality with a critical role in the induced inflammatory and immune responses that contribute to the therapeutic outcome. PMID:15705903

  9. The effect of latent heat release on synoptic-to-planetary wave interactions and its implication for satellite observations: Theoretical modeling

    NASA Technical Reports Server (NTRS)

    Branscome, Lee E.; Bleck, Rainer

    1989-01-01

    Simple models are being developed to simulate interaction of planetary and synoptic-scale waves incorporating the effects of large-scale topography; eddy heat and momentum fluxes (or nonlinear dynamics); radiative heating/cooling; and latent heat release (precipitation) in synoptic-scale waves. The importance of latent heat release is determined in oceanic storm tracks for temporal variability and time-mean behavior of planetary waves. The model results were compared with available observations of planetary and synoptic-scale wave variability and time-mean circulation. The usefulness of monitoring precipitation in oceanic storm tracks by satellite observing systems was ascertained. The modeling effort includes two different low-order quasi-geostrophic models-time-dependent version and climatological mean version. The modeling also includes a low-order primitive equation model. A time-dependent, multi-level version will be used to validate the two-level Q-G models and examine effects of spherical geometry.

  10. Enhanced flow injection leaching of rocks by focused microwave heating with in-line monitoring of released elements by inductively coupled plasma mass spectrometry.

    PubMed

    Silva, Milithza; Kyser, Kurt; Beauchemin, Diane

    2007-02-19

    A focused microwave digestion system was used to heat a mini-column of sample of crushed rock (hematite) during its successive leaching by repeated 250-microL injections of water, HNO(3) 1%, 10% and 30% (v/v). The mini-column was connected to the nebulizer of an inductively coupled plasma mass spectrometry instrument, which allowed a continuous monitoring of the progressive release of elements by a given leaching reagent. Quantitation of the accessible fraction of Mg, V, Cr, Mn, Co, Ni, Cu, Zn, Mo, Sb and Pb was done by calibration using 250-microL injections of standard solutions prepared in the leaching reagent matrices. Total digestion of the sample residue was also done to verify mass balance. With the exception of Mg, V and Co, where the same total amount was released with or without microwave heating, an increased release resulted from focused microwave heating, by up to an order of magnitude. Furthermore, mass balance was verified for more elements using microwave heating, presumably because of a lower relative proportion of spectroscopic interference as a result of an increased release of analytes. Using microwave energy in general resulted in the dissolution of additional phases, as evidenced by significantly different (208)Pb/(206)Pb ratios as well as the increased release of elements with milder reagents. In fact, in the case of Pb, leaching with 30% HNO(3) was no longer necessary as all the Pb was released in the first three leaching reagents. Microwave heating could therefore be used advantageously in on-line leaching for exploration geochemistry and environmental monitoring. PMID:17386636

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

    PubMed

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

    2016-09-01

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

  12. Partial fuel stratification to control HCCI heat release rates : fuel composition and other factors affecting pre-ignition reactions of two-stage ignition fuels.

    SciTech Connect

    Dec, John E.; Sjoberg, Carl-Magnus G.; Cannella, William; Yang, Yi; Dronniou, Nicolas

    2010-11-01

    Homogeneous charge compression ignition (HCCI) combustion with fully premixed charge is severely limited at high-load operation due to the rapid pressure-rise rates (PRR) which can lead to engine knock and potential engine damage. Recent studies have shown that two-stage ignition fuels possess a significant potential to reduce the combustion heat release rate, thus enabling higher load without knock.

  13. Cyclic ADP-Ribose and Heat Regulate Oxytocin Release via CD38 and TRPM2 in the Hypothalamus during Social or Psychological Stress in Mice

    PubMed Central

    Zhong, Jing; Amina, Sarwat; Liang, Mingkun; Akther, Shirin; Yuhi, Teruko; Nishimura, Tomoko; Tsuji, Chiharu; Tsuji, Takahiro; Liu, Hong-Xiang; Hashii, Minako; Furuhara, Kazumi; Yokoyama, Shigeru; Yamamoto, Yasuhiko; Okamoto, Hiroshi; Zhao, Yong Juan; Lee, Hon Cheung; Tominaga, Makoto; Lopatina, Olga; Higashida, Haruhiro

    2016-01-01

    Hypothalamic oxytocin (OT) is released into the brain by cyclic ADP-ribose (cADPR) with or without depolarizing stimulation. Previously, we showed that the intracellular free calcium concentration ([Ca2+]i) that seems to trigger OT release can be elevated by β-NAD+, cADPR, and ADP in mouse oxytocinergic neurons. As these β-NAD+ metabolites activate warm-sensitive TRPM2 cation channels, when the incubation temperature is increased, the [Ca2+]i in hypothalamic neurons is elevated. However, it has not been determined whether OT release is facilitated by heat in vitro or hyperthermia in vivo in combination with cADPR. Furthermore, it has not been examined whether CD38 and TRPM2 exert their functions on OT release during stress or stress-induced hyperthermia in relation to the anxiolytic roles and social behaviors of OT under stress conditions. Here, we report that OT release from the isolated hypothalami of male mice in culture was enhanced by extracellular application of cADPR or increasing the incubation temperature from 35°C to 38.5°C, and simultaneous stimulation showed a greater effect. This release was inhibited by a cADPR-dependent ryanodine receptor inhibitor and a nonspecific TRPM2 inhibitor. The facilitated release by heat and cADPR was suppressed in the hypothalamus isolated from CD38 knockout mice and CD38- or TRPM2-knockdown mice. In the course of these experiments, we noted that OT release differed markedly between individual mice under stress with group housing. That is, when male mice received cage-switch stress and eliminated due to their social subclass, significantly higher levels of OT release were found in subordinates compared with ordinates. In mice exposed to anxiety stress in an open field, the cerebrospinal fluid (CSF) OT level increased transiently at 5 min after exposure, and the rectal temperature also increased from 36.6°C to 37.8°C. OT levels in the CSF of mice with lipopolysaccharide-induced fever (+0.8°C) were higher than those

  14. Cyclic ADP-Ribose and Heat Regulate Oxytocin Release via CD38 and TRPM2 in the Hypothalamus during Social or Psychological Stress in Mice.

    PubMed

    Zhong, Jing; Amina, Sarwat; Liang, Mingkun; Akther, Shirin; Yuhi, Teruko; Nishimura, Tomoko; Tsuji, Chiharu; Tsuji, Takahiro; Liu, Hong-Xiang; Hashii, Minako; Furuhara, Kazumi; Yokoyama, Shigeru; Yamamoto, Yasuhiko; Okamoto, Hiroshi; Zhao, Yong Juan; Lee, Hon Cheung; Tominaga, Makoto; Lopatina, Olga; Higashida, Haruhiro

    2016-01-01

    Hypothalamic oxytocin (OT) is released into the brain by cyclic ADP-ribose (cADPR) with or without depolarizing stimulation. Previously, we showed that the intracellular free calcium concentration ([Ca(2+)]i) that seems to trigger OT release can be elevated by β-NAD(+), cADPR, and ADP in mouse oxytocinergic neurons. As these β-NAD(+) metabolites activate warm-sensitive TRPM2 cation channels, when the incubation temperature is increased, the [Ca(2+)]i in hypothalamic neurons is elevated. However, it has not been determined whether OT release is facilitated by heat in vitro or hyperthermia in vivo in combination with cADPR. Furthermore, it has not been examined whether CD38 and TRPM2 exert their functions on OT release during stress or stress-induced hyperthermia in relation to the anxiolytic roles and social behaviors of OT under stress conditions. Here, we report that OT release from the isolated hypothalami of male mice in culture was enhanced by extracellular application of cADPR or increasing the incubation temperature from 35°C to 38.5°C, and simultaneous stimulation showed a greater effect. This release was inhibited by a cADPR-dependent ryanodine receptor inhibitor and a nonspecific TRPM2 inhibitor. The facilitated release by heat and cADPR was suppressed in the hypothalamus isolated from CD38 knockout mice and CD38- or TRPM2-knockdown mice. In the course of these experiments, we noted that OT release differed markedly between individual mice under stress with group housing. That is, when male mice received cage-switch stress and eliminated due to their social subclass, significantly higher levels of OT release were found in subordinates compared with ordinates. In mice exposed to anxiety stress in an open field, the cerebrospinal fluid (CSF) OT level increased transiently at 5 min after exposure, and the rectal temperature also increased from 36.6°C to 37.8°C. OT levels in the CSF of mice with lipopolysaccharide-induced fever (+0.8°C) were higher than

  15. Arabidopsis HIT4, a regulator involved in heat-triggered reorganization of chromatin and release of transcriptional gene silencing, relocates from chromocenters to the nucleolus in response to heat stress.

    PubMed

    Wang, Lian-Chin; Wu, Jia-Rong; Hsu, Yi-Ju; Wu, Shaw-Jye

    2015-01-01

    Arabidopsis HIT4 is known to mediate heat-induced decondensation of chromocenters and release from transcriptional gene silencing (TGS) with no change in the level of DNA methylation. It is unclear whether HIT4 and MOM1, a well-known DNA methylation-independent transcriptional silencer, have overlapping regulatory functions. A hit4-1/mom1 double mutant strain was generated. Its nuclear morphology and TGS state were compared with those of wild-type, hit4-1, and mom1 plants. Fluorescent protein tagging was employed to track the fates of HIT4, hit4-1 and MOM1 in vivo under heat stress. HIT4- and MOM1-mediated TGS were distinguishable. Both HIT4 and MOM1 were localized normally to chromocenters. Under heat stress, HIT4 relocated to the nucleolus, whereas MOM1 dispersed with the chromocenters. hit4-1 was able to relocate to the nucleolus under heat stress, but its relocation was insufficient to trigger the decompaction of chromocenters. The hypersensitivity to heat associated with the impaired reactivation of TGS in hit4-1 was not alleviated by mom1-induced release from TGS. HIT4 delineates a novel and MOM1-independent TGS regulation pathway. The involvement of a currently unidentified component that links HIT4 relocation and the large-scale reorganization of chromatin, and which is essential for heat tolerance in plants is hypothesized. PMID:25329561

  16. Vertical Profiles of Latent Heat Release over the Global Tropics using TRMM Rainfall Products from December 1997 to November 2002

    NASA Technical Reports Server (NTRS)

    Tao, W.-K.; Lang, S.; Simpson, J.; Meneghini, R.; Halverson, J.; Johnson, R.; Adler, R.

    2003-01-01

    NASA Tropical Rainfall Measuring Mission (TRMM) precipitation radar (PR) derived rainfall information will be used to estimate the four-dimensional structure of global monthly latent heating and rainfall profiles over the global tropics from December 1997 to November 2000. Rainfall, latent heating and radar reflectivity structures between El Nino (DJF 1997-98) and La Nina (DJF 1998-99) will be examined and compared. The seasonal variation of heating over various geographic locations (i.e., oceanic vs continental, Indian ocean vs west Pacific, Africa vs. S. America ) will also be analyzed. In addition, the relationship between rainfall, latent heating (maximum heating level), radar reflectivity and SST is examined and will be presented in the meeting. The impact of random error and bias in stratiform percentage estimates from PR on latent heating profiles is studied and will also be presented in the meeting. The Goddard Cumulus Ensemble Model is being used to simulate various mesoscale convective systems that developed in different geographic locations. Specifically, the model estimated rainfall, radar reflectivity and latent heating profiles will be compared to observational data collected from TRMM field campaigns over the South China Sea in 1998 (SCSMEX), Brazil in 1999 (TRMM-LBA), and the central Pacific in 1999 (KWAJEX). Sounding diagnosed heating budgets and radar reflectivity from these experiments can provide the means to validate (heating product) as well as improve the GCE model. Review of other latent heating algorithms will be discussed in the workshop.

  17. Vertical Profiles of Latent Heat Release Over the Global Tropics using TRMM Rainfall Products from December 1997 to November 2001

    NASA Technical Reports Server (NTRS)

    Tao, W.-K.; Lang, S.; Simpson, J.; Meneghini, R.; Halverson, J.; Johnson, R.; Adler, R.; Starr, David (Technical Monitor)

    2002-01-01

    NASA Tropical Rainfall Measuring Mission (TRMM) precipitation radar (PR) derived rainfall information will be used to estimate the four-dimensional structure of global monthly latent heating and rainfall profiles over the global tropics from December 1997 to November 2000. Rainfall, latent heating and radar reflectivity structures between El Nino (DJF 1997-98) and La Nina (DJF 1998-99) will be examined and compared. The seasonal variation of heating over various geographic locations (i.e., oceanic vs continental, Indian ocean vs west Pacific, Africa vs S. America) will also be analyzed. In addition, the relationship between rainfall, latent heating (maximum heating level), radar reflectivity and SST is examined and will be presented in the meeting. The impact of random error and bias in stratiform percentage estimates from PR on latent heating profiles is studied and will also be presented in the meeting. Additional information is included in the original extended abstract.

  18. Vertical Profiles of Latent Heat Release over the Global Tropics using TRMM rainfall products from December 1997 to November 2001

    NASA Technical Reports Server (NTRS)

    Tao, W.-K.; Lang, S.; Simpson, J.; Meneghini, R.; Halverson, J.; Johnson, R.; Adler, R.

    2002-01-01

    NASA Tropical Rainfall Measuring Mission (TRMM) precipitation radar (PR) derived rainfall information will be used to estimate the four-dimensional structure of global monthly latent heating and rainfall profiles over the global tropics from December 1997 to November 2001. Rainfall, latent heating and radar reflectivity structures between El Nino (DE 1997-98) and La Nina (DJF 1998-99) will be examined and compared. The seasonal variation of heating over various geographic locations (i.e., oceanic vs continental, Indian ocean vs. west Pacific, Africa vs. S. America) will also be analyzed. In addition, the relationship between rainfall, latent heating (maximum heating level), radar reflectivity and SST is examined and will be presented in the meeting. The impact of random error and bias in strtaiform percentage estimates from PR on latent heating profiles is studied and will also be presented in the meeting. The Goddard Cumulus Ensemble Model is being used to simulate various mesoscale convective systems that developed in different geographic locations. Specifically, the model estimated rainfall, radar reflectivity and latent heating profiles will be compared to observational data collected from TRMM field campaigns over the South China Sea in 1998 (SCSMEX), Brazil in 1999 (TRMM-LBA), and the central Pacific in 1999 (KWAJEX). Sounding diagnosed heating budgets and radar reflectivity from these experiments can provide the means to validate (heating product) as well as improve the GCE model.

  19. Vertical Profiles of Latent Heat Release over the Global Tropics Using TRMM Rainfall Products from December 1997 to November 2002

    NASA Technical Reports Server (NTRS)

    Tao, W.-K.

    2003-01-01

    NASA Tropical Rainfall Measuring Mission (TRMM) precipitation radar (PR) derived rainfall information will be used to estimate the four-dimensional structure of global monthly latent heating and rainfall profiles over the global tropics from December 1997 to November 2000. Rainfall, latent heating and radar reflectivity structures between El Nino (DJF 1997-98) and La Nina (DJF 1998-99) will be examined and compared. The seasonal variation of heating over various geographic locations (i.e., oceanic vs continental, Indian ocean vs west Pacific, Africa vs S. America) will also be analyzed. In addition, the relationship between rainfall, latent heating (maximum heating level), radar reflectivity and SST is examined and will be presented in the meeting. The impact of random error and bias in straitform percentage estimates from PR on latent heating profiles is studied and will also be presented in the meeting. The Goddard Cumulus Ensemble Model is being used to simulate various mesoscale convective systems that developed in different geographic locations. Specifically, the model estimated rainfall, radar reflectivity and latent heating profiles will be compared to observational data collected from TRMM field campaigns over the South China Sea in 1998 (SCSMXX), Brazil in 1999 (TRMM- LBA), and the central Pacific in 1999 (KWAJEX). Sounding diagnosed heating budgets and radar reflectivity from these experiments can provide the means to validate (heating product) as well as improve the GCE model.

  20. Vertical Profiles of Latent Heat Release Over the Global Tropics using TRMM Rainfall Products from December 1997 to November 2001

    NASA Technical Reports Server (NTRS)

    Tao, W.-K.; Lang, S.; Simpson, J.; Meneghini, R.; Halverson, J.; Johnson, R.; Adler, R.; Starr, David (Technical Monitor)

    2002-01-01

    NASA Tropical Rainfall Measuring Mission (TRMM) precipitation radar (PR) derived rainfall information will be used to estimate the four-dimensional structure of global monthly latent heating and rainfall profiles over the global tropics from December 1997 to November 2000. Rainfall, latent heating and radar reflectivity structures between El Nino (DJF 1997-98) and La Nina (DJF 1998-99) will be examined and compared. The seasonal variation of heating over various geographic locations (i.e., oceanic vs continental, Indian ocean vs west Pacific, Africa vs S. America) will also be analyzed. In addition, the relationship between rainfall, latent heating (maximum heating level), radar reflectivity and SST is examined and will be presented in the meeting. The impact of random error and bias in stratiform percentage estimates from PR on latent heating profiles is studied and will also be presented in the meeting. The Goddard Cumulus Ensemble Model is being used to simulate various mesoscale convective systems that developed in different geographic locations. Specifically, the model estimated rainfall, radar reflectivity and latent heating profiles will be compared to observational data collected from TRMM field campaigns over the South China Sea in 1998 (SCSMEX), Brazil in 1999 (TRMM-LBA), and the central Pacific in 1999 (KWAJEX). Sounding diagnosed heating budgets and radar reflectivity from these experiments can provide the means to validate (heating product) as well as improve the GCE model.

  1. Heat shock protein 70 overexpression affects the response to ultraviolet light in murine fibroblasts. Evidence for increased cell viability and suppression of cytokine release.

    PubMed Central

    Simon, M M; Reikerstorfer, A; Schwarz, A; Krone, C; Luger, T A; Jäättelä, M; Schwarz, T

    1995-01-01

    To elucidate cellular concepts for protection against ultraviolet (UV) light we investigated the effect of heat shock protein 70 (hsp70) overexpression on cell viability and on the secretion of UV-inducible immunological cytokines. Transfected murine fibrosarcoma cells (WEHI-S), overexpressing hsp70 or a sham transfected control were used. Overexpression of hsp70 was sufficient to markedly increase cell viability upon treatment with UVB (290-320 nm). Since long wave UV (UVA, 320-400 nm) as well as UVB turned out to stimulate the release of O2- radicals we studied the cell viability upon oxidative stress. Hsp70 overexpression increased viability upon treatment with hydrogen peroxide or menadione, but had no influence on UV-induced O2- release. UV-light is known to upregulate immunologic and proinflammatory cytokines such as IL-1 and IL-6. Oxidative stress appeared to exert a similar effect. Hsp70 overexpression markedly decreased the release of IL-6 induced by UVA, UVB and oxidative stress. To test whether the hsp70 mediated suppression is confined to events caused by UV-light we determined IL-1-mediated effects. IL-1-induced IL-6 release was reduced by hsp70 overexpression, whereas the IL-1 mediated activation of nuclear factor kappa B was not affected. Our data suggests that hsp70 plays a central role not only in cell protection against UV-light, but also in the regulation of proinflammatory cytokine release induced by UV-exposure. Images PMID:7883992

  2. Gas chromatography using a resistively heated column with mass spectrometric detection for rapid analysis of pyridine released from Bacillus spores.

    PubMed

    Smith, Philip A; MacDonald, Stephen

    2004-05-21

    Gas chromatography using a resistively heated analytical column with full scan electron impact mass spectrometry (EI-MS) was used to detect pyridine generated from heating Bacillus spores in a custom designed furnace inlet, along with gasoline range aromatic (GRA) hydrocarbons representing an environmental contaminant that could interfere with detection of the biologically-derived compound. Gas phase materials from the furnace inlet were collected onto a section of cooled open tubular column, and carrier gas flow was then routed through the trapping column onto the analytical column. Both sections of column were contained within low thermal mass tubular metal sheaths, with each independently and resistively heated allowing rapid temperature ramps and cooling. An analysis time of 2 min resolved spore-derived pyridine from the other organics, and allowed identification by mass spectrum match. Throughput of 20 analyses per hour was shown to be possible with a 1-min column cool-down time between analyses. PMID:15146930

  3. Cytochrome c Is Released in a Reactive Oxygen Species-Dependent Manner and Is Degraded via Caspase-Like Proteases in Tobacco Bright-Yellow 2 Cells en Route to Heat Shock-Induced Cell Death1

    PubMed Central

    Vacca, Rosa Anna; Valenti, Daniela; Bobba, Antonella; Merafina, Riccardo Sandro; Passarella, Salvatore; Marra, Ersilia

    2006-01-01

    To gain some insight into the mechanism of plant programmed cell death, certain features of cytochrome c (cyt c) release were investigated in heat-shocked tobacco (Nicotiana tabacum) Bright-Yellow 2 cells in the 2- to 6-h time range. We found that 2 h after heat shock, cyt c is released from intact mitochondria into the cytoplasm as a functionally active protein. Such a release did not occur in the presence of superoxide anion dismutase and catalase, thus showing that it depends on reactive oxygen species (ROS). Interestingly, ROS production due to xanthine plus xanthine oxidase results in cyt c release in sister control cultures. Maximal cyt c release was found 2 h after heat shock; later, activation of caspase-3-like protease was found to increase with time. Activation of this protease did not occur in the presence of ROS scavenger enzymes. The released cyt c was found to be progressively degraded in a manner prevented by either the broad-range caspase inhibitor (zVAD-fmk) or the specific inhibitor of caspase-3 (AC-DEVD-CHO), which have no effect on cyt c release. In the presence of these inhibitors, a significant increase in survival of the cells undergoing programmed cell death was found. We conclude that ROS can trigger release of cyt c, but do not cause cell death, which requires caspase-like activation. PMID:16531480

  4. 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

  5. A DIRECT MEASUREMENT OF THE HEAT RELEASE IN THE OUTER CRUST OF THE TRANSIENTLY ACCRETING NEUTRON STAR XTE J1709-267

    SciTech Connect

    Degenaar, N.; Miller, J. M.; Wijnands, R.

    2013-04-20

    The heating and cooling of transiently accreting neutron stars provides a powerful probe of the structure and composition of their crust. Observations of superbursts and cooling of accretion-heated neutron stars require more heat release than is accounted for in current models. Obtaining firm constraints on the depth and magnitude of this extra heat is challenging and therefore its origin remains uncertain. We report on Swift and XMM-Newton observations of the transient neutron star low-mass X-ray binary XTE J1709-267, which were made in 2012 September-October when it transitioned to quiescence after a {approx_equal}10 week long accretion outburst. The source is detected with XMM-Newton at a 0.5-10 keV luminosity of L{sub X} {approx_equal} 2 Multiplication-Sign 10{sup 34}(D/8.5 kpc){sup 2} erg s{sup -1}. The X-ray spectrum consists of a thermal component that fits to a neutron star atmosphere model and a non-thermal emission tail, each of which contribute {approx_equal}50% to the total flux. The neutron star temperature decreases from {approx_equal}158 to {approx_equal}152 eV during the {approx_equal}8 hr long observation. This can be interpreted as cooling of a crustal layer located at a column density of y {approx_equal} 5 Multiplication-Sign 10{sup 12} g cm{sup -2} ({approx_equal}50 m inside the neutron star), which is just below the ignition depth of superbursts. The required heat generation in the layers on top would be {approx_equal}0.06-0.13 MeV per accreted nucleon. The magnitude and depth rule out electron captures and nuclear fusion reactions as the heat source, but it may be accounted for by chemical separation of light and heavy nuclei. Low-level accretion offers an alternative explanation for the observed variability.

  6. Electric field triggering the spin reorientation and controlling the absorption and release of heat in the induced multiferroic compound EuTiO3

    NASA Astrophysics Data System (ADS)

    von Ranke, P. J.; Gama, S.; Ribeiro, P. O.; Carvalho, A. Magnus G.; Alho, B. P.; Alvarenga, T. S. T.; Nobrega, E. P.; Caldas, A.; de Sousa, V. S. R.; Lopes, P. H. O.; de Oliveira, N. A.

    2015-12-01

    We report remarkable results due to the coupling between the magnetization and the electric field induced polarization in EuTiO3. Using a microscopic model Hamiltonian to describe the three coupled sublattices, Eu-(spin-up), Eu-(spin-down), and Ti-(moment), the spin flop and spin reorientation phase transitions were described with and without the electric-magnetic coupling interaction. The external electric field can be used to tune the temperature of the spin reorientation phase transition TSR = TSR(E). When the TSR is tuned around the EuTiO3—Néel temperature (TN = 5.5 K), an outstanding effect emerges in which EuTiO3 releases heat under magnetic field change. The electric field controlling the spin reorientation transition and the endo-exothermic processes are discussed through the microscopic interactions model parameters.

  7. Heat Shock Protein 70B′ (HSP70B′) Expression and Release in Response to Human Oxidized Low Density Lipoprotein Immune Complexes in Macrophages*

    PubMed Central

    Smith, Kent J.; Twal, Waleed O.; Soodavar, Farzan; Virella, Gabriel; Lopes-Virella, Maria F.; Hammad, Samar M.

    2010-01-01

    Heat shock proteins (HSPs) have been implicated in the activation and survival of macrophages. This study examined the role of HSP70B′, a poorly characterized member of the HSP70 family, in response to oxidatively modified LDL (oxLDL) and immune complexes prepared with human oxLDL and purified human antibodies to oxLDL (oxLDL-IC) in monocytic and macrophage cell lines. Immunoblot analysis of cell lysates and conditioned medium from U937 cells treated with oxLDL alone revealed an increase in intracellular HSP70B′ protein levels accompanied by a concomitant increase in HSP70B′ extracellular levels. Fluorescence immunohistochemistry and confocal microscopy, however, demonstrated that oxLDL-IC stimulated the release of HSP70B′, which co-localized with cell-associated oxLDL-IC. In HSP70B′-green fluorescent protein-transfected mouse RAW 264.7 cells, oxLDL-IC-induced HSP70B′ co-localized with membrane-associated oxLDL-IC as well as the lipid moiety of internalized oxLDL-IC. Furthermore, the data demonstrated that HSP70B′ is involved in cell survival, and this effect could be mediated by sphingosine kinase 1 (SK1) activation. An examination of regularly implicated cytokines revealed a significant relationship between HSP70B′ and the release of the anti-inflammatory cytokine interleukin-10 (IL-10). Small interfering RNA knockdown of HSP70B′ resulted in a corresponding decrease in SK1 mRNA levels and SK1 phosphorylation as well as increased release of IL-10. In conclusion, these findings suggest that oxLDL-IC induce the synthesis and release of HSP70B′, and once stimulated, HSP70B′ binds to the cell-associated and internalized lipid moiety of oxLDL-IC. The data also implicate HSP70B′ in key cellular functions, such as regulation of SK1 activity and release of IL-10, which influence macrophage activation and survival. PMID:20348092

  8. Heats of formation of diphosphene, phosphinophosphinidene, diphosphine, and their methyl derivatives, and mechanism of the borane-assisted hydrogen release.

    PubMed

    Matus, Myrna H; Nguyen, Minh Tho; Dixon, David A

    2007-03-01

    The heats of formation of diphosphene (cis- and trans-P2H2), phopshinophosphinidene (singlet and triplet H2PP) and diphosphine (P2H4), as well as those of the P2H and P2H3 radicals resulting from PH bond cleavages, have been calculated by using high-level ab initio electronic structure theory. Energies were calculated using coupled-cluster theory with a perturbative treatment for triple excitations (CCSD(T)) and employing augmented correlation consistent basis sets with additional tight d-functions on P (aug-cc-pV(n+d)Z) up to quadruple- or quintuple-zeta, to perform a complete basis set extrapolation for the energy. Geometries and vibrational frequencies were determined with the CCSD(T) method. Core-valence and scalar relativistic corrections were included, as well as scaled zero-point energies. We find the following heats of formation (kcal/mol) at 298 [0] K: DeltaH(degree)(f)(P2H) = 53.4 [54.4]; DeltaH(degree)(f)(cis-P2H2) = 32.0 [33.9]; DeltaH(degree)(f)(trans-P2H2) = 28.7 [30.6]; DeltaH(degree)(f)(H2PP) = 53.7 [55.6]; DeltaH(degree)(f)(3H2PP) = 56.5 [58.3]; DeltaH(degree)(f)(P2H3) = 32.3 [34.8]; DeltaH(degree)(f)(P2H4) = 5.7 [9.1] (expt, 5.0 +/- 1.0 at 298 K); and DeltaH(degree)(f)(CH3PH2) = -5.0 [-1.4]. We estimate these values to have an accuracy of +/-1.0 kcal/mol. In contrast to earlier results, we found a singlet ground state for phosphinophosphinidene (H2PP) with a singlet-triplet energy gap of 2.8 kcal/mol. We calculated the heats of formation of the methylated derivatives CH3PPH, CH3HPPH2, CH3PPCH3, CH3HPP, (CH3)2PP, (CH3)2PPH2, and CH3HPPHCH3 by using isodesmic reactions at the MP2/CBS level. The calculated results for the hydrogenation reactions RPPR + H2 --> RHPPHR and R2PP + H2 --> R2PPH2 show that substitution of an organic substituent for H improves the energetics, suggesting that secondary diphosphines and diphosphenes are potential candidates for use in a chemical hydrogen storage system. A comparison with the nitrogen analogues is given. The

  9. Treatment of lactating dairy cows with gonadotropin-releasing hormone before first insemination during summer heat stress.

    PubMed

    Voelz, B E; Rocha, L; Scortegagna, F; Stevenson, J S; Mendonça, L G D

    2016-09-01

    The objectives of the experiments were to compare ovarian responses, pregnancy per artificial insemination, and pattern of insemination of 2 estrus detection-based presynchronization protocols before first artificial insemination (AI) during heat stress. In experiment 1, primiparous lactating dairy cows (n=1,358) from 3 dairies were assigned randomly to 2 treatments at 60±3 (±SD) DIM (study d 0): (1) treatment with 100 µg of GnRH on study d 0 (Gpresynch), or (2) no treatment on study d 0 (control). In experiment 2, multiparous lactating dairy cows (n=1,971) from 3 dairies were assigned randomly to 2 treatments at 49±3 (±SD) DIM (study d 0), similar to experiment 1. In both experiments, PGF2α injections were administered 14 d apart starting on study d 7 for all cows. Cows not inseminated after detection of estrus were submitted to a timed artificial insemination protocol at study d 35. In a subgroup of cows from 2 dairies, concentrations of progesterone were determined from blood samples collected on study d 0 and 7. Furthermore, ovaries were examined by ultrasonography on study d -14, 0, and 7 to determine cyclic status and ovulation in response to GnRH treatment. In experiment 1, progesterone concentration was not different on d 0, but progesterone was increased for Gpresynch compared with control cows on study d 7 (3.6±0.3 vs. 2.7±0.4 ng/mL), respectively. Ovulation risk from study d 0 to 7 was increased for Gpresynch compared with control (50.6 vs. 15.2%). Control cows were inseminated at a faster rate than Gpresynch cows [adjusted hazard ratio (AHR)=0.89, 95% confidence interval=0.80 to 1.00], and the interaction between treatment and dairy affected pregnancy per artificial insemination at 36 and 94 d post-artificial insemination. In experiment 2, concentrations of progesterone did not differ on study d 0 or 7, despite ovulation risk from study d 0 to 7 being greater in Gpresynch than control cows (46.9 vs. 23.8%). The interaction between treatment and

  10. The effect of latent heat release on synoptic-to-planetary wave interactions and its implication for satellite observations: Theoretical modeling

    NASA Technical Reports Server (NTRS)

    Branscome, Lee E.; Bleck, Rainer; Obrien, Enda

    1990-01-01

    The project objectives are to develop process models to investigate the interaction of planetary and synoptic-scale waves including the effects of latent heat release (precipitation), nonlinear dynamics, physical and boundary-layer processes, and large-scale topography; to determine the importance of latent heat release for temporal variability and time-mean behavior of planetary and synoptic-scale waves; to compare the model results with available observations of planetary and synoptic wave variability; and to assess the implications of the results for monitoring precipitation in oceanic-storm tracks by satellite observing systems. Researchers have utilized two different models for this project: a two-level quasi-geostrophic model to study intraseasonal variability, anomalous circulations and the seasonal cycle, and a 10-level, multi-wave primitive equation model to validate the two-level Q-G model and examine effects of convection, surface processes, and spherical geometry. It explicitly resolves several planetary and synoptic waves and includes specific humidity (as a predicted variable), moist convection, and large-scale precipitation. In the past year researchers have concentrated on experiments with the multi-level primitive equation model. The dynamical part of that model is similar to the spectral model used by the National Meteorological Center for medium-range forecasts. The model includes parameterizations of large-scale condensation and moist convection. To test the validity of results regarding the influence of convective precipitation, researchers can use either one of two different convective schemes in the model, a Kuo convective scheme or a modified Arakawa-Schubert scheme which includes downdrafts. By choosing one or the other scheme, they can evaluate the impact of the convective parameterization on the circulation. In the past year researchers performed a variety of initial-value experiments with the primitive-equation model. Using initial

  11. Electric field triggering the spin reorientation and controlling the absorption and release of heat in the induced multiferroic compound EuTiO{sub 3}

    SciTech Connect

    Ranke, P. J. von Ribeiro, P. O.; Alho, B. P.; Alvarenga, T. S. T.; Nobrega, E. P.; Caldas, A.; Sousa, V. S. R. de; Lopes, P. H. O.; Oliveira, N. A. de; Gama, S.; Carvalho, A. Magnus G.

    2015-12-28

    We report remarkable results due to the coupling between the magnetization and the electric field induced polarization in EuTiO{sub 3}. Using a microscopic model Hamiltonian to describe the three coupled sublattices, Eu-(spin-up), Eu-(spin-down), and Ti-(moment), the spin flop and spin reorientation phase transitions were described with and without the electric-magnetic coupling interaction. The external electric field can be used to tune the temperature of the spin reorientation phase transition T{sub SR} = T{sub SR}(E). When the T{sub SR} is tuned around the EuTiO{sub 3}—Néel temperature (T{sub N} = 5.5 K), an outstanding effect emerges in which EuTiO{sub 3} releases heat under magnetic field change. The electric field controlling the spin reorientation transition and the endo-exothermic processes are discussed through the microscopic interactions model parameters.

  12. Chick heat-shock protein of Mr = 90,000, free or released from progesterone receptor, is in a dimeric form.

    PubMed

    Radanyi, C; Renoir, J M; Sabbah, M; Baulieu, E E

    1989-02-15

    A monoclonal antibody (BF4) has been used to characterize and purify the heat-shock protein of Mr approximately 90,000 (hsp 90) present in the chick oviduct. In low salt cytosol, the sedimentation coefficient of hsp 90 is approximately 6.8 S, the Stokes radius approximately 7.1 nm, and the calculated Mr approximately 204,000, thus suggesting a dimeric structure. In 0.4 M KCl cytosol, only slightly smaller values were determined (approximately 6.5 S, approximately 6.8 nm, and approximately 187,000). Following purification by ion exchange and immunoaffinity chromatography, hsp 90 migrated as a single silver-stained band at Mr approximately 90,000 in sodium dodecyl sulfate-polyacrylamide gel electrophoresis, while the sedimentation coefficient 6.2 S, the Stokes radius approximately 6.8 nm, and the Mr approximately 178,000 confirmed the dimeric structure. However, in both antigen or antibody excess conditions, only one molecule of monoclonal antibody could be bound to the hsp 90 dimer. Whether steric hindrance in a homodimer or the presence of two different 90-kDa proteins in a heterodimer explains this result cannot yet be decided. The dimer is not dissociated by high salt (1 M KCl) or the chaotropic agent (0.5 M NaSCN), but is disrupted by 4 M urea, suggesting a stabilization of the structure by hydrogen bonds. The molybdate-stabilized progesterone receptor hetero-oligomer form of approximately 8 S sedimentation coefficient was purified, and its hsp 90 component was then released by salt treatment. It was found to sediment at approximately 5.8 S and have a Stokes radius approximately 7.1 nm, giving Mr approximately 174,000. This observation is consistent with a previous report suggesting from specific activity determination, scanning of polyacrylamide gels, and cross-linking experiments that each purified nontransformed progesterone receptor molecule includes one progesterone binding unit per two 90-kDa protein molecules (Renoir, J. M., Buchou, T., Mester, J

  13. Evaluating temperature and fuel stratification for heat-release rate control in a reactivity-controlled compression-ignition engine using optical diagnostics and chemical kinetics modeling

    SciTech Connect

    Musculus, Mark P. B.; Kokjohn, Sage L.; Reitz, Rolf D.

    2015-04-23

    We investigated the combustion process in a dual-fuel, reactivity-controlled compression-ignition (RCCI) engine using a combination of optical diagnostics and chemical kinetics modeling to explain the role of equivalence ratio, temperature, and fuel reactivity stratification for heat-release rate control. An optically accessible engine is operated in the RCCI combustion mode using gasoline primary reference fuels (PRF). A well-mixed charge of iso-octane (PRF = 100) is created by injecting fuel into the engine cylinder during the intake stroke using a gasoline-type direct injector. Later in the cycle, n-heptane (PRF = 0) is delivered through a centrally mounted diesel-type common-rail injector. This injection strategy generates stratification in equivalence ratio, fuel blend, and temperature. The first part of this study uses a high-speed camera to image the injection events and record high-temperature combustion chemiluminescence. Moreover, the chemiluminescence imaging showed that, at the operating condition studied in the present work, mixtures in the squish region ignite first, and the reaction zone proceeds inward toward the center of the combustion chamber. The second part of this study investigates the charge preparation of the RCCI strategy using planar laser-induced fluorescence (PLIF) of a fuel tracer under non-reacting conditions to quantify fuel concentration distributions prior to ignition. The fuel-tracer PLIF data show that the combustion event proceeds down gradients in the n-heptane distribution. The third part of the study uses chemical kinetics modeling over a range of mixtures spanning the distributions observed from the fuel-tracer fluorescence imaging to isolate the roles of temperature, equivalence ratio, and PRF number stratification. The simulations predict that PRF number stratification is the dominant factor controlling the ignition location and growth rate of the reaction zone. Equivalence ratio has a smaller, but still significant

  14. Evaluating temperature and fuel stratification for heat-release rate control in a reactivity-controlled compression-ignition engine using optical diagnostics and chemical kinetics modeling

    DOE PAGESBeta

    Musculus, Mark P. B.; Kokjohn, Sage L.; Reitz, Rolf D.

    2015-04-23

    We investigated the combustion process in a dual-fuel, reactivity-controlled compression-ignition (RCCI) engine using a combination of optical diagnostics and chemical kinetics modeling to explain the role of equivalence ratio, temperature, and fuel reactivity stratification for heat-release rate control. An optically accessible engine is operated in the RCCI combustion mode using gasoline primary reference fuels (PRF). A well-mixed charge of iso-octane (PRF = 100) is created by injecting fuel into the engine cylinder during the intake stroke using a gasoline-type direct injector. Later in the cycle, n-heptane (PRF = 0) is delivered through a centrally mounted diesel-type common-rail injector. This injectionmore » strategy generates stratification in equivalence ratio, fuel blend, and temperature. The first part of this study uses a high-speed camera to image the injection events and record high-temperature combustion chemiluminescence. Moreover, the chemiluminescence imaging showed that, at the operating condition studied in the present work, mixtures in the squish region ignite first, and the reaction zone proceeds inward toward the center of the combustion chamber. The second part of this study investigates the charge preparation of the RCCI strategy using planar laser-induced fluorescence (PLIF) of a fuel tracer under non-reacting conditions to quantify fuel concentration distributions prior to ignition. The fuel-tracer PLIF data show that the combustion event proceeds down gradients in the n-heptane distribution. The third part of the study uses chemical kinetics modeling over a range of mixtures spanning the distributions observed from the fuel-tracer fluorescence imaging to isolate the roles of temperature, equivalence ratio, and PRF number stratification. The simulations predict that PRF number stratification is the dominant factor controlling the ignition location and growth rate of the reaction zone. Equivalence ratio has a smaller, but still

  15. Multicomponent Implant Releasing Dexamethasone

    NASA Astrophysics Data System (ADS)

    Nikkola, L.; Vapalahti, K.; Ashammakhi, N.

    2008-02-01

    Several inflammatory conditions are usually treated with corticosteroids. There are various problems like side effects with traditional applications of steroids, e.g. topical, or systemic routes. Local drug delivery systems have been studied and developed to gain more efficient administration with fewer side effects. Earlier, we reported on developing Dexamethasone (DX) releasing biodegradable fibers. However, their drug release properties were not satisfactory in terms of onset of drug release. Thus, we assessed the development of multicomponent (MC) implant to enhance earlier drug release from such biodegradable fibers. Poly (lactide-co-glycolide) (PLGA) and 2 wt-% and 8 wt-% DX were compounded and extruded with twin-screw extruder to form of fibers. Some of the fibers were sterilized to obtain a change in drug release properties. Four different fiber classes were studied: 2 wt-%, 8 wt-%, sterilized 2 wt-%, and sterilized 8 wt-%. 3×4 different DX-releasing fibers were then heat-pressed to form one multicomponent rod. Half of the rods where sterilized. Drug release was measured from initial fibers and multicomponent rods using a UV/VIS spectrometer. Shear strength and changes in viscosity were also measured. Drug release studies showed that drug release commenced earlier from multicomponent rods than from component fibers. Drug release from multicomponent rods lasted from day 30 to day 70. The release period of sterilized rods extended from day 23 to day 57. When compared to the original component fibers, the drug release from MC rods commenced earlier. The initial shear strength of MC rods was 135 MPa and decreased to 105 MPa during four weeks of immersion in phosphate buffer solution. Accordingly, heat pressing has a positive effect on drug release. After four weeks in hydrolysis, no disintegration was observed.

  16. 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.

  17. Fate of organic matter during moderate heat treatment of sludge: kinetics of biopolymer and hydrolytic activity release and impact on sludge reduction by anaerobic digestion.

    PubMed

    Lefebvre, D; Dossat-Létisse, V; Lefebvre, X; Girbal-Neuhauser, E

    2014-01-01

    Temperature-phased anaerobic digestion with a 50-70 °C pre-treatment is widely proposed for sludge. Here, such a sludge pre-treatment (65 °C) was studied against the physical, enzymatic and biodegradation processes. The soluble and particulate fractions were analysed in terms of biochemical composition and hydrolytic enzymatic activities. Two kinetics of organic matter solubilisation were observed: a rapid transfer of the weak-linked biopolymers to the water phase, including sugars, proteins or humic acid-like substances, to the water phase, followed by a slow and long-term solubilisation of proteins and humic acid-like substances. In addition, during the heat treatment a significant pool of thermostable hydrolytic enzymes including proteases, lipases and glucosidases remains active. Consequently, a global impact on organic matter was the transfer of the biodegradable chemical oxygen demand (COD) from the particulate to the soluble fraction as evaluated by the biological methane potential test. However, the total biodegradable COD content of the treated sludge remained constant. The heat process improves the bio-accessibility of the biodegradable molecules but doesn't increase the inherent sludge biodegradability, suggesting that the chemistry of the refractory proteins and humic acids seems to be the real limit to sludge digestion. PMID:24804656

  18. Release of copper from embedded solid copper bullets into muscle and fat tissues of fallow deer (Dama dama), roe deer (Capreolus capreolus), and wild boar (Sus scrofa) and effect of copper content on oxidative stability of heat-processed meat.

    PubMed

    Schuhmann-Irschik, I; Sager, M; Paulsen, P; Tichy, A; Bauer, F

    2015-10-01

    When venison with embedded copper bullets was subjected to different culinary processing procedures, the amount of copper released from the embedded bullet was affected more by the retention period of the bullet in the meat during cool storage, than by the different heating protocols. The presence of copper fragments had no significant effect on levels of thiobarbituric acid reactive substances (TBARS). Conversely, TBARS in lean meat (fallow deer, wild boar, roe deer) were significantly affected by culinary treatment (higher TBARS in boiled and boiled-stored meat than in meat barbecued or boiled in brine). In pork-beef patties doped with up to 28mg/kg Cu, TBARS increased after dry-heating and subsequently storing the meat patties. The amount of copper doping had no effect on TBARS for 0 and 7days of storage, but a significant effect at day 14 (fat oxidation retarded at higher Cu doses). Evidence is presented that wild boar meat may be more sensitive to fat oxidation than pork-beef. PMID:26005913

  19. Toggle release

    NASA Technical Reports Server (NTRS)

    Graves, Thomas Joseph (Inventor); Yang, Robert Alexander (Inventor); Brown, Christopher William (Inventor)

    1988-01-01

    The invention relates to a pyrotechnic actuated release mechanism which is mechanically two fault tolerant for effecting release. It is particularly well suited for releasably connecting structures to be used in the space environment or in other aerospace applications. The device comprises a fastener plate and fastener body, each attachable to either one of a pair of structures to be joined. The fastener plate and the body are fastenable by a toggle supported at one end on the fastener plate and mounted for universal pivotal movement thereon. At its other end, which is received in a central opening in the fastener body and adapted for limited pivotal movement therein, the toggle is restrained by three retractable latching pins. Each pin is individually retractable by combustion of a pyrotechnic charge. While retraction of all three pins releases the toggle, the fastener is mechanically two fault tolerant since the failure of any single or pair of the latch pins to retract results in an asymmetrical loading on the toggle and its pivotal movement to effect a release. An annular bolt is mounted on the fastener plate as a support for the socket mounting of the toggle whereby its selective axial movement provides a means for pre-loading the toggle.

  20. Cellular response to heat shock studied by multiconfocal fluorescence correlation spectroscopy.

    PubMed

    Kloster-Landsberg, Meike; Herbomel, Gaëtan; Wang, Irène; Derouard, Jacques; Vourc'h, Claire; Usson, Yves; Souchier, Catherine; Delon, Antoine

    2012-09-19

    Heat shock triggers a transient and ubiquitous response, the function of which is to protect cells against stress-induced damage. The heat-shock response is controlled by a key transcription factor known as heat shock factor 1 (HSF1). We have developed a multiconfocal fluorescence correlation spectroscopy setup to measure the dynamics of HSF1 during the course of the heat-shock response. The system combines a spatial light modulator, to address several points of interest, and an electron-multiplying charge-coupled camera for fast multiconfocal recording of the photon streams. Autocorrelation curves with a temporal resolution of 14 μs were analyzed before and after heat shock on eGFP and HSF1-eGFP-expressing cells. Evaluation of the dynamic parameters of a diffusion-and-binding model showed a slower HSF1 diffusion after heat shock. It is also observed that the dissociation rate decreases after heat shock, whereas the association rate is not affected. In addition, thanks to the multiconfocal fluorescence correlation spectroscopy system, up to five spots could be simultaneously located in each cell nucleus. This made it possible to quantify the intracellular variability of the diffusion constant of HSF1, which is higher than that of inert eGFP molecules and increases after heat shock. This finding is consistent with the fact that heat-shock response is associated with an increase of HSF1 interactions with DNA and cannot be explained even partially by heat-induced modifications of nuclear organization. PMID:22995483

  1. Toggle release

    NASA Technical Reports Server (NTRS)

    Graves, Thomas J. (Inventor); Yang, Robert A. (Inventor); Brown, Christopher W. (Inventor)

    1989-01-01

    A pyrotechnic actuated structural release device 10 which is mechanically two fault tolerant for release. The device 10 comprises a fastener plate 11 and fastener body 12, each attachable to a different one of a pair of structures to be joined. The fastener plate 11 and body 12 are fastenable by a toggle 13 supported at one end on the fastener plate and mounted for universal pivotal movement thereon. At its other end which is received in a central opening in the fastener body 12 and adapted for limited pivotal movement therein the toggle 13 is restrained by three retractable latching pins 61 symmetrically disposed in equiangular spacing about the axis of the toggle 13 and positionable in latching engagement with an end fitting on the toggle. Each pin 61 is individually retractable by combustion of a pyrotechnic charge 77, the expanding gases of which are applied to a pressure receiving face 67 on the latch pin 61 to effect its retraction from the toggle. While retraction of all three pins 62 releases the toggle, the fastener is mechanically two fault tolerant since the failure of any single one or pair of the latch pins to retract results in an asymmetrical loading on the toggle and its pivotal movement to effect a release. An annular bolt 18 is mounted on the fastener plate 11 as a support for the socket mounting 30, 37 of the toggle whereby its selective axial movement provides a means for preloading the toggle.

  2. Laser heated thermoluminescence dosimetry

    SciTech Connect

    Justus, B.L.; Huston, A.L.

    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.

  3. Heat pipe array heat exchanger

    DOEpatents

    Reimann, Robert C.

    1987-08-25

    A heat pipe arrangement for exchanging heat between two different temperature fluids. The heat pipe arrangement is in a ounterflow relationship to increase the efficiency of the coupling of the heat from a heat source to a heat sink.

  4. 21 CFR 181.28 - Release agents.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... heating 4 hours at 200 °C.; viscosity 300 centisokes, 600 centisokes at 25 °C, specific gravity 0.96 to 0... FOOD INGREDIENTS Specific Prior-Sanctioned Food Ingredients § 181.28 Release agents....

  5. Method for releasing hydrogen from ammonia borane

    SciTech Connect

    Varma, Arvind; Diwan, Moiz; Shafirovich, Evgeny; Hwang, Hyun-Tae; Al-Kukhun, Ahmad

    2013-02-19

    A method of releasing hydrogen from ammonia borane is disclosed. The method comprises heating an aqueous ammonia borane solution to between about 80-135.degree. C. at between about 14.7 and 200 pounds per square inch absolute (psia) to release hydrogen by hydrothermolysis.

  6. A Comparison of the Beneficial Effects of Live and Heat-Inactivated Baker's Yeast on Nile Tilapia: Suggestions on the Role and Function of the Secretory Metabolites Released from the Yeast.

    PubMed

    Ran, Chao; Huang, Lu; Liu, Zhi; Xu, Li; Yang, Yalin; Tacon, Philippe; Auclair, Eric; Zhou, Zhigang

    2015-01-01

    Yeast is frequently used as a probiotic in aquaculture with the potential to substitute for antibiotics. In this study, the involvement and extent to which the viability of yeast cells and thus the secretory metabolites released from the yeast contribute to effects of baker's yeast was investigated in Nile tilapia. No yeast, live yeast or heat-inactivated baker's yeast were added to basal diets high in fishmeal and low in soybean (diet A) or low in fishmeal and high in soybean (diet B), which were fed to fish for 8 weeks. Growth, feed utilization, gut microvilli morphology, and expressions of hsp70 and inflammation-related cytokines in the intestine and head kidney were assessed. Intestinal microbiota was investigated using 16S rRNA gene pyrosequencing. Gut alkaline phosphatase (AKP) activity was measured after challenging the fish with Aeromonas hydrophila. Results showed that live yeast significantly improved FBW and WG (P < 0.05), and tended to improve FCR (P = 0.06) of fish compared to the control (no yeast). No significant differences were observed between inactivated yeast and control. Live yeast improved gut microvilli length (P < 0.001) and density (P < 0.05) while inactivated yeast did not. The hsp70 expression level in both the intestine and head kidney of fish was significantly reduced by live yeast (P < 0.05) but not inactivated yeast. Live yeast but not inactivated yeast reduced intestinal expression of tnfα (P < 0.05), tgfβ (P < 0.05 under diet A) and il1β (P = 0.08). Intestinal Lactococcus spp. numbers were enriched by both live and inactivated yeast. Lastly, both live and inactivated yeast reduced the gut AKP activity compared to the control (P < 0.001), indicating protection of the host against infection by A. hydrophila. In conclusion, secretory metabolites did not play major roles in the growth promotion and disease protection effects of yeast. Nevertheless, secretory metabolites were the major contributing factor towards improved gut

  7. A Comparison of the Beneficial Effects of Live and Heat-Inactivated Baker’s Yeast on Nile Tilapia: Suggestions on the Role and Function of the Secretory Metabolites Released from the Yeast

    PubMed Central

    Liu, Zhi; Xu, Li; Yang, Yalin; Tacon, Philippe; Auclair, Eric; Zhou, Zhigang

    2015-01-01

    Yeast is frequently used as a probiotic in aquaculture with the potential to substitute for antibiotics. In this study, the involvement and extent to which the viability of yeast cells and thus the secretory metabolites released from the yeast contribute to effects of baker’s yeast was investigated in Nile tilapia. No yeast, live yeast or heat-inactivated baker’s yeast were added to basal diets high in fishmeal and low in soybean (diet A) or low in fishmeal and high in soybean (diet B), which were fed to fish for 8 weeks. Growth, feed utilization, gut microvilli morphology, and expressions of hsp70 and inflammation-related cytokines in the intestine and head kidney were assessed. Intestinal microbiota was investigated using 16S rRNA gene pyrosequencing. Gut alkaline phosphatase (AKP) activity was measured after challenging the fish with Aeromonas hydrophila. Results showed that live yeast significantly improved FBW and WG (P < 0.05), and tended to improve FCR (P = 0.06) of fish compared to the control (no yeast). No significant differences were observed between inactivated yeast and control. Live yeast improved gut microvilli length (P < 0.001) and density (P < 0.05) while inactivated yeast did not. The hsp70 expression level in both the intestine and head kidney of fish was significantly reduced by live yeast (P < 0.05) but not inactivated yeast. Live yeast but not inactivated yeast reduced intestinal expression of tnfα (P < 0.05), tgfβ (P < 0.05 under diet A) and il1β (P = 0.08). Intestinal Lactococcus spp. numbers were enriched by both live and inactivated yeast. Lastly, both live and inactivated yeast reduced the gut AKP activity compared to the control (P < 0.001), indicating protection of the host against infection by A. hydrophila. In conclusion, secretory metabolites did not play major roles in the growth promotion and disease protection effects of yeast. Nevertheless, secretory metabolites were the major contributing factor towards improved gut

  8. Heat Waves

    MedlinePlus

    Heat Waves Dangers we face during periods of very high temperatures include: Heat cramps: These are muscular pains and spasms due ... that the body is having trouble with the heat. If a heat wave is predicted or happening… - ...

  9. Heat emergencies

    MedlinePlus

    Heat emergencies or illnesses are caused by exposure to extreme heat and sun. Heat illnesses can be prevented by ... to regulate the temperature, and make a heat emergency more likely: Drinking alcohol before or during exposure ...

  10. Release-rate calorimetry of multilayered materials for aircraft seats

    NASA Technical Reports Server (NTRS)

    Fewell, L. L.; Parker, J. A.; Duskin, F.; Speith, H.; Trabold, E.

    1980-01-01

    Multilayered samples of contemporary and improved fire-resistant aircraft seat materials were evaluated for their rates of heat release and smoke generation. Top layers with glass-fiber block cushion were evaluated to determine which materials, based on their minimum contributions to the total heat release of the multilayered assembly, may be added or deleted. The smoke and heat release rates of multilayered seat materials were then measured at heat fluxes of 1.5 and 3.5 W/cm2. Abrasion tests were conducted on the decorative fabric covering and slip sheet to ascertain service life and compatibility of layers

  11. Shape memory actuated release devices

    NASA Astrophysics Data System (ADS)

    Carpenter, Bernie F.; Clark, Cary R.; Weems, Weyman

    1996-05-01

    Spacecraft require a variety of separation and release devices to accomplish mission related functions. Current off-the-shelf devices such as pyrotechnics, gas-discharge systems, paraffin wax actuators, and other electro-mechanical devices may not be able to meet future design needs. The use of pyrotechnics on advanced lightweight spacecraft, for example, will expose fragile sensors and electronics to high shock levels and sensitive optics might be subject to contamination. Other areas of consideration include reliability, safety, and cost reduction. Shape memory alloys (SMA) are one class of actuator material that provides a solution to these design problems. SMA's utilize a thermally activated reversible phase transformation to recover their original heat treated shape (up to 8% strain) or to generate high recovery stresses (> 700 Mpa) when heated above a critical transition temperature. NiTiCu alloy actuators have been fabricated to provide synchronized, shockless separation within release mechanisms. In addition, a shape memory damper has been incorporated to absorb the elastic energy of the preload bolt and to electrically reset the device during ground testing. Direct resistive heating of the SMA actuators was accomplished using a programmable electric control system. Release times less than 40 msec have been determined using 90 watt-sec of power. Accelerometer data indicate less than 500 g's of shock were generated using a bolt preload of 1350 kgs.

  12. Improved solar heating systems

    DOEpatents

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

    1980-05-16

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

  13. Solar heating system

    DOEpatents

    Schreyer, James M.; Dorsey, George F.

    1982-01-01

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

  14. 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

  15. Heat Without Heat

    NASA Astrophysics Data System (ADS)

    Lubkin, Elihu

    1997-04-01

    Logic of the Second Law of Thermodynamics demands acquisition of naked entropy. Accordingly, the leanest liaison between systems is not a diathermic membrane, it is a purely informational tickler, leaking no appreciable energy. The subsystem here is a thermodynamic universe, which gets `heated' entropically, yet without gaining calories. Quantum Mechanics graciously supports that(Lubkin, E. and Lubkin, T., International Journal of Theoretical Physics,32), 933-943 (1993) (at a cost of about 1 bit) through entanglement---across this least permeable of membranes---with what is beyond that universe. Heat without heat(Also v. forthcoming Proceedings of the 4th Drexel University Conference of September 1994) is the aspirin for Boltzmann's headache, conserving entropy in mechanical isolation, even while increasing entropy in thermodynamic isolation.

  16. Chemical release module facility

    NASA Technical Reports Server (NTRS)

    Reasoner, D. L.

    1980-01-01

    The chemical release module provides the capability to conduct: (1) thermite based metal vapor releases; (2) pressurized gas releases; (3) dispersed liquid releases; (4) shaped charge releases from ejected submodules; and (5) diagnostic measurements with pi supplied instruments. It also provides a basic R-F and electrical system for: (1) receiving and executing commands; (2) telemetering housekeeping data; (3) tracking; (4) monitoring housekeeping and control units; and (5) ultrasafe disarming and control monitoring.

  17. Gas release and conductivity modification studies

    NASA Technical Reports Server (NTRS)

    Linson, L. M.; Baxter, D. C.

    1979-01-01

    The behavior of gas clouds produced by releases from orbital velocity in either a point release or venting mode is described by the modification of snowplow equations valid in an intermediate altitude regime. Quantitative estimates are produced for the time dependence of the radius of the cloud, the average internal energy, the translational velocity, and the distance traveled. The dependence of these quantities on the assumed density profile, the internal energy of the gas, and the ratio of specific heats is examined. The new feature is the inclusion of the effect of the large orbital velocity. The resulting gas cloud models are used to calculate the characteristics of the field line integrated Pedersen conductivity enhancements that would be produced by the release of barium thermite at orbital velocity in either the point release or venting modes as a function of release altitude and chemical payload weight.

  18. Very low shock release pyromechanisms

    NASA Astrophysics Data System (ADS)

    Soulier, Grégory; Gaechter, J. Pierre

    2003-09-01

    Pyromechanisms have long been used in space for launchers and satellites applications, particularly for release or separation purposes, such as bolt cutters, release nuts, pyrovalves, etc. They offer a great variety of uses, a high potential between the power supplied and the weight on board with, at the same time, a high reliability. However, they also feature a drawback due to the high dynamics generated by their functioning. Pyroshocks levels may damage adjacent sensible equipments (eg electronic boxes, reaction wheels,...) and require to design damping systems or to remove those equipments from the shock source. In a mechanism using standard pyrodevices, shock generation comes from three sources: 1. Pyrotechnic reaction. 2. Energy from internal parts in motion. 3. The release of structural constraints. Devices developed by E. LACROIX have the objectives to avoid the two last ones by: Using heat and gas generated by pyrotechnic effects. Reducing speed of parts in motion. Reducing release speed of mechanical constraints. In this paper, LACROIX presents two products named "PYROSOFT" and "VIROSOFT " designed by LACROIX and supported by CNES Toulouse (French Space Agency). R&T contracts.

  19. Delayed simultaneous release mechanism

    NASA Technical Reports Server (NTRS)

    Moyer, X. W.; Webb, J. B. (Inventor)

    1973-01-01

    The disclosed appendage release mechanism is particularly adapted for use with spacecraft operating with despin mechanisms and releasable appendages. It includes a flexible loop and a number of appendage releasing devices which are attached to the flexible loop. The appendage releasing devices are made up of piston-cams and ball latches which hold the appendages as long as the flexible loop is maintained in a taut condition, but which release the appendages upon relaxation of the flexible loop. The flexible loop remains taut as long as the despin weights remain attached, but relaxes when the despin weights are released.

  20. Triggered energy releases in solid hydrogen hosts containing unpaired atoms

    SciTech Connect

    Collins, G.W.; Fearon, E.M.; Maienschein, J.L.; Mapoles, E.R.; Tsugawa, R.T.; Souers, P.C. ); Gaines, J.R. )

    1990-07-23

    We have observed both triggered and spontaneous energy releases in tritiated solid hydrogens at temperatures above 1.2 K in several different experiments. These energy releases, which can be triggered by a temperature increase, were observed by monitoring the temperature excursion ( heat spike'') versus time, the atom spin density, and nuclear-magnetic-resonance signal heights. The heat spikes correlate with a disappearance of free-atom spin density so that fast atomic recombination is the probable cause. The spontaneous heat spikes may be suppressed by improved heat extraction.

  1. Heating Structures Derived from Satellite

    NASA Technical Reports Server (NTRS)

    Tao, W.-K.; Adler, R.; Haddad, Z.; Hou, A.; Kakar, R.; Krishnamurti, T. N.; Kummerow, C.; Lang, S.; Meneghini, R.; Olson, W.

    2004-01-01

    Rainfall is a key link in the hydrologic cycle and is a primary heat source for the atmosphere. The vertical distribution of latent-heat release, which is accompanied by rainfall, modulates the large-scale circulations of the tropics and in turn can impact midlatitude weather. This latent heat release is a consequence of phase changes between vapor, liquid, and solid water. The Tropical Rainfall Measuring Mission (TRMM), a joint U.S./Japan space project, was launched in November 1997. It provides an accurate measurement of rainfall over the global tropics which can be used to estimate the four-dimensional structure of latent heating over the global tropics. The distributions of rainfall and inferred heating can be used to advance our understanding of the global energy and water cycle. This paper describes several different algorithms for estimating latent heating using TRMM observations. The strengths and weaknesses of each algorithm as well as the heating products are also discussed. The validation of heating products will be exhibited. Finally, the application of this heating information to global circulation and climate models is presented.

  2. TOXICS RELEASE INVENTORY (TRI)

    EPA Science Inventory

    The Toxics Release Inventory (TRI) site is designed to provide information on toxic chemical releases including collected data, guidance documents, program planning, background, history, and, program contacts, among other things. The data included in this homepage have been submi...

  3. Release of toxic microvesicles by Actinobacillus actinomycetemcomitans.

    PubMed Central

    Nowotny, A; Behling, U H; Hammond, B; Lai, C H; Listgarten, M; Pham, P H; Sanavi, F

    1982-01-01

    Oral isolates of Actinobacillus actinomycetemcomitans (strain Y4) release spherical microvesicles in large numbers during normal growth. The biological activities of these products were studied, and it was estimated that approximately 1/10 of their dry weight was made up of heat- and proteolysis-resistant endotoxin. The chicken embryo lethality and bone-resorbing activity of the microvesicles were heat stable but proteolysis sensitive. Other laboratories have reported the presence of a heat- and proteolysis-sensitive leukotoxin in similar preparations. Accordingly, the microvesicles released by strain Y4 may contain, in addition to endotoxin, several potent substances which are highly toxic and active in bone resorption, and these may be significant factors in the pathogenesis of periodontal diseases. PMID:7049947

  4. Release of toxic microvesicles by Actinobacillus actinomycetemcomitans.

    PubMed

    Nowotny, A; Behling, U H; Hammond, B; Lai, C H; Listgarten, M; Pham, P H; Sanavi, F

    1982-07-01

    Oral isolates of Actinobacillus actinomycetemcomitans (strain Y4) release spherical microvesicles in large numbers during normal growth. The biological activities of these products were studied, and it was estimated that approximately 1/10 of their dry weight was made up of heat- and proteolysis-resistant endotoxin. The chicken embryo lethality and bone-resorbing activity of the microvesicles were heat stable but proteolysis sensitive. Other laboratories have reported the presence of a heat- and proteolysis-sensitive leukotoxin in similar preparations. Accordingly, the microvesicles released by strain Y4 may contain, in addition to endotoxin, several potent substances which are highly toxic and active in bone resorption, and these may be significant factors in the pathogenesis of periodontal diseases. PMID:7049947

  5. Heat Stress

    MedlinePlus

    ... Stress Learn some tips to protect workers including: acclimatization, rest breaks, and fluid recommendations. NIOSH Workplace Solution: ... Blog: Adjusting to Work in the Heat: Why Acclimatization Matters The natural adaptation to the heat takes ...

  6. Heating Safety

    MedlinePlus

    ... from heating equipment, such as the furnace, fireplace, wood stove, or portable heater. • Only use heating equipment ... into the room and burn only dry, seasoned wood. Allow ashes to cool before disposing in a ...

  7. Heat exchanger

    DOEpatents

    Daman, Ernest L.; McCallister, Robert A.

    1979-01-01

    A heat exchanger is provided having first and second fluid chambers for passing primary and secondary fluids. The chambers are spaced apart and have heat pipes extending from inside one chamber to inside the other chamber. A third chamber is provided for passing a purge fluid, and the heat pipe portion between the first and second chambers lies within the third chamber.

  8. ELECTROMAGNETIC RELEASE MECHANISM

    DOEpatents

    Michelson, C.

    1960-09-13

    An electromagnetic release mechanism is offered that may be used, for example, for supporting a safety rod for a nuclear reactor. The release mechanism is designed to have a large excess holding force and a rapid, uniform, and dependable release. The fast release is accomplished by providing the electromagnet with slotttd polts separated by an insulating potting resin, and by constructing the poles with a ferro-nickel alloy. The combination of these two features materially reduces the eddy current power density whenever the magnetic field changes during a release operation. In addition to these features, the design of the armature is such as to provide ready entrance of fluid into any void that might tend to form during release of the armature. This also improves the release time for the mechanism. The large holding force for the mechanism is accomplished by providing a small, selected, uniform air gap between the inner pole piece and the armature.

  9. Heat exchanger containing a component capable of discontinuous movement

    DOEpatents

    Wilson, David Gordon

    2001-04-17

    Regenerative heat exchangers are described for transferring heat between hot and cold fluids. The heat exchangers have seal-leakage rates significantly less than those of conventional regenerative heat exchangers because the matrix is discontinuously moved and is releasably sealed while in a stationary position. Both rotary and modular heat exchangers are described. Also described are methods for transferring heat between a hot and cold fluid using the discontinuous movement of matrices.

  10. Heat exchanger containing a component capable of discontinuous movement

    DOEpatents

    Wilson, David G.

    1993-01-01

    Regenerative heat exchangers are described for transferring heat between hot and cold fluids. The heat exchangers have seal-leakage rates significantly less than those of conventional regenerative heat exchangers because the matrix is discontinuously moved and is releasably sealed while in a stationary position. Both rotary and modular heat exchangers are described. Also described are methods for transferring heat between a hot and cold fluid using the discontinuous movement of matrices.

  11. Heat exchanger containing a component capable of discontinuous movement

    DOEpatents

    Wilson, D.G.

    1993-11-09

    Regenerative heat exchangers are described for transferring heat between hot and cold fluids. The heat exchangers have seal-leakage rates significantly less than those of conventional regenerative heat exchangers because the matrix is discontinuously moved and is releasably sealed while in a stationary position. Both rotary and modular heat exchangers are described. Also described are methods for transferring heat between a hot and cold fluid using the discontinuous movement of matrices. 11 figures.

  12. Heat exchanger containing a component capable of discontinuous movement

    DOEpatents

    Wilson, David Gordon

    2002-01-01

    Regenerative heat exchangers are described for transferring heat between hot and cold fluids. The heat exchangers have seal-leakage rates significantly less than those of conventional regenerative heat exchangers because the matrix is discontinuously moved and is releasably sealed while in a stationary position. Both rotary and modular heat exchangers are described. Also described are methods for transferring heat between a hot and cold fluid using the discontinuous movement of matrices.

  13. Timed-release polymer nanoparticles.

    PubMed

    Tran, Nguyen T D; Truong, Nghia P; Gu, Wenyi; Jia, Zhongfan; Cooper, Matthew A; Monteiro, Michael J

    2013-02-11

    Triggered-release of encapsulated therapeutics from nanoparticles without remote or environmental triggers was demonstrated in this work. Disassembly of the polymer nanoparticles to unimers at precise times allowed the controlled release of oligo DNA. The polymers used in this study consisted of a hydrophilic block for stabilization and second thermoresponsive block for self-assembly and disassembly. At temperatures below the second block's LCST (i.e., below 37 °C for in vitro assays), the diblock copolymer was fully water-soluble, and when heated to 37 °C, the polymer self-assembled into a narrow size distribution of nanoparticles with an average diameter of approximately 25 nm. The thermoresponsive nature of the second block could be manipulated in situ by the self-catalyzed degradation of cationic 2-(dimethylamino)ethyl acrylate (DMAEA) units to negatively charged acrylic acid groups and when the amount of acid groups was sufficiently high to increase the LCST of the second block above 37 °C. The disassembly of the nanoparticles could be controlled from 10 to 70 h. The use of these nanoparticles as a combined therapy, in which one or more agents can be released in a predetermined way, has the potential to improve the personal point of care treatment of patients. PMID:23298322

  14. Heat Pipes

    NASA Technical Reports Server (NTRS)

    1991-01-01

    Phoenix Refrigeration Systems, Inc.'s heat pipe addition to the Phoenix 2000, a supermarket rooftop refrigeration/air conditioning system, resulted from the company's participation in a field test of heat pipes. Originally developed by NASA to control temperatures in space electronic systems, the heat pipe is a simple, effective, heat transfer system. It has been used successfully in candy storage facilities where it has provided significant energy savings. Additional data is expected to fully quantify the impact of the heat pipes on supermarket air conditioning systems.

  15. Heat Pipes

    NASA Technical Reports Server (NTRS)

    1996-01-01

    Heat Pipes were originally developed by NASA and the Los Alamos Scientific Laboratory during the 1960s to dissipate excessive heat build- up in critical areas of spacecraft and maintain even temperatures of satellites. Heat pipes are tubular devices where a working fluid alternately evaporates and condenses, transferring heat from one region of the tube to another. KONA Corporation refined and applied the same technology to solve complex heating requirements of hot runner systems in injection molds. KONA Hot Runner Systems are used throughout the plastics industry for products ranging in size from tiny medical devices to large single cavity automobile bumpers and instrument panels.

  16. Mechanism For Guided Release

    NASA Technical Reports Server (NTRS)

    Kull, Richard A.

    1990-01-01

    Proposed mechanism retains protective shield until no longer needed, then releases shield and guides it away for safe ejection from vehicle (spacecraft, according to original concept). Intended for use with shield like one described in article "Crash-Resistant Shield" (NPO-17616). Mechanism for guided release separates shield from base and from supporting truss on command. Band holding shield on base released by explosive separator.

  17. Release the Body, Release the Mind.

    ERIC Educational Resources Information Center

    Stoner, Martha Goff

    1998-01-01

    A college English teacher describes the anxiety and resentment of students during in-class writing assignments and the successful classroom use of meditation and body movement. Movement seemed to relax the students, change their attitudes, and release their creative impulses to write. Implications related to the body-mind connection are pondered.…

  18. Electrically heated diaphragm eliminates use of pyrotechnics

    NASA Technical Reports Server (NTRS)

    Mathewson, R. C.

    1965-01-01

    Membrane-type diaphragm is used in systems where fluids are contained under pressure until a certain pressure threshold or point of time has been reached when the fluids are automatically released. The diaphragm is resistance heated until its strength is degraded to the point of rupture, thus releasing the contained fluids.

  19. Heated Goggles

    NASA Technical Reports Server (NTRS)

    1978-01-01

    The electrically heated ski goggles shown incorporate technology similar to that once used in Apollo astronauts' helmet visors, and for the same reason-providing fogfree sight in an activity that demands total vision. Defogging is accomplished by applying heat to prevent moisture condensation. Electric heat is supplied by a small battery built into the h goggles' headband. Heat is spread across the lenses by means of an invisible coating of electrically conductive metallic film. The goggles were introduced to the market last fall. They were designed by Sierracin Corporation, Sylmar, California, specialists in the field of heated transparent materials. The company produces heated windshields for military planes and for such civil aircraft as the Boeing 747, McDonnell Douglas DC-10 and Lockheed L-1011 TriStar.

  20. Method and apparatus for controlling accidental releases of tritium

    DOEpatents

    Galloway, Terry R. [Berkeley, CA

    1980-04-01

    An improvement in a tritium control system based on a catalytic oxidation reactor wherein accidental releases of tritium into room air are controlled by flooding the catalytic oxidation reactor with hydrogen when the tritium concentration in the room air exceeds a specified limit. The sudden flooding with hydrogen heats the catalyst to a high temperature within seconds, thereby greatly increasing the catalytic oxidation rate of tritium to tritiated water vapor. Thus, the catalyst is heated only when needed. In addition to the heating effect, the hydrogen flow also swamps the tritium and further reduces the tritium release.

  1. Method and apparatus for controlling accidental releases of tritium

    DOEpatents

    Galloway, T.R.

    1980-04-01

    An improvement is described in a tritium control system based on a catalytic oxidation reactor wherein accidental releases of tritium into room air are controlled by flooding the catalytic oxidation reactor with hydrogen when the tritium concentration in the room air exceeds a specified limit. The sudden flooding with hydrogen heats the catalyst to a high temperature within seconds, thereby greatly increasing the catalytic oxidation rate of tritium to tritiated water vapor. Thus, the catalyst is heated only when needed. In addition to the heating effect, the hydrogen flow also swamps the tritium and further reduces the tritium release. 1 fig.

  2. Critical heat flux test apparatus

    DOEpatents

    Welsh, Robert E.; Doman, Marvin J.; Wilson, Edward C.

    1992-01-01

    An apparatus for testing, in situ, highly irradiated specimens at high temperature transients is provided. A specimen, which has a thermocouple device attached thereto, is manipulated into test position in a sealed quartz heating tube by a robot. An induction coil around a heating portion of the tube is powered by a radio frequency generator to heat the specimen. Sensors are connected to monitor the temperatures of the specimen and the induction coil. A quench chamber is located below the heating portion to permit rapid cooling of the specimen which is moved into this quench chamber once it is heated to a critical temperature. A vacuum pump is connected to the apparatus to collect any released fission gases which are analyzed at a remote location.

  3. Release-rate calorimetry of multilayered materials for aircraft seats

    NASA Technical Reports Server (NTRS)

    Fewell, L. L.; Parker, J. A.; Duskin, F.; Spieth, H.; Trabold, E.

    1980-01-01

    Multilayered samples of contemporary and improved fire-resistant aircraft seat materials (foam cushion, decorative fabric, slip sheet, fire-blocking layer, and cushion-reinforcement layer) were evaluated for their rates of heat release and smoke generation. Top layers (decorative fabric, slip sheet, fire blocking, and cushion reinforcement) with glass-fiber block cushion were evaluated to determine which materials, based on their minimum contributions to the total heat release of the multilayered assembly, may be added or deleted. Top layers exhibiting desirable burning profiles were combined with foam cushion materials. The smoke and heat-release rate of multilayered seat materials were then measured at heat fluxes of 1.5 and 3.5 W/sq cm. Choices of contact and silicon adhesives for bonding multilayered assemblies were based on flammability, burn and smoke generation, animal toxicity tests, and thermal gravimetric analysis.

  4. Large scientific releases

    SciTech Connect

    Pongratz, M.B.

    1981-01-01

    The motivation for active experiments in space is considered, taking into account the use of active techniques to obtain a better understanding of the natural space environment, the utilization of the advantages of space as a laboratory to study fundamental plasma physics, and the employment of active techniques to determine the magnitude, degree, and consequences of artificial modification of the space environment. It is pointed out that mass-injection experiments in space plasmas began about twenty years ago with the Project Firefly releases. Attention is given to mass-release techniques and diagnostics, operational aspects of mass release active experiments, the active observation of mass release experiments, active perturbation mass release experiments, simulating an artificial modification of the space environment, and active experiments to study fundamental plasma physics.

  5. Large scientific releases

    NASA Astrophysics Data System (ADS)

    Pongratz, M. B.

    The motivation for active experiments in space is considered, taking into account the use of active techniques to obtain a better understanding of the natural space environment, the utilization of the advantages of space as a laboratory to study fundamental plasma physics, and the employment of active techniques to determine the magnitude, degree, and consequences of artificial modification of the space environment. It is pointed out that mass-injection experiments in space plasmas began about twenty years ago with the Project Firefly releases. Attention is given to mass-release techniques and diagnostics, operational aspects of mass release active experiments, the active observation of mass release experiments, active perturbation mass release experiments, simulating an artificial modification of the space environment, and active experiments to study fundamental plasma physics.

  6. Solar heat storage in phase change material

    SciTech Connect

    Phillips, H.J.

    1984-02-28

    The objective of this project was to develop a chemical heat storage system that had a phase change with release of latent heat at about 105/sup 0/F. The primary reason this kind on system was sought was that heat storage capacity of commonly used storage systems do not match the heat collection capacity of open air collectors. In addition to the phase change three other factors were considered: the cost of the material, the amount of heat the system would hold per unit volume, and the rate at which the system released sensible and latent heat. One hundred nineteen tests were made on 32 systems. Only data on six of the more promising are presented. In the six systems, borax was used as the major component with other materials used as nucleating agents toraise the temperature of phase change.

  7. 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

  8. 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)…

  9. Gas release in comet nuclei

    NASA Technical Reports Server (NTRS)

    Prialnik, Dina; Bar-Nun, Akiva

    1990-01-01

    Processes taking place during the evolution of a comet nucleus are examined, taking into account the release of gas on crystallization and the gas flow through the porous nucleus. In particular, the stresses caused by the gas pressure, the contribution of gas flow to the heat transfer, and the rate of gas emission by the comet along its orbit were determined using a model of spherically symmetric comet nucleus made of porous amorphous ice, with 10 percent CO gas trapped in it. Several values of density and pore size are considered, and for each combination of parameters, the model is evolved for 20-30 revolutions in Comet P/Halley's orbit. It is shown that a model of 0.2 g/cu cm density reproduces well many of the light-curve and activity characteristics of Comet P/Halley.

  10. Correlation of recent fission product release data

    SciTech Connect

    Kress, T.S.; Lorenz, R.A.; Nakamura, T.; Osborne, M.F.

    1989-01-01

    For the calculation of source terms associated with severe accidents, it is necessary to model the release of fission products from fuel as it heats and melts. Perhaps the most definitive model for fission product release is that of the FASTGRASS computer code developed at Argonne National Laboratory. There is persuasive evidence that these processes, as well as additional chemical and gas phase mass transport processes, are important in the release of fission products from fuel. Nevertheless, it has been found convenient to have simplified fission product release correlations that may not be as definitive as models like FASTGRASS but which attempt in some simple way to capture the essence of the mechanisms. One of the most widely used such correlation is called CORSOR-M which is the present fission product/aerosol release model used in the NRC Source Term Code Package. CORSOR has been criticized as having too much uncertainty in the calculated releases and as not accurately reproducing some experimental data. It is currently believed that these discrepancies between CORSOR and the more recent data have resulted because of the better time resolution of the more recent data compared to the data base that went into the CORSOR correlation. This document discusses a simple correlational model for use in connection with NUREG risk uncertainty exercises. 8 refs., 4 figs., 1 tab.

  11. Lactococcus lactis release from calcium alginate beads.

    PubMed Central

    Champagne, C P; Gaudy, C; Poncelet, D; Neufeld, R J

    1992-01-01

    Cell release during milk fermentation by Lactococcus lactis immobilized in calcium alginate beads was examined. Numbers of free cells in the milk gradually increased from 1 x 10(6) to 3 x 10(7) CFU/ml upon successive reutilization of the beads. Rinsing the beads between fermentations did not influence the numbers of free cells in the milk. Cell release was not affected by initial cell density within the beads or by alginate concentration, although higher acidification rates were achieved with increased cell loading. Coating alginate beads with poly-L-lysine (PLL) did not significantly reduce the release of cells during five consecutive fermentations. A double coating of PLL and alginate reduced cell release by a factor of approximately 50. However, acidification of milk with beads having the PLL-alginate coating was slower than that with uncoated beads. Immersing the beads in ethanol to kill cells on the periphery reduced cell release, but acidification activity was maintained. Dipping the beads in aluminum nitrate or a hot CaCl2 solution was not as effective as dipping them in ethanol. Ethanol treatment or heating of the beads appears to be a promising method for maintaining acidification activity while minimizing viable cell release due to loosely entrapped cells near the surface of the alginate beads. PMID:1622208

  12. Fission product release from irradiated LWR fuel under accident conditions

    SciTech Connect

    Strain, R.V.; Sanecki, J.E.; Osborne, M.F.

    1984-01-01

    Fission product release from irradiated LWR fuel is being studied by heating fuel rod segments in flowing steam and an inert carrier gas to simulate accident conditions. Fuels with a range of irradiation histories are being subjected to several steam flow rates over a wide range of temperatures. Fission product release during each test is measured by gamma spectroscopy and by detailed examination of the collection apparatus after the test has been completed. These release results are complemented by a detailed posttest examination of samples of the fuel rod segment. Results of release measurements and fuel rod characterizations for tests at 1400 through 2000/sup 0/C are presented in this paper.

  13. High performance solar heating in the Rockies

    SciTech Connect

    Lichtwardt, M.

    2000-04-01

    Many industrial and commercial buildings require large amounts of ventilation air to maintain adequate indoor air quality and--as facility managers know--heating all that fresh air can be expensive. An innovative solar air heating technology offers an elegantly simple and cost-effective solution to the problem of heating makeup air, and helps protect the environment in the bargain by avoiding the release of greenhouse gases and other pollutants.

  14. Latent Heating from TRMM Satellite Measurements

    NASA Technical Reports Server (NTRS)

    Tao, Wei-Kuo; Smith, E. A.; Adler, R.; Haddad, Z.; Hou, A.; Iguchi, T.; Kakar, R.; Krishnamurti, T.; Kummerow, C.; Lang, S.

    2004-01-01

    Rainfall production is the fundamental variable within the Earth's hydrological cycle because it is both the principal forcing term in surface water budgets and its energetics corollary, latent heating, is the principal source of atmospheric diabatic heating. Latent heat release itself is a consequence of phase changes between the vapor, liquid, and frozen states of water. The properties of the vertical distribution of latent heat release modulate large-scale meridional and zonal circulations within the tropics - as well as modifying the energetic efficiencies of midlatitude weather systems. This paper focuses on the retrieval of latent heat release from satellite measurements generated by the Tropical Rainfall Measuring Mission (TRMM) satellite observatory, which was launched in November 1997 as a joint American-Japanese space endeavor. Since then, TRMM measurements have been providing an accurate four-dimensional account of rainfall over the global tropics and sub-tropics, information which can be used to estimate the space-time structure of latent heating across the Earth's low latitudes. The paper examines how the observed TRMM distribution of rainfall has advanced an understanding of the global water and energy cycle and its consequent relationship to the atmospheric general circulation and climate via latent heat release. A set of algorithm methodologies that are being used to estimate latent heating based on rain rate retrievals from the TRMM observations are described. The characteristics of these algorithms and the latent heating products that can be generated from them are also described, along with validation analyses of the heating products themselves. Finally, the investigation provides an overview of how TRMM-derived latent heating information is currently being used in conjunction with global weather and climate models, concluding with remarks intended to stimulate further research on latent heating retrieval from satellites.

  15. Solar corona top heating

    NASA Astrophysics Data System (ADS)

    Molotkov, I. A.; Ryabova, N. A.

    2016-05-01

    The solar magnetic field fragmentation into thin magnetic tubes above the photosphere makes it possible to transform and factorize MHD equations analytically and to obtain explicit expressions for Alfvén and magnetosonic fields. A physical model that enables an explanation of the effect of strong heating of the solar chromosphere and corona has been proposed. This model makes it possible to estimate analytically a powerful Alfvén disturbance entering the chromosphere due to convective motions of the photosphere and a thermal release due to a three-wave interaction within the chromosphere.

  16. EIA new releases, November--December 1995

    SciTech Connect

    1996-02-09

    Thus publication contains information compiled by the Energy information administration (EIA) on the following topics: heating fuel supplies; alternative fuel vehicles; natural gas production; clean air laws and coal transportation; EIA`s world Wide Web Site; EIA`s CD-ROM; Press Releases; Microfiched products; electronic publishing; new reports; machine-readable files; how to order EIA publications; and Energy Data Information Contracts.

  17. Release Resistant Electrical Interconnections For Mems Devices

    DOEpatents

    Peterson, Kenneth A.; Garrett, Stephen E.; Reber, Cathleen A.

    2005-02-22

    A release resistant electrical interconnection comprising a gold-based electrical conductor compression bonded directly to a highly-doped polysilicon bonding pad in a MEMS, IMEMS, or MOEMS device, without using any intermediate layers of aluminum, titanium, solder, or conductive adhesive disposed in-between the conductor and polysilicon pad. After the initial compression bond has been formed, subsequent heat treatment of the joint above 363 C creates a liquid eutectic phase at the bondline comprising gold plus approximately 3 wt % silicon, which, upon re-solidification, significantly improves the bond strength by reforming and enhancing the initial bond. This type of electrical interconnection is resistant to chemical attack from acids used for releasing MEMS elements (HF, HCL), thereby enabling the use of a "package-first, release-second" sequence for fabricating MEMS devices. Likewise, the bond strength of an Au--Ge compression bond may be increased by forming a transient liquid eutectic phase comprising Au-12 wt % Ge.

  18. Kinetics of hydrogen release from lunar soil

    NASA Technical Reports Server (NTRS)

    Bustin, Roberta

    1990-01-01

    With increasing interest in a lunar base, there is a need for extensive examination of possible lunar resources. Hydrogen will be needed on a lunar base for many activities including providing fuel, making water, and serving as a reducing agent in the extraction of oxygen from its ores. Previous studies have shown the solar wind has implanted hydrogen in the lunar regolith and that hydrogen is present not only in the outer layer of soil but to considerable depths, depending on the sampling site. If this hydrogen is to be mined and used on the lunar surface, a number of questions need to be answered. How much energy must be expended in order to release the hydrogen from the soil. What temperatures must be attained, and how long must the soil be heated. This study was undertaken to provide answers to practical questions such as these. Hydrogen was determined using a Pyrolysis/GC technique in which hydrogen was released by heating the soil sample contained in a quartz tube in a resistance wire furnace, followed by separation and quantitative determination using a gas chromatograph with a helium ionization detector. Heating times and temperatures were varied, and particle separates were studied in addition to bulk soils. The typical sample size was 10 mg of lunar soil. All of the soils used were mature soils with similar hydrogen abundances. Pre-treatments with air and steam were used in an effort to find a more efficient way of releasing hydrogen.

  19. Kinetics of hydrogen release from lunar soil

    NASA Astrophysics Data System (ADS)

    Bustin, Roberta

    1990-10-01

    With increasing interest in a lunar base, there is a need for extensive examination of possible lunar resources. Hydrogen will be needed on a lunar base for many activities including providing fuel, making water, and serving as a reducing agent in the extraction of oxygen from its ores. Previous studies have shown the solar wind has implanted hydrogen in the lunar regolith and that hydrogen is present not only in the outer layer of soil but to considerable depths, depending on the sampling site. If this hydrogen is to be mined and used on the lunar surface, a number of questions need to be answered. How much energy must be expended in order to release the hydrogen from the soil. What temperatures must be attained, and how long must the soil be heated. This study was undertaken to provide answers to practical questions such as these. Hydrogen was determined using a Pyrolysis/GC technique in which hydrogen was released by heating the soil sample contained in a quartz tube in a resistance wire furnace, followed by separation and quantitative determination using a gas chromatograph with a helium ionization detector. Heating times and temperatures were varied, and particle separates were studied in addition to bulk soils. The typical sample size was 10 mg of lunar soil. All of the soils used were mature soils with similar hydrogen abundances. Pre-treatments with air and steam were used in an effort to find a more efficient way of releasing hydrogen.

  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. Heat collector

    DOEpatents

    Merrigan, M.A.

    1981-06-29

    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.

  2. Heat collector

    DOEpatents

    Merrigan, Michael A.

    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.

  3. Release of inorganic material during coal devolatilization

    SciTech Connect

    Baxter, L.L.; Mitchell, R.E.; Fletcher, T.H.

    1997-03-01

    Experimental results presented in this paper indicate that coal devolatilization products convectively remove a fraction of the nonvolatile components of inorganic material atomically dispersed in the coal matrix. Results from three facilities burning six different coals illustrate this mechanism of ash transformation and release from coal particles. Titanium is chosen to illustrate this mechanism of ash transformation and release from coal particles. Titanium is chosen to illustrate this type of mass release from coal particles on the basis of its low volatility and mode of occurrence in the coal. During moderate rates of devolatilization (10{sup 4} K/s heating rate), no significant loss of titanium is noted. At more rapid rates of heating/devolatilization (10{sup 5} K/s) a consistent but minot (3%--4%) loss of titanium is noted. During rapid devolatilization (5 {times} 10{sup 5} K/s and higher), significant (10%--20%) amounts of titanium leave the coal. The loss of titanium monitored in coals ranging in rank from subbituminous to high-volatile bituminous coals and under conditions typical of pulverized-coal combustion. The amount of titanium lost during devolatilization exhibits a complex rank dependence. These results imply that other atomically dispersed material (alkali and alkaline earth elements) may undergo similar mechanisms of transformation and release.

  4. The Sympathetic Release Test: A Test Used to Assess Thermoregulation and Autonomic Control of Blood Flow

    ERIC Educational Resources Information Center

    Tansey, E. A.; Roe, S. M.; Johnson, C. J.

    2014-01-01

    When a subject is heated, the stimulation of temperature-sensitive nerve endings in the skin, and the raising of the central body temperature, results in the reflex release of sympathetic vasoconstrictor tone in the skin of the extremities, causing a measurable temperature increase at the site of release. In the sympathetic release test, the…

  5. Enceladus' Enigmatic Heat Flow

    NASA Astrophysics Data System (ADS)

    Howett, C.; Spencer, J. R.; Spencer, D.; Verbiscer, A.; Hurford, T.; Segura, M.

    2013-12-01

    Accurate knowledge of Enceladus' heat flow is important because it provides a vital constraint on Enceladus' tidal dissipation mechanisms, orbital evolution, and the physical processes that generate the plumes. In 2011 we published an estimate of the current heat flow from Enceladus' active south polar terrain: 15.8 +/- 3.1 GW (Howett et al., 2011). This value was calculated by first estimating by modeling, and then removing, the passive component from 17 to 1000 micron observations made of the entire south polar terrain by Cassini's Composite Infrared Spectrometer (CIRS). The heat flow was then directly calculated from the residual, assumed endogenic, component. The derived heat flow of 15.8 GW was surprisingly high, about 10 times greater than that predicted by steady-state tidal heating (Meyer and Wisdom, 2007). CIRS has also returned high spatial resolution observations of Enceladus' active south polar terrain. Two separate observations are used: 9 to 16 micron observations taken over nearly the complete south polar terrain and a single 17 to 1000 micron scan over Damascus, Baghdad and Cairo. The shorter wavelength observations are only sensitive to high temperature emission (>70 K), and so longer wavelength observations are required (despite their limited spatial coverage) to estimate the low temperature emission from the stripes. Analysis of these higher resolution observations tells a different story of Enceladus' endogenic heat flow: the preliminary estimate of the heat flow from the active tiger stripes using these observations is 4.2 GW. An additional 0.5 GW must be added to this number to account for the latent heat release by the plumes (Ingersoll and Pankine 2009), giving a total preliminary estimate of 4.9 GW. The discrepancy in these two numbers is significant and we are currently investigating the cause. One possible reason is that there is significantly higher endogenic emission from the regions between the tiger stripes than we currently estimate

  6. Rad-Release

    SciTech Connect

    2011-01-01

    The R&D 100 Award winning Rad-Release Chemical Decontamination Technology is a highly effective (up to 99% removal rate), affordable, patented chemical-foam-clay decontamination process tailored to specific radiological and metal contaminants, which is applicable to a wide variety of substrates. For more information about this project, visit http://www.inl.gov/rd100/2011/rad-release/

  7. Rad-Release

    ScienceCinema

    None

    2013-05-28

    The R&D 100 Award winning Rad-Release Chemical Decontamination Technology is a highly effective (up to 99% removal rate), affordable, patented chemical-foam-clay decontamination process tailored to specific radiological and metal contaminants, which is applicable to a wide variety of substrates. For more information about this project, visit http://www.inl.gov/rd100/2011/rad-release/

  8. Local Affinity Release.

    PubMed

    Delplace, Vianney; Obermeyer, Jaclyn; Shoichet, Molly S

    2016-07-26

    The use of hydrogels for therapeutic delivery is a burgeoning area of investigation. These water-swollen polymer matrices are ideal platforms for localized drug delivery that can be further combined with specific ligands or nanotechnologies to advance the controlled release of small-molecule drugs and proteins. Due to the advantage of hydrophobic, electrostatic, or specific extracellular matrix interactions, affinity-based strategies can overcome burst release and challenges associated with encapsulation. Future studies will provide innovative binding tools, truly stimuli-responsive systems, and original combinations of emerging technologies to control the release of therapeutics spatially and temporally. Local drug delivery can be achieved by directly injecting a therapeutic to its site of action and is advantageous because off-target effects associated with systemic delivery can be minimized. For prolonged benefit, a vehicle that provides sustained drug release is required. Hydrogels are versatile platforms for localized drug release, owing to the large library of biocompatible building blocks from which they can be formed. Injectable hydrogel formulations that gel quickly in situ and provide sustained release of therapeutics are particularly advantageous to minimize invasiveness. The incorporation of polymers, ligands or nanoparticles that have an affinity for the therapeutic of interest improve control over the release of small-molecule drugs and proteins from hydrogels, enabling spatial and temporal control over the delivery. Such affinity-based strategies can overcome drug burst release and challenges associated with protein instability, allowing more effective therapeutic molecule delivery for a range of applications from therapeutic contact lenses to ischemic tissue regeneration. PMID:27403513

  9. Advanced release technologies program

    NASA Technical Reports Server (NTRS)

    Purdy, Bill

    1994-01-01

    The objective of the ARTS program was to develop lighter and less expensive spacecraft ordnance and release systems that answer to the requirements of a wide variety of spacecraft applications. These improvements were to be evaluated at the spacecraft system level, as it was determined that there were substantial system-level costs associated with the present ordnance and release subsystems. New, better devices were to be developed, then flight qualified, then integrated into a flight experiment in order to prove the reliability required for their subsequent use on high-reliability spacecraft. The secondary goal of the program was to quantify the system-level benefits of these new subsystems based upon the development program results. Three non-explosive release mechanisms and one laser-diode-based ordnance system were qualified under the program. The release devices being developed were required to release high preloads because it is easier to scale down a release mechanism than to scale it up. The laser initiator developed was required to be a direct replacement for NASA Standard Initiators, since these are the most common initiator in use presently. The program began in October, 1991, with completion of the flight experiment scheduled for February, 1994. This paper provides an overview of the ARTS program, discusses the benefits of using the ARTS components, introduces the new components, compares them with conventional systems and each other, and provides recommendations on how best to implement them.

  10. Heat intolerance

    MedlinePlus

    ... this page: //medlineplus.gov/ency/article/003094.htm Heat intolerance To use the sharing features on this ... must be authorized in writing by ADAM Health Solutions. About MedlinePlus Site Map FAQs Contact Us Get ...

  11. HEAT EXCHANGER

    DOEpatents

    Fox, T.H. III; Richey, T. Jr.; Winders, G.R.

    1962-10-23

    A heat exchanger is designed for use in the transfer of heat between a radioactive fiuid and a non-radioactive fiuid. The exchanger employs a removable section containing the non-hazardous fluid extending into the section designed to contain the radioactive fluid. The removable section is provided with a construction to cancel out thermal stresses. The stationary section is pressurized to prevent leakage of the radioactive fiuid and to maintain a safe, desirable level for this fiuid. (AEC)

  12. Corrosive resistant heat exchanger

    DOEpatents

    Richlen, Scott L.

    1989-01-01

    A corrosive and errosive resistant heat exchanger which recovers heat from a contaminated heat stream. The heat exchanger utilizes a boundary layer of innocuous gas, which is continuously replenished, to protect the heat exchanger surface from the hot contaminated gas. The innocuous gas is conveyed through ducts or perforations in the heat exchanger wall. Heat from the heat stream is transferred by radiation to the heat exchanger wall. Heat is removed from the outer heat exchanger wall by a heat recovery medium.

  13. Fission product release from nuclear fuel by recoil and knockout

    NASA Astrophysics Data System (ADS)

    Lewis, B. J.

    1987-03-01

    An analytical model has been developed to describe the fission product release from nuclear fuel arising from the surface-fission release mechanisms of recoil and knockout. Release expressions are evaluated and compared to the short-lived activity measurements from in-reactor experiments with intact operating fuel. Recoil is shown to be an important process for releasing fission products from free UO 2 surfaces into the fuel-to-sheath gap. The model is also applied to tramp uranium in a power reactor primary heat transport circuit where it is demonstrated that recoil is the dominant release mechanism for small particles of fuel which are deposited on in-core surfaces. A methodology is established whereby release from surface contamination can be distinguished from that of fuel pin failure.

  14. Latent Heating Structures Derived from TRMM

    NASA Technical Reports Server (NTRS)

    Tao, W.-K.; Smith, E. A.; Adler, R.; Hou, A.; Kakar, R.; Krishnamurti, T.; Kummerow, C.; Lang, S.; Olson, W.; Satoh, S.

    2004-01-01

    Rainfall is the fundamental variable within the Earth's hydrological cycle because it is both the main forcing term leading to variations in continental and oceanic surface water budgets. The vertical distribution of latent heat release, which is accompanied with rain, modulates large-scale meridional and zonal circulations within the tropics as well as modifying the energetic efficiency of mid-latitude weather systems. Latent heat release itself is a consequence of phase changes between the vapor, liquid, and frozen states of water.This paper focuses on the retrieval of latent heat release from satellite measurements generated by the Tropical Rainfall Measuring Mission 0. The TRMM observatory, whose development was a joint US-Japan space endeavor, was launched in November 1997. TRMM measurements provide an accurate account of rainfall over the global tropics, information which can be .used to estimate the four-dimensional structure of latent heating across the entire tropical and sub-tropical regions. Various algorithm methodologies for estimating latent heating based on rain rate measurements from TRMM observations are described. The strengths and weaknesses of these algorithms, as well as the latent heating products generated by these algorithms, are also discussed along with validation analyses of the products. The investigation paper provides an overview of how TRMM-derived latent heating information is currently being used in conjunction with global weather and climate models, and concludes with remarks designed to stimulate further research on latent heating retrieval

  15. Enceladus Heat Pump Model

    NASA Astrophysics Data System (ADS)

    Matson, Dennis L.; Johnson, T. V.; Lunine, J. I.; Castillo-Rogez, J. C.

    2010-10-01

    Plume gas composition and the presence of dust grains rich in sodium salts [1,2] support a subsurface liquid as the source of the plumes observed at the South pole of Enceladus. We suggest that seawater circulating from the ocean to the surface supplies water, gas, dust and heat to the plumes. Our model needs only a percent or two of gas dissolved in the ocean, a value that is very much consistent with available observations ([1] suggest 10 percent of various gas species in the plume). As seawater comes up, pressure is released and bubbles form. Bubbly seawater is less dense than ice. Expanding gas provides lifting energy (cf. [6], [7]). The model delivers the materials that Postberg et al. [2] use for plume eruptions. Popping bubbles throw a fine spray that contains salt. This aerosol exits with the plume gas [2]. Most significant is the south polar heat flow >15 GW [4]. Water-borne oceanic heat is transferred to the surface ice. Less this heat, the water becomes colder, dissolves the bubble gases and becomes dense. It returns to the ocean via cracks in the ice. A large volume of ice is accessible via cracks SO THAT chemical interactions, heat exchange and other processes are possible. [1] Waite Jr et al., Nature, 460, 487 (2009). [2] Postberg et al., Nature, 459, 1098 (2009). [4] Howett et al BAAS., 41, 1122 (2009). [6] Crawford, and Stevenson, Icarus, 73, 66 (1988). [7] Murchie, and Head, LPS XVII, 583 (1986). This work was conducted at the Jet Propulsion Laboratory, California Institute of Technology under NASA contract, and for JIL under "Incentivazione alla mobilita' di studiosi straineri e italiani residenti all'estero" of Italy.

  16. Heat Pipes

    NASA Technical Reports Server (NTRS)

    1990-01-01

    Bobs Candies, Inc. produces some 24 million pounds of candy a year, much of it 'Christmas candy.' To meet Christmas demand, it must produce year-round. Thousands of cases of candy must be stored a good part of the year in two huge warehouses. The candy is very sensitive to temperature. The warehouses must be maintained at temperatures of 78-80 degrees Fahrenheit with relative humidities of 38- 42 percent. Such precise climate control of enormous buildings can be very expensive. In 1985, energy costs for the single warehouse ran to more than $57,000 for the year. NASA and the Florida Solar Energy Center (FSEC) were adapting heat pipe technology to control humidity in building environments. The heat pipes handle the jobs of precooling and reheating without using energy. The company contacted a FSEC systems engineer and from that contact eventually emerged a cooperative test project to install a heat pipe system at Bobs' warehouses, operate it for a period of time to determine accurately the cost benefits, and gather data applicable to development of future heat pipe systems. Installation was completed in mid-1987 and data collection is still in progress. In 1989, total energy cost for two warehouses, with the heat pipes complementing the air conditioning system was $28,706, and that figures out to a cost reduction.

  17. The Role of Compressibility in Energy Release by Magnetic Reconnection

    NASA Technical Reports Server (NTRS)

    Birn, J.; Borovosky, J. E.; Hesse, M.

    2012-01-01

    Using resistive compressible magnetohydrodynamics, we investigate the energy release and transfer by magnetic reconnection in finite (closed or periodic) systems. The emphasis is on the magnitude of energy released and transferred to plasma heating in configurations that range from highly compressible to incompressible, based on the magnitude of the background beta (ratio of plasma pressure over magnetic pressure) and of a guide field in two-dimensional reconnection. As expected, the system becomes more incompressible, and the role of compressional heating diminishes, with increasing beta or increasing guide field. Nevertheless, compressional heating may dominate over Joule heating for values of the guide field of 2 or 3 (in relation to the reconnecting magnetic field component) and beta of 5-10. This result stems from the strong localization of the dissipation near the reconnection site, which is modeled based on particle simulation results. Imposing uniform resistivity, corresponding to a Lundquist number of 10(exp 3) to 10(exp 4), leads to significantly larger Ohmic heating. Increasing incompressibility greatly reduces the magnetic flux transfer and the amount of energy released, from approx. 10% of the energy associated with the reconnecting field component, for zero guide field and low beta, to approx. 0.2%-0.4% for large values of the guide field B(sub y0) > 5 or large beta. The results demonstrate the importance of taking into account plasma compressibility and localization of dissipation in investigations of heating by turbulent reconnection, possibly relevant for solar wind or coronal heating.

  18. Altitude release mechanism

    DOEpatents

    Kulhanek, Frank C.

    1977-01-01

    An altitude release mechanism for releasing a radiosonde or other measuring instrument from a balloon carrying it up into the atmosphere includes a bottle partially filled with water, a tube sealed into the bottle having one end submerged in the water in the bottle and the free end extending above the top of the bottle and a strip of water-disintegrable paper held within the free end of the tube linking the balloon to the remainder of the package. As the balloon ascends, the lowered atmospheric air pressure causes the air in the bottle to expand, forcing the water in the bottle up the tubing to wet and disintegrate the paper, releasing the package from the balloon.

  19. Magnetic heating of stellar chromospheres and coronae

    NASA Technical Reports Server (NTRS)

    Van Ballegooijen, A. A.

    1990-01-01

    The theoretical discussion of magnetic heating focuses on heating by dissipation of field-aligned electric currents. Several mechanisms are set forth to account for the very high current densities needed to generate the heat, but observed radiative losses do not justify the resultant Ohmic heating rate. Tearing modes, 'turbulent resistivity', and 'hyper-resistivity' are considered to resolve the implied inefficiency of coronal heating. Because the mechanisms are not readily applicable to the sun, transverse magnetic energy flows and magnetic flare release are considered to account for the magnitude of observed radiative loss. High-resolution observations of the sun are concluded to be an efficient way to examine the issues of magnetic heating in spite of the very small spatial scales of the heating processes.

  20. Low gravity exothermic heating/cooling apparatus

    NASA Technical Reports Server (NTRS)

    Poorman, R. M. (Inventor)

    1985-01-01

    A low gravity exothermic heating/cooling apparatus is disclosed for processing materials in space which includes an insulated casing and a sample support carried within the casing which support a sample container. An exothermic heat source includes a plurality of segments of exothermic material stacked one upon another to produce a desired temperature profile when ignited. The sample container is arranged within the core of the stacked exothermic heating material. Igniters are spaced vertically along the axis of the heating material to ignite the exothermic material at spaced points to provide total rapid burn and release of heat. To rapidly cool and quench the heat, a source of liquid carbon dixoide is provided which is conveyed through a conduit and a metering orifice into a distribution manifold where the carbon dioxide is gasified and dispersed around the exothermic heating material and the sample container via tubes for rapidly cooling the material sample.

  1. Heat generation in aircraft tires

    NASA Technical Reports Server (NTRS)

    Clark, S. K.; Dodge, R. N.

    1985-01-01

    A method was developed for calculating the internal temperature distribution in an aircraft tire while free rolling under load. The method uses an approximate stress analysis of each point in the tire as it rolls through the contact patch, and from this stress change the mechanical work done on each volume element may be obtained and converted into a heat release rate through a knowledge of material characteristics. The tire cross-section is then considered as a body with internal heat generation, and the diffusion equation is solved numerically with appropriate boundary conditions of the wheel and runway surface. Comparison with data obtained with buried thermocouples in tires shows good agreement.

  2. [Sustained-release dextropropoxyphene.].

    PubMed

    Kurz-Müller, K; Zenz, M

    1991-12-01

    Dextropropoxyphene is a mild opioid analgesic whose analgesic potency corresponds to that of acetylsalicylic acid and paracetamol. It has a similar analgesic effect to codeine but also a considerably lower addiction and dependence potential. Dextropropoxyphene is a therapeutic alternative to other weak opioids such as codeine or dihydrocodeine. In the case of absolute intolerance of non-steroidal anti-inflammatory agents, their analgesic effect can be replaced by that of dextropropoxyphene. In case of relative intolerance, i.e. occurrence of non-tolerable side-effects, the dose of non-steroidal anti-inflammatory agents can be kept low by additional administration of dextropropoxyphene, which simultaneously enhances analgesia. Analgesics are prescribed according to a definite time schedule for the long-term treatment of chronic pain. The oral route of administration is preferred since it enables the patient to be independent of the nursing staff. Sustained-release drugs with a duration of action of at least 8 h are used in preference to other preparations. Sustained-release dextropropoxyphene provides analgesia for 8-12 h. Sustained-release dextropropoxyphene clearly differs from non-sustained-release dextropropoxyphene in its pharmacokinetics. Repeated administration of the sustained-release form at the therapeutically recommended intervals does not lead to cumulation, and the risk of accidental overdosage is extremely low. Intoxication can only occur after simultaneous ingestion of alcohol or other centrally depressant substances or in the presence of hepatic and/or renal failure. Sustained-release dextropropoxyphene is a sensible and undeniable alternative for the second stage in the analgesic ladder of chronic pain therapy. PMID:18415177

  3. Stored energy release behaviour of disordered carbon

    NASA Astrophysics Data System (ADS)

    Dasgupta, K.; Barat, P.; Sarkar, A.; Mukherjee, P.; Sathiyamoorthy, D.

    2007-06-01

    The use of graphite as a moderator in a low temperature thermal nuclear reactor is restricted due to accumulation of energy caused by displacement of atoms by neutrons and high energetic particles. Thermal transients may lead to a release of stored energy that may raise the temperature of the fuel clad above the design limit. Disordered carbon is thought to be an alternative choice for this purpose. Two types of disordered carbon composites, namely, CB (made up of 15 wt. % carbon black dispersed in carbonized phenolic resin) and PAN (made up of 20 vol. % chopped polyacrylonitrile carbon fibre dispersed in carbonized phenolic resin matrix) have been irradiated with 145 MeV Ne6+ ions at three fluence levels of 1.0×1013, 5.0×1013 and 1.5×1014 Ne6+/cm2, respectively. The XRD patterns revealed that both the samples remained disordered even after irradiation. The maximum release of stored energy for CB was 212 J/g and that of PAN was 906 J/g. For CB, the release of stored energy was a first order reaction with activation energy of 2.79 eV and a frequency factor of 3.72×1028 per second. 13% of the defects got annealed by heating up to 700 °C. PAN showed a third-order release rate with activation energy of 1.69 eV and a frequency factor of 1.77×1014 per second. 56% of the total defects got annealed by heating it up to 700 °C. CB seems to be the better choice than PAN as it showed less energy release with a slower rate.

  4. Barium release system

    NASA Technical Reports Server (NTRS)

    Lewis, B. W.; Stokes, C. S.; Smith, E. W.; Murphy, W. J. (Inventor)

    1973-01-01

    A chemical system is described for releasing a good yield of free barium neutral atoms and barium ions in the upper atmosphere and interplanetary space for the study of the geophysical properties of the medium. The barium is released in the vapor phase so that it can be ionized by solar radiation and also be excited to emit resonance radiation in the visible range. The ionized luminous cloud of barium becomes a visible indication of magnetic and electrical characteristics in space and allows determination of these properties over relatively large areas at a given time.

  5. Benzene release. status report

    SciTech Connect

    Dworjanyn, L.O.; Rappe, K.G.; Gauglitz, P.A.

    1997-11-04

    Scoping benzene release measurements were conducted on 4 wt percent KTPB `DEMO` formulation slurry using a round, flat bottomed 100-mL flask containing 75 mL slurry. The slurry was agitated with a magnetic stirrer bar to keep the surface refreshed without creating a vortex. Benzene release measurements were made by purging the vapor space at a constant rate and analyzing for benzene by gas chromatography with automatic data acquisition. Some of the data have been rounded or simplified in view of the scoping nature of this study.

  6. HEAT GENERATION

    DOEpatents

    Imhoff, D.H.; Harker, W.H.

    1963-12-01

    Heat is generated by the utilization of high energy neutrons produced as by nuclear reactions between hydrogen isotopes in a blanket zone containing lithium, a neutron moderator, and uranium and/or thorium effective to achieve multtplicatton of the high energy neutron. The rnultiplied and moderated neutrons produced react further with lithium-6 to produce tritium in the blanket. Thermal neutron fissionable materials are also produced and consumed in situ in the blanket zone. The heat produced by the aggregate of the various nuclear reactions is then withdrawn from the blanket zone to be used or otherwise disposed externally. (AEC)

  7. Heat exchanger

    SciTech Connect

    Drury, C.R.

    1988-02-02

    A heat exchanger having primary and secondary conduits in heat-exchanging relationship is described comprising: at least one serpentine tube having parallel sections connected by reverse bends, the serpentine tube constituting one of the conduits; a group of open-ended tubes disposed adjacent to the parallel sections, the open-ended tubes constituting the other of the conduits, and forming a continuous mass of contacting tubes extending between and surrounding the serpentine tube sections; and means securing the mass of tubes together to form a predetermined cross-section of the entirety of the mass of open-ended tubes and tube sections.

  8. Gas turbine combustor stabilization by heat recirculation

    NASA Technical Reports Server (NTRS)

    Ganji, A.; Short, J.; Branch, M. C.; Oppenheim, A. K.

    1975-01-01

    The feasibility of heat recirculation for stabilization of lean mixtures and emission reduction has been studied in detail for a typical aircraft gas turbine combustor. Thermodynamic calculations have indicated temperature and heat recirculation rates for operation of the combustor over a range of combustion zone equivalence ratios and for varying modes of desired engine operation. Calculations indicate the feasibility of stabilizing the combustion zone at equivalence ratios as low as 0.2 with achievable heat recirculation rates. Detailed chemical kinetic calculations suggest that combustor heat release is maintained with reaction completion substantially before the NO forming reactions, even though CO is rapidly oxidized in this same region.

  9. Nonventing, Regenerable, Lightweight Heat Absorber

    NASA Technical Reports Server (NTRS)

    Izenson, Michael G.; Chen, Weibo

    2008-01-01

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

  10. Infrared Heating

    Technology Transfer Automated Retrieval System (TEKTRAN)

    IR heating was first industrially used in the 1930s for automotive curing applications and rapidly became a widely applied technology in the manufacturing industry. Contrarily, a slower pace in the development of IR technologies for processing foods and agricultural products was observed, due to lim...

  11. Release the Prisoners Game

    ERIC Educational Resources Information Center

    Van Hecke, Tanja

    2011-01-01

    This article presents the mathematical approach of the optimal strategy to win the "Release the prisoners" game and the integration of this analysis in a math class. Outline lesson plans at three different levels are given, where simulations are suggested as well as theoretical findings about the probability distribution function and its mean…

  12. Release of OLe peanut

    Technology Transfer Automated Retrieval System (TEKTRAN)

    OLe is a high oleic Spanish-type peanut that has excellent yield and enhanced Sclerotinia blight and pod rot resistance when compared to other high oleic Spanish cultivars. The purpose for releasing OLe is to provide peanut producers with a true Spanish peanut that is high oleic and has enhanced yi...

  13. Trabeculectomy with releasable sutures.

    PubMed Central

    Kolker, A E; Kass, M A; Rait, J L

    1993-01-01

    We attempted to reduce some of the postoperative complications of trabeculectomy by using releasable scleral flap sutures. This technique allows an initial tight closure of the scleral flap with the option to increase aqueous humor outflow in the early postoperative period. We reviewed our experience with trabeculectomy and releasable sutures in 146 eyes (134 patients) and compared these cases with a prior series of 128 eyes (124 patients) that underwent trabeculectomy with permanent scleral flap sutures. In the control group, 42 eyes (32.8%) had clinically detectable shallowing of the anterior chamber in the postoperative period. In contrast, shallow anterior chamber was noted in 21 eyes (14.4%) in the group with releasable sutures (P = .0003). Flat anterior chamber, defined as iridocorneal touch to the pupil margin, occurred in 11 control eyes (8.6%) but in only 2 eyes (1.4%) with releasable sutures (P = .0078). Surgical intervention to drain suprachoroidal fluid and re-form the anterior chamber was required in eight control eyes (6.2%) but in only one study eye (0.7%) (P = .014). At 1 year of follow-up, the two groups were similar in terms of mean intraocular pressure, the need for ocular hypotensive medications, and failure rate. PMID:8140688

  14. DSCOVR Public Release Statement

    Atmospheric Science Data Center

    2016-08-04

    ... Wednesday, July 20, 2016 The Deep Space Climate Observatory (DSCOVR) is a NOAA/NASA mission located near the ... Control Book .    NOAA will release data from the space weather instruments on July 27 th . The data, as well as space weather ...

  15. Literature: Released Exercises.

    ERIC Educational Resources Information Center

    Education Commission of the States, Denver, CO. National Assessment of Educational Progress.

    This volume contains 1970-71 Literature assessment exercises (all in the public domain) which have been selected for release at this time by the National Assessment of Educational Progress. Information furnished for each exercise includes: the literature objective it was designed to measure, the theme (section) in which it appears, relevant…

  16. Double swivel toggle release

    NASA Technical Reports Server (NTRS)

    King, Guy L.; Schneider, William C.

    1989-01-01

    A pyrotechnic actuated structural release device is disclosed which is mechanically two fault tolerant for release. The device comprises a fastener plate and fastener body each attachable to one of a pair of structures to be joined. The fastener plate and the fastener body are fastened by a dual swivel toggle member. The toggle member is supported at one end on the fastener plate and mounted for universal pivotal movement thereon. Its other end is received in a central opening in the fastener body, and has a universally mounted retainer ring member. The toggle member is restrained by three retractable latching pins symmetrically disposed in equiangular spacing about the axis of the toggle member and positionable in latching engagement with the retainer ring member on the toggle member. Each pin is retractable by a pyrotechnic charge, the expanding gases of which are applied to a pressure receiving face on the latch pins to effect retraction from the ring member. While retraction of all three pins releases the ring member, the fastener is mechanically two fault tolerant since the failure of any single one or pair of the latch pins to retract results in an asymmetrical loading on the ring member and its dual pivotal movement ensures a release.

  17. Releasable Asbestos Field Sampler

    EPA Science Inventory

    Asbestos aerosolization (or releasability) is the potential for fibrous asbestos structures that are present in a material or on a solid surface to become airborne when the source is disturbed by human activities or natural forces. In turn, the magnitude of the airborne concentra...

  18. Latent Heating from TRMM Satellite Measurements

    NASA Technical Reports Server (NTRS)

    Tao, W.-K.; Smith, E.; Olson, W.

    2005-01-01

    Rainfall production is a fundamental process within the Earth;s hydrological cycle because it represents both a principal forcing term in surface water budgets, and its energetics corollary, latent heating, is the principal source of atmospheric diabatic heating. Latent heat release itself is a consequence of phase changes between the vapor, liquid, and frozen states of water. The properties of the vertical distribution of latent heat release modulate large-scale meridional and zonal circulations with the Tropics - as well as modify the energetic efficiencies of mid-latitude weather systems. This paper highlights the retrieval of observatory, which was launched in November 1997 as a joint American-Japanese space endeavor. Since then, TRMM measurements have been providing an accurate four-dimensional amount of rainfall over the global Tropics and sub-tropics - information which can be used to estimate the spacetime structure of latent heating across the Earth's low latitudes. A set of algorithm methodologies has and continues to be developed to estimate latent heating based on rain rate profile retrievals obtained from TRMM measurements. These algorithms are briefly described followed by a discussion of the foremost latent heating products that can be generate from them. The investigation then provides an overview of how TRMM-derived latent heating information is currently being used in conjunction with global weather and climate models, concluding with remarks intended to stimulate further research on latent heating retrieval from satellites.

  19. REVIVAL OF THE STALLED CORE-COLLAPSE SUPERNOVA SHOCK TRIGGERED BY PRECOLLAPSE ASPHERICITY IN THE PROGENITOR STAR

    SciTech Connect

    Couch, Sean M.; Ott, Christian D. E-mail: cott@tapir.caltech.edu

    2013-11-20

    Multi-dimensional simulations of advanced nuclear burning stages of massive stars suggest that the Si/O layers of presupernova stars harbor large deviations from the spherical symmetry typically assumed for presupernova stellar structure. We carry out three-dimensional core-collapse supernova simulations with and without aspherical velocity perturbations to assess their potential impact on the supernova hydrodynamics in the stalled-shock phase. Our results show that realistic perturbations can qualitatively alter the postbounce evolution, triggering an explosion in a model that fails to explode without them. This finding underlines the need for a multi-dimensional treatment of the presupernova stage of stellar evolution.

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

    SciTech Connect

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

    1998-07-01

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

  1. Release Fraction Evaluation

    SciTech Connect

    Bamberger, Judith A.; Glissmeyer, John A.

    2004-01-01

    This document presents results of experiments conducted to measure release fractions during certain tank retrieval processes. The tests were performed in a 1/4 scale model of a waste storage tank. The retrieval processes simulated were: (1) Discharging liquid or slurry from the mouth of a vertically oriented two-in. Schedule 40 pipe. The discharging material was in free-fall from the mouth of the pipe near the top of the tank into a liquid or slurry pool at the bottom of the tank. (2) The jet from a 9/16-in.-diameter nozzle transferring liquid or slurry waste from one side of the tank to the other. The discharging liquid was aimed at the opposite side of the tank from the nozzle and either impacted the tank wall or fell into a liquid or slurry pool in the bottom of the tank. (3) A high pressure fan jet of liquid striking a steel plate or simulated waste from a stand-off distance of a few inches. For each process, a water-soluble fluorescent dye was added to the liquid fraction as a tracer. Kaolin clay was used to represent the solids. The tank was covered and there was no forced ventilation in the tank during the tests. Six air samples were collected during each test. The air samples were collected at fixed positions in the tank. The air sample filters were dried and weighed to determine the solids collection. The fluorescent dye was then leached from each filter and quantified with a fluorometer to determine the collection of liquid. Samples of the slurry and liquid simulants were also collected to determine the quantities of simulant used in each test. To calculate the release fraction, the quantity collected on each air sample was adjusted for the fraction of the tank volume sampled and divided by the quantity of material exposed in the simulation. The method was not as sensitive for the solids content as it was for the liquid content, but in those instances where a solids release fraction was determined, it was in relatively good agreement with that of the

  2. Food odor, visual danger stimulus, and retrieval of an aversive memory trigger heat shock protein HSP70 expression in the olfactory lobe of the crab Chasmagnathus granulatus.

    PubMed

    Frenkel, L; Dimant, B; Suárez, L D; Portiansky, E L; Delorenzi, A

    2012-01-10

    Although some of the neuronal substrates that support memory process have been shown in optic ganglia, the brain areas activated by memory process are still unknown in crustaceans. Heat shock proteins (HSPs) are synthesized in the CNS not only in response to traumas but also after changes in metabolic activity triggered by the processing of different types of sensory information. Indeed, the expression of citosolic/nuclear forms of HSP70 (HSC/HSP70) has been repeatedly used as a marker for increases in neural metabolic activity in several processes, including psychophysiological stress, fear conditioning, and spatial learning in vertebrates. Previously, we have shown that, in the crab Chasmagnathus, two different environmental challenges, water deprivation and heat shock, trigger a rise in the number of glomeruli of the olfactory lobes (OLs) expressing HSC/HSP70. In this study, we initially performed a morphometric analysis and identified a total of 154 glomeruli in each OL of Chasmagnathus. Here, we found that crabs exposed to food odor stimuli also showed a significant rise in the number of olfactory glomeruli expressing HSC/HSP70. In the crab Chasmagnathus, a powerful memory paradigm based on a change in its defensive strategy against a visual danger stimulus (VDS) has been extensively studied. Remarkably, the iterative presentation of a VDS caused an increase as well. This increase was triggered in animals visually stimulated using protocols that either build up a long-term memory or generate only short-term habituation. Besides, memory reactivation was sufficient to trigger the increase in HSC/HSP70 expression in the OL. Present and previous results strongly suggest that, directly or indirectly, an increase in arousal is a sufficient condition to bring about an increase in HSC/HSP70 expression in the OL of Chasmagnathus. PMID:22100787

  3. Heat conduction

    SciTech Connect

    Lilley, D.G.

    1987-01-01

    Analytical and numerical methods, including both finite difference and finite element techniques, are presented with applications to heat conduction problems. Numerical and analytical methods are integrated throughout the text and a variety of complexities are thoroughly treated with many problems, solutions and computer programs. This book is presented as a fundamental course suitable for senior undergraduate and first year graduate students, with end-of-chapter problems and answers included. Sample case studies and suggested projects are included.

  4. Atmospheric Release Advisory Capability

    SciTech Connect

    Dickerson, M.H.; Gudiksen, P.H.; Sullivan, T.J.

    1983-02-01

    The Atmospheric Release Advisory Capability (ARAC) project is a Department of Energy (DOE) sponsored real-time emergency response service available for use by both federal and state agencies in case of a potential or actual atmospheric release of nuclear material. The project, initiated in 1972, is currently evolving from the research and development phase to full operation. Plans are underway to expand the existing capability to continuous operation by 1984 and to establish a National ARAC Center (NARAC) by 1988. This report describes the ARAC system, its utilization during the past two years, and plans for its expansion during the next five to six years. An integral part of this expansion is due to a very important and crucial effort sponsored by the Defense Nuclear Agency to extend the ARAC service to approximately 45 Department of Defense (DOD) sites throughout the continental US over the next three years.

  5. Releasable locking mechanisms

    NASA Technical Reports Server (NTRS)

    Ahmed, Rafiq (Inventor); Wingate, Robert J. (Inventor)

    2005-01-01

    In the aerospace field spacecraft components are held together by separation systems until a specific time when they must be separated or deployed. Customarily a threaded joining bolt engages one of the components to be joined, and a threaded nut is placed on that bolt against the other component so they can be drawn together by a releasable locking assembly. The releasable locking assembly herein includes a plunger having one end coupled to one end of a plunger bolt. The other end is flanged to abut and compress a coil spring when the plunger is advanced toward the interface plane between the two components. When the plunger is so advanced toward the interface plane, the end of the plunger bolt can be connected to the joining bolt. Thus during retraction the joining bolt is drawn to one side of the interface plane by the force of the expanding spring.

  6. Releasable Locking Mechanisms

    NASA Technical Reports Server (NTRS)

    Ahmed, Rafiq (Inventor); Wingate, Robert J. (Inventor)

    2005-01-01

    In the aerospace field spacecraft components are held together by separation systems until a specific time when they must be separated or deployed. Customarily a threaded joining bolt engages one of the components to be joined, and a threaded nut is placed on that bolt against the other component so they can be drawn together by a releasable locking assembly. The releasable locking assembly herein includes a plunger having one end coupled to one end of a plunger bolt. The other end is flanged to abut and compress a coil spring when the plunger is advanced toward the interface plane between the two components. When the plunger is so advanced toward the interface plane, the end of the plunger bolt can be connected to the joining bolt. Thus during retraction the joining bolt is drawn to one side of the interface plane by the force of the expanding spring.

  7. Key aspects of coronal heating

    PubMed Central

    Klimchuk, James A.

    2015-01-01

    We highlight 10 key aspects of coronal heating that must be understood before we can consider the problem to be solved. (1) All coronal heating is impulsive. (2) The details of coronal heating matter. (3) The corona is filled with elemental magnetic stands. (4) The corona is densely populated with current sheets. (5) The strands must reconnect to prevent an infinite build-up of stress. (6) Nanoflares repeat with different frequencies. (7) What is the characteristic magnitude of energy release? (8) What causes the collective behaviour responsible for loops? (9) What are the onset conditions for energy release? (10) Chromospheric nanoflares are not a primary source of coronal plasma. Significant progress in solving the coronal heating problem will require coordination of approaches: observational studies, field-aligned hydrodynamic simulations, large-scale and localized three-dimensional magnetohydrodynamic simulations, and possibly also kinetic simulations. There is a unique value to each of these approaches, and the community must strive to coordinate better. PMID:25897094

  8. Slow-release fertilizer

    NASA Astrophysics Data System (ADS)

    Ming, Douglas W.; Golden, D. C.

    1992-10-01

    A synthetic apatite containing agronutrients and a method for making the apatite are disclosed. The apatite comprises crystalline calcium phosphate having agronutrients dispersed in the crystalline structure. The agronutrients can comprise potassium, magnesium, sulfur, iron, manganese, molybdenum, chlorine, boron, copper and zinc in amounts suited for plant growth. The apatite can optionally comprise a carbonate and/or silicon solubility control agent. The agronutrients are released slowly as the apatite dissolves.

  9. EIA new releases

    SciTech Connect

    Not Available

    1994-12-01

    This report was prepared by the Energy Information Administration. It contains news releases on items of interest to the petroleum, coal, nuclear, electric and alternate fuels industries ranging from economic outlooks to environmental concerns. There is also a listing of reports by industry and an energy education resource listing containing sources for free or low-cost energy-related educational materials for educators and primary and secondary students.

  10. Cryogenic hydrogen release research.

    SciTech Connect

    LaFleur, Angela Christine

    2015-12-01

    The objective of this project was to devolop a plan for modifying the Turbulent Combustion Laboratory (TCL) with the necessary infrastructure to produce a cold (near liquid temperature) hydrogen jet. The necessary infrastructure has been specified and laboratory modifications are currently underway. Once complete, experiments from this platform will be used to develop and validate models that inform codes and standards which specify protection criteria for unintended releases from liquid hydrogen storage, transport, and delivery infrastructure.

  11. Slow-release fertilizer

    NASA Technical Reports Server (NTRS)

    Ming, Douglas W. (Inventor); Golden, Dadigamuwage C. (Inventor)

    1995-01-01

    A synthetic apatite containing agronutrients and a method for making the apatite are disclosed. The apatite comprises crystalline calcium phosphate having agronutrients dispersed in the crystalline structure. The agronutrients can comprise potassium, magnesium, sulfur, iron, manganese, molybdenum, chlorine, boron, copper and zinc in amounts suited for plant growth. The apatite can optionally comprise a carbonate and/or silicon solubility control agent. The agronutrients are released slowly as the apatite dissolves.

  12. Slow-release fertilizer

    NASA Technical Reports Server (NTRS)

    Ming, Douglas W. (Inventor); Golden, D. C. (Inventor)

    1992-01-01

    A synthetic apatite containing agronutrients and a method for making the apatite are disclosed. The apatite comprises crystalline calcium phosphate having agronutrients dispersed in the crystalline structure. The agronutrients can comprise potassium, magnesium, sulfur, iron, manganese, molybdenum, chlorine, boron, copper and zinc in amounts suited for plant growth. The apatite can optionally comprise a carbonate and/or silicon solubility control agent. The agronutrients are released slowly as the apatite dissolves.

  13. Contact: Releasing the news

    NASA Astrophysics Data System (ADS)

    Pinotti, Roberto

    The problem of mass behavior after man's future contacts with other intelligences in the universe is not only a challenge for social scientists and political leaders all over the world, but also a cultural time bomb as well. In fact, since the impact of CETI (Contact with Extraterrestrial Intelligence) on human civilization, with its different cultures, might cause a serious socio-anthropological shock, a common and predetermined worldwide strategy is necessary in releasing the news after the contact, in order to keep possible manifestations of fear, panic and hysteria under control. An analysis of past studies in this field and of parallel historical situations as analogs suggests a definite "authority crisis" in the public as a direct consequence of an unexpected release of the news, involving a devastating "chain reaction" process (from both the psychological and sociological viewpoints) of anomie and maybe the collapse of today's society. The only way to prevent all this is to prepare the world's public opinion concerning contact before releasing the news, and to develop a long-term strategy through the combined efforts of scientists, political leaders, intelligence agencies and the mass media, in order to create the cultural conditions in which a confrontation with ETI won't affect mankind in a traumatic way. Definite roles and tasks in this multi-level model are suggested.

  14. Preload release mechanism

    NASA Technical Reports Server (NTRS)

    Generoli, Robert M. (Inventor); Young, Harry J. (Inventor)

    1995-01-01

    This invention relates to a preload release mechanism comprising a preload spring assembly adapted to apply a preload to a first connector member which is mounted on a support structure and adapted for connection with a second connector member on an object. The assembly comprises telescoped bushings and a preload spring. A tubular shaft extends through the spring assembly and openings in the first connector member and support structure, on which it is clamped. A plunger rod in the shaft is provided with a tip end and a recess in the rod near the other end thereof. A retainer precludes passage of the rod through the shaft in one direction and an end cap closes the bore of the shaft at the other end and provides a shoulder which extends radially of the shaft. A plunger return spring biases the plunger rod against the plunger retainer with the plunger tip protruding from the shaft and a spring assembly return spring engages at its ends the shoulder of the end cap and one end of the spring assembly. Detents received in lateral openings in the tubular shaft are held captive by the plunger rod and one end of the spring assembly to lock the spring assembly on the tubular shaft and apply a preload to the first connector member. Upon completion of the connection, detents and spring assembly are released by plunger contact with the object to be connected, thereby releasing the preload while the connection is maintained.

  15. 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.

  16. Towards understanding of heat effects in metallic glasses on the basis of macroscopic shear elasticity.

    PubMed

    Mitrofanov, Y P; Wang, D P; Makarov, A S; Wang, W H; Khonik, V A

    2016-01-01

    It is shown that all heat effects taking place upon annealing of a metallic glass within the glassy and supercooled liquid states, i.e. heat release below the glass transition temperature and heat absorption above it, as well as crystallization-induced heat release, are related to the macroscopic shear elasticity. The underlying physical reason can be understood as relaxation in the system of interstitialcy-type "defects" (elastic dipoles) frozen-in from the melt upon glass production. PMID:26975587

  17. Towards understanding of heat effects in metallic glasses on the basis of macroscopic shear elasticity

    NASA Astrophysics Data System (ADS)

    Mitrofanov, Y. P.; Wang, D. P.; Makarov, A. S.; Wang, W. H.; Khonik, V. A.

    2016-03-01

    It is shown that all heat effects taking place upon annealing of a metallic glass within the glassy and supercooled liquid states, i.e. heat release below the glass transition temperature and heat absorption above it, as well as crystallization-induced heat release, are related to the macroscopic shear elasticity. The underlying physical reason can be understood as relaxation in the system of interstitialcy-type ”defects” (elastic dipoles) frozen-in from the melt upon glass production.

  18. Triggered Release from Polymer Capsules

    SciTech Connect

    Esser-Kahn, Aaron P.; Odom, Susan A.; Sottos, Nancy R.; White, Scott R.; Moore, Jeffrey S.

    2011-07-06

    Stimuli-responsive capsules are of interest in drug delivery, fragrance release, food preservation, and self-healing materials. Many methods are used to trigger the release of encapsulated contents. Here we highlight mechanisms for the controlled release of encapsulated cargo that utilize chemical reactions occurring in solid polymeric shell walls. Triggering mechanisms responsible for covalent bond cleavage that result in the release of capsule contents include chemical, biological, light, thermal, magnetic, and electrical stimuli. We present methods for encapsulation and release, triggering methods, and mechanisms and conclude with our opinions on interesting obstacles for chemically induced activation with relevance for controlled release.

  19. Design of the cryogenic hydrogen release laboratory

    SciTech Connect

    Hecht, Ethan S.; Zimmerman, Mark D.; LaFleur, Angela Christine; Ciotti, Michael

    2015-09-01

    A cooperative research and development agreement was made between Linde, LLC and Sandia to develop a plan for modifying the Turbulent Combustion Laboratory (TCL) with the necessary infrastructure to produce a cold (near liquid temperature) hydrogen jet. A three-stage heat exchanger will be used to cool gaseous hydrogen using liquid nitrogen, gaseous helium, and liquid helium. A cryogenic line from the heat exchanger into the lab will allow high-fidelity diagnostics already in place in the lab to be applied to cold hydrogen jets. Data from these experiments will be used to develop and validate models that inform codes and standards which specify protection criteria for unintended releases from liquid hydrogen storage, transport, and delivery infrastructure.

  20. 'Heat Dome' Heats Up United States

    MedlinePlus

    ... news/fullstory_160028.html 'Heat Dome' Heats Up United States Much of the country to be under ... As a massive "heat dome" stretches across the United States this week, sending temperatures and humidity levels ...

  1. Heat pump system

    DOEpatents

    Swenson, Paul F.; Moore, Paul B.

    1979-01-01

    An air heating and cooling system for a building includes an expansion-type refrigeration circuit and a heat engine. 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 heat engine includes a heat rejection circuit having a source of rejected heat and a primary heat exchanger connected to the source of rejected heat. The heat rejection circuit also includes an evaporator in heat exchange relation with the primary heat exchanger, a heat engine indoor heat exchanger, and a heat engine outdoor heat exchanger. The indoor heat exchangers are disposed in series air flow relationship, with the heat engine indoor heat exchanger being disposed downstream from the refrigeration circuit indoor heat exchanger. The outdoor heat exchangers are also disposed in series air flow relationship, with the heat engine outdoor heat exchanger disposed downstream from the refrigeration circuit outdoor heat exchanger. A common fluid is used in both of the indoor heat exchangers and in both of the outdoor heat exchangers. In a first embodiment, the heat engine is a Rankine cycle engine. In a second embodiment, the heat engine is a non-Rankine cycle engine.

  2. Heat pump system

    DOEpatents

    Swenson, Paul F.; Moore, Paul B.

    1982-01-01

    An air heating and cooling system for a building includes an expansion-type refrigeration circuit and a heat engine. 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 heat engine includes a heat rejection circuit having a source of rejected heat and a primary heat exchanger connected to the source of rejected heat. The heat rejection circuit also includes an evaporator in heat exchange relation with the primary heat exchanger, a heat engine indoor heat exchanger, and a heat engine outdoor heat exchanger. The indoor heat exchangers are disposed in series air flow relationship, with the heat engine indoor heat exchanger being disposed downstream from the refrigeration circuit indoor heat exchanger. The outdoor heat exchangers are also disposed in series air flow relationship, with the heat engine outdoor heat exchanger disposed downstream from the refrigeration circuit outdoor heat exchanger. A common fluid is used in both of the indoor heat exchanges and in both of the outdoor heat exchangers. In a first embodiment, the heat engine is a Rankine cycle engine. In a second embodiment, the heat engine is a non-Rankine cycle engine.

  3. Heat-Transfer Coupling For Heat Pipes

    NASA Technical Reports Server (NTRS)

    Nesmith, Bill J.

    1991-01-01

    Proposed welded heat-transfer coupling joins set of heat pipes to thermoelectric converter. Design avoids difficult brazing operation. Includes pair of mating flanged cups. Upper cup integral part of housing of thermoelectric converter, while lower cup integral part of plate supporting filled heat pipes. Heat pipes prefilled. Heat of welding applied around periphery of coupling, far enough from heat pipes so it would not degrade working fluid or create excessive vapor pressure in the pipes.

  4. MICROWAVE POPCORN EMISSIONS RELEASED DURING COOKING AND BAG OPENING

    EPA Science Inventory

    Data are not currently available on the contaminants released when microwave popcorn, flavorings and bags are heated to microwave temperatures. Thus, the primary goal of this work is to identify and quantify contaminants emitted while popping and opening a bag of microwave popcor...

  5. Cellulases released during the germination of Dictyostelium discoideum spores.

    PubMed Central

    Jones, T H; de Renobales, M; Pon, N

    1979-01-01

    Dormant spores of Dictyostelium discoideum contained cellulase at a specific activity of 130 to 140 U/mg of protein; when heat activated, the spores germinated, progressively releasing the cellulase activity into the extracellular medium. The cellulase release was a selective process and resulted in recovery of the cellulase activity at a specific activity of 2,000 U/mg of protein; beta-glucosidase in the spores remained completely associated with the emerging amoebae. Release of the cellulase required heat activation of the spores and occurred during the swelling stage of germination; inhibition of the emergence stage with cycloheximide had no effect on the release of the cellulase. The cellulase activity released consisted of two enzymes whose molecular weights were 136,000 and 69,000. Studies of their pH optima, heat lability, and of their sensitivity to inhibition revealed no distinctive differences between these two proteins. Analysis on diethylaminoethyl-Sephadex columns showed that the higher-molecular-weight protein could be converted into the lower-molecular-weight component in vitro. PMID:33962

  6. Hydride heat pump with heat regenerator

    NASA Technical Reports Server (NTRS)

    Jones, Jack A. (Inventor)

    1991-01-01

    A regenerative hydride heat pump process and system is provided which can regenerate a high percentage of the sensible heat of the system. A series of at least four canisters containing a lower temperature performing hydride and a series of at least four canisters containing a higher temperature performing hydride is provided. Each canister contains a heat conductive passageway through which a heat transfer fluid is circulated so that sensible 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.

  7. Heating systems for heating subsurface formations

    DOEpatents

    Nguyen, Scott Vinh; Vinegar, Harold J.

    2011-04-26

    Methods and systems for heating a subsurface formation are described herein. A heating system for a subsurface formation includes a sealed conduit positioned in an opening in the formation and a heat source. The sealed conduit includes a heat transfer fluid. The heat source provides heat to a portion of the sealed conduit to change phase of the heat transfer fluid from a liquid to a vapor. The vapor in the sealed conduit rises in the sealed conduit, condenses to transfer heat to the formation and returns to the conduit portion as a liquid.

  8. Heat exchanger

    DOEpatents

    Brackenbury, Phillip J.

    1986-04-01

    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.

  9. Pyrotechnic-actuated cable release

    NASA Technical Reports Server (NTRS)

    Hanson, R. W.

    1968-01-01

    Remote, unattended means has been designed and reduced to practice that retains and then releases an attached load by means of a restrained cable. The cable is released by an electrical impulse on signal.

  10. Riola release report

    SciTech Connect

    Woodward, E.C.

    1983-08-04

    Eleven hours after execution of the Riola Event (at 0826 PDT on 25 September 1980) in hole U2eq of the Nevada Test Site (NTS), a release of radioactivity began. When the seepage stopped at about noon the following day, up to some 3200 Ci of activity had been dispersed by light variable winds. On 26 September, examination of the geophone records showed six hours of low-level, but fairly continuous, activity before the release. Electrical measurements indicated that most cables were still intact to a depth below the stemming platform. A survey of the ground zero area showed that the seepage came through cracks between the surface conductor and the pad, through cracks in the pad, and through a crack adjacent to the pad around the mousehole (a small hole adjacent to the emplacement hole). To preclude undue radiation exposure or injury from a surprise subsidence, safety measures were instituted. Tritium seepage was suffucient to postpone site activities until a box and pipeline were emplaced to contain and remove the gas. Radiation release modeling and calculations were generally consistent with observations. Plug-hole interaction calculations showed that the alluvium near the bottom of the plug may have been overstressed and that improvements in the design of the plug-medium interface can be made. Experimental studies verified that the surface appearance of the plug core was caused by erosion, but, assuming a normal strength for the plug material, that erosion alone could not account for the disappearance of such a large portion of the stemming platform. Samples from downhole plug experiments show that the plug may have been considerably weaker than had been indicted by quality assurance (QA) samples. 19 references, 32 figures, 10 tables.

  11. Gas releases from salt

    SciTech Connect

    Ehgartner, B.; Neal, J.; Hinkebein, T.

    1998-06-01

    The occurrence of gas in salt mines and caverns has presented some serious problems to facility operators. Salt mines have long experienced sudden, usually unexpected expulsions of gas and salt from a production face, commonly known as outbursts. Outbursts can release over one million cubic feet of methane and fractured salt, and are responsible for the lives of numerous miners and explosions. Equipment, production time, and even entire mines have been lost due to outbursts. An outburst creates a cornucopian shaped hole that can reach heights of several hundred feet. The potential occurrence of outbursts must be factored into mine design and mining methods. In caverns, the occurrence of outbursts and steady infiltration of gas into stored product can effect the quality of the product, particularly over the long-term, and in some cases renders the product unusable as is or difficult to transport. Gas has also been known to collect in the roof traps of caverns resulting in safety and operational concerns. The intent of this paper is to summarize the existing knowledge on gas releases from salt. The compiled information can provide a better understanding of the phenomena and gain insight into the causative mechanisms that, once established, can help mitigate the variety of problems associated with gas releases from salt. Outbursts, as documented in mines, are discussed first. This is followed by a discussion of the relatively slow gas infiltration into stored crude oil, as observed and modeled in the caverns of the US Strategic Petroleum Reserve. A model that predicts outburst pressure kicks in caverns is also discussed.

  12. Evaluation of microbial release probabilities

    NASA Technical Reports Server (NTRS)

    1972-01-01

    Work undertaken to improve the estimation of the probability of release of microorganisms from unmanned Martian landing spacecraft is summarized. An analytical model is described for the development of numerical values for release parameters and release mechanisms applicable to flight missions are defined. Laboratory test data are used to evolve parameter values for use by flight projects in estimating numerical values for release probabilities. The analysis treats microbial burden located on spacecraft surfaces, between mated surfaces, and encapsulated within materials.

  13. ORNL fission product release tests VI-6

    SciTech Connect

    Osborne, M.F.; Lorenz, R.A.; Collins, J.L.; Lee, C.S.

    1991-01-01

    The ORNL fission product release tests investigate release and transport of the major fission products from high-burnup fuel under LWR accident conditions. The two most recent tests (VI-4 and VI-5) were conducted in hydrogen. In three previous tests in this series (VI-1, VI-2, and VI-3), which had been conducted in steam, the oxidized Zircaloy cladding remained largely intact and acted as a barrier to steam reaction with the UO{sub 2}. Test VI-6 was designed to insure significant oxidation of the UO{sub 2} fuel, which has been shown to enhance release of certain fission products, especially molybdenum and ruthenium. The BR3 fuel specimen used in test VI-6 will be heated in hydrogen to 2300 K; the Zircaloy cladding is expected to melt and runoff at {approximately}2150 K. Upon reaching the 2300 K test temperature, the test atmosphere will be changed to steam, and that temperature will be maintained for 60 min, with the three collection trains being operated for 2-, 18-, and 40-min periods. The releases of {sup 85}Kr and {sup 137}Cs will be monitored continuously throughout the test. Posttest analyses of the material collected on the three trains will provide results on the release and transport of Mo, Ru, Sb, Te, Ba, Ce, and Eu as a function of time at 2300 K. Continuous monitoring of the hydrogen produced during the steam atmosphere period at high temperature will provide a measure of the oxidation rate of the cladding and fuel. Following delays in approval of the safety documentation and in decontamination of the hot cell and test apparatus, test VI-6 will be conducted in late May.

  14. Strategies to Mitigate Ammonia Release on the International Space Station

    NASA Technical Reports Server (NTRS)

    Macatangay, Ariel V.; Prokhorov, Kimberlee S.; Sweterlitsch, Jeffrey J.

    2007-01-01

    International Space Station (ISS) is crucial to its continuous operation. Off-nominal situations can arise from virtually any aspect of ISS operations. One situation of particular concern is the inadvertent release of a chemical into the ISS atmosphere. In sufficient quantities, a chemical release can render the ISS uninhabitable regardless of the chemical s toxicity as a result of its effect on the hardware used to maintain the environment. This is certainly true with system chemicals which are integral components to the function and purpose of the system. Safeguards, such as design for minimum risk, multiple containment, hazard assessments, rigorous safety reviews, and others, are in place to minimize the probability of a chemical release to the ISS environment thereby allowing the benefits of system chemicals to outweigh the risks associated with them. The thermal control system is an example of such a system. Heat generated within the ISS is transferred from the internal thermal control system (ITCS) to the external thermal control system (ETCS) via two, single-barrier interface heat exchangers (IFHX). The ITCS and ETCS are closed-loop systems which utilize water and anhydrous ammonia, respectively, as heat-transfer fluids. There is approximately 1200 lbs. (208 gallons) of anhydrous ammonia in the ETCS circulating through the two heat exchangers, transferring heat from the ITCS water lines. At the amounts present in the ETCS, anhydrous ammonia is one system chemical that can easily overwhelm the station atmosphere scrubbing capabilities and render the ISS uninhabitable in the event of a catastrophic rupture. Although safeguards have certainly minimized the risk of an ammonia release into the Station atmosphere, credible release scenarios and controls to manage these scenarios are examined.

  15. Heat pipe methanator

    DOEpatents

    Ranken, William A.; Kemme, Joseph E.

    1976-07-27

    A heat pipe methanator for converting coal gas to methane. Gravity return heat pipes are employed to remove the heat of reaction from the methanation promoting catalyst, transmitting a portion of this heat to an incoming gas pre-heat section and delivering the remainder to a steam generating heat exchanger.

  16. Source of released carbon fibers

    NASA Technical Reports Server (NTRS)

    Bell, V. L.

    1979-01-01

    The potential for the release of carbon fibers from aircraft crashes/fires is addressed. Simulation of the conditions of aircraft crash fires in order to predict the quantities and forms of fibrous materials which might be released from civilian aircraft crashes/fires is considered. Figures are presented which describe some typical fiber release test activities together with some very preliminary results of those activities. The state of the art of carbon fiber release is summarized as well as some of the uncertainties concerning accidental fiber release.

  17. Flashing Slurry Releases

    SciTech Connect

    Schmitt, Bruce E.; Young, Jonathan

    2007-03-14

    The Hanford K Basin Closure Project involves the retrieval, transfer and processing of radioactive contaminated slurries containing partially corroded spent nuclear fuel from the K Basin spent fuel pools. The spent fuel is primarily metallic fuel from the operation of the Hanford reactors. The Sludge Treatment Project is being designed to treat and package this material in preparation for ultimate disposal. The processing of the contaminated slurries includes further corrosion of the remaining uncorroded uranium metal in a large heated vessel to form a more stable metal oxide for packaging and storage.

  18. Latent Heat in Soil Heat Flux Measurements

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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, the...

  19. Dual source heat pump

    DOEpatents

    Ecker, Amir L.; Pietsch, Joseph A.

    1982-01-01

    What is disclosed is a heat pump apparatus for conditioning a fluid characterized by a fluid handler and path for circulating the fluid in heat exchange relationship with a refrigerant fluid; at least two refrigerant heat exchangers, one for effecting heat exchange with the fluid and a second for effecting heat exchange between refrigerant and a heat exchange fluid and the ambient air; a compressor for efficiently compressing the refrigerant; at least one throttling valve for throttling liquid refrigerant; a refrigerant circuit; refrigerant; a source of heat exchange fluid; heat exchange fluid circulating device and heat exchange fluid circuit for circulating the heat exchange fluid in heat exchange relationship with the refrigerant; and valves or switches for selecting the heat exchangers and direction of flow of the refrigerant therethrough for selecting a particular mode of operation. The heat exchange fluid provides energy for defrosting the second heat exchanger when operating in the air source mode and also provides a alternate source of heat.

  20. Segmented heat exchanger

    DOEpatents

    Baldwin, Darryl Dean; Willi, Martin Leo; Fiveland, Scott Byron; Timmons, Kristine Ann

    2010-12-14

    A segmented heat exchanger system for transferring heat energy from an exhaust fluid to a working fluid. The heat exchanger system may include a first heat exchanger for receiving incoming working fluid and the exhaust fluid. The working fluid and exhaust fluid may travel through at least a portion of the first heat exchanger in a parallel flow configuration. In addition, the heat exchanger system may include a second heat exchanger for receiving working fluid from the first heat exchanger and exhaust fluid from a third heat exchanger. The working fluid and exhaust fluid may travel through at least a portion of the second heat exchanger in a counter flow configuration. Furthermore, the heat exchanger system may include a third heat exchanger for receiving working fluid from the second heat exchanger and exhaust fluid from the first heat exchanger. The working fluid and exhaust fluid may travel through at least a portion of the third heat exchanger in a parallel flow configuration.

  1. 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.

  2. Temperature-Controlled Clamping and Releasing Mechanism

    NASA Technical Reports Server (NTRS)

    Rosing, David; Ford, Virginia

    2005-01-01

    A report describes the development of a mechanism that automatically clamps upon warming and releases upon cooling between temperature limits of approx. =180 K and approx. =293 K. The mechanism satisfied a need specific to a program that involved repeated excursions of a spectrometer between a room-temperature atmospheric environment and a cryogenic vacuum testing environment. The mechanism was also to be utilized in the intended application of the spectrometer, in which the spectrometer would be clamped for protection during launch of a spacecraft and released in the cold of outer space to allow it to assume its nominal configuration for scientific observations. The mechanism is passive in the sense that its operation does not depend on a control system and does not require any power other than that incidental to heating and cooling. The clamping and releasing action is effected by bolt-preloaded stacks of shape-memory-alloy (SMA) cylinders. In designing this mechanism, as in designing other, similar SMA mechanisms, it was necessary to account for the complex interplay among thermal expansion, elastic and inelastic deformation under load, and SMA thermomechanical properties.

  3. Strain Release Amination

    PubMed Central

    Gianatassio, Ryan; Lopchuk, Justin M.; Wang, Jie; Pan, Chung-Mao; Malins, Lara R.; Prieto, Liher; Brandt, Thomas A.; Collins, Michael R.; Gallego, Gary M.; Sach, Neal W.; Spangler, Jillian E.; Zhu, Huichin; Zhu, Jinjiang; Baran, Phil S.

    2015-01-01

    To optimize drug candidates, modern medicinal chemists are increasingly turning to an unconventional structural motif: small, strained ring systems. However, the difficulty of introducing substituents such as bicyclo[1.1.1]pentanes, azetidines, or cyclobutanes often outweighs the challenge of synthesizing the parent scaffold itself. Thus, there is an urgent need for general methods to rapidly and directly append such groups onto core scaffolds. Here we report a general strategy to harness the embedded potential energy of effectively spring-loaded C–C and C–N bonds with the most oft-encountered nucleophiles in pharmaceutical chemistry, amines. Strain release amination can diversify a range of substrates with a multitude of desirable bioisosteres at both the early and late-stages of a synthesis. The technique has also been applied to peptide labeling and bioconjugation. PMID:26816372

  4. QUICK RELEASABLE DRIVE

    DOEpatents

    Dickson, J.J.

    1958-07-01

    A quick releasable mechanical drive system suitable for use in a nuclear reactor is described. A small reversible motor positions a control rod by means of a worm and gear speed reducer, a magnetic torque clutch, and a bell crank. As the control rod is raised to the operating position, a heavy coil spring is compressed. In the event of an emergency indicated by either a''scram'' signal or a power failure, the current to the magnetic clutch is cut off, thereby freeing the coil spring and the bell crank positioner from the motor and speed reduction gearing. The coil spring will immediately act upon the bell crank to cause the insertion of the control rod. This arrangement will allow the slow, accurate positioning of the control rod during reactor operation, while providing an independent force to rapidly insert the rod in the event of an emergency.

  5. Quick release engine cylinder

    DOEpatents

    Sunnarborg, Duane A.

    2000-01-01

    A quick release engine cylinder allows optical access to an essentially unaltered combustion chamber, is suitable for use with actual combustion processes, and is amenable to rapid and repeated disassembly and cleaning. A cylinder member, adapted to constrain a piston to a defined path through the cylinder member, sealingly engages a cylinder head to provide a production-like combustion chamber. A support member mounts with the cylinder member. The support-to-cylinder mounting allows two relationships therebetween. In the first mounting relationship, the support engages the cylinder member and restrains the cylinder against the head. In the second mounting relationship, the cylinder member can pass through the support member, moving away from the head and providing access to the piston-top and head.

  6. Thiophenic Sulfur Compounds Released During Coal Pyrolysis

    PubMed Central

    Xing, Mengwen; Kong, Jiao; Dong, Jie; Jiao, Haili; Li, Fan

    2013-01-01

    Abstract Thiophenic sulfur compounds are released during coal gasification, carbonization, and combustion. Previous studies indicate that thiophenic sulfur compounds degrade very slowly in the environment, and are more carcinogenic than polycyclic aromatic hydrocarbons and nitrogenous compounds. Therefore, it is very important to study the principle of thiophenic sulfur compounds during coal conversion, in order to control their emission and promote clean coal utilization. To realize this goal and understand the formation mechanism of thiophenic sulfur compounds, this study focused on the release behavior of thiophenic sulfur compounds during coal pyrolysis, which is an important phase for all coal thermal conversion processes. The pyrolyzer (CDS-5250) and gas chromatography–mass spectrometry (Focus GC-DSQII) were used to analyze thiophenic sulfur compounds in situ. Several coals with different coal ranks and sulfur contents were chosen as experimental samples, and thiophenic sulfur compounds of the gas produced during pyrolysis under different temperatures and heating rates were investigated. Levels of benzothiophene and dibenzothiophene were obtained during pyrolysis at temperatures ranging from 200°C to 1300°C, and heating rates ranging from 6°C/ms to 14°C/ms and 6°C/s to 14°C/s. Moreover, the relationship between the total amount of benzothiophene and dibenzothiophene released during coal pyrolysis and the organic sulfur content in coal was also discussed. This study is beneficial for understanding the formation and control of thiophenic sulfur compounds, since it provides a series of significant results that show the impact that operation conditions and organic sulfur content in coal have on the amount and species of thiophenic sulfur compounds produced during coal pyrolysis. PMID:23781126

  7. Thiophenic Sulfur Compounds Released During Coal Pyrolysis.

    PubMed

    Xing, Mengwen; Kong, Jiao; Dong, Jie; Jiao, Haili; Li, Fan

    2013-06-01

    Thiophenic sulfur compounds are released during coal gasification, carbonization, and combustion. Previous studies indicate that thiophenic sulfur compounds degrade very slowly in the environment, and are more carcinogenic than polycyclic aromatic hydrocarbons and nitrogenous compounds. Therefore, it is very important to study the principle of thiophenic sulfur compounds during coal conversion, in order to control their emission and promote clean coal utilization. To realize this goal and understand the formation mechanism of thiophenic sulfur compounds, this study focused on the release behavior of thiophenic sulfur compounds during coal pyrolysis, which is an important phase for all coal thermal conversion processes. The pyrolyzer (CDS-5250) and gas chromatography-mass spectrometry (Focus GC-DSQII) were used to analyze thiophenic sulfur compounds in situ. Several coals with different coal ranks and sulfur contents were chosen as experimental samples, and thiophenic sulfur compounds of the gas produced during pyrolysis under different temperatures and heating rates were investigated. Levels of benzothiophene and dibenzothiophene were obtained during pyrolysis at temperatures ranging from 200°C to 1300°C, and heating rates ranging from 6°C/ms to 14°C/ms and 6°C/s to 14°C/s. Moreover, the relationship between the total amount of benzothiophene and dibenzothiophene released during coal pyrolysis and the organic sulfur content in coal was also discussed. This study is beneficial for understanding the formation and control of thiophenic sulfur compounds, since it provides a series of significant results that show the impact that operation conditions and organic sulfur content in coal have on the amount and species of thiophenic sulfur compounds produced during coal pyrolysis. PMID:23781126

  8. Shape memory polymer (SMP) gripper with a release sensing system

    DOEpatents

    Maitland, Duncan J.; Lee, Abraham P.; Schumann, Daniel L.; Silva, Luiz Da

    2000-01-01

    A system for releasing a target material, such as an embolic coil from an SMP located at the end of a catheter utilizing an optical arrangement for releasing the material. The system includes a laser, laser driver, display panel, photodetector, fiber optics coupler, fiber optics and connectors, a catheter, and an SMP-based gripper, and includes a release sensing and feedback arrangement. The SMP-based gripper is heated via laser light through an optic fiber causing the gripper to release a target material (e.g., embolic coil for therapeutic treatment of aneurysms). Various embodiments are provided for coupling the laser light into the SMP, which includes specific positioning of the coils, removal of the fiber cladding adjacent the coil, a metal coating on the SMP, doping the SMP with a gradient absorbing dye, tapering the fiber optic end, coating the SMP with low refractive index material, and locating an insert between the fiber optic and the coil.

  9. Remotely Triggered Cisplatin Release from Carbon Nanocapsules by Radiofrequency Fields

    PubMed Central

    Raoof, Mustafa; Cisneros, Brandon T.; Guven, Adem; Corr, Stuart J.; Wilson, Lon J.; Curley, Steven A.

    2013-01-01

    The efficacy of nanoparticle-mediated drug delivery is limited by its peri-vascular sequestration, thus necessitating a strategy to trigger drug release from such intra-tumoral nanocarrier-drug depots. In our efforts to explore remotely-activated nanocarriers, we have developed carbon nanocapsules comprised of an ultrashort carbon nanotube shell (US-tubes) loaded with cisplatin (CDDP@US-tubes) and covered with a Pluronic surfactant wrapping to minimize passive release. We demonstrate here that non-invasive radiofrequency (RF) field activation of the CDDP@US-tubes produces heat that causes Pluronic disruption which triggers cisplatin release in an RF-dependent manner. Furthermore, release-dependent cytotoxicity is demonstrated in human hepatocellular carcinoma cell lines. PMID:23228421

  10. Nanoflare Heating of Solar and Stellar Coronae

    NASA Technical Reports Server (NTRS)

    Klimchuk, James A.

    2010-01-01

    A combination of observational and theoretical evidence suggests that much, and perhaps most, of the Sun's corona is heated by small unresolved bursts of energy called nanoflares. It seems likely that stellar coronae are heated in a similar fashion. Kanoflares are here taken to mean any impulsive heating that occurs within a magnetic flux strand. Many mechanisms have this property, including waves, but we prefer Parker's picture of tangled magnetic fields. The tangling is caused by turbulent convection at the stellar surface, and magnetic energy is released when the stresses reach a critical level. We suggest that the mechanism of energy release is the "secondary instability" of electric current sheets that are present at the boundaries between misaligned strands. I will discuss the collective evidence for solar and stellar nanoflares and hopefully present new results from the Solar Dynamics Observatory that was just launched.

  11. 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.

  12. 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.

  13. High heat flux single phase heat exchanger

    NASA Technical Reports Server (NTRS)

    Valenzuela, Javier A.; Izenson, Michael G.

    1990-01-01

    This paper presents the results obtained to date in a program to develop a high heat flux, single-phase heat exchanger for spacecraft thermal management. The intended application is a net generation interface heat exchanger to couple the crew module water thermal bus to the two-phase ammonia main thermal bus in the Space Station Freedom. The large size of the interface heat exchanger is dictated by the relatively poor water-side heat transfer characteristics. The objective of this program is to develop a single-phase heat transfer approach which can achieve heat fluxes and heat transfer coefficients comparable to those of the evaporation ammonia side. A new heat exchanger concept has been developed to meet these objecties. The main feature of this heat exchanger is that it can achieve very high heat fluxes with a pressure drop one to two orders of magnitude lower than those of previous microchannel or jet impingement high heat flux heat exchangers. This paper describes proof-of-concept experiments performed in air and water and presents analytical model of the heat exchanger.

  14. Solar heating

    SciTech Connect

    Resnick, M.; Startevant, R.C.

    1985-01-22

    A solar heater has an outlet conduit above an inlet conduit intercoupling a solar heating chamber with the inside of a building through a window opening. In one form the solar collecting chamber is outside the building below the window and the outlet conduit and inlet conduit are contiguous and pass through the window opening between the windowsill and the lower sash. In another form of the invention the solar collecting chambers are located beside each side of the window and joined at the top by the outlet conduit that passes through an opening between the upper window sash and the top of the window frame and at the bottom by an inlet conduit that passes through an opening between the lower sash and the windowsill. The outlet conduit carries photoelectric cells that provide electrical energy for driving a squirrel-cage fan in the outlet conduit through a mercury switch seated on a damper actuated by a bimetallic coil that closes the damper when the temperature in the outlet conduit goes below a predetermined temperature.

  15. Optogenetic control of ATP release

    NASA Astrophysics Data System (ADS)

    Lewis, Matthew A.; Joshi, Bipin; Gu, Ling; Feranchak, Andrew; Mohanty, Samarendra K.

    2013-03-01

    Controlled release of ATP can be used for understanding extracellular purinergic signaling. While coarse mechanical forces and hypotonic stimulation have been utilized in the past to initiate ATP release from cells, these methods are neither spatially accurate nor temporally precise. Further, these methods cannot be utilized in a highly effective cell-specific manner. To mitigate the uncertainties regarding cellular-specificity and spatio-temporal release of ATP, we herein demonstrate use of optogenetics for ATP release. ATP release in response to optogenetic stimulation was monitored by Luciferin-Luciferase assay (North American firefly, photinus pyralis) using luminometer as well as mesoscopic bioluminescence imaging. Our result demonstrates repetitive release of ATP subsequent to optogenetic stimulation. It is thus feasible that purinergic signaling can be directly detected via imaging if the stimulus can be confined to single cell or in a spatially-defined group of cells. This study opens up new avenue to interrogate the mechanisms of purinergic signaling.

  16. Fluoride release from fissure sealants.

    PubMed

    Garcia-Godoy, F; Abarzua, I; De Goes, M F; Chan, D C

    1997-01-01

    This 30-day study, compared the amounts and patterns of fluoride release from 5 commercially available fluoride-containing pit and fissure sealants: FluroShield, Helioseal-F, Ultraseal XT, Baritone L3, and Teethmate-F; Delton without fluoride, was used as control. Disc-shaped samples of each sealant were immersed in distilled water and the fluoride release was measured periodically until day 30. All the fluoridated sealants tested released measurable fluoride throughout the test period in a similar pattern: the greatest amount of fluoride was released in the first 24 hours after mixing, fell sharply on the second day and decreased slowly for the last days. On day one, Baritone L3 released significantly more fluoride than all other materials. Teethmate-F released the highest amount of fluoride during all the other time intervals from day 2, until day 30. PMID:9643204

  17. COMMERCIAL SNF ACCIDENT RELEASE FRACTIONS

    SciTech Connect

    S.O. Bader

    1999-10-18

    The purpose of this design analysis is to specify and document the total and respirable fractions for radioactive materials that are released from an accident event at the Monitored Geologic Repository (MGR) involving commercial spent nuclear fuel (CSNF) in a dry environment. The total and respirable release fractions will be used to support the preclosure licensing basis for the MGR. The total release fraction is defined as the fraction of total CSNF assembly inventory, typically expressed as an activity inventory (e.g., curies), of a given radionuclide that is released to the environment from a waste form. The radionuclides are released from the inside of breached fuel rods (or pins) and from the detachment of radioactive material (crud) from the outside surfaces of fuel rods and other components of fuel assemblies. The total release fraction accounts for several mechanisms that tend to retain, retard, or diminish the amount of radionuclides that are available for transport to dose receptors or otherwise can be shown to reduce exposure of receptors to radiological releases. The total release fraction includes a fraction of airborne material that is respirable and could result in inhalation doses. This subset of the total release fraction is referred to as the respirable release fraction. Potential accidents may involve waste forms that are characterized as either bare (unconfined) fuel assemblies or confined fuel assemblies. The confined CSNF assemblies at the MGR are contained in shipping casks, canisters, or disposal containers (waste packages). In contrast to the bare fuel assemblies, the container that confines the fuel assemblies has the potential of providing an additional barrier for diminishing the total release fraction should the fuel rod cladding breach during an accident. However, this analysis will not take credit for this additional bamer and will establish only the total release fractions for bare unconfined CSNF assemblies, which may however be

  18. Multiple source heat pump

    DOEpatents

    Ecker, Amir L.

    1983-01-01

    A heat pump apparatus for conditioning a fluid characterized by a fluid handler and path for circulating a fluid in heat exchange relationship with a refrigerant fluid, at least three refrigerant heat exchangers, one for effecting heat exchange with the fluid, a second for effecting heat exchange with a heat exchange fluid, and a third for effecting heat exchange with ambient air; a compressor for compressing the refrigerant; at least one throttling valve connected at the inlet side of a heat exchanger in which liquid refrigerant is vaporized; a refrigerant circuit; refrigerant; a source of heat exchange fluid; heat exchange fluid circuit and pump for circulating the heat exchange fluid in heat exchange relationship with the refrigerant; and valves or switches for selecting the heat exchangers and directional flow of refrigerant therethrough for selecting a particular mode of operation. Also disclosed are a variety of embodiments, modes of operation, and schematics therefor.

  19. Sustained-Release Corticosteroid Options

    PubMed Central

    Cabrera, Mariana; Yeh, Steven; Albini, Thomas A.

    2014-01-01

    Sustained-release corticosteroid treatment has shown to be a promising strategy for macular edema due to retinovascular disease (i.e., diabetes and retinal vein occlusion) and for the treatment of noninfectious posterior uveitis. Clinicians now have the option of three sustained-release corticosteroid implants: Ozurdex (Allergan Inc., Irvine, CA) which releases dexamethasone and two devices that release fluocinolone acetonide, Retisert (Bausch & Lomb, Rochester, NY), and Iluvien (Alimera Science, Alpharetta, GA). Each has different physical characteristics and duration effect and has been approved for different indications. Herein we provide a summary of the current clinical knowledge regarding these implants. PMID:25140246

  20. 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.

  1. Heated tool for autoclaves

    NASA Technical Reports Server (NTRS)

    Serafini, T. T.; Vanucci, R. D.; Cavano, P. J.; Winters, W. E.

    1980-01-01

    Components made of composite materials are heated in autoclaves by employing electrical resistance heating blankets, thus avoiding need to heat entire autoclave volume. Method provides not only significant energy savings compared to heating entire pressure vessel but offers time savings in accelerated heat-up and cool-down cycles.

  2. Heat Rash or Prickly Heat (Miliaria Rubra)

    MedlinePlus

    ... heat rash consist of controlling heat and humidity. Acetaminophen or ibuprofen can help to reduce fever. Remove ... without any sweat. Your child may complain of dizziness, nausea, weakness, headache, confusion, or difficulty breathing. This ...

  3. Heat Wave Safety Checklist

    MedlinePlus

    ... heat has caused more deaths than all other weather events, including floods. A heat wave is a ... care for heat- related emergencies … ❏ Listen to local weather forecasts and stay aware of upcoming temperature changes. ❏ ...

  4. Heat Exhaustion, First Aid

    MedlinePlus

    ... rashes clinical tools newsletter | contact Share | Heat Exhaustion, First Aid A A A Heat exhaustion signs and symptoms ... specific to the other stages of heat illness. First Aid Guide Use a combination of the following measures ...

  5. Heat Cramps, First Aid

    MedlinePlus

    ... rashes clinical tools newsletter | contact Share | Heat Cramps, First Aid A A A Heat cramp signs and symptoms ... if later stages of heat illness are suspected. First Aid Guide Use a combination of the following measures, ...

  6. Absorption heat pump system

    DOEpatents

    Grossman, Gershon

    1984-01-01

    The efficiency of an absorption heat pump system is improved by conducting liquid from a second stage evaporator thereof to an auxiliary heat exchanger positioned downstream of a primary heat exchanger in the desorber of the system.

  7. 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 ...

  8. Absorption heat pump system

    DOEpatents

    Grossman, G.

    1982-06-16

    The efficiency of an absorption heat pump system is improved by conducting liquid from a second stage evaporator thereof to an auxiliary heat exchanger positioned downstream of a primary heat exchanger in the desorber of the system.

  9. Controlled Release Applications of Organometals.

    ERIC Educational Resources Information Center

    Thayer, John S.

    1981-01-01

    Reviews two classes of controlled release organometals: (1) distributional, to distribute bioactive materials to control a certain target organism; and (2) protective, to protect surface or interior of some structure from attach by organisms. Specific examples are given including a discussion of controlled release for schistosomiasis. (SK)

  10. Woven heat exchanger

    DOEpatents

    Piscitella, R.R.

    1984-07-16

    This invention relates to a heat exchanger for waste heat recovery from high temperature industrial exhaust streams. In a woven ceramic heat exchanger using the basic tube-in-shell design, each heat exchanger consisting of tube sheets and tube, is woven separately. Individual heat exchangers are assembled in cross-flow configuration. Each heat exchanger is woven from high temperature ceramic fiber, the warp is continuous from tube to tube sheet providing a smooth transition and unitized construction.

  11. Sucrose release from polysaccharide gels.

    PubMed

    Nishinari, Katsuyoshi; Fang, Yapeng

    2016-05-18

    Sucrose release from polysaccharide gels has been studied extensively because it is expected to be useful in understanding flavour release from solid foods and to find a new processing method which produces more palatable and healthier foods. We provide an overview of the release of sucrose and other sugars from gels of agar and related polysaccharides. The addition of sucrose to agar solutions leads to the increase in transparency of the resulting gels and the decrease in syneresis, which is attributed to the decrease in mesh size in gels. The syneresis occurring in the quiescent condition and fluid release induced by compression is discussed. The relationship between the sugar release and the structural, rheological and thermal properties of gels is also discussed. Finally, the future research direction is proposed. PMID:26952168

  12. Toxic releases from power plants

    SciTech Connect

    Rubin, E.S.

    1999-09-15

    Beginning in 1998, electric power plants burning coal or oil must estimate and report their annual releases of toxic chemicals listed in the Toxics Release Inventory (TRI) published by the US Environmental Protection Agency (EPA). This paper identifies the toxic chemicals of greatest significance for the electric utility sector and develops quantitative estimates of the toxic releases reportable to the TRI for a representative coal-fired power plant. Key factors affecting the magnitude and types of toxic releases for individual power plants also are discussed. A national projection suggests that the magnitude of electric utility industry releases will surpass those of the manufacturing industries which current report to the TRI. Risk communication activities at the community level will be essential to interpret and provide context for the new TRI results.

  13. Kepler Data Release 4 Notes

    NASA Technical Reports Server (NTRS)

    Van Cleve, Jeffrey (Editor); Jenkins, Jon; Caldwell, Doug; Allen, Christopher L.; Batalha, Natalie; Bryson, Stephen T.; Chandrasekaran, Hema; Clarke, Bruce D.; Cote, Miles T.; Dotson, Jessie L.; Gilliland, Ron; Girouard, Forrest; Haas, Michael R.; Hall, Jennifer; Ibrahim, Khadeejah; Klaus, Todd; Kolodziejczak, Jeff; Li, Jie; McCauliff, Sean D.; Middour, Christopher K.; Pletcher, David L.; Quintana, Elisa V.; Tenenbaum, Peter G.; Twicken, Joe; Uddin, Akm Kamal

    2010-01-01

    The Data Analysis Working Group have released long and short cadence materials, including FFIs and Dropped Targets for the Public. The Kepler Science Office considers Data Release 4 to provide "browse quality" data. These notes have been prepared to give Kepler users of the Multimission Archive at STScl (MAST) a summary of how the data were collected and prepared, and how well the data processing pipeline is functioning on flight data. They will be updated for each release of data to the public archive and placed on MAST along with other Kepler documentation, at http://archive.stsci.edu/kepler/documents.html. Data release 3 is meant to give users the opportunity to examine the data for possibly interesting science and to involve the users in improving the pipeline for future data releases. To perform the latter service, users are encouraged to notice and document artifacts, either in the raw or processed data, and report them to the Science Office.

  14. Enhancement of heat transfer in waste-heat heat exchangers

    NASA Astrophysics Data System (ADS)

    Stoeffler, R. C.

    1980-07-01

    The Fluidfire shallow fluidized bed heat transfer facility was modified to give increased air flow capacity and to allow testing with different distributor plates and with two stage heat exchangers. The effect of reduced distributor plate pressure loss and amount and type of bed material on the heat transfer performance of a single stage fluidized bed heat exchanger is explored. Elutriation from the bed was measured for different bed materials and distributor plates; alternate heat exchanger surfaces having different fin spacings were also tested. Two types of two stage fluidized bed heat exchangers were tested: one having a baffle (having almost no pressure loss) located between the stages and which allowed bed material to recirculate between upper and lower beds; the second having two distributor plates in series with no recirculation of the bed material.

  15. 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.

  16. Nitrogen release during coal combustion

    SciTech Connect

    Baxter, L.L.; Mitchell, R.E.; Fletcher, T.H.; Hurt, R.H.

    1995-02-01

    Experiments in entrained flow reactors at combustion temperatures are performed to resolve the rank dependence of nitrogen release on an elemental basis for a suite of 15 U.S. coals ranging from lignite to low-volatile bituminous. Data were obtained as a function of particle conversion, with overall mass loss up to 99% on a dry, ash-free basis. Nitrogen release rates are presented relative to both carbon loss and overall mass loss. During devolatilization, fractional nitrogen release from low-rank coals is much slower than fractional mass release and noticeably slower than fractional carbon release. As coal rank increases, fractional nitrogen release rate relative to that of carbon and mass increases, with fractional nitrogen release rates exceeding fractional mass and fractional carbon release rates during devolatilization for high-rank (low-volatile bituminous) coals. At the onset of combustion, nitrogen release rates increase significantly. For all coals investigated, cumulative fractional nitrogen loss rates relative to those of mass and carbon passes through a maximum during the earliest stages of oxidation. The mechanism for generating this maximum is postulated to involve nascent thermal rupture of nitrogen-containing compounds and possible preferential oxidation of nitrogen sites. During later stages of oxidation, the cumulative fractional loss of nitrogen approaches that of carbon for all coals. Changes in the relative release rates of nitrogen compared to those of both overall mass and carbon during all stages of combustion are attributed to a combination of the chemical structure of coals, temperature histories during combustion, and char chemistry.

  17. A new release device based on styrene-based SMP reinforced by carbon fiber

    NASA Astrophysics Data System (ADS)

    Wei, Hanqing; Guan, Chunyang; Du, Haiyang; Liu, Liwu; Leng, Jinsong

    2013-08-01

    Shape memory polymer composites (SMPC) release device can be fabricated to solve the disadvantages of traditional explosive release device, such as large weight, bad stability, and strong impact force and damage due to explosion. The release device is made up of two thin-walled tubes, the first one is responsible for the torsion, and the second is used to fit the first tube. The tubes are made from carbon fiber reinforced styrene-based shape memory polymer (SMP). Resistor heater is applied to heat the device and actuate the shape recovery process. This SMPC release device can connect the main device and the device which need released. When the instruction comes, it can separate the two devices immediately. Firstly, the first tube is heated by the resistor heater, then the twisting and stretching force is exited on the heating part of the tube, unloading after cooling, the two thin-walled tubes of release device is connected. Secondly, the twisted part of the first tube is heated, it twisted to the original angle, and then the stretched part drew back to the original shape after heating. So the working part pulled the claws of it out of the second tube automatically, and separated the release device to two parts, thus the release is completed. Optimal solutions are designed to achieve high driving efficiency. This paper has evaluated the strength and verified the feasibility of the SMPC release device, measured the tensile strength and the reverse effect, compared with the theoretical and experimental results. Finite element analysis is used to simulate the deformation.

  18. Controlled release of tocopherols from polymer blend films

    NASA Astrophysics Data System (ADS)

    Obinata, Noe

    Controlled release packaging has great potential to increase storage stability of foods by releasing active compounds into foods continuously over time. However, a major limitation in development of this technology is the inability to control the release and provide rates useful for long term storage of foods. Better understanding of the factors affecting active compound release is needed to overcome this limitation. The objective of this research was to investigate the relationship between polymer composition, polymer processing method, polymer morphology, and release properties of active compounds, and to provide proof of principle that compound release is controlled by film morphology. A natural antioxidant, tocopherol was used as a model active compound because it is natural, effective, heat stable, and soluble in most packaging polymers. Polymer blend films were produced from combination of linear low density polyethylene (LLDPE) and high density polyethylene (HDPE), polypropylene (PP), or polystyrene (PS) with 3000 ppm mixed tocopherols using conventional blending method and innovative blending method, smart blending with a novel mixer using chaotic advection. Film morphologies were visualized with scanning electron microscopy (SEM). Release of tocopherols into 95% ethanol as a food simulant was measured by UV/Visible spectrophotometry or HPLC, and diffusivity of tocopherols in the polymers was estimated from this data. Polymer composition (blend proportions) and processing methods have major effects on film morphology. Four different types of morphologies, dispersed, co-continuous, fiber, and multilayer structures were developed by either conventional extrusion or smart blending. With smart blending of fixed polymer compositions, different morphologies were progressively developed with fixed polymer composition as the number of rod rotations increased, providing a way to separate effects of polymer composition and morphology. The different morphologies

  19. Heating apparatus comprising a heat recovery apparatus

    SciTech Connect

    Pibernat, T.

    1983-08-09

    A heating apparatus includes at least one combustion air inlet, a reverse-draft hearth having a grill positioned within a hearth plate, an ash receptacle for recovering combustion wastes, a fume outlet combustion chamber positoned under the reverse-draft hearth, and a heat recovery device. A heat transport and exchange fluid is adapted to be fed through the heat recovery device, and it circulates through the device in order to recover heat generated in the hearth. The heat recovery device also includes at least one casing positioned beneath the hearth, over the ash receptacle, and which is spaced from the walls of the heating apparatus. The rear portion of the casing is connected to the hearth plate so as to block combustion gases so that the combustion gases will pass over and thereafter under the casing prior to leaving the apparatus via the fume outlet.

  20. Thermosensitive liposomes entrapping iron oxide nanoparticles for controllable drug release.

    PubMed

    Tai, Lin-Ai; Tsai, Pi-Ju; Wang, Yu-Chao; Wang, Yu-Jing; Lo, Leu-Wei; Yang, Chung-Shi

    2009-04-01

    Iron oxide nanoparticles can serve as a heating source upon alternative magnetic field (AMF) exposure. Iron oxide nanoparticles can be mixed with thermosensitive nanovehicles for hyperthermia-induced drug release, yet such a design and mechanism may not be suitable for controllable drug release applications in which the tissues are susceptible to environmental temperature change such as brain tissue. In the present study, iron oxide nanoparticles were entrapped inside of thermosensitive liposomes for AMF-induced drug release while the environmental temperature was maintained at a constant level. Carboxyfluorescein was co-entrapped with the iron oxide nanoparticles in the liposomes as a model compound for monitoring drug release and environmental temperature was maintained with a water circulator jacket. These experiments have been successfully performed in solution, in phantom and in anesthetized animals. Furthermore, the thermosensitive liposomes were administered into rat forearm skeletal muscle, and the release of carboxylfluorescein triggered by the external alternative magnetic field was monitored by an implanted microdialysis perfusion probe with an on-line laser-induced fluorescence detector. In the future such a device could be applied to simultaneous magnetic resonance imaging and non-invasive drug release in temperature-sensitive applications. PMID:19420485

  1. Microfabricated therapeutic actuators and release mechanisms therefor

    DOEpatents

    Lee, Abraham P.; Fitch, Joseph P.; Schumann, Daniel L.; Da Silva, Luiz; Benett, William J.; Krulevitch, Peter A.

    2000-01-01

    Microfabricated therapeutic actuators are fabricated using a shape memory polymer (SMP), a polyurethane-based material that undergoes a phase transformation at a specified temperature (Tg). At a temperature above temperature Tg material is soft and can be easily reshaped into another configuration. As the temperature is lowered below temperature Tg the new shape is fixed and locked in as long as the material stays below temperature Tg. Upon reheating the material to a temperature above Tg, the material will return to its original shape. By the use of such SMP material, SMP microtubing can be used as a retaining/release actuator for the delivery of material, such as embolic coils, for example, through catheters into aneurysms, for example. The microtubing can be manufactured in various sizes and the phase change temperature Tg is determinate for an intended temperature target and intended use. The SMP microtubing can be positioned around or within an end of a deposit material. Various heating arrangements can be utilized with the SMP release mechanism, and the SMP microtubing can include a metallic coating for enhanced light absorption.

  2. Toxic chemical release inventory information.

    PubMed

    Bronson, R J

    1991-01-01

    As part of a U.S. government effort to inform the public about toxic or hazardous chemicals released into the environment, the National Library of Medicine (NLM) and the Environmental Protection Agency (EPA) are jointly producing the TRI (Toxic Chemical Release Inventory) databanks which consist of two separate files, TRI87 and TRI88. Both files reside on NLM's TOX-NET system. The files contain geographic information about reporting facilities and land, air, and water release data for approximately 300 listed chemicals. PMID:10111718

  3. Controlled release liquid dosage formulation

    DOEpatents

    Benton, Ben F.; Gardner, David L.

    1989-01-01

    A liquid dual coated dosage formulation sustained release pharmaceutic having substantial shelf life prior to ingestion is disclosed. A dual coating is applied over controlled release cores to form dosage forms and the coatings comprise fats melting at less than approximately 101.degree. F. overcoated with cellulose acetate phthalate or zein. The dual coated dosage forms are dispersed in a sugar based acidic liquid carrier such as high fructose corn syrup and display a shelf life of up to approximately at least 45 days while still retaining their release profiles following ingestion. Cellulose acetate phthalate coated dosage form cores can in addition be dispersed in aqueous liquids of pH <5.

  4. Commercial SNF Accident Release Fractions

    SciTech Connect

    J. Schulz

    2004-11-05

    The purpose of this analysis is to specify and document the total and respirable fractions for radioactive materials that could be potentially released from an accident at the repository involving commercial spent nuclear fuel (SNF) in a dry environment. The total and respirable release fractions are used to support the preclosure licensing basis for the repository. The total release fraction is defined as the fraction of total commercial SNF assembly inventory, typically expressed as an activity inventory (e.g., curies), of a given radionuclide that is released to the environment from a waste form. Radionuclides are released from the inside of breached fuel rods (or pins) and from the detachment of radioactive material (crud) from the outside surfaces of fuel rods and other components of fuel assemblies. The total release fraction accounts for several mechanisms that tend to retain, retard, or diminish the amount of radionuclides that are available for transport to dose receptors or otherwise can be shown to reduce exposure of receptors to radiological releases. The total release fraction includes a fraction of airborne material that is respirable and could result in inhalation doses; this subset of the total release fraction is referred to as the respirable release fraction. Accidents may involve waste forms characterized as: (1) bare unconfined intact fuel assemblies, (2) confined intact fuel assemblies, or (3) canistered failed commercial SNF. Confined intact commercial SNF assemblies at the repository are contained in shipping casks, canisters, or waste packages. Four categories of failed commercial SNF are identified: (1) mechanically and cladding-penetration damaged commercial SNF, (2) consolidated/reconstituted assemblies, (3) fuel rods, pieces, and debris, and (4) nonfuel components. It is assumed that failed commercial SNF is placed into waste packages with a mesh screen at each end (CRWMS M&O 1999). In contrast to bare unconfined fuel assemblies, the

  5. ORNL studies of fission product release under LWR accident conditions

    SciTech Connect

    Osborne, M.F.; Lorenz, R.A.; Collins, J.L.

    1991-01-01

    High burnup Zircaloy-clad UO{sub 2} fuel specimens have been heated to study the release of fission products in tests simulating LWR accident conditions. The dominant variable was found to be temperature, with atmosphere, time, and burnup also being significant variables. Comparison of data from tests in steam and hydrogen, at temperatures of 2000 to 2700 K, have shown that the releases of the most volatile species (Kr, Xe, I, and Cs) are relatively insensitive to atmosphere. The releases of the less-volatile species (Sr, Mo, Ru, Sb, Te, Ba, and Eu), however, may vary by orders of magnitude depending on atmosphere. In addition, the atmosphere may drastically affect the mode and extent of fuel destruction.

  6. Examining the Release Mechanism of Intermittent Streamer Blobs

    NASA Astrophysics Data System (ADS)

    Ozturk, D. S.; van der Holst, B.; Sokolov, I.; Gombosi, T. I.

    2015-12-01

    The white light images from the Large-Angle and Spectrometric Coronagraph (LASCO) C2 and C3 have shown small-scale periodic plasmoid releases from the tip of the Helmet Streamers. The density and velocity of these blobs show similarities with the slow solar wind. There are various scenarios proposed to comprehend the release mechanism for these plasmoids. Most widely accepted explanations include interchange reconnection and significant proton coronal heating at the streamer tip. A three-dimensional global coronal model will be used to examine this intermittent blob release over a several day period. We use the new real time version of Alfven Wave Solar Model (AWSoM-R) to decrease the computational costs. In AWSoM-R, the global magnetohydrodynamic (MHD) equations for the lower corona are solved along one-dimensional magnetic field line threads. The Alfven wave dissipation is partitioned into coronal heating of protons and electrons. We study how this heat partitioning affects plasmoid formation. We investigate the size and periodicity of the streamer blobs for Carrington Rotation 2109 (12 April 2011-09 May 2011) by constructing synthetic white light images from the time-dependent model and comparing our results with observations.

  7. REACH. Heating Units.

    ERIC Educational Resources Information Center

    Stanfield, Carter; And Others

    As a part of the REACH (Refrigeration, Electro-Mechanical, Air-Conditioning, Heating) electromechanical cluster, this student manual contains individualized units in the area of heating. The instructional units focus on electric heating systems, gas heating systems, and oil burning systems. Each unit follows a typical format that includes a unit…

  8. 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.

  9. Rotary magnetic heat pump

    DOEpatents

    Kirol, Lance D.

    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.

  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. Direct fired heat exchanger

    DOEpatents

    Reimann, Robert C.; Root, Richard A.

    1986-01-01

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

  12. A heat flow calorimeter

    NASA Technical Reports Server (NTRS)

    Johnston, W. V.

    1973-01-01

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

  13. 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.

  14. Woven heat exchanger

    DOEpatents

    Piscitella, Roger R.

    1987-05-05

    In a woven ceramic heat exchanger using the basic tube-in-shell design, each heat exchanger consisting of tube sheets and tube, is woven separately. Individual heat exchangers are assembled in cross-flow configuration. Each heat exchanger is woven from high temperature ceramic fiber, the warp is continuous from tube to tube sheet providing a smooth transition and unitized construction.

  15. Thermodynamic and heat transfer analysis of heat recovery from engine test cell by Organic Rankine Cycle

    NASA Astrophysics Data System (ADS)

    Shokati, Naser; Mohammadkhani, Farzad; Farrokhi, Navid; Ranjbar, Faramarz

    2014-12-01

    During manufacture of engines, evaluation of engine performance is essential. This is accomplished in test cells. During the test, a significant portion of heat energy released by the fuel is wasted. In this study, in order to recover these heat losses, Organic Rankine Cycle (ORC) is recommended. The study has been conducted assuming the diesel oil to be composed of a single hydrocarbon such as C12H26. The composition of exhaust gases (products of combustion) have been computed (and not determined experimentally) from the stoichiometric equation representing the combustion reaction. The test cell heat losses are recovered in three separate heat exchangers (preheater, evaporator and superheater). These heat exchangers are separately designed, and the whole system is analyzed from energy and exergy viewpoints. Finally, a parametric study is performed to investigate the effect of different variables on the system performance characteristics such as the ORC net power, heat exchangers effectiveness, the first law efficiency, exergy destruction and heat transfer surfaces. The results of the study show that by utilizing ORC, heat recovery equivalent to 8.85 % of the engine power is possible. The evaporator has the highest exergy destruction rate, while the pump has the lowest among the system components. Heat transfer surfaces are calculated to be 173.6, 58.7, and 11.87 m2 for the preheater, evaporator and superheater, respectively.

  16. Nanoparticle heating: nanoscale to bulk effects of electromagnetically heated iron oxide and gold for biomedical applications

    NASA Astrophysics Data System (ADS)

    Qin, Zhenpeng; Etheridge, Michael; Bischof, John C.

    2011-03-01

    Biomedical applications of nanoparticle heating range in scale from molecular activation (i.e. molecular beacons, protein denaturation, lipid melting and drug release), cellular heating (i.e. nanophotolysis and membrane permeability control and rupture) to whole tumor heating (deep and superficial). This work will present a review on the heating of two classes of biologically compatible metallic nanoparticles: iron oxide and gold with particular focus on spatial and temporal scales of the heating event. The size range of nanoparticles under discussion will focus predominantly in the 10 - 200 nm diameter size range. Mechanisms of heating range from Néelian and Brownian relaxation due to magnetic susceptibility at 100s of kHz, optical absorption due to VIS and NIR lasers and "Joule" heating at higher frequency RF (13.56 MHz). The heat generation of individual nanoparticles and the thermal responses at nano-, micro-, and macroscales are presented. This review will also discuss how to estimate a specific absorption rate (SAR, W/g) based on individual nanoparticles heating in bulk samples. Experimental setups are designed to measure the SAR and the results are compared with theoretical predictions.

  17. Heat Pipe Planets

    NASA Technical Reports Server (NTRS)

    Moore, William B.; Simon, Justin I.; Webb, A. Alexander G.

    2014-01-01

    When volcanism dominates heat transport, a terrestrial body enters a heat-pipe mode, in which hot magma moves through the lithosphere in narrow channels. Even at high heat flow, a heat-pipe planet develops a thick, cold, downwards-advecting lithosphere dominated by (ultra-)mafic flows and contractional deformation at the surface. Heat-pipes are an important feature of terrestrial planets at high heat flow, as illustrated by Io. Evidence for their operation early in Earth's history suggests that all terrestrial bodies should experience an episode of heat-pipe cooling early in their histories.

  18. Heat Treating Apparatus

    DOEpatents

    De Saro, Robert; Bateman, Willis

    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.

  19. 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.

  20. Thulium-170 heat source

    DOEpatents

    Walter, Carl E.; Van Konynenburg, Richard; VanSant, James H.

    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.

  1. Best practices for code release

    NASA Astrophysics Data System (ADS)

    Berriman, G. Bruce

    2016-01-01

    In this talk, I want to describe what I think are the best practices for releasing code and having it adopted by end users. Make sure your code is licensed, so users will know how the software can be used and modified, and place your code in a public repository that (and make sure that you follow institutional policies in doing this). Yet licensing and releasing code are not enough: the code must be organized and documented so users can understand what it does, what its limitations are, and how to build and use it. I will describe what I think are best practices in developing the content to support release, including tutorials, design documents, specifications of interfaces and so on. Much of what I have learned on based on ten years of experience in supporting releases of the Montage Image Mosaic Engine.

  2. Gliotransmission: Exocytotic release from astrocytes

    PubMed Central

    Parpura, Vladimir; Zorec, Robert

    2009-01-01

    Gliotransmitters are chemicals released from glial cells fulfilling a following set of criteria: i) they are synthesized by and/or stored in glia; ii) their regulated release is triggered by physiological and/or pathological stimuli; iii) they activate rapid (milliseconds to seconds) responses in neighboring cells; and iv) they play a role in (patho)physiological processes. Astrocytes can release a variety of gliotransmitters into the extracellular space using several different mechanisms. In this review, we focus on exocytotic mechanism(s) underlying the release of three classes of gliotransmitters: (i) amino acids, such as, glutamate and D-serine; (ii) nucleotides, like adenosine 5'-triphosphate; and (iii) peptides, such as, atrial natriuretic peptide and brain-derived neurotrophic factor. It is becoming clear that astrocytes are endowed with elements that qualify them as cells communicating with neurons and other cells within the central nervous system by employing regulated exocytosis. PMID:19948188

  3. Tyrosine - Effects on catecholamine release

    NASA Technical Reports Server (NTRS)

    Acworth, Ian N.; During, Matthew J.; Wurtman, Richard J.

    1988-01-01

    Tyrosine administration elevates striatal levels of dopamine metabolites in animals given treatments that accelerate nigrostriatal firing, but not in untreated rats. We examined the possibility that the amino acid might actually enhance dopamine release in untreated animals, but that the technique of measuring striatal dopamine metabolism was too insensitive to demonstrate such an effect. Dopamine release was assessed directly, using brain microdialysis of striatal extracellular fluid. Tyrosine administration (50-200 mg/kg IP) did indeed cause a dose related increase in extracellular fluid dopamine levels with minor elevations in levels of DOPAC and HVA, its major metabolites, which were not dose-related. The rise in dopamine was short-lived, suggesting that receptor-mediated feedback mechanisms responded to the increased dopamine release by diminishing neuronal firing or sensitivity to tyrosine. These observations indicate that measurement of changes in striatal DOPAC and HVA, if negative, need not rule out increases in nigrostriatal dopamine release.

  4. SELF-RELEASING GRAPPLING DEVICE

    DOEpatents

    Hoover, D.A. Sr.

    1963-11-01

    >A self-releasing grappling device that lifts by virtue of engagement between clamping jaws and the undercut lower side of a conical head of a lifting lug attached to the object to be lifted and employs a releasing sleeve on the lug to free the jaws from the lug is presented. When the jaws are to be released, they are dropped over the releasing sleeve, which is located well below lug head. When the jaws are lifted, they engage a conical surface on the sleeve and lift it up to the head of the lifting lug. In this position of the sleeve, the lower side of the lug head is covered by the sleeve and so cannot be engaged by the jaws, which move past before clearing the sleeve. (AEC)

  5. Fundamentals of heat measurement. [heat flux transducers

    NASA Technical Reports Server (NTRS)

    Gerashchenko, O. A.

    1979-01-01

    Various methods and devices for obtaining experimental data on heat flux density over wide ranges of temperature and pressure are examined. Laboratory tests and device fabrication details are supplemented by theoretical analyses of heat-conduction and thermoelectric effects, providing design guidelines and information relevant to further research and development. A theory defining the measure of correspondence between transducer signal and the measured heat flux is established for individual (isolated) heat flux transducers subject to space and time-dependent loading. An analysis of the properties of stacked (series-connected) transducers of various types (sandwich-type, plane, and spiral) is used to derive a similarity theory providing general governing relationships. The transducers examined are used in 36 types of derivative devices involving direct heat loss measurements, heat conduction studies, radiation pyrometry, calorimetry in medicine and industry and nuclear reactor dosimetry.

  6. Energy release in solar flares

    NASA Technical Reports Server (NTRS)

    Brown, John C.; Correia, Emilia; Farnik, Frantisek; Garcia, Howard; Henoux, Jean-Claude; La Rosa, Ted N.; Machado, Marcos E. (Compiler); Nakajima, Hiroshi; Priest, Eric R.

    1994-01-01

    Team 2 of the Ottawa Flares 22 Workshop dealt with observational and theoretical aspects of the characteristics and processes of energy release in flares. Main results summarized in this article stress the global character of the flaring phenomenon in active regions, the importance of discontinuities in magnetic connectivity, the role of field-aligned currents in free energy storage, and the fragmentation of energy release in time and space.

  7. Thermoelectric heat exchange element

    DOEpatents

    Callas, James J.; Taher, Mahmoud A.

    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.

  8. [Heat waves: health impacts].

    PubMed

    Marto, Natália

    2005-01-01

    During the summer of 2003, record high temperatures were reported across Europe, causing thousands of casualties. Heat waves are sporadic recurrent events, characterised by intense and prolonged heat, associated with excess mortality and morbidity. The most frequent cause of death directly attributable to heat is heat stroke but heat waves are known to cause increases in all-cause mortality, specially circulatory and respiratory mortality. Epidemiological studies demonstrate excess casualties cluster in specific risk groups. The elderly, those with chronic medical conditions and the socially isolated are particularly vulnerable. Air conditioning is the strongest protective factor against heat-related disorders. Heat waves cause disease indirectly, by aggravating chronic disorders, and directly, by causing heat-related illnesses (HRI). Classic HRI include skin eruptions, heat cramps, heat syncope, heat exhaustion and heat stroke. Heat stroke is a medical emergency characterised by hyperthermia and central nervous system dysfunction. Treatment includes immediate cooling and support of organ-system function. Despite aggressive treatment, heat stroke is often fatal and permanent neurological damage is frequent in those who survive. Heat related illness and death are preventable through behavioural adaptations, such as use of air conditioning and increased fluid intake. Other adaptation measures include heat emergency warning systems and intervention plans and environmental heat stress reduction. Heat related mortality is expected to rise as a consequence of the increasing proportion of elderly persons, the growing urban population, and the anticipated increase in number and intensity of heat waves associated with global warming. Improvements in surveillance and response capability may limit the adverse health conditions of future heat waves. It is crucial that health professionals are prepared to recognise, prevent and treat HRI and learn to cooperate with local health

  9. Heat cascading regenerative sorption heat pump

    NASA Technical Reports Server (NTRS)

    Jones, Jack A. (Inventor)

    1995-01-01

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

  10. Sulfuric acid-sulfur heat storage cycle

    DOEpatents

    Norman, John H.

    1983-12-20

    A method of storing heat is provided utilizing a chemical cycle which interconverts sulfuric acid and sulfur. The method can be used to levelize the energy obtained from intermittent heat sources, such as solar collectors. Dilute sulfuric acid is concentrated by evaporation of water, and the concentrated sulfuric acid is boiled and decomposed using intense heat from the heat source, forming sulfur dioxide and oxygen. The sulfur dioxide is reacted with water in a disproportionation reaction yielding dilute sulfuric acid, which is recycled, and elemental sulfur. The sulfur has substantial potential chemical energy and represents the storage of a significant portion of the energy obtained from the heat source. The sulfur is burned whenever required to release the stored energy. A particularly advantageous use of the heat storage method is in conjunction with a solar-powered facility which uses the Bunsen reaction in a water-splitting process. The energy storage method is used to levelize the availability of solar energy while some of the sulfur dioxide produced in the heat storage reactions is converted to sulfuric acid in the Bunsen reaction.

  11. GABA release by hippocampal astrocytes

    PubMed Central

    Le Meur, Karim; Mendizabal-Zubiaga, Juan; Grandes, Pedro; Audinat, Etienne

    2012-01-01

    Astrocytes can directly influence neuronal activity through the release of various transmitters acting on membrane receptors expressed by neurons. However, in contrast to glutamate and ATP for instance, the release of GABA (γ-amino-butyric acid) by astrocytes is still poorly documented. Here, we used whole-cell recordings in rat acute brain slices and electron microscopy to test whether hippocampal astrocytes release the inhibitory transmitter GABA. We observed that slow transient inhibitory currents due to the activation of GABAA receptors occur spontaneously in principal neurons of the three main hippocampal fields (CA1, CA3, and dentate gyrus). These currents share characteristics with the slow NMDA receptor-mediated currents previously shown to result from astrocytic glutamate release: they occur in the absence of synaptic transmission and have variable kinetics and amplitudes as well as low frequencies. Osmotic pressure reduction, known to enhance transmitter release from astrocytes, similarly increased the frequency of non-synaptic GABA and glutamate currents. Simultaneous occurrence of slow inhibitory and excitatory currents was extremely rare. Yet, electron microscopy examination of immunostained hippocampal sections shows that about 80% of hippocampal astrocytes [positive for glial fibrillary acidic protein (GFAP)] were immunostained for GABA. Our results provide quantitative characteristics of the astrocyte-to-neuron GABAergic signaling. They also suggest that all principal neurons of the hippocampal network are under a dual, excitatory and inhibitory, influence of astrocytes. The relevance of the astrocytic release of GABA, and glutamate, on the physiopathology of the hippocampus remains to be established. PMID:22912614

  12. Observations in Nonurban Heat Islands.

    NASA Astrophysics Data System (ADS)

    Hogan, A. W.; Ferrick, M. G.

    1998-02-01

    The urban heat island is a well-known and well-described temperature anomaly, but other types of heat islands are also infrequently reported. A 10 km × 30 km data field containing more than 100 individual winter morning air temperature measurement points was examined for areas characteristically warmer than surrounding areas. The very small `downtown' of Hanover, New Hampshire, was found to be 1°-2°C warmer than nearby open areas at the same elevation. The same technique was applied to examine the morning air temperature within a nearby hamlet consisting of about 60 wooden buildings within an area less than 0.3 km2. The bulk of observations and observations stratified by snow and sky cover showed no systematic difference between hamlet air temperatures and those obtained in surrounding terrain. Morning air temperatures along a freezing river were measured and found to be systematically warmer than nearby air temperatures for several days, until a significant snowfall diminished the ice growth rate. A thorough examination of temperature profiles near the river showed that the increase in air temperature beneath the overnight inversion during this freezing period was proportional to the heat release resulting from river ice growth.

  13. Coronal heating in multiple magnetic threads

    NASA Astrophysics Data System (ADS)

    Tam, K. V.; Hood, A. W.; Browning, P. K.; Cargill, P. J.

    2015-08-01

    Context. Heating the solar corona to several million degrees requires the conversion of magnetic energy into thermal energy. In this paper, we investigate whether an unstable magnetic thread within a coronal loop can destabilise a neighbouring magnetic thread. Aims: By running a series of simulations, we aim to understand under what conditions the destabilisation of a single magnetic thread can also trigger a release of energy in a nearby thread. Methods: The 3D magnetohydrodynamics code, Lare3d, is used to simulate the temporal evolution of coronal magnetic fields during a kink instability and the subsequent relaxation process. We assume that a coronal magnetic loop consists of non-potential magnetic threads that are initially in an equilibrium state. Results: The non-linear kink instability in one magnetic thread forms a helical current sheet and initiates magnetic reconnection. The current sheet fragments, and magnetic energy is released throughout that thread. We find that, under certain conditions, this event can destabilise a nearby thread, which is a necessary requirement for starting an avalanche of energy release in magnetic threads. Conclusions: It is possible to initiate an energy release in a nearby, non-potential magnetic thread, because the energy released from one unstable magnetic thread can trigger energy release in nearby threads, provided that the nearby structures are close to marginal stability.

  14. Added release time in diffusion/dissolution coupled release.

    PubMed

    Nuxoll, Eric

    2015-10-15

    While increasingly sophisticated models have been developed to more accurately predict dispersed solute release from complex systems, distillation of their results into quantitative trends has been difficult. Here, the numerically calculated release profiles of coupled diffusion/dissolution systems are quantified by their cumulative release time (CRT) and compared against corresponding diffusion-controlled limits. The increase in CRT due to a finite dissolution rate was found to vary inversely with the second Damköhler number across several orders of magnitude, and also vary linearly with the amount of solid drug loaded in the system. The analytical nature of the relationship provides new physical insights into the system and appears to be indifferent to the form of the secondary rate-limiting step. This work provides a simple analytical expression with which one can not only predict the mean release time for a given set of parameter values, but understand precisely how each parameter value will affect it. The simplicity of the correlation and the lack of apparent limits to its validity also suggest the existence of an analytical pathway for its derivation, which may yield additional insights into the effect of secondary rate processes on controlled release. PMID:26276252

  15. Protecting Yourself from Heat Stress

    MedlinePlus

    ... Contact NIOSH NIOSH Fast Facts: Protecting Yourself from Heat Stress Language: English Español (Spanish) Kreyol Haitien (Haitian ... as heat stroke, heat exhaustion, or heat cramps. Heat Stroke A condition that occurs when the body ...

  16. TRMM observations of latent heat distribution over the Indian summer monsoon region and associated dynamics

    NASA Astrophysics Data System (ADS)

    Subrahmanyam, Kandula V.; Kishore Kumar, Karanam

    2016-05-01

    The latent heat released/absorbed in the Earth's atmosphere due to phase change of water molecule plays a vital role in various atmospheric processes. It is now well established that the latent heat released in the clouds is the secondary source of energy for driving the atmosphere, the Sun being the primary. In this context, studies on latent heat released in the atmosphere become important to understand the some of the physical processes taking place in the atmosphere. One of the important implications of latent heat release is its role in driving the circulations on various temporal and spatial scales. Realizing the importance of latent heat released in the clouds, a comprehensive study is carried out to understand its role in driving the mesoscale circulation. As Indian summer monsoon (ISM) serves as natural laboratory for studying the clouds and their microphysics, an attempt is made to explore the latent heat distribution over this region using 13 years of Tropical Rainfall Measuring Mission (TRMM) observations. The observed profiles of latent heating over ISM region showed large spatial and temporal variability in the magnitude thus reflecting the presence of organization of convection on mesoscale. The latent profiles in convective and stratiform regions are segregated to study the differences in their interaction with large-scale environment. Various re-analysis dataset were used to examine the role of latent heating distribution on the mesoscale circulation. The significance of the present study lies in establishing the vertical distribution of latent heating and their impact on the background circulation.

  17. Heat Pipe Technology

    NASA Technical Reports Server (NTRS)

    1981-01-01

    The heat pipe, a sealed chamber whose walls are lined with a "wick," a thin capillary network containing a working fluid in liquid form was developed for a heat distribution system for non-rotating satellites. Use of the heat pipe provides a continuous heat transfer mechanism. "Heat tubes" that improve temperature control in plastics manufacturing equipment incorporated the heat pipe technology. James M. Stewart, an independent consultant, patented the heat tubes he developed and granted a license to Kona Corporation. The Kona Nozzle for heaterless injection molding gets heat for its operation from an external source and has no internal heating bands, reducing machine maintenance and also eliminating electrical hazards associated with heater bands. The nozzles are used by Eastman Kodak, Bic Pen Corporation, Polaroid, Tupperware, Ford Motor Company, RCA, and Western Electric in the molding of their products.

  18. Highly Efficient Thermoresponsive Nanocomposite for Controlled Release Applications

    PubMed Central

    Yassine, Omar; Zaher, Amir; Li, Er Qiang; Alfadhel, Ahmed; Perez, Jose E.; Kavaldzhiev, Mincho; Contreras, Maria F.; Thoroddsen, Sigurdur T.; Khashab, Niveen M.; Kosel, Jurgen

    2016-01-01

    Highly efficient magnetic release from nanocomposite microparticles is shown, which are made of Poly (N-isopropylacrylamide) hydrogel with embedded iron nanowires. A simple microfluidic technique was adopted to fabricate the microparticles with a high control of the nanowire concentration and in a relatively short time compared to chemical synthesis methods. The thermoresponsive microparticles were used for the remotely triggered release of Rhodamine (B). With a magnetic field of only 1 mT and 20 kHz a drug release of 6.5% and 70% was achieved in the continuous and pulsatile modes, respectively. Those release values are similar to the ones commonly obtained using superparamagnetic beads but accomplished with a magnetic field of five orders of magnitude lower power. The high efficiency is a result of the high remanent magnetization of the nanowires, which produce a large torque when exposed to a magnetic field. This causes the nanowires to vibrate, resulting in friction losses and heating. For comparison, microparticles with superparamagnetic beads were also fabricated and tested; while those worked at 73 mT and 600 kHz, no release was observed at the low field conditions. Cytotoxicity assays showed similar and high cell viability for microparticles with nanowires and beads. PMID:27335342

  19. Highly Efficient Thermoresponsive Nanocomposite for Controlled Release Applications.

    PubMed

    Yassine, Omar; Zaher, Amir; Li, Er Qiang; Alfadhel, Ahmed; Perez, Jose E; Kavaldzhiev, Mincho; Contreras, Maria F; Thoroddsen, Sigurdur T; Khashab, Niveen M; Kosel, Jurgen

    2016-01-01

    Highly efficient magnetic release from nanocomposite microparticles is shown, which are made of Poly (N-isopropylacrylamide) hydrogel with embedded iron nanowires. A simple microfluidic technique was adopted to fabricate the microparticles with a high control of the nanowire concentration and in a relatively short time compared to chemical synthesis methods. The thermoresponsive microparticles were used for the remotely triggered release of Rhodamine (B). With a magnetic field of only 1 mT and 20 kHz a drug release of 6.5% and 70% was achieved in the continuous and pulsatile modes, respectively. Those release values are similar to the ones commonly obtained using superparamagnetic beads but accomplished with a magnetic field of five orders of magnitude lower power. The high efficiency is a result of the high remanent magnetization of the nanowires, which produce a large torque when exposed to a magnetic field. This causes the nanowires to vibrate, resulting in friction losses and heating. For comparison, microparticles with superparamagnetic beads were also fabricated and tested; while those worked at 73 mT and 600 kHz, no release was observed at the low field conditions. Cytotoxicity assays showed similar and high cell viability for microparticles with nanowires and beads. PMID:27335342

  20. Highly Efficient Thermoresponsive Nanocomposite for Controlled Release Applications

    NASA Astrophysics Data System (ADS)

    Yassine, Omar; Zaher, Amir; Li, Er Qiang; Alfadhel, Ahmed; Perez, Jose E.; Kavaldzhiev, Mincho; Contreras, Maria F.; Thoroddsen, Sigurdur T.; Khashab, Niveen M.; Kosel, Jurgen

    2016-06-01

    Highly efficient magnetic release from nanocomposite microparticles is shown, which are made of Poly (N-isopropylacrylamide) hydrogel with embedded iron nanowires. A simple microfluidic technique was adopted to fabricate the microparticles with a high control of the nanowire concentration and in a relatively short time compared to chemical synthesis methods. The thermoresponsive microparticles were used for the remotely triggered release of Rhodamine (B). With a magnetic field of only 1 mT and 20 kHz a drug release of 6.5% and 70% was achieved in the continuous and pulsatile modes, respectively. Those release values are similar to the ones commonly obtained using superparamagnetic beads but accomplished with a magnetic field of five orders of magnitude lower power. The high efficiency is a result of the high remanent magnetization of the nanowires, which produce a large torque when exposed to a magnetic field. This causes the nanowires to vibrate, resulting in friction losses and heating. For comparison, microparticles with superparamagnetic beads were also fabricated and tested; while those worked at 73 mT and 600 kHz, no release was observed at the low field conditions. Cytotoxicity assays showed similar and high cell viability for microparticles with nanowires and beads.

  1. Heat transfer system

    DOEpatents

    McGuire, Joseph C.

    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.

  2. Microscale Regenerative Heat Exchanger

    NASA Technical Reports Server (NTRS)

    Moran, Matthew E.; Stelter, Stephan; Stelter, Manfred

    2006-01-01

    The device described herein is designed primarily for use as a regenerative heat exchanger in a miniature Stirling engine or Stirling-cycle heat pump. A regenerative heat exchanger (sometimes called, simply, a "regenerator" in the Stirling-engine art) is basically a thermal capacitor: Its role in the Stirling cycle is to alternately accept heat from, then deliver heat to, an oscillating flow of a working fluid between compression and expansion volumes, without introducing an excessive pressure drop. These volumes are at different temperatures, and conduction of heat between these volumes is undesirable because it reduces the energy-conversion efficiency of the Stirling cycle.

  3. Heating and cooling system

    SciTech Connect

    Imig, L.A.; Gardner, M.R.

    1982-08-01

    A heating and cooling apparatus capable of cyclic heating and cooling of a test specimen undergoing fatigue testing is discussed. Cryogenic fluid is passed through a block clamped to the speciment to cool the block and the specimen. Heating cartridges penetrate the block to heat the block and the specimen to very hot temperaures. Control apparatus is provided to alternatively activate the cooling and heating modes to effect cyclic heating and cooling between very hot and very cold temperatures. The block is constructed of minimal mass to facilitate the rapid temperature changes. Official Gazette of the U.S. Patent and Trademark Office.

  4. Wound tube heat exchanger

    DOEpatents

    Ecker, Amir L.

    1983-01-01

    What is disclosed is a wound tube heat exchanger in which a plurality of tubes having flattened areas are held contiguous adjacent flattened areas of tubes by a plurality of windings to give a double walled heat exchanger. The plurality of windings serve as a plurality of effective force vectors holding the conduits contiguous heat conducting walls of another conduit and result in highly efficient heat transfer. The resulting heat exchange bundle is economical and can be coiled into the desired shape. Also disclosed are specific embodiments such as the one in which the tubes are expanded against their windings after being coiled to insure highly efficient heat transfer.

  5. 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.

  6. Thermophysical and heat transfer properties of phase change material candidate for waste heat transportation system

    NASA Astrophysics Data System (ADS)

    Kaizawa, Akihide; Maruoka, Nobuhiro; Kawai, Atsushi; Kamano, Hiroomi; Jozuka, Tetsuji; Senda, Takeshi; Akiyama, Tomohiro

    2008-05-01

    A waste heat transportation system trans-heat (TH) system is quite attractive that uses the latent heat of a phase change material (PCM). The purpose of this paper is to study the thermophysical properties of various sugars and sodium acetate trihydrate (SAT) as PCMs for a practical TH system and the heat transfer property between PCM selected and heat transfer oil, by using differential scanning calorimetry (DSC), thermogravimetry-differential thermal analysis (TG-DTA) and a heat storage tube. As a result, erythritol, with a large latent heat of 344 kJ/kg at melting point of 117°C, high decomposition point of 160°C and excellent chemical stability under repeated phase change cycles was found to be the best PCM among them for the practical TH system. In the heat release experiments between liquid erythritol and flowing cold oil, we observed foaming phenomena of encapsulated oil, in which oil droplet was coated by solidification of PCM.

  7. Capture of Heat Energy from Diesel Engine Exhaust

    SciTech Connect

    Chuen-Sen Lin

    2008-12-31

    Diesel generators produce waste heat as well as electrical power. About one-third of the fuel energy is released from the exhaust manifolds of the diesel engines and normally is not captured for useful applications. This project studied different waste heat applications that may effectively use the heat released from exhaust of Alaskan village diesel generators, selected the most desirable application, designed and fabricated a prototype for performance measurements, and evaluated the feasibility and economic impact of the selected application. Exhaust flow rate, composition, and temperature may affect the heat recovery system design and the amount of heat that is recoverable. In comparison with the other two parameters, the effect of exhaust composition may be less important due to the large air/fuel ratio for diesel engines. This project also compared heat content and qualities (i.e., temperatures) of exhaust for three types of fuel: conventional diesel, a synthetic diesel, and conventional diesel with a small amount of hydrogen. Another task of this project was the development of a computer-aided design tool for the economic analysis of selected exhaust heat recovery applications to any Alaskan village diesel generator set. The exhaust heat recovery application selected from this study was for heating. An exhaust heat recovery system was fabricated, and 350 hours of testing was conducted. Based on testing data, the exhaust heat recovery heating system showed insignificant effects on engine performance and maintenance requirements. From measurements, it was determined that the amount of heat recovered from the system was about 50% of the heat energy contained in the exhaust (heat contained in exhaust was evaluated based on environment temperature). The estimated payback time for 100% use of recovered heat would be less than 3 years at a fuel price of $3.50 per gallon, an interest rate of 10%, and an engine operation of 8 hours per day. Based on experimental data

  8. Using Sea Level to Probe Linkages Between Heat Transport Convergence, Heat Storage Rate, and Air-Sea Heat Exchange in the Subtropical North Atlantic

    NASA Astrophysics Data System (ADS)

    Thompson, L.; Kelly, K. A.; Booth, J. F.

    2014-12-01

    anomalies generated control the exchange of heat between the ocean and the atmosphere. Seasonal analysis shows that the Gulf Stream region's heat content primarily is primarily released in winter and that in winter, SSH also gives significant predictive skill for mid-level cloud fraction.

  9. Thermodynamical effects during carbon dioxide release

    NASA Astrophysics Data System (ADS)

    Singh, A. K.; Böttcher, N.; Görke, U.-J.; Kolditz, O.

    2012-04-01

    Pruess [1] investigated the risk of carbon dioxide leakage from shallow storage sites by modeling scenarios. Such a fluid release is associated with mechanical work performed by formation fluid against expansion without taking heat from ambient environment. Understanding of heat related to mechanical work is essential to predict the temperature at the leak. According to the first law of thermodynamics, internal energy of working fluid decreases with an amount which is equivalent to this work hence, working fluid lost its own heat. Such kind of heat loss depends strongly on whether the expansion process is adiabatic or isothermal. Isothermal expansion allows the working fluid to interact thermally with the solid matrix. Adiabatic expansion is an isenthalpic process that takes heat from the working fluid and the ambient environment remains unchanged. This work is part of the CLEAN research project [6]. In this study, thermodynamic effects of mechanical work during eventual carbon dioxide leakage are investigated numerically. In particular, we are interested to detect the temperature at leakage scenarios and its deviation with different thermodynamic processes. Finite element simulation is conducted with a two-dimensional rectangular geometry representing a shallow storage site which bottom was located at -300m below the land surface. A fully saturated porous medium is assumed where the pore space is filled completely with carbon dioxide. Carbon dioxide accumulated in the secondary trap at 30 Bar and 24 °C is allowed to leak from top right point of rectangle with atmospheric pressure. With (i) adiabatic and (ii) isothermal compressibility factors, temperature around leakage area has been calculated which show a significant difference. With some simplification, this study detects leak temperature which is very close with [1]. Temporal evaluation at the leaky area shows that the working fluid temperature can be reduced to -20 °C when the leakage scenario is performed

  10. Study on release and transport of aerial radioactive materials in reprocessing plants

    SciTech Connect

    Amano, Y.; Tashiro, S.; Uchiyama, G.; Abe, H.; Yamane, Y.; Yoshida, K.; Kodama, T.

    2013-07-01

    The release and transport characteristics of radioactive materials at a boiling accident of the high active liquid waste (HALW) in a reprocessing plant have been studied for improving experimental data of source terms of the boiling accident. In the study, a heating test and a thermogravimetry and differential thermal analysis (TG-DTA) test were conducted. In the heating test using a simulated HALW, it was found that ruthenium was mainly released into the air in the form of gas and that non-volatile elements were released into the air in the form of mist. In the TG-DTA test, the rate constants and reaction heat of thermal decomposition of ruthenium nitrosyl nitrate were obtained from TG and DTA curves. (authors)

  11. Controlled Release from Recombinant Polymers

    PubMed Central

    Price, Robert; Poursaid, Azadeh; Ghandehari, Hamidreza

    2014-01-01

    Recombinant polymers provide a high degree of molecular definition for correlating structure with function in controlled release. The wide array of amino acids available as building blocks for these materials lend many advantages including biorecognition, biodegradability, potential biocompatibility, and control over mechanical properties among other attributes. Genetic engineering and DNA manipulation techniques enable the optimization of structure for precise control over spatial and temporal release. Unlike the majority of chemical synthetic strategies used, recombinant DNA technology has allowed for the production of monodisperse polymers with specifically defined sequences. Several classes of recombinant polymers have been used for controlled drug delivery. These include, but are not limited to, elastin-like, silk-like, and silk-elastinlike proteins, as well as emerging cationic polymers for gene delivery. In this article, progress and prospects of recombinant polymers used in controlled release will be reviewed. PMID:24956486

  12. Payload holddown and release mechanism

    NASA Technical Reports Server (NTRS)

    Chaput, Dale; Visconti, Mark; Edwards, Michael; Moran, Tom

    1994-01-01

    A payload holddown and release mechanism, designated the Model 1172, was designed and built at G&H Technology during the winter of 1992/1993. The mechanism is able to restrain and release a 45-pound payload with minimal tipoff. The payload is held in place by a stainless steel band and released using electrically triggered non-explosive actuators. These actuators provide reliable operation with negligible shock and no special handling requirements. The performance of the mechanism was demonstrated in two flight tests. Data showed pitch and yaw tipoff rates of less than 0.07 radian (4 degree) per second. The Model 1172 design is an efficient replacement for conventional payload deployment devices, especially where low transmitted shock is required.

  13. Nanostructured Diclofenac Sodium Releasing Material

    NASA Astrophysics Data System (ADS)

    Nikkola, L.; Vapalahti, K.; Harlin, A.; Seppälä, J.; Ashammakhi, N.

    2008-02-01

    Various techniques have been developed to produce second generation biomaterials for tissue repair. These include extrusion, molding, salt leaching, spinning etc, but success in regenerating tissues has been limited. It is important to develop porous material, yet with a fibrous structure for it to be biomimetic. To mimic biological tissues, the extra-cellular matrix usually contains fibers in nano scale. To produce nanostructures, self-assembly or electrospinning can be used. Adding a drug release function to such a material may advance applications further for use in controlled tissue repair. This turns the resulting device into a multifunctional porous, fibrous structure to support cells and drug releasing properties in order to control tissue reactions. A bioabsorbable poly(ɛ-caprolactone-co-D,L lactide) 95/5 (PCL) was made into diluted solution using a solvent, to which was added 2w-% of diclofenac sodium (DS). Nano-fibers were made by electrospinning onto substrate. Microstructure of the resulting nanomat was studied using SEM and drug release profiles with UV/VIS spectroscopy. Thickness of the electrospun nanomat was about 2 mm. SEM analysis showed that polymeric nano-fibers containing drug particles form a highly interconnected porous nano structure. Average diameter of the nano-fibers was 130 nm. There was a high burst peak in drug release, which decreased to low levels after one day. The used polymer has slow a degradation rate and though the nanomat was highly porous with a large surface area, drug release rate is slow. It is feasible to develop a nano-fibrous porous structure of bioabsorbable polymer, which is loaded with test drug. Drug release is targeted at improving the properties of biomaterial for use in controlled tissue repair and regeneration.

  14. Metal hydride heat pump

    SciTech Connect

    Nishizaki, T.; Miyamoto, K.; Miyamoto, M.; Nakata, Y.; Yamaji, K.; Yoshida, K.

    1983-12-27

    A metal hydride heat pump is disclosed comprising a first and a second heat medium receptacle having heat media flowing therein and a plurality of closed vessels each containing a hydrogen gas atmosphere and divided into a first chamber having a first metal hydride filled therein and a second chamber having a second metal hydride filled therein. The first and second chambers of each closed vessel are made to communicate with each other so that hydrogen gas passes from one chamber to the other but the metal hydrides do not, and a group of the first chambers of the closed vessels being located within the first heat medium receptacle and a group of the second chambers of the closed vessels being located within the second heat medium receptacle, whereby heat exchange is carried out between the heat media in the first and second heat medium receptacles and the first and second metal hydrides through the external walls of the closed vessels.

  15. Radial heat flux transformer

    NASA Technical Reports Server (NTRS)

    Basiulis, A.; Buzzard, R. J.

    1971-01-01

    Unit moves heat radially from small diameter shell to larger diameter shell, or vice versa, with negligible temperature drop, making device useful wherever heating or cooling of concentrically arranged materials, substances, and structures is desired.

  16. An electrohydrodynamic heat pipe

    NASA Technical Reports Server (NTRS)

    Jones, T. B.

    1972-01-01

    Dielectric liquid for transfer of heat provides liquid flow from the condenser section to the evaporator section in conventional heat pipes. Working fluid is guided or pumped by an array of wire electrodes connected to a high-voltage source.

  17. 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).

  18. Geothermal District Heating Economics

    Energy Science and Technology Software Center (ESTSC)

    1995-07-12

    GEOCITY is a large-scale simulation model which combines both engineering and economic submodels to systematically calculate the cost of geothermal district heating systems for space heating, hot-water heating, and process heating based upon hydrothermal geothermal resources. The GEOCITY program simulates the entire production, distribution, and waste disposal process for geothermal district heating systems, but does not include the cost of radiators, convectors, or other in-house heating systems. GEOCITY calculates the cost of district heating basedmore » on the climate, population, and heat demand of the district; characteristics of the geothermal resource and distance from the distribution center; well-drilling costs; design of the distribution system; tax rates; and financial conditions.« less

  19. Hydrocarbon release investigations in Missouri

    SciTech Connect

    Fels, J.B.

    1996-09-01

    Hydrocarbon releases are among the most common environmental problems in Missouri, as well as across the country. Old, unprotected underground storage tanks and buried piping from the tanks to pumps are notorious sources of petroleum contamination at LUST (leaking underground storage tank) sites. Missouri has an estimated 5000 LUST sites across the state with the majority being simple spills into clay-rich soils or into a shallow perched water system. However, in the southern half of the state, where residual soils and karst bedrock are not conducive to trapping such releases, significant groundwater supplies are at risk. This article discusses the process used to identify the source of contamination.

  20. Activation heat, activation metabolism and tension-related heat in frog semitendinosus muscles

    PubMed Central

    Homsher, E.; Mommaerts, W. F. H. M.; Ricchiuti, N. V.; Wallner, A.

    1972-01-01

    1. Frog semitendinosus muscles were stretched to various lengths beyond the rest length (l0) and their initial heat and isometric tension production were measured. 2. As the overlap between the thick and thin filaments is reduced, the initial twitch heat and tension decline in a linear manner. At a point at which the twitch tension approaches zero, the initial heat is 30% of that seen at l0. It is concluded that this heat is the activation heat and reflects the energetics of calcium release and reaccumulation. The initial heat at shorter sarcomere lengths appears to be the sum of the activation heat plus a heat production associated with the interaction of the thick and thin filaments. 3. A similar relationship between heat and tension production is seen in tetanic contractions. 4. The time course of activation heat production in a twitch can be resolved into two phases: a temperature insensitive (Q10 < 1·3) `fast' phase (with a time constant of 45 msec) and a temperature sensitive (Q10 = 2·8) `slow' phase (with a time constant of 330 msec at 0° C). 5. Measurements of the creatine phosphate (PC) hydrolysis by muscles contracting isometrically at various muscle lengths at and beyond l0, indicate an enthalpy change of -11·2 kcal/mole PC hydrolysed. The enthalpy change for the ATP hydrolysis by muscles stretched so that little or no tension was produced with stimulation was -9·9 kcal/mole ATP hydrolysed. It is concluded that the net activation heat is produced by the hydrolysis of PC or ATP. PMID:4536938

  1. Heat of freezing for supercooled water: measurements at atmospheric pressure.

    PubMed

    Cantrell, Will; Kostinski, Alexander; Szedlak, Anthony; Johnson, Alexandria

    2011-06-16

    Unlike reversible phase transitions, the amount of heat released upon freezing of a metastable supercooled liquid depends on the degree of supercooling. Although terrestrial supercooled water is ubiquitous and has implications for cloud dynamics and nucleation, measurements of its heat of freezing are scarce. We have performed calorimetric measurements of the heat released by freezing water at atmospheric pressure as a function of supercooling. Our measurements show that the heat of freezing can be considerably below one predicted from a reversible hydrostatic process. Our measurements also indicate that the state of the resulting ice is not fully specified by the final pressure and temperature; the ice is likely to be strained on a variety of scales, implying a higher vapor pressure. This would reduce the vapor gradient between supercooled water and ice in mixed phase atmospheric clouds. PMID:21087023

  2. 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.

  3. Solar heating and cooling

    NASA Technical Reports Server (NTRS)

    Bartera, R. E.

    1978-01-01

    To emphasize energy conservation and low cost energy, the systems of solar heating and cooling are analyzed and compared with fossil fuel systems. The application of solar heating and cooling systems for industrial and domestic use are discussed. Topics of discussion include: solar collectors; space heating; pools and spas; domestic hot water; industrial heat less than 200 F; space cooling; industrial steam; and initial systems cost. A question and answer period is generated which closes out the discussion.

  4. Abrasion resistant heat pipe

    DOEpatents

    Ernst, Donald M.

    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.

  5. 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.

  6. Magnetic heat pumping near room temperature

    NASA Technical Reports Server (NTRS)

    Brown, G. V.

    1976-01-01

    It is shown that magnetic heat pumping can be made practical at room temperature by using a ferromagnetic material with a Curie point at or near operating temperature and an appropriate regenerative thermodynamic cycle. Measurements are performed which show that gadolinium is a resonable working material and it is found that the application of a 7-T magnetic field to gadolinium at the Curie point (293 K) causes a heat release of 4 kJ/kg under isothermal conditions or a temperature rise of 14 K under adiabatic conditions. A regeneration technique can be used to lift the load of the lattice and electronic heat capacities off the magnetic system in order to span a reasonable temperature difference and to pump as much entropy per cycle as possible

  7. Decay heat studies for nuclear energy

    NASA Astrophysics Data System (ADS)

    Algora, A.; Jordan, D.; Taín, J. L.; Rubio, B.; Agramunt, J.; Caballero, L.; Nácher, E.; Perez-Cerdan, A. B.; Molina, F.; Estevez, E.; Valencia, E.; Krasznahorkay, A.; Hunyadi, M. D.; Gulyás, J.; Vitéz, A.; Csatlós, M.; Csige, L.; Eronen, T.; Rissanen, J.; Saastamoinen, A.; Moore, I. D.; Penttilä, H.; Kolhinen, V. S.; Burkard, K.; Hüller, W.; Batist, L.; Gelletly, W.; Nichols, A. L.; Yoshida, T.; Sonzogni, A. A.; Peräjärvi, K.

    2014-01-01

    The energy associated with the decay of fission products plays an important role in the estimation of the amount of heat released by nuclear fuel in reactors. In this article we present results of the study of the beta decay of some refractory isotopes that were considered important contributors to the decay heat in reactors. The measurements were performed at the IGISOL facility of the University of Jyväskylä, Finland. In these studies we have combined for the first time a Penning trap (JYFLTRAP), which was used as a high resolution isobaric separator, with a total absorption spectrometer. The results of the measurements as well as their consequences for decay heat summation calculations are discussed.

  8. Towards understanding of heat effects in metallic glasses on the basis of macroscopic shear elasticity

    PubMed Central

    Mitrofanov, Y. P.; Wang, D. P.; Makarov, A. S.; Wang, W. H.; Khonik, V. A.

    2016-01-01

    It is shown that all heat effects taking place upon annealing of a metallic glass within the glassy and supercooled liquid states, i.e. heat release below the glass transition temperature and heat absorption above it, as well as crystallization-induced heat release, are related to the macroscopic shear elasticity. The underlying physical reason can be understood as relaxation in the system of interstitialcy-type ”defects” (elastic dipoles) frozen-in from the melt upon glass production. PMID:26975587

  9. Heat of Hydration of Low Activity Cementitious Waste Forms

    SciTech Connect

    Nasol, D.

    2015-07-23

    During the curing of secondary waste grout, the hydraulic materials in the dry mix react exothermally with the water in the secondary low-activity waste (LAW). The heat released, called the heat of hydration, can be measured using a TAM Air Isothermal Calorimeter. By holding temperature constant in the instrument, the heat of hydration during the curing process can be determined. This will provide information that can be used in the design of a waste solidification facility. At the Savannah River National Laboratory (SRNL), the heat of hydration and other physical properties are being collected on grout prepared using three simulants of liquid secondary waste generated at the Hanford Site. From this study it was found that both the simulant and dry mix each had an effect on the heat of hydration. It was also concluded that the higher the cement content in the dry materials mix, the greater the heat of hydration during the curing of grout.

  10. PLASMA HEATING AND CONFINING DEVICE

    DOEpatents

    Baker, W.R.; Bratenahl, Al.; Kunkel, W.B.

    1962-02-13

    ABS> A device is designed for generating, heating, and containing a very pure electrical plasma. Plasma purity is maintained by preventing the hot plasma from contacting insulators, which are a principal source of impurities in prior constructions. An insulator is disposed at each end of a pair of long coaxial cylinders forming an annular chamber therebetween. High voltage is applied between the cylinders and an axial magnetic field is created therethrough. At a middle position on the inner cylinder, a fastopening valve releases a quantity of gas into the chamber, and before the gas can diffuse to the distant insulators, a discharge occurs between the cylinders and plasma is formed in the central region of the chamber away from the insulators. (AEC)

  11. Photoinduced drug release from thermosensitive AuNPs-liposome using a AuNPs-switch.

    PubMed

    An, Xueqin; Zhang, Fan; Zhu, Yinyan; Shen, Weiguo

    2010-10-14

    A thermosensitive liposome with embedded AuNPs in a bilayer was prepared using supercritical CO(2). The AuNPs-liposome can absorb a certain wavelength light, convert optical energy into heat, induce phase transition, and release drug. The results show that drug release from the liposome is due to the photothermic effects inducing phase transition of the liposome rather than destruction of the liposome structure. PMID:20820547

  12. 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.

  13. Heat pipes for industrial waste heat recovery

    NASA Astrophysics Data System (ADS)

    Merrigan, M. A.

    1981-01-01

    Development work on the high temperature ceramic recuperator at Los Alamos National Laboratory is described and involved material investigations, fabrication methods development, compatibility tests, heat pipe operation, and the modeling of application conditions based on current industrial usage. Solid ceramic heat pipes, ceramic coated refractory pipes, and high-temperature oxide protected metallic pipes are investigated. Economic studies of the use of heat pipe based recuperators in industrial furnaces are conducted and payback periods determined as a function of material, fabrication, and installation cost.

  14. Heat pipes. [technology utilization

    NASA Technical Reports Server (NTRS)

    1975-01-01

    The development and use of heat pipes are described, including space requirements and contributions. Controllable heat pipes, and designs for automatically maintaining a selected constant temperature, are discussed which would add to the versatility and usefulness of heat pipes in industrial processing, manufacture of integrated circuits, and in temperature stabilization of electronics.

  15. Liquid heat capacity lasers

    DOEpatents

    Comaskey, Brian J.; Scheibner, Karl F.; Ault, Earl R.

    2007-05-01

    The heat capacity laser concept is extended to systems in which the heat capacity lasing media is a liquid. The laser active liquid is circulated from a reservoir (where the bulk of the media and hence waste heat resides) through a channel so configured for both optical pumping of the media for gain and for light amplification from the resulting gain.

  16. HEAT TRANSFER MEANS

    DOEpatents

    Fraas, A.P.; Wislicenus, G.F.

    1961-07-11

    A heat exchanger is adapted to unifomly cool a spherical surface. Equations for the design of a spherical heat exchanger hav~g tubes with a uniform center-to-center spining are given. The heat exchanger is illustrated in connection with a liquid-fueled reactor.

  17. 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.

  18. Heat transfer simulation of motorcycle fins under varying velocity using CFD method

    NASA Astrophysics Data System (ADS)

    Shahril, K.; Mohd Kasim, Nurhayati Binti; Sabri, M.

    2013-12-01

    Motorcycle engine releases heat to the atmosphere through the mode of force convection. To solve this, fins are provided on the outer of the cylinder. The heat transfer rate is defined depending on the velocity of vehicle, fin geometry and the ambient temperature. Increasing the temperature difference between the object and the environment, increasing the convection heat transfer coefficient, or increasing the surface area of the object increases the heat transfer. Many experimental methods are available in literature to analyze the effect of these factors on the heat transfer rate. However, CFD analysis will be use to simulate the heat transfer of the engine block. ANSYS software is selected to run the simulation.

  19. Tests of a protective shell passive release mechanism for hypersonic wind-tunnel models

    NASA Technical Reports Server (NTRS)

    Puster, R. L.; Dunn, J. E.

    1979-01-01

    A protective shell mechanism for wind tunnel models was developed and tested. The mechanism is passive in operation, reliable, and imposes no new structural design changes for wind tunnel models. Methods of predicting the release time and the measured loads associated with the release of the shell are given. The mechanism was tested in a series of wind tunnel tests to validate the removal process and measure the pressure loads on the model. The protective shell can be used for wind tunnel models that require a step input of heating and loading such as a thin skin heat transfer model. The mechanism may have other potential applications.

  20. Chemical heat pump

    DOEpatents

    Greiner, Leonard

    1980-01-01

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

  1. A corrosive resistant heat exchanger

    DOEpatents

    Richlen, S.L.

    1987-08-10

    A corrosive and erosive resistant heat exchanger which recovers heat from a contaminated heat stream. The heat exchanger utilizes a boundary layer of innocuous gas, which is continuously replenished, to protect the heat exchanger surface from the hot contaminated gas. The innocuous gas is pumped through ducts or perforations in the heat exchanger wall. Heat from the heat stream is transferred by radiation to the heat exchanger wall. Heat is removed from the outer heat exchanger wall by a heat recovery medium. 3 figs., 3 tabs.

  2. 78 FR 73083 - Compassionate Release

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-05

    ... the regulations in 28 CFR part 571, subpart G, on December 21, 2006 (71 FR 76619). We also published an interim rule making a technical change to the regulations on February 28, 2013 (78 FR 13478). We... of Prisons 28 CFR Part 571 RIN 1120-AB68 Compassionate Release AGENCY: Bureau of Prisons,...

  3. 2014 Pee Dee germplasm releases

    Technology Transfer Automated Retrieval System (TEKTRAN)

    PD 05035, PD 05041, PD 05064, PD 05069, PD 05070, PD 05071, PD 06001, and PD 06078 are noncommercial breeding lines of cotton jointly released by the Agricultural Research Service, United States Department of Agriculture, Clemson University Experiment Station, and Cotton Incorporated in 2014. These ...

  4. Photodegradable Polyesters for Triggered Release

    PubMed Central

    Lv, Cong; Wang, Zhen; Wang, Peng; Tang, Xinjing

    2012-01-01

    Photodegradable polyesters were synthesized with a photolabile monomer 2-nitrophenylethylene glycol and dioyl chlorides with different lengths. These polymers can be assembled to form polymeric particles with encapsulation of target substances. Light activation can degrade these particles and release payloads in both aqueous solutions and RAW 264.7 cells. PMID:23208376

  5. 28 CFR 2.83 - Release planning.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 28 Judicial Administration 1 2010-07-01 2010-07-01 false Release planning. 2.83 Section 2.83... Release planning. (a) All grants of parole shall be conditioned on the development of a suitable release... correctional or supervision staff shall assist the prisoner in formulating a release plan for investigation....

  6. Index to NASA News Releases 1995

    NASA Technical Reports Server (NTRS)

    1996-01-01

    This issue of the index to NASA News Releases contains a listing of news releases distributed by the Office of Public Affairs, NASA Headquarters, during 1995. The index is arranged in six sections: Subject index, Personal name index, News release number index, Accession number index, Speeches, and News releases.

  7. 19 CFR 142.41 - Line Release.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 19 Customs Duties 2 2013-04-01 2013-04-01 false Line Release. 142.41 Section 142.41 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY (CONTINUED) ENTRY PROCESS Line Release § 142.41 Line Release. Line Release is an automated system designed...

  8. 19 CFR 142.41 - Line Release.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 19 Customs Duties 2 2014-04-01 2014-04-01 false Line Release. 142.41 Section 142.41 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY (CONTINUED) ENTRY PROCESS Line Release § 142.41 Line Release. Line Release is an automated system designed...

  9. 19 CFR 142.41 - Line Release.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 19 Customs Duties 2 2012-04-01 2012-04-01 false Line Release. 142.41 Section 142.41 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY (CONTINUED) ENTRY PROCESS Line Release § 142.41 Line Release. Line Release is an automated system designed...

  10. 19 CFR 142.41 - Line Release.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 19 Customs Duties 2 2010-04-01 2010-04-01 false Line Release. 142.41 Section 142.41 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY (CONTINUED) ENTRY PROCESS Line Release § 142.41 Line Release. Line Release is an automated system designed...

  11. Coronal Energy Release via Explosive Three-Dimensional Instability

    NASA Astrophysics Data System (ADS)

    Dahlburg, R. B.; Klimchuk, J. A.; Antiochos, S. K.

    2003-05-01

    It is widely believed that most coronal phenomena involve the release of magnetic free energy that is stored within stressed magnetic field configurations. The availability of sufficient free energy to explain everything from coronal heating to flares and coronal mass ejections is well established, but how this energy is released remains a major puzzle. Observations reveal that an important property of the energy release mechanism is its ``switch on" character. The mechanism must remain dormant for long periods of time to allow the magnetic stresses build, then it must operate very vigorously once it finally turns on. We discuss a mechanism called the ``secondary instability" which exhibits this behavior. It is essentially the ideal kinking of thin twisted magnetic flux tubes that form from the resistive instability of current sheets. We relate the mechanism to the coronal heating idea of Parker in which the coronal magnetic field becomes tangled by random motions of the photospheric footpoints. Global energy balance considerations imply that magnetic energy dissipation occurs at a particular angle in the field, and the secondary instability offers the first quantitative explanation for why this should be. It thus places Parker's popular idea on a much firmer physical footing. This research was funded by NASA.

  12. Release of inorganic material during coal devolatilization. Milestone report

    SciTech Connect

    Baxter, L.L.

    1995-07-01

    Experimental results presented in this paper indicate that coal devolatilization products convectively remove a fraction of the nonvolatile components of inorganic material atomically dispersed in the coal matrix. Results from three facilities burning six different coals illustrate this mechanism of ash transformation and release from coal particles. Titanium is chosen to illustrate this type of mass release from coal particles on the basis of its low volatility and mode of occurrence in the coal. During moderate rates of devolatilization (10{sup 4} K/s heating rate), no significant loss of titanium is noted. At more rapid rates of heating/devolatilization (10{sup 5} K/s) a consistent but minor (3-4 %) loss of titanium is noted. During rapid devolatilization (5xl0{sup 5} K/s and higher), significant (10-20 %) amounts of titanium leave the coal. The loss of titanium monitored in coals ranging in rank from subbituminous to high-volatile bituminous coals and under conditions typical of pulverized-coal combustion. The amount of titanium lost during devolatilization exhibits a complex rank dependence. These results imply that other atomically dispersed material (alkali and alkaline earth elements) may undergo similar mechanisms of transformation and release.

  13. EARTHQUAKE CAUSED RELEASES FROM A NUCLEAR FUEL CYCLE FACILITY

    SciTech Connect

    Charles W. Solbrig; Chad Pope; Jason Andrus

    2014-08-01

    The fuel cycle facility (FCF) at the Idaho National Laboratory is a nuclear facility which must be licensed in order to operate. A safety analysis is required for a license. This paper describes the analysis of the Design Basis Accident for this facility. This analysis involves a model of the transient behavior of the FCF inert atmosphere hot cell following an earthquake initiated breach of pipes passing through the cell boundary. The hot cell is used to process spent metallic nuclear fuel. Such breaches allow the introduction of air and subsequent burning of pyrophoric metals. The model predicts the pressure, temperature, volumetric releases, cell heat transfer, metal fuel combustion, heat generation rates, radiological releases and other quantities. The results show that releases from the cell are minimal and satisfactory for safety. This analysis method should be useful in other facilities that have potential for damage from an earthquake and could eliminate the need to back fit facilities with earthquake proof boundaries or lessen the cost of new facilities.

  14. Heat exchanger with heat transfer control

    SciTech Connect

    Wiard, M.R.

    1986-11-18

    This patent describes a multi-sided plate and fin type heat exchanger core in which plate elements, intermediately positioning spacer elements and fin strips are stacked in a layered assembly providing fluid passages for different fluids to flow in a segregated heat transfer relation to one another. The core is characterized in that at certain locations in a stacked assembly layers include spacer elements substantially closing all sides of the heat exchangers to define between adjacent fluid passages layers of increased heat transfer resistance. The fin strips are sheet-like elements corrugated to forms specifically identifiable in terms of fins per inch, there being fin strips in at least certain resistance layers differing in terms of fins per inch from other strips in certain resistance layers.

  15. 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.

  16. Absorption heat pump system

    DOEpatents

    Grossman, Gershon; Perez-Blanco, Horacio

    1984-01-01

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

  17. Heat pipe investigations

    NASA Technical Reports Server (NTRS)

    Marshburn, J. P.

    1972-01-01

    The OAO-C spacecraft has three circular heat pipes, each of a different internal design, located in the space between the spacecraft structural tube and the experiment tube, which are designed to isothermalize the structure. Two of the pipes are used to transport high heat loads, and the third is for low heat loads. The test problems deal with the charging of the pipes, modifications, the mobile tilt table, the position indicator, and the heat input mechanisms. The final results showed that the techniques used were adequate for thermal-vacuum testing of heat pipes.

  18. Quenching fundamentals: Heat transfer

    SciTech Connect

    MacKenzie, D.S.; Totten, G.E.; Webster, G.M.

    1996-12-31

    Quenching is essentially a heat transfer problem. It is necessary to quench parts fast enough that adequate mechanical and corrosion properties are achieved, but not so fast that detrimental distortion and residual stresses are formed. In addition, non-uniform heat transfer across the surface of a part will produce thermal gradients which will also create distortion or residual stresses. In this paper, the role of agitation will be discussed in terms of the heat transfer coefficient. A brief review of the published heat transfer literature will be discussed in terms of the fluid flow on heat transfer coefficient, with implications on quenching.

  19. Flexible heating head for induction heating

    NASA Technical Reports Server (NTRS)

    Fox, Robert L. (Inventor); Johnson, Samuel D. (Inventor); Coultrip, Robert H. (Inventor); Phillips, W. Morris (Inventor)

    1993-01-01

    An induction heating head includes a length of wire having first and second opposite ends and being wound in a flat spiral shape to form an induction coil, a capacitor connected to the first and second ends of the wire, the induction coil and capacitor defining a tank circuit, and a flexible, elastomeric body molded to encase the induction coil. When a susceptor is placed in juxtaposition to the body, and the tank circuit is powered, the susceptor is inductively heated.

  20. Kepler Data Release 3 Notes

    NASA Technical Reports Server (NTRS)

    Cleve, Jeffrey E.

    2010-01-01

    This describes the collection of data and the processing done on it so when researchers around the world get the Kepler data sets (which are a set of pixels from the telescope of a particular target (star, galaxy or whatever) over a 3 month period) they can adjust their algorithms fro things that were done (like subtracting all of one particular wavelength for example). This is used to calibrate their own algorithms so that they know what it is they are starting with. It is posted so that whoever is accessing the publicly available data (not all of it is made public) can understand it .. (most of the Kepler data is under restriction for 1 - 4 years and is not available, but the handbook is for everyone (public and restricted) The Data Analysis Working Group have released long and short cadence materials, including FFls and Dropped Targets for the Public. The Kepler Science Office considers Data Release 3 to provide "browse quality" data. These notes have been prepared to give Kepler users of the Multimission Archive at STScl (MAST) a summary of how the data were collected and prepared, and how well the data processing pipeline is functioning on flight data. They will be updated for each release of data to the public archive and placed on MAST along with other Kepler documentation, at http:// archive.stsci.edu/kepler/documents.html .Data release 3 is meant to give users the opportunity to examine the data for possibly interesting science and to involve the users in improving the pipeline for future data releases. To perform the latter service, users are encouraged to notice and document artifacts, either in the raw or processed data, and report them to the Science Office.

  1. Heat stress abatement during the dry period influences prolactin signaling in lymphocytes Heat stress abatement during the dry period influences prolactin signaling in lymphocytes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Heat stress perturbs PRL release and affects dairy cow lactational performance and immune cell function. We hypothesized that greater PRL concentration in plasma of heat-stressed cows would decrease expression of PRL-R mRNA and increase mRNA expression of suppressors of cytokine signaling (SOCS) in ...

  2. Heat pump apparatus

    DOEpatents

    Nelson, Paul A.; Horowitz, Jeffrey S.

    1983-01-01

    A heat pump apparatus including a compact arrangement of individual tubular reactors containing hydride-dehydride beds in opposite end sections, each pair of beds in each reactor being operable by sequential and coordinated treatment with a plurality of heat transfer fluids in a plurality of processing stages, and first and second valves located adjacent the reactor end sections with rotatable members having multiple ports and associated portions for separating the hydride beds at each of the end sections into groups and for simultaneously directing a plurality of heat transfer fluids to the different groups. As heat is being generated by a group of beds, others are being regenerated so that heat is continuously available for space heating. As each of the processing stages is completed for a hydride bed or group of beds, each valve member is rotated causing the heat transfer fluid for the heat processing stage to be directed to that bed or group of beds. Each of the end sections are arranged to form a closed perimeter and the valve member may be rotated repeatedly about the perimeter to provide a continuous operation. Both valves are driven by a common motor to provide a coordinated treatment of beds in the same reactors. The heat pump apparatus is particularly suitable for the utilization of thermal energy supplied by solar collectors and concentrators but may be used with any source of heat, including a source of low-grade heat.

  3. Fission gas release restrictor for breached fuel rod

    DOEpatents

    Kadambi, N. Prasad; Tilbrook, Roger W.; Spencer, Daniel R.; Schwallie, Ambrose L.

    1986-01-01

    In the event of a breach in the cladding of a rod in an operating liquid metal fast breeder reactor, the rapid release of high-pressure gas from the fission gas plenum may result in a gas blanketing of the breached rod and rods adjacent thereto which impairs the heat transfer to the liquid metal coolant. In order to control the release rate of fission gas in the event of a breached rod, the substantial portion of the conventional fission gas plenum is formed as a gas bottle means which includes a gas pervious means in a small portion thereof. During normal reactor operation, as the fission gas pressure gradually increases, the gas pressure interiorly of and exteriorly of the gas bottle means equalizes. In the event of a breach in the cladding, the gas pervious means in the gas bottle means constitutes a sufficient restriction to the rapid flow of gas therethrough that under maximum design pressure differential conditions, the fission gas flow through the breach will not significantly reduce the heat transfer from the affected rod and adjacent rods to the liquid metal heat transfer fluid flowing therebetween.

  4. 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.

  5. Active microchannel heat exchanger

    DOEpatents

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

  6. 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.

  7. 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.

  8. Nanofluid heat capacities

    NASA Astrophysics Data System (ADS)

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

    2011-12-01

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

  9. Absorption heat pumps

    NASA Astrophysics Data System (ADS)

    Huhtinen, M.; Heikkilae, M.; Andersson, R.

    1987-03-01

    The aim of the study was to analyze the technical and economic feasibility of absorption heat pumps in Finland. The work was done as a case study: the technical and economic analyses have been carried out for six different cases, where in each the suitable size and type of the heat pump plant and the auxiliary components and connections were specified. The study also detailed the costs concerning the procurement, installation and test runs of the machinery, as well as the savings in energy costs incurred by the introduction of the plant. Conclusions were drawn of the economic viability of the applications studied. The following cases were analyzed: heat recovery from flue gases and productin of district heat in plants using peat, natural gas, and municipal wastes as a fuel. Heat recovery in the pulp and paper industry for the upgrading of pressure of secondary steam and for the heating of white liquor and combustion and drying the air. Heat recovery in a peat-fulled heat and power plant from flue gases that have been used for the drying of peat. According to the study, the absorption heat pump suits best to the production of district heat, when the heat source is the primary energy is steam produced by the boiler. Included in the flue as condensing is the purification of flue gases. Accordingly, benefit is gained on two levels in thick applications. In heat and power plants the use of absorption heat pumps is less economical, due to the fact that the steam used by the pump reduces the production of electricity, which is rated clearly higher than heat.

  10. 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.

  11. 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.

  12. Energy released at Teide Volcano,Tenerife, Canary Islands

    NASA Astrophysics Data System (ADS)

    Lopez, D. L.; Perez, N. M.; Marrero, R.

    2003-12-01

    Teide volcano (3715 m high) is located at the northern scarp of the Las Ca¤adas caldera, a large depression at the center of Tenerife Island. Las Ca¤adas has been produced by multiple episodes of caldera collapse and giant landslides. The basanite-phonolite magmatic system associated with Teide volcano is emitting gases that reach the summit producing weak fumaroles. The chemical composition of these fumaroles and the flux of diffuse soil CO2 degassing at the summit cone (0.5 km2) has been used to determine the energy released as passive degassing in this volcano. Previous investigations show that Teide's summit is emitting 400 tons m2 day-1 of CO2 to the atmosphere. The composition of CH4, CO2, CO, and H2O indicate a chemical equilibrium temperature of 234° C and 75% condensation of water vapor within the volcanic edifice (Chiodini and Marini, 1998). The composition of the gases before condensation was restored and assumed to represent the composition at the equilibrium zone. The energy stored by the gases at the equilibration zone is assumed to be released as the gases move towards the discharge zone. The following processes are considered: change in pressure and temperature for water from the equilibration zone to the zone of condensation, latent heat released during the water condensation process, cooling of the condensed water from the condensation temperature to ambient temperature, and change of pressure and temperature for CO2 from the equilibrium to the discharge zone. Thermodynamic calculations of the energy released in each one of these processes indicate that 144 MW are released at Teide. Energy flux is 288 MW m-2. Most of this energy is released during the condensation process. This energy output compares with other hydrothermal systems of the world. These results show that during periods of passive degassing, fumarolic activity is limited by the geometry and elevation of the volcanic structure and the internal thermodynamic conditions.

  13. CRRES: The combined release and radiation effects satellite program directory

    NASA Technical Reports Server (NTRS)

    Layman, Laura D.; Miller, George P.

    1992-01-01

    As a result of natural processes, plasma clouds are often injected into the magnetosphere. These chemical releases can be used to study many aspects of such injections. When a dense plasma is injected into the inner magnetosphere, it is expected to take up the motion of the ambient plasma. However, it has been observed in previous releases at moderate altitudes that the cloud preserved its momentum for some time following the release and that parts of the cloud peeled off from the main cloud presumable due to the action of an instability. As one moves outward into the magnetosphere, the mirror force becomes less dominant and the initial conditions following a release are dominated by the formation of a diamagnetic cavity since the initial plasma pressure from the injected Ba ions is greater than the magnetic field energy density. A previous high-altitude release (31,300 km) showed this to be the case initially, but at later times there was evidence for acceleration of the Ba plasma to velocities corresponding to 60,000 K. This effect is not explained. This series of experiments is therefore designed to inject plasma clouds into the magnetosphere under widely varying conditions of magnetic field strength and ambient plasma density. In this way the coupling of injected clouds to the ambient plasma and magnetic field, the formation of striations due to instabilities, and possible heating and acceleration of the injected Ba plasma can be studied over a wide range of magnetosphere parameters. Adding to the scientific yield will be the availability of measurements for the DOD/SPACERAD instruments which can monitor plasma parameters, electric and magnetic fields, and waves before, during and after the releases.

  14. Data summary report for fission product release test VI-6

    SciTech Connect

    Osborne, M.F.; Lorenz, R.A.; Travis, J.R.; Webster, C.S.; Collins, J.L.

    1994-03-01

    Test VI-6 was the sixth test in the VI series conducted in the vertical furnace. The fuel specimen was a 15.2-cm-long section of a fuel rod from the BR3 reactor in Belgium. The fuel had experienced a burnup of {approximately}42 MWd/kg, with inert gas release during irradiation of {approximately}2%. The fuel specimen was heated in an induction furnace at 2300 K for 60 min, initially in hydrogen, then in a steam atmosphere. The released fission products were collected in three sequentially operated collection trains designed to facilitate sampling and analysis. The fission product inventories in the fuel were measured directly by gamma-ray spectrometry, where possible, and were calculated by ORIGEN2. Integral releases were 75% for {sup 85}Kr, 67% for {sup 129}I, 64% for {sup 125}Sb, 80% for both {sup 134}Cs and {sup 137}Cs, 14% for {sup 154}Eu, 63% for Te, 32% for Ba, 13% for Mo, and 5.8% for Sr. Of the totals released from the fuel, 43% of the Cs, 32% of the Sb, and 98% of the Eu were deposited in the outlet end of the furnace. During the heatup in hydrogen, the Zircaloy cladding melted, ran down, and reacted with some of the UO{sub 2} and fission products, especially Te and Sb. The total mass released from the furnace to the collection system, including fission products, fuel, and structural materials, was 0.57 g, almost equally divided between thermal gradient tubes and filters. The release behaviors for the most volatile elements, Kr and Cs, were in good agreement with the ORNL Diffusion Model.

  15. Bacterial Killing by Light-Triggered Release of Silver from Biomimetic Metal Nanorods

    PubMed Central

    Yi, Ji; Zhang, Ran; Rivera, José G.; Messersmith, Phillip B.

    2014-01-01

    Illumination of noble metal nanoparticles at the plasmon resonance causes substantial heat generation, and the transient and highly localized temperature increases that result from this energy conversion can be exploited for photothermal therapy by plasmonically heating gold nanorods (NRs) bound to cell surfaces. Here, we report the first use of plasmonic heating to locally release silver from gold core/silver shell (Au@Ag) NRs targeted to bacterial cell walls. A novel biomimetic method of preparing Au@Ag core-shell NRs was employed, involving deposition of a thin organic polydopamine (PD) primer onto Au NR surfaces, followed by spontaneous electroless silver metallization, and conjugation of antibacterial antibodies and passivating polymers for targeting to gram-negative and gram-positive bacteria. Dramatic cytotoxicity of S. epidermidis and E. coli cells targeted with Au@Ag NRs was observed upon exposure to light as a result of the combined antibacterial effects of plasmonic heating and silver release. The antibacterial effect was much greater than with either plasmonic heating or silver alone, implying a strong therapeutic synergy between cell-targeted plasmonic heating and the associated silver release upon irradiation. Our findings suggest a potential antibacterial use of Au@Ag NRs when coupled with light irradiation, which was not previously described. PMID:23847147

  16. Design of a quick response SMA actuated segmented nut for space release applications

    NASA Astrophysics Data System (ADS)

    Zhang, Xiaoyong; Yan, Xiaojun; Yang, Qiaolong

    2010-04-01

    Spacecrafts require a variety of separation and release devices to accommodate separation from the launch vehicle or deployment of heat radiation panels, solar arrays and other appendages. In order to overcome drawbacks of the current release devices, this paper proposes a design scheme of release device with a form of segmented nut and actuated with SMA (Shape Memory Alloy) wire. In order to validate the release device's function and performance, ground tests including single device response time tests, synchronous tests of two devices, fatigue life tests were carried out. Tests results show that the innovative space release device developed in this paper owning the advantages of small size, quick response, long fatigue life, high simultaneity and auto-reset has a potential use in space engineering.

  17. 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.

  18. Lunar base heat pump

    NASA Astrophysics Data System (ADS)

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

    1994-10-01

    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.

  19. Heat pump system

    DOEpatents

    Swenson, Paul F.; Moore, Paul B.

    1977-01-01

    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.

  20. Heat pump system

    DOEpatents

    Swenson, Paul F.; Moore, Paul B.

    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.

  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. 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.

  3. Explosive Release Atmospheric Dispersal 3.2

    SciTech Connect

    2001-06-26

    ERAD (Explosive Release Atmospheric Dispersal) is a 3D numerical transport and diffusion model, used to model the consequences associated with the buoyant (or nonbuoyant) dispersal of radioactive material It incorporates an integral plume rise model to simulate the buoyant rise of heated gases following an explosive detonation. treating buoyancy effects from time zero onward, eliminating the need for the stabilized doud assumption, and enabling the penetration of inversions. Modeling of the atmospheric boundary layer uses contemporary parameterization based on scaling theories derived from observational, laboratory and numerical studies. A Monte Carlo stochastic process simulates particle dispersion. Results were validated for both dose and deposition against measurements taken during Operation Roller Coaster (a joint US-UK test performed at NTS). Meteorology is defined using a single vertical sounding containing wind speed and direction and temperature as a function of height. Post processing applies 50-year CEDE DCFs (either ICRP 26 or 60) to determine the contribution of the relevant dose pathways (inhalation, submersion, and ground shine) as well as the total dose received. Dose and deposition contours are overlaid on a fully integrated worldwide GIS and tabulates hearth effects (fatalities and casualties) to resident population. The software runs on a laptop and takes less than 2 minutes to process. The Municipal version of ERAD does not include the ability to model the mitigation effects of aqueous foam.

  4. Explosive Release Atmospheric Dispersal 3.2

    Energy Science and Technology Software Center (ESTSC)

    2001-06-26

    ERAD (Explosive Release Atmospheric Dispersal) is a 3D numerical transport and diffusion model, used to model the consequences associated with the buoyant (or nonbuoyant) dispersal of radioactive material It incorporates an integral plume rise model to simulate the buoyant rise of heated gases following an explosive detonation. treating buoyancy effects from time zero onward, eliminating the need for the stabilized doud assumption, and enabling the penetration of inversions. Modeling of the atmospheric boundary layer usesmore » contemporary parameterization based on scaling theories derived from observational, laboratory and numerical studies. A Monte Carlo stochastic process simulates particle dispersion. Results were validated for both dose and deposition against measurements taken during Operation Roller Coaster (a joint US-UK test performed at NTS). Meteorology is defined using a single vertical sounding containing wind speed and direction and temperature as a function of height. Post processing applies 50-year CEDE DCFs (either ICRP 26 or 60) to determine the contribution of the relevant dose pathways (inhalation, submersion, and ground shine) as well as the total dose received. Dose and deposition contours are overlaid on a fully integrated worldwide GIS and tabulates hearth effects (fatalities and casualties) to resident population. The software runs on a laptop and takes less than 2 minutes to process. The Municipal version of ERAD does not include the ability to model the mitigation effects of aqueous foam.« less

  5. Tritium release from SS316 under vacuum condition

    SciTech Connect

    Torikai, Y.; Penzhorn, R.D.

    2015-03-15

    The plasma facing surface of the ITER vacuum vessel, partly made of low carbon austenitic stainless steel type 316L, will incorporate tritium during machine operation. In this paper the kinetics of tritium release from stainless steel type 316 into vacuum and into a noble gas stream are compared and modelled. Type 316 stainless steel specimens loaded with tritium either by exposure to 1.2 kPa HT at 573 K or submersion into liquid HTO at 298 K showed characteristic thin surface layers trapping tritium in concentrations far higher than those determined in the bulk. The evolution of the tritium depth profile in the bulk during heating under vacuum was non-discernible from that of tritium liberated into a stream of argon. Only the relative amount of the two released tritium-species, i.e. HT or HTO, was different. Temperature-dependent depth profiles could be predicted with a one-dimensional diffusion model. Diffusion coefficients derived from fitting of the tritium release into an evacuated vessel or a stream of argon were found to be (1.4 ± 1.0)*10{sup -7} and (1.3 ± 0.9)*10{sup -9} cm{sup 2}/s at 573 and 423 K, respectively. Polished surfaces on type SS316 stainless steel inhibit considerably the thermal release rate of tritium.

  6. Data summary report for fission product release test VI-5

    SciTech Connect

    Osborne, M.F.; Lorenz, R.A.; Travis, J.R.; Webster, C.S.; Collins, J.L. )

    1991-10-01

    Test VI-5, the fifth in a series of high-temperature fission product release tests in a vertical test apparatus, was conducted in a flowing mixture of hydrogen and helium. The test specimen was a 15.2-cm-long section of a fuel rod from the BR3 reactor in Belgium which had been irradiated to a burnup of {approximately}42 MWd/kg. Using a hot cell-mounted test apparatus, the fuel rod was heated in an induction furnace under simulated LWR accident conditions to two test temperatures, 2000 K for 20 min and then 2700 K for an additional 20 min. The released fission products were collected in three sequentially operated collection trains on components designed to measure fission product transport characteristics and facilitate sampling and analysis. The results from this test were compared with those obtained in previous tests in this series and with the CORSOR-M and ORNL diffusion release models for fission product release. 21 refs., 19 figs., 12 tabs.

  7. Lithium orthosilicate surfaces: Characterization and effect on tritium release

    NASA Astrophysics Data System (ADS)

    Kolb, M. H. H.; Bruns, M.; Knitter, R.; van Til, S.

    2012-08-01

    Within the European Union, slightly hyperstoichiometric lithium orthosilicate has evolved as one of the candidate solid breeder materials for the helium cooled pebble bed blanket, which will be tested in ITER. In the past, several long-term irradiation experiments proved that lithium orthosilicate shows excellent tritium release behavior when purged with helium with 0.1% hydrogen. In this work, short-term irradiation experiments at the High Flux Reactor in Petten with two standard pebble qualities, as-received and heat-treated lithium orthosilicate were carried out to investigate possible differences in tritium release. Since the surface of the pebbles may play a significant role, especially for short-term irradiation, and the mechanism of desorption from the surface determines the chemical form and very likely the release rate of tritium, the aim of this work is to link the chemical composition of the surface to the Thermal Programmed Desorption (TPD) tritium release experiments. Therefore X-ray photoelectron spectroscopy and time-of-flight secondary ion mass spectrometry were applied to characterize the surface of the unirradiated pebbles and to obtain sputter depth profiles of up to 800 nm. In addition, X-ray diffractometry was used to determine the composition of phases of the samples before and after irradiation.

  8. Data summary report for fission product release Test VI-7

    SciTech Connect

    Osborne, M.F.; Lorentz, R.A.; Travis, J.R.; Collins, J.L.; Webster, C.S.

    1995-05-01

    Test VI-7 was the final test in the VI series conducted in the vertical furnace. The fuel specimen was a 15.2-cm-long section of a fuel rod from the Monticello boiling water reactor (BWR). The fuel had experienced a burnup of {approximately}-40 Mwd/kg U. It was heated in an induction furnace for successive 20-min periods at 2000 and 2300 K in a moist air-helium atmosphere. Integral releases were 69% for {sup 85}Kr, 52% for {sup 125}Sb, 71% for both {sup 134}Cs and {sup 137}Cs, and 0.04% for {sup 154}Eu. For the non-gamma-emitting species, release values for 42% for I, 4.1% for Ba, 5.3% for Mo, and 1.2% for Sr were determined. The total mass released from the furnace to the collection system, including fission products, fuel, and structural materials, was 0.89 g, with 37% being collected on the thermal gradient tubes and 63% downstream on filters. Posttest examination of the fuel specimen indicated that most of the cladding was completely oxidized to ZrO{sub 2}, but that oxidation was not quite complete at the upper end. The release behaviors for the most volatile elements, Kr and Cs, were in good agreement with the ORNL-Booth Model.

  9. 14 CFR 125.373 - Original flight release or amendment of flight release.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Original flight release or amendment of flight release. 125.373 Section 125.373 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT... Flight Release Rules § 125.373 Original flight release or amendment of flight release. (a) A...

  10. Evidence of strong ocean heating during glacial periods

    NASA Astrophysics Data System (ADS)

    Zimov, S. A.; Zimov, N.

    2013-12-01

    Numerous hypotheses have addressed glacial-interglacial climatic dynamics, but none of them explain the sharp 25C temperature increase in Greenland in the last deglaciation (Cuffey et al. 1995; Dahl-Jensen et al. 1998). These robust data were obtained through analyzing the temperature profile in the Greenland ice sheet where cold from the last glaciation is preserved in the depth of the glacial sheet. We suggest that during glaciations the ocean accumulated energy: interior ocean water heated up to ~20-30C and during deglaciation this energy is released. In the analogy with reconstructing the ice sheet temperature profiles, the most reliable proof of ocean interior warming during the last glaciation is the heat flux profiles in the bottom sediments. In the final reports based on temperature measurements conducted during the DSDP (Deep Sea Drilling Project) it is stated that heat flux in the bottom sediments doesn't vary with depth and consequently there were no substantial temperature changes in the ocean interior during the last glacial cycle, and heat flux on the surface of the ocean bottom is the geothermal heat flux (Erickson et al., 1975, Hyndman et al., 1987). However, we have critically investigated data in all initial reports of all deep sea drilling projects and have noticed that all temperature data show that heat flow decreases strongly with depth (a minimum of 40 mW/m2), i.e. most of the heat flux detected on the surface of the ocean floor is not the geothermal heat flux but remaining heat that bottom sediments release. Sharp shifts in heat flow are seen within boreholes at depths crossing gas hydrate bottom. All this means that during the last glacial period interior water temperature was on 25-30C degrees warmer. Conversely, in isolated seas heat flow in the sediments shows little change with depth.

  11. Testing sources and size of carbon release during the PETM

    NASA Astrophysics Data System (ADS)

    Chun, C. O.; Ridgwell, A. J.; Marsh, R.

    2010-12-01

    Using an intermediate complexity Earth system model (GENIE) configured for the early Eocene, we aim to test hypotheses about the size and magnitude of carbon release during the PETM. We have improved the model by adding a background wetland CH4 flux at x5 preindustrial levels. Ensemble simulations of varying alkalinity, detrital flux, and CaCO3:POC ratios are compared with pre-PETM observations of wt% CaCO3 determined initial conditions. We are then able to compare a series of transient experiments of varying amounts and sources of carbon to the same initial conditions, noting the effects of subtle changes in deep ocean ventilation that are due to perturbed surface heat and freshwater fluxes. Finally, we will discuss the potential role of CH4 released to the atmosphere during the PETM and implications for climate sensitivity.

  12. Neutron-absorber release device

    DOEpatents

    VAN Erp, Jan B.; Kimont, Edward L.

    1976-01-01

    A resettable device is provided for supporting an object, sensing when an environment reaches a critical temperature and releasing the object when the critical temperature is reached. It includes a flexible container having a material inside with a melting point at the critical temperature. The object's weight is supported by the solid material which gives rigidity to the container until the critical temperature is reached at which point the material in the container melts. The flexible container with the now fluid material inside has insufficient strength to support the object which is thereby released. Biasing means forces the container back to its original shape so that when the temperature falls below the melting temperature the material again solidifies, and the object may again be supported by the device.

  13. [Peculiarities of Water Heating by a Bilogical Object].

    PubMed

    Ageev, I M; Rybin, Yu M; Shishkin, G G

    2015-01-01

    Experimental results of the study on causes of the difference in thermal conductivity coefficient of water under water heating by a biological object (operator hand) compared to heating by an electric radiator of the same temperature are given. Two possible causes of the observed effect, which are associated with the difference in the spectral composition of radiation generated by the operator hand compared to an electrical source of heat and solubility in water of CO2 released from human skin, are discussed. PMID:26394484

  14. Plasma heat pump and heat engine

    SciTech Connect

    Avinash, K.

    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.

  15. Heat transfer from oriented heat exchange areas

    NASA Astrophysics Data System (ADS)

    Vantuch, Martin; Huzvar, Jozef; Kapjor, Andrej

    2014-03-01

    This paper deals with the transfer of heat-driven heat transfer surface area in relation to the construction of the criterion equation for "n" horizontal pipe one about another. On the bases of theoretical models have been developed for calculating the thermal performance of natural convection by Churilla and Morgan, for various pipe diameters and temperatures. These models were compared with models created in CFD-Fluent Ansys the same boundary conditions. The aim of the analyse of heat and fluxional pipe fields "n" pipes one about another at natural convection is the creation of criterion equation on the basis of which the heat output of heat transfer from pipe oriented areas one above another with given spacing could be quantified. At presence a sum of criterion equations exists for simple geometrical shapes of individual oriented geometrical areas but the criterion equation which would consider interaction of fluxional field generated by free convection from multiple oriented areas is not mentioned in standardly accessible technical literature and other magazine publications.

  16. Magnetic Reconnection Onset and Energy Release at Current Sheets

    NASA Astrophysics Data System (ADS)

    DeVore, C. R.; Antiochos, Spiro K.

    2015-04-01

    Reconnection and energy release at current sheets are important at the Sun (coronal heating, coronal mass ejections, flares, and jets) and at the Earth (magnetopause flux transfer events and magnetotail substorms) and other magnetized planets, and occur also at the interface between the Heliosphere and the interstellar medium, the heliopause. The consequences range from relatively quiescent heating of the ambient plasma to highly explosive releases of energy and accelerated particles. We use the Adaptively Refined Magnetohydrodynamics Solver (ARMS) model to investigate the self-consistent formation and reconnection of current sheets in an initially potential 2D magnetic field containing a magnetic null point. Unequal stresses applied to the four quadrants bounded by the X-line separatrix distort the potential null into a double-Y-type current sheet. We find that this distortion eventually leads to onset of fast magnetic reconnection across the sheet, with copious production, merging, and ejection of magnetic islands due to plasmoid instability. In the absence of a mechanism for ideal instability or loss of equilibrium of the global structure, however, this reconnection leads to minimal energy release. Essentially, the current sheet oscillates about its force-free equilibrium configuration. When the structure is susceptible to a large-scale rearrangement of the magnetic field, on the other hand, the energy release becomes explosive. We identify the conditions required for reconnection to transform rapidly a large fraction of the magnetic free energy into kinetic and other forms of plasma energy, and to restructure the current sheet and its surrounding magnetic field dramatically. We discuss the implications of our results for understanding heliophysical activity, particularly eruptions, flares, and jets in the corona.Our research was supported by NASA’s Heliophysics Supporting Research and Living With a Star Targeted Research and Technology programs.

  17. Performance characteristic of thermosyphon heat pipe at radiant heat source

    NASA Astrophysics Data System (ADS)

    Hrabovský, Peter; Papučík, Štefan; Kaduchová, Katarína

    2016-06-01

    This article discusses about device, which is called heat pipe. This device is with heat source with radiant heat source. Heat pipe is device with high efficiency of heat transfer. The heat pipe, which is describe in this article is termosyphon heat pipe. The experiment with termosyphon heat pipe get a result. On the base of result, it will be in future to create mathematical model in Ansys. Thermosyphon heat pipe is made of copper and distilled water is working fluid. The significance of this experiment consists in getting of the heat transfer and performance characteristic. On the basis of measured and calculated data can be constructed the plots.

  18. Water-heating dehumidifier

    DOEpatents

    Tomlinson, John J.

    2006-04-18

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

  19. 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

  20. Heat pipe development

    NASA Technical Reports Server (NTRS)

    Bienart, W. B.

    1973-01-01

    The objective of this program was to investigate analytically and experimentally the performance of heat pipes with composite wicks--specifically, those having pedestal arteries and screwthread circumferential grooves. An analytical model was developed to describe the effects of screwthreads and screen secondary wicks on the transport capability of the artery. The model describes the hydrodynamics of the circumferential flow in triangular grooves with azimuthally varying capillary menisci and liquid cross-sections. Normalized results were obtained which give the influence of evaporator heat flux on the axial heat transport capability of the arterial wick. In order to evaluate the priming behavior of composite wicks under actual load conditions, an 'inverted' glass heat pipe was designed and constructed. The results obtained from the analysis and from the tests with the glass heat pipe were applied to the OAO-C Level 5 heat pipe, and an improved correlation between predicted and measured evaporator and transport performance were obtained.

  1. The effect of polymer properties on direct compression and drug release from water-insoluble controlled release matrix tablets.

    PubMed

    Grund, Julia; Koerber, Martin; Walther, Mathias; Bodmeier, Roland

    2014-07-20

    The objective of this study was to identify and evaluate key polymer properties affecting direct compression and drug release from water-insoluble matrices. Commonly used polymers, such as Kollidon(®) SR, Eudragit(®) RS and ethyl cellulose, were characterized, formulated into tablets and compared with regard to their properties in dry and wet state. A similar site percolation threshold of 65% v/v was found for all polymers in dry state. Key parameters influencing polymer compactibility were the surface properties and the glass transition temperature (T(g)), affecting polymer elasticity and particle size-dependent binding. The important properties observed in dry state also governed matrix characteristics and therefore drug release in wet state. A low T(g) (Kollidon(®) SRheat/humidity treatment. Hence, lower permeability and higher stability are benefits of a high-T(g) polymer (ethyl cellulose). However, release retardation was observed in the same order as matrix integrity (Eudragit(®) RSrelease matrix systems. PMID:24746409

  2. Heat transfer in energy problems

    NASA Astrophysics Data System (ADS)

    Mizushina, T.; Yang, W. J.

    Results of recent research are presented concerning heat transfer in energy problems, including high-temperature heat transfer, high-flux heat transfer, high-performance heat transfer, heat transfer in nonconventional energy (power and propulsion) systems, and novel heat transfer techniques. Topics discussed include studies of full-coverage film cooling, radiative properties of metals and alloys at high temperature, critical heat flux conditions in high-quality boiling systems, heat transfer characteristics of the evaporation of a liquid droplet on heated surfaces, high-performance surfaces for non-boiling heat transfer, and high performance heat transfer surfaces for boiling and condensation. Also examined are high flux heat transfer in gaseous solid suspension flow, nuclear process heat applications of high temperature heat exchange, heat transfer considerations in the use of new energy resources, and high performance mist-cooled condensers for geothermal binary cycle plants. No individual items are abstracted in this volume

  3. Fluidized bed heat treating system

    SciTech Connect

    Ripley, Edward B; Pfennigwerth, Glenn L

    2014-05-06

    Systems for heat treating materials are presented. The systems typically involve a fluidized bed that contains granulated heat treating material. In some embodiments a fluid, such as an inert gas, is flowed through the granulated heat treating medium, which homogenizes the temperature of the heat treating medium. In some embodiments the fluid may be heated in a heating vessel and flowed into the process chamber where the fluid is then flowed through the granulated heat treating medium. In some embodiments the heat treating material may be liquid or granulated heat treating material and the heat treating material may be circulated through a heating vessel into a process chamber where the heat treating material contacts the material to be heat treated. Microwave energy may be used to provide the source of heat for heat treating systems.

  4. 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.

  5. 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.

  6. Heat Loss Imagery

    NASA Technical Reports Server (NTRS)

    1981-01-01

    Infrared scanning devices are being used to produce images that show, by color or black-and-white shading differences, which buildings and homes are losing heat to the outdoors, and how much. Heat loss surveys done by Texas Instruments, Daedalus Enterprises, Inc. and other companies have growing acceptance of their services among industrial firms, utilities, local governments, and state and federal agencies interested in promoting heat loss awareness and inspiring corrective actions.

  7. Radioisotopic heat source

    DOEpatents

    Sayell, E.H.

    1973-10-23

    A radioisotopic heat source is described which includes a core of heat productive, radioisotopic material, an impact resistant layer of graphite surrounding said core, and a shell of iridium metal intermediate the core and the impact layer. The source may also include a compliant mat of iridium between the core and the iridium shell, as well as an outer covering of iridium metal about the entire heat source. (Official Gazette)

  8. Heat-related illnesses.

    PubMed

    Khosla, R; Guntupalli, K K

    1999-04-01

    The majority of clinicians will encounter patients with heat-related illness in one form or the other. Early recognition and management are important to prevent morbidity and mortality. In children and elderly, the clinical signs may be subtle and in such situations a sound knowledge of heat-related illnesses is crucial. Besides diagnosing and treating heat-related illnesses, it is equally important to know how to prevent them as they are easily preventable. PMID:10331127

  9. Heat pipe flight experiments

    NASA Technical Reports Server (NTRS)

    Ollendorf, S.

    1973-01-01

    OAO 3 heat pipe flight experiments to check out weightlessness behavior are reported. Tested were a hollow channel screen system with helical grooves, a heat pipe with a wicking system of horizontal grooves, and a spiral artery pipe with multichannel fluid return to the evaporator. Flight experiment data proved that all heat pipe geometries containing wicking systems provided uninterrupted fluid return to the condensators during weightlessness and sufficient cooling for isothermalizing optical instruments onboard OAO.

  10. Counterflow Regolith Heat Exchanger

    NASA Technical Reports Server (NTRS)

    Zubrin, Robert; Jonscher, Peter

    2013-01-01

    A problem exists in reducing the total heating power required to extract oxygen from lunar regolith. All such processes require heating a great deal of soil, and the heat energy is wasted if it cannot be recycled from processed material back into new material. The counterflow regolith heat exchanger (CoRHE) is a device that transfers heat from hot regolith to cold regolith. The CoRHE is essentially a tube-in-tube heat exchanger with internal and external augers attached to the inner rotating tube to move the regolith. Hot regolith in the outer tube is moved in one direction by a right-hand - ed auger, and the cool regolith in the inner tube is moved in the opposite direction by a left-handed auger attached to the inside of the rotating tube. In this counterflow arrangement, a large fraction of the heat from the expended regolith is transferred to the new regolith. The spent regolith leaves the heat exchanger close to the temperature of the cold new regolith, and the new regolith is pre-heated close to the initial temperature of the spent regolith. Using the CoRHE can reduce the heating requirement of a lunar ISRU system by 80%, reducing the total power consumption by a factor of two. The unique feature of this system is that it allows for counterflow heat exchange to occur between solids, instead of liquids or gases, as is commonly done. In addition, in variants of this concept, the hydrogen reduction can be made to occur within the counterflow heat exchanger itself, enabling a simplified lunar ISRU (in situ resource utilization) system with excellent energy economy and continuous nonbatch mode operation.

  11. Saturn base heating handbook

    NASA Technical Reports Server (NTRS)

    Mullen, C. R.; Bender, R. L.; Bevill, R. L.; Reardon, J.; Hartley, L.

    1972-01-01

    A handbook containing a summary of model and flight test base heating data from the S-1, S-1B, S-4, S-1C, and S-2 stages is presented. A review of the available prediction methods is included. Experimental data are provided to make the handbook a single source of Saturn base heating data which can be used for preliminary base heating design predictions of launch vehicles.

  12. Heat Flow of the Norwegian Continental Shelf

    NASA Astrophysics Data System (ADS)

    Pascal, C.

    2015-12-01

    Terrestrial heat flow determination is of prime interest for oil industry because it impacts directly maturation histories and economic potential of oil fields. Published systematic heat flow determinations from major oil provinces are however seldom. Robust heat flow determinations in drillholes require logging of undisturbed temperatures and intensive sampling of core material for petrophysical measurements. Temperature logging in exploration drillholes is traditionally conducted during drill breaks or shortly after drilling, resulting in temperatures severely disturbed by mud circulation and coring is restricted to selected intervals. Alternatively, test temperatures, information from electric logs and lithological descriptions of drill cuttings can be used to overcome these limitations. The present contribution introduces new heat flow determinations based on 63 exploration drillholes from the Norwegian North Sea, the Mid Norway Margin and the Barents Shelf. Our analyses are based on released DST temperatures, precise lithological descriptions of drill cuttings, previously measured rock matrix thermal conductivities and established porosity laws. For the sake of comparison, we carefully review previous heat flow studies carried out both onshore and offshore Norway. Our results suggest median heat flow values of 64 mW/m2, 65 mW/m2 and 72 mW/m2 for the North Sea, the Mid Norway Margin (mainly the Trøndelag Platform) and the SW Barents Shelf respectively. In detail, heat flow increases by ~ 10 mW/m2 from the southern Norwegian North Sea towards the Mid Norway Margin. This result appears to be in very good agreement with seismic tomographic studies suggesting northward thinning of the underlying mantle lithosphere. Our results together with published marine heat flow data from the Mid Norway Margin suggest a gradual decrease in heat flow levels from both the North Sea and the Trøndelag Platform towards the centres of the deep Møre and Vøring basins. This latter

  13. Heat flow of the Norwegian continental shelf

    NASA Astrophysics Data System (ADS)

    Pascal, Christophe

    2015-04-01

    Terrestrial heat flow influences a large collection of geological processes. Its determination is a requirement to assess the economic potential of deep sedimentary basins. Published heat flow calculations from e.g. major oil provinces are however seldom. Robust heat flow determinations in drillholes require logging of undisturbed temperatures and intensive sampling of core material for petrophysical measurements. Temperature logging in exploration drillholes is traditionally conducted during drill breaks or shortly after drilling, resulting in temperatures severely disturbed by mud circulation and coring is restricted to selected intervals. Alternatively, test temperatures, information from electric logs and lithological descriptions of drill cuttings can be used to overcome these limitations. The present contribution introduces new heat flow determinations based on 63 exploration drillholes from the Norwegian North Sea, the Mid Norway Margin and the Barents Shelf. Our analyses are based on released DST temperatures, precise lithological descriptions of drill cuttings, previously measured rock matrix thermal conductivities and established porosity laws. Our results suggest median heat flow values of 64 mW/m2, 65 mW/m2 and 72 mW/m2 for the North Sea, the Mid Norway Margin (mainly the Trøndelag Platform) and the SW Barents Shelf respectively. The Barents Shelf shows significantly high heat flow, suggesting lateral transfer of heat from the mantle of the adjacent young ocean. In detail, heat flow increases by ~ 10 mW/m2 from the southern Norwegian North Sea towards the Mid Norway Margin. This result appears to be in very good agreement with seismic tomographic studies suggesting northward thinning of the underlying mantle lithosphere. Our results together with published marine heat flow data from the Mid Norway Margin suggest a gradual decrease in heat flow levels from both the North Sea and the Trøndelag Platform towards the centres of the deep Møre and V

  14. Heat Pipe Materials Compatibility

    NASA Technical Reports Server (NTRS)

    Eninger, J. E.; Fleischman, G. L.; Luedke, E. E.

    1976-01-01

    An experimental program to evaluate noncondensable gas generation in ammonia heat pipes was completed. A total of 37 heat pipes made of aluminum, stainless steel and combinations of these materials were processed by various techniques, operated at different temperatures and tested at low temperature to quantitatively determine gas generation rates. In order of increasing stability are aluminum/stainless combination, all aluminum and all stainless heat pipes. One interesting result is the identification of intentionally introduced water in the ammonia during a reflux step as a means of surface passivation to reduce gas generation in stainless-steel/aluminum heat pipes.

  15. 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.

  16. 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.

  17. 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

  18. Introduction to Heat Pipes

    NASA Technical Reports Server (NTRS)

    Ku, Jentung

    2015-01-01

    This is the presentation file for the short course Introduction to Heat Pipes, to be conducted at the 2015 Thermal Fluids and Analysis Workshop, August 3-7, 2015, Silver Spring, Maryland. NCTS 21070-15. Course Description: This course will present operating principles of the heat pipe with emphases on the underlying physical processes and requirements of pressure and energy balance. Performance characterizations and design considerations of the heat pipe will be highlighted. Guidelines for thermal engineers in the selection of heat pipes as part of the spacecraft thermal control system, testing methodology, and analytical modeling will also be discussed.

  19. Heat pipe cooled probe

    NASA Technical Reports Server (NTRS)

    Camarda, C. J. (Inventor); Couch, L. M.

    1984-01-01

    The basic heat pipe principle is employed to provide a self-contained passively cooled probe that may be placed into a high temperature environment. The probe consists of an evaporator region of a heat pipe and a sensing instrument. Heat is absorbed as the working fluid evaporates in the probe. The vapor is transported to the vapor space of the condenser region. Heat is dissipated from the condenser region and fins causing condensation of the working fluid, which returns to the probe by gravity and the capillary action of the wick. Working fluid, wick and condenser configurations and structure materials can be selected to maintain the probe within an acceptable temperature range.

  20. An electrohydrodynamic heat pipe.

    NASA Technical Reports Server (NTRS)

    Jones, T. B.

    1972-01-01

    A heat pipe of new design, using an electrode structure to orient and guide the dielectric liquid phase flow, is proposed. Analysis indicates that the operation of the electrohydrodynamic heat pipe is in direct analogy to capillary devices, with the polarization force acting in place of capillarity. Advantages of these new heat pipes include greatly reduced liquid friction, electrohydrodynamically enhanced evaporation and condensation heat transfer, and a possible voltage-controlled on/off feature. Preliminary calculations indicate that relatively high performance devices are possible.

  1. Reclaiming Waste Heat

    NASA Technical Reports Server (NTRS)

    1976-01-01

    'Air-O-Space' heater, based on spacecraft heat, requires no fuel other than electricity to run fan. Installed in chimney flue, heat pipes transfer heat from waste hot gases (but not the gases themselves) to fresh air blown across the other end of the pipes. It can transport roughly 500 times the heat flux of the best solid conductors with a temperature drop of less than 3 degrees per foot. This instrument has also been used by Kin-Tek Laboratories Inc. to produce an instrument to calibrate gas analyzers for air-pollution monitoring.

  2. Heat rejection system

    DOEpatents

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

    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.

  3. Heat and mass exchanger

    SciTech Connect

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

    2011-06-28

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

  4. Heat and mass exchanger

    SciTech Connect

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

    2007-09-18

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

  5. Heat Flux Sensor

    NASA Technical Reports Server (NTRS)

    1994-01-01

    A heat flux microsensor developed under a NASP Small Business Innovation Research (SBIR) has a wide range of potential commercial applications. Vatell Corporation originally designed microsensors for use in very high temperatures. The company then used the technology to develop heat flux sensors to measure the rate of heat energy flowing in and out of a surface as well as readings on the surface temperature. Additional major advantages include response to heat flux in less than 10 microseconds and the ability to withstand temperatures up to 1,200 degrees centigrade. Commercial applications are used in high speed aerodynamics, supersonic combustion, blade cooling, and mass flow measurements, etc.

  6. Estimating heat capacity and heat content of rocks

    USGS Publications Warehouse

    Robertson, Eugene C.; Hemingway, Bruch S.

    1995-01-01

    Our measured heat-capacity values for rocks and other measurements of heat capacity or heat content of rocks found in the literature have been compared with estimated rock heat capacities calculated from the summation of heat capacities of both minerals and oxide components. The validity of calculating the heat content or heat capacity of rocks to better than about ± 3% from its mineral or chemical composition is well demonstrated by the data presented here.

  7. Thermal release of volatile fission products from irradiated nuclear fuel

    SciTech Connect

    Bray, L.A.; Burger, L.L.; Morgan, L.G.; Baldwin, D.L.

    1983-06-01

    An effective procedure for removing /sup 3/H, Xe and Kr from irradiated fuels was demonstrated using Shippingport UO/sub 2/ fuel. The release characteristics of /sup 3/H, Kr, Xe, and I from irradiated nuclear fuel have been determined as a function of temperature and gaseous environment. Vacuum outgassing and a flowing gas stream have been used to vary the gaseous environment. Vacuum outgassing released about 99% of the /sup 3/H and 20% of both Kr and Xe within a 3 h at 1500/sup 0/C. Similar results were obtained using a carrier gas of He containing 6% H/sub 2/. However, a carrier gas containing only He resulted in the release of approximately 80% of the /sup 3/H and 99% of both Kr and Xe. These results indicate that the release of these volatile fission products from irradiated nuclear fuel is a function of the chemical composition of the gaseous environment. The rate of tritium release increased with increasing temperature (1100 to 1500/sup 0/C) and with the addition of hydrogen to the gas stream. Using crushed UO/sub 2/ fuel without cladding and He as the carrier gas, Kr was completely released at 1500/sup 0/C in 2.5 h. Below 1350/sup 0/C, no Kr-Xe release was observed. Approximately 86% of the /sup 129/I and 95% of the cesium was released from a piece (3.9 g) of UO/sub 2/ fuel at 1500/sup 0/C in He. The zirconium cladding was observed to fracture during heat treatment. A large-scale thermal outgassing system was conceptually designed by the General Atomic Company from an engineering analysis of available experimental data. The direct cost of a 0.5 metric/ton day thermal outgassing system is estimated to be $1,926,000 (1982 dollars), including equipment, installation, instrumentation and controls, piping, and services. The thermal outgassing process was determined to be a technically feasible and cost-competitive process to remove tritium in the head-end portion of a LWR fuel reprocessing plant. Additional laboratory-scale development has been recommended.

  8. Thermal ramp tritium release in COBRA-1A2 C03 beryllium pebbles

    SciTech Connect

    Baldwin, D.L.

    1998-03-01

    Tritium release kinetics, using the method of thermal ramp heating at three linear ramp rates, were measured on the COBRA-1A2 C03 1-mm beryllium pebbles. This report includes a brief discussion of the test, and the test data in graph format.

  9. EVALUATION OF ORGANIC VAPOR RELEASE FROM CEMENT-BASED WASTE FORMS

    SciTech Connect

    Cozzi, A; Jack Zamecnik, J; Russell Eibling, R

    2006-09-27

    A cement based waste form was evaluated to determine the rates at which various organics were released during heating caused by the cementitious heat-of-hydration reaction. Saltstone is a cement-based waste form for the disposal of low-level salt solution. Samples were prepared with either Isopar{reg_sign} L, a long straight chained hydrocarbon, or (Cs,K) tetraphenylborate, a solid that, upon heating, decomposes to benzene and other aromatic compounds. The saltstone samples were heated over a range of temperatures. Periodically, sample headspaces were purged and the organic constituents were captured on carbon beds and analyzed. Isopar{reg_sign} L was released from the saltstone in a direct relationship to temperature. An equation was developed to correlate the release rate of Isopar{reg_sign} L from the saltstone to the temperature at which the samples were cured. The release of benzene was more complex and relied on both the decomposition of the tetraphenylborate as well as the transport of the manufactured benzene through the curing saltstone. Additional testing with saltstone prepared with different surface area/volume also was performed.

  10. Thermally Released Arsenic in Porewater from Sediments in the Cold Lake Area of Alberta, Canada.

    PubMed

    Javed, Muhammad Babar; Siddique, Tariq

    2016-03-01

    Elevated arsenic (As) in aquifers in close proximity to in situ oil sands extraction in the Cold Lake area, Alberta, Canada is attributed to high temperature steam (~200 °C) injected into oil sands deposits to liquefy bitumen. Heat propagated from hot injection wells alters physicochemical properties of the surrounding sediments and associated porewater. Seven sediments from four different cores drilled up to ~300 m depth collected from different locations in the area were used to study the thermal effect (~200 °C) on As distribution in the sediments and its release into porewater. Sediments were moistened with synthetic aquifer or deionized water according to the moisture regimes present in aquitard, aquifer and fractured zones. Heat application greatly released As in the porewater (500-5200 and 1200-6600 μg L(-1)) from aquifer and fractured sediments, respectively. Mass balance of As chemical fractionation showed that ~89-100% of As in porewater was released from exchangeable and specifically adsorbed As in the sediments. Heat application also altered As distribution in the sediments releasing As from exchange surfaces and amorphous Fe oxides to soluble As fraction. The results provide great insight into As release mechanisms warranting development of strategies to mitigate groundwater As contamination during industrial operation. PMID:26839972

  11. Graphene as a photothermal switch for controlled drug release

    NASA Astrophysics Data System (ADS)

    Matteini, Paolo; Tatini, Francesca; Cavigli, Lucia; Ottaviano, Stefania; Ghini, Giacomo; Pini, Roberto

    2014-06-01

    Graphene has recently emerged as a novel material in the biomedical field owing to its optical properties, biocompatibility, large specific surface area and low cost. In this paper, we provide the first demonstration of the possibility of using light to remotely trigger the release of drugs from graphene in a highly controlled manner. Different drugs including chemotherapeutics and proteins are firmly adsorbed onto reduced graphene oxide (rGO) nanosheets dispersed in a biopolymer film and then released by individual millisecond-long light pulses generated by a near infrared (NIR) laser. Here graphene plays the dual role of a versatile substrate for temporary storage of drugs and an effective transducer of NIR-light into heat. Drug release appears to be narrowly confined within the size of the laser spot under noninvasive conditions and can be precisely dosed depending on the number of pulses. The approach proposed paves the way for tailor-made pharmacological treatments of chronic diseases, including cancer, anaemia and diabetes.Graphene has recently emerged as a novel material in the biomedical field owing to its optical properties, biocompatibility, large specific surface area and low cost. In this paper, we provide the first demonstration of the possibility of using light to remotely trigger the release of drugs from graphene in a highly controlled manner. Different drugs including chemotherapeutics and proteins are firmly adsorbed onto reduced graphene oxide (rGO) nanosheets dispersed in a biopolymer film and then released by individual millisecond-long light pulses generated by a near infrared (NIR) laser. Here graphene plays the dual role of a versatile substrate for temporary storage of drugs and an effective transducer of NIR-light into heat. Drug release appears to be narrowly confined within the size of the laser spot under noninvasive conditions and can be precisely dosed depending on the number of pulses. The approach proposed paves the way for tailor

  12. Heat Pipe Integrated Microsystems

    SciTech Connect

    Gass, K.; Robertson, P.J.; Shul, R.; Tigges, C.

    1999-03-30

    The trend in commercial electronics packaging to deliver ever smaller component packaging has enabled the development of new highly integrated modules meeting the demands of the next generation nano satellites. At under ten kilograms, these nano satellites will require both a greater density electronics and a melding of satellite structure and function. Better techniques must be developed to remove the subsequent heat generated by the active components required to-meet future computing requirements. Integration of commercially available electronics must be achieved without the increased costs normally associated with current generation multi chip modules. In this paper we present a method of component integration that uses silicon heat pipe technology and advanced flexible laminate circuit board technology to achieve thermal control and satellite structure. The' electronics/heat pipe stack then becomes an integral component of the spacecraft structure. Thermal management on satellites has always been a problem. The shrinking size of electronics and voltage requirements and the accompanying reduction in power dissipation has helped the situation somewhat. Nevertheless, the demands for increased onboard processing power have resulted in an ever increasing power density within the satellite body. With the introduction of nano satellites, small satellites under ten kilograms and under 1000 cubic inches, the area available on which to place hot components for proper heat dissipation has dwindled dramatically. The resulting satellite has become nearly a solid mass of electronics with nowhere to dissipate heat to space. The silicon heat pipe is attached to an aluminum frame using a thermally conductive epoxy or solder preform. The frame serves three purposes. First, the aluminum frame provides a heat conduction path from the edge of the heat pipe to radiators on the surface of the satellite. Secondly, it serves as an attachment point for extended structures attached to

  13. 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.

  14. 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

  15. Nickel release from stainless steels.

    PubMed

    Haudrechy, P; Mantout, B; Frappaz, A; Rousseau, D; Chabeau, G; Faure, M; Claudy, A

    1997-09-01

    In 1994, a study of nickel release and allergic contact dermatitis from nickel-plated metals and stainless steels was published in this journal. It was shown that low-sulfur stainless steel grades like AISI 304, 316L or 430 (S < or = 0.007%) release less than 0.03 microgram/cm2/week of nickel in acid artificial sweat and elicit no reactions in patients already sensitized to nickel. In contrast, nickel-plated samples release around 100 micrograms/cm2/week of Ni and high-sulfur stainless steel (AISI 303-S approximately 0.3%) releases about 1.5 micrograms/cm2/week in this acid artificial sweat. Applied on patients sensitized to nickel, these metals elicit positive reactions in 96% and 14%, respectively, of the patients. The main conclusion was that low-sulfur stainless steels like AISI 304, 316L or 430, even when containing Ni, should not elicit nickel contact dermatitis, while metals having a mean corrosion resistance like a high-sulfur stainless steel (AISI 303) or nickel-plated steel should be avoided. The determining characteristic was in fact the corrosion resistance in chloride media, which, for stainless steels, is connected, among other factors, to the sulfur content. Thus, a question remained concerning the grades with an intermediate sulfur content, around 0.03%, which were not studied. They are the object of the study presented in this paper. 3 tests were performed: leaching experiments, dimethylglyoxime and HNO3 spot tests, and clinical patch tests; however, only stainless steels were tested: a low-sulfur AISI 304 and AISI 303 as references and 3 grades with a sulfur content around 0.03%: AISI 304L, AISI 304L added with Ca, AISI 304L+Cu. Leaching experiments showed that the 4 non-resulfurised grades released less than 0.5 microgram/cm2/week in acid sweat while the reulfurized AISI 303 released around or more than 0.5 microgram/cm2/week. This is explained by the poorer corrosion resistance of the resulfurized grade. Yet all these grades had the same

  16. Final report: In situ radio frequency heating demonstration

    SciTech Connect

    Jarosch, T.R.; Beleski, R.J.; Faust, D.

    1994-01-05

    A field demonstration of in situ radio frequency heating was performed at the Savannah River Site (SRS) as part of the US Department of Energy-Office of Technology Development`s Integrated Demonstration. The objective of the demonstration was to investigate the effectiveness of in situ radio frequency (RF) heating as an enhancement to vacuum extraction of residual solvents (primarily trichloroethylene and perchloroethylene) held in vadose zone clay deposits. Conventional soil vacuum extraction techniques are mass transfer limited because of the low permeabilities of the clays. By selectively heating the clays to temperatures at or above 100{degrees}C, the release or transport of the solvent vapors will be enhanced as a result of several factors including an increase in the contaminant vapor pressure and diffusivity and an increase in the effective permeability of the formation with the release of water vapor.

  17. Mars Express releases Beagle 2

    NASA Astrophysics Data System (ADS)

    2003-12-01

    At 9:31 CET, the crucial sequence started to separate the Beagle 2 lander from Mars Express. As data from Mars Express confirm, the pyrotechnic device was fired to slowly release a loaded spring, which gently pushed Beagle 2 away from the mother spacecraft. An image from the onboard visual monitoring camera (VMC) showing the lander drifting away is expected to be available later today. Since the Beagle 2 lander has no propulsion system of its own, it had to be put on the correct course for its descent before it was released. For this reason, on 16 December the trajectory of the whole Mars Express spacecraft had to be adjusted to ensure that Beagle 2 would be on course to enter the atmosphere of Mars. This manoeuvre, called "retargeting'' was critical: if the entry angle is too steep, the lander could overheat and burn up in the atmosphere; if the angle is too shallow, the lander might skim like a pebble on the surface of a lake and miss its target. This fine targeting and today's release were crucial manoeuvres for which ESA's Ground Control Team at ESOC (European Space Operations Centre) had trained over the past several months. The next major milestone for Mars Express will be the manoeuvre to enter into orbit around Mars. This will happen at 3:52 CET on Christmas morning, when Beagle 2 is expected to land on the surface of Mars. "Good teamwork by everybody - ESA, industry and the Beagle 2 team - has got one more critical step accomplished. Mars, here comes Europe!" said David Southwood, ESA Director of Science.

  18. 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.

  19. 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,…

  20. 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.

  1. 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.

  2. Heat exchange enhancement structure

    SciTech Connect

    Cornelison, R.C.; Kreith, F.

    1980-12-02

    A passive heat exchange enhancement structure which operates by free convection includes a flat mounting portion having a plurality of integral fins bent outwardly from one side edge thereof. The mounting portion is securable around a stovepipe, to a flat surface or the like for transferring heat from the pipe through the fins to the surrounding air by rotation-enhanced free convection.

  3. Electrostatic heat flux instabilities

    NASA Technical Reports Server (NTRS)

    Morrison, P. J.; Ionson, J. A.

    1980-01-01

    The electrostatic cyclotron and ion acoustic instabilities in a plasma driven by a combined heat flux and current were investigated. The minimum critical heat conduction speed (above which the plasma is unstable) is given as a function of the ratio of electron to ion temperatures.

  4. Chemical heat pump

    DOEpatents

    Greiner, Leonard

    1984-01-01

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

  5. Chemical heat pump

    DOEpatents

    Greiner, Leonard

    1981-01-01

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

  6. Chemical heat pump

    DOEpatents

    Greiner, Leonard

    1984-01-01

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

  7. Chemical heat pump

    DOEpatents

    Greiner, Leonard

    1984-01-01

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

  8. Microchannel heat sink assembly

    DOEpatents

    Bonde, Wayne L.; Contolini, Robert J.

    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.

  9. 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.

  10. 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…

  11. 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…

  12. Microchannel heat sink assembly

    DOEpatents

    Bonde, W.L.; Contolini, R.J.

    1992-03-24

    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 watertight 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. 13 figs.

  13. Heat pipe investigations

    NASA Technical Reports Server (NTRS)

    Marshburn, J. P.

    1973-01-01

    Techniques associated with thermal-vacuum and bench testing, along with flight testing of the OAO-C spacecraft heat pipes are outlined, to show that the processes used in heat transfer design and testing are adequate for good performance evaluations.

  14. Radioisotopic heat source

    DOEpatents

    Jones, G.J.; Selle, J.E.; Teaney, P.E.

    1975-09-30

    Disclosed is a radioisotopic heat source and method for a long life electrical generator. The source includes plutonium dioxide shards and yttrium or hafnium in a container of tantalum-tungsten-hafnium alloy, all being in a nickel alloy outer container, and subjected to heat treatment of from about 1570$sup 0$F to about 1720$sup 0$F for about one h. (auth)

  15. Flexible Timed-Release Encryption

    NASA Astrophysics Data System (ADS)

    Yoshida, Maki; Fujiwara, Toru

    This paper presents a new scheme for Timed-Release Encryption (TRE), which is mainly designed for global use. TRE aims to control the timing of disclosing information. The major approach to TRE assumes that any participants can receive a time token broadcasted by a trusted agent, called a time server. Our scheme is based on this approach and allows participants to generate an encrypted message that can be decrypted using designated or any authenticated time servers including even those which are authenticated after encryption. In this sense, our scheme has a more flexible framework in terms of message decryption.

  16. Reflux heat-pipe solar receivers for dish-electric systems

    NASA Astrophysics Data System (ADS)

    Andraka, Charles E.; Diver, Richard B.

    Electrical generation by solar means may be undertaken more efficiently through the use of a gravity-assisted 'reflux' heat pipe receiver combining a heat engine with a paraboloidal dish concentrator. In the reflux heat-pipe solar energy receiver, concentrated solar radiation causes a low melting-point liquid metal to evaporate; the vapor then flows to the engine interface heat exchanger, where it condenses and releases the latent heat. The condensate is returned to the receiver-absorber by gravity and distributed by capillary forces through a wick that lines the receiver.

  17. Knudsen heat capacity

    SciTech Connect

    Babac, Gulru; Reese, Jason M.

    2014-05-15

    We present a “Knudsen heat capacity” as a more appropriate and useful fluid property in micro/nanoscale gas systems than the constant pressure heat capacity. At these scales, different fluid processes come to the fore that are not normally observed at the macroscale. For thermodynamic analyses that include these Knudsen processes, using the Knudsen heat capacity can be more effective and physical. We calculate this heat capacity theoretically for non-ideal monatomic and diatomic gases, in particular, helium, nitrogen, and hydrogen. The quantum modification for para and ortho hydrogen is also considered. We numerically model the Knudsen heat capacity using molecular dynamics simulations for the considered gases, and compare these results with the theoretical ones.

  18. Advanced heat pump

    NASA Astrophysics Data System (ADS)

    Ashley, Joseph L.; Matthews, John D.

    1989-09-01

    This patent application discloses a heat pump which includes a first packed bed of liquid desiccant for removing moisture from outside air in the heating mode of operation, and a pump for transferring the moisture laden desiccant to a second packed bed which humidifies condenser heated inside air by adding water vapor to the air. The first packed bed, by removing moisture from the outside air before it passes through the heat pump's evaporator coils, prevents frost from forming on the coils. In the cooling mode of operation the second packed bed of liquid desiccant removes water vapor from the air inside of the building. The moisture laden desiccant is then transferred to the first packed bed by a second pump where condenser heat transfers the moisture from the desiccant to outside air.

  19. 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.

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

    SciTech Connect

    Polcyn, Adam D.

    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.